495 results on '"Juez J"'
Search Results
52. The transition towards a sustainable circular economy through life cycle assessment in the building and construction sector: a review and bibliometric analysis.
- Author
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Salimi R and Taherkhani R
- Abstract
Transitioning to a circular economy is indispensable for the construction industry to achieve sustainable development goals. Understanding trends, gaps, and opportunities in life cycle assessment (LCA) for adopting a circular economy is critical. This study investigates the development of publications, identifies the most effective documents, authors, and countries, and highlights critical issues, knowledge axes, active research areas, and knowledge gaps. The study screened 196 out of 280 articles from the Scopus database and conducted a bibliometric analysis using CiteSpace and VOSviewer. Document clustering analysis identified the main research domains, and thematic classifications of knowledge areas and axes were provided. Additionally, development opportunities and knowledge gaps were identified through a full-text analysis of selected articles. The results show an increase in publications post-2017, with key research clusters including "Critical consideration," "Circular building component," "Building material," "Design for disassembly," "Integrated load match analysis," "Adaptive reuse project," "Data bank," "Prospective life cycle assessment," "Investment decision," and "Environmental comparison." Over 60% of the documents propose circular design solutions, end-of-life strategies, and alternative materials, while more than 80% focus solely on the environmental aspect. Only 4.6% develop integrated indicators, 2.5% automate LCA, 2.1% compile life cycle inventory databases, and 2% consider the social dimension. The findings emphasize the need to develop integrated indicators, methods, life cycle inventory databases, and automation tools based on integrated platforms and emerging technologies like building information modeling. This research identifies current knowledge gaps, suggests future research directions, and enhances understanding of how to make LCA more compatible with the circular economy., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2024
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53. A custom-built single-channel in-ear electroencephalography sensor for sleep phase detection: an interdependent solution for at-home sleep studies.
- Author
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Borges DF, Soares JI, Silva H, Felgueiras J, Batista C, Ferreira S, Rocha NB, and Leal A
- Abstract
Sleep is vital for health. It has regenerative and protective functions. Its disruption reduces the quality of life and increases susceptibility to disease. During sleep, there is a cyclicity of distinct phases that are studied for clinical purposes using polysomnography (PSG), a costly and technically demanding method that compromises the quality of natural sleep. The search for simpler devices for recording biological signals at home addresses some of these issues. We have reworked a single-channel in-ear electroencephalography (EEG) sensor grounded to a commercially available memory foam earplug with conductive tape. A total of 14 healthy volunteers underwent a full night of simultaneous PSG, in-ear EEG and actigraphy recordings. We analysed the performance of the methods in terms of sleep metrics and staging. In another group of 14 patients evaluated for sleep-related pathologies, PSG and in-ear EEG were recorded simultaneously, the latter in two different configurations (with and without a contralateral reference on the scalp). In both groups, the in-ear EEG sensor showed a strong correlation, agreement and reliability with the 'gold standard' of PSG and thus supported accurate sleep classification, which is not feasible with actigraphy. Single-channel in-ear EEG offers compelling prospects for simplifying sleep parameterisation in both healthy individuals and clinical patients and paves the way for reliable assessments in a broader range of clinical situations, namely by integrating Level 3 polysomnography devices. In addition, addressing the recognised overestimation of the apnea-hypopnea index, due to the lack of an EEG signal, and the sparse information on sleep metrics could prove fundamental for optimised clinical decision making., (© 2024 European Sleep Research Society.)
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- 2024
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54. An Evaluation of the Strength for Recycled Fine Aggregate Replacement in Cementitious Mortars.
- Author
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Mahmood, Ali, Nanos, Nikos, and Begg, David
- Subjects
MORTAR ,RECYCLED concrete aggregates ,FLEXURAL strength testing ,COMPRESSIVE strength ,FLEXURAL strength ,SUSTAINABLE construction - Abstract
This research investigates the viability of high-strength Recycled Concrete Aggregate (RCA) sourced from demolished structures containing high-strength concrete as a substitute for natural fine aggregates (NA) in cementitious mortar applications. Concrete specimens (40 × 40 × 160 mm) were prepared in a controlled environment with varying percentages of RCA replacing NA, ranging from 0% to 100% in 10% increments. The resulting RCA aggregates exhibited lower weight for sizes from 0.01 to 1 mm compared to NA, and for 1 to 3 mm sizes, RCA weights were 145% to 177% higher than SS aggregates. After curing for 28 days, flexural and compressive strength tests were conducted on the batches. The average compressive strength for the 0% RCA batch was 66.26 MPa, while the 50% RCA batch showed the closest average compressive strength at 63.10 MPa. Batches with varying RCA levels displayed compressive strengths between 49.52 and 58.18 MPa. The highest flexural strength was observed in the 0% RCA batch, with the closest result for a batch containing RCA being the 50% RCA batch. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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55. A Review: Construction and Demolition Waste as a Novel Source for CO 2 Reduction in Portland Cement Production for Concrete.
- Author
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Kaptan, Kubilay, Cunha, Sandra, and Aguiar, José
- Abstract
There is an increasing global recognition of the need for environmental sustainability in mitigating the adverse impacts of cement production. Despite the implementation of various carbon dioxide (CO
2 ) mitigation strategies in the cement industry, such as waste heat recovery, the use of alternative raw materials and alternative fuels, energy efficiency improvements, and carbon capture and storage, overall emissions have still increased due to the higher production levels. The resolution of this matter can be efficiently achieved by the substitution of traditional materials with an alternative material, such as calcined clay (CC), construction and demolition waste (CDW), which have a significant impact on various areas of sustainable development, including environmental, economic, and social considerations. The primary objectives of employing CDW in the Portland cement production are twofold: firstly, to mitigate the release of CO2 into the atmosphere, as it is a significant contributor to environmental pollution and climate change; and secondly, to optimize the utilization of waste materials, thereby addressing the challenges associated with their disposal. The purpose of this work is to present a thorough examination of the existing body of literature pertaining to the partial replacement of traditional raw materials by CDW and the partial replacement of Portland cement by CDW and to analyze the resulting impact on CO2 emissions. [ABSTRACT FROM AUTHOR]- Published
- 2024
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56. Performance evaluation of mortar with ground and thermo-activated recycled concrete cement.
- Author
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Getachew, Ephrem Melaku, Yifru, Begashaw Worku, Habtegebreal, Betelhem Tilahun, and Yehualaw, Mitiku Damtie
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ULTRASONIC testing ,MORTAR ,PORTLAND cement ,CHEMICAL testing ,ROUGH surfaces ,COMPRESSIVE strength - Abstract
The main objective of this study was to examine the combined effect of ground recycled concrete cement (GRC) and thermo-activated recycled concrete cement (TARC) on properties of mortar. The physical, chemical and microstructural tests were conducted to characterize GRC and TARC before mortar mixtures were produced. The microscopic morphology of GRC and TARC revealed uneven edges and a rough surface that is slightly porous. The GRC and TARC powders were used to replace cement in the range of 0-50% at increments of 10% by volume. The fresh, mechanical, microstructure, and durability characteristics of mortar were tested for different proportion of GRC and TARC as partial replacement of cement. The usage of GRC and TARC decreases the workability of mortar marginally. However, the mechanical performance of the mortar mixtures showed an increasing trend when GRC and TARC share increases in the mixture. Predominantly, compressive strength, bulk density, and ultrasonic pulse velocity (UPV) have all been increased by as much as 20% cement replacement. Furthermore, the incorporation of GRC and TARC enhances the mortar's durability properties. The microstructure analysis reveals that 20% replacement (GT20) mix has superior structural compactness. In general, partially substitution of GRC and TARC by ordinary Portland cement improves several characteristics of mortar. This will help solve the most prevalent problems that concrete produces, including the high embedded carbon dioxide creation, the high resource usage, and the high waste generation after demolition. [ABSTRACT FROM AUTHOR]
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- 2024
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57. Cómo detectar y analizar la atenuación: una ficha de análisis.
- Author
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Uclés-Ramada, Gloria
- Subjects
DISCOURSE analysis - Abstract
Copyright of Boletín de Filología is the property of Universidad de Chile, Facultad de Filosofia y Humanidades and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
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58. Eco-Friendly Pavements Manufactured from Mixed Recycled Aggregates Obtained from Construction and Demolition Waste: An Industrial-Scale Validation.
