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1. ПРОЦЕССЫ ЭЛЕКТРОСТАТИЧЕСКОЙ СЕПАРАЦИИ И ФЛОТАЦИИ В ОБОГАЩЕНИИ ИЛЬМЕНИТОВЫХ РУД ИЗ ВЬЕТНАМА И ХИМИЧЕСКАЯ ПЕРЕРАБОТКА ПОЛУЧЕННЫХ КОНЦЕНТРАТОВ

Author

Karelin, Vladimir Aleksandrovich, Hai Shawn Le, Karelina, Nadezhda Vladimirovna, Huong Le Thi Mai, and Graduate University of Science and Technology, Vietnam academy of Science and Technology, Hoang Quoc Viet street, Cau Giay district, Vietnam

Subjects
щелочные металлы, Ilmenite ore and concentrate from Vietnam, Materials Science (miscellaneous), electrolysis in low-melting eutectic of alkali metal and titanium fluorides, флотация, фториды, гранулометрический состав, химический состав, Management, Monitoring, Policy and Law, электростатическая сепарация, Geotechnical Engineering and Engineering Geology, Fuel Technology, электролиз, Вьетнам, beneficiation by electrostatic separation and flotation, низкоплавкая эвтектика, титан, Economic Geology, granulometric and chemical compositions of titanium powder, концентраты, Waste Management and Disposal, ильменитовые руды, титановые порошки, химическая переработка
Abstract

Актуальность исследования определяется созданием принципиально нового способа синтеза титановых порошков высокой степени чистоты из ильменитовых руд месторождений Вьетнама, содержащих в тяжелой фракции смесь ильменита с рутилом. Это одно из приоритетных направлений комплексного развития месторождений редких и редкоземельных элементов во Вьетнаме. Цель: выбор условий, методов и последовательности проведения технологических операций по обогащению вьетнамских ильменитовых руд и последующей их химической переработки с получением высокочистого титана. Объекты: ильменитовая руда месторождения Ха Тинь (Вьетнам) с высоким содержанием оксидов титана, железа, циркония и низким содержанием кремния, алюминия, редкоземельных элементов, ванадия, а также ильменитовый концентрат, полученный в результате обогащения исходной ильменитовой руды. Методы: в процессе обогащения - электростатическая сепарация, флотация, использование коллекторов, активаторов и депрессоров, добавляемых к флотореагентам; при электролитическом синтезе титана - применение расплава в виде смеси фторидов лития, натрия и калия, обладающих минимальной температурой плавления, с добавкой тетрафторида титана; выбор условий запуска электролизера, катодной плотности тока, силы тока и напряжения для осаждения титана на катоде; исследование оптимальных условий выделения титанового порошка при низких температурах с использованием безводного фтороводорода. Результаты. Показана перспективность использования методов электростатической сепарации и флотации при обогащении вьетнамских ильменитовых руд месторождения Ха Тинь. Получен ильменитовый концентрат с содержанием диоксида титана более 50 %. Обоснованы преимущества использования метода прямого фторирования ильменитового концентрата элементным фтором, позволяющего обеспечить полноту его вскрытия и отделить летучие фториды титана, ниобия, ванадия и кремния от нелетучих - фторидов железа, циркония, гафния и церия. Это позволяет оптимизировать число стадий при дальнейшем применении TiF4 в качестве материала для получения титанового порошка. При электролитическом получении титана обоснована необходимость применения расплава фторидных солей лития, натрия и калия, имеющих состав: LiF (0,465 М)-NaF (0,115 М)-KF (0,42 М), обладающего минимальной температурой плавления (454 °С) и пределами изменения концентрации K2TiF6 (25-30 %). При этом величины плотности тока и выхода по току приближаются к максимальным значениям - 3,5-4,0 А/см2 и 60-65 % соответственно. Содержание примесей в титановом порошке не превышает 0,135 %, что удовлетворяет требованиям для изготовления изделий из компактного титана. The relevance of the study is determined by the creation of a fundamentally new method for the synthesis of titanium powders of high purity from ilmenite ores of Vietnam deposits, containing a mixture of ilmenite with rutile in the heavy fraction. This is one of the priority areas for the integrated development of deposits of rare and rare earth elements in Vietnam. The main aim: selection of conditions, methods and sequence of technological operations for the beneficiation of Vietnamese ilmenite ores and their subsequent chemical processing to obtain high-purity titanium. Objects: ilmenite ore of the Ha Tinh deposit (Vietnam) with a high content of oxides of titanium, iron, zirconium and a low content of silicon, aluminum, rare earth elements, vanadium, as well as ilmenite concentrate obtained as a result of enrichment of the original ilmenite ore. Methods: in the beneficiation process - electrostatic separation, flotation, the use of collectors, activators and depressants added to flotation reagents; in the electrolytic synthesis of titanium - the use of a low-melting eutectic of fluoride salts of alkali metals with the addition of titanium tetrafluoride; selection of the conditions for starting the electrolyzer, cathode current density, current and voltage for the deposition of titanium on the cathode; investigation of the optimal conditions for the release of titanium powder at low temperatures using anhydrous hydrogen fluoride. Results. The prospects of using the methods of electrostatic separation and flotation in the dressing of Vietnamese ilmenite ores of the Ha Tinh deposit are shown. An ilmenite concentrate with a titanium dioxide content of more than 50 % was obtained. The advantages of using the method of direct fluorination of an ilmenite concentrate with gaseous fluorine are substantiated, which makes it possible to ensure both the completeness of the decomposition of the solid phase and to separate the fluorides of titanium, niobium, vanadium and silicon that pass into the gas phase from those remaining in the condensed state - fluorides of iron, zirconium, hafnium and cerium. This allows you to optimize the number of stages in the subsequent processing of titanium tetrafluoride and the synthesis of metallic titanium. In titanium electrolysis, the authors have substantiated the use of composition of the eutectic of fluoride salts of alkali metals LiF (0,465 M)-NaF (0,115 M)- KF (0,42 M), which has a minimum melting point (454 °C) and the range of changes in the concentration of K2TiF6 (25-30 %). In this case, the values of current density and current efficiency approach the maximum values of 3,5-4,0 A/cm2 and 60-65 %, respectively. The content of impurities in titanium powder does not exceed 0,135 %, which meets the requirements for the manufacture of products from compact titanium.

Published
2022

2. Contribution to Taxonomy and Distribution of the Genus Elaphropoda (Hymenoptera: Apidae: Apinae) in Vietnam

Author

Nguyen, Minh Phuong, Tran, Ngat Thi, Nguyen, Dai Dac, and Nguyen, Lien Thi Phuong Email (Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology)

Subjects
Apidae, Apinae, Elaphropoda, new records, Vietnam, Biology (General), QH301-705.5, Zoology, QL1-991
Abstract

Taxonomic notes on the genus Elaphropoda Lieftinck, 1966 (Hymenoptera: Apidae) from Vietnam are presented. Two species of the genus are reported: Elaphropoda percarinata (Cockerell, 1930) was first recorded from Vietnam based on specimens collected from Ha Tinh province in 1998, and is reconfirmed with a specimens collected from Bac Kan province in the Northeastern part of the country in this study, and Elaphropoda khasiana (Schulz, 1906) is recorded from Vietnam for the first time. Redescriptions of the male of E. percarinata and the female of E. khasiana are given with illustrations.

Published
2016
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3. Exhaustive existence and non-existence results for some prototype polyharmonic equations in the whole space

Author

Quoc Hung Phan, Quôc-Anh Ngô, Van Hoang Nguyen, Dong Ye, The University of Tokyo (UTokyo), Vietnam National University [Hanoï] (VNU), Vietnam Academy of Science and Technology (VAST), FPT University, Duy Tan University (DTU), Institut Élie Cartan de Lorraine (IECL), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), East China Normal University [Shangaï] (ECNU), The research of QAN was partially funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 101.02-2016.02 and is supported by the Tosio Kato Fellowship awarded in 2018, The research of VHN was partially funded by the Simons Foundation Grant Targeted for Institute of Mathematics, Vietnam Academy of Science and Technology, The research of QHP is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 101.02-2017.307, and DY is partially supported by Science and Technology Commission of Shanghai Municipality (STCSM) under grant No. 18dz2271000.

Subjects
Applied Mathematics, 010102 general mathematics, Mathematical analysis, Maximum principle type result, Space (mathematics), 01 natural sciences, 35B53, 35J91, 35B33, 010101 applied mathematics, Range (mathematics), Nonlinear system, Mathematics - Analysis of PDEs, Existence and non-existence, FOS: Mathematics, Exponent, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Polyharmonic equation, 0101 mathematics, Liouville theorem, 2010 MSC: Primary 35B53, 35J91, 35B33, Secondary 35B08, 35B51, 35A01, Analysis, Analysis of PDEs (math.AP), Mathematics
Abstract

In this paper, we are interested in entire, non-trivial, non-negative solutions and/or entire, positive solutions to the simplest models of polyharmonic equations with power-type nonlinearity \[ \Delta^m u = \pm u^{\alpha} \quad \text{ in } \mathbb R^n \] with $n \geqslant 1$, $m \geqslant 1$, and $\alpha \in \mathbb R$. We aim to study the existence and non-existence of such classical solutions to the above equations in the full range of the constants $n$, $m$ and $\alpha$. Remarkably, we are able to provide necessary and sufficient conditions on the exponent $\alpha$ to guarantee the existence of such solutions in $\mathbb R^n$. Finally, we identify all the situations where any entire non-trivial, non-negative classical solution must be positive., Comment: 18 pages, 0 figure

Published
2020

4. Camellia proensis (Theaceae, sect. Piquetia), a new species from Southern Vietnam

Author

HOI, Q. V., DUNG, L. V., DOUDKIN, R. V., AVERYANOV, L. V., THINH, B. B., LIEU, N. T., TRUONG, L. H., Tay Nguyen Institute for Scientific Research, Vietnam Academy of Science and Technology, Far Eastern Federal University (FEFU), Faculty of Biology, Dalat University, Botanical Garden-Institute, Far-East Branch, Russian Academy of Sciences, Vladivostok, Russia, Komarov Botanical Institute of Russian Academy of Science, Russian Academy of Sciences [Moscow] (RAS), Southern Institute of Ecology, Vietnam Academy of Science and Technology, and Thinh, Bui Bao

Subjects
taxonomy, Vietnam, Magnoliids, Camellia proensis, Theaceae, [SDV.BID]Life Sciences [q-bio]/Biodiversity, [SDV.BID] Life Sciences [q-bio]/Biodiversity, Lam Dong
Abstract

International audience; A new species of the genus Camellia L. (Theaceae) from Southern Vietnam is described and illustrated under the name Camellia proensis. Morphological differences between C. proensis and closely related species in the genus Camellia L. (sect. Piquetia) were identified. C. proensis is easily distinguishable from C. honbaensis, C. piquetiana and C. longii by the yellow flowers; from C. dalatensis by the glabrous twigs and leaves; from C. dongnaiensis by light yellow flowers; from C. sonthaiensis by mature fruit flat-globose, 4.0–5.5 cm tall and 8.5–10.0 cm wide. Ecological environment and distribution were also provided for this new species. The images and type specimens of this species were processed and stored in Vietnam (holotype, isotypes, DLU).

Published
2021

5. Fatty acid composition and oil content during coriander fruit development

Author

Thierry Talou, Muriel Cerny, Philippe Evon, Othmane Merah, Quang Hung Nguyen, Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement - INRAE (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Vietnam Academy of Science and Technology - VAST (VIETNAM), Chimie Agro-Industrielle (CAI), Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology (VAST), Institut Universitaire de Technologie - Paul Sabatier (IUT Paul Sabatier), Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées

Subjects
Petroselinic acid, Fruit development, Oil content, Coriandrum, Lipid accumulation, 01 natural sciences, Analytical Chemistry, Ingredient, chemistry.chemical_compound, Ripening stage, 0404 agricultural biotechnology, Isomerism, media_common.cataloged_instance, Plant Oils, [CHIM]Chemical Sciences, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Food science, European union, Coriandrum sativum, media_common, 2. Zero hunger, chemistry.chemical_classification, [CHIM.ORGA]Chemical Sciences/Organic chemistry, 010401 analytical chemistry, Fatty Acids, fungi, Fatty acid, food and beverages, 04 agricultural and veterinary sciences, General Medicine, 040401 food science, 0104 chemical sciences, Oleic acid, Chimie organique, chemistry, Fruit, Seeds, Food Science, Polyunsaturated fatty acid, Oleic Acid
Abstract

Coriander contains petroselinic acid, an isomer fatty acid of oleic acid. Coriander seed oil has been proposed as novel food ingredient in the European Union. Field experiments were performed at Auch (France) during two seasons (2010 and 2011). From flowering to maturity, fruits were harvested weekly and oil content and fatty acid (FA) compositions were determined. Fruits presented 2% more oil in 2010 than in 2011. Petroselinic acid (PA) contents was higher in 2011 than in 2010. Oil accumulation began earlier after flowering (2 DAF) in 2011. A first step in accumulation was identified between two and 21 DAF characterized by high SFA and PUFA, which decreased 21 DAF. Subsequently, PA increased to its highest concentration (30–55 DAF) and SFA and PUFA reached their lowest. These results suggest that higher concentrations of PA can be achieved by collecting fruits before full maturity.

Published
2020

6. Effect of cast iron microstructure on adherence of an epoxy protection

Author

Jacques Lacaze, Alexandre Freulon, Ke Oanh Vu, Benoit Malard, Anh Truc Trinh, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Vietnam Academy of Science and Technology - VAST (VIETNAM), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Vietnam Academy of Science and Technology (VAST), and Institute for Tropical Technology

Subjects
epoxy coating, Materials science, Matériaux, 0211 other engineering and technologies, 02 engineering and technology, engineering.material, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, 0103 physical sciences, Pearlitic, Composite material, ADI -Epoxy coating, 021102 mining & metallurgy, 010302 applied physics, Spheroidal graphite cast iron, Mechanical Engineering, ADI - Epoxy coating, Metals and Alloys, [CHIM.MATE]Chemical Sciences/Material chemistry, Adhesion, Epoxy, Microstructure, Mechanics of Materials, Ferritic, visual_art, engineering, visual_art.visual_art_medium, ADI, Cast iron
Abstract

International audience; To study the influence of the microstructure of cast iron on the adhesion of an epoxy coating, ferritic, pearlitic and austempered samples were prepared in as-received, polished and oxidized states. A pull-off test (dry adhesion) was performed before immersing in water while the cross-cut test was made after 24 days of exposition in distilled water (wet adhesion). X-rays were combined with optical microscopy (LOM) and scanning electron microscopy (SEM) for surface analysis. The adhesion of the epoxy coating on the cast iron surface firstly depends on the roughness of the surface; polished samples showed high adherence by comparison with as-received samples. On the oxidized samples, the surface oxide significantly improves the adhesion of the coating in both dry and wet states for all three sample microstructure. The presence of carbide in the structure was observed to decrease adherence.

Published
2020

7. Effect of Maleic Anhydride Grafted Ethylene Vinyl Acetate Compatibilizer on the Mechanical, Thermal Properties and Weathering Resistance of Polyamide 11/Bamboo Fiber Composite

Author

Tran Huu Trung, Colette Lacabanne, Mai Duc Huynh, Nguyen Vu Giang, Do Van Cong, Thai Hoang, Eric Dantras, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Vietnam Academy of Science and Technology - VAST (VIETNAM), Centre Interuniversitaire de Recherche et d'Ingénierie des Matériaux - CIRIMAT (Toulouse, France), Vietnam Academy of Science and Technology (VAST), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)

Subjects
Materials science, EVAgMA compatibilizer, Matériaux, Composite number, Mechanical properties, 02 engineering and technology, Polymer composite, 01 natural sciences, chemistry.chemical_compound, Differential scanning calorimetry, Short bamboo fiber, 0103 physical sciences, Ultimate tensile strength, General Materials Science, Composite material, Thermal analysis, 010302 applied physics, Flexural modulus, Mechanical Engineering, Ethylene-vinyl acetate, Maleic anhydride, Dynamic mechanical analysis, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Polymères, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Mechanics of Materials, Weathering resistance, 0210 nano-technology
Abstract

International audience; In this research, short bamboo fiber (BF) has been used as filler in the fabrication of the composite based on polyamide 11 (PA11) by melt-mixing method. In order to improve the compatibility between BF and PA11, maleic anhydride grafted ethylene vinyl acetate copolymer (EVAgMA) was introduced into the composite preparation process. The effect of EVAgMA contents on mechanical, thermal or weathering resistant properties of the composites was investigated. In the presence of the EVAgMA, the tensile strength, impact strength and flexural modulus of composites showed the improvement in comparison to without compatibilizer. Differential scanning calorimetry (DSC) analysis indicated that the melting temperature of composites did not depend on the EVAgMA contents, while its fusion heat (ΔHm) decreased with increasing EVAgMA contents. Dynamic mechanical thermal analysis (DMTA) evaluated the role of EVAgMA on the enhancement of composites’s storage modulus (G′) in the glassy plateau and the interaction between BF and PA11 matrix. After 840 hours of accelerated weathering test, the composites using EVAgMA were decomposed faster than that of neat PA11 and PA11/BF composite. This result was also agreed with the observation of scanning electronic microscopy (SEM) images and the change of carbonyl index (CI). However, the retention of tensile properties of PA11/EVAgMA/BF composites is higher than that of PA11/BF composite.

