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Fuel Source (fuel + source)
Selected AbstractsFate of fatty acids at rest and during exercise: regulatory mechanismsACTA PHYSIOLOGICA, Issue 4 2003M. D. Jensen Abstract Fatty acids are a major fuel source for humans both at rest and during exercise. Plasma free fatty acids (FFA), although present only in micromolar concentrations, are the major circulating lipid fuel. FFA availability can increase two- to four-fold with moderate intensity exercise. Other potential sources of fatty acids include circulating very low-density lipoprotein (VLDL) triglycerides (TGs) (,1/5 the fuel availability of FFA) and intramyocellular TGs (,2 mmol kg,1 muscle). At rest ,40% of systemic FFA uptake occurs in the splanchnic bed and uptake in legs is ,15,20%. During leg exercise the uptake of FFA in leg tissue increases to 30,60% of systemic uptake and splanchnic uptake decreases to 15%. The fate of VLDL TG fatty acids has not been adequately studied. Intramyocellular TG hydrolysis increases during exercise, but the factors that regulate this response are not clear. The fact that contraction of isolated muscles can stimulate the hydrolysis and oxidation of intramyocellular TGs (in the absence of hormonal or neural input) suggests an intracellular regulation of this process. Additional regulation from changes in catecholamines and insulin may also occur. During moderate intensity exercise circulating FFA and intramyocellular TG provide roughly equal portions of fatty acids for oxidation. In addition to endurance training, dietary factors have been shown to modulate the fatty acid oxidation response to exercise. Much remains to be learned about fatty acid trafficking during exercise. What role do VLDL TG play? How is the oxidation of intramyocellular TGs regulated? Techniques to address these questions in humans are only now becoming available. [source] Lignocellulosic ethanol: Is it economically and financially viable as a fuel source?ENVIRONMENTAL QUALITY MANAGEMENT, Issue 1 2008Robert E. Froese First page of article [source] The Physicochemical Quality Characteristics of Charcoal Grilled MackerelsJOURNAL OF FOOD SCIENCE, Issue 3 2002M-Y. Kim ABSTRACT: : The effects of different fuel sources used in grilling on the physicochemical and sensory characteristics of mackerel were investigated. Oak and sawdust charcoals were used as fuel sources. The content of saturated fatty acids was increased during grilling. Histidine was the most predominant amino acid; grilling significantly increased glutamic acid. Mackerel shows a high inosine 5,-monophosphate content that is increased during grilling. Oak charcoal and sawdust charcoal contained high levels of potassium and sodium, respectively. Potassium content was increased at the surface muscle of oak charcoal grilled mackerel (OM). The flavor preference for OM was significantly (p < 0.05%) higher than for sawdust charcoal grilled mackerel. These results indicate that physicochemical and sensory properties of grilled foods can be affected by the fuel source. [source] Black gold to green gold: regional energy policy and the rehabilitation of coal in response to climate changeAREA, Issue 1 2009Frances Drake Energy production has come under increasing scrutiny as concerns about energy security and climate change have risen. In the UK changes in government structure and privatisation of the electricity industry have led to the emergence of multi-level governance. This means that decisions on how to reduce carbon dioxide emissions from the electricity-generating sector should no longer be solely a national policy decision. Previous studies have sought to explore how renewable energy may develop under multi-level governance, but this paper pays attention to a traditional fossil fuel source, coal, which is still an important means of electricity generation. Coal is the most abundant fossil fuel and advocates argue that carbon capture and storage techniques could make coal ,clean', paving the way for a long-term, secure and low emission way to produce energy. This study focuses on the Yorkshire and Humber Region, which has had a long association with coal mining and looks at the implications of this as the region seeks to develop a climate change action plan and an energy strategy within the new regional governance structures. The paper argues that the regional networks developed to address climate change are influenced by existing social power structures and alliances. The region as a territorial structure becomes a useful device in promoting national priorities. [source] The perspectives of energy production from coal-fired power plants in an enlarged EUINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 9 2004P. Grammelis Abstract The aim of this paper is to present the current status of the coal-fired power sector in an enlarged EU (EU-15 plus EU member candidate states) in relation with the main topics of the European Strategy for the energy production and supply. It is estimated that 731 thermoelectric units, larger than 100 MWe, are operating nowadays, and their total installed capacity equals to 200.7 GWe. Coal contribution to the total electricity generation with reference to other fuel sources, is by far more intensive in the non-EU part (EU member candidate states), compared to the EU member states. It is expected that even after the enlargement, the European Union will strongly being related to coal. Enlargement will bring additional factors into play in order to meet the requirements of rising consumption, growing demand for conventional fuels and increasing dependence on imports. Besides the technology, boiler