The mechanical properties and deformation features of AZ31-0.84% Sb alloy have been studied by means of the measurement of the properties and morphology observation. Results show that UTS of AZ31-0.84% Sb alloy at roo...The mechanical properties and deformation features of AZ31-0.84% Sb alloy have been studied by means of the measurement of the properties and morphology observation. Results show that UTS of AZ31-0.84% Sb alloy at room temperature is 297MPa, a higher value of UTS is still maintained up to 189MPa as temperature elevated to 200℃. One of the main reasons for enhancing UTS of the alloy is attributed to the high volume fraction of the precipitates dispersed in the matrix, including Mg3Sb2 phase, which effectively hindered the movement of dislocations during the elevated temperature deformation. The deformation mechanisms of AZ31-0.84% Sb alloy are the twins and dislocations activated on basal and non-basal planes. a+c dislocations may be activated on the basal and non-basal planes in twins regions, and some of the thinner twins may shear through the dense dislocations within the thicker twins.展开更多
Microporous chitosan （CS） membranes were directly prepared by extraction of poly（ethylene glycol） （PEG） from CS/PEG blend membrane and were examined for iron and manganese ions removal from aqueous solutions. Th...Microporous chitosan （CS） membranes were directly prepared by extraction of poly（ethylene glycol） （PEG） from CS/PEG blend membrane and were examined for iron and manganese ions removal from aqueous solutions. The different variables affecting the adsorption capacity of the membranes such as contact time, pH of the sorption medium, and initial metal ion concentration in the feed solution were investigated on a batch adsorption basis. The affinity of CS/PEG blend membrane to adsorb Fe（II） ions is higher than that of Mn（II） ions, with adsorption equilibrium achieved after 60 min for Fe（II） and Mn（II） ions. By increasing CS]PEG ratio in the blend membrane the adsorption capacity of metal ions increased. Among all parameters, pH has the most significant effect on the adsorption capacity, particularly in the range of 2.9-5.9. The increase in CS/PEG ratio was found to enhance the adsorption capacity of the membranes. The effects of initial concentration of metal ions on the extent of metal ions removal were investigated in detail. The experimental data were better fitted to Freundlich equation than Langmuir. In addition, it was found that the iron and manganese ions adsorbed on the membranes can be effectively desorbed in 0.1 mol/L HCl solution （up to 98% desorption efficiency） and the blend membranes can be reused almost without loss of the adsorption capacity for iron and manganese ions.展开更多
An eco-friendly chemical reduction method was successfully used for the preparation of chitosan （CTS） composite films loaded with silver nanoparticles （AgNPs） by self assembly method using poly（ethylene glycol） ...An eco-friendly chemical reduction method was successfully used for the preparation of chitosan （CTS） composite films loaded with silver nanoparticles （AgNPs） by self assembly method using poly（ethylene glycol） as both reducing and stabilizing agent. UV-Vis spectra of the prepared chitosan loaded silver nanoparticles （CTSLAg） films reveal that full reduction of silver ions to silver nanoparticles takes place at 90 ℃. The effect of reaction conditions on the silver nanoparticles formation was investigated using UV-Vis spectrophotometer. The morphology of the films was tested by scanning electron microscopy （SEM）. The DSC curves showed that the CTSLAg film had a favorable compatibility and heat stability. AgNPs were confirmed by XRD and UV-Vis spectroscopy. The TEM findings revealed that the silver nanoparticles synthesized were spherical in shape with uniform dispersal, and by increasing CTS：PEG ratio larger silver nanoparticles could be obtained. The results of antibacterial study reveal that the prepared nanoeomposite films exhibited potential inhibition.展开更多
The main objective of this study was to compare the results obtained with both virtual and experimental research methods, when the biomechanical behavior of teeth restored with esthetic posts was investigated. The fin...The main objective of this study was to compare the results obtained with both virtual and experimental research methods, when the biomechanical behavior of teeth restored with esthetic posts was investigated. The finite element method was used to develop models of healthy maxillary canines and maxillary canines restored with definitive crowns and glass-fiber posts, quartzfiber posts, and titanium posts. Stress distribution was observed when external loads were applied. Load was applied in-vitro to analyse the fracture resistance of 48 maxillary canines restored in the same way as it was considered in the virtual method. The analysis of results using the finite element method led to the conclusion that restored teeth, in which the elastic modulus of the post was similar to that of the dentine and the material of the core had the best biomechanical performance. The experimental study validated the virtual analysis.展开更多
