A comparative assessment of the structural, elastic and electronic properties of Nb3Pt and NbPt3 phases through firstprinciples study
- Fono-Tamo, R.S., Tien-Chien, Jen, Bhila, O.
- Authors: Fono-Tamo, R.S. , Tien-Chien, Jen , Bhila, O.
- Date: 2018
- Language: English
- Type: Conference proceeding
- Identifier: http://hdl.handle.net/10210/290302 , uj:31513 , Citation: Fono-Tamo, R.S., Tien-Chien, J. & Bhila, O. 2018. A comparative assessment of the structural, elastic and electronic properties of Nb3Pt and NbPt3 phases through firstprinciples study.
- Description: Abstract: Two phases of the Nb-Pt system namely Nb3Pt and NbPt3 have been studied using first principles approach in CASTEP. Structural, elastic and electronic properties of the concerned binary alloys were determined and examined against each other. Although both alloys have the same structure, it was observed that the percentage difference in the change of lattice parameters varied. Nb3Pt exhibited a 0.073% change while NbPt3 had a 14.809% change making Nb3Pt more stable struturaly than NbPt3. The elastic properties showed that both binaries are ductile materials but NbPt3 proved to be more ductile than Nb3Pt based on Born, Pugh’s and Frantsevich’s criteria. Through the electronic properties, both binaries were proven to be conducting and their bonding nature seen as a combination of ionic metallic and covalent bond.
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- Authors: Fono-Tamo, R.S. , Tien-Chien, Jen , Bhila, O.
- Date: 2018
- Language: English
- Type: Conference proceeding
- Identifier: http://hdl.handle.net/10210/290302 , uj:31513 , Citation: Fono-Tamo, R.S., Tien-Chien, J. & Bhila, O. 2018. A comparative assessment of the structural, elastic and electronic properties of Nb3Pt and NbPt3 phases through firstprinciples study.
- Description: Abstract: Two phases of the Nb-Pt system namely Nb3Pt and NbPt3 have been studied using first principles approach in CASTEP. Structural, elastic and electronic properties of the concerned binary alloys were determined and examined against each other. Although both alloys have the same structure, it was observed that the percentage difference in the change of lattice parameters varied. Nb3Pt exhibited a 0.073% change while NbPt3 had a 14.809% change making Nb3Pt more stable struturaly than NbPt3. The elastic properties showed that both binaries are ductile materials but NbPt3 proved to be more ductile than Nb3Pt based on Born, Pugh’s and Frantsevich’s criteria. Through the electronic properties, both binaries were proven to be conducting and their bonding nature seen as a combination of ionic metallic and covalent bond.
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Effect of ingredient particle sizes on surface roughness characteristics of PKS brake lining
- Fono-Tamo, R.S., Tien-Chien, Jen
- Authors: Fono-Tamo, R.S. , Tien-Chien, Jen
- Date: 2017
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/260171 , uj:27389 , Citation: Fono-Tamo, R.S. & Tien-Chien, J. 2017. Effect of ingredient particle sizes on surface roughness characteristics of PKS brake lining.
- Description: Abstract: experience mechanical damage when they are exposed to a corrosive environment. A typical solid surface like a brake pad has a complex structure and complex properties depending on the nature of the solids, the method of surface preparation, and the interaction between the surface and the environment. The surface roughness of a novel friction linings prepared using varying palm kernel shell (PKS) powder particle sizes (0.300 mm, 0.425 mm and 0.850 mm) as reinforcements were investigated. The investigation was conducted via a profilometer dotted with a diamond stylus at a speed of 0.2 mm/s. The determined surface roughness parameters values were in ascending order with S0.300 having the least values (Ra = 6.13 μm, Rz = 24.04 μm and Rmax = 37.3 μm) and S0.850 having the highest values (Ra = 9.87 μm, Rz = 37.28 μm and Rmax = 53.8 μm). This was an indication that the roughness characteristics of the reinforced composite were associated to the presence of pulverised PKS particles. It was further shown by scanning electron microscope images that pulverised PKS grain sizes by nature have rough surfaces and this could have contributed to the overall roughness behaviour of the reinforced composite since PKS was the only ingredient with grain size variation in the experiment.
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- Authors: Fono-Tamo, R.S. , Tien-Chien, Jen
- Date: 2017
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/260171 , uj:27389 , Citation: Fono-Tamo, R.S. & Tien-Chien, J. 2017. Effect of ingredient particle sizes on surface roughness characteristics of PKS brake lining.
