107 results on '"Goulas A"'
Search Results
2. Direct ink writing of bismuth molybdate microwave dielectric ceramics
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Bala Vaidhyanathan, William Whittow, George Chi-Tangyie, Annapoorani Ketharam, Darren Cadman, J.C. Vardaxoglou, Ian M. Reaney, Dawei Wang, Athanasios Goulas, Shiyu Zhang, and Daniel S. Engstrøm
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010302 applied physics ,Materials science ,Process Chemistry and Technology ,chemistry.chemical_element ,Relative permittivity ,Sintering ,02 engineering and technology ,Dielectric ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Bismuth ,chemistry ,visual_art ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Relative density ,Dielectric loss ,Ceramic ,Composite material ,0210 nano-technology ,Microwave - Abstract
Additive manufacturing via direct ink writing and microwave dielectric characterisation of commercially produced low sintering temperature bismuth molybdenum oxide ceramics, have been both performed for the first time, following a powder-to-product holistic approach. We demonstrated that direct ink writing is an excellent candidate for producing dielectric substrates to be used for wireless telecommunication applications operating at microwave (MW) frequencies, with great repeatability and properties comparable to ceramics fabricated via conventional processing routes. The optimum density (relative density of ρr ≈ 93%) of the 3D printed test samples was obtained by sintering at 660 °C for 2 h, resulting in a relative permittivity er = 35.7, dielectric loss tanδ = 0.0004 and microwave quality factor Q × f = 14,928 GHz. Sintering at higher temperatures promoted a porosity increase due to mismatching grain growth mechanisms and phase decomposition, that collectively hindered the test samples’ microwave dielectric performance in terms of achievable relative permittivity (er) and dielectric loss (tanδ).
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- 2021
3. Additively manufactured ultra-low sintering temperature, low loss Ag2Mo2O7 ceramic substrates
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Annapoorani Ketharam, J.C. Vardaxoglou, Dawei Wang, Daniel S. Engstrøm, Shiyu Zhang, Darren Cadman, Athanasios Goulas, Bala Vaidhyanathan, William Whittow, Ian M. Reaney, and George Chi-Tangyie
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010302 applied physics ,Materials science ,Sintering ,Relative permittivity ,02 engineering and technology ,Dielectric ,021001 nanoscience & nanotechnology ,01 natural sciences ,visual_art ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Extrusion ,Dielectric loss ,Ceramic ,Composite material ,0210 nano-technology ,Temperature coefficient ,Microwave - Abstract
Ultra-low sintering temperature silver molybdenum oxide (Ag2Mo2O7) ceramics have been printed using direct ink writing (a material extrusion additive manufacturing process) for the first time. An optimum densification conditions of 460 °C / 2 h was determined, resulting in relative permittivity, er = 13.45, dielectric loss, tanδ = 0.0005, microwave quality factor, Q × f = 17,056 GHz and the temperature coefficient of resonant frequency τf = −121 ppm/°C. The results were comparable to the dielectric properties of conventionally fabricated ceramics. A series of metal/ceramic antenna designs were produced via dual-printing and co-firing, to demonstrate the potential of Ag2Mo2O7, to be used as a co-firable dielectric material for functional integrated circuits and/or microwave RF devices through multi-material direct ink writing.
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- 2021
4. Balanced Constrained Carbon Equilibrium Accompanied by Carbide Precipitation
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F. M. Castro Cerda, C. Goulas, Leo A.I. Kestens, and Design Engineering
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010302 applied physics ,Austenite ,Structural material ,Materials science ,Precipitation (chemistry) ,Metallurgy ,0211 other engineering and technologies ,Metals and Alloys ,chemistry.chemical_element ,02 engineering and technology ,Condensed Matter Physics ,01 natural sciences ,Carbide ,chemistry ,Mechanics of Materials ,Diffusionless transformation ,Martensite ,0103 physical sciences ,Metallic materials ,Carbon ,021102 mining & metallurgy - Abstract
The final carbon content of austenite in equilibrium with tempered martensite can be estimated by the so-called constrained carbon equilibrium in the presence of carbide (CCEθ) model. However, the linear predictions under CCEθ deviate from both the initial and the experimentally measured carbon content. A modified approach to the CCEθ model is proposed, which predicts an increase of the carbon content in austenite with the decrease of temperature below the onset of martensitic transformation.
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- 2021
5. Direct Catalytic Conversion of Ethanol to C 5+ Ketones: Role of Pd–Zn Alloy on Catalytic Activity and Stability
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Konstantinos A. Goulas, Karthikeyan K. Ramasamy, Tanmayi Bathena, Senthil Subramaniam, Mond F. Guo, Xiao Zhang, Michel J. Gray, Libor Kovarik, and Abraham Martinez
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Ethanol ,010405 organic chemistry ,Acetaldehyde ,chemistry.chemical_element ,General Chemistry ,Reaction intermediate ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Yield (chemistry) ,Acetone ,Organic chemistry ,Aldol condensation ,Palladium - Abstract
Ethanol can be used as a platform molecule for synthesizing valuable chemicals and fuel precursors. Direct synthesis of C5+ ketones, building blocks for lubricants and hydrocarbon fuels, from ethanol was achieved over a stable Pd-promoted ZnO-ZrO2 catalyst. The sequence of reaction steps involved in the C5+ ketone formation from ethanol was determined. The key reaction steps were found to be the in situ generation of the acetone intermediate and the cross-aldol condensation between the reaction intermediates acetaldehyde and acetone. The formation of a Pd-Zn alloy in situ was identified to be the critical factor in maintaining high yield to the C5+ ketones and the stability of the catalyst. A yield of >70 % to C5+ ketones was achieved over a 0.1 % Pd-ZnO-ZrO2 mixed oxide catalyst, and the catalyst was demonstrated to be stable beyond 2000 hours on stream without any catalyst deactivation.
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- 2020
6. Tissue-specific elucidation of lycopene metabolism in commercial tomato fruit cultivars during ripening
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Panagiota Filippou, Iwona Majak, Vlasios Goulas, Chrystalla Antoniou, Vasileios Fotopoulos, Egli C. Georgiadou, Beata Smolińska, and Joanna Leszczyńska
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0106 biological sciences ,0301 basic medicine ,Antioxidant ,medicine.medical_treatment ,β-Carotene ,Horticulture ,Biology ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Lycopene ,Antioxidant activity ,medicine ,Food science ,Cultivar ,Carotenoid ,Tomato cultivars ,chemistry.chemical_classification ,Catabolism ,Agricultural Sciences ,Carotene ,food and beverages ,Ripening ,Agriculture Forestry and Fisheries ,030104 developmental biology ,chemistry ,Chlorophyll ,Gene expression ,010606 plant biology & botany - Abstract
Lycopene is a naturally occurring chemical compound that gives fruits and vegetables a red/orange color. As an intermediate metabolite of β-carotene biosynthesis, lycopene represents one of the major carotenoids. This work studies the gene expression pattern of lycopene biosynthesis/catabolism transcripts and the accumulation pattern of lycopene/β-carotene/chlorophyll contents at three developmental stages and three tissues in five widely consumed, commercial tomato cultivars (cvs. ‘Cherry Ninolino F1’, ‘Elpida F1’, ‘Daphne F1’, ‘Eliseo Plum F1’, and ‘Oxheart’). These contents were correlated with in vitro antioxidant activity. Higher levels of lycopene were observed in the peel than other tissues and in the fully ripe stage, with ‘Oxheart’ displaying the highest content. Differential regulation of lycopene biosynthetic genes (SlZDS and SlCRTISO) was demonstrated in all cultivars. Interestingly, a gene implicated in lycopene catabolism (SlLCYB) demonstrated a general induction in the tested tissues. High lycopene content correlates with significant induction of both SlZDS and SlCRTISO in ‘Oxheart’. Significantly increased antioxidant activity was observed in the peel of ‘Cherry Ninolino F1’ and ‘Elpida F1’ cultivars compared with other tested tissues across all cultivars. The exploration of lycopene activity in different cultivars and the consumption of ripe tomatoes including the peel could be useful for the protection of human health.
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- 2021
7. Dramatic response of STRN-NTRK-fused malignant glioneuronal tumor to larotrectinib in adult
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Julie Boyer, Franck Bielle, Cristina Birzu, Carine Karachi, Ahmed Idbaih, Clara Goulas, Julien Savatovsky, HAL-SU, Gestionnaire, Institut du Cerveau = Paris Brain Institute (ICM), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Service de neurologie 2 [CHU Pitié-Salpêtrière], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU), Service de Neuropathologie [CHU Pitié Salpêtrière], CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Service de Pharmacologie médicale [CHU Pitié-Salpêtrière], Fondation Ophtalmologique Adolphe de Rothschild [Paris], Service de Neurochirurgie [CHU Pitié-Salpêtrière], Institut du Cerveau et de la Moëlle Epinière = Brain and Spine Institute (ICM), Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Service de pharmacologie médicale [CHU Pitié-Salpêtrière]
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Adult ,NTRK fusion ,Cancer Research ,Oncogene Proteins, Fusion ,molecular targeted therapy ,Nerve Tissue Proteins ,01 natural sciences ,03 medical and health sciences ,0302 clinical medicine ,Glioneuronal tumor ,Neoplasms ,Humans ,Letters to the Editor ,Protein Kinase Inhibitors ,ComputingMilieux_MISCELLANEOUS ,[SDV.MHEP] Life Sciences [q-bio]/Human health and pathology ,Chemistry ,010401 analytical chemistry ,Membrane Proteins ,3. Good health ,0104 chemical sciences ,Pyrimidines ,Oncology ,030220 oncology & carcinogenesis ,Cancer research ,Pyrazoles ,Calmodulin-Binding Proteins ,glioneuronal tumor ,Neurology (clinical) ,[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology - Abstract
International audience
- Published
- 2021
8. X-ray tomography measurements identify structure-reactivity correlations in catalysts for oxygenates coupling reactions
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Shahar Dery, Adam Grippo, Konstantinos A. Goulas, Paul J. Dietrich, Elad Gross, Young Chung Wang, and Gregory R. Johnson
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Anatase ,Materials science ,Oxide ,Nanoparticle ,Sintering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,Coupling reaction ,0104 chemical sciences ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Reactivity (chemistry) ,0210 nano-technology ,Spectroscopy - Abstract
The impact of tandem dehydrogenation-aldol condensation reactions on the structure of oxide-supported PdCu catalysts was studied by a combination of X-ray tomography measurements, ensemble-averaging spectroscopy techniques and reactivity measurements. X-ray tomography measurements generated 3D images at submicron resolution of the packed catalyst in the flow reactor following its exposure to various reaction conditions. Quantitative analysis of the tomography data revealed that exposure of the catalyst to reaction conditions induced structural deformation of the mixed Mg-Al oxide supports, accompanied by sintering of the PdCu nanoparticles into micron-sized aggregates. Improved stability was achieved once the PdCu particles were supported on an oxide, such as anatase TiO2, which does not undergo restructuring or phase transition under reaction conditions. This study demonstrates that structural information extracted by X-ray tomography measurements may uncover important structure-reactivity correlations and identify the reasons for catalysts deactivation.
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- 2019
9. Dynamic changes in targeted phenolic compounds and antioxidant potency of carob fruit (Ceratonia siliqua L.) products during in vitro digestion
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Andriani Hadjisolomou and Vlasios Goulas
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0106 biological sciences ,chemistry.chemical_classification ,Antioxidant ,medicine.medical_treatment ,Chemical structure ,04 agricultural and veterinary sciences ,040401 food science ,01 natural sciences ,food.food ,Matrix (chemical analysis) ,Ceratonia siliqua ,0404 agricultural biotechnology ,food ,Enzyme ,Flavonols ,chemistry ,010608 biotechnology ,medicine ,Potency ,Food science ,Digestion ,Food Science - Abstract
Carob fruit is considered as a rich source of phenolics that are linked with potent health effects. The aim of this work was to study the effect of a triple-step digestion on the stability of phenolics and antioxidant potency in carob products. Results showed that the gastric and intestinal steps induced the most significant changes in the stability of pure phenolics; their recovery ranged between 61 and 88% at oral, 40–87% at gastric and 16–57% at intestinal step. Regarding to the carob products, the yield of phenolic contents were ranged from 0.83 to 1.41 for gastric and from 0.43 to 0.82 for intestinal phase. The counterpart yield of antioxidant potency was 0.84–1.66 and 0.48–0.67, respectively. HPLC analysis also disclosed interesting findings; the stability of phenolics is strongly influenced by their chemical structure. In general, the phenolic acids are quite resistant under digestion procedure, whereas the flavonols are mostly degraded when they were subjected into digestion. Results points out that the carob phenolics are degraded, released from food matrix or attached to other food or digestive juice constituents. Furthermore, the critical role of food matrix was underlined as the food components had a protective effect against pH changes and enzymatic activities along digestion.
