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Electricity
Kinds of Electricity Terms modified by Electricity Selected AbstractsOptimization models and solution methods for load managementINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 4 2004Stig-Inge Gustafsson Abstract The electricity market in Sweden has changed during recent years. Electricity for industrial use can now be purchased from a number of competing electricity suppliers. Hence, the price for each kilowatt-hour is significantly lower than it was just two years ago and interest in electricity conservation measures has declined. However, part of the electricity tariff, i.e. the demand cost expressed in Swedish Kronor (SEK) for each kilowatt, is almost the same as before. Attention has thereby been drawn to load management measures in order to reduce this specific cost. Saving one kWh might lead to a monetary saving of between SEK 0.22 and SEK 914; this paper demonstrates how to eliminate only those kWh that actually save a significant amount of money. A load management system has been installed in a small carpentry factory that can turn off equipment based on a pre-set priority and number of minutes each hour. The question now is what level of the electricity load is optimal in a strictly mathematical sense, i.e. how many kW should be set in the load management computer in order to maximise profitability? In this paper, we develop a mathematical model that can be used as a tool both to find the most profitable subscription level and to control the choices to be made. Numerical results from a case study are presented. Copyright © 2004 John Wiley & Sons, Ltd. [source] Effect of Slaughter Method on Postmortem Changes of Grass Carp (Ctenopharyngodon idella) Stored in IcestiJOURNAL OF FOOD SCIENCE, Issue 5 2005Rodrigo Scherer ABSTRACT: The effect of 2 slaughter methods (immersion in ice-water slurry and electrical stunning followed by ice slurry asphyxiation) on the quality of grass carp (Ctenopharyngodon idella) stored in ice for 20 d was evaluated using sensory and chemical analysis. Electricity immediately stunned the fish and did not induce blood spots in the flesh. Fish killed by electricity showed a faster initial rate of ATP degradation and entered into rigor mortis earlier, but did not show significant differences in the sensory score when compared with fish killed by immersion in ice-water slurry. Thus, no differences were observed in the shelf life of carps between the 2 slaughter methods evaluated. The limit for acceptability of grass carp stored in ice was around 13 to 16 d. Grass carp accumulated more inosine than hypoxanthine. K, Ki, P, Fr, and H values were highly correlated with storage time and with the TFRU sensory scores in both groups; these could be used to assess the freshness quality of grass carp. [source] Factors mediating the effect of gender on ninth-grade Turkish students' misconceptions concerning electric circuitsJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 6 2004Selen Sencar This study was designed to identify and analyze possible factors that mediate the effect of gender on ninth-grade Turkish students' misconceptions concerning electric circuits. A Simple Electric Circuit Concept Test (SECCT), including items with both practical and theoretical contexts, and an Interest-Experience Questionnaire about Electricity (IEQ) were administered to 1,678 ninth-grade students (764 male, 914 female) after the completion of a unit on electricity to assess students' misconceptions and interests-experiences about electricity. Results of the concept test indicated that general performances of the students were relatively low and that many students had misconceptions in interpreting electric circuits. When the data were analyzed using MANOVA and follow-up ANOVAs, a gender difference for males was observed on the dependent variable of total scores on the 10 practical items; however, there was no significant gender difference on the dependent variable of total scores on the six theoretical items. Moreover, when the same data were analyzed using MANCOVA and follow-up ANCOVAs, controlling students' age and interest-experience related to electricity, the observed gender difference was mediated on the total scores on the practical items. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 603,616, 2004 [source] The Impact of Electricity: Development, Desires and Dilemmas by Tanja WintherAMERICAN ANTHROPOLOGIST, Issue 4 2009MICHAEL BRIAN SCHIFFER No abstract is available for this article. [source] The Emergence of Structural Faults on the Supply Side in Deregulated ,Energy Only' Electricity MarketsTHE AUSTRALIAN ECONOMIC REVIEW, Issue 2 2006Paul Simshauser This article examines the effect of plant entry and exit in a deregulated ,energy only' electricity market. A partial equilibrium framework is presented that determines the optimal portfolio of base, intermediate and peaking plant for a given electricity load curve. An optimal result for Queensland is compared against the actual plant stock. Analysis of the portfolio indicates that deregulation is failing a key objective, namely enhancing dynamic efficiency, because too much base plant has been delivered. The research presents scenarios of structural corrections, using the theory of the generalised war of attrition to develop the cases. Results from simulation experiments are clear,consumers will secure lower electricity prices in the short run. But oversupply of base plant may suppress prices to such an extent that they fail to signal timely entry of peaking plant,the consequence of this failure being eventual price shocks and, potentially, load shedding. [source] Reducing Greenhouse Gas Emissions in the Queensland Electricity Supply Industry: Gas and Carbon Tax ScenariosTHE AUSTRALIAN ECONOMIC REVIEW, Issue 3 2004Paul Simshauser This article examines various greenhouse gas scenarios for the electricity supply industry in the coal-rich state of Queensland. The authors use a dynamic partial equilibrium model of the Queensland electricity system to examine the effects of four alternate policy scenarios: a business-as-usual case, a centrally planned gas-fired case, and two carbon tax scenarios, the first in which the merit order of coal and gas plant is reversed, and the second in which fuel switching is undertaken. The results indicate that no scenario is capable of delivering sufficient cuts in emissions to meet a ,Kyoto equivalent' industry target. While fuel switching brought about the greatest reduction in emissions, the high cost of this scenario indicates that a more efficient outcome for the electricity supply industry in Queensland would be a broad-based Australia-wide approach to emissions abatement, so that carbon reductions can be accessed from industries capable of achieving lower cost emissions abatement. [source] Electricity Forward Prices: A High-Frequency Empirical AnalysisTHE JOURNAL OF FINANCE, Issue 4 2004Francis A. Longstaff ABSTRACT We conduct an empirical analysis of forward prices in the PJM electricity market using a high-frequency data set of hourly spot and day-ahead forward prices. We find that there are significant risk premia in electricity forward prices. These premia vary systematically throughout the day and are directly related to economic risk factors, such as the volatility of unexpected changes in demand, spot prices, and total revenues. These results support the hypothesis that electricity forward prices in the Pennsylvania, New Jersey, and Maryland market are determined rationally by risk-averse economic agents. [source] ChemInform Abstract: Catalysis of Salicylaldehydes and Two Different C,H Acids with Electricity: First Example of an Efficient Multicomponent Approach to the Design of Functionalized Medicinally Privileged 2-Amino-4H-Chromene Scaffold.CHEMINFORM, Issue 26 2008Michail N. Elison Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Regional industrial recycling network in energy supply,the case of Joensuu city, FinlandCORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 3 2002Jouni Korhonen Industrial recycling networks offer an example of the practical application of some of the industrial ecology (IE) principles. In the industrial ecosystem and eco-industrial park approaches the material cycles and energy cascades in a natural ecosystem serve as the metaphoric vision for a local/regional industrial system in which waste material and waste (residual) energy are utilized through cooperation between the actors in the system. In this paper, a local/regional recycling network scenario is presented with the energy supply system of the city of Joensuu in Finland. The conditions of success include the co-production of heat and electricity (heat and power, CHP), waste energy utilization for industrial steam and renewable flow use as fuel. Some difficulties in the industrial ecosystem-type development of the system are discussed. Methodological suggestions for industrial ecosystem and eco-industrial park case studies are considered and the experience from this Finnish case is discussed in terms of wider application of IE in local/regional economic energy systems. For future research on the theme, it is suggested that regional industrial ecology may benefit from regional economics theory and, vice versa, regional economics theory may find a new area of application in regional industrial ecology. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment. [source] Climate-Change Mitigation Revisited: Low-Carbon Energy Transitions for China and IndiaDEVELOPMENT POLICY REVIEW, Issue 6 2009Frauke Urban China and India are heavily dependent on high-carbon fossil fuels. This article elaborates the implications of low-carbon energy transitions in the two countries, which can mitigate their serious contribution to climate change while allowing economic growth. Three modelling case studies are presented: for the Chinese power sector, the economy of Beijing and rural Indian households without access to electricity. They demonstrate a significant reduction in greenhouse gas emissions and energy use, while costs are likely to increase. Financial assistance and technology transfer will be needed to support their efforts towards a climate-friendly low-carbon economy. [source] Growth and Poverty Reduction in Uganda, 1999,2000: Panel Data EvidenceDEVELOPMENT POLICY REVIEW, Issue 4 2003Klaus Deininger To explore factors underlying growth and poverty reduction in Africa while overcoming some of the limitations of cross-country analysis, this article uses micro-level survey and panel-data evidence from Uganda spanning 1992,2000. The high elasticity of both income growth and poverty reduction with respect to agricultural output (coffee) prices confirms the benefits from Uganda's decisive liberalisation of output markets. It also suggests the importance of product diversification to protect the poor against price shocks and the potential of cotton-market improvements in tackling persistent poverty in the North. The importance of improving access to basic education and health care emerges more clearly than in cross-country analysis, but benefits depend on complementary investments in electricity and other infrastructure, and reductions in civil strife. [source] Failure to reduce drinking and driving in France: a 6-year prospective study in the GAZEL cohortADDICTION, Issue 1 2010Aymery Constant ABSTRACT Aim An unprecedented decline in alcohol consumption and road mortality has been observed recently in France, but it is still unclear whether or not these changes affected driving while alcohol-intoxicated (DWI). The objective of the study was to estimate prospectively trends of excessive speed on the roads, alcohol consumption and DWI between 2001 and 2007 in a large cohort of experienced drivers. Methods Participants were current employees or recent retirees of the French national electricity and gas company, who volunteered to participate in a research cohort established in 1989 under strict conditions of anonymity. An annual cohort questionnaire is sent to participants that includes two questions about overall alcohol consumption. In 2001 and 2007, 10 684 participants reported their driving behaviours using the same self-administered questionnaire. Results Between 2001 and 2007, the proportion of participants (n = 10 684) who reported having driven at speeds at least 20 km/hour above the limit decreased from 23.7% to 4.1% in built-up areas (P < 0.001), from 34.3% to 9.3% on rural roads (P < 0.001) and from 24.3% to 2.7% on highways (P < 0.001). Regular and non-regular excessive alcohol consumption decreased from 22.7% to 19.7% and from 18.0% to 14.9%, respectively, whereas DWI increased from 22.9% to 25.3% over the same period (P < 0.001). Conclusions A recent crackdown on road violations by the French government has failed to deter DWI. Given that DWI seems to be a sporadic and rarely punished behaviour, its prevention requires more coercive measures, such as using a breath alcohol ignition interlock device. [source] A study of economic evaluation of demand-side energy storage system in consideration of market clearing priceELECTRICAL ENGINEERING IN JAPAN, Issue 1 2007Ken Furusawa Abstract In Japan the electricity market will open on April 1, 2004. Electric utility, Power Producer and Supplier (PPS), and Load Service Entity (LSE) will join the electricity market. LSEs purchase electricity based on the Market Clearing Price (:MCP) from the electricity market. LSEs supply electricity to the customers that contracted with the LSEs on a certain electricity price, and one to the customers that introduced Energy Storage System (:ES) on a time-of-use pricing. It is difficult for LSEs to estimate whether they have any incentive to promote customers to introduce ES or not. This paper evaluates the reduction of LSEs' purchasing cost from the electricity market and other LSEs' purchasing cost by introducing ES to customers. It is clarified which kind of customers has the effect of decreasing LSEs' purchasing cost and how much MCP of the whole power system the demand-side energy storage systems change. Through numerical examples, this paper evaluates the possibility of giving the cost merit to both customers with energy storage systems and LSE by using real data for a year's worth of MCP. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 158(1): 22,35, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20447 [source] Smokers with financial stress are more likely to want to quit but less likely to try or succeed: findings from the International Tobacco Control (ITC) Four Country SurveyADDICTION, Issue 8 2009Mohammad Siahpush ABSTRACT Objective To examine the association of financial stress with interest in quitting smoking, making a quit attempt and quit success. Design and participants The analysis used data from 4984 smokers who participated in waves 4 and 5 (2005,07) of the International Tobacco Control (ITC) Four Country Survey, a prospective study of a cohort of smokers in the United States, Canada, the United Kingdom and Australia. Measurement The outcomes were interest in quitting at wave 4, making a quit attempt and quit success at wave 5. The main predictor was financial stress at wave 4: ,. . . because of a shortage of money, were you unable to pay any important bills on time, such as electricity, telephone or rent bills?'. Additional socio-demographic and smoking-related covariates were also examined. Findings Smokers with financial stress were more likely than others to have an interest in quitting at baseline [odds ratio (OR): 1.63; 95% confidence interval (CI): 1.22,2.19], but were less likely to have made a quit attempt at follow-up (OR: 0.74; 95% CI: 0.57,0.96). Among those who made a quit attempt, financial stress was associated with a lower probability of abstinence at follow-up (OR: 0.53; 95% CI: 0.33,0.87). Conclusions Cessation treatment efforts should consider assessing routinely the financial stress of their clients and providing additional counseling and resources for smokers who experience financial stress. Social policies that provide a safety net for people who might otherwise face severe financial problems, such as not being able to pay for rent or food, may have a favorable impact on cessation rates. [source] Review article: Emergency department implications of the TASEREMERGENCY MEDICINE AUSTRALASIA, Issue 4 2009Megan Robb Abstract The TASER is a conducted electricity device currently being introduced to the Australian and New Zealand police forces as an alternative to firearms in dealing with violent and dangerous individuals. It incapacitates the subject by delivering rapid pulses of electricity causing involuntary muscle contraction and pain. The use of this device might lead to cardiovascular, respiratory, biochemical, obstetric, ocular and traumatic sequelae. This article will summarize the current literature and propose assessment and management recommendations to guide emergency physicians who will be required to review these patients. [source] Microbial Fuel Cells in Relation to Conventional Anaerobic Digestion TechnologyENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 3 2006H. Pham Abstract Conventional anaerobic digestion based bioconversion processes produce biogas and have as such been widely applied for the production of renewable energy so far. An innovative technology, based on the use of microbial fuel cells, is considered as a new pathway for bioconversion processes towards electricity. In comparison with conventional anaerobic digestion, the microbial fuel cell technology holds some specific advantages, such as its applicability for the treatment of low concentration substrates at temperatures below 20,°C, where anaerobic digestion generally fails to function. This provides some specific application niches of the microbial fuel cell technology where it does not compete with but complements the anaerobic digestion technology. However, microbial fuel cells still face important limitations in terms of large-scale application. The limitations involve the investment costs, upscale technical issues and the factors limiting the performance, both in terms of anodic and cathodic electron transfer. Research to render the microbial fuel cell technology more economically feasible and applicable should focus on reactor configuration, power density and the material costs. [source] Exocellular electron transfer in anaerobic microbial communitiesENVIRONMENTAL MICROBIOLOGY, Issue 3 2006Alfons J. M. Stams Summary Exocellular electron transfer plays an important role in anaerobic microbial communities that degrade organic matter. Interspecies hydrogen transfer between microorganisms is the driving force for complete biodegradation in methanogenic environments. Many organic compounds are degraded by obligatory syntrophic consortia of proton-reducing acetogenic bacteria and hydrogen-consuming methanogenic archaea. Anaerobic microorganisms that use insoluble electron acceptors for growth, such as iron- and manganese-oxide as well as inert graphite electrodes in microbial fuel cells, also transfer electrons exocellularly. Soluble compounds, like humic substances, quinones, phenazines and riboflavin, can function as exocellular electron mediators enhancing this type of anaerobic respiration. However, direct electron transfer by cell,cell contact is important as well. This review addresses the mechanisms of exocellular electron transfer in anaerobic microbial communities. There are fundamental differences but also similarities between electron transfer to another microorganism or to an insoluble electron acceptor. The physical separation of the electron donor and electron acceptor metabolism