- Description: Abstract: experience mechanical damage when they are exposed to a corrosive environment. A typical solid surface like a brake pad has a complex structure and complex properties depending on the nature of the solids, the method of surface preparation, and the interaction between the surface and the environment. The surface roughness of a novel friction linings prepared using varying palm kernel shell (PKS) powder particle sizes (0.300 mm, 0.425 mm and 0.850 mm) as reinforcements were investigated. The investigation was conducted via a profilometer dotted with a diamond stylus at a speed of 0.2 mm/s. The determined surface roughness parameters values were in ascending order with S0.300 having the least values (Ra = 6.13 μm, Rz = 24.04 μm and Rmax = 37.3 μm) and S0.850 having the highest values (Ra = 9.87 μm, Rz = 37.28 μm and Rmax = 53.8 μm). This was an indication that the roughness characteristics of the reinforced composite were associated to the presence of pulverised PKS particles. It was further shown by scanning electron microscope images that pulverised PKS grain sizes by nature have rough surfaces and this could have contributed to the overall roughness behaviour of the reinforced composite since PKS was the only ingredient with grain size variation in the experiment.
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Efficient low-cost materials for solar energy applications : roles of nanotechnology
- Ebhota, Williams S., Tien-Chien, Jen
- Authors: Ebhota, Williams S. , Tien-Chien, Jen
- Date: 2018
- Subjects: Photovoltaic cell low-cost materials , Photovoltaic solar technologies , CO2 emission
- Language: English
- Type: Book Chapter
- Identifier: http://hdl.handle.net/10210/290318 , uj:31515 , Citation: Ebhota, W.S. & Tien-Chien, J. 2018. Efficient low-cost materials for solar energy applications : roles of nanotechnology.
- Description: Abstract: The generation of energy to meet the increasing global demand should not compromise the environment and the future. Therefore, renewable energies have been identified as potential alternatives to fossil fuels that are associated with CO2 emissions. Subsequently, photovoltaic (PV) solar system is seen as the most versatile and the largest source of electricity for the future globally. Nanotechnology is a facilitating tool that offers a wide range of resources to resolve material challenges in different application areas. This studies X-rays, energy trilemma, potential nanotechnology-based materials for low-cost PV solar cell fabrication, and atomic layer deposition (ALD). In pursuance of improved performance, PV solar-cell technologies have revolutionized from first-generation PV solar cells to third-generation PV solar cells. The efficiency (19%) of second-generation PV cells is higher than the efficiency (15%) of first-generation cells. The second-generation PV cell technologies include a-Si, CdTe and Cu(In,Ga)Se2), Cu(In,Ga)Se2 (CIGS) cells. The third-generation PV cells are organic-inorganic hybrid assemblies, nanostructured semiconductors, and molecular assemblies. This nanocomposite- based technology aims at developing low-cost high efficiency PV solar cells. The nanotechnology manufacturing technique, ALD, is seen as the future technology of PV solar cell production.
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- Authors: Ebhota, Williams S. , Tien-Chien, Jen
- Date: 2018
- Subjects: Photovoltaic cell low-cost materials , Photovoltaic solar technologies , CO2 emission
- Language: English
- Type: Book Chapter
- Identifier: http://hdl.handle.net/10210/290318 , uj:31515 , Citation: Ebhota, W.S. & Tien-Chien, J. 2018. Efficient low-cost materials for solar energy applications : roles of nanotechnology.
- Description: Abstract: The generation of energy to meet the increasing global demand should not compromise the environment and the future. Therefore, renewable energies have been identified as potential alternatives to fossil fuels that are associated with CO2 emissions. Subsequently, photovoltaic (PV) solar system is seen as the most versatile and the largest source of electricity for the future globally. Nanotechnology is a facilitating tool that offers a wide range of resources to resolve material challenges in different application areas. This studies X-rays, energy trilemma, potential nanotechnology-based materials for low-cost PV solar cell fabrication, and atomic layer deposition (ALD). In pursuance of improved performance, PV solar-cell technologies have revolutionized from first-generation PV solar cells to third-generation PV solar cells. The efficiency (19%) of second-generation PV cells is higher than the efficiency (15%) of first-generation cells. The second-generation PV cell technologies include a-Si, CdTe and Cu(In,Ga)Se2), Cu(In,Ga)Se2 (CIGS) cells. The third-generation PV cells are organic-inorganic hybrid assemblies, nanostructured semiconductors, and molecular assemblies. This nanocomposite- based technology aims at developing low-cost high efficiency PV solar cells. The nanotechnology manufacturing technique, ALD, is seen as the future technology of PV solar cell production.