Published
2020

8. 8-hydroxyquinoline-modified clay incorporated in an epoxy coating for the corrosion protection of carbon steel

Author

Thai Thu Thuy, To Thi Xuan Hang, Trinh Anh Truc, Nicolas Caussé, Anh Son Nguyen, Vu Ke Oanh, Nadine Pébère, Vietnam Academy of Science and Technology (VAST), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Vietnam Academy of Science and Technology - VAST (VIETNAM), and Institut National Polytechnique de Toulouse - INPT (FRANCE)

Subjects
Materials science, Carbon steel, Matériaux, General Physics and Astronomy, 02 engineering and technology, engineering.material, 010402 general chemistry, Corrosion inhibition, 01 natural sciences, Corrosion, [SPI.MAT]Engineering Sciences [physics]/Materials, Corrosion inhibitor, chemistry.chemical_compound, Coating, Composite material, Rotating disk electrode, Montmorillonite, Barrier properties, Surfaces and Interfaces, General Chemistry, Epoxy, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Surfaces, Coatings and Films, Dielectric spectroscopy, chemistry, visual_art, visual_art.visual_art_medium, engineering, Adhesion, 0210 nano-technology, Electrochemical impedance spectroscopy
Abstract

International audience; In the present work, a well-known corrosion inhibitor (8-hydroxyquinoline (8HQ)) was inserted within the montmorillonite platelets (8HQ-MMT) and the modified clay was incorporated (3 wt.%) into a solvent-free epoxy coating which was afterwards deposited on carbon steel substrates. First, the inhibitive action of 8HQ was investigated by electrochemical methods carried out on a bare carbon steel rotating disk electrode in a 0.1 M NaCl solution. Then, electrochemical impedance measurements were performed to assess the effect of the 8HQ-MMT in the epoxy coating for the corrosion protection. The results were compared with a reference sample constituted by the epoxy coating containing an ammonium quaternary salt-modified clay. It was shown that the two coatings presented good barrier properties. Dry and wet adherence measurements revealed an improvement of the adherence when the 8HQ-MMT was incorporated into the coating by comparison with the reference sample. It was concluded that the 8HQ mainly had an effect at the metal/coating interface but its concentration was too low to afford significant corrosion protection of the carbon steel.

Published
2019

9. Mechanical properties of continuous bamboo fiber-reinforced biobased polyamide 11 composites

Author

Huynh Maiduc, Philippe Ponteins, Colette Lacabanne, Geoffrey Haddou, Tran Huu Trung, Eric Dantras, Hoang Thai, Jany Dandurand, Nguyen Vu Giang, Assystem France, Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Vietnam Academy of Science and Technology (VAST), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Assystem (FRANCE), Vietnam Academy of Science and Technology - VAST (VIETNAM), Centre Interuniversitaire de Recherche et d'Ingénierie des Matériaux - CIRIMAT (Toulouse, France), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Dynamic mechanical shear modulus, Materials science, Polymers and Plastics, Matériaux, Modulus, Young's modulus, 02 engineering and technology, Polyamide/continuous bamboo fiber composite, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Shear modulus, symbols.namesake, Crystallinity, Differential scanning calorimetry, Ultimate tensile strength, Materials Chemistry, Fiber, Young’s modulus, Composite material, Viscoelasticity, General Chemistry, Dynamic mechanical analysis, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, Polyamide, symbols, 0210 nano-technology
Abstract

International audience; This study is devoted to the analysis of the properties of continuous bamboo fiber (BF)‐reinforced polyamide 11 (PA 11) composites. The SEM observations highlighted continuity between BFs and the polymeric matrix showing a high density of hydrogen bonds. The comparative calorimetric study of the matrix and its composites showed that the crystallinity of PA 11 was not modified by the presence of bamboo fibers. The physical aging observed in PA 11 is no more observed in composites due to physical interactions between PA 11 and BFs. The mechanical properties were investigated by tensile strength and dynamic mechanical analysis. The introduction of BFs enhanced Young's modulus of the matrix by a factor of 10. The presence of BFs also improved the storage shear modulus G′ over the whole temperature range.

Published
2019

10. Characterization of Endophytic Streptomyces griseorubens MPT42 and Assessment of Antimicrobial Synergistic Interactions of its Extract and Essential Oil from Host Plant Litsea cubeba

Author

Wen-Jun Li, Ha Hoang, Quang Huy Nguyen, Thi Lien Bui, Hai Van Nguyen, Quyet-Tien Phi, Thi Hanh Nguyen Vu, Ngoc Tung Quach, Thi Nhan Khieu, Samira Sarter, Thu Trang Vu, Hoang Ha Chu, Son Chu-Ky, Graduate University of Science and Technology [Hanoi] (GUST), Vietnam Academy of Science and Technology (VAST), School of Biotechnology and Food Technology, Hanoi University of Science and Technology, 1, Dai Co Viet, Hai Ba Trung, Hanoi 10000, Vietnam, Institute of Biotechnology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 10000, Vietnam, Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China. Yunnan Institute of Microbiology, Yunnan University, Kunming 650091, China, École pratique des hautes études (EPHE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226

Subjects
0301 basic medicine, [SDV.SA]Life Sciences [q-bio]/Agricultural sciences, [SDV]Life Sciences [q-bio], Antibiotics, [SDV.SA.AGRO]Life Sciences [q-bio]/Agricultural sciences/Agronomy, Biochemistry, law.invention, chemistry.chemical_compound, law, Pharmacology (medical), Food science, General Pharmacology, Toxicology and Pharmaceutics, Synergisme, biology, Chemistry, Litsea cubeba, Antimicrobial, Streptomyces, 3. Good health, Infectious Diseases, S50 - Santé humaine, Huile essentielle, endophytic actinomycete, Microbiology (medical), Carveol, Membrane permeability, medicine.drug_class, 030106 microbiology, [SDV.BID]Life Sciences [q-bio]/Biodiversity, Citral, Microbiology, Article, essential oil, 03 medical and health sciences, Plante médicinale, Actinomycetales, medicine, litsea cubeba, Q60 - Traitement des produits agricoles non alimentaires, Essential oil, antimicrobial activity, synergistic effect and Streptomyces griseorubens, synergistic effect and streptomyces griseorubens, lcsh:RM1-950, biology.organism_classification, 030104 developmental biology, lcsh:Therapeutics. Pharmacology, membrane permeability, Antimicrobien, Keywords: Antimicrobial activity, Streptomyces griseorubens, medicinal plants
Abstract

The present study aimed to evaluate the synergistic effects of the crude ethyl acetate extract (CEAE) from endophytic actinomycete MPT42 and essential oil (EO) of the same host plant Litsea cubeba. The isolate MPT42, exhibiting broad-spectrum antimicrobial activities and harboring all three antibiotic-related biosynthetic genes pks-I, pks-II, and nrps, was identified as Streptomycete griseorubens based on an analysis of the morphology, physiology, and 16S rDNA sequence. Minimum inhibitory concentrations (MICs) and the fractional inhibitory concentration index were used to estimate the synergistic effects of various combined ratios between CEAE or antibiotics (erythromycin, vancomycin) and EO toward 13 microbial strains including pathogens. L. cubeba fruit EO, showing the main chemical constituents of 36.0% citral, 29.6% carveol, and 20.5% limonene, revealed an active-low against tested microbes (MICs &ge, 600 &mu, g/mL). The CEAE of S. griseorubens culture exhibited moderate&ndash, strong antimicrobial activities against microbes (MICs = 80&ndash, g/mL). Analysis of the mechanism of action of EO on Escherichia coli ATCC 25922 found that bacterial cells were dead after 7 h of the EO treatment at 1 MIC (5.5 mg/mL), where 62% cells were permeabilized after 2 h and 3% of them were filament (length &ge, 6 &mu, m). Combinations of CEAE, erythromycin, or vancomycin with EO led to significant synergistic antimicrobial effects against microbes with 4&ndash, 16 fold reduction in MIC values when compared to their single use. Interestingly, the vancomycin&ndash, EO combinations exhibited a strong synergistic effect against five Gram-negative bacterial species. This could assume that the synergy was possibly due to increasing the cell membrane permeability by the EO acting on the bacterial cells, which allows the uptake and diffusion of antimicrobial substances inside the cell easily. These findings in the present study therefore propose a possible alternative to combat the emergence of multidrug-resistant microbes in veterinary and clinics.

Published
2019

11. Probing the Fluorescence Dipoles of Single Cubic CdSe/CdS Nanoplatelets with Vertical or Horizontal Orientations

Author

Brice Nadal, Michel Nasilowski, Loan Thu Nguyen, Agnès Maître, Laurent Coolen, Fu Feng, Benoit Dubertret, Nanostructures et optique ( INSP-E4 ), Institut des Nanosciences de Paris ( INSP ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), Vietnam Academy of Science and Technology ( VAST ), Laboratoire de Physique et d'Etude des Matériaux ( LPEM ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -ESPCI ParisTech-Centre National de la Recherche Scientifique ( CNRS ), Nanostructures et optique (INSP-E4), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Vietnam Academy of Science and Technology (VAST), Laboratoire de Physique et d'Etude des Matériaux (UMR 8213) (LPEM), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, nanoplatelet, Nanophotonics, Physics::Optics, 02 engineering and technology, 01 natural sciences, single fluorescent emitter, [ CHIM ] Chemical Sciences, Vertical orientation, Radiation pattern, symbols.namesake, 0103 physical sciences, [CHIM]Chemical Sciences, Electrical and Electronic Engineering, 010306 general physics, Plasmon, business.industry, 021001 nanoscience & nanotechnology, Polarization (waves), Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Dipole, Fourier analysis, symbols, emission polarization, Optoelectronics, 0210 nano-technology, business, Excitation, radiation pattern, Biotechnology
Abstract

International audience; Measuring the orientation of a single fluorescent nanoemitter and obtaining emitters with a desired orientation is of highest importance for nanophotonics, especially in plasmonics where an emitting dipole close to a metallic surface will couple efficiently to plasmonic modes only if it is deposited vertically. Control of the orientation of a nano-object remains a challenge. Achieving vertical orientation, or having an information on the dipole orientation are key steps for efficient plasmonic excitation. We consider here cubic-shaped nanoplatelets with a thin CdSe core sandwiched in a thick CdS shell. By a combination of polarization measurement and radiation pattern Fourier analysis, we show that each single platelet behaves with excellent precision as a 2D dipole (sum of 2 orthogonal incoherent dipoles) and having only two possible orientations: either they lie horizontally on the substrate or they stand vertically on the edge. The cubic shape allows some platelets to deposit vertically so that they present a deterministic vertical dipole component.

Published
2018

12. Microstructure, microhardness and thermal expansion of CNT/Al composites prepared by flake powder metallurgy

Author

Alicia Weibel, Doan Dinh Phuong, Pham Van Trinh, Phan Ngoc Minh, David Mesguich, Nguyen Van Luan, Christophe Laurent, Vietnam Academy of Science and Technology (VAST), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Vietnam Academy of Science and Technology - VAST (VIETNAM), Centre Interuniversitaire de Recherche et d'Ingénierie des Matériaux - CIRIMAT (Toulouse, France), and Institut National Polytechnique de Toulouse - INPT (FRANCE)

Subjects
Materials science, Thermal properties, Matériaux, B. Thermal properties, A. Carbon nanotubes, Carbon nanotubes, chemistry.chemical_element, 02 engineering and technology, Carbon nanotube, 010402 general chemistry, Science des matériaux, 01 natural sciences, Thermal expansion, law.invention, [SPI.MAT]Engineering Sciences [physics]/Materials, Optical microscope, law, Powder metallurgy, Composite material, Powder processing, Metal matrix composite, 021001 nanoscience & nanotechnology, Microstructure, A. Metal matrix composite, Polymères, 0104 chemical sciences, chemistry, E. Powder processing, Mechanics of Materials, Transmission electron microscopy, Ceramics and Composites, 0210 nano-technology, Carbon
Abstract

International audience; Carbon nanotube/aluminum (CNT/Al) composites are prepared by a combination of flake powder metallurgy and hot-isostatic-pressing. The specimens are investigated by several techniques including Raman spectroscopy, optical microscopy, scanning- and transmission electron microscopy. The composites show a layered-microstructure with a stacking of CNT/Al flakes with a CNT-rich layer between two flakes. The individual Al grains forming the flakes are about 500 nm in size. The CNTs are well dispersed within a flake and they bridge the micro-cracks. The results reveal that the coefficient of thermal expansion (CTE) decreases markedly upon the increase in carbon content, reaching 15.4 x 10-6 K-1 for the specimen with a carbon content of 2.0 wt% (2.9 vol%), i.e. a 30% decrease compared to the CTE of pure Al. This could arise from the layered-microstructure resulting from the utilization of Al flakes as opposed to rounded particles.

Published
2018

13. Partial quenching of electronic Raman scattering in double-wall carbon nanotubes by interlayer coupling

Author

Dmitry I. Levshov, Marina V. Avramenko, Maksiem Erkens, Huy-Nam Tran, Thi Thanh Cao, Van Chuc Nguyen, Emmanuel Flahaut, Valentin N. Popov, Ahmed-Azmi Zahab, Jean-Louis Sauvajol, Raul Arenal, Wim Wenseleers, Sofie Cambré, Matthieu Paillet, Russian Foundation for Basic Research, Research Foundation - Flanders, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission, Gobierno de Aragón, Diputación General de Aragón, Bulgarian National Science Fund, Vietnam Academy of Science and Technology, Agence Nationale de la Recherche (France), and University of Antwerp

Subjects
Chemistry, Physics, General Materials Science, General Chemistry
Abstract

Measuring electronic Raman scattering (ERS) has become an efficient method for structural characterization of metallic single-wall carbon nanotubes (SWCNT). However, applying this method to other types of SWCNT-based structures, e.g., those with strong van der Waals (VDW) coupling, is currently not well studied. In this work, we combine electron diffraction, Rayleigh and Raman spectroscopies to investigate the ERS process near 36 metallic transitions in 21 individual double-wall carbon nanotubes (DWCNTs) with all types of electronic configurations. We observe the partial suppression of ERS intensity in DWCNTs compared to SWCNTs and mainly attribute it to the effect of dielectric screening of Coulomb interactions. We probe ultra-pure macroscopic multi-chirality DWCNT solutions and identify the role of inhomogeneous broadening in observing ERS peaks in Raman spectra. Based on the experimental findings, we propose an adapted method for the structural identification of DWCNT samples from the ERS data. The obtained results can be generalized to the characterization of the emerging 1D VDW heterostructures based on metallic SWCNTs., DL thanks Prof. S. Rochal and D. Chalin for providing MAPLE code for calculating DWCNT transition energy shifts and W. Van Werveke and M. De Clercq for providing MATLAB code for creating chirality distribution maps. A part of the experimental data (i.e., microscopic Rayleigh and Raman spectra, ED patterns) was obtained and preliminary processed within the framework of Russian Foundation for Basic Research grant 18-32-00397 mol_a. Further data analysis (i.e., developing models for ERS, Raman and Rayleigh spectra fitting) was performed by DL with the support of the postdoctoral grant (12ZP720N) of the Fund for Scientific Research Flanders (FWO). The TEM measurements were performed in the Laboratorio de Microscopias Avanzadas (LMA), Universidad de Zaragoza (Spain). R.A. gratefully acknowledges the support from the Spanish MICINN (PID2019-104739 GB-100/AEI/10.13039/501100011033), Government of Aragon (projects DGA E13-20R (FEDER, EU)) and from the European Union H2020 program “ESTEEM3” (Grant number 823717). V.N.P. acknowledges financial support for NTB calculations from the National Science Fund of Bulgaria under grant KP-06-N38/10 from 06.12.2019. T.T.C acknowledges financial support from Vietnam Academy of Science and Technology (grant number: VAST03.06/22-23). H.N.T, E.F., A.A.Z, J.L.S. and M.P. acknowledge financial support by the ANR GAMBIT project, grant ANR-13-BS10-0014 of the French Agence Nationale de la Recherche. The characterization of the macroscopic UP-DWCNT samples was financially supported by a PhD fellowship for M. Erkens of the Research Foundation of Flanders (FWO, grant number: 11C9220N). D.L. acknowledges the financial support from the University of Antwerp Research Fund (grant BOF KP 43770). D.L., M.A., W.W. and S.C. also acknowledge funding from FWO projects (G040011N, G02112N, G035918N and G036618N).