allows energy conservation in compounds as methane and hydrogen or as electricity. Furthermore, this separation is essential in the donation or acceptance of electrons in some environmental technological processes, e.g. soil remediation, wastewater purification and corrosion. [source] Regional development, nature production and the techno-bureaucratic shortcut: the Douro River catchment in PortugalENVIRONMENTAL POLICY AND GOVERNANCE, Issue 6 2008Antonio A. R. Ioris Abstract The introduction of the Water Framework Directive in Europe represents a unique opportunity to promote more inclusive strategies for the long-term preservation of (socionatural) water systems. However, the analysis of the Portuguese experience, using the River Douro as a case study, reveals still considerable shortcomings in the assessment of problems and the formulation of solutions. Instead of promoting a meaningful dialogue between social groups and spatial areas, there is a systematic attempt to conform to legal requisites by taking a ,techno-bureaucratic' shortcut that largely reproduces the distortions of previous regulatory approaches. Decisions on water management are part of political disputes about regional development and state reform, such as in relation to the provision of water and electricity by public utilities. Nonetheless, these broader issues have been kept tacitly away from the WFD agenda, which has been concentrated on adjusting established procedures to the (formal) requirements of the new regulation. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment. [source] The promotion of green electricity in Europe: present and futureENVIRONMENTAL POLICY AND GOVERNANCE, Issue 4 2004Pablo del Río Public support schemes for electricity from renewable energy sources (RES-E) are undergoing a period of change. Two interrelated processes can be discerned at both the EU and member state (MS) levels. On the one hand, the RES-E Directive sets targets for consumption of renewable electricity for the year 2010 and opens the possibility that the European Commission sets a community support framework for RES-E promotion in the future. On the other hand, different types of support scheme have been and are used by countries in order to promote the deployment of renewable electricity. A move from tendering/bidding systems and feed-in tariffs to tradable green certificates can be observed in some MSs. This move may take place in the future in some other MSs while others will certainly continue to rely on their current scheme. This paper provides an overview and assessment of the instruments currently used to promote renewable electricity in Europe and considers some possible trends in the choice of support schemes in the future. Copyright © 2004 John Wiley &,Sons, Ltd and ERP,Environment. [source] Thermal modeling and simulation of an integrated solid oxide fuel cell and charcoal gasification systemENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2009C. Ozgur Colpan Abstract In this study we propose a novel integrated charcoal gasification and solid oxide fuel cell (SOFC) system, which is intended to produce electricity and heat simultaneously. This system mainly consists of an updraft gasifier using air and steam as the gasification agents, a planar and direct internal reforming SOFC and a low temperature gas cleanup system. The performance of this system is assessed through numerical modeling using a pre-developed and validated heat transfer model of the SOFC and thermodynamic models for the rest of the components. These models are used to simulate the performance of the cell and system for a case study. In addition, a parametric study is conducted to assess the effect of Reynolds number at the fuel channel inlet of the SOFC on the cell performance, e.g., fuel utilization and power density, and the system performance, e.g., electrical efficiency, exergetic efficiency, and power to heat ratio. The number of stacks is also calculated for different Reynolds numbers to discuss the economical feasibility of the integrated system. The results show that the electrical efficiency, exergetic efficiency and power to heat ratio of this system are 33.31%, 45.72%, and 1.004, respectively, for the base case. The parametric study points out that taking the Reynolds number low yields higher electrical and exergetic efficiencies for the system, but it also increases the cost of the system. © 2009 American Institute of Chemical Engineers Environ Prog, 2009 [source] Financial stress, smoking cessation and relapse: results from a prospective study of an Australian national sampleADDICTION, Issue 1 2006Mohammad Siahpush ABSTRACT Aims Our aim was to examine the association between financial stress and subsequent smoking cessation among smokers, and relapse among ex-smokers. Design and participants Data came from the first two waves of the Household Income and Labour Dynamics in Australia (HILDA) survey. The size of the