Pub Date : 2021-10-11DOI: 10.4028/www.scientific.net/NHC.33.93
W. R. Saleh, S. Hassan, S. Y. Al-Dabagh, M. Marwa
Infrared photoconductive detectors working in the far-infrared region and room temperature were fabricated. The detectors were fabricated using three types of carbon nanotubes (CNTs); MWCNTs, COOH-MWCNTs, and short-MWCNTs. The carbon nontubes suspension is deposited by dip coating and drop–casting techniques to prepare thin films of CNTs. These films were deposited on porous silicon (PSi) substrates of n-type Si. The I-V characteristics and the figures of merit of the fabricated detectors were measured at a forward bias voltage of 3 and 5 volts as well as at dark and under illumination by IR radiation from a CO2 laser of 10.6 μm wavelengths and power of 2.2 W. The responsivity and figures of merit of the photoconductive detector are improved by coating the MWCNTs films with a thin layer of a blend (polyaniline - polymethyl methacrylate) polymer with methylene blue dye. The coated MWCNTs films showed better performances, so this type of coating can be considered as a surface treatment of the detector film, which highly increased the responsivity and specific detectivity of the fabricated IR laser detector-based MWCNTs. The photocurrent response for the coated films was increased about 25 times than that for uncoated films. The results proved the role of the polymer in the enhancement of the performance of the IR photoconductive detectors. Keywords: Carbon nanotubes, Infrared detector, Polyaniline polymer, Polymethyl methacrylate polymer, Methyl Blue dye.
{"title":"Far Infrared Laser Detector Based on Multi-Walled Carbon Nanotubes and Blend of (Polyaniline - Polymethyl Methacrylate) Polymers with Methyl Blue Dye for Photoconductive Applications","authors":"W. R. Saleh, S. Hassan, S. Y. Al-Dabagh, M. Marwa","doi":"10.4028/www.scientific.net/NHC.33.93","DOIUrl":"https://doi.org/10.4028/www.scientific.net/NHC.33.93","url":null,"abstract":"Infrared photoconductive detectors working in the far-infrared region and room temperature were fabricated. The detectors were fabricated using three types of carbon nanotubes (CNTs); MWCNTs, COOH-MWCNTs, and short-MWCNTs. The carbon nontubes suspension is deposited by dip coating and drop–casting techniques to prepare thin films of CNTs. These films were deposited on porous silicon (PSi) substrates of n-type Si. The I-V characteristics and the figures of merit of the fabricated detectors were measured at a forward bias voltage of 3 and 5 volts as well as at dark and under illumination by IR radiation from a CO2 laser of 10.6 μm wavelengths and power of 2.2 W. The responsivity and figures of merit of the photoconductive detector are improved by coating the MWCNTs films with a thin layer of a blend (polyaniline - polymethyl methacrylate) polymer with methylene blue dye. The coated MWCNTs films showed better performances, so this type of coating can be considered as a surface treatment of the detector film, which highly increased the responsivity and specific detectivity of the fabricated IR laser detector-based MWCNTs. The photocurrent response for the coated films was increased about 25 times than that for uncoated films. The results proved the role of the polymer in the enhancement of the performance of the IR photoconductive detectors. Keywords: Carbon nanotubes, Infrared detector, Polyaniline polymer, Polymethyl methacrylate polymer, Methyl Blue dye.","PeriodicalId":18861,"journal":{"name":"Nano Hybrids and Composites","volume":"29 1","pages":"93 - 103"},"PeriodicalIF":0.4,"publicationDate":"2021-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80406622","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 : 2021-10-11DOI: 10.4028/www.scientific.net/NHC.33.47
S. A. Shah, H. Nasir, S. Honey
In this work, graphene was produced by liquid-phase exfoliation of graphite in different organic solvents with addition of picric acid. The graphene was easily produced by one step ultra-sonication of graphite powder in the organic solvents. The addition of picric acid has increased the graphene production yield in most of the solvents tested in this work. Picric acid serves as a “molecular wedge” to intercalate into the edge of graphite, which plays a key role during sonication and significantly improves the production yield of graphene. The products were analyzed by microscopic techniques, including atomic force microscopy (AFM) and scanning electron microscope (SEM). The AFM images indicate that the exfoliation efficiency and amount of graphene increased by addition of picric acid in organic solvents. Moreover, the AFM images also indicate presence of bilayer graphene. SEM analysis also shows that the addition of picric acid into the organic solvent favors the exfoliation process. The produced graphene was also analyzed by XRD, FTIR, Raman and UV-visible spectroscopy. The XRD results illustrate that exfoliation was best achieved in N-methyl-2-pyrrolidone (NMP) as a solvent. FTIR and Raman results indicate that addition of picric acid has slightly defected the produced graphene surface. The amount of graphene concentration was calculated by using Beer Lambert law, and it was observed that the graphene production yield was increased by using picric acid in most of the solvents. The maximum amount of graphene concentration (0.159 mg/ml) was achieved by adding 30 mg of picric acid in NMP.