Published
2023

14. Bioturbation effects on bioaccumulation of cadmium in the wetland plant Typha latifolia: A nature-based experiment

Author

Sabina Bassil, Franck Gilbert, Jean Kallerhoff, Anne Probst, Thi Thuy Duong, Trung Kien Hoang, Magali Gerino, François Laurent, Arnaud Elger, Didier Orange, Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, International Water Management Institute - South East Asia (IWMI-SEA), IWMI, Laboratoire Agronomie - Environnement - Ecotoxicologie (A2E), Ecole Nationale Supérieure Agronomique-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, ToxAlim (ToxAlim), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole d'Ingénieurs de Purpan (INPT - EI Purpan), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Recherche Agronomique (INRA), Chimie Agro-Industrielle (CAI), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), University of sciences and technologies of hanoi (USTH), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes (UMR Eco&Sols), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA), Vietnam Academy of Science and Technology (VAST), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Supérieure Agronomique d'Alger, Métabolisme et Xénobiotiques (ToxAlim-MeX), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Recherche Agronomique (INRA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), NUCOWS project University of Science and Technology of Hanoi (USTH), 'Programme de Bourses d'Excellence de l'Ambassade de France au Vietnam'., Centre de Coopération Internationale en Recherche Agronomique - CIRAD (FRANCE), Centre National de la Recherche Scientifique - CNRS (FRANCE), Ecole Nationale Vétérinaire de Toulouse - ENVT (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université des Sciences et des Technologies de Hanoi - USTH (VIETNAM), Graduate University of Science and Technology - GUST (VIETNAM), Vietnam Academy of Science and Technology - VAST (VIETNAM), Laboratoire Ecologie fonctionnelle et Environnement - EcoLab (Toulouse, France), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Geologic Sediments, 010504 meteorology & atmospheric sciences, 010501 environmental sciences, Typhaceae, 01 natural sciences, Riparian plants, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, Cadmium, biology, [SDE.IE]Environmental Sciences/Environmental Engineering, Pollution, 6. Clean water, Bioaccumulation, [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology, Bioturbation, Microcosm, Environmental Engineering, [SDE.MCG]Environmental Sciences/Global Changes, chemistry.chemical_element, Cadmium-Sediment, [SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study, Bioremediation, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Environmental Chemistry, Animals, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, Oligochaeta, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Ecosystem, 0105 earth and related environmental sciences, Ecologie, Environnement, Pollutant, Environmental engineering, Sediment, 15. Life on land, biology.organism_classification, Ecological engineering, Phytoremediation, chemistry, 13. Climate action, Tubifex tubifex, Wetlands, Environmental science, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Water Pollutants, Chemical
Abstract

International audience; The development of efficient bioremediation techniques to reduce aquatic pollutant load in natural sediment is one of the current challenges in ecological engineering. A nature-based solution for metal bioremediation is proposed through a combination of bioturbation and phytoremediation processes in experimental indoor microcosms. The invertebrates Tubifex tubifex (Oligochaeta Tubificidae) was used as an active ecological engineer for bioturbation enhancement. The riparian plant species Typha latifolia was selected for its efficiency in phyto-accumulating pollutants from sediment. Phytoremediation efficiency was estimated by using cadmium as a conservative pollutant known to bio-accumulate in plants, and initially introduced in the overlying water (20 μg Cd/L of cadmium nitrate – Cd(NO3)2·4H2O). Biological sediment reworking by invertebrates' activity was quantified using luminophores (inert particulates). Our results showed that bioturbation caused by tubificid worms' activity followed the bio-conveying transport model with a downward vertical velocity (V) of luminophores ranging from 16.7 ± 4.5 to 18.5 ± 3.9 cm·year− 1. The biotransport changed the granulometric properties of the surface sediments, and this natural process was still efficient under cadmium contamination. The highest value of Cd enrichment coefficient for plant roots was observed in subsurface sediment layer (below 1 cm to 5 cm depth) with tubificids addition. We demonstrated that biotransport changed the distribution of cadmium across the sediment column as well as it enhanced the pumping of this metal from the surface to the anoxic sediment layers, thereby increasing the bioaccumulation of cadmium in the root system of Typha latifolia. This therefore highlights the potential of bioturbation as a tool to be considered in future as integrated bioremediation strategies of metallic polluted sediment in aquatic ecosystems.

Published
2017

15. Physical structure and mechanical properties of polyamide/bamboo composites

Author

Tran Huu Trung, Hoang Thai, Eric Dantras, Jany Dandurand, Huynh Maiduc, Nguyen Vu Giang, Philippe Ponteins, Colette Lacabanne, Geoffrey Haddou, Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Institute for Tropical Technology, Vietnam Academy of Science and Technology (VAST), Assystem France, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Assystem (FRANCE), and Vietnam Academy of Science and Technology - VAST (VIETNAM)

Subjects
Materials science, Context (language use), 02 engineering and technology, 010402 general chemistry, 01 natural sciences, DSC, Shear modulus, Crystallinity, chemistry.chemical_compound, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], Physical and Theoretical Chemistry, Composite material, Génie des procédés, Bamboo flour, Dynamic mechanical analysis, Viscoelasticity, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Amorphous solid, Tetraethyl orthosilicate, Polymères, chemistry, Polyamide/bamboo composite, Coupling agent, Polyamide, 0210 nano-technology, Glass transition
Abstract

International audience; The main objective of this work is to process innovative bamboo flour (BF)-reinforced polymer composites.In this context, polyamide 11 (PA 11) is used as technical matrix. Moreover, BF is treated with tetraethyl orthosilicate (TEOS) playing the role of coupling agent. SEM observations show no influence of TEOS on the affinity. The composites were analysed by DSC and DMA, in comparison with neat PA 11. DSC analyses of PA 11/BF highlight that there is no significant modification of the percentage of crystallinity upon introduction of BF whatever the treatment is. Concerning the amorphous phase, only a slight shift of the glass transition of PA 11 from 35°C (PA 11) to 38°C (PA 11/BF composites) is recorded. This shift can be explained by physical bonds at the interface PA 11/BF. DMA analyses allow us to explore the role of BF fillers onto the properties of PA 11/BF composites. The first observation is a slight improvement of the shear modulus G0 when the concentration in TEOS increases. The b relaxation at -80°C is associated with the mobility of the complexes free amide groups/water molecules. There is no shift of the peak due to the presence of BF fillers. The magnitude and width of the relaxation increase with BF and also with TEOS treatment. These observations highlight the increase of hydrogen-bonded water in various sites of the vitreous state. The a relaxation is associated with the anelastic mobility liberated at the glass transition. For PA 11/BF composites, it is constituted by two components: the lower-temperature one due to neat polyamide and a higher-temperature one associated with PA 11/BF amorphous domains with a lower thermal conductivity

Published
2017

16. Responses of Aquatic Bacteria to Terrestrial Runoff: Effects on Community Structure and Key Taxonomic Groups

Author

Jean L. Janeau, Emma Rochelle-Newall, Quan H. Trinh, Minh T. N. Luu, Hai S. Tran, Duc Anh Trinh, Didier Orange, Cuong Tu Ho, Huong T. Le, Thomas Pommier, Asmaa Merroune, Vietnam Academy of Science and Technology (VAST), Institut d'écologie et des sciences de l'environnement de Paris (iEES), Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Soils and Fertilizers Research Institute (SFRI), Vietnam Academy of Agricultural Sciences (VAAS), Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes (UMR Eco&Sols), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), LOTUS 44/2012/HD-NDT, MOST, PHC Hoa Sen Lotus 23970QM, JEAI BioGEAQ, Institut de Recherche pour le Developpement (IRD), UMR laboratories iEES-Paris, LEM, USTH, Vietnam, IRD (ARTS), Institut d'écologie et des sciences de l'environnement de Paris (IEES), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire de Lyon (ENVL)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Institute of Ecology and Environmental Sciences, University Pierre et Marie Curie, Institut National de la Recherche Agronomique (INRA)-Institut de Recherche pour le Développement (IRD)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Vietnam Academy of Science and Technology ( VAST ), Institut d'écologie et des sciences de l'environnement de Paris ( IEES ), Institut National de la Recherche Agronomique ( INRA ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ) -Centre National de la Recherche Scientifique ( CNRS ), Ecologie microbienne ( EM ), Centre National de la Recherche Scientifique ( CNRS ) -Ecole Nationale Vétérinaire de Lyon ( ENVL ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique ( INRA ) -VetAgro Sup ( VAS ), Soils and Fertilizers Research Institute ( SFRI ), VAAS, Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes ( Eco&Sols ), Centre de Coopération Internationale en Recherche Agronomique pour le Développement ( CIRAD ) -Institut de Recherche pour le Développement ( IRD ) -Institut National de la Recherche Agronomique ( INRA ) -Centre international d'études supérieures en sciences agronomiques ( Montpellier SupAgro ) -Institut national d’études supérieures agronomiques de Montpellier ( Montpellier SupAgro ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Ecole Nationale Vétérinaire de Lyon (ENVL), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)

Subjects
0301 basic medicine, Microbiology (medical), compost, engrais organique, engineering.material, DOC, Microbiology, complex mixtures, 03 medical and health sciences, [ SDV.MP ] Life Sciences [q-bio]/Microbiology and Parasitology, Dissolved organic carbon, Biochar, biochar, Original Research, 2. Zero hunger, Total organic carbon, communauté microbienne, Ecology, Compost, Aquatic ecosystem, Microbiology and Parasitology, fungi, 04 agricultural and veterinary sciences, 15. Life on land, ruissellement, Microbiologie et Parasitologie, carbone organique, écosystème aquatique, fertilité du sol, 030104 developmental biology, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, 13. Climate action, Environmental chemistry, 040103 agronomy & agriculture, engineering, 0401 agriculture, forestry, and fisheries, Environmental science, aquatic microbial community, mesocosms, Surface runoff, Organic fertilizer, Vermicompost
Abstract

International audience; Organic fertilizer application is often touted as an economical and effective method to increase soil fertility. However, this amendment may increase dissolved organic carbon (DOC) runoff into downstream aquatic ecosystems and may consequently alter aquatic microbial community. We focused on understanding the effects of DOC runoff from soils amended with compost, vermicompost, or biochar on the aquatic microbial community of a tropical reservoir. Runoff collected from a series of rainfall simulations on soils amended with different organic fertilizers was incubated for 16 days in a series of 200 L mesocosms filled with water from a downstream reservoir. We applied 454 high throughput pyrosequencing for bacterial 16S rRNA genes to analyze microbial communities. After 16 days of incubation, the richness and evenness of the microbial communities present decreased in the mesocosms amended with any organic fertilizers, except for the evenness in the mesocosms amended with compost runoff. In contrast, they increased in the reservoir water control and soil-only amended mesocosms. Community structure was mainly affected by pH and DOC concentration. Compared to the autochthonous organic carbon produced during primary production, the addition of allochthonous DOC from these organic amendments seemed to exert a stronger effect on the communities over the period of incubation. While the Proteobacteria and Actinobacteria classes were positively associated with higher DOC concentration, the number of sequences representing key bacterial groups differed between mesocosms particularly between the biochar runoff addition and the compost or vermi-compost runoff additions. The genera of Propionibacterium spp. and Methylobacterium spp. were highly abundant in the compost runoff additions suggesting that they may represent sentinel species of complex organic carbon inputs. Overall, this work further underlines the importance of studying the off-site impacts of organic fertilizers as their impact on downstream aquatic systems is not negligible.

Published
2016

17. Improvement of adherence and anticorrosion properties of an epoxy-polyamide coating on steel by incorporation of an indole-3 butyric acid-modified nanomagnetite

Author

Xuan Hoan Nguyen, Anh Truc Trinh, Nadine Pébère, Thu Trang Nguyen, Maëlenn Aufray, Anh Son Nguyen, Thu Thuy Thai, Thi Xuan Hang To, Vietnam Academy of Science and Technology (VAST), Vietnam National University [Hanoï] (VNU), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique - CNRS (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Vietnam Academy of Science and Technology - VAST (VIETNAM), and Centre Interuniversitaire de Recherche et d'Ingénierie des Matériaux - CIRIMAT (Toulouse, France)

Subjects
Materials science, Carbon steel, Matériaux, Nanoparticle, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Epoxy-polyamide-based coating, Corrosion, [SPI.MAT]Engineering Sciences [physics]/Materials, Corrosion inhibitor, chemistry.chemical_compound, Colloid and Surface Chemistry, Coating, Fe 3 O 4 nanoparticles, Zeta potential, Salt spray test, Composite material, Surfaces and Interfaces, General Chemistry, Epoxy, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, chemistry, visual_art, engineering, visual_art.visual_art_medium, 0210 nano-technology, Adherence tests, Nuclear chemistry
Abstract

International audience; In this study, synthesized magnetite (Fe 3 O 4 ) nanoparticles were treated with a corrosion inhibitor, indole-3 butyric acid (IBA) and incorporated in an epoxy-polyamide coating. The coating was applied on a carbon steel substrate. For comparison, coatings with- out particles or with nontreated Fe 3 O 4 particles were also prepared. The IBA-modified nanomagnetite (IBA–Fe 3 O 4 ) was characterized by infrared spec- troscopy and Zeta potential measurements. The inhibitive action of IBA was shown by electrochemical measurements (polarization curves) performed for a bare carbon steel in 0.1 M NaCl solution containing Fe 3 O 4 or IBA–Fe 3 O 4 nanoparticles. Adherence and anticorrosion properties of the epoxy-based coatings containing Fe 3 O 4 or IBA–Fe 3 O 4 were compared to those of the pure epoxy-polyamide resin by dry and wet adherence measurements and by salt spray test. The results showed significant improvement of the film adherence and higher corrosion protection of the carbon steel in the presence of IBA–Fe 3 O 4 . It was concluded that the IBA effect was restricted to the metal/coating interface.

Published
2016

18. Exploration de la biodiversité végétale et microbienne pour la qualité et la sureté des aliments

Author

Son , Chu-Ky, Li , Wen-Jun, Tien , Phi Quyet, Thuy , Nguyen Thi Thanh, Phong , Lai Quoc, Le , Van Viet Man, Le Nguyen , Doan Duy, Anil Kumar , Anal, Dao , Thien, Try , Sophal, Sarter , Samira, Trang , Vu Thu, Khieu , Thi Nhan, Waché , Yves, université de Bourgogne, PAM, Huazhong University of Science & Technology [Wuhan] ( HUST ), Sun Yat-Sen University, Vietnam Academy of Science and Technology ( VAST ), Vietnam National University of Agriculture ( VNUA ), Food Industries Research Institute [Vietnam] ( FIRI ), Ho Chi Minh City University of Technology ( HCMUT ), Can Tho University [Vietnam] ( CTU ), Asian Institute of Technology [Pathumthani] ( AIT ), Ho Chi Minh City University of Food Industry [Vietnam] ( HUFI ), Institute of Technology of Cambodia [Cambodge] ( KHM ), Institut des Sciences de l'Evolution de Montpellier ( ISEM ), Université de Montpellier ( UM ) -Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique ( CNRS ), Procédés Alimentaires et Microbiologiques ( PAM ), Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, CIRUISEF, Huazhong University of Science and Technology [Wuhan] (HUST), Sun Yat-Sen University [Guangzhou] (SYSU), Vietnam Academy of Science and Technology (VAST), Vietnam National University of Agriculture (VNUA), Food Industries Research Institute [Vietnam] (FIRI), Ho Chi Minh City University of Technology (HCMUT), Can Tho University [Vietnam] (CTU), Asian Institute of Technology [Pathumthani] (AIT), Ho Chi Minh City University of Food Industry [Vietnam] (HUFI), Institute of Technology of Cambodia [Cambodge] (KHM), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Procédés Alimentaires et Microbiologiques (PAM), and Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement

Subjects
toxicologie alimentaires, Recherche agronomique, A50 - Recherche agronomique, Contamination, [SDV.IDA]Life Sciences [q-bio]/Food engineering, Q03 - Contamination et toxicologie alimentaires, [ SDV.IDA ] Life Sciences [q-bio]/Food engineering, [SDV.IDA] Life Sciences [q-bio]/Food engineering
Abstract

International audience; La qualité et sureté des aliments jouent un rôle important au Vietnam et dans la région de l'Asie du Sud Est. Dans son programme intégral, l'ASEAN met la sureté des aliments parmi des 12 priorités. Plusieurs travaux ont été focalises sur l'exploration de la biodiversité et des innovations technologiques en Asie du Sud Est afin d'améliorer la qualité et de gérer la sureté des aliments. C'est pour ces raisons, nous avons crée un réseau régional avec les soutiens des partenaires francophones et non-francophones en se basant sur les besoins de la région, l'expertise des partenaires et les coopérations étroites. Ce réseau est composé des 10 partenaires dynamiques et actifs provenant de la France, la Thaïlande, la Chine, et le Vietnam qui ont fait partie du Pre-projet de Coopération Scientifique Inter-universitaire PCSI http://pcsi2013.hust.edu.vn) de l'Agence Universitaire de la Francophonie (AUF) et le Laboratoire International Associe UB/AgroSup Dijon/HUST "Tropical Bioresources & Biotechnology"(www.umr-pam.fr/relation-internationale/tropical-bioresources-biotechnology.html). Notre présentation partagera nos expériences pour monter ce réseau a travers les régions et avec les partenaires francophones, souligner nos activités de recherche multidisciplinaires ainsi que notre point de vue vis-a-vis les interactions Nord-Sud et Sud-Sud. Nous allons aborder nos résultats issus de différents projets associes a ce réseau donc tels que la biodiversité des actinomycètes associes aux plantes médicinales, les bactéries lactiques dans les produits traditionnels fermentes du Vietnam et la valorisation de l'agriculture (riz, manioc) et leurs sous-produits par voies biologiques. (Résumé d'auteur)

Published
2016

19. Layered double hydroxides as containers of inhibitors in organic coatings for corrosion protection of carbon steel

Author

Trinh Anh Truc, To Thi Xuan Hang, Marie-Georges Olivier, Nguyen Thuy Duong, Nadine Pébère, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Mons - UMONS (BELGIUM), Vietnam Academy of Science and Technology - VAST (VIETNAM), Centre Interuniversitaire de Recherche et d'Ingénierie des Matériaux - CIRIMAT (Toulouse, France), Vietnam Academy of Science and Technology (VAST), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Université de Mons (UMons), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
Materials science, Carbon steel, Matériaux, Layered double hydroxides, General Chemical Engineering, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Corrosion, chemistry.chemical_compound, Corrosion inhibitor, Materials Chemistry, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Polarization (electrochemistry), Corrosion inhibitors, Organic Chemistry, Metallurgy, Organic coatings, Epoxy, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, Dielectric spectroscopy, Micro et nanotechnologies/Microélectronique, chemistry, Release, visual_art, engineering, visual_art.visual_art_medium, Hydroxide, 0210 nano-technology, Nuclear chemistry
Abstract

International audience; The present work focuses on the use of layered double hydroxides (LDH) as containers for corrosion inhibitors in an epoxy coating. 2-Benzothiazolylthio-succinic acid (BTSA), used as corrosion inhibitor, was intercalated by co-precipitation in magnesium-aluminum layered double hydroxides. The obtained LDH-BTSA was characterized by infrared spectroscopy, X-ray diffraction and scanning electron microscopy. BTSA release from LDH-BTSA in NaCl solutions was investigated by UV-vis spectroscopy. The inhibitive action of LDH-BTSA on carbon steel corrosion was characterized by electrochemical methods and the protective properties of an epoxy coating containing LDH-BTSA were evaluated by electrochemical impedance spectroscopy. It was shown that the BTSA was intercalated in the layered double hydroxide and its loading was about 33%. The BTSA release was dependent on the NaCl concentration in the electrolyte. The polarization curves obtained on the carbon steel sample showed that the LDH-BTSA is an anodic inhibitor. Its efficiency was about 90% at a concentration of 3 g/l. The impedance results showed that the incorporation of LDH-BTSA (3%) in the epoxy matrix improved the corrosion protection of the carbon steel.

