Case studies to assess and compare different energy sources in sustainable energy and electricity supply strategies. Final report of a co-ordinated project 1997-2000

International Nuclear Information System (INIS)

2003-08-01

easy integration into other energy planning or analysis tools. DECADES was thus organized as a data management system rather than as an overall or long range energy planning tool. In 1997, the IAEA initiated a co-ordinated research project (CRP) on Case Studies to Assess and Compare Different Sources in Sustainable Energy and Electricity Supply Strategies under the aegis of the DECADES project to conduct a series of national studies using the DECADES package (DECPAC). Under this CRP, experts from more than twenty countries utilized databases and methodologies developed and reviewed under the DECADES project to carry out national comparative assessment studies. At a final Research Co-ordination Meeting (RCM), held from 14 to 16 December 1999, meeting participants agreed on the format of executive summaries to be prepared for each of the national case studies. This publication summarizes the results obtained and the lessons learned from national case studies carried out under the CRP. The report is intended primarily for managers and senior experts in governmental organizations, research institutes and power utilities who are involved in energy and environmental analysis, interpretation of model results and translation into decision and policy making

A brief comparative study of the wind and nuclear energy

International Nuclear Information System (INIS)

Flores, Tarcisio Santos

2015-01-01

It is apparent the human need to use electricity in the current globalized world. And along with the social and industrial and beyond the everyday comfort evolution came the abuse of power. Aware that Brazil is used as an energy source originating from hydroelectric and that it does not include all domestic demand, should be studied energy sources that can assist it. Two clean and cheap energy alternatives which can contribute to reducing the environmental impacts such as global warming and water shortages are wind and nuclear energy. Which again, exhibit ideal characteristics to serve as alternative sources for electricity production, mainly in the dry season. (author)

Comparative study of energy conversion system dedicated to a small wind turbine; Etude comparative de chaines de conversion d'energie dediees a une eolienne de petite puissance

Energy Technology Data Exchange (ETDEWEB)

Mirecki, A

2005-07-01

This study presents a comparison of architectures and strategies of energy management dedicated to VAWT turbines such as Savonius. A Maximum Power Point Tracking must be implemented in order to optimize the energetic behavior. A torque or a speed control, or an indirect control of the DC bus current is possible. In the fact that the wind turbine characteristic is unknown, an operational research based on fuzzy logic is proposed. Aiming to minimize the cost of the static conversion structure, simple structures (diode bridge inverter, associated with DC-DC chopper) are analyzed and compared with a system based on a PWM Voltage Source Inverter. A test bench has been realized in the meantime as a system simulation. Comparisons of the provided energy are made for different wind speeds allowing to evaluate the performance of each structure and of the control strategies. (author)

A Comparative Study of the Impact of Students' Feelings regarding the Use of Nuclear Energy

Science.gov (United States)

Maharaj-Sharma, Rawatee

2011-01-01

This article presents the results of a comparative study of two groups of learners--group 1 (25 non-science students) and group 2 (25 A-level physics students). It explores the extent to which their feelings and emotions in conjunction with their knowledge about nuclear energy impacts and influences their views and feelings about the use of…

Comparative study of low-energy neutral atom imaging techniques

International Nuclear Information System (INIS)

Funsten, H.O.; McComas, D.J.; Scime, E.E.

1994-01-01

Low-energy neutral atom (LENA) imaging promise to be a revolutionary tool for global imaging of space plasmas. The technical challenges of LENA detection include separating them from the intense ambient UV without losing information about their incident trajectories, quantifying their trajectories, and obtaining high-sensitivity measurements. Two techniques that have been proposed for this purpose are based on fundamentally different atomic interaction mechanisms between LENAs and a solid; LENA transmission through an ultra thin foil and LENA reflection from a solid surface. Both of these methods provide LENA ionization (for subsequent removal from the UV by electrostatic deflection) and secondary electron emission (for time-of-flight start pulse generation and/or coincidence). They present a comparative study of the transmission and reflection techniques based on differences in atomic interactions with solids and surfaces. Transmission methods are shown to be superior for secondary electron emission rather than reflection methods. Furthermore, transmission methods are shown to be a sufficient for LENA imaging at LENA energies of approximately 1 keV to greater than 30 keV. A hybrid instrument using reflection from a low work function surface for LENA ionization and transmission for secondary electron emission is optimal for imaging of LENAs with energies less than approximately 1 keV

Health, Well-Being and Energy Poverty in Europe: A Comparative Study of 32 European Countries

Directory of Open Access Journals (Sweden)

Harriet Thomson

2017-05-01

Full Text Available Despite growing pan-European interest in and awareness of the wide-ranging health and well-being impacts of energy poverty—which is characterised by an inability to secure adequate levels of energy services in the home—the knowledge base is largely British-centric and dominated by single-country studies. In response, this paper investigates the relationship between energy poverty, health and well-being across 32 European countries, using 2012 data from the European Quality of Life Survey. We find an uneven concentration of energy poverty, poor health, and poor well-being across Europe, with Eastern and Central Europe worst affected. At the intersection of energy poverty and health, there is a higher incidence of poor health (both physical and mental amongst the energy poor populations of most countries, compared to non-energy poor households. Interestingly, we find the largest disparities in health and well-being levels between energy poor and non-energy poor households occur within relatively equal societies, such as Sweden and Slovenia. As well as the unique challenges brought about by rapidly changing energy landscapes in these countries, we also suggest the relative deprivation theory and processes of social comparison hold some value in explaining these findings.

Calculation of the energy provided by a PV generator. Comparative study: Conventional methods vs. artificial neural networks

International Nuclear Information System (INIS)

Almonacid, F.; Rus, C.; Perez-Higueras, P.; Hontoria, L.

2011-01-01

The use of photovoltaics for electricity generation purposes has recorded one of the largest increases in the field of renewable energies. The energy production of a grid-connected PV system depends on various factors. In a wide sense, it is considered that the annual energy provided by a generator is directly proportional to the annual radiation incident on the plane of the generator and to the installed nominal power. However, a range of factors is influencing the expected outcome by reducing the generation of energy. The aim of this study is to compare the results of four different methods for estimating the annual energy produced by a PV generator: three of them are classical methods and the fourth one is based on an artificial neural network developed by the R and D Group for Solar and Automatic Energy at the University of Jaen. The results obtained shown that the method based on an artificial neural network provides better results than the alternative classical methods in study, mainly due to the fact that this method takes also into account some second order effects, such as low irradiance, angular and spectral effects. -- Research highlights: → It is considered that the annual energy provided by a PV generator is directly proportional to the annual radiation incident on the plane of the generator and to the installed nominal power. → A range of factors are influencing the expected outcome by reducing the generation of energy (mismatch losses, dirt and dust, Ohmic losses,.). → The aim of this study is to compare the results of four different methods for estimating the annual energy produced by a PV generator: three of them are classical methods and the fourth one is based on an artificial neural network. → The results obtained shown that the method based on an artificial neural network provides better results than the alternative classical methods in study. While classical methods have only taken into account temperature losses, the method based in

A comparative table of various energy sources

International Nuclear Information System (INIS)

Anon.

1976-01-01

This table provides wide informations on the technological facets of various sources of primary energy. One of the outstanding features of this table is that it exposes and compares various technological problems involved in the energy conversion processes. The primary energy sources treated here are the solar energy (heat and light are treated separately), the geothermal energy, coal (gasification and liquefaction are treated separately), oil, natural gas, oceano-energy (tidal energy, temperature difference, and wave energy are treated separately), organic wastes, oil shale, tar sand, hydraulic power, wind power, biomass, uranium, thorium, and deuterium and lithium. On the other hand, the comparisons are made in three major items, i.e. charactersitics as natural resources, conversion or refinement to secondary energy sources, and economical characteristics. The first item includes the estimated and recognized amount of deposits, easiness of mining, storage, and transportation, and cleanliness and safety. As for conversion characteristics, the easiness, controlability, efficiency, cleanliness, and safety of various conversion processes are compared. Finally, as for economical problems, cost comparisons are made for gathering or mining those resources, including required energy input, man power, required facilities, and site conditions. (Aoki, K.)

Comparative study of energy conversion system dedicated to a small wind turbine; Etude comparative de chaines de conversion d'energie dediees a une eolienne de petite puissance

Energy Technology Data Exchange (ETDEWEB)

Mirecki, A

2005-07-01

This study presents a comparison of architectures and strategies of energy management dedicated to VAWT turbines such as Savonius. A Maximum Power Point Tracking must be implemented in order to optimize the energetic behavior. A torque or a speed control, or an indirect control of the DC bus current is possible. In the fact that the wind turbine characteristic is unknown, an operational research based on fuzzy logic is proposed. Aiming to minimize the cost of the static conversion structure, simple structures (diode bridge inverter, associated with DC-DC chopper) are analyzed and compared with a system based on a PWM Voltage Source Inverter. A test bench has been realized in the meantime as a system simulation. Comparisons of the provided energy are made for different wind speeds allowing to evaluate the performance of each structure and of the control strategies. (author)

Comparative study of hydrogen and methanol as energy carriers

Energy Technology Data Exchange (ETDEWEB)

Johansson, Anna

1998-06-01

This report has been written with the purpose to compare hydrogen and methanol, with gasoline, as energy carriers for new energy systems in the future. This energy system must satisfy the demands for sustainable development. The report focuses on motor vehicle applications. A few different criteria has been developed to help form the characterisation method. The criteria proposed in this thesis are developed for an environmental comparison mainly based on emissions from combustion. The criteria concerns the following areas: Renewable resources, The ozone layer, The greenhouse effect, The acidification, and Toxic substances. In many ways, hydrogen may seem as a very good alternative compared with gasoline and diesel oil. Combustion of hydrogen in air results in water and small amounts of oxides of nitrogen. In this report, hydrogen produced from renewable resources is investigated. This is necessary to fulfill the demands for sustainable development. Today, however, steam reforming of fossil fuels represent 99% of the hydrogen production market. Problem areas connected with hydrogen use are for instance storage and distribution. Methanol has many advantages, while comparing methanol and gasoline, like lower emissions of nitrogen oxides and hydrocarbons, limited emissions of carbon dioxide and no sulphur content. Methanol can be produced from many different resources, for example natural gas, naphtha, oil, coal or peat, and biomass. To meet demands for sustainable production, methanol has to be produced from biomass Examination paper. 32 refs, 20 figs, 13 tabs

Comparative study on γ energy spectrum denoise by fourier and wavelet transforms

International Nuclear Information System (INIS)

Shi Dongsheng; Di Yuming; Zhou Chunlin

2007-01-01

This paper introduces the basic principle of wavelet and Fourier transforms, applies wavelet transform method to denoise γ energy spectrum of 60 Co and compares it with Fourier transform method. The result of simulation with MATLAB software tool showed that as compared with traditional Fourier transform, wavelet transform has comparatively higher accuracy for γ energy spectrum denoising and is more feasible to γ energy spectrum denoising. (authors)

Methodology for Analysing Energy Demand in Biogas Production Plants—A Comparative Study of Two Biogas Plants

Directory of Open Access Journals (Sweden)

Emma Lindkvist

2017-11-01

Full Text Available Biogas production through anaerobic digestion may play an important role in a circular economy because of the opportunity to produce a renewable fuel from organic waste. However, the production of biogas may require energy in the form of heat and electricity. Therefore, resource-effective biogas production must consider both biological and energy performance. For the individual biogas plant to improve its energy performance, a robust methodology to analyse and evaluate the energy demand on a detailed level is needed. Moreover, to compare the energy performance of different biogas plants, a methodology with a consistent terminology, system boundary and procedure is vital. The aim of this study was to develop a methodology for analysing the energy demand in biogas plants on a detailed level. In the methodology, the energy carriers are allocated to: (1 sub-processes (e.g., pretreatment, anaerobic digestion, gas cleaning, (2 unit processes (e.g., heating, mixing, pumping, lighting and (3 a combination of these. For a thorough energy analysis, a combination of allocations is recommended. The methodology was validated by applying it to two different biogas plants. The results show that the methodology is applicable to biogas plants with different configurations of their production system.

A comparative study of ammonia energy systems as a future energy carrier, with particular reference to vehicle use in Japan

International Nuclear Information System (INIS)

Miura, Daisuke; Tezuka, Tetsuo

2014-01-01

The choice of secondary energy carriers, such as electricity, hydrogen and ammonia, influences not only economic and environmental performances but also the reliability of an entire energy system. This article focuses on ammonia because of its excellent property in energy storage, and assesses the relative advantages of several ammonia energy systems for vehicle use in Japan by estimating energy efficiency, CO 2 emissions, and the supply cost of several ammonia energy paths, which are then compared with alternative paths using different energy carriers including hydrogen and electricity. The article also discusses inherent merits and challenges of ammonia energy systems and identifies directions for future research and development. Using ammonia as an energy carrier was demonstrated to be competitive in terms of efficiency, CO 2 emissions and supply cost for energy systems requiring fairly large numbers of storage days. This assessment shows that the use of ammonia in an energy system can improve the continuity of the energy supply in a country or region with insecurity of supply. On the other hand, we argue that further technical improvements and cost reduction associated with both conventional and unconventional ammonia production is imperative for using ammonia in a normal energy system. - Highlights: • We assess merits of energy supply systems using ammonia as an energy carrier. • Comparison with hydrogen or electricity-based energy systems was carried out. • We find ammonia is competitive when requiring large numbers of storage days. • The use of ammonia in energy systems can improve the continuity of energy supply. • Technical improvements are needed to make ammonia attractive in normal systems

A Framework for Comparative Assessments of Energy Efficiency Policy Measures

Energy Technology Data Exchange (ETDEWEB)

Blum, Helcio; Atkinson, Barbara; Lekov, Alex

2011-05-24

When policy makers propose new policies, there is a need to assess the costs and benefits of the proposed policy measures, to compare them to existing and alternative policies, and to rank them according to their effectiveness. In the case of equipment energy efficiency regulations, comparing the effects of a range of alternative policy measures requires evaluating their effects on consumers’ budgets, on national energy consumption and economics, and on the environment. Such an approach should be able to represent in a single framework the particularities of each policy measure and provide comparable results. This report presents an integrated methodological framework to assess prospectively the energy, economic, and environmental impacts of energy efficiency policy measures. The framework builds on the premise that the comparative assessment of energy efficiency policy measures should (a) rely on a common set of primary data and parameters, (b) follow a single functional approach to estimate the energy, economic, and emissions savings resulting from each assessed measure, and (c) present results through a set of comparable indicators. This framework elaborates on models that the U.S. Department of Energy (DOE) has used in support of its rulemakings on mandatory energy efficiency standards. In addition to a rigorous analysis of the impacts of mandatory standards, DOE compares the projected results of alternative policy measures to those projected to be achieved by the standards. The framework extends such an approach to provide a broad, generic methodology, with no geographic or sectoral limitations, that is useful for evaluating any type of equipment energy efficiency market intervention. The report concludes with a demonstration of how to use the framework to compare the impacts estimated for twelve policy measures focusing on increasing the energy efficiency of gas furnaces in the United States.

Comparative risk assessment of total energy systems

International Nuclear Information System (INIS)

Soerensen, B.

1982-01-01

The paper discusses a methodology for total impact assessment of energy systems, ideally evaluating all the impacts that a given energy system has on the society in which it is imbedded or into which its introduction is being considered. Impacts from the entire energy conversion chain ('fuel cycle' if the system is fuel-based), including energy storage, transport and transmission, as well as the institutions formed in order to manage the system, should be compared on the basis of the energy service provided. A number of impacts are considered, broadly classified as impacts on satisfaction of biological needs, on health, on environment, on social relations and on the structure of society. Further considerations include impacts related to cost and resilience, and, last but not least, impacts on global relations. The paper discusses a number of published energy studies in the light of the comparative impact assessment methodology outlined above. (author)

A comparative study of energy utilization efficiency between Taiwan and China

International Nuclear Information System (INIS)

Yeh Tsailien; Chen Tseryieth; Lai Peiying

2010-01-01

This paper employs data envelopment analysis to evaluate energy utilization efficiency between China and Taiwan from 2002 to 2007. The most important contributions of this paper are the clear description of the systematic process of energy utilization efficiency, the efficiency comparison between China and Taiwan, the remarkable demonstration of their outputs through two non-desirable outputs (CO 2 emissions and SO 2 emissions) in the data envelopment analysis framework, and the valuable results and insights gained from the application of economic development and environmental protection. Empirical results show that the Eastern region of China enjoy higher energy utilization efficiency than the Western region. Energy utilization efficiency in Taiwan is higher than that in the Eastern region of China. In China, CO 2 emissions were 11.28% greater than they should be (from 2002 to 2007). By contrast, CO 2 emissions in Taiwan were only 1.50% in excess of what they should be since Taiwan began conducting an uninterrupted energy-saving policy and a CO 2 emission regulation policy. Finally, this study employs the business strategy matrix constructed by the Boston Consulting Group (BCG Matrix) to illustrate individual evidence of the relationship between economic development efficiency and greenhouse gas efficiency.

Energy expenditure in adults living in developing compared with industrialized countries: a meta-analysis of doubly labeled water studies.

Science.gov (United States)

Dugas, Lara R; Harders, Regina; Merrill, Sarah; Ebersole, Kara; Shoham, David A; Rush, Elaine C; Assah, Felix K; Forrester, Terrence; Durazo-Arvizu, Ramon A; Luke, Amy

2011-02-01

There is an assumption that people in developing countries have a higher total energy expenditure (TEE) and physical activity level (PAL) than do people in developed nations, but few objective data for this assertion exist. We conducted a meta-analysis of TEE and PAL by using data from countries that have a low or middle human development index (HDI) compared with those with a high HDI to better understand how energy-expenditure variables are associated with development status and population differences in body size. We performed a literature search for studies in which energy expenditure was measured by using doubly labeled water. Mean data on age, weight, body mass index (BMI; in kg/m(2)), TEE, and PAL were extracted, and HDI status was assessed. Pooled estimates of the mean effect by sex were obtained, and the extent to which age, weight, HDI status, and year of publication explained heterogeneity was assessed. A total of 98 studies (14 studies from low- or middle-HDI countries) that represented 183 cohorts and 4972 individuals were included. Mean (±SE) BMI was lower in countries with a low or middle HDI than in those with a high HDI for both men and women (22.7 ± 1.0 compared with 26.0 ± 0.7, respectively, in men and 24.3 ± 0.7 compared with 26.6 ± 0.4, respectively, in women). In meta-regression models, there was an inverse association of age (P developing and industrialized countries, which calls into question the role of energy expenditure in the cause of obesity at the population level.

Socio-economic barriers and success factors in the development of low energy consumption housing. A comparative study in three European countries

Energy Technology Data Exchange (ETDEWEB)

Beillan, Veronique (EDF Recherche and Developpement, ICAME Dept. (France)); Cayre, Emmanuelle (EDF Recherche and Developpement, ENERBAT Dept. (France)); Goater, Aurelie (Alpheeis Energy and Environment Consulting, Valbonne (France)); Laborgne, Pia; Huber, Andreas (EIFERifer (Germany)); Trotignon, Regine (ADEME (France)); Rochard, Ulrich (Eboek, Tuebingen (Germany)); Pouget, Andre (POUGET Consultants, Paris (France)); Novakov, Dusan (Novasystem En+) (Switzerland))

2009-07-01

This study, conducted in 2007-2008, analyses the key factors for allowing the offer of low energy buildings to meet the demand of the households and making low energy consumption operations succeed. It applies a qualitative (on-site survey of several houses) as well as a European comparative approach. Three countries with different levels of development of energy efficient buildings have been chosen: Germany, Switzerland and France. In each country several new single houses with a high-energy performance level - compared to the current regulatory level - have been selected. Around forty interviews have been conducted with inhabitants of the single-family house sector where the final users are also the decision-makers, and with professionals involved in the building of these low energy houses. Main results show the role of meso actors like professionals, association and local communities and the importance of regulations and constructions standards to be taken into account in future policies. Beforehand, an historical analysis in the three countries has enabled us to identify the main facts occurring these thirty last years and their effect on the implementation of low energy buildings: major societal events like the oil crisis, the evolution of the legislation and the regulation, governments' incentives, RandD progress, voluntary initiatives of market players. To provide a reliable comparative analysis, a detailed study has also been conducted on the three energy efficient building labels existing in the selected countries. This analysis showed in which point a comparison based only on a first reading of the objectives of energy consumptions to be reached doesn't correspond to the reality of the aimed performances: although expressed in kWh/m2, the requirements do not recover the same domain and are not calculated with equivalent hypotheses. This study has been carried out in a framework of a partnership between energy providers, public and private energy

Energy consumption, prices and economic growth in three SSA countries: A comparative study

International Nuclear Information System (INIS)

Odhiambo, Nicholas M.

2010-01-01

In this paper we examine the causal relationship between energy consumption and economic growth in three sub-Saharan African countries, namely South Africa, Kenya and Congo (DRC). We incorporate prices as an intermittent variable in a bivariate setting between energy consumption and economic growth-thereby creating a simple trivariate framework. Using the ARDL-bounds testing procedure, we find that the causality between energy consumption and economic growth varies significantly across the countries under study. The results show that for South Africa and Kenya there is a unidirectional causal flow from energy consumption to economic growth. However, for Congo (DRC) it is economic growth that drives energy consumption. These findings have important policy implications insofar as energy conservation policies are concerned. In the case of Congo (DRC), for example, the implementation of energy conservation policies may not significantly affect economic growth because the country's economy is not entirely energy dependent. However, for South Africa and Kenya there is a need for more energy supply augmentations in order to cope with the long-run energy demand. In the short-run, however, the two countries should explore more efficient and cost-effective sources of energy in order to address the energy dependency problem.

A Comparative Review of a Dozen National Energy Plans. Focus on Renewable and Efficient Energy

Energy Technology Data Exchange (ETDEWEB)

Logan, Jeffrey [National Renewable Energy Lab. (NREL), Golden, CO (United States); James, Ted L. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2009-03-01

Dozens of groups have submitted energy, environmental, and economic recovery plans for consideration by the Obama administration and the 111th Congress. This report provides a comparative analysis of 12 national proposals, focusing especially on energy efficiency (EE) and renewable energy (RE) market and policy issues.

A comparative analysis of urban energy governance in four European cities

International Nuclear Information System (INIS)

Morlet, Clémence; Keirstead, James

2013-01-01

Cities are at the forefront of efforts to combat climate change and in this paper, we examine the influence of urban energy governance on these policy goals. An innovative framework for quantifying the combined governance of cities and energy systems is presented before focusing on a detailed study of London, Paris, Berlin and Copenhagen. By applying an optimization model to assess the lowest cost technology pathways to achieve emission reduction targets, the links between the governance of urban energy systems and the cost of achieving carbon targets are shown. Additionally a novel metric of scenario similarity is introduced in order to evaluate the difficulty of hypothesized energy system transitions. The results indicate that these tools can be valuable in identifying similar cities for the sharing of best practice, for performing comparative evaluations of energy transitions, and for reinforcing the need to complement quantitative assessments with a more holistic appreciation of local context. - Highlights: • Novel framework for comparing urban energy systems and their governance is presented. • Applied to four European cities with focus on climate change issues. • Bhattacharyya's distance introduced as measure of energy system scenario similarity. • Results suggest Paris is closest to its 2020 climate goals, London furthest

A comparative study on the modeling of a latent heat energy storage system and evaluating its thermal performance in a greenhouse

Science.gov (United States)

Mirahmad, A.; Sadrameli, S. M.

2018-03-01

Thermal Energy Storage (TES) systems can be compared with batteries. As batteries can be charged when electricity is available for using during the power failure, TES systems can do the same for the thermal energy, i.e., they can absorb the available heat in one cycle, called charge cycle, and release it in a consecutive cycle, called discharge cycle. Among different kinds of TES systems, Phase Change Materials (PCM) have drawn considerable attention, since by changing from one phase to another, they can exchange a significant amount of energy in a small temperature difference. In this quest, a one dimensional mathematical model is solved using two different techniques and the results are compared together; one method is based on the enthalpy and the other is based on the effective heat capacity as well. Secondly, through eight experiments designed by using factorial approach, effects of inlet air velocity and temperature on the outlet stream has been investigated. The results proved that having a determined temperature difference between the inlet air and the PCM in both hot and cold cycles can enhance the efficiency. Finally, the feasible applications of a LHTES system for reducing the temperature swing in a greenhouse is studied numerically and the results are compared with experimental values. As a result, by using this passive coolant system diurnal internal temperature can be reduced for 10 °C.

A SOFTWARE TOOL TO COMPARE MEASURED AND SIMULATED BUILDING ENERGY PERFORMANCE DATA

Energy Technology Data Exchange (ETDEWEB)

Maile, Tobias; Bazjanac, Vladimir; O' Donnell, James; Garr, Matthew

2011-11-01

Building energy performance is often inadequate when compared to design goals. To link design goals to actual operation one can compare measured with simulated energy performance data. Our previously developed comparison approach is the Energy Performance Comparison Methodology (EPCM), which enables the identification of performance problems based on a comparison of measured and simulated performance data. In context of this method, we developed a software tool that provides graphing and data processing capabilities of the two performance data sets. The software tool called SEE IT (Stanford Energy Efficiency Information Tool) eliminates the need for manual generation of data plots and data reformatting. SEE IT makes the generation of time series, scatter and carpet plots independent of the source of data (measured or simulated) and provides a valuable tool for comparing measurements with simulation results. SEE IT also allows assigning data points on a predefined building object hierarchy and supports different versions of simulated performance data. This paper briefly introduces the EPCM, describes the SEE IT tool and illustrates its use in the context of a building case study.

A comparative study of floor construction on sloping sites: an analysis of cumulative energy demand and greenhouse gas emissions

Directory of Open Access Journals (Sweden)

Grace Ding

2016-03-01

Full Text Available In order to make environmentally aware decisions, there is growing interest in the comparative energy and greenhouse gas (GHG performance of competing construction methods. Little research has been done concerning competing ground floor construction methods, especially given different site variables, such as slope and soil type. A life cycle assessment approach was adopted to analyse environmental impacts, including cumulative energy demand and GHG emissions for detached housing construction in Australia. Data was drawn from 24 case study housing projects, including 12 reinforced concrete and 12 suspended timber floor projects. The data presented in the paper compares cumulative energy demand, GHG and the constituent parts of competing construction methods. The findings indicate that the timber floors use/create significantly less cumulative energy demand and GHG emissions than concrete floors—approximately 2.1 to 2.7 times less energy and 2.3 to 2.9 times less GHG. These findings are limited to the site slope and foundation soil types identified in the paper. The main application of the work is in guidance concerning the lowest environmental impact options for detached housing construction.

Comparing long term energy scenarios

International Nuclear Information System (INIS)

Cumo, M.; Simbolotti, G.

2001-01-01

Major projection studies by international organizations and senior analysts have been compared with reference to individual key parameters (population, energy demand/supply, resources, technology, emissions and global warming) to understand trends and implications of the different scenarios. Then, looking at the long term (i.e., 2050 and beyond), parameters and trends have been compared together to understand and quantify whether and when possible crisis or market turbulence might occur due to shortage of resources or environmental problems [it

Comparing Waste-to-Energy technologies by applying energy system analysis

DEFF Research Database (Denmark)

Münster, Marie; Lund, Henrik

2010-01-01

Even when policies of waste prevention, re-use and recycling are prioritised a fraction of waste will still be left which can be used for energy recovery. This article asks the question: How to utilise waste for energy in the best way seen from an energy system perspective? Eight different Waste......-to-Energy technologies are compared with a focus on fuel efficiency, CO2 reductions and costs. The comparison is carried out by conducting detailed energy system analyses of the present as well as a potential future Danish energy system with a large share of combined heat and power as well as wind power. The study shows...... potential of using waste for the production of transport fuels. Biogas and thermal gasification technologies are hence interesting alternatives to waste incineration and it is recommended to support the use of biogas based on manure and organic waste. It is also recommended to support research...

Comparative Review of a Dozen National Energy Plans: Focus on Renewable and Efficient Energy

Energy Technology Data Exchange (ETDEWEB)

Logan, J.; James, T. L.

2009-03-01

Dozens of groups have submitted energy, environmental, and economic recovery plans for consideration by the Obama administration and the 111th Congress. This report provides a comparative analysis of 12 national proposals, focusing especially on energy efficiency (EE) and renewable energy (RE) market and policy issues.

Assessment of comparative and non-comparative factors in alternate energy system

Energy Technology Data Exchange (ETDEWEB)

Rowe, W D; Oterson, P

1983-01-01

The American University Institute for Risk Analysis (AURA) has undertaken a study for the European Economic Community to critically evaluate the methodologies for comparative risk analyses and costs and benefits of alternative energy systems used to generate electricity, principally nuclear, coal, and oil. Other energy systems and related industries with major hazards are also addressed where pertinent. This is particularly true for cases where electrical energy may be an inefficient form for end use as for transportation and space heating. Here, comparison on an end use basis by the most efficient method, electrical or otherwise, is required. The starting point and basis for this evaluation has been the array of existing studies of alternative energy systems already published. These studies, including those already undertaken by the Community, are over 50 in number. The purpose of this study is not to make a comparison of alternative energy systems, but to evaluate what is and what is not useful in existing studies, as well as to provide insight on how meaningful studies can be conducted. There has been considerable criticism and discussion about the conduct and validity of several studies, particularly the Inhaber study and the critiques of Holdren et al. While much of the critiques deal with methods and approaches, substantial criticism and discussion has focused on the motivations of the investigators and how the studies were applied. This latter set of issues is hardly a technological or methodological argument.

Energy sources and nuclear energy. Comparative analysis and ethical reflections

International Nuclear Information System (INIS)

Hoenraet, C.

1999-01-01

Under the authority of the episcopacy of Brugge in Belgium an independent working group Ethics and Nuclear Energy was set up. The purpose of the working group was to collect all the necessary information on existing energy sources and to carry out a comparative analysis of their impact on mankind and the environment. Also attention was paid to economical and social aspects. The results of the study are subjected to an ethical reflection. The book is aimed at politicians, teachers, journalists and every interested layman who wants to gain insight into the consequences of the use of nuclear energy and other energy sources. Based on the information in this book one should be able to objectively define one's position in future debates on this subject

A comparative study on the influential factors of China's provincial energy intensity

International Nuclear Information System (INIS)

Yang, Guangfei; Li, Wenli; Wang, Jianliang; Zhang, Dongqing

2016-01-01

China has become the largest energy consumer worldwide, and it is important to study the energy intensity to realize the sustainable development goal of China. This paper focuses on investigating the influential factors of China's energy intensity using provincial-level panel data from 1985 to 2012. More specifically, we try to identify which factor is relatively more important to pay attention to. A novel approach based on evolutionary computation is proposed to intelligently mine the intrinsic relations between observed phenomena and to let the important factors automatically emerge from the discovered nonlinear models. However, due to China's vast territory and significant heterogeneities, this approach may fail to examine some detailed or hidden information when analyzing the country as a whole. Instead, we concentrate on the provincial level because the provinces play vital roles in reducing energy intensity in China. From our analytical results, the main findings are as follows: (1) the Total Population is the most important influential factor across China's provinces, while the Energy Price Index has the least impact; and (2) the provinces could be naturally classified into four categories based on the primary factors emerged from data, and such classification could reveal more about the true underlying features of each area. - Highlights: • Identify the important factors of China's energy intensity by symbolic regression. • Analyze China's energy intensity using provincial-level panel data from 1985 to 2012. • Intelligently investigate nonlinear models and the emergence of important factors. • The Total Population is discovered to be the most important influential factor. • Provinces are naturally classified into four categories by the influential factors.

A comparative study of all-vanadium and iron-chromium redox flow batteries for large-scale energy storage

Science.gov (United States)

Zeng, Y. K.; Zhao, T. S.; An, L.; Zhou, X. L.; Wei, L.

2015-12-01

The promise of redox flow batteries (RFBs) utilizing soluble redox couples, such as all vanadium ions as well as iron and chromium ions, is becoming increasingly recognized for large-scale energy storage of renewables such as wind and solar, owing to their unique advantages including scalability, intrinsic safety, and long cycle life. An ongoing question associated with these two RFBs is determining whether the vanadium redox flow battery (VRFB) or iron-chromium redox flow battery (ICRFB) is more suitable and competitive for large-scale energy storage. To address this concern, a comparative study has been conducted for the two types of battery based on their charge-discharge performance, cycle performance, and capital cost. It is found that: i) the two batteries have similar energy efficiencies at high current densities; ii) the ICRFB exhibits a higher capacity decay rate than does the VRFB; and iii) the ICRFB is much less expensive in capital costs when operated at high power densities or at large capacities.

Integrating geothermal into coal-fired power plant with carbon capture: A comparative study with solar energy

International Nuclear Information System (INIS)

Wang, Fu; Deng, Shuai; Zhao, Jun; Zhao, Jiapei; Yang, Guohua; Yan, Jinyue

2017-01-01

Highlights: • Post-combustion carbon capture integrating geothermal energy was proposed. • A 300 MWe subcritical coal-fired plant was selected as the baseline. • The geothermal assisted carbon capture system was compared with solar assisted carbon capture plant. • Two different locations were chosen for the technical and economical comparison. • Using medium temperature geothermal thermal energy to replace steam extraction performs better performance. - Abstract: A new system integrating geothermal energy into post-combustion carbon capture is proposed in this paper. Geothermal energy at medium temperatures is used to provide the required thermal heat for solvent regeneration. The performance of this system is compared with solar assisted carbon capture plant via technical and economic evaluation. A 300 MWe coal-fired power plant is selected as the reference case, and two different locations based on the local climatic conditions and geothermal resources are chosen for the comparison. The results show that the geothermal assisted post-combustion carbon capture plant has better performances than the solar assisted one in term of the net power output and annual electricity generation. The net plant average efficiency based on lower heating value can be increased by 2.75% with a thermal load fraction of about 41%. Results of economic assessment show that the proposed geothermal assisted post-combustion carbon capture system has lower levelized costs of electricity and cost of carbon dioxide avoidance compared to the solar assisted post-combustion carbon capture plant. In order to achieve comparative advantages over the reference post-combustion carbon capture plant in both locations, the price of solar collector has to be lower than 70 USD/m 2 , and the drilling depth of the geothermal well shall be less than 2.1 km.

Comparative study of energy accounting for heavy ion fusion with various driver accelerators

International Nuclear Information System (INIS)

Kawasaki, S.; Miyahara, A.

1980-04-01

Typical designs of driver heavy ion accelerator systems are referred and compared with regard to the assessment of the energy payback problem involved in their applications to the inertial fusion. Detailed analyses show that the energy investment for the construction of the HIF power station is fairly smaller than the energy produced by the station in its lifetime, in spite of the large scale of its hardware. The situation could be more favourable than, or at least comparable with, the case of the magnetically confined fusion. (author)

Green Energy-Industrial Innovation: A Comparative Study of Green Energy Transformations in Northern Europe

Energy Technology Data Exchange (ETDEWEB)

Eikeland, Per Ove; Christiansen, Atle Christer; Koefoed, Anne Louise; Midttun, Atle; Tangen, Kristian

1999-07-01

Greening of industry is a prominent topic on the European agenda and has received a new impetus with the Kyoto process, where the European Union and its member states are facing new obligations. Due to its role as a major infrastructure sector and due to its extensive emissions, the electricity sector has become a focal industry in this context. These same factors, as well as the large public ownership has, in fact, traditionally placed energy in a central public political focus. The energy and electricity sector hence exemplify the intertwined nature of economics and politics in sector developments, where technology choices and capacity expansions have numerous motivations and diverse interests to please. This report discusses ''green'' innovation in the energy industry. By selecting some of the most advanced examples of breakthrough for new green technologies in Europe, it explores the basic elements of successful greening of industry. To account for the fact that product innovation- and diffusion-processes are embedded in a complex politico-economic setting, we have developed an analytical framework, incorporating both economic, political and societal elements and the interplay between them. More specifically, environmentally oriented innovation is seen as evolving out of the interplay between: 1) a technical-commercial core (major market agents, i.e. the renewable energy supply industry, associated complementary industries and consumers); 2) the political-administrative system; and 3) the societal basis, referring to existing societal customs, norms, and modes of social organisation. Drawing on Porter's (1990) analysis of business clusters, we have termed our focus ''green energy-industrial cluster'' emergence and growth. We have taken Porter's attempt to break out of a limited market analysis into a broader strategic focus one step further, where the political and institutional dimensions are more explicitly included. This implies that we see the emergence of

Green Energy-Industrial Innovation: A Comparative Study of Green Energy Transformations in Northern Europe

International Nuclear Information System (INIS)

Eikeland, Per Ove; Christiansen, Atle Christer; Koefoed, Anne Louise; Midttun, Atle; Tangen, Kristian

1999-01-01

Greening of industry is a prominent topic on the European agenda and has received a new impetus with the Kyoto process, where the European Union and its member states are facing new obligations. Due to its role as a major infrastructure sector and due to its extensive emissions, the electricity sector has become a focal industry in this context. These same factors, as well as the large public ownership has, in fact, traditionally placed energy in a central public political focus. The energy and electricity sector hence exemplify the intertwined nature of economics and politics in sector developments, where technology choices and capacity expansions have numerous motivations and diverse interests to please. This report discusses ''green'' innovation in the energy industry. By selecting some of the most advanced examples of breakthrough for new green technologies in Europe, it explores the basic elements of successful greening of industry. To account for the fact that product innovation- and diffusion-processes are embedded in a complex politico-economic setting, we have developed an analytical framework, incorporating both economic, political and societal elements and the interplay between them. More specifically, environmentally oriented innovation is seen as evolving out of the interplay between: 1) a technical-commercial core (major market agents, i.e. the renewable energy supply industry, associated complementary industries and consumers); 2) the political-administrative system; and 3) the societal basis, referring to existing societal customs, norms, and modes of social organisation. Drawing on Porter's (1990) analysis of business clusters, we have termed our focus ''green energy-industrial cluster'' emergence and growth. We have taken Porter's attempt to break out of a limited market analysis into a broader strategic focus one step further, where the political and institutional dimensions are more explicitly included. This implies that we see the emergence of

Energy efficiency and indoor thermal perception. A comparative study between radiant panel and portable convective heaters

Energy Technology Data Exchange (ETDEWEB)

Ali, Ahmed Hamza H.; Morsy, Mahmoud Gaber [Department of Mechanical Engineering, Faculty of Engineering, Assiut University, Assiut, 71516 (Egypt)

2010-11-15

This study investigates experimentally the thermal perception of indoor environment for evaluating the ability of radiant panel heaters to produce thermal comfort for space occupants as well as the energy consumption in comparison with conventional portable natural convective heaters. The thermal perception results show that, compared with conventional convection heater, a radiantly heated office room maintains a lower ambient air temperature while providing equal levels of thermal perception on the thermal dummy head as the convective heater and saves up to 39.1% of the energy consumption per day. However, for human subjects' vote experiments, the results show that for an environmentally controlled test room at outdoor environment temperatures of 0C and 5C, using two radiant panel heaters with a total capacity of 580 W leads to a better comfort sensation than the conventional portable natural convective heater with a 670 W capacity, with an energy saving of about 13.4%. In addition, for an outdoor environment temperature of 10C, using one radiant panel heater with a capacity of 290 W leads to a better comfort sensation than the conventional convection heater with a 670 W capacity, with an energy saving of about 56.7%. From the analytical results, it is found that distributing the radiant panel heater inside the office room, one on the wall facing the window and the other on the wall close to the window, provides the best operative temperature distribution within the room.

Assessing the Impact of Renewable Energy on Regional Sustainability—A Comparative Study of Sogn og Fjordane (Norway and Okinawa (Japan

Directory of Open Access Journals (Sweden)

Valeria Jana Schwanitz

2017-10-01

Full Text Available The drive to expand renewable energies is often in direct conflict with sustainable development goals. Thus, it is important that energy policies account for potential trade-offs. We assess the interlinkages between energy, food, water and land, for two case studies, Okinawa and Sogn og Fjordane. We apply a range of assessment methods and study their usefulness as tools to identify trade-offs and to compare the sustainability performance. We calculate cross-sectoral footprints, self-sufficiency ratios and perform a simplified Energy-Water-Food nexus analysis. We use the latter for assessing scenarios to increase energy and food self-sufficiency in Okinawa, while we use ecosystem service (ESS accounting for Sogn og Fjordane. For Okinawa, we find that constraints on the energy, food and water sectors urgently call for integrated approaches to energy policy; for Sogn og Fjordane, the further expansion of renewables comes at the expense of cultural and supporting ESS, which could outweigh gains from increased energy exports. We recommend a general upgrade to indicators and visualization methods that look beyond averages and a fostering of infrastructure for data on sustainable development based on harmonized international protocols. We warn against rankings of countries or regions based on benchmarks that are neither theory-driven nor location-specific.

