Pub Date : 2022-01-01DOI: 10.3934/matersci.2022014
François Njock Bayock, P. Kah, Kibong Marius Tony
This study aims to investigate the optimum heat input required to overcome the negative consequence of the thermal properties of austenitic stainless steel to produce welded joints free of distortion. An experimental investigation using robotic-MAG and fiber-laser welding processes has been used in other to investigate angular, longitudinal distortion (bending), and microstructural constituents in the heat-affected zone (HAZ) of different welded joints. Ten 316L steel, butt-joints were made by different travel 25 speeds at the range of (7–11 mm/s). A highly sensitive 2D-laser device has been used to measure the distortion then, a microstructural investigation was done using an optical micrograph, Scanning Electron Microscopy (SEM) coupled with the Electron Dispersive Spectrometer (EDS). The laser-fiber welding process results indicated optimum parameters to prevent distortion when applying welding speed of 2.2 m/min, the power source of 2.5 kW, and the focal position of 3 mm. In MAG welding, test results revealed an increase of longitudinal distortion (bending) from 1.2 mm to 3.6 mm when raising the heat input from 0.3 to 0.472 kJ/mm. When increases welding speed (11 mm/s), angular distortion was approximately 2.1° on the left side and 1.7° on the right side. Microstructural investigations revealed the proportionality between heat input and carbides formations on the grain boundaries of HAZ. They were also the formation of etching pores and some ferrite content (10%) on the weld center.
{"title":"Heat input effects on mechanical constraints and microstructural constituents of MAG and laser 316L austenitic stainless-steel welded joints","authors":"François Njock Bayock, P. Kah, Kibong Marius Tony","doi":"10.3934/matersci.2022014","DOIUrl":"https://doi.org/10.3934/matersci.2022014","url":null,"abstract":"This study aims to investigate the optimum heat input required to overcome the negative consequence of the thermal properties of austenitic stainless steel to produce welded joints free of distortion. An experimental investigation using robotic-MAG and fiber-laser welding processes has been used in other to investigate angular, longitudinal distortion (bending), and microstructural constituents in the heat-affected zone (HAZ) of different welded joints. Ten 316L steel, butt-joints were made by different travel 25 speeds at the range of (7–11 mm/s). A highly sensitive 2D-laser device has been used to measure the distortion then, a microstructural investigation was done using an optical micrograph, Scanning Electron Microscopy (SEM) coupled with the Electron Dispersive Spectrometer (EDS). The laser-fiber welding process results indicated optimum parameters to prevent distortion when applying welding speed of 2.2 m/min, the power source of 2.5 kW, and the focal position of 3 mm. In MAG welding, test results revealed an increase of longitudinal distortion (bending) from 1.2 mm to 3.6 mm when raising the heat input from 0.3 to 0.472 kJ/mm. When increases welding speed (11 mm/s), angular distortion was approximately 2.1° on the left side and 1.7° on the right side. Microstructural investigations revealed the proportionality between heat input and carbides formations on the grain boundaries of HAZ. They were also the formation of etching pores and some ferrite content (10%) on the weld center.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022016
Nuriya Mukhamedova, Yernat Kozhakhmetov, M. Skakov, S. Kurbanbekov, N. Mukhamedov
In this work, the stability of the microstructure of the experimentally obtained two-phase (O + B2) alloy of the Ti–25Al–25Nb (at.%) system were studied during thermal cycling in a hydrogen atmosphere. It was found that the two-phase structure (O + B2) of the alloy of the Ti–Al–Nb system shows high thermodynamic stability. In this case, phase transformations of secondary phases (α2, AlNb2) are observed in the microstructure of the alloy, the volumetric content of which at all stages of testing does not exceed 2%. Thus, after the first cycle of high-temperature exposure, single inclusions of the α2 phase precipitate, while in the areas enriched in Ti and Al, due to the redistribution of Nb, a new colony of the α2 phase is observed. After five test cycles, it was found that large accumulations of the α2 colony, due to the α2 → B2 phase transformations, form new micron-sized grains of the B2 phase. A volumetric accumulation of nanosized precipitates of the AlNb2 phase was found near the triple joints of the grain boundaries of the B2 phase after 10 cycles of thermal exposure, which is caused by the supersaturation of B2 grains with niobium.
