The climate change and limitation of natural resources becomes main obstacle for the global economical development. So, the Vietnamese Government is very much concerned with reduction of harmful gas discharging from t...The climate change and limitation of natural resources becomes main obstacle for the global economical development. So, the Vietnamese Government is very much concerned with reduction of harmful gas discharging from the inland-water way ships. To overcome the problems, there are many counter-measures proposed such as： renovation of machinery and equipment, using re-creative energy and so on. The author＇s idea is to find a suitable method which can be applied on board of the inland-water ships to reduce discharging toxic gas by using blended palm oil as alternative fuel for marine diesel engines. Due to some disadvantages of the bended palm oil in comparison with traditional DO （diesel oil）, such as： low freezing point, high viscosity, low stability of blended fue, therefore somehow, the blended palm oil must be made a ship directly on board. With this idea, the author has designed and made agitate mixing equipment working on-line with fuel supply system of a diesel engine. The mixing equipment, then, has been tested at shore-side laboratory as well as on board ships. The research results showed that the fuel mixture （palm oil-DO） made by this mixing equipment is fully usable to replace traditional DO for marine diesel engines installed on board ships of inland water way in Vietnam. The Vietnamese Government accepted the research results as prerequisite to devise specific and practical action plans to reduce the pollution from the inland water way ships in coming years.展开更多
For years the interest of the UDR1 researcher group has been focused on the development of a Hybrid Series (HS) vehicle, different from the standard one, using a Gas Turbine (GT) set as a thermal engine. The reason of...For years the interest of the UDR1 researcher group has been focused on the development of a Hybrid Series (HS) vehicle, different from the standard one, using a Gas Turbine (GT) set as a thermal engine. The reason of this choice resides in the opportunity to reduce weight and dimension, in comparison to a traditional In- ternal Combustion Engine (ICE). It’s not possible to use the GT engine directly for the vehicle traction, so the UDR1 HS configuration shows the GT set connected with the electric generator only. The result is that the traction is pure electric. Many efforts are spent in the definition of a generic scientific method to define the correct ratio HD (the Hybridization Degree) between the installed power of the battery pack and that of the GT electric generator which simultaneously guarantee the main life for the battery package and the ca- pacity of the vehicle to complete a common mission (about 15 km - 30 km) without lack of energy or stop. This paper reports all studies carried out and finally proposes a possible configuration (weight distribution, VMU logic control, GT dimensions and power rate, battery package characteristics and so on) for mid term solution in the Italian transport system.展开更多
In this study, the estimates of approximation numbers of embedding operators in weighted spaces have been analyzed. These estimates depend on orders of differential operators, dimensions of function spaces and weighte...In this study, the estimates of approximation numbers of embedding operators in weighted spaces have been analyzed. These estimates depend on orders of differential operators, dimensions of function spaces and weighted functions. This fact implies that the associated embedding operators belong to Schatten class of compact operators. By using these estimates, the discreetness of spectrum and completion of root elements relating to principal nonselfedjoint degenerate differential operators is obtained.展开更多
文摘The climate change and limitation of natural resources becomes main obstacle for the global economical development. So, the Vietnamese Government is very much concerned with reduction of harmful gas discharging from the inland-water way ships. To overcome the problems, there are many counter-measures proposed such as： renovation of machinery and equipment, using re-creative energy and so on. The author＇s idea is to find a suitable method which can be applied on board of the inland-water ships to reduce discharging toxic gas by using blended palm oil as alternative fuel for marine diesel engines. Due to some disadvantages of the bended palm oil in comparison with traditional DO （diesel oil）, such as： low freezing point, high viscosity, low stability of blended fue, therefore somehow, the blended palm oil must be made a ship directly on board. With this idea, the author has designed and made agitate mixing equipment working on-line with fuel supply system of a diesel engine. The mixing equipment, then, has been tested at shore-side laboratory as well as on board ships. The research results showed that the fuel mixture （palm oil-DO） made by this mixing equipment is fully usable to replace traditional DO for marine diesel engines installed on board ships of inland water way in Vietnam. The Vietnamese Government accepted the research results as prerequisite to devise specific and practical action plans to reduce the pollution from the inland water way ships in coming years.
文摘For years the interest of the UDR1 researcher group has been focused on the development of a Hybrid Series (HS) vehicle, different from the standard one, using a Gas Turbine (GT) set as a thermal engine. The reason of this choice resides in the opportunity to reduce weight and dimension, in comparison to a traditional In- ternal Combustion Engine (ICE). It’s not possible to use the GT engine directly for the vehicle traction, so the UDR1 HS configuration shows the GT set connected with the electric generator only. The result is that the traction is pure electric. Many efforts are spent in the definition of a generic scientific method to define the correct ratio HD (the Hybridization Degree) between the installed power of the battery pack and that of the GT electric generator which simultaneously guarantee the main life for the battery package and the ca- pacity of the vehicle to complete a common mission (about 15 km - 30 km) without lack of energy or stop. This paper reports all studies carried out and finally proposes a possible configuration (weight distribution, VMU logic control, GT dimensions and power rate, battery package characteristics and so on) for mid term solution in the Italian transport system.
文摘In this study, the estimates of approximation numbers of embedding operators in weighted spaces have been analyzed. These estimates depend on orders of differential operators, dimensions of function spaces and weighted functions. This fact implies that the associated embedding operators belong to Schatten class of compact operators. By using these estimates, the discreetness of spectrum and completion of root elements relating to principal nonselfedjoint degenerate differential operators is obtained.