Published
2012

20. Comparison between IRI-2012, IRI-2016 models and F2 peak parameters in two stations of the EIA in Vietnam during different solar activity periods

Author

Ngoc Luong Thi, Thanh Le Truong, Minh Le Huy, Hung Luu Viet, Hong Pham Thi Thu, Christine Amory Mazaudier, Kornyanat Hozumi, Dung Nguyen Thanh, Institute of Geophysics [Hanoi], Vietnam Academy of Science and Technology (VAST), Graduate University of Science and Technology [Hanoi] (GUST), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Abdus Salam International Centre for Theoretical Physics [Trieste] (ICTP), Ho Chi Minh city University of Technology and Education, and National Institute of Information and Communications Technology [Tokyo, Japan] (NICT)

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Aerospace Engineering, Trough (economics), Atmospheric sciences, 01 natural sciences, 7. Clean energy, solar activity, International Reference Ionosphere, equatorial ionization anomaly (EIA), 0103 physical sciences, Solstice, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Ionogram, ionogram, food and beverages, Astronomy and Astrophysics, IRI model, Geophysics, Critical frequency, 13. Climate action, Space and Planetary Science, Solar Activities, hmF2, General Earth and Planetary Sciences, Environmental science, Crest, foF2
Abstract

International audience; This paper presents observations of the F2-layer critical frequency (foF2) and height (hmF2) obtained at Phu Thuy (21.03°N, 105.95°E) and Bac Lieu (9.28°N, 105.73°E) observatories in Vietnam. The data have been examined for all seasons, during high and low solar activities, and compared with the foF2 and hmF2 of the International Reference Ionosphere model (IRI-2012, IRI-2016 two options: AMTB, SHU). Phu Thuy observatory is located at the Northern Crest of the EIA and Bac Lieu in the trough of the EIA, therefore the foF2 values at Phu Thuy are higher than at Bac Lieu. The results show that the IRI-2012 model estimates well the observed foF2 at both stations during high and low solar activities.During high solar activity, models estimate well the calculated hmF2 in summer for both stations. At Phu Thuy in equinoxes AMTB reproduces the night peak better than IRI-2012 and SHU, but higher and later about 2-3 hours, in winter the performance of AMTB is worst. At Bac Lieu, the IRI-2016 options reproduce the night peak and underestimates it, but IRI-2012 does not do it. The pre-noon peaks are underestimated by all the models, except IRI-2012 which overestimates the hmF2 pre-noon peaks at Bac Lieu. At Phu Thuy the pre-noon hmF2 peak is higher than the post-dusk one. At Bac Lieu the post-dusk peak is higher except in summer.During low solar activity, the IRI models estimate relatively well the shape of the calculated hmF2 at both stations. The IRI-2012 models explained better the observed foF2 (deviation of 2.5%) during solstices than during equinoxes (14.2%) for high solar activity. The IRI-2012 model explained better the observed foF2 in spring (7.8%) than in autumn (19.9%), matched better the calculated hmF2 in solstice (5.4%) than during equinoxes (11.8%).The performance of AMTB is worst at both stations for both the high and low solar activity periods except in autumn at Bac Lieu for the low solar year. IRI-2012 is best at the stations for both high and low solar activity periods, except in summer for the high solar activiy year when SHU is the best at Phu Thuy. These results can be used to improve the future IRI model.

Published
2021

21. Complete Genome Sequence of Tepidibacter sp. Strain 8C15b, Isolated from Bank Sediments of Haiphong Bay, Vietnam

Author

Fouteau, Stéphanie, Bui Van, Vuong, Rouy, Zoé, Beraud, Mélanie, Cruaud, Corinne, Cayol, Jean-Luc, Chifflet, Sandrine, Chu Van, Thuoc, Pham The, Thu, Vallenet, David, Oliveira, Pedro, Mari, Xavier, Pradel, Nathalie, Institut de Biologie François JACOB (JACOB), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institute of Marine Environment and Resources (IMER), Vietnam Academy of Science and Technology (VAST), Institut méditerranéen d'océanologie (MIO), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDE]Environmental Sciences
Abstract

International audience; We report the complete genome sequence of Tepidibacter sp. strain 8C15b, isolated from bank sediments of Haiphong Bay, Vietnam. The genome includes a 3,628,320-bp circular chromosome and a plasmid of 38,213 bp.

Published
2022

22. Viral distribution and life strategies in the Bach Dang Estuary, Vietnam

Author

Yvan Bettarel, Thierry Bouvier, Martin Agis, Corinne Bouvier, Thuoc Van Chu, Marine Combe, Xavier Mari, Minh Ngoc Nghiem, Thuy Thanh Nguyen, Thu The Pham, Olivier Pringault, Emma Rochelle-Newall, Jean-Pascal Torréton, Huy Quang Tran, Ecologie des systèmes marins côtiers (Ecosym), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS), Institute of Marine Environment and Resources (IMER), Vietnam Academy of Science and Technology (VAST), National Institute of Hygiene and Epidemiology [Hanoi, Vietnam] (NIHE), Réseau International des Instituts Pasteur (RIIP), Biogéochimie et écologie des milieux continentaux (Bioemco), Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut National d'Hygiène et d'Épidémiologie de Hanoi (NIHE), This work was financed by the EC2CO-PNEC project 'HAIPHONG', and grants from the French IRD, CNRS, Groupement De Recherche (GDR) 2476 Réseaux Trophiques Pélagiques, and the Vietnam Academy of Science and Technology (VAST)., École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS)

Subjects
0106 biological sciences, viruses, Molecular Sequence Data, Soil Science, Fresh Water, Sodium Chloride, Biology, 01 natural sciences, 03 medical and health sciences, Lysogen, Microbial ecology, Lysogenic cycle, Dry season, Seawater, 14. Life underwater, Phylogeny, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology, 0303 health sciences, geography, geography.geographical_feature_category, Ecology, 010604 marine biology & hydrobiology, Estuary, Plankton, 6. Clean water, Virus Latency, Salinity, Vietnam, Lytic cycle, Viruses, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Virus Physiological Phenomena
Abstract

International audience; Although the structure and dynamics of planktonic viruses in freshwater and seawater environments are relatively well documented, little is known about the occurrence and activity of these viruses in estuaries, especially in the tropics. Viral abundance, life strategies, and morphotype distribution were examined in the Bach Dang Estuary (Vietnam) during the dry season in 2009. The abundance of both viruses and their prokaryotic hosts decreased significantly from upstream to downstream, probably as the result of nutrient dilution and osmotic stress faced by the freshwater communities. The antibiotic mitomycin-C revealed that the fraction of lysogenic cells was substantially higher in the lower seawater part of the estuary (max 27.1%) than in the upper freshwater area where no inducible lysogens were observed. The question of whether there is a massive, continuous induction of marine lysogens caused by the mixing with freshwater is considered. Conversely, the production of lytic viruses declined as salinity increased, indicating a spatial succession of viral life strategies in this tropical estuary. Icosahedral tailless viruses with capsids smaller than 60 nm dominated the viral assemblage throughout the estuary (63.0% to 72.1% of the total viral counts), and their distribution was positively correlated with that of viral lytic production. Interestingly, the gamma-proteobacteria explained a significant portion of the variance in the 90 nm) was explained by the beta-proteobacteria. Overall, these results support the view that the environment, through selection mechanisms, probably shapes the structure of the prokaryotic community. This might be in turn a source of selection for the virioplankton community via specific affiliation favoring particular morphotypes and life strategies.

Published
2011

23. Neodymium Isotopic Composition and Rare Earth Element Concentration Variations in the Coral and Solomon Seas

Author

Viet Quoc Pham, Catherine Jeandel, Melanie Grenier, Sophie Cravatte, Gerard Eldin, Moustafa Belhadj, Cyril Germineaud, Tu Van Vu, Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institute of Environmental Technology [Hanoi] (IET), Vietnam Academy of Science and Technology (VAST), Mercator Ocean International [Toulouse], Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDE]Environmental Sciences, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography
Abstract

Significant progress has been made in the last decade on the understanding of the role of the Coral and Solomon Seas as major suppliers of waters and chemical elements to the equatorial Pacific. Yet, the location, depth, and processes of chemical enrichment of these waters remain poorly constrained. Neodymium (Nd) isotopic compositions (εNd) and rare earth element concentrations (REE) are powerful tracers of land-ocean chemical exchanges. Combined, they can greatly refine the characterization of these exchanges. Here we report profiles of εNd at 21 stations located in the Coral and Solomon Seas as part of the GEOTRACES GP-12 cruise that complement the rare earth element concentration (REE) profiles of Pham (Chemical Geology, 2019, 524 (May), 11–36). Waters exiting the Solomon Sea are generally slightly more radiogenic than the incoming ones, suggesting inputs of radiogenic material along their pathways across the Solomon Sea. This radiogenic material is brought to the surface waters via natural processes (rivers, volcanic dusts) and likely local mining activities. Noticeable εNd increases are also observed in subsurface and intermediate layers. All these processes indicate the occurrence of local Boundary Exchange (BE) processes, which are estimated to occur within a few days. Coupling hydrological and chemical tracers allows highlighting the land-ocean interactions affecting some water layers and quantifying the exchanged fluxes of Nd. Modifications of the Nd concentration and isotopic composition in the lower thermocline layer require an external flux of 7.9 ± 2.0 t(Nd)/yr only partly balanced by a scavenging flux of 1.8 ± 2.3 t(Nd)/yr, leading to a net influx of 6.1 ± 1.7 t(Nd)/yr. Regarding the Upper Circumpolar Deep Water, a total net flux of 105 ± 50 t(Nd)/yr is estimated, the external flux is relatively high (86 ± 31 t(Nd)/yr while the scavenging flux remains. These results refine the role of the Solomon Sea as a supplier of continental chemical elements to the Pacific equatorial waters.

Published
2022

24. Duplication of NRAMP3 Gene in Poplars Generated Two Homologous Transporters with Distinct Functions

Author

Mathieu Pottier, Van Anh Le Thi, Catherine Primard-Brisset, Jessica Marion, Michele Bianchi, Cindy Victor, Annabelle Déjardin, Gilles Pilate, Sébastien Thomine, Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Heinrich Heine Universität Düsseldorf = Heinrich Heine University [Düsseldorf], Vietnam Academy of Science and Technology (VAST), Biologie intégrée pour la valorisation de la diversité des Arbres et de la Forêt (BioForA), Office national des forêts (ONF)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), This work has benefited from a French State France 2030 program (Saclay Plant Sciences, reference n° ANR-17-EUR-0007, EUR SPS-GSR, ANR-06-ECOT-0015,PHYTOTOP,Stratégies culturales, valorisation de la biomasse, et sélection d'espèces plus performantes appliqués à l'utilisation du peuplier pour la remédiation de sols pollués(2006), ANR-17-CE20-0008,MOBIFER,Dynamique de la sécrétion de coumarines dans le sol, un processus développé par les plantes pour améliorer la nutrition en fer(2017), ANR-11-EQPX-0029,MORPHOSCOPE 2,Imagerie et reconstruction multiéchelles de la morphogenèse. (Plateforme d'innovation technologique et méthodologique pour l'imagerie in vivo et la reconstruction des dynamiques multiéchelles de la morphogenèse)(2011), and ANR-10-INBS-0004,France-BioImaging,Développment d'une infrastructure française distribuée coordonnée(2010)

Subjects
vacuole, metal, Arabidopsis, Salix, apoplasmic transport, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, recycling, selective pressure, Populus, nutrition, Golgi apparatus, evolution, manganese, Genetics, micronutrient, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, symplasmic transport, Molecular Biology, Ecology, Evolution, Behavior and Systematics
Abstract

Transition metals are essential for a wealth of metabolic reactions, but their concentrations need to be tightly controlled across cells and cell compartments, as metal excess or imbalance has deleterious effects. Metal homeostasis is achieved by a combination of metal transport across membranes and metal binding to a variety of molecules. Gene duplication is a key process in evolution, as emergence of advantageous mutations on one of the copies can confer a new function. Here, we report that the poplar genome contains two paralogues encoding NRAMP3 metal transporters localized in tandem. All Populus species analyzed had two copies of NRAMP3, whereas only one could be identified in Salix species indicating that duplication occurred when the two genera separated. Both copies are under purifying selection and encode functional transporters, as shown by expression in the yeast heterologous expression system. However, genetic complementation revealed that only one of the paralogues has retained the original function in release of metals stored in the vacuole previously characterized in A. thaliana. Confocal imaging showed that the other copy has acquired a distinct localization to the Trans Golgi Network (TGN). Expression in poplar suggested that the copy of NRAMP3 localized on the TGN has a novel function in the control of cell-to-cell transport of manganese. This work provides a clear case of neo-functionalization through change in the subcellular localization of a metal transporter as well as evidence for the involvement of the secretory pathway in cell-to-cell transport of manganese.

Published
2022

25. Application of Atmospheric Non Thermal Plasma-Catalysis Hybrid System for Air Pollution Control in HCMC-Vietnam

Author

Than Quoc An, Ha, Pham Huu, Thien, Nguyen Quoc, Thiet, Le Van, Tiep, Cormier, Jean Marie, Khacef, Ahmed, Institute of Applied Material Science (IAMS), Vietnam Academy of Science and Technology (VAST), Groupe de recherches sur l'énergétique des milieux ionisés (GREMI), Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), P. Da Costa, C. dujardin, T. Grzybek, A. Krzton, CNRS (France) - Vietnam Academy of Science and Technology Collaboration, and KHACEF, Ahmed

Subjects
[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph]
Abstract

International audience; Atmospheric Non-Thermal Plasma (ANTP) technology for indoor air treatment has the disadvantage to produce undesirable by-products such as ozone and NOx. To overcome the by-products formation and increasing energy efficiency, ANTP could take advantage of its synergetic effect through combination with heterogeneous catalysts. Various catalysts based on Ag, Au, Cu, Co, Mn, La (supported on OMS-2, Al2O3 or CeO2) and Nb has been investigated with and without a dielectric barrier discharge (DBD). In the absence of catalysts, the toluene removal efficiency was about 60% with O3, CO, CO2, and NOx as reaction products. Without plasma, the reaction of toluene conversion over Al2O3, OMS-2, and perovskite based catalysts are promoted only at high temperature (200-400°C). When the plasma was combined to catalyst at room temperature, the toluene removal efficiency strongly increased when the catalysts are in the discharge region. Best results, up to 96% toluene conversion, were obtained when using 1wt%Au/Al2O3 or Nb2O5 catalysts. The products of the toluene oxidation were CO and CO2.