{"title":"Microstructural stability of a two-phase (O + B2) alloy of the Ti-25Al-25Nb system (at.%) during thermal cycling in a hydrogen atmosphere","authors":"Nuriya Mukhamedova, Yernat Kozhakhmetov, M. Skakov, S. Kurbanbekov, N. Mukhamedov","doi":"10.3934/matersci.2022016","DOIUrl":"https://doi.org/10.3934/matersci.2022016","url":null,"abstract":"In this work, the stability of the microstructure of the experimentally obtained two-phase (O + B2) alloy of the Ti–25Al–25Nb (at.%) system were studied during thermal cycling in a hydrogen atmosphere. It was found that the two-phase structure (O + B2) of the alloy of the Ti–Al–Nb system shows high thermodynamic stability. In this case, phase transformations of secondary phases (α2, AlNb2) are observed in the microstructure of the alloy, the volumetric content of which at all stages of testing does not exceed 2%. Thus, after the first cycle of high-temperature exposure, single inclusions of the α2 phase precipitate, while in the areas enriched in Ti and Al, due to the redistribution of Nb, a new colony of the α2 phase is observed. After five test cycles, it was found that large accumulations of the α2 colony, due to the α2 → B2 phase transformations, form new micron-sized grains of the B2 phase. A volumetric accumulation of nanosized precipitates of the AlNb2 phase was found near the triple joints of the grain boundaries of the B2 phase after 10 cycles of thermal exposure, which is caused by the supersaturation of B2 grains with niobium.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022025
R. Tilkin, A. P. Monteiro, J. Mahy, Jérôme Hurlet, Nicolas Régibeau, C. Grandfils, S. Lambert
Over the last decades, different materials have been investigated to overcome some flaws of bone substitutes. Even though various materials have been proposed for this conception, the in vivo assessments have still highlighted a lack of bioactivity and integration. In this context, this work focuses on the development of hybrid gel with surface properties specifically designed to promote bone regeneration by a sustained local delivery of active agents. We propose a new approach using modified-silica with high specific surface area and superior hydrophilicity dispersed in agarose hydrogel. In this optic, silica particles were dispersed in agarose solutions before the gelation of the composite upon cooling. The dispersion of the silica particles in the agarose gel was determined via scanning electronic microscopy. The degradation of the silica/agarose gels was also studied over a period of 12 weeks. Finally, the influence of the addition of silica on the permeability of the agarose gel was assessed via a diffusion test. The results showed that modified-silica particles exhibit a wide size distribution (500 nm and 10 µm) and can form clusters with higher size after their dispersion in agarose (up to 100 µm). The hybrid gel was stable over 12 weeks in aqueous solution. Moreover, no difference in permeability was noted between the hybrid gel and agarose hydrogel, allowing molecules up to 3 nm in diameter to diffuse freely within 1 mm thick agarose gels in less than 24 h. The present results indicate that hybrid agarose gel could represent an attractive matrix to disperse silica for scaffold applications.
{"title":"Hybrid agarose gel for bone substitutes","authors":"R. Tilkin, A. P. Monteiro, J. Mahy, Jérôme Hurlet, Nicolas Régibeau, C. Grandfils, S. Lambert","doi":"10.3934/matersci.2022025","DOIUrl":"https://doi.org/10.3934/matersci.2022025","url":null,"abstract":"Over the last decades, different materials have been investigated to overcome some flaws of bone substitutes. Even though various materials have been proposed for this conception, the in vivo assessments have still highlighted a lack of bioactivity and integration. In this context, this work focuses on the development of hybrid gel with surface properties specifically designed to promote bone regeneration by a sustained local delivery of active agents. We propose a new approach using modified-silica with high specific surface area and superior hydrophilicity dispersed in agarose hydrogel. In this optic, silica particles were dispersed in agarose solutions before the gelation of the composite upon cooling. The dispersion of the silica particles in the agarose gel was determined via scanning electronic microscopy. The degradation of the silica/agarose gels was also studied over a period of 12 weeks. Finally, the influence of the addition of silica on the permeability of the agarose gel was assessed via a diffusion test. The results showed that modified-silica particles exhibit a wide size distribution (500 nm and 10 µm) and can form clusters with higher size after their dispersion in agarose (up to 100 µm). The hybrid gel was stable over 12 weeks in aqueous solution. Moreover, no difference in permeability was noted between the hybrid gel and agarose hydrogel, allowing molecules up to 3 nm in diameter to diffuse freely within 1 mm thick agarose gels in less than 24 h. The present results indicate that hybrid agarose gel could represent an attractive matrix to disperse silica for scaffold applications.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2023002
Rebai Billel
The principal goal of the current work is to study the impact of three homogenization models (Reuss, LRVE, Tamura) on the axial and shear stress of sandwich functionally graded plate materials subjected on linear and nonlinear thermal loads with static and elastic behavior and it is simply supported using an integral higher shear deformation theory (HSDT). The governing partial differential equations are solved in the spatial coordinate by Navier solution. Those Numerous micromechanical models have been examined to attain the effective material properties of the two-phase FGM plate. The numerical results are compared with those given by other model existing in the literature to confirm the accuracy of the (HSDT). The present results are in good agreement with all models studied of homogenization for all values of the material index and all geometry configurations of the FG-sandwich plates.