- Author
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Contreras-Llanes, Manuel, Gázquez, Manuel Jesús, and Romero, Maximina
- Subjects
CONSTRUCTION & demolition debris ,MORTAR ,PAVEMENTS ,PRECAST concrete ,PARTICLE size distribution ,ABRASION resistance ,RAW materials ,CONCRETE pavements - Abstract
This study aimed to validate that laboratory-scale results could be commercially replicated when manufacturing marketable precast concrete. Construction and demolition waste (CDW) was separated into two (fine and coarse) recycled aggregates (RAs). Precast paver and kerb units were fabricated by partial or total substitution of natural aggregates (NAs) by RAs. The study involved the comprehensive characterisation of raw materials, including particle size distribution, mineral composition, and elemental composition. Paver blocks and kerbs manufactured with up to 50% RAs showed mechanical resistance (T = 3.7 ± 0.2 and B = 5.3 ± 0.6 MPa, respectively), water absorption between 5.3–5.7%, and abrasion resistance (approximately 20.2 mm), which met the standard requirements (UNE-EN 1340:2004 and UNE-EN 1338:2004). Furthermore, industrial-scale precast pavement units demonstrated strength and durability suitable for heavy traffic areas. A reduction of 13% in cement content could maintain the requirements with a partial RA substitution of 25%, offering economic and environmental benefits. Therefore, it is feasible at an industrial level to replace NAs with RAs, promoting durability and technological properties with a positive environmental impact and considerably reducing CO
2 emissions by up to 65%. Overall, pavers with RAs manufactured at the laboratory scale met mechanical standards, and the kerb stones showed improvements in abrasion resistance. On an industrial scale, kerb stones and precast blocks with specific substitutions can meet strength, water absorption, and abrasion requirements, allowing a reduction in cement content. [ABSTRACT FROM AUTHOR]- Published
- 2023
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59. Building a large affordable optical-NIR telescope (I): an alternate way to handle segmented primary mirror.
- Author
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Dharmadhikari, Radhika, Parihar, Padmakar, and Jacob, Annu
- Subjects
OPTICAL telescopes ,MIRRORS ,INFECTIOUS disease transmission ,TIME management - Abstract
The use of innovative ideas and the latest technology have undoubtedly brought down telescope costs substantially. However, there are still ways to further reduce the cost of optical ground-based telescopes and make them affordable to much larger and wide spread astronomical communities. In this and subsequent papers we are presenting our studies carried out towards building affordable mid-size telescopes of 4.0-6.0m in size. In the present era, segmented mirror technology has become the first choice for building moderate to large-size telescopes. In any Segmented Mirror Telescope (SMT) the most important part is its primary mirror control system (M1CS). The conventional M1CS is based on edge sensors and actuators, but such a system introduces many design and implementation complexities. In this paper, we propose to make use of an Off-axis Alignment and Phasing System (OAPS), which is an active mirror kind of control system working in real time to maintain the figure of a segmented primary mirror without the use of edge-sensors. The alignment and phasing system which is an integral part of any segmented telescope can be used in the real time at the off-axis. Through extensive simulations we have explored the feasibility of using an OAPS for co-alignment, co-focusing as well as co-phasing of segmented mirror telescopes. From our simulations we find that the co-alignment and co-focusing of the segments can be achieved with a guide star as faint as 16-18 th magnitude. This implies that seeing limited performance for any segmented telescope can be easily accomplished without use of a complex edge sensor based control system. Whereas, to attain diffraction limited performance, mirror segments need to be co-phased with an accuracy of few tens of nanometers. In our simulations we have used a dispersed fringe sensor based phasing scheme, which can effectively work up to guide stars of 14 th magnitude. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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60. Modeling of the Hot Deformation of Cast Super Duplex Corrosion-Resistant Steel.
- Author
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Rushchits, S. V., Shaburova, N. A., Sedukhin, V. V., Akhmed'yanov, A. M., Samoilov, S. P., Anikeev, A. N., and Chumanov, I. V.
- Abstract
The deformation behavior of cast super duplex steel is studied in the temperature range 1100–1250°C and the strain rate range 0.1–10 s
–1 . Hot deformation is performed by uniaxial compression of cylindrical specimens on a Gleeble 3800 simulator of thermomechanical processes. The flow stresses are shown to decrease with increasing temperature and decreasing strain rate in accordance with a change in the Zener–Hollomon parameter of the temperature–rate deformation conditions. The shape of the flow curves indicates that hot deformation is accompanied by intense dynamic softening, as a result of which the flow stresses decrease or remain unchanged after reaching peak values. Under all hot deformation conditions, ferrite acquires a dynamically recrystallized structure. At the lowest deformation temperature (1100°C) and relatively high strain rates (1–10 s–1 ), the mechanism of austenite softening is dynamic recovery. A decrease in the strain rate or an increase in the deformation temperature causes partial dynamic recrystallization of austenite. Under similar deformation conditions, the plastic flow stress of the steel under study is significantly higher than that in standard duplex stainless steels. When analyzing the peak flow stresses, we determined the effective hot deformation activation energy (Q = 501.31 kJ/mol) required for calculating the Zener–Hollomon parameter. An expression for describing the peak flow stress is obtained in the form of a hyperbolic function of the Zener–Hollomon parameter. This expression describes the experimental data array with a high accuracy and can be used to estimate the required energy–force parameters of forging and rolling equipment. A comparative estimation of the hot ductility of the super duplex steel is performed by finding the strain corresponding to the appearance of the first macrocracks on the specimen surface. At a strain rate of 10 s–1 (which is characteristic of hot forging processes), the safest deformation temperature range of the steel is shown to be 1150–1250°C, in which austenite undergoes partial dynamic recrystallization reducing the risks of cracking. [ABSTRACT FROM AUTHOR]- Published
- 2023
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61. The effect of attapulgite powder on the mechanical properties of cement mortar containing optimum silica fume percentage.
- Author
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Abdulrasool, Abdulrasool Thamer, Hussain, Wail Asim Mohammad, Kadhim, Noor R., Mohammed, Safaa S., and Abdulhadi, Ahmed M.
- Subjects
SILICA fume ,MORTAR ,CONCRETE additives ,FULLER'S earth ,FLEXURAL strength testing ,CEMENT ,CONCRETE industry ,CONCRETE mixing - Abstract
The current concern for the concrete industry is to make concrete more sustainable and more environmentally friendly. So, the objective of this study is to determine the optimum amount of Attapulgite clay to cement in concrete with an optimum percentage of silica fume replacement to provide the most durable concrete while enhancing its mechanical characteristics. Different percentages of attapulgite were used, including 0%, 4%, 8%, 12%, and 16%, which were prepared for testing the compressive strength and flexural strength. Other properties of mortar concrete were measured, such as absorption and density, to investigate the effect of attapulgite clay on these properties. The findings indicate that using attapulgite clay in replacement of cement content results in sustainable concrete with enhanced mechanical properties for percentages of 4% the compressive strength increased by 9% in comparison with the control sample. While for flexural strength the 8% percentage was the highest with only 3% reduction from the reference sample. In general all concrete mortar mixes that were prepared with different attapulgite percentages results in acceptable mechanical properties. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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62. Increasing the Pozzolanic Reactivity of Recovered CDW Cement Stone by Mechanical Activation †.
- Author
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Szabó, Roland, Szűcs, Máté, Ambrus, Mária, and Mucsi, Gábor
- Subjects
PORTLAND cement ,CONSTRUCTION industry ,FOURIER transform infrared spectroscopy ,PARTICLE size distribution ,GRINDING & polishing - Abstract
The study focuses on enhancing the reactivity of the fine size fraction of construction and demolition waste (CDW) by mechanical activation in a stirred media mill. Systematic measurements were carried out to monitor the change in cement stone reactivity. The fine size fraction of CDW (<200 µm) was milled in a stirred media mill for 1, 3, 5, and 10 min. The dispersion characteristics (particle size distribution, specific surface area (SSA)) of the mechanically activated CDW powder were determined using a laser particle size analyzer. Changes in the structure of the mechanically activated CDW powder particles were determined by Fourier transform infrared spectroscopy (FTIR) measurements. The effect of the mechanical activation on the pozzolanic reactivity of CDW powder was measured by lime sorption test and compressive strength measurements. The results clearly show that Portland cement can be replaced with mechanically activated CDW powder; however, increasing its amount decreases the strength. Furthermore, the grinding fineness significantly influenced the pozzolanic reactivity of the mechanically activated CDW powder, and thus the strength of the specimens. The CDW powder milled for 10 min had 51% more lime uptake than the initial CDW sample, and the specimen strength at the age of 7 days was 23% higher using ground CDW powder than using initial CDW at a 20% cement replacement ratio. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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63. A comprehensive analysis for classification and regression of surface points based on geodesics and machine learning algorithms.
- Author
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Bulut, Vahide
- Subjects
MACHINE learning ,PATTERN recognition systems ,CLASSIFICATION algorithms ,REGRESSION analysis ,GEODESICS ,FEATURE extraction - Abstract
Purpose: Feature extraction from 3D datasets is a current problem. Machine learning is an important tool for classification of complex 3D datasets. Machine learning classification techniques are widely used in various fields, such as text classification, pattern recognition, medical disease analysis, etc. The aim of this study is to apply the most popular classification and regression methods to determine the best classification and regression method based on the geodesics. Design/methodology/approach: The feature vector is determined by the unit normal vector and the unit principal vector at each point of the 3D surface along with the point coordinates themselves. Moreover, different examples are compared according to the classification methods in terms of accuracy and the regression algorithms in terms of R-squared value. Findings: Several surface examples are analyzed for the feature vector using classification (31 methods) and regression (23 methods) machine learning algorithms. In addition, two ensemble methods XGBoost and LightGBM are used for classification and regression. Also, the scores for each surface example are compared. Originality/value: To the best of the author's knowledge, this is the first study to analyze datasets based on geodesics using machine learning algorithms for classification and regression. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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64. A Deformed Wedge‐Top Basin Inverted During the Collapse of the Variscan Belt: The Permo‐Carboniferous Lorraine Basin (NE France).