A comparative assessment of the role of energy in Qatar's East Asian foreign relations: case studies on China, Japan and South Korea

OpenAIRE

Park, Rebekah

2017-01-01

Energy is an important factor in international relations and recently the global energy paradigm has been seen to be shifting towards the East. In light of such change, a comparative assessment of the role of energy in Qatar’ East Asian foreign relations will be conducted by taking China, Japan and South Korea as case studies. The research aimed to assess each of the bilateral relationship in terms of their origin and development in the energy sector generating an interpretation of their grow...

Environmental Comparative Risk Assessment: A Case Study

International Nuclear Information System (INIS)

Ali, M.M.

2007-01-01

Health and environmental impacts associated with energy production and industrial activities as well as food production and agricultural activities have had great concern in the last decades. Early activities emerged in late 80s of the last century through an Inter- Agency project (lAEA, UNDY, WHO, ... ) on the comparative risk assessment from energy systems and industrial complexes. A work-shop on Risk Assessment and Management in large industrial areas was held in Alexandria Egypt on 20-33 Det 1993, sponsored by IAEA. Several conferences, experts work groups and workshops were held there of Recent trends in determining risks are: 1. Use of probabilistic risk assessment approach to identify hazardous activities and accident scenario. 2. development of data base on failure probabilities and appropriate physical models. 3. Development of related directives and regulations and criteria Comparative risk assessment case study as a tool for comparing risk is emphasized Criteria of exposure to human and ecological risks are addressed

Comparative study of energy-efficiency and conservation systems for ceramic metal-halide discharge lamps

International Nuclear Information System (INIS)

Hermoso Orzáez, Manuel Jesús; Andrés Díaz, José Ramón de

2013-01-01

Interest in energy savings in urban lighting is gaining traction and has become a priority for municipal administrations. LED (light-emitting diode) technology appears to be the clear future lighting choice. However, this technology is still rapidly developing and has not been sufficiently tested. As an intermediate step, alternative proposals for energy-saving equipment for traditional discharge lamps are desirable so that the current technologies can coexist with the new LED counterparts for the short and medium term. This article provides a comparative study between two efficiency and energy-saving systems for discharge lamps with metal-halide and ceramic technologies, i.e., a lighting flow dimmer-stabilizer and a double-level electronic ballast. - Highlights: ► It has been demonstrated the possibility of regulating ceramic metal-halide lamps with lighting flow dimmer-stabilizer. ► Electronic ballasts can save approximately double quantity of energy than lighting flow dimmer-stabilizers. ► The use of lighting flow dimmer-stabilizer is more profitable than electronic ballasts due to costs and reliability

A “Grammar” for assessing the performance of power-supply systems: Comparing nuclear energy to fossil energy

International Nuclear Information System (INIS)

Diaz-Maurin, François; Giampietro, Mario

2013-01-01

This article illustrates an innovative approach for the characterization and comparison of the performance of power-supply systems. The concept of ‘grammar’ forces to declare the pre-analytical decisions about: (i) semantic and formal categories used for the accounting – primary energy sources (PES), energy carriers (EC), and production factors; (ii) the set of functional and structural elements of the power-supply system included in the analysis. After having tamed the systemic ambiguity associated with energy accounting, it becomes possible to generate a double assessment referring to: (i) external constraints – the consumption of PES and the generation of waste and pollution; and (ii) internal constraints – the requirements of production factors such as human labor, power capacity, internal consumption of EC for making EC. The case study provided compares the production of EC (electricity) with “nuclear energy” and “fossil energy”. When considering internal constraints, nuclear energy requires about twice as much power capacity (5.9–9.5 kW/GWh vs. 2.6–2.9 kW/GWh) and 5–8 times more labor (570–640 h/GWh vs. 80–115 h/GWh). Things do not improve for nuclear energy when looking at external constraints – e.g. the relative scarcity of PES. This may explain the difficulties faced by nuclear energy to gain interest from investors. -- Highlights: ► A new approach to assess the performance of power-supply systems is provided. ► A biophysical analysis of the production process is based on the concept of grammar. ► A grammar is capable of handling the inherent ambiguity associated with energy. ► The performance of nuclear energy and fossil energy is compared using this grammar. ► Nuclear energy demonstrates a lower performance than fossil energy in making electricity.

Comparative risks in the energy scene

International Nuclear Information System (INIS)

Cohen, A.V.

1981-01-01

Studies comparing the risks in different energy systems are discussed, and the usefulness of the quantified risk assessment to the decision maker is outlined. Information is presented on (a) risks from fuel extraction, processing and fabrication (for coal, oil and nuclear); (b) annual risk per unit output (coal, oil and nuclear); (c) major events (nuclear, coal, oil and chemical). (U.K.)

Energy Consumption Trends in Energy Scarce and Rich Countries: Comparative Study for Pakistan and Saudi Arabia

Science.gov (United States)

Gazder, Uneb

2017-11-01

Energy crisis is raising serious concerns throughout the world. There has been constant rise in energy consumption corresponding to the increase in global population. This sector affects the other pillars of national economy including industries and transportation. Because of these reasons, the traditional fossil-based energy sources are depleting rapidly, resulting in high and unstable energy prices. Saudi Arabia and Pakistan, although different from each other in terms of their economic stability and political systems, still rely heavily on the traditional fossil fuels. This paper presents the comparison of these two countries in terms of their energy consumption and factors affecting it. These factors include, but not limited to, economic development, and growth in population and other sectors such as; industries, transportation, etc. The comparison is also made with the regional and global energy consumption trends and these countries. Moreover, regression models were built to predict energy consumption till 2040 and compare the growth in this sector and share in global energy demand. Energy consumption in oil-rich countries (Saudi Arabia) has been driven through its economic development, while for energy insecure country (Pakistan) it is mainly because of population growth. It was also found that in the next two decades the share of Pakistan in the global energy demand will increase. This concludes that population growth will have more impact on energy consumption than economic growth. It could mean that the shift in energy sector would shift towards sustenance instead of using energy for commercial or industrial usage. Conference Track: Policy and Finance and Strategies

A Comparative Computational Fluid Dynamics Study on an Innovative Exhaust Air Energy Recovery Wind Turbine Generator

Directory of Open Access Journals (Sweden)

Seyedsaeed Tabatabaeikia

2016-05-01

Full Text Available Recovering energy from exhaust air systems of building cooling towers is an innovative idea. A specific wind turbine generator was designed in order to achieve this goal. This device consists of two Giromill vertical axis wind turbines (VAWT combined with four guide vanes and two diffuser plates. It was clear from previous literatures that no comprehensive flow behavior study had been carried out on this innovative device. Therefore, the working principle of this design was simulated using the Analysis System (ANSYS Fluent computational fluid dynamics (CFD package and the results were compared to experimental ones. It was perceived from the results that by introducing the diffusers and then the guide vanes, the overall power output of the wind turbine was improved by approximately 5% and 34%, respectively, compared to using VAWT alone. In the case of the diffusers, the optimum angle was found to be 7°, while for guide vanes A and B, it was 70° and 60° respectively. These results were in good agreement with experimental results obtained in the previous experimental study. Overall, it can be concluded that exhaust air recovery turbines are a promising form of green technology.

Asymmetric energy flow in liquid alkylbenzenes: A computational study

International Nuclear Information System (INIS)

Leitner, David M.; Pandey, Hari Datt

2015-01-01

Ultrafast IR-Raman experiments on substituted benzenes [B. C. Pein et al., J. Phys. Chem. B 117, 10898–10904 (2013)] reveal that energy can flow more efficiently in one direction along a molecule than in others. We carry out a computational study of energy flow in the three alkyl benzenes, toluene, isopropylbenzene, and t-butylbenzene, studied in these experiments, and find an asymmetry in the flow of vibrational energy between the two chemical groups of the molecule due to quantum mechanical vibrational relaxation bottlenecks, which give rise to a preferred direction of energy flow. We compare energy flow computed for all modes of the three alkylbenzenes over the relaxation time into the liquid with energy flow through the subset of modes monitored in the time-resolved Raman experiments and find qualitatively similar results when using the subset compared to all the modes

Studying Wind Energy/Bird Interactions: A Guidance Document

Energy Technology Data Exchange (ETDEWEB)

Anderson, R. [California Energy Commission (US); Morrison, M. [California State Univ., Sacramento, CA (US); Sinclair, K. [Dept. of Energy/National Renewable Energy Lab. (US); Strickland, D. [WEST, Inc. (US)

1999-12-01

This guidance document is a product of the Avian Subcommittee of the National Wind Coordinating Committee (NWCC). The NWCC was formed to better understand and promote responsible, credible, and comparable avian/wind energy interaction studies. Bird mortality is a concern and wind power is a potential clean and green source of electricity, making study of wind energy/bird interactions essential. This document provides an overview for regulators and stakeholders concerned with wind energy/bird interactions, as well as a more technical discussion of the basic concepts and tools for studying such interactions.

A Comparative Study on Substation Types and Network Layouts in Connection with Low-Energy District Heating Systems

DEFF Research Database (Denmark)

Tol, Hakan; Svendsen, Svend

2012-01-01

The study deals with low-energy district heating (DH) networks operating in low temperatures such as 55 °C in terms of supply and 25 °C in terms of return. The network layout, additional booster pumps, and different substation types such as storage tanks either equipped or not equipped in domesti...... for end-consumers were also studied, heat loss from these networks and the drop in temperature in the heat-carrier-supply medium being compared.......The study deals with low-energy district heating (DH) networks operating in low temperatures such as 55 °C in terms of supply and 25 °C in terms of return. The network layout, additional booster pumps, and different substation types such as storage tanks either equipped or not equipped in domestic...... hot water production site were examined. Effects of booster pumps on pipe dimensions in the latter case were investigated. Temperature drops during the summer months due to low heat demands of consumers were explored. Use of approaches such as looped networks and branched network layouts with bypasses...

Energy Efficiency and Universal Design in Home Renovations - A Comparative Review.

Science.gov (United States)

Kapedani, Ermal; Herssens, Jasmien; Verbeeck, Griet

2016-01-01

Policy and societal objectives indicate a large need for housing renovations that both accommodate lifelong living and significantly increase energy efficiency. However, these two areas of research are not yet examined in conjunction and this paper hypothesizes this as a missed opportunity to create better renovation concepts. The paper outlines a comparative review on research in Energy Efficiency and Universal Design in order to find the similarities and differences in both depth and breadth of knowledge. Scientific literature in the two fields reveals a disparate depth of knowledge in areas of theory, research approach, and degree of implementation in society. Universal Design and Energy Efficiency are part of a trajectory of expanding scope towards greater sustainability and, although social urgency has been a driver of the research intensity and approach in both fields, in energy efficiency there is an engineering, problem solving approach while Universal Design has a more sociological, user-focused one. These different approaches are reflected in the way home owners in Energy Efficiency research are viewed as consumers and decision makers whose drivers are studied, while Universal Design treats home owners as informants in the design process and studies their needs. There is an inherent difficulty in directly merging Universal Design and Energy Efficiency at a conceptual level because Energy Efficiency is understood as a set of measures, i.e. a product, while Universal Design is part of a (design) process. The conceptual difference is apparent in their implementation as well. Internationally energy efficiency in housing has been largely imposed through legislation, while legislation directly mandating Universal Design is either non-existent or it has an explicit focus on accessibility. However, Energy Efficiency and Universal Design can be complementary concepts and, even though it is more complex than expected, the combination offers possibilities to advance

Comparative study of the efficiency of public supports to investments in energy management in the European Union

International Nuclear Information System (INIS)

Scheuer, Stefan; Ballu, Matthieu; Di Stefano, Paolo

2013-01-01

This study proposes a detailed overview of public budgets invested by the different member States of the European Union via subsidy systems, loans or tax arrangements in order to support investments in energy efficiency in buildings. The author also studied results published for these public instruments in terms of energy savings, and proposed a comparison which takes the lifetime of these savings into account. The study is based on available official information. Thus, before presenting the obtained results, the author describes how data have been collected and harmonised, presents the comparative analysis and discusses the lifetime measurement issue

Comparative Study of Antenna Designs for RF Energy Harvesting

Directory of Open Access Journals (Sweden)

Sika Shrestha

2013-01-01

Full Text Available In the last few years, several antenna designs of rectenna that meet various objectives have been proposed for use in RF energy harvesting. Among various antennas, microstrip patch antennas are widely used because of their low profile, light weight, and planar structure. Conventional patch antennas are rectangular or circular in shape, but variations in their basic design are made for different purposes. This paper begins with an explanation and discussion of different designs, put forward with an aim of miniaturization, harmonic rejection, and reconfigurability. Finally, microstrip patch structured rectennas are evaluated and compared with an emphasis on the various methods adopted to obtain a compact rectenna, harmonic rejection functionality, and frequency and polarization selectivity.

Comparative Study of Single-glazed and Double-glazed Windows in Terms of Energy Efficiency and Economic Expenses

Directory of Open Access Journals (Sweden)

Samaneh Forughian

2017-06-01

Full Text Available Saving fossil fuels and the use of clean sources of energy lead to reduce in building operating costs, protect the environment and people's health. Windows are the most vulnerable part of building where energy loss occurs. Double-glazed windows are very effective in keeping inside temperature isolated from outside; thereby, saving electrical and thermal energy. The current study estimates the numerical changes in cooling and heating load in case of replacement double-glazed window with single-glazed window and calculates saving level for this replacement. In this context, this paper presents a model of real samples taken in Mashhad climate. To ensure the accuracy of the simulation results, real results were compared with electricity and gas bills. To calculate energy related parameters such as cooling load, heating load, the consumption of gas and electricity, the energy simulation software (Design Builder was used. The research method was a quantitative analysis based on energy consumption modeling, associated with building windows which comes in four sections. The field study was also used to compare with real electricity and gas bills. As the first stage, samples of the plan were identified, based on the observation of climate models and library studies. Then, simulation parameters such as window materials and internal and external walls were considered. The simulation was performed based software’s parameters and model limitations were determined based on thermal, lighting, climatic and architectural parameters. Finally, the experimental and practical data were used to determine the validity of the model under Mashhad climate conditions. Overall, the results indicated that double-glazed windows could save 50% of entire building loads, 0.2% on power consumption, 16.2% on gas and 12.4% on overall households’ energy consumption.

Comparing primary energy attributed to renewable energy with primary energy equivalent to determine carbon abatement in a national context.

Science.gov (United States)

Gallachóir, Brian P O; O'Leary, Fergal; Bazilian, Morgan; Howley, Martin; McKeogh, Eamon J

2006-01-01

The current conventional approach to determining the primary energy associated with non-combustible renewable energy (RE) sources such as wind energy and hydro power is to equate the electricity generated from these sources with the primary energy supply. This paper compares this with an approach that was formerly used by the IEA, in which the primary energy equivalent attributed to renewable energy was equated with the fossil fuel energy it displaces. Difficulties with implementing this approach in a meaningful way for international comparisons lead to most international organisations abandoning the primary energy equivalent methodology. It has recently re-emerged in prominence however, as efforts grow to develop baseline procedures for quantifying the greenhouse gas (GHG) emissions avoided by renewable energy within the context of the Kyoto Protocol credit trading mechanisms. This paper discusses the primary energy equivalent approach and in particular the distinctions between displacing fossil fuel energy in existing plant or in new plant. The approach is then extended provide insight into future primary energy displacement by renewable energy and to quantify the amount of CO2 emissions avoided by renewable energy. The usefulness of this approach in quantifying the benefits of renewable energy is also discussed in an energy policy context, with regard to increasing security of energy supply as well as reducing energy-related GHG (and other) emissions. The approach is applied in a national context and Ireland is case study country selected for this research. The choice of Ireland is interesting in two respects. The first relates to the high proportion of electricity only fossil fuel plants in Ireland resulting in a significant variation between primary energy and primary energy equivalent. The second concerns Ireland's poor performance to date in limiting GHG emissions in line with its Kyoto target and points to the need for techniques to quantify the potential

Comparative table of various energy sources

Energy Technology Data Exchange (ETDEWEB)

1976-08-01

This table provides wide informations on the technological facets of various sources of primary energy. One of the outstanding features of this table is that it exposes and compares various technological problems involved in the energy conversion processes. The primary energy sources treated here are the solar energy (heat and light are treated separately), the geothermal energy, coal (gasification and liquefaction are treated separately), oil, natural gas, oceano-energy (tidal energy, temperature difference, and wave energy are treated separately), organic wastes, oil shale, tar sand, hydraulic power, wind power, biomass, uranium, thorium, and deuterium and lithium. On the other hand, the comparisons are made in three major items, i.e. charactersitics as natural resources, conversion or refinement to secondary energy sources, and economical characteristics. The first item includes the estimated and recognized amount of deposits, easiness of mining, storage, and transportation, and cleanliness and safety. As for conversion characteristics, the easiness, controlability, efficiency, cleanliness, and safety of various conversion processes are compared. Finally, as for economical problems, cost comparisons are made for gathering or mining those resources, including required energy input, man power, required facilities, and site conditions.

Energy input in conventional and organic paddy rice production in Missouri and Italy: A comparative case study.

Science.gov (United States)

Pagani, Marco; Johnson, Thomas G; Vittuari, Matteo

2017-03-01

The expected decline in availability of fossil fuels over the next several decades, either because of resource depletion or because of limits on carbon emissions, is leading to a keen interest in finding more sustainable energy sources. For this reason, it is useful to assess the energy footprint of alternative agricultural systems for crops and animal production and to identify potential transition scenarios to systems largely based on renewable energy. The present work aims to assess for the first time a comparative analysis of energy inputs in rice production systems in Southern Europe (Piemonte, Italy) and in North America (Missouri, USA). A total of twelve rice farms, either conventional or organic, were selected, collecting detailed data on direct (fuel and electricity) and indirect (machinery, fertilizers, pesticides, and seeds) energy inputs. While energy input of conventional farms ranged from 3.5 to 7 MJ/kg paddy rice, organic farming could reduce inputs by more than 50% with only 8% yield decrease. A significant reduction in fuel or electricity use can be achieved also with no till and surface irrigation. The use of renewable energy sources, as already practiced by some farms, could more than cover their electrical energy requirements. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative Embodied Energy Analysis of a Steel and Concrete Structural System in Ireland

OpenAIRE

Acquaye, Adolf; Duffy, Aidan; Basu, Biswajit

2007-01-01

Engineering building design focuses on optimising operational energy use and ignores the energy required to procure and construct a building. This energy, termed ‘embodied energy’, can be very significant when compared to operational energy. Therefore, it is important to minimise the embodied in buildings; this must be done at the design stage. This paper presents a comparative embodied energy analysis of two structural design solutions for a modern office building: one in concrete and one in...

Time-dependent opportunities in energy business. A comparative study of locally available renewable and conventional fuels

International Nuclear Information System (INIS)

Tolis, Athanasios I.; Rentizelas, Athanasios A.; Tatsiopoulos, Ilias P.

2010-01-01

This work investigates and compares energy-related, private business strategies, potentially interesting for investors willing to exploit either local biomass sources or strategic conventional fuels. Two distinct fuels and related power-production technologies are compared as a case study, in terms of economic efficiency: the biomass of cotton stalks and the natural gas. The carbon capture and storage option are also investigated for power plants based on both fuel types. The model used in this study investigates important economic aspects using a 'real options' method instead of traditional Discounted Cash Flow techniques, as it might handle in a more effective way the problems arising from the stochastic nature of significant cash flow contributors' evolution like electricity, fuel and CO 2 allowance prices. The capital costs have also a functional relationship with time, thus providing an additional reason for implementing 'real options' as well as the learning-curves technique. The methodology as well as the results presented in this work, may lead to interesting conclusions and affect potential private investment strategies and future decision making. This study indicates that both technologies lead to positive investment yields, with the natural gas being more profitable for the case study examined, while the carbon capture and storage does not seem to be cost efficient with the current CO 2 allowance prices. Furthermore, low interest rates might encourage potential investors to wait before actualising their business plans while higher interest rates favor immediate investment decisions. (author)

Linear pneumatic motors – a comparative study

Directory of Open Access Journals (Sweden)

Deaconescu Tudor

2017-01-01

Full Text Available The paper presents a comparative study of the performance of single-acting cylinders, diaphragm cylinders and pneumatic muscles, and offers users information that allows the selection of an optimum technical solution. Such a study was necessary, in view of the numerous papers on pneumatic muscle applications found in literature, that assert the superiority of pneumatic muscles over other pneumatic linear motors in relation to quantities like dimensions, mass, developed force or energy-to-mass ratios, however without offering concrete data.

Environmental management in sugar-energy sector: a comparative analysis

Directory of Open Access Journals (Sweden)

Andréia Marize Rodrigues

2014-11-01

Full Text Available With the rise of the environmental variable in the business environment, companies started to give greater attention to strategies and practices focused on the rational use of natural resources and minimize the environmental impacts of their business operations. Many productive sectors stood out in the reflections on production and the environment, as is the case of the sugar energy industry, which constitutes a sector with a highly demanding industrial activity of natural resources, whether as sources of inputs as depositories of waste production. Thus, the aim of this paper is a comparative analysis of environmental practices of two sugar energy plants, both from the point of view of their operational strategy and regarding the suitability of the disposal of waste generated by the industrial area. It was concluded that, although many practices adopted by businesses are analogous, one of the studied plants have distinctive environmental performance, because of the increased attention given to the implementation of environmental practices and especially the inclusion of the environmental variable in their strategies.

Comparative assessment of severe accident risks in the energy sector

International Nuclear Information System (INIS)

Hirschberg, S.; Spiekerman, G.; Dones, R.

1997-01-01

This paper addresses one of the major limitations of the current comparative studies of environmental and health impacts of energy systems, i.e. the treatment of severe accidents. The work covers technical aspects of severe accidents and thus primarily reflects an engineering perspective on the energy-related risk issues. The assessments concern full energy chains associated with fossil sources (coal, oil and gas), nuclear power and hydro power. A comprehensive severe accidents database has been established. Thanks to the variety of information sources used, it exhibits in comparison with other corresponding databases a far more extensive coverage of the energy-related accidents. For hypothetical nuclear accidents the probabilistic approach has been employed and extended to cover the economic consequences of power reactor accidents. Results of comparisons between the various energy chains are shown and discussed along with a number of current issues in comparative assessment of severe accidents. As opposed to the previous studies, the aim of the present work has been, to cover whenever possible, a relatively broad spectrum of damage categories of interest. (author) 5 figs., 1 tab., 18 refs

Injury Characteristics of Low-Energy Lisfranc Injuries Compared With High-Energy Injuries.

Science.gov (United States)

Renninger, Christopher H; Cochran, Grant; Tompane, Trevor; Bellamy, Joseph; Kuhn, Kevin

2017-09-01

Lisfranc injuries result from high- and low-energy mechanisms though the literature has been more focused on high-energy mechanisms. A comparison of high-energy (HE) and low-energy (LE) injury patterns is lacking. The objective of this study was to report injury patterns in LE Lisfranc joint injuries and compare them to HE injury patterns. Operative Lisfranc injuries were identified over a 5-year period. Patient demographics, mechanism of injury, injury pattern, associated injuries, missed diagnoses, clinical course, and imaging studies were reviewed and compared. HE mechanism was defined as motor vehicle crash, motorcycle crash, direct crush, and fall from greater than 4 feet and LE mechanism as athletic activity, ground level twisting, or fall from less than 4 feet. Thirty-two HE and 48 LE cases were identified with 19.3 months of average follow-up. There were no differences in demographics or missed diagnosis frequency (21% HE vs 18% LE). Time to seek care was not significantly different. HE injuries were more likely to have concomitant nonfoot fractures (37% vs 6%), concomitant foot fractures (78% vs 4%), cuboid fractures (31% vs 6%), metatarsal base fractures (84% vs 29%), displaced intra-articular fractures (59% vs 4%), and involvement of all 5 rays (23% vs 6%). LE injuries were more commonly ligamentous (68% vs 16%), with fewer rays involved (2.7 vs 4.1). LE mechanisms were a more common cause of Lisfranc joint injury in this cohort. These mechanisms generally resulted in an isolated, primarily ligamentous injury sparing the lateral column. Both types had high rates of missed injury that could result in delayed treatment. Differences in injury patterns could help direct future research to optimize treatment algorithms. Level III, comparative series.

A Comparative Analysis of Renewable Energy Use and Policies: Global and Turkish Perspectives

Directory of Open Access Journals (Sweden)

Mahmure Övül Arıoğlu Akan

2015-12-01

Full Text Available The utilization of renewable energy sources (RES has become inevitable, not only due to the increasing scarcity of fossil fuels, but also to sustain life on Earth. Consequently, countries have started developing renewable energy policies individually and as part of global organizations and networks, such as the Organization for Economic Co-operation and Development (OECD, the European Union (EU and the International Energy Agency (IEA. Turkey is a developing OECD member country and in the accession process to the EU. Thus, the renewable energy policies should be aligned with those of the EU. Moreover, despite the substantial amount and wide range of RES, it is still in a position to import more than half of its energy demand. In the light of these facts, this study aims to analyze and compare the renewable energy policies in Turkey with those adopted worldwide to lay out possible solutions regarding its energy problems.

A retrospective randomized study to compare the energy delivered using CDE with different techniques and OZil settings by different surgeons in phacoemulsification.

Science.gov (United States)

Chen, Ming; Sweeney, Henry W; Luke, Becky; Chen, Mindy; Brown, Mathew

2009-01-01

Cumulative dissipated energy (CDE) was used with Infiniti((R)) Vision System (Alcon Labs) as an energy delivery guide to compare four different phaco techniques and phaco settings. The supracapsular phaco technique and burst mode is known for efficiency and surgery is faster compared with the old phaco unit. In this study, we found that supracapsular phaco with burst mode had the least CDE in both cataract and nuclear sclerosis cataract with the new Infiniti((R)) unit. We suggest that CDE can be used as one of the references to modify technique and setting to improve outcome for surgeons, especially for new surgeons.

A Comparative Case Study of Electric Utility Companies’ Use of Energy Democracy in Strategic Communication

Directory of Open Access Journals (Sweden)

Meaghan McKasy

2018-02-01

Full Text Available A substantial increase in distributed renewable energy resources is changing the face of the energy environment, leading to strategic communication efforts by key stakeholders. The energy democracy movement supports this transformation from fossil fuels to distributed renewable energy and aims for equitable involvement of publics in energy decision making. These tenets challenge utility company earnings as they are directly related to energy sales and infrastructure returns on investment. Proposals by electric utility companies to restructure net-metering policies as a solution to financial issues have been criticized as prohibitive to the success of renewable energy advancement. To address these disagreements, the Edison Electric Institute and a communication firm, Maslansky & Partners, created The Future of Energy: A Working Communication Guide for Discussion. This handbook provides utility companies with strategic communication guidelines to portray themselves as supportive of renewables within a dynamic energy industry. We posit that aspects of the energy democracy movement have been employed by electric utility companies, as shown through the use of the handbook, as a strategy for communicating with customers in discussions around net metering. We examine two case studies in states with recent controversial net-metering policy changes by analyzing utility company websites and press releases for the use of the communication handbook terminology. We found that, in both cases, the suggested language was used to position their companies as pro-renewable energy and their utility-scale projects as more equitable for their customers. In addition, we found differences between each company’s use of key terms from the handbook. We posit that this is due to the temporal context of each net-metering debate at the time of the handbook release. Conclusions and future directions for research in the growing area of energy democracy are discussed.

Security of energy supply: Comparing scenarios from a European perspective

International Nuclear Information System (INIS)

Costantini, V.; Markandya, A.; Vicini, G.

2007-01-01

This policy compares different results from a set of energy scenarios produced by international energy experts, in order to analyse projections on increasing European external energy dependence and vulnerability. Comparison among different scenarios constitutes the basis of a critical review of existing energy security policies, suggesting alternative or complementary future actions. According to the analysis, the main risks and negative impacts in the long term could be the increasing risk of collusion among exporters due to growing dependence of industrialized countries and insufficient diversification; and a risk of demand/supply imbalance, with consequent instability for exporting regions due to insufficient demand, and lack of infrastructures due to insufficient supply. Cooperation with exporting countries enhancing investments in production capacity, and with developing countries in order to reinforce negotiation capacity of energy-importing countries seem to be the most effective policies at international level. (author)

Security of energy supply: Comparing scenarios from a European perspective

International Nuclear Information System (INIS)

Costantini, Valeria; Gracceva, Francesco; Markandya, Anil; Vicini, Giorgio

2007-01-01

This paper compares different results from a set of energy scenarios produced by international energy experts, in order to analyse projections on increasing European external energy dependence and vulnerability. Comparison among different scenarios constitutes the basis of a critical review of existing energy security policies, suggesting alternative or complementary future actions. According to the analysis, the main risks and negative impacts in the long term could be the increasing risk of collusion among exporters due to growing dependence of industrialized countries and insufficient diversification; and a risk of demand/supply imbalance, with consequent instability for exporting regions due to insufficient demand, and lack of infrastructures due to insufficient supply. Cooperation with exporting countries enhancing investments in production capacity, and with developing countries in order to reinforce negotiation capacity of energy-importing countries seem to be the most effective policies at international level

A Comparative Assessment of the Role of Energy in Qatar's East Asian Foreign Relations: Case Studies on China, Japan and South Korea

Science.gov (United States)

Park, Rebekah

Energy is an important factor in international relations and recently the global energy paradigm has been seen to be shifting towards the East. In light of such change, a comparative assessment of the role of energy in Qatar' East Asian foreign relations will be conducted by taking China, Japan and South Korea as case studies. The research aimed to assess each of the bilateral relationship in terms of their origin and development in the energy sector generating an interpretation of their growing interdependence, taking into consideration the various domestic, regional and international influencing factors. At this level, LNG development and trade was adopted to see the extent of energy cooperation. In general, energy cooperation played the leading role in the three relationships, but to different degrees. Furthermore, all three bilateral relationship pertain to the 'complex interdependence approach' that is supported by the use of institutionalism and soft power.

Mac protocols for wireless sensor network (wsn): a comparative study

International Nuclear Information System (INIS)

Arshad, J.; Akram, Q.; Saleem, Y.

2014-01-01

Data communication between nodes is carried out under Medium Access Control (MAC) protocol which is defined at data link layer. The MAC protocols are responsible to communicate and coordinate between nodes according to the defined standards in WSN (Wireless Sensor Networks). The design of a MAC protocol should also address the issues of energy efficiency and transmission efficiency. There are number of MAC protocols that exist in the literature proposed for WSN. In this paper, nine MAC protocols which includes S-MAC, T-MAC, Wise-MAC, Mu-MAC, Z-MAC, A-MAC, D-MAC, B-MAC and B-MAC+ for WSN have been explored, studied and analyzed. These nine protocols are classified in contention based and hybrid (combination of contention and schedule based) MAC protocols. The goal of this comparative study is to provide a basis for MAC protocols and to highlight different mechanisms used with respect to parameters for the evaluation of energy and transmission efficiency in WSN. This study also aims to give reader a better understanding of the concepts, processes and flow of information used in these MAC protocols for WSN. A comparison with respect to energy reservation scheme, idle listening avoidance, latency, fairness, data synchronization, and throughput maximization has been presented. It was analyzed that contention based MAC protocols are less energy efficient as compared to hybrid MAC protocols. From the analysis of contention based MAC protocols in term of energy consumption, it was being observed that protocols based on preamble sampling consume lesser energy than protocols based on static or dynamic sleep schedule. (author)

Can Plant-Based Natural Flax Replace Basalt and E-Glass for Fiber-Reinforced Polymer Tubular Energy Absorbers? A Comparative Study on Quasi-Static Axial Crushing

Directory of Open Access Journals (Sweden)

Libo Yan

2017-12-01

Full Text Available Using plant-based natural fibers to substitute glass fibers as reinforcement of composite materials is of particular interest due to their economic, technical, and environmental significance. One potential application of plant-based natural fiber reinforced polymer (FRP composites is in automotive engineering as crushable energy absorbers. Current study experimentally investigated and compared the energy absorption efficiency of plant-based natural flax, mineral-based basalt, and glass FRP (GFRP composite tubular energy absorbers subjected to quasi-static axial crushing. The effects of number of flax fabric layer, the use of foam filler and the type of fiber materials on the crashworthiness characteristics, and energy absorption capacities were discussed. In addition, the failure mechanisms of the hollow and foam-filled flax, basalt, and GFRP tubes in quasi-static axial crushing were analyzed and compared. The test results showed that the energy absorption capabilities of both hollow and foam-filled energy absorbers made of flax were superior to the corresponding energy absorbers made of basalt and were close to energy absorbers made of glass. This study, therefore, indicated that flax fiber has the great potential to be suitable replacement of basalt and glass fibers for crushable energy absorber application.

Comparative Assessment of Energy Supply Options

International Nuclear Information System (INIS)

Rogner, H.-H.; Vladu, I. F.

2000-01-01

The complexity facing today's energy planners and decision-makers, particularly in electricity sector, has increased. They must take into account many elements in selecting technologies and strategies that will impact near term energy development and applications in their countries. While costs remain a key factor, tradeoffs between the demands of environmental protection and economic development will have to be made. This fact, together with the needs of many countries to define their energy and electricity programmes in a sustainable manner, has resulted in a growing interest in the application of improved data, tools and techniques for comparative assessment of different electricity generation options, particularly from an environmental and human health viewpoint. Although global emissions of greenhouse gases and other pollutants, e.g. SO 2 , NO x and particulate, must be reduced, the reality today is that these emissions are increasing and are expected to continue increasing. In examining the air pollutants, as well as water effluents and solid waste generated by electricity production, it is necessary to assess the full energy chain from fuel extraction to waste disposal, including the production of construction and auxiliary materials. The paper describes this concept and illustrates its implementation for assessing and comparing electricity generation costs, emissions, wastes and other environmental burdens from different energy sources. (author)

Comparative analysis for energy production processes (EPPs): Sustainable energy futures for Turkey

International Nuclear Information System (INIS)

Talinli, Ilhan; Topuz, Emel; Uygar Akbay, Mehmet

2010-01-01

This study presents a comparative analysis of three different energy production process (EPP) scenarios for Turkey. Main goal is to incorporate the prioritization criteria for the assessment of various energy policies for power alternatives, and evaluating these policies against these criteria. The three types of EPPs reviewed in this study are: electricity production from wind farms in the future, existing coal-based thermal power plants and planned nuclear power plants. The analytical hierarchy process (AHP) is utilized to assess the main and sub-factors of EPPs. Main factors such as economic, technical, social and environmental are assigned in first level of the AHP. The importance weights of factors are produced and priority values with realistic numbers are obtained using Fuzzy-AHP Chang's Model. Priority value for wind energy was determined as two times higher than the others when making the ultimate decision. On aggregate, importance weights of environmental (0.68) and social (0.69) factors make wind power leader. Sub-factors such as public acceptance, waste-emission and environmental impacts cause both nuclear and thermal power to have the lowest priority numbers. Additionally, the CO 2 emissions trade was determined to be a very important criterion associated with both economic and environmental factors according to Kyoto Protocol. This study concludes that Turkey's existing thermal power stations should gradually be substituted by renewable energy options according to a schedule of Turkish energy policies in future.

Energy supply modelling of a low-CO 2 emitting energy system: Case study of a Danish municipality

DEFF Research Database (Denmark)

Sveinbjörnsson, Dadi Þorsteinn; Ben Amer-Allam, Sara; Hansen, Anders Bavnhøj

2017-01-01

Municipal activities play an important role in national and global CO2-emission reduction efforts, with Nordic countries at the forefront thanks to their energy planning tradition and high penetration of renewable energy sources. In this work, we present a case study of the Danish municipality...... dependent on changes in energy prices.We conclude that in order to achieve their CO2 emission goals in the most energy-efficient, cost-effective and sustainable way, municipalities similar to Sønderborg should compare a wide range of energy system configurations, for example, scenarios with a high degree...

Energy conversion alternatives study

Science.gov (United States)

Shure, L. T.

1979-01-01

Comparison of coal based energy systems is given. Study identifies and compares various advanced energy conversion systems using coal or coal derived fuels for baselaoad electric power generation. Energy Conversion Alternatives Study (ECAS) reports provede government, industry, and general public with technically consistent basis for comparison of system's options of interest for fossilfired electric-utility application.

Comparing energy technology alternatives from an environmental perspective

International Nuclear Information System (INIS)

House, P.W.; Coleman, J.A.; Shull, R.D.; Matheny, R.W.; Hock, J.C.

1981-02-01

A number of individuals and organizations advocate the use of comparative, formal analysis to determine which are the safest methods for producing and using energy. Some have suggested that the findings of such analyses should be the basis upon which final decisions are made about whether to actually deploy energy technologies. Some of those who support formal comparative analysis are in a position to shape the policy debate on energy and environment. An opposing viewpoint is presented, arguing that for technical reasons, analysis can provide no definitive or rationally credible answers to the question of overall safety. Analysis has not and cannot determine the sum total of damage to human welfare and ecological communities from energy technologies. Analysis has produced estimates of particular types of damage; however, it is impossible to make such estimates comparable and commensurate across different classes of technologies and environmental effects. As a result of the deficiencies, comparative analysis connot form the basis of a credible, viable energy policy. Yet, without formal comparative analysis, how can health, safety, and the natural environment be protected. This paper proposes a method for improving the Nation's approach to this problem. The proposal essentially is that health and the environment should be considered as constraints on the deployment of energy technologies, constraints that are embodied in Government regulations. Whichever technologies can function within these constraints should then compete among themselves. This competition should be based on market factors like cost and efficiency and on political factors like national security and the questions of equity

Comparative energy analysis on a new regenerative Brayton cycle

International Nuclear Information System (INIS)

Goodarzi, M.

2016-01-01

Highlights: • New regenerative Brayton cycle has been introduced. • New cycle has higher thermal efficiency and lower exhausted heat per output power. • Regenerator may remain useful in the new cycle even at high pressure ratio. • New regenerative Brayton cycle is suggested for low pressure ratio operations. - Abstract: Gas turbines are frequently used for power generation. Brayton cycle is the basis for gas turbine operation and developing the alternative cycles. Regenerative Brayton cycle is a developed cycle for basic Brayton cycle with higher thermal efficiency at low to moderate pressure ratios. A new regenerative Brayton cycle has been introduced in the present study. Energy analysis has been conducted on ideal cycles to compare them from the first law of thermodynamics viewpoint. Comparative analyses showed that the new regenerative Brayton cycle has higher thermal efficiency than the original one at the same pressure ratio, and also lower heat absorption and exhausted heat per unite output power. Computed results show that new cycle improves thermal efficiency from 12% to 26% relative to the original regenerative Brayton cycle in the range of studied pressure ratios. Contrary to the original regenerative Brayton cycle, regenerator remains useful in the new regenerative Brayton cycle even at higher pressure ratio.

Comparative analysis of hospital energy use: pacific northwest and scandinavia.

Science.gov (United States)

Burpee, Heather; McDade, Erin

2014-01-01

This study aimed to establish the potential for significant energy reduction in hospitals in the United States by providing evidence of Scandinavian operational precedents with high Interior Environmental Quality (IEQ) and substantially lower energy profiles than comparable U.S. facilities. These facilities set important precedents for design teams seeking operational examples for achieving aggressive energy and interior environmental quality goals. This examination of operational hospitals is intended to offer hospital owners, designers, and building managers a strong case and concrete framework for strategies to achieve exceptionally high performing buildings. Energy efficient hospitals have the potential to significantly impact the U.S.'s overall energy profile, and key stakeholders in the hospital industry need specific, operationally grounded precedents in order to successfully implement informed energy reduction strategies. This study is an outgrowth of previous research evaluating high quality, low energy hospitals that serve as examples for new high performance hospital design, construction, and operation. Through extensive interviews, numerous site visits, the development of case studies, and data collection, this team has established thorough qualitative and quantitative analyses of several contemporary hospitals in Scandinavia and the Pacific Northwest. Many Scandinavian hospitals demonstrate a low energy profile, and when analyzed in comparison with U.S. hospitals, such Scandinavian precedents help define the framework required to make significant changes in the U.S. hospital building industry. Eight hospitals, four Scandinavian and four Pacific Northwest, were quantitatively compared using the Environmental Protection Agency's Portfolio Manager, allowing researchers to answer specific questions about the impact of energy source and architectural and mechanical strategies on energy efficiency in operational hospitals. Specific architectural, mechanical

Comparative studies of energy supply options in Poland for 1997-2020

International Nuclear Information System (INIS)

2002-08-01

Poland depends heavily on coal to satisfy national demands for electricity. Currently, over 90% of electricity generation is produced by coal fired power plants. Because of the large dependence on coal and environmental impacts of large-scale coal combustion the country looks for a more diversified energy mix. As ways of diversification, Poland is considering the expanded role of natural gas and, potentially, nuclear power in the future energy mix. This publication describes the analysis of several diversification options for the Polish energy sector conducted by a national team in the framework of an IAEA Technical Cooperation project implemented in 1999-2000. The project provided a set of proven IAEA methodologies and tools that was utilized for a comprehensive analysis and comparison of the options including their economic competitiveness and environmental impacts. The publication is intended primarily for senior experts and technical staff in governmental organizations, research institutes, industries and utilities, who are in charge of technical analysis or decision making related to long term energy and power supply options. The report was prepared in 2001 by the staff of the Energy Market Agency (EMA, Warsaw, Poland) that was the leading Polish organization in carrying out the study

Comparative analysis of traditional and alternative energy sources

Directory of Open Access Journals (Sweden)

Adriana Csikósová

2008-11-01

Full Text Available The presented thesis with designation of Comparing analysis of traditional and alternative energy resources includes, on basisof theoretical information source, research in firm, internal data, trends in company development and market, descriptionof the problem and its application. Theoretical information source is dedicated to the traditional and alternative energy resources,reserves of it, trends in using and development, the balance of it in the world, EU and in Slovakia as well. Analysis of the thesisis reflecting profile of the company and the thermal pump market evaluation using General Electric method. While the companyis implementing, except other products, the thermal pumps on geothermal energy base and surround energy base (air, the missionof the comparing analysis is to compare traditional energy resources with thermal pump from the ecological, utility and economic sideof it. The results of the comparing analysis are resumed in to the SWOT analysis. The part of the thesis includes he questionnaire offerfor effectiveness improvement and customer satisfaction analysis, and expected possibilities of alternative energy resources assistance(benefits from the government and EU funds.