subsample of smokers was 2076, and that of ex-smokers was 2717. Data collection was based on face-to-face interviews. Measurement Eight questionnaire items (e.g. difficulty paying electricity, gas or telephone bills and going without meals due to shortage of money) were used to construct a nine-point financial stress index. Findings Smokers with more financial stress were less likely to quit, with the odds of quitting reducing by 13% (95% CI: 4,21%; P = 0.008) per unit of the financial stress index. Ex-smokers with more financial stress were more likely to relapse (P < 0.001). Conclusions Special programmes may have to be implemented to counter the potentially adverse effects of tobacco price increases on smokers who have financial stress and fail to quit smoking. [source] The Contribution of Bioenergy to a New Energy ParadigmEUROCHOICES, Issue 3 2005Daniel De La Torre Ugarte Biomass is a widely available resource that is receiving increased consideration as a renewable substitute for fossil fuels. Developed sustainably and used efficiently, it can induce growth in developing countries, reduce oil demand, and address environmental problems. The potential benefits include: reduction of greenhouse gases, recuperation of soil productivity and degraded land, economic benefits from adding value to agricultural activities and improving access to and quality of energy services. The production of bioenergy involves a range of technologies, including solid combustion, gasification, and fermentation. These technologies produce energy from a diverse set of biological resources - traditional crops, crop residues, energy-dedicated crops, dung, and the organic component of urban waste. The results are bioenergy products that provide multiple energy services: cooking fuel, heat, electricity and transportation fuels. It is this very diversity that holds the potential of a win-win-win for the environment, social and economic development. Bioenergy has to be viewed not as a replacement for oil, but as an element of a portfolio of renewable sources of energy. Coherent and mutually supportive environmental and economic policies may be needed to encourage the emergence of a globally dispersed bioenergy industry that will pursue a path of sustainable development. La biomasse est une resource largement répandue, qui commence à retenir l'attention comme substitut renouvelable aux énergies fossiles. En l'utilisant de façon efficace et durable, on peut accélérer la croissance des pays en voie de développement, réduire la demandepour le pétrole et résoudre certains problèmes d'environnement. Au nombre des bénéfices potentiels il faut mettre : la réduction des émissions de gaz à effet de serre, la reconstitution de la fertilité dessols et des terres dégradées, les avantages économiques liés à l'accroissement de la production agricole et à l'amélioration des services énergétiques, tant en qualité qu'en accessibilité. La production de bioénergie met en oeuvre un large éventail de techniques parmi lesquelles la combustionde produits solides, la gazéification et la fermentation. Elles produisent de l'énergie à partir d'une grande variété de sources biologiques : cultures traditionnelles, résidus de cultures, cultures spécialisées, fumiers et déchets organiques urbains. Les produits bio-énergétiques qui en résultent couvrent une grande variété d'usages : énergie de cuisson, chauffage, électricité et transports. C'est précisément sur cette diversité que repose l'espoir de gains dans toutes les directions, sociales, environnementales et économiques. Il ne faut pas voir la bioénergie comme un simple substitut au pétrole, mais comme un portefeuille de ressources renouvelables. Pour encourager l'émergence d'une industrie bioénergétique largement répandue et susceptible de contribuer au développement durable, il faudra sans doute élaborer des politiques économiques et environnementales cohérentes, capables de se soutenir mutuellement. Bei Biomasse handelt es sich umeine weithin verfügbare Ressource, welche zunehmend als erneuerbarer Ersatz für fossile Brennstoffe in Betracht gezogen wird. Sie kann bei nachhaltiger Entwicklung und effizienter Nutzung zu Wachstum in den Entwicklungsländern führen, die Nachfrage nach Öl senken und dazu beitragen, die Umweltprobleme in den Griff zu bekommen. Zu den potenziellen Nutzen gehÖren: Verringerung der Treibhausgase, Wiederherstellung von Bodenproduktivität sowie von erodiertem Land, wirtschaftlicher Nutzen durch zusätzliche Wertschöpfung aus landwirtschaftlicher Aktivität und besserer Zugang zu und Qualität in der Energieversorgung. Bei der Erzeugungvon Bioenergie kommen eine Reihe von verschiedenen Technologien zur Anwendung, z.B. Verbrennung fester Brennstoffe, Vergasung sowie Gärung. Diese Technologien erzeugen Energie mittels unterschiedlicher biologischer Ressourcen , traditionelle Feldfrüchte und deren Rückstände, spezielle Energiepflanzen, Mist sowie der organische