- Author
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Hemelsdaël, R., Averbuch, O., Beccaletto, L., Izart, A., Marc, S., Capar, L., and Michels, R.
- Abstract
A new structural model is presented for the Permo‐Carboniferous Lorraine Basin (NE France), a major intramountain basin that developed during the latest stages of the Variscan orogeny (ca. 315–270 Ma). Digitalized well logs and reprocessed seismic data were used to decipher the kinematic evolution of this basin located along the Rhenohercynian orogenic suture zone. The basin was initiated during the late collision stage (Early to Middle Pennsylvanian) in a wedge‐top position upon the Saxothuringian retro‐wedge. The syn‐orogenic sequence is delimited to the north by the major SE‐verging Metz Thrust, which is part of the backthrust system that propagated during Middle Pennsylvanian (Late Westphalian). Seismic data provide evidence of negative tectonic inversion, allowing the formation of syn‐rift depocenters (Late Pennsylvanian‐Early Permian) above the former anticlines. Erosion of these anticlines results in a major unconformity marking the onset of post‐orogenic collapse. The late Early Permian shortening (Saalian phase) is suggested to reactivate former thrusts and normal faults, thus generating late uplift of the basin. The post‐orogenic phase is complex and diachronous at basin scale, and both compression and extension can be recorded in the same area over a short period (<10 Myr). The Late Carboniferous negative tectonic inversion along the Rhenohercynian suture zone is proposed to result from the lithospheric delamination of the Variscan orogenic roots. The associated upwelling of asthenospheric material is recorded by intense magmatic activity, and can be, in turn, considered as the main trigger for the subsequent thermal subsidence of the Mesozoic Paris Basin. Key Points: A new structural model of the Permo‐Carboniferous Lorraine Basin (NE France) is proposed based on 438 km of reprocessed seismic dataThis major intramountain basin developed during Early‐Middle Pennsylvanian times as a wedge‐top basin upon the Variscan Saxothuringian retro‐wedgeExtensional reactivation of thrusts controlled the development of syn‐rift depocenters above the former thrust‐related anticlines [ABSTRACT FROM AUTHOR]
- Published
- 2023
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65. Dynamic Change of Rh Oxidation State During Lean‐Rich Perturbation and Light‐Off of Three‐Way Catalysis Analysed using In Situ Diffuse Reflectance UV‐vis Spectroscopy.
- Author
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Fujiwara, Ayumi, Tsurunari, Yutaro, Iwashita, Shundai, Yoshida, Hiroshi, Ohyama, Junya, and Machida, Masato
- Subjects
OXIDATION states ,ULTRAVIOLET-visible spectroscopy ,REFLECTANCE spectroscopy ,CATALYSIS ,TIME-resolved spectroscopy - Abstract
This study investigated the redox behaviour of Rh in three‐way catalysts (TWC) using time‐resolved in situ diffuse reflectance UV‐vis spectroscopy in different modes with air‐to‐fuel ratio (A/F) step, A/F perturbation, and temperature ramping. When Rh/ZrO2−CeO2 (Rh/ZC) and Rh/ZrO2 (Rh/Z) containing fully oxidised Rh were treated at 400 °C under simulated TWC conditions with A/F stepping from 15.0 (fuel‐lean) to 14.1 (fuel‐rich), a steep increase in the metallic fraction (Rh0/Rh) and a simultaneous increase in Kubelka–Munk function (ΔKM) at λ=450 nm occurred near the stoichiometric point (A/F=14.6). Metallic Rh became abundant until A/F=14.1, where the largest ΔKM was attained. In the A/F perturbation mode, the Rh oxidation state fluctuated with repetitious switching of rich and lean gas feeds, but the ΔKM oscillation amplitude was lessened for Rh/ZC compared to Rh/Z because of the oxygen‐scavenging function of ZC. Furthermore, the changes in Rh oxidation state during TWC light‐off were analysed in the temperature‐ramping mode. Under rich conditions, Rh0/Rh and ΔKM increased after 200 °C, where the formation of Rh metal led to efficient conversions of CO and NO. However, metallic Rh did not appear during light‐off under the lean condition, where NO conversion was negligible. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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66. Forest-PointNet: A Deep Learning Model for Vertical Structure Segmentation in Complex Forest Scenes.
- Author
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Ma, Zhibin, Dong, Yanqi, Zi, Jiali, Xu, Fu, and Chen, Feixiang
- Subjects
DEEP learning ,POINT cloud ,FEATURE extraction - Abstract
The vertical structure of forest ecosystems influences and reflects ecosystem functioning. Terrestrial laser scanning (TLS) enables the rapid acquisition of 3D forest information and subsequent reconstruction of the vertical structure, which provides new support for acquiring forest vertical structure information. We focused on artificial forest sample plots in the north-central of Nanning, Guangxi, China as the research area. Forest sample point cloud data were obtained through TLS. By accurately capturing the gradient information of the forest vertical structure, a classification boundary was delineated. A complex forest vertical structure segmentation method was proposed based on the Forest-PointNet model. This method comprehensively utilized the spatial and shape features of the point cloud. The study accurately segmented four types of vertical structure features in the forest sample location cloud data: ground, bushes, trunks, and leaves. With optimal training, the average classification accuracy reaches 90.98%. The results indicated that segmentation errors are mainly concentrated at the branch intersections of the canopy. Our model demonstrates significant advantages, including effective segmentation of vertical structures, strong generalization ability, and feature extraction capability. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
67. Disruption of LEAF LESION MIMIC 4 affects ABA synthesis and ROS accumulation in rice.
- Author
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Hao Wu, Gaoxing Dai, Rao Yuchun, Kaixiong Wu, Junge Wang, Peng Hu, Yi Wen, Yueying Wang, Lixin Zhu, Bingze Chai, Jialong Liu, Guofu Deng, Qian Qian, and Jiang Hu
- Subjects
RICE yields ,REACTIVE oxygen species ,APOPTOSIS ,ZEAXANTHIN ,ABSCISIC acid - Abstract
Lesion mimic mutants (LMMs) are advantageous materials for studying programmed cell death (PCD). Although some rice LMM genes have been cloned, the diversity of functions of these genes indicates that the mechanism of cell death regulation in LMMs needs further study. In this study, we identified a rice light-dependent leaf lesion mimic mutant 4 (llm4) that showed abnormal chloroplast structure, photoinhibition, reduced photosynthetic protein levels, massive accumulation of reactive oxygen species (ROS), and PCD. Map-based cloning and complementation testing revealed that LLM4 encodes zeaxanthin epoxidase (ZEP), an enzyme involved in the xanthophyll cycle, which functions in plant photoprotection, ROS scavenging, and carotenoid and abscisic acid (ABA) biosynthesis. The ABA content was decreased, and the contents of 24 carotenoids differed between the llm4 mutant and the wild type (WT). The llm4 mutant showed reduced dormancy and greater sensitive to ABA than the WT. We concluded that the mutation of LLM4 resulted in the failure of xanthophyll cycle, in turn causing ROS accumulation. The excessive ROS accumulation damaged chloroplast structure and induced PCD, leading eventually to the formation of lesion mimics. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
68. Scientific mapping of smart tourism: a content analysis study.
- Author
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Özköse, Hakan, Oğuz, Hande Uyar, and Aslan, Ahmet
- Subjects
CONTENT analysis ,CONCEPTUAL structures ,TOURISM ,TOURISM websites ,SCIENTIFIC method ,DATABASES - Abstract
Smart tourism can be thought of as a whole ecosystem of smart tourists, smart technologies, and smart businesses. There are more than 952 academic studies related to Smart Tourism in the Web of Science (WoS) database. Therefore, it would be useful to examine the conceptual structure and thematic development of Smart Tourism. This study is to analyze the field of smart tourism using scientific mapping methods. Bibliometric data of 489 articles were downloaded from the WoS. This paper first conducts a co-occurrence analysis using VosViewer to determine the prominent terms and connections between them. Then, a content analysis is performed using SciMat to gain a deeper understanding of the field and its evolution from 2013 to 2022 for Smart Tourism. In this context, strategic maps, thematic networks of topics, and an evolutionary map were obtained to understand the field better by using SciMAT. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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69. Gray Model Study of Strength and Pore Structure of Recycled Concrete Powder (RCP) Concrete Based on Low-Field NMR Technology.
