The effect of Mn on the microstructure and mechanical properties of as-extruded Mg-0.5Sr alloy we... more The effect of Mn on the microstructure and mechanical properties of as-extruded Mg-0.5Sr alloy were discussed in this work. The results showed that high Mn alloying (2 wt.%) could significantly improve the mechanical properties of the alloys, namely, the tensile and compressive yield strength. The grain size of as-extruded Mg-0.5Sr alloys significantly was refined from 2.78 μm to 1.15 μm due to the pinning effect by fine α-Mn precipitates during the extrusion. Moreover, it also showed that the tensile yield strength and the compressive yield strength of Mg-0.5Sr-2Mn alloy were 32 and 40 percent age higher than those of Mg-0.5Sr alloy, respectively. Moreover, the strain hardening behaviors of the Mg-0.5Sr-2Mn alloy were discussed, which proved that a large number of small grains and texture have an important role in improving mechanical properties.
This paper investigates the distributed finite-time event-triggered bipartite consensus control f... more This paper investigates the distributed finite-time event-triggered bipartite consensus control for multiagent systems over antagonistic networks. Under the constraint of energy conservation, a distributed nonlinear finite-time control protocol only depending upon local information is proposed coupled with event-triggered strategies, where controllers of agents at triggered instants are only updated to reduce the computation. It is proved that when the antagonistic network is structurally balanced with a spanning tree, a necessary and sufficient condition is established to guarantee all agents to reach consensus values with identical magnitude but opposite signs. More interestingly, the settling time depending on the initial state is obtained over the whole process. Comparing to asymptotic control algorithms, the proposed control method has better disturbance rejection properties and convergence rate. Simulations are given to demonstrate the effectiveness of the theoretical results.
Hot rolling was carried out in this study to modify the microstructures of an extruded Mg–6Al–1Sn... more Hot rolling was carried out in this study to modify the microstructures of an extruded Mg–6Al–1Sn–0.3Mn alloy sheet and investigate its effects on mechanical properties. After hot rolling, the grains and second phase of the extruded alloy sheet were remarkably refined, and the c-axis of a few grains was parallel to the transverse direction. The strength improvement was mainly attributed to the grain and Mg17Al12 particle refinement due to the Hall–Petch effect and the Orowan mechanism. The random orientation of the fine grains resulted in improving ductility and anisotropy.
Western Undergraduate Research Journal Health and Natural Sciences
Introduction: Previous studies have shown that fatigue of the plantar flexor muscles and mental t... more Introduction: Previous studies have shown that fatigue of the plantar flexor muscles and mental tasks each can lead to impaired balance. The purpose of this study is to analyze the effects of a combined increase in cognitive load and plantar flexor fatigue can have on standing balance. Methods: Fifteen (7 males, 8 females) healthy individuals participated in one testing session. Prior to testing, participants were screened for existing balance and plantar flexor health issues via a medical history questionnaire. Participants performed a total of twelve standing balance trials, each 30 seconds in duration. These trials consisted of three control, three recall, three fatigue, and three fatigue recall trials. For each trial, participants closed their eyes and stood with their feet together on a force plate. Recall ability was evaluated based on the participant’s ability to accurately complete the reverse digit recall section of the SCAT-3. Plantar flexor fatigue was achieved by perform...
IEEE Transactions on Aerospace and Electronic Systems
To ensure successful future planetary landing mission, the lander must be capable of detecting an... more To ensure successful future planetary landing mission, the lander must be capable of detecting and assessing terrain hazard in the nominal landing zone. This paper presents an innovative method of planetary terrain hazard detection. The concept of feature density is introduced into the process of terrain hazard detection. Moreover, the statistical information of the terrain feature density is utilized to represent the terrain hazard level. Opposed to other methods of hazard detection, the research in this paper focuses on how to build a unified terrain representation by the terrain features rather than detecting the specific one or several types of hazard obstacles in traditional sense. Computer simulations demonstrates that the method presented in this paper is able to conduct multitype of complex terrain hazard detecting by the terrain feature detected in the visual image obtained from onboard camera during the landing phase.