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- 2019
10. Sun-induced chlorophyll fluorescence III: benchmarking retrieval methods and sensor characteristics for proximal sensing
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Sebastian Wieneke, Luis Guanter, Alasdair Mac Arthur, Marco Celesti, Neus Sabater, Francisco de Assis de Carvalho Pinto, M. Pilar Cendrero-Mateo, Javier Pacheco-Labrador, Yves Goulas, Jose Moreno, Tommaso Julitta, Micol Rossini, Luis Alonso, Alexander Damm, Helge Aasen, Sergio Cogliati, Uwe Rascher, Cendrero-Mateo, M, Wieneke, S, Damm, A, Alonso, L, Pinto, F, Moreno, J, Guanter, L, Celesti, M, Rossini, M, Sabater, N, Cogliati, S, Julitta, T, Rascher, U, Goulas, Y, Aasen, H, Pacheco-Labrador, J, Arthur, A, University of Zurich, and Cendrero-Mateo, M Pilar
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010504 meteorology & atmospheric sciences ,Computer science ,Economics ,Ground spectrometers ,Science ,0211 other engineering and technologies ,Context (language use) ,02 engineering and technology ,Ground spectrometer ,01 natural sciences ,Spectral line ,Retrieval method ,Approximation error ,Sun-induced chlorophyll fluorescence ,Sensitivity (control systems) ,910 Geography & travel ,Chlorophyll fluorescence ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,Retrieval methods ,Spectrometer ,1900 General Earth and Planetary Sciences ,Hyperspectral imaging ,sun-induced chlorophyll fluorescence ,ground spectrometers ,retrieval methods ,3. Good health ,10122 Institute of Geography ,FISICA APLICADA ,Line (geometry) ,General Earth and Planetary Sciences ,ddc:620 ,Interpolation - Abstract
[EN] The interest of the scientific community on the remote observation of sun-induced chlorophyll fluorescence (SIF) has increased in the recent years. In this context, hyperspectral ground measurements play a crucial role in the calibration and validation of future satellite missions. For this reason, the European cooperation in science and technology (COST) Action ES1309 OPTIMISE has compiled three papers on instrument characterization, measurement setups and protocols, and retrieval methods (current paper). This study is divided in two sections; first, we evaluated the uncertainties in SIF retrieval methods (e.g., Fraunhofer line depth (FLD) approaches and spectral fitting method (SFM)) for a combination of off-the-shelf commercial spectrometers. Secondly, we evaluated how an erroneous implementation of the retrieval methods increases the uncertainty in the estimated SIF values. Results show that the SFM approach applied to high-resolution spectra provided the most reliable SIF retrieval with a relative error (RE) 6% and, This article is based upon work from COST Action ES1309 OPTIMISE, supported by COST (European Cooperation in Science and Technology; www.cost.eu).Cendrero-Mateo M.P. and Alonso L. are currently funded by AVANFLEX project (Advanced Products for the FLEX mission), no ESP2016-79503-C2-1-P, Ministry of Economy and Competitiveness, Spain. Wieneke S. is currently funded by the individual fellowship of the European Union's H2020 Marie Sklodowska-Curie actions under the grant agreement ReSPEc no [795299]. Goulas Y. is currently funded by the ECOFLUO project (In-situ Remote Sensing of Chlorophyll Fluorescence to Monitor Carbon Dynamics in Ecosystems in support of the FLEX mission), no 4500058116 and 4500058229, Centre National d'Etudes Spatiales (CNES), France. Mac Arthur, A. was funded by the UK's NERC/NCEO Field Spectroscopy Facility, at the University of Edinburgh. Pacheco-Labrador, J. was supported by the EnMAP project MoReDEHESHyReS "Modelling Responses of Dehesas with Hyperspectral Remote Sensing" (Contract No. 50EE1621, German Aerospace Center (DLR) and the German Federal Ministry of Economic Affairs and Energy) and the Alexander von Humboldt Foundation via Max-Planck Prize to Markus Reichstein.
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- 2019
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11. Remote sensing of solar-induced chlorophyll fluorescence (SIF) in vegetation: 50 years of progress
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Zbyněk Malenovský, Uwe Rascher, Wouter Verhoef, Joseph A. Berry, Alexander Damm, Jose Moreno, Ladislav Nedbal, Pablo J. Zarco-Tejada, Roberto Colombo, Luis Guanter, Joanna Joiner, Christiaan van der Tol, Oscar Perez-Priego, Yves Goulas, Ismael Moya, Sergio Cogliati, Elizabeth M. Middleton, Gina H. Mohammed, Michele Meroni, John R. Miller, Jean-Philippe Gastellu-Etchegorry, Christian Frankenberg, Australian Research Council, European Space Agency, University of Zurich, Mohammed, Gina H, Mohammed, G, Colombo, R, Middleton, E, Rascher, U, van der Tol, C, Nedbal, L, Goulas, Y, Pérez-Priego, O, Damm, A, Meroni, M, Joiner, J, Cogliati, S, Verhoef, W, Malenovský, Z, Gastellu-Etchegorry, J, Miller, J, Guanter, L, Moreno, J, Moya, I, Berry, J, Frankenberg, C, and Zarco-Tejada, P
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010504 meteorology & atmospheric sciences ,FIS/06 - FISICA PER IL SISTEMA TERRA E PER IL MEZZO CIRCUMTERRESTRE ,0208 environmental biotechnology ,Soil Science ,Review ,02 engineering and technology ,Photochemical Reflectance Index ,01 natural sciences ,Article ,GEO/11 - GEOFISICA APPLICATA ,SIF retrieval methods ,Radiative transfer modelling ,Radiative transfer ,910 Geography & travel ,Computers in Earth Sciences ,Chlorophyll fluorescence ,1111 Soil Science ,1907 Geology ,Airborne instruments ,0105 earth and related environmental sciences ,Remote sensing ,Stress detection ,GEO/12 - OCEANOGRAFIA E FISICA DELL'ATMOSFERA ,1903 Computers in Earth Sciences ,Primary production ,Geology ,Vegetation ,Passive optical techniques ,Field (geography) ,020801 environmental engineering ,GEO/10 - GEOFISICA DELLA TERRA SOLIDA ,10122 Institute of Geography ,Sun-induced fluorescence ,Remote sensing (archaeology) ,Sun-induced fluorescence, Steady-state photosynthesis, Stress detection, Radiative transfer modelling, SIF retrieval methods. Satellite sensors, Airborne instruments, Applications, Terrestrial vegetation, Passive optical techniques. Review ,Applications ,Terrestrial vegetation ,Environmental science ,Satellite ,Steady-state photosynthesis ,Satellite sensors - Abstract
Remote sensing of solar-induced chlorophyll fluorescence (SIF) is a rapidly advancing front in terrestrial vegetation science, with emerging capability in space-based methodologies and diverse application prospects. Although remote sensing of SIF – especially from space – is seen as a contemporary new specialty for terrestrial plants, it is founded upon a multi-decadal history of research, applications, and sensor developments in active and passive sensing of chlorophyll fluorescence. Current technical capabilities allow SIF to be measured across a range of biological, spatial, and temporal scales. As an optical signal, SIF may be assessed remotely using high-resolution spectral sensors in tandem with state-of-the-art algorithms to distinguish the emission from reflected and/or scattered ambient light. Because the red to far-red SIF emission is detectable non-invasively, it may be sampled repeatedly to acquire spatio-temporally explicit information about photosynthetic light responses and steady-state behaviour in vegetation. Progress in this field is accelerating with innovative sensor developments, retrieval methods, and modelling advances. This review distills the historical and current developments spanning the last several decades. It highlights SIF heritage and complementarity within the broader field of fluorescence science, the maturation of physiological and radiative transfer modelling, SIF signal retrieval strategies, techniques for field and airborne sensing, advances in satellite-based systems, and applications of these capabilities in evaluation of photosynthesis and stress effects. Progress, challenges, and future directions are considered for this unique avenue of remote sensing., In addition, we recognize the following funding: Zbyněk Malenovský was supported by the Australian Research Council Future Fellowship Bridging Scales in Remote Sensing of Vegetation Stress (FT160100477). Uwe Rascher acknowledges the SEN2Exp project funded by the European Space Agency in supporting part of this work.
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- 2019
12. Evaluation of capacitive micromachined ultrasonic transducers for passive monitoring of microbubble-assisted ultrasound therapies
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Jean-Luc Gennisson, Ambre Dauba, Anthony Novell, Dominique Certon, Jordane Goulas, Laurène Jourdain, Laurent Colin, Benoit Larrat, GREMAN (matériaux, microélectronique, acoustique et nanotechnologies) (GREMAN - UMR 7347), Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours-Centre National de la Recherche Scientifique (CNRS), Unité BioMaps (BIOMAPS), Service Hospitalier Frédéric Joliot (SHFJ), 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)-Université Paris-Saclay-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)-Université Paris-Saclay-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Tours (UT)-Institut National des Sciences Appliquées - Centre Val de Loire (INSA CVL), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), LaBoratoire d'Imagerie biOmédicale MultimodAle Paris-Saclay (BIOMAPS), Université Paris-Saclay-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)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), ANR-19-CE19-0011,DROPMUT,Thérpie du ceveau augmentée par nano-gouttelettes et contrôlée par CMUT(2019), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)
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Materials science ,Acoustics and Ultrasonics ,Acoustics ,Ultrasonic Therapy ,Transducers ,Ultrasound exposure ,01 natural sciences ,030218 nuclear medicine & medical imaging ,Physics::Fluid Dynamics ,03 medical and health sciences ,[SPI]Engineering Sciences [physics] ,0302 clinical medicine ,Capacitive micromachined ultrasonic transducers ,Harmonic response ,Arts and Humanities (miscellaneous) ,0103 physical sciences ,Physics::Atomic and Molecular Clusters ,Animals ,Ultrasonics ,010301 acoustics ,Ultrasonography ,Microbubbles ,business.industry ,Ultrasound ,Skull ,Passive monitoring ,Biasing ,Rats ,Physics::Space Physics ,Macaca ,Microtechnology ,business - Abstract
Passive cavitation detection can be performed to monitor microbubble activity during brain therapy. Microbubbles under ultrasound exposure generate a response characterized by multiple nonlinear emissions. Here, the wide bandwidth of capacitive micromachined ultrasonic transducers (CMUTs) was exploited to monitor the microbubble signature through a rat skull and a macaque skull. The intrinsic nonlinearity of the CMUTs was characterized in receive mode. Indeed, undesirable nonlinear components generated by the CMUTs must be minimized as they can mask the microbubble harmonic response. The microbubble signature at harmonic and ultra-harmonic components (0.5–6 MHz) was successfully extracted through a rat skull using moderate bias voltage.
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- 2020
13. Manufacturability, Mechanical Properties, Mass-Transport Properties and Biocompatibility of Triply Periodic Minimal Surface (TPMS) Porous Scaffolds Fabricated by Selective Laser Melting
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Qixiang Feng, Yang Liu, Ni Zhen, Ying Liu, Shuai Ma, Y. Y. Tse, Xiaoxiao Han, Rossitza Setchi, Qian Tang, Jun Song, Athanasios Goulas, and Daniel S. Engstrøm
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Materials science ,Biocompatibility ,Transmission properties ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Bone scaffold ,lcsh:TA401-492 ,General Materials Science ,Triply periodic minimal surface ,Selective laser melting ,Composite material ,Porosity ,Elastic modulus ,Mechanical Engineering ,Mechanical behaviour ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Design for manufacturability ,Mechanics of Materials ,Permeability (electromagnetism) ,lcsh:Materials of engineering and construction. Mechanics of materials ,0210 nano-technology ,Gyroid - Abstract
Selective laser melting is a promising additive manufacturing technology for manufacturing porous metallic bone scaffolds. Bone repair requires scaffolds that meet various mechanical and biological requirements. This paper addresses this challenge by comprehensively studying the performance of porous scaffolds. The main novelty is exploring scaffolds with different porosities, verifying various aspects of their performance and revealing the effect of their permeability on cell growth. This study evaluates the manufacturability, mechanical behaviour, permeability and biocompatibility of gyroid scaffolds. In simulations, mechanical behaviour and permeability exhibited up to 56% and 73% accuracy, respectively, compared to the experimental data. The compression and permeability experiments showed that the elastic modulus and the permeability of the scaffolds were both in the range of human bones. The morphological experiment showed that manufacturing accuracy increased with greater designed porosity, while the in vitro experiments revealed that permeability played the main role in cell proliferation. The significance of this work is improving the understanding of the effect of design parameters on the mechanical properties, permeability and cell growth of the scaffolds, which will enable the design of porous bone scaffolds with better bone-repair effects.
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- 2020
14. Fused filament fabrication of functionally graded polymer composites with variable relative permittivity for microwave devices
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William Whittow, Shiyu Zhang, J.C. Vardaxoglou, Athanasios Goulas, Jack R. McGhee, Darren Cadman, and Daniel S. Engstrøm
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Materials science ,Relative permittivity ,3D printing ,Fused filament fabrication ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Protein filament ,lcsh:TA401-492 ,General Materials Science ,High permittivity composites, graded-index lens ,Microwave materials ,business.industry ,Mechanical Engineering ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Variable (computer science) ,Mechanics of Materials ,Optoelectronics ,Dissipation factor ,lcsh:Materials of engineering and construction. Mechanics of materials ,0210 nano-technology ,business ,Layer (electronics) ,Microwave - Abstract
Fused filament fabrication (FFF) is a continuously growing additive manufacturing technology that aside from physical prototypes can also deliver functional prototypes and devices for radiofrequency (RF) and microwave applications. The very recent introduction of high-permittivity filaments for FFF has been one of the main facilitators for this major advancement, aiding microwave engineers to realise academics concepts that have thus far been impossible to fabricate and therefore invent new designs. However, the value to the RF community of these devices depends on accurate knowledge and repeatability of the electromagnetic properties of the materials being used which strongly relies on the processing strategy used during printing. This paper investigates the use of a high-permittivity filament and studies the impact of layer height and infill density on the relative permittivity (er) and loss tangent (tanδ). A maximum relative permittivity of er = 9.63 ± 0.16 and tanδ = 0.003 ± 0.0003 was achieved with a 200 μm layer thickness and 100% infill density. Finally, the results of this study are used in designing, simulating, 3D printing and measuring the performance of a novel graded-index dielectric lens operating at 10 GHz.
