This paper presents a general analytical model of flexible isolation system for application to the installation of high-speed machines and lightweight structures. Piezoelectric stack actuators are employed in the mode...This paper presents a general analytical model of flexible isolation system for application to the installation of high-speed machines and lightweight structures. Piezoelectric stack actuators are employed in the model to achieve vibration control of flexible structures, and dynamic characteristics are also investigated. Mobility technique is used to derive the governing equations of the system. The power flow transmitted into the foundation is solved and considered as a cost function to achieve optimal control of vibration isolation. Some numerical simulations revealed that the analytical model is effective as piezoelectric stack actuators can achieve substantial vibration attenuation by selecting proper value of the input voltage.展开更多
The Unified Power Flow Controller （UPFC） is one of the most versatile Flexible AC Transmission Systems （FACTS） devices that has unique capability of independently controlling the real and reactive power flows, in ...The Unified Power Flow Controller （UPFC） is one of the most versatile Flexible AC Transmission Systems （FACTS） devices that has unique capability of independently controlling the real and reactive power flows, in addition to regulate the system bus voltage. This paper presents performance analysis of Unified Power Flow Controller based on two axis theory. Based on this analysis, a new Artificial Neural Network （ANN） based controller has been proposed to improve the system performance. The controller rules are structured depending upon the relationship between series inserted voltage and the desired changes in real/reactive power flow in the power system. The effects of different controllers along with parameters of series transformer and transmission line have been investigated through developed control block model in SIMULINK tool box of MATLAB. The effectiveness of the proposed scheme is demonstrated by case studies.展开更多
This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient cond...This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient conditions. ICBP is a totally implantable LVAD （left ventricular assist device） with ceramic bearings developed for long term circulatory assistance. FwC uses PI （proportional-integral） control to adjust rotational speed in order to provide blood flow. FwC does not use sensor for feedback, as there is an estimation system to provide blood flow measurement. Control strategy has being studied in a HCS （hybrid cardiovascular simulator） as a tool that allows the physical connection of ICBP during evaluation. In addition, HCS allows changes of some cardiovascular parameters in order to simulate specific heart disease： ejection fraction （10-25%） and heart rate （50-110 bpm）. FwC was able to adjust blood flow with steady error less than 2%. Results demonstrated that FwC is adequate to LVAD control irL different left ventricle failure conditions.展开更多
In recent years, we have entered a period of increasing impact of world affairs on national politics and international security. Notwithstanding, the present debate on national security and nuclear proliferation, Angl...In recent years, we have entered a period of increasing impact of world affairs on national politics and international security. Notwithstanding, the present debate on national security and nuclear proliferation, Anglo-American ＂special relations＂ continue to be a subject of vigorous discussion influenced by the impact of new international emergencies as unstable countries acquire nuclear power and refuse ＂to reign＂ in their nuclear programmes （The Globe and Mail, 12 January 2012）. Along these lines the 71st anniversary of the Anglo-American Manhattan Project presents a unique opportunity to reappraise the Anglo-American wartime collaboration （or lack of） in atomic energy developments that resulted in the tragedy of nuclear weapons escalation. The Quebec Agreements of 1943-1944 were crafted to address the controlled flow of scientific information. But did this mean a trend toward more effective collaboration or toward greater American control of the atomic project？ This study explores the subject of nuclear politics from an unique vantage point of Anglo-Canadian and American-Canadian atomic diplomacy. In doing so, it will show that both the American and British atomic policy makers violated the Quebec Agreements. It seeks to demonstrate that （1） in the tangle of competition replacing cooperation, Canada was more important to the American atomic monopolists than the Anglo-AmcTican partnership, （2） the US-Canada Trade and Defence Agreements contributed to United States retaining exclusive control of the ＂absolute weapon＂, and that （3） their post-war nuclear energy agenda delayed Britain＇s atomic venture and isolated Britain from full participation in Arctic research. In practical terms, the emerging atomic policy in Washington boiled down to maintaining the American edge, come what may, and reducing British prestige in the post-war world. The article concludes by raising the question： did the United States, Britain, and Canada really work for atomic control？展开更多