Published
2010

26. Using morpho-anatomical traits to predict the effect of earthworms on soil water infiltration

Author

Pham, Q.V., Nguyen, T.T., Lam, D.H., Capowiez, Y., Nguyen, A.D., Jouquet, Pascal, Tran, T.M., Bottinelli, Nicolas, Soils and Fertilizers Research Institute (SFRI), Vietnam Academy of Agricultural Sciences (VAAS), Vietnam Natl Univ, Institut d'écologie et des sciences de l'environnement de Paris (iEES Paris ), Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Can Tho University [Vietnam] (CTU), Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes (EMMAH), Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Vietnam Academy of Science and Technology (VAST)

Subjects
Biostructure, [SDV.SA.STA]Life Sciences [q-bio]/Agricultural sciences/Sciences and technics of agriculture, Soil Science, Biopore, Macrofauna, Bioturbation
Abstract

International audience; Despite the well-known potential of earthworms to modify soil macroporosity , water infiltration through their burrowing activities, it is still difficult to predict which species are more effective in increasing water infiltration. We thus investigated the relationships between soil water infiltration, burrow network properties, morphology and anatomy of a diversity of earthworm species. We sampled 23 earthworm species in northern Vietnam and measured 16 morpho-anatomical traits a priori linked to their feeding, vertical distribution or burrowing behaviour. One individual was then incubated in a repacked soil core for four weeks under laboratory conditions, each in four replicates. After incubation, burrow network properties were assessed using X-ray computed tomography , soil saturated hydraulic conductivity was measured using the falling head method. We found large differences among species belonging to similar or different ecological categories in their effect on soil saturated hydraulic conductivity. We observed neutral to positive effects with an increase of up to 30-fold compared to cores without earthworms. The effect of earthworms on soil hydraulic conductivity was well pre-dicted by burrow network properties (volume and continuity of burrows) or morpho-anatomical traits (body weight, circular and longitudinal muscles thickness) using the random forest regression models (R2 > 0.95 in both cases). Earthworms with a large body weight and circular and longitudinal muscle thicknesses have the highest probability of increasing soil saturated hydraulic conductivity compared to other species. In addition, we showed from the coinertia analysis that body weight and circular and longitudinal muscle thickness were positively associated with the volume and continuity of burrows. Our findings therefore illustrate the power of employing a trait-based approach to predict the effect of non-Lumbricidae earthworms on water infiltration in comparison to the classical ecological category approach. Such trait information could be used to prioritize practices that favour the expression of more desirable earthworm traits to increase soil water infiltration.

Published
2023

27. Sun-Earth System Interaction studies over Vietnam: an international cooperative project

Author

C. Amory-Mazaudier, M. Le Huy, Y. Cohen, V. Doumbia, A. Bourdillon, R. Fleury, B. Fontaine, C. Ha Duyen, A. Kobea, P. Laroche, P. Lassudrie-Duchesne, H. Le Viet, T. Le Truong, H. Luu Viet, M. Menvielle, T. Nguyen Chien, A. Nguyen Xuan, F. Ouattara, M. Petitdidier, H. Pham Thi Thu, T. Pham Xuan, N. Philippon, L. Tran Thi, H. Vu Thien, P. Vila, Centre d'étude des environnements terrestre et planétaires ( CETP ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Institute of Geophysics [Hanoi], Vietnam Academy of Science and Technology ( VAST ), Institut de Physique du Globe de Paris ( IPGP ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -IPG PARIS-Université Paris Diderot - Paris 7 ( UPD7 ) -Université de la Réunion ( UR ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique de l'Atmosphère [Abidjan] ( LAPA ), Université de Cocody, Institut d'Electronique et de Télécommunications de Rennes ( IETR ), Université de Nantes ( UN ) -Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Institut National des Sciences Appliquées - Rennes ( INSA Rennes ) -CentraleSupélec-Centre National de la Recherche Scientifique ( CNRS ), Département Micro-Ondes ( MO ), Institut Mines-Télécom [Paris]-Télécom Bretagne-Université européenne de Bretagne ( UEB ), Traitement Algorithmique et Matériel de la Communication, de l'Information et de la Connaissance ( TAMCIC ), Ecole Nationale Supérieure des Télécommunications de Bretagne-Centre National de la Recherche Scientifique ( CNRS ), Centre de Recherches de Climatologie ( CRC ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), ONERA - The French Aerospace Lab ( Palaiseau ), ONERA, Université de Koudougou, Université de kOUDOUGOU, Conservatoire National des Arts et Métiers - Paris ( CNAM Paris ), Conservatoire National des Arts et Métiers [CNAM] ( CNAM ), Administateur, HAL Sorbonne Université, Centre d'étude des environnements terrestre et planétaires (CETP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Vietnam Academy of Science and Technology (VAST), Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de l'Atmosphère [Abidjan] (LAPA), Institut d'Électronique et des Technologies du numéRique (IETR), Nantes Université (NU)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Département Micro-Ondes (MO), Université européenne de Bretagne - European University of Brittany (UEB)-Télécom Bretagne-Institut Mines-Télécom [Paris] (IMT), Traitement Algorithmique et Matériel de la Communication, de l'Information et de la Connaissance (TAMCIC), Ecole Nationale Supérieure des Télécommunications de Bretagne-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches de Climatologie (CRC), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), ONERA - The French Aerospace Lab [Palaiseau], ONERA-Université Paris Saclay (COmUE), Université Norbert ZONGO de Koudougou, Laboratoire Signaux et systèmes, Conservatoire National des Arts et Métiers [CNAM] (CNAM), Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES), laboratoire de physique de l'atmosphère, (LPA), université d'Abidjan Cocody, École Normale Supérieure - Koudougou (ENSK), No affiliation (No affiliation), Institut Mines-Télécom [Paris] (IMT)-Télécom Bretagne-Université européenne de Bretagne - European University of Brittany (UEB), Université de Nantes (UN)-Université de Rennes 1 (UR1), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), and HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, [SDE.MCG]Environmental Sciences/Global Changes, Context (language use), Monsoon, 01 natural sciences, [SDU.STU.CL] Sciences of the Universe [physics]/Earth Sciences/Climatology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), lcsh:Science, 010303 astronomy & astrophysics, diurnal to secular), 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:QC801-809, Geology, Astronomy and Astrophysics, Equatorial electrojet, Orography, lcsh:QC1-999, International Heliophysical Year, Ionosphere (Electric fields and currents), lcsh:Geophysics. Cosmic physics, [SDE.MCG] Environmental Sciences/Global Changes, [ SDE.MCG ] Environmental Sciences/Global Changes, Geography, 13. Climate action, Space and Planetary Science, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Geomagnetism and paleomagnetism (Time variations, Meteorology and dynamics (Tropical meteorology), lcsh:Q, Tropical cyclone, Ionosphere, [ SDU.STU.CL ] Sciences of the Universe [physics]/Earth Sciences/Climatology, Longitude, lcsh:Physics
Abstract

International audience; During many past decades, scientists from various countries have studied separately the atmospheric motions in the lower atmosphere, in the Earth's magnetic field, in the magnetospheric currents, etc. All of these separate studies lead today to the global study of the Sun and Earth connections, and as a consequence, new scientific programs (IHY- International Heliophysical Year, CAWSES- Climate and Weather in the Sun-Earth System) are defined, in order to assume this new challenge. In the past, many scientists did not have the possibility to collect data at the same time in the various latitude and longitude sectors. Now, with the progress of geophysical sciences in many developing countries, it is possible to have access to worldwide data sets. This paper presents the particularities of geophysical parameters measured by the Vietnamese instrument networks. It introduces a cooperative Vietnamese-IGRGEA (International Geophysical Research Group Europe Africa) project, and presents, for the first time, to the international community, the geophysical context of Vietnam. Concerning the ionosphere: since 1963, during four solar cycles, the ionosonde at Phu Thuy (North Vietnam) was operating. The Phu Thuy data exhibits the common features for the ionospheric parameters, previously observed in other longitude and latitude sectors. The critical frequencies of the E, F1 and F2 ionospheric layers follow the variation of the sunspot cycle. F2 and E critical frequencies also exhibit an annual variation. The first maps of TEC made with data from GPS receivers recently installed in Vietnam illustrate the regional equatorial pattern, i.e. two maxima of electronic density at 15 N and 15 S from the magnetic equator and a trough of density at the magnetic equator. These features illustrate the equatorial fountain effect. Concerning the Earth's magnetic field: a strong amplitude of the equatorial electrojet was first observed by the CHAMP satellite at the height of 400 km in the Vietnamese longitude sector. In this paper we compare the ground magnetic observations of the Indian and Vietnamese magnetometer networks. This comparison highlights the regional structure of the amplitude of the equatorial electrojet, which is stronger in Vietnam than in India. Concerning the monsoon: Vietnam exhibits a strong monsoon and has mainly one rainy season peaking in August, hence associated with the southwest monsoon flow. But some monsoon variability from one place to another is related to the orography. In the mountainous northern regions of Vietnam, there is an "early" monsoon peaking in July. In the coastal regions between 12 N and 19 N the monsoon season is centered on October. Concerning lightning: Vietnam is a country of strong atmospheric storms with some areas of very intense lightning in North Vietnam (22,5 N, 105 E) and in South Vietnam (11 N, 107 E). In North Vietnam strong lightning is associated with the most intense rainy region. Keywords. Ionosphere (Electric fields and currents) - Meteorology and dynamics (Tropical meteorology) - Geomagnetism and paleomagnetism (Time variations, diurnal to secular)

Published
2006

28. Stable doped hybrid sol-gel materials for solid-state dye laser

Author

Jean-Pierre Boilot, Alain Brun, Frederic Chaput, Nguyen Dai Hung, Michael Canva, Tran Hong Nhung, Truon Thi Anh Dao, Institut of Physics and Electronics, Vietnamese Academy of Science and Technogy, Laboratoire Charles Fabry de l'Institut d'Optique / Macsybio, Laboratoire Charles Fabry de l'Institut d'Optique (LCFIO), Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de la matière condensée (LPMC), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Charles Fabry de l'Institut d'Optique / Elsa, Center for Quantum Electronics [Hanoi], Institute of Physics [Hanoi], and Vietnam Academy of Science and Technology (VAST)-Vietnam Academy of Science and Technology (VAST)

Subjects
[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Dye laser, Materials science, business.industry, Materials Science (miscellaneous), Doping, 02 engineering and technology, 021001 nanoscience & nanotechnology, Laser, 01 natural sciences, Industrial and Manufacturing Engineering, law.invention, 010309 optics, Optics, law, Optical cavity, 0103 physical sciences, Business and International Management, 0210 nano-technology, business, Absorption (electromagnetic radiation), Tunable laser, Solid-state dye lasers, Sol-gel
Abstract

International audience; Laser effects have been obtained with dye-doped hybrid xerogel samples prepared several years ago and stored in different "classical" conditions. Firstly, using the same configuration of the laser cavity as was used 4-5 years ago, we have obtained almost identical laser performances, and slope conversion efficiencies were measured up to 80% and operational lifetimes, with 1-mJ initial output energy and 10-Hz repetition rate of several hundred thousand pulses obtained. Secondly, we have introduced the new pyrromethene 605 dye into a hybrid xerogel matrix and obtained good laser performances similar to the rest of the pyrromethene family

Published
2003

29. MINIATURE CIRCULARLY POLARIZED ANTENNA FOR UHF RFID HANDHELD READER: DESIGN AND EXPERIMENTS

Author

L.H. Trinh, Nguyen-Vu Truong, Khai-Thong Lu, Manh-Thao Nguyen, Fabien Ferrero, Guangdong University of Science and Technology (GUST), University of Technology, Vietnam National University - Ho Chi Minh City (Faculty of Chemical Engineering), Ho Chi Minh City University of Technology (HCMUT), Vietnam Academy of Science and Technology (VAST), University of Sciences [Ho Chi Minh City] (HCMC), Ho Chi Minh City University of Science (HCMUS), International University HCMC [Vietnam], International University, Institute of Applied Mechanics and Informatics, Laboratoire d'Electronique, Antennes et Télécommunications (LEAT), Université Nice Sophia Antipolis (... - 2019) (UNS), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)

Subjects
Computer science, business.industry, 020208 electrical & electronic engineering, 020206 networking & telecommunications, 02 engineering and technology, Condensed Matter Physics, 7. Clean energy, Electronic, Optical and Magnetic Materials, Circularly polarized antenna, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Optics, Ultra high frequency, 0202 electrical engineering, electronic engineering, information engineering, business, Mobile device
Abstract

International audience; A low-profile circularly polarized (CP) antenna for a handheld Ultra-High Frequency RadioFrequency Identification (UHF RFID) reader is proposed in this paper. The radiating part on the topsubstrate is composed of three inverted-F elements rotated 120◦around the center of the structure. Apower splitting circuit, placed on the bottom substrate, based on a series transmission line feed deliversequal amplitude to the three IFAs with a sequential 120◦phase shift. Both layers are fabricated onlow-cost FR4 material. This design has a disk form factor with a compact size of 35 mm circle radiusand an 8.6 mm height. The measurement shows good results withS11as lower than−10 dB for thewhole band, 3 dB-axial ratio around 110◦(10 MHz of bandwidth), directivity reaching 4.4 dBic, and thetotal gain of the antenna is 1.9 dBic. In order to validate the proposed antenna performance, a UHFRFID handheld reader is built based on the ThingMagic M6E-Nano module. Different scenarios areinvestigated to validate the proposed antenna performance in a real environment

Published
2020

30. Measuring Ground Subsidence in Ha Noi Through the Radar Interferometry Technique Using TerraSAR-X and Cosmos SkyMed Data

Author

Dinh Ho Tong Minh, Thuy Le Toan, Duc Anh Nguyen, Ibrahim El-Moussawi, Quoc Cuong Tran, Quy Nhan Pham, Tran Trung Dang, Territoires, Environnement, Télédétection et Information Spatiale (UMR TETIS), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Vietnam Academy of Science and Technology (VAST), Vietnam National University [Hanoï] (VNU), NATIONAL CENTER FOR WATER RESOURCES PLANNING AND INVESTIGATION HA NOI, VNM, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Centre d'études spatiales de la biosphère (CESBIO), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
SYNTHETIC APERTURE RADAR (SAR), Atmospheric Science, 010504 meteorology & atmospheric sciences, ATMOSPHERIC PHASE SCREEN (APS), 0211 other engineering and technologies, X-BAND, 02 engineering and technology, 01 natural sciences, SPACE-BASED RADAR, law.invention, RADAR MEASUREMENT, law, Interferometric synthetic aperture radar, Radar, X BANDS, COSMOS, TROPICAL ENGINEERING, HANOI, Interferometry, PHASE SCREEN, SATELLITE DATA, [SDE]Environmental Sciences, CORRELATION, MULTITEMPORAL SYNTHETIC APERTURE RADAR INTERFEROMETRY (INSAR), Geology, VIETNAM, Synthetic aperture radar, SUBSIDENCE, INTERFEROMETRY, SYNTHETIC APERTURE RADAR INTERFEROMETRY, Atmosphere, GROUND SUBSIDENCE, SYNTHETIC APERTURE RADAR, GROUND SETTLEMENT, SCATTERING, TROPICS, Computers in Earth Sciences, PERMANENT SCATTERERS, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Remote sensing, RADAR INTERFEROMETRY, Subsidence (atmosphere), TERRASAR-X, GROUND-BASED MEASUREMENT, JV-LOTUSAT, 13. Climate action, Spatial ecology, PERMANENT SCATTERERS/DISTRIBUTED SCATTERERS (PS/DS) PROCESSING, Groundwater
Abstract

International audience; Multitemporal synthetic aperture radar (SAR) interferometry (InSAR) is a widely used technique to measure the ground subsidence and has already shown its ability to map such phenomena on a large spatial scale with millimetric accuracy from space. In Vietnam, to have independent SAR data for surface risk applications, a new X-band SAR mission (JV-LOTUSat) has been scheduled for launch for the 2019-2020 timeframe. However, Vietnam is located in tropical regions where their conditions are impacted by strong atmosphere. The aim of this article is to provide a better understanding of the capabilities of the X-band for estimating the ground subsidence under tropical atmospheric conditions. Analysis is carried out on two stacks, TerraSAR-X and Cosmos SkyMed X-band, from 2011 to 2014 in Ha Noi. We show that the results on the ground subsidence from InSAR processing can describe consistently the subsidence area based on ground measurements. This article demonstrates that the InSAR technique can be effective at detecting and estimating the subsidence phenomena even with the X-band and under conditions typical of tropical regions. The displacement results from TerraSAR-X and Cosmos SkyMed datasets are consistent, with a correlation coefficient (R2) of 0.91 for the period during which their coverage overlaps. Groundwater overexploitation is one of the main causes of the ground subsidence in Ha Noi. This study provides strong support for the scientific potential of the X-band SAR space-borne mission in Vietnam and other tropical countries because it demonstrates the feasibility of the ground subsidence estimates by the X-band SAR, even in conditions impacted by strong atmosphere.