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- 2020
15. GeantV: Results from the prototype of concurrent vector particle transport simulation in HEP
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Harphool Kumawat, O. Chaparro-Amaro, Ph Canal, Dmitri Konstantinov, A. Maldonado-Romo, Sergio F Novaes, T Nikitina, R. Schmitz, R. Seghal, Farah Hariri, D. Elvira, Calebe De Paula Bianchini, G. Cosmo, A. Ananya, M. Gravey, Mihaly Novak, Pere Mato, A. Bhattacharyya, W. Pokorski, Sw. Banerjee, Y. Zhang, J. Martínez-Castro, Alberto Ribon, G. Bitzes, Sandro Christian Wenzel, Joel Fuentes, Marilena Bandieramonte, John Apostolakis, Oksana Shadura, E. Tcherniaev, Andrei Gheata, V. Drogan, Guilherme Amadio, Federico Carminati, S. Vallecorsa, I. Goulas, L Duhem, Mihaela Gheata, Kevin Pedro, Soon Yung Jun, J. G. Lima, and J. C. De Fine Licht
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Nuclear and High Energy Physics ,Computer science ,Other Fields of Physics ,FOS: Physical sciences ,Context (language use) ,computer.software_genre ,01 natural sciences ,Computational science ,High Energy Physics - Experiment ,High Energy Physics - Experiment (hep-ex) ,Software ,0103 physical sciences ,Computer Science (miscellaneous) ,Code (cryptography) ,Use case ,010306 general physics ,Large Hadron Collider ,010308 nuclear & particles physics ,business.industry ,hep-ex ,Detector ,Computational Physics (physics.comp-ph) ,Simulation software ,physics.comp-ph ,Vectorization (mathematics) ,business ,computer ,Physics - Computational Physics ,Particle Physics - Experiment - Abstract
Full detector simulation was among the largest CPU consumer in all CERN experiment software stacks for the first two runs of the Large Hadron Collider (LHC). In the early 2010's, the projections were that simulation demands would scale linearly with luminosity increase, compensated only partially by an increase of computing resources. The extension of fast simulation approaches to more use cases, covering a larger fraction of the simulation budget, is only part of the solution due to intrinsic precision limitations. The remainder corresponds to speeding-up the simulation software by several factors, which is out of reach using simple optimizations on the current code base. In this context, the GeantV R&D project was launched, aiming to redesign the legacy particle transport codes in order to make them benefit from fine-grained parallelism features such as vectorization, but also from increased code and data locality. This paper presents extensively the results and achievements of this R&D, as well as the conclusions and lessons learnt from the beta prototype., 34 pages, 26 figures, 24 tables
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- 2020
16. Reduction of structural impacts and distinction of photosynthetic pathways in a global estimation of GPP from space-borne solar-induced chlorophyll fluorescence
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Luis Guanter, James Cleverly, Zhaohui Li, Yongguang Zhang, Zhaoying Zhang, Shiping Chen, Hezhou Wang, David Martini, Albert Porcar-Castell, Mirco Migliavacca, Xi Yang, Zhigang Sun, Joanna Joiner, Yves Goulas, Weimin Ju, Qian Zhang, Viikki Plant Science Centre (ViPS), Department of Forest Sciences, Ecosystem processes (INAR Forest Sciences), and Forest Ecology and Management
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Canopy ,010504 meteorology & atmospheric sciences ,0208 environmental biotechnology ,Biome ,Soil Science ,02 engineering and technology ,Atmospheric sciences ,01 natural sciences ,CARBON-DIOXIDE ,CANOPY PHOTOSYNTHESIS ,Ecosystem ,FEEDBACK MECHANISM ,Computers in Earth Sciences ,Photosynthesis ,Spectral invariant theory ,Chlorophyll fluorescence ,1172 Environmental sciences ,0105 earth and related environmental sciences ,Remote sensing ,NET ECOSYSTEM EXCHANGE ,Empirical modelling ,SUN-INDUCED FLUORESCENCE ,Primary production ,Photosynthetic pathway ,Geology ,GROSS PRIMARY PRODUCTION ,ENERGY FLUXES ,CO2 UPTAKE ,15. Life on land ,020801 environmental engineering ,MODEL ,13. Climate action ,1181 Ecology, evolutionary biology ,Environmental science ,Satellite ,Canopy structure ,Scale (map) ,PRIMARY PRODUCTIVITY - Abstract
Quantifying global photosynthesis remains a challenge due to a lack of accurate remote sensing proxies. Solar-induced chlorophyll fluorescence (SIF) has been shown to be a good indicator of photosynthetic activity across various spatial scales. However, a global and spatially challenging estimate of terrestrial gross primary production (GPP) based on satellite SIF remains unresolved due to the confounding effects of species-specific physical and physiological traits and external factors, such as canopy structure or photosynthetic pathway (C-3 or C-4). Here we analyze an ensemble of far-red SIF data from OCO-2 satellite and ground observations at multiple sites, using the spectral invariant theory to reduce the effects of canopy structure and to retrieve a structure-corrected total canopy SIF emission (SIFtotal). We find that the relationships between observed canopy-leaving SIF and ecosystem GPP vary significantly among biomes. In contrast, the relationships between SIFtotal and GPP converge around two unique models, one for C-3 and one for C-4 plants. We show that the two single empirical models can be used to globally scale satellite SIF observations to terrestrial GPP. We obtain an independent estimate of global terrestrial GPP of 129.56 +/- 6.54 PgC/year for the 2015-2017 period, which is consistent with the state-of-the-art data- and process-oriented models. The new GPP product shows improved sensitivity to previously undetected 'hotspots' of productivity, being able to resolve the double-peak in GPP due to rotational cropping systems. We suggest that the direct scheme to estimate GPP presented here, which is based on satellite SIF, may open up new possibilities to resolve the dynamics of global terrestrial GPP across space and time.
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- 2020
17. The impact of genotype and harvesting day on qualitative attributes, postharvest performance and bioactive content of loquat fruit
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George A. Manganaris, M. Hadjipieri, M. Christofi, and Vlasios Goulas
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0106 biological sciences ,0301 basic medicine ,Free phenolics ,Phytochemicals ,Titratable acid ,Horticulture ,Biology ,Shelf life ,01 natural sciences ,03 medical and health sciences ,Cultivar ,Bound phenolics ,Agricultural Sciences ,Flesh ,food and beverages ,Ripening ,Agriculture Forestry and Fisheries ,Antioxidant capacity ,030104 developmental biology ,Phytochemical ,Eriobotrya japonica ,Harvest ,Postharvest ,010606 plant biology & botany - Abstract
Due to scalar on-tree ripening, harvest of loquat fruit is successive, spanning for several weeks, depending on the cultivar considered and the cultivation practices applied. Notably, early harvested fruit receive appreciably high prices on the market. The aim of the current study was to dissect the effect of harvesting day on mechanical properties, postharvest performance and phytochemical attributes (free and bound phenolic compounds and antioxidant capacity) of the predominant loquat cultivars grown in Cyprus (cvs. ‘Karantoki’ and ‘Morphitiki’). Determination of the aforementioned attributes at harvest (H) and after additional maintenance at room temperature for 3 days (H+3) for four successive harvesting dates (H1-4) were determined. Flesh firmness was slightly higher in early-harvested compared to late-harvested fruit, while slight or no differences after shelf life period for both cultivars were monitored. ‘Karantoki’ fruits manifested higher values of ripening index (SSC/TA) than ‘Morphitiki’; such values were higher with the progress of harvest date due to a significant decrease of titratable acidity. ‘Morphitiki’ fruits were generally characterized by higher phenolic content, along with higher antioxidant capacity. No evident differences were registered between the harvest date and the shelf life period for both cultivars regarding free phenolic content. This study also highlights the significance of bound phenolics that contribute to the phenolic fraction of loquat fruit by 21.6–37.5%, depending on the cultivar and storage condition applied. Overall, the current study sheds light in the unexploited area of phytochemical properties of loquat fruits derived from successive harvesting dates.
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- 2020
18. How effective are strategies to control the dissemination of antibiotic resistance in the environment? A systematic review
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David Makowski, Drifa Belhadi, Sylvie Nazaret, Céline Roose-Amsaleg, Fabienne Petit, Dominique Patureau, Sylvie Nélieu, Antoine Andremont, Cédric Laouénan, Marion Vittecoq, Nathalie Grall, Sophie Courtois, Anais Goulas, Alexandre Descamps, Christophe Dagot, Barbara Livoreil, Pierre Benoit, Infection, Anti-microbiens, Modélisation, Evolution (IAME (UMR_S_1137 / U1137)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Cité (UPCité)-Université Sorbonne Paris Nord, Fondation pour la recherche sur la Biodiversité (FRB), Département d'épidémiologie, biostatistique et recherche clinique, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-AP-HP - Hôpital Bichat - Claude Bernard [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre International de Recherche Sur l'Eau et l'Environnement [Suez] (CIRSEE), SUEZ ENVIRONNEMENT (FRANCE), Anti-infectieux : supports moléculaires des résistances et innovations thérapeutiques (RESINFIT), CHU Limoges-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Agronomie, Centre International de Recherche sur l'Environnement et le Développement (CIRED), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École des hautes études en sciences sociales (EHESS)-AgroParisTech-École des Ponts ParisTech (ENPC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), 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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire de Biotechnologie de l'Environnement [Narbonne] (LBE), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - 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), Morphodynamique Continentale et Côtière (M2C), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols (METIS), École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche de la Tour du Valat, Maladies infectieuses et vecteurs : écologie, génétique, évolution et contrôle (MIVEGEC), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), French Ministry of Ecological and Inclusive Transition (CGDD/SR, DGPR), Foundation for Research on Biodiversity (FRB), SUEZ company., Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Paris (UP)-Université Sorbonne Paris Nord, 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), 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), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Mathématiques et Informatique Appliquées (MIA-Paris), Département Environnements et Sociétés (Cirad-ES), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Tour du Valat, bibliothèque, and Génétique et évolution des maladies infectieuses (GEMI)
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0211 other engineering and technologies ,résistance aux antibiotiques ,02 engineering and technology ,Aquaculture ,010501 environmental sciences ,Wastewater ,Wildlife ,01 natural sciences ,One-Health ,lcsh:Environmental sciences ,ComputingMilieux_MISCELLANEOUS ,lcsh:GE1-350 ,Ecology ,élément génétique mobile ,Agriculture ,Contamination ,gène de résistance ,Pollution ,6. Clean water ,Meta-analysis ,[SDE]Environmental Sciences ,revue systématique ,Veterinary medicine and animal Health ,Sewage treatment ,Livestock ,bactérie résistante ,[SDE.MCG]Environmental Sciences/Global Changes ,Management, Monitoring, Policy and Law ,Biology ,Ecosystems ,External validity ,Antibiotic resistance ,Effluent ,Organic waste ,0105 earth and related environmental sciences ,021110 strategic, defence & security studies ,business.industry ,Biodegradable waste ,[SDE.ES]Environmental Sciences/Environmental and Society ,Biotechnology ,[SDE.BE] Environmental Sciences/Biodiversity and Ecology ,[SDE.MCG] Environmental Sciences/Global Changes ,Anaerobic digestion ,Médecine vétérinaire et santé animal ,13. Climate action ,Antimicrobial ,[SDE.ES] Environmental Sciences/Environmental and Society ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,business - Abstract
Background Antibiotic resistance is a major concern for public and environmental health. The role played by the environment in disseminating resistance is increasingly considered, as well as its capacity for mitigation. We reviewed the literature on strategies to control dissemination of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARG) and mobile genetic elements (MGE) in the environment. Methods This systematic review focused on three main strategies: (i) restriction of antibiotic use (S1), (ii) treatments of liquid/solid matrices (S2) and (iii) management of natural environment (S3). Articles were collected from seven scientific databases until July 2017 and from Web of Science until June 2018. Only studies reporting measurements of ARB, ARG or MGE in environmental samples were included. An evidence map was drawn from metadata extracted from all studies eligible for S1, S2 and S3. Subsets of studies were assessed for internal and external validity to perform narrative and quantitative syntheses. A meta-analysis was carried out to assess the effects of organic waste treatments (random-effect models). Review findings Nine hundred and thirty-one articles representing 1316 individual studies (n) were eligible for S1 (n = 59), S2 (n = 781) and S3 (n = 476) strategies, respectively. Effects of interventions to control the dissemination of antibiotic resistance in the environment were primarily studied in strategy S2. A partial efficiency of wastewater treatment plants (WWTPs) to reduce antibiotic resistance in treated effluent was reported in 118 high validity studies. In spite of the heterogeneity in published results, the meta-analysis showed that composting and drying were efficient treatments to reduce the relative abundance of ARG and MGE in organic waste, by 84% [65%; 93%] and 98% [80%; 100%], respectively. The effect of anaerobic digestion was not statistically significant (51% reduction [− 2%; 77%]) when organic waste treatments were compared together in the same model. Studies in strategies S1 and S3 mainly assessed the effects of exposure to sources of contamination. For instance, 28 medium/high validity studies showed an increase of antibiotic resistance in aquatic environments at the WWTP discharge point. Some of these studies also showed a decrease of resistance as the distance from the WWTP increases, related to a natural resilience capacity of aquatic environments. Concerning wildlife, nine medium/high validity studies showed that animals exposed to anthropogenic activities carried more ARB. Conclusions and implications Knowledge gaps were identified for the relationship between restriction of antibiotic use and variation of antibiotic resistance in the environment, as well as on possible interventions in situ in natural environment. Organic waste treatments with thermophilic phase (> 50 °C) should be implemented before the use/release of organic waste in the environment. More investigation should be conducted with the datasets available in this review to determine the treatment efficiency on ARG carried by specific bacterial communities.