{"title":"Contribution to study the effect of (Reuss, LRVE, Tamura) models on the axial and shear stress of sandwich FGM plate (Ti–6A1–4V/ZrO2) subjected on linear and nonlinear thermal loads","authors":"Rebai Billel","doi":"10.3934/matersci.2023002","DOIUrl":"https://doi.org/10.3934/matersci.2023002","url":null,"abstract":"The principal goal of the current work is to study the impact of three homogenization models (Reuss, LRVE, Tamura) on the axial and shear stress of sandwich functionally graded plate materials subjected on linear and nonlinear thermal loads with static and elastic behavior and it is simply supported using an integral higher shear deformation theory (HSDT). The governing partial differential equations are solved in the spatial coordinate by Navier solution. Those Numerous micromechanical models have been examined to attain the effective material properties of the two-phase FGM plate. The numerical results are compared with those given by other model existing in the literature to confirm the accuracy of the (HSDT). The present results are in good agreement with all models studied of homogenization for all values of the material index and all geometry configurations of the FG-sandwich plates.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70089452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022012
X. Chen, Anguo Xiao, D. Rodrigue
Propylene/propane separations are generally performed by distillation which are energy intensive and costly to build and operate. There is therefore high interest to develop new separation technologies like membrane modules. In our previous paper, we collected, analyzed and reported data for neat polymers and mixed matrix membranes (MMM) based on flat and hollow fiber configurations for propylene/propane separations. In this second part, we collected the data for carbon molecular sieving (CMS) membranes from polymer pyrolysis reaction and metal-organic framework (MOF) membranes from different fabrication methods, as well as data on facilitated transport membrane-polymer electrolyte membranes (PEM). CMS membranes show great potential for C3H6/C3H8 separation with an optimum pyrolysis temperature around 500–600 ℃. However, physical aging is a concern as the micro-pores shrink over time leading to lower permeability. The performance of MOF membranes are above the 2020 upper bound of polymer-based membranes, but have limited commercial application because they are fragile and difficult to produce. Finally, facilitated transport membranes show excellent propylene/propane separation performance, but are less stable compared to commercial polymeric membranes limiting their long-term operation and practical applications. As usual, there is no universal membrane and the selection must be made based on the operating conditions.
{"title":"Polymer based membranes for propylene/propane separation: CMS, MOF and polymer electrolyte membranes","authors":"X. Chen, Anguo Xiao, D. Rodrigue","doi":"10.3934/matersci.2022012","DOIUrl":"https://doi.org/10.3934/matersci.2022012","url":null,"abstract":"Propylene/propane separations are generally performed by distillation which are energy intensive and costly to build and operate. There is therefore high interest to develop new separation technologies like membrane modules. In our previous paper, we collected, analyzed and reported data for neat polymers and mixed matrix membranes (MMM) based on flat and hollow fiber configurations for propylene/propane separations. In this second part, we collected the data for carbon molecular sieving (CMS) membranes from polymer pyrolysis reaction and metal-organic framework (MOF) membranes from different fabrication methods, as well as data on facilitated transport membrane-polymer electrolyte membranes (PEM). CMS membranes show great potential for C3H6/C3H8 separation with an optimum pyrolysis temperature around 500–600 ℃. However, physical aging is a concern as the micro-pores shrink over time leading to lower permeability. The performance of MOF membranes are above the 2020 upper bound of polymer-based membranes, but have limited commercial application because they are fragile and difficult to produce. Finally, facilitated transport membranes show excellent propylene/propane separation performance, but are less stable compared to commercial polymeric membranes limiting their long-term operation and practical applications. As usual, there is no universal membrane and the selection must be made based on the operating conditions.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70087535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022051
V. Jatti, N. Khedkar, Vinaykumar S. Jatti, Pawandeep Dhall
In this competitive world, manufacturers must embrace new technology in order to differentiate their products and capture market leadership. This can be achieved using advanced materials; however, these materials are difficult to machine by using traditional machining processes. A very viable and practical unconventional machining process is electrical discharge machining (EDM). EDM processes need proper selection of input parameters to get optimum productivity aspects, namely, the material removal rate and tool wear rate. Thus, the present study aims at investigating the effect of cryogenically treated work pieces and tools, gap currents, gap voltages, pulse on time and pulse off time on the material removal rate and tool wear rate during EDM of Nitinol (NiTi) alloy, Monel (NiCu) alloy and beryllium copper (BeCu) alloy. The experimental results showed that cryogenic treatment significantly improved the electrical conductivity of the workpieces and tool electrodes, which resulted in an enhanced material removal rate and reduced tool wear rate.
