2019 Advances in Science and Engineering Technology International Conferences (ASET)
Micro-turning is very similar to conventional turning, but is a cutting operation in which the to... more Micro-turning is very similar to conventional turning, but is a cutting operation in which the tool geometry effect is more important. For this reason, the cutting geometry and cutting parameters used in micro turning must be carefully selected. In this work, during the machining of the Ti6Al4V alloy in micro cutting conditions, the effect of different edge radii of the insert on the cutting forces, tool stresses, and residual stresses was investigated. The appropriate material model is determined by comparing the force data obtained from the cutting experiments with the model results. Numerical solutions have been made for different edge radii. The cutting speed and depth of cut were considered as constant. Different feed rate values and different edge radii were chosen as variables. According to the results obtained, the increasing edge radius causes an increase in cutting (especially in the direction of feed) forces. Increasing edge radius causes a decrease in tool stresses. Most importantly, the increase of the edge radius causes the residual stresses under the surface to occur, usually in the form of compression.
Traditional ways of delivering lectures in classrooms proved to be inadequate and inefficient. Re... more Traditional ways of delivering lectures in classrooms proved to be inadequate and inefficient. Recently, the education sector is witnessing a dramatic progress and is undergoing a major shift. This shift has been influenced largely by technological and pedagogical trends and the greater worldwide access to the Internet. Videos were seen to be a major contributor to the shift in the educational landscape, acting as a powerful agent that adds value and enhances the quality of the learning experience. To be an effective player, videos continue to have a dramatic impact on higher education challenging the traditional way of delivering course content. While some lecturers may be embracing the use of videos in teaching, there are still lecturers who are reluctant to integrate this technology into their teaching methodology or do not have the skills to do so. This paper highlights the use of videos in teaching undergraduate courses in an international institution in order to boost students...
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects
Magneto-free convective of hybrid nanofluid with an inner adiabatically rotating cylinder and a h... more Magneto-free convective of hybrid nanofluid with an inner adiabatically rotating cylinder and a hot side wall was analyzed in a non-Darcy-permeable cavity. The Darcy-Forchheimer model has been used...
Institutional review board statement: The study was approved by King Faisal Specialist Hospital a... more Institutional review board statement: The study was approved by King Faisal Specialist Hospital and Research Center Institutional Review Board, and reviewed for waiver by the institutional review board of each of the participating hospitals. Informed consent statement: Consent to participate in this study was not required due to the design of our study and no follow up. However, an invitation letter was given to all participants who affirmed verbal consent prior to their enrollment.
This work investigates the influence of the interfacial debonding in a nanofiber reinforced compo... more This work investigates the influence of the interfacial debonding in a nanofiber reinforced composite on the mechanical properties. Mainly, three dimensional-axisymmetric finite element analysis is adopted to study a representative volume element (RVE) which is consist of carbon nanofiber confined by a polymeric matrix and subjected to axial tension. Besides, a longitudinal interfacial debonding is imposed along the interfacial nanofiber/matrix. The result of the FEA demonstrate a significant impact of the interfacial debonding on the Young's modulus of the nanocomposite.
ABSTRACT While efforts have been made to synthesize quaternary alloy nanostructures with high sur... more ABSTRACT While efforts have been made to synthesize quaternary alloy nanostructures with high surface area for application in many fields, a detailed exploration of quinternary alloy nanostructures has not been reported until now. This work investigates the optimum crystallization parameters for reducing crystal defects in Cu2Zn1−xCdxSnS4 quinternary alloy nanostructures. Alloy nanostructures with different Zn and Cd contents were grown by a sol–gel method. The analytical results confirmed a multi-phase polycrystallinity of the samples, and the variations in their energetic transitions and optical properties with Cd content were investigated. The morphology and topography of the samples were also observed. Our results are supported by several related studies in the literature.