{"title":"Liquid-Phase Exfoliation of Graphene in Organic Solvents with Addition of Picric Acid","authors":"S. A. Shah, H. Nasir, S. Honey","doi":"10.4028/www.scientific.net/NHC.33.47","DOIUrl":"https://doi.org/10.4028/www.scientific.net/NHC.33.47","url":null,"abstract":"In this work, graphene was produced by liquid-phase exfoliation of graphite in different organic solvents with addition of picric acid. The graphene was easily produced by one step ultra-sonication of graphite powder in the organic solvents. The addition of picric acid has increased the graphene production yield in most of the solvents tested in this work. Picric acid serves as a “molecular wedge” to intercalate into the edge of graphite, which plays a key role during sonication and significantly improves the production yield of graphene. The products were analyzed by microscopic techniques, including atomic force microscopy (AFM) and scanning electron microscope (SEM). The AFM images indicate that the exfoliation efficiency and amount of graphene increased by addition of picric acid in organic solvents. Moreover, the AFM images also indicate presence of bilayer graphene. SEM analysis also shows that the addition of picric acid into the organic solvent favors the exfoliation process. The produced graphene was also analyzed by XRD, FTIR, Raman and UV-visible spectroscopy. The XRD results illustrate that exfoliation was best achieved in N-methyl-2-pyrrolidone (NMP) as a solvent. FTIR and Raman results indicate that addition of picric acid has slightly defected the produced graphene surface. The amount of graphene concentration was calculated by using Beer Lambert law, and it was observed that the graphene production yield was increased by using picric acid in most of the solvents. The maximum amount of graphene concentration (0.159 mg/ml) was achieved by adding 30 mg of picric acid in NMP.","PeriodicalId":18861,"journal":{"name":"Nano Hybrids and Composites","volume":"37 1","pages":"47 - 60"},"PeriodicalIF":0.4,"publicationDate":"2021-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90788307","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 : 2021-10-11DOI: 10.4028/www.scientific.net/NHC.33.105
Fateme Shayestenia, Mohadese Janmohammadi, S. Sadatsakkak, M. Ghadiri
Analysis of vibration stability of simply supported Euler-Bernoulli functionally graded (FG) nanobeam embedded in viscous elastic medium with thermal effect under external parametric excitation is presented in this work. An attempt has been made for the first time is investigating the effect of thermal load on dynamic behavior, amplitude response, instability region and bifurcation points of functionally graded nanobeam. Thermal loads are supposed to be uniform, linear or nonlinear distribution along the thickness direction. Nonlocal continuum theory and the principle of the minimum total potential energy are applied to derive the governing equations. The partial differential equations (PDE) are transported to the ordinary differential equations (ODE) by using the Petrov-Galerkin method and the multiple time scales method are manipulated to solve the motion equation. To study the effect of external parametric excitation and thermal effect, different temperature distributions along the thickness such as uniform, linear, and nonlinear distribution are considered. Moreover, stable and unstable regions and bifurcation points are determined. It is obtained that the thermal load can affect the amplitude response of FG nanobeam. Also, it is observed that the instability of the system is affected by the detuning parameter and the parametric excitation amplitude plays great role in the instability of system. Nanobeams are used in many devices like nanoresonators, nanosensors and nanoswitches. This paper is helpful for designing and manufacturing nanoscale structures specially nanoresonators under different thermal loads.