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- 2020
19. Improved thermal energy storage of nanoencapsulated phase change materials by atomic layer deposition
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David Valdesueiro, Rosa Mondragón, Nuria Navarrete, Leonor Hernández, J. Ruud van Ommen, Aristeidis Goulas, and Damiano La Zara
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Materials science ,Renewable Energy, Sustainability and the Environment ,business.industry ,thermal energy storage ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Thermal energy storage ,01 natural sciences ,Phase-change material ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Renewable energy ,nanoencapsulation ,Atomic layer deposition ,Nanofluid ,Chemical engineering ,Latent heat ,Concentrated solar power ,atomic layer deposition ,Thermal stability ,0210 nano-technology ,business ,phase change material - Abstract
Renewable energy has become of great interest over the past years in order to mitigate Global Warming. One of the actions gaining attention is the enhancement of the thermal energy storage capacity of Concentrated Solar Power plants. The addition of nanoencapsulated phase change materials (core-shell nanoparticles) to the already used materials has been proposed for that purpose, due to the possibility of increasing thermal storage through the contribution of both core latent heat and sensible heat. In this work, Atomic Layer Deposition has been used to synthesise SiO2 and Al2O3 nanoscale coatings on tin nanoparticles. The multi-encapsulated phase change materials have been characterised in terms of chemical composition, crystalline structure, particle size, thermal stability and thermal storage capacity. Sn@Al2O3 nanoparticles present the best thermal behaviour as they show the lowest reduction in the phase change enthalpy over 100 cycles due to the oxidation barrier of the coating. Moreover, the specific heat of both nanoparticles and solar salt-based nanofluids is increased, making the nanoencapsulated phase change material suitable for thermal energy storage applications.
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- 2020
20. Hybrid Biological–Chemical Approach Offers Flexibility and Reduces the Carbon Footprint of Biobased Plastics, Rubbers, and Fuels
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F. Dean Toste, Konstantinos A. Goulas, Amit A. Gokhale, Lipeng Wu, Corinne D. Scown, and John E. Myers
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Ethylene ,010405 organic chemistry ,Renewable Energy, Sustainability and the Environment ,business.industry ,Chemistry ,General Chemical Engineering ,General Chemistry ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Renewable energy ,chemistry.chemical_compound ,Petrochemical ,Bioenergy ,Biofuel ,Bioproducts ,Environmental Chemistry ,Biorefining ,business ,Process engineering ,Life-cycle assessment - Abstract
A critical challenge for the bioenergy research community has been producing drop-in hydrocarbon fuels and chemicals at yields sufficient to compete with their petroleum-derived counterparts. Biological production of highly reduced compounds poses fundamental challenges. Conversely, glucose, xylose, and sucrose can be fermented to ethanol at near-theoretical yields. Just as olefin crackers are often considered a gateway for petrochemical complexes that produce an array of downstream products, catalytic ethanol upgrading can potentially enable an entire biorefining complex able to produce renewable, low-carbon fuels and chemicals. By doping the Ta2O5/SiO2 catalyst with different transition metals, we show that Ostromyslensky catalysts can be utilized for direct conversion of ethanol to varying ratios of 1,3-butadiene (1,3-BD), dietheylether (DEE), and ethylene. These results are integrated into the first comprehensive analysis of ethanol conversion to 1,3-BD, DEE, and ethylene that incorporates empirical d...
- Published
- 2018
21. Utilization of Carob Fruit as Sources of Phenolic Compounds with Antioxidant Potential: Extraction Optimization and Application in Food Models
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Vlasios Goulas and Eva Georgiou
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Health (social science) ,Antioxidant ,medicine.medical_treatment ,Flavonoid ,antioxidant activity ,Plant Science ,lcsh:Chemical technology ,01 natural sciences ,Health Professions (miscellaneous) ,Microbiology ,Article ,chemistry.chemical_compound ,Rutin ,Carob ,0404 agricultural biotechnology ,Antioxidant activity ,Lipid oxidation ,lipid oxidation ,medicine ,lcsh:TP1-1185 ,Gallic acid ,Food science ,Ceratonia siliqua L ,polyphenols ,chemistry.chemical_classification ,emulsion ,ultrasound assisted extraction ,Agricultural Sciences ,Chemistry ,Emulsion ,010401 analytical chemistry ,Polyphenols ,Catechin ,04 agricultural and veterinary sciences ,040401 food science ,0104 chemical sciences ,HPLC-DPPH ,carob ,Other Agricultural Sciences ,Polyphenol ,Ultrasound assisted extraction ,Quercetin ,Food Science - Abstract
The goal of this study was to explore the potential of carob extracts to act as lipid inhibitors in model food systems. First, the extraction efficacy of fourteen solvents on the phenolic and flavonoid contents as well as on the antioxidant activity was assessed. Results showed that the phenolic composition and antioxidant activity of the extracts were strongly affected by solvents. Subsequently, the antioxidant potential of the most promising extracts (water, methanol, acidic acetone, and acetone&ndash, water) against four model food systems were evaluated. The acidic acetone extract had the highest antioxidant activity (70.3 ±, 5.3%) in the &beta, carotene-linoleic acid system, followed by the acetone&ndash, water extract (62.1 ±, 4.9%). Both extracts significantly prevented the lipid oxidation in sunflower oil and cooked comminuted pork, the inhibition activity at the end of storage period was 36.7&ndash, 50.5% and 17.4&ndash, 24.8%, respectively. A reduction of 49.5&ndash, 54.8% in the formation of dienes in the oil-in-water emulsion was also found. The inhibitory effect of methanolic and aqueous extracts was significantly lower. Qualitative and quantitative variations in extracts are responsible for this antioxidant behavior in food systems. Gallic acid, myrecetin, rutin, and catechin are the main components of the extracts while myricetin and quercetin play an essential role in the antioxidant activity, according to the biochromatograms.
- Published
- 2019
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22. Acylation of methylfuran with Brønsted and Lewis acid zeolites
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Dionisios G. Vlachos, Maura Koehle, Stavros Caratzoulas, Konstantinos A. Goulas, Raul F. Lobo, and Zhiqiang Zhang
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010405 organic chemistry ,Process Chemistry and Technology ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Catalysis ,0104 chemical sciences ,Lewis acid catalysis ,Acylation ,chemistry.chemical_compound ,Electrophilic substitution ,chemistry ,Furan ,Kinetic isotope effect ,Lewis acids and bases ,Brønsted–Lowry acid–base theory - Abstract
The acylation of methylfuran has been investigated using Bronsted and Lewis acid zeolite catalysts. The highest reaction rate for acylation on a per gram basis is found on zeolite Beta with high aluminum content (Si/Al = 23) and the highest turnover frequency on a per metal site basis is found on zeolite Beta with low aluminum content (Si/Al = 138). Among Lewis acid zeolites, [Sn]-Beta shows higher turnover frequency than [Hf]-, [Zr]- or [Ti]-Beta. Similar apparent activation energies were found for [Al]-Beta with different Si/Al ratios and a lower apparent activation energy was found for [Sn]-Beta. Electronic structure calculations reveal that on both [Al]- and [Sn]-Beta the most favorable pathway follows the classic addition-elimination aromatic electrophilic substitution mechanism. The calculations also reveal that, on both [Al]- and [Sn]-Beta, the rate of methylfuran acylation is controlled by the dissociation of the C O C linkage of the anhydride while hydrogen elimination is the rate-determining step in the acylation of furan. The latter is in complete agreement with measured primary kinetic isotope effects. One remarkable and unexpected finding from our calculations is that the most favorable catalytic pathway in [Sn]-Beta involves Bronsted acid catalysis by the silanol group of the hydrolyzed “open” site and not Lewis acid catalysis by the Sn metal center.
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- 2018
23. Mechanical behaviour of additively manufactured lunar regolith simulant components
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Ross J. Friel, Athanasios Goulas, Russell A. Harris, Jon Binner, and Daniel S. Engstrøm
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lunar construction ,0209 industrial biotechnology ,Applied Mechanics ,Teknisk mekanik ,010504 meteorology & atmospheric sciences ,Lunar regolith simulant ,Mechanical Engineering ,Laser additive manufacturing ,laser additive manufacturing ,02 engineering and technology ,mechanical properties ,01 natural sciences ,Regolith ,lunar regolith ,Astrobiology ,powder bed fusion ,020901 industrial engineering & automation ,Environmental science ,General Materials Science ,In-situ resource utilisation ,0105 earth and related environmental sciences - Abstract
Additive manufacturing and its related techniques have frequently been put forward as a promising candidate for planetary in-situ manufacturing, from building life-sustaining habitats on the Moon to fabricating various replacements parts, aiming to support future extra-terrestrial human activity. This paper investigates the mechanical behaviour of lunar regolith simulant material components, which is a potential future space engineering material, manufactured by a laser-based powder bed fusion additive manufacturing system. The influence of laser energy input during processing was associated with the evolution of component porosity, measured via optical and scanning electron microscopy in combination with gas expansion pycnometry. The compressive strength performance and Vickers micro-hardness of the components were analysed and related back to the processing history and resultant microstructure of the lunar regolith simulant build material. Fabricated structures exhibited a relative porosity of 44–49% and densities ranging from 1.76 to 2.3 g cm−3, with a maximum compressive strength of 4.2 ± 0.1 MPa and elastic modulus of 287.3 ± 6.6 MPa, the former is comparable to a typical masonry clay brick (3.5 MPa). The additive manufacturing parts also had an average hardness value of 657 ± 14 HV0.05/15, better than borosilicate glass (580 HV). This study has shed significant insight into realising the potential of a laser-based powder bed fusion additive manufacturing process to deliver functional engineering assets via in-situ and abundant material sources that can be potentially used for future engineering applications in aerospace and astronautics.
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- 2018
24. Kinetics of the Homogeneous and Heterogeneous Coupling of Furfural with Biomass-Derived Alcohols
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Konstantinos A. Goulas and Amit A. Gokhale
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010405 organic chemistry ,Organic Chemistry ,Kinetics ,Biomass ,010402 general chemistry ,Furfural ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Inorganic Chemistry ,Coupling (electronics) ,chemistry.chemical_compound ,Aldol reaction ,chemistry ,Homogeneous ,Computational chemistry ,Kinetic isotope effect ,Dehydrogenation ,Physical and Theoretical Chemistry - Published
- 2018
25. Perceptions and clustering of Greek farmers on the new CAP: Opportunity or threat?
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George Theodossiou, Christos Karelakis, and Apostolos Goulas
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Descriptive statistics ,business.industry ,media_common.quotation_subject ,0211 other engineering and technologies ,021107 urban & regional planning ,02 engineering and technology ,010501 environmental sciences ,Disease cluster ,01 natural sciences ,Agricultural economics ,Geography ,Agriculture ,Perception ,Added value ,Agricultural productivity ,General Agricultural and Biological Sciences ,business ,Common Agricultural Policy ,Comparative advantage ,0105 earth and related environmental sciences ,media_common - Abstract
This study aims to highlight the problems of the Greek agriculture and to identify the level of information that the farmers have regarding the Common Agricultural Policy (CAP). Here, primary data were collected from in-depth interviews (structured questionnaire) with 241 farmers in the region of Thessaly-Greece. The study was conducted in November 2016, within the geographical boundaries of the Region of Thessaly. The data were analyzed via descriptive statistics, the non-parametric Friedman test, Factor Analysis and Cluster Analysis. The results indicate that Greek farmers are not adequately informed about the CAP. The research findings showed that Greece requires an agricultural sector that will also be eco-friendly, producing high added value products. These factors are important and could become the country's comparative advantage. The innovation of the study lies in the fact that the survey was conducted in a highly representative Greek rural prefecture, investigating the farmer's information level as it concerns the CAP policy schemes. Key words: Common agricultural policy, agricultural sector, agricultural production, Thessaly, Greece.
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- 2018
26. Oxidation of aromatic oxygenates for the production of terephthalic acid
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James R. Lattner, Dionisios G. Vlachos, Konstantinos A. Goulas, Basudeb Saha, and Mika L. Shiramizu
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Terephthalic acid ,010405 organic chemistry ,Chemistry ,Process Chemistry and Technology ,Alcohol ,010402 general chemistry ,Heterogeneous catalysis ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Solvent ,chemistry.chemical_compound ,Yield (chemistry) ,Organic chemistry ,Dehydrogenation ,Oxygenate - Abstract
We study the production of terephthalic acid (TA) from biomass-derived aromatic oxygenates. Among several heterogeneous catalysts tested, a carbon-supported Ir catalyst in 4-heptanone solvent gives the best TA yield from 1,4-dihydroxymethylbenzene. A maximum 76% TA yield is achieved at 100 °C and 12 bar O2. Based on kinetic measurements, we show that the reaction progresses in two distinct pathways. First, the alcohol groups of the substrate are converted to the aldehydes via an O-assisted dehydrogenation pathway over Ir, and then the aldehydes are oxidized to the acid in the solution via a free radical mechanism. We demonstrate that it is easier to oxidize aromatic diols than p-xylene over a heterogeneous catalyst, and thus, the biomass route to TA may be an attractive alternative to the commercial crude oil-based process.