ABSTRACT A method for the growth of Diamond/WC bilayers in a single process is presented with int... more ABSTRACT A method for the growth of Diamond/WC bilayers in a single process is presented with interest for the production of well adhered electrical contacts to diamond surfaces. This process uses a common hot filament chemical vapor deposition (HFCVD) reactor, with W filaments as the source for the deposition of the metallic layer, and H2 and CH4 gasses as the reactive species for the diamond growth. The method begins by vaporizing the filaments in vacuum for a few minutes, followed by the chemical vapor deposition of diamond. The results have shown that by varying the filament vaporization time and temperature it is possible to deposit on the Si substrate tungsten containing coatings of different thicknesses. The process starts by vaporization of naturally oxidized filaments and deposition on the substrate. Afterward, the tungsten oxide carburises to W2C and WC phases. The CVD growth of the diamond layers on these carbide layers is dependent on the CH4/H2 ratios, system pressure and substrate temperature. The seeding of the Si substrates with diamond powder before the CVD process, guarantees that diamond is nucleated inside the metallic carbide layer, anchoring the top nanocrystalline diamond layer.
Peroxisome proliferator-activated receptors (PPARs) as ligand-activated nuclear receptors involve... more Peroxisome proliferator-activated receptors (PPARs) as ligand-activated nuclear receptors involved in the transcriptional regulation of lipid metabolism, energy balance, inflammation, and atherosclerosis are at the intersection of key pathways involved in the pathogenesis of diabetes and cardiovascular disease. Synthetic PPAR agonists like fibrates (PPAR-a) and thiazolidinediones (PPAR-c) are in therapeutic use to treat dyslipidaemia and diabetes. Despite strong encouraging in vitro, animal model, and human surrogate marker studies with these agents, recent prospective clinical cardiovascular trials have yielded mixed results, perhaps explained by concomitant drug use, study design, or a lack of efficacy of these agents on cardiovascular disease (independent of their current metabolic indications). The use of PPAR agents has also been limited by untoward effects. An alternative strategy to PPAR therapeutics is better understanding PPAR biology, the nature of natural PPAR agonists, and how these molecules are generated. Such insight might also provide valuable information about pathways that protect against the metabolic problems for which PPAR agents are currently indicated. This approach underscores the important distinction between the effects of synthetic PPAR agonists and the unequivocal biologic role of PPARs as key transcriptional regulators of metabolic and inflammatory pathways relevant to diabetes and atherosclerosis.
The present paper demonstrates the route used for solving differential equations for the engineer... more The present paper demonstrates the route used for solving differential equations for the engineering applications at UAEU. Usually students at the Engineering Requirements Unit (ERU) stage of the Faculty of Engineering at the UAEU must enroll in a course of Differential Equations and Engineering Applications (MATH 2210) as a prerequisite for the subsequent stages of their study. Mainly, one of the objectives of this course is that the students practice MATLAB software package during the course. The aim of using this software is to solve differential equations individually and as a system of equation in parallel with analytical mathematics trends. In general, mathematical models of the engineering systems like mechanical, thermal, electrical, chemical and civil are modeled and solve to predict the behavior of the system under different conditions. The paper presents the technique which is used to solve DE using MATLAB. The main code that utilized and presented is MATLAB/ode45 to enable the students solving initial value DE and experience the response of the engineering systems for different applied conditions. Moreover, both advantages and disadvantages are presented especially the student mostly face in solving system of DE using ode45 code
The aim of this paper is to investigate numerically, through a finite element method, the influen... more The aim of this paper is to investigate numerically, through a finite element method, the influence of a Nano-Circular Inclusion on the interfacial stresses around a Nano-Fiber composite subjected to axial load to explain some of the causes that affect the failures of Nano-Composites. Previous investigations studied the effect of Nano-Fiber tip shape, Nano-Holes and its location around the Nano-Fiber on the interfacial stresses in a Nanocomposite, while the current study focuses on studying the effect of the Nano-Circular Inclusion. It was assumed that Nano-Circular Inclusions were embedded in a discontinuous Nano-Fiber composite around a carbon Nano-Fiber composite. A tensile load was applied to the specimens in order to study the influence of these Nano-Circular Inclusions. It was found from the numerical analysis that Nano-Circular Inclusions have a great influence on the increase of the interfacial contact stresses around the Nano-Fiber in Nano-Composite.