ABSTRACT The formation of carbon-coating layer on Co3O4 hexagonal micro-platelets is conducted th... more ABSTRACT The formation of carbon-coating layer on Co3O4 hexagonal micro-platelets is conducted through ethyne thermal decomposition at 600 C. The optimum reaction time for the production of carbon-coating layer during the decomposition process is investigated. The obtained Co3O4–C hybrid material synthesized at the optimum reaction time of 15 min is evaluated as an anode for lithium-ion batteries. It exhibits better energy storage properties in reversible capacity, cycling stability, and rate performance than the unmodified Co3O4 micro-platelets. The effects of carbon-coating layer on the improvement of electrochemical performance are investigated by a series of measurements on cyclic voltammogram, electrochemical impedance spectra, and surface morphology contrast of the related anodes.
ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared ... more ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared by a low-temperature hydrothermal method and subsequent C2H2 chemical vapor deposition (CVD) for the first time. The synthesized precursor Co3O4 has a size of 8–10 μm, which is assembled by lots of aligned Co3O4 wire with 4–5 μm in length. After carbon coating, Co3O4 microparticles were proved to be coated in amorphous carbon of ~10 nm. A plausible formation process of the dendrite-like Co3O4 and Co3O4@C is proposed based on the morphology and structure characterizations of the materials. As an anode material for lithium-ion batteries, the Co3O4@C composite electrode exhibits higher reversible capacity and better cycling performance than the unmodified Co3O4 electrode. The reversible capacity of the Co3O4@C composite after 40 cycles is 500 mAh g−1, much higher than that of Co3O4 (148 mAh g−1). Electrochemical impedance spectra and cyclic voltammogram indicate that the carbon layer coated on Co3O4 by CVD can improve the electrochemical activity and enhance the reversibility of Co3O4 during charge/discharge cycles.
The effect of Mn on the microstructure and mechanical properties of as-extruded Mg-0.5Sr alloy we... more The effect of Mn on the microstructure and mechanical properties of as-extruded Mg-0.5Sr alloy were discussed in this work. The results showed that high Mn alloying (2 wt.%) could significantly improve the mechanical properties of the alloys, namely, the tensile and compressive yield strength. The grain size of as-extruded Mg-0.5Sr alloys significantly was refined from 2.78 μm to 1.15 μm due to the pinning effect by fine α-Mn precipitates during the extrusion. Moreover, it also showed that the tensile yield strength and the compressive yield strength of Mg-0.5Sr-2Mn alloy were 32 and 40 percent age higher than those of Mg-0.5Sr alloy, respectively. Moreover, the strain hardening behaviors of the Mg-0.5Sr-2Mn alloy were discussed, which proved that a large number of small grains and texture have an important role in improving mechanical properties.
This paper investigates the distributed finite-time event-triggered bipartite consensus control f... more This paper investigates the distributed finite-time event-triggered bipartite consensus control for multiagent systems over antagonistic networks. Under the constraint of energy conservation, a distributed nonlinear finite-time control protocol only depending upon local information is proposed coupled with event-triggered strategies, where controllers of agents at triggered instants are only updated to reduce the computation. It is proved that when the antagonistic network is structurally balanced with a spanning tree, a necessary and sufficient condition is established to guarantee all agents to reach consensus values with identical magnitude but opposite signs. More interestingly, the settling time depending on the initial state is obtained over the whole process. Comparing to asymptotic control algorithms, the proposed control method has better disturbance rejection properties and convergence rate. Simulations are given to demonstrate the effectiveness of the theoretical results.
IEEE Transactions on Aerospace and Electronic Systems
To ensure successful future planetary landing mission, the lander must be capable of detecting an... more To ensure successful future planetary landing mission, the lander must be capable of detecting and assessing terrain hazard in the nominal landing zone. This paper presents an innovative method of planetary terrain hazard detection. The concept of feature density is introduced into the process of terrain hazard detection. Moreover, the statistical information of the terrain feature density is utilized to represent the terrain hazard level. Opposed to other methods of hazard detection, the research in this paper focuses on how to build a unified terrain representation by the terrain features rather than detecting the specific one or several types of hazard obstacles in traditional sense. Computer simulations demonstrates that the method presented in this paper is able to conduct multitype of complex terrain hazard detecting by the terrain feature detected in the visual image obtained from onboard camera during the landing phase.
ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared ... more ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared by a low-temperature hydrothermal method and subsequent C2H2 chemical vapor deposition (CVD) for the first time. The synthesized precursor Co3O4 has a size of 8–10 μm, which is assembled by lots of aligned Co3O4 wire with 4–5 μm in length. After carbon coating, Co3O4 microparticles were proved to be coated in amorphous carbon of ~10 nm. A plausible formation process of the dendrite-like Co3O4 and Co3O4@C is proposed based on the morphology and structure characterizations of the materials. As an anode material for lithium-ion batteries, the Co3O4@C composite electrode exhibits higher reversible capacity and better cycling performance than the unmodified Co3O4 electrode. The reversible capacity of the Co3O4@C composite after 40 cycles is 500 mAh g−1, much higher than that of Co3O4 (148 mAh g−1). Electrochemical impedance spectra and cyclic voltammogram indicate that the carbon layer coated on Co3O4 by CVD can improve the electrochemical activity and enhance the reversibility of Co3O4 during charge/discharge cycles.
ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared ... more ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared by a low-temperature hydrothermal method and subsequent C2H2 chemical vapor deposition (CVD) for the first time. The synthesized precursor Co3O4 has a size of 8–10 μm, which is assembled by lots of aligned Co3O4 wire with 4–5 μm in length. After carbon coating, Co3O4 microparticles were proved to be coated in amorphous carbon of ~10 nm. A plausible formation process of the dendrite-like Co3O4 and Co3O4@C is proposed based on the morphology and structure characterizations of the materials. As an anode material for lithium-ion batteries, the Co3O4@C composite electrode exhibits higher reversible capacity and better cycling performance than the unmodified Co3O4 electrode. The reversible capacity of the Co3O4@C composite after 40 cycles is 500 mAh g−1, much higher than that of Co3O4 (148 mAh g−1). Electrochemical impedance spectra and cyclic voltammogram indicate that the carbon layer coated on Co3O4 by CVD can improve the electrochemical activity and enhance the reversibility of Co3O4 during charge/discharge cycles.
The effect of Mn on the microstructure and mechanical properties of as-extruded Mg-0.5Sr alloy we... more The effect of Mn on the microstructure and mechanical properties of as-extruded Mg-0.5Sr alloy were discussed in this work. The results showed that high Mn alloying (2 wt.%) could significantly improve the mechanical properties of the alloys, namely, the tensile and compressive yield strength. The grain size of as-extruded Mg-0.5Sr alloys significantly was refined from 2.78 μm to 1.15 μm due to the pinning effect by fine α-Mn precipitates during the extrusion. Moreover, it also showed that the tensile yield strength and the compressive yield strength of Mg-0.5Sr-2Mn alloy were 32 and 40 percent age higher than those of Mg-0.5Sr alloy, respectively. Moreover, the strain hardening behaviors of the Mg-0.5Sr-2Mn alloy were discussed, which proved that a large number of small grains and texture have an important role in improving mechanical properties.
This paper investigates the distributed finite-time event-triggered bipartite consensus control f... more This paper investigates the distributed finite-time event-triggered bipartite consensus control for multiagent systems over antagonistic networks. Under the constraint of energy conservation, a distributed nonlinear finite-time control protocol only depending upon local information is proposed coupled with event-triggered strategies, where controllers of agents at triggered instants are only updated to reduce the computation. It is proved that when the antagonistic network is structurally balanced with a spanning tree, a necessary and sufficient condition is established to guarantee all agents to reach consensus values with identical magnitude but opposite signs. More interestingly, the settling time depending on the initial state is obtained over the whole process. Comparing to asymptotic control algorithms, the proposed control method has better disturbance rejection properties and convergence rate. Simulations are given to demonstrate the effectiveness of the theoretical results.
Hot rolling was carried out in this study to modify the microstructures of an extruded Mg–6Al–1Sn... more Hot rolling was carried out in this study to modify the microstructures of an extruded Mg–6Al–1Sn–0.3Mn alloy sheet and investigate its effects on mechanical properties. After hot rolling, the grains and second phase of the extruded alloy sheet were remarkably refined, and the c-axis of a few grains was parallel to the transverse direction. The strength improvement was mainly attributed to the grain and Mg17Al12 particle refinement due to the Hall–Petch effect and the Orowan mechanism. The random orientation of the fine grains resulted in improving ductility and anisotropy.