{"title":"Nonlinear Vibration and Stability Analysis of Functionally Graded Nanobeam Subjected to External Parametric Excitation and Thermal Load","authors":"Fateme Shayestenia, Mohadese Janmohammadi, S. Sadatsakkak, M. Ghadiri","doi":"10.4028/www.scientific.net/NHC.33.105","DOIUrl":"https://doi.org/10.4028/www.scientific.net/NHC.33.105","url":null,"abstract":"Analysis of vibration stability of simply supported Euler-Bernoulli functionally graded (FG) nanobeam embedded in viscous elastic medium with thermal effect under external parametric excitation is presented in this work. An attempt has been made for the first time is investigating the effect of thermal load on dynamic behavior, amplitude response, instability region and bifurcation points of functionally graded nanobeam. Thermal loads are supposed to be uniform, linear or nonlinear distribution along the thickness direction. Nonlocal continuum theory and the principle of the minimum total potential energy are applied to derive the governing equations. The partial differential equations (PDE) are transported to the ordinary differential equations (ODE) by using the Petrov-Galerkin method and the multiple time scales method are manipulated to solve the motion equation. To study the effect of external parametric excitation and thermal effect, different temperature distributions along the thickness such as uniform, linear, and nonlinear distribution are considered. Moreover, stable and unstable regions and bifurcation points are determined. It is obtained that the thermal load can affect the amplitude response of FG nanobeam. Also, it is observed that the instability of the system is affected by the detuning parameter and the parametric excitation amplitude plays great role in the instability of system. Nanobeams are used in many devices like nanoresonators, nanosensors and nanoswitches. This paper is helpful for designing and manufacturing nanoscale structures specially nanoresonators under different thermal loads.","PeriodicalId":18861,"journal":{"name":"Nano Hybrids and Composites","volume":"2 1","pages":"105 - 132"},"PeriodicalIF":0.4,"publicationDate":"2021-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89503951","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 : 2021-10-11DOI: 10.4028/www.scientific.net/NHC.33.13
A. A. Mohammed, Jawad K. Oleiwi, E. Al-Hassani
Polyetheretherketone (PEEK), as implants is broadly employed in orthopedic and dental uses owing to the brilliant chemical stability, biocompatibility and mechanical strength in addition to the modulus of elasticity alike the human bone. In the present work, the composite materials with PEEK as matrix and (n-HAp, n-TiO2) as the reinforced fillers loaded up to (1.5 wt%) were prepared by internal mixer and hot press. Following analysis by physical properties includes the thermal conductivity and the differential scanning calorimetry. Finite element analysis (FEA) was used to find the total deformation, Max. Von mises stress, elastic strain and safety factor. The results manifested that the thermal properties, total deformation and strain decreased with the increase of the reinforcement weight fraction, while, the stress and safety factor increased with the increased reinforcement weight fraction.