2019 Advances in Science and Engineering Technology International Conferences (ASET)
Micro-turning is very similar to conventional turning, but is a cutting operation in which the to... more Micro-turning is very similar to conventional turning, but is a cutting operation in which the tool geometry effect is more important. For this reason, the cutting geometry and cutting parameters used in micro turning must be carefully selected. In this work, during the machining of the Ti6Al4V alloy in micro cutting conditions, the effect of different edge radii of the insert on the cutting forces, tool stresses, and residual stresses was investigated. The appropriate material model is determined by comparing the force data obtained from the cutting experiments with the model results. Numerical solutions have been made for different edge radii. The cutting speed and depth of cut were considered as constant. Different feed rate values and different edge radii were chosen as variables. According to the results obtained, the increasing edge radius causes an increase in cutting (especially in the direction of feed) forces. Increasing edge radius causes a decrease in tool stresses. Most importantly, the increase of the edge radius causes the residual stresses under the surface to occur, usually in the form of compression.
Traditional ways of delivering lectures in classrooms proved to be inadequate and inefficient. Re... more Traditional ways of delivering lectures in classrooms proved to be inadequate and inefficient. Recently, the education sector is witnessing a dramatic progress and is undergoing a major shift. This shift has been influenced largely by technological and pedagogical trends and the greater worldwide access to the Internet. Videos were seen to be a major contributor to the shift in the educational landscape, acting as a powerful agent that adds value and enhances the quality of the learning experience. To be an effective player, videos continue to have a dramatic impact on higher education challenging the traditional way of delivering course content. While some lecturers may be embracing the use of videos in teaching, there are still lecturers who are reluctant to integrate this technology into their teaching methodology or do not have the skills to do so. This paper highlights the use of videos in teaching undergraduate courses in an international institution in order to boost students...
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects
Magneto-free convective of hybrid nanofluid with an inner adiabatically rotating cylinder and a h... more Magneto-free convective of hybrid nanofluid with an inner adiabatically rotating cylinder and a hot side wall was analyzed in a non-Darcy-permeable cavity. The Darcy-Forchheimer model has been used...
Institutional review board statement: The study was approved by King Faisal Specialist Hospital a... more Institutional review board statement: The study was approved by King Faisal Specialist Hospital and Research Center Institutional Review Board, and reviewed for waiver by the institutional review board of each of the participating hospitals. Informed consent statement: Consent to participate in this study was not required due to the design of our study and no follow up. However, an invitation letter was given to all participants who affirmed verbal consent prior to their enrollment.
This work investigates the influence of the interfacial debonding in a nanofiber reinforced compo... more This work investigates the influence of the interfacial debonding in a nanofiber reinforced composite on the mechanical properties. Mainly, three dimensional-axisymmetric finite element analysis is adopted to study a representative volume element (RVE) which is consist of carbon nanofiber confined by a polymeric matrix and subjected to axial tension. Besides, a longitudinal interfacial debonding is imposed along the interfacial nanofiber/matrix. The result of the FEA demonstrate a significant impact of the interfacial debonding on the Young's modulus of the nanocomposite.
ABSTRACT While efforts have been made to synthesize quaternary alloy nanostructures with high sur... more ABSTRACT While efforts have been made to synthesize quaternary alloy nanostructures with high surface area for application in many fields, a detailed exploration of quinternary alloy nanostructures has not been reported until now. This work investigates the optimum crystallization parameters for reducing crystal defects in Cu2Zn1−xCdxSnS4 quinternary alloy nanostructures. Alloy nanostructures with different Zn and Cd contents were grown by a sol–gel method. The analytical results confirmed a multi-phase polycrystallinity of the samples, and the variations in their energetic transitions and optical properties with Cd content were investigated. The morphology and topography of the samples were also observed. Our results are supported by several related studies in the literature.