It is a great advantage to design advanced materials with outstanding porosity and controllable band gab. In this study, （Fe, Ti）-containing mesoporous silica （x Fe/Ti-HMS） nanoparticles were prepared by a photo-a...It is a great advantage to design advanced materials with outstanding porosity and controllable band gab. In this study, （Fe, Ti）-containing mesoporous silica （x Fe/Ti-HMS） nanoparticles were prepared by a photo-assisted deposition PAD technique, where x is a nominal composition ofFe （l to 4 wt%））. The prepared samples were characterized by DR-UV, XRD, and TEM techniques. The results showed the insertion of Fe into intra-framework of Ti-HMS resulted in a gradual narrowing of the band gap of Ti-HMS samples with increment of Fe wt%. TEM observations reveal that Fe nanoparticles are evenly distributed within Ti-HSM matrix at different Fe wt%. Such results indicate the possibility to control the band gap of a single-site photocatalyst （Ti-HMS） by coupling it with the conventional nano-sized Fe catalysts.展开更多
In this paper an attempt is made to recover sillimanite by flotation tree analysis process and conventional flotation process from non magnetic fraction of red sediments.The experimental results of both the processes ...In this paper an attempt is made to recover sillimanite by flotation tree analysis process and conventional flotation process from non magnetic fraction of red sediments.The experimental results of both the processes are presented.The data reveal that the deslimed sample contains 33.2%(by weight) total heavy minerals and out of which the sillimanite mineral content is 3.6%(by weight).It is observed that flotation tree analysis needs 10 cells to get five output products and where as conventional flotation process needs 15 cells to recover similar grade of five output products.Thus,flotation tree analysis is not only economic process but also efficient process(to say efficient process,the tree analysis product should be higher grade).展开更多
When a relatively new building is not being fully utilized, there must have existed, at one time, a change in its initial conditions. The aim of this research is to study the changes in the initial conditions which ca...When a relatively new building is not being fully utilized, there must have existed, at one time, a change in its initial conditions. The aim of this research is to study the changes in the initial conditions which cause buildings to be underutilized and analyze whether the demolition was justified. Causes can be found in problems due to the building＇s management, as the owners make the main decisions concerning the buildings. Additionally problems are due to the location where the building is constructed because site conditions changes a lot in one generation. The use of the building can also be a cause of abandonment as the original use can end before the lifespan of the building. Architectural style can be dated as fashions and styles change rapidly. Finally, causes can be in the physical condition of the buildings： structure, construction, installations and adherence to current regulations. In this article, the authors provide guidelines demonstrating how buildings of a past generation which were initially considered obsolete, can be properly reused.展开更多
Over the last decade,the oriented strand board(OSB)market presented meaningful growth.However,as a woodbased product,because of its anatomical structure and chemical composition,OSB can be damaged by biodeterioration ...Over the last decade,the oriented strand board(OSB)market presented meaningful growth.However,as a woodbased product,because of its anatomical structure and chemical composition,OSB can be damaged by biodeterioration agents.Given that,the biodeterioration of OSB panels must be investigated to improve its durability.In this way,this work analyses the biological resistance against termites(Cryptotermes brevis and Nasutitermes corniger)of heat-treated OSB panels made with Eucalyptus wood glued with vegetable-based polyurethane-an ecofriendly and sustainable adhesive derived from castor oil.Various panels were produced with different layers compositions(face:core:face of 25:50:25 and 30:40:30)in wood mass proportion and were submitted to postproduction heat treatment(at 175℃ and 200℃)replacing the use of chemical insecticides.The influence of the layers variation and heat treatment temperature were evaluated,and these results were compared with commercial panels(made from pinus wood with insecticide).The results showed that the heat treatment did not improve the resistance against termite attack.However,all the experimental panels presented a satisfactory performance that was compatible with the commercial panels produced with insecticide available in the Brazilian market.The combination of Eucalyptus wood and castor oil adhesive to produce OSB,in any variation of layer composition,demonstrated natural resistance against termite attack compatible with the commercial panels,even without using chemical additives to increase durability.展开更多