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Optimizing electric adjustment mechanism using the combination of multi-body dynamics and control
- Congyanga, Yu, Dequana, Zhu, Chaoxiana, Wang, Lin, Zhu, Tingting, Chu, Tien-Chien, Jen, Liao Juana
- Authors: Congyanga, Yu , Dequana, Zhu , Chaoxiana, Wang , Lin, Zhu , Tingting, Chu , Tien-Chien, Jen , Liao Juana
- Date: 2019
- Subjects: Collaborative optimization , Multi-objective , Hybrid algorithm
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/406451 , uj:34173 , Citation: Chongyang, Z.D., et al. 2019 : Optimizing electric adjustment mechanism using the combination of multi-body dynamics and control.
- Description: Abstract : Optimization was carried out on the electric adjustment mechanism for transplanter by using the multidisciplinary design with weight, transmission efficiency, vibration frequency, and control error as the optimization goals. Then, a collaborative optimization model for the multidisciplinary design of a mechanism system was constructed. Based on ISIGHT software, the multidisciplinary design integration platform for the electric adjustment mechanism was built. A hybrid algorithm comprising the dual sequential quadratic programming method and the multi-island genetic algorithm was used to calculate the model. Optimization results show that the weight of the electric adjustment mechanism drops by 13.10%, its vibration frequency decreases by 27.71%, its transmission efficiency increases by 20.26%, and the control error decreases by 36.98%. Under the mutual coordination and balance of all discipline goals, the optimal values of the design variables of the electric adjustment mechanism indicate overall optimal performance.
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- Authors: Congyanga, Yu , Dequana, Zhu , Chaoxiana, Wang , Lin, Zhu , Tingting, Chu , Tien-Chien, Jen , Liao Juana
- Date: 2019
- Subjects: Collaborative optimization , Multi-objective , Hybrid algorithm
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/406451 , uj:34173 , Citation: Chongyang, Z.D., et al. 2019 : Optimizing electric adjustment mechanism using the combination of multi-body dynamics and control.
- Description: Abstract : Optimization was carried out on the electric adjustment mechanism for transplanter by using the multidisciplinary design with weight, transmission efficiency, vibration frequency, and control error as the optimization goals. Then, a collaborative optimization model for the multidisciplinary design of a mechanism system was constructed. Based on ISIGHT software, the multidisciplinary design integration platform for the electric adjustment mechanism was built. A hybrid algorithm comprising the dual sequential quadratic programming method and the multi-island genetic algorithm was used to calculate the model. Optimization results show that the weight of the electric adjustment mechanism drops by 13.10%, its vibration frequency decreases by 27.71%, its transmission efficiency increases by 20.26%, and the control error decreases by 36.98%. Under the mutual coordination and balance of all discipline goals, the optimal values of the design variables of the electric adjustment mechanism indicate overall optimal performance.
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Optimizing transplanting mechanism with planetary elliptic gears based on multi-body dynamic analysis and approximate models
- Tingting, Chu, Dequana, Zhu, Wei, Xiong, Lin, Zhu, Shun, Zhang, Tien-Chien, Jen, Juana, Liao
- Authors: Tingting, Chu , Dequana, Zhu , Wei, Xiong , Lin, Zhu , Shun, Zhang , Tien-Chien, Jen , Juana, Liao
- Date: 2019
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/406491 , uj:34178 , Citation: Tingting, C., et al. 2019 : Optimizing transplanting mechanism with planetary elliptic gears based on multi-body dynamic analysis and approximate models.
