Nowadays, silicon-based photovoltaic (PV) panels that directly convert sunlight into electricity have been commercially available for both individual buildings and small-scale power plants. However, the production of crystalline silicon PV modules consumes a lot of energy and fossil fuels, thus the whole life cycle of silicon solar cells is not as green as you think. Therefore, researchers have been exploring low-cost and energy-efficient non-silicon-based PV technologies for decades, among which the halide perovskitebased PV quickly stood out and has attracted tremendous research efforts due to its simple solution-based fabrication and competitive power conversion efficiency (PCE). Pioneered by Prof. Tsutomu Miyasaka and colleagues from Toin University of Yokohama in Japan in 2009, the labscale halide perovskite PV device has witnessed a PCE enhancement from 3.8% to above 20%, which is comparable to silicon, during just one decade. Currently, the commercialization of halide perovskite solar cells is hindered by two profound issues. The first obstacle is the long-term instability under operational conditions involving atmospheric moisture, raised temperature, and real sunlight. For example, CH3NH3PbI3, a typical high-efficiency perovskite PV material, degrades easily at 120 °C. Second, the high-efficiency perovskites contain the toxic lead element, which can potentially harm the environment and human health and thus has been a major concern for commercialization. Many efforts have been devoted to addressing these issues. Especially, the compositional tuning of the perovskites, like the mixing of cations and anions, has led to remarkable improvements. At present, further research in the direction of compositional engineering is urgently desired to balance the stability, efficiency, and toxicity issues of perovskites. In this issue, we have two articles on halide perovskites with non-traditional compositions. Bhorde et al. incorporated Rb in Bi-based double perovskite and synthesized Rb2AgBiI6 perovskite thin films for the first time. This lead-free halide double perovskite showed a bandgap of about 1.98 eV and superior thermal stability at a temperature as high as 440 °C, which indicates promising applications in non-toxic and thermally-stable perovskite photovoltaics and optoelectronics. Jathar et al. report a facile synthesis method of an inorganic metal halide perovskite, CsPbBr3, which could help accelerate the synthesis of compositionally adjusted perovskites. Besides the perovskite research, this issue also collects articles on the compositional engineering of other important materials. The (Gd,Y)AG:Ce based phosphors have attracted much attention because of the excellent yellow light emission properties. Ma et al. partly substituted Al in (Gd,Y)AG:Ce by Ga or Mg, Si ions, and observed tunable color emission as the concentrations of the compositions changed. As for ceramic composites, Yang et al. added 0.3% content of graphene platelets to t
{"title":"Compositional Engineering of Halide Perovskites","authors":"Qin-Yi Li","doi":"10.30919/ESMM5F430","DOIUrl":"https://doi.org/10.30919/ESMM5F430","url":null,"abstract":"Nowadays, silicon-based photovoltaic (PV) panels that directly convert sunlight into electricity have been commercially available for both individual buildings and small-scale power plants. However, the production of crystalline silicon PV modules consumes a lot of energy and fossil fuels, thus the whole life cycle of silicon solar cells is not as green as you think. Therefore, researchers have been exploring low-cost and energy-efficient non-silicon-based PV technologies for decades, among which the halide perovskitebased PV quickly stood out and has attracted tremendous research efforts due to its simple solution-based fabrication and competitive power conversion efficiency (PCE). Pioneered by Prof. Tsutomu Miyasaka and colleagues from Toin University of Yokohama in Japan in 2009, the labscale halide perovskite PV device has witnessed a PCE enhancement from 3.8% to above 20%, which is comparable to silicon, during just one decade. Currently, the commercialization of halide perovskite solar cells is hindered by two profound issues. The first obstacle is the long-term instability under operational conditions involving atmospheric moisture, raised temperature, and real sunlight. For example, CH3NH3PbI3, a typical high-efficiency perovskite PV material, degrades easily at 120 °C. Second, the high-efficiency perovskites contain the toxic lead element, which can potentially harm the environment and human health and thus has been a major concern for commercialization. Many efforts have been devoted to addressing these issues. Especially, the compositional tuning of the perovskites, like the mixing of cations and anions, has led to remarkable improvements. At present, further research in the direction of compositional engineering is urgently desired to balance the stability, efficiency, and toxicity issues of