Polymer crystallization,an everlasting subject in polymeric materials,holds great significance not only as a fundamental theoretical issue but also as a pivotal basis for directing polymer processing.Given its multist...Polymer crystallization,an everlasting subject in polymeric materials,holds great significance not only as a fundamental theoretical issue but also as a pivotal basis for directing polymer processing.Given its multistep,rapid,and thermodynamic nature,tracing and comprehending polymer crystallization pose a formidable challenge,particularly when it encounters practical processing scenarios that involve complex coupledfields(such as temperature,flow,and pressure).The advent of high-time and spatially resolved experiments paves the way for in situ investigations of polymer crystallization.In this review,we delve into the strides in studying polymer crystallization under the effects of coupled externalfields via state-of-the-art high-throughput experiments.We highlight the intricate setup of these high-throughput experimental devices,spanning from the laboratory and pilot levels to the industrial level.The individual and combined effects of externalfields on polymer crystallization are discussed.By breaking away from the conventional“black box”research approach,special interest is paid to the in situ crystalline behavior of polymers during realistic processing.Finally,we underscore the advancements in polymer crystallization via high-throughput experiments and outline its promising development.展开更多
We synthesized the pure and indium-doped （IZO） ZnO films with a facile composition control spray pyrolysis route. The substrate temperature （Ts） and In-doping effects on the properties of as-grown films are inves-...We synthesized the pure and indium-doped （IZO） ZnO films with a facile composition control spray pyrolysis route. The substrate temperature （Ts） and In-doping effects on the properties of as-grown films are inves- tigated. The X-ray pattern confirms that the as-synthesized ZnO phase is grown along a （002） preferential plane. It is revealed that the crystalline structure is improved with a substrate temperature of 350 ℃ Moreover, the morphol- ogy of as-grown films, analyzed by AFM, shows nanostructures that have grown along the c-axis. The （3 ×3 μm2） area scanned AFM surface studies give the smooth film surface RMS 〈 40 nm. The UV-VIS-IR measurements reveal that the sprayed films are highly transparent in the visible and IR bands. The photoluminescence analysis shows that the strong blue and yellow luminescences of 2.11 and 2.81 eV are emitted from ZnO and IZO films with a slight shift in photon energy caused by In-doping. The band gap is a bit widened by In-doping, 3.21 eV （ZnO） and 3.31 eV （IZO） and the resistivity is reduced from 385 to 8Ω·m. An interesting result is the resistivity linear dependence on the substrate temperature of pure ZnO films.展开更多
The thin films of Cu2O are deposited by electrodeposition technique onto indium tin oxide（ITO）-coated glass substrate at different potentials. The precursor is an aqueous solution which contains respectively 0.05 M ...The thin films of Cu2O are deposited by electrodeposition technique onto indium tin oxide（ITO）-coated glass substrate at different potentials. The precursor is an aqueous solution which contains respectively 0.05 M of CuSO4 and citric acid at kept temperature of 60℃ and the applied potential varies within the {-0：4 V,-0：7 V}SCE range. Based on the chronocoulometry（CC） process, the electrochemical, structural and optical parameters are determined. We measured the current as function of potential within the {-0：4 V,-0：7 V} range and the higher current is found to be within the {-0：7 V,-0：3 V} band. The grain sizes are of 12.12 nm and 35.47 nm according to（110） and（221） orientations respectively. The high textural coefficient of 0.943 is recorded for the potential -0：7 V.The transmittance of 72.25 %, within the visible band, is obtained for the as-grown layer at -0：4 V and the band gap is found to be 2.2 e V for the electrodeposition potential of -0：7 V.展开更多