Anteil städtischer Abfälle. Die daraus erzeugte Bioenergie kann zum Kochen, zum Heizen, als Elektrizität oder als Treibstoff genutzt werden. Gerade in dieser Vielfalt liegt der potenzielle Gewinn für die Umwelt und die soziale sowie die wirtschaftliche Entwicklung. Bioenergie sollte nicht als ein Ersatz für Öl, sondern als Bestandteil des Portfolios erneuerbarer Energiequellen angesehen werden. Kohärente und sich gegenseitig unterstützende ökologische und Ökonomische Politikmaßnahmen könntenerforderlich sein, um die Entstehung einer global verbreiteten Bioenergieindustrie zu begünstigen, welche eine nachhaltige Entwicklung verfolgt. [source] The assessment of the impacts of the security management in a competitive environmentEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 5 2009Ettore Bompard Abstract Security management is of the utmost importance in power system and many efforts have been made on this issue since a reliable supply of electricity is crucial to the modern societies. The traditional approach adopted in Europe is based on the "n,,,1" steady-state security that is efficient, although restrictive, and can continue to play an important role also in the new competitive context. In this paper, three alternative market-based models for security consideration are introduced, according to preventive and corrective control approaches. The models are presented and analyzed in terms of their economic impacts on the market throughout a set of useful indexes that allows for a ranking of the advantages got from the re-enforcement of the lines. Moreover, the positive impacts of the phase-shifter (PS) installation for the security and congestion management are quantified and indexes are derived to assess their optimal location. The different models and the exploitation of the proposed indexes are illustrated with reference to a 34-bus test system. Copyright © 2008 John Wiley & Sons, Ltd. [source] Operational and structural optimization of multi-carrier energy systemsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 5 2006Martin Geidl Abstract This paper presents an approach for the combined optimization of energy systems including multiple energy carriers such as electricity, natural gas, and district heat. Power flow and conversion between the different energy infrastructures are described as multi-input multi-output coupling, what enables simple analysis and optimization of the flows. While previous work deals with operational optimization (multi-carrier optimal dispatch and power flow), this paper focuses on optimization of the couplings between the different networks, that is the structure of the system. Copyright © 2006 John Wiley & Sons, Ltd. [source] Solar Energy Collectors with Tunable TransmissionADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Michael G. Debije Abstract A new type of "smart" window is proposed that makes use of fluorescent dye guests in a liquid-crystal host sandwiched between glass panels. The dye absorbs a variable amount of light depending on its orientation, and re-emits this light, of which a significant fraction is trapped by total internal reflection at the glass,air interface, and becomes concentrated along the edges. Such a device could both generate electricity via an attached photovoltaic as well as allow user control of the amount of transmitted light. By applying a voltage across the cell, absorption could be varied 31%, while the usable light output only varied 11% due to the increased efficiency of light collection at homeotropic dye orientation. [source] Energy Harvesting with Single-Ion-Selective Nanopores: A Concentration-Gradient-Driven Nanofluidic Power SourceADVANCED FUNCTIONAL MATERIALS, Issue 8 2010Wei Guo Abstract Inspired by biological systems that have the inherent skill to generate considerable bioelectricity from the salt content in fluids with highly selective ion channels and pumps on cell membranes, herein, a fully abiotic single-pore nanofluidic energy-harvesting system that efficiently converts Gibbs free energy in the form of a salinity gradient into electricity is demonstrated. The maximum power output with the individual nanopore approaches ,26,pW. By exploiting parallelization, the estimated power density can be enhanced by one to three orders over previous ion-exchange membranes. A theoretical description is proposed to explain the power generation with the salinity-gradient-driven nanofluidic system. Calculation results suggest that the electric-power generation and its efficiency can be further optimized by enhancing the surface-charge density (up to 100,mC m,2) and adopting the appropriate nanopore size (between 10 and 50,nm). This facile and cost-efficient energy-harvesting system has the potential to power biomedical tiny devices or construct future clean-energy recovery plants. [source] Experimental Analysis on Performance and Durability of SOFC Demonstration UnitFUEL CELLS, Issue 3 