{"title":"The Effect of Nanoparticles (n-HAp, n-TiO2) on the Thermal Properties and Biomechanical Analysis of Polymeric Composite Materials for Dental Applications","authors":"A. A. Mohammed, Jawad K. Oleiwi, E. Al-Hassani","doi":"10.4028/www.scientific.net/NHC.33.13","DOIUrl":"https://doi.org/10.4028/www.scientific.net/NHC.33.13","url":null,"abstract":"Polyetheretherketone (PEEK), as implants is broadly employed in orthopedic and dental uses owing to the brilliant chemical stability, biocompatibility and mechanical strength in addition to the modulus of elasticity alike the human bone. In the present work, the composite materials with PEEK as matrix and (n-HAp, n-TiO2) as the reinforced fillers loaded up to (1.5 wt%) were prepared by internal mixer and hot press. Following analysis by physical properties includes the thermal conductivity and the differential scanning calorimetry. Finite element analysis (FEA) was used to find the total deformation, Max. Von mises stress, elastic strain and safety factor. The results manifested that the thermal properties, total deformation and strain decreased with the increase of the reinforcement weight fraction, while, the stress and safety factor increased with the increased reinforcement weight fraction.","PeriodicalId":18861,"journal":{"name":"Nano Hybrids and Composites","volume":"22 15 1","pages":"13 - 34"},"PeriodicalIF":0.4,"publicationDate":"2021-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82926208","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 : 2021-10-11DOI: 10.4028/www.scientific.net/NHC.33.61
P. Di Sia
Graphene has particularly interesting chemical and physical properties, including high chemical and mechanical resistance, excellent thermal and electric transport, high transparency. It combines the peculiarity of being an extremely light material with exceptional mechanical strength properties. Micro/nanoelectronics represents one of the key enabling technologies (KETs) of the future; it is the basis of innovation and competitiveness of almost all scientific and applicative sectors. Activities involving it are aimed at the development of new materials, processes, devices and technologies in a wide range of sectors, involving quantum information manipulation, multi-functional platforms, advanced materials, devices on flexible substrates. In the field of sensoristics, it is possible to create devices for applications in most sectors of global interest, such as punctual sensors, biosensors, specific transducers, multisensoristic systems, flexible sensoristic systems, multifunctional systems, advanced MEMS/MOEMS technologies for sensoristics, micro/nanoactuators, devices for energy convertion, gravimetric-electrochemical sensors. The paper provides an interesting overview of the possible applications of graphene in relation to its mechanical, thermal and optical properties, and relatively to the gas and biological sensoristic aspects, so as interesting informations for the increase in nanobio-devices performance by last efforts in theoretical nanophysics.
{"title":"New Results on Diffusion in Graphene Nanostructures for Sensoristics","authors":"P. Di Sia","doi":"10.4028/www.scientific.net/NHC.33.61","DOIUrl":"https://doi.org/10.4028/www.scientific.net/NHC.33.61","url":null,"abstract":"Graphene has particularly interesting chemical and physical properties, including high chemical and mechanical resistance, excellent thermal and electric transport, high transparency. It combines the peculiarity of being an extremely light material with exceptional mechanical strength properties. Micro/nanoelectronics represents one of the key enabling technologies (KETs) of the future; it is the basis of innovation and competitiveness of almost all scientific and applicative sectors. Activities involving it are aimed at the development of new materials, processes, devices and technologies in a wide range of sectors, involving quantum information manipulation, multi-functional platforms, advanced materials, devices on flexible substrates. In the field of sensoristics, it is possible to create devices for applications in most sectors of global interest, such as punctual sensors, biosensors, specific transducers, multisensoristic systems, flexible sensoristic systems, multifunctional systems, advanced MEMS/MOEMS technologies for sensoristics, micro/nanoactuators, devices for energy convertion, gravimetric-electrochemical sensors. The paper provides an interesting overview of the possible applications of graphene in relation to its mechanical, thermal and optical properties, and relatively to the gas and biological sensoristic aspects, so as interesting informations for the increase in nanobio-devices performance by last efforts in theoretical nanophysics.","PeriodicalId":18861,"journal":{"name":"Nano Hybrids and Composites","volume":"3 1","pages":"61 - 72"},"PeriodicalIF":0.4,"publicationDate":"2021-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76942248","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 : 2021-04-06DOI: 10.4028/www.scientific.net/NHC.32.25
Thi Luong Nguyen, Pham Khanh Van Nguyen, Hoc Thang Nguyen, V. K. Nguyen, T. Pham, Thanh-Tung Nguyen
The ability to plasticize Hydroxypropyl Methyl Cellulose/Beeswax (HPMC/BW) composites depends on plasticizers and their concentration. This paper conducted studying on the impacts of plasticizers to HPMC/BW properties. The plasticizers were used in this research included Glycerol (G), Propylene Glycol (PG), and Polyethylene Glycol 400 (PEG 400) which had the concentration changed in range of 1-3%. HPMC/BW composite films incorporated with 2% of plasticizers formed films with the best characteristics among three tested concentration. Tensile strength and elastic modulus of films were decreased when adding plasticizers, whereas elongation at break were increased. Therefore, it caused an increase in oxygen permeability of HPMC/BW films in comparison with the control film. However, Glycerol showed the lowest Oxygen Permeability (OP) values compared to other composite films. The films were evaluated its microstructural quality using method of scanning electron microscopy (SEM) which had the effects of plasticizers and their efficiencies of plasticizing polymer networks.