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- 2018
27. Spectroscopic characterization of a highly selective NiCu3/C hydrodeoxygenation catalyst
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Konstantinos A. Goulas, Jonathan Lym, Jingguang G. Chen, Weiqing Zheng, Jennifer D. Lee, Christopher B. Murray, Cong Wang, Dionisios G. Vlachos, Deborah S. Oh, Siyu Yao, and Raymond J. Gorte
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X-ray absorption spectroscopy ,Materials science ,Hydrogen ,010405 organic chemistry ,Non-blocking I/O ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,X-ray photoelectron spectroscopy ,Chemical engineering ,chemistry ,Mixed oxide ,Hydrodeoxygenation ,Bimetallic strip - Abstract
The design of selective and active heterogeneous catalysts for the hydrodeoxygenation (HDO) of biomass-derived platform molecules requires understanding of the catalyst structure under reaction conditions. In this work, we design, build and qualify an operando X-ray absorption (XAS) cell to characterize a highly selective NiCu3 catalyst under HDO conditions. We complement XAS measurements with X-ray photoelectron spectroscopy (XPS) studies and theoretical calculations to show that in bimetallic NiCu catalysts, Ni and Cu are segregated. The as-made catalysts are mixed oxides, with a NiO shell over a NiCuOx core. The core becomes a partially reduced metal alloy after treatment with hydrogen at temperatures below 473 K, while the shell becomes fully reduced at higher treatment temperatures. The liquid-phase reaction results in gradual reoxidation of the catalyst to a core–shell mixed oxide, in which the Cu in the core is predominately Cu(I) and the Ni shell is predominately Ni(II).
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- 2018
28. What are the effective solutions to control the dissemination of antibiotic resistance in the environment? A systematic review protocol
- Author
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Cédric Laouénan, Antoine Andremont, Nathalie Grall, Dominique Patureau, Céline Couderc-Obert, Anais Goulas, Fabienne Petit, Barbara Livoreil, Christophe Dagot, Pierre Benoit, Infection, Anti-microbiens, Modélisation, Evolution (IAME (UMR_S_1137 / U1137)), Université Paris 13 (UP13)-Université Paris Diderot - Paris 7 (UPD7)-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Fondation pour la Recherche sur la Biodiversité, Assistance Publique - Hôpitaux de Paris, Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Université Paris-Saclay, Ministère de la Transition Ecologique et Solidaire (MTES), Anti-infectieux : supports moléculaires des résistances et innovations thérapeutiques (RESINFIT), CHU Limoges-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Laboratoire de Biotechnologie de l'Environnement [Narbonne] (LBE), Institut National de la Recherche Agronomique (INRA)-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), Morphodynamique Continentale et Côtière (M2C), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols (METIS), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris 13 (UP13)-Université Paris Diderot - Paris 7 (UPD7)-Université Sorbonne Paris Cité (USPC), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-CHU Limoges, Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), and Goulas, Anais
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0301 basic medicine ,Computer science ,[SDV]Life Sciences [q-bio] ,Control (management) ,Aquatic compartment ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,Resistome ,World Wide Web ,03 medical and health sciences ,Soil ,Contamination ,Environmental policy ,Wastes ,One-health ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,lcsh:GE1-350 ,Protocol (science) ,Ecology ,Bacteria ,Antimicrobial ,Genes ,Management ,Pollution ,030104 developmental biology ,13. Climate action - Abstract
Background Antibiotic treatments are indispensable for human and animal health. However, the heavy usage of antibiotics has led to the emergence of resistance. Antibiotic residues, antibiotic-resistant bacteria and genes are introduced into the terrestrial and aquatic environments via application of human and animal wastes. The emergence and the spread of antibiotic resistance in environmental reservoirs (i.e., soil, water, wildlife) threatens the efficacy of all antibiotics. Therefore, there is an urgent need to determine what effective solutions exist to minimize the dissemination of antibiotic resistance in the environment. The aim of this article is to describe the protocol of a systematic review of the literature considering these solutions. Methods The primary questions addressed by the systematic review protocol are: how antibiotic resistance in the environment is impacted by changes in practice concerning (i) the use of antibiotics, (ii) the management of wastes or (iii) the management of the natural compartment. Bibliographic searches will be made in eleven publication databases as well as in specialist databases. Grey literature will also be searched. Articles will be screened regarding the inclusion and exclusion criteria at title, abstract and full-text levels. Studies where a causal relationship between the intervention and the outcome is made will be retained. After critical appraisal, data from the selected articles will be extracted and saved in a database validated by the expert panel. Study quality will be assessed by critical appraisal. Data will be compiled into a qualitative synthesis. If data availability and quality allow it, a quantitative synthesis will be carried out.
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- 2018
29. Optimum replications and locations for cotton cultivar trials under Mediterranean conditions
- Author
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C. Goulas, J. T. Tsialtas, D. Baxevanos, and D. Vlachostergios
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0106 biological sciences ,Mediterranean climate ,Lint ,Biplot ,biology ,04 agricultural and veterinary sciences ,Heritability ,Verticillium ,biology.organism_classification ,01 natural sciences ,Agronomy ,040103 agronomy & agriculture ,Genetics ,0401 agriculture, forestry, and fisheries ,Animal Science and Zoology ,Verticillium dahliae ,Cultivar ,Verticillium wilt ,Agronomy and Crop Science ,010606 plant biology & botany ,Mathematics - Abstract
SUMMARYThe number of replications and locations used in a cultivar evaluation scheme is an important factor affecting the trial heritability (H) and optimum resource allocation. The aim of the present study was to calculate the required number of replications and locations for realizing an optimumHof 0·75 and to identify the most effective test locations for cotton (Gossypium hirsutumL.) in Greece. The data for lint yield, plant height, verticillium wilt (Verticillium dahliaeKleb.) and fibre quality were derived from an 8-year experiment (2000–2007) conducted under irrigated, Mediterranean conditions at 14 locations along the Greek mega-environment. Analysis of variance was performed to calculateHas well as genotype plus genotype × environment (GGE) biplot analysis to determine the location's desirability. It was determined that the four replications currently used in the evaluation of lint yield were sufficient, whereas four locations were proposed as optimum in lieu of the current 8–14 locations used in the evaluation. Two locations excelled as the most effective for lint yield evaluation and one for selection of genotypes tolerant to verticillium wilt using as criteria: the high and consistent across yearsH(0·75), GGE biplot representativeness and discriminating ability. Moreover, one location was selected as a backup based on average trial failures. Plant height was sufficiently evaluated by four replications and two locations, while verticillium required four replications for realizing lowerH(0·60) and three locations for even lowerH(0·40). Regarding quality, an increase of replications from the two currently used to four was sufficient for evaluation of all the traits. The advantage of reducing the number of locations for evaluation of lint yield to just four casts no doubt on the evaluation precision of lint percentage, length, strength and elongation but does for micronaire, short fibre index and uniformity, which realized lowerH(0·60 or 0·50).
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- 2017
30. Deciphering the interplay among genotype, maturity stage and low-temperature storage on phytochemical composition and transcript levels of enzymatic antioxidants in Prunus persica fruit
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G. Pantelidis, Vlasios Goulas, A. Manganaris, Konstantinos A. Paschalidis, Vasileios Fotopoulos, Pavlina Drogoudi, Egli C. Georgiadou, Georgia Tanou, and George A. Manganaris
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0106 biological sciences ,Genotype ,Transcription, Genetic ,Physiology ,Agricultural Biotechnology ,Cold storage ,Plant Science ,Shelf life ,01 natural sciences ,Antioxidants ,040501 horticulture ,Non-destructive ,chemistry.chemical_compound ,Prunus ,Botany ,Genetics ,Cultivar ,Procyanidin B1 ,Procyanidins ,Plant Proteins ,Prunus persica ,Neochlorogenic acid ,Agricultural Sciences ,food and beverages ,Catechin ,Ripening ,04 agricultural and veterinary sciences ,Peach ,Phenolic compounds ,Antioxidant capacity ,Horticulture ,chemistry ,DNA oxidation protection ,Fruit ,Oxidoreductases ,0405 other agricultural sciences ,010606 plant biology & botany - Abstract
The aim of this study was to understand the antioxidant metabolic changes of peach (cvs. ‘Royal Glory’, ‘Red Haven’ and ‘Sun Cloud’) and nectarine fruits (cv. ‘Big Top’) exposed to different combinations of low-temperature storage (0, 2, 4 weeks storage at 0 °C, 90% R.H.) and additional ripening at room temperature (1, 3 and 5 d, shelf life, 20 °C) with an array of analytical, biochemical and molecular approaches. Initially, harvested fruit of the examined cultivars were segregated non-destructively at advanced and less pronounced maturity stages and qualitative traits, physiological parameters, phytochemical composition and antioxidant capacity were determined. ‘Big Top’ and ‘Royal Glory’ fruits were characterized by slower softening rate and less pronounced ripening-related alterations. The coupling of HPLC fingerprints, consisted of 7 phenolic compounds (chlorogenic, neochlorogenic acid, catechin, epicatechin, rutin, quecetin-3-O-glucoside, procyanidin B1) and spectrophotometric methods disclosed a great impact of genotype on peach bioactive composition, with ‘Sun Cloud’ generally displaying the highest contents. Maturity stage at harvest did not seem to affect fruit phenolic composition and no general guidelines for the impact of cold storage and shelf-life on individual phenolic compounds can be extrapolated. Subsequently, fruit of less pronounced maturity at harvest were used for further molecular analysis. ‘Sun Cloud’ was proven efficient in protecting plasmid pBR322 DNA against ROO[rad] attack throughout the experimental period and against HO[rad] attack after 2 and 4 weeks of cold storage. Interestingly, a general down-regulation of key genes implicated in the antioxidant apparatus with the prolongation of storage period was recorded; this was more evident for CAT, cAPX, Cu/ZnSOD2, perAPX3 and GPX8 genes. Higher antioxidant capacity of ‘Sun Cloud’ fruit could potentially be linked with compounds other than enzymatic antioxidants that further regulate peach fruit ripening.
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- 2017
31. Determination of PAHs by ultra fast liquid chromatography using a core-shell technology – Application to their determination after using biochar as adsorbent
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Francis Douay, Christophe Waterlot, Adeline Janus, Anaïs Goulas, and Aurélie Pelfrêne
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Detection limit ,chemistry.chemical_classification ,Aqueous solution ,Materials science ,Chromatography ,Applied Mathematics ,010401 analytical chemistry ,Polycyclic aromatic hydrocarbon ,Sorption ,010501 environmental sciences ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Adsorption ,chemistry ,Chromatography detector ,Biochar ,Electrical and Electronic Engineering ,Porosity ,Instrumentation ,0105 earth and related environmental sciences - Abstract
The C18 column (250 mm × 4.6 mm) packed with 5 μm core-shell particles was used in an effort to optimize the separation of 8 polycyclic aromatic hydrocarbons under very low pressure values (44–52 bars), low temperature (16 °C) and in 13 min. Chromatogram and peaks of each polycyclic aromatic hydrocarbon studied, obtained using an ultra fast liquid chromatography fitted with this column and equipped with a diode array detector, were compared with those obtained using two other traditional C18 columns, packed with fully porous 5 μm particles, usually used in our laboratory and specifically designed for the separation of polycyclic aromatic hydrocarbons. Thinnest peaks, highest sensitivity and efficiency are the main results related to the core-shell technology of the recent Kinetex column compared to more common C18 columns due to the bed uniformity and packing quality of the recent core-shell column. On the other hand, reduced retention time was highlighted for each polycyclic aromatic hydrocarbon using the column packed with core-shell particles resulting from the lower surface area of these particles compared to the totally porous particles of the both other columns used. Limits of detection and quantification, linearity range and repeatability were determined for the method developed with the core-shell column. A practical application was realized by evaluating the sorption capacity of the 8 polycyclic aromatic hydrocarbons studied in mixture using a biochar made from woody plants. To this end, the biochar was mixed with aqueous solution spiked with the mixture of polycyclic aromatic hydrocarbons and a kinetic study of their sorption was conducted. Sorption percentage was higher than 89% for each polycyclic aromatic hydrocarbon studied showing that the studied biochar could be good and low cost alternative products for the sorption of this type of pollutants.