Published
2019

31. Covalent Grafting of Ruthenium Complexes on Iron Oxide Nanoparticles: Hybrid Materials for Photocatalytic Water Oxidation

Author

Pierre Lecante, Vincent Collière, Marc Respaud, Phong D. Tran, Quyen Nguyen, Van Nguyen, Jérôme Esvan, Karine Philippot, Wantana Klysubun, Catherine Amiens, Gilles Lemercier, Elodie Rousset, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), University of Science and Technology of Hanoi (USTH), Institut de Chimie Moléculaire de Reims - UMR 7312 (ICMR), Université de Reims Champagne-Ardenne (URCA)-Institut de Chimie du CNRS (INC)-SFR CAP Santé (Champagne-Ardenne Picardie Santé), Université de Reims Champagne-Ardenne (URCA)-Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS)-SFR Condorcet, Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS)-Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Synchrotron Light Research Institute (SLRI), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Laboratoire de physique et chimie des nano-objets (LPCNO), Université de Toulouse (UT)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), CNRS, Université de Toulouse Paul-Sabatier, Vietnam Academy of Science and Technology (grant D̵L0000.03/19-21), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), University of sciences and technologies of hanoi (USTH), SFR Condorcet, Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-SFR CAP Santé (Champagne-Ardenne Picardie Santé), Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Université de Reims Champagne-Ardenne (URCA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National des Sciences Appliquées de Toulouse - INSA (FRANCE), Synchrotron Light Research Institute (THAILAND), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université des Sciences et des Technologies de Hanoi - USTH (VIETNAM), Université de Reims - Champagne-Ardenne (FRANCE), Institut de Chimie Moléculaire de Reims - ICMR (Reims, France), and Centre Interuniversitaire de Recherche et d'Ingénierie des Matériaux - CIRIMAT (Toulouse, France)

Subjects
Materials science, Matériaux, Nanoparticle, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, Photochemistry, 01 natural sciences, 7. Clean energy, Catalysis, [SPI.MAT]Engineering Sciences [physics]/Materials, Iron oxide nanoparticles, General Materials Science, Pendant group, Water oxidation catalysis, Ruthenium-based photosensitizer, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Ruthenium, chemistry, Covalent bond, Photocatalysis, Hybrid photoanode, Reversible hydrogen electrode, 0210 nano-technology, Hybrid material, Covalent grafting
Abstract

International audience; The present environmental crisis prompts the search for renewable energy sources such as solar-driven production of hydrogen from water. Herein, we report an efficient hybrid photocatalyst for water oxidation, consisting of a ruthenium polypyridyl complex covalently grafted on core/shell Fe@FeOx nanoparticles via a phosphonic acid group. The photoelectrochemical measurements were performed under 1 sun illumination in 1 M KOH. The photocurrent density of this hybrid photoanode reached 20 μA/cm2 (applied potential of +1.0 V vs reversible hydrogen electrode), corresponding to a turnover frequency of 0.02 s–1. This performance represents a 9-fold enhancement of that achieved with a mixture of Fe@FeOx nanoparticles and a linker-free ruthenium polypyridyl photosensitizer. This increase in performance could be attributed to a more efficient electron transfer between the ruthenium photosensitizer and the Fe@FeOx catalyst as a consequence of the covalent link between these two species through the phosphonate pendant group.

Published
2021

32. Investigation on magnetic properties of mechanically alloyed τ-MnAlC with Fe addition

Author

Florent Calvayrac, Quang Minh Ngo, Frederic Mazaleyrat, N. Randrianantoandro, Van Tang Nguyen, Hanoi University of Science and Technology (HUST), Graduate University of Science and Technology [Hanoi] (GUST), Vietnam Academy of Science and Technology (VAST), Systèmes et Applications des Technologies de l'Information et de l'Energie (SATIE), École normale supérieure - Rennes (ENS Rennes)-Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay)-Université Gustave Eiffel-CY Cergy Paris Université (CY), Institut des Molécules et Matériaux du Mans (IMMM), and Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Materials science, Magnetic moment, Alloy, Analytical chemistry, Ab initio, Thermal Stability, 02 engineering and technology, Coercivity, engineering.material, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Electronic, Optical and Magnetic Materials, [PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], Magnetization, Fe doped, 0103 physical sciences, Magnetic properties, engineering, Curie temperature, Thermal stability, Mechanical alloying, 0210 nano-technology, MnFeAlC alloy
Abstract

International audience; The influence of Fe addition on thermal stability, crystallography, and magnetic properties of τ-Mn51Al47C2 was investigated. Alloys with composition Mn51-xFexAl47C2 (x = 0, 0.5, 1, 2, and 4) were synthesized by mechanical alloying method. High purity of τ-Mn(Fe)AlC up to 98% could be obtained after 10 h of milling, then annealed at 1050 °C for 1 h, and followed by an aging process at appropriate temperatures from 515 to 540 °C for 50 min. It was found that the thermal stability of both ε and τ phases was enhanced by the addition of Fe up to 4 at.% into MnAlC alloy through a shifting of ε-to-τ transformation temperature to high temperature region and a reduction in c/a ratio of Fe doped τ-MnAlC compared to iron free τ-MnAlC. While the magnetization and Curie temperature of Fe doped τ-MnAlC showed a reduction compared to iron free τ-Mn51Al47C2, coercivity seems not to be significantly affected. Ab initio calculation showed a lower magnetic moment of Fe (μFe = 1.77 μB) compared to Mn (μMn_average = 2.36 μB) in τ-Mn(Fe)AlC when Fe substituted Mn position at 1a site.

Published
2021

33. A novel thermostable prokaryotic fucoidan active sulfatase PsFucS1 with an unusual quaternary hexameric structure

Author

Mirjam Czjzek, Anne S. Meyer, Van Thi Thanh Tran, Thuan Thi Nguyen, Thomas Roret, Nanna Rhein-Knudsen, Vy Ha Nguyen Tran, Jesper Holck, Thinh Duc Pham, Jan Muschiol, Hang Thi Thuy Cao, Maria Dalgaard Mikkelsen, Mateusz Jakub Lezyk, Technical University of Denmark [Lyngby] (DTU), Vietnam Academy of Science and Technology (VAST), Station biologique de Roscoff (SBR), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Models, Molecular, Protein Conformation, Stereochemistry, Science, Sea Cucumbers, [SDV]Life Sciences [q-bio], Dimer, Oligosaccharides, Random hexamer, Polysaccharide, Biochemistry, Article, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Sulfation, Polysaccharides, Catalytic Domain, Enzyme Stability, Animals, SDG 14 - Life Below Water, 030304 developmental biology, Thermostability, chemistry.chemical_classification, 0303 health sciences, Multidisciplinary, Fucoidan, Sulfatase, Gastrointestinal Microbiome, Enzyme Activation, Monomer, Prokaryotic Cells, chemistry, Medicine, Sulfatases, 030217 neurology & neurosurgery, Biotechnology
Abstract

Fucoidans are sulfated, fucose-rich marine polysaccharides primarily found in cell walls of brown seaweeds (macroalgae). Fucoidans are known to possess beneficial bioactivities depending on their structure and sulfation degree. Here, we report the first functional characterization and the first crystal structure of a prokaryotic sulfatase, PsFucS1, belonging to sulfatase subfamily S1_13, able to release sulfate from fucoidan oligosaccharides. PsFucS1 was identified in the genome of a Pseudoalteromonas sp. isolated from sea cucumber gut. PsFucS1 (57 kDa) is Ca2+ dependent and has an unusually high optimal temperature (68 °C) and thermostability. Further, the PsFucS1 displays a unique quaternary hexameric structure comprising a tight trimeric dimer complex. The structural data imply that this hexamer formation results from an uncommon interaction of each PsFucS1 monomer that is oriented perpendicular to the common dimer interface (~ 1500 Å2) that can be found in analogous sulfatases. The uncommon interaction involves interfacing (1246 Å2) through a bundle of α-helices in the N-terminal domain to form a trimeric ring structure. The high thermostability may be related to this unusual quaternary hexameric structure formation that is suggested to represent a novel protein thermostabilization mechanism.

Published
2021

34. The Hungry Snail, the Fragile Coral, and the Friendly Microbe

Author

Christelle Desnues, Emma Rochelle-Newall, Elyse Boudin, Jean Péronnin, Jean-Christophe Auguet, Yvan Bettarel, Thierry Bouvier, Van Ngoc Bui, Sébastien Halary, MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Molécules de Communication et Adaptation des Micro-organismes (MCAM), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), Institut d'écologie et des sciences de l'environnement de Paris (iEES Paris ), Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD), Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)

Subjects
0303 health sciences, geography, geography.geographical_feature_category, biology, 030306 microbiology, Ecology, Coral, fungi, technology, industry, and agriculture, General Medicine, Coral reef, Snail, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, Mucus, 03 medical and health sciences, biology.animal, population characteristics, Drupella, 14. Life underwater, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, geographic locations, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis, 030304 developmental biology
Abstract

Off the coast of Vietnam, two recent events seem to have contributed to the death of coral reefs: the rapid invasion of a small marine snail called Drupella, and the emergence of a disease that spreads over corals. We decided to investigate whether there is a link between the corals, the snails, and the disease. We analyzed the mucus covering the surface of corals, both in healthy corals and those infested by Drupella snails. Mucus produced by corals is usually full of helpful microbes, protecting the corals from harmful microbes that can make them ill or kill them. Our analyses showed that, when Drupella eats corals, the snail also removes one of the corals’ primary defenses by eliminating most of the tiny protectors in their mucus. This allows harmful microbes to cause additional damage to the corals.

Published
2021

35. Environmental Regulation of the Nitrogen Supply, Mean Trophic Position, and Trophic Enrichment of Mesozooplankton in the Mekong River Plume and Southern South China Sea

Author

Ajit Subramaniam, Iris Liskow, Maren Voss, Natalie Loick-Wilde, Dirk Wodarg, Joseph P. Montoya, Hai Doan-Nhu, Lam Nguyen-Ngoc, Melvin Bach, Sarah C. Weber, Weber, Sarah C., 1 Department of Biological Oceanography Leibniz Institute for Baltic Sea Research Warnemuende Rostock Germany, Montoya, Joseph P., 3 School of Biological Sciences Georgia Institute of Technology Atlanta GA USA, Bach, Melvin, Doan‐Nhu, Hai, 4 Institute of Oceanography Vietnam Academy of Science and Technology Nha Trang Vietnam, Subramaniam, Ajit, 5 Lamont‐Doherty Earth Observatory Columbia University Palisades NY USA, Liskow, Iris, Nguyen‐Ngoc, Lam, Wodarg, Dirk, 6 Department of Marine Chemistry Leibniz Institute for Baltic Sea Research Warnemuende Rostock Germany, and Voss, Maren

Subjects
zooplankton, South china, trophodynamics, chemistry.chemical_element, Biogeochemistry, Oceanography, Nitrogen, Zooplankton, Mekong River plume, Plume, upwelling, Geophysics, chemistry, biogeochemistry, Space and Planetary Science, Geochemistry and Petrology, amino acid nitrogen stable isotopes, ddc:577.7, Earth and Planetary Sciences (miscellaneous), Mekong river, Upwelling, Environmental science, Trophic level
Abstract

The mean trophic position (TP) of mesozooplankton largely determines how much mass and energy is available for higher trophic levels like fish. Unfortunately, the ratio of herbivores to carnivores in mesozooplankton is difficult to identify in field samples. Here, we investigated changes in the mean TP of mesozooplankton in a highly dynamic environment encompassing four distinct habitats in the southern South China Sea: the Mekong River plume, coastal upwelling region, shelf waters, and offshore oceanic waters. We used a set of variables derived from bulk and amino acid nitrogen stable isotopes from particulate organic matter and four mesozooplankton size fractions to identify changes in the nitrogen source and TP of mesozooplankton across these habitats. We found clear indications of a shift in N sources for biological production from nitrate in near‐coastal waters with shallow mixed layer depths toward an increase in diazotroph‐N inputs in oceanic waters with deep mixed layer depths where diazotrophs shaped the phytoplankton community. The N source shift was accompanied by a lengthening of the food chain (increase in the TP). This may provide further support for the connection between diazotrophy and the indirect routing of N through the marine food web. Our combined bulk and amino acid δ15N approach also allowed us to estimate the trophic enrichment (TE) of mesozooplankton across the entire regional ecosystem. When put in the context of literature values, a high TE of 5.1‰ suggested a link between ecosystem heterogeneity and the less efficient transfer of mass and energy across trophic levels., Plain Language Summary: Zooplankton are one of the central pillars of the marine food web and form an important link between the production of organic matter by phytoplankton and biomass at higher trophic levels (e.g., fish). Of particular interest are mesozooplankton (0.2–20 mm in size), which encompass a diverse assemblage of animals utilizing a range of feeding strategies, including herbivory, omnivory, and carnivory. Since mass and energy are lost with each trophic step, their prevailing feeding strategy determines the availability of mass and energy to the upper food web. The exact relationship between carnivores and herbivores in mesozooplankton has so far only been studied with complex experiments or in homogenous environments. We have now resolved zooplankton feeding relationships in a highly dynamic marine environment. Specifically, we used stable nitrogen isotopes in amino acids and bulk organic matter in combination with a habitat‐delineating method for phytoplankton to directly determine the ratio of carnivores to herbivores in zooplankton from dynamic habitats in the South China Sea. The mass and energy transfer across trophic levels is less efficient in such variable marine environments compared to stable open ocean systems. These findings represent a big step toward understanding the dynamics of planktonic food webs in general., Key Points: Trophic structure of mesozooplankton is regulated by similar environmental factors such as phytoplankton assemblages. Diazotrophy and nutrient availability correlated with enhanced mesozooplankton carnivory in a complex tropical marine ecosystem. Mass and energy transfer across trophic levels of planktonic food webs are less efficient in spatially and temporally variable ecosystems., Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659, National Foundation for Science and Technology Development (NAFOSTED) http://dx.doi.org/10.13039/100007224, National Aeronautics and Space Administration (NASA) http://dx.doi.org/10.13039/100000104, Schmidt Ocean Institute, National Science Foundation (NSF) http://dx.doi.org/10.13039/100000001, https://doi.org/10.5061/dryad.bk3j9kdbv

Published
2021

36. Inferring the ecological niche of bat viruses closely related to SARS-CoV-2 using phylogeographic analyses of Rhinolophus species

Author

Hassanin, Alexandre, Tu, Vuong Tan, Curaudeau, Manon, Csorba, Gabor, Institut de Systématique, Evolution, Biodiversité (ISYEB ), Muséum national d'Histoire naturelle (MNHN)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Vietnam Academy of Science and Technology (VAST), and Hungarian Natural History Museum (Magyar Természettudományi Múzeum)

Subjects
China, SARS-CoV-2, Population genetics, Science, viruses, [SDV]Life Sciences [q-bio], COVID-19, virus diseases, Evolutionary biology, Animal migration, Evolutionary ecology, Article, Phylogeography, Biogeography, Haplotypes, Viral infection, Chiroptera, Viruses, Medicine, Animals, Infectious diseases, Asia, Southeastern, Ecological modelling
Abstract

International audience; The Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is the causal agent of the coronavirus disease 2019 (COVID-19) pandemic. To date, viruses closely related to SARS-CoV-2 have been reported in four bat species: Rhinolophus acuminatus, Rhinolophus affinis, Rhinolophus malayanus, and Rhinolophus shameli. Here, we analysed 343 sequences of the mitochondrial cytochrome c oxidase subunit 1 gene (CO1) from georeferenced bats of the four Rhinolophus species identified as reservoirs of viruses closely related to SARS-CoV-2. Haplotype networks were constructed in order to investigate patterns of genetic diversity among bat populations of Southeast Asia and China. No strong geographic structure was found for the four Rhinolophus species, suggesting high dispersal capacity. The ecological niche of bat viruses closely related to SARS-CoV-2 was predicted using the four localities in which bat viruses were recently discovered and the localities where bats showed the same CO1 haplotypes than virus-positive bats. The ecological niche of bat viruses related to SARS-CoV was deduced from the localities where bat viruses were previously detected. The results show that the ecological niche of bat viruses related to SARS-CoV2 includes several regions of mainland Southeast Asia whereas the ecological niche of bat viruses related to SARS-CoV is mainly restricted to China. In agreement with these results, human populations in Laos, Vietnam, Cambodia, and Thailand appear to be much less affected by the COVID-19 pandemic than other countries of Southeast Asia. In the climatic transitional zone between the two ecological niches (southern Yunnan, northern Laos, northern Vietnam), genomic recombination between highly divergent viruses is more likely to occur. Considering the limited data and the risk of recombinant bat-CoVs emergence as the source of new pandemics in humans, the bat populations in these regions should be under surveillance.

Published
2021

37. One-step purification/extraction method to access glyphosate, glufosinate, and their metabolites in natural waters

Author

Phuong Thu Le, Cam Tu Vu, Marine Herrmann, Thi Lan Anh Phung, Philippe Behra, Dinh Binh Chu, Hoang Yen Nguyen Le, Van Hoi Bui, Leslie Mondamert, Jérôme Labanowski, Vietnam Academy of Science and Technology (VAST), Hanoi University of Science and Technology (HUST), Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Institut de Chimie du CNRS (INC)-Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Chimie Agro-Industrielle (CAI), Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), This study was funded by the University of Science and Technology (USTH), Vietnam (PENROSE project, no. USTH.WEO. 01/18-19), and benefited from the support of the LOTUS international joint laboratory funded by the Institute of Research of Environment (IRD) (https://lotus.usth.edu.vn)., University of Science and Technology of Hanoi (USTH), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques (ENSIACET), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and University of sciences and technologies of hanoi (USTH)

Subjects
Glufosinate, Analyte, Glyphosate, [SDV]Life Sciences [q-bio], Glycine, Organophosphonates, Fresh Water, 010402 general chemistry, Tandem mass spectrometry, 01 natural sciences, Biochemistry, Analytical Chemistry, Aminomethylphosphonic acid, chemistry.chemical_compound, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Tandem Mass Spectrometry, Aminomethyl phosphonic acid, Derivatization, Chromatography, High Pressure Liquid, Red River Delta, Chromatography, [SDE.IE]Environmental Sciences/Environmental Engineering, Elution, Herbicides, Aminobutyrates, 010401 analytical chemistry, Organic Chemistry, Extraction (chemistry), Solid Phase Extraction, General Medicine, 3-(methyl phosphinico)-propionic acid, 6. Clean water, 0104 chemical sciences, chemistry, UPLC-MS/MS, Water Pollutants, Chemical
Abstract

International audience; A new green method for trace level quantification of four herbicides, glyphosate (GLYP), glufosinate (GLUF), and their main metabolites, aminomethylphosphonic acid (AMPA) and 3-(methyl-phosphinico)propionic acid (MPPA), was developed. The purification step without any derivatization was conducted by solid-phase extraction using Chelex-100 resin in the Fe (III) form, followed by elution with 5% NH4OH. The four analytes were quantified by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry. The developed extraction method was validated on five fresh and sea water matrices with mean recoveries ranging from 80.1% to 109.4% (relative standard deviation < 20%). The extraction conditions were evaluated and certified for the high applicability of the extraction method too. The limits of detection (ng/L) in the five water matrices were in ranges 0.70 - 4.0, 2.4 - 3.9, 1.8 - 4.7, and 1.6 - 4.0 for GLYP, AMPA, GLUF, and MPPA, respectively. The method was successfully applied to detect the four compounds in surface waters sampled along the Red River Delta region in July 2019. The highest concentrations were detected at 565, 1,330, 234, and 871 ng/L for GLYP, AMPA, GLUF, and MPPA, respectively. These results showed the potential capacity of this new method for convenient monitoring of herbicides and their metabolites in the diverse natural water system.