{"title":"Effects of Plasticizers on Mechanical Properties, Oxygen Permeability, and Microstructural Characteristics of HPMC/Beeswax Composite Film","authors":"Thi Luong Nguyen, Pham Khanh Van Nguyen, Hoc Thang Nguyen, V. K. Nguyen, T. Pham, Thanh-Tung Nguyen","doi":"10.4028/www.scientific.net/NHC.32.25","DOIUrl":"https://doi.org/10.4028/www.scientific.net/NHC.32.25","url":null,"abstract":"The ability to plasticize Hydroxypropyl Methyl Cellulose/Beeswax (HPMC/BW) composites depends on plasticizers and their concentration. This paper conducted studying on the impacts of plasticizers to HPMC/BW properties. The plasticizers were used in this research included Glycerol (G), Propylene Glycol (PG), and Polyethylene Glycol 400 (PEG 400) which had the concentration changed in range of 1-3%. HPMC/BW composite films incorporated with 2% of plasticizers formed films with the best characteristics among three tested concentration. Tensile strength and elastic modulus of films were decreased when adding plasticizers, whereas elongation at break were increased. Therefore, it caused an increase in oxygen permeability of HPMC/BW films in comparison with the control film. However, Glycerol showed the lowest Oxygen Permeability (OP) values compared to other composite films. The films were evaluated its microstructural quality using method of scanning electron microscopy (SEM) which had the effects of plasticizers and their efficiencies of plasticizing polymer networks.","PeriodicalId":18861,"journal":{"name":"Nano Hybrids and Composites","volume":"303 1","pages":"25 - 34"},"PeriodicalIF":0.4,"publicationDate":"2021-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76141398","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 : 2021-04-06DOI: 10.4028/www.scientific.net/NHC.32.1
S. Bello, J. Agunsoye, Nasirudeen Kolawole Raji, J. A. Adebisi, I. Raheem, S. B. Hassan
Fibres anisotropy and their poor adhesion to the epoxy matrix are challenges in developing polymeric epoxy composite for structural applications. Filling of epoxy with reinforcing particles has potential for producing isotropic composites. In this study, epoxy-aluminium particulate composites were developed through combined-stir-techniques. Their interfacial adhesion and microstructural properties were examined. Results obtained indicated bonding of aluminium particles to epoxy through bidentate coordinate bond. Variations observed in the Fourier Transform Infrared spectrographs (FTIR) of both composites’ grades confirm discrepancies in interactions of aluminium micro and nanoparticles with epoxy. A good interfacial adhesion of aluminium nanoparticle with epoxy established by both optical and scanning electron microscopes is an indication of good mechanical performance of the epoxy composites.