Control of the electronic parameters on a novel metal–oxide–semiconductor（MOS）diode by indium doping incorporation is emphasized and investigated.The electronic parameters,such as ideality factor,barrier height（B...Control of the electronic parameters on a novel metal–oxide–semiconductor（MOS）diode by indium doping incorporation is emphasized and investigated.The electronic parameters,such as ideality factor,barrier height（BH）,series resistance,and charge carrier density are extracted from the current–voltage（I–V）and the capacitance–voltage（C–V）characteristics.The properties of the MOS diode based on 4%,6% and 8% indium doped tin oxide are largely studied.The Ag/SnO2/nSi/Au MOS diode is fabricated by spray pyrolysis route,at 300℃ from the In-doped SnO2layer.This was grown onto n-type silicon and metallic（Au）contacts which were made by thermal evaporation under a vacuum@10^-5 Torr and having a thickness of 120 nm and a diameter of 1 mm.Determined by the Cheung-Cheung approximation method,the series resistance increases（334–534Ω）with the In doping level while the barrier height（BH）remains constant around 0.57 V.The Norde calculation technique gives a similar BH value of 0.69 V but the series resistance reaches higher values of 5500Ω.The indium doping level influences on the characteristics of Ag/SnO2：In/Si/Au MOS diode while the 4% indium level causes the capacitance inversion and the device turns into p-type material.展开更多
The environmentally sustainable disposal and recycling of ever increasing volumes of electronic waste has become a global waste management issue. The addition of up to 25% polymeric waste PCBs （printed circuit boards...The environmentally sustainable disposal and recycling of ever increasing volumes of electronic waste has become a global waste management issue. The addition of up to 25% polymeric waste PCBs （printed circuit boards） as fillers in polypropylene （PP） composites was partially successful： while the tensile modulus, flexural strength and tlexural modulus of composites were enhanced, the tenstle and impact strengths were found to decrease. As a lowering of impact strength can significantly limit the application of PP based composites, it is necessary to incorporate impact modifying polymers such as rubbery particles in the mix. We report on a novel investigation on the simultaneous utilization of electronic and automotive rubber waste as fillers in PP composites. These composites were prepared by using 25 wt.% polymeric PCB powder, up to 9% of ethylene propylene rubber （EPR）, and PP： balance. The influence of EPR on the structural, thermal, mechanical and rheological properties of PP/PCB/ EPR composites was investigated. While the addition of EPR caused the nucleation of the I~ crystalline phase of PP, the onset temperature for thermal degradation was found to decrease by 8%. The tensile modulus and strength decreased by 1 b% and 19%, respectively; and the elongataon at break increased by -71%. The impact strength showed a maximum increase of-18% at 7 wt.%-9 wt.% EPR content. Various rheological properties were found to be well within the range of processing limits. This novel eco-friendly approach could help utilize significant amounts of polymeric electronic and automotive waste for fabricating valuable polymer composites.展开更多
文摘The mechanical properties and deformation features of AZ31-0.84% Sb alloy have been studied by means of the measurement of the properties and morphology observation. Results show that UTS of AZ31-0.84% Sb alloy at room temperature is 297MPa, a higher value of UTS is still maintained up to 189MPa as temperature elevated to 200℃. One of the main reasons for enhancing UTS of the alloy is attributed to the high volume fraction of the precipitates dispersed in the matrix, including Mg3Sb2 phase, which effectively hindered the movement of dislocations during the elevated temperature deformation. The deformation mechanisms of AZ31-0.84% Sb alloy are the twins and dislocations activated on basal and non-basal planes. a+c dislocations may be activated on the basal and non-basal planes in twins regions, and some of the thinner twins may shear through the dense dislocations within the thicker twins.
基金supported by the Housing & Building National Research Centre in EgyptCentral Metallurgical R & D Institute (CMRDI)
文摘Microporous chitosan （CS） membranes were directly prepared by extraction of poly（ethylene glycol） （PEG） from CS/PEG blend membrane and were examined for iron and manganese ions removal from aqueous solutions. The different variables affecting the adsorption capacity of the membranes such as contact time, pH of the sorption medium, and initial metal ion concentration in the feed solution were investigated on a batch adsorption basis. The affinity of CS/PEG blend membrane to adsorb Fe（II） ions is higher than that of Mn（II） ions, with adsorption equilibrium achieved after 60 min for Fe（II） and Mn（II） ions. By increasing CS]PEG ratio in the blend membrane the adsorption capacity of metal ions increased. Among all parameters, pH has the most significant effect on the adsorption capacity, particularly in the range of 2.9-5.9. The increase in CS/PEG ratio was found to enhance the adsorption capacity of the membranes. The effects of initial concentration of metal ions on the extent of metal ions removal were investigated in detail. The experimental data were better fitted to Freundlich equation than Langmuir. In addition, it was found that the iron and manganese ions adsorbed on the membranes can be effectively desorbed in 0.1 mol/L HCl solution （up to 98% desorption efficiency） and the blend membranes can be reused almost without loss of the adsorption capacity for iron and manganese ions.