Our civilization is facing an urgent need to include innovative, large-scale sources of energy and raw materials into its technological cycles. One potential source is magma, which now still inspires awe with its unpr...Our civilization is facing an urgent need to include innovative, large-scale sources of energy and raw materials into its technological cycles. One potential source is magma, which now still inspires awe with its unpredictable power of volcanic eruptions. We propose a method of remote control of lava flow which is based on a special design of a pipe which is lowered into the crater of a volcano. The magma is raised with the help of a well-known method for raising liquids, the airlift. This article includes a detailed description of the structure of the disperser that we shall use to introduce gas into the magma, explains the possible ways to manage the flow of magma, and describes the results that can be achieved. There is potential for the establishment of a whole new industry that will produce cheap electricity, hydrogen, rare metals, fertilizers and innovative construction materials.展开更多
In 2006, except the basic improvement on HL-2A tokamak control system, data acquisition and processing system, a series of research activities have been developed in computer and control division. They include the con...In 2006, except the basic improvement on HL-2A tokamak control system, data acquisition and processing system, a series of research activities have been developed in computer and control division. They include the construction of the high performance computer （HPC） system, the plasma configuration real-time reconstruction with EFIT code, the immigration of plasma simulation codes, the improvement of the poloidal field control system with circulating current, the design of the new data acquiring device with higher anti-disturbing power, the new software on soft X-ray spectrum measurement providing the multi-channel Te evolution, the upgrade to the HL-2A data storage system and experimental net. On the other hand, according to the arrangement of HL-2A modification project, a series of designs such as new plasma configuration, poloidal field coils distribution and plasma shape and position control system are on the processing.展开更多
This paper presents a new idea to reduce the solidity of low-pressure turbine(LPT) blade cascades,while remain the structural integrity of LPT blade.Aerodynamic performance of a low solidity LPT cascade was improved b...This paper presents a new idea to reduce the solidity of low-pressure turbine(LPT) blade cascades,while remain the structural integrity of LPT blade.Aerodynamic performance of a low solidity LPT cascade was improved by increasing blade trailing edge thickness(TET).The solidity of the LPT cascade blade can be reduced by about12.5% through increasing the TET of the blade without a significant drop in energy efficiency.For the low solidity LPT cascade,increasing the TET can decrease energy loss by 23.30% and increase the flow turning angle by1.86% for Reynolds number(Re) of 25,000 and freestream turbulence intensities(FSTT) of 2.35%.The flow control mechanism governing behavior around the trailing edge of an LPT cascade is also presented.The results show that appropriate TET is important for the optimal design of high-lift load LPT blade cascades.展开更多
基金Project (No. 2004035223) supported by the Postdoctoral ScienceFoundation of China
文摘This paper presents a general analytical model of flexible isolation system for application to the installation of high-speed machines and lightweight structures. Piezoelectric stack actuators are employed in the model to achieve vibration control of flexible structures, and dynamic characteristics are also investigated. Mobility technique is used to derive the governing equations of the system. The power flow transmitted into the foundation is solved and considered as a cost function to achieve optimal control of vibration isolation. Some numerical simulations revealed that the analytical model is effective as piezoelectric stack actuators can achieve substantial vibration attenuation by selecting proper value of the input voltage.
文摘The Unified Power Flow Controller （UPFC） is one of the most versatile Flexible AC Transmission Systems （FACTS） devices that has unique capability of independently controlling the real and reactive power flows, in addition to regulate the system bus voltage. This paper presents performance analysis of Unified Power Flow Controller based on two axis theory. Based on this analysis, a new Artificial Neural Network （ANN） based controller has been proposed to improve the system performance. The controller rules are structured depending upon the relationship between series inserted voltage and the desired changes in real/reactive power flow in the power system. The effects of different controllers along with parameters of series transformer and transmission line have been investigated through developed control block model in SIMULINK tool box of MATLAB. The effectiveness of the proposed scheme is demonstrated by case studies.
文摘This paper shows the blood flow control （FwC） performance to adjust rotational speed of an ICBP （implantable centrifugal blood pump） in order to provide an adequate flow to left ventricle in different patient conditions. ICBP is a totally implantable LVAD （left ventricular assist device） with ceramic bearings developed for long term circulatory assistance. FwC uses PI （proportional-integral） control to adjust rotational speed in order to provide blood flow. FwC does not use sensor for feedback, as there is an estimation system to provide blood flow measurement. Control strategy has being studied in a HCS （hybrid cardiovascular simulator） as a tool that allows the physical connection of ICBP during evaluation. In addition, HCS allows changes of some cardiovascular parameters in order to simulate specific heart disease： ejection fraction （10-25%） and heart rate （50-110 bpm）. FwC was able to adjust blood flow with steady error less than 2%. Results demonstrated that FwC is adequate to LVAD control irL different left ventricle failure conditions.