size, efficiency, age and environmental performance will determine the necessities of the coal-fired power sector in each country. Depending on the case, lifetime extension measures in operating coal-fired power plants or clean coal technologies can play an important role towards the energy sector restructuring. Low efficiency values in the non-EU coal-fired units and heavily aged power plants in EU countries will certainly affect decisions in favour of upgrading or reconstruction. The overall increase of efficiency, the reduction of harmful emissions from generating processes and the co-combustion of coal with biomass and wastes for generating purposes indicate that coal can be cleaner and more efficient. Additionally, plenty of rehabilitation projects based on CCT applications, have already been carried out or are under progress in the EU energy sector. The proclamations of the countries' energy policies in the coming decades, includes integrated renovation concepts of the coal-fired power sector. Further to the natural gas penetration in the electricity generation and CO2 sequestration and underground storage, the implementation of CCT projects will strongly contribute to the reduction of CO2 emissions in the European Union, according to the targets set in the Kyoto protocol. In consequence, clean coal technologies can open up new markets not only in the EU member candidate states, but also in other parts of the world. Copyright © 2004 John Wiley & Sons, Ltd. [source] The Physicochemical Quality Characteristics of Charcoal Grilled MackerelsJOURNAL OF FOOD SCIENCE, Issue 3 2002M-Y. Kim ABSTRACT: : The effects of different fuel sources used in grilling on the physicochemical and sensory characteristics of mackerel were investigated. Oak and sawdust charcoals were used as fuel sources. The content of saturated fatty acids was increased during grilling. Histidine was the most predominant amino acid; grilling significantly increased glutamic acid. Mackerel shows a high inosine 5,-monophosphate content that is increased during grilling. Oak charcoal and sawdust charcoal contained high levels of potassium and sodium, respectively. Potassium content was increased at the surface muscle of oak charcoal grilled mackerel (OM). The flavor preference for OM was significantly (p < 0.05%) higher than for sawdust charcoal grilled mackerel. These results indicate that physicochemical and sensory properties of grilled foods can be affected by the fuel source. [source] Greenhouse Gas Profile of a Plastic Material Derived from a Genetically Modified PlantJOURNAL OF INDUSTRIAL ECOLOGY, Issue 3 2000Devdatt Kurdikar Abstract: This article reports an assessment of the global warming potential associated with the life cycle of a biopolymer (poly(hydroxyalkanoate) or PHA) produced in genetically engineered corn developed by Monsanto. The grain corn is harvested in a conventional manner, and the polymer is extracted from the corn stover (i.e., residues such as stalks, leaves and cobs), which would be otherwise left on the field. While corn farming was assessed based on current practice, four different hypothetical PHA production scenarios were tested for the extraction process. Each scenario differed in the energy source used for polymer extraction and compounding, and the results were compared to polyethylene (PE). The first scenario involved burning of the residual biomass (primarily cellulose) remaining after the polymer was extracted from the stover. In the three other scenarios, the use of conventional energy sources of coal, oil, and natural gas were investigated. This study indicates that an integrated system, wherein biomass energy from corn stover provides energy for polymer processing, would result in a better greenhouse gas profile for PHA than for PE. However, plant-based PHA production using fossil fuel sources provides no greenhouse gas advantage over PE, in fact scoring worse than PE. These results are based on a "cradle-to-pellet" modeling as the PHA end-of-life was not quantitatively studied due to complex issues surrounding the actual fate of postconsumer PHA. [source] Ultrathin polymeric interpenetration network with separation performance approaching ceramic membranes for biofuelAICHE JOURNAL, Issue 1 2009Lan Ying Jiang Abstract Biofuel has emerged as one of the most strategically important sustainable fuel sources. The success of biofuel development is not only dependent on the advances in genetic transformation of biomass into biofuel, but also on the breakthroughs in separation of biofuel from biomass. The "separation" alone currently accounts for 60,80% of the biofuel production cost. Ceramic membranes made of sophisticated processes have shown separation performance far superior to polymeric membranes, but suffers fragility and high fabrication cost. We report the discovery of novel molecular engineering and membrane fabrication that can synergistically produce polymeric membranes exhibiting separation performance approaching ceramic membranes. The newly discovered Polysulfone/Matrimid composite membranes are fabricated by dual-layer coextrusion technology in just one step through phase inversion. An ultrathin dense-selective layer made of an interpenetration network of the two materials with a targeted and stable interstitial space is formed at the interface of two layers for biofuel separation. The combined molecular engineering and membrane fabrication approach may revolutionize future membrane research and development for purification and separation in energy, environment, and pharmaceuticals. © 2008 American Institute of Chemical Engineers AIChE J, 2009 [source] | |||||||||||||