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Sample records for analysis increases power

  1. Filtering for increased power for microarray data analysis

    Directory of Open Access Journals (Sweden)

    Hess Ann M

    2009-01-01

    Full Text Available Abstract Background Due to the large number of hypothesis tests performed during the process of routine analysis of microarray data, a multiple testing adjustment is certainly warranted. However, when the number of tests is very large and the proportion of differentially expressed genes is relatively low, the use of a multiple testing adjustment can result in very low power to detect those genes which are truly differentially expressed. Filtering allows for a reduction in the number of tests and a corresponding increase in power. Common filtering methods include filtering by variance, average signal or MAS detection call (for Affymetrix arrays. We study the effects of filtering in combination with the Benjamini-Hochberg method for false discovery rate control and q-value for false discovery rate estimation. Results Three case studies are used to compare three different filtering methods in combination with the two false discovery rate methods and three different preprocessing methods. For the case studies considered, filtering by detection call and variance (on the original scale consistently led to an increase in the number of differentially expressed genes identified. On the other hand, filtering by variance on the log2 scale had a detrimental effect when paired with MAS5 or PLIER preprocessing methods, even when the testing was done on the log2 scale. A simulation study was done to further examine the effect of filtering by variance. We find that filtering by variance leads to higher power, often with a decrease in false discovery rate, when paired with either of the false discovery rate methods considered. This holds regardless of the proportion of genes which are differentially expressed or whether we assume dependence or independence among genes. Conclusion The case studies show that both detection call and variance filtering are viable methods of filtering which can increase the number of differentially expressed genes identified. The

  2. Analysis of power and frequency control requirements in view of increased decentralized production and market liberalization

    NARCIS (Netherlands)

    Roffel, Brian; Boer, de Wouter W.

    2003-01-01

    This paper presents a systematic approach of the analysis of the minimum control requirements that are imposed on power producing units in the Netherlands, especially in the case when decentralized production increases. Also some effects of the liberalization on the control behavior are analyzed. Fi

  3. Economic Analysis of Cikaso Mini Hydro Power Plant as a CDM Project for Increasing IRR

    Directory of Open Access Journals (Sweden)

    Irhan Febijanto

    2013-12-01

    Full Text Available Renewable energy fueled power generations are few developed by private sector in Indonesia. High-cost investment and low electricity selling price to PT PLN as a single buyer is main barriers for private sector to involve in the development of renewable energy fueled power generations. In this project, the economic feasibility of Mini Hydro Power Plant of Cikaso with capacity of 5.3 MW, located at Sukabumi Regency, West Java province was assessed. This project utilized revenue generated from carbon market to increase the economic feasibility. Procedure to register the project to United Nation for Climate Change Convention (UNFCCC as a Clean Development Mechanism project was explained in detail. Approved Consolidation Methodology (ACM 0002 Version 12.3.0 was used to calculate grid emission factor in Jawa-Bali-Madura the grid electricity system. It was calculated that the grid emission factor is 0.833 (t-CO2/MWh, and the carbon emission reduction generated for this project is 21,982 ton/year. From the analysis result, it can be proven that the additional revenue from carbon credit could increase the project IRR from 10.28% to 13.52%.

  4. UV-visible microscope spectrophotometric polarization and dichroism with increased discrimination power in forensic analysis

    Science.gov (United States)

    Purcell, Dale Kevin

    merit investigated included: 1) wavelength accuracy, 2) wavelength precision, 3) wavelength resolution stability, 4) photometric accuracy, 5) photometric precision, 6) photometric linearity, 7) photometric noise, and 8) short-term baseline stability. In addition, intrinsic instrument polarization effects were investigated to determine the impact of these properties on spectral interpretation and data quality. Finally, a set of recommendations were developed which describe instrument performance characteristics for microscope and spectrometer features and functions, and specific instrument parameters that must be controlled in order to acquire high quality data from an ultraviolet-visible forensic microscope spectrophotometer system for increased discrimination power.

  5. Analysis of liquid relief valves opening demand during pressure increase abnormal scenarios at Embalse nuclear power plant

    International Nuclear Information System (INIS)

    Two hypothetical scenarios have been analyzed where, after an initiating event, Embalse nuclear power plant primary heat transport system could undergo a pressure increase. These abnormal events are a loss of feedwater to the steam generators and a loss of Class IV power supply with Class III restoration. This analysis focuses on primary system liquid relief valves action, specially on their opening demand. Calculation results show that even when these valves are expected to open during the transient, primary system maximum allowable pressure would not be exceeded if they failed to open. System response was also studied in case that one of these relief valves did not close once primary system pressure decreases. For the scenario of loss of feedwater to steam generators, if the degasser-condenser could not be bottled-up, Emergency Cooling Injection conditions would be reached due to a continuos loss of coolant. In case of loss of Class IV -and assuming degasser-condenser bottling-up as service water would not be available- it was observed that primary system should remain pressurized, and with core cooled by thermo siphoning mechanism. (author)

  6. Program increasing of nuclear power plant safeness

    International Nuclear Information System (INIS)

    The results achieved within the project of national task 'Program increasing of nuclear power plant safeness' are presented in the document. The project was aimed to extend and deepen activities relating to safety increase of nuclear power units WWER-440 which play significant part in electricity production in the Slovak Republic. The application of advanced foreign calculating programs and calculation of radionuclide spreading in environment and techniques will influence the increase of extent, quality and international acceptance of safety analysis of nuclear power plant blocks WWER-440 and the risk valuation from operating nuclear power plants. Methodic resources for coping in emergency situation in nuclear energetics will be used for support in decision making in real time during radiation emergency on nuclear plant, region and state level. A long-term strategy in dealing with burnt fuel and radioactive substance formatting during nuclear power plant liquidation particularly with waste which is un acceptable in regional dump, has developed into a theoretical and practical preparation of solvable group for operating the converting centre Bohunice and in inactivating the nuclear power plant A-1. The diagnostic activities in nuclear power plants in the Slovak Republic have been elaborated into a project of norm documents in accordance with international norms for diagnostic systems. Presentation of new technologies and materials for repairs and reconstructions of components and nuclear power plant knots qualify increase in their reliability, safety and life. New objective methods and criterions for valuation and monitoring of the residual life and safety of fixed nuclear power plants. Results of problem solving linked with connecting the blocks of nuclear power plants to frequency regulation in electric network in the Slovak Republic are also presented in the document

  7. Analysis of current state of transformer equipment, its role and place in affording safety, increasing power- and ecological effectiveness operation of units of nuclear power stations of Ukraine

    International Nuclear Information System (INIS)

    Analysis of technical state, life service and reliability of modern transformer equipment of power generating units of nuclear power stations (NPS) was conducted. Cause-and-effect factors of pre-emergency and emergency faults of transformers have been analyzed. Technical offers aimed at improvement of efficiency and reliability parameters of transformer equipment operation on NPS units were developed.

  8. RETRAN safety analysis to increase the over-pressure safety margin for OPR1000 nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Woon [Dongguk Univ., Gyeongju (Korea, Republic of). Nuclear and Energy Engineering Dept.

    2016-02-15

    A need to enlarge the pressurizer set point tolerances is desirable to prevent unnecessary tests. The increase of test tolerances needs verification by safety analyses. Existing safety analysis method are too conservative to accommodate the expanded tolerance. To overcome this insufficient margin, two approaches are taken: First one is to increase valve discharge flow rate, reactor coolant pump coast down delay time and trip delay time retaining the analysis code, CESEC. The second one is changing a computer code to a realistic code such as RETRAN.

  9. Alternative analysis to increase the power in combined-cycle power plants; Analisis de alternativas para el incremento de potencia en plantas termoelectricas de Ciclo Combinado

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco Cruz, Hector; Arriola Medellin, Alejandro M. [Gerencia de Procesos Termicos, Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: hpacheco@iie.org.mx; aarriola@iie.org.mx

    2010-11-15

    The electricity industry traditionally had two thermodynamic cycles for power generation: conventional steam turbine (Rankine cycle) used to supply a base load during the day, and gas turbines (Brayton cycle), for its speed response, normally used to cover peak loads. However, to provide variable peak loads, the gas turbine, as a volumetric machine is affected by the change in air density by changing the combustion temperature. This paper shows the scheme of integration of both systems, that it's known as combined cycle and the different options that would have these power plants, to maintain or increase their power in variable ambient conditions. It analyzes different options, such as: 1. Supplementary fire in the stove. 2. Air cooling intake in the gas turbine (evaporation system or mechanical system). 3. Steam injection in the combustion chamber. [Spanish] La industria electrica tradicionalmente a contado con dos ciclos termodinamicos para generacion electrica: las turbinas convencionales de vapor (ciclo de Rankine) se utilizan para suministrar una carga base durante el dia, y las turbinas de gas (ciclo de Brayton), por su rapidez de respuesta, se utilizan normalmente para cubrir las cargas pico. Sin embargo, para suministrar las cargas variables pico, la turbina a gas, por ser una maquina volumetrica, se ve afectada por el cambio de la densidad del aire de combustion al cambiar la temperatura ambiente. En este trabajo se muestra el esquema de integracion de ambos sistemas, en lo que se conoce como ciclo combinado y las diferentes opciones que tendrian estas plantas de generacion electrica para mantener o incrementar su potencia en condiciones ambiente variable. Para ello se analizan diferentes opciones, tales como: 1.- Combustion suplementaria en el recuperador de calor. 2.- Enfriamiento del aire de admision a la turbina de gas (mediante un sistema de evaporacion o mediante un sistema mecanico). 3.- Inyeccion de vapor a la camara de combustion. Palabras

  10. NEPAL AND INDIA MAY INCREASE POWER TRADING

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Nepal and India may increase the quantity of power exchanged between the two nations to meet shortages in bordering areas. Technical paneles from the two countries have recommended that the power exchange be raised from 50MW to 150MW, according to Bholanath Chalise, chief of the state-run Nepal Electricity Authority(NEA).

  11. System-wide emissions implications of increased wind power penetration.

    Science.gov (United States)

    Valentino, Lauren; Valenzuela, Viviana; Botterud, Audun; Zhou, Zhi; Conzelmann, Guenter

    2012-04-01

    This paper discusses the environmental effects of incorporating wind energy into the electric power system. We present a detailed emissions analysis based on comprehensive modeling of power system operations with unit commitment and economic dispatch for different wind penetration levels. First, by minimizing cost, the unit commitment model decides which thermal power plants will be utilized based on a wind power forecast, and then, the economic dispatch model dictates the level of production for each unit as a function of the realized wind power generation. Finally, knowing the power production from each power plant, the emissions are calculated. The emissions model incorporates the effects of both cycling and start-ups of thermal power plants in analyzing emissions from an electric power system with increasing levels of wind power. Our results for the power system in the state of Illinois show significant emissions effects from increased cycling and particularly start-ups of thermal power plants. However, we conclude that as the wind power penetration increases, pollutant emissions decrease overall due to the replacement of fossil fuels.