perovskites. In this issue, we have two articles on halide perovskites with non-traditional compositions. Bhorde et al. incorporated Rb in Bi-based double perovskite and synthesized Rb2AgBiI6 perovskite thin films for the first time. This lead-free halide double perovskite showed a bandgap of about 1.98 eV and superior thermal stability at a temperature as high as 440 °C, which indicates promising applications in non-toxic and thermally-stable perovskite photovoltaics and optoelectronics. Jathar et al. report a facile synthesis method of an inorganic metal halide perovskite, CsPbBr3, which could help accelerate the synthesis of compositionally adjusted perovskites. Besides the perovskite research, this issue also collects articles on the compositional engineering of other important materials. The (Gd,Y)AG:Ce based phosphors have attracted much attention because of the excellent yellow light emission properties. Ma et al. partly substituted Al in (Gd,Y)AG:Ce by Ga or Mg, Si ions, and observed tunable color emission as the concentrations of the compositions changed. As for ceramic composites, Yang et al. added 0.3% content of graphene platelets to t","PeriodicalId":11851,"journal":{"name":"ES Materials & Manufacturing","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75396843","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}
Pure Sr 2 CeO 4 phosphor and Sr 2 CeO 4 doped with europium (0.5, 1.0, 1.5, 2.0, 4.0 mol%) phosphor were synthesized by the sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectra were used to characterize the pure Sr 2 CeO 4 and Sr 2 CeO 4 :Eu 3+ nano phosphor. It is a well-known fact that the crystallinity of the material increases with increase in the calcination temperature. Hence to study the effect of calcination temperature on the sol-gel synthesized phosphor (Sr 2 CeO 4 :Eu 3+ (2.0 mol%)), the phosphor was fired at various temperatures 1000, 1100 and 1200 ℃ for 2hrs respectively and it was found that the photoluminescence intensity of Sr 2 CeO 4 :Eu 3+ nano phosphor increases with the increase of calcination temperature. Sr 2 CeO 4 :Eu 3+ nano phosphor has an excellent colour tunability of red light with different concentration of europium and hence it can be a promising candidate for LED lighting Applications.
{"title":"Effect of Calcination Temperature on Photoluminescence Intensity of Sol-Gel prepared Sr2CeO4: Eu3+ Nano Phosphor","authors":"Paleena Thulimilli","doi":"10.30919/ESMM5F429","DOIUrl":"https://doi.org/10.30919/ESMM5F429","url":null,"abstract":"Pure Sr 2 CeO 4 phosphor and Sr 2 CeO 4 doped with europium (0.5, 1.0, 1.5, 2.0, 4.0 mol%) phosphor were synthesized by the sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectra were used to characterize the pure Sr 2 CeO 4 and Sr 2 CeO 4 :Eu 3+ nano phosphor. It is a well-known fact that the crystallinity of the material increases with increase in the calcination temperature. Hence to study the effect of calcination temperature on the sol-gel synthesized phosphor (Sr 2 CeO 4 :Eu 3+ (2.0 mol%)), the phosphor was fired at various temperatures 1000, 1100 and 1200 ℃ for 2hrs respectively and it was found that the photoluminescence intensity of Sr 2 CeO 4 :Eu 3+ nano phosphor increases with the increase of calcination temperature. Sr 2 CeO 4 :Eu 3+ nano phosphor has an excellent colour tunability of red light with different concentration of europium and hence it can be a promising candidate for LED lighting Applications.","PeriodicalId":11851,"journal":{"name":"ES Materials & Manufacturing","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78468144","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}
Hexagonal boron nitride nanofibers with high specific surface were successfully prepared through precursor pyrolysis method via boric acid, melamine and polyethylene glycol (PEG) as raw materials. The field emission scanning electron microscopy images showed that hexagonal boron nitride (h-BN) nanofibers were well aligned, and exhibited good fibrous structure. Chemical composition of the synthesized h-BN nanofibers was analyzed by X-ray diffraction, fourier transform infrared spectroscopy and thermogravimetric. Effects of precursor drying method and the PEG contents on morphologies and the specific surface area were investigated and optimized. Results indicated that the diameter of h-BN nanofibers increased with the ratio of boric acid to melamine, and their aspect ratios were greatly improved from 20 to 30 after freeze-drying treatment. Specific surface area of the h-BN nanofibers was increased from 65.25 to 319.07 m 2 /g due to the freeze-drying treatment. Besides, the content of PEG also obviously improved specific surface area. When the PEG content reached 2%, specific surface area of the h-BN nanofibers from the air-dried precursor was increased by 12.4 times to 874.58 m 2 /g. The resulted h-BN nanofibers show promising and potential applications in many fields including catalysis, hydrogen storage and environment.