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- 2017
32. ABE Condensation over Monometallic Catalysts: Catalyst Characterization and Kinetics
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Paul J. Dietrich, Amit A. Gokhale, F. Dean Toste, Gorkem Gunbas, Justin Chen, Sanil Sreekumar, Konstantinos A. Goulas, and Adam Grippo
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Hydrotalcite ,010405 organic chemistry ,Organic Chemistry ,Condensation ,Kinetics ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Catalysis ,0104 chemical sciences ,Inorganic Chemistry ,Reaction rate ,chemistry.chemical_compound ,Deprotonation ,chemistry ,Acetone ,Aldol condensation ,Physical and Theoretical Chemistry - Abstract
Author(s): Goulas, KA; Gunbas, G; Dietrich, PJ; Sreekumar, S; Grippo, A; Chen, JP; Gokhale, AA; Toste, FD | Abstract: Herein, we present work on the catalyst development and the kinetics of acetone-butanol-ethanol (ABE) condensation. After examining multiple combinations of metal and basic catalysts reported in the literature, Cu supported on calcined hydrotalcites (HT) was found to be the optimal catalyst for the ABE condensation. This catalyst gave a six-fold increase in reaction rates over previously reported catalysts. Kinetic analysis of the reaction over CuHT and HT revealed that the rate-determining step is the C−H bond activation of alkoxides that are formed from alcohols on the Cu surface. This step is followed by the addition of the resulting aldehydes to an acetone enolate formed by deprotonation of the acetone over basic sites on the HT surface. The presence of alcohols reduces aldol condensation rates, as a result of the coverage of catalytic sites by alkoxides.
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- 2017
33. Austenite formation in 0.2% C and 0.45% C steels under conventional and ultrafast heating
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Alberto Monsalve, F. M. Castro Cerda, C. Goulas, Ilchat Sabirov, Jilt Sietsma, and Roumen Petrov
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010302 applied physics ,Austenite ,Materials science ,Scanning electron microscope ,Mechanical Engineering ,Diffusion ,Metallurgy ,Nucleation ,Thermodynamics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Condensed Matter::Materials Science ,Mechanics of Materials ,Ferrite (iron) ,0103 physical sciences ,lcsh:TA401-492 ,lcsh:Materials of engineering and construction. Mechanics of materials ,General Materials Science ,Pearlite ,0210 nano-technology ,Electron backscatter diffraction - Abstract
The austenite formation in 0.2% C and 0.45% C steels with the initial microstructure of ferrite and pearlite has been studied. The effect of conventional (10 °C/s), fast (50 °C/s–100 °C/s) and ultrafast heating rates (>100 °C/s) on the austenite nucleation and growth mechanisms is rationalized. Scanning Electron Microscopy (SEM), and Electron BackScatter Diffraction (EBSD) analyses provide novel experimental evidence of the austenite nucleation and growth mechanisms operating at ultrafast heating rates. Two mechanisms of austenite formation are identified: diffusional and massive. It is demonstrated that at conventional heating rates the austenite formation kinetics are determined by carbon diffusion, whereas at ultrafast heating rates formation of austenite starts by carbon diffusion control, which is later overtaken by a massive mechanism. Comprehensive thermodynamic and kinetic descriptions of austenite nucleation and growth are developed based on experimental results. Keywords: Austenite, Ultrafast heating, Thermodynamics, Kinetics, Steel, Phase transformation
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- 2017
34. Selective hydrodeoxygenation of tartaric acid to succinic acid
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Basudeb Saha, Dionisios G. Vlachos, Efterpi S. Vasiliadou, Jiayi Fu, and Konstantinos A. Goulas
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Fumaric acid ,010405 organic chemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Acetic acid ,chemistry ,Succinic acid ,Tartaric acid ,Organic chemistry ,Hydrobromic acid ,Hydrodeoxygenation ,Bond cleavage - Abstract
A novel one-step process for catalytic production of succinic acid from tartaric acid, which is largely available in the waste streams of wine making, is developed. A liquid-phase system comprised of a molybdenum oxide catalyst supported on carbon black (MoOx/BC) and hydrobromic acid in acetic acid under a H2 atmosphere is effective for selective cleavage of the C–O bonds of tartaric acid and selective hydrogenation of the resulting unsaturated carbons. Temperature, hydrogen pressure, and catalyst pre-treatment are optimized to understand their impact on catalytic activity and product distribution, leading to an 87% yield of succinic acid at 170 °C. Importantly, reduction of the carboxyl groups and C–C bond cleavage are retarded. Pre-reduction and characterization studies (TPR, XRD, XPS, and XAS) reveal that the high catalyst activity of MoOx/BC is correlated with the lower Mo oxidation states (+4 to 0) formed during pre-reduction that promote cleavage of the C–O bonds of tartaric acid and hydrogenation of the CC bond of the intermediate fumaric acid. Recyclability studies and structural characterization of the recovered catalyst indicate that MoOx/BC remains active upon reuse.
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- 2017
35. Quantitative global mapping of terrestrial vegetation photosynthesis
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Gina H. Mohammed, Elizabeth M. Middleton, Jose Moreno, Uwe Rascher, Alexander Damm, Matthias Drusch, Christiaan van der Tol, Yves Goulas, Matti Mõttus, Franco Miglietta, Peter North, Roberto Colombo, University of Zurich, Moreno, J, Colombo, R, Damm, A, Goulas, Y, Middleton, E, Miglietta, F, Mohammed, G, Mottus, M, North, P, Rascher, U, Van Der Tol, C, and Drusch, M
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Canopy ,010504 meteorology & atmospheric sciences ,0211 other engineering and technologies ,02 engineering and technology ,imaging spectroscopy ,01 natural sciences ,photosynthesi ,vegetation ,photosyntesis ,1706 Computer Science Applications ,Spectral resolution ,910 Geography & travel ,Image resolution ,FLEX earth explorer ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,Spectrometer ,1900 General Earth and Planetary Sciences ,imaging spectrocopy ,Vegetation ,15. Life on land ,Imaging spectroscopy ,10122 Institute of Geography ,13. Climate action ,Radiance ,Environmental science ,Satellite ,fluorescence - Abstract
Although traditional remote sensing systems based on spectral reflectance can already provide estimates of the 'potential' photosynthetic activity of terrestrial vegetation through the quantification of total canopy chlorophyll content or absorbed photosynthetic radiation, the determination of the 'actual' photosynthetic activity of terrestrial vegetation requires information about how the absorbed light is used by plants, such as vegetation fluorescence, using very high spectral resolution spectroscopy in the range 650-800 nm. The Fluorescence Explorer (FLEX) mission, selected in November 2015 as the 8th Earth Explorer by the European Space Agency (ESA), carries the FLORIS spectrometer, with a spectral resolution of 0.3 nm and a spatial resolution of 300 m, with a swath of 150 km. The FLEX mission is designed to fly in tandem with the Copernicus Sentinel-3 satellite, in order to provide all the necessary information to disentangle emitted fluorescence from the background reflected radiance, and to allow proper interpretation of the fluorescence spatial and temporal changes in relation to photosynthesis dynamics, accounting for non-photochemical energy dissipation and canopy temperature effects.
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- 2017
36. Canopy structure explains the relationship between photosynthesis and sun-induced chlorophyll fluorescence in crops
- Author
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Yongguang Zhang, Grayson Badgley, Qian Zhang, Yelu Zeng, Zhaohui Li, Youngryel Ryu, Yves Goulas, Ismael Moya, Benjamin Dechant, Ji Li, Joseph A. Berry, and Minseok Kang
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Canopy ,010504 meteorology & atmospheric sciences ,0208 environmental biotechnology ,Soil Science ,02 engineering and technology ,Positive correlation ,Photosynthesis ,Atmospheric sciences ,01 natural sciences ,EarthArXiv|Life Sciences|Plant Sciences|Agricultural Science ,Gross primary productivity ,bepress|Life Sciences ,EarthArXiv|Life Sciences ,Computers in Earth Sciences ,Chlorophyll fluorescence ,bepress|Life Sciences|Physiology ,0105 earth and related environmental sciences ,Remote sensing ,bepress|Life Sciences|Plant Sciences|Agricultural Science ,EarthArXiv|Life Sciences|Physiology ,Geology ,Vegetation ,Reflectivity ,Uncorrelated ,020801 environmental engineering ,EarthArXiv|Life Sciences|Plant Sciences ,Environmental science ,bepress|Life Sciences|Plant Sciences - Abstract
Remote sensing of far-red sun-induced chlorophyll fluorescence (SIF) has emerged as an important tool for studying gross primary productivity (GPP) at the global scale. However, the relationship between SIF and GPP at the canopy scale lacks a clear mechanistic explanation. This is largely due to the poorly characterized role of the relative contributions from canopy structure and leaf physiology to the variability of the top-of-canopy, observed SIF signal. In particular, the effect of the canopy structure beyond light absorption is that only a fraction (fesc) of the SIF emitted from all leaves in the canopy can escape from the canopy due to the strong scattering of near-infrared radiation. We combined rice, wheat and corn canopy-level in-situ datasets to study how the physiological and structural components of SIF individually relate to measures of photosynthesis. At seasonal time scales, we found a considerably strong positive correlation (R2 = 0.4–0.6) of fesc to the seasonal dynamics of the photosynthetic light use efficiency (LUEP), while the estimated physiological SIF yield was almost entirely uncorrelated to LUEP both at seasonal and diurnal time scales, with the partial exception of wheat. Consistent with these findings, the canopy structure and radiation component of SIF, defined as the product of APAR and fesc, explained the relationship of observed SIF to GPP and even outperformed GPP estimation based on observed SIF at two of the three sites investigated. These results held for both half-hourly and daily mean values. In contrast, the total emitted SIF, obtained by normalizing observed SIF for fesc, improved only the relationship to APAR but considerably decreased the correlation to GPP for all three crops. Our findings demonstrate the dominant role of canopy structure in the SIF-GPP relationship and establish a strong, mechanistic link between the near-infrared reflectance of vegetation (NIRV) and the relevant canopy structure information contained in the SIF signal. These insights are expected to be useful in improving remote sensing based GPP estimates.
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- 2019
37. Valorization of Carob Fruit Residues for the Preparation of Novel Bi-Functional Polyphenolic Coating for Food Packaging Applications
- Author
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George Botsaris, Ioannis P. Gerothanassis, Andreas G. Tzakos, Alexandra Primikyri, Christodoulos Michael, Vlasios Goulas, and Loukas Hadjivasileiou
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Antioxidant ,Food industry ,Carob fruit ,medicine.medical_treatment ,Proton Magnetic Resonance Spectroscopy ,Active packaging ,Pharmaceutical Science ,antioxidant activity ,Antimicrobial activity ,01 natural sciences ,Galactans ,Antioxidants ,Analytical Chemistry ,Polymerization ,Coating ,Mannans ,Salmon ,carob fruit ,Drug Discovery ,Plant Gums ,Food science ,Chemistry ,Agricultural Sciences ,Food Packaging ,food and beverages ,coating ,salmon ,04 agricultural and veterinary sciences ,Antimicrobial ,040401 food science ,Food packaging ,Other Agricultural Sciences ,Chemistry (miscellaneous) ,polymerization ,Molecular Medicine ,Cold storage ,engineering.material ,Article ,lcsh:QD241-441 ,0404 agricultural biotechnology ,Lipid oxidation ,Antioxidant activity ,Phenols ,lcsh:Organic chemistry ,medicine ,Animals ,Physical and Theoretical Chemistry ,polyphenols ,antimicrobial activity ,010405 organic chemistry ,business.industry ,Organic Chemistry ,Polyphenols ,Listeria monocytogenes ,0104 chemical sciences ,Seafood ,Fruit ,engineering ,business - Abstract
The food industry has become interested in the development of innovative biomaterials with antioxidant and antimicrobial properties. Although several biopolymers have been evaluated for food packaging, the use of polyphenolic coatings has been unexplored. The purpose of this work was to develop an antioxidant and antimicrobial coating for food packaging through the polymerization of carob phenolics. At first, the polyphenolic coatings were deposited in glass surfaces polymerizing different concentrations of carob extracts (2 and 4 mg mL&minus, 1) at three pH values (7, 8 and 9). Results demonstrated that the coating produced at pH 8 and at a concentration of 4 mg mL&minus, 1 had the most potent antioxidant and antimicrobial potential. Then, the coating was applied directly on the salmon fillet (coating) and on the plastic container (active packaging). Peroxide and thiobarbituric acid-reactive substances (TBARS) methods were used to measure the potency to inhibit lipid oxidation in salmon fillets. Furthermore, the anti-Listeria activity of coatings was also assessed. Results showed a significant decrease of lipid oxidation during cold storage of salmon fillets for both treatments, the superiority of applied coating directly on the salmon fillets was also highlighted. Regarding the antimicrobial potency, the polyphenolic coating depleted the growth of Listeria monocytogenes after 10 days storage, while the active packaging had no effect on Listeria monocytogenes. Overall, we describe the use of low-cost carob polyphenols as precursors for the formation of bifunctional coatings with promising applications in food packaging.
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- 2019
38. Atomic-scale investigations of isothermally formed bainite microstructures in 51CrV4 spring steel
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Ankit Kumar, C. Goulas, Roumen Petrov, Jilt Sietsma, Felipe Manuel Castro-Cerda, Maria-Giuseppina Mecozzi, and Michael Herbig
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Materials science ,Bainite ,02 engineering and technology ,engineering.material ,01 natural sciences ,Carbide ,chemistry.chemical_compound ,Ferrite (iron) ,0103 physical sciences ,General Materials Science ,010302 applied physics ,Austenite ,Cementite ,Mechanical Engineering ,Metallurgy ,Spring steel ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atom probe tomography ,chemistry ,Isothermal transformation diagram ,Mechanics of Materials ,Martensite ,engineering ,Microalloyed steel ,0210 nano-technology ,Transmission electron microscopy - Abstract
Atomic-scale investigation was performed on 51CrV4 steel, isothermally held at different temperatures within the bainitic temperature range. Transmission electron microscopy (TEM) analysis revealed three different morphologies: lower, upper, and inverse bainite. Atom Probe Tomography (APT) analysis of lower bainite revealed cementite particles, which showed no evidence of partitioning of substitutional elements; only carbon partitioned into cementite to the equilibrium value. Carbon in the bainitic ferrite was found to segregate at dislocations and to form Cottrell atmospheres. The concentration of carbon remaining in solution measured by APT was more than expected at the equilibrium. Upper bainite contained cementite as well. Chromium and manganese were found to redistribute at the cementite-austenite interface and the concentration of carbon in the ferritic matrix was found to be lower than the one measured in the case of lower bainite. After isothermal treatments close to the bainite start temperature, another austenite decomposition product was found at locations with high concentration of Mn and Cr, resembling inverse bainite. Site-specific APT analysis of the inverse bainite reveals significant partitioning of manganese and chromium at the carbides and at the ferrite/martensite interfaces, unlike what is found at isothermal transformation products at lower temperatures.
