Logging residue can be defined as any form of wood, which under the highest stage of technological development could be used in manufacturing but is left in the forest during logging. Lumber production from logging re...Logging residue can be defined as any form of wood, which under the highest stage of technological development could be used in manufacturing but is left in the forest during logging. Lumber production from logging residues of a previous logging activity by a timber firm was undertaken with the objective of determining the suitability of utilizing buttressed-stumps as raw material for the timber industry. A horizontal mobile bandsaw machine was used to process the buttressed-stumps into lumber. The machine was characterized by a thin-kerr sawing technology （kerf-width 1.6 mm） compared to the conventional bandsaw machines of kerr-widths ranging from 3.0-4.5 mm. Lumber value and volume yields, fuel consumption rate, frequency of tool replacement and lumber production rate were assessed. Results indicated that there is the potential to increase timber production from logging residues by utilizing buttressed-stumps. Lumber value and volume yields of eight timber species investigated in this study ranged from 5%-31% and 34%-54% respectively. Fuel consumption rate which increased with increasing wood density, ranged from 5-14.5 liters/m3 of lumber produced. Frequency of saw replacement increased with increasing wood density. The number of saws required to produce one cubic meter of lumber, ranged from 1 to 7. Lumber production rate ranged from 0.10-0.38 m3/hour, increasing with decreasing wood density.展开更多
A new clutch configuration with dual diaphragm spring is proposed. It is proper designed for electric and hybrid powertrain system. With this design, the clutch engagement is controlled by current in electrornagnet co...A new clutch configuration with dual diaphragm spring is proposed. It is proper designed for electric and hybrid powertrain system. With this design, the clutch engagement is controlled by current in electrornagnet coil. For special characteristic of dual diaphragm spring, the clutch does not consume energy in steady state after engaging or disengaging. To validate the feasibility of this design, author builds the mathematical model and imports it into MATLAB Simulink. The simulation shows the behavior of clutch in different control strategies.展开更多
In the near future, the use of FCVs （fuel cell vehicles） is expected to help mitigate environmental problems such as exhaustion of fossil fuels and greenhouse gas emissions. Manufacturers publish an FCV＇s specific ...In the near future, the use of FCVs （fuel cell vehicles） is expected to help mitigate environmental problems such as exhaustion of fossil fuels and greenhouse gas emissions. Manufacturers publish an FCV＇s specific fuel consumption, but not its dynamic characteristics such as fuel consumption ratio and motor power ratio. Thus, it is difficult to reflect the dynamic characteristics of FCVs in lifecycle system evaluation. To solve this problem, we propose a fuel-consumption simulation method for FCVs using a 1.2 kW stationary PEMFC （proton exchange membrane fuel cell）. In this study, the specific fuel consumption under driving cycles such as the Japanese 10-15 and the JC08 modes are determined and compared with the FCV simulation results obtained using fuel consumption ratios derived from the stationary PEMFC. In the simulation, the specific fuel consumption was found to be 1.16 kg-H2/100-km for the base case under the Japanese 10-15 driving cycle.展开更多
文摘Logging residue can be defined as any form of wood, which under the highest stage of technological development could be used in manufacturing but is left in the forest during logging. Lumber production from logging residues of a previous logging activity by a timber firm was undertaken with the objective of determining the suitability of utilizing buttressed-stumps as raw material for the timber industry. A horizontal mobile bandsaw machine was used to process the buttressed-stumps into lumber. The machine was characterized by a thin-kerr sawing technology （kerf-width 1.6 mm） compared to the conventional bandsaw machines of kerr-widths ranging from 3.0-4.5 mm. Lumber value and volume yields, fuel consumption rate, frequency of tool replacement and lumber production rate were assessed. Results indicated that there is the potential to increase timber production from logging residues by utilizing buttressed-stumps. Lumber value and volume yields of eight timber species investigated in this study ranged from 5%-31% and 34%-54% respectively. Fuel consumption rate which increased with increasing wood density, ranged from 5-14.5 liters/m3 of lumber produced. Frequency of saw replacement increased with increasing wood density. The number of saws required to produce one cubic meter of lumber, ranged from 1 to 7. Lumber production rate ranged from 0.10-0.38 m3/hour, increasing with decreasing wood density.
文摘A new clutch configuration with dual diaphragm spring is proposed. It is proper designed for electric and hybrid powertrain system. With this design, the clutch engagement is controlled by current in electrornagnet coil. For special characteristic of dual diaphragm spring, the clutch does not consume energy in steady state after engaging or disengaging. To validate the feasibility of this design, author builds the mathematical model and imports it into MATLAB Simulink. The simulation shows the behavior of clutch in different control strategies.
文摘In the near future, the use of FCVs （fuel cell vehicles） is expected to help mitigate environmental problems such as exhaustion of fossil fuels and greenhouse gas emissions. Manufacturers publish an FCV＇s specific fuel consumption, but not its dynamic characteristics such as fuel consumption ratio and motor power ratio. Thus, it is difficult to reflect the dynamic characteristics of FCVs in lifecycle system evaluation. To solve this problem, we propose a fuel-consumption simulation method for FCVs using a 1.2 kW stationary PEMFC （proton exchange membrane fuel cell）. In this study, the specific fuel consumption under driving cycles such as the Japanese 10-15 and the JC08 modes are determined and compared with the FCV simulation results obtained using fuel consumption ratios derived from the stationary PEMFC. In the simulation, the specific fuel consumption was found to be 1.16 kg-H2/100-km for the base case under the Japanese 10-15 driving cycle.