文摘An eco-friendly chemical reduction method was successfully used for the preparation of chitosan （CTS） composite films loaded with silver nanoparticles （AgNPs） by self assembly method using poly（ethylene glycol） as both reducing and stabilizing agent. UV-Vis spectra of the prepared chitosan loaded silver nanoparticles （CTSLAg） films reveal that full reduction of silver ions to silver nanoparticles takes place at 90 ℃. The effect of reaction conditions on the silver nanoparticles formation was investigated using UV-Vis spectrophotometer. The morphology of the films was tested by scanning electron microscopy （SEM）. The DSC curves showed that the CTSLAg film had a favorable compatibility and heat stability. AgNPs were confirmed by XRD and UV-Vis spectroscopy. The TEM findings revealed that the silver nanoparticles synthesized were spherical in shape with uniform dispersal, and by increasing CTS：PEG ratio larger silver nanoparticles could be obtained. The results of antibacterial study reveal that the prepared nanoeomposite films exhibited potential inhibition.
文摘The main objective of this study was to compare the results obtained with both virtual and experimental research methods, when the biomechanical behavior of teeth restored with esthetic posts was investigated. The finite element method was used to develop models of healthy maxillary canines and maxillary canines restored with definitive crowns and glass-fiber posts, quartzfiber posts, and titanium posts. Stress distribution was observed when external loads were applied. Load was applied in-vitro to analyse the fracture resistance of 48 maxillary canines restored in the same way as it was considered in the virtual method. The analysis of results using the finite element method led to the conclusion that restored teeth, in which the elastic modulus of the post was similar to that of the dentine and the material of the core had the best biomechanical performance. The experimental study validated the virtual analysis.
文摘It is a great advantage to design advanced materials with outstanding porosity and controllable band gab. In this study, （Fe, Ti）-containing mesoporous silica （x Fe/Ti-HMS） nanoparticles were prepared by a photo-assisted deposition PAD technique, where x is a nominal composition ofFe （l to 4 wt%））. The prepared samples were characterized by DR-UV, XRD, and TEM techniques. The results showed the insertion of Fe into intra-framework of Ti-HMS resulted in a gradual narrowing of the band gap of Ti-HMS samples with increment of Fe wt%. TEM observations reveal that Fe nanoparticles are evenly distributed within Ti-HSM matrix at different Fe wt%. Such results indicate the possibility to control the band gap of a single-site photocatalyst （Ti-HMS） by coupling it with the conventional nano-sized Fe catalysts.
文摘In this paper an attempt is made to recover sillimanite by flotation tree analysis process and conventional flotation process from non magnetic fraction of red sediments.The experimental results of both the processes are presented.The data reveal that the deslimed sample contains 33.2%(by weight) total heavy minerals and out of which the sillimanite mineral content is 3.6%(by weight).It is observed that flotation tree analysis needs 10 cells to get five output products and where as conventional flotation process needs 15 cells to recover similar grade of five output products.Thus,flotation tree analysis is not only economic process but also efficient process(to say efficient process,the tree analysis product should be higher grade).
文摘When a relatively new building is not being fully utilized, there must have existed, at one time, a change in its initial conditions. The aim of this research is to study the changes in the initial conditions which cause buildings to be underutilized and analyze whether the demolition was justified. Causes can be found in problems due to the building＇s management, as the owners make the main decisions concerning the buildings. Additionally problems are due to the location where the building is constructed because site conditions changes a lot in one generation. The use of the building can also be a cause of abandonment as the original use can end before the lifespan of the building. Architectural style can be dated as fashions and styles change rapidly. Finally, causes can be in the physical condition of the buildings： structure, construction, installations and adherence to current regulations. In this article, the authors provide guidelines demonstrating how buildings of a past generation which were initially considered obsolete, can be properly reused.