{"title":"Investigating the effect of cryogenic treatment of workpieces and tools on electrical discharge machining performance","authors":"V. Jatti, N. Khedkar, Vinaykumar S. Jatti, Pawandeep Dhall","doi":"10.3934/matersci.2022051","DOIUrl":"https://doi.org/10.3934/matersci.2022051","url":null,"abstract":"In this competitive world, manufacturers must embrace new technology in order to differentiate their products and capture market leadership. This can be achieved using advanced materials; however, these materials are difficult to machine by using traditional machining processes. A very viable and practical unconventional machining process is electrical discharge machining (EDM). EDM processes need proper selection of input parameters to get optimum productivity aspects, namely, the material removal rate and tool wear rate. Thus, the present study aims at investigating the effect of cryogenically treated work pieces and tools, gap currents, gap voltages, pulse on time and pulse off time on the material removal rate and tool wear rate during EDM of Nitinol (NiTi) alloy, Monel (NiCu) alloy and beryllium copper (BeCu) alloy. The experimental results showed that cryogenic treatment significantly improved the electrical conductivity of the workpieces and tool electrodes, which resulted in an enhanced material removal rate and reduced tool wear rate.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70089208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022035
R. A. Ghazi, Khalidah H. Al-Mayalee, E. Al‐Bermany, F. Hashim, Abdul Kareem J. Albermany
Molecular weight (Mw) is an important feature that affects the physicochemical properties of polymers and their matrices. This study focused on the impact of increasing the Mw of polyethylene glycol (PEG) (4, 8 and 20 K) mixed with polyvinyl alcohol (PVA). Graphene oxide (GO) nanosheets were employed to reinforce the polymer matrix by aquatic mixing-sonication-casting to prepare the nanocomposites and investigate their optical properties. Fourier transform infrared spectroscopy revealed strong interfacial interactions among the components and successful fabrication of the nanocomposites. Optical microscopy and scanning electron microscopy confirmed the fine homogeneity of the polymers and the excellent dispersion of nanosheets in the matrix. The absorption peak was located in the ultraviolet region related to GO. PEG Mw and GO additive significantly improved optical properties such as absorbance, real and imaginary dielectrics and the absorption coefficient constant up to 75%, 40%, 120% and 77%, respectively. An enhancement in the optical properties was also observed after the energy gap values for allowed and forbidden transitions were improved up to 90% and 375%, respectively. These findings suggest the potential of these materials for several applications, such as in photovoltaic devices and heavy metal ion absorption for nuclear waste management.