A Study on Energy Security for Electricity Generation in Peninsular Malaysia

International Nuclear Information System (INIS)

Fairuz Suzana Mohd Chachuli

2013-01-01

The study was analyzed 12 case studies comprises of energy strategies proposed by the Government for electricity generation in Peninsular Malaysia using the simulation by Model for Energy Supply System Alternatives and their General Environmental Impacts (MESSAGE) software for period of year 2009 until 2030. From this study it was found that the appropriate and efficient case study to overcome the energy security issues in Peninsular Malaysia is integrated energy strategies particularly on nuclear energy, electricity import from Sarawak and the development of renewable energy resources. The total expansion cost for the case study is RM19.489 billion with the increament only 3.27 % compared with reference case. The total CO 2 emission for this scenario is 1.825 M tonne with declination up to 27.16 % compared with reference case. Due to limited time and crucial problem on domestic natural gas supply to the power generation industry, the Government should formulate a comprehensive energy strategy to support the mission of Malaysia to become one of the developed country and high income country by year 2020. (author)

Study of developing a database of energy statistics

Energy Technology Data Exchange (ETDEWEB)

Park, T.S. [Korea Energy Economics Institute, Euiwang (Korea, Republic of)

1997-08-01

An integrated energy database should be prepared in advance for managing energy statistics comprehensively. However, since much manpower and budget is required for developing an integrated energy database, it is difficult to establish a database within a short period of time. Therefore, this study sets the purpose in drawing methods to analyze existing statistical data lists and to consolidate insufficient data as first stage work for the energy database, and at the same time, in analyzing general concepts and the data structure of the database. I also studied the data content and items of energy databases in operation in international energy-related organizations such as IEA, APEC, Japan, and the USA as overseas cases as well as domestic conditions in energy databases, and the hardware operating systems of Japanese databases. I analyzed the making-out system of Korean energy databases, discussed the KEDB system which is representative of total energy databases, and present design concepts for new energy databases. In addition, I present the establishment directions and their contents of future Korean energy databases, data contents that should be collected by supply and demand statistics, and the establishment of data collection organization, etc. by analyzing the Korean energy statistical data and comparing them with the system of OECD/IEA. 26 refs., 15 figs., 11 tabs.

A comparative study of health hazards and environmental impacts for electricity generation through nuclear energy hidroelectricity and coal fired thermoeletrical generation

International Nuclear Information System (INIS)

Guimaraes, C.A.

1982-01-01

Environmental impacts and health hazards were comparatively assessed in regard to electricity generation via nuclear energy, hidraulic dams and coal firing. The main aspects covered the nuclear reactor and its associated nuclear fuel cycle, coal fired thermoelectrical power plant its associated coal industry, and hidroelectrical power plant and its dam. Besides specific comparisons of impacts in the air, water, soil and health hazards an evaluation for the Brazilian case was made based on a forecast of electricity demand up to the year 2020. For the nuclear option the consequences were analysed based on American data since no data is yet available for Brazil. Coal firing option was also analised for based heavily on American data due to small Brazilian experience in this sector of energy generation. For hydroelectrical option Brazilian data were used mostly from CESP for comparative purposes. These alternatives for generation of electricity considered in this study are the most relevant for the next four decades for Brazil. (Author) [pt

Radiological impacts of spent nuclear fuel management options. A comparative study

International Nuclear Information System (INIS)

2000-01-01

Given its potential significance for public health and the environment, the impact of radioactive releases during important steps of nuclear energy production must be considered when selecting among different fuel cycles. With this in mind, the OECD Nuclear Energy Agency (NEA) has undertaken a comparative study to the radiological impacts of two main fuel cycle options : one with and one without reprocessing of spent nuclear fuel. The study compares the respective impacts of the two options based on generic models and assumptions as well as actual data. It concludes that the difference between them is not significant. A wealth of recent data assembled and evaluated by an international expert team is provided in annex. (authors)

Neural networks vs Gaussian process regression for representing potential energy surfaces: A comparative study of fit quality and vibrational spectrum accuracy

Science.gov (United States)

Kamath, Aditya; Vargas-Hernández, Rodrigo A.; Krems, Roman V.; Carrington, Tucker; Manzhos, Sergei

2018-06-01

For molecules with more than three atoms, it is difficult to fit or interpolate a potential energy surface (PES) from a small number of (usually ab initio) energies at points. Many methods have been proposed in recent decades, each claiming a set of advantages. Unfortunately, there are few comparative studies. In this paper, we compare neural networks (NNs) with Gaussian process (GP) regression. We re-fit an accurate PES of formaldehyde and compare PES errors on the entire point set used to solve the vibrational Schrödinger equation, i.e., the only error that matters in quantum dynamics calculations. We also compare the vibrational spectra computed on the underlying reference PES and the NN and GP potential surfaces. The NN and GP surfaces are constructed with exactly the same points, and the corresponding spectra are computed with the same points and the same basis. The GP fitting error is lower, and the GP spectrum is more accurate. The best NN fits to 625/1250/2500 symmetry unique potential energy points have global PES root mean square errors (RMSEs) of 6.53/2.54/0.86 cm-1, whereas the best GP surfaces have RMSE values of 3.87/1.13/0.62 cm-1, respectively. When fitting 625 symmetry unique points, the error in the first 100 vibrational levels is only 0.06 cm-1 with the best GP fit, whereas the spectrum on the best NN PES has an error of 0.22 cm-1, with respect to the spectrum computed on the reference PES. This error is reduced to about 0.01 cm-1 when fitting 2500 points with either the NN or GP. We also find that the GP surface produces a relatively accurate spectrum when obtained based on as few as 313 points.

Study of energy dependence of a extrapolation chamber in low energy X-rays beams

International Nuclear Information System (INIS)

Bastos, Fernanda M.; Silva, Teogenes A. da

2014-01-01

This work was with the main objective to study the energy dependence of extrapolation chamber in low energy X-rays to determine the value of the uncertainty associated with the variation of the incident radiation energy in the measures in which it is used. For studying the dependence of energy, were conducted comparative ionization current measurements between the extrapolation chamber and two ionization chambers: a chamber mammography, RC6M model, Radcal with energy dependence less than 5% and a 2575 model radioprotection chamber NE Technology; both chambers have very thin windows, allowing its application in low power beams. Measurements were made at four different depths of 1.0 to 4.0 mm extrapolation chamber, 1.0 mm interval, for each reference radiation. The study showed that there is a variable energy dependence on the volume of the extrapolation chamber. In other analysis, it is concluded that the energy dependence of extrapolation chamber becomes smaller when using the slope of the ionization current versus depth for the different radiation reference; this shows that the extrapolation technique, used for the absorbed dose calculation, reduces the uncertainty associated with the influence of the response variation with energy radiation

A retrospective randomized study to compare the energy delivered using CDE with different techniques and OZil® settings by different surgeons in phacoemulsification

Science.gov (United States)

Chen, Ming; Sweeney, Henry W; Luke, Becky; Chen, Mindy; Brown, Mathew

2009-01-01

Cumulative dissipated energy (CDE) was used with Infiniti® Vision System (Alcon Labs) as an energy delivery guide to compare four different phaco techniques and phaco settings. The supracapsular phaco technique and burst mode is known for efficiency and surgery is faster compared with the old phaco unit. In this study, we found that supracapsular phaco with burst mode had the least CDE in both cataract and nuclear sclerosis cataract with the new Infiniti® unit. We suggest that CDE can be used as one of the references to modify technique and setting to improve outcome for surgeons, especially for new surgeons. PMID:19688027

Comparative study of fuel cell, battery and hybrid buses for renewable energy constrained areas

Science.gov (United States)

Stempien, J. P.; Chan, S. H.

2017-02-01

Fuel cell- and battery-based public bus technologies are reviewed and compared for application in tropical urban areas. This paper scrutinizes the reported literature on fuel cell bus, fuel cell electric bus, battery electric bus, hybrid electric bus, internal combustion diesel bus and compressed natural gas bus. The comparison includes the capital and operating costs, fuel consumption and fuel cycle emissions. To the best of authors knowledge, this is the first study to holistically compare hydrogen and battery powered buses, which is the original contribution of this paper. Moreover, this is the first study to focus on supplying hydrogen and electricity from fossil resources, while including the associated emissions. The study shows that compressed natural gas and hybrid electric buses appear to be the cheapest options in terms of total cost of ownership, but they are unable to meet the EURO VI emissions' standard requirement. Only fuel cell based buses have the potential to achieve the emissions' standard when the fuel cycle based on fossil energy was considered. Fuel cell electric buses are identified as a technology allowing for the largest CO2 emission reduction, making ∼61% decrease in annual emissions possible.

Comparative Study of Electric Energy Storages and Thermal Energy Auxiliaries for Improving Wind Power Integration in the Cogeneration System

Directory of Open Access Journals (Sweden)

Yanjuan Yu

2018-01-01

Full Text Available In regards to the cogeneration system in Northern China, mainly supported by combined heat and power (CHP plants, it usually offers limited operation flexibility due to the joint production of electric and thermal power. For that large-scale wind farms included in the cogeneration system, a large amount of wind energy may have to be wasted. To solve this issue, the utilization of the electric energy storages and the thermal energy auxiliaries are recommended, including pumped hydro storage (PHS, compressed air energy storage (CAES, hydrogen-based energy storage (HES, heat storage (HS, electric boilers (EB, and heat pumps (HP. This paper proposes a general evaluation method to compare the performance of these six different approaches for promoting wind power integration. In consideration of saving coal consumption, reducing CO2 emissions, and increasing investment cost, the comprehensive benefit is defined as the evaluation index. Specifically, a wind-thermal conflicting expression (WTCE is put forward to simplify the formulation of the comprehensive benefit. Further, according to the cogeneration system of the West Inner Mongolia (WIM power grid, a test system is modelled to perform the comparison of the six different approaches. The results show that introducing the electric energy storages and the thermal energy auxiliaries can both contribute to facilitating wind power integration, and the HP can provide the best comprehensive benefit.

Accident Risks In The Energy Sector: Comparative Evaluations

International Nuclear Information System (INIS)

Hirschberg, S.; Burgherr, P.

2005-01-01

Severe accidents are considered one of the most controversial issues in current comparative studies of the environmental and health impact of energy systems. The present work focuses on severe accident scenarios relating to fossil energy chains (coal, oil and gas), nuclear power and hydro-power. The scope of the study is not limited to the power production (conversion) step of these energy chains, but, wherever applicable, also includes full energy chains. With the exception of the nuclear chain, the focus of the present work is on the evaluation of the historical experience of accidents. The basis for this evaluation is the comprehensive database ENSAD (Energy-Related Severe Accident Database), which has been established at PSI. For hypothetical nuclear accidents, a probabilistic technique has also been employed. The broader picture, derived from examination of full energy chains, leads, on a world-wide basis, to the conclusion that immediate fatality rates are much higher for the fossil chains than expected if only power plants are considered. Generally, immediate fatality rates are significantly higher for non-OECD countries than for OECD countries, and, in the case of hydro and nuclear, the difference is rather dramatic. In addition to aggregated values, frequency-consequence curves are also provided, since they not only reflect implicitly a ranking based on aggregated values, but also include such information as the observed, or predicted, chain-specific maximum extent of damages. Finally, damage and external costs of severe accidents for the different energy chains have been estimated, based on the unit cost values for the various consequence types. (author)

Resource efficiency of urban sanitation systems. A comparative assessment using material and energy flow analysis

Energy Technology Data Exchange (ETDEWEB)

Meinzinger, Franziska

2010-07-01

Within the framework of sustainable development it is important to find ways of reducing natural resource consumption and to change towards closed-loop management. As in many other spheres increased resource efficiency has also become an important issue in sanitation. Particularly nutrient recovery for agriculture, increased energy-efficiency and saving of natural water resources, can make a contribution to more resource efficient sanitation systems. To assess the resource efficiency of alternative developments a systems perspective is required. The present study applies a combined cost, energy and material flow analysis (ceMFA) as a system analysis method to assess the resource efficiency of urban sanitation systems. This includes the discussion of relevant criteria and assessment methods. The main focus of this thesis is the comparative assessment of different systems, based on two case studies; Hamburg in Germany and Arba Minch in Ethiopia. A range of possible system developments including source separation (e.g. diversion of urine or blackwater) is defined and compared with the current situation as a reference system. The assessment is carried out using computer simulations based on model equations. The model equations not only integrate mass and nutrient flows, but also the energy and cost balances of the different systems. In order to assess the impact of different assumptions and calculation parameters, sensitivity analyses and parameter variations complete the calculations. Based on the simulations, following general conclusions can be drawn: None of the systems show an overall benefit with regard to all investigated criteria, namely nutrients, energy, water and costs. Yet, the results of the system analysis can be used as basis for decision making if a case-related weighting is introduced. The systems show varying potential for the recovery of nutrients from (source separated) wastewater flows. For the case study of Hamburg up to 29% of the mineral

Comparing solar energy alternatives

Energy Technology Data Exchange (ETDEWEB)

White, J R

1984-01-01

The paper outlines a computational procedure for comparing the merits of alternative processes to convert solar radiation to heat, electrical power, or chemical energy. The procedure uses the ratio of equipment investment to useful work as an index. Comparisons with conversion counterparts based on conventional fuels are also facilitated by examining this index. The procedure is illustrated by comparisons of (1) photovoltaic converters of differing efficiencies; (2) photovoltaic converters with and without focusing concentrators; (3) photovoltaic conversion plus electrolysis vs photocatalysis for the production of hydrogen; (4) photovoltaic conversion plus plasma arcs vs photocatalysis for nitrogen fixation. Estimates for conventionally-fuelled processes are included for comparison. The reasons why solar-based concepts fare poorly in such comparisons are traced to the low energy density of solar radiation and its low stream time factor resulting from the limited number of daylight hours available and clouds obscuring the sun.

Comparing solar energy alternatives

Energy Technology Data Exchange (ETDEWEB)

White, J R

1984-01-01

This paper outlines a computational procedure for comparing the merits of alternative processes to convert solar radiation to heat, electrical power, or chemical energy. The procedure uses the ratio of equipment investment to useful work as an index. Comparisons with conversion counterparts based on conventional fuels are also facilitated by examining this index. The procedure is illustrated by comparisons of (1) photovoltaic converters of differing efficiencies; (2) photovoltaic converters with and without focusing concentrators; (3) photovoltaic conversion plus electrolysis vs photocatalysis for the production of hydrogen; (4) photovoltaic conversion plus plasma arcs vs photocatalysis for nitrogen fixation. Estimates for conventionally-fuelled processes are included for comparison. The reasons why solar-based concepts fare poorly in such comparisons are traced to the low energy density of solar radiation and its low stream time factor resulting from the limited number of daylight hours available and clouds obscuring the sun. 11 references.

A comparative study of inelastic scattering models at energy levels ranging from 0.5 keV to 10 keV

Energy Technology Data Exchange (ETDEWEB)

Hu, Chia-Yu [Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan (China); Lin, Chun-Hung, E-mail: chlin@mail.ncku.edu.tw [Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan (China)

2017-03-01

Six models, including a single-scattering model, four hybrid models, and one dielectric function model, were evaluated using Monte Carlo simulations for aluminum and copper at incident beam energies ranging from 0.5 keV to 10 keV. The inelastic mean free path, mean energy loss per unit path length, and backscattering coefficients obtained by these models are compared and discussed to understand the merits of the various models. ANOVA (analysis of variance) statistical models were used to quantify the effects of inelastic cross section and energy loss models on the basis of the simulated results deviation from the experimental data for the inelastic mean free path, the mean energy loss per unit path length, and the backscattering coefficient, as well as their correlations. This work in this study is believed to be the first application of ANOVA models towards evaluating inelastic electron beam scattering models. This approach is an improvement over the traditional approach which involves only visual estimation of the difference between the experimental data and simulated results. The data suggests that the optimization of the effective electron number per atom, binding energy, and cut-off energy of an inelastic model for different materials at different beam energies is more important than the selection of inelastic models for Monte Carlo electron scattering simulation. During the simulations, parameters in the equations should be tuned according to different materials for different beam energies rather than merely employing default parameters for an arbitrary material. Energy loss models and cross-section formulas are not the main factors influencing energy loss. Comparison of the deviation of the simulated results from the experimental data shows a significant correlation (p < 0.05) between the backscattering coefficient and energy loss per unit path length. The inclusion of backscattering electrons generated by both primary and secondary electrons for

Emergy-based comparative analysis of energy intensity in different industrial systems.

Science.gov (United States)

Liu, Zhe; Geng, Yong; Wang, Hui; Sun, Lu; Ma, Zhixiao; Tian, Xu; Yu, Xiaoman

2015-12-01

With the rapid economic development, energy consumption of China has been the second place in the world next to the USA. Usually, measuring energy consumption intensity or efficiency applies heat unit which is joule per gross domestic production (GDP) or coal equivalent per GDP. However, this measuring approach is only oriented by the conversion coefficient of heat combustion which does not match the real value of the materials during their formation in the ecological system. This study applied emergy analysis to evaluate the energy consumption intensity to fill this gap. Emergy analysis is considered as a bridge between ecological system and economic system, which can evaluate the contribution of ecological products and services as well as the load placed on environmental systems. In this study, emergy indicator for performing energy consumption intensity of primary energy was proposed. Industrial production is assumed as the main contributor of energy consumption compared to primary and tertiary industries. Therefore, this study validated this method by investigating the two industrial case studies which were Dalian Economic Development Area (DEDA) and Fuzhou economic and technological area (FETA), to comparatively study on their energy consumption intensity between the different kinds of industrial systems and investigate the reasons behind the differences. The results show that primary energy consumption (PEC) of DEDA was much higher than that of FETA during 2006 to 2010 and its primary energy consumption ratio (PECR) to total emergy involvement had a dramatically decline from year 2006 to 2010. In the same time, nonrenewable energy of PEC in DEDA was also much higher than that in FETA. The reason was that industrial structure of DEDA was mainly formed by heavy industries like petro-chemistry industry, manufacturing industries, and high energy-intensive industries. However, FETA was formed by electronic business, food industry, and light industries. Although

Energy policy: Comparative effects on minority population groups

Energy Technology Data Exchange (ETDEWEB)

Poyer, D.A.; Henderson, L.

1995-06-01

For a number of years, analyses of minority household energy demand have been supported by the United States Department of Energy (DOE), Office of Economic Impact and Diversity (formerly the Office of Minority Economic Impact). The intention of these analyses has been to characterize patterns of energy demand by various demographic, regional and socioeconomic groups and to develop analytical tools to assess the distributive impact of energy prices and policy on these groups. The model supports strategic objectives outlined by the Department of Energy to explicitly recognize and promote equity in state public utility commission decisions and to assess the potential impact of federal and state energy policy on demographically diverse groups as reported in the Department`s Annual Energy Outlook and the upcoming National Energy Policy Plan. The legislation mandating the Office of Economic Impact and Diversity had been premised on the assumption that patterns of energy demand for minority households are different from the population as a whole. Determining the validity of this premise and its potential economic impact on different population groups has been a major objective of these analyses. Consequently, the recripriocal impacts of energy policy on demographic groups and energy consumption and expenditure dynamics on policy formulation and strategy is a central objective of these studies. Residential energy demand research has been substantial in the past twenty years. Insightful and useful research has been done in this area. However, none of this research has addressed the potential differences in the residential energy demand structure among various population groups. Recent work does compare energy and electricity demand elasticities for non-Latino Whites, with the demand elasticities for Latinos and Blacks. This research is particularly important for examination of questions related to the economic welfare implications of national energy policy.

Comparative study originated photoneutrons different energy linear accelerators, manufacturer and model

International Nuclear Information System (INIS)

Exposito, M. R.; Terron, J. A.; Domingo, C.; Amgarou, K.; Garcia-Fuente, M. J.; Gonzalez-Soto, J.; Legares, J. I.; Gomez, F.; Sanchez-Doblado, F.

2011-01-01

Pollution neutron radiotherapy with photon beams of energy greater than 10 MV represents a major inconvenience for patients in treatment, given the increased likelihood of developing a second radiation-induced cancer. Most of these neutrons are generated in the accelerator head as a result of the interaction of photons with heavy metals. As a result, knowledge of the effect on patients in the fields of neutrons from the accelerator should lead to improvements in design and selection of components from manufacturers. For this purpose, we have performed comparative measurements of the neutron fields present in both the patient (represented by an anthropomorphic phantom) and in the treatment room, considering almost all types of machines currently operating in the world.

Comparative study between rib imaging of DR dual energy subtraction technology and chest imaging

International Nuclear Information System (INIS)

Yu Jianming; Lei Ziqiao; Kong Xiangchuang

2006-01-01

Objective: To investigate the application value of DR dual energy subtraction technology in rib lesions. Methods: 200 patients were performed with chest DR dual energy subtraction, comparing the rib imaging between DR of thorax and chest imaging using ROC analysis. Results: Among the total of 200 patients, there are 50 cases of rib calcification, 7 cases of rib destruction, 22 cases of rib fracture. The calcification, destruction and fracture were displayed respectively by ribs below diaphragm and rib markings. The analytic parameter of rib imaging of DR dual energy subtraction Az is 0.9367, while that of rib imaging of chest Az is 0.6830. Conclusion: DR dual energy subtraction technology is superior to chest imaging in the displaying of rib lesion and ribs below diaphragm. (authors)

Computational and the real energy performance of a single-family residential building in Poland – an attempt to compare: a case study

Directory of Open Access Journals (Sweden)

Kowalski Piotr

2017-01-01

Full Text Available The paper presents energy use for heating and ventilation (one of the energy performance components determined in three ways. A case of a single family building located near Wroclaw in Poland is analyzed. The first and the second variant are both computational and the third presents actual measured energy consumption. Computational variants are based on the Polish methodology for the EPC (the Energy Performance Certificate. This methodology is based on ‘the Energy Performance of Buildings Directive 2010/31/EU’. Energy use for heating and ventilation is calculated using monthly method presented in EN ISO 13790. In the first computational option standard input data (parameters such as indoor and outdoor air temperature etc. are taken from standards and regulations are implemented. In the second variant this input data are partially taken from measurements. The results of energy use from both computational variants are compared to the actual measured energy consumption. On the basis of this comparison the influence of three factors: solar radiation heat gains, building air tightness and the SCOP of the heat pump on energy use calculations are analyzed. Conclusions aim to point the differences between them and the actual energy consumption.

Energy Cost and Gait Efficiency of Below-Knee Amputee and Normal Subject with Similar Physical Parameters & Quality of Life: A Comparative Case Study

Directory of Open Access Journals (Sweden)

Durbadal Biswas

2010-10-01

Full Text Available The study focused on the comparative analysis of energy cost and gait efficiency between a below knee (BK amputee and a reference subject (without amputation. It also attempted to indicate the specific feature responsible for a controlled gait with optimum energy cost for BK amputees. Selection criteria of the subjects were similar physical parameters and quality of life studied with WHOQOL-100 quality of life assessment. A Cosmed® k4 b2 Respiratory Analyzer system was used for the measurement of Oxygen Uptake (VO2, Energy Expenditure per minute (EE and Heart Rate (HR. Gait efficiency (p < 0.0002 was found higher for BK amputee than normal subject. The therapeutic activities and mainly walking rhythm contributed to improve the mobility & balance. This ensures the optimum time & co-ordination of movements and hence improves the gait efficiency for the BK amputee. Comparison with control group was performed to validate the data.

A retrospective randomized study to compare the energy delivered using CDE with different techniques and OZil settings by different surgeons in phacoemulsification

Directory of Open Access Journals (Sweden)

Ming Chen

2009-07-01

Full Text Available Ming Chen1, Henry W Sweeney2, Becky Luke3, Mindy Chen4, Mathew Brown51University of Hawaii, Honolulu, Hawaii, USA; 2Research Support Services, the Queens Medical Center, Honolulu, Hawaii, USA; 3Surgical Suite, Honolulu, Hawaii, USA; 4University of California, Irvine, CA, USA; 5University of California, San Diego, CA, USAAbstract: Cumulative dissipated energy (CDE was used with Infiniti® Vision System (Alcon Labs as an energy delivery guide to compare four different phaco techniques and phaco settings. The supracapsular phaco technique and burst mode is known for efficiency and surgery is faster compared with the old phaco unit. In this study, we found that supracapsular phaco with burst mode had the least CDE in both cataract and nuclear sclerosis cataract with the new Infiniti® unit. We suggest that CDE can be used as one of the references to modify technique and setting to improve outcome for surgeons, especially for new surgeons. Keywords: CDE (cumulative dissipated energy, cataract surgery, phacoemulsification, supracapsular, burst mode, Divide–Conquer

Energy indicators for electricity production : comparing technologies and the nature of the indicators Energy Payback Ratio (EPR), Net Energy Ratio (NER) and Cumulative Energy Demand (CED). [Oestfoldforskning AS

Energy Technology Data Exchange (ETDEWEB)

Raadal, Hanne Lerche [Ostfold research, Fredrikstad (Norway); Modahl, Ingunn Saur [Ostfold research, Fredrikstad (Norway); Bakken, Tor Haakon [SINTEF Energy, Trondheim (Norway)

2012-11-01

CEDREN (Centre for Environmental Design of Renewable Energy) is founded by The Research Council of Norway and energy companies and is one of eight centres that were part of the scheme Centre for Environment-friendly Energy Research (FME) when the scheme was launched in 2009. The main objective of CEDREN is to develop and communicate design solutions for transforming renewable energy sources to the desired energy products, and at the same time address the environmental and societal challenges at local, regional, national and global levels. CEDREN's board initiated in 2011 a pilot project on the topics 'Energy Pay-back Ratio (EPR)', 'Ecosystem services' and 'multi-criteria analysis (MCA)' in order to investigate the possible use of these concepts/indices in the management of regulated river basins and as tools to benchmark strategies for the development of energy projects/resources. The energy indicator part (documented in this report) has aimed at reviewing the applicability of different energy efficiency indicators, as such, in the strategic management and development of energy resources, and to compare and benchmark technologies for production of electricity. The main findings from this pilot study is also reported in a policy memo (in Norwegian), that is available at www.cedren.no. The work carried out in this project will be continued in the succeeding research project EcoManage, which was granted by the Research Council of Norway's RENERGI programme in December 2011. Energy indicators: Several energy indicators for extraction and delivery of an energy product (e.g. transport fuel, heat, electricity etc.) exist today. The main objective of such indicators is to give information about the energy efficiency of the needed extraction and transforming processes throughout the value chain related to the delivered energy product. In this project the indicators Energy Payback Ratio (EPR), Net Energy Ration (NER) and Cumulative

Comparing nuclear power with other energy sources

International Nuclear Information System (INIS)

Rey, Francisco C.

2001-01-01

The economics of electric generation of nuclear, hydro, oil and gas origin are compared. A similar comparison is also made from the health and environment standpoint for the fossil, nuclear, solar and wind generation. A risk assessment for energies of different origin is outlined and the significance of the greenhouse effect is emphasised. A comprehensive economic and environmental evaluation is recommended for the energy planning

Financing schemes increasing energy efficiency and renewable energy use in public and private buildings. Comparative study

International Nuclear Information System (INIS)

2014-03-01

resources to financial engineering and creation of innovative financing schemes that will help them keep the money spent on energy near home. They strive for sustainable, long-term financing solutions capable to generate large-scale investments. Indeed, financing energy transition will require strong technical, financial, legal and coordination skills and expertise in local authorities. Many different players at all levels of governance have already tested and implemented successful innovative financing schemes. However, the existing and emerging financing solutions remain isolated and not well known. Energy Cities - the European association of local authorities in energy transition - aims at strengthening the skills of local authorities in this field and facilitating the exchange of their experiences so that successful schemes can be more easily replicated all over the EU and beyond. Thus, Energy Cities identified 9 existing local, regional and national financing schemes aiming at increasing energy efficiency and renewable energy use in public and private buildings, which are usually the biggest energy consumer at local level. They are presented in this study. The financing schemes have been selected with the aim to present a myriad of different solutions that are implemented to address the same problem: - Local investment funds (Almada in Portugal, Amsterdam in the Netherlands and Region Centre in France). - Local public and semi-public companies (Ile de France and Rhone-Alpes Regions in France). - Revolving funds linked to grants and soft-loan schemes (Lithuania, Estonia, Brussels-Capital Region, Delft in the Netherlands)

A Comparative Study for Orthogonal Subspace Projection and Constrained Energy Minimization

National Research Council Canada - National Science Library

Du, Qian; Ren, Hsuan; Chang, Chein-I

2003-01-01

...: orthogonal subspace projection (OSP) and constrained energy minimization (CEM). It is shown that they are closely related and essentially equivalent provided that the noise is white with large SNR...

Probability of detection - Comparative study of computed and film radiography for high-energy applications

International Nuclear Information System (INIS)

Venkatachalam, R.; Venugopal, M.; Prasad, T.

2007-01-01

Full text of publication follows: Suitability of computed radiography with Ir-192, Co-60 and up to 9 MeV x-rays for weld inspections is of importance to many heavy engineering and aerospace industries. CR is preferred because of lesser exposure and processing time as compared to film based radiography and also digital images offers other advantages such as image enhancements, quantitative measurements and easier archival. This paper describes systemic experimental approaches and image quality metrics to compare imaging performance of CR with film-based radiography. Experiments were designed using six-sigma methodology to validate performance of CR for steel thickness up to 160 mm with Ir- 192, Co-60 and x-ray energies varying from 100 kV up to 9 MeV. Weld specimens with defects such as lack of fusion, penetration, cracks, concavity, and porosities were studied for evaluating radiographic sensitivity and imaging performance of the system. Attempts were also made to quantify probability of detection using specimens with artificial and natural defects for various experimental conditions and were compared with film based systems. (authors)

Comparative numerical and experimental study of two combined wind and wave energy concepts

Directory of Open Access Journals (Sweden)

Zhen Gao

2016-01-01

Full Text Available With a successful and rapid development of offshore wind industry and increased research activities on wave energy conversion in recent years, there is an interest in investigating the technological and economic feasibility of combining offshore wind turbines (WTs with wave energy converters (WECs. In the EU FP7 MARINA Platform project, three floating combined concepts, namely the spar torus combination (STC, the semi-submersible flap combination (SFC and the oscillating water column (OWC array with a wind turbine, were selected and studied in detail by numerical and experimental methods. This paper summarizes the numerical modeling and analysis of the two concepts: STC and SFC, the model tests at a 1:50 scale under simultaneous wave and wind excitation, as well as the comparison between the numerical and experimental results. Both operational and survival wind and wave conditions were considered. The numerical analysis was based on a time-domain global model using potential flow theory for hydrodynamics and blade element momentum theory (for SFC or simplified thrust force model (for STC for aerodynamics. Different techniques for model testing of combined wind and wave concepts were discussed with focus on modeling of wind turbines by disk or redesigned small-scale rotor and modeling of power take-off (PTO system for wave energy conversion by pneumatic damper or hydraulic rotary damper. In order to reduce the uncertainty due to scaling, the numerical analysis was performed at model scale and both the numerical and experimental results were then up-scaled to full scale for comparison. The comparison shows that the current numerical model can well predict the responses (motions, PTO forces, power production of the combined concepts for most of the cases. However, the linear hydrodynamic model is not adequate for the STC concept in extreme wave conditions with the torus fixed to the spar at the mean water level for which the wave slamming on the

Urban form and heat consumption, a comparative study in Copenhagen districts

DEFF Research Database (Denmark)

Mohammadi Dehcheshme, Mostafa; Jensen, Jesper Ole

Since urban form and land use patterns significantly influence the cities energy needs, the study linkage of energy consumption and urban form is an interdisciplinary issue and one the current central topics of urban planners in recent years. Our concern in this paper, therefore, is to address...... the implications of urban development and form in terms of its impact on energy consumption in ten districts of Copenhagen city. As comparative study, this paper is trying to respond the question: How does urban form impact the heat consumption in households in Copenhagen districts? To respond this question, two...

A comparative study of low energy radiation responses of SiC, TiC and ZrC

International Nuclear Information System (INIS)

Jiang, M.; Xiao, H.Y.; Zhang, H.B.; Peng, S.M.; Xu, C.H.; Liu, Z.J.; Zu, X.T.

2016-01-01

In this study, an ab initio molecular dynamics method is employed to compare the responses of SiC, TiC and ZrC to low energy irradiation. It reveals that C displacements are dominant in the cascade events of the three carbides. The associated defects in SiC are mainly Frenkel pairs and antisite defects, whereas damage end states in TiC and ZrC generally consist of Frenkel pairs and very few antisite defects are created. It is proposed that the susceptibility to antisite formation in SiC contributes to its crystalline-to-amorphous transformation under irradiation that is observed experimentally. The stronger radiation tolerance of TiC and ZrC than SiC can be originated from their different electronic structures, i.e., the and bonds are a mixture of covalent, metallic, and ionic character, whereas the bond is mainly covalent. The presented results provide underlying mechanisms for defect generation in SiC, TiC and ZrC, and advance the fundamental understanding of the radiation resistances of carbide materials.

Methods for comparative risk assessment of different energy sources

International Nuclear Information System (INIS)

1992-10-01

The environmental and health aspects of different energy systems, particularly those associated with the generation of electricity, are emerging as significant issues for policy formulation and implementation. This, together with the growing need of many countries to define their energy programmes for the next century, has provided the basis for a renewed interest in the comparative risk assessment of different energy sources (fossil, nuclear, renewables). This document is the outcome of a Specialists Meeting on the procedural and methodological issues associated with comparative health and environmental risks of different energy sources. After an introductory chapter outlining the issues under consideration the papers presented at the Meeting, which have been indexed separately, are given. Refs, figs and tabs

A comparative analysis of environmental impacts of non-fossil energy production methods

Directory of Open Access Journals (Sweden)

Kiss Adam

2014-01-01

Full Text Available The widespread proliferation of other then fossil based energy production methods is a development, which inevitable comes in the next future. It is proven that the photovoltaic conversion or the use of heat of Sun radiation, the water energy, the utilization of the wind, the biomass production, the use of geothermal energy can all produce big amounts of energy for human use. In addition, the nuclear energy from fission is a technology, which has already long history and is widely used. However, these all, like the fossil energy sources, have great impacts on the environment. Nevertheless, the comparison of the environmental effects of these alternative energy sources is not easy. The effects are of considerable different natures and their spatial and the time distributions vary on large scales. The present work overviews the principles and the methodological prerequisites of performing a comparative analysis of the environmental effects for the non-fossil energy production methods. After establishing the basic principles for comparison, we shall go through all the non-fossil energy sources and analyze the most important environmental impacts of each energy production method. In conclusion, the comparison of the environmental effects will be discussed.

A comparative analysis of environmental impacts of non-fossil energy production methods

Science.gov (United States)

Kiss, Adam

2014-12-01

The widespread proliferation of other then fossil based energy production methods is a development, which inevitable comes in the next future. It is proven that the photovoltaic conversion or the use of heat of Sun radiation, the water energy, the utilization of the wind, the biomass production, the use of geothermal energy can all produce big amounts of energy for human use. In addition, the nuclear energy from fission is a technology, which has already long history and is widely used. However, these all, like the fossil energy sources, have great impacts on the environment. Nevertheless, the comparison of the environmental effects of these alternative energy sources is not easy. The effects are of considerable different natures and their spatial and the time distributions vary on large scales. The present work overviews the principles and the methodological prerequisites of performing a comparative analysis of the environmental effects for the non-fossil energy production methods. After establishing the basic principles for comparison, we shall go through all the non-fossil energy sources and analyze the most important environmental impacts of each energy production method. In conclusion, the comparison of the environmental effects will be discussed.

Comparative study of speed estimators with highly noisy measurement signals for Wind Energy Generation Systems

Energy Technology Data Exchange (ETDEWEB)

Carranza, O. [Escuela Superior de Computo, Instituto Politecnico Nacional, Av. Juan de Dios Batiz S/N, Col. Lindavista, Del. Gustavo A. Madero 7738, D.F. (Mexico); Figueres, E.; Garcera, G. [Grupo de Sistemas Electronicos Industriales, Departamento de Ingenieria Electronica, Universidad Politecnica de Valencia, Camino de Vera S/N, 7F, 46020 Valencia (Spain); Gonzalez, L.G. [Departamento de Ingenieria Electronica, Universidad de los Andes, Merida (Venezuela)

2011-03-15

This paper presents a comparative study of several speed estimators to implement a sensorless speed control loop in Wind Energy Generation Systems driven by power factor correction three-phase boost rectifiers. This rectifier topology reduces the low frequency harmonics contents of the generator currents and, consequently, the generator power factor approaches unity whereas undesired vibrations of the mechanical system decrease. For implementation of the speed estimators, the compared techniques start from the measurement of electrical variables like currents and voltages, which contain low frequency harmonics of the fundamental frequency of the wind generator, as well as switching frequency components due to the boost rectifier. In this noisy environment it has been analyzed the performance of the following estimation techniques: Synchronous Reference Frame Phase Locked Loop, speed reconstruction by measuring the dc current and voltage of the rectifier and speed estimation by means of both an Extended Kalman Filter and a Linear Kalman Filter. (author)

Deciding the way. Comparing energy risks: methodologies and issues

International Nuclear Information System (INIS)

Matsuki, Yoshio; Lee, R.

1999-01-01

The following major issues in comparative assessment of energy systems are discussed: target users; decision making process; subject policy-making; setting boundaries; aggregated health indicators; monetary valuation; long-term health effects; global warming; methods to reflect uncertainties. Suggestions for study approaches of the mentioned issues are proposed

A comparative study of the perceptions of nuclear and environmental risk

International Nuclear Information System (INIS)

Boemer, Veronica Araujo

2011-01-01

With the necessity for new forms of energy production to contain the environmental crisis and the global warming, new technologies have been studied and the nuclear energy has been placed as one of the ways out for clean energy production. The study of the risk is directly related to the study of its perception, that determines the human being's actions, therefore it influences in new technologies applications, since the awareness of something as dangerous is determined by socio-historical factors. The purpose of this study was compare the perceptions of nuclear and environmental risks, considering a group of university students, with the application of research in the period from March 31 to May 31, 2010, containing: images of historical facts to be nominated; structuring of a risk scale for certain activities, and a questionnaire about risks and benefits related to the subject research. The analysis of results evidenced a reduction in the perception of nuclear risk over the perception of environmental risk in this population. (author)

Coherent error study in a retarding field energy analyzer

International Nuclear Information System (INIS)

Cui, Y.; Zou, Y.; Reiser, M.; Kishek, R.A.; Haber, I.; Bernal, S.; O'Shea, P.G.