- Author
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Hou, Yongli, Yu, Zhengxing, Zhang, Jianhua, Yang, Hongrui, and Song, Weiqing
- Subjects
POROSITY ,CONCRETE curing ,CONCRETE ,FLEXURAL strength ,TENSILE strength ,POWDERS - Abstract
In order to improve the resource utilization of recycled concrete powder (RCP), this study aimed to investigate the effect of RCP admixture, curing age, and alkali excitation on the strength of RCP concrete. In addition, the pore structure characteristics of RCP concrete were analyzed in combination with low-field NMR. Furthermore, a gray predictive GM (1, 4) model was established to predict the mechanical properties of the concrete based on the pore structure parameters, especially the compressive and flexural tensile strengths. The results of the study indicate that the mechanical properties, namely compressive strength and flexural strength, of RCP concrete exhibit an initial increase followed by a subsequent decrease with increasing RCP content at 3 d, 7 d, and 28 d curing ages. In particular, the concrete exhibits the highest mechanical properties when the RCP content reaches 10%. As the curing age increases, the RCP gradually achieves full hydration, resulting in further refinement of the concrete pores and a denser structure, which subsequently improves the mechanical properties. In addition, the strength growth rate of alkali-excited recycled concrete (ARC) showed a continuous increase, indicating that alkali excitation increasingly improved the mechanical properties of the concrete. Furthermore, the study accurately predicted the mechanical properties of RCP concrete by using GM (1, 4) prediction models for its compressive strength and flexural tensile strength using pore characteristic parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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70. Explorando la problemática de la deforestación en la Amazonía ecuatoriana.
- Author
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Gavilanes González, Erika Paola, López Zea, Marcelo Alejandro, López Gavilanes, Erick Alejandro, and Chávez Fonseca, Lila Galicia
- Subjects
WILDLIFE conservation ,LUNGS ,RESOURCE exploitation ,TRANSVERSAL lines ,HERMENEUTICS - Abstract
Copyright of Dilemas Contemporáneos: Educación, Política y Valores is the property of Dilemas Contemporaneos: Educacion, Politica y Valores and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
71. Dispersion of copper oxide species on nanostructured ceria.
- Author
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Ning, Jing, Dong, Chunyan, Li, Mingrun, Zhou, Yan, and Shen, Wenjie
- Subjects
COPPER oxide ,DISPERSION (Chemistry) ,CERIUM oxides ,CHARGE transfer ,CATALYTIC activity ,SPECIES - Abstract
Copper oxides species deposited on ceria rods, particles, and cubes were examined for low-temperature oxidation of CO. It was found that the shape of ceria altered the dispersion and chemical state of copper species considerably. CuO
x monolayers and bilayers were formed on ceria rods and particles, while multilayers and faceted particles co-existed on ceria cubes. The formation of Cu+ species at the copper–ceria interface involved a significant charge transfer from copper oxides to the ceria surface via a strong electronic interaction, which was more pronounced on ceria rods. The concentrations of surface Cu+ and oxygen vacancies followed the order rods > particles > cubes, in line with their catalytic activity for CO oxidation at 343 K. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
72. The promise of portable remote auditory stimulation tools to enhance slow‐wave sleep and prevent cognitive decline.
- Author
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Zeller, Céline J., Züst, Marc A., Wunderlin, Marina, Nissen, Christoph, and Klöppel, Stefan
- Subjects
ACOUSTIC stimulation ,SLOW wave sleep ,COGNITION disorders ,SLEEP physiology ,OLDER people ,NON-REM sleep - Abstract
Summary: Dementia is the seventh leading cause of mortality, and a major source of disability and dependency in older individuals globally. Cognitive decline (and, to a lesser extent, normal ageing) are associated with sleep fragmentation and loss of slow‐wave sleep. Evidence suggests a bidirectional causal link between these losses. Phase‐locked auditory stimulation has emerged as a promising non‐invasive tool to enhance slow‐wave sleep, potentially ameliorating cognitive decline. In laboratory settings, auditory stimulation is usually supervised by trained experts. Different algorithms (simple amplitude thresholds, topographic correlation, sine‐wave fitting, phase‐locked loop, and phase vocoder) are used to precisely target auditory stimulation to a desired phase of the slow wave. While all algorithms work well in younger adults, the altered sleep physiology of older adults and particularly those with neurodegenerative disorders requires a tailored approach that can adapt to older adults' fragmented sleep and reduced amplitudes of slow waves. Moreover, older adults might require a continuous intervention that is not feasible in laboratory settings. Recently, several auditory stimulation‐capable portable devices ('Dreem®', 'SmartSleep®' and 'SleepLoop®') have been developed. We discuss these three devices regarding their potential as tools for science, and as clinical remote‐intervention tools to combat cognitive decline. Currently, SleepLoop® shows the most promise for scientific research in older adults due to high transparency and customizability but is not commercially available. Studies evaluating down‐stream effects on cognitive abilities, especially in patient populations, are required before a portable auditory stimulation device can be recommended as a clinical preventative remote‐intervention tool. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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73. Study of Microstructure, Crystallographic Phases and Setting Time Evolution over Time of Portland Cement, Coarse Silica Fume, and Limestone (PC-SF-LS) Ternary Portland Cements.
- Author
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Menéndez, Esperanza, Sanjuán, Miguel Ángel, and Recino, Hairon
- Subjects
SILICA fume ,PORTLAND cement ,LIMESTONE ,POZZOLANIC reaction ,MICROSTRUCTURE ,NATURAL resources - Abstract
The use of silica fume as a partial replacement for Ordinary Portland Cement provides a wide variety of benefits, such as reduced pressure on natural resources, reduced CO
2 footprint, and improved mechanical and durability properties. The formation of more stable crystallographic phases in the hardened cement paste can promote resistance to concrete attacks. However, using coarse silica fume may result in lower expenses and shorter workdays. In this work, coarse silica fume was used as a partial replacement of cement, by weight, at 3%, 5%, and 7%, and it was used as limestone filler at different particle sizes. The size of coarse silica fume used was 238 μm. The microstructural, compositional analysis, and crystalline phase content of mixed cements at different ages were evaluated. The addition of coarse silica fume and limestone promoted pore refinement of the composites and increased the calcium and silica content. The filling effect of fine limestone and coarse silica fume particles, as well as the formation of CSH gel, was found to be the main reason for the densified microstructure. The contributions of combined coarse silica fume and limestone improve the stability of CSH gels and pozzolanic reaction. [ABSTRACT FROM AUTHOR]- Published
- 2023
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- View/download PDF
74. Numerical modeling of the dam-break flood over natural rivers on movable beds.
- Author
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Issakhov, Alibek, Borsikbayeva, Aliya, Abylkassymova, Aizhan, Issakhov, Assylbek, and Khikmetov, Askar
- Subjects
RIVER channels ,NEWTONIAN fluids ,NON-Newtonian fluids ,DAMS ,THREE-dimensional flow ,MUDFLOWS - Abstract
In the present work, a modified numerical model was developed to simulate the water flow during a dam break with the mud layer transfer of different heights, consisting of three phases (water, air, and a phase for deposition). To carry out a numerical simulation of this process, a mathematical model based on the VOF (volume of fluid) method was modified, taking into account the movement of the water-free surface, which is carried out by the movement of water flow based on the Newtonian fluid model, and the movement of mud impurities is based on the non-Newtonian fluid model. Validation of the constructed model for the influence of three-dimensional features of the flow on morphological changes is carried out by a modified mathematical model and compared with the results of calculation for two-dimensional (2D) and three-dimensional (3D) models. The proposed method for modeling is applied on a real complex terrain, which was based on the Kargalinka – a river in Almaty and the Almaty region of Kazakhstan, the right tributary of the Kaskelen River. Simulation analysis is carried out for cases with different deposit heights. All results of the numerical simulation can be visually viewed using graphs and illustrations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
75. The Microstructure Evolution and Dynamic Softening Mechanism of a 00Cr27Ni7Mo5N Hyper Duplex Stainless Steel.
- Author
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Wang, Hang, Wang, Aiqin, Li, Changyi, Yu, Xingsheng, Xie, Jingpei, and Liu, Chenlu
- Subjects
MICROSTRUCTURE ,STRAIN rate ,RECRYSTALLIZATION (Metallurgy) ,TRANSMISSION electron microscopy ,STAINLESS steel ,AUSTENITE ,DUPLEX stainless steel - Abstract
The microstructure evolution and dynamic softening mechanism of a 00Cr27Ni7Mo5N hyper duplex stainless steel during uniaxial hot compression are investigated based on the electron backscattered diffraction and transmission electron microscopy. The (sub)grains of ferrite are significantly refined at the temperature of 1050 °C using the strain rate of 0.01 to 1 s−1. The softening mechanism within ferrite are classified as continuous dynamic recrystallization (CDRX). However, the dynamic softening within ferrite is diminished at a strain rate of 10 s−1. A softening mechanism analogous to discontinuous dynamic recrystallization (DDRX) is observed in the ferrite/austenite interphase mantle regions. The dynamic softening within austenite is remarkably limited at the temperature of 1050 °C, which appears to be complex‐shaped deformation bands. There are a small number of recrystallized grains within austenite. The dynamic softening of hyper duplex stainless steel is dominated by ferrite. The formation of DRX nuclei and growth of austenite by strain‐induced boundary migration mechanism is observed at the temperature of 1250 °C with different strain rates, indicating its softening mechanism is akin to DDRX. In addition, the increase in temperature and the decrease in strain rate is favorable to the dynamic softening of austenite. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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- View/download PDF
76. La Ley sobre responsabilidad penal de los menores en España.
- Author
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DÍAZ-MAROTO Y VILLAREJO, JULIO
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JUVENILE offenders ,CRIMINAL liability ,MINORS ,AGE ,MINORITIES - Abstract
Copyright of Nuevo Foro Penal is the property of Universidad EAFIT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
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- View/download PDF
77. Interpretación, verdad y la forma lógica del discurso interpretativo.
- Author
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Chiassoni, Pierluigi
- Abstract
Copyright of Analisi e Diritto is the property of Edizioni ETS s.r.l. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
78. The role of mantle upwelling on the thermal history of the Tertiary‐Piedmont Basin at the Alps‐Apennines tectonic boundary.