{"title":"Impact of polymer molecular weights and graphene nanosheets on fabricated PVA-PEG/GO nanocomposites: Morphology, sorption behavior and shielding application","authors":"R. A. Ghazi, Khalidah H. Al-Mayalee, E. Al‐Bermany, F. Hashim, Abdul Kareem J. Albermany","doi":"10.3934/matersci.2022035","DOIUrl":"https://doi.org/10.3934/matersci.2022035","url":null,"abstract":"Molecular weight (Mw) is an important feature that affects the physicochemical properties of polymers and their matrices. This study focused on the impact of increasing the Mw of polyethylene glycol (PEG) (4, 8 and 20 K) mixed with polyvinyl alcohol (PVA). Graphene oxide (GO) nanosheets were employed to reinforce the polymer matrix by aquatic mixing-sonication-casting to prepare the nanocomposites and investigate their optical properties. Fourier transform infrared spectroscopy revealed strong interfacial interactions among the components and successful fabrication of the nanocomposites. Optical microscopy and scanning electron microscopy confirmed the fine homogeneity of the polymers and the excellent dispersion of nanosheets in the matrix. The absorption peak was located in the ultraviolet region related to GO. PEG Mw and GO additive significantly improved optical properties such as absorbance, real and imaginary dielectrics and the absorption coefficient constant up to 75%, 40%, 120% and 77%, respectively. An enhancement in the optical properties was also observed after the energy gap values for allowed and forbidden transitions were improved up to 90% and 375%, respectively. These findings suggest the potential of these materials for several applications, such as in photovoltaic devices and heavy metal ion absorption for nuclear waste management.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022022
M. Meshaly, Hamdy Abou-Elfath
Buckling-restrained braces (BRBs) have proven to be a valuable earthquake resisting system. They demonstrated substantial ability in providing structures with ductility and energy dissipation. However, they are prone to exhibit large residual deformations after earthquake loading because of their low post-yield stiffnesses. In this study, the seismic response of RC frames equipped with BRBs has been investigated. The focus of this research work is on evaluating the effect of the BRB yielding-core length on both the maximum and the residual lateral deformations of the braced RC frames. This is achieved by performing inelastic static pushover and dynamic time-history analyses on three- and nine-story X-braced RC frames having yielding-core length ratios of 25%, 50%, and 75% of the total brace length. The effects of the yielding-core length on both the maximum and the residual lateral deformations of the braced RC frames have been evaluated. Also, the safety of the short-yielding-core BRBs against fracture failures has been checked. An empirical equation has been derived for estimating the critical length of the BRB yielding cores. The results indicated that the high strain hardening capability of reduced length yielding-cores improves the post-yield stiffness and consequently reduces the maximum and residual drifts of the braced RC frames.
{"title":"Seismic response of RC frames equipped with buckling-restrained braces having different yielding lengths","authors":"M. Meshaly, Hamdy Abou-Elfath","doi":"10.3934/matersci.2022022","DOIUrl":"https://doi.org/10.3934/matersci.2022022","url":null,"abstract":"Buckling-restrained braces (BRBs) have proven to be a valuable earthquake resisting system. They demonstrated substantial ability in providing structures with ductility and energy dissipation. However, they are prone to exhibit large residual deformations after earthquake loading because of their low post-yield stiffnesses. In this study, the seismic response of RC frames equipped with BRBs has been investigated. The focus of this research work is on evaluating the effect of the BRB yielding-core length on both the maximum and the residual lateral deformations of the braced RC frames. This is achieved by performing inelastic static pushover and dynamic time-history analyses on three- and nine-story X-braced RC frames having yielding-core length ratios of 25%, 50%, and 75% of the total brace length. The effects of the yielding-core length on both the maximum and the residual lateral deformations of the braced RC frames have been evaluated. Also, the safety of the short-yielding-core BRBs against fracture failures has been checked. An empirical equation has been derived for estimating the critical length of the BRB yielding cores. The results indicated that the high strain hardening capability of reduced length yielding-cores improves the post-yield stiffness and consequently reduces the maximum and residual drifts of the braced RC frames.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022023
C. Aris Chatzidimitriou-Dreismann
Quantum correlations phenomena, such as entanglement, quantum discord and quantum coherence, are ubiquitous effects caused by interactions between physical systems—such as electrons and ions in a piece of metal, or H atoms/molecules adsorbed in nanoporous materials. Here, we address time-asymmetric quantumness of correlations (QoC), with particular emphasis on their energetic consequences for dynamics and non-equilibrium thermodynamics in condensed matter and/or many-body systems. Some known theoretical models—for example, the quantum Zeno effect and GKSL-type Markovian equations-of-motion, all of them being time-asymmetric—are shortly considered, with emphasis on the general character of one of their common and most intriguing result. Namely, that in clear contradistinction to conventional expectations, degradation (or destruction, decoherence, consumption, smearing out, coarse-graining) of quantum correlations can be a source of work (instead of heat production). The experimental relevance of the theoretical considerations is shown with the aid of a recent scattering experiment exploring the impulsively driven (by neutron collisions) translational dynamics of H$ _2 $ molecules in carbon nanotubes and other nanostructured materials—a topic of immediate relevance for material sciences and related technologies.