Published
2021

38. Fe/S-Catalyzed synthesis of 2-benzoylbenzoxazoles and 2-quinolylbenzoxazoles via redox condensation of o-nitrophenols with acetophenones and methylquinolines

Author

Thi Thu Tram Nguyen, Thanh Binh Nguyen, Le Anh Nguyen, Quoc Anh Ngo, Graduate University of Science and Technology [Hanoi] (GUST), Vietnam Academy of Science and Technology (VAST), Institut de Chimie des Substances Naturelles (ICSN), and Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
chemistry.chemical_classification, Tertiary amine, Base (chemistry), 010405 organic chemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Organic Chemistry, Condensation, chemistry.chemical_element, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, 01 natural sciences, Biochemistry, Sulfur, Redox, 0104 chemical sciences, Catalysis, chemistry, Polymer chemistry, Physical and Theoretical Chemistry
Abstract

International audience; Fe/S catalyst generated in situ from FeCl2•4H2O and elemental sulfur S8 in the presence of a tertiary amine as a base was found to catalyze efficiently a 6eredox condensation of o-nitrophenols with acetophenones and methylquinolines. The condensed products 2benzoyl benzoxazoles and 2-quinolyl benzoxazoles were obtained in reasonable yields with water as the only byproduct at temperature as low as 80 °C.

Published
2021

39. SOME RESEARCH ON THE GENUS CAMELLIA L. (THEACEAE) WITH REPRESENTATIVES IN VIETNAM

Author

Dau B. Thin, Quach Van Hoi, Bui Bao Thinh, Far Eastern Federal University (FEFU), Tay Nguyen Institute for Scientific Research, Vietnam Academy of Science and Technology, and Hong Duc University

Subjects
biology, Applied Mathematics, General Mathematics, Theaceae, food and beverages, Morphology (biology), Camellia, 15. Life on land, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, biology.organism_classification, medicine.disease_cause, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, taxonomy, Vietnam, Genus, Evolutionary biology, Pollen, medicine, Taxonomy (biology), classification system
Abstract

International audience; Many studies have been conducted to classify the genus Camellia, yet they have not been entirely consistent. Therefore, doing research on some of the taxonomic systems of the genus Camellia will serve as the basis for the classification and arrangement of recently discovered species into a consistent system. A series of studies based on morphology as well as molecular biology techniques, the classification of pollen spores, and the analysis of leaf anatomy were examined. The systems based on morphological characteristics were inherited and widely recognized, thereby becoming an appropriate method to classify the genus Camellia with representatives in Vietnam.

Published
2021

40. Stakeholder Expectations of Future Policy Implementation Compared to Formal Policy Trajectories: Scenarios for Agricultural Food Systems in the Mekong Delta

Author

Thi Ngoc Ha Bui, Stephen E. Darby, Nguyen Huy, Hal Voepel, Thi My Thi Tong, Tristan Berchoux, Daniel R. Parsons, Oliver Hensengerth, Craig W. Hutton, Nghia Hung, Van Pham Dang Tri, Duong Du Bui, University of Southampton, University of Northumbria at Newcastle [United Kingdom], Centre International de Hautes Etudes Agronomiques Méditerranéennes - Institut Agronomique Méditerranéen de Montpellier (CIHEAM-IAMM), Centre International de Hautes Études Agronomiques Méditerranéennes (CIHEAM), Territoires, Environnement, Télédétection et Information Spatiale (UMR TETIS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Can Tho University [Vietnam] (CTU), Vietnamese Academy of Social Sciences, Geography and Environment, Institute of Biotechnology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 10000, Vietnam, BRaGS: Building Resilient Agricultural Systems: sustainable livelihoods in Mega Deltas under environmental change, BBSRC/GCRF 2017/19 & At-Risk Mega-Delta, UK Research & Innovation (UKRI) - Natural Environment Research Council (NERC) - NE/S002847/1, Vingroup Innovation Foundation - VINIF.2019.DA17, and UK Research & Innovation (UKRI) - Natural Environment Research Council (NERC) - NE/P014704/1

Subjects
010504 meteorology & atmospheric sciences, Geography, Planning and Development, D400, TJ807-830, Stakeholder engagement, 010501 environmental sciences, Management, Monitoring, Policy and Law, livelihoods, TD194-195, 01 natural sciences, Renewable energy sources, stakeholders, D900, 12. Responsible consumption, Mekong Delta, 11. Sustainability, GE1-350, L200, L100, Agricultural productivity, Environmental planning, 0105 earth and related environmental sciences, 2. Zero hunger, Environmental effects of industries and plants, Land use, Renewable Energy, Sustainability and the Environment, scenarios, Stakeholder, Building and Construction, 15. Life on land, Environmental sciences, Development plan, 13. Climate action, Sustainability, [SDE]Environmental Sciences, Food systems, Strategic management, Business, agricultural systems
Abstract

The development of a coherent and coordinated policy for the management of large socio-agricultural systems, such as the Mekong delta in southern Vietnam, is reliant on aligning the development, delivery, and implementation of policy on national to local scales. Effective decision making is linked to a coherent, broadly-shared vision of the strategic management of socio-agricultural systems. However, when policies are ambiguous, and at worst contradictory, long-term management and planning can consequently suffer. These potential adverse impacts may be compounded if stakeholders have divergent visions of the current and future states of socio-agricultural systems. Herein we used a transferable, scenario-based methodology which uses a standard quadrant matrix in order to explore both anticipated and idealized future states. Our case study was the Mekong delta. The scenario matrix was based upon two key strategic choices (axis) for the delta, derived from analysis of policy documents, literature, stakeholder engagement, and land use models. These are: (i) who will run agriculture in the future, agri-business or the established commune system, and (ii) to what degree sustainability will be incorporated into production. During a workshop meeting, stakeholders identified that agri-business will dominate future agricultural production in the delta but showed a clear concern that sustainability might consequently be undermined despite policy claims of the contrary. As such, our study highlights an important gap between national expectations and regional perspectives. Our results suggest that the new development plans for the Mekong delta (which comprise a new Master Plan and a new 5-year socio-economic development plan), which emphasize agro-business development, should adopt approaches that address concerns of sustainability as well as a more streamlined policy formulation and implementation that accounts for stakeholder concerns at both provincial and national levels.

Published
2021

41. Key factors explaining severe air pollution episodes in Hanoi during 2019 winter season

Author

Bao Anh Phung Ngoc, Hervé Delbarre, François Ravetta, Son Le Thanh, Jacques Pelon, Dien Nguyen Tran, Elsa Dieudonné, Karine Deboudt, Laboratoire de Physico-Chimie de l'Atmosphère (LPCA), Université du Littoral Côte d'Opale (ULCO), Institute of Environmental Technology [Hanoi] (IET), Vietnam Academy of Science and Technology (VAST), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
Pollution, Atmospheric Science, 010504 meteorology & atmospheric sciences, media_common.quotation_subject, Air pollution, PM2.5, 010501 environmental sciences, Monsoon, medicine.disease_cause, Atmospheric sciences, 01 natural sciences, Vertical mixing, medicine, Waste Management and Disposal, 0105 earth and related environmental sciences, media_common, Lidar, Southeast Asia, Aerosol, Key factors, Boundary layer, 13. Climate action, [SDE]Environmental Sciences, Environmental science, Haze, Winter season
Abstract

International audience; With the aim of identifying key factors explaining the severe pollution events that occur under the impact of the Northeast monsoon during the winter period in Hanoi, a two-month campaign was carried out (11 January to 22 March 2019). The local meteorological parameters and the origin of the air masses were investigated, notably using a Doppler Lidar, and the structure of the boundary layer was thoroughly studied using elastic Lidar measurements for the first time in Hanoi. Four heavily polluted events occurred during the campaign, which were associated with hazy days; the highest daily PM2.5 concentrations reached ∼130 μg m−3 while the mean concentration during the campaign was 45 ± 25 μg m−3. These severe polluted events in Hanoi were mainly related to LRT coming from China besides local emission or LRT from other polluted regions of Vietnam. BLH proved to be one of the key factors controlling air pollution in Hanoi. Indeed, the elastic Lidar measurements showed that the daily maximum of the hourly BLH varied from 700m to 1200m during cloudy days, while it was always below 1000m during hazy days. The lower BLH on the hazy days weakened the vertical mixing and was directly related to an increase in aerosol concentrations at the surface.

Published
2021

42. Microorganisms, the Ultimate Tool for Clean Label Foods ?

Author

Thi Kim Chi Nguyen, Saowalak Adunphatcharaphon, Le-Ha Quan, Hélène Licandro, Rosanna Tofalo, Quyet-Tien Phi, Giorgia Perpetuini, Valentin Pereyron, Warissara Kasikonsunthonchai, Son Chu-Ky, Tien-Thanh Nguyen, Yves Waché, Da Lorn, Thi-Yen Do, Phu-Ha Ho, Awanwee Petchkongkaew, Pumnat Chuenchomrat, Maxime Haure, Faculty of BioScience and Technology for Food, Agriculture and Environment, University of Teramo (UT), Thammasat University (TU), International Joint Laboratory Tropical Bioresources & Biotechnology [Hanoi] (SBFT), Hanoi University of Science and Technology (HUST), Food Biotech&Innovation (FBI), Procédés Alimentaires et Microbiologiques [Dijon] (PAM), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Institute of Technology of Cambodia [Cambodge] (KHM), School of Biotechnology and Food Technology, Institute of Biotechnology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi 10000, Vietnam, Institute for Global Food Security [Belfast], Queen's University [Belfast] (QUB), and Research Network: Tropical Fermentation Network

Subjects
Technological innovations. Automation, 0106 biological sciences, 0301 basic medicine, Food industry, Sensorial additive, Microorganism, Beneficial microorganisms, anti-staling, clean-label, 01 natural sciences, law.invention, Beneficial microorganism, biosurfactants, 03 medical and health sciences, Probiotic, Clean-label, bioremediation, law, 010608 biotechnology, Anti-staling, Antibiofilm, Antinutrition, Bio-preservation, Bioremediation, Biosurfactants, Technology additive, sensorial additive, 2. Zero hunger, bio-preservation, beneficial microorganism, antibiofilm, business.industry, HD45-45.2, digestive, oral, and skin physiology, General Engineering, TA213-215, antinutrition, Biotechnology, Engineering machinery, tools, and implements, 030104 developmental biology, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, technology additive, business, [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition
Abstract

International audience; Clean label is an important trend in the food industry. It aims at washing foods of chemicals perceived as unhealthy by consumers. Microorganisms are present in many foods (usually fermented), they exhibit a diversity of metabolism and some can bring probiotic properties. They are usually well considered by consumers and, with progresses in the knowledge of their physiology and behavior, they can become very precise tools to produce or degrade specific compounds. They are thus an interesting means to obtain clean label foods. In this review, we propose to discuss some current research to use microorganisms to produce clean label foods with examples improving sensorial, textural, health and nutritional properties.

Published
2021

43. Effect of Soluble Adenylyl Cyclase (ADCY10) Inhibitors on the LH-Stimulated cAMP Synthesis in Mltc-1 Leydig Cell Line

Author

Thi Mong Diep Nguyen, Laura Filliatreau, Danièle Klett, Nong Van Hai, Nguyen Thuy Duong, Yves Combarnous, Physiologie de la reproduction et des comportements [Nouzilly] (PRC), Institut Français du Cheval et de l'Equitation [Saumur]-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Quy Nhon University, Vietnam Academy of Science and Technology (VAST), and Institut Français du Cheval et de l'Equitation [Saumur]-Université de Tours-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)

Subjects
Male, QH301-705.5, [SDV]Life Sciences [q-bio], Leydig Cells, Luteinizing Hormone, Article, Chemistry, Mice, Leydig cell, cAMP, Cell Line, Tumor, Adenylyl Cyclase Inhibitors, Cyclic AMP, Animals, Biology (General), adenylyl cyclase, QD1-999, Adenylyl Cyclases
Abstract

International audience; In contrast to all transmembrane adenylyl cyclases except ADCY9, the cytosolic soluble adenylyl cyclase (ADCY10) is insensitive to forskolin stimulation and is uniquely modulated by calcium and bicarbonate ions. In the present paper, we focus on ADCY10 localization and a kinetic analysis of intracellular cAMP accumulation in response to human LH in the absence or presence of four different ADCY10 inhibitors (KH7, LRE1, 2-CE and 4-CE) in MTLC-1 cells. ADCY10 was immuno-detected in the cytoplasm of MLTC-1 cells and all four inhibitors were found to inhibit LH-stimulated cAMP accumulation and progesterone level in MLTC-1 and testosterone level primary Leydig cells. Interestingly, similar inhibitions were also evidenced in mouse testicular Leydig cells. In contrast, the tmAC-specific inhibitors ddAdo3′ and ddAdo5′, even at high concentration, exerted weak or no inhibition on cAMP accumulation, suggesting an important role of ADCY10 relative to tmACs in the MLTC-1 response to LH. The strong synergistic effect of HCO3− under LH stimulation further supports the involvement of ADCY10 in the response to LH.

Published
2021

44. A viscosity approach to the Dirichlet problem for degenerate complex Hessian-type equations

Author

Tat Dat Tô, Hoang-Son Do, Sławomir Dinew, Institute of Mathematics of the Jagiellonian University, Institute of Mathematics of the Jagellonian University, Uniwersytet Jagielloński w Krakowie = Jagiellonian University (UJ)-Uniwersytet Jagielloński w Krakowie = Jagiellonian University (UJ), Vietnam Academy of Science and Technology (VAST), Institut de Mathématiques de Toulouse UMR5219 (IMT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Hessian matrix, viscosity solutions, 32U15, Mathematics::Analysis of PDEs, Type (model theory), pluripotential theory, 01 natural sciences, 35J70, symbols.namesake, Mathematics - Analysis of PDEs, 0103 physical sciences, FOS: Mathematics, 32U05, 35J70, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Applied mathematics, Complex Variables (math.CV), 0101 mathematics, Quotient, Mathematics, Dirichlet problem, Numerical Analysis, Mathematics - Complex Variables, Applied Mathematics, 010102 general mathematics, Degenerate energy levels, [MATH.MATH-CV]Mathematics [math]/Complex Variables [math.CV], 16. Peace & justice, Viscosity (programming), symbols, 010307 mathematical physics, nonlinear elliptic PDEs, Analysis, Lagrangian, Analysis of PDEs (math.AP)
Abstract

A viscosity approach is introduced for the Dirichlet problem associated to complex Hessian type equations on domains in $\C^n$. The arguments are modelled on the theory of viscosity solutions for real Hessian type equations developed by Trudinger. As consequence we solve the Dirichlet problem for the Hessian quotient and special Lagrangian equations. We also establish basic regularity results for the solutions., 29 pages

Published
2019

45. A spherical cap model of the geomagnetic field over southeast Asia from CHAMP and Swarm satellite observations

Author

Le Truong Thanh, V. Doumbia, Nguyen Thanh Dung, Le Huy Minh, Christine Amory-Mazaudier, Ha Duyen Chau, Institute of Geophysics, Vietnam Academy of Science and Technology (VAST), Université Félix Houphouët-Boigny (UFHB), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Graduate University of Science and Technology [Hanoi] (GUST), Vietnam Academy of Sciences and Technology, and Institute of Geophysics [Hanoi]

Subjects
CHAMP and Swarm satellites, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Epoch (astronomy), Spherical cap, 010502 geochemistry & geophysics, Geodesy, 01 natural sciences, Latitude, Earth's magnetic field, Amplitude, Vietnam and adjacent area, [SDE]Environmental Sciences, General Earth and Planetary Sciences, Satellite, Longitude, Variation (astronomy), regional geomagnetic Beld, ComputingMilieux_MISCELLANEOUS, Geology, Spherical cap harmonic analysis, 0105 earth and related environmental sciences
Abstract

In this paper, Spherical Cap Harmonic Analysis (SCHA) method was applied to model the geomagnetic field over Vietnam and adjacent area between 15°S and 25°N latitude and 90°E and 130°E in longitude by using magnetic data recorded on CHAMP and Swarm satellites. The characteristic parameters of the method were set at the maximum index Kint = 8 for internal fields, the spherical cap half-angle θ0 = 20°. The regional geomagnetic field over Vietnam and adjacent areas are modelled for the two epochs (2007.0 and 2015.0). Comparison between the SCHA regional geomagnetic field intensity and its time variation with those from IGRF was carried out. The geomagnetic field intensity $$ (E_{F}^{SCHA} ) $$ from SCHA model varies between −90 and 98 nT for epoch 2007.0 and between −139 and 143 nT for epoch 2015.0; however, the trends of their time variations are the same over Vietnam. The RMS between the magnetic components from SCHA model and ground observations are in the same order. The amplitude of time variation of total field intensity from SCHA model is about tens nT greater than from IGRF over Vietnam.