{"title":"Highly Efficient Synthesis of Hexagonal Boron Nitride Nanofibers with High Specific Surface Area","authors":"Hongshou Liu, Zhaoqian Yan, Zhihao Sun, Anran Li, Zihao Guo, Lei Qian","doi":"10.30919/esmm5f561","DOIUrl":"https://doi.org/10.30919/esmm5f561","url":null,"abstract":"Hexagonal boron nitride nanofibers with high specific surface were successfully prepared through precursor pyrolysis method via boric acid, melamine and polyethylene glycol (PEG) as raw materials. The field emission scanning electron microscopy images showed that hexagonal boron nitride (h-BN) nanofibers were well aligned, and exhibited good fibrous structure. Chemical composition of the synthesized h-BN nanofibers was analyzed by X-ray diffraction, fourier transform infrared spectroscopy and thermogravimetric. Effects of precursor drying method and the PEG contents on morphologies and the specific surface area were investigated and optimized. Results indicated that the diameter of h-BN nanofibers increased with the ratio of boric acid to melamine, and their aspect ratios were greatly improved from 20 to 30 after freeze-drying treatment. Specific surface area of the h-BN nanofibers was increased from 65.25 to 319.07 m 2 /g due to the freeze-drying treatment. Besides, the content of PEG also obviously improved specific surface area. When the PEG content reached 2%, specific surface area of the h-BN nanofibers from the air-dried precursor was increased by 12.4 times to 874.58 m 2 /g. The resulted h-BN nanofibers show promising and potential applications in many fields including catalysis, hydrogen storage and environment.","PeriodicalId":11851,"journal":{"name":"ES Materials & Manufacturing","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81212432","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}
The tunable friction behavior of Chitosan (CS)-Ag hydrogel enabled by altering silver ions is evaluated. Friction control could be achieved under boundary lubrication. When adding Ag + into a CS solution, the formed gel provided lower friction. The difference in friction coefficient between the two phases can be reversibly switched by adding Cl - or excessive Ag + ions. It also can be found that the gel phased lubricant has a better anti-wear ability under boundary lubrication conditions. Both solution and gel typed lubricants could achieve superlubricity under elastohydrodynamic lubrication. The switchable and tunable frictional hydrogels can extend the application in the design of smart control equipment. hydrogels to very The gel-network to the facile of metal ions with amino and hydroxy groups in chitosan (CS) chains. These hydrogels were also shown to be responsive to a variety of external stimuli, including pH-value, chemical redox reactions, cations, anions, and neutral species.