- Author
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Amadori, Chiara, Maino, Matteo, Marini, Mattia, Casini, Leonardo, Carrapa, Barbara, Jepson, Gilby, Hayes, Robert George, Nicola, Chiara, Reguzzi, Simone, and Di Giulio, Andrea
- Subjects
TURBIDITES ,OLIGOCENE Epoch ,EOCENE Epoch ,ACCRETIONARY wedges (Geology) ,APATITE ,RIFTS (Geology) ,FLUID inclusions - Abstract
The Tertiary‐Piedmont Basin (NW Italy) is an episutural basin that developed from the late Eocene on the Alps–Apennines tectonic junction. Several coeval geodynamic processes, including the loading and exhumation of the Western Alps, the outward migration of the Apennine accretionary wedge and the opening of the Liguro‐Provençal rift basin, controlled the basin evolution. We integrate fluid‐inclusion microthermometry, low‐temperature thermochronology and burial history with numerical modelling to constrain the palaeo‐geothermal gradients required and evaluate the mechanisms that governed the basin thermal history. Apatite fission‐track and (U‐Th‐Sm)/He analyses of the basal late Eocene turbidites show reset ages of ca. 25 and 20 Ma, respectively, which require temperatures to be >120°C. Homogenization temperatures up to ca. 130°C from fluid inclusion analyses from authigenic minerals confirm the thermochronometric data, supporting a significant post‐depositional heating in the lower sequence of the basin. Stratigraphic reconstructions and decompaction of the basin fill indicate that the maximum burial experienced by the basal strata at 25 Ma is 2.3 ± 0.1 km, which is not sufficient to reset the AFT thermochronometric system when applying a typical geothermal gradient (ca. 20–30°C/km). An elevated geothermal gradient of 45 ± 5°C/km is thus necessary to explain the thermochronometric dates and the elevated thermal signature at shallow depths. 2D numerical simulations indicate that such an elevated palaeo‐geothermal gradient can be best explained by mantle upwelling, consistent with crustal thinning caused by the inception of the Liguro‐Provençal rift basin and related outward migration of the Alpine and Apennine fronts during the Oligocene. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
79. Ir‐CoO Active Centers Supported on Porous Al2O3 Nanosheets as Efficient and Durable Photo‐Thermal Catalysts for CO2 Conversion.
- Author
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Tang, Yunxiang, Zhao, Tingting, Han, Hecheng, Yang, Zhengyi, Liu, Jiurong, Wen, Xiaodong, and Wang, Fenglong
- Subjects
NANOSTRUCTURED materials ,CATALYSTS ,FOURIER transform infrared spectroscopy ,ELECTRON temperature ,CATALYTIC hydrogenation ,NUMERICAL calculations ,REFLECTANCE spectroscopy - Abstract
Photo‐thermal catalytic CO2 hydrogenation is currently extensively studied as one of the most promising approaches for the conversion of CO2 into value‐added chemicals under mild conditions; however, achieving desirable conversion efficiency and target product selectivity remains challenging. Herein, the fabrication of Ir‐CoO/Al2O3 catalysts derived from Ir/CoAl LDH composites is reported for photo‐thermal CO2 methanation, which consist of Ir‐CoO ensembles as active centers that are evenly anchored on amorphous Al2O3 nanosheets. A CH4 production rate of 128.9 mmol gcat⁻1 h⁻1 is achieved at 250 °C under ambient pressure and visible light irradiation, outperforming most reported metal‐based catalysts. Mechanism studies based on density functional theory (DFT) calculations and numerical simulations reveal that the CoO nanoparticles function as photocatalysts to donate electrons for Ir nanoparticles and meanwhile act as "nanoheaters" to effectively elevate the local temperature around Ir active sites, thus promoting the adsorption, activation, and conversion of reactant molecules. In situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) demonstrates that illumination also efficiently boosts the conversion of formate intermediates. The mechanism of dual functions of photothermal semiconductors as photocatalysts for electron donation and as nano‐heaters for local temperature enhancement provides new insight in the exploration for efficient photo‐thermal catalysts. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
80. Characteristics of Alkali-Activated Slag Filler and Its Effects on Rheology of Asphalt Mastic.
- Author
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Do, Ngoc-Duy, Liao, Min-Chih, Mamuye, Yibas, and Vo, Duy-Hai
- Subjects
ASPHALT ,RHEOLOGY ,SLAG ,MINE waste ,X-ray fluorescence ,MASS production ,SCANNING electron microscopes - Abstract
Attributes of filler play a significant role in the overall performance of asphalt mixtures through their direct influences on asphalt mastic. Alkali-activated slag (AAS), which is currently in the beta stage of development, is a promising and innovative cementitious replacement material. However, mass production AAS for experimental use generates significant quantities of waste discharge. The purpose of this study was to explore the potential of using AAS waste as a mineral filler in asphalt mastic. Properties of AAS waste were assessed and compared to limestone (LS) filler using scanning electron microscope (SEM), X-ray diffraction (XRD) analysis, X-ray fluorescence (XRF) spectrometry, laser particle size analysis, hydrophilic coefficient, mesoscopic void characteristic, and Rigden void tests. The penetration, softening point, Brookfield viscosity, and rheological properties of the asphalt mastic samples made, respectively, using AAS and LS fillers, were examined using complex modulus (G*), phase angle (δ), and rutting factor (G*/sinδ) results and two interaction indices (ΔG* and K–B–G*). Furthermore, models used to test relative viscosity (ηr) were applied to predict the complex viscosity (η*) of the samples. Results indicated that comparing to LS filler, AAS filler was shown to deliver superior compatibility to asphalt matrix, and the properties of the asphalt mastic containing AAS filler were superior to those of the asphalt mastic containing LS filler. Of particular note, the models used to predict relative viscosity demonstrated validity in predicting the complex viscosity of asphalt mastics. The results support using AAS filler as a replacement for LS filler in asphalt mastic. Further research should be conducted to maximize the potential benefits of using AAS filler in asphalt mixtures. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
81. Impedance evaluation of textile electrodes for EEG measurements.
- Author
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Rahman, S M Musfequr, Mattila, Henna, Janka, Marika, and Virkki, Johanna
- Subjects
ELECTRODES ,SILVER chloride ,ELECTROENCEPHALOGRAPHY ,SALINE waters ,DRINKING water - Abstract
In this paper, we evaluated the impedance of textile electrodes for electroencephalography measurements. We compared the commercially available standard dry silver/silver chloride dry electrodes, copper-based, and silver-based textile electrodes by measuring impedance on the skin. First, on dry skin, the impedance range of the electrodes was 93–350 kΩ at 0 min; after 60 min, the range was 20–56 kΩ. The commercial electrode showed the lowest impedance of 20 kΩ, and the silver-based textile electrode showed the highest impedance of 56 kΩ in dry skin conditions after 60 min. When tap water was applied as an electrolyte, the impedance range was 13–15 kΩ at 0 min; after 60 min, the range was 17–22 kΩ for all three types of electrodes. In this case, the copper-based textile electrode showed the lowest impedance of 17 kΩ and the commercial electrode showed the highest impedance of 22 kΩ after 60 min. When saline water was applied as an electrolyte, at 0 min, the impedance range was 8–11 kΩ; after 60 min, the range became 11–12 kΩ for all three types of electrodes. Thus, all electrodes showed similar results. It was concluded that the copper-based textile electrodes were more suitable than the silver-based textile electrodes and comparable to commercial electrodes regarding impedance in all three skin conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
82. The Influence of Recycled Cement, Fly Ash, and Magnesium Oxide on the Mechanical Performance of Sustainable Cementitious Materials.
