Obtaining petroleum at the cost of electrical energy is a common problem in almost all oil fields, and it is mainly caused by low duty radio of induction motor used in beam pumping units. Traditional beam-pumping unit...Obtaining petroleum at the cost of electrical energy is a common problem in almost all oil fields, and it is mainly caused by low duty radio of induction motor used in beam pumping units. Traditional beam-pumping units have many intrinsic disadvantages such as low efficiency, complex transmission devices, poor flexibility, tremendous volume and weight in long stroke, etc.Therefore, a novel direct driven linear electromagnetic pumping unit (EMPU) has been developed by combining oil extraction technology with linear motor technology. The thrust of EMPU matches the changing of suspension center load to improve the system efficiency and cut down the consumption of energy. Based on previous experience, a small-scale prototype was developed and a simulation was conducted with it. Both theoretical analyses and experimental study showed that the problems exiting in beam pumping units can be solved with EMPU system, and this is a new method which can be used to solve high energy waste in oil fields.展开更多
This research was to assess the sustainability of fisheries in Pangandaran, West Java. This fishery is an important one in the region, but is threatened by increasing over-exploitation which has led to a steady decrea...This research was to assess the sustainability of fisheries in Pangandaran, West Java. This fishery is an important one in the region, but is threatened by increasing over-exploitation which has led to a steady decrease in the production. In addition to over-exploitation problem, a record of tsunami disaster makes this fishery a unique case. This research, based on a set of primary and secondary data was carried out using the Rapfish analytical approach. Primary data were collected using a stratified cluster random sampling technique, where as many as 186 outboard fishing operators were selected. Meanwhile, relevant complementary data were solicited purposively from five employees of Pangandaran Marine and Fisheries Service. Following from the Rapfish approach, it was found through this research that sustainability levels of fisheries in Pangandaran fall into poor category. For all types of fisheries that exist in the region, almost all sustainability dimensions namely ecological, social, technological and ethical dimensions were scored below 50 of the 100 maximum values. This paper concludes with a suggestion, pointing out attributes that should receive government attention in order that the sustainability of the fisheries in the future.展开更多
文摘Obtaining petroleum at the cost of electrical energy is a common problem in almost all oil fields, and it is mainly caused by low duty radio of induction motor used in beam pumping units. Traditional beam-pumping units have many intrinsic disadvantages such as low efficiency, complex transmission devices, poor flexibility, tremendous volume and weight in long stroke, etc.Therefore, a novel direct driven linear electromagnetic pumping unit (EMPU) has been developed by combining oil extraction technology with linear motor technology. The thrust of EMPU matches the changing of suspension center load to improve the system efficiency and cut down the consumption of energy. Based on previous experience, a small-scale prototype was developed and a simulation was conducted with it. Both theoretical analyses and experimental study showed that the problems exiting in beam pumping units can be solved with EMPU system, and this is a new method which can be used to solve high energy waste in oil fields.
文摘This research was to assess the sustainability of fisheries in Pangandaran, West Java. This fishery is an important one in the region, but is threatened by increasing over-exploitation which has led to a steady decrease in the production. In addition to over-exploitation problem, a record of tsunami disaster makes this fishery a unique case. This research, based on a set of primary and secondary data was carried out using the Rapfish analytical approach. Primary data were collected using a stratified cluster random sampling technique, where as many as 186 outboard fishing operators were selected. Meanwhile, relevant complementary data were solicited purposively from five employees of Pangandaran Marine and Fisheries Service. Following from the Rapfish approach, it was found through this research that sustainability levels of fisheries in Pangandaran fall into poor category. For all types of fisheries that exist in the region, almost all sustainability dimensions namely ecological, social, technological and ethical dimensions were scored below 50 of the 100 maximum values. This paper concludes with a suggestion, pointing out attributes that should receive government attention in order that the sustainability of the fisheries in the future.