{"title":"Interfacial Adhesion and Microstructure of Epoxy/Aluminium Particulate Nanocomposites","authors":"S. Bello, J. Agunsoye, Nasirudeen Kolawole Raji, J. A. Adebisi, I. Raheem, S. B. Hassan","doi":"10.4028/www.scientific.net/NHC.32.1","DOIUrl":"https://doi.org/10.4028/www.scientific.net/NHC.32.1","url":null,"abstract":"Fibres anisotropy and their poor adhesion to the epoxy matrix are challenges in developing polymeric epoxy composite for structural applications. Filling of epoxy with reinforcing particles has potential for producing isotropic composites. In this study, epoxy-aluminium particulate composites were developed through combined-stir-techniques. Their interfacial adhesion and microstructural properties were examined. Results obtained indicated bonding of aluminium particles to epoxy through bidentate coordinate bond. Variations observed in the Fourier Transform Infrared spectrographs (FTIR) of both composites’ grades confirm discrepancies in interactions of aluminium micro and nanoparticles with epoxy. A good interfacial adhesion of aluminium nanoparticle with epoxy established by both optical and scanning electron microscopes is an indication of good mechanical performance of the epoxy composites.","PeriodicalId":18861,"journal":{"name":"Nano Hybrids and Composites","volume":"45 1","pages":"1 - 14"},"PeriodicalIF":0.4,"publicationDate":"2021-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82265681","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 : 2021-04-06DOI: 10.4028/www.scientific.net/NHC.32.35
Ibrahim Ali Ahmed Amar, M. M. Ahwidi
Carbon-free electrosynthesis of ammonia using water (H2 source) and air (N2 source) is promising technology to reduce the global CO2 emission resulting from the industrial ammonia production process (Haber-Bosch). In this study, electrocatalysis activity of non-noble metal perovskite-based catalyst (La0.75Sr0.25Cr0.5Fe0.5O3-δ-Ce0.8Gd0.18Ca0.02O2-δ, LSCrF-CGDC) for ammonia synthesis directly from air and water was explored. Ammonia was successfully from wet air (3%H2O) synthesized in a single-chamber type reactor. The highest ammonia formation rate and Faradaic efficiency of about 1.94×10-11 mol s-1 cm-2 and 2.01% were achieved at 375 oC and 1.2 V, respectively. The observed ammonia formation rate is higher than reported for an expensive noble metal-based catalyst (Ru/MgO). The obtained results indicated that the direct synthesis of ammonia from air and water is a promising technology for green and sustainable ammonia synthesis.
{"title":"Synthesis of Ammonia Directly from Air and Water via a Single-Chamber Reactor Using Lanthanum Chromite-Based Composite as an Electrocatalyst","authors":"Ibrahim Ali Ahmed Amar, M. M. Ahwidi","doi":"10.4028/www.scientific.net/NHC.32.35","DOIUrl":"https://doi.org/10.4028/www.scientific.net/NHC.32.35","url":null,"abstract":"Carbon-free electrosynthesis of ammonia using water (H2 source) and air (N2 source) is promising technology to reduce the global CO2 emission resulting from the industrial ammonia production process (Haber-Bosch). In this study, electrocatalysis activity of non-noble metal perovskite-based catalyst (La0.75Sr0.25Cr0.5Fe0.5O3-δ-Ce0.8Gd0.18Ca0.02O2-δ, LSCrF-CGDC) for ammonia synthesis directly from air and water was explored. Ammonia was successfully from wet air (3%H2O) synthesized in a single-chamber type reactor. The highest ammonia formation rate and Faradaic efficiency of about 1.94×10-11 mol s-1 cm-2 and 2.01% were achieved at 375 oC and 1.2 V, respectively. The observed ammonia formation rate is higher than reported for an expensive noble metal-based catalyst (Ru/MgO). The obtained results indicated that the direct synthesis of ammonia from air and water is a promising technology for green and sustainable ammonia synthesis.","PeriodicalId":18861,"journal":{"name":"Nano Hybrids and Composites","volume":"7 1","pages":"35 - 44"},"PeriodicalIF":0.4,"publicationDate":"2021-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82210638","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 : 2021-04-06DOI: 10.4028/www.scientific.net/NHC.32.45
Mohamed Khodjet Kesba, Noureddine El Meiche, A. Benkhedda
The influence of linear and non-linear temperature and moisture concentration distribution on the stress distribution was studied for metal/ceramic sandwich plate with transverse cracks. An interlaminar adhesive layer between two different layers is taken into account which transferring the normal stress and the interlaminar shear stress. The validation of the used model was done with the comparison of the stiffness reduction as a function of crack density and the experimental data. A comparison showed that a satisfactory qualitative and quantitative agreement was obtained. The temperature and moisture concentration variation are studied using the linear and non-linear distribution around the cracks to predict the stress distributions along the axis x. Finally, it observed through this study that the variations of the thermal and moisture concentration distribution largely impact the stress distribution for a sandwich plate with transverse cracks in the central layer and also with different mechanical properties of each layers.