2005-01-01

A novel cylindrical retarding electrostatic field energy analyzer for low-energy beams has been designed, simulated, and tested with electron beams of several keV, in which space charge effects play an important role. A cylindrical focusing electrode is used to overcome the beam expansion inside the device due to space-charge forces, beam emittance, etc. In this paper, we present the coherent error analysis for this energy analyzer with beam envelope equation including space charge and emittance effects. The study shows that this energy analyzer can achieve very high resolution (with relative error of around 10 -5 ) if taking away the coherent errors by using proper focusing voltages. The theoretical analysis is compared with experimental results

Spatial structure, inequality and trading community of renewable energy networks: A comparative study of solar and hydro energy product trades

International Nuclear Information System (INIS)

Fu, Xin; Yang, Yu; Dong, Wen; Wang, Changjian; Liu, Yi

2017-01-01

Renewable energy trade is booming and has formed complicated networks worldwide. However, our knowledge of the spatial structures and evolution of these networks is limited. In this paper, network analyses are used to examine the geographic characteristics of selected renewable energy trades and their evolution based on the United Nations COMTRADE Database from 1988 to 2013. The results show that the networks are expanding to include more and more countries and relationships, and scale of the networks is larger than ever. A tripartite confrontational renewable energy trading system has been forming and is strengthening. Europe, the USA, China and other Asian countries are the main players, and China has overtaken the USA and Europe as the leading player. Inequality and ‘small-world’ characteristics appear in renewable energy trade. Solar energy trade presents a triadic community structure with Europe, the USA and China as the dominant players, while hydro energy trade presents a smaller and more dispersed structure. The core–periphery structure strongly suggests a trade dependency between hubs and peripheral elements in renewable energy trade. Developing countries should design appropriate incentives and contribute to particular segments in renewable energy value chain to accelerate and benefit from the South–South renewable energy trade. - Highlights: • Renewable energy trade networks are identified and analyzed. • Tripartite confrontational renewable energy trade systems have been formed and are strengthening. • Unequal and ‘small world’ characteristics have appeared in the renewable energy trade. • China has overtaken the USA and Europe as the leading player in the renewable energy trade. • Developing countries should make efforts to benefit from the South–South energy trade.

Making the results of bottom-up energy savings comparable

Directory of Open Access Journals (Sweden)

Moser Simon

2012-01-01

Full Text Available The Energy Service Directive (ESD has pushed forward the issue of energy savings calculations without clarifying the methodological basis. Savings achieved in the Member States are calculated with rather non-transparent and hardly comparable Bottom-up (BU methods. This paper develops the idea of parallel evaluation tracks separating the Member States’ issue of ESD verification and comparable savings calculations. Comparability is ensured by developing a standardised BU calculation kernel for different energy efficiency improvement (EEI actions which simultaneously depicts the different calculation options in a structured way (e.g. baseline definition, system boundaries, double counting. Due to the heterogeneity of BU calculations the approach requires a central database where Member States feed in input data on BU actions according to a predefined structure. The paper demonstrates the proposed approach including a concrete example of application.

Comparative study of commercial building energy-efficiency retrofit policies in four pilot cities in China

International Nuclear Information System (INIS)

Hou, Jing; Liu, Yisheng; Wu, Yong; Zhou, Nan; Feng, Wei

2016-01-01

The energy efficiency of existing commercial buildings is more challenging to regulate and improve than the energy efficiency of new constructions. In 2011 and 2012, the Chinese Government selected four cities- Shanghai, Tianjin, Shenzhen, and Chongqing- to implement pilot commercial building energy efficiency retrofit program. Based on site surveys and expert interviews in these pilot cities, this research conducted a comparative analysis on incentive policies of local city level. The analysis results show that policy designs of existing commercial buildings should be further improved. The aspects that influence the implementation effect in the future, such as subsidy level, installments, and business model promotion, should be specified in the policy clauses. Referring to the technical solution and cost-benefit in Chongqing, we found that lighting system is the most common retrofit objects while envelope system is the least common one. And the subsidy incentive is greatest for educational buildings, followed by office buildings. In the end, we further discussed the problems and obstacles in commercial building retrofit market, and provided a series of recommendations. - Highlights: • Data and information were collected through site surveys to the four pilot cities. • Policy design and effectiveness in four cities were comparatively analyzed. • Well-designed policy increases market response, energy savings and EMC adoption. • Lighting is the most common retrofit while envelope is the least common one. • Subsidy incentive is greatest for educational buildings due to the utility tariff.

Comparative studies of atomic independent-particle potentials

International Nuclear Information System (INIS)

Talman, J.D.; Ganas, P.S.; Green, A.E.S.

1979-01-01

A number of atomic properties are compared in various independent-particle models for atoms. The models studied are the Hartree-Fock method, a variationally optimized potential model, a parametrized analytic form of the same model, parametrized analytic models constructed to fit atomic energy levels, the so-called Hartree-Fock-Slater model, and the Xα model. The physical properties compared are single-particle energy levels, total energies, and dipole polarizabilities. The extent to which the virial theorem is satisfied in the different models is also considered. The atoms Be, Ne, Ar, Kr, and Xe and ions O v and Al iv hav been compared. The results show that the experimental properties can be well represented by several of the independent-particle models. Since it has been shown that the optimized potential models yield wavefunctions that are almost the same as Hartree-Fock wavefunctions, they provide a natural solution to the problem of extending the Hartree-Fock method to excited states

Expanding the power base. Building capacities for comparative energy assessment

International Nuclear Information System (INIS)

Hamilton, B.; Bui, D.T.; Conzelmann, G.

2000-01-01

Analysis of national energy systems is reaching unprecedented degrees of complexity. In addition to uncertainty of future energy demand, technology performance and costs, planners and decision makers are confronted with issues such as environment protection, sustainable development, deregulation and market liberalization. At the same time, public sector funds for energy investment projects are being progressively reduced. The IAEA offers its Member States a comprehensive programme of technical assistance and cooperation which covers many diverse areas related to peaceful uses of nuclear energy. In the area of comparative energy assessment, the objective of assistance is to strengthen national capabilities for elaborating sustainable patterns of energy supply and use. Assistance is provided in three ways, namely by: distributing state-of-the-art methodologies and decision-making tools tailored to the special needs of developing countries; providing training in model application, interpretation of results and translation into decision or policy making; and carrying out national studies in co-operation with requesting Member States

Energy storage systems cost update : a study for the DOE Energy Storage Systems Program.

Energy Technology Data Exchange (ETDEWEB)

Schoenung, Susan M. (Longitude 122 West, Menlo Park, CA)

2011-04-01

This paper reports the methodology for calculating present worth of system and operating costs for a number of energy storage technologies for representative electric utility applications. The values are an update from earlier reports, categorized by application use parameters. This work presents an update of energy storage system costs assessed previously and separately by the U.S. Department of Energy (DOE) Energy Storage Systems Program. The primary objective of the series of studies has been to express electricity storage benefits and costs using consistent assumptions, so that helpful benefit/cost comparisons can be made. Costs of energy storage systems depend not only on the type of technology, but also on the planned operation and especially the hours of storage needed. Calculating the present worth of life-cycle costs makes it possible to compare benefit values estimated on the same basis.

Energy implications of mechanical and mechanical–biological treatment compared to direct waste-to-energy

International Nuclear Information System (INIS)

Cimpan, Ciprian; Wenzel, Henrik

2013-01-01

Highlights: • Compared systems achieve primary energy savings between 34 and 140 MJ primary /100 MJ input waste. • Savings magnitude is foremost determined by chosen primary energy and materials production. • Energy consumption and process losses can be upset by increased technology efficiency. • Material recovery accounts for significant shares of primary energy savings. • Direct waste-to-energy is highly efficient if cogeneration (CHP) is possible. - Abstract: Primary energy savings potential is used to compare five residual municipal solid waste treatment systems, including configurations with mechanical (MT) and mechanical–biological (MBT) pre-treatment, which produce waste-derived fuels (RDF and SRF), biogas and/or recover additional materials for recycling, alongside a system based on conventional mass burn waste-to-energy and ash treatment. To examine the magnitude of potential savings we consider two energy efficiency levels (state-of-the-art and best available technology), the inclusion/exclusion of heat recovery (CHP vs. PP) and three different background end-use energy production systems (coal condensing electricity and natural gas heat, Nordic electricity mix and natural gas heat, and coal CHP energy quality allocation). The systems achieved net primary energy savings in a range between 34 and 140 MJ primary /100 MJ input waste , in the different scenario settings. The energy footprint of transportation needs, pre-treatment and reprocessing of recyclable materials was 3–9.5%, 1–18% and 1–8% respectively, relative to total energy savings. Mass combustion WtE achieved the highest savings in scenarios with CHP production, nonetheless, MBT-based systems had similarly high performance if SRF streams were co-combusted with coal. When RDF and SRF was only used in dedicated WtE plants, MBT-based systems totalled lower savings due to inherent system losses and additional energy costs. In scenarios without heat recovery, the biodrying MBS

Energy implications of mechanical and mechanical–biological treatment compared to direct waste-to-energy

Energy Technology Data Exchange (ETDEWEB)

Cimpan, Ciprian, E-mail: cic@kbm.sdu.dk; Wenzel, Henrik

2013-07-15

Highlights: • Compared systems achieve primary energy savings between 34 and 140 MJ{sub primary}/100 MJ{sub input} {sub waste.} • Savings magnitude is foremost determined by chosen primary energy and materials production. • Energy consumption and process losses can be upset by increased technology efficiency. • Material recovery accounts for significant shares of primary energy savings. • Direct waste-to-energy is highly efficient if cogeneration (CHP) is possible. - Abstract: Primary energy savings potential is used to compare five residual municipal solid waste treatment systems, including configurations with mechanical (MT) and mechanical–biological (MBT) pre-treatment, which produce waste-derived fuels (RDF and SRF), biogas and/or recover additional materials for recycling, alongside a system based on conventional mass burn waste-to-energy and ash treatment. To examine the magnitude of potential savings we consider two energy efficiency levels (state-of-the-art and best available technology), the inclusion/exclusion of heat recovery (CHP vs. PP) and three different background end-use energy production systems (coal condensing electricity and natural gas heat, Nordic electricity mix and natural gas heat, and coal CHP energy quality allocation). The systems achieved net primary energy savings in a range between 34 and 140 MJ{sub primary}/100 MJ{sub input} {sub waste}, in the different scenario settings. The energy footprint of transportation needs, pre-treatment and reprocessing of recyclable materials was 3–9.5%, 1–18% and 1–8% respectively, relative to total energy savings. Mass combustion WtE achieved the highest savings in scenarios with CHP production, nonetheless, MBT-based systems had similarly high performance if SRF streams were co-combusted with coal. When RDF and SRF was only used in dedicated WtE plants, MBT-based systems totalled lower savings due to inherent system losses and additional energy costs. In scenarios without heat

Profiling technological failure and disaster in the energy sector: A comparative analysis of historical energy accidents

International Nuclear Information System (INIS)

Sovacool, Benjamin K.; Kryman, Matthew; Laine, Emily

2015-01-01

This study assesses the risk of energy accidents using an original historical dataset over the period 1874-2014, and it evaluates that risk across 11 energy systems: biofuels, biomass, coal, geothermal, hydroelectricity, hydrogen, natural gas, nuclear power, oil, solar energy, and wind energy. Our study shows how these energy systems collectively involved almost 1,100 accidents resulting in more than 210,000 human fatalities and almost $350 billion in property damages. Across the entire sample, the mean amount of property damage was $319 million and 196 fatalities per accident, though when reflected as a median the numbers substantially improve to $3 million in damages per accident and 0 fatalities. We found that wind energy is the most frequent to incur an accident within our sample, accounting for almost one third of accidents. Accidents at hydroelectric dams were the most fatal, accounting for 85 percent of fatalities. Nuclear power accidents are by far the most expensive, accounting for 70 percent of damages. We then utilize this data to test six hypotheses, drawn from the energy studies literature, related to energy systems, energy policy and regulation, and technological learning. - Highlights: • 1085 energy accidents have resulted in 211,529 human fatalities and $344.4 billion in property damages. • Wind energy is the most frequent to incur an accident. • Hydroelectric dam accidents tend to be the most fatal. • Nuclear energy accidents tend to be the most expensive. • Coal, natural gas, and oil are the least likely to incur an accident, when normalized to energy output.

Comparative study between hadron and heavy ion dissociation at high energies

International Nuclear Information System (INIS)

El-Bakry, Y.M.N.; Abd-Elhalim, S.M.

2002-01-01

The present work deals with the dissociation of hadrons and heavy ions at high energies. In investigating hadron nucleus and nucleus-nucleus collisions, it is important to classify the experimental data, into two main classes; the coherent. and incoherent reactions. The coherent production is the main of our study. This process called electromagnetic dissociation (ED) and can be differentiate into coulomb dissociation (CD) and diffraction dissociation (DD). This work explains the experimental data of collisions of hadrons K± (70 GeV/c) and π(340 Gc V/c) and heavy ions 6 L i, 7 L i, 1 2C and1 6O at Dubna energies (3-4.5 A GeV/c)with emulsion target, in the frame of some models and theories which describe the mechanism of ED dissociation

Comparative study of different waste biomass for energy application.

Science.gov (United States)

Motghare, Kalyani A; Rathod, Ajit P; Wasewar, Kailas L; Labhsetwar, Nitin K

2016-01-01

Biomass is available in many varieties, consisting of crops as well as its residues from agriculture, forestry, and the agro-industry. These different biomass find their way as freely available fuel in rural areas but are also responsible for air pollution. Emissions from such solid fuel combustion to indoor, regional and global air pollution largely depend on fuel types, combustion device, fuel properties, fuel moisture, amount of air supply for combustion and also on climatic conditions. In both economic and environment point of view, gasification constitutes an attractive alternative for the use of biomass as a fuel, than the combustion process. A large number of studies have been reported on a variety of biomass and agriculture residues for their possible use as renewable fuels. Considering the area specific agriculture residues and biomass availability and related transportation cost, it is important to explore various local biomass for their suitability as a fuel. Maharashtra (India) is the mainstay for the agriculture and therefore, produces a significant amount of waste biomass. The aim of the present research work is to analyze different local biomass wastes for their proximate analysis and calorific value to assess their potential as fuel. The biomass explored include cotton waste, leaf, soybean waste, wheat straw, rice straw, coconut coir, forest residues, etc. mainly due to their abundance. The calorific value and the proximate analysis of the different components of the biomass helped in assessing its potential for utilization in different industries. It is observed that ash content of these biomass species is quite low, while the volatile matter content is high as compared to Indian Coal. This may be appropriate for briquetting and thus can be used as a domestic fuel in biomass based gasifier cook stoves. Utilizing these biomass species as fuel in improved cook-stove and domestic gasifier cook-stoves would be a perspective step in the rural energy and

Comparative study of two weir type cascade solar stills with and without PCM storage using energy and exergy analysis

International Nuclear Information System (INIS)

Sarhaddi, Faramarz; Farshchi Tabrizi, Farshad; Aghaei Zoori, Halimeh; Mousavi, Seyed Amir Hossein Seyed

2017-01-01

Highlights: • Performance evaluation of cascade solar stills with PCM storage is carried out. • Model of cascade solar still is weir type. • Present study is based on numerical simulation. • Effect of operating parameters is studies on yield, energy and exergy efficiencies. - Abstract: In this paper, the comparative study of energy and exergy performance of two weir type cascade solar stills with and without PCM storage in sunny and semi-cloudy days is carried out. The governing equations of energy analysis include a set of nonlinear equations which is obtained by writing energy balance for the various components of a solar still (i.e. glass cover, brackish water, absorber plate, phase change materials). A detailed exergy analysis is carried out and various irreversibility rates in the solar still system and its exergy efficiency are introduced. In order to solve the governing equations a computer simulation program is developed. The results of a numerical simulation of the present study are in good agreement with the experimental data of previous literatures. The numerical results of the present study show that the energy and exergy performance of solar still without PCM storage is better than the solar still with PCM storage in sunny days. On the other hand, the solar still with PCM storage is preferred for semi-cloudy days due to its better energy and exergy performance. The maximum value of the energy and exergy efficiencies of the solar still without PCM for a typical sunny day are 76.69% and 6.53%, respectively. While, the maximum energy and exergy efficiencies of the solar still with PCM for a sample semi-cloudy day are 74.35% and 8.59%, respectively. Furthermore, it is observed that the highest irreversibility rate belongs to the absorber plate and its value for the solar still without PCM on typical sunny day and the solar still with PCM on semi-cloudy days is 83.1% and 78.8% of the whole of system irreversibility rates, respectively. Whereas, the

International energy conservation: comparative law and policy

Energy Technology Data Exchange (ETDEWEB)

1979-02-01

Ernest C. Baynard III, in the Foreword to the conference, told of the purpose of the conference - to compare and discuss the policies and laws that highly industrialized nations have used and considered to meet the challenge of energy conservation. The following countries participated in the conference: U.K.; Australia; Federal Republic of Germany; Japan; France; Canada; Sweden; Italy; the Netherlands; and the U.S. The IEA and the Commission of the European Communities also participated. The conference format consisted of ministerial addresses to the conference, interspersed with panel discussions focusing on energy conservation in transportation, industry, agriculture, and utilities; residential, commercial, and industrial buildings; and emergency situations. There was also a panel discussion on the role of government in energy conservation and energy information collection. The panels were composed of participating countries' representatives. (MCW)

Comparative study of energy of particles ejected from coulomb explosion of rare gas and metallic clusters irradiated by intense femtosecond laser field

Science.gov (United States)

Boucerredj, N.; Beggas, K.

2016-10-01

We present our study of high intensity femtosecond laser field interaction with large cluster of Kr and Na (contained 2.103 to 2.107 atoms). When laser intensity is above a critical value, it blows off all of electrons from the cluster and forms a non neutral ion cloud. The irradiation of these clusters by the intense laser field leads to highly excitation energy which can be the source of energetic electrons, electronic emission, highly charge, energetic ions and fragmentation process. During the Coulomb explosion of the resulting highly ionized, high temperature nanoplasma, ions acquire again their energy. It is shown that ultra fast ions are produced. The goal of our study is to investigate in detail a comparative study of the expansion and explosion then the ion energy of metallic and rare gas clusters irradiated by an intense femtosecond laser field. We have found that ions have a kinetic energy up to 105 eV and the Coulomb pressure is little than the hydrodynamic pressure. The Coulomb explosion of a cluster may provide a new high energy ion source.

Comparative risk assessment of severe accidents in the energy sector

International Nuclear Information System (INIS)

Burgherr, Peter; Hirschberg, Stefan

2014-01-01

Comparative assessment of accident risks in the energy sector is a key aspect in a comprehensive evaluation of sustainability and energy security concerns. Safety performance of energy systems can have important implications on the environmental, economic and social dimensions of sustainability as well as availability, acceptability and accessibility aspects of energy security. Therefore, this study provides a broad comparison of energy technologies based on the objective expression of accident risks for complete energy chains. For fossil chains and hydropower the extensive historical experience available in PSI's Energy-related Severe Accident Database (ENSAD) is used, whereas for nuclear a simplified probabilistic safety assessment (PSA) is applied, and evaluations of new renewables are based on a combination of available data, modeling, and expert judgment. Generally, OECD and EU 27 countries perform better than non-OECD. Fatality rates are lowest for Western hydropower and nuclear as well as for new renewables. In contrast, maximum consequences can be by far highest for nuclear and hydro, intermediate for fossil, and very small for new renewables, which are less prone to severe accidents. Centralized, low-carbon technology options could generally contribute to achieve large reductions in CO 2 -emissions; however, the principal challenge for both fossil with Carbon Capture and Storage and nuclear is public acceptance. Although, external costs of severe accidents are significantly smaller than those caused by air pollution, accidents can have disastrous and long-term impacts. Overall, no technology performs best or worst in all respects, thus tradeoffs and priorities are needed to balance the conflicting objectives such as energy security, sustainability and risk aversion to support rationale decision making. - Highlights: • Accident risks are compared across a broad range of energy technologies. • Analysis of historical experience was based on the

A comparative analysis of meta-heuristic methods for power management of a dual energy storage system for electric vehicles

International Nuclear Information System (INIS)

Trovão, João P.; Antunes, Carlos Henggeler

2015-01-01

Highlights: • Two meta-heuristic approaches are evaluated for multi-ESS management in electric vehicles. • An online global energy management strategy with two different layers is studied. • Meta-heuristic techniques are used to define optimized energy sharing mechanisms. • A comparative analysis for ARTEMIS driving cycle is addressed. • The effectiveness of the double-layer management with meta-heuristic is presented. - Abstract: This work is focused on the performance evaluation of two meta-heuristic approaches, simulated annealing and particle swarm optimization, to deal with power management of a dual energy storage system for electric vehicles. The proposed strategy is based on a global energy management system with two layers: long-term (energy) and short-term (power) management. A rule-based system deals with the long-term (strategic) layer and for the short-term (action) layer meta-heuristic techniques are developed to define optimized online energy sharing mechanisms. Simulations have been made for several driving cycles to validate the proposed strategy. A comparative analysis for ARTEMIS driving cycle is presented evaluating three performance indicators (computation time, final value of battery state of charge, and minimum value of supercapacitors state of charge) as a function of input parameters. The results show the effectiveness of an implementation based on a double-layer management system using meta-heuristic methods for online power management supported by a rule set that restricts the search space

Evaluating fuel ethanol feedstocks from energy policy perspectives: A comparative energy assessment of corn and corn stover

International Nuclear Information System (INIS)

Lavigne, Amanda; Powers, Susan E.

2007-01-01

Concerns surrounding the continued, un-checked use of petroleum-based fuels in the transportation sector, the search for more sustainable, renewable alternatives, and the constraints of the existing supply infrastructure in the United States have placed a spotlight on biomass-derived fuels. The central question of the ethanol debate has changed from 'Should we make ethanol?' to 'From what should we make ethanol?' emphasizing the importance of understanding the differences between specific biomass supply systems for fuel ethanol. When presented with numerous options, the priorities of an individual decision maker will define which feedstock alternative is the most appropriate choice for development from their perspective. This paper demonstrates how energy data can be successfully used to quantify assessment metrics beyond a standard net energy value calculation, thus quantifying the relative 'value' of ethanol supply systems. This value is defined based on decision-maker priorities that were adopted from national energy policy priorities: increased national energy security and increased conservation of energy resources. Nine energy assessment metrics that quantify detailed system energy data are calculated and a straightforward comparative assessment is performed between corn and corn stover feedstocks produced under the same farm scenario. Corn stover is shown to be more compatible with the national energy policy priorities and it is recommended that additional research be performed on utilizing this feedstock from the corn farm

Comparative study of quantum anharmonic potentials

International Nuclear Information System (INIS)

Amore, Paolo; Aranda, Alfredo; De Pace, Arturo; Lopez, Jorge A.

2004-01-01

We perform a study of various anharmonic potentials using a recently developed method. We calculate both the wave functions and the energy eigenvalues for the ground and first excited states of the quartic, sextic and octic potentials with high precision, comparing the results with other techniques available in the literature

Computed tomography with energy-resolved detection: a feasibility study

Science.gov (United States)

Shikhaliev, Polad M.

2008-03-01

The feasibility of computed tomography (CT) with energy-resolved x-ray detection has been investigated. A breast CT design with multi slit multi slice (MSMS) data acquisition was used for this study. The MSMS CT includes linear arrays of photon counting detectors separated by gaps. This CT configuration allows for efficient scatter rejection and 3D data acquisition. The energy-resolved CT images were simulated using a digital breast phantom and the design parameters of the proposed MSMS CT. The phantom had 14 cm diameter and 50/50 adipose/glandular composition, and included carcinoma, adipose, blood, iodine and CaCO3 as contrast elements. The x-ray technique was 90 kVp tube voltage with 660 mR skin exposure. Photon counting, charge (energy) integrating and photon energy weighting CT images were generated. The contrast-to-noise (CNR) improvement with photon energy weighting was quantified. The dual energy subtracted images of CaCO3 and iodine were generated using a single CT scan at a fixed x-ray tube voltage. The x-ray spectrum was electronically split into low- and high-energy parts by a photon counting detector. The CNR of the energy weighting CT images of carcinoma, blood, adipose, iodine, and CaCO3 was higher by a factor of 1.16, 1.20, 1.21, 1.36 and 1.35, respectively, as compared to CT with a conventional charge (energy) integrating detector. Photon energy weighting was applied to CT projections prior to dual energy subtraction and reconstruction. Photon energy weighting improved the CNR in dual energy subtracted CT images of CaCO3 and iodine by a factor of 1.35 and 1.33, respectively. The combination of CNR improvements due to scatter rejection and energy weighting was in the range of 1.71-2 depending on the type of the contrast element. The tilted angle CZT detector was considered as the detector of choice. Experiments were performed to test the effect of the tilting angle on the energy spectrum. Using the CZT detector with 20° tilting angle decreased the

Comparing the health impacts of different energy sources

International Nuclear Information System (INIS)

Hamilton, L.D.

1982-01-01

Assessing health impacts of different energy sources requires synthesis of research results from many different disciplines into a rational framework. Information is often scanty; qualitatively different risks, or energy systems with substantially different end uses, must be put on a common footing. Historically institutional constraints have inhibited agencies from making incisive intercomparisons necessary for formulating energy policy; this has exacerbated public controversy over appropriate energy sources. Risk assessment methods reviewed include examples drawn from work of the Biomedical and Environmental Assessment Division at Brookhaven National Laboratory and elsewhere. Uncertainty over the mechanism and size of air pollution health damage is addressed through a probabilistic health-damage function, using sulphate-particle exposure as an indicator. This facilitates intercomparison through analysis of each step in the whole fuel cycle between a typical coal and nuclear power plant. Occupational health impacts, a significant fraction of overall damage, are illustrated by accident trends in coal-mining. In broadening comparisons to include new technologies, one must include the impact of manufacturing the energy-producing device as part of an expanded fuel cycle, via input/output methods. Throughout the analysis, uncertainties must be made explicit in the results, including uncertainty of data and uncertainty in choice of appropriate models and methods. No single method of comparative risk assessment is fully satisfactory; each has its limitations. Several methods must be compared if decision-making is to be realistic. (author)

A theoretical study of rotatable renewable energy system for stratospheric airship

International Nuclear Information System (INIS)

Lv, Mingyun; Li, Jun; Zhu, Weiyu; Du, Huafei; Meng, Junhui; Sun, Kangwen

2017-01-01

Highlights: • A new rotatable renewable energy system is designed for stratospheric airship. • A theoretical model of optimal rotation angle and required area are studied. • The effects of latitude and date on output energy per day are investigated. • The advantages of the rotatable renewable energy system are studied. - Abstract: Renewable energy system is very critical for solving the energy problem of a long endurance stratospheric airship. Output performance of the traditional solar array fixed on the upper surface of the airship remains to be improved to reduce the area and weight of renewable energy system. Inspired by the solar tracking system and kirigami, a rotatable renewable energy system (mainly including solar array) is designed to improve the current status of the energy system. The advantages of the rotatable solar array are studied using a MATLAB computer program based on the theoretical model established in this paper. The improvements in output energy and required area of the solar array were compared between the traditional airship and improved one. Studies had shown that the rotatable renewable energy system made the total weight of energy system decreased by 1000 kg when the maximum design speed of the airship was greater than 22 m/s. The results demonstrate that the rotatable renewable energy system for the airship can be a good way to improve the output performance of solar array, and the conceptual design and theoretical model suggest a pathway towards solving the energy problem of a stratospheric airship.

Comparative energy and exergy performance assessments of a microcogenerator unit in different electricity mix scenarios

International Nuclear Information System (INIS)

Gonçalves, Pedro; Angrisani, Giovanni; Roselli, Carlo; Gaspar, Adélio R.; Gameiro da Silva, Manuel

2013-01-01

Highlights: • Experimental and energy–exergy modelling of a 6 kW micro-combined heat and power unit. • Evaluation of energy and exergy efficiencies for performance assessment. • Use of exergy and energy indicators for comparison with a reference system. • Use of different renewables supply options into the electric and heat reference system. • The electric grid mix of Portugal and Italy is used and discussed. - Abstract: The Directive 2004/8/EC on the promotion of cogeneration proposes a comparative indicator based on primary energy savings, neglecting some important thermodynamic aspects, such as exergy. This study aims to compare and discuss the usefulness of a set of complementary indicators for performance assessments of cogeneration systems, concerning thermodynamic principles based on first and second law (the exergy approach). As case study, a 6 kW electric output micro-combined heat and power unit was experimentally tested and a model of the unit was developed in TRNSYS. Considering as reference a set of different heat and electricity scenarios, including the actual electric mixes of Portugal and Italy, the indicators case incon (PES) and Primary and Total Irreversibilities Savings (PIS and TIS), as well as energy and exergy renewability ratios were assessed and discussed. The results show that the use of MCHP has higher advantages for the Italian electric grid, than an equivalent scenario considering the Portuguese electric network as reference. As result, for a particular scenario analysed, PES and PIS have 3% and 6% for Portugal, and 10% and 18% for Italy, respectively. Furthermore, for one particular scenario evaluated, the indicators energetic and exergetic renewability ratios have 23% and 14%, respectively for the Portuguese electric grid, and 19% and 10% for the Italian electric system

Energy Analysis at a Near Zero Energy Building. A Case-Study in Spain

Directory of Open Access Journals (Sweden)

Javier M. Rey-Hernández

2018-04-01

Full Text Available This paper develops an energy analysis for an existing near Zero Energy (nZEB and Zero Carbon Emissions building called LUCIA, located at the university campus in Valladolid (Spain. It is designed to supply electricity, cooling and heating needs through solar energy (Photovoltaic Systems, PV, biomass and an Earth–Air Heat Exchanger (EAHE, besides a Combined Heat Power (CHP. It is currently among the top three buildings with the highest LEED certification in the World. The building model is simulated with DesignBuilder version 5. The results of the energy analysis illustrate the heating, cooling and lighting consumptions expected, besides other demands and energy uses. From this data, we carried out an energy balance of the nZEB, which will help to plan preventive actions when compared to the actual energy consumptions, improving the management and control of both the building and its systems. The primary energy indicator obtained is 67 kWh/m2 a year, and 121 kWh/m2 a year for renewable energy generation, with respect to 55 kWh/m2 and 45 kWh/m2 set as reference in Europe. The Renewable Energy Ratio (RER is 0.66. These indicators become a useful tool for the energy analysis of the nZEB according to the requirements in the European regulations and for its comparison with further nZEB.

Early small-bowel ischemia: dual-energy CT improves conspicuity compared with conventional CT in a swine model.

Science.gov (United States)

Potretzke, Theodora A; Brace, Christopher L; Lubner, Meghan G; Sampson, Lisa A; Willey, Bridgett J; Lee, Fred T

2015-04-01

To compare dual-energy computed tomography (CT) with conventional CT for the detection of small-bowel ischemia in an experimental animal model. The study was approved by the animal care and use committee and was performed in accordance with the Guide for Care and Use of Laboratory Animals issued by the National Research Council. Ischemic bowel segments (n = 8) were created in swine (n = 4) by means of surgical occlusion of distal mesenteric arteries and veins. Contrast material-enhanced dual-energy CT and conventional single-energy CT (120 kVp) sequences were performed during the portal venous phase with a single-source fast-switching dual-energy CT scanner. Attenuation values and contrast-to-noise ratios of ischemic and perfused segments on iodine material-density, monospectral dual-energy CT (51 keV, 65 keV, and 70 keV), and conventional 120-kVp CT images were compared. Linear mixed-effects models were used for comparisons. The attenuation difference between ischemic and perfused segments was significantly greater on dual-energy 51-keV CT images than on conventional 120-kVp CT images (mean difference, 91.7 HU vs 47.6 HU; P conventional CT by increasing attenuation differences between ischemic and perfused segments on low-kiloelectron volt and iodine material density images. © RSNA, 2014.

Comparative risks from different energy systems: Evolution of the methods of studies

Energy Technology Data Exchange (ETDEWEB)

Hamilton, L D [Brookhaven National Lab., Upton, NY (USA)

1980-10-01

This conference has emphasized the difficulty in estimating energy-entailed health risks engendered by the differences between objective measures of risk - the estimated real or actual risk of a process - and the subjective perception of these risks. The subjective perception of risk colours the thinking of most decision-makers (including governments and their regulatory bodies), likewise the public. This confusion (apart from any fundamental psychological processes that may be involved) stems from the following: 1. Assessment of the health effects from different energy systems has had only brief and sparsely supported investigations to date, e.g., only seven years ago did government agencies in the USA evince interest in assessing their health effects. Less than seven years ago was there funding for work at Brookhaven. 2. Assessment differs from research. Assessing the health and environmental costs of energy production and use requires scrutiny of various diverse areas of research. Research is needed to define the pollutants emitted by various stages in various fuel cycles, including end-use, and to trace, then quantitate their chemical transformations, transport, including chemical and biological conversion through air, water, food, finally reaching man and important animals and crops. 3. In assessment, because of the state of knowledge (or lack of it), one frequently must make do with, say, only 60 per cent certainty rather than with the 95 per cent significance level that one strives to achieve from research. This statistical gap itself attracts special interest groups, e.g., governments and utilities, who, from the earliest beginnings of comparative assessments, have for one or another reason exploited confusion between reality and perception of risk.

Comparative risks from different energy systems: Evolution of the methods of studies

International Nuclear Information System (INIS)

Hamilton, L.D.

1980-01-01

This conference has emphasized the difficulty in estimating energy-entailed health risks engendered by the differences between objective measures of risk - the estimated real or actual risk of a process - and the subjective perception of these risks. The subjective perception of risk colours the thinking of most decision-makers (including governments and their regulatory bodies), likewise the public. This confusion (apart from any fundamental psychological processes that may be involved) stems from the following: 1. Assessment of the health effects from different energy systems has had only brief and sparsely supported investigations to date, e.g., only seven years ago did government agencies in the USA evince interest in assessing their health effects. Less than seven years ago was there funding for work at Brookhaven. 2. Assessment differs from research. Assessing the health and environmental costs of energy production and use requires scrutiny of various diverse areas of research. Research is needed to define the pollutants emitted by various stages in various fuel cycles, including end-use, and to trace, then quantitate their chemical transformations, transport, including chemical and biological conversion through air, water, food, finally reaching man and important animals and crops. 3. In assessment, because of the state of knowledge (or lack of it), one frequently must make do with, say, only 60 per cent certainty rather than with the 95 per cent significance level that one strives to achieve from research. This statistical gap itself attracts special interest groups, e.g., governments and utilities, who, from the earliest beginnings of comparative assessments, have for one or another reason exploited confusion between reality and perception of risk

Comparing the energy required for fine grinding torrefied and fast heat treated pine

International Nuclear Information System (INIS)

Kokko, Lauri; Tolvanen, Henrik; Hämäläinen, Kai; Raiko, Risto

2012-01-01

The purpose of the study was to compare torrefaction to partial pyrolysis conducted with a fast heat treatment process. Both torrefaction and the fast heat treatment tests were performed in a bubbling fluidized bed reactor. The study investigated the anhydrous weight losses, the fine grinding energy requirements, and the lower heating values of the samples produced with the two methods i.e. torrefaction and the fast heat treatment. The effect of particle size to these quantities was also investigated. The measurements demonstrated that the fine grinding energy requirement decreased rapidly as a function of anhydrous weight loss. The overall energy content remaining in the solid product decreased linearly as a function of anhydrous weight loss. The study shows that there is only little difference in the final products of the two processes when using particle sizes less than 4 mm. This means that it is possible to get similar products from the fast heat treatment process that takes only seconds compared to the slower torrefaction process that takes minutes. -- Highlights: ► Fine grinding energy requirement is dependent on anhydrous weight loss. ► A fast heat treatment process of only 10 s is possible for pine wood. ► A particle size of less than 4 mm is required for the fast process.

Comparative Study of Dynamic Programming and Pontryagin’s Minimum Principle on Energy Management for a Parallel Hybrid Electric Vehicle

Directory of Open Access Journals (Sweden)

Huei Peng

2013-04-01

Full Text Available This paper compares two optimal energy management methods for parallel hybrid electric vehicles using an Automatic Manual Transmission (AMT. A control-oriented model of the powertrain and vehicle dynamics is built first. The energy management is formulated as a typical optimal control problem to trade off the fuel consumption and gear shifting frequency under admissible constraints. The Dynamic Programming (DP and Pontryagin’s Minimum Principle (PMP are applied to obtain the optimal solutions. Tuning with the appropriate co-states, the PMP solution is found to be very close to that from DP. The solution for the gear shifting in PMP has an algebraic expression associated with the vehicular velocity and can be implemented more efficiently in the control algorithm. The computation time of PMP is significantly less than DP.

Sexual function following high energy microwave thermotherapy: results of a randomized controlled study comparing transurethral microwave thermotherapy to transurethral prostatic resection

NARCIS (Netherlands)

Francisca, E. A.; D'Ancona, F. C.; Meuleman, E. J.; Debruyne, F. M.; de la Rosette, J. J.

1999-01-01

We evaluate changes in sexual function in patients treated with high energy transurethral microwave thermotherapy compared to transurethral resection of the prostate. A total of 147 patients randomized to undergo transurethral microwave thermotherapy or transurethral resection of the prostate were

Energy expenditure in frontotemporal dementia: a behavioural and imaging study

Science.gov (United States)

Ahmed, Rebekah M; Landin-Romero, Ramon; Collet, Tinh-Hai; van der Klaauw, Agatha A; Devenney, Emma; Henning, Elana; Kiernan, Matthew C; Piguet, Olivier; Farooqi, I Sadaf; Hodges, John R

2017-01-01

Abstract See Finger (doi:10.1093/aww312) for a scientific commentary on this article. Abnormal eating behaviour and metabolic parameters including insulin resistance, dyslipidaemia and body mass index are increasingly recognized as important components of neurodegenerative disease and may contribute to survival. It has previously been established that behavioural variant frontotemporal dementia is associated with abnormal eating behaviour characterized by increased sweet preference. In this study, it was hypothesized that behavioural variant frontotemporal dementia might also be associated with altered energy expenditure. A cohort of 19 patients with behavioural variant frontotemporal dementia, 13 with Alzheimer’s disease and 16 (age- and sex-matched) healthy control subjects were studied using Actiheart devices (CamNtech) to assess resting and stressed heart rate. Actiheart devices were fitted for 7 days to measure sleeping heart rate, activity levels, and resting, active and total energy expenditure. Using high resolution structural magnetic resonance imaging the neural correlates of increased resting heart rate were investigated including cortical thickness and region of interest analyses. In behavioural variant frontotemporal dementia, resting (P = 0.001), stressed (P = 0.037) and sleeping heart rate (P = 0.038) were increased compared to control subjects, and resting heart rate (P = 0.020) compared to Alzheimer disease patients. Behavioural variant frontotemporal dementia was associated with decreased activity levels compared to controls (P = 0.002) and increased resting energy expenditure (P = 0.045) and total energy expenditure (P = 0.035). Increased resting heart rate correlated with behavioural (Cambridge Behavioural Inventory) and cognitive measures (Addenbrooke’s Cognitive Examination). Increased resting heart rate in behavioural variant frontotemporal dementia correlated with atrophy involving the mesial temporal cortex, insula, and amygdala

Comparing the Life Cycle Energy Consumption, Global ...

Science.gov (United States)

Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG) emissions and aqueous nutrient releases of the whole anthropogenic municipal water cycle starting from raw water extraction to wastewater treatment and reuse/discharge for five municipal water and wastewater systems. The assessed options included conventional centralized services and four alternative options following the principles of source-separation and water fit-for-purpose. The comparative life cycle assessment identified that centralized drinking water supply coupled with blackwater energy recovery and on-site greywater treatment and reuse was the most energyand carbon-efficient water service system evaluated, while the conventional (drinking water and sewerage) centralized system ranked as the most energy- and carbon-intensive system. The electricity generated from blackwater and food residuals co-digestion was estimated to offset at least 40% of life cycle energy consumption for water/waste services. The dry composting toilet option demonstrated the lowest life cycle eutrophication potential. The nutrients in wastewater effluent are the dominating contributors for the eutrophication potential for the assessed system configurations. Among the parameters for which variability

Educating Future Energy Engineers for Sustainability: Case Study in Energy Economy

Directory of Open Access Journals (Sweden)

Şiir Kilkiş

2015-03-01

Full Text Available This paper analyzes the case study of an interdisciplinary course in Energy Economy that was developed at the Energy Engineering Graduate Program at Başkent University. The course integrated several unique pedagogical features to satisfy the aim of developing a working knowledge in energy economy with an energy systems perspective. The novel aspects of the course thematically led to a capstone research project where 5 teams of 17 course participants analyzed their prioritized solutions towards improving the energy self-sufficiency of the campus based on the practice of energy economy. The results of the teams’ solutions towards a net-zero energy/exergy campus included electric buses for city-campus transport, poly-generation for the new Arts Center, LED/OLED lighting for campus lighting, dynamo driven/piezoelectric sports center, biofuels from the university-owned dairy products farm, and an energy efficient technology incubation center. This unique course with participatory learning is compared with others before concluding that the case study is a useful international example for energy economy.

A comparative evaluation of low-energy, passive and zero-energy houses in The Netherlands and Belgium

NARCIS (Netherlands)

Mlecnik, E.; Jansen, S.; Schuetze, T.; De Vries, G.

2011-01-01

The presented research aims to evaluate highly energy-efficient dwellings, in particular Passive Houses (PH), in Flanders and in The Netherlands, based on end-user experiences. In the introduction the definition of PH in the Benelux countries Belgium and The Netherlands is compared with the Nordic

Energy implications of mechanical and mechanical-biological treatment compared to direct waste-to-energy.

Science.gov (United States)

Cimpan, Ciprian; Wenzel, Henrik

2013-07-01

Primary energy savings potential is used to compare five residual municipal solid waste treatment systems, including configurations with mechanical (MT) and mechanical-biological (MBT) pre-treatment, which produce waste-derived fuels (RDF and SRF), biogas and/or recover additional materials for recycling, alongside a system based on conventional mass burn waste-to-energy and ash treatment. To examine the magnitude of potential savings we consider two energy efficiency levels (state-of-the-art and best available technology), the inclusion/exclusion of heat recovery (CHP vs. PP) and three different background end-use energy production systems (coal condensing electricity and natural gas heat, Nordic electricity mix and natural gas heat, and coal CHP energy quality allocation). The systems achieved net primary energy savings in a range between 34 and 140 MJprimary/100 MJinput waste, in the different scenario settings. The energy footprint of transportation needs, pre-treatment and reprocessing of recyclable materials was 3-9.5%, 1-18% and 1-8% respectively, relative to total energy savings. Mass combustion WtE achieved the highest savings in scenarios with CHP production, nonetheless, MBT-based systems had similarly high performance if SRF streams were co-combusted with coal. When RDF and SRF was only used in dedicated WtE plants, MBT-based systems totalled lower savings due to inherent system losses and additional energy costs. In scenarios without heat recovery, the biodrying MBS-based system achieved the highest savings, on the condition of SRF co-combustion. As a sensitivity scenario, alternative utilisation of SRF in cement kilns was modelled. It supported similar or higher net savings for all pre-treatment systems compared to mass combustion WtE, except when WtE CHP was possible in the first two background energy scenarios. Recovery of plastics for recycling before energy recovery increased net energy savings in most scenario variations, over those of full

Comparative study for endenergy supply with nuclear district heating and with nuclear long distance energy

International Nuclear Information System (INIS)

Dietrich, G.

1975-07-01

The future energy supply of the Federal Republic of Germany will be orientated to secure energy carriers. Moreover economical energy consumption and environmental protection will be a force for an increased application of district heating and nuclear long distance energy. The technics of generation, transport and distribution of the two energy carriers will be discussed, besides a short review of application areas and potentials. The cost comparisons by models show that there are special advantages for both systems. Nevertheless the conclusions from the study can be to favour nuclear long distance energy because of its wide application range in the whole heat market. But there is also the competition with combined heat and power generation on fossil basis, as practised in many industrial companies. As a result of a regional analysis of the area Aachen-Moenchengladbach-Koeln, the cost advantages of the nuclear long distance energy as a parameter of current prices are confirmed. Nuclear long distance energy, in combination with the high temperature reactor and a developed technic of catalysts up to temperatures of 900 K, is an energy source which will be independant of regional necessities, secure, non pollutant and economic. (orig.) [de

A comparative study of fluorescent and LED lighting in industrial facilities

Science.gov (United States)

Perdahci PhD, C.; Akin BSc, H. C.; Cekic Msc, O.

2018-05-01

Industrial facilities have always been in search for reducing outgoings and minimizing energy consumption. Rapid developments in lighting technology require more energy efficient solutions not only for industries but also for many sectors and for households. Addition of solid-state technology has brought LED lamps into play and with LED lamp usage, efficacy level has reached its current values. Lighting systems which uses fluorescent and LED lamps have become the prior choice for many industrial facilities. This paper presents a comparative study about fluorescent and LED based indoor lighting systems for a warehouse building in an industrial facility in terms of lighting distribution values, colour rendering, power consumption, energy efficiency and visual comfort. Both scenarios have been modelled and simulated by using Relux and photometric data for the luminaires have been gathered by conducting tests and measurements in an accredited laboratory.

Mass attenuation coefficient (μ/ρ), effective atomic number (Zeff) and measurement of x-ray energy spectra using based calcium phosphate biomaterials: a comparative study

International Nuclear Information System (INIS)

Fernandes Z, M. A.; Da Silva, T. A.; Nogueira, M. S.; Goncalves Z, E.

2015-10-01

In dentistry, alveolar bone regeneration procedures using based calcium phosphate biomaterials have been shown effective. However,there are not reports in the literature of studies the interaction of low energy radiation in these biomaterials used as attenuator and not being then allowed a comparison between the theoretical values and experimental.The objective of this study was to determine the interaction of radiation parameters of four dental biomaterials - BioOss, Cerasorb M Dental, Straumann Boneceramic and Osteogen for diagnostic radiology qualities. As a material and methods, the composition of the biomaterials was determined by the analytical techniques. The samples with 0.181 cm to 0,297 cm thickness were experimentally used as attenuators for the measurement of the transmitted X-rays spectra in X-ray equipment with 50 to 90 kV range by spectrometric system comprising the Cd Te detector. After this procedure, the mass attenuation coefficient, the effective atomic number were determined and compared between all the specimens analyzed, using the program WinXCOM in the range of 10 to 200 keV. In all strains examined observed that the energy spectrum of x-rays transmitted through the BioOss has the mean energy slightly smaller than the others biomaterials for close thickness. The μ/ρ and Z eff of the biomaterials showed its dependence on photon energy and atomic number of the elements of the material analyzed. It is concluded according to the methodology employed in this study that the measurements of x-ray spectrum, μ/ρ and Z eff using biomaterials as attenuators confirmed that the thickness, density, composition of the samples, the incident photon energy are factors that determine the characteristics of radiation in a tissue or equivalent material. (Author)

A comparative study of the energy resolution achievable with digital signal processors in x-ray spectroscopy

International Nuclear Information System (INIS)

Geraci, A.; Zambusi, M.; Ripamonti, G.

1996-01-01

Interest for digital processing of signals from radiation detectors is subject to a growing attention due to its intrinsic adaptivity, easiness of calibration, etc. This work compares two digital processing methods: a multiple-delay-line (DL) N filter and a least-mean-squares (LMS) adaptive filter for applications in high resolution X-ray spectroscopy. The signal pulse, as appears at the output of a proper analog conditioning circuit, is digitized; the samples undergo a digital filtering procedure. Both digital filters take advantage of the possibility of synthesizing the best possible weighting function with respect to the actual noise conditions. A noticeable improvement of more than 10% in energy resolution has been achieved with both systems with respect to state-of-the-art systems based on analog circuitry. In particular, the two digital processors are shown to be the best choice respectively; for on-line use with critical ballistic deficit conditions and for very-high-resolution spectroscopy systems, ultimately limited by 1/f noise

Environment and energy in Iceland: A comparative analysis of values and impacts

International Nuclear Information System (INIS)

Thorhallsdottir, Thora Ellen

2007-01-01

Within an Icelandic framework plan for energy, environmental values and impacts were estimated in multicriteria analyses for 19 hydroelectric and 22 geothermal developments. Four natural environment classes were defined (geology + hydrology, species, ecosystems + soils, landscape + wilderness) with cultural heritage as the fifth class. Values and impacts were assessed through 6 agglomerated attributes: richness/diversity, rarity, size/continuity/pristineness, information/symbolic value, international responsibility and visual value. The project offers a unique opportunity for comparing environmental values and impacts within a large sample of sites and energy alternatives treated within a common methodological framework. Total values were higher in hydroelectric than in geothermal areas. Hydroelectric areas scored high for cultural heritage (particularly in rarity and information value), landscape and wilderness. Geothermal areas had high bedrock and hydrological diversity and information values, and a high landscape visual value but little cultural heritage. High values were correlated among some classes of the natural environment, all of which are likely to reflect functional relationships. In contrast, cultural heritage values were not related to natural environment values. Overall, landscape and wilderness had the highest mean value and were also most affected by energy development. Over 40% of the hydroelectric development had a predicted mean impact value of > 4 (out of a maximum of 10), compared with 10% of the geothermal projects. Excluding two outsized hydropower options, there was a significant correlation between plant capacity and impact on geology and hydrology but not with other environmental variables

A feasibility study for anatomical noise reduction in dual-energy chest digital tomosynthesis

Science.gov (United States)

Lee, D.; Kim, Y.-s.; Choi, S.; Lee, H.; Choi, S.; Kim, H.-J.

2016-01-01

Lung cancer is the leading cause of cancer death worldwide. Thus, early diagnosis is of considerable importance. For early screening of lung cancer, computed tomography (CT) has been used as the gold standard. Chest digital tomosynthesis (CDT) is a recently introduced modality for lung cancer screening with a relatively low radiation dose compared to CT. The dual energy material decomposition method has been proposed for better detection of pulmonary nodules by means of reducing anatomical noise. In this study, the possibility of material decomposition in CDT was tested by both a simulation study and an experimental study using a CDT prototype. The Geant4 application for tomographic emission (GATE) v6 and tungsten anode spectral model using interpolating polynomials (TASMIP) codes were used for the simulation study to create simulated phantom shapes consisting of five inner cylinders filled with different densities of bone and airequivalent materials. Furthermore, the CDT prototype system and human phantom chest were used for the experimental study. CDT scan in both the simulation and experimental studies was performed with linear movement and 21 projection images were obtained over a 30 degree angular range with a 1.5 degree angular interval. To obtain materialselective images, a projectionbased energy subtraction technique was applied to high and low energy images. The resultant simulation images showed that dual-energy reconstruction could achieve an approximately 32% higher contrast to noise ratio (CNR) in images and the difference in CNR value according to bone density was significant compared to single energy CDT. Additionally, image artifacts were effectively corrected in dual energy CDT simulation studies. Likewise the experimental study with dual energy produced clear images of lung fields and bone structure by removing unnecessary anatomical structures. Dual energy tomosynthesis is a new technique; therefore, there is little guidance regarding its

A feasibility study for anatomical noise reduction in dual-energy chest digital tomosynthesis

International Nuclear Information System (INIS)

Lee, D.; Choi, S.; Kim, H.-J.; Kim, Y.-S.; Choi, S.; Lee, H.

2016-01-01

Lung cancer is the leading cause of cancer death worldwide. Thus, early diagnosis is of considerable importance. For early screening of lung cancer, computed tomography (CT) has been used as the gold standard. Chest digital tomosynthesis (CDT) is a recently introduced modality for lung cancer screening with a relatively low radiation dose compared to CT. The dual energy material decomposition method has been proposed for better detection of pulmonary nodules by means of reducing anatomical noise. In this study, the possibility of material decomposition in CDT was tested by both a simulation study and an experimental study using a CDT prototype. The Geant4 application for tomographic emission (GATE) v6 and tungsten anode spectral model using interpolating polynomials (TASMIP) codes were used for the simulation study to create simulated phantom shapes consisting of five inner cylinders filled with different densities of bone and airequivalent materials. Furthermore, the CDT prototype system and human phantom chest were used for the experimental study. CDT scan in both the simulation and experimental studies was performed with linear movement and 21 projection images were obtained over a 30 degree angular range with a 1.5 degree angular interval. To obtain materialselective images, a projectionbased energy subtraction technique was applied to high and low energy images. The resultant simulation images showed that dual-energy reconstruction could achieve an approximately 32% higher contrast to noise ratio (CNR) in images and the difference in CNR value according to bone density was significant compared to single energy CDT. Additionally, image artifacts were effectively corrected in dual energy CDT simulation studies. Likewise the experimental study with dual energy produced clear images of lung fields and bone structure by removing unnecessary anatomical structures. Dual energy tomosynthesis is a new technique; therefore, there is little guidance regarding its

A comparative study of cross sections at few energy groups for thermal reactors fuel cells

International Nuclear Information System (INIS)

Claro, L.H.; Prati, A.

1992-01-01

A comparative study of nuclear constant calculated with LEOPARD and WIMSD-4 codes using a typical PWR cell was done. Few groups macroscopic cross section, spectral index burnup and power distribution were analyzed. (author)

Greening the networks: a comparative analysis of different energy efficient techniques

International Nuclear Information System (INIS)

Arshad, M.J.; Saeed, S.S.

2014-01-01

From a room electric bulb to the gigantic backbone networks energy savings have now become a matter of considerable concern. Issues such as resource depletion, global warming, high energy consumptions and environmental threats gave birth to the idea of green networking. Serious efforts have been done in this regard on large scale in the ICT sector. In this work first we give an idea of how and why this modern technology emerged. We then formulate a precise definition of the term green technology. We then discuss some leading techniques which are promising to produce green-results when implemented on real time network systems. These technologies are viewed from different perspectives e.g. hardware implementations, software mechanisms and protocol changing etc. We then compare these techniques based on some pivotal points. The main conclusion is that a detailed comparison is needed for selecting a technology to implement on a network system. (author)

Studies of global warming and global energy

International Nuclear Information System (INIS)

Inaba, Atsushi

1993-01-01

Global warming caused by increase in atmospheric CO 2 concentration has been the focus of many recent global energy studies. CO 2 is emitted to the atmosphere mainly from the combustion of fossil fuels. This means that global warming is fundamentally a problem of the global energy system. An analysis of the findings of recent global energy studies is made in this report. The results are categorized from the viewpoint of concern about global warming. The analysis includes energy use and CO 2 emissions, measures taken to restrain CO 2 emissions and the cost of such measure, and suggestions for long term global energy generation. Following this comparative analysis, each of the studies is reviewed in detail. (author) 63 refs

Renewable energy in eastern Asia: Renewable energy policy review and comparative SWOT analysis for promoting renewable energy in Japan, South Korea, and Taiwan

International Nuclear Information System (INIS)

Chen, Wei-Ming; Kim, Hana; Yamaguchi, Hideka

2014-01-01

Japan, South Korea, and Taiwan are deficient of domestic fossil energy sources and depend significantly on imported fuels. Since the oil shock in the 1970s, all three countries have promoted renewable energy as an alternative energy source to improve energy security. Currently, renewable energy is being promoted to build low-carbon economies. This study reviews the development of renewable energy policies and roadmaps. It also examines and compares strengths, weaknesses, opportunities, and threats (SWOT) of these countries in the context of advancing renewable energy policies and technologies and expanding domestic renewable energy installations, as well as strategically positioning themselves in the international renewable energy market as exporters of clean energy technologies. Through the SWOT analysis, this paper identifies a capacity for additional renewable energy deployment in these countries and highlights the necessity of increased cooperation between the three countries to strengthen their domestic and regional renewable energy sectors and compete in the global renewable energy market in the post-Fukushima era. - Highlights: • Japan, South Korea and Taiwan need to develop renewable energy (RE). • These countries have been too conservative to achieve a notable share of RE. • Pro-nuclear energy policies have hindered the RE development in these countries. • The Fukushima disaster made these countries more favorable to RE. • Joint cooperation for R and D and deployment of RE is recommended

Comparing energy levels in isotropic and anisotropic potentials

Energy Technology Data Exchange (ETDEWEB)

Pikovski, Alexander, E-mail: alexander.pikovski@colorado.edu

2015-11-06

Qualitative information about the quantized energy levels of a system can be of great value. We study the relationship between the bound-state energies of an anisotropic potential and those of its spherical average. It is shown that the two ground-state energies satisfy an inequality, and there is a similar inequality for the first excited states. - Highlights: • Quantized energy levels in an arbitrary non-central potential are studied. • We derive inequalities between energies in a potential and its spherical average. • The results hold in three and two dimensions for any ground state and, with additional symmetry requirements for the first excited state.

Comparing energy levels in isotropic and anisotropic potentials

International Nuclear Information System (INIS)

Pikovski, Alexander

2015-01-01

Qualitative information about the quantized energy levels of a system can be of great value. We study the relationship between the bound-state energies of an anisotropic potential and those of its spherical average. It is shown that the two ground-state energies satisfy an inequality, and there is a similar inequality for the first excited states. - Highlights: • Quantized energy levels in an arbitrary non-central potential are studied. • We derive inequalities between energies in a potential and its spherical average. • The results hold in three and two dimensions for any ground state and, with additional symmetry requirements for the first excited state.

Study of renewable energy, fuel cell and demotics integration for stationary energy production

Energy Technology Data Exchange (ETDEWEB)

Andaloro, L.; Ferraro, M.; Sergi, F.; Brunaccini, G.; Antonucci, V. [National Research Inst., Messina (Italy)

2009-07-01

This paper described a study in which a small house equipped with various renewable technologies was modelled. The aim of the study was to evaluated the integration of fuel cells with various other energy sources. Technologies installed in the house included a photovoltaic (PV) system; a hydrogen system; fuel cells; a battery-storage system; and a thermal solar panel. Maximum energy savings were evaluated for different configurations and combinations of the installed energy sources. A domotic system was also used to automatically control the use of electrical appliances and improve safety and comfort. An energy side management system was designed and compared with a demand side management system. Various scenarios were simulated in order to test the energy management systems in relation to the automated domotic system.

Finite element analysis of vibration energy harvesting using lead-free piezoelectric materials: A comparative study

Directory of Open Access Journals (Sweden)

Anuruddh Kumar

2014-06-01

Full Text Available In this article, the performance of various piezoelectric materials is simulated for the unimorph cantilever-type piezoelectric energy harvester. The finite element method (FEM is used to model the piezolaminated unimorph cantilever structure. The first-order shear deformation theory (FSDT and linear piezoelectric theory are implemented in finite element simulations. The genetic algorithm (GA optimization approach is carried out to optimize the structural parameters of mechanical energy-based energy harvester for maximum power density and power output. The numerical simulation demonstrates the performance of lead-free piezoelectric materials in unimorph cantilever-based energy harvester. The lead-free piezoelectric material K0.5Na0.5NbO3-LiSbO3-CaTiO3 (2 wt.% has demonstrated maximum mean power and maximum mean power density for piezoelectric energy harvester in the ambient frequency range of 90–110 Hz. Overall, the lead-free piezoelectric materials of K0.5Na0.5NbO3-LiSbO3 (KNN-LS family have shown better performance than the conventional lead-based piezoelectric material lead zirconate titanate (PZT in the context of piezoelectric energy harvesting devices.

Development of a predictive energy equation for maintenance hemodialysis patients: a pilot study.

Science.gov (United States)

Byham-Gray, Laura; Parrott, J Scott; Ho, Wai Yin; Sundell, Mary B; Ikizler, T Alp

2014-01-01

The study objectives were to explore the predictors of measured resting energy expenditure (mREE) among a sample of maintenance hemodialysis (MHD) patients, to generate a predictive energy equation (MHDE), and to compare such models to another commonly used predictive energy equation in nutritional care, the Mifflin-St. Jeor equation (MSJE). The study was a retrospective, cross-sectional cohort design conducted at the Vanderbilt University Medical Center. Study subjects were adult MHD patients (N = 67). Data collected from several clinical trials were analyzed using Pearson's correlation and multivariate linear regression procedures. Demographic, anthropometric, clinical, and laboratory data were examined as potential predictors of mREE. Limits of agreement between the MHDE and the MSJE were evaluated using Bland-Altman plots. The a priori α was set at P lean body mass [LBM]) of mREE included (R(2) = 0.489) FFM, ALB, age, and CRP. Two additional models (MHDE-CRP and MHDE-CR) with acceptable predictability (R(2) = 0.460 and R(2) = 0.451) were derived to improve the clinical utility of the developed energy equation (MHDE-LBM). Using Bland-Altman plots, the MHDE over- and underpredicted mREE less often than the MSJE. Predictive models (MHDE) including selective demographic, clinical, and anthropometric data explained less than 50% variance of mREE but had better precision in determining energy requirements for MHD patients when compared with MSJE. Further research is necessary to improve predictive models of mREE in the MHD population and to test its validity and clinical application. Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

A comparative study on prediction methods for China's medium- and long-term coal demand

International Nuclear Information System (INIS)

Li, Bing-Bing; Liang, Qiao-Mei; Wang, Jin-Cheng

2015-01-01

Given the dominant position of coal in China's energy structure and in order to ensure a safe and stable energy supply, it is essential to perform a scientific and effective prediction of China's medium- and long-term coal demand. Based on the historical data of coal consumption and related factors such as GDP (Gross domestic product), coal price, industrial structure, total population, energy structure, energy efficiency, coal production and urbanization rate from 1987 to 2012, this study compared the prediction effects of five types of models. These models include the VAR (vector autoregressive model), RBF (radial basis function) neural network model, GA-DEM (genetic algorithm demand estimation model), PSO-DEM (particle swarm optimization demand estimation model) and IO (input–output model). By comparing the results of different models with the corresponding actual coal consumption, it is concluded that with a testing period from 2006 to 2012, the PSO-DEM model has a relatively optimal predicted effect on China's total coal demand, where the MAPE (mean absolute percentage error) is close to or below 2%. - Highlights: • The prediction effects of five methods for China's coal demand were compared. • Each model has acceptable prediction results, with MAPE below 5%. • Particle swarm optimization demand estimation model has better forecast efficacy.

A comparative study of the design and construction process of energy efficient buildings in Germany and Sweden

International Nuclear Information System (INIS)

Schade, Jutta; Wallström, Peter; Olofsson, Thomas; Lagerqvist, Ove

2013-01-01

Reducing the energy consumption of buildings is an important goal for the European Union. However, it is therefore of interest to investigate how different member states address these goals. Countries like Sweden and Germany have developed different strategies for energy conservation within the building sector. A longitudinal comparison between implemented energy conservation key policy instruments in Sweden and Germany and a survey regarding the management of energy requirements in the building process shows that: –No evidence is found that energy consumption is of great importance for producing competitive offers, either for Swedish or German clients. –The Swedish market-driven policy has not been as successful as the German regulation policy in decreasing the energy consumption of new buildings. –Building standards and regulations regarding energy performance affects how professionals are educated and the way energy requirements and demands are managed throughout the building process. In conclusion, the client's demand will govern the development of energy efficient buildings. Therefore, in order to use market-driven policies, the desired parameters must be of concern for the customer to influence the majority of building projects to be more energy efficient than is specified in national standards and regulations. - Highlights: ► Longitudinal comparison between implemented energy key policy instruments. ► A survey regarding the management of energy requirements in the building process. ► German energy regulation policy more successful as the Swedish marked orientation. ► The gap between technological possible and regulation need to be balanced

A comparative analysis of China’s regional energy and emission performance: Which is the better way to deal with undesirable outputs?

International Nuclear Information System (INIS)

Wang Ke; Wei Yiming; Zhang Xian

2012-01-01

Measuring and improving the energy performance with considering emission constraints is an important issue for China’s energy conservation, pollutant emissions reduction and environment protection. This study utilizes several data envelopment analysis (DEA) based models to evaluate the total-factor energy and emission performance of China’s 30 regions within a joint production framework of considering desirable and undesirable outputs as well as separated energy and non-energy inputs. DEA window analysis is applied in this study to deal with cross-sectional and time-varying data, so as to measure the performance during the period of 2000–2009. Two treatments for undesirable outputs are combined with DEA models and the associated indicators for simplex energy performance and unified energy and emission performance measurement are proposed and compared. The evaluation results indicate that the treatment of undesirable outputs transformation is more appropriate for China’s regional energy and emission performance evaluation because it has stronger discriminating power and can provide more reasonable evaluation results that characterize China’s regions. The empirical result shows that east China has the highest and the most balanced energy and emission performance. The energy and emission performance of China remained stable during 2000–2003, decreased slightly during 2004–2006, and has continuously increased since 2007. - Highlights: ► We evaluate China’s regional energy and emission performance using DEA based models. ► We compare two undesirable outputs treatments according to the evaluation results. ► To treat undesirable outputs as inputs has weaker discriminating power in evaluation. ► Simplex energy performance, without environmental factors, is a biased evaluation. ► China’s energy and emission performance is approximately stable during study period.

E-commerce, paper and energy use: a case study concerning a Dutch electronic computer retailer

Energy Technology Data Exchange (ETDEWEB)

Hoogeveen, M.J.; Reijnders, L. [Open University Netherlands, Heerlen (Netherlands)

2002-07-01

Impacts of the application of c-commerce on paper and energy use are analysed in a case study concerning a Dutch electronic retailer (e-tailer) of computers. The estimated use of paper associated with the e-tailer concerned was substantially reduced if compared with physical retailing or traditional mail-order retailing. However, the overall effect of e-tailing on paper use strongly depends on customer behaviour. Some characteristics of c-commerce, as practised by the e-tailer concerned, such as diminished floor space requirements, reduced need for personal transport and simplified logistics, improve energy efficiency compared with physical retailing. Substitution of paper information by online information has an energetic effect that is dependent on the time of online information perusal and the extent to which downloaded information is printed. Increasing distances from producers to consumers, outsourcing, and increased use of computers, associated equipment and electronic networks are characteristics of e-commerce that may have an upward effect on energy use. In this case study, the upward effects thereof on energy use were less than the direct energy efficiency gains. However, the indirect effects associated with increased buying power and the rebound effect on transport following from freefalling travel time, greatly exceeded direct energy efficiency gains. (author)

Deployment and Maintenance of Wave Energy Converters at the Lysekil Research Site: A Comparative Study on the Use of Divers and Remotely-Operated Vehicles

Directory of Open Access Journals (Sweden)

Flore Rémouit

2018-04-01

Full Text Available Ocean renewable technologies have been rapidly developing over the past years. However, current high installation, operation, maintenance, and decommissioning costs are hindering these offshore technologies to reach a commercialization stage. In this paper we focus on the use of divers and remotely-operated vehicles during the installation and monitoring phase of wave energy converters. Methods and results are based on the wave energy converter system developed by Uppsala University, and our experience in offshore deployments obtained during the past eleven years. The complexity of underwater operations, carried out by either divers or remotely-operated vehicles, is emphasized. Three methods for the deployment of wave energy converters are economically and technically analyzed and compared: one using divers alone, a fully-automated approach using remotely-operated vehicles, and an intermediate approach, involving both divers and underwater vehicles. The monitoring of wave energy converters by robots is also studied, both in terms of costs and technical challenges. The results show that choosing an autonomous deployment method is more advantageous than a diver-assisted method in terms of operational time, but that numerous factors prevent the wide application of robotized operations. Technical solutions are presented to enable the use of remotely-operated vehicles instead of divers in ocean renewable technology operations. Economically, it is more efficient to use divers than autonomous vehicles for the deployment of six or fewer wave energy converters. From seven devices, remotely-operated vehicles become advantageous.

Nuts Improve Diet Quality Compared to Other Energy-Dense Snacks While Maintaining Body Weight

Directory of Open Access Journals (Sweden)

Siew Ling Tey

2011-01-01

Full Text Available Previous studies have reported that regular nut consumption reduces cardiovascular disease (CVD risk and does not promote weight gain despite the fact that nuts are energy-dense. However, no studies have investigated the body composition of those regularly consuming nuts compared to similar intakes of other snacks of equal energy density. This parallel study (n = 118 examined the effects of providing daily portions (~1100 kJ/d of hazelnuts, chocolate, or potato crisps compared to a control group receiving no snacks for twelve weeks. Effects on body weight and composition, blood lipids and lipoproteins, resting metabolic rate (RMR, appetite indices, and dietary quality were compared. At week 12, there was no significant difference in any of the outcome measurements between the groups except for dietary quality, which improved significantly in the nut group. Nuts can be incorporated into the diet without adversely affecting body weight and can improve diet quality.

The meaning of results. Understanding comparative risk assessments of energy options

International Nuclear Information System (INIS)

Wilson, R.; Holland, M.; Rabl, A.; Dreicer, M.

1999-01-01

Results of comparative risk assessments can be used for a range of potential applications: choice and balance of technologies for strategic energy planning; choice of a new power plant; optimal dispatching of existing plants; optimization of regulations (emission limits, environmental quality objectives such as air quality limits, tradable permits, pollution taxes); accounting for climate change. When reporting the results of comparative risk assessment, a number of factors should be clear: precise nature of the energy system being assessed; what has been excluded from the analysis; sources of data used in assessment; assumptions that have been made; and what the analysts and other experts have regarded as the key sensitivities in the analysis. If all factors are addressed, the results of comparative risk assessment will prove to be an essential resource for making the best decisions about energy options and policies

Comparing the health and environmental hazards of different energy systems

Energy Technology Data Exchange (ETDEWEB)

Hamilton, L.D.

1982-01-01

Energy and environment can pose difficult challenges for policy makers and scientists. Assessing health impacts of different energy sources requires synthesis of research results from many different disciplines into a rational framework. Information is often scanty; qualitatively different risks, or energy systems with quite different end uses, must be put on a common footing. Risk-assessment methods reviewed include examples drawn from work of the Biomedical and Environmental Assessment Division at Brookhaven National Laboratory and elsewhere. Coal and nuclear fuel cycles are compared in respect to morbidity and mortality. Other cycles (oil, gas and renewables) are also examined. In broadening comparisons to include new technologies, one must include the impact of manufacturing the energy-producing devices as part of an expanded fuel cycle, via input-output methods. Input-output analysis allows comparisons of direct and system-wide impacts. Throughout the analysis, uncertainties must be explicitly recognized in the results, including uncertainty in validity of data and uncertainty in choice of appropriate models. No single method of comparative risk assessment is fully satisfactory; each has its limitations. By use of several methods progress has been made in understanding the relative impact of energy technologies.

Comparing the health and environmental hazards of different energy systems

International Nuclear Information System (INIS)

Hamilton, L.D.

1982-01-01

Energy and environment can pose difficult challenges for policy makers and scientists. Assessing health impacts of different energy sources requires synthesis of research results from many different disciplines into a rational framework. Information is often scanty; qualitatively different risks, or energy systems with quite different end uses, must be put on a common footing. Risk-assessment methods reviewed include examples drawn from work of the Biomedical and Environmental Assessment Division at Brookhaven National Laboratory and elsewhere. Coal and nuclear fuel cycles are compared in respect to morbidity and mortality. Other cycles (oil, gas and renewables) are also examined. In broadening comparisons to include new technologies, one must include the impact of manufacturing the energy-producing devices as part of an expanded fuel cycle, via input-output methods. Input-output analysis allows comparisons of direct and system-wide impacts. Throughout the analysis, uncertainties must be explicitly recognized in the results, including uncertainty in validity of data and uncertainty in choice of appropriate models. No single method of comparative risk assessment is fully satisfactory; each has its limitations. By use of several methods progress has been made in understanding the relative impact of energy technologies

A comparative study of health and safety aspects in the utilisation of coal and nuclear energy for power production

International Nuclear Information System (INIS)

Vohra, K.G.

1979-01-01

Some aspects of the analysis of the risks associated with nuclear energy systems and coal-fired power stations are discussed and compared. The average dose has been estimated to be less than 5 mrem/a for a fully developed ruclear power programme. This dose is about 5% of the natural dose of 100 mrem/a. On the basis an average of 1500 spontaneous cancer deaths per million per year, the contribution due to 5 mrem/a would be one additional cancer death of the exposed group i.e. 0.066%. On the other hand, effluents from the coal-fired stations have been found to contribute 5.5% to 19% of the total lung cancer deaths. A point often not noticed is the radiological hazards due to the natural radioactive content of coal. The fly-ash contains radium-226 and radium-228. The plumes of the coal-fired stations contain radon and its daughter products. Taking into account the radiological and chemical hazards of coal burning, the nuclear energy systems are far better than coal-fired power stations. (M.G.B.)

Differentiation-Dependent Energy Production and Metabolite Utilization: A Comparative Study on Neural Stem Cells, Neurons, and Astrocytes

Science.gov (United States)

Jády, Attila Gy.; Nagy, Ádám M.; Kőhidi, Tímea; Ferenczi, Szilamér; Tretter, László

2016-01-01

While it is evident that the metabolic machinery of stem cells should be fairly different from that of differentiated neurons, the basic energy production pathways in neural stem cells (NSCs) or in neurons are far from clear. Using the model of in vitro neuron production by NE-4C NSCs, this study focused on the metabolic changes taking place during the in vitro neuronal differentiation. O2 consumption, H+ production, and metabolic responses to single metabolites were measured in cultures of NSCs and in their neuronal derivatives, as well as in primary neuronal and astroglial cultures. In metabolite-free solutions, NSCs consumed little O2 and displayed a higher level of mitochondrial proton leak than neurons. In stem cells, glycolysis was the main source of energy for the survival of a 2.5-h period of metabolite deprivation. In contrast, stem cell-derived or primary neurons sustained a high-level oxidative phosphorylation during metabolite deprivation, indicating the consumption of own cellular material for energy production. The stem cells increased O2 consumption and mitochondrial ATP production in response to single metabolites (with the exception of glucose), showing rapid adaptation of the metabolic machinery to the available resources. In contrast, single metabolites did not increase the O2 consumption of neurons or astrocytes. In “starving” neurons, neither lactate nor pyruvate was utilized for mitochondrial ATP production. Gene expression studies also suggested that aerobic glycolysis and rapid metabolic adaptation characterize the NE-4C NSCs, while autophagy and alternative glucose utilization play important roles in the metabolism of stem cell-derived neurons. PMID:27116891

Energy performance of building fabric - Comparing two types of vernacular residential houses

Science.gov (United States)

Draganova, Vanya Y.; Matsumoto, Hiroshi; Tsuzuki, Kazuyo

2017-10-01

Notwithstanding apparent differences, Japanese and Bulgarian traditional residential houses share a lot of common features - building materials, building techniques, even layout design. Despite the similarities, these two types of houses have not been compared so far. The study initiates such comparison. The focus is on houses in areas with similar climate in both countries. Current legislation requirements are compared, as well as the criteria for thermal comfort of people. Achieving high energy performance results from a dynamic system of 4 main key factors - thermal comfort range, heating/cooling source, building envelope and climatic conditions. A change in any single one of them can affect the final energy performance. However, it can be expected that a combination of changes in more than one factor usually occurs. The aim of this study is to evaluate the correlation between the thermal performance of building envelope designed under current regulations and a traditional one, having in mind the different thermal comfort range in the two countries. A sample building model is calculated in Scenario 1 - Japanese traditional building fabric, Scenario 2 - Bulgarian traditional building fabric and Scenario 3 - meeting the requirements of the more demanding current regulations. The energy modelling is conducted using EnergyPlus through OpenStudio cross-platform of software tools. The 3D geometry for the simulation is created using OpenStudio SketchUp Plug-in. Equal number of inhabitants, electricity consumption and natural ventilation is assumed. The results show that overall low energy consumption can be achieved using traditional building fabric as well, when paired with a wider thermal comfort range. Under these conditions traditional building design is still viable today. This knowledge can reestablish the use of traditional building fabric in contemporary design, stimulate preservation of local culture, building traditions and community identity.

Comparing Whole Building Energy Implications of Sidelighting Systems with Alternate Manual Blind Control Algorithms

Directory of Open Access Journals (Sweden)

Christopher Dyke

2015-05-01

Full Text Available Currently, there is no manual blind control guideline used consistently throughout the energy modeling community. This paper identifies and compares five manual blind control algorithms with unique control patterns and reports blind occlusion, rate of change data, and annual building energy consumption. The blind control schemes detailed here represent five reasonable candidates for use in lighting and energy simulation based on difference driving factors. This study was performed on a medium-sized office building using EnergyPlus with the internal daylight harvesting engine. Results show that applying manual blind control algorithms affects the total annual consumption of the building by as much as 12.5% and 11.5% for interior and exterior blinds respectively, compared to the Always Retracted blinds algorithm. Peak demand was also compared showing blind algorithms affected zone load sizing by as much as 9.8%. The alternate algorithms were tested for their impact on American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE Guideline 14 calibration metrics and all models were found to differ from the original calibrated baseline by more than the recommended ±15% for coefficient of variance of the mean square error (CVRMSE and ±5% for normalized mean bias error (NMBE. The paper recommends that energy modelers use one or more manual blind control algorithms during design stages when making decisions about energy efficiency and other design alternatives.

Comparative analysis of hourly and dynamic power balancing models for validating future energy scenarios

DEFF Research Database (Denmark)

Pillai, Jayakrishnan R.; Heussen, Kai; Østergaard, Poul Alberg

2011-01-01

Energy system analyses on the basis of fast and simple tools have proven particularly useful for interdisciplinary planning projects with frequent iterations and re-evaluation of alternative scenarios. As such, the tool “EnergyPLAN” is used for hourly balanced and spatially aggregate annual......, the model is verified on the basis of the existing energy mix on Bornholm as an islanded energy system. Future energy scenarios for the year 2030 are analysed to study a feasible technology mix for a higher share of wind power. Finally, the results of the hourly simulations are compared to dynamic frequency...... simulations incorporating the Vehicle-to-grid technology. The results indicate how the EnergyPLAN model may be improved in terms of intra-hour variability, stability and ancillary services to achieve a better reflection of energy and power capacity requirements....

A retrospective randomized study to compare the energy delivered using CDE with different techniques and OZil? settings by different surgeons in phacoemulsification

OpenAIRE

Chen, Ming; Sweeney, Henry W; Luke, Becky; Chen, Mindy; Brown, Mathew

2009-01-01

Ming Chen1, Henry W Sweeney2, Becky Luke3, Mindy Chen4, Mathew Brown51University of Hawaii, Honolulu, Hawaii, USA; 2Research Support Services, the Queens Medical Center, Honolulu, Hawaii, USA; 3Surgical Suite, Honolulu, Hawaii, USA; 4University of California, Irvine, CA, USA; 5University of California, San Diego, CA, USAAbstract: Cumulative dissipated energy (CDE) was used with Infiniti® Vision System (Alcon Labs) as an energy delivery guide to compare four different phaco techniques ...

A retrospective randomized study to compare the energy delivered using CDE with different techniques and OZil settings by different surgeons in phacoemulsification

OpenAIRE

Chen, Ming

2009-01-01

Ming Chen1, Henry W Sweeney2, Becky Luke3, Mindy Chen4, Mathew Brown51University of Hawaii, Honolulu, Hawaii, USA; 2Research Support Services, the Queens Medical Center, Honolulu, Hawaii, USA; 3Surgical Suite, Honolulu, Hawaii, USA; 4University of California, Irvine, CA, USA; 5University of California, San Diego, CA, USAAbstract: Cumulative dissipated energy (CDE) was used with Infiniti® Vision System (Alcon Labs) as an energy delivery guide to compare four different phaco techniques ...

Energy Provider: Delivered Energy Efficiency: A global stock-taking based on case studies

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-06-01

In 2011 the IEA and the Regulatory Assistance Project (RAP) took on a work programme focused on the role of energy providers in delivering energy efficiency to end-users. This work was part of the IEA’s contribution to the PEPDEE Task Group, which falls under the umbrella of the International Partnership on Energy Efficiency Cooperation (IPEEC). In addition to organizing regional dialogues between governments, regulators, and energy providers, the PEPDEE work stream conducted global stock-takings of regulatory mechanisms adopted by governments to obligate or encourage energy providers to delivery energy savings and the energy savings activities of energy providers. For its part the IEA conducted a global review of energy provider-delivered energy savings programmes. The IEA reached out to energy providers to identify the energy savings activities they engaged in. Some 250 energy saving activities were considered, and 41 detailed case studies spanning 18 countries were developed. Geographic balance was a major consideration, and much effort was expended identifying energy provider-delivered energy savings case studies from around the world. Taken together these case studies represent over USD 1 billion in annual spending, or about 8% of estimated energy provider spending on energy efficiency.

Emissions, energy return and economics from utilizing forest residues for thermal energy compared to onsite pile burning

Science.gov (United States)

Greg Jones; Dan Loeffler; Edward Butler; Woodam Chung; Susan Hummel

2010-01-01

The emissions from delivering and burning forest treatment residue biomass in a boiler for thermal energy were compared with onsite disposal by pile-burning and using fossil fuels for the equivalent energy. Using biomass for thermal energy reduced carbon dioxide emissions on average by 39 percent and particulate matter emissions by 89 percent for boilers with emission...

Energy Systems With Renewable Hydrogen Compared to Direct Use of Renewable Energy in Austria

International Nuclear Information System (INIS)

Gerfried Jungmeier; Kurt Konighofer; Josef Spitzer; R Haas; A Ajanovic

2006-01-01

The current Austrian energy system has a renewable energy share of 20% - 11% hydropower and 9 % biomass - of total primary energy consumption. Whereas a possible future introduction of renewable hydrogen must be seen in the context of current energy policies in Austria e.g. increase of energy efficiency and use of renewable energy, reduction of greenhouse gas emissions. The aim of the research project is a life cycle based comparison of energy systems with renewable hydrogen from hydropower, wind, photovoltaic and biomass compared to the direct use of renewable energy for combined heat and power applications and transportation services. In particular this paper focuses on the main question, if renewable energy should be used directly or indirectly via renewable hydrogen. The assessment is based on a life cycle approach to analyse the energy efficiency, the material demand, the greenhouse gas emissions and economic aspects e.g. energy costs and some qualitative aspects e.g. energy service. The overall comparison of the considered energy systems for transportation service and combined heat and electricity application shows, that renewable hydrogen might be beneficial mainly for transportation services, if the electric vehicle will not be further developed to a feasibly wide-spread application for transportation service in future. For combined heat and electricity production there is no advantage of renewable hydrogen versus the direct use of renewable energy. Conclusions for Austria are therefore: 1) renewable hydrogen is an interesting energy carrier and might play an important role in a future sustainable Austrian energy system; 2) renewable hydrogen applications look most promising in the transportation sector; 3) renewable hydrogen applications will be of low importance for combined heat and electricity applications, as existing technologies for direct use of renewable energy for heat and electricity are well developed and very efficient; 4) In a future '100

Comparing Life-Cycle Costs of ESPCs and Appropriations-Funded Energy Projects: An Update to the 2002 Report

International Nuclear Information System (INIS)

Shonder, John A.; Hughes, Patrick; Atkin, Erica

2006-01-01

A study was sponsored by FEMP in 2001 - 2002 to develop methods to compare life-cycle costs of federal energy conservation projects carried out through energy savings performance contracts (ESPCs) and projects that are directly funded by appropriations. The study described in this report follows up on the original work, taking advantage of new pricing data on equipment and on $500 million worth of Super ESPC projects awarded since the end of FY 2001. The methods developed to compare life-cycle costs of ESPCs and directly funded energy projects are based on the following tasks: (1) Verify the parity of equipment prices in ESPC vs. directly funded projects; (2) Develop a representative energy conservation project; (3) Determine representative cycle times for both ESPCs and appropriations-funded projects; (4) Model the representative energy project implemented through an ESPC and through appropriations funding; and (5) Calculate the life-cycle costs for each project.

TRANSIENT GALACTIC COSMIC-RAY MODULATION DURING SOLAR CYCLE 24: A COMPARATIVE STUDY OF TWO PROMINENT FORBUSH DECREASE EVENTS

International Nuclear Information System (INIS)

Zhao, L.-L.; Zhang, H.

2016-01-01

Forbush decrease (FD) events are of great interest for transient galactic cosmic-ray (GCR) modulation study. In this study, we perform comparative analysis of two prominent Forbush events during cycle 24, occurring on 2012 March 8 (Event 1) and 2015 June 22 (Event 2), utilizing the measurements from the worldwide neutron monitor (NM) network. Despite their comparable magnitudes, the two Forbush events are distinctly different in terms of evolving GCR energy spectrum and energy dependence of the recovery time. The recovery time of Event 1 is strongly dependent on the median energy, compared to the nearly constant recovery time of Event 2 over the studied energy range. Additionally, while the evolutions of the energy spectra during the two FD events exhibit similar variation patterns, the spectrum of Event 2 is significantly harder, especially at the time of deepest depression. These difference are essentially related to their associated solar wind disturbances. Event 1 is associated with a complicated shock-associated interplanetary coronal mass ejection (ICME) disturbance with large radial extent, probably formed by the merging of multiple shocks and transient flows, and which delivered a glancing blow to Earth. Conversely, Event 2 is accompanied by a relatively simple halo ICME with small radial extent that hit Earth more head-on.

TRANSIENT GALACTIC COSMIC-RAY MODULATION DURING SOLAR CYCLE 24: A COMPARATIVE STUDY OF TWO PROMINENT FORBUSH DECREASE EVENTS

Energy Technology Data Exchange (ETDEWEB)

Zhao, L.-L.; Zhang, H., E-mail: zhaolingling@ucas.edu.cn [Key Laboratory of Computational Geodynamics, University of Chinese Academy of Sciences, Beijing 100049 (China)

2016-08-10

Forbush decrease (FD) events are of great interest for transient galactic cosmic-ray (GCR) modulation study. In this study, we perform comparative analysis of two prominent Forbush events during cycle 24, occurring on 2012 March 8 (Event 1) and 2015 June 22 (Event 2), utilizing the measurements from the worldwide neutron monitor (NM) network. Despite their comparable magnitudes, the two Forbush events are distinctly different in terms of evolving GCR energy spectrum and energy dependence of the recovery time. The recovery time of Event 1 is strongly dependent on the median energy, compared to the nearly constant recovery time of Event 2 over the studied energy range. Additionally, while the evolutions of the energy spectra during the two FD events exhibit similar variation patterns, the spectrum of Event 2 is significantly harder, especially at the time of deepest depression. These difference are essentially related to their associated solar wind disturbances. Event 1 is associated with a complicated shock-associated interplanetary coronal mass ejection (ICME) disturbance with large radial extent, probably formed by the merging of multiple shocks and transient flows, and which delivered a glancing blow to Earth. Conversely, Event 2 is accompanied by a relatively simple halo ICME with small radial extent that hit Earth more head-on.

Sustainable energy provision: a comparative assessment of the various electricity supply options

International Nuclear Information System (INIS)

Voss, A.

2000-01-01

The provision of electricity is of central importance for economic growth and societal development. While numerous societal and economic benefits arise from the use of electricity, the production of electricity can also have negative impacts on the environment and the climate system. The commitment to sustainable development calls for the evaluation of the extent to which the different electricity supply options fulfill the sustainability criteria. The conceptual framework of Life Cycle Assessment (LCA) can provide a solid basis for a comparative assessment of different electricity supply options with regard to their environmental impacts, raw material requirements as well as their resulting external costs. Results of a comprehensive comparative assessment of nuclear energy and other electricity options are presented. (author)

The environmental impacts of production and use of energy. Part IV - The comparative assessment of the environmental impacts of energy sources. Phase I - Comparative data on the emissions, residuals and health hazards of energy sources. Report of the Executive Director

Energy Technology Data Exchange (ETDEWEB)

Tolba, Mostafa K [United Nations Environment Programme, Nairobi (Kenya)

1985-01-01

UNEP has undertaken a number of in-depth reviews of the environmental aspects of production and use of all sources of energy. Three major studies have so far been carried out. The first one, dealing with the environmental impacts of production, transport, processing and use of fossil fuels, was reviewed by an International Panel of Experts that met in Warsaw in April 1978. The second study, which deals with the environmental impacts of nuclear energy, was reviewed by an International Panel of Experts that met in Geneva in November 1978, and was revised at a second meeting held in Nairobi in April 1979. The third study, dealing with the environmental aspects of renewable sources of energy, was reviewed by an International Panel of Experts that met in Bangkok in January 1980. Preparations are already underway to update these three reports. This report was prepared by Dr. Yehia ElMahgary of the UNEP secretariat on the basis of papers prepared for, and discussed in, the course of UNEP's International Panel of Experts on the Comparative Assessment of the Environmental Impacts of Commercial Sources of Energy prepared for by Dr. Essam El-Hinnawi and held in Munich in November 1980, and information provided by participants after the meeting and collected by UNEP from other sources. In the course of the meeting it was realized that our knowledge was not sufficient on several issues, that many approaches existed for tackling the problem, and that it was difficult to agree on unique procedures to undertake the comparison. The draft version of this report was revised again at a second meeting held in December 1983 in New York and additional comments were collected. The Biomedical Laboratory Group of Brookhaven National Laboratory has assisted the UNEP secretariat to collect and update many figures in this cost-benefit analysis of the different sources from the bulk of the report and to treat it in a separate and more comprehensive study. The study is being undertaken by the

The environmental impacts of production and use of energy. Part IV - The comparative assessment of the environmental impacts of energy sources. Phase I - Comparative data on the emissions, residuals and health hazards of energy sources. Report of the Executive Director

International Nuclear Information System (INIS)

Tolba, Mostafa K.

1985-01-01

UNEP has undertaken a number of in-depth reviews of the environmental aspects of production and use of all sources of energy. Three major studies have so far been carried out. The first one, dealing with the environmental impacts of production, transport, processing and use of fossil fuels, was reviewed by an International Panel of Experts that met in Warsaw in April 1978. The second study, which deals with the environmental impacts of nuclear energy, was reviewed by an International Panel of Experts that met in Geneva in November 1978, and was revised at a second meeting held in Nairobi in April 1979. The third study, dealing with the environmental aspects of renewable sources of energy, was reviewed by an International Panel of Experts that met in Bangkok in January 1980. Preparations are already underway to update these three reports. This report was prepared by Dr. Yehia ElMahgary of the UNEP secretariat on the basis of papers prepared for, and discussed in, the course of UNEP's International Panel of Experts on the Comparative Assessment of the Environmental Impacts of Commercial Sources of Energy prepared for by Dr. Essam El-Hinnawi and held in Munich in November 1980, and information provided by participants after the meeting and collected by UNEP from other sources. In the course of the meeting it was realized that our knowledge was not sufficient on several issues, that many approaches existed for tackling the problem, and that it was difficult to agree on unique procedures to undertake the comparison. The draft version of this report was revised again at a second meeting held in December 1983 in New York and additional comments were collected. The Biomedical Laboratory Group of Brookhaven National Laboratory has assisted the UNEP secretariat to collect and update many figures in this cost-benefit analysis of the different sources from the bulk of the report and to treat it in a separate and more comprehensive study. The study is being undertaken by the

A comparative study on the energy policies in Japan and Malaysia in fulfilling their nations' obligations towards the Kyoto Protocol

International Nuclear Information System (INIS)

Lau, Lee Chung; Tan, Kok Tat; Lee, Keat Teong; Mohamed, Abdul Rahman

2009-01-01

Global warming and the associated changes in the world climate pattern have been accepted world wide as the gravest threat to humanity in the 20th century. To mitigate the impacts of global warming, the Kyoto Protocol was established in 1997 with the objective of reducing global greenhouse gases (GHGs) emission, in particular carbon dioxide (CO 2 ), by 5.2% below 1990 levels. Developed nations that ratified the Protocol are committed to GHG reduction targets while developing nations are encouraged to reduce GHG emissions on a voluntary basis. Since most of the GHGs emissions come from the energy sector, energy policy plays an important role in fulfilling the Kyoto Protocol obligations. This year marks the beginning of the commitment period for the 2012 Kyoto Protocol. In this case, it would be worthwhile to compare the energy policies in Malaysia and Japan as these nations move towards fulfilling their obligations towards the Kyoto Protocol; bearing in mind that both countries ratified the Protocol, but that Japan commits a reduction target of 6% while Malaysia bears no obligation. Based on the comparison, recommendations were made on how a developing nation like Malaysia could adopt the policies implemented in Japan to suit local conditions and contribute significantly to GHG reduction.

Validation of energy intake estimated from a food frequency questionnaire: a doubly labelled water study.

Science.gov (United States)

Andersen, L Frost; Tomten, H; Haggarty, P; Løvø, A; Hustvedt, B-E

2003-02-01

The validation of dietary assessment methods is critical in the evaluation of the relation between dietary intake and health. The aim of this study was to assess the validity of a food frequency questionnaire by comparing energy intake with energy expenditure measured with the doubly labelled water method. Total energy expenditure was measured with the doubly labelled water (DLW) method during a 10 day period. Furthermore, the subjects filled in the food frequency questionnaire about 18-35 days after the DLW phase of the study was completed. Twenty-one healthy, non-pregnant females volunteered to participate in the study; only 17 subjects completed the study. The group energy intake was on average 10% lower than the energy expenditure, but the difference was not statistically significant. However, there was a wide range in reporting accuracy: seven subjects were identified as acceptable reporters, eight as under-reporters and two were identified as over-reporters. The width of the 95% confidence limits of agreement in a Bland and Altman plot for energy intake and energy expenditure varied from -5 to 3 MJ. The data showed that there was substantial variability in the accuracy of the food frequency questionnaire at the individual level. Furthermore, the results showed that the questionnaire was more accurate for groups than individuals.

Analysis of energy efficiency and energy consumption costs: a case study for regional wastewater treatment plant in Malaysia

Directory of Open Access Journals (Sweden)

Nor Azuana Ramli

2017-03-01

Full Text Available The objective of this study is to analyze the possibilities of increasing energy efficiency in the central region wastewater treatment plant by focusing on two aspects: biogas production and prediction of energy production. The analysis is based on one of the biggest central region wastewater treatment plants in Malaysia. After studying the energy efficiency, which consists of optimization of energy consumption and enhancing gas generation, the prediction of power consumption is performed using an autoregressive integrated moving average (ARIMA model. The prediction results are compared with the linear regression method. Comparison shows that even though the total cost of savings is greater by using linear regression, the prediction through ARIMA is more accurate and has smaller root mean square error. The implementation of these two aspects managed to increase energy efficiency by 10% of energy recovery that could further reduce electricity cost and reduction of sludge cake disposal off site. The study recommends other aspects, such as modification in setting up the frequency of variable speed drive for aerators and blowers and optimizing number of feeds into train unit processes within aeration tanks in increasing energy efficiency.

A Comparative Density Functional Theory and Density Functional Tight Binding Study of Phases of Nitrogen Including a High Energy Density Material N8

Directory of Open Access Journals (Sweden)

Nicholas Capel

2015-11-01

Full Text Available We present a comparative dispersion-corrected Density Functional Theory (DFT and Density Functional Tight Binding (DFTB-D study of several phases of nitrogen, including the well-known alpha, beta, and gamma phases as well as recently discovered highly energetic phases: covalently bound cubic gauche (cg nitrogen and molecular (vdW-bound N8 crystals. Among several tested parametrizations of N–N interactions for DFTB, we identify only one that is suitable for modeling of all these phases. This work therefore establishes the applicability of DFTB-D to studies of phases, including highly metastable phases, of nitrogen, which will be of great use for modelling of dynamics of reactions involving these phases, which may not be practical with DFT due to large required space and time scales. We also derive a dispersion-corrected DFT (DFT-D setup (atom-centered basis parameters and Grimme dispersion parameters tuned for accurate description simultaneously of several nitrogen allotropes including covalently and vdW-bound crystals and including high-energy phases.

Comparative assessment of energy options and strategies in Mexico until 2025. Final report of a coordinated research project 2000-2004

International Nuclear Information System (INIS)

2005-10-01

Mexico is undergoing significant changes in the energy sector, in particular in the electric power sector, such as the restructuring of power markets; increasing emphasis on socioeconomic and environmental impacts of the electric power system; and consideration of an higher role for energy technologies compatible with sustainable development. The Mexican Government has identified the need for ensuring a sustainable pattern of production, distribution and use of energy and electricity. In this context, a comparative assessment analysis is a prerequisite for planning of the future energy and electricity facilities of the country in order to make timely decisions. It requires the identification of the expected levels of energy and electricity demand and the options that are available to meet these demands, taking special note of the national energy resources and potential imported sources. Further analysis would be needed for the optimization of the supply options to meet the demand in the most efficient and economic manner with due consideration of the environmental impacts and resource requirements. In accordance with its mandate, the IAEA has developed a systematic approach along with a set of computer-based models for elaborating national energy strategies covering the analysis of all of the above aspects. Under its Technical Cooperation Programme, the IAEA provides assistance to its Member States to enhance national capabilities for elaborating sustainable energy development strategies and assessing the role of nuclear power and other energy options, by transferring the analytical tools along with training and providing expertise. The present report describes the results of the Comparative Assessment of Energy Options and Strategies until 2025 study for Mexico conducted by the Secretaria de Energia, in cooperation with several national institutions, in particular the University of Mexico. The comprehensive national analysis focuses on energy and electricity

Energy expenditure in people with transtibial amputation walking with crossover and energy storing prosthetic feet: A randomized within-subject study.

Science.gov (United States)

McDonald, Cody L; Kramer, Patricia A; Morgan, Sara J; Halsne, Elizabeth G; Cheever, Sarah M; Hafner, Brian J

2018-05-01

Energy storing feet are unable to reduce the energy required for normal locomotion among people with transtibial amputation. Crossover feet, which incorporate aspects of energy storing and running specific feet, are designed to maximize energy return while providing stability for everyday activities. Do crossover prosthetic feet reduce the energy expenditure of walking across a range of speeds, when compared with energy storing feet among people with transtibial amputation due to non-dysvascular causes? A randomized within-subject study was conducted with a volunteer sample of twenty-seven adults with unilateral transtibial amputation due to non-dysvascular causes. Participants were fit with two prostheses. One had an energy storing foot (Össur Variflex) and the other a crossover foot (Össur Cheetah Xplore). Other components, including sockets, suspension, and interface were standardized. Energy expenditure was measured with a portable respirometer (Cosmed K4b2) while participants walked on a treadmill at self-selected slow, comfortable, and fast speeds with each prosthesis. Gross oxygen consumption rates (VO 2  ml/min) were compared between foot conditions. Energy storing feet were used as the baseline condition because they are used by most people with a lower limb prosthesis. Analyses were performed to identify people who may benefit from transition to crossover feet. On average, participants had lower oxygen consumption in the crossover foot condition compared to the energy storing foot condition at each self-selected walking speed, but this difference was not statistically significant. Participants with farther six-minute walk test distances, higher daily step counts, and higher Medicare Functional Classification Levels at baseline were more likely to use less energy in the crossover foot. Crossover feet may be most beneficial for people with higher activity levels and physical fitness. Further research is needed to examine the effect of crossover feet on

System analysis of energy utilization from waste - evaluation of energy, environment and economy. Case study - Uppsala

International Nuclear Information System (INIS)

Sundqvist, Jan-Olov; Granath, Jessica; Frostell, Bjoern; Bjoerklund, Anna; Eriksson, Ola; Carlsson, Marcus

1999-12-01

Energy, environmental, and economic consequences of different management systems for municipal solid waste have been studied in a systems analysis. In the systems analysis, different combinations of incineration, materials recycling of separated plastic and cardboard containers, and biological treatment (anaerobic digestion and composting) of easily degradable organic waste, were studied and also compared to landfilling. In the study a computer model (ORWARE) based on LCA methodology was used. The following parameters were used for evaluating the different waste management options: consumption of energy resources, global warming potential, acidification, eutrophication, photo oxidant formation, heavy metal flows, financial economy and welfare economy, where welfare economy is the sum of financial economy and environmental economy. The study shows that reduced landfilling to the benefit of an increased use of energy and material from waste is positive from an environmental and energy as well as economic aspect. This is mainly due to the fact that the choice of waste management method affects processes outside the waste management system, such as production of district heating, electricity, vehicle fuel, plastic, cardboard, and fertiliser. This means that landfilling of energy-rich waste should be avoided as far as possible, both because of the the environmental impact, and because of the low recovery of resources. Incineration should constitute a basis in the waste management system of Uppsala. Once the waste is collected, longer regional transports are of little significance, as long as the transports are carried out in an efficient manner. Comparing materials recycling and incineration, and biological treatment and incineration, no unambiguous conclusions can be drawn. There are benefits and drawbacks associated with all these waste management options. Materials recycling of plastic containers is comparable to incineration from a welfare economic aspect, but gives

Comparative Studies of Traditional (Non-Energy Integration and Energy Integration of Catalytic Reforming Unit using Pinch Analysis

Directory of Open Access Journals (Sweden)

M. Alta

2012-12-01

Full Text Available Energy Integration of Catalytic Reforming Unit (CRU of Kaduna Refinery and petrochemicals Company Kaduna Nigeria was carried out using Pinch Technology. The pinch analysis was carried out using Maple. Optimum minimum approach temperature of 20 °C was used to determine the energy target. The pinch point temperature was found to be 278 °C. The utilities targets for the minimum approach temperature were found to be 72711839.47 kJ/hr and 87105834.43 kJ/hr for hot and cold utilities respectively. Pinch analysis as an energy integration technique was found to save more energy and utilities cost than the traditional energy technique. Key words: Pinch point, CRU, Energy Target, Maple

Dosimetry study comparing NCS report-2 versus IAEA TRS-398 protocol for high energy photon beams

International Nuclear Information System (INIS)

Attalaa, E.M.; Khaled, N.E.; Abou Elenein, H.S.; Elsayed, A.A.

2005-01-01

In this work a dosimetry study is presented in which the results of absorbed dose determined at reference condition according to the IAEA TRS-398 protocol and the NCS report-2 are compared. The IAEA TRS-398 protocol for absorbed dose calibration is based on ionization chamber having absorbed dose to water calibration factor N d w, while the NCS-2 dosimetry report for absorbed dose calibration is based on an ionization chamber having air- kerma calibration factor N k . This study shows that the absorbed dose which is calculated with The IAEA TRS-398 formalisms is higher than that calculated with NCS report-2 formalisms within range from 0.4 to 0.9% in cobalt-60 beam as sensed by different ionization chambers, and from 0.2 to 1.1% for different higher energy photon beams of 6, 8 and 18 MV. The chambers used are PTW 30001, 30004, and NE-2571; which have calibration factors N k and N d w traceable to the BIPM (Bureau International des Poids et Mesures)

Mass attenuation coefficient (μ/ρ), effective atomic number (Z{sub eff}) and measurement of x-ray energy spectra using based calcium phosphate biomaterials: a comparative study

Energy Technology Data Exchange (ETDEWEB)

Fernandes Z, M. A.; Da Silva, T. A.; Nogueira, M. S. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Pte. Antonio Carlos 6627, Belo Horizonte 31270-901, Minas Gerais (Brazil); Goncalves Z, E., E-mail: madelon@cdtn.br [Pontifice Catholic University of Minas Gerais, Av. Dom Jose Gaspar 500, Belo Horizonte 30535-901, Minas Gerais (Brazil)

2015-10-15

In dentistry, alveolar bone regeneration procedures using based calcium phosphate biomaterials have been shown effective. However,there are not reports in the literature of studies the interaction of low energy radiation in these biomaterials used as attenuator and not being then allowed a comparison between the theoretical values and experimental.The objective of this study was to determine the interaction of radiation parameters of four dental biomaterials - BioOss, Cerasorb M Dental, Straumann Boneceramic and Osteogen for diagnostic radiology qualities. As a material and methods, the composition of the biomaterials was determined by the analytical techniques. The samples with 0.181 cm to 0,297 cm thickness were experimentally used as attenuators for the measurement of the transmitted X-rays spectra in X-ray equipment with 50 to 90 kV range by spectrometric system comprising the Cd Te detector. After this procedure, the mass attenuation coefficient, the effective atomic number were determined and compared between all the specimens analyzed, using the program WinXCOM in the range of 10 to 200 keV. In all strains examined observed that the energy spectrum of x-rays transmitted through the BioOss has the mean energy slightly smaller than the others biomaterials for close thickness. The μ/ρ and Z{sub eff} of the biomaterials showed its dependence on photon energy and atomic number of the elements of the material analyzed. It is concluded according to the methodology employed in this study that the measurements of x-ray spectrum, μ/ρ and Z{sub eff} using biomaterials as attenuators confirmed that the thickness, density, composition of the samples, the incident photon energy are factors that determine the characteristics of radiation in a tissue or equivalent material. (Author)

Biofuel: A Comparative Case Study

Science.gov (United States)

2013-06-01

encouraging the use of renewable energy. Congress defines renewable energy as energy coming from biomass, geothermal , wind, solar, and hydropower...day, and non-OECD countries, led by China , experienced a surge in use of 1.2 million barrels per day (BP, 2012). Figure 6 illustrates the world oil...America is driven by the monies from petroleum sales (CFR, 2006). Countries such as China constrain the United States’ ability to form partnerships to

A comparative study on the edge states in phosphorene quantum dots and rings

Energy Technology Data Exchange (ETDEWEB)

Jiang, Z.T., E-mail: jiangzhaotan@bit.edu.cn; Liang, F.X.; Zhang, X.D.

2017-01-30

Using the tight-binding Hamiltonian approach, we comparatively investigate the energy spectrums of triangular zigzag phosphorene quantum dots (PQDs) and rings (PQRs), as well as their potential applications. In comparison with the outer edge states in the PQD, new extra inner edge states can be produced in the PQR by its internal hole. A transition from the uncoupled to coupled edge states can be induced by decreasing the width between the outer and inner edges of the PQR. Also, the edge states in PQD/PQR are all anisotropically localized in one side, rather than three sides as in triangular graphene quantum dots (QDs) and rings (QRs). Furthermore, the PQD/PQR energy levels can be anisotropically manipulated by the external electric fields and strains, clearly demonstrating their potential applications in field effect transistors or electromechanical devices. In the meanwhile, we also consider the electron probability distributions corresponding to the different energy levels, clearly exposing the characteristics of the PQD/PQR energy levels. The comparison between the asymmetrical triangular PQDs/PQRs and the symmetrical triangular QDs/QRs in graphene should be instructive for understanding the similar triangular QDs/QRs in other two-dimensional layered materials, as well as other types of QDs/QRs of different shapes. - Highlights: • We make a comparative study on the energy levels of the phosphorene quantum dots and rings. • The energy levels can be anisotropically controlled by the electric field and the strains, different from those in graphene counterparts. • The edge states in phosphorene triangular quantum dot and rings are anisotropic. • A helpful reference for understanding phosphorene nanostructures of other shapes and designing devices.

A study on electric bicycle energy efficiency

Directory of Open Access Journals (Sweden)

Ivan EVTIMOV

2015-09-01

Full Text Available The paper presents a construction of an experimental electric bicycle for evaluation of the energy efficiency. The bicycle is equipped with onboard computer which can store the information about motion and energy consumption. The result concerning power, energy consumption, recharging during brake process, etc. are given. Energy consumption for 3 typical city routes is studied.

Local acceptance of renewable energy-A case study from southeast Germany

International Nuclear Information System (INIS)

Musall, Fabian David; Kuik, Onno

2011-01-01

The European 20-20-20 goals, as well as national targets for the next decade, require a substantial increase in installed renewable capacity in Germany. While public support for such measures is high on an abstract level, the situation in the local context is often very different. Here, the impact of renewable energy might cause resistance. Empirical research shows that a community ownership model can have a positive effect on local acceptance. Our study explores whether such an effect can also be demonstrated in a community co-ownership model. The question is relevant since larger projects exceed the financial possibilities of most communities, leaving them with only co-ownership as an option. The research design is based on a comparative case study, utilizing a questionnaire-based survey. The results of the survey clearly show that a significant difference in local acceptance exists between the two cases. The residents of Zschadrass, where a community co-ownership model exists, are consistently more positive towards local renewable energy and also towards renewable energy in general. The results provide evidence that the co-ownership model is a means to reconcile local acceptance with an increased use of renewable energy in Germany. - Highlights: → We study if community co-ownership affects local acceptance of renewable energy → We interviewed residents from two villages with different ownership models → Residents with co-ownership are consistently more positive towards renewable energy → Local acceptance is higher with co-ownership than with a private ownership model.

System analysis of energy utilization from waste - evaluation of energy, environment and economy. Case study - Aelvdalen

International Nuclear Information System (INIS)

Sundqvist, Jan-Olov; Granath, Jessica; Frostell, Bjoern; Bjoerklund, Anna; Eriksson, Ola; Carlsson, Marcus

1999-12-01

Energy, environmental, and economic consequences of different management systems for municipal solid waste have been studied in a systems analysis. In the systems analysis, different combinations of incineration, materials recycling of separated plastic and cardboard containers, and biological treatment (anaerobic digestion and composting) of easily degradable organic waste, were studied and also compared to landfilling. In the study a computer model (ORWARE) based on LCA methodology was used. The following parameters were used for evaluating the different waste management options: consumption of energy resources, global warming potential, acidification, eutrophication, photo oxidant formation, heavy metal flows, financial economy and welfare economy, where welfare economy is the sum of financial economy and environmental economy. The study shows that reduced landfilling to the benefit of an increased use of energy and material from waste is positive from an environmental and energy as well as economic aspect. This is mainly due to the fact that the choice of waste management method affects processes outside the waste management system, such as production of district heating, vehicle fuel, plastic, cardboard, and fertiliser. This means that landfilling of energy-rich waste should be avoided as far as possible, both because of the the environmental impact, and because of the low recovery of resources. Incineration should constitute a basis in the waste management system of Aelvdalen, even if the waste has to be transported to a regional facility. Once the waste is collected, longer regional transports are of little significance, as long as the transports are carried out in an efficient manner. Comparing materials recycling and incineration, and biological treatment and incineration, no unambiguous conclusions can be drawn. There are benefits and drawbacks associated with all these waste management options. Materials recycling of plastic containers is comparable to

A comparative evaluation of energy storage systems for a fuel cell vehicle. Paper no. IGEC-1-142

International Nuclear Information System (INIS)

Marshall, J.; Kazerani, M.

2005-01-01

The widespread operation of internal combustion engine (ICE) vehicles has today become a great cause for concern due to the uncertainty of fossil fuel reserves, energy security issues, and numerous adverse environmental effects. Alternatives such as fuel cell vehicles, electric vehicles, hybrid vehicles, and biodiesel vehicles provide the possibility to ease some or all of these concerns. The fuel cell vehicle, however, offers an excellent combination of reducing ICE vehicle problems while maintaining the performance, driving range, and convenience that consumers require. This paper documents a comparative evaluation of an extremely important facet of the fuel cell vehicle: the energy storage system (ESS). Batteries and ultracapacitors, the two most common choices for an ESS, are compared qualitatively to illustrate the advantages and disadvantages of each. Also, a quantitative comparison is made to choose the best technology for a small fuel cell-powered SUV having the design objectives of high performance and high efficiency. Practical issues such as availability and cost are also considered. The results of the analysis indicate that a battery ESS provides the best combination of efficiency, performance, and cost for a present-day fuel cell vehicle design. Yet, if the anticipated cost reductions and improvements in the energy storage capabilities of ultracapacitors do occur, ultracapacitors will become a very strong contender for energy storage solutions of future fuel cell vehicles. (author)

Transfer and partitioning of energy and mass through seafloor hydrothermal systems: comparative studies at the Ridge2000 Integrated Study Sites (ISS) (Invited)

Science.gov (United States)

Tivey, M. K.

2010-12-01

Seafloor hydrothermal systems are major players in the transfer of mass and energy from the mantle and crust to the ocean and biosphere. Over the past thirty years, much has been learned about this transfer to the ocean, but considerably less is known about the transfer to the biosphere. Study of hydrothermal systems in a diverse range of geologic settings has shown relationships between spreading rate and hydrothermal heat flux, substrate composition (including rock geochemistry, presence/absence of sediment) and hydrothermal fluid composition, and magmatic/tectonic events and temporal variability of fluid composition (e.g., German and Von Damm, Treatise On Geochemistry, 2004; Baker et al. AGU Monograph Series 91, 1995). Studies in arc and back-arc settings are documenting the effects of magmatic acid volatiles on fluid-rock reaction and fluid and vent deposit compositions (e.g., Ishibashi and Urabe, Backarc Basins: Tectonics and Magmatism, 1995). These comparative studies in a wide range of geologic settings, including at the three Ridge2000 ISS, have provided a fairly good understanding of the flux of heat and many elements to the ocean associated with high temperature seafloor hydrothermal systems. Considerably less is known, however, about the partitioning of heat and mass (particularly metals and sulfur) in hydrothermal systems. The deposits that form at vent sites are intimately linked within paths of energy and mass transport from the mantle and crust to the oceans. Transport differs greatly through different types of deposits (e.g., black smokers, white smokers/diffusers, flanges). Estimates of heat flux from measured temperatures of flow (unless integrated over and around an entire vent field) require an understanding of the partitioning of flow between focused black smokers and more diffuse flow from diffusers, flanges, and surfaces of deposits, and from the igneous substrate. Estimates of mass flux into the ocean require an understanding of the

Comparative study of various methods of primary energy estimation in nucleon-nucleon interactions

International Nuclear Information System (INIS)

Goyal, D.P.; Yugindro Singh, K.; Singh, S.

1986-01-01

The various available methods for the estimation of primary energy in nucleon-nucleon interactions have been examined by using the experimental data on angular distributions of shower particles from p-N interactions at two accelerator energies, 67 and 400 GeV. Three different groups of shower particle multiplicities have been considered for interactions at both energies. It is found that the different methods give quite different estimates of primary energy. Moreover, each method is found to give different values of energy according to the choice of multiplicity groups. It is concluded that the E ch method is relatively the better method among all the methods available, and that within this method, the consideration of the group of small multiplicities gives a much better result. The method also yields plausible estimates of inelasticity in high energy nucleon-nucleon interactions. (orig.)

Potential impacts of energy efficiency policies in the U.S. industry: Results from the clean energy futures study

International Nuclear Information System (INIS)

Worrell, Ernst; Price, Lynn

2001-01-01

Scenarios for a Clean Energy Future (CEF) studied the role that efficient clean energy technologies can play in meeting the economic and environmental challenges for our future energy supply. The study describes a portfolio of policies that would motivate energy users and businesses to invest in innovative energy efficient technologies. On the basis of the portfolios, two policy scenarios have been developed, i.e. a moderate scenario and an advanced scenario. We focus on the industrial part of the CEF-study. The studied policies include a wide scope of activities, which are organized under the umbrella of voluntary industrial sector agreements. The policies for the policy scenarios have been modeled using the National Energy Modeling System (CEF-NEMS). Under the reference scenario industrial energy use would grow to 41 Quads in 2020, compared to 34.8 Quads in 1997, with an average improvement of the energy intensity by 1.1% per year. In the Moderate scenario the annual improvement is a bout 1.5%/year, leading to primary energy use of 37.8 Quads in 2020, resulting in 10% lower CO2 emissions by 2020 compared to the reference scenario. In the Advanced scenario the annual improvement increases to 1.8% per year, leading to primary energy use of 34.3 Quads in 2020, and 29% lower CO2 emissions. We report on the policies, assumptions and results for industry

A US-China Interview Study: Biology Students' Argumentation and Explanation about Energy Consumption Issues

Science.gov (United States)

Jin, Hui; Hokayem, Hayat; Wang, Sasha; Wei, Xin

2016-01-01

As China and the United States become the top two carbon emitters in the world, it is crucial for citizens in both countries to construct a sophisticated understanding of energy consumption issues. This interview study examines how U.S. and Chinese students compare in explaining and arguing about two critical energy consumption issues: burning…

A brief comparative study of the wind and nuclear energy; Um breve estudo comparativo entre as energias eolica e nuclear

Energy Technology Data Exchange (ETDEWEB)

Flores, Tarcisio Santos [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil). Inst. de Ciencia e Tecnologia

2015-07-01

It is apparent the human need to use electricity in the current globalized world. And along with the social and industrial and beyond the everyday comfort evolution came the abuse of power. Aware that Brazil is used as an energy source originating from hydroelectric and that it does not include all domestic demand, should be studied energy sources that can assist it. Two clean and cheap energy alternatives which can contribute to reducing the environmental impacts such as global warming and water shortages are wind and nuclear energy. Which again, exhibit ideal characteristics to serve as alternative sources for electricity production, mainly in the dry season. (author)

A comparative multi-disciplinary policy review in wind energy developments in Europe

Science.gov (United States)

Mytilinou, V.; Kolios, A. J.; Di Lorenzo, G.

2017-09-01

Over recent decades, European Union countries have committed to increasing their electricity production from renewable energy sources (RESs). Wind energy plays a significant role in a sustainable future. This paper presents a political, economic, social, technological, legal and environmental analysis. Although these countries have made many improvements in their legal frameworks aiming to attract investors and boost the RE sector, there are still challenges. The UK focuses on offshore wind energy, adjusts the economic strategy and changes the legislation context. Germany has the healthiest economic conditions, as it keeps following its initiative to design a new programme for an energy transition from conventional to RESs with emphasis on the onshore. Greece has only a few installations and much room for development but needs to make further changes in the legislation and economy so as to attract more investors in the long term. The purpose of this research is to analyse, highlight and discuss vital aspects of these countries as well as the European environment, with reference to their current wind energy activities. Ultimately, it attempts to give a wider perspective and to serve as a guide for future studies on the wind energy sector.

System analysis of energy utilization from waste - evaluation of energy, environment and economy. Case study - Stockholm

International Nuclear Information System (INIS)

Sundqvist, Jan-Olov; Granath, Jessica; Frostell, Bjoern; Bjoerklund, Anna; Eriksson, Ola; Carlsson, Marcus

1999-12-01

Energy, environmental, and economic consequences of different management systems for municipal solid waste have been studied in a systems analysis. In the systems analysis, different combinations of incineration, materials recycling of separated plastic and cardboard containers, and biological treatment (anaerobic digestion) of easily degradable organic waste, were studied and also compared to landfilling. In the study a computer model (ORWARE) based on LCA methodology was used. The following parameters were used for evaluating the different waste management options: consumption of energy resources, global warming potential, acidification, eutrophication, photo oxidant formation, heavy metal flows, financial economy and welfare economy, where welfare economy is the sum of financial economy and environmental economy. The study shows that reduced landfilling to the benefit of an increased use of energy and material from the waste is positive, from an environmental and energy as well as economic aspect. This is mainly due to the fact that the choice of waste management method affects processes outside the waste management system, such as production of district heating, electricity, vehicle fuel, plastic, cardboard, and fertiliser. This means that landfilling of energy-rich waste should be avoided as far as possible, both because of the the environmental impact, and because of the low recovery of resources. Incineration should constitute a basis in the waste management system of Stockholm. Once the waste is collected, longer regional transports are of little significance, as long as the transports are carried out in an efficient manner. Comparing materials recycling and incineration, and biological treatment and incineration, no unambiguous conclusions can be drawn. There are benefits and drawbacks associated with all these waste management options. Materials recycling of plastic containers is comparable to incineration from a welfare economic aspect, but gives less

An Energy-Based Control Strategy for Battery Energy Storage Systems: A Case Study on Microgrid Applications

Directory of Open Access Journals (Sweden)

Rui Hou

2017-02-01

Full Text Available Battery energy storage systems (BESSs with proportional-integral (PI control methods have been widely studied in microgrids (MGs. However, the performance of PI control methods might be unsatisfactory for BESSs due to the nonlinear characteristics of the system. To overcome this problem, an energy-based (EB control method is applied to control the converter of a BESS in this study. The EB method is a robust nonlinear control method based on passivity theory with good performance in both transient and steady states. The detailed design process of the EB method in the BESS by adopting an interconnection and damping assignment (IDA strategy is described. The design process comprises three steps: the construction of the port-controlled Hamiltonian model, the determination of the equilibrium point and the solution of the undetermined matrix. In addition, integral action is combined to eliminate the steady state error generated by the model mismatch. To establish the correctness and validity of the proposed method, we implement several case simulation studies based on a test MG system and compare the control performance of the EB and PI methods carefully. The case simulation results demonstrate that the EB method has better tracking and anti-disturbance performance compared with the classic PI method. Moreover, the proposed EB method shows stronger robustness to the uncertainty of system parameters.

Comparing energy storage options for renewable energy integration

DEFF Research Database (Denmark)

Østergaard, Poul Alberg

-inclusive 100% renewable energy scenario developed for the Danish city Aalborg based on wind power, bio-resources and low-temperature geothermal heat. The paper investigates the system impact of different types of energy storage systems including district heating storage, biogas storage and electricity storage......Increasing penetrations of fluctuating energy sources for electricity generation, heating, cooling and transportation increase the need for flexibility of the energy system to accommodate the fluctuations of these energy sources. Controlling production, controlling demand and utilizing storage...... options are the three general categories of measures that may be applied for ensuring balance between production and demand, however with fluctuating energy sources, options are limited, and flexible demand has also demonstrated limited perspective. This paper takes its point of departure in an all...

Using data-driven approach for wind power prediction: A comparative study

International Nuclear Information System (INIS)

Taslimi Renani, Ehsan; Elias, Mohamad Fathi Mohamad; Rahim, Nasrudin Abd.

2016-01-01

Highlights: • Double exponential smoothing is the most accurate model in wind speed prediction. • A two-stage feature selection method is proposed to select most important inputs. • Direct prediction illustrates better accuracy than indirect prediction. • Adaptive neuro fuzzy inference system outperforms data mining algorithms. • Random forest performs the worst compared to other data mining algorithm. - Abstract: Although wind energy is intermittent and stochastic in nature, it is increasingly important in the power generation due to its sustainability and pollution-free. Increased utilization of wind energy sources calls for more robust and efficient prediction models to mitigate uncertainties associated with wind power. This research compares two different approaches in wind power forecasting which are indirect and direct prediction methods. In indirect method, several times series are applied to forecast the wind speed, whereas the logistic function with five parameters is then used to forecast the wind power. In this study, backtracking search algorithm with novel crossover and mutation operators is employed to find the best parameters of five-parameter logistic function. A new feature selection technique, combining the mutual information and neural network is proposed in this paper to extract the most informative features with a maximum relevancy and minimum redundancy. From the comparative study, the results demonstrate that, in the direct prediction approach where the historical weather data are used to predict the wind power generation directly, adaptive neuro fuzzy inference system outperforms five data mining algorithms namely, random forest, M5Rules, k-nearest neighbor, support vector machine and multilayer perceptron. Moreover, it is also found that the mean absolute percentage error of the direct prediction method using adaptive neuro fuzzy inference system is 1.47% which is approximately less than half of the error obtained with the

Methods and models used in comparative risk studies

International Nuclear Information System (INIS)

Devooght, J.

1983-01-01

Comparative risk studies make use of a large number of methods and models based upon a set of assumptions incompletely formulated or of value judgements. Owing to the multidimensionality of risks and benefits, the economic and social context may notably influence the final result. Five classes of models are briefly reviewed: accounting of fluxes of effluents, radiation and energy; transport models and health effects; systems reliability and bayesian analysis; economic analysis of reliability and cost-risk-benefit analysis; decision theory in presence of uncertainty and multiple objectives. Purpose and prospect of comparative studies are assessed in view of probable diminishing returns for large generic comparisons [fr

Energy structure, marginal efficiency and substitution rate: An empirical study of China

International Nuclear Information System (INIS)

Han Zhiyong; Fan Ying; Jiao Jianling; Yan Jisheng; Wei Yiming

2007-01-01

Energy efficiency is an important factor in developing energy policies as it represents the extent to which resources support economic output. In recent literature, relevant studies have mainly focused on aggregate energy efficiency, but rarely touched on the marginal efficiency of diverse energy resources and their comparative substitution rate. During 1978-2003, China's energy efficiency continually increased; and consequently became a hot topic in contemporary literature. However, there is no empirical study on the relationship between energy structure and energy efficiency. In order to close the gap, this paper reports the empirical study of the impact of China's energy structure on its energy efficiency from 1978 to 2003. The work covered primary estimation of the marginal efficiency of coal and petroleum in China, as well as the comparative substitution rate. Results indicate that the substitution rate between petroleum and coal is a factor of 5.38

Risk indices in comparative risk assessment studies

International Nuclear Information System (INIS)

Hubert, P.

1984-01-01

More than a decade ago the development of comparative risk assessment studies aroused overwhelming interest. There was no doubt that data on the health and safety aspects of energy systems would greatly benefit, or even end, the debate on nuclear energy. Although such attempts are still strongly supported, the rose-coloured expectations of the early days have faded. The high uncertainties, and the contradictory aspect, of the first results might explain this evolution. The loose connection between the range of computed risk indices and the questions on which the debate was focused is another reason for this decline in interest. Important research work is being carried out aiming at reducing the different kinds of uncertainties. Rather than the uncertainties, the paper considers the meaning of available risk indices and proposes more significant indices with respect to the goals of risk assessment. First, the indices which are of frequent use in comparative studies are listed. The stress is put on a French comparative study from which most examples are drawn. Secondly, the increase in magnitude of the indices and the decrease in the attributability of the risk to a given system is shown to be a consequence of the trend towards more comprehensive analyses. Thirdly, the ambiguity of such indices as the collective occupational risk is underlined, and a possible solution is suggested. Whenever risk assessments are related to pragmatic decision making problems it is possible to find satisfactory risk indices. The development of cost-effectiveness analyses and the proposals for quantitative safety goals clearly demonstrate this point. In the field of comparison of social impacts some proposals are made, but there remain some gaps still to be filled. (author)

A benchmark study of electronic excitation energies, transition moments, and excited-state energy gradients on the nicotine molecule

Energy Technology Data Exchange (ETDEWEB)

Egidi, Franco, E-mail: franco.egidi@sns.it; Segado, Mireia; Barone, Vincenzo, E-mail: vincenzo.barone@sns.it [Scuola Normale Superiore, Piazza dei Cavalieri, 7 I-56126 Pisa (Italy); Koch, Henrik [Department of Chemistry, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Cappelli, Chiara [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via G. Moruzzi, 3 I-56124 Pisa (Italy)

2014-12-14

In this work, we report a comparative study of computed excitation energies, oscillator strengths, and excited-state energy gradients of (S)-nicotine, chosen as a test case, using multireference methods, coupled cluster singles and doubles, and methods based on time-dependent density functional theory. This system was chosen because its apparent simplicity hides a complex electronic structure, as several different types of valence excitations are possible, including n-π{sup *}, π-π{sup *}, and charge-transfer states, and in order to simulate its spectrum it is necessary to describe all of them consistently well by the chosen method.

Numerical study on design for wave energy generation of a floater for energy absorption

International Nuclear Information System (INIS)

Li, Kui Ming; Parthasarathy, Nanjundan; Choi, Yoon Hwan; Lee, Yeon Won

2012-01-01

In order to design a wave energy generating system of a floater type, a 6 DOF motion technique was applied to the three Dimensional CFD analysis on a floating body and the behavior was interpreted according to the nature of the incoming waves. Waves in a tank model were generated using a single floater comparing with that of a Pelamis wave energy converter. In this paper, we focus on four variables, namely the wave height, angular velocity, diameter and length of the floater. The process was carried out in three stages and it was found that there are energy absorption differences in different parameters of wave height, length and the diameter of a floater during simulation, thus leading for the necessity of an optimal design for wave energy generation

Observing Protein & Energy Nutrition (OPEN) Study

Science.gov (United States)

The Observing Protein and Energy Nutrition (OPEN) Study was designed to assess dietary measurement error by comparing results from self-reported dietary intake data with four dietary biomarkers: doubly labeled water and urinary nitrogen, sodium, and potassium.

A comparative study on energy use and cost analysis of potato production under different farming technologies in Hamadan province of Iran

Energy Technology Data Exchange (ETDEWEB)

Zangeneh, Morteza; Omid, Mahmoud; Akram, Asadollah [Department of Agricultural Machinery Engineering, Faculty of Agricultural Engineering and Technology, School of Agriculture and Natural Resources, University of Tehran, Karaj (Iran)

2010-07-15

The aim of this study was to determine the amount of input-output energy used in potato production and to make an economic analysis of potato production in Hamadan province, Iran. Data for the production of potatoes were collected from 100 producers by using a face to face questionnaire method. The population investigated was divided into two groups. Group I was consisted of 68 farmers (owner of machinery and high level of farming technology) and Group II of 32 farmers (non-owner of machinery and low level of farming technology). The results revealed that 153071.40 MJ ha{sup -1} energy consumed by Group I and 157151.12 MJ ha{sup -1} energy consumed by Group II. The energy ratio, energy productivity, specific energy, net energy gain and energy intensiveness were calculated. The net energy of potato production in Group I and Group II was 4110.95 MJ ha{sup -1} and -21744.67 MJ ha{sup -1}, respectively. Cost analysis showed that total cost of potato production in Groups I and II were 4784.68 and 4172.64 $ ha{sup -1}, respectively. The corresponding, benefit to cost ratio from potato production in the surveyed groups were 1.09 and 0.96, respectively. It was concluded that extension activities are needed to improve the efficiency of energy consumption in potato production. (author)

Comparing projections of industrial energy demand and greenhouse gas emissions in long-term energy models

NARCIS (Netherlands)

Edelenbosch, O. Y.|info:eu-repo/dai/nl/412493373; Kermeli, K.|info:eu-repo/dai/nl/411260553; Crijns-Graus, W.|info:eu-repo/dai/nl/308005015; Worrell, E.|info:eu-repo/dai/nl/106856715; Bibas, R.; Fais, B.; Fujimori, S.; Kyle, P.; Sano, F.; van Vuuren, Detlef|info:eu-repo/dai/nl/11522016X

2017-01-01

The industry sector is a major energy consumer and GHG emitter. Effective climate change mitigation strategies will require a significant reduction of industrial emissions. To better understand the variations in the projected industrial pathways for both baseline and mitigation scenarios, we compare

Energy Profit Ratio Compared

International Nuclear Information System (INIS)

Amano, Osamu

2007-01-01

We need more oil energy to take out oil under the ground. Limit resources make us consider other candidates of energy source instead of oil. Electricity shall be the main role more and more like electric vehicles and air conditioners so we should consider electricity generation ways. When we consider what kind of electric power generation is the best or suitable, we should not only power generation plant but whole process from mining to power generation. It is good way to use EPR, Energy Profit Ratio, to analysis which type is more efficient and which part is to do research and development when you see the input breakdown analysis. Electricity by the light water nuclear power plant, the hydrogen power plant and the geothermal power plant are better candidates from EPR analysis. Forecasting the world primly energy supply in 2050, it is said that the demand will be double of the demand in 2000 and the supply will not be able to satisfy the demand in 2050. We should save 30% of the demand and increase nuclear power plants 3.5 times more and recyclable energy like hydropower plants 3 times more. When the nuclear power plants are 3.5 times more then uranium peak will come and we will need breed uranium. I will analysis the EPR of FBR. Conclusion: A) the EPR of NPS in Japan is 17.4 and it is the best of all. B) Many countries will introduce new nuclear power plants rapidly may be 3.5 times in 2050. C) Uranium peak will happen around 2050. (author)

A Comparative Analysis of Energy Usage and Energy Efficiency Behavior in Low- and High-Income Households: The Case of Kitwe, Zambia

Directory of Open Access Journals (Sweden)

Albert Malama

2015-11-01

Full Text Available Energy efficiency has been an important topic since the latter part of the last century. This is because adoption of energy efficiency measures has been acknowledged as one of the key methods of addressing the negative impact of climate change. In Zambia, however, the need to adopt energy efficiency measures has not just been driven by the imperative to mitigate the negative effects of climate change but also by a critical shortage of energy. This research looks at households’ energy consumption behavior in low- and high-income areas of Kitwe. Recent studies on the relationship between household energy consumption and behavioral lifestyle have been descriptive, with limited emphasis on the relationships between various variables. In this study, descriptive and inferential statistics have been used to investigate relationships between the two income groups and various energy consumption-related variables such as knowledge about energy reduction measures, energy saving strategies, barriers to the use of energy saving strategies, and the motives for using energy reduction strategies. Methodologically, the study was largely quantitative in nature, with questionnaires administered to a combined total of 56 households. However, key interviews were also conducted that helped us to get a clearer understanding of some of the issues covered in the research. Key findings are that whereas the descriptive statistics show that there are behavioral differences between the two income groups, the inferential statistics show that there is no relationship between income level and the energy efficiency variables. This has been found to be consistent with results from studies done elsewhere. The key lesson is that there is low usage of energy efficiency measures in both low- and high-income areas and that the authorities need to change the way information is disseminated to consumers from the current method of advertising to social diffusion.

The Energy Balance Study: The Design and Baseline Results for a Longitudinal Study of Energy Balance

Science.gov (United States)

Hand, Gregory A.; Shook, Robin P.; Paluch, Amanda E.; Baruth, Meghan; Crowley, E. Patrick; Jaggers, Jason R.; Prasad, Vivek K.; Hurley, Thomas G.; Hebert, James R.; O'Connor, Daniel P.; Archer, Edward; Burgess, Stephanie; Blair, Steven N.

2013-01-01

Purpose: The Energy Balance Study (EBS) was a comprehensive study designed to determine over a period of 12 months the associations of caloric intake and energy expenditure on changes in body weight and composition in a population of healthy men and women. Method: EBS recruited men and women aged 21 to 35 years with a body mass index between 20…

On the coherence between high-energy total cross-section data when compared with general principles

International Nuclear Information System (INIS)

Gauron, P.; Nicolescu, B.; Paris-6 Univ., 75

1993-12-01

An essential model is performed - an independent study of the internal coherence between high-energy total cross-section data by using classes of functions satisfying general principles. The study is practically independent of the ρ-parameter values. This general analysis, made without any fit, reveals certain inconsistencies in the existing set of high-energy data. Some of these inconsistencies are eliminated by giving up arbitrary assumptions sometimes made in 'fitology'. It is shown that the ln 2 s increase of total cross-sections at high energies is clearly favoured when compared with other possible behaviours. (authors). 16 refs., 3 figs

Comparative analysis of two hybrid energy storage systems used in a two front wheel driven electric vehicle during extreme start-up and regenerative braking operations

International Nuclear Information System (INIS)

Itani, Khaled; De Bernardinis, Alexandre; Khatir, Zoubir; Jammal, Ahmad

2017-01-01

Highlights: • Comparison of HESS Ultracapacitor and Flywheel for maximizing EV energy recovery. • Energy recovery performed for extreme two front-wheel driven EV brake conditions. • Regenerative EV braking control strategies and constraints for HESS. • Comparative cost effectiveness for two HESS solutions Ultracapacitors and Flywheel. - Abstract: This paper presents the comparative study of two hybrid energy storage systems (HESS) of a two front wheel driven electric vehicle. The primary energy source of the HESS is a Li-Ion battery, whereas the secondary energy source is either an ultracapacitor (UC) or a flywheel energy system (FES). The main role of the secondary source is to deliver/recover energy during high peak power demand, but also to increase battery lifetime, considered among the most expensive items in the electric vehicle. As a first step, a techno-economic comparative study, supported by strong literature research, is performed between the UC and the FES. The design and sizing of each element will be presented. The comparison criteria and specifications are also described. The adopted approach in this paper is based on an academic non-oriented point of view. In a second step, each of the HESS will be integrated in a more global Simulink model which includes the vehicle model, the traction control system (TCS), the regenerative braking system and the vehicle actuators. Simulation tests are performed for an extreme braking and vehicle starting-up operations. Tests are realized on two different surface road types and conditions (high and low friction roads) and for different initial system states. In order to show the most appropriate storage system regarding compactness, weight and battery constraints minimization, deep comparative analysis is provided.

Development of German energy consumption: A deterministic study of energy-relevant customer groups

International Nuclear Information System (INIS)

Baumert, M.

1994-01-01

A detailed study of the characteristic features of group-specific energy consumption was conducted (identification of the factors determining energy consumption of the productive sector, private households and private mobility demand). The question of who shall determine energy consumption in the future is analysed. This question is answered in a demand-specific study of consumption patterns and -effects. (orig./UA) [de

Comparing the health impacts of different sources of energy. Keynote address

International Nuclear Information System (INIS)

Hamilton, L.D.

1981-01-01

Assessing health impacts of different energy sources requires synthesis of research results from any different disciplines into a rational framework. Information is often scanty; qualitatively different risks, or energy systems with substantially different end uses, must be put on a common footing. Historically institutional constraints have inhibited agencies from making incisive comparisons necessary for formulating energy policy; this has exacerbated public controversy over appropriate energy sources. Risk assessment methods reviewed include examples drawn from work of the Biomedical and Environmental Assessment Division at Brookhaven National Laboratory and elsewhere. Uncertainty over the mechanism and size of air pollution health damage is addressed through a probabilistic health-damage function, using sulfate-particle exposure as an indicator. This facilitates intercomparison through analysis of each step in the whole fuel cycle between a typical coal and nuclear powerplant. Occupational health impacts, a significant fraction of overall damage, are illustrated by accident trends in coal mining. In broadening comparisons to include new technologies, one must include the impact of manufacturing the energy-producing device as part of an expanded fuel cycle, via input/output methods. Throughout the analysis, uncertainties must be made explicit in the results, including uncertainty of data and uncertainty in choice of appropriate models and methods. No single method of comparative risk assessment is fully satisfactory; each has its limitations. One needs to compare several methods if decision-making is to be realistic

A Comparative Study on Error Analysis

DEFF Research Database (Denmark)

Wu, Xiaoli; Zhang, Chun

2015-01-01

Title: A Comparative Study on Error Analysis Subtitle: - Belgian (L1) and Danish (L1) learners’ use of Chinese (L2) comparative sentences in written production Xiaoli Wu, Chun Zhang Abstract: Making errors is an inevitable and necessary part of learning. The collection, classification and analysis...... the occurrence of errors either in linguistic or pedagogical terms. The purpose of the current study is to demonstrate the theoretical and practical relevance of error analysis approach in CFL by investigating two cases - (1) Belgian (L1) learners’ use of Chinese (L2) comparative sentences in written production...... of errors in the written and spoken production of L2 learners has a long tradition in L2 pedagogy. Yet, in teaching and learning Chinese as a foreign language (CFL), only handful studies have been made either to define the ‘error’ in a pedagogically insightful way or to empirically investigate...

Comparative Analysis of Resonant Converters for Energy Storage Systems

Directory of Open Access Journals (Sweden)

Vuchev Stoyan

2017-01-01

Full Text Available The following paperwork presents a comparative analysis of multiphase resonant converters for applications in energy storage systems. Models of the examined converters are developed in the software environments of MATLAB and LTspice. Results from the simulation examination of the converters during charging of supercapacitors and rechargeable batteries are presented. These results are compared to results obtained from experimental examination of the converters via a laboratory stand. For the purposes of the experimental examination, a control system is developed on the base of a virtual instrument in LabVIEW. The advantages and disadvantages of the different converters are discussed.

Comparative studies of chemically synthesized and RF plasma ...

Indian Academy of Sciences (India)

journal of. April 2015 physics pp. 653–665. Comparative studies of ... MS received 16 April 2013; revised 5 February 2014; accepted 28 May 2014 ... RF plasma polymerization; poly(o-toluidine); Fourier transform infrared; UV–visible ... tial applications, e.g., as electrodes and membranes for electrochemical energy ...

Barriers to Energy Efficiency in Swedish Non-Energy-Intensive Micro- and Small-Sized Enterprises—A Case Study of a Local Energy Program

Directory of Open Access Journals (Sweden)

Fredrik Backman

2017-01-01

Full Text Available Improved energy efficiency has become a strategic issue and represents a priority for European competitiveness. Countries adopt various energy policies on local and national levels where energy audit programs are the most common energy end-use efficiency policy for industrial small- and medium-sized enterprises (SMEs. However, studies indicate that cost-efficient energy conservation measures are not always implemented, which can be explained by the existence of barriers to energy efficiency. This paper investigates how Swedish municipalities can support local micro- and small-sized enterprises with improved energy efficiency and the existence of different barriers to the implementation of energy efficiency. Relating this empirical case study to the theoretical barriers outlined in the text, this study found that the major explanatory factors related to non-implementation of cost-effective energy efficiency measures among micro- and small-sized industrial enterprises were bounded rationality (lack of time and/or other priorities, split incentives (having other priorities for capital investments, and imperfect information (slim organization and lack of technical skill. This study also found that information in the form of a report was the main thing that companies gained from working on the project “Energy-Driven Business”. Notably, the study involved companies that had participated in a local energy program and, still, companies face major barriers inhibiting implementation, indicating a need to further study other alternative policy models and how knowledge transfer can be improved.

Excitation decay due to incoherent energy transfer : A comparative study by means of an exact density expansion

NARCIS (Netherlands)

Knoester, J.; Himbergen, J.E. Van

1984-01-01

In this paper we consider a system of identical, randomly distributed donors, between which incoherent energy transfer takes place, described by coupled rate equations. It is proved, that the well-known diagrammatic series expansion of Gochanour, Andersen, and Fayer for the self-energy, while not an

Comparative study of passive and semi-active energy dissipation devices intended for overhead cranes

International Nuclear Information System (INIS)

Guihot, P.; Revaud, D.

1996-04-01

This paper deals with the results of a bibliographic survey of energy dissipation devices which could be adapted for overhead cranes. The principle of passive devices using friction, yielding steel systems of viscous and viscoelastic systems are remembered. An active control system, which needs a minimum of external control energy is also presented. The application to overhead cranes which have a strong non linear behaviour under strong seismic motion (sliding between rails and wheels, local yielding and damage) is further discussed. The first results of a numerical study in progress are likewise purposed. The criterion of selection of the devices turn on the performance, the robustness and the reliability. The behaviour in the presence of non linearities, the sensitivity to the variations of the vibratory characteristics, and lastly the sensitivity to the response delay of the active controller are taken into account. (authors). 14 refs., 4 figs

Comparative Evaluation of Phase 1 Results from the Energy Conversion Alternatives Study (ECAS). [coal utilization for electric power plants feasibility analysis

Science.gov (United States)

1976-01-01

Ten advanced energy conversion systems for central-station, based-load electric power generation using coal and coal-derived fuels which were studied by NASA are presented. Various contractors were selected by competitive bidding to study these systems. A comparative evaluation is provided of the contractor results on both a system-by-system and an overall basis. Ground rules specified by NASA, such as coal specifications, fuel costs, labor costs, method of cost comparison, escalation and interest during construction, fixed charges, emission standards, and environmental conditions, are presented. Each system discussion includes the potential advantages of the system, the scope of each contractor's analysis, typical schematics of systems, comparison of cost of electricity and efficiency for each contractor, identification and reconciliation of differences, identification of future improvements, and discussion of outside comments. Considerations common to all systems, such as materials and furnaces, are also discussed. Results of selected in-house analyses are presented, in addition to contractor data. The results for all systems are then compared.

Hanford Nuclear Energy Center study

Energy Technology Data Exchange (ETDEWEB)

Harty, H.

1976-03-16

Studies of a Nuclear Energy Center (NEC) at Hanford have not revealed any insurmountable technical problems, but problems have been identified that appear to be more difficult to resolve than for dispersed siting. Major technical developments in meteorology, and probably in seismology, are needed before an environmental report or safety analysis report could be prepared for an NEC. It would be helpful in further NEC studies if licensing requirements (and related criteria) were defined for them. An NEC will likely cause a step change in the amount of planning and involvement of regional groups in the energy picture compared to dispersed siting. The tools that must be developed for analysis of NECs will probably be used for evaluating dispersed siting in greater detail. NECs will probably bring about the use of dry or wet/dry cooling before it is required in equivalent amount for dispersed plants.

Hanford Nuclear Energy Center study

International Nuclear Information System (INIS)

Harty, H.

1976-01-01

Studies of a Nuclear Energy Center (NEC) at Hanford have not revealed any insurmountable technical problems, but problems have been identified that appear to be more difficult to resolve than for dispersed siting. Major technical developments in meteorology, and probably in seismology, are needed before an environmental report or safety analysis report could be prepared for an NEC. It would be helpful in further NEC studies if licensing requirements (and related criteria) were defined for them. An NEC will likely cause a step change in the amount of planning and involvement of regional groups in the energy picture compared to dispersed siting. The tools that must be developed for analysis of NECs will probably be used for evaluating dispersed siting in greater detail. NECs will probably bring about the use of dry or wet/dry cooling before it is required in equivalent amount for dispersed plants

Superiority of Low Energy 160 KV X-Rays Compared to High Energy 6 MV X-Rays in Heavy Element Radiosensitization for Cancer Treatment

Science.gov (United States)

Lim, Sara N.; Pradhan, Anil K.; Nahar, Sultana N.; Barth, Rolf F.; Yang, Weilian; Nakkula, Robin J.; Palmer, Alycia; Turro, Claudia

2013-06-01

High energy X-rays in the MeV range are generally employed in conventional radiation therapy from linear accelerators (LINAC) to ensure sufficient penetration depths. However, lower energy X-rays in the keV range may be more effective when coupled with heavy element (high-Z or HZ) radiosensitizers. Numerical simulations of X-ray energy deposition for tumor phantoms sensitized with HZ radiosensitizers were performed using the Monte Carlo code Geant4. The results showed enhancement in energy deposition to radiosensitized phantoms relative to unsensitized phantoms for low energy X-rays in the keV range. In contrast, minimal enhancement was seen using high energy X-rays in the MeV range. Dose enhancement factors (DEFs) were computed and showed radiosensitization only in the low energy range nitrate, was initially used because it was 7x less toxic that an equivalent amount of carboplatin in vitro studies. This would allow us to separate the radiotoxic and the chemotoxic effects of HZ sensitizers. Results from this study showed a 10-fold dose dependent reduction in surviving fractions (SF) of radiosensitized cells treated with low energy 160 kV X-rays compared to those treated with 6 MV X-rays. This is in agreement with our simulations that show an increase in dose deposition in radiosensitized tumors for low energy X-rays. Due to unforeen in vivo toxicity, however, another in vitro study was performed using the commonly used, Pt-based chemotherapeutic drug carboplatin which confirmed earlier results. This lays the ground work for a planned in vivo study using F98 glioma bearing rats. This study demonstrates that while high energy X-rays are commonly used in cancer radiotherapy, low energy keV X-rays might be much more effective with HZ radiosensitization.

Safety Aspects of Radioactive Waste Management in Different Nuclear Fuel Cycle Policies, a Comparative Study

International Nuclear Information System (INIS)

Gad Allah, A.A.

2009-01-01

With the increasing demand of energy worldwide, and due to the depletion of conventional natural energy resources, energy policies in many countries have been devoted to nuclear energy option. On the other hand, adopting a safe and reliable nuclear fuel cycle concept guarantees future nuclear energy sustain ability is a vital request from environmental and economic point of views. The safety aspects of radioactive waste management in the nuclear fuel cycle is a topic of great importance relevant to public acceptance of nuclear energy and the development of nuclear technology. As a part of nuclear fuel cycle safety evaluation studies in the department of nuclear fuel cycle safety, National Center for Nuclear Safety and Radiation Control (NCNSRC), this study evaluates the radioactive waste management policies and radiological safety aspects of three different nuclear fuel cycle policies. The once-through fuel cycle (OT- fuel cycle) or the direct spent fuel disposal concept for both pressurized light water reactor ( PWR) and pressurized heavy water reactor (PHWR or CANDU) systems and the s elf-generated o r recycling fuel cycle concept in PWR have been considered in the assessment. The environmental radiological safety aspects of different nuclear fuel cycle options have been evaluated and discussed throughout the estimation of radioactive waste generated from spent fuel from these fuel cycle options. The decay heat stored in the spent fuel was estimated and a comparative safety study between the three fuel cycle policies has been implemented

Comparative assessment of nuclear power and other energy sources: the DECADES project

International Nuclear Information System (INIS)

Bennett, L.L.

1996-01-01

The environmental and health related impacts of different energy systems are emerging as significant issues. To promote international cooperation in this field, the inter-agency project on databases and methodologies for comparative assessment of different energy sources for electricity generation, called DECADES, was established at the end of 1992. In October 1995 was held the International Symposium on ''Electricity, Health and the Environment - Comparative Assessment in Support of Decision Making''. Through its programs and activities, the IAEA plays a leading role, in cooperation with other organizations, in the DECADES project, to examine areas in which international expertise and support can best be applied to assist national policy and decision makers in objectively and comprehensively assessing their energy systems and strategies

A Multi-Model Study of Energy Supply Investments in Latin America under Climate Control Policy Energy Economics

NARCIS (Netherlands)

Kober, T.; Falzon, J.; van der Zwaan, B.; Calvin, K.; Kanudia, A.; Kitous, A.; Labriet, M.

In this paper we investigate energy supply investment requirements in Latin America until 2050 through a multi-model approach as jointly applied in the CLIMACAP-LAMP research project. We compare a business-as-usual scenario needed to satisfy anticipated future energy demand with a set of scenarios

Towards a 90% renewable energy future: A case study of an island in the South China Sea

International Nuclear Information System (INIS)

Ye, Bin; Zhang, Kai; Jiang, JingJing; Miao, Lixin; Li, Ji

2017-01-01

Highlights: • Renewable energy dominated power system is applied to an isolated island. • Cost-effective comparison study between hydrogen and battery energy storage. • CO_2 reduction potential estimation of the renewable energy power system. • Cost reduction effect of DSM is estimated to be approximately 20% - Abstract: Exploiting renewable energy is a critical greenhouse gases reduction strategy for China, especially in areas where new power plants are needed. Challenges in energy storage, however, always complicate the design of renewable energy-dominated power generation systems. This study attempt to provide a solution to the energy storage problem through the synergy of both the power supply and demand sides. Based on local natural energy resources endowments, this paper applies the hybrid optimization model for multiple energy resources and load types to analyse the feasibility of satisfying energy demand. To verify the model’s technological and economic feasibility, this research applies its synergy model to a 2.8 km"2 isolated island in the South China Sea. The simulation results demonstrate that the cost of energy and net present cost of the power supply system are $0.212/kW h and $127 M when hydrogen energy storage equipment is used, and $0.178/kW h and $101 M when traditional-battery energy storage equipment is utilized. This study also reveals that using flywheels to supplement the hydrogen and traditional-battery energy storage equipment could reduce the cost of energy by 5.6% and 3.4%, respectively. In addition, power system demand-side management can further reduce the cost of energy by approximately 20% for all technology scenarios considered in this study. A carbon emissions analysis demonstrates that the carbon reduction rates of the proposed power systems are between 87.7% and 95.1% compared with a fossil-energy based power system. In brief, this study indicates that solar and wind energy combined with appropriate energy storage

A Comparative Study of virtual and operational met mast data

International Nuclear Information System (INIS)

Orhan, Dr Ö Emre; Ahmet, Gökhan

2014-01-01

Performance of wind assessment studies depend on the adequacy and duration of the wind data. For a reasonable wind assessment, at least one full year wind data is needed so that, all the variations throughout the year are represented. On the other hand, it is always a question of time and cost how to get the wind data. On-site measurements are the most common way of obtaining wind data but it is the most expensive and time consuming as well. Apart from onsite data, there are also reanalysis long term data sources like MERRA, NCAR, etc. Time and spatial resolution of these long term data are lower compared to on-site measurements but in cases where on-site measurements are not available, they are also utilized. On top of on-site and reanalysis wind data, weather forecasting models like WRF, MM5 are available. Although, these models mainly are used for forecasting services, flexibility of the models makes them suitable for preliminary resource assessment purposes. In this study, comparisons of annual energy production estimations are computed using virtual and on-site met mast data separately for a specific time range. The widely used weather research and forecasting model (WRF) is used to provide virtual met mast data. Once WRF simulations are completed, interpolation routines are employed in order to extract data for a specific location. The on-site met mast is located inside a wind farm project area which is under development. Project site is located in the south of Turkey. There are four different met masts, three of them recording wind data presently. On-site measurements together with WRF results are used to obtain energy yields for the project area. The performance of both methodologies is compared. It has been observed that WRF can as well serve as a preliminary model in cases where no other data source is available but the model has to be implemented with great care depending on the project site conditions

Transmission of neutrons in serpentine mixed and ordinary concrete a comparative study

International Nuclear Information System (INIS)

Ravishankar, R.; Bhattacharyya, Sarmishtha; Bandyopadhyay, Tapas; Sarkar, P.K.

2002-01-01

Full text: In particle accelerator facilities, for radiation shielding, concrete is commonly used for its effectiveness in attenuating neutrons in addition to its good structural and mechanical properties. Neutron attenuation depends largely on the water content in the concrete. Serpentine mixed concrete is reported to retain better water content than ordinary concrete. Experiments have been carried out to compare neutron attenuation properties of Serpentine mixed concrete slabs and ordinary concrete slabs of different thickness. Transmission of neutrons from a 185 GBq Pu-Be neutron source has been studied using NE-213 liquid scintillator detector, along with the associated electronics to discriminate neutron from gamma using pulse shape discrimination techniques. The energy differential neutron spectra transmitted through the concrete slabs and the corresponding dose have been obtained by unfolding the pulse height spectra using the FERDOR-U computer code and proper response matrix data of the NE-213 detector. The neutron transmission factors through both Serpentine and Ordinary concrete slabs have been studied. The results show serpentine mixed concrete slabs can attenuate more neutrons of varying energies compared to ordinary concrete slabs of equal dimensions. From the trend, it has been found out, with the increase in slab thickness, the gain in neutron attenuation increases. This is due to increase in quantity of serpentine with the increase in thickness of, concrete. A Monte Carlo simulation carried out, for theoretical analysis of the results, has been found to be in order

Transmission of neutrons in serpentine mixed and ordinary concrete- a comparative study

International Nuclear Information System (INIS)

Ravishankar, R.; Bhattacharyya, Sarmishtha; Bandyopadhyay, Tapas; Sarkar, P. K.

2002-01-01

In particle accelerator facilities, for radiation shielding, concrete is commonly used for its effectiveness in attenuating neutrons in addition to its good structural and mechanical properties. Neutron attenuation depends largely on the water content in the concrete. Serpentine mixed concrete is reported to retain better water content than ordinary concrete. Experiments have been carried out to compare neutron attenuation properties of Serpentine mixed concrete slabs and ordinary concrete slabs of different thickness. Transmission of neutrons from a 185 GBq Pu-Be neutron source has been studied using NE-213 liquid scintillator detector, along with the associated electronics to discriminate neutron from gamma using pulse shape discrimination techniques. The energy differential neutron spectra transmitted through the concrete slabs and the corresponding dose have been obtained by unfolding the pulse height spectra using the FERDOR-U computer code and proper response matrix data of the NE-213 detector. The neutron transmission factors through both Serpentine and Ordinary concrete slabs have been studied. The results show serpentine mixed concrete slabs can attenuate more neutrons of varying energies compared to ordinary concrete slabs of equal dimensions. From the trend, it has been found out, with the increase in slab thickness, the gain in neutron attenuation increases. This is due to increase in quantity of serpentine with the increase in thickness of concrete. A Monte Carlo simulation carried out, for theoretical analysis of the results, has been found to be in order

Comparative life cycle assessment of biowaste to resource management systems - A Danish case study

DEFF Research Database (Denmark)

Thomsen, Marianne; Seghetta, Michele; Mikkelsen, Mette Hjorth

2017-01-01

Waste to Energy combustion plants currently process most of the organic fraction of the household waste. This study presents an assessment of the environmental performance of an increased circular bioresource management system obtained by reallocating the organic fraction of the household waste...... from combustion (Reference Scenario) to biogas and fertilizer production (Alternative Scenario). The goals defined in the Danish National resource action plan for waste management, i.e. 33% reduction of organic fraction household waste dry weight, is taken as a case study. A comparative life cycle...... assessment of the diverting of the organic fraction of the household waste away from a Waste to Energy combustion plant towards sludge- and manure-based biogas plants in North Zealand (Denmark) shows a net increase in renewable electricity production of 39% at the expense of a reduction in heat production...

Energy expenditure of sedentary screen time compared with active screen time for children.

Science.gov (United States)

Lanningham-Foster, Lorraine; Jensen, Teresa B; Foster, Randal C; Redmond, Aoife B; Walker, Brian A; Heinz, Dieter; Levine, James A

2006-12-01

We examined the effect of activity-enhancing screen devices on children's energy expenditure compared with performing the same activities while seated. Our hypothesis was that energy expenditure would be significantly greater when children played activity-promoting video games, compared with sedentary video games. Energy expenditure was measured for 25 children aged 8 to 12 years, 15 of whom were lean, while they were watching television seated, playing a traditional video game seated, watching television while walking on a treadmill at 1.5 miles per hour, and playing activity-promoting video games. Watching television and playing video games while seated increased energy expenditure by 20 +/- 13% and 22 +/- 12% above resting values, respectively. When subjects were walking on the treadmill and watching television, energy expenditure increased by 138 +/- 40% over resting values. For the activity-promoting video games, energy expenditure increased by 108 +/- 40% with the EyeToy (Sony Computer Entertainment) and by 172 +/- 68% with Dance Dance Revolution Ultramix 2 (Konami Digital Entertainment). Energy expenditure more than doubles when sedentary screen time is converted to active screen time. Such interventions might be considered for obesity prevention and treatment.

Water-energy nexus for urban water systems: A comparative review on energy intensity and environmental impacts in relation to global water risks

International Nuclear Information System (INIS)

Lee, Mengshan; Keller, Arturo A.; Chiang, Pen-Chi; Den, Walter; Wang, Hongtao; Hou, Chia-Hung; Wu, Jiang; Wang, Xin; Yan, Jinyue

2017-01-01

Highlights: •This study quantifies the nexus as energy intensity and greenhouse gas potential. •Baseline water stress and return flow ratio are identified as water risks. •Source water accessibility significantly contributes to variations in the nexus. •Water risks have little impact on the nexus of wastewater systems. •Study on the nexus is suggested to be conducted at regional levels. -- Abstract: The importance of the interdependence between water and energy, also known as the water-energy nexus, is well recognized. The water-energy nexus is typically characterized in resource use efficiency terms such as energy intensity. This study aims to explore the quantitative results of the nexus in terms of energy intensity and environmental impacts (mainly greenhouse gas emissions) on existing water systems within urban water cycles. We also characterized the influence of water risks on the water-energy nexus, including baseline water stress (a water quantity indicator) and return flow ratio (a water quality indicator). For the 20 regions and 4 countries surveyed (including regions with low to extremely high water risks that are geographically located in Africa, Australia, Asia, Europe, and North America), their energy intensities were positively related to the water risks. Regions with higher water risks were observed to have relatively higher energy and GHG intensities associated with their water supply systems. This mainly reflected the major influence of source water accessibility on the nexus, particularly for regions requiring energy-intensive imported or groundwater supplies, or desalination. Regions that use tertiary treatment (for water reclamation or environmental protection) for their wastewater treatment systems also had relatively higher energy and GHG emission intensities, but the intensities seemed to be independent from the water risks. On-site energy recovery (e.g., biogas or waste heat) in the wastewater treatment systems offered a great

A feasibility study of microgrids for reducing energy use and GHG emissions in an industrial application

International Nuclear Information System (INIS)

Li, Mengyu; Zhang, Xiongwen; Li, Guojun; Jiang, Chaoyang

2016-01-01

Highlights: • A life cycle assessment is conducted on the microgrids for an industry application. • The effect of renewable energy on the LCA performances of microgrids is illustrated. • The minimal life cycle energy use and GHG emissions of microgrids are evaluated. • The LCA of different pathways for electricity, heat and hydrogen are presented. - Abstract: Microgrids provide a new energy paradigm with the benefits of higher energy supply reliability, lower greenhouse gas (GHG) emissions through a higher penetration of renewable sources, higher energy efficiencies through the use of local waste heat and the avoidance of losses in transmission and distribution. This study reports a life cycle assessment (LCA) of microgrids for an industry application of an ammonia plant in central Inner Mongolia, China. The life cycle energy use and GHG emissions of the microgrids are evaluated and compared to the existing fossil fuel-based energy system. The electricity, heat and hydrogen fuel loads of the ammonia plant are all modelled in the study. An optimization model is developed to estimate the minimum life cycle energy use and GHG emissions with the microgrids under three scenarios (natural gas (NG)-based, optimized, and maximum renewable energy microgrids). The results indicate that the use of wind and solar in the NG-based microgrid can only slightly reduce the energy use and GHG emissions. If there are no land area limitations on the deployment of solar and wind power, the maximum renewable energy microgrid offers significant reductions of fossil fuel energy of up to 56.9% and GHG emissions reductions of up to 66.3% compared to the existing energy system.

Driving factors for the regional implementation of renewable energy ‐ A multiple case study on the German energy transition

International Nuclear Information System (INIS)

Lutz, Lotte Marie; Fischer, Lisa-Britt; Newig, Jens; Lang, Daniel Johannes

2017-01-01

Understanding what drives the regional implementation of renewable energy is a prerequisite for energy transitions toward a post-fossil-based energy economy. This paper presents an empirical analysis of driving factors for the regional implementation and use of renewable energy. We tested literature-derived driving factors in a comparative analysis of 18 selected study regions using Rough Set Analysis and performance analysis. We paid special attention to common combinations of driving factors, which we understand as established practices concerning the use and implementation of renewable energy. Our findings confirm most of the driving factors identified in the literature, for example the existence of key actors, knowledge exchange, or the use of goals and milestones. We also observe differences in key driving factors between highly successful and less successful regions, especially regarding funding opportunities. The results may support policy makers who aim to successfully implement renewable energy at a regional level. - Highlights: • We analyzed driving factors for RE implementation in 18 best-practice regions. • Most driving factors from transition and governance literature were confirmed. • We identified common successful practices concerning RE implementation.

Impact of different LEED versions for green building certification and energy efficiency rating system: A Multifamily Midrise case study

International Nuclear Information System (INIS)

Rastogi, Ankush; Choi, Jun-Ki; Hong, Taehoon; Lee, Minhyun

2017-01-01

Highlights: •Energy consumption change from applying different LEED versions were investigated. •Four analysis scenarios were compared using different versions of ASHRAE Standard. •A case study of a mid-rise multi-family building was conducted using energy simulation. •Residential buildings could benefit from LEED v4 due to the low prerequisite. •Renovation buildings are highly incentivized regardless of LEED version used. -- Abstract: Various versions of the Leadership in Energy and Environmental Design (LEED ® ) have been introduced with the addition of more stringent sustainability parameters and credit scoring schemes over the past decade. Such changes in LEED versions strongly affect the energy performance and LEED scores of the target building in the LEED certification process. Therefore, to validate and improve the current LEED version, it is crucial to investigate and compare the impact of different LEED versions on the building energy performance and scoring scheme. However, researches comparing the sustainability metrics for mid-rise multi-family buildings are rare. Therefore, this paper investigates the potential changes in the energy performance resulted from applying different LEED versions (i.e., LEED v3 and v4) for the Energy and Atmosphere (EA) category. Towards this end, a case study was carried out with energy modeling and simulation using TRACE 700 to compare the changes in the energy performance of four analysis scenarios applied to an existing mid-rise multi-family building located in Ohio. Results showed notable changes in LEED points when different versions of LEED using different ASHRAE Standards (i.e., ASHRAE Standards 90.1-2007 and 90.1-2010) are applied for the building energy analysis. In particular, mid-rise multi-family buildings could benefit from LEED v4 in terms of LEED credits as the prerequisite for the minimum energy performance improvement in EA category became significantly lenient compared to LEED v3. On the

The environmental aspect of using renewables for hydrogen production compared to a fossil based system : A specific case study for a remote application

International Nuclear Information System (INIS)

Spath, P.; Padro, C.G.; Glockner, R.; Ulleberg, O.

2002-01-01

Under the umbrella of the International Energy Agency Hydrogen Implementing Agreement Annex 13 : Design and optimization of Integrated Systems, a number of studies are currently being conducted, touching on modeling, economics, and environmental consequences of hydrogen fuels. The use of hydrogen as a fuel in buses on a remote island of the coast of Norway is the topic of one such study, which represents a joint effort between the United States and Norway. The study involved the examination of two comparative systems, namely (1) hydrogen via wind/electrolysis and (2) hydrogen produced from steam methane reforming (SMR). The two systems were described and a comparative analysis performed of the life cycle assessments results, such as resource requirement, air emissions, fossil energy consumption and others. 4 refs., 3 tabs., 4 figs

Case Study of a Nearly Zero Energy Building in Italian Climatic Conditions

Directory of Open Access Journals (Sweden)

Hassan Saeed Khan

2017-11-01

Full Text Available The building sector is an important stakeholder in the energy and environmental scenario of any country. It continues to grow across the world due to factors such as population growth, and economic and infrastructure development. Within the European Union, buildings account for 40% of the total energy requirements and 30% of carbon dioxide emissions. The building sector is keen to improve its sustainability standards and also to help achieve the 20-20-20 targets set by the European Union. The present work aims to design a nearly zero energy sports gymnasium building in Calolziocorte, Italy. Various sustainability techniques are applied in an integrated design project approach using ECOTECT software to undertake the energy modelling exercise. Firstly, the base-case is modelled with conventional building materials and the total energy demand is calculated. Duly considering the local climatic conditions, sustainable materials are chosen for walls, the floor, the roof, and windows and a 38% reduction is noted in the total energy demand of the building compared to the base-case. The impact of louvers as a passive design technique has also been examined on the total energy demand of the building. The monthly load/discomfort analysis is undertaken for various individual functions inside the building to identify the critical areas that consume more energy. The monthly load/discomfort analysis is performed with the proposed materials and the air infiltration rate is improved through the building envelope and 63% reduction is noted in the total energy demand of the building compared to the base-case. A solar access analysis is conducted to understand the on-site energy production and then the building net energy demand is calculated, which is reduced to 90% compared to the base-case.

Differences in weight status and energy-balance related behaviors among schoolchildren in German-speaking Switzerland compared to seven countries in Europe

Directory of Open Access Journals (Sweden)

Herzig Michael

2012-11-01

Full Text Available Abstract Background Overweight in children and adolescents have increased significantly and are a major public health problem. To allow international comparisons, Switzerland joined the European study ‘ENERGY’ cross sectional survey consortium that investigated the prevalence of overweight and obesity as well as selected dietary, physical and sedentary behaviors of 10–12 years old pupils across seven other countries in Europe. The aims of the present study was to compare body composition and energy-balance related behaviors of Swiss schoolchildren to those of the seven European ENERGY-countries and to analyze overweight and energy-balance related behaviors of Swiss children according to socio-demographic factors. Methods A school-based cross-sectional study among 10–12 year old children was conducted in Switzerland and seven other European countries using a standardized protocol. Body height, weight and waist-circumference were measured by trained research assistants. Energy-balance related behaviors –i.e. selected dietary, physical activity and screen-viewing behaviors were assessed by questionnaires. Weight status and behaviors in Switzerland were compared to the seven European ENERGY countries. Within the Swiss sample, analyses stratified by gender, parental education and ethnicity were performed. Results Data of 546 Swiss children (mean age 11.6±0.8y, 48% girls were obtained and compared to the ENERGY- results (N=7.148; mean age 11.5±0.8y, 48% girls. In Switzerland significantly less children were overweight (13.9% or obese (2.3% compared to the average across the ENERGY-countries (23.7% and 4.7%, respectively, and were even somewhat lower than the ENERGY countries with the lowest prevalence. Sugar sweetened beverage intakes and breakfast habits of Swiss children did not differ significantly from those of ENERGY. However, the mean time devoted by Swiss children to walking or cycling to school and attending sports activities was

Comparing centralized and decentralized bio-energy systems in rural China

International Nuclear Information System (INIS)

He, Guizhen; Bluemling, Bettina; Mol, Arthur P.J.; Zhang, Lei; Lu, Yonglong

2013-01-01

Under the dual pressures of an energy crisis and rising greenhouse gas emissions, biomass energy development and utilisation has become part of the national energy strategy in China. The last decade has witnessed a strong promotion of both centralised and decentralised bio-energy systems in rural China. The government seems to have a strong preference for centralised (village-based) bio-energy systems in recent years. However, these government-driven systems have not worked without difficulties, particularly regarding economic and technological viability and maintenance. Studies on the advantages and disadvantages of decentralised and centralised bio-energy systems are rare. This study aims to shed light on the performances of these two systems in terms of social, economic and environmental effects. Through interviewing local officials and village leaders and surveying farmers in 12 villages in Shandong Province, it was found that bio-energy systems should be selected based on the local circumstances. The diversity of the local natural, economic and social situations determines the size, place, technology and organisational model of the bio-energy system. - Highlights: • Biomass energy development has become part of the national energy strategy in China. • The dis-/advantages of decentralized and centralized bio-energy systems are evaluated. • Bio-energy systems should be selected based on the local circumstances

Comparing Server Energy Use and Efficiency Using Small Sample Sizes

Energy Technology Data Exchange (ETDEWEB)

Coles, Henry C.; Qin, Yong; Price, Phillip N.

2014-11-01

This report documents a demonstration that compared the energy consumption and efficiency of a limited sample size of server-type IT equipment from different manufacturers by measuring power at the server power supply power cords. The results are specific to the equipment and methods used. However, it is hoped that those responsible for IT equipment selection can used the methods described to choose models that optimize energy use efficiency. The demonstration was conducted in a data center at Lawrence Berkeley National Laboratory in Berkeley, California. It was performed with five servers of similar mechanical and electronic specifications; three from Intel and one each from Dell and Supermicro. Server IT equipment is constructed using commodity components, server manufacturer-designed assemblies, and control systems. Server compute efficiency is constrained by the commodity component specifications and integration requirements. The design freedom, outside of the commodity component constraints, provides room for the manufacturer to offer a product with competitive efficiency that meets market needs at a compelling price. A goal of the demonstration was to compare and quantify the server efficiency for three different brands. The efficiency is defined as the average compute rate (computations per unit of time) divided by the average energy consumption rate. The research team used an industry standard benchmark software package to provide a repeatable software load to obtain the compute rate and provide a variety of power consumption levels. Energy use when the servers were in an idle state (not providing computing work) were also measured. At high server compute loads, all brands, using the same key components (processors and memory), had similar results; therefore, from these results, it could not be concluded that one brand is more efficient than the other brands. The test results show that the power consumption variability caused by the key components as a

Investigation of the process energy demand in polymer extrusion: A brief review and an experimental study

International Nuclear Information System (INIS)

Abeykoon, Chamil; Kelly, Adrian L.; Brown, Elaine C.; Vera-Sorroche, Javier; Coates, Phil D.; Harkin-Jones, Eileen; Howell, Ken B.; Deng, Jing; Li, Kang; Price, Mark

2014-01-01

Highlights: • Energy consumption and losses in polymer extrusion are discussed. • This compares energy consumption in polymer extrusion at different conditions. • The role of power factor on energy efficiency in polymer extrusion is explored. • Empirical models on extruder energy consumption are provided. • Computer modelling of energy consumption of polymer extrusion is performed. - Abstract: Extrusion is one of the fundamental production methods in the polymer processing industry and is used in the production of a large number of commodities in a diverse industrial sector. Being an energy intensive production method, process energy efficiency is one of the major concerns and the selection of the most energy efficient processing conditions is a key to reducing operating costs. Usually, extruders consume energy through the drive motor, barrel heaters, cooling fans, cooling water pumps, gear pumps, etc. Typically the drive motor is the largest energy consuming device in an extruder while barrel/die heaters are responsible for the second largest energy demand. This study is focused on investigating the total energy demand of an extrusion plant under various processing conditions while identifying ways to optimise the energy efficiency. Initially, a review was carried out on the monitoring and modelling of the energy consumption in polymer extrusion. Also, the power factor, energy demand and losses of a typical extrusion plant were discussed in detail. The mass throughput, total energy consumption and power factor of an extruder were experimentally observed over different processing conditions and the total extruder energy demand was modelled empirically and also using a commercially available extrusion simulation software. The experimental results show that extruder energy demand is heavily coupled between the machine, material and process parameters. The total power predicted by the simulation software exhibits a lagging offset compared with the

Utilizing primary energy savings and exergy destruction to compare centralized thermal plants and cogeneration/trigeneration systems

International Nuclear Information System (INIS)

Espirito Santo, Denilson Boschiero do; Gallo, Waldyr Luiz Ribeiro

2017-01-01

Rising energy conversion processes efficiencies reduces CO_2 emissions and global warming implications. Decentralized electricity production through cogeneration/trigeneration systems can save primary energy if it operates with high efficiency. High efficiency is obtained when the system produces electricity and a substantial amount of the energy rejected by the prime mover is used to meet site thermal demands. Environmental concerns and international agreements are directing governments of different countries to incentive high efficiency solutions. Centralized thermal plants and cogeneration/trigeneration efficiency are compared through efficiency indicators using the first law of thermodynamics and the second law of thermodynamics. This paper proposes the use of the primary energy savings analysis and the exergy destruction analysis to compare decentralized power production through cogeneration/trigeneration systems and centralized thermal plants. The analysis concluded that both methods achieve the same results if the thermal efficiency indicator is used to compare the methods. The analysis also revealed that trigeneration systems with the same energy input are comparable with quite different thermal efficiency centralized thermal plants. Case 1 is comparable to a 53% thermal efficiency power plant and case 2 is comparable to a 77% thermal efficiency power plant. - Highlights: • Trigeneration and thermal plants are compared using PES and exergy destruction. • The thermal efficiency indicator is used to compare both methods. • The same equivalent thermal efficiency is achieved by both methods. • Same energy input trigeneration is similar to different thermal efficiency plants. • Evaluated trigeneration are comparable to a 53–77% thermal efficiency power plant.

Photovoltaic power stations in Germany and the United States: A comparative study by data envelopment analysis

International Nuclear Information System (INIS)

Sueyoshi, Toshiyuki; Goto, Mika

2014-01-01

This study compares Photovoltaic (PV) power stations between Germany and the United States to examine which country more efficiently provides renewable energy in their usages. For the comparative analysis, this study utilizes Data Envelopment Analysis (DEA) as a methodology to evaluate the performance of PV power stations from the perspective of both solar and land usages. A total of one hundred sixty PV power stations (eighty in Germany and eighty in the United States) are used for this comparison. The demand for sustainable energy and energy security has been rapidly increasing over the past decade because of concerns about environment and limited resources. PV solutions are one of many renewable technologies that are being developed to satisfy a recent demand of electricity. Germany is the world's top installer and consumer of PV power and the United States is one of the top five nations. Germany leads the way in installed PV capacity even though the nation has less solar resources and land area. Due to limited solar resources, low insolation and sunshine, and land area, the United States should have a clear advantage over Germany. However, the empirical result of this study exhibits that PV power stations in Germany operate more efficiently than those of the United States even if the latter has many solar and land advantages. The surprising result indicates that the United States has room for improvement when it comes to utilizing solar and land resources and needs to reform the solar policy. For such a purpose, Feed-In Tariff (FIT) may be an effective energy policy at the state level in the United States because the FIT provides investors such as utility companies and other types of energy firms with financial incentives to develop large PV power stations and generation facilities for other renewable energy. It may be true that the FIT is a powerful policy tool to promote PV and other renewable installation and support a reduction of an amount of greenhouse

A Boiler Room in a 600-Bed Hospital Complex: Study, Analysis, and Implementation of Energy Efficiency Improvements

Directory of Open Access Journals (Sweden)

Juan-Carlos Fraile

2014-05-01

Full Text Available The aim of energy efficiency is to use less energy to provide the same service. In hospitals, energy efficiency offers a powerful and cost-effective tool to reduce greenhouse gas emissions, fuel consumption, and also running costs. Over a six-month period, the six gas-fired boilers that provide both a hospital’s heat and hot water were monitored. Analysis of the data obtained led to several actions being implemented in the hospital boiler room control system to improve the efficiency of the heat production system. Comparative studies were conducted, during similar weather periods, of the performance of the hospital’s hot water production system before and after the controls were implemented. Results indicate that the control actions applied proved to be effective. Finally; the paper offers a financial; primary energy saving and CO2 reduction analysis that points to a 3,434.00 €/week savings in natural gas consumption; and a cut in CO2 emissions of 20.3 tons/week; as compared to the reference facility.

Comparative assessment of risks from Philippine energy systems in the far future

International Nuclear Information System (INIS)

Leonin, Teofilo V.

1998-01-01

The growing demand for electricity to support the economic development of the country has prompted the Philippine government to emphasize sustainable development and the integration of environmental concerns in the planning and implementation of energy programs. Based on the new long term Philippine Energy Plan, the total energy requirement will increase by an annual average of 66% up to the year 2025. There will be a growing dependence on coal fuel which will contribute significantly to the total carbon dioxide emissions in the next century. Activities on the comparative assessment of impacts of the different energy sources are also discussed. (author)

Geothermal energy and the public: A case study on deliberative citizens’ engagement in central Italy

International Nuclear Information System (INIS)

Pellizzone, Anna; Allansdottir, Agnes; De Franco, Roberto; Muttoni, Giovanni; Manzella, Adele

2017-01-01

This paper reports on a case study on the citizens’ engagement with developments towards the harnessing of geothermal energy in central Italy. The research has been conducted within the framework of a larger project on the feasibility of further geothermal developments in Italy, funded by the Italian government. The aims of the case study research were first to explore the role of public and stakeholder engagement in the processes of innovation in the geothermal energy sector. Second, to design, implement and consolidate a methodological framework for comparative analysis of case studies on citizens’ engagement, thus bringing a social scientific perspective into geothermal energy research. The results show general support for renewable energy but knowledge and understanding of the potential of geothermal is remarkably low. Lack of trust in politics and unsure public communication emerged as prominent themes where the common good and community developments are sharply contrasted with corporate and private interests. As geothermal energy is included and encouraged under the European Strategic Energy Plan and in the Paris agreement on halting climate change, the results can make significant input into future policy making, by providing concrete guidelines on citizens’ engagement in processes of culturally sustainable innovation. - Highlights: • Original research, case study on citizens’ engagement with geothermal energy. • Considerable public uncertainty over geothermal energy. • Information is a key issue for all stakeholder and citizens cooperation in the energy sector. • Everyday notions of “the common good” strongly shape community discussions about energy. • Geothermal energy developments need to take the views of communities into account.

Comparative energy analysis of agricultural crops used for producing ethanol and CO2 emissions

International Nuclear Information System (INIS)

Santos, M.A. dos

1997-01-01

A variety of biomass sources can be used for producing ethanol. Among these are sugar cane (Brazil), corn (USA), sweet sorghum (USA and Europe), sugar beets (Europe) and wheat (USA and Europe). The production of fuel alcohol worldwide has been analyzed from various perspectives: productivity, the competition between food and energy crops, the social and economic aspects and, more recently, the environmental dimension. Another relevant study is aimed at calculating the energy costs of the production and use of alcohol from sugar cane as compared to other primary sources for this fuel. The present analysis employs the methodology of energy balance, highlighting local conditions that influence how biomass is transformed into ethanol: technology, agricultural productivity, environmental conditions and an estimate of the carbon dioxide emissions from these different processes. (author)

Dual-energy mammography: simulation studies

International Nuclear Information System (INIS)

Bliznakova, K; Kolitsi, Z; Pallikarakis, N

2006-01-01

This paper presents a mammography simulator and demonstrates its applicability in feasibility studies in dual-energy (DE) subtraction mammography. This mammography simulator is an evolution of a previously presented x-ray imaging simulation system, which has been extended with new functionalities that are specific for DE simulations. The new features include incident exposure and dose calculations, the implementation of a DE subtraction algorithm as well as amendments to the detector and source modelling. The system was then verified by simulating experiments and comparing their results against published data. The simulator was used to carry out a feasibility study of the applicability of DE techniques in mammography, and more precisely to examine whether this modality could result in better visualization and detection of microcalcifications. Investigations were carried out using a 3D breast software phantom of average thickness, monoenergetic and polyenergetic beam spectra and various detector configurations. Dual-shot techniques were simulated. Results showed the advantage of using monoenergetic in comparison with polyenergetic beams. Optimization studies with monochromatic sources were carried out to obtain the optimal low and high incident energies, based on the assessment of the figure of merit of the simulated microcalcifications in the subtracted images. The results of the simulation study with the optimal energies demonstrated that the use of the DE technique can improve visualization and increase detectability, allowing identification of microcalcifications of sizes as small as 200 μm. The quantitative results are also verified by means of a visual inspection of the synthetic images

A study on energy security and nuclear energy role

International Nuclear Information System (INIS)

Ujita, Hiroshi

2011-01-01

Energy security was a major concern for OECD governments in the early 1970s. Since then, successive oil crises, volatility of hydrocarbon prices, as well as terrorist risks and natural disasters, have brought the issue back to the centre stage of policy agendas. Here, an energy security concept has been proposed, which is defined by time frame and space frame as well. Wide-meaning energy security is divided broadly into two categories. One is short-term (∼10 y) energy crisis, which is narrow-meaning energy security. Short-term energy crisis is further divided into contingent crisis, such as energy supply chain (sealane) interruption due to conflict, accident, terrorism, etc., and structural crisis, such as price fluctuations, supply shortage, energy demand increase in Asia, technology development stagnation, etc. The other is long-term (∼100 y) energy crisis and global energy problems, such as fossil fuel exhaustion and global warming. (author)

Study of heavy quarkonium with energy dependent potential

International Nuclear Information System (INIS)

Gupta, Pramila; Mehrotra, I

2009-01-01

It is well known that charmonium and bottonium states can be calculated by using a nonrelativistic Schrodinger equation. The basic reasons are: 1) the mass of charm and bottom quarks is much larger than QCD scale, which makes this system free of strong normalization effects and 2) the binding energy is small compared to the mass energy ψ and γ states in terms of nonrelativistic qq system governed by more or less phenomenological potentials. In the present work we have studied mass spectra of charmonium and bottonium using the following energy dependent model in the framework of nonrelativistic Schrodinger equation

Study deep geothermal energy; Studie dypgeotermisk energi

Energy Technology Data Exchange (ETDEWEB)

Havellen, Vidar; Eri, Lars Sigurd; Andersen, Andreas; Tuttle, Kevin J.; Ruden, Dorottya Bartucz; Ruden, Fridtjof; Rigler, Balazs; Pascal, Christophe; Larsen, Bjoern Tore

2012-07-01

The study aims to analyze the potential energy with current technology, challenges, issues and opportunities for deep geothermal energy using quantitative analysis. It should especially be made to identify and investigate critical connections between geothermal potential, the size of the heating requirements and technical solutions. Examples of critical relationships may be acceptable cost of technology in relation to heating, local geothermal gradient / drilling depth / temperature levels and profitability. (eb)

A comparative study on performance of CBN inserts when turning steel under dry and wet conditions

Science.gov (United States)

Abdullah Bagaber, Salem; Razlan Yusoff, Ahmad

2017-10-01

Cutting fluids is the most unsustainable components of machining processes, it is negatively impacting on the environmental and additional energy required. Due to its high strength and corrosion resistance, the machinability of stainless steel has attracted considerable interest. This study aims to evaluate performance of cubic boron nitride (CBN) inserts for the machining parameters includes the power consumption and surface roughness. Due to the high single cutting-edge cost of CBN, the performance of significant is importance for hard finish turning. The present work also deals with a comparative study on power consumption and surface roughness under dry and flood conditions. Turning process of the stainless steel 316 was performed. A response surface methodology based box-behnken design (BBD) was utilized for statistical analysis. The optimum process parameters are determined as the overall performance index. The comparison study has been done between dry and wet stainless-steel cut in terms of minimum value of energy and surface roughness. The result shows the stainless still can be machined under dry condition with 18.57% improvement of power consumption and acceptable quality compare to the wet cutting. The CBN tools under dry cutting stainless steel can be used to reduce the environment impacts in terms of no cutting fluid use and less energy required which is effected in machining productivity and profit.

A comparative review of accident studies from recent environmental impact statements

International Nuclear Information System (INIS)

Mueller, C.; Folga, S.; Nabelssi, B.

1996-01-01

The U.S. Department of Energy (DOE) has recently prepared or is in the process of preparing a number of programmatic and site-specific environmental impact statements (EISs). This study was conducted for the purpose of reviewing the self-consistency of programmatic alternatives, associated relative impacts, and supporting data, methods, and assumptions in EISs prepared for related activities. The following EISs, which deal with waste management issues, are reviewed in this paper (the parenthetical acronyms are referred to in Table 1): (1) Final Environmental Impact Statement, Savannah River Site Waste Management, DOE/EIS-0217, Vol. II, July 1995. (SRS WM-EIS), (2) Draft Waste Management Programmatic Environmental Impact Statement for Managing Treatment, Storage, and Disposal of Radioactive and Hazardous Waste, DOE/EIS-0200-D, Vol. IV, Aug. 1995. (WM PEIS), (3) Final Environmental Impact Statement, Interim Management of Nuclear Materials at the Savannah River Site. DOE/EIS-0220, Oct. 1995. (IMNM EIS), (4) Department of Energy Programmatic Spent Nuclear Fuel Management and Idaho National Engineering Laboratory Environmental Restoration and Waste Management Programs Environmental Impact Statement, DOE/EIS-0203-F, April 1995. (INEL Site-Wide-EIS), (5) Draft Environmental Impact Statement, Disposition of Surplus Highly Enriched Uranium, DOE/EIS-0240-D, Oct. 1995. (HEU Disposition EIS), (6) Final Environmental Impact Statement, Safe Interim Storage of Hanford Tank Wastes, Hanford Site, Richland, Washington, DOE/EIS-0212, Oct. 1995. (SIS EIS). This study compares the facility accident analysis approaches used in these EISs vis-a-vis the National Environmental Policy Act (NEPA) guidance developed by DOE (Recommendations for the Preparation of Environmental Assessments and Environmental Impact Statements, Office of NEPA Oversight). The purpose of the comparative review of these approaches with NEPA guidance is to identify potential preferred paths for future EISs

Compare of Energy Efficiency of Windows in Aalborg and Chongqing

DEFF Research Database (Denmark)

Lin, Zhenguo; Heiselberg, Per; Yao, Runming

2007-01-01

Focus on window's energy efficiency, this paper compared the difference of windows in Aalborg and Chongqing. The author analysed the designing process, the thermal insulation performances, the sun shading devices and the ventilation of windows in Aalborg and Chongqing respectively. Furthermore......, the author explored the reasons for window problems in Chongqing, found out the main barriers to overcome and measures to take for solving the problem. Deeper analysis should be made before the energy efficient windows of Aalborg used in Chongqing....

An Energy Consumption Study for a Malaysian University

OpenAIRE

Fu E. Tang

2012-01-01

The increase in energy demand has raised concerns over adverse impacts on the environment from energy generation. It is important to understand the status of energy consumption for institutions such as Curtin Sarawak to ensure the sustainability of energy usage, and also to reduce its costs. In this study, a preliminary audit framework was developed and was conducted around the Malaysian campus to obtain information such as the number and specifications of electrical appl...

A comparative analysis of energy demand and expenditures by minority and majority households within the context of a conditional demand system

Energy Technology Data Exchange (ETDEWEB)

Poyer, D.A.

1992-08-01

Analysis and evaluation of the impact that programs and policies have on energy consumption and expenditures are confounded by many intervening variables. A clear understanding of how these variables influence energy consumption patterns should be grounded in a rigorously developed framework. In this regard much is documented in the literature. However, an analysis of the comparative relationship between energy demand and variables which influence it among different socioeconomic groups has not been thoroughly explored with any theoretical rigor. It is proposed that differences in patterns of energy use between black, Hispanic, and majority households (where the household head is neither black nor Hispanic) are due to both structural and distribution differences. It is felt that the structural dissimilarities are primarily due to the dynamic nature in which energy consumption patterns evolve, with differences in changing housing patterns playing a significant role. For minorities, this implies a potential difference in the effect of policy and programs on economic welfare when compared to majority households.To test this hypothesis, separate conditional demand systems are estimated for majority, black, and Hispanic households. With the use of separate variance/covariance matrices, various parameter groups are tested for statistically significant differences.

A comparative analysis of energy demand and expenditures by minority and majority households within the context of a conditional demand system

Energy Technology Data Exchange (ETDEWEB)

Poyer, D.A.

1992-01-01

Analysis and evaluation of the impact that programs and policies have on energy consumption and expenditures are confounded by many intervening variables. A clear understanding of how these variables influence energy consumption patterns should be grounded in a rigorously developed framework. In this regard much is documented in the literature. However, an analysis of the comparative relationship between energy demand and variables which influence it among different socioeconomic groups has not been thoroughly explored with any theoretical rigor. It is proposed that differences in patterns of energy use between black, Hispanic, and majority households (where the household head is neither black nor Hispanic) are due to both structural and distribution differences. It is felt that the structural dissimilarities are primarily due to the dynamic nature in which energy consumption patterns evolve, with differences in changing housing patterns playing a significant role. For minorities, this implies a potential difference in the effect of policy and programs on economic welfare when compared to majority households.To test this hypothesis, separate conditional demand systems are estimated for majority, black, and Hispanic households. With the use of separate variance/covariance matrices, various parameter groups are tested for statistically significant differences.

A COMPARATIVE ANALYSIS OF ENERGY MANAGEMENT STRATEGIES FOR ELECTRIC VEHICLES

OpenAIRE

ÇAKAR, Fahri; YILMAZ, Musa; ASKER, Mehmet Emin

2016-01-01

In next two decade duration the electric car will participate a significant role in auto marketing. The electrical car use electric that is supported by current electrical network. Indeed the current electrical network cannot support the hole system in specific time in the case of loading electric car to it that will increase the demand in that specific time duration. To support the electric car energy requirement you have to manage both energy generation and energy consumption. The solution ...

Italian energy scenarios comparative evaluations

International Nuclear Information System (INIS)

Contaldi, Mario

2005-01-01

This paper reviews some representative scenarios of the evolution of the Italian primary energy consumption, updated recently. After an overview of the main macroeconomics assumptions the scenario results are cross checked at sectorial level, with a brief discussion of the underlining data and energy intensity trends. The emissions of CO 2 , SO 2 and NO x resulting from the considered scenarios are also reported and discussed [it

Empirical Study on Annual Energy-Saving Performance of Energy Performance Contracting in China

Directory of Open Access Journals (Sweden)

Hongquan Ruan

2018-05-01

Full Text Available A lack of trust in Energy Service Company (ESCo is the most critical factor affecting the development of Energy Performance Contracting (EPC in China, compared with other constraints. One cannot easily estimate the energy-saving performance of an EPC project. Under that condition, lack of trust may cause the Energy-Consuming Unit (ECU to suspect the energy-saving performance promised by the ESCo, thus leaving potentially profitable projects without necessary funding. Currently, specific studies taking an across-projects viewpoint on annual energy-saving performance of EPC projects in multiple subsectors, objectively and quantitatively, are lacking. This paper studies the regression relationships of annual energy-saving quantity in terms of revamping cost and the regression relationships of annual cost saving in terms of revamping cost. The regression results show that there are statistically significant correlations in the above relationships in the nine subsectors investigated. This is significant for ESCos and ECUs, because knowledge on energy-saving performance could contribute to EPC investment decisions and trust relationships between ESCos and ECUs. Then, a multiple linear regression model of revamping cost is set up to analyze its influencing factors. The model indicates that the subsector the sample belongs to, financing, registered capital of the ESCo, and contract period have significant effects on revamping cost. Thus, policy implications regarding innovation of EE promotion technology, clarifying ESCos’ exit mechanism, innovation of financing mechanism, and improving the market credit environment for promoting investment in EPC projects, are provided.

Radioactive Reversal? The Fukushima Accident as a Focusing Event for Comparative Policy Change on Nuclear Energy

Science.gov (United States)

Sanchez, Victoria Justine

This dissertation project examines the 2011 Fukushima nuclear accident as a focusing event for policy change on nuclear energy. For example, following the accident, Germany (and much of Europe) experienced a reversal of policy on nuclear energy. Conversely, many others such as China, Russia, and France, did not exhibit such a retraction against nuclear power, albeit with public debate about the risks and consequences of accidents. Why has there been dramatic policy change in some cases but not others? The political and literal fallout of Fukushima has provoked a wave of policy change towards nuclear energy at the national level. Through qualitative and quantitative measures, we can view Fukushima as an impetus for comparing the dynamics of nuclear policy change. Quantitatively, this project employs logistic regression to explore variables such as regime type, energy security, trade supply and demand, climate change concerns, and public acceptance are related to policy outcomes and change on nuclear energy in the post-Fukushima context of 49 different countries. Qualitatively, country cases (Russia, Germany, and Canada) are assessed into three categories based on the outcome of policy decisions on nuclear energy following Fukushima for a richer analysis. Beyond the Fukushima example, we can hope to better understand how political focusing events can gain influence in an international context.

A critical assessment of energy accident studies

International Nuclear Information System (INIS)

Felder, Frank A.

2009-01-01

A comparison of two studies conducted ten years apart on energy accidents provides important insights into methodological issues and policy implications. Recommendations for further improvements in energy accident studies are developed including accounting for differences between average and incremental accident damages, testing for appropriate levels of aggregation of accidents, making references and databases publicly available, more precisely defining and reporting different types of economic damages, accounting for involuntary and voluntary risks, reporting normalized damages, raising broader public policy and planning implications and updating existing accident databases.

A critical assessment of energy accident studies

Energy Technology Data Exchange (ETDEWEB)

Felder, Frank A. [Edward J. Bloustein School of Planning and Public Policy, Rutgers, The State University of New Jersey, 33 Livingston Avenue, New Brunswick, NJ 08901 (United States)

2009-12-15

A comparison of two studies conducted ten years apart on energy accidents provides important insights into methodological issues and policy implications. Recommendations for further improvements in energy accident studies are developed including accounting for differences between average and incremental accident damages, testing for appropriate levels of aggregation of accidents, making references and databases publicly available, more precisely defining and reporting different types of economic damages, accounting for involuntary and voluntary risks, reporting normalized damages, raising broader public policy and planning implications and updating existing accident databases. (author)

Preliminary design studies for a 100 MW Energy Amplifier prototype

CERN Document Server

Abánades, A

2000-01-01

The Energy Amplifier (EA) is a new concept of fission system based on a subcritical assembly sustained with the neutrons generated by proton beam impact on a heavy element (spallation). This concept, proposed by the Nobel Laureate C. Rubbia (Rubbia, 1995), has remarkable capabilities in the nuclear energy field. First, it can be used to transmute radioactive wastes with a high efficiency alleviating the requirements of the geological repositories, and, second, it provides a massive energy source with the intrinsic safety derived from the use of a subcritical system and an almost null production of long-lived radioactive wastes. EA concept principles have been successfully tested by two experiments at CERN: FEAT (Andriamonge, 1995), that proved there is a net energy gain, by comparing the energy needed by the accelerator with the generated one by fission in the subcritical system. The second experiment, TARC (Abanades, 1997; Arnould, 1999) demonstrated the capability to transmute radioactive elements. The next...

An Optimisation Study on Integrating and Incentivising Thermal Energy Storage (TES in a Dwelling Energy System

Directory of Open Access Journals (Sweden)

Gbemi Oluleye

2018-04-01

Full Text Available In spite of the benefits from thermal energy storage (TES integration in dwellings, the penetration rate in Europe is 5%. Effective fiscal policies are necessary to accelerate deployment. However, there is currently no direct support for TES in buildings compared to support for electricity storage. This could be due to lack of evidence to support incentivisation. In this study, a novel systematic framework is developed to provide a case in support of TES incentivisation. The model determines the costs, CO2 emissions, dispatch strategy and sizes of technologies, and TES for a domestic user under policy neutral and policy intensive scenarios. The model is applied to different building types in the UK. The model is applied to a case study for a detached dwelling in the UK (floor area of 122 m2, where heat demand is satisfied by a boiler and electricity imported from the grid. Results show that under a policy neutral scenario, integrating a micro-Combined Heat and Power (CHP reduces the primary energy demand by 11%, CO2 emissions by 21%, but with a 16 year payback. Additional benefits from TES integration can pay for the investment within the first 9 years, reducing to 3.5–6 years when the CO2 levy is accounted for. Under a policy intensive scenario (for example considering the Feed in Tariff (FIT, primary energy demand and CO2 emissions reduce by 17 and 33% respectively with a 5 year payback. In this case, the additional benefits for TES integration can pay for the investment in TES within the first 2 years. The framework developed is a useful tool is determining the role TES in decarbonising domestic energy systems.

A comparative study of density functional and density functional tight binding calculations of defects in graphene

Energy Technology Data Exchange (ETDEWEB)

Zobelli, Alberto [Laboratoire de Physique des Solides, Univ. Paris Sud, CNRS UMR, Orsay (France); Ivanovskaya, Viktoria; Wagner, Philipp; Yaya, Abu; Ewels, Chris P. [Institut des Materiaux Jean Rouxel (IMN), CNRS UMR, University of Nantes (France); Suarez-Martinez, Irene [Nanochemistry Research Institute, Curtin University of Technology, Perth, Western Australia (Australia)

2012-02-15

The density functional tight binding approach (DFTB) is well adapted for the study of point and line defects in graphene based systems. After briefly reviewing the use of DFTB in this area, we present a comparative study of defect structures, energies, and dynamics between DFTB results obtained using the dftb+ code, and density functional results using the localized Gaussian orbital code, AIMPRO. DFTB accurately reproduces structures and energies for a range of point defect structures such as vacancies and Stone-Wales defects in graphene, as well as various unfunctionalized and hydroxylated graphene sheet edges. Migration barriers for the vacancy and Stone-Wales defect formation barriers are accurately reproduced using a nudged elastic band approach. Finally we explore the potential for dynamic defect simulations using DFTB, taking as an example electron irradiation damage in graphene. DFTB-MD derived sputtering energy threshold map for a carbon atom in a graphene plane. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A comparative study of the tail ion distribution with reduced Fokker-Planck models

Science.gov (United States)

McDevitt, C. J.; Tang, Xian-Zhu; Guo, Zehua; Berk, H. L.

2014-03-01

A series of reduced models are used to study the fast ion tail in the vicinity of a transition layer between plasmas at disparate temperatures and densities, which is typical of the gas and pusher interface in inertial confinement fusion targets. Emphasis is placed on utilizing progressively more comprehensive models in order to identify the essential physics for computing the fast ion tail at energies comparable to the Gamow peak. The resulting fast ion tail distribution is subsequently used to compute the fusion reactivity as a function of collisionality and temperature. While a significant reduction of the fusion reactivity in the hot spot compared to the nominal Maxwellian case is present, this reduction is found to be partially recovered by an increase of the fusion reactivity in the neighboring cold region.

Computer usage and national energy consumption: Results from a field-metering study

Energy Technology Data Exchange (ETDEWEB)

Desroches, Louis-Benoit [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Fuchs, Heidi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Greenblatt, Jeffery [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Pratt, Stacy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Willem, Henry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Claybaugh, Erin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Beraki, Bereket [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Nagaraju, Mythri [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Price, Sarah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division; Young, Scott [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis & Environmental Impacts Dept., Environmental Energy Technologies Division

2014-12-01

The electricity consumption of miscellaneous electronic loads (MELs) in the home has grown in recent years, and is expected to continue rising. Consumer electronics, in particular, are characterized by swift technological innovation, with varying impacts on energy use. Desktop and laptop computers make up a significant share of MELs electricity consumption, but their national energy use is difficult to estimate, given uncertainties around shifting user behavior. This report analyzes usage data from 64 computers (45 desktop, 11 laptop, and 8 unknown) collected in 2012 as part of a larger field monitoring effort of 880 households in the San Francisco Bay Area, and compares our results to recent values from the literature. We find that desktop computers are used for an average of 7.3 hours per day (median = 4.2 h/d), while laptops are used for a mean 4.8 hours per day (median = 2.1 h/d). The results for laptops are likely underestimated since they can be charged in other, unmetered outlets. Average unit annual energy consumption (AEC) for desktops is estimated to be 194 kWh/yr (median = 125 kWh/yr), and for laptops 75 kWh/yr (median = 31 kWh/yr). We estimate national annual energy consumption for desktop computers to be 20 TWh. National annual energy use for laptops is estimated to be 11 TWh, markedly higher than previous estimates, likely reflective of laptops drawing more power in On mode in addition to greater market penetration. This result for laptops, however, carries relatively higher uncertainty compared to desktops. Different study methodologies and definitions, changing usage patterns, and uncertainty about how consumers use computers must be considered when interpreting our results with respect to existing analyses. Finally, as energy consumption in On mode is predominant, we outline several energy savings opportunities: improved power management (defaulting to low-power modes after periods of inactivity as well as power scaling), matching the rated power

A field study of energy consumption in wheat production in Canterbury, New Zealand

International Nuclear Information System (INIS)

Safa, M.; Samarasinghe, S.; Mohssen, M.

2011-01-01

Research highlights: → We determine the energy use in wheat production base on farm operation and energy sources on dryland and irrigated farms in New Zealand. → The study estimate and compare different energy inputs in wheat production using around 40 samples. → The results show fertilizer is the most important energy inputs on farms. → The significant correlation between energy use and wheat production must be taken into consideration. -- Abstract: This paper examines the energy consumption of wheat production in Canterbury province, New Zealand. This study was conducted within a 35,300 ha of irrigated and dry land wheat fields in Canterbury in the 2007-2008 harvest year. Total energy consumption for wheat production was estimated at 25,600 MJ/ha. On average, fertilizer and electricity were used more than other energy sources, at around 10,654 (47%) and 4870 (22%) MJ/ha, respectively. The energy consumption for wheat in irrigated farming systems and dry land farming systems was estimated at 25,600 and 17,458 MJ/ha, respectively. The main source of energy in both systems is fertilizer and it consumed around 10,188 and 11,429 MJ/ha for irrigated farming and dry land farming, respectively. The average operational energy consumption was 7997 MJ/ha. In irrigated farming system, operational energy was approximately three times more than that in dry land farming. The maximum energy consumed in operational wheat production was about 7762 (71%) MJ/ha for irrigated farming systems, including irrigation, and it was 1451 (46%) MJ/ha for dry land farming including tillage. The average values of estimated output to input energy ratio for wheat in irrigated and dry land farming systems were 11.5 and 15.1, respectively.

40-Hz square-wave stimulation requires less energy to produce muscle contraction: compared with the TASER® X26 conducted energy weapon.

Science.gov (United States)

Comeaux, James A; Jauchem, James R; Cox, D Duane; Crane, Carrie C; D'Andrea, John A

2013-07-01

Conducted energy weapons (CEWs) (including the Advanced TASER(®) X26 model produced by TASER International, Inc.) incapacitate individuals by causing muscle contractions. In this study using anesthetized swine, the potential incapacitating effect of primarily monophasic, 19-Hz voltage imposed by the commercial CEW was compared with the effect of voltages imposed by a laboratory device that created 40-Hz square waves. Forces of muscle contraction were measured with the use of strain gauges. Stimulation with 40-Hz square waves required less pulse energy than stimulation with the commercial CEW to produce similar muscle contraction. The square-pulse stimulation, at the higher repetition rate, caused a more complete tetanus at a lower energy. Use of such a simple shape of waveform may be used to make future nonlethal weapon devices more efficient. © 2013 American Academy of Forensic Sciences Published 2013. This article is a U.S. Government work and is in the public domain in the U.S.A.

Comparing long term energy scenarios; Scenari energetici di lungo termine

Energy Technology Data Exchange (ETDEWEB)

Cumo, M.; Simbolotti, G. [Rome Univ. La Sapienza, Rome (Italy)

2001-02-01

Major projection studies by international organizations and senior analysts have been compared with reference to individual key parameters (population, energy demand/supply, resources, technology, emissions and global warming) to understand trends and implications of the different scenarios. Then, looking at the long term (i.e., 2050 and beyond), parameters and trends have been compared together to understand and quantify whether and when possible crisis or market turbulence might occur due to shortage of resources or environmental problems. [Italian] Viene presentato un confronto degli scenari energetici di lungo termine formulati dalle agenzie internazionali e dai maggiori analisti del settore con particolare riferimento alla evoluzione di specifici parametri quali sviluppo demografico, domanda e offerta di energia, risorse energetiche, sviluppo tecnologico, emissioni e relativi cambiamenti climatici. L'evoluzione e l'interdipendenza dei singoli aspetti vengono analizzate al fine di individuare la possibile evenienza di crisi o turbolenze dei mercati energetici indotte da carenza di risorse o da problemi ambientali.

Feasibility of generating quantitative composition images in dual energy mammography: a simulation study