- Description: Abstract : The multidisciplinary design optimization (MDO) strategy of the transplanting mechanism was determined, which was decomposed into three disciplines of kinematics, dynamics, and structural mechanics. The multidisciplinary design collaborative optimization models of the transplanting mechanism were established. The Latin hypercube design method was used to generate the initial sample points and construct the kriging model between the system-level variables and the discipline-level optimization. The MDO platform on the planetary elliptic gears transplanting mechanism was established on the basis of ISIGHT software and calculated by using the hybrid algorithm of multi-island genetic algorithm and sequential quadratic programming method. Optimization results showed that the width of the trajectory dynamic hole of the seedling needle tip, the frame vibration peak force, and the overall quality of the transplanting mechanism decreased by 55.6%, 20.5%, and 9.33%, respectively. The optimum overall performance of the transplanting mechanism was obtained by using the MDO based on approximation technique to meet the agronomic requirements of rice transplanting under high-accuracy computation and low computation time.
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- Authors: Tingting, Chu , Dequana, Zhu , Wei, Xiong , Lin, Zhu , Shun, Zhang , Tien-Chien, Jen , Juana, Liao
- Date: 2019
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/406491 , uj:34178 , Citation: Tingting, C., et al. 2019 : Optimizing transplanting mechanism with planetary elliptic gears based on multi-body dynamic analysis and approximate models.
- Description: Abstract : The multidisciplinary design optimization (MDO) strategy of the transplanting mechanism was determined, which was decomposed into three disciplines of kinematics, dynamics, and structural mechanics. The multidisciplinary design collaborative optimization models of the transplanting mechanism were established. The Latin hypercube design method was used to generate the initial sample points and construct the kriging model between the system-level variables and the discipline-level optimization. The MDO platform on the planetary elliptic gears transplanting mechanism was established on the basis of ISIGHT software and calculated by using the hybrid algorithm of multi-island genetic algorithm and sequential quadratic programming method. Optimization results showed that the width of the trajectory dynamic hole of the seedling needle tip, the frame vibration peak force, and the overall quality of the transplanting mechanism decreased by 55.6%, 20.5%, and 9.33%, respectively. The optimum overall performance of the transplanting mechanism was obtained by using the MDO based on approximation technique to meet the agronomic requirements of rice transplanting under high-accuracy computation and low computation time.
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Particle bonding mechanism in CGDS-a three-dimensional approach
- Tien-Chien, Jen, Yen-Ting, Pan, Lin, Zhu, Hong-Sheng, Chen
- Authors: Tien-Chien, Jen , Yen-Ting, Pan , Lin, Zhu , Hong-Sheng, Chen
- Date: 2017
- Subjects: CGDS , Critical velocity , particle impact
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/260192 , uj:27391 , Citation: Tien-Chien, J. et al. 2017. Particle bonding mechanism in CGDS-a three-dimensional approach.
- Description: Abstract: Cold gas dynamics spray (CGDS) is a surface coating process using highly accelerated particles to form the surface coating by high speed impact of the particles. In the CGDS process, metal particles of generally 1-50 μm diameter is carried by a gas stream in high pressure (typically 20-30 atm) through a DE Laval type nozzle to achieve supersonic flying so as to impact on the substrate. Typically, the impact velocity ranges between 300 and 1200 m/s in the CGDS process. When the particle gains its critical velocity, the minimum in-flight speed at which it can deposit, adiabatic shear instabilities will occur. Herein, to ascertain the critical velocities of different particle sizes on the bonding efficiency in CGDS process, three-dimensional numerical simulations of single particle deposition process were performed. In the CGDS process, one of the most important parameters which determine the bonding strength with the substrate is particle impact temperature. Bonding will occur when the particle’s impacting velocity surpass the critical velocity, at which the interface can achieve 60 % of melting temperature of particle material (Ref 1). Therefore, critical velocity should be a main parameter on the coating quality. The particle critical velocity is determined not only by its size, but also by its material properties. This study numerically investigate the critical velocity for the particle deposition process in CGDS. In the present numerical analysis, copper (Cu) was chosen as particle material and aluminum (Al) as substrate material for this study. The impacting velocities were selected between 300 m/s and 800 m/s increasing in steps of 100 m/s. The simulation result reveals temporal and spatial interfacial temperature distribution and deformation between particle(s) and substrate. Finally, comparison is carried out between the computed results and experimental data.
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- Authors: Tien-Chien, Jen , Yen-Ting, Pan , Lin, Zhu , Hong-Sheng, Chen
- Date: 2017
- Subjects: CGDS , Critical velocity , particle impact
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/260192 , uj:27391 , Citation: Tien-Chien, J. et al. 2017. Particle bonding mechanism in CGDS-a three-dimensional approach.