2010M. Halinen Abstract A technical description and experimental analysis of a SOFC demonstration unit is presented. The unit contains most of the primary BoP-components of a complete SOFC system, except of air and fuel recirculation equipment or fuel system compressor. Natural gas is used as the fuel and electricity is supplied to the electric grid. A 5,kW power class planar SOFC stack from Research Centre Jülich is assembled to the demo unit and a long-term experiment is conducted to assess the characteristic performance and durability of different components of the unit (e.g. the SOFC stack, the fuel pre-reformer and air heat exchangers). The evolution of absolute voltage drop of the stack over time is found to be of the same magnitude when compared to short stack experiments. Thus, other system components are not observed to cause an increase in the characteristic voltage drop of the stack. Two BoP-components, the afterburner and the power conversion unit failed to operate as designed. The performance of other BoP-components i.e. fuel pre-reformer and heat exchangers were satisfactory during the test run, and no significant performance loss could be measured. [source] Controlling Light Emission in Luminescent Solar Concentrators Through Use of Dye Molecules Aligned in a Planar Manner by Liquid CrystalsADVANCED FUNCTIONAL MATERIALS, Issue 17 2009Paul P. C. Verbunt Abstract A luminescent solar concentrator (LSC) is a potential low-cost enhancement of the standard large-area silicon photovoltaic panels for the generation of electricity from sunlight. In this work, guest,host systems are investigated using anisotropic fluorescent dyes and liquid crystal mesogens to control the direction of emitted light in the LSC. It is determined that up to 30% more light is emitted from the edge of an LSC waveguide with planar dye alignment parallel to the alignment direction than from any edge of an LSC with no alignment (isotropic). The aligned samples continue to show dichroic performance after additions of both edge mirrors and rear scattering layer. [source] Use of Percutaneous Electrical Nerve Stimulation (PENS) in the Short-term Management of HeadacheHEADACHE, Issue 4 2000Hesham E. Ahmed MD Objective.,To evaluate the short-term effects of percutaneous electrical nerve stimulation (PENS) in the management of three types of chronic headache. Background.,Traditional electroanalgesic therapies have been reported to be effective in the management of acute headache symptoms. However, no controlled studies have been performed in patients with chronic headache. Methods.,Thirty patients with either tension headache, migraine, or posttraumatic headache symptoms of at least 6 months' duration were randomized to receive PENS (needles with electricity) or "needles alone" according to a crossover study design. All treatments were administered for 30 minutes, three times a week for 2 consecutive weeks with 1 week off between the two different treatments. For the PENS treatments, an alternating electrical stimulation frequency of 15 and 30 Hz was used. Pain, activity, and sleep scores were assessed using a 10-cm visual analog scale, with 0 corresponding to the best and 10 to the worst, during the 48-hour period prior to the beginning of the two treatments, immediately before and after each treatment session, and 48 hours after completing each treatment modality. Results.,Compared with the needles alone, PENS therapy was significantly more effective in decreasing the overall VAS pain scores for tension-type headache, migraine and posttraumatic headache (58%, 59%, and 52% versus 20%, 15%, and 20%, respectively). Similarly, PENS therapy produced greater improvement in the patients' physical activity (41% to 58% for PENS versus 11% to 21% for needles only) and quality of sleep (41% to 48% for PENS versus 12% to 20% for needles only). However, there were no differences in the pattern of the response to PENS therapy among the three headache groups. Conclusions.,Percutaneous electrical nerve stimulation appears to be a useful complementary therapy to analgesic and antimigraine drugs for the short-term management of headache. Interestingly, the analgesic response to PENS therapy appears to be independent of the origin of the headache symptoms. [source] Organic Electronics: Improved Performance of Polymer Bulk Heterojunction Solar Cells Through the Reduction of Phase Separation via Solvent Additives (Adv. Mater.ADVANCED MATERIALS, Issue 8 20108/2010) The fabrication of bulk heterojunction organic solar cells from solution-casting techniques using low-cost materials makes them a promising new technology for converting sunlight into electricity. T.-Q. Nguyen, G. C. Bazan, et al. report on p. E63 that undesirable large-scale aggregation and phase separation that may arise during deposition can be reduced by incorporating a small amount of a well-chosen solvent additive. [source] | ||||||||||||||||||||||||||||||||||