Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing...Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.展开更多
Kaempferol,a natural plant-origin flavonoid,exhibits therapeutic anti-inflammatory,antioxidant,anticancer,antidiabetic,and neuroprotective properties.Kaempferol acts within several distinct mechanisms like apoptotic i...Kaempferol,a natural plant-origin flavonoid,exhibits therapeutic anti-inflammatory,antioxidant,anticancer,antidiabetic,and neuroprotective properties.Kaempferol acts within several distinct mechanisms like apoptotic induction in cancer cells,enzymatic inhibition,signalling pathway inhibition,and downregulation in cell viability during the G2/M phase of cell division.This review summarizes the therapeutic effects of kaempferol against several health ailments.The recent progress on kaempferol obtained from fruits and vegetables as an antioxidant,anti-inflammatory,anticancer,antidiabetic,and neuroprotective agent and its mechanisms of action are also discussed.In addition,kaempferol has been reported to be present in wastes and byproducts from post-fruit and vegetable processing.Thus,a paradigm shift towards valorizing fruits and vegetable industrial wastes/byproducts to obtain bioactive kaempferol can support the circular economy pillar for generating wealth from waste and for finding a sustainable alternative source.展开更多
The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design ...The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design of burners and combustion chambers.Also,these experimental data are needed for the validation and optimization within the construction and development of detailed chemical kinetic reaction mechanisms.Within this study,an overview of the different applications of fuel characterization regarding the specific area of interest(road transport,aviation,and aerospace)will be given.Depending on the application,effects of different molecular characteristics on the laminar burning velocity are evaluated:the presence of oxygen atoms and the grade of branching in a specific fuel molecule as well as the difference in the type of a chemical bond,here,single and double bonds.Examples of alternative fuels being discussed in the present study are:(Ⅰ)oxymethylene ether(OMEn)in the field of road transport;(Ⅱ)a paraffinic Alcohol-to-Jet fuel as sustainable aviation fuel;and(Ⅲ)mixtures of ethane or ethene with nitrous oxide as green propellants for rocket propulsion applications.展开更多
文摘Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.
文摘Kaempferol,a natural plant-origin flavonoid,exhibits therapeutic anti-inflammatory,antioxidant,anticancer,antidiabetic,and neuroprotective properties.Kaempferol acts within several distinct mechanisms like apoptotic induction in cancer cells,enzymatic inhibition,signalling pathway inhibition,and downregulation in cell viability during the G2/M phase of cell division.This review summarizes the therapeutic effects of kaempferol against several health ailments.The recent progress on kaempferol obtained from fruits and vegetables as an antioxidant,anti-inflammatory,anticancer,antidiabetic,and neuroprotective agent and its mechanisms of action are also discussed.In addition,kaempferol has been reported to be present in wastes and byproducts from post-fruit and vegetable processing.Thus,a paradigm shift towards valorizing fruits and vegetable industrial wastes/byproducts to obtain bioactive kaempferol can support the circular economy pillar for generating wealth from waste and for finding a sustainable alternative source.
文摘The laminar burning velocity belongs to the fundamental combustion properties of fuels being a measure for their heat release,flame length,as well as reactivity and combustion stability,and thus,may impact the design of burners and combustion chambers.Also,these experimental data are needed for the validation and optimization within the construction and development of detailed chemical kinetic reaction mechanisms.Within this study,an overview of the different applications of fuel characterization regarding the specific area of interest(road transport,aviation,and aerospace)will be given.Depending on the application,effects of different molecular characteristics on the laminar burning velocity are evaluated:the presence of oxygen atoms and the grade of branching in a specific fuel molecule as well as the difference in the type of a chemical bond,here,single and double bonds.Examples of alternative fuels being discussed in the present study are:(Ⅰ)oxymethylene ether(OMEn)in the field of road transport;(Ⅱ)a paraffinic Alcohol-to-Jet fuel as sustainable aviation fuel;and(Ⅲ)mixtures of ethane or ethene with nitrous oxide as green propellants for rocket propulsion applications.