- Author
-
Sequeira, Lucas, Cantero, Blas, Bravo, Miguel, de Brito, Jorge, and Medina, César
- Subjects
MORTAR ,FLY ash ,ULTRASONIC testing ,MAGNESIUM oxide ,CEMENT ,ECOLOGICAL impact - Abstract
In the construction industry, cement is the most widely used material. So, to achieve greater sustainability in this industry, it is imperative to improve the sustainability of this material. One way to reduce the ecological footprint of cement is to replace it, even if partially, with other more sustainable materials that can act as binders. This paper analyses the mechanical properties of more sustainable mortars containing recycled cement (RC), fly ash (FA), and magnesium oxide (MgO). Different types of binary, ternary, and quaternary mortars were used: containing recycled cement (5% and 10%), fly ash (10% and 20%), and MgO (7.5% and 15%). An experimental campaign was carried out analysing air content, density, compressive and flexural strengths, modulus of elasticity, and ultrasonic pulse velocity. The ternary mortars showed decreases between 0.4% (M-5RC10FA) and 35.3% (M-10RC15Mg) in terms of compressive strength at 365 days (compared to RM), when the theoretically expected decrease (the sum of the decreases obtained with the individual incorporation of these materials) would be between 16.6% and 41.5%, respectively. The results obtained allow for concluding that the joint use of these materials in ternary mortars improves the mechanical capacity, relative to the individual incorporation of each material in binary mortars. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
83. Mechanical behavior of cementitious composites reinforced with the fiber of sugarcane bagasse and glass wool waste.
- Author
-
Preve Machado, J., da Silva, T. C., Henrique Borgert, C., Rosso Neto, L., Batista Gesuino, D., de Oliveira, J. R., Elias Allievi Frizon, T., Fardin Grillo, F., and Junca, E.
- Subjects
FIBROUS composites ,GLASS waste ,NATURAL fibers ,BAGASSE ,SUGARCANE ,POWDERED glass ,CEMENT composites - Abstract
The use of natural fibers and powdered glasses can improve the mechanical properties of the concretes and increase the cracks resistance generated by tensile and concrete stresses. Thus, the aim of this paper is to evaluate the mechanical behavior of concrete with the addition of fibers of sugarcane bagasse and/or glass wool. Physical, chemical and morphological characterizations were performed. Sugarcane bagasse was chemically treated. Concretes were produced containing additions of ground glass wool and/or fibers of sugarcane bagasse cured in 28 days. The results of this research showed that the exclusive addition of glass wool (10%) in concrete contributed to higher values of compressive strength, flexion tensile and diametrical compression tensile, reaching 34.22 MPa, 6.65 MPa and 16.44 MPa, respectively. The ground glass wool contributed to the reduction in the concrete porosity (void index equal to 9.38%). [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
84. Effects of Solid Waste Reutilization on Performance of Pervious Concrete: A Review.
- Author
-
Xie, Hui-Zhu, Li, Leo Gu, Ng, Pui-Lam, and Liu, Feng
- Abstract
With rapid urban development, natural aggregate resources have become scarce and a large number of ageing buildings are being demolished, which has resulted in a significant reduction in natural resources and a large increase in construction waste. Therefore, the reuse of solid waste, including waste powder and recycled aggregate, has attracted more and more attention. Additionally, as a prominent way to alleviate the urban heat island effect and manage stormwater runoff, pervious concrete has been widely studied and applied. In this paper, the effects of waste powder (fly ash, volcanic powder and blast furnace slag) and recycled aggregate (recycled concrete aggregate and recycled brick aggregate) on the mechanical properties, water permeability, water filtration and durability of pervious concrete are summarized and introduced, and some prospects are put forward. From the literature review, it can be found that adding the appropriate amount of solid waste or applying proper treatment methods to solid waste will not bring negative effects; rather, it would even improve the performance attributes of pervious concrete. Therefore, the use of solid waste in pervious concrete has great potential for urban construction and environmental protection. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
85. EFFECT OF COOLING RATES AND INTERMEDIATE SLAB BLANK THICKNESS ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF THE X70 PIPELINE STEEL.
- Author
-
HAIJIAN XU, CHUFEI HAN, PINGYUAN YAN, BAOCHUN ZHAO, and WEIJUAN LI
- Subjects
MICROSTRUCTURE ,STEEL ,PIPELINE corrosion ,STEEL pipe ,FERRITES - Abstract
In this study, the microstructures and mechanical properties of X70 pipeline steels produced with varying Mo contents, accelerated cooling rate and intermediate slab blank thickness are systematically investigated. Results showed that the microstructures and mechanical properties of the X70 pipeline steels were strongly affected by Mo addition. The pearlite and proeutectoid ferrite formation is obviously inhibited in containing-Mo steel and the acicular ferrite (AF) is obtained in a wide range of cooling rates. With the increasing the cooling rates, the AF constituent amount increases. The grains can be refined by increasing the thickness of intermediate slab for enhancing the cumulative reduction rates, and meanwhile increase the number density of precipitates. It was proved by simulation and industrial trials that the low-alloy X70 pipeline steels can be produced increasing cooling rates and the thickness of intermediate slab without strength and toughness degradation which also reduce alloy cost. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
86. Sistema de realidad virtual para teleoperación de robots tipo centauro
- Author
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Cruz, Christyan, Juez, Jorge, Cerro, Jaime del, Barrientos, Antonio, Cruz, Christyan, Juez, Jorge, Cerro, Jaime del, and Barrientos, Antonio
- Abstract
[Resumen] Los robots de búsqueda y rescate juegan un papel fundamental en la exploración de entornos peligrosos y desastres naturales. Su empleo permite a los equipos de rescate trabajar de manera más segura y eficiente en entornos de alto riesgo. La implementación de sistemas de teleoperación mediante realidad virtual (RV) permite a los usuarios controlar estos robots de forma remota con un alto grado de precisión. En este artículo se analiza, diseña e implementa un sistema de telecontrol para la operación remota del torso robotizado de un robot tipo centauro (formado por 11 servomotores) con capacidad de manipulación dual, utilizando un sistema RV. El desarrollo se ha realizado en dos fases. En la primera, se ha llevado a cabo el modelado e implementación física del torso del robot acoplado a diferentes bases móviles (robot cuadrúpedo y de orugas). En la segunda se ha creado el entorno virtual de teleoperación mediante Unity3D y ha realizado la conexión de este con el sistema real mediante Unity-Matlab. Para llevar a cabo las pruebas, se han planteado una serie de retos en interiores y exteriores, que van desde la manipulación dual de escombros, asistencia a víctimas con equipos de primeros auxilios como botiquines u oxígeno. Los principales resultados han mostrado un incremento en la confianza del operador para llevar tareas de precisión y contacto, frente a métodos de telecontrol convencionales., [Abstract] Search and rescue robots have a critical role in exploring dangerous environments and natural disasters. Its use allows rescue teams to work more safely and efficiently in high-risk environments. Implementing teleoperation systems through virtual reality (VR) allows users to control these robots remotely with high precision. This article analyzes, designs and implements a remote control system for the remote operation of the robotic torso of a centaur-type robot (formed by 11 servomotors) with dual manipulation capacity using a VR system. The development has been carried out in two phases. First, the modelling and physical implementation of the robot’s torso coupled to different mobile bases (quadruped and tracked robot) have been carried out. In the second, the virtual teleoperation environment has been created using Unity3D, and the connection with the real system has been made using Unity-Matlab. Different challenges have been raised indoors and outdoors to carry out the tests phase, from the dual manipulation f debris to victims’ assistance with first aid equipment, such as first aid kits or oxygen. Compared to conventional remote control methods, the main results have shown an increase in the operator’s confidence to carry out precision and contact tasks.
- Published
- 2023
87. Photo‐Induced Switching of CO2 Hydrogenation Pathway towards CH3OH Production over Pt@UiO‐66‐NH2(Co).
- Author
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Chen, Jianmin, Wang, Yajing, Wang, Fengliang, and Li, Yingwei
- Subjects
CHARGE exchange ,WATER-gas ,IRRADIATION ,CARBON dioxide ,HETEROGENEOUS catalysis ,HYDROGENATION - Abstract
It is highly desired to achieve controllable product selectivity in CO2 hydrogenation. Herein, we report light‐induced switching of reaction pathways of CO2 hydrogenation towards CH3OH production over actomically dispersed Co decorated Pt@UiO‐66‐NH2. CO, being the main product in the reverse water gas shift (RWGS) pathway under thermocatalysis condition, is switched to CH3OH via the formate pathway with the assistance of light irradiation. Impressively, the space‐time yield of CH3OH in photo‐assisted thermocatalysis (1916.3 μmol gcat−1 h−1) is about 7.8 times higher than that without light at 240 °C and 1.5 MPa. Mechanism investigation indicates that upon light irradiation, excited UiO‐66‐NH2 can transfer electrons to Pt nanoparticles and Co sites, which can efficiently catalyze the critical elementary steps (i.e. CO2‐to‐*HCOO conversion), thus suppressing the RWGS pathway to achieve a high CH3OH selectivity. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
88. Emotional intelligence as a mediator in the relationship between neuroticism and L2 achievement.
- Author
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Ożańska-Ponikwia, Katarzyna, Piechurska-Kuciel, Ewa, and Skałacka, Katarzyna
- Subjects
NEUROTICISM ,PERSONALITY ,EMOTIONAL intelligence ,LANGUAGE acquisition ,LANGUAGE & languages ,ACHIEVEMENT - Abstract
The present study investigates the interaction of the higher-order personality trait of Neuroticism and the lower-order personality trait of Emotional Intelligence (trait EI) in the context of foreign language acquisition (FLA). A mediation model was applied to explore the pathway from Neuroticism via trait EI to self-rated L2 skills. The reported results show that the trait EI is not only a significant predictor of the self-reported L2 speaking proficiency, but also a mediator in the relationship between Neuroticism and self-rated L2 speaking proficiency. Consequently, trait EI could be regarded as an important variable in the FLA context because its positive impact on self-perceived L2 speaking skills might diminish the negative influence of Neuroticism. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
89. Mechanical Properties, Dry Shrinkage, and Water Penetration of Reusing Fine and Ultrafine Recycled Concrete Aggregate.