- Description: Abstract: Cold gas dynamics spray (CGDS) is a surface coating process using highly accelerated particles to form the surface coating by high speed impact of the particles. In the CGDS process, metal particles of generally 1-50 μm diameter is carried by a gas stream in high pressure (typically 20-30 atm) through a DE Laval type nozzle to achieve supersonic flying so as to impact on the substrate. Typically, the impact velocity ranges between 300 and 1200 m/s in the CGDS process. When the particle gains its critical velocity, the minimum in-flight speed at which it can deposit, adiabatic shear instabilities will occur. Herein, to ascertain the critical velocities of different particle sizes on the bonding efficiency in CGDS process, three-dimensional numerical simulations of single particle deposition process were performed. In the CGDS process, one of the most important parameters which determine the bonding strength with the substrate is particle impact temperature. Bonding will occur when the particle’s impacting velocity surpass the critical velocity, at which the interface can achieve 60 % of melting temperature of particle material (Ref 1). Therefore, critical velocity should be a main parameter on the coating quality. The particle critical velocity is determined not only by its size, but also by its material properties. This study numerically investigate the critical velocity for the particle deposition process in CGDS. In the present numerical analysis, copper (Cu) was chosen as particle material and aluminum (Al) as substrate material for this study. The impacting velocities were selected between 300 m/s and 800 m/s increasing in steps of 100 m/s. The simulation result reveals temporal and spatial interfacial temperature distribution and deformation between particle(s) and substrate. Finally, comparison is carried out between the computed results and experimental data.
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The characteristics of heat transfer in plate phase change energy storage unit
- Chen, Changnian, Xu, Zhen, Zhao, Hongxia, Yu, Zeting, Han, Jitian, Tien-Chien, Jen
- Authors: Chen, Changnian , Xu, Zhen , Zhao, Hongxia , Yu, Zeting , Han, Jitian , Tien-Chien, Jen
- Date: 2019
- Subjects: Fluent , Heat transfer characteristics , PCM energy storage
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/406507 , uj:34180 , Citation: Chen, C., et al. 2019 : The characteristics of heat transfer in plate phase change energy storage unit.
- Description: Abstract : was used to simulate the heat storage and release process of the plate phase change materials (PCM) energy storage unit. The simulation results show that the main heat transfer zone will advance along the direction of the flat plate (air flow direction), and the speed of the main heat transfer zone is proportional to the air velocity with the continuous heat transfer process. In heat storage, the speed of the main heat transfer zone will accelerate with the increase of air velocities; while in the heat release process, the main heat transfer zone will accelerate with the increase of air velocities. Meanwhile, the liquid phase ratio of PCM material is also changing continuously which increases with time and is affected by the liquefaction or solidification speed. The faster the liquefaction and solidification speed are, the faster it will change. As the fluid inlet velocity increases, the heat storage exothermic efficiency also increases as the heat transfer fluid inlet velocity increases. Overall, the total heat transfer rate is gradually reduced compared with the initial heat transfer, and then tends to be consistent with the temperature of the heat transferfluid.
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- Authors: Chen, Changnian , Xu, Zhen , Zhao, Hongxia , Yu, Zeting , Han, Jitian , Tien-Chien, Jen
- Date: 2019
- Subjects: Fluent , Heat transfer characteristics , PCM energy storage
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/406507 , uj:34180 , Citation: Chen, C., et al. 2019 : The characteristics of heat transfer in plate phase change energy storage unit.
- Description: Abstract : was used to simulate the heat storage and release process of the plate phase change materials (PCM) energy storage unit. The simulation results show that the main heat transfer zone will advance along the direction of the flat plate (air flow direction), and the speed of the main heat transfer zone is proportional to the air velocity with the continuous heat transfer process. In heat storage, the speed of the main heat transfer zone will accelerate with the increase of air velocities; while in the heat release process, the main heat transfer zone will accelerate with the increase of air velocities. Meanwhile, the liquid phase ratio of PCM material is also changing continuously which increases with time and is affected by the liquefaction or solidification speed. The faster the liquefaction and solidification speed are, the faster it will change. As the fluid inlet velocity increases, the heat storage exothermic efficiency also increases as the heat transfer fluid inlet velocity increases. Overall, the total heat transfer rate is gradually reduced compared with the initial heat transfer, and then tends to be consistent with the temperature of the heat transferfluid.
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