  12. Power system analysis

    CERN Document Server

    Murty, PSR

    2007-01-01

    Power system analysis is a pre-requisite course for electrical engineering students. This book introduces concepts of a power system, network model faults and analysis and the primitive network stability. It also deals with graph theory relevant to various incidence matrices, building of network matrices and power flow studies. It further discusses with short circuit analysis, unbalanced fault analysis and power system stability problems, such as, steady state stability, transient stability and dynamic stability. Salient Features: Number of worked examples are followed after explaining theory

  13. Wind Power Ramping Product for Increasing Power System Flexibility

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Mingjian; Zhang, Jie; Wu, Hongyu; Hodge, Bri-Mathias; Ke, Deping; Sun, Yuanzhang

    2016-05-05

    With increasing penetrations of wind power, system operators are concerned about a potential lack of system flexibility and ramping capacity in real-time dispatch stages. In this paper, a modified dispatch formulation is proposed considering the wind power ramping product (WPRP). A swinging door algorithm (SDA) and dynamic programming are combined and used to detect WPRPs in the next scheduling periods. The detected WPRPs are included in the unit commitment (UC) formulation considering ramping capacity limits, active power limits, and flexible ramping requirements. The modified formulation is solved by mixed integer linear programming. Numerical simulations on a modified PJM 5-bus System show the effectiveness of the model considering WPRP, which not only reduces the production cost but also does not affect the generation schedules of thermal units.

  14. Combined analysis of data from two granddaughter designs: A simple strategy for QTL confirmation and increasing experimental power in dairy cattle

    Directory of Open Access Journals (Sweden)

    Blümel Jürgen

    2003-05-01

    Full Text Available Abstract A joint analysis of five paternal half-sib Holstein families that were part of two different granddaughter designs (ADR- or Inra-design was carried out for five milk production traits and somatic cell score in order to conduct a QTL confirmation study and to increase the experimental power. Data were exchanged in a coded and standardised form. The combined data set (JOINT-design consisted of on average 231 sires per grandsire. Genetic maps were calculated for 133 markers distributed over nine chromosomes. QTL analyses were performed separately for each design and each trait. The results revealed QTL for milk production on chromosome 14, for milk yield on chromosome 5, and for fat content on chromosome 19 in both the ADR- and the Inra-design (confirmed within this study. Some QTL could only be mapped in either the ADR- or in the Inra-design (not confirmed within this study. Additional QTL previously undetected in the single designs were mapped in the JOINT-design for fat yield (chromosome 19 and 26, protein yield (chromosome 26, protein content (chromosome 5, and somatic cell score (chromosome 2 and 19 with genomewide significance. This study demonstrated the potential benefits of a combined analysis of data from different granddaughter designs.

  15. Structural Power: The limits of neorealist power analysis

    OpenAIRE

    GUZZINI, Stefano

    1993-01-01

    (The article is an earlier version of Chapters 5 and 6 of the author's EUI PhD Thesis, 1994.) http://hdl.handle.net/1814/5139 Realism explains the ruling of the international system through the underlying distribution of power among states. Increasingly, analysts have found this power analysis inadequate, and they have developed new concepts, most prominently structural power. The usage of structural power actually entails three different meanings, namely indirect institutional power, ...

  16. Soil Parameter Mapping and Ad Hoc Power Analysis to Increase Blocking Efficiency Prior to Establishing a Long-Term Field Experiment

    Directory of Open Access Journals (Sweden)

    Doug Collins

    2015-01-01

    Full Text Available The spatial heterogeneity of soil and weed populations poses a challenge to researchers. Unlike aboveground variability, below-ground variability is more difficult to discern without a strategic soil sampling pattern. While blocking is commonly used to control environmental variation, this strategy is rarely informed by data about current soil conditions. Fifty georeferenced sites were located in a 0.65 ha area prior to establishing a long-term field experiment. Soil organic matter (OM and weed seed bank populations were analyzed at each site and the spatial structure was modeled with semivariograms and interpolated with kriging to map the surface. These maps were used to formulate three strategic blocking patterns and the efficiency of each pattern was compared to a completely randomized design and a west to east model not informed by soil variability. Compared to OM, weeds were more variable across the landscape and had a shorter range of autocorrelation, and models to increase blocking efficiency resulted in less increase in power. Weeds and OM were not correlated, so no model examined improved power equally for both parameters. Compared to the west to east blocking pattern, the final blocking pattern chosen resulted in a 7-fold increase in power for OM and a 36% increase in power for weeds.

  17. Valka to increase biofuel power capacity

    Index Scriptorium Estoniae

    2011-01-01

    Eesti Energia omandas enamusosaluse Valka soojusettevõttes Host Energo. Eesti Energiale kuulub nüüd 90% ettevõttest ja linnale 10%. Ettevõte uus nimi on Enefit Heat&Power Valka ja viimane rajab aastaks 2012 Valka uue biokütusel koostootmisjaama

  18. Power electronics reliability analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mark A.; Atcitty, Stanley

    2009-12-01

    This report provides the DOE and industry with a general process for analyzing power electronics reliability. The analysis can help with understanding the main causes of failures, downtime, and cost and how to reduce them. One approach is to collect field maintenance data and use it directly to calculate reliability metrics related to each cause. Another approach is to model the functional structure of the equipment using a fault tree to derive system reliability from component reliability. Analysis of a fictitious device demonstrates the latter process. Optimization can use the resulting baseline model to decide how to improve reliability and/or lower costs. It is recommended that both electric utilities and equipment manufacturers make provisions to collect and share data in order to lay the groundwork for improving reliability into the future. Reliability analysis helps guide reliability improvements in hardware and software technology including condition monitoring and prognostics and health management.

  19. Power system analysis

    CERN Document Server

    Kumar, Narenkumarsanjiv

    2010-01-01

    This book has been written for B. Tech/B.Sc (Engg.)/B.E. students. It consists of seven chapters in all, covering the complete topics systematically and exhaustively. The book is designed as a complete course text of 'Power System Analysis' for undergraduate students of electrical engineering in accordance with the syllabi of Delhi Technological University, Indraprastha University, and Other India Universities/Institutions. This book is to meet the needs of Third Year (6th Semester) students of B.Tech. (Electrical Engineering and Electrical & Electronics Engineering) studying in Engineering co

  20. Investigating power control in autonomous power systems with increasing wind power penetration

    Energy Technology Data Exchange (ETDEWEB)

    Margaris, Ioannis D. [National Technical Univ. of Athens (Greece). Electric Energy Systems Lab.; Hansen, Anca D.; Sorensen, Poul [Risoe National Laboratory, Roskilde (Denmark). Wind Energy Dept.; Hatziargyriou, Nikos D. [National Technical Univ. of Athens (Greece). Electric Energy Systems Lab.; Public Power Corporation S.A., Athens (Greece)

    2009-07-01

    Increasing levels of wind penetration in autonomous power systems has set intensively high standards with respect to wind turbine technology during the last years. Special features of non-interconnected power systems make security issues rather critical, as the operation of large wind farms like conventional power plants is becoming a necessity. This paper includes the study case of Rhodos island, in Greece, where rapidly increasing wind penetration has started to impose serious security issues for the immediate future. The scenarios studied here correspond to reference year of study 2012 and include wind farms with three different wind turbine technologies - namely Doubly Fed Induction Generator (DFIG), Permanent Magnet Synchronous Generator (PMSG) and Active Stall Induction Generator (ASIG) based wind turbines. Aggregated models of the wind farms are being used and results for different load cases are being analyzed and discussed. The ability of wind farms to assist in some of the power system control services traditionally carried out by conventional synchronous generation is being investigated and discussed. The power grid of the island, including speed governors and automatic voltage regulators, is simulated in the dedicated power system simulation program Power Factory from DIgSILENT. (orig.)

  1. Prospects of increasing the power of a two-circuit geothermal power plant

    International Nuclear Information System (INIS)

    The results of analysis of the thermodynamical cycle of the geothermal NPPs secondary circuit with various versions of the geothermal circulation system are presented. It is shown, that the technological scheme with horizontal well is the optimal one. The conclusion is made that by further assimilation of thermal power with application of the experience, accumulated by petroleum specialist, it is necessary to built up geothermal circulation systems with horizontal wells. This will sharply increase the indices of the geothermal branch, its efficiency and competivity as compared to the traditional power engineering

  2. Power and death: Mortality salience increases power seeking while feeling powerful reduces death anxiety.

    Science.gov (United States)

    Belmi, Peter; Pfeffer, Jeffrey

    2016-05-01

    According to Terror Management Theory, people respond to reminders of mortality by seeking psychological security and bolstering their self-esteem. Because previous research suggests that having power can provide individuals a sense of security and self-worth, we hypothesize that mortality salience leads to an increased motivation to acquire power, especially among men. Study 1 found that men (but not women) who wrote about their death reported more interest in acquiring power. Study 2A and Study 2B demonstrated that when primed with reminders of death, men (but not women) reported behaving more dominantly during the subsequent week, while both men and women reported behaving more prosocially during that week. Thus, mortality salience prompts people to respond in ways that help them manage their death anxiety but in ways consistent with normative gender expectations. Furthermore, Studies 3-5 showed that feeling powerful reduces anxiety when mortality is salient. Specifically, we found that when primed to feel more powerful, both men and women experienced less mortality anxiety. (PsycINFO Database Record PMID:26867106

  3. Gov't to Spur Consumption by Increasing Purchasing Power

    Institute of Scientific and Technical Information of China (English)

    Xinhua

    2005-01-01

    @@ The Chinese central government aims to spur domestic consump tion by increasing consumer purchasing power in the coming years in a bid to continue maintaining a steady development of the nation's economy.

  4. Gov't to Spur Consumption by Increasing Purchasing Power

    Institute of Scientific and Technical Information of China (English)

    Xinhua

    2005-01-01

      The Chinese central government aims to spur domestic consump tion by increasing consumer purchasing power in the coming years in a bid to continue maintaining a steady development of the nation's economy.……

  5. Prony Analysis for Power System Transient Harmonics

    Directory of Open Access Journals (Sweden)

    Qi Li

    2007-01-01

    Full Text Available Proliferation of nonlinear loads in power systems has increased harmonic pollution and deteriorated power quality. Not required to have prior knowledge of existing harmonics, Prony analysis detects frequencies, magnitudes, phases, and especially damping factors of exponential decaying or growing transient harmonics. In this paper, Prony analysis is implemented to supervise power system transient harmonics, or time-varying harmonics. Further, to improve power quality when transient harmonics appear, the dominant harmonics identified from Prony analysis are used as the harmonic reference for harmonic selective active filters. Simulation results of two test systems during transformer energizing and induction motor starting confirm the effectiveness of the Prony analysis in supervising and canceling power system transient harmonics.

  6. RF Power Amplifier Analysis

    Directory of Open Access Journals (Sweden)

    M. Lokay

    1993-04-01

    Full Text Available The special program is presented for the demonstration of RF power transistor amplifiers for the purposes of the high-school education in courses of radio transmitters. The program is written in Turbo Pascal 6. 0 and enables to study the waveforms in selected points of the amplifier and to draw the trajectories of the working point in a plot of output transistor characteristics.