{"title":"Quantumness of correlations in nanomaterials—experimental evidence and unconventional effects","authors":"C. Aris Chatzidimitriou-Dreismann","doi":"10.3934/matersci.2022023","DOIUrl":"https://doi.org/10.3934/matersci.2022023","url":null,"abstract":"Quantum correlations phenomena, such as entanglement, quantum discord and quantum coherence, are ubiquitous effects caused by interactions between physical systems—such as electrons and ions in a piece of metal, or H atoms/molecules adsorbed in nanoporous materials. Here, we address time-asymmetric quantumness of correlations (QoC), with particular emphasis on their energetic consequences for dynamics and non-equilibrium thermodynamics in condensed matter and/or many-body systems. Some known theoretical models—for example, the quantum Zeno effect and GKSL-type Markovian equations-of-motion, all of them being time-asymmetric—are shortly considered, with emphasis on the general character of one of their common and most intriguing result. Namely, that in clear contradistinction to conventional expectations, degradation (or destruction, decoherence, consumption, smearing out, coarse-graining) of quantum correlations can be a source of work (instead of heat production). The experimental relevance of the theoretical considerations is shown with the aid of a recent scattering experiment exploring the impulsively driven (by neutron collisions) translational dynamics of H$ _2 $ molecules in carbon nanotubes and other nanostructured materials—a topic of immediate relevance for material sciences and related technologies.","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70088853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.3934/matersci.2022047
Hung-Nguyen Manh, Oanh Le Thi Mai, Chung Pham Do, Mai Vu Thanh, Anh Nguyen Thi Diep, Dao La Bich, Hang Lam Thi, Duyen Pham Thi, Minh Nguyen Van
Ag3PO4 was prepared by the precipitation method using monobasic/dibasic phosphate salts (K2HPO4, KH2PO4, Na2HPO4, NaH2PO4) as a precipitating agent. The environment created by the precursor salts strong affected on the crystallinity and the morphology of Ag3PO4. Ag3PO4 synthesized from dibasic phosphate salts exhibited pseudospherical morphology and small particle size while monobasic phosphate salts promoted crystallization, resulting in a large grain size and a very diverse grain morphology. Ag3PO4 prepared from dibasic phosphate salts (K2HPO4 and Na2HPO4) exhibited superior photocatalytic ability, completely degrading rhodamine B (RhB) in 8 min and 10 min under Xenon lamp irradiation, respectively. This result once again confirms the necessity of particle size reduction in the production of photocatalysts.
{"title":"Effect of monobasic/dibasic phosphate salts on the crystallinity, physical properties and photocatalytic performance of Ag3PO4 material","authors":"Hung-Nguyen Manh, Oanh Le Thi Mai, Chung Pham Do, Mai Vu Thanh, Anh Nguyen Thi Diep, Dao La Bich, Hang Lam Thi, Duyen Pham Thi, Minh Nguyen Van","doi":"10.3934/matersci.2022047","DOIUrl":"https://doi.org/10.3934/matersci.2022047","url":null,"abstract":"<abstract> <p>Ag<sub>3</sub>PO<sub>4</sub> was prepared by the precipitation method using monobasic/dibasic phosphate salts (K<sub>2</sub>HPO<sub>4</sub>, KH<sub>2</sub>PO<sub>4</sub>, Na<sub>2</sub>HPO<sub>4</sub>, NaH<sub>2</sub>PO<sub>4</sub>) as a precipitating agent. The environment created by the precursor salts strong affected on the crystallinity and the morphology of Ag<sub>3</sub>PO<sub>4</sub>. Ag<sub>3</sub>PO<sub>4</sub> synthesized from dibasic phosphate salts exhibited pseudospherical morphology and small particle size while monobasic phosphate salts promoted crystallization, resulting in a large grain size and a very diverse grain morphology. Ag<sub>3</sub>PO<sub>4</sub> prepared from dibasic phosphate salts (K<sub>2</sub>HPO<sub>4</sub> and Na<sub>2</sub>HPO<sub>4</sub>) exhibited superior photocatalytic ability, completely degrading rhodamine B (RhB) in 8 min and 10 min under Xenon lamp irradiation, respectively. This result once again confirms the necessity of particle size reduction in the production of photocatalysts.</p> </abstract>","PeriodicalId":7670,"journal":{"name":"AIMS Materials Science","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70089045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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