Western Undergraduate Research Journal Health and Natural Sciences
Introduction: Previous studies have shown that fatigue of the plantar flexor muscles and mental t... more Introduction: Previous studies have shown that fatigue of the plantar flexor muscles and mental tasks each can lead to impaired balance. The purpose of this study is to analyze the effects of a combined increase in cognitive load and plantar flexor fatigue can have on standing balance. Methods: Fifteen (7 males, 8 females) healthy individuals participated in one testing session. Prior to testing, participants were screened for existing balance and plantar flexor health issues via a medical history questionnaire. Participants performed a total of twelve standing balance trials, each 30 seconds in duration. These trials consisted of three control, three recall, three fatigue, and three fatigue recall trials. For each trial, participants closed their eyes and stood with their feet together on a force plate. Recall ability was evaluated based on the participant’s ability to accurately complete the reverse digit recall section of the SCAT-3. Plantar flexor fatigue was achieved by perform...
IEEE Transactions on Aerospace and Electronic Systems
To ensure successful future planetary landing mission, the lander must be capable of detecting an... more To ensure successful future planetary landing mission, the lander must be capable of detecting and assessing terrain hazard in the nominal landing zone. This paper presents an innovative method of planetary terrain hazard detection. The concept of feature density is introduced into the process of terrain hazard detection. Moreover, the statistical information of the terrain feature density is utilized to represent the terrain hazard level. Opposed to other methods of hazard detection, the research in this paper focuses on how to build a unified terrain representation by the terrain features rather than detecting the specific one or several types of hazard obstacles in traditional sense. Computer simulations demonstrates that the method presented in this paper is able to conduct multitype of complex terrain hazard detecting by the terrain feature detected in the visual image obtained from onboard camera during the landing phase.
ABSTRACT The formation of carbon-coating layer on Co3O4 hexagonal micro-platelets is conducted th... more ABSTRACT The formation of carbon-coating layer on Co3O4 hexagonal micro-platelets is conducted through ethyne thermal decomposition at 600 C. The optimum reaction time for the production of carbon-coating layer during the decomposition process is investigated. The obtained Co3O4–C hybrid material synthesized at the optimum reaction time of 15 min is evaluated as an anode for lithium-ion batteries. It exhibits better energy storage properties in reversible capacity, cycling stability, and rate performance than the unmodified Co3O4 micro-platelets. The effects of carbon-coating layer on the improvement of electrochemical performance are investigated by a series of measurements on cyclic voltammogram, electrochemical impedance spectra, and surface morphology contrast of the related anodes.
ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared ... more ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared by a low-temperature hydrothermal method and subsequent C2H2 chemical vapor deposition (CVD) for the first time. The synthesized precursor Co3O4 has a size of 8–10 μm, which is assembled by lots of aligned Co3O4 wire with 4–5 μm in length. After carbon coating, Co3O4 microparticles were proved to be coated in amorphous carbon of ~10 nm. A plausible formation process of the dendrite-like Co3O4 and Co3O4@C is proposed based on the morphology and structure characterizations of the materials. As an anode material for lithium-ion batteries, the Co3O4@C composite electrode exhibits higher reversible capacity and better cycling performance than the unmodified Co3O4 electrode. The reversible capacity of the Co3O4@C composite after 40 cycles is 500 mAh g−1, much higher than that of Co3O4 (148 mAh g−1). Electrochemical impedance spectra and cyclic voltammogram indicate that the carbon layer coated on Co3O4 by CVD can improve the electrochemical activity and enhance the reversibility of Co3O4 during charge/discharge cycles.
The effect of Mn on the microstructure and mechanical properties of as-extruded Mg-0.5Sr alloy we... more The effect of Mn on the microstructure and mechanical properties of as-extruded Mg-0.5Sr alloy were discussed in this work. The results showed that high Mn alloying (2 wt.%) could significantly improve the mechanical properties of the alloys, namely, the tensile and compressive yield strength. The grain size of as-extruded Mg-0.5Sr alloys significantly was refined from 2.78 μm to 1.15 μm due to the pinning effect by fine α-Mn precipitates during the extrusion. Moreover, it also showed that the tensile yield strength and the compressive yield strength of Mg-0.5Sr-2Mn alloy were 32 and 40 percent age higher than those of Mg-0.5Sr alloy, respectively. Moreover, the strain hardening behaviors of the Mg-0.5Sr-2Mn alloy were discussed, which proved that a large number of small grains and texture have an important role in improving mechanical properties.