{"title":"Friction Control of Chitosan-Ag Hydrogel by Silver Ion","authors":"Jing Hua, M. Björling, R. Larsson, Y. Shi","doi":"10.30919/esmm5f555","DOIUrl":"https://doi.org/10.30919/esmm5f555","url":null,"abstract":"The tunable friction behavior of Chitosan (CS)-Ag hydrogel enabled by altering silver ions is evaluated. Friction control could be achieved under boundary lubrication. When adding Ag + into a CS solution, the formed gel provided lower friction. The difference in friction coefficient between the two phases can be reversibly switched by adding Cl - or excessive Ag + ions. It also can be found that the gel phased lubricant has a better anti-wear ability under boundary lubrication conditions. Both solution and gel typed lubricants could achieve superlubricity under elastohydrodynamic lubrication. The switchable and tunable frictional hydrogels can extend the application in the design of smart control equipment. hydrogels to very The gel-network to the facile of metal ions with amino and hydroxy groups in chitosan (CS) chains. These hydrogels were also shown to be responsive to a variety of external stimuli, including pH-value, chemical redox reactions, cations, anions, and neutral species.","PeriodicalId":11851,"journal":{"name":"ES Materials & Manufacturing","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74400433","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}
Vitus Mwinteribo Tabie, Xiao-jing Xu, Liangliang Wei, Xiangzhong Shi
Ti-4Si-xZr-yY2O3/5TiO2 matrix composites, containing various weight percentages (0 and 1.3) of zirconium and (0 and 0.3) yttrium oxide, were synthesized via ball milling and powder metallurgical route. Mechanical alloying of the powders was confirmed after ball milling using x-ray diffraction (XRD) and scanning electron microscope (SEM). The ball-milled powders were cold compacted at a pressure of 550 MPa. Sintering was done first at 600 °C for 2h, followed by 800 °C for 2h, then 1000 °C for 2h and finally at 1250 °C for 3h, all in a controlled vacuum environment. The effect of the addition in weight percentages of Zr and Y2O3 on the microstructure, porosity, hardness, elastic modulus, and fracture toughness of the sintered composites, were studied. The results show improvements in the microhardness by 2.2 times, elastic modulus by 34.3%, porosity by 50 %, and fracture toughness by 57%, when Zr and Y2O3 content was 1.3 wt% and 0.3 wt%, respectively. The improvements in the microstructure and mechanical properties can be attributed to the formation of more stable; Ti5Si3 and Ti5Si4 phases and the solid solutions of Ti2Zr, Zr3Si2, and Ti2Zr3Si3 compounds.
{"title":"The Effect of Zirconium and Yttrium Oxide on the Microstructure and Mechanical Properties of Ti-Si-Zr Based Composites","authors":"Vitus Mwinteribo Tabie, Xiao-jing Xu, Liangliang Wei, Xiangzhong Shi","doi":"10.30919/esmm5f551","DOIUrl":"https://doi.org/10.30919/esmm5f551","url":null,"abstract":"Ti-4Si-xZr-yY2O3/5TiO2 matrix composites, containing various weight percentages (0 and 1.3) of zirconium and (0 and 0.3) yttrium oxide, were synthesized via ball milling and powder metallurgical route. Mechanical alloying of the powders was confirmed after ball milling using x-ray diffraction (XRD) and scanning electron microscope (SEM). The ball-milled powders were cold compacted at a pressure of 550 MPa. Sintering was done first at 600 °C for 2h, followed by 800 °C for 2h, then 1000 °C for 2h and finally at 1250 °C for 3h, all in a controlled vacuum environment. The effect of the addition in weight percentages of Zr and Y2O3 on the microstructure, porosity, hardness, elastic modulus, and fracture toughness of the sintered composites, were studied. The results show improvements in the microhardness by 2.2 times, elastic modulus by 34.3%, porosity by 50 %, and fracture toughness by 57%, when Zr and Y2O3 content was 1.3 wt% and 0.3 wt%, respectively. The improvements in the microstructure and mechanical properties can be attributed to the formation of more stable; Ti5Si3 and Ti5Si4 phases and the solid solutions of Ti2Zr, Zr3Si2, and Ti2Zr3Si3 compounds.","PeriodicalId":11851,"journal":{"name":"ES Materials & Manufacturing","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82010739","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}