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- 2019
39. Environmental availability of sulfamethoxazole and its acetylated metabolite added to soils via sludge compost or bovine manure
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Anaïs Goulas, Claire-Sophie Haudin, Valérie Dumény, Valérie Bergheaud, Pierre Benoit, Nicolas Sertillanges, Patricia Garnier, Khaled Brimo, Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, and Université Paris-Saclay
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[SDV.SA]Life Sciences [q-bio]/Agricultural sciences ,Environmental Engineering ,Sulfamethoxazole ,010504 meteorology & atmospheric sciences ,Metabolite ,[SDV]Life Sciences [q-bio] ,010501 environmental sciences ,[SDV.SA.SDS]Life Sciences [q-bio]/Agricultural sciences/Soil study ,01 natural sciences ,chemistry.chemical_compound ,Anti-Infective Agents ,Animals ,Soil Pollutants ,Environmental Chemistry ,Organic matter ,Waste Management and Disposal ,Soil Microbiology ,Organic waste ,0105 earth and related environmental sciences ,2. Zero hunger ,chemistry.chemical_classification ,[SDV.EE]Life Sciences [q-bio]/Ecology, environment ,Composting ,Acetylation ,Mineralization (soil science) ,Biodegradable waste ,Biodegradation ,Pollution ,Manure ,Biodegradation, Environmental ,chemistry ,Aqueous extraction ,Environmental chemistry ,Soil water ,Co-metabolism ,Cattle ,Antimicrobial ,Cow dung - Abstract
International audience; The fate of antibiotics and their metabolites in soils after application of organic waste depends on their environmental availability, which depends on the quality and biodegradability of the added exogenous organic matter (EOM). This study aimed at better understanding the fate of sulfamethoxazole (SMX) and N‑acetyl‑sulfamethoxazole (AcSMX) metabolite added to soils via sludge compost or cow manure application, during a 28-day incubation. Experimental results obtained for mineralized, extractable, and non-extractable fractions as well as EOM mineralization were used to couple SMX and AcSMX dynamics to the EOM evolution using the COP-Soil model. According to various mechanisms of extraction, CaCl2, EDTA and cyclodextrin solutions extracted contrasted available fractions (31–96% on day 0), resulting in different sets of parameter values in the model. CaCl2 extraction was the best method to assess the sulfonamide availability, leading to low relative root mean squared errors and best simulations of SMX and AcSMX dynamics. The decrease of SMX and AcSMX availability over time went with the formation of non-extractable residues, mostly of physicochemical origin. Using the COP-Soil model, the co-metabolism was assumed to be responsible for the formation of biogenic non-extractable residues and the low mineralization of SMX and AcSMX.
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- 2019
40. Sun-Induced Chlorophyll Fluorescence I: Instrumental Considerations for Proximal Spectroradiometers
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Tommaso Julitta, Andreas Burkart, Dan Sporea, Luis Alonso, Karolina Sakowska, Yves Goulas, Laura Mihai, Javier Pacheco-Labrador, Alasdair Mac Arthur, Joel Kuusk, M. Pilar Cendrero-Mateo, Helge Aasen, Andreas Hueni, University of Zurich, and Pacheco-Labrador, Javier
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010504 meteorology & atmospheric sciences ,UFSP13-8 Global Change and Biodiversity ,Sensor model ,0211 other engineering and technologies ,Earth and Planetary Sciences(all) ,02 engineering and technology ,01 natural sciences ,Error ,sensor model ,Spectroradiometer ,Sun-induced chlorophyll fluorescence ,sun-induced chlorophyll fluorescence ,spectroradiometer ,uncertainty ,error ,Calibration ,Cost action ,lcsh:Science ,Chlorophyll fluorescence ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,Noise (signal processing) ,1900 General Earth and Planetary Sciences ,Uncertainty ,Reflectivity ,3. Good health ,Validation methods ,Environmental science ,570 Life sciences ,biology ,General Earth and Planetary Sciences ,lcsh:Q - Abstract
Growing interest in the proximal sensing of sun-induced chlorophyll fluorescence (SIF) has been boosted by space-based retrievals and up-coming missions such as the FLuorescence EXplorer (FLEX). The European COST Action ES1309 “Innovative optical tools for proximal sensing of ecophysiological processes” (OPTIMISE, ES1309; https://optimise.dcs.aber.ac.uk/) has produced three manuscripts addressing the main current challenges in this field. This article provides a framework to model the impact of different instrument noise and bias on the retrieval of SIF; and to assess uncertainty requirements for the calibration and characterization of state-of-the-art SIF-oriented spectroradiometers. We developed a sensor simulator capable of reproducing biases and noises usually found in field spectroradiometers. First the sensor simulator was calibrated and characterized using synthetic datasets of known uncertainties defined from laboratory measurements and literature. Secondly, we used the sensor simulator and the characterized sensor models to simulate the acquisition of atmospheric and vegetation radiances from a synthetic dataset. Each of the sensor models predicted biases with propagated uncertainties that modified the simulated measurements as a function of different factors. Finally, the impact of each sensor model on SIF retrieval was analyzed. Results show that SIF retrieval can be significantly affected in situations where reflectance factors are barely modified. SIF errors were found to correlate with drivers of instrumental-induced biases which are as also drivers of plant physiology. This jeopardizes not only the retrieval of SIF, but also the understanding of its relationship with vegetation function, the study of diel and seasonal cycles and the validation of remote sensing SIF products. Further work is needed to determine the optimal requirements in terms of sensor design, characterization and signal correction for SIF retrieval by proximal sensing. In addition, evaluation/validation methods to characterize and correct instrumental responses should be developed and used to test sensors performance in operational conditions.
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- 2019
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41. Modeling canopy conductance and transpiration from solar-induced chlorophyll fluorescence
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David Martini, Yongguang Zhang, Nan Shan, Jingming Chen, Yves Goulas, Weimin Ju, Luis Guanter, and Mirco Migliavacca
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0106 biological sciences ,Canopy ,Atmospheric Science ,Global and Planetary Change ,Stomatal conductance ,010504 meteorology & atmospheric sciences ,Eddy covariance ,Forestry ,Vegetation ,Atmospheric sciences ,01 natural sciences ,Canopy conductance ,Latent heat ,Environmental science ,Agronomy and Crop Science ,Chlorophyll fluorescence ,010606 plant biology & botany ,0105 earth and related environmental sciences ,Transpiration - Abstract
Vegetation transpiration (T) is the process of plant water loss through the stomata on the leaf surface and plays a key role in the energy and water balance of the land surface, especially with dense vegetation cover. To date, however, estimation of ecosystem-scale T is still rather uncertain mainly due to errors in modeling canopy resistance or conductance. Considering the intrinsic link between photosynthesis and chlorophyll fluorescence, the recent available remote sensing of solar-induced chlorophyll fluorescence (SIF) provides a valuable opportunity to estimate plants T at large scales. In this study, we demonstrate how remote sensing of SIF relates to canopy stomatal conductance and transpiration at diurnal and seasonal scales with continuous ground measurements of SIF at three flux sites in forest, cropland and grassland ecosystems. The results show that both ground and spaceborne SIF observations are good indicators of canopy conductance at both diurnal and seasonal scales (R2 = 0.57 and 0.74 for forest, R2 = 0.62 and 0.80 for cropland, R2 = 0.52 and 0.63 for grassland, respectively). Then, empirical SIF-based canopy conductance models are employed to estimate hourly and daily transpiration. We evaluate our ecosystem T estimations against latent heat fluxes measured by eddy covariance systems with more satisfactory results for forest (R2 = 0.57 and 0.71), and cropland (R2 = 0.77 and 0.83) than for grassland (R2 = 0.13 and 0.22) at hourly and daily time scales. Our results suggest the potential of remotely-sensed SIF for estimating canopy conductance and plant transpiration, but a more mechanistic understanding is needed for their link.
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- 2019
42. Canopy chlorophyll fluorescence applied to stress detection using an easy-to-build micro-lidar
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Yves Goulas, Ismael Moya, Abderrahmane Ounis, Hildo Loayza, Roberto Quiroz, Maria Llanos López, Centro Agronómico Tropical de Investigación y Enseñanza - Tropical Agricultural Research and Higher Education Center (CATIE), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), International Potato Center [Lima] (CIP), Consultative Group on International Agricultural Research [CGIAR] (CGIAR), AgriSat, Universidad de Castilla-La Mancha = University of Castilla-La Mancha (UCLM), Centro Agronómico Tropical de Investigación y Enseñanza (CATIE), CATIE, École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), École normale supérieure - Paris (ENS Paris)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), International Potato Center, University of Castilla-La Mancha (UCLM), École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris)
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0106 biological sciences ,0301 basic medicine ,Canopy ,Chlorophyll ,Crops, Agricultural ,Holcus ,Irradiance ,Flux ,Plant Science ,[SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology ,01 natural sciences ,Biochemistry ,Fluorescence ,03 medical and health sciences ,chemistry.chemical_compound ,Diurnal cycle ,Stress, Physiological ,Photosynthesis ,Chlorophyll fluorescence ,Remote sensing ,Stress detection ,SIF ,LIF ,[SDE.IE]Environmental Sciences/Environmental Engineering ,Water ,Cell Biology ,General Medicine ,15. Life on land ,µ-lidar ,Plant Leaves ,030104 developmental biology ,Lidar ,LEDFLEX ,chemistry ,Photosynthetically active radiation ,Sunlight ,Environmental science ,Original Article ,μ-lidar ,010606 plant biology & botany ,Mentha - Abstract
International audience; LEDFLEX is a micro-lidar dedicated to the measurement of vegetation fluorescence. The light source consists of 4 blue Light-Emitting Diodes (LED) to illuminate part of the canopy in order to average the spatial variability of small crops. The fluorescence emitted in response to a 5-μs width pulse is separated from the ambient light through a synchronized detection. Both the reflectance and the fluorescence of the target are acquired simultaneously in exactly the same field of view, as well as the photosynthetic active radiation and air temperature. The footprint is about 1 m 2 at a distance of 8 m. By increasing the number of LEDs longer ranges can be reached. The micro-lidar has been successfully applied under full sunlight conditions to establish the signature of water stress on pea (Pisum Sativum) canopy. Under well-watered conditions the diurnal cycle presents an M shape with a minimum (Fmin) at noon which is Fmin > Fo. After several days withholding watering, Fs decreases and Fmin < Fo. The same patterns were observed on mint (Menta Spicata) and sweet potatoes (Ipomoea batatas) canopies. Active fluorescence measurements with LEDFLEX produced robust fluorescence yield data as a result of the constancy of the excitation intensity and its geometry fixity. Passive methods based on Sun-Induced chlorophyll Fluores-cence (SIF) that uses high-resolution spectrometers generate only flux data and are dependent on both the 3D structure of vegetation and variable irradiance conditions along the day. Parallel measurements with LEDFLEX should greatly improve the interpretation of SIF changes.