文摘In recent years, we have entered a period of increasing impact of world affairs on national politics and international security. Notwithstanding, the present debate on national security and nuclear proliferation, Anglo-American ＂special relations＂ continue to be a subject of vigorous discussion influenced by the impact of new international emergencies as unstable countries acquire nuclear power and refuse ＂to reign＂ in their nuclear programmes （The Globe and Mail, 12 January 2012）. Along these lines the 71st anniversary of the Anglo-American Manhattan Project presents a unique opportunity to reappraise the Anglo-American wartime collaboration （or lack of） in atomic energy developments that resulted in the tragedy of nuclear weapons escalation. The Quebec Agreements of 1943-1944 were crafted to address the controlled flow of scientific information. But did this mean a trend toward more effective collaboration or toward greater American control of the atomic project？ This study explores the subject of nuclear politics from an unique vantage point of Anglo-Canadian and American-Canadian atomic diplomacy. In doing so, it will show that both the American and British atomic policy makers violated the Quebec Agreements. It seeks to demonstrate that （1） in the tangle of competition replacing cooperation, Canada was more important to the American atomic monopolists than the Anglo-AmcTican partnership, （2） the US-Canada Trade and Defence Agreements contributed to United States retaining exclusive control of the ＂absolute weapon＂, and that （3） their post-war nuclear energy agenda delayed Britain＇s atomic venture and isolated Britain from full participation in Arctic research. In practical terms, the emerging atomic policy in Washington boiled down to maintaining the American edge, come what may, and reducing British prestige in the post-war world. The article concludes by raising the question： did the United States, Britain, and Canada really work for atomic control？
文摘Our civilization is facing an urgent need to include innovative, large-scale sources of energy and raw materials into its technological cycles. One potential source is magma, which now still inspires awe with its unpredictable power of volcanic eruptions. We propose a method of remote control of lava flow which is based on a special design of a pipe which is lowered into the crater of a volcano. The magma is raised with the help of a well-known method for raising liquids, the airlift. This article includes a detailed description of the structure of the disperser that we shall use to introduce gas into the magma, explains the possible ways to manage the flow of magma, and describes the results that can be achieved. There is potential for the establishment of a whole new industry that will produce cheap electricity, hydrogen, rare metals, fertilizers and innovative construction materials.
文摘In 2006, except the basic improvement on HL-2A tokamak control system, data acquisition and processing system, a series of research activities have been developed in computer and control division. They include the construction of the high performance computer （HPC） system, the plasma configuration real-time reconstruction with EFIT code, the immigration of plasma simulation codes, the improvement of the poloidal field control system with circulating current, the design of the new data acquiring device with higher anti-disturbing power, the new software on soft X-ray spectrum measurement providing the multi-channel Te evolution, the upgrade to the HL-2A data storage system and experimental net. On the other hand, according to the arrangement of HL-2A modification project, a series of designs such as new plasma configuration, poloidal field coils distribution and plasma shape and position control system are on the processing.
基金supported by the National Foundation for Innovative Research Groups of China(Grant No.51421063)
文摘This paper presents a new idea to reduce the solidity of low-pressure turbine(LPT) blade cascades,while remain the structural integrity of LPT blade.Aerodynamic performance of a low solidity LPT cascade was improved by increasing blade trailing edge thickness(TET).The solidity of the LPT cascade blade can be reduced by about12.5% through increasing the TET of the blade without a significant drop in energy efficiency.For the low solidity LPT cascade,increasing the TET can decrease energy loss by 23.30% and increase the flow turning angle by1.86% for Reynolds number(Re) of 25,000 and freestream turbulence intensities(FSTT) of 2.35%.The flow control mechanism governing behavior around the trailing edge of an LPT cascade is also presented.The results show that appropriate TET is important for the optimal design of high-lift load LPT blade cascades.