Civilian air transportation is changing rapidly, is undergoing a renaissance with truly major societal and wide-ranging commercial and industrial level implications. This renaissance is enabled by a plethora of advanced to revolutionary technologies including renewable / “green”/ increasingly inexpensive energy, electric propulsion, nanomaterials and materials processing, printing manufacture, artificial intelligence (AI)/autonomy, an emerging global sensor grid, safety/reliability attainment, miniaturization and resilient navigation and communications. The major component of this renaissance is an ongoing shift to essentially emissionless fly/drive aircraft including personal aircraft, the latter flown from the local street, eventually replacing much of ground transportation and scheduled commercial air traffic. Due to the projected tremendous increase in the number of flying vehicles, autonomous vehicle operation and air traffic control will be essential. The buildout of the personal aircraft markets is projected to be the order of $1T/ year. The benefits of such personal air transportation include major reduced costs for roads and bridges and current auto infrastructures, much shortened travel time, the electric propulsion recharged by renewables resulting in major favorable climate, ecosystem and pollution impacts, and autonomous operation proffers the possibility of saving lives. The applications for small/personal class aircraft include an extensive number of service, business, and governmental uses and far longer, easier, faster commute possibilities. Given projected vehicle improvements and a suitable air traffic control (ATC) system, personal air vehicles could replace much of domestic airline service. They can be used for sport, and should be suitable, being autonomous, for use by the aged and the infirm. The emerging competition for this aero renaissance was apparent in the major-to-historic COVID-19 impacts upon air travel. Tele-travel, immersive, virtual presence as an alternative to air travel has long been under development. The technology, especially bandwidth and virtual reality, has been developed to where this alternative to physical travel is now a serious competition for physical travel of all varieties as proven in the COVID 19 impacts. Tele-travel is one aspect of the rapidly developing tele-everything virtual age that we are entering, including tele-work, tele-commuting, tele-education, tele-medicine, tele-shopping, tele-commerce writ large, telepolitics/entertainment/socialization and with onsite printers, tele-manufacturing. The tele-travel benefits include far less cost, major reductions in climate impacts, far less time, minimal time away from family etc., and far more engagement opportunities, efficiency. For long haul air transport at transonic and supersonic speeds, projections include emissionless electrics with increasing ranges recharged or via green fuels produced by the cost reductions of renewable energy. Then
{"title":"Prospective Futures of Civilian Air Transportation","authors":"D. Bushnell","doi":"10.30919/esmm5f565","DOIUrl":"https://doi.org/10.30919/esmm5f565","url":null,"abstract":"Civilian air transportation is changing rapidly, is undergoing a renaissance with truly major societal and wide-ranging commercial and industrial level implications. This renaissance is enabled by a plethora of advanced to revolutionary technologies including renewable / “green”/ increasingly inexpensive energy, electric propulsion, nanomaterials and materials processing, printing manufacture, artificial intelligence (AI)/autonomy, an emerging global sensor grid, safety/reliability attainment, miniaturization and resilient navigation and communications. The major component of this renaissance is an ongoing shift to essentially emissionless fly/drive aircraft including personal aircraft, the latter flown from the local street, eventually replacing much of ground transportation and scheduled commercial air traffic. Due to the projected tremendous increase in the number of flying vehicles, autonomous vehicle operation and air traffic control will be essential. The buildout of the personal aircraft markets is projected to be the order of $1T/ year. The benefits of such personal air transportation include major reduced costs for roads and bridges and current auto infrastructures, much shortened travel time, the electric propulsion recharged by renewables resulting in major favorable climate, ecosystem and pollution impacts, and autonomous operation proffers the possibility of saving lives. The applications for small/personal class aircraft include an extensive number of service, business, and governmental uses and far longer, easier, faster commute possibilities. Given projected vehicle improvements and a suitable air traffic control (ATC) system, personal air vehicles could replace much of domestic airline service. They can be used for sport, and should be suitable, being autonomous, for use by the aged and the infirm. The emerging competition for this aero renaissance was apparent in the major-to-historic COVID-19 impacts upon air travel. Tele-travel, immersive, virtual presence as an alternative to air travel has long been under development. The technology, especially bandwidth and virtual reality, has been developed to where this alternative to physical travel is now a serious