This paper investigates the distributed finite-time event-triggered bipartite consensus control f... more This paper investigates the distributed finite-time event-triggered bipartite consensus control for multiagent systems over antagonistic networks. Under the constraint of energy conservation, a distributed nonlinear finite-time control protocol only depending upon local information is proposed coupled with event-triggered strategies, where controllers of agents at triggered instants are only updated to reduce the computation. It is proved that when the antagonistic network is structurally balanced with a spanning tree, a necessary and sufficient condition is established to guarantee all agents to reach consensus values with identical magnitude but opposite signs. More interestingly, the settling time depending on the initial state is obtained over the whole process. Comparing to asymptotic control algorithms, the proposed control method has better disturbance rejection properties and convergence rate. Simulations are given to demonstrate the effectiveness of the theoretical results.
IEEE Transactions on Aerospace and Electronic Systems
To ensure successful future planetary landing mission, the lander must be capable of detecting an... more To ensure successful future planetary landing mission, the lander must be capable of detecting and assessing terrain hazard in the nominal landing zone. This paper presents an innovative method of planetary terrain hazard detection. The concept of feature density is introduced into the process of terrain hazard detection. Moreover, the statistical information of the terrain feature density is utilized to represent the terrain hazard level. Opposed to other methods of hazard detection, the research in this paper focuses on how to build a unified terrain representation by the terrain features rather than detecting the specific one or several types of hazard obstacles in traditional sense. Computer simulations demonstrates that the method presented in this paper is able to conduct multitype of complex terrain hazard detecting by the terrain feature detected in the visual image obtained from onboard camera during the landing phase.
ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared ... more ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared by a low-temperature hydrothermal method and subsequent C2H2 chemical vapor deposition (CVD) for the first time. The synthesized precursor Co3O4 has a size of 8–10 μm, which is assembled by lots of aligned Co3O4 wire with 4–5 μm in length. After carbon coating, Co3O4 microparticles were proved to be coated in amorphous carbon of ~10 nm. A plausible formation process of the dendrite-like Co3O4 and Co3O4@C is proposed based on the morphology and structure characterizations of the materials. As an anode material for lithium-ion batteries, the Co3O4@C composite electrode exhibits higher reversible capacity and better cycling performance than the unmodified Co3O4 electrode. The reversible capacity of the Co3O4@C composite after 40 cycles is 500 mAh g−1, much higher than that of Co3O4 (148 mAh g−1). Electrochemical impedance spectra and cyclic voltammogram indicate that the carbon layer coated on Co3O4 by CVD can improve the electrochemical activity and enhance the reversibility of Co3O4 during charge/discharge cycles.
ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared ... more ABSTRACT Carbon-coated Co3O4 microparticles (Co3O4@C) with dendrite-like morphology are prepared by a low-temperature hydrothermal method and subsequent C2H2 chemical vapor deposition (CVD) for the first time. The synthesized precursor Co3O4 has a size of 8–10 μm, which is assembled by lots of aligned Co3O4 wire with 4–5 μm in length. After carbon coating, Co3O4 microparticles were proved to be coated in amorphous carbon of ~10 nm. A plausible formation process of the dendrite-like Co3O4 and Co3O4@C is proposed based on the morphology and structure characterizations of the materials. As an anode material for lithium-ion batteries, the Co3O4@C composite electrode exhibits higher reversible capacity and better cycling performance than the unmodified Co3O4 electrode. The reversible capacity of the Co3O4@C composite after 40 cycles is 500 mAh g−1, much higher than that of Co3O4 (148 mAh g−1). Electrochemical impedance spectra and cyclic voltammogram indicate that the carbon layer coated on Co3O4 by CVD can improve the electrochemical activity and enhance the reversibility of Co3O4 during charge/discharge cycles.
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