Published
2021

46. A modelling-based assessment of suspended sediment transport related to new damming in the Red River basin from 2000 to 2013

Author

Sylvain Ouillon, Thi Phuong Quynh Le, José-Miguel Sánchez-Pérez, Sabine Sauvage, Didier Orange, Marine Herrmann, Xi Wei, Centre National de la Recherche Scientifique (CNRS), Laboratoire Ecologie Fonctionnelle et Environnement (ECOLAB), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Echanges Côte-Large (ECOLA), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), University of sciences and technologies of hanoi (USTH), Vietnam Academy of Science and Technology (VAST), Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes (UMR Eco&Sols), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Land-Ocean-aTmosphere regional coUpled System study center (LOTUS), an international joint Vietnamese/French laboratory (http://lotus.usth.edu.vn/) funded by the Institut de Recherche pour le Développement (IRD)., China Scholarship Council (CSC), grant number 201606240088., Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), University of Science and Technology of Hanoi (USTH), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
Short-term climate, Delta, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, Drainage basin, Flux, Short-term climate variability, [SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study, Structural basin, 01 natural sciences, Modelling, Tributary, The Red River, Precipitation, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth-Surface Processes, Hydrology, geography, geography.geographical_feature_category, Dam, variability, Sediment, 04 agricultural and veterinary sciences, 15. Life on land, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, 6. Clean water, 13. Climate action, Suspended sediment, Soil erosion, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Environmental science, Sediment transport
Abstract

International audience; The Red River is an Asian river system strongly affected by global changes. This paper aims to characterize and quantify the suspended sediment flux (SF) over the basin under the influences of short-term climate variability and dam constructions. SF was evaluated at the outlets of main tributaries and along the main course of the Red River from 2000 to 2013 based on daily simulations from a modelling study. A reference scenario (without dams) was carried out to disentangle the impacts of short-term climate variability and damming by comparing to actual conditions. Without dams (reference scenario), the basin would generate 106.9 Mt yr−1 of SF to the downstream delta from 2000 to 2013, with a specific sediment yield (SSY) of 778.8 t km−2 yr−1. However, under the impacts of short-term climate variability and dams, the mean annual SSY decreased to 84.5 t km−2 yr−1. At the outlet of the basin, the annual mean SF of 2008–2013 (after new dam constructions) got reduced by 90% (10% related to short-term climate or atmospheric variability and 80% to dam constructions) compared to the reference scenario (without dams) during 2000–2007. The Thao tributary is the most sensitive to short-term climate variability while the Da tributary is mostly affected by the huge-capacity dams. Mean annual retentions of sediment by dams ranged from 7.1 to 111.0 Mt yr−1. Simple rating curves between monthly mean discharge (Q) and SF were established for estimating SF at the outlet of the tributaries and the Red River. High soil erosion (above 2000 t km−2 yr−1) occurred in the middle Thao and the lower Da tributaries. Precipitation, slope and agriculture practices are the key influence factors for soil erosion in the basin.

Published
2021

47. The gem5 Simulator: Version 20.0+

Author

Lowe-Power, Jason, Ahmad, Abdul, Armejach, Adria, Herrera, Adrian, Roelke, Alec, Farmahini-Farahani, Amin, Mondelli, Andrea, Hansson, Andreas, Sandberg, Andreas, Gutierrez, Anthony, Harris, Austin, Akram, Ayaz, Hanindhito, Bagus, Pham, Binh, Bruce, Bobby, Shingarov, Boris, Beckmann, Brad, Escuin, Carlos, Menard, Christian, Weis, Christian, Rodrigues Carvalho, Daniel, Wood, David, Gope, Dibakar, Zulian, Éder, Black, Gabe, Bloom, Gedare, Travaglini, Giacomo, Khaleghzadeh, Hamidreza, Jang, Hanhwi, Nguyen, Hoa, Yoon, Hongil, Vougioukas, Ilias, Setoain, Javier, Gandhi, Jayneel, Castrillon, Jeronimo, Nathella, Krishnendra, Olson, Lena, Chen, Lizhong, Samani, Mahyar, Orr, Marc, Fariborz, Marjan, Andreozzi, Matteo, Sinclair, Matthew, Horsnell, Matthew, Jung, Matthias, Upton, Michael, Moreto, Miquel, Alian, Mohammad, Derumigny, Nicolas, Nikoleris, Nikos, Vaish, Nilay, Asmussen, Nils, Wehn, Norbert, Naji, Omar, Prieto, Pablo, Fotouhi, Pouya, Jagtap, Radhika, Thakur, Rahul, Jafri, Raza, Jeyapaul, Reiley, Amslinger, Rico, Gambord, Ryan, Bharadwaj, Srikant, Diestelhorst, Stephan, Kannoth, Subash, Haria, Swapnil, Ali, Syed, Grass, Thomas, Mück, Tiago, Hayes, Timothy, Jones, Timothy, Marinelli, Tommaso, Reddy, Trivikram, Ta, Tuan, Krishna, Tushar, Elsasser, Wendy, Wang, William, Kodama, Yuetsu, Wang, Zhengrong, University of California [Davis] (UC Davis), University of California (UC), University of Kaiserslautern [Kaiserslautern], Barcelona Supercomputing Center - Centro Nacional de Supercomputacion (BSC - CNS), University of Virginia, ARM Ltd [Cambridge] (ARM), Western Michigan University [Kalamazoo], Institut Teknologi Bandung (ITB), Institute of Materials Science, Vietnam Academy of Science and Technology, Department of Computer Science [Univ California Davis] (CS - UC Davis), University of California (UC)-University of California (UC), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Technische Universität Kaiserslautern (TU Kaiserslautern), Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria), Pushing Architecture and Compilation for Application Performance (PACAP), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-ARCHITECTURE (IRISA-D3), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Fraunhofer Institute for Experimental Software Engineering (Fraunhofer IESE), Fraunhofer (Fraunhofer-Gesellschaft), University of Illinois at Urbana-Champaign [Urbana], University of Illinois System, Uppsala University, Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), Georgia Institute of Technology [Atlanta], Rodrigues Carvalho, Daniel, University of California, University of Virginia [Charlottesville], Bandung Institute of Technology [Indonesia], Department of Computer Science [Davis] (UC Davis), University of California-University of California, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Rennes 1 (UR1), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), and RWTH Aachen University

Subjects
[INFO.INFO-AR]Computer Science [cs]/Hardware Architecture [cs.AR], [INFO.INFO-AR] Computer Science [cs]/Hardware Architecture [cs.AR], [INFO.INFO-MO] Computer Science [cs]/Modeling and Simulation, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation
Abstract

The open-source and community-supported gem5 simulator is one of the most popular tools for computer architecture research. This simulation infrastructure allows researchers to model modern computer hardware at the cycle level, and it has enough fidelity to boot unmodified Linux-based operating systems and run full applications for multiple architectures including x86, Arm®, and RISC-V. The gem5 simulator has been under active development over the last nine years since the original gem5 release. In this time, there have been over 7000 commits to the codebase from over 250 unique contributors which have improved the simulator by adding new features, fixing bugs, and increasing the code quality. In this paper, we give an overview of gem5's usage and features, describe the current state of the gem5 simulator, and enumerate the major changes since the initial release of gem5. We also discuss how the gem5 simulator has transitioned to a formal governance model to enable continued improvement and community support for the next 20 years of computer architecture research.

Published
2021

48. Integrative taxonomy and biogeography of Asian yellow house bats (Vespertilionidae: Scotophilus) in the Indomalayan Region

Author

Neil M. Furey, Phillip A. Alviola, Vuong Tan Tu, Nguyen Truong Son, Chu Thi Hang, Tran Anh Tuan, Gábor Csorba, Daisuke Koyabu, Kyaw San Lin, Saw Bawm, Satoru Arai, Fuka Kikuchi, Alexandre Hassanin, Dai Fukui, Tamás Görföl, Institut de Systématique, Evolution, Biodiversité (ISYEB ), Muséum national d'Histoire naturelle (MNHN)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Acquisition et Analyse de Données pour l'Histoire naturelle (2AD), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Vietnam Academy of Science and Technology (VAST), Hungarian Natural History Museum (Magyar Természettudományi Múzeum), University of Pecs, National Institute of Infectious Diseases [Tokyo], Tokyo University of Science [Tokyo], Tokyo University of Agriculture and Technology (TUAT), City University of Hong Kong [Hong Kong] (CUHK), Tokyo Medical and Dental University [Japan] (TMDU), Ministry of Agriculture, Forestry and Fisheries [Cambodia], Harrison Institute, University of Veterinary Science, and University of the Philippines Los Baños (UP Los Baños)

Subjects
0106 biological sciences, Sympatry, comparative phylogeography, Biogeography, multiple datasets, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 010603 evolutionary biology, 01 natural sciences, Intraspecific competition, Genus, [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology, Genetics, Molecular Biology, Ecology, Evolution, Behavior and Systematics, integrative taxonomy, Scotophilus, biology, sympatric species, 15. Life on land, biology.organism_classification, Phylogeography, Evolutionary biology, Sympatric speciation, Animal Science and Zoology, Taxonomy (biology)
Abstract

International audience; Yellow house bats (Scotophilus) have been known for centuries as a widespread genus of vesper bats in the Indomalayan Region. Despite this, their taxonomic status and phylogeographical patterns remain unclear due to differing criteria employed by early taxonomists and inconsistencies between morphological and molecular assessments. To address these issues, we undertook a comparative phylogeographic analysis of Asian Scotophilus spp. using integrated genetic and morphological analyses of samples collected across the region. These demonstrate that yellow house bats in Asia can be classified into just two widespread species, namely the smaller S. kuhlii (e.g., FA ≤ 53.1 mm, GLS ≤ 20.18 mm) and the larger S. heathii (e.g., FA ≥ 53.4 mm, GLS ≥ 20.85 mm), which occur in sympatry in different parts of the Indomalayan Region. Although these two sympatric species share similar eco‐ethological preferences, they differ considerably in their geographic distributions and intraspecific variation in mtDNA sequences and morphological traits. These disparities were likely misinterpreted as indicating potential cryptic diversity in previous studies, whereas we suggest they are related to interspecific differences in sex‐biased gene flow and phenotypic plasticity to adapt to varying environments. Our study highlights the importance of using multiple datasets to resolve taxonomic uncertainties and reconstruct demographic and phylogeographic histories of sympatric species.

Published
2021

49. Multigram‐scale HPLC enantioseparation as a rescue pathway for circumventing racemization problem during enantioselective synthesis of ethyl 3,4‐dihydro‐ 2H ‐1,4‐benzoxazine‐2‐carboxylate

Author

Samir Acherar, Hong-Ngoc Pham, Axelle Arrault, Nicolas Vanthuyne, Laboratoire de Chimie Physique Macromoléculaire (LCPM), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institute of Geological Sciences [Hanoi] (VAST), Vietnam Academy of Science and Technology (VAST), Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)

Subjects
Pharmacology, 010405 organic chemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Organic Chemistry, Synthon, Enantioselective synthesis, 010402 general chemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Analytical Chemistry, Solvent, chemistry.chemical_compound, Enantiopure drug, chemistry, Drug Discovery, Acetone, Organic chemistry, Carboxylate, Enantiomer, Racemization, Spectroscopy, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; Racemic ethyl 3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate is a key synthon for the design of promising therapeutic drugs. It is mainly synthesized from racemic ethyl 2,3-dibromopropionate and 2-aminophenol in presence of K2CO3 in refluxed acetone. Unfortunately, synthesis of (R)- and (S)-enantiomers using the enantioselective version of this reaction, which should normally be performed with a double SN2 mechanism, is unsuitable due to a racemization process involving the dehydrobromination of enantiopure ethyl 2,3-dibromopropionate into ethyl 2-bromoacrylate. For the first time, the enantioselective version is studied (ee ≈ 55–66%), and the percentage of racemization process has estimated to around 34–46% after determination of the optimal experimental conditions for analytical HPLC enantioseparation of racemate. The influence of the experimental and purification conditions on the racemization rate is also studied. The results indicate that racemization occurs faster at the beginning of the reaction but the initiation of the double SN2 process takes place more faster to limit the racemization rate. The study of the influence of experimental conditions (reaction times, temperature, solvent or type of base, etc.) on the degree of racemization of the (R)- enantiomer is performed and shows that despite changes in the experimental conditions, the synthesis of the (R)- enantiomer is always accompanied by a racemization rate which is difficult in reducing. In parallel, (R)- and (S)-enantiomers areobtained in high enantiopurity (ee > 99.5%) by preparative HPLC enantioseparation of racemate on multigram scale and characterized by optical rotation measurements, ECD and UV spectra.

Published
2021

50. Towards scalable estimation of plant functional diversity from Sentinel-2

Author

Nadejda A. Soudzilovskaia, Nguyen An Binh, Leon T. Hauser, Peter M. van Bodegom, Ângelo Filipe dos Reis Pereira e Cortinhas Sil, J. Timmermans, Jean-Baptiste Féret, Niels van der Windt, Leiden University, Territoires, Environnement, Télédétection et Information Spatiale (UMR TETIS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Vietnam Academy of Science and Technology (VAST), Universidade do Porto, and Theoretical and Computational Ecology (IBED, FNWI)

Subjects
010504 meteorology & atmospheric sciences, Plant functional diversity, Chloropyll content, Computer science, Multispectral, 0208 environmental biotechnology, Canopy diversity, Soil Science, 02 engineering and technology, 01 natural sciences, Biodiversity Plant functional diversity Terrestrial ecosystems Remote sensing Sentinel-2 Multispectral Radiative transfer modeling PROSAIL ARTMO Traitbased Ecology Montesinho Portugal Canopy diversity LMA Leaf mass per area LAI Leaf area index CAB Chloropyll content, Terrestrial ecosystems, LMA, ARTMO, Montesinho, Computers in Earth Sciences, Leaf area index, Traitbased, Independence (probability theory), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Remote sensing, CAB, Ground truth, Ecology, Portugal, PROSAIL, Sampling (statistics), Geology, Inversion (meteorology), Biodiversity, 15. Life on land, Radiative transfer modeling, 020801 environmental engineering, Leaf mass per area, LAI, [SDE]Environmental Sciences, Trait, Satellite, Sentinel-2, Cartography, Diversity (business)
Abstract

Large-scale high-resolution satellite observations of plant functional diversity patterns will greatly benefit our ability to study ecosystem functioning. Here, we demonstrate a potentially scalable approach that uses aggregate plant traits estimated from radiative transfer model (RTM) inversion of Sentinel-2 satellite images to calculate community patterns of plant functional diversity. Trait retrieval relied on simulations and Look-up Tables (LUTs) generated by a RTM rather than heavily depending on a priori field data and data-driven statistical learning. This independence from in-situ training data benefits its scalability as relevant field data remains scarce and difficult to acquire. We ran a total of three different inversion algorithms that are representative of commonly applied approaches and we used two different metrics to calculate functional diversity. In tandem with Sentinel-2 image-based estimation of plant traits, we measured Leaf Area Index (LAI), leaf Chlorophyll content (CAB), and Leaf Mass per Area (LMA) in-situ in a (semi-)natural heterogeneous landscape (Montesinho region) located in northern Portugal. Sampling plots were scaled and georeferenced to match the satellite observed pixels and thereby allowed for a direct one-to-one posterior ground truth validation of individual traits and functional diversity. Across approaches, we observe a reasonable correspondence between the satellite-based retrievals and the insitu observations in terms of the relative distribution of individual trait means and plant functional diversity across locations despite the heterogeneity of the landscape and canopies. The functional diversity estimates, based on a combination of canopy and leaf traits, were robust against estimation biases in trait means. Particularly, the convex hull volume estimate of functional diversity showed strong concordance with in-situ observations across all three inversion methods (Spearman's rho: 0.67-0.80). The remotely sensed estimates of functional diversity also related to in-situ taxonomic diversity (Spearman's rho: 0.55-0.63). Our work highlights the potential and challenges of RTM-based functional diversity metrics to study spatial community-level ecological patterns using currently operational and publicly available Sentinel-2 imagery. While further validation and assessment across different ecosystems and larger datasets are needed, the study contributes towards a further maturation of scalable, spatially, and temporally explicit methods for functional diversity assessments from space. The authors would like to acknowledge Christian Rossi, Prof. Geof-frey M. Henebry, and the anonymous reviewers for their valuable comments and suggestions that greatly improved the manuscript. This work was supported financially by the Ecology Fund of the RoyalNetherlands Academy of Arts and Sciences (‘KNAW Fonds Ecologie’; KNAWWF/807/19011). We thank Altino Geraldes, Joao Carlos Aze-vedo, and the local farmers and foresters in the Montesinho-Nogueira Natura 2000 site for their help and collaboration. We thank Emilie Didaskalou for her lab assistance. J.-B. F ́eret acknowledges financial support from Agence Nationale de la Recherche (BioCop project—ANR- 17-32CE-0001).

Published
2021

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