  7. Thermal Analysis of Power Transformer

    OpenAIRE

    Kravchenko E.V.; Ivleva D. Yu.

    2015-01-01

    A new approach for predicting the reliability indices based on the numerical analysis of nonuniform temperature fields of power transformer is reported. The failure rates of a power transformer in a real thermal mode of device under natural convection were compared with statistical data.. The necessity of unsteady temperature field consideration was shown to enchance the reliability prediction

  8. Empirical analysis of buyer power

    OpenAIRE

    Beckert, Walter

    2009-01-01

    This paper provides a comprehensive econometric framework for the empirical analysis of buyer power. It encompasses the two main features of pricing schemes in business-to-business relationships: nonlinear price schedules and bargaining over rents. Disentangling them is critical to the empirical identification of buyer power. Testable predictions from the theoretical analysis are delineated, and a pragmatic empirical methodology is presented. It is readily implementable on the basis of transa...

  9. High power beam analysis

    Science.gov (United States)

    Aharon, Oren

    2014-02-01

    In various modern scientific and industrial laser applications, beam-shaping optics manipulates the laser spot size and its intensity distribution. However the designed laser spot frequently deviates from the design goal due to real life imperfections and effects, such as: input laser distortions, optical distortion, heating, overall instabilities, and non-linear effects. Lasers provide the ability to accurately deliver large amounts of energy to a target area with very high accuracy. Thus monitoring beam size power and beam location is of high importance for high quality results and repeatability. Depending on the combination of wavelength, beam size and pulse duration , laser energy is absorbed by the material surface, yielding into processes such as cutting, welding, surface treatment, brazing and many other applications. This article will cover the aspect of laser beam measurements, especially at the focal point where it matters the most. A brief introduction to the material processing interactions will be covered, followed by fundamentals of laser beam propagation, novel measurement techniques, actual measurement and brief conclusions.

  10. Does green consumerism increase the acceptance of wind power?

    International Nuclear Information System (INIS)

    In this paper, we discuss what might be termed an action-based learning approach to promoting important pro-environmental actions, such as support for or acceptance of environmental policy. Such an approach involves promoting simple and easy behaviours as entry points for more radical steps towards sustainability, referred to as “catalytic” or “wedge” behaviours. Despite the obvious need for innovative approaches to promote important pro-environmental behaviour, and sound theoretical backing for such concepts, there is a lack of research testing the key propositions of this approach. In a survey study based on a random sample of residents of the state of Maine, USA, we find that both everyday “green” behaviour and the acceptance of an expansion of wind power are rooted in environmental concern and that everyday “green” behaviour gives a significant contribution to predicting acceptance of wind power when controlling for environmental concern. Hence, the promotion of everyday “green” behaviours may prepare the grounds for increasing acceptance of more far-reaching changes in the population, such as an expansion of wind power. - Highlights: ► Acceptance of wind power increases with environmental concern. ► So does everyday “green” consumerism. ► Green consumerism further increases acceptance of wind power. ► The effect of environmental concern on acceptance is partly mediated through green consumerism. ► Participants in the study are a random sample of residents of Maine, USA.

  11. Configuration for sudden power increase in steam turbines

    International Nuclear Information System (INIS)

    For a sudden increase of the power of a steam turbine without impairing feedwater supply to the boiler, the patent proposes to install another heat transfer element, separately heated, in the feedwater circuit. This heat transfer element starts operation when the flow of extraction steam to the feedwater heaters is cut off. The configuration is described in detail. (HP)

  12. Thermal Power Plant Performance Analysis

    CERN Document Server

    2012-01-01

    The analysis of the reliability and availability of power plants is frequently based on simple indexes that do not take into account the criticality of some failures used for availability analysis. This criticality should be evaluated based on concepts of reliability which consider the effect of a component failure on the performance of the entire plant. System reliability analysis tools provide a root-cause analysis leading to the improvement of the plant maintenance plan.   Taking in view that the power plant performance can be evaluated not only based on  thermodynamic related indexes, such as heat-rate, Thermal Power Plant Performance Analysis focuses on the presentation of reliability-based tools used to define performance of complex systems and introduces the basic concepts of reliability, maintainability and risk analysis aiming at their application as tools for power plant performance improvement, including: ·         selection of critical equipment and components, ·         defini...

  13. Aspects on Dynamic Power Flow Controllers and Related Devices for Increased Flexibility in Electric Power Systems

    OpenAIRE

    Johansson, Nicklas

    2011-01-01

    This thesis studies different aspects of Flexible AC Transmission System (FACTS) devices which are used to improve the power transfer capability and increase the controllability in electric power systems. In the thesis, different aspects on the usage and control of Dynamic Power Flow Controllers (DPFC) and related FACTS devices are studied. The DPFC is a combination of a Phase Shifting Transformer (PST) and a Thyristor Switched Series Capacitor (TSSC)/Thyristor Switched Series Reactor (TSSR)....

  14. Optical Gravitational Wave Antenna with Increased Power Handling Capability

    CERN Document Server

    Matsko, Andrey B; Yamamoto, Hiroaki; Vyatchanin, Sergey P

    2015-01-01

    Fundamental sensitivity of an optical interferometric gravitational wave detector increases with increase of the optical power which, in turn, limited because of the opto-mechanical parametric instabilities of the interferometer. We propose to optimize geometrical shape of the mirrors of the detector to reduce the diffraction-limited finesse of unessential optical modes of the interferometer resulting in increase of the threshold of the opto-mechanical instabilities and subsequent increase of the measurement sensitivity. Utilizing parameters of the LIGO interferometer we found that the proposed technique allows constructing a Fabry-Perot interferometer with round trip diffraction loss of the fundamental mode not exceeding $5$~ppm, whereas the loss of the first dipole as well as the other high order modes exceed $1,000$~ppm and $8,000$~ppm, respectively. The optimization comes at the price of tighter tolerances on the mirror tilt stability, but does not result in a significant modification of the optical beam ...

  15. Power electronic systems Walsh analysis with Matlab

    CERN Document Server

    Deb, Anish

    2014-01-01

    A Totally Different Outlook on Power Electronic System AnalysisPower Electronic Systems: Walsh Analysis with MATLAB® builds a case for Walsh analysis as a powerful tool in the study of power electronic systems. It considers the application of Walsh functions in analyzing power electronic systems, and the advantages offered by Walsh domain analysis of power electronic systems. Solves Power Electronic Systems in an Unconventional WayThis book successfully integrates power electronics as well as systems and control. Incorporating a complete orthonormal function set very much unlike the sine-cosin

  16. Power Quality Analysis in Off-Grid Power Platform

    Directory of Open Access Journals (Sweden)

    Stanislav Misak

    2014-01-01

    Full Text Available Research projects in the field of electrical distribution systems are moving to a new philosophy of Smart Grids, where the effort is to use the maximum possible share of power from renewable energy potential. Under this philosophy the emphasis is on energy independence, reliability and safety of operation of energy distribution system. Research in this area leads for example to developing of autonomous local microgrids with the several specific requirements. However, the problem of parameters keeping of quality of electric energy can arise together with increased penetration of distributed generation in microgrids. This problem is caused by decreased short-circuit power of local renewable energy sources, stochastic supply of electric energy from renewable energy sources and operating of active distribution grid in autonomous mode without connection to the external distribution system. General introduction to the power quality evaluation in off-grid power system is introduced in this paper. Initial results from power quality analysis from small off-grids system is presented in this text too.

  17. Application of Interline Power Flow Controller to Increase Transient Stability of Power System

    Directory of Open Access Journals (Sweden)

    Prechanon Kumkratug

    2010-01-01

    Full Text Available Problem statement: The Interline Power Flow Controller (IPFC is a novel device which can increase transient stability of power system. To verify the capability of the effect of IPFC on stability improvement of power system, the suitable mathematical model and control strategy of IPFC are needed to be presented. Approach: This study presented the mathematical model and control strategy of IPFC. The multi-series converters of IPFC are represented by multi-series voltage sources with associate transformer leakage reactance. The parameters of IPFC are modeled into power flow equation and thus it is used to determine control strategy. This study used Bang-Bang control strategy. The swing curves of the three phase faulted power system without and with an IPFC are tested and compared in various cases. Results: The swing curve of system without an IPFC get increased monotonically and thus the system can be considered as unstable whereas the swing curves of system with an IPFC can return to stable equilibrium point. Conclusion: The presented model of IPFC can help us to comprehend the effect of IPFC on transient stability improvement of power system. From simulation results, the IPFC can increase transient stability of power system.

  18. Effects of increased impeller power in a production-scale Aspergillus oryzae fermentation.

    Science.gov (United States)

    Li, Zheng Jian; Shukla, Vivek; Wenger, Kevin S; Fordyce, Andrew P; Pedersen, Annemarie Gade; Marten, Mark R

    2002-01-01

    The goal in this study was to determine how increased impeller power affects enzyme expression in large-scale (80 m(3)), fed-batch Aspergillus oryzae fermentations. An approximate 50% increase in average impeller power was achieved by increasing impeller diameter approximately 10%, while operating at slightly reduced speed. Measured decreases in terminal (95%) mixing time show increased power improved bulk mixing. However, batches operated at increased power had lower recombinant enzyme productivity. Biomass assays and image analysis tests showed no significant difference between "high power" and control batches, suggesting that slower growth, altered morphology, or increased hyphal fragmentation were not the cause of reduced productivity. Off-line tests on the shear-thinning, highly viscous broth show oxygen limitation occurred after transport through the air-liquid interface and imply the limitation may involve bulk mixing. Specifically, oxygen transfer may be limited to a small zone surrounding each impeller. When this is the case, oxygen mass transfer will be determined by both impeller shear and fluid circulation, which have been characterized with the energy dissipation/circulation function (EDCF). EDCF values during control fermentations were approximately constant at 25 kW m (-3) s(-1), while EDCF values during "high power" batches fell linearly from 40 to 15 kW m (-3) s(-1). The point at which "high power" EDCF values drop below those in control fermentations corresponds almost exactly with the point at which product titer stops increasing. Thus, our findings suggest oxygen mass transfer was less efficient during the latter half of "high power" fermentations because of reductions in impeller speed and subsequent decreases in EDCF values. This observation has clear implications during the scale-up of viscous fungal fermentations, implying that not only is the level of impeller power important, but also relevant is how this power is applied. PMID:12052056

  19. Increasing Power of Groupwise Association Test with Likelihood Ratio Test

    Science.gov (United States)

    Sul, Jae Hoon; Han, Buhm; Eskin, Eleazar

    Sequencing studies have been discovering a numerous number of rare variants, allowing the identification of the effects of rare variants on disease susceptibility. As a method to increase the statistical power of studies on rare variants, several groupwise association tests that group rare variants in genes and detect associations between groups and diseases have been proposed. One major challenge in these methods is to determine which variants are causal in a group, and to overcome this challenge, previous methods used prior information that specifies how likely each variant is causal. Another source of information that can be used to determine causal variants is observation data because case individuals are likely to have more causal variants than control individuals. In this paper, we introduce a likelihood ratio test (LRT) that uses both data and prior information to infer which variants are causal and uses this finding to determine whether a group of variants is involved in a disease. We demonstrate through simulations that LRT achieves higher power than previous methods. We also evaluate our method on mutation screening data of the susceptibility gene for ataxia telangiectasia, and show that LRT can detect an association in real data. To increase the computational speed of our method, we show how we can decompose the computation of LRT, and propose an efficient permutation test. With this optimization, we can efficiently compute an LRT statistic and its significance at a genome-wide level. The software for our method is publicly available at http://genetics.cs.ucla.edu/rarevariants.