- Author
-
Liu, Tao, Fan, Jianfeng, and Peng, Ziqiang
- Subjects
RECYCLED concrete aggregates ,WATER reuse ,ROAD construction ,CRUMB rubber ,COMPRESSIVE strength ,WASTE products as building materials - Abstract
The effect of fine and ultrafine recycled concrete aggregate (RCA) on road construction still lacks investigation. This study investigates the properties of fine and ultrafine RCA, further, the influence of the different proportions of ultrafine RCA on the long-term performance of the designed matrix. The fine and ultrafine RCA are thoroughly characterized. Simultaneously, the mechanical properties, shrinkage properties, and water penetration of the designed matrix are evaluated. The results indicate that RCA shows low density, high porosity, and high water absorption. Furthermore, elevated ultrafine RCA contents result in higher compressive strength of up to 43.14% at 90 days and higher resistance of water penetration of up to 50% at 28 days due to the refined microstructure. However, higher drying shrinkage is observed with higher ultrafine RCA, which is associated with the high water absorption of the ultrafine RCA. The understanding of the utilization of ultrafine RCA in the construction of road base courses has been explored. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
90. Recycled Aggregates from Ceramic and Concrete in Mortar Mixes: A Study of Their Mechanical Properties.
- Author
-
Rosado, Santiago, Costafreda, Jorge, Martín, Domingo, Presa, Leticia, and Gullón, Lidia
- Subjects
MORTAR ,CONCRETE mixing ,CONSTRUCTION & demolition debris ,CERAMICS ,CIRCULAR economy ,COMPRESSIVE strength - Abstract
In recent decades, large amounts of construction and demolition waste (CDW) have been generated and accumulated throughout Europe, which is a challenge to manage and control nowadays. This work shows the results of a study carried out with samples of ceramic recycled aggregates (CRAs) and recycled concrete aggregates (RCAs) mixed with cement (C) in mortars. The main objective of this research is to demonstrate how, by adding CRAs and RCAs to a mixture of cement and natural aggregate (NA), it is possible to develop a high-strength mortar and achieve the best mixing ratio. To achieve these objectives, the characterization of the samples was initially carried out such as XRF, XRD and SEM. Next, tests were carried out on the products obtained, such as the consistency of the fresh mortar and the density of the specimens. Finally, a study of mechanical compressive strength was performed at 7, 28 and 200 days. The results show that although both CRAs and RCAs negatively affect the curing process of the specimens, it is possible to develop mortars with compressive strengths greater than 20 MPa. An obvious increase in mechanical compressive strengths was seen between 7 and 200 days of analysis. The results achieved in this research could be an important guide for the management of CDWs by local industries, thus favouring the development of the circular economy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
91. Recycling Old Concrete as Waste Concrete Powder for Use in Pervious Concrete: Effects on Permeability, Strength and Eco-Friendliness.
- Author
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Xie, Hui Zhu, Li, Leo Gu, Liu, Feng, and Kwan, Albert Kwok Hung
- Subjects
CONCRETE waste ,RECYCLED concrete aggregates ,PERMEABILITY ,CONCRETE mixing ,POWDERS ,PASTE ,LIGHTWEIGHT concrete - Abstract
The fine portion of crushed old concrete is difficult to be recycled for use in new concrete because it contains old cement paste, which generally has high porosity and low strength. Hence, in practice, the coarse portion is recycled as coarse aggregate and the fine portion is mostly not recycled. Nevertheless, attempts have been made in recent years to recycle the fine portion as waste concrete powder (WCP) by grinding before use. In this research, WCP was used to make pervious concrete. The WCP was added using the paste replacement method (PR method) of replacing an equal volume of cementitious paste. A series of pervious concrete mixes containing 100% recycled coarse aggregate and having different amounts of WCP added were produced for testing of interconnected porosity, water permeability and strength. The results showed that the addition of WCP using the PR method can improve the interconnected porosity by 9% and water permeability by 18%, greatly enhance the strength by 86%, as well as decrease the cement consumption by 10% at the same time. Therefore, the addition of WCP as paste replacement has great potential to be applied to the production of eco-friendly high-performance pervious concrete. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
92. The Effect of Pressure on the Oxidative Dehydrogenation of Ethane with Molecular Oxygen over a MoVNbTeOx Mixed Oxide Catalyst.
- Author
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Mishanin, I. I. and Bogdan, V. I.
- Abstract
The process of oxidative dehydrogenation of ethane (ODE) at an elevated pressure over a MoVNbTeO
x mixed oxide catalyst is studied. It is found that when the reaction is carried out at 280°C, the fraction of the total amount of reacted oxygen consumed for the formation of ethylene decreases from 100 to 68% with the increase in pressure from 0.1 to 10.0 MPa, which may indicate an increase in the role of chemisorbed oxygen in the ODE process at a high pressure. Here, the productivity with respect to ethylene at 280°C and 10.0 MPa is higher in comparison with the value obtained at 360°C and 0.1 MPa. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
93. Influences of Efficient Spraying of Cement-Based Slurries on Recycled Coarse Aggregate.
- Author
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Yin, Jinming, Kang, Aihong, Xiao, Peng, Wu, Zhengguang, Kou, Changjiang, Gong, Yongfan, and Xiao, Chenghui
- Subjects
ASSEMBLY line methods ,SLURRY - Abstract
The inferior property is usually one of the major problems of recycled coarse aggregate (RCA), and the utilization of the RCA is limited. Strengthening the RCA is being widely explored. Immersing the RCA in the cement-based slurry is an effective approach. However, lots of slurry and time are required, and it is difficult to integrate the immersing method into the production line of the RCA. In this paper, a circular spraying method was proposed to treat the RCA using cement-based slurry. The immersing method was also conducted to verify the feasibility of the spraying method. The crushing value (CV), 24 h water absorption (WA), apparent density (AD) and dynamic water absorption (DWA) were tested, and the micro-morphology was also observed to explore the strengthening mechanism. Results showed that the CV and the WA decreased by up to 30.0% and 14.3% when the spraying method was used. The AD was slightly influenced by the cement-based slurry regardless of the treatment method. Considering the CV, WA and AD, the comprehensive grade of the RCA could be enhanced from III to II by using the spraying method. It was worth noting that the effects of the spraying method and the immersing method were basically equivalent. When the spraying method was adopted, only about 1 min and a small amount of slurry (about 5% of the RCA mass) were required to treat the RCA. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
94. Circular Bioeconomy in the Amazon Rainforest: Evaluation of Açaí Seed Ash as a Regional Solution for Partial Cement Replacement.
- Author
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Rocha, Joaquin Humberto Aquino, de Siqueira, Andréia Arenari, de Oliveira, Marco Antonio Barbosa, Castro, Lucas da Silva, Caldas, Lucas Rosse, Monteiro, Nathalie Barbosa Reis, and Toledo Filho, Romildo Dias
- Abstract
Açaí seed ash (ASA) is a waste product from processing the açaí fruit and burning the seeds for cogeneration purposes. The present study evaluated the use of ASA from the Brazilian Amazon as partial Portland cement replacement in self-leveling mortars (SLM) for social-interest buildings. The fresh and hardened state properties of mortars were accessed with 5% and 10% ASA content, and a life cycle assessment was performed to evaluate the greenhouse gas (GHG) emissions. The maximum transport distance to enable ASA as a building material was determined by a sensitivity analysis, and specific carbon-efficiency indicators for SLM were proposed and validated. The results showed that using up to 10% ASA as cement replacement was technically and environmentally feasible since the mechanical performance was maintained and GHG emissions decreased up to 8%. The sensitivity analysis revealed that transport efficiency is crucial for ASA applications far from its production area; therefore, it should be evaluated as a regional building material. The work brings an important contribution to regional sustainable development by assessing the characteristics of a residual material and proposing the reuse of waste, reducing GHG emissions from the cement industry, and stimulating the circular bioeconomy in the Brazilian Amazon region. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
95. Biological models and replicas in Museu de História Natural e da Ciência da Universidade do Porto, Portugal.
- Author
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Vieira, Cristiana, Muchagata, João, Gaspar, Rita, Gonçalves, Helena, Mateus, Simão, and João Fonseca, Maria
- Subjects
BIOLOGICAL models ,NATURAL history museums ,ANATOMY ,COMPARATIVE biology ,UNIVERSITIES & colleges - Abstract
Biological models and replicas were in their heyday in the nineteenth century when they were common in primary, elementary, secondary and higher education institutions, as they were frequently used to illustrate anatomical structures mentioned in textbooks and scientific papers. Biological models and replicas are part of the heritage of the Museu de História Natural e da Ciência da Universidade do Porto (Natural History and Science Museum, University of Oporto) offering insights into the world of these unique collections. We performed a study on the use of these industrial-made models and replicas of the internal or/and external anatomy of animals and plants that accompanied many of the practical demonstrations in comparative biology and anatomy classes at the Academia Politécnica do Porto and, later on, at the Universidade do Porto, its successor. Artisanal models and replicas were also used in biology and anthropology classes. This research on these special items helps promote their value and contributes to the dissemination of information and may be relevant to other institutions owning identical models. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