ABSTRACT A method for the growth of Diamond/WC bilayers in a single process is presented with int... more ABSTRACT A method for the growth of Diamond/WC bilayers in a single process is presented with interest for the production of well adhered electrical contacts to diamond surfaces. This process uses a common hot filament chemical vapor deposition (HFCVD) reactor, with W filaments as the source for the deposition of the metallic layer, and H2 and CH4 gasses as the reactive species for the diamond growth. The method begins by vaporizing the filaments in vacuum for a few minutes, followed by the chemical vapor deposition of diamond. The results have shown that by varying the filament vaporization time and temperature it is possible to deposit on the Si substrate tungsten containing coatings of different thicknesses. The process starts by vaporization of naturally oxidized filaments and deposition on the substrate. Afterward, the tungsten oxide carburises to W2C and WC phases. The CVD growth of the diamond layers on these carbide layers is dependent on the CH4/H2 ratios, system pressure and substrate temperature. The seeding of the Si substrates with diamond powder before the CVD process, guarantees that diamond is nucleated inside the metallic carbide layer, anchoring the top nanocrystalline diamond layer.
Peroxisome proliferator-activated receptors (PPARs) as ligand-activated nuclear receptors involve... more Peroxisome proliferator-activated receptors (PPARs) as ligand-activated nuclear receptors involved in the transcriptional regulation of lipid metabolism, energy balance, inflammation, and atherosclerosis are at the intersection of key pathways involved in the pathogenesis of diabetes and cardiovascular disease. Synthetic PPAR agonists like fibrates (PPAR-a) and thiazolidinediones (PPAR-c) are in therapeutic use to treat dyslipidaemia and diabetes. Despite strong encouraging in vitro, animal model, and human surrogate marker studies with these agents, recent prospective clinical cardiovascular trials have yielded mixed results, perhaps explained by concomitant drug use, study design, or a lack of efficacy of these agents on cardiovascular disease (independent of their current metabolic indications). The use of PPAR agents has also been limited by untoward effects. An alternative strategy to PPAR therapeutics is better understanding PPAR biology, the nature of natural PPAR agonists, and how these molecules are generated. Such insight might also provide valuable information about pathways that protect against the metabolic problems for which PPAR agents are currently indicated. This approach underscores the important distinction between the effects of synthetic PPAR agonists and the unequivocal biologic role of PPARs as key transcriptional regulators of metabolic and inflammatory pathways relevant to diabetes and atherosclerosis.
The present paper demonstrates the route used for solving differential equations for the engineer... more The present paper demonstrates the route used for solving differential equations for the engineering applications at UAEU. Usually students at the Engineering Requirements Unit (ERU) stage of the Faculty of Engineering at the UAEU must enroll in a course of Differential Equations and Engineering Applications (MATH 2210) as a prerequisite for the subsequent stages of their study. Mainly, one of the objectives of this course is that the students practice MATLAB software package during the course. The aim of using this software is to solve differential equations individually and as a system of equation in parallel with analytical mathematics trends. In general, mathematical models of the engineering systems like mechanical, thermal, electrical, chemical and civil are modeled and solve to predict the behavior of the system under different conditions. The paper presents the technique which is used to solve DE using MATLAB. The main code that utilized and presented is MATLAB/ode45 to enable the students solving initial value DE and experience the response of the engineering systems for different applied conditions. Moreover, both advantages and disadvantages are presented especially the student mostly face in solving system of DE using ode45 code
The aim of this paper is to investigate numerically, through a finite element method, the influen... more The aim of this paper is to investigate numerically, through a finite element method, the influence of a Nano-Circular Inclusion on the interfacial stresses around a Nano-Fiber composite subjected to axial load to explain some of the causes that affect the failures of Nano-Composites. Previous investigations studied the effect of Nano-Fiber tip shape, Nano-Holes and its location around the Nano-Fiber on the interfacial stresses in a Nanocomposite, while the current study focuses on studying the effect of the Nano-Circular Inclusion. It was assumed that Nano-Circular Inclusions were embedded in a discontinuous Nano-Fiber composite around a carbon Nano-Fiber composite. A tensile load was applied to the specimens in order to study the influence of these Nano-Circular Inclusions. It was found from the numerical analysis that Nano-Circular Inclusions have a great influence on the increase of the interfacial contact stresses around the Nano-Fiber in Nano-Composite.
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Papers by Waleed Ahmed