competition for physical travel of all varieties as proven in the COVID 19 impacts. Tele-travel is one aspect of the rapidly developing tele-everything virtual age that we are entering, including tele-work, tele-commuting, tele-education, tele-medicine, tele-shopping, tele-commerce writ large, telepolitics/entertainment/socialization and with onsite printers, tele-manufacturing. The tele-travel benefits include far less cost, major reductions in climate impacts, far less time, minimal time away from family etc., and far more engagement opportunities, efficiency. For long haul air transport at transonic and supersonic speeds, projections include emissionless electrics with increasing ranges recharged or via green fuels produced by the cost reductions of renewable energy. Then","PeriodicalId":11851,"journal":{"name":"ES Materials & Manufacturing","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90570317","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}
Medha Gijare, Sharmila Chaudhari, S. Ekar, A. Garje
Present work proposes green synthesis of reduced graphene oxide using lemon peel extract(vitamin-c) and its application as an electrochemical nonenzymatic human serum glucose sensor. Improved modified Hummer’s method was preferred for the preparation of graphene oxide. X-ray diffraction (XRD), Ultraviolet-visible absorption spectroscopy (UV-Vis) and X-ray photon spectroscopy (XPS) analysis revealed the successful reduction of Graphene oxide (GO) using lemon peel extract. Field emission scanning electron microscopy (FESEM), Fourier transform infra-red spectroscopy (FTIR) and Raman spectroscopy supports the formation of reduced graphene oxide (rGO) nanosheets. The proposed glucose sensor exhibits high sensitivity of 1402 μA·cm −2 mM −1 (S/N=3) along with correlation coefficient of 0.9887 and low detection limit of 0.011 μM. The sensor has detected glucose with RSD of 1.99% in human blood serum. The measured values are well agreed with the values obtained using professional glucose sensor used in hospitals.
{"title":"Reduced Graphene Oxide Based Electrochemical Nonenzymatic Human Serum Glucose Sensor","authors":"Medha Gijare, Sharmila Chaudhari, S. Ekar, A. Garje","doi":"10.30919/esmm5f486","DOIUrl":"https://doi.org/10.30919/esmm5f486","url":null,"abstract":"Present work proposes green synthesis of reduced graphene oxide using lemon peel extract(vitamin-c) and its application as an electrochemical nonenzymatic human serum glucose sensor. Improved modified Hummer’s method was preferred for the preparation of graphene oxide. X-ray diffraction (XRD), Ultraviolet-visible absorption spectroscopy (UV-Vis) and X-ray photon spectroscopy (XPS) analysis revealed the successful reduction of Graphene oxide (GO) using lemon peel extract. Field emission scanning electron microscopy (FESEM), Fourier transform infra-red spectroscopy (FTIR) and Raman spectroscopy supports the formation of reduced graphene oxide (rGO) nanosheets. The proposed glucose sensor exhibits high sensitivity of 1402 μA·cm −2 mM −1 (S/N=3) along with correlation coefficient of 0.9887 and low detection limit of 0.011 μM. The sensor has detected glucose with RSD of 1.99% in human blood serum. The measured values are well agreed with the values obtained using professional glucose sensor used in hospitals.","PeriodicalId":11851,"journal":{"name":"ES Materials & Manufacturing","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76233984","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}
Jinrui Zhang, Ziye Kang, D. Hou, Biqin Dong, Hongyan Ma
Acoustic emission (AE) signals detected from corrosion test on a steel reinforced concrete beam subjected to the coupling effects of corrosive wet-dry cycles and static load are analyzed by power spectral density, wavelet transform, and Shannon entropy. The degradation process of the corroded reinforced concrete beam can be divided into four stages on the basis of the accumulated event number (AEN). Due to the difference of material properties, steel reinforcement and concrete matrix have distinguished AE features. The time-frequency characteristics of AE signals can reflect the microstructural degradation mechanism of steel corrosion and concrete cracking. The corrosion evaluation entails investigating the evolution of the wavelet power mathematically by Shannon entropy. The frequency-entropy clearly exhibits the relative power distribution of AE signal in a certain frequency region. With the accumulation of steel corrosion and concrete deterioration, the increment of the overall entropy integration is considerably apparent. The variation of frequency-entropy curve reveals the corrosion revolution of the reinforced concrete members under static load, which is represented by a transforming from corrosion-induced micro cracking to load-induced localized cracking.