{"title":"Stress Distribution on the Cracked Sandwich Plate with Non Linear Thermal and Moisture Concentration","authors":"Mohamed Khodjet Kesba, Noureddine El Meiche, A. Benkhedda","doi":"10.4028/www.scientific.net/NHC.32.45","DOIUrl":"https://doi.org/10.4028/www.scientific.net/NHC.32.45","url":null,"abstract":"The influence of linear and non-linear temperature and moisture concentration distribution on the stress distribution was studied for metal/ceramic sandwich plate with transverse cracks. An interlaminar adhesive layer between two different layers is taken into account which transferring the normal stress and the interlaminar shear stress. The validation of the used model was done with the comparison of the stiffness reduction as a function of crack density and the experimental data. A comparison showed that a satisfactory qualitative and quantitative agreement was obtained. The temperature and moisture concentration variation are studied using the linear and non-linear distribution around the cracks to predict the stress distributions along the axis x. Finally, it observed through this study that the variations of the thermal and moisture concentration distribution largely impact the stress distribution for a sandwich plate with transverse cracks in the central layer and also with different mechanical properties of each layers.","PeriodicalId":18861,"journal":{"name":"Nano Hybrids and Composites","volume":"9 1","pages":"45 - 62"},"PeriodicalIF":0.4,"publicationDate":"2021-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75732829","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 : 2021-04-06DOI: 10.4028/www.scientific.net/NHC.32.85
G. Bujjibabu, V. C. Das, M. Ramakrishna, K. Nagarjuna
Banana/Coir fiber reinforced polypropylene hybrid composites was formulated by using twin screw extruder and injection molding machine. Specimens were prepared untreated and treated B/C Hybrid composites with 4% and 8% of MA-g-PP to increase its compatibility with the polypropylene matrix. Both the without MA-g-PP and with MA-g-PP B/C hybrid composites was utilized and three levels of B/C fiber loadings 15/5, 10/10 and 5/15 % were used during manufacturing of B/C reinforced polypropylene hybrid composites. In this work mechanical performance (tensile, flexural and impact strengths) of untreated and treated (coupling agent) with 4% and 8% of MA-g-PP B/C fibers reinforced polypropylene hybrid composite have been investigated. Treated with MA-g-PP B/C fibers reinforced specimens explored better mechanical properties compared to untreated B/C fibers reinforced polypropylene hybrid composites. Mechanical tests represents that tensile, flexural and impact strength increases with increase in concentration of coupling agent compared to without coupling agent MA-g-PP hybrid composites . B/C fibers reinforced polymer composites exhibited higher tensile, flexural and impact strength at 5% of Banana fiber, 15% of fiber Coir in the presence of 8% of MA-g-PP compared to 4% of MA-g-PP and untreated hybrid composites. The percentage of water absorption in the B/C fibers reinforced polypropylene hybrid composites resisted due to the presence of coupling agent MA-g-PP and thermogravimetry analysis (TGA) also has done.
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