96. THE USE OF GLASS POWDER WASTE AS A PARTIAL SUBSTITUTE FOR CEMENT ON THE COMPRESSIVE STRENGTH OF CONCRETE.
- Author
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Martina, Nunung, Kinanti, Mely Duta, Hasan, Muhammad Fathur Rouf, Agung, Putera Agung Maha, and Setiawan, Yanuar
- Subjects
POWDERED glass ,GLASS waste ,COMPRESSIVE strength ,CONCRETE ,CEMENT ,FUSED silica - Abstract
Excessive use of cement can cause damage to the environment. Using materials that have similar properties to cement as a concrete mixture can reduce the use of cement. Because the silica content in glass is quite large, glass has the potential to be used as a partial substitute for cement in concrete. This study aims to determine the effect of glass powder used as a partial cement substitute on the compressive strength of normal concrete. This study uses cylindrical specimens with 15 cm in diameter and 30 cm in height according to SNI 03-2834-2002. They were tested at seventh, fourteenth, and twenty-eighth day. The variations of the glass powder are 0%, 4%, 8%, 12%, and 16%. Based on the results of the testing at the twenty eighth days, the concrete's compressive strength at 0% variation is 22.8 MPa, at 4% variation is 24.0 MPa, at 8% variation is 17.5 MPa, at 12% variation is 17.6 MPa, and at 16% variation is 7.9 MPa. Thus, using glass powder as a partial substitute for cement in concrete mixtures affects the compressive strength of normal concrete. At the twenty-eighth day, the compressive strength of the concrete has increased by 5% to 24.0 MPa. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
97. Interaction of Geopolymer Filler and Alkali Molarity Concentration towards the Fire Properties of Glass-Reinforced Epoxy Composites Fabricated Using Filament Winding Technique.
- Author
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Hashim, Mohammad Firdaus Abu, Faris, Meor Ahmad, Mydin, Md Azree Othuman, Ghazali, Che Mohd Ruzaidi, Daud, Yusrina Mat, Abdullah, Mohd Mustafa Al Bakri, Zainal, Farah Farhana, Saloma, Mohd Tahir, Muhammad Faheem, Yong, Heah Cheng, and Khorami, Morteza
- Subjects
FILAMENT winding ,MOLARITY ,EPOXY resins ,POLYMER-impregnated concrete ,GLASS fibers ,HIGH temperatures - Abstract
This paper aims to find out the effect of different weight percentages of geopolymer filler in glass-reinforced epoxy pipe, and which can achieve the best mechanical properties and adhesion between high calcium pozzolanic-based geopolymer matrices. Different weight percentages and molarities of epoxy hardener resin and high calcium pozzolanic-based geopolymer were injected into the glass fiber. By manually winding filaments, composite samples were produced, and they were then allowed to cure at room temperature. To determine how well the geopolymer matrices adhere to the fiber reinforcement, the microstructure of the composites' surfaces and perpendicular sections were examined. Maximum values of compressive strength and compressive modulus were 94.64 MPa and 2373.58 MPa, respectively, for the sample with a weight percentage of filler loading of 30 wt% for an alkali concentration of 12 M. This is a relatively wide range of geopolymer weight percentage of filler loading from 10 wt% to 40 wt%, at which we can obtain high compressive properties. By referring to microstructural analysis, adhesion, and interaction of the geopolymer matrix to glass fiber, it shows that the filler is well-dispersed and embedded at the fiber glass, and it was difficult to determine the differences within the range of optimal geopolymer filler content. By determining the optimum weight percent of 30 wt% of geopolymer filler and microstructural analysis, the maximum parameter has been achieved via analysis of high calcium pozzolanic-based geopolymer filler. Fire or elevated temperature represents one of the extreme ambient conditions that any structure may be exposed to during its service life. The heat resistance or thermal analysis between glass-reinforced epoxy (GRE) pipe and glass-reinforced epoxy pipe filled with high calcium pozzolanic-based geopolymer filler was studied by investigating burning tests on the samples, which shows that the addition of high calcium pozzolanic-based geopolymer filler results in a significant reduction of the melted epoxy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
98. Sustainable Public Procurement in the Building Construction Sector.
- Author
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Fregonara, Elena, Ferrando, Diego Giuseppe, and Tulliani, Jean-Marc
- Abstract
Considering that in the E.U. public procurement in the construction sector is highly represented, the Directive 2014/24/EU is implemented for harmonizing procurement processes across European countries. The Directive is transposed in Italy, through the Sustainable Public Procurement (SPP) national action plan, for supporting public procurement and public–private partnership (PPP) interventions. SPP is founded on two pillars: according to an economic viewpoint, the financial efficiency is the key aspect to verify, and, according to a sustainability viewpoint, externalities are a key element in the environmental evaluation, despite the fact that their monetary quantification into the global cost calculation is quite complex. Thus, this work aims to explore a methodology for the joint evaluation of economic–environmental sustainability of project options, in the tender evaluation phase of the SPP. The methodology is based on the life cycle costing (LCC) and CO
2 emissions joint assessment, including criteria weighting and uncertainty components. Two alternative technologies—a timber and an aluminum window frame—are assumed as a case for a simulation, implemented with the software "Smart SPP LCC-CO2 Tool" (developed through the research "Smart SPP—Innovation through sustainable procurement", supported by Intelligent Energy Europe). The simulation demonstrates that the methodology is a fast and effective modality for selecting alternative options, introducing sustainability in the decision-making process. The work is a contribution to the growing literature on the topic, and for giving support to subjects (public authorities and private operators) involved in public procurement processes/PPP interventions. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
99. Morpho-Structural Setting of the Ligurian Sea: The Role of Structural Heritage and Neotectonic Inversion.
- Author
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Morelli, Danilo, Locatelli, Michele, Corradi, Nicola, Cianfarra, Paola, Crispini, Laura, Federico, Laura, and Migeon, Sébastien
- Abstract
The review of recent bathymetric and geophysical data collected in the framework of several research and cartographic projects have allowed a detailed reconstruction of the morpho-structural setting and the (neo)tectonic evolution for both the Alpine and Apennine margins of the Ligurian Sea (Italy). The widespread occurrence of erosional processes and sediment mass movements along the steep continental slope and within the system of submarine canyons reflect the close correlation between the active tectonics and the recent morpho-dynamic evolution of the Ligurian Margin. This relation is better constrained in the western sector (Alpine) of the Ligurian Sea, where the recent uplift of the continental margin is associated to a well-developed system of inherited structures reactivated under a compressive/transpressive regime and widespread seismicity. In the eastern sector, where the seismicity is lower or absent, the mass movements are limited to few areas (e.g., the Portofino slope) coinciding with seismic clusters. Additionally, this sector is characterized by moderate and episodic fault reactivations under a compressive regime. The evidence of compressive deformation along the inherited fault systems has been revealed in some areas of the Ligurian Sea where the post-drifting extensional tectonics is interrupted by episodic tectonic inversion (at least) during the Middle–Upper Miocene and the Plio–Pleistocene until present. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
100. Green Synthesis of Dimethyl Carbonate from CO2 and Methanol: New Strategies and Industrial Perspective.
- Author
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Raza, Ali, Ikram, Muhammad, Guo, Song, Baiker, Alfons, and Li, Gao
- Subjects
ORGANOMETALLIC compounds ,ETHANES ,MEMBRANE reactors ,HETEROPOLY acids ,METHANOL ,CARBONATES - Abstract
Dimethyl carbonate (DMC) is a commonly used and environmentally sustainable chemical compound and intermediate in a variety of industrial applications. To date, several large‐scale industrial DMC synthesis routes have been developed, including methanol phosgenation, transesterification, and oxidative carbonylation of methanol. However, these manufacturing routes have several disadvantages, such as the use of hypertoxic phosgene as raw material, costly processing, and explosion risks. The most encouraging and ecofriendly path is the green production of DMC from CO2 and methanol. Various catalytic materials have been examined concerning their suitability for DMC synthesis. The issues of low yield and difficulty in tests have not been resolved fundamentally, which is caused by the inherent problems of the synthetic pathway and limitations imposed by thermodynamics. The search for more efficient production routes has driven the activation of CO2 via electro‐assisted synthesis as well as membrane reactors, which can isolate products in real‐time to maximize DMC yield. The green synthesis of dimethyl carbonate catalyzed by different catalysts including Zr/Ce/Cu‐based nanocomposites, organometallic compounds, heteropoly acid, ionic liquid, metal‐organic frameworks, etc, is discussed in detail. Further, the structure–activity relationships and insights into molecular activation and catalytic mechanisms, as well as the identification of active sites on catalysts are addressed. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
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