{"title":"Wavelet Power and Shannon Entropy Applied to Acoustic Emission Signals for Corrosion Detection and Evaluation of Reinforced Concrete","authors":"Jinrui Zhang, Ziye Kang, D. Hou, Biqin Dong, Hongyan Ma","doi":"10.30919/esmm5f554","DOIUrl":"https://doi.org/10.30919/esmm5f554","url":null,"abstract":"Acoustic emission (AE) signals detected from corrosion test on a steel reinforced concrete beam subjected to the coupling effects of corrosive wet-dry cycles and static load are analyzed by power spectral density, wavelet transform, and Shannon entropy. The degradation process of the corroded reinforced concrete beam can be divided into four stages on the basis of the accumulated event number (AEN). Due to the difference of material properties, steel reinforcement and concrete matrix have distinguished AE features. The time-frequency characteristics of AE signals can reflect the microstructural degradation mechanism of steel corrosion and concrete cracking. The corrosion evaluation entails investigating the evolution of the wavelet power mathematically by Shannon entropy. The frequency-entropy clearly exhibits the relative power distribution of AE signal in a certain frequency region. With the accumulation of steel corrosion and concrete deterioration, the increment of the overall entropy integration is considerably apparent. The variation of frequency-entropy curve reveals the corrosion revolution of the reinforced concrete members under static load, which is represented by a transforming from corrosion-induced micro cracking to load-induced localized cracking.","PeriodicalId":11851,"journal":{"name":"ES Materials & Manufacturing","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90492086","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}
Avinash R. Kachere, Prashant M. Kakade, Archana R. Kanwade, Priyanka Dani, Nandkumar T. Mandlik, Sachin R. Rondiya, N. Dzade, S. Jadkar, S. Bhosale
In this research, the synthesis of high-quality zinc oxide (ZnO) and graphene oxide (GO) nanocomposite (ZnO/GO nanocomposite) was carried out using the simple and efficient hydrothermal method. The ZnO and GO were separately synthesised by using the precipitation and modified Hummer’s method, respectively. Likewise, the effects of different concentrations of GO on the structural and optical properties of ZnO nanoparticles were investigated. All the desired samples were structurally characterized by X-ray diffraction (XRD) and Raman spectroscopy. Those structural characterised techniques indicate the presence of characteristic peaks of ZnO, GO and related elements in the ZnO/GO nanocomposite. Scanning electron microscopy showed that some portions of the spherical shaped ZnO nanoparticles reacted with GO nanosheets to form ZnO nanorods with the formation of reduced graphene oxide (r-GO). UV-Visible and photoluminescence spectroscopy revealed that the optical properties of the ZnO/GO nanocomposite were affected by the GO concentration. The narrowing of optical band gap in the ZnO/GO nanocomposite was observed to pure ZnO sample. The improved optical properties displayed by the ZnO/GO nanocomposites makes them suitable for applications like UV-Vis optoelectronics devices and photocatalytic applications.
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