基金financed by Coordination for the Improvement of Higher Education Personnel,Brazil(CAPES,https://www.gov.br/capes/pt-br)(accessed on 22 September 2024)Finance Code 001(ESS,FDM)+1 种基金Sao Paulo State Research Support Foundation(FAPESP,https://fapesp.br/)(accessed on 22 September 2024)(CIC,grant number 2015/04660-0)National Council for Scientific and Technological Development(CNPq,https://www.gov.br/cnpq/pt-br)(accessed on 22 September 2024)(grant numbers 308937/2021-0(CIC),306576/2020-1(ECB),and 303099/2022-4(JBP)).
文摘Over the last decade,the oriented strand board(OSB)market presented meaningful growth.However,as a woodbased product,because of its anatomical structure and chemical composition,OSB can be damaged by biodeterioration agents.Given that,the biodeterioration of OSB panels must be investigated to improve its durability.In this way,this work analyses the biological resistance against termites(Cryptotermes brevis and Nasutitermes corniger)of heat-treated OSB panels made with Eucalyptus wood glued with vegetable-based polyurethane-an ecofriendly and sustainable adhesive derived from castor oil.Various panels were produced with different layers compositions(face:core:face of 25:50:25 and 30:40:30)in wood mass proportion and were submitted to postproduction heat treatment(at 175℃ and 200℃)replacing the use of chemical insecticides.The influence of the layers variation and heat treatment temperature were evaluated,and these results were compared with commercial panels(made from pinus wood with insecticide).The results showed that the heat treatment did not improve the resistance against termite attack.However,all the experimental panels presented a satisfactory performance that was compatible with the commercial panels produced with insecticide available in the Brazilian market.The combination of Eucalyptus wood and castor oil adhesive to produce OSB,in any variation of layer composition,demonstrated natural resistance against termite attack compatible with the commercial panels,even without using chemical additives to increase durability.
基金supported by the National Key Research and Development Program of China(2023YFB3712500)the National Natural Science Foundation of China(52273142,52033005,U23A20583)the Science and Technology Department of Sichuan Province(2024NSFTD0003).
文摘Polymer crystallization,an everlasting subject in polymeric materials,holds great significance not only as a fundamental theoretical issue but also as a pivotal basis for directing polymer processing.Given its multistep,rapid,and thermodynamic nature,tracing and comprehending polymer crystallization pose a formidable challenge,particularly when it encounters practical processing scenarios that involve complex coupledfields(such as temperature,flow,and pressure).The advent of high-time and spatially resolved experiments paves the way for in situ investigations of polymer crystallization.In this review,we delve into the strides in studying polymer crystallization under the effects of coupled externalfields via state-of-the-art high-throughput experiments.We highlight the intricate setup of these high-throughput experimental devices,spanning from the laboratory and pilot levels to the industrial level.The individual and combined effects of externalfields on polymer crystallization are discussed.By breaking away from the conventional“black box”research approach,special interest is paid to the in situ crystalline behavior of polymers during realistic processing.Finally,we underscore the advancements in polymer crystallization via high-throughput experiments and outline its promising development.
基金a part of the CNEPRU project N° D01920120039 supported by the ministry of high teaching and scientific research MESRS www.mesrs.dz
文摘We synthesized the pure and indium-doped （IZO） ZnO films with a facile composition control spray pyrolysis route. The substrate temperature （Ts） and In-doping effects on the properties of as-grown films are inves- tigated. The X-ray pattern confirms that the as-synthesized ZnO phase is grown along a （002） preferential plane. It is revealed that the crystalline structure is improved with a substrate temperature of 350 ℃ Moreover, the morphol- ogy of as-grown films, analyzed by AFM, shows nanostructures that have grown along the c-axis. The （3 ×3 μm2） area scanned AFM surface studies give the smooth film surface RMS 〈 40 nm. The UV-VIS-IR measurements reveal that the sprayed films are highly transparent in the visible and IR bands. The photoluminescence analysis shows that the strong blue and yellow luminescences of 2.11 and 2.81 eV are emitted from ZnO and IZO films with a slight shift in photon energy caused by In-doping. The band gap is a bit widened by In-doping, 3.21 eV （ZnO） and 3.31 eV （IZO） and the resistivity is reduced from 385 to 8Ω·m. An interesting result is the resistivity linear dependence on the substrate temperature of pure ZnO films.
基金Project supported the PNR (Nos. 8/U311/R77, U311/R81)the "Agencethematique de rechercheen science ettechnologie" (ATRST)+2 种基金the National Administration of Scientific Researchthe CNEPRU of Oran University of Sciences and Technology (No. B00L02UN310220130011)the Scientific Research Projects Coordination (Nos. 2012-01-01-KAP05, 2012-01-01-KAP06) Yildiz Technical University
文摘The thin films of Cu2O are deposited by electrodeposition technique onto indium tin oxide（ITO）-coated glass substrate at different potentials. The precursor is an aqueous solution which contains respectively 0.05 M of CuSO4 and citric acid at kept temperature of 60℃ and the applied potential varies within the {-0：4 V,-0：7 V}SCE range. Based on the chronocoulometry（CC） process, the electrochemical, structural and optical parameters are determined. We measured the current as function of potential within the {-0：4 V,-0：7 V} range and the higher current is found to be within the {-0：7 V,-0：3 V} band. The grain sizes are of 12.12 nm and 35.47 nm according to（110） and（221） orientations respectively. The high textural coefficient of 0.943 is recorded for the potential -0：7 V.The transmittance of 72.25 %, within the visible band, is obtained for the as-grown layer at -0：4 V and the band gap is found to be 2.2 e V for the electrodeposition potential of -0：7 V.
基金supported by the Algerian Ministry of High Education and Scientific Research through the CNEPRU Project(No.B00L002UN310220130011)the Anvredet Project N°18/DG/2016 “Projet Innovant:Synthèse et Caractérisation de Films Semiconducteurs Nanostructurés et Fabrication de Cellule Solaire”
文摘Control of the electronic parameters on a novel metal–oxide–semiconductor（MOS）diode by indium doping incorporation is emphasized and investigated.The electronic parameters,such as ideality factor,barrier height（BH）,series resistance,and charge carrier density are extracted from the current–voltage（I–V）and the capacitance–voltage（C–V）characteristics.The properties of the MOS diode based on 4%,6% and 8% indium doped tin oxide are largely studied.The Ag/SnO2/nSi/Au MOS diode is fabricated by spray pyrolysis route,at 300℃ from the In-doped SnO2layer.This was grown onto n-type silicon and metallic（Au）contacts which were made by thermal evaporation under a vacuum@10^-5 Torr and having a thickness of 120 nm and a diameter of 1 mm.Determined by the Cheung-Cheung approximation method,the series resistance increases（334–534Ω）with the In doping level while the barrier height（BH）remains constant around 0.57 V.The Norde calculation technique gives a similar BH value of 0.69 V but the series resistance reaches higher values of 5500Ω.The indium doping level influences on the characteristics of Ag/SnO2：In/Si/Au MOS diode while the 4% indium level causes the capacitance inversion and the device turns into p-type material.
文摘The environmentally sustainable disposal and recycling of ever increasing volumes of electronic waste has become a global waste management issue. The addition of up to 25% polymeric waste PCBs （printed circuit boards） as fillers in polypropylene （PP） composites was partially successful： while the tensile modulus, flexural strength and tlexural modulus of composites were enhanced, the tenstle and impact strengths were found to decrease. As a lowering of impact strength can significantly limit the application of PP based composites, it is necessary to incorporate impact modifying polymers such as rubbery particles in the mix. We report on a novel investigation on the simultaneous utilization of electronic and automotive rubber waste as fillers in PP composites. These composites were prepared by using 25 wt.% polymeric PCB powder, up to 9% of ethylene propylene rubber （EPR）, and PP： balance. The influence of EPR on the structural, thermal, mechanical and rheological properties of PP/PCB/ EPR composites was investigated. While the addition of EPR caused the nucleation of the I~ crystalline phase of PP, the onset temperature for thermal degradation was found to decrease by 8%. The tensile modulus and strength decreased by 1 b% and 19%, respectively; and the elongataon at break increased by -71%. The impact strength showed a maximum increase of-18% at 7 wt.%-9 wt.% EPR content. Various rheological properties were found to be well within the range of processing limits. This novel eco-friendly approach could help utilize significant amounts of polymeric electronic and automotive waste for fabricating valuable polymer composites.