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- 2019
43. Correction to: What are the effective solutions to control the dissemination of antibiotic resistance in the environment? A systematic review protocol
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Anaïs Goulas, Barbara Livoreil, Nathalie Grall, Pierre Benoit, Céline Couderc-Obert, Christophe Dagot, Dominique Patureau, Fabienne Petit, Cédric Laouénan, Antoine Andremont, Infection, Anti-microbiens, Modélisation, Evolution (IAME (UMR_S_1137 / U1137)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Cité (UPCité)-Université Sorbonne Paris Nord, Fondation pour la recherche sur la Biodiversité (FRB), AP-HP - Hôpital Bichat - Claude Bernard [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Ministère de la Transition Ecologique et Solidaire (MTES), Université de Limoges (UNILIM), Laboratoire de Biotechnologie de l'Environnement [Narbonne] (LBE), Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), UNIROUEN - UFR Santé (UNIROUEN UFR Santé), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU), Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols (METIS), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Pavlidès, Marina, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Paris (UP)-Université Sorbonne Paris Nord, 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), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
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lcsh:GE1-350 ,0106 biological sciences ,[SDV.EE]Life Sciences [q-bio]/Ecology, environment ,[SDE] Environmental Sciences ,Ecology ,010604 marine biology & hydrobiology ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,Pollution ,3. Good health ,[SDV.EE] Life Sciences [q-bio]/Ecology, environment ,[SDE]Environmental Sciences ,lcsh:Environmental sciences ,0105 earth and related environmental sciences - Abstract
International audience; Correction to: Environ Evid (2018) 7:3 https ://doi.org/10.1186/s1375 0-018-0118-2 : Following publication of the original article [1], the authors reported that wrong website were hyperlinked in the “Methods” section of the paper. The article has been updated and the links have been removed.Reference :1. Goulas A, Livoreil B, Grall N, Benoit P, Couderc-Obert C, Dagot C, Patureau D, Petit F, Laouénan C, Andremont A. What are the effective solutionsto control the dissemination of antibiotic resistance in the environment? A systematic review protocol. Environ Evid. 2018;7:3. https ://doi.org/10.1186/s1375 0-018-0118-2. HAL Id : hal-01724879
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- 2019
44. A model for estimating transpiration from remotely sensed solar-induced chlorophyll fluorescence
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Weimin Ju, Xi Yang, Yves Goulas, Yongguang Zhang, Josep Peñuelas, Jacob A. Nelson, Mirco Migliavacca, Zhaoying Zhang, Nan Shan, and Jing M. Chen
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Stomatal conductance ,010504 meteorology & atmospheric sciences ,Vapour Pressure Deficit ,0208 environmental biotechnology ,Eddy covariance ,Soil Science ,Flux ,Geology ,02 engineering and technology ,Atmospheric sciences ,01 natural sciences ,020801 environmental engineering ,Latent heat ,Evapotranspiration ,Environmental science ,Computers in Earth Sciences ,Chlorophyll fluorescence ,0105 earth and related environmental sciences ,Transpiration ,Remote sensing - Abstract
Terrestrial evapotranspiration (ET) is an important flux that links global cycles of carbon, water and energy and is largely driven by transpiration (T) through leaf stomata in vegetated areas during the growing season. ET, however, remains one of the most uncertain hydrological variables at the global scale. In this study, we proposed a semi-mechanistic model for estimating terrestrial T by deriving an analytical solution between solar-induced chlorophyll fluorescence (SIF) and stomatal conductance (gc) as well as vapor pressure deficit (VPD), combining theories on the photosynthetic pathway and optimal stomatal behavior. The relationships of SIF-ETR and ETR-gc·VPD0.5 was calibrated by the Soil-Canopy Observation of Photosynthesis and Energy (SCOPE) model. This model was validated by hourly canopy SIF and concurrent eddy covariance flux observations at both forest and cropland ecosystems. Results showed that the SIF combined with VPD can better predict gc than using SIF alone with a more consistent seasonal trends found in both SIF and gc·VPD0.5. The correlation between gc·VPD0.5 and SIF was stronger than those between gc and SIF and between gc and VIs. Canopy T was accurately predicted from SIF at both hourly (R2 > 0.65) and daily (R2 > 0.76) scales and was also successfully estimated using SIF observations from the TROPOspheric Monitoring Instrument (TROPOMI) at cropland ecosystems. In comparison with empirical relationships of directly linking gc with SIF or VIs, the proposed model produced latent heat flux (λE) estimation in best agreement with measured values at all three sites. Our model could be a step forward in understanding the coupling of carbon and water cycles and may be used in ecosystem models for improving ET estimation over large areas.
- Published
- 2021
45. Microstructure and microwave dielectric properties of 3D printed low loss Bi2Mo2O9 ceramics for LTCC applications
- Author
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Bala Vaidhyanathan, William Whittow, J.C. Vardaxoglou, Athanasios Goulas, Annapoorani Ketharam, Shiyu Zhang, George Chi-Tangyie, Dawei Wang, Daniel S. Engstrøm, Darren Cadman, and Ian M. Reaney
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Materials science ,chemistry.chemical_element ,Sintering ,Relative permittivity ,02 engineering and technology ,Dielectric ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,0104 chemical sciences ,Bismuth ,chemistry ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,Dielectric loss ,Ceramic ,Composite material ,0210 nano-technology ,Microwave - Abstract
Low sintering temperature, ultra-low loss microwave ceramics are envisaged as future dielectrics for fabricating low temperature co-fired ceramic (LTCC) components for 5G applications. Low sintering temperature bismuth molybdate β-Bi2Mo2O9 ceramic powders have been synthesised using a solid-state reaction method. Their additive manufacture and resulting microwave properties are reported for the first time. Optimum densification occurred for 3D printed samples sintered 4 hours at 670°C which resulted in a maximum relative density (ρr) of 92%, relative permittivity (er) of 34, dielectric loss (tanδ) of 0.0007, giving a microwave quality factor (Qxf) of 10,050 GHz, properties attractive for LTCC applications.
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- 2020
46. Indium tin oxide nanowires manufactured via printing and laser irradiation
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Jack R. McGhee, Claire J. Carmalt, K.G.U. Wijayantha, P. S. A. Evans, Daniel S. Engstrøm, Athanasios Goulas, Paul Conway, David A. Hutt, Zhaoxia Zhou, Darren J. Southee, Jagdeep S. Sagu, and Jing Wang
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Materials science ,business.industry ,Nanowire ,Context (language use) ,02 engineering and technology ,Conductivity ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,0104 chemical sciences ,Indium tin oxide ,law.invention ,Semiconductor ,X-ray photoelectron spectroscopy ,Photovoltaics ,law ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business - Abstract
Metallic and semiconductor nanowires can provide dramatically increased electrical and optical properties in a wide range of fields, ranging from photovoltaics to sensors and catalysts. In this research, a rapid manufacturing process has been developed for printing indium tin oxide microparticles and converting them into nanowires. Microparticle indium tin oxide (ITO) inks were formulated and printed. These were then converted into hierarchical nanowire films via laser irradiation (980 nm, NIR) with raster speeds of 40 mm s−1 in air, much faster compared to traditional manufacturing processes. For a 4 cm2 film, only 40 s of processing were required. A full materials characterization was performed on the materials pre and post laser processing with the most probable conversion mechanism found to be a laser induced carbothermal reduction process. Microstructural, chemical, and crystallographic evidence of the laser induced carbothermal reduction process were derived from SEM, XRD, XPS and TEM analysis. Compared to conventionally heat-treated printed samples, laser processing was found to increase the conductivity of the printed ITO from 0.88% to 40.47% bulk conductivity. This research demonstrates the ability of printing and laser processing to form nanowires in a high-speed manufacturing context, thereby enabling the development of printed non-transparent ITO nanowire electronics and devices.
- Published
- 2020
47. How E-gov in Greece Affects Life-long Learning for Public Servants, Working on Technical Field
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Efthymios Valkanos, Kassiani Droulia, and Dimitrios Goulas
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Government ,Emerging technologies ,business.industry ,05 social sciences ,Lifelong learning ,Professional development ,Information technology ,Public relations ,010502 geochemistry & geophysics ,01 natural sciences ,Education ,Work (electrical) ,Information and Communications Technology ,0502 economics and business ,050211 marketing ,The Internet ,Business ,0105 earth and related environmental sciences - Abstract
Engineers that work as civil servants cover a wide range of competences, administrative and scientific, which implies that they deal with many difficulties in the exercise of their duties as executives. Electronic government (e-gov), through the use of new Technologies of Information and Communications (ICT) at public technical services, has changed the procedures and the daily operation of public services. These changes create new needs but also new prospects in education/training of public services' executives. In this research, authors made a case study, examining the case of the municipality of Patras, one of the bigger municipalities of Greece. They used the method of review and the quantitative methodological approach. Their objectives concentrated on recording the aspects of Engineers working as Public Employees, regarding new needs, possibilities and choices of training in the frames of e-gov and comparing their opinions with their appositeness and their role in the organization they serve.
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- 2016
48. Microstructure, texture and mechanical properties in a low carbon steel after ultrafast heating
- Author
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Ilchat Sabirov, Roumen Petrov, Spyros Papaefthymiou, F. M. Castro Cerda, Alberto Monsalve, and C. Goulas
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010302 applied physics ,Materials science ,Carbon steel ,Annealing (metallurgy) ,Mechanical Engineering ,Metallurgy ,Recrystallization (metallurgy) ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,Grain size ,Mechanics of Materials ,Ferrite (iron) ,Martensite ,0103 physical sciences ,engineering ,General Materials Science ,Pearlite ,0210 nano-technology - Abstract
Heating experiments in a wide range of heating rates from 10 °C/s to 1200 °C/s and subsequent quenching without isothermal soaking have been carried out on a low carbon steel. The thermal cycles were run on two different cold rolled microstructures, namely ferrite+pearlite and ferrite+martensite. It is shown that the average ferritic grain size, the ferrite grain size distribution, the phase volume fractions and the corresponding mechanical properties (ultimate tensile strength and ductility) after quenching are strongly influenced by the heating rates and the initial microstructure. The ferrite grain size distribution is significantly modified by the heating rate, showing a markedly bimodal distribution after fast annealing. The rise of the heating rate has produced a change in the relative intensities of texture components, favouring those of the cold-deformed structure (RD fibre) over the recrystallization components (ND fibre).
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- 2016
49. Condensation and esterification reactions of alkanals, alkanones, and alkanols on TiO2: Elementary steps, site requirements, and synergistic effects of bifunctional strategies
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Konstantinos A. Goulas, Shuai Wang, and Enrique Iglesia
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010405 organic chemistry ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Catalysis ,Transition state ,0104 chemical sciences ,chemistry.chemical_compound ,Propanoic acid ,chemistry ,Pyridine ,Kinetic isotope effect ,Organic chemistry ,Aldol condensation ,Reactivity (chemistry) ,Physical and Theoretical Chemistry ,Bifunctional - Abstract
Rates and selectivity of TiO 2 -catalyzed condensation of C 3 oxygenates (propanal, acetone) are limited by ubiquitous effects of side reactions, deactivation, and thermodynamic bottlenecks. H 2 together with a Cu function, present as physical mixtures with TiO 2 , circumvents such hurdles by scavenging unsaturated intermediates. They also render alkanols and alkanals/alkanones equivalent as reactants through rapid interconversion, while allowing esterification turnovers by dehydrogenating unstable hemiacetals. Oxygenates form molecules with new C C and C O bonds and fewer O-atoms at nearly complete conversions with stable rates and selectivities. Kinetic, isotopic, and theoretical methods showed that rates are limited by α-C H cleavage from carbonyl reactants to form enolate intermediates, which undergo C C coupling with another carbonyl species to form α,β-unsaturated oxygenates or with alkanols to form hemiacetals with new C O bonds, via an intervening H-shift that forms alkoxide–alkanal pairs. Titrations with 2,6-di-tert-butylpyridine, pyridine, CO 2 , and propanoic acid during catalysis showed that Lewis acid–base site pairs of moderate strength mediate enolate formation steps via concerted interactions with the α-H atom and the enolate moiety at transition states. The resulting site-counts allow rigorous comparisons between theory and experiments and among catalysts on the basis of turnover rates and activation free energies. Theoretical treatments give barriers, kinetic isotope effects, and esterification/condensation ratios in excellent agreement with experiments and confirm the strong effects of reactant substituents at the α-C-atom and of surface structure on reactivity. Surfaces with Ti O Ti sites exhibiting intermediate acid–base strength and Ti O distances, prevalent on anatase but not rutile TiO 2 , are required for facile α-C H activation in reactants and reprotonation of the adsorbed intermediates that mediate condensation and esterification turnovers.
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- 2016
50. Edible coating composed of chitosan andSalvia fruticosaMill. extract for the control of grey mould of table grapes
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Vlasios Goulas, Zinovia Charalambous, Loukas Kanetis, and Vassiliki Exarchou
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0106 biological sciences ,Nutrition and Dietetics ,biology ,food and beverages ,Cold storage ,Carnosic acid ,Titratable acid ,04 agricultural and veterinary sciences ,biology.organism_classification ,01 natural sciences ,040501 horticulture ,Chitosan ,chemistry.chemical_compound ,Salvia fruticosa ,chemistry ,Botany ,Spore germination ,Postharvest ,Food science ,0405 other agricultural sciences ,Agronomy and Crop Science ,010606 plant biology & botany ,Food Science ,Biotechnology ,Botrytis cinerea - Abstract
Consumer concerns regarding high-quality produce, free of pesticide residues, direct research towards disease management strategies that minimise or even exclude the use of synthetic chemistries in crop production. The efficacy of a chitosan-based edible coating combined with the acetonic extract of Salvia fruticosa Mill. (ASF) was assessed against the grey mould of table grapes.; Results: HPLC-SPE-NMR and q-NMR analyses defined major constituents of ASF to be the flavonoids hispidulin, salvigenin and cirsimaritin and the diterpenes carnosic acid, carnosol and the 12-methoxycarnosic acid. The extract was found to be efficacious in reducing spore germination and mycelial growth of Botrytis cinerea in vitro at 10 and 25 °C. However, the combination of the ASF with chitosan 1% (w/v; CHIT) significantly improved fungal inhibition. Similarly, in fruit inoculation trials at 10 °C, the efficacy of the combined application of the ASF at 500 mg L-1 with CHIT against grey mould was statistically equal to the synthetic fungicide thiabendazole, ranging from 98.4% to 92.7% at 12 and 21 days post-inoculation, respectively. Furthermore, chitosan coating alone and in combination with ASF decreased the rate of fruit weight loss during cold storage, while preserved soluble solids content and titratable acidity. Chitosan-based coatings did not affect quality attributes and the bioactive compounds in table grapes.; Conclusion: The combined application of the ASF in the form of an edible coating with chitosan could effectively control B. cinerea without deteriorating quality and physico-chemical properties of grapes. © 2016 Society of Chemical Industry.; © 2016 Society of Chemical Industry.
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- 2016
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