  20. Power analysis of trials with multilevel data

    CERN Document Server

    Moerbeek, Mirjam

    2015-01-01

    Power Analysis of Trials with Multilevel Data covers using power and sample size calculations to design trials that involve nested data structures. The book gives a thorough overview of power analysis that details terminology and notation, outlines key concepts of statistical power and power analysis, and explains why they are necessary in trial design. It guides you in performing power calculations with hierarchical data, which enables more effective trial design.The authors are leading experts in the field who recognize that power analysis has attracted attention from applied statisticians i

  1. Cree criticize HQ power analysis

    International Nuclear Information System (INIS)

    Response of the Grand Council of the Crees in Quebec to the development of hydro-electric resources on the Great Whale River in the James Bay region and its impact on Quebec's Cree population was discussed. The Cree have condemned the generation market power analysis which Hydro-Quebec Energy Services submitted to the U.S. Federal Energy Regulatory Commission (FERC) in support of an application for a FERC power marketer license. The Cree argued that the license would result in the flooding of Cree hunting lands and the destruction of prime wildlife habitat. Hydro-Quebec argued that the utility would not act without the agreement of the Cree, and would not do anything that is not acceptable to the people living in the area

  2. Gas-core reactor power transient analysis.

    Science.gov (United States)

    Kascak, A. F.

    1972-01-01

    The nuclear fuel in the gas-core reactor concept is a ball of uranium plasma radiating thermal photons. The photons are met by an inflowing hydrogen stream, which is seeded with submicron size, depleted uranium particles. A 'wall-burnout' condition exists if the thermal photons can reach the cavity liner because of insufficient absorption by the hydrogen. An analysis was conducted in order to determine the time for which the maximum steady state reactor power could be exceeded without damage to the cavity liner due to burnout. Wall-burnout time as a function of the power increase above the initial steady state condition is shown in a graph.

  3. PowerFactory applications for power system analysis

    CERN Document Server

    Gonzalez-Longatt, Francisco

    2014-01-01

    This book presents a comprehensive set of guidelines and applications of DIgSILENT PowerFactory, an advanced power system simulation software package, for different types of power systems studies. Written by specialists in the field, it combines expertise and years of experience in the use of DIgSILENT PowerFactory with a deep understanding of power systems analysis. These complementary approaches therefore provide a fresh perspective on how to model, simulate and analyse power systems. It presents methodological approaches for modelling of system components, including both classical and non-

  4. Impact of Production from Photovoltaic Power Plants on Increase of Ancillary Services in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Martin Smocek

    2016-01-01

    Full Text Available Renewable energy resources represent a noticeable part of the overall energetic concept development. New integration of renewable energy resources into power grids has a significant impact on the reliability and quality of power supply. The major problem of the photovoltaic and wind power plants is their dependency on weather conditions, since it has a direct effect on their immediate output produced that shows stochastic behaviour. These stochastic outputs result in very adverse impacts on the power grid. Further development of these resources could lead to exceeding of the control and absorption abilities of the power grid. The power grid must be set in balance with respect to the production and consumption of electric power at any time. The operation of photovoltaic power plants impair keeping this balance. That has an adverse impact on the very operation and maintenance of network parameters within the extent required. This survey deals with analysis focused on operation of the photovoltaic power plants with respect to the increase of reserve power in ancillary services in the Czech Republic.

  5. How fast increasing powers of a continuous random variable converge to Benford's law

    OpenAIRE

    Wójcik, Michał Ryszard

    2013-01-01

    It is known that increasing powers of a continuous random variable converge in distribution to Benford's law as the exponent approaches infinity. The rate of convergence has been estimated using Fourier analysis, but we present an elementary method, which is easier to apply and provides a better estimation in the widely studied case of a uniformly distributed random variable.

  6. Focus: Increasing profitability from powerful assets. Annual report for 1998

    International Nuclear Information System (INIS)

    Report on operations at the end of fiscal year 1998 and on the year-end financial position of PanCanadian Petroleum Limited is provided. By all accounts the company had a successful year: increased production by seven percent to 796 mmcf/day, making the company the largest publicly traded gas producer in Canada; ranked as one of lowest-cost producers in western Canada with average operating costs of $ 0.37/mcf; drilled 1,081 new wells at a success rate of 85 per cent and increased royalty interest production five per cent to an average of 26,700 barrels of oil equivalent per day. Other achievements included drilling in Nova Scotia, land and license aquisition in the Gulf of Mexico and in the North Sea respectively, acquisition of a 15 per cent interest in two exploration blocks off the Ivory Coast in West Africa, refining of proprietory seismic technologies developed in recent years, reduction of average well costs by 10 per cent by using new drill bit technology, consolidation of Canadian and American natural gas marketing groups to increase market access across North America, and management reorganization of the Heavy Oil Business Unit. In addition to details of these and other achievements, the report also contains management analysis of key business results, the consolidated financial statements and various operating and financial statistics and results

  7. Energy system, electricity market and economic studies on increasing nuclear power capacity

    International Nuclear Information System (INIS)

    Objective of this research project is to examine effects of addition of nuclear capacity from three different angles by using energy system, electricity market and economic analysis. In each area the analysis is based on computational methods. Finland is a member of Nordic electricity market which is further connected to networks of Continental Europe and Russia. Due to the foreign connections Finland has been able to import inexpensive electricity from its neighboring countries and this state is expected to continue. Addition of nuclear capacity lowers electricity import demand, affects level of electricity price decreasingly and decreases shortfall of installed production capacity. Substantial additions of nuclear power capacity and generous import supply have disadvantageous effect on profitability of combined heat and power production. The development of import possibilities depends on progression of difficult-to-estimate balance between electricity consumption and production in the neighboring countries. Investments on nuclear power increase national product during the construction phase. Growth of employment is also rather significant, especially during the construction phase. In the long term permanent jobs will be created too. Increase of employment is held back by increasing real wages, but it is though evident that consumer purchasing power is improved due to these nuclear power developments. (orig.)

  8. Analysis of a solar powered absorption system

    International Nuclear Information System (INIS)

    Highlights: • Conventional absorption system modified to increase COP. • Results indicated increase of 10% in COP due to dephlegmator heat recovery. • Results indicated increase of 8% in COP due to refrigerant storage unit. • Results indicated increase of 18% in COP due to combined effect of modifications. • Simulation results indicated a very good agreement with the measured results. - Abstract: Today, fossil fuel is the primary extensively used source of energy. However, its negative impact on the environment have forced the energy research continuity to seriously consider renewable sources of energy. Solar energy, in particular, has been the main focus in this regard because it is a source of clean energy and naturally available. This study presents the design and analysis of a solar powered absorption refrigeration system modified to increase its coefficient of performance (COP). The modifications include recovering of waste heat from a dephlegmator and utilization of a refrigerant storage unit. The simulation results indicate an increase of 10% in the COP of the conventional design using dephlegmator heat recovery and an increase of 8% in the COP of the conventional design due to the use of a refrigerant storage. The analysis for the combined effect of modifications indicates an increase of 18% in the COP compared to conventional design. Calculated values of coefficient of performance indicate a very good agreement with the ones obtained based on measurement

  9. Increasing power generation in horizontal axis wind turbines using optimized flow control

    Science.gov (United States)

    Cooney, John A., Jr.

    In order to effectively realize future goals for wind energy, the efficiency of wind turbines must increase beyond existing technology. One direct method for achieving increased efficiency is by improving the individual power generation characteristics of horizontal axis wind turbines. The potential for additional improvement by traditional approaches is diminishing rapidly however. As a result, a research program was undertaken to assess the potential of using distributed flow control to increase power generation. The overall objective was the development of validated aerodynamic simulations and flow control approaches to improve wind turbine power generation characteristics. BEM analysis was conducted for a general set of wind turbine models encompassing last, current, and next generation designs. This analysis indicated that rotor lift control applied in Region II of the turbine power curve would produce a notable increase in annual power generated. This was achieved by optimizing induction factors along the rotor blade for maximum power generation. In order to demonstrate this approach and other advanced concepts, the University of Notre Dame established the Laboratory for Enhanced Wind Energy Design (eWiND). This initiative includes a fully instrumented meteorological tower and two pitch-controlled wind turbines. The wind turbines are representative in their design and operation to larger multi-megawatt turbines, but of a scale that allows rotors to be easily instrumented and replaced to explore new design concepts. Baseline data detailing typical site conditions and turbine operation is presented. To realize optimized performance, lift control systems were designed and evaluated in CFD simulations coupled with shape optimization tools. These were integrated into a systematic design methodology involving BEM simulations, CFD simulations and shape optimization, and selected experimental validation. To refine and illustrate the proposed design methodology, a

  10. Invertible Clipping for Increasing the Power Efficiency of OFDM Amplification

    OpenAIRE

    Ragusa, Salvatore; Palicot, Jacques; Louët, Yves; Lereau, Christian

    2006-01-01

    International audience Large fluctuations of OFDM signal amplitude represent an important problem for power amplification in mobile communication systems. In this paper, we propose a new Peak-to-Average Power Ratio (PAPR) reduction method based on the well known clipping and filtering one. Called "invertible clipping", it is performed thanks to a "soft clipping function". Since this soft clipping can be inverted in reception side, degradations are compensated. The derived method benefits f...

  11. GAS POWERED MUCOADHESIVE SYSTEM TO INCREASE GASTRIC RETENTION

    OpenAIRE

    Zikriya Abrar; Quazi Aamer; Jathar Rajashree; Supute Trupti

    2012-01-01

    A lot of scientific and technological advancements have been made in the drug delivery research in the recent years. Physiological problems like short Gastric Residence Time (GRT) and the unpredictable Gastric Emptying Time (GET) were overcome with the use of gas powered mucoadhesive dosage forms which provide opportunity for both local and systemic drug action. Several approaches are currently being used in the prolongation of GRT, which includes the Gas Powered Drug Delivery Systems (GPDDS)...

  12. SYNTHESIS OF MODULAR UNINTERRUPTED POWER SUPPLY SYSTEMS WITH INCREASED RELIABILITY

    Directory of Open Access Journals (Sweden)

    Grigorash O. V.

    2015-04-01

    Full Text Available The level of technical development today requires the creation of highly effective, including reliable, uninter-rupted power supply systems. We have shown modern requirements and design features of modern systems of uninterruptible power supply, which should be built on a modular principle. It is shown that the problem of synthesis of systems in a modular approach is addressing three issues: development of the structure of the system subject to the requirements of consumers to quality of power and the allowable time of power outage; determining the required level redundancy of major functional units (blocks, elements to ensure the required reliability of the system; - ensuring the most effective interconnection of modules, including electromagnetic compatibility, and the rational use during normal and emergency operation of the system. We have proposed new structural solution of the main functional units and uninterrupted power supply systems in modular design. To reduce EMI and improve efficiency uninterruptible power supply systems in the design of static converters we need to use a transformer with a rotating magnetic field. In addition, the prospective current is to be used as a source of renewable energy. Another promising approach is the use of direct frequency converters as voltage stabilizers and frequency of the current

  13. Net energy analysis - powerful tool for selecting elective power options

    Energy Technology Data Exchange (ETDEWEB)

    Baron, S. [Brookhaven National Laboratory, Upton, NY (United States)

    1995-12-01

    A number of net energy analysis studies have been conducted in recent years for electric power production from coal, oil and uranium fuels; synthetic fuels from coal and oil shale; and heat and electric power from solar energy. This technique is an excellent indicator of investment costs, environmental impact and potential economic competitiveness of alternative electric power systems for energy planners from the Eastern European countries considering future options. Energy conservation is also important to energy planners and the net energy analysis technique is an excellent accounting system on the extent of energy resource conservation. The author proposes to discuss the technique and to present the results of his studies and others in the field. The information supplied to the attendees will serve as a powerful tool to the energy planners considering their electric power options in the future.

  14. WAYS OF POWER EFFICIENCY INCREASE AT DRYING DISPERSABLE PRODUCTS

    OpenAIRE

    Burdo O.G.; Kazmiruk Iu.A.

    2008-01-01

    In the article questions of power, duration of process and quality production’s quality during drying are discussed. The new approach to modeling of drying and drying equipment is proved. Ways of perfection technologies of drying are analyzed. The mechanism and mathematical model of drying’s process of dispersive staffs by the combined way are presented.

  15. Laser power conversion system analysis

    Science.gov (United States)

    1982-01-01

    Orbit to orbit and orbit to ground laser power conversion systems and power transfer are discussed. A system overview is presented. Pilot program parameters are considered: SLPS assumptions are listed, a laser SPS overview is presented, specifications are listed, and SLPS coats are considered.

  16. Probabilistic analysis of power assignments

    NARCIS (Netherlands)

    Graaf, de Maurits; Manthey, Bodo

    2014-01-01

    A fundamental problem for wireless ad hoc networks is the assignment of suitable transmission powers to the wireless devices such that the resulting communication graph is connected. The goal is to minimize the total transmit power in order to maximize the life-time of the network. Our aim is a prob

  17. Modelling of electrical power systems for power flow analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cogo, Joao Roberto [Escola Federal de Engenharia de Itajuba, MG (Brazil)

    1994-12-31

    The industry systems in Brazil are responsible for a consumption of over 50% (fifty per cent) of the total electrical power generated: therefore, they are import loads in power flow studies, and their modeling should be as much the best. Usually, in power flow studies, the industry systems are modeled by taking the influence of the power (active and reactive) and of the current on the voltage into account. Since the inducting motors, within the industry systems, represent at least 50% (fifty per cent) of the power consumption, and a large part of them is oversize, it is proposed to represent the industry systems as a function of the characteristic of power on shaft versus voltage into account. Since the induction motors, within the industry systems, represent at least 50% (fifty per cent) of the power consumption, and a large part of them is oversized, it is proposed to represent the industry systems as a function of the characteristics of power on shaft versus voltage for the analysis of power systems, aiming a load flow study. Thereafter, a model of an equivalent motor which has a basis the typical performance curve of an induction motor is present. This model is obtained from empirical parameters, surveyed from a population of over 1000 motors. (author) 3 refs., 1 fig., 4 tabs.

  18. Mandatory direct marketing of wind power increases financing costs

    OpenAIRE

    Grau, Thilo; Neuhoff, Karsten; Tisdale, Matthew

    2015-01-01

    The 2014 reform of the Renewable Energy Sources Act (Erneuerbare-Energien- Gesetz, or EEG) entailed that a mandatory direct marketing of green electricity be introduced. According to this law, operators of larger wind turbines must sell their electricity production on the electricity market. In addition to the wholesale price they receive a floating market premium, which is based on the average market value of all wind power in Germany. The mandatory direct marketing affects both the costs in...

  19. Mandatory Direct Marketing of Wind Power Increases Financing Costs

    OpenAIRE

    Thilo Grau; Karsten Neuhoff; Matthew Tisdale

    2015-01-01

    The 2014 reform of the Renewable Energy Sources Act (Erneuerbare-Energien- Gesetz, or EEG) entailed that a mandatory direct marketing of green electricity be introduced. According to this law, operators of larger wind turbines must sell their electricity production on the electricity market. In addition to the wholesale price they receive a floating market premium, which is based on the average market value of all wind power in Germany. The mandatory direct marketing affects both the costs in...

  20. Power Analysis Software for Educational Researchers

    Science.gov (United States)

    Peng, Chao-Ying Joanne; Long, Haiying; Abaci, Serdar

    2012-01-01

    Given the importance of statistical power analysis in quantitative research and the repeated emphasis on it by American Educational Research Association/American Psychological Association journals, the authors examined the reporting practice of power analysis by the quantitative studies published in 12 education/psychology journals between 2005…

  1. Supplement analysis, Southpoint power project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-16

    The Calpine Corporation applied to interconnect its proposed power plant with the Western Area Power Administration`s (Western) Parker-Davis project in western Arizona. Western, as a major electric transmission system owner is required by existing policies and regulations, to provide access to its transmission system, when requested by an eligible organization. The proposed interconnection would integrate a major source of new generation into the Parker-Davis system which would allow Calpine to supply its power to the electric wholesale market. Based on this application, Western`s proposed action is to enter into an interconnection agreement with Calpine.

  2. Failure analysis on China power grid based on power law

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng WENG; Yiguang HONG; Ancheng XUE; Shengwei MEI

    2006-01-01

    This paper is concerned with the mechanism of blackouts in China power system from the viewpoint of self-organized criticality. By using two estimation algorithms of scaled window variance (SWV) and rescaled rangestatistics (R/S), this paper studies the blackout data in China power system during 1988-1997. The result of analysis shows that the blackout data of 1994-1997 coincides well with the autocorrelation. Furthermore, it is found that the function of blackout probability vs. blackout size exhibits power law distribution.

  3. An Effective Distributed Model for Power System Transient Stability Analysis

    Directory of Open Access Journals (Sweden)

    MUTHU, B. M.

    2011-08-01

    Full Text Available The modern power systems consist of many interconnected synchronous generators having different inertia constants, connected with large transmission network and ever increasing demand for power exchange. The size of the power system grows exponentially due to increase in power demand. The data required for various power system applications have been stored in different formats in a heterogeneous environment. The power system applications themselves have been developed and deployed in different platforms and language paradigms. Interoperability between power system applications becomes a major issue because of the heterogeneous nature. The main aim of the paper is to develop a generalized distributed model for carrying out power system stability analysis. The more flexible and loosely coupled JAX-RPC model has been developed for representing transient stability analysis in large interconnected power systems. The proposed model includes Pre-Fault, During-Fault, Post-Fault and Swing Curve services which are accessible to the remote power system clients when the system is subjected to large disturbances. A generalized XML based model for data representation has also been proposed for exchanging data in order to enhance the interoperability between legacy power system applications. The performance measure, Round Trip Time (RTT is estimated for different power systems using the proposed JAX-RPC model and compared with the results obtained using traditional client-server and Java RMI models.

  4. Safety analysis of nuclear power plants

    International Nuclear Information System (INIS)

    A study about the safety analysis of nuclear power plant, giving emphasis to how and why to do is presented. The utilization of the safety analysis aiming to perform the licensing requirements is discussed, and an example of the Angra 2 and 3 safety analysis is shown. Some presented tendency of the safety analysis are presented and examples are shown.(E.G.)

  5. Hippocampal pattern completion is linked to gamma power increases and alpha power decreases during recollection.

    Science.gov (United States)

    Staresina, Bernhard P; Michelmann, Sebastian; Bonnefond, Mathilde; Jensen, Ole; Axmacher, Nikolai; Fell, Juergen

    2016-01-01

    How do we retrieve vivid memories upon encountering a simple cue? Computational models suggest that this feat is accomplished by pattern completion processes involving the hippocampus. However, empirical evidence for hippocampal pattern completion and its underlying mechanisms has remained elusive. Here, we recorded direct intracranial EEG as human participants performed an associative memory task. For each study (encoding) and test (retrieval) event, we derived time-frequency resolved representational patterns in the hippocampus and compared the extent of pattern reinstatement for different mnemonic outcomes. Results show that successful associative recognition (AR) yields enhanced event-specific reinstatement of encoding patterns compared to non-associative item recognition (IR). Moreover, we found that gamma power (50-90 Hz) increases - in conjunction with alpha power (8-12 Hz) decreases not only distinguish AR from IR, but also correlate with the level of hippocampal reinstatement. These results link single-shot hippocampal pattern completion to episodic recollection and reveal how oscillatory dynamics in the gamma and alpha bands orchestrate these mnemonic processes. PMID:27508355

  6. Increasing flexibility of coal power plant by control system modifications

    Directory of Open Access Journals (Sweden)

    Marušić Ante

    2016-01-01

    Full Text Available Expanding implementation of intermittent renewable energy sources has already started to change the role of thermal power plants in energy systems across Europe. Traditionally base load plants are now forced to operate as peaking plants. A familiar transition in upcoming years is expected in Croatia and coal power plant operators are preparing accordingly. To evaluate cycling capabilities and control system operation for flexible operation of selected 210 MW coal plant, series of tests with different load gradients were performed and results were thoroughly analyzed. Two possible “bottlenecks” are identified, thermal stress in superheater header, and achievable ramping rate considering operational limitations of coal feeders, firing system and evaporator dynamics. Several unexpected readings were observed, usually caused by malfunctioning sensors and equipment, resulting in unexpected oscillations of superheated steam temperature. Based on superheater geometry and experimental data, maximal steam temperature gradient during ramping was evaluated. Since thermal stress was well inside the safety margins, the simulation model of the whole boiler was used to evaluate achievable ramping on electric side.

  7. Exergoeconomic analysis of a nuclear power plant

    Science.gov (United States)

    Moreno, Roman Miguel

    Exergoeconomic analysis of a nuclear power plant is a focus of this dissertation. Specifically, the performance of the Palo Verde Nuclear Power Plant in Arizona is examined. The analysis combines thermodynamic second law exergy analysis with economics in order to assign costs to the loss and destruction of exergy. This work was done entirely with an interacting spreadsheets notebook. The procedures are to first determine conventional energy flow, where the thermodynamic stream state points are calculated automatically. Exergy flow is then evaluated along with destruction and losses. The capital cost and fixed investment rate used for the economics do not apply specifically to the Palo Verde Plant. Exergy costing is done next involving the solution of about 90 equations by matrix inversion. Finally, the analysis assigns cost to the exergy destruction and losses in each component. In this work, the cost of electricity (exergy), including capital cost, leaving the generator came to 38,400 /hr. The major exergy destruction occurs in the reactor where fission energy transfer is limited by the maxiμm permissible clad temperature. Exergy destruction costs were: reactor--18,207 hr, the low pressure turbine-2,000 /hr, the condenser--1,700 hr, the steam generator-1,200 $/hr. The inclusion of capital cost and O&M are important in new system design assessments. When investigating operational performance, however, these are sunk costs; only fuel cost needs to be considered. The application of a case study is included based on a real modification instituted at Palo Verde to reduce corrosion steam generator problems; the pressure in the steam generator was reduced from 1072 to 980 psi. Exergy destruction costs increased in the low pressure turbine and in the steam generator, but decreased in the reactor vessel and the condenser. The dissertation demonstrates the procedures and tools required for exergoeconomic analysis whether in the evaluation of a new nuclear reactor system

  8. Power System Transients Analysis by Wavelet Transforms

    Institute of Scientific and Technical Information of China (English)

    陈维荣; 宋永华; 赵蔚

    2002-01-01

    In contrast to Fourier transform, wavelet transform is especially suitable for transient analysis because of its time-frequency characteristics with automatically-adjusted window lengths. Research shows that wavelet transform is one of the most powerful tools for power system transient analysis. The basic ideas of wavelet transform are presented in the paper together with several power system applications. It is clear that wavelet transform has some clear advantages over other transforms in detecting, analyzing, and identifying various types of power system transients.

  9. Computer-aided power systems analysis

    CERN Document Server

    Kusic, George

    2008-01-01

    Computer applications yield more insight into system behavior than is possible by using hand calculations on system elements. Computer-Aided Power Systems Analysis: Second Edition is a state-of-the-art presentation of basic principles and software for power systems in steady-state operation. Originally published in 1985, this revised edition explores power systems from the point of view of the central control facility. It covers the elements of transmission networks, bus reference frame, network fault and contingency calculations, power flow on transmission networks, generator base power setti

  10. Dynamic security issues in autonomous power systems with increasing wind power penetration

    DEFF Research Database (Denmark)

    Margaris, I.D.; Hansen, Anca Daniela; Sørensen, Poul Ejnar;

    2011-01-01

    Asynchronous Generator (DFAG) and Permanent Magnet Synchronous Generator (PMSG) – are applied and issues regarding interaction with the power system are investigated. This paper provides conclusions about the dynamic security of non-interconnected power systems with high wind power penetration based...

  11. Statistical Analysis of the Impact of Wind Power on Market Quantities and Power Flows

    DEFF Research Database (Denmark)

    Pinson, Pierre; Jónsson, Tryggvi; Zugno, Marco;

    2012-01-01

    In view of the increasing penetration of wind power in a number of power systems and markets worldwide, we discuss some of the impacts that wind energy may have on market quantities and cross-border power flows. These impacts are uncovered through statistical analyses of actual market and flow data...... in Europe. Due to the dimensionality and nonlinearity of these effects, the necessary concepts of dimension reduction using Principal Component Analysis (PCA), as well as nonlinear regression are described. Example application results are given for European cross-border flows, as well as for the impact...... of load and wind power forecasts on Danish and German electricity markets....

  12. Power System Transient Stability Analysis Using SIMULINK

    OpenAIRE

    Ekinci, Serdar

    2015-01-01

    SIMULINK is one of the most widely used software in academia and industry for modelling, analysis and simulating dynamical systems. Using SIMULINK, the simulation model can be established systematically beginning from easy sub-models. This paper covers modelling, simulation and transient stability analysis of a multi-machine power system using SIMULINK for educational and research purposes. The detailed model is developed for power system transient stability simulation and its implementation ...

  13. Computational methods in power system analysis

    CERN Document Server

    Idema, Reijer

    2014-01-01

    This book treats state-of-the-art computational methods for power flow studies and contingency analysis. In the first part the authors present the relevant computational methods and mathematical concepts. In the second part, power flow and contingency analysis are treated. Furthermore, traditional methods to solve such problems are compared to modern solvers, developed using the knowledge of the first part of the book. Finally, these solvers are analyzed both theoretically and experimentally, clearly showing the benefits of the modern approach.

  14. An Analysis of the Internal Audit of Ningde Nuclear Power Company to Increase the Value of the Target%浅析宁德核电以增值为目标的内部审计

    Institute of Scientific and Technical Information of China (English)

    屈志鹏

    2015-01-01

    To increase the value of the organizationˊs objectives is to achieve the inte rnal audit of the internal audit of the important functions of the new definition of value-added services for enterprises as the fundamental objective of internal audit. Internal audit of Ningde nuclear power company is will add value to the enterprise as its ultimate goal and positioning, fully explain the meaning of the unique value of internal audit, and on this basis into practice.%增加价值从而实现组织目标是内部审计的重要职能,内部审计新的定义将为企业提供增值服务作为内部审计的根本目标. 宁德核电内部审计正是将为企业增加价值作为其最终目标与定位,充分阐释了其独有的内部审计增值的内涵,并在此基础上付诸实践.

  15. Having the Power to Forgive: When the Experience of Power Increases Interpersonal Forgiveness

    NARCIS (Netherlands)

    Karremans, J.C.T.M.; Smith, P.K.

    2010-01-01

    The present research examined the association between power, defined in terms of experienced control over outcomes and resources in a relationship, and interpersonal forgiveness. Based on recent findings in the literature suggesting that power is associated with goal directedness, it was hypothesize

  16. Analysis on Resources Utilization of Thermal Power Industry

    Institute of Scientific and Technical Information of China (English)

    Mi Jianhua

    2005-01-01

    Based on the analysis and comparison of coal, oil and water consumptions in thermal power plants, thispaper introduces the present state of resources utilization in thermal power industry, and points out that the poten-tial of resources saving lies mainly in cutting down coal consumption and increasing the ratio of large-sized thermalunits. Measures and suggestions for upgrading resources utilization are put forward, such as to optimize coal-firedthermal power structure, develop cogeneration, clean coal combustion techniques and gas-steam combined cycletechniques. The existing thermal power plants shall execute technical retrofits and popularize water saving techniques.

  17. Development of Standardized Power Electronic Components, Subsystems, and Systems for Increased Modularity and Scalability

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, S.; Pink, C.; Price, J.; Kroposki, B.; Kern, G.

    2007-11-01

    Power electronics devices hold substantial promise for making distributed energy applications more efficient and cost effective. This project is motivated towards developing and testing inverters that will allow distributed energy systems to provide ancillary services such as voltage and VAR regulation, and increased grid reliability by seamlessly transitioning between grid-tied and stand-alone operation modes. The objectives of this project are to identify system integration and optimization issues and technologies and to provide solutions through research, analysis, and testing of power electronic interfaces for distributed energy applications that are cost-competitive and have substantially faster response times than conventional technologies. In addition, the testing of power electronics interfaces will develop a technical basis for performance assessment for distributed energy systems, subsystems, and components that will finally create a foundation for standardized measurements and test procedures. The ultimate goal for this research is to advance the potential benefits of distributed energy to provide ancillary services, enhance power system reliability, and allow customer choice.

  18. Forecasting increasing rate of power consumption based on immune genetic algorithm combined with neural network

    Institute of Scientific and Technical Information of China (English)

    杨淑霞

    2008-01-01

    Considering the factors affecting the increasing rate of power consumption, the BP neural network structure and the neural network forecasting model of the increasing rate of power consumption were established. Immune genetic algorithm was applied to optimizing the weight from input layer to hidden layer, from hidden layer to output layer, and the threshold value of neuron nodes in hidden and output layers. Finally, training the related data of the increasing rate of power consumption from 1980 to 2000 in China, a nonlinear network model between the increasing rate of power consumption and influencing factors was obtained. The model was adopted to forecasting the increasing rate of power consumption from 2001 to 2005, and the average absolute error ratio of forecasting results is 13.521 8%. Compared with the ordinary neural network optimized by genetic algorithm, the results show that this method has better forecasting accuracy and stability for forecasting the increasing rate of power consumption.

  19. 77 FR 40092 - License Amendment To Increase the Maximum Reactor Power Level, Florida Power & Light Company, St...

    Science.gov (United States)

    2012-07-06

    ... and limit high temperatures to the mixing zone area specified in the IWFP. The NRC also analyzed the... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION License Amendment To Increase the Maximum Reactor Power Level, Florida Power & Light Company,...

  20. Joint Operation of Several Types of Power Plants to Increasing Net Profit in Deregulated Power Market

    Directory of Open Access Journals (Sweden)

    S. Sajedi

    2012-03-01

    Full Text Available This study proposes joint operation of power plant and electric energy storage plant in order to maximizing overall profit in a restructured electricity market. The goal is investigating the coupling efficiency on profit increment considering various intensities of power plant’s fuel constraint. In order to reach this goal, the amount of overall profits of fuel-constrained power plant, battery plant and their coupling are first calculated in a specific time interval. Then, the coupling efficiency is determined using incremental profit rate. Having an appropriate strategy to calculate this parameter is essential. Hence, a comprehensive approach to selfschedule of individual and coupled plants is developed. This comprehensive self-scheduling approach is therefore formulated and solved as a Mixed Integer Non-linear Programming (MINLP problem. Numerical results for a case study are discussed.

  1. Operating the Irish power system with increased levels of wind power

    DEFF Research Database (Denmark)

    Tuohy, A.; Denny, E.; Meibom, Peter;

    2008-01-01

    This paper summarises some of the main impacts of large amounts of wind power installed in the island of Ireland. Using results from various studies performed on this system, it is shown that wind power will impact on all time frames, from seconds to daily planning of the system operation. Results...... from studies examining operation of the system with up to approximately 40% of electricity provided by wind show that some of the most important aspects to be considered include the type of wind turbine technology, the provision of reserve to accommodate wind forecasting error and the method used...

  2. Analysis of Increased Information Technology Outsourcing Factors

    Directory of Open Access Journals (Sweden)

    Brcar Franc

    2013-01-01

    Full Text Available The study explores the field of IT outsourcing. The narrow field of research is to build a model of IT outsourcing based on influential factors. The purpose of this research is to determine the influential factors on IT outsourcing expansion. A survey was conducted with 141 large-sized Slovenian companies. Data were statistically analyzed using binary logistic regression. The final model contains five factors: (1 management’s support; (2 knowledge on IT outsourcing; (3 improvement of efficiency and effectiveness; (4 quality improvement of IT services; and (5 innovation improvement of IT. Managers immediately can use the results of this research in their decision-making. Increased performance of each individual organization is to the benefit of the entire society. The examination of IT outsourcing with the methods used is the first such research in Slovenia.

  3. Increase of pulse power of power supply systems of induction linacs with current pulse magnettic compression

    International Nuclear Information System (INIS)

    A powerful three section magnetic pulse generator of a nanosecond range designed for supply of a small-sectioned sccelerating structure up to GW units is developed. The pumping generator is mounted using the TTI2500/50 pulsed hydrogen thyratron according to the sections of magnetic compression. 2 refs.; 2 figs.; 1 tab

  4. Power and performance software analysis and optimization

    CERN Document Server

    Kukunas, Jim

    2015-01-01

    Power and Performance: Software Analysis and Optimization is a guide to solving performance problems in modern Linux systems. Power-efficient chips are no help if the software those chips run on is inefficient. Starting with the necessary architectural background as a foundation, the book demonstrates the proper usage of performance analysis tools in order to pinpoint the cause of performance problems, and includes best practices for handling common performance issues those tools identify. Provides expert perspective from a key member of Intel's optimization team on how processors and memory

  5. Obesity is not associated with increased knee joint torque and power during level walking.

    Science.gov (United States)

    DeVita, Paul; Hortobágyi, Tibor

    2003-09-01

    While it is widely speculated that obesity causes increased loads on the knee leading to joint degeneration, this concept is untested. The purpose of the study was to identify the effects of obesity on lower extremity joint kinetics and energetics during walking. Twenty-one obese adults were tested at self-selected (1.29m/s) and standard speeds (1.50m/s) and 18 lean adults were tested at the standard speed. Motion analysis and force platform data were combined to calculate joint torques and powers during the stance phase of walking. Obese participants were more erect with 12% less knee flexion and 11% more ankle plantarflexion in self-selected compared to standard speeds (both pKnee and ankle torques were 17% and 11% higher (pknee work and positive ankle work were 68% and 11% higher (ppowers were statistically identical at the hip and knee but were 88% and 61% higher (both pknee torque and power at their self-selected walking speed and equal knee torque and power while walking at the same speed as lean individuals. We propose that the ability to reorganize neuromuscular function during gait may enable some obese individuals to maintain skeletal health of the knee joint and this ability may also be a more accurate risk indicator for knee osteoarthritis than body weight.

  6. Power Estimation in Multivariate Analysis of Variance

    Directory of Open Access Journals (Sweden)

    Jean François Allaire

    2007-09-01

    Full Text Available Power is often overlooked in designing multivariate studies for the simple reason that it is believed to be too complicated. In this paper, it is shown that power estimation in multivariate analysis of variance (MANOVA can be approximated using a F distribution for the three popular statistics (Hotelling-Lawley trace, Pillai-Bartlett trace, Wilk`s likelihood ratio. Consequently, the same procedure, as in any statistical test, can be used: computation of the critical F value, computation of the noncentral parameter (as a function of the effect size and finally estimation of power using a noncentral F distribution. Various numerical examples are provided which help to understand and to apply the method. Problems related to post hoc power estimation are discussed.

  7. Shuttle Electrical Power Analysis Program (SEPAP) distribution circuit analysis report

    Science.gov (United States)

    Torina, E. M.

    1975-01-01

    An analysis and evaluation was made of the operating parameters of the shuttle electrical power distribution circuit under load conditions encountered during a normal Sortie 2 Mission with emphasis on main periods of liftoff and landing.

  8. Market Based Analysis of Power System Interconnections

    OpenAIRE

    Obuševs, A; Turcik, M; Oļeiņikova, I; Junghāns, G

    2011-01-01

    Analysis in this Article is focused on usage of transmission grid under liberalized market with implicit transmission capacity allocation method, e.g. Nordic market. Attention is paid on fundamental changes in transmission utilization and its economical effective operation. For interconnection and power flow analysis and losses calculation model of Nordic grid was developed and transmission losses calculation method was created. Given approach will improve economical efficiency of system oper...

  9. Power analysis attacks revealing the secrets of smart cards

    CERN Document Server

    Mangard, Stefan; Popp, Thomas

    2008-01-01

    A comprehensive treatment of power analysis attacks and countermeasures. Based on the principle that the only way to defend against power analysis attacks is to understand them, this book explains how power analysis attacks work. It discusses simple and differential power analysis as well as advanced techniques like template attacks.

  10. Improve your word power a concise way to increase your word power

    CERN Document Server

    Sawhney, Clifford

    2012-01-01

    English is a unique language which has innumerable great poets and authors from the past as well as the present, who have contributed profusely to its rich heritage. Nonetheless, we can not ignore the complexities of the English language which sometimes perplex a reader or even a scholar of this language. Improve your word power by Clifford Sawhney simplifies all these complexities of the language by providing answers to the many nagging grammatical queries, syntax, style, choice of words, spellings, etc. This book serves as a complete guide and elaborately explains the different usages of no

  11. Energy and exergy analysis of solar power tower plants

    International Nuclear Information System (INIS)

    Establishing the renewable electricity contribution from solar thermal power systems based on energy analysis alone cannot legitimately be complete unless the exergy concept becomes a part of that analysis. This paper presents a theoretical framework for the energy analysis and exergy analysis of the solar power tower system using molten salt as the heat transfer fluid. Both the energy losses and exergy losses in each component and in the overall system are evaluated to identify the causes and locations of the thermodynamic imperfection. Several design parameters including the direct normal irradiation (DNI), the concentration ratio, and the type of power cycle are also tested to evaluate their effects on the energy and exergy performance. The results show that the maximum exergy loss occurs in the receiver system, followed by the heliostat field system, although main energy loss occurs in the power cycle system. The energy and exergy efficiencies of the receiver and the overall system can be increased by increasing the DNI and the concentration ratio, but that increment in the efficiencies varies with the values of DNI and the concentration ratio. It is also found that the overall energy and exergy efficiencies of the solar tower system can be increased to some extent by integrating advanced power cycles including reheat Rankine cycles and supercritical Rankine cycles. - Highlights: →We presented a theoretical framework for the energy and exergy analysis of the solar tower system. →We tested the effects of several design parameters on the energy and exergy performance. →The maximum exergy loss occurs in the receiver system, followed by the heliostat field system. →Integrating advanced power cycles leads to increases in the overall energy and exergy efficiencies.

  12. Comparative analysis of existing models for power-grid synchronization

    CERN Document Server

    Nishikawa, Takashi

    2015-01-01

    The dynamics of power-grid networks is becoming an increasingly active area of research within the physics and network science communities. The results from such studies are typically insightful and illustrative, but are often based on simplifying assumptions that can be either difficult to assess or not fully justified for realistic applications. Here we perform a comprehensive comparative analysis of three leading models recently used to study synchronization dynamics in power-grid networks -- a fundamental problem of practical significance given that frequency synchronization of all power generators in the same interconnection is a necessary condition for a power grid to operate. We show that each of these models can be derived from first principles within a common framework based on the classical model of a generator, thereby clarifying all assumptions involved. This framework allows us to view power grids as complex networks of coupled second-order phase oscillators with both forcing and damping terms. U...

  13. DENINT power plant cost benefit analysis code: Analysis of methane fuelled power plant/district heating system

    International Nuclear Information System (INIS)

    The DENINT power plant cost benefit analysis code takes into consideration, not only power production costs at the generator terminals, but also, in the case of cogeneration, the costs of the fuel supply and heat and power distribution systems which depend greatly on the location of the plant. The code is able to allow comparisons of alternatives with varying annual operation hours, fuel cost increases, and different types of fossil fuels and production systems. For illustrative purposes, this paper examines two methane fired cogeneration plant/district heating alternatives

  14. Energy analysis of nuclear power plants and their fuel cycle

    International Nuclear Information System (INIS)

    Energy analysis has become an increasingly feasible and practical additional method for evaluating the engineering, economic and environmental aspects of power-producing systems. It compares total direct and indirect energy investment into construction and operation of power plants with their lifetime energy output. This method was applied to nuclear power-producing systems and their fuel cycles. Results were adapted to countries with various levels of industrialization and resources. With dynamic energy analysis different scenarios were investigated. For comparison purposes fossil-fuelled and solar power plants were analysed. The global results of static evaluation analysis were specifically modified according to the economic situations of countries with various levels of industrialization. The influence of energy imports upon energy analysis is also discussed. By dynamic energy analyses the cumulative energy requirements for specific power plant construction programmes have been compared with their total energy output. Investigations of this sort are extremely valuable not only for economic reasons, but especially for their usefulness in showing the advantages and disadvantages of a specific power programme with respect to its alternatives. Naturally the impact of these investigations on the fuel requirements is of importance, especially because of the frequently cited ''valuable cumulated fossil fuel savings''. (author)

  15. Principles for Soft-Hardware Complex Development to Increase Efficiency of Power Transformers

    OpenAIRE

    A. L. Trushnikov

    2014-01-01

    The paper reveals principles for development and operation of soft-hardware complex which is designed to control transformer substations of industrial enterprisers. Purpose of soft-hardware components of the complex is considered in the paper.Development and application of such complex allow to increase an efficiency of power transformer resource and decrease electric power losses in the elements of power-supply system at industrial enterprisers.

  16. Power Systems Life Cycle Analysis Tool (Power L-CAT).

    Energy Technology Data Exchange (ETDEWEB)

    Andruski, Joel; Drennen, Thomas E.

    2011-01-01

    The Power Systems L-CAT is a high-level dynamic model that calculates levelized production costs and tracks environmental performance for a range of electricity generation technologies: natural gas combined cycle (using either imported (LNGCC) or domestic natural gas (NGCC)), integrated gasification combined cycle (IGCC), supercritical pulverized coal (SCPC), existing pulverized coal (EXPC), nuclear, and wind. All of the fossil fuel technologies also include an option for including carbon capture and sequestration technologies (CCS). The model allows for quick sensitivity analysis on key technical and financial assumptions, such as: capital, O&M, and fuel costs; interest rates; construction time; heat rates; taxes; depreciation; and capacity factors. The fossil fuel options are based on detailed life cycle analysis reports conducted by the National Energy Technology Laboratory (NETL). For each of these technologies, NETL's detailed LCAs include consideration of five stages associated with energy production: raw material acquisition (RMA), raw material transport (RMT), energy conversion facility (ECF), product transportation and distribution (PT&D), and end user electricity consumption. The goal of the NETL studies is to compare existing and future fossil fuel technology options using a cradle-to-grave analysis. The NETL reports consider constant dollar levelized cost of delivered electricity, total plant costs, greenhouse gas emissions, criteria air pollutants, mercury (Hg) and ammonia (NH3) emissions, water withdrawal and consumption, and land use (acreage).

  17. Multi Megawatt Power System Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, Glen Reed; Harvego, Edwin Allan; Schnitzler, Bruce Gordon; Seifert, Gary Dean; Sharpe, John Phillip; Verrill, Donald Alan; Watts, Kenneth Donald; Parks, Benjamin Travis

    2001-11-01

    Missions to the outer planets or to near-by planets requiring short times and/or increased payload carrying capability will benefit from nuclear power. A concept study was undertaken to evaluate options for a multi-megawatt power source for nuclear electric propulsion. The nominal electric power requirement was set at 15 MWe with an assumed mission profile of 120 days at full power, 60 days in hot standby, and another 120 days of full power, repeated several times for 7 years of service. Of the numerous options considered, two that appeared to have the greatest promise were a gas-cooled reactor based on the NERVA Derivative design, operating a closed cycle Brayton power conversion system; and a molten lithium-cooled reactor based on SP-100 technology, driving a boiling potassium Rankine power conversion system. This study examined the relative merits of these two systems, seeking to optimize the specific mass. Conclusions were that either concept appeared capable of approaching the specific mass goal of 3-5 kg/kWe estimated to be needed for this class of mission, though neither could be realized without substantial development in reactor fuels technology, thermal radiator mass efficiency, and power conversion and distribution electronics and systems capable of operating at high temperatures. Though the gas-Brayton systems showed an apparent advantage in specific mass, differences in the degree of conservatism inherent in the models used suggests expectations for the two approaches may be similar. Brayton systems eliminate the need to deal with two-phase flows in the microgravity environment of space.

  18. Increasing power output from Francis turbines : Effektøkning i vannkraftverk med Francis turbiner

    OpenAIRE

    Brunes, Bente Taraldsten

    2009-01-01

    The main objective in this thesis was to investigate a potential increase of power output from the existing turbines at Ruacana Hydropower Station. This was restricted to only consider a runner replacement, and only technical aspects of a rehabilitation project has been evaluated. This involved an investigation of hydraulic condtions, limited to surge oscilliation and water hammer calculations. The results was thereafter used in a calculation model to estimate potential increase in power outp...

  19. Analysis of higher power research reactors' parameters

    International Nuclear Information System (INIS)

    The objective of this monograph was to analyze and compare parameters of different types of research reactors having higher power. This analysis could be used for decision making and choice of a reactor which could possibly replace the existing ageing RA reactor in Vinca. Present experimental and irradiation needs are taken into account together with the existing reactors operated in our country, RB and TRIGA reactor

  20. Energy system, electricity market and economic studies on increasing nuclear power capacity; Ydinvoimahankkeiden periaatepaeaetoekseen liittyvaet energia- ja kansantaloudelliset selvitykset

    Energy Technology Data Exchange (ETDEWEB)

    Forsstrom, J.; Pursiheimo, E.; Kekkonen, V.; Honkatukia, J.

    2010-04-15

    Objective of this research project is to examine effects of addition of nuclear capacity from three different angles by using energy system, electricity market and economic analysis. In each area the analysis is based on computational methods. Finland is a member of Nordic electricity market which is further connected to networks of Continental Europe and Russia. Due to the foreign connections Finland has been able to import inexpensive electricity from its neighboring countries and this state is expected to continue. Addition of nuclear capacity lowers electricity import demand, affects level of electricity price decreasingly and decreases shortfall of installed production capacity. Substantial additions of nuclear power capacity and generous import supply have disadvantageous effect on profitability of combined heat and power production. The development of import possibilities depends on progression of difficult-to-estimate balance between electricity consumption and production in the neighboring countries. Investments on nuclear power increase national product during the construction phase. Growth of employment is also rather significant, especially during the construction phase. In the long term permanent jobs will be created too. Increase of employment is held back by increasing real wages, but it is though evident that consumer purchasing power is improved due to these nuclear power developments. (orig.)

  1. Dynamic analysis of Leningrad nuclear power plant

    International Nuclear Information System (INIS)

    Within the scope of this study a preliminary dynamic analysis for the detonation explosion and earthquake load cases was carried out for the Leningrad Nuclear Power Plant. A soil model was added to the three-dimensional shell model which was taken over from IVO (Finland). During this Research Program the model was translated into the STARDYNE program and was investigated by means of time history modal analysis. Since the status quo of the documentation available at that time had to be completed through useful technical assumptions this report only considers exemplary selected results

  2. Increased power to weight ratio of piezoelectric energy harvesters through integration of cellular honeycomb structures

    Science.gov (United States)

    Chandrasekharan, N.; Thompson, L. L.

    2016-04-01

    The limitations posed by batteries have compelled the need to investigate energy harvesting methods to power small electronic devices that require very low operational power. Vibration based energy harvesting methods with piezoelectric transduction in particular has been shown to possess potential towards energy harvesters replacing batteries. Current piezoelectric energy harvesters exhibit considerably lower power to weight ratio or specific power when compared to batteries the harvesters seek to replace. To attain the goal of battery-less self-sustainable device operation the power to weight ratio gap between piezoelectric energy harvesters and batteries need to be bridged. In this paper the potential of integrating lightweight honeycomb structures with existing piezoelectric device configurations (bimorph) towards achieving higher specific power is investigated. It is shown in this study that at low excitation frequency ranges, replacing the solid continuous substrate of conventional bimorph with honeycomb structures of the same material results in a significant increase in power to weight ratio of the piezoelectric harvester. At higher driving frequency ranges it is shown that unlike the traditional piezoelectric bimorph with solid continuous substrate, the honeycomb substrate bimorph can preserve optimum global design parameters through manipulation of honeycomb unit cell parameters. Increased operating lifetime and design flexibility of the honeycomb core piezoelectric bimorph is demonstrated as unit cell parameters of the honeycomb structures can be manipulated to alter mass and stiffness properties of the substrate, resulting in unit cell parameter significantly influencing power generation.

  3. Balance of the LVC plant with increase in 15 % of power

    International Nuclear Information System (INIS)

    One of the tendencies in many power reactors has been to modify some operation conditions, in order to increasing the electricity generation. The Laguna Verde Nuclear power plant (CNLV) it has not been the exception and in the recent past an increment of 5% was made in the original nominal thermal power. In the face of the possibility of carrying out more modifications, a study was made in the one that one simulates an eventual increment of the power of the reactor in 15% of the original value. With this increment one carries out the balance of the plant and the thermodynamic properties were determined. With this purpose it was developed a computer tool to calculate the thermodynamic properties of the plant in several points of the power cycle, as well as to carry out energy and mass balances to determine the flows in the different extractions of steam of the turbines. The program is compared with the results to 100% and 105% of increase of power obtaining good results, for what it is concluded that the extrapolation to 115% of power increase is acceptable. (Author)

  4. A coherency-based method to increase dynamic security in power systems

    Energy Technology Data Exchange (ETDEWEB)

    De Tuglie, E. [Dipartimento di Ingegneria dell' Ambiente e per lo Sviluppo Sostenibile - DIASS, Politecnico di Bari, Viale del Turismo 8, 74100 Taranto (Italy); Iannone, S.M.; Torelli, F. [Dipartimento di Elettrotecnica ed Elettronica - DEE, Politecnico di Bari, Via Re David 200, 70125 Bari (Italy)

    2008-08-15

    Dynamic security analysis is the evaluation of the ability of a system to withstand contingencies by surviving transient conditions to acceptable steady-state operative states. When potential instability due to contingency is detected, preventive action may be desired to improve the system security. This is very important in the on-line operation of a power system, especially when the system is stability-limited. The method proposed in this paper is based on the idea that increasing coherency between generators in the transient behaviour following a system perturbation gives rise to a more stable system. In this paper, we suggest the use of the ''input-output feedback-linearization'' with a reference trajectory obtained using a system dynamic equivalent based on the centre of inertia. To quantify coherency levels a new coherency indicator has been assumed for the given reference trajectory. The result is an increasing level in coherency, critical clearing time and system stability. The method is tested on the IEEE 30 bus test system. (author)

  5. Stability analysis of large electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Elwood, D.M.

    1993-01-01

    Modern electric power systems are large and complicated, and, in many regions of the world, the generation and transmission systems are operating near their limits. Ensuring the reliable operation of the power system requires engineers to study the response of the system to various disturbances. The responses to large disturbances are examined by numerically solving the nonlinear differential-algebraic equations describing the power system. The response to small disturbances is typically studied via eigenanalysis. The Electric Power Research Institute (EPRI) recently developed the Extended Transient/Mid-term Stability Program (ETMSP) to study large disturbance stability and the Small Signal Stability Program Package (SSSP) to study small signal stability. The primary objectives of the work described in this report were to (1) explore ways of speeding up ETMSP, especially on mid-term voltage stability problems, (2) explore ways of speeding up the Multi-Area Small-Signal Stability program (MASS), one of the codes in SSSP, and (3) explore ways of increasing the size of problem that can be solved by the Cray version of MASS.

  6. Hydropower: a vital asset in a power system with increased need for flexibility and firm capacity

    International Nuclear Information System (INIS)

    In a power system with increased need for flexibility, wind and solar power are characterised by considerable volatility across different scales and their output cannot be predicted with certainty. In order to deal with the resulting variations and forecast errors, system operators as well as electricity markets will need to have access to increasing volumes of flexibility as the penetration of wind and solar power grows. Due to their flexibility and size, hydropower plants are perfectly suited for supplying these capabilities to current and future electricity markets and power systems. Storage as well as pump storage plants can be quickly started within a few minutes and adjust their output within seconds. Consequently, hydropower plants are able to follow even major variations in real time. (author)

  7. Advanced Wireless Power Transfer Vehicle and Infrastructure Analysis (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Gonder, J.; Brooker, A.; Burton, E.; Wang, J.; Konan, A.

    2014-06-01

    This presentation discusses current research at NREL on advanced wireless power transfer vehicle and infrastructure analysis. The potential benefits of E-roadway include more electrified driving miles from battery electric vehicles, plug-in hybrid electric vehicles, or even properly equipped hybrid electric vehicles (i.e., more electrified miles could be obtained from a given battery size, or electrified driving miles could be maintained while using smaller and less expensive batteries, thereby increasing cost competitiveness and potential market penetration). The system optimization aspect is key given the potential impact of this technology on the vehicles, the power grid and the road infrastructure.

  8. 76 FR 16394 - Analysis of Horizontal Market Power Under the Federal Power Act

    Science.gov (United States)

    2011-03-23

    ..., identify potential suppliers to each identified customer (includes a delivered price test (DPT) analysis... Energy Regulatory Commission Analysis of Horizontal Market Power Under the Federal Power Act AGENCY... Guidelines should have, if any, on the Commission's analysis of horizontal market power in its...

  9. Complex Evaluation of Light Sources in Case of Electric Power Cost Increase

    OpenAIRE

    Y. N. Kolesnik; A. V. Ivaneychik

    2008-01-01

    The paper gives complex evaluation of efficiency of incandescent lamps, luminescent and light-emitting-diode (LED) light sources in case of electric power price increase. On the basis of experimental table lamp electric power indices of light-emitting-diode (LED) light sources with equivalent luminous flux have been determined. Dependences of main indices of economic efficiency of various light sources on their operational regimes have been obtained and rate of influence on these indices of e...

  10. Increasing power generation for scaling up single-chamber air cathode microbial fuel cells

    KAUST Repository

    Cheng, Shaoan

    2011-03-01

    Scaling up microbial fuel cells (MFCs) requires a better understanding the importance of the different factors such as electrode surface area and reactor geometry relative to solution conditions such as conductivity and substrate concentration. It is shown here that the substrate concentration has significant effect on anode but not cathode performance, while the solution conductivity has a significant effect on the cathode but not the anode. The cathode surface area is always important for increasing power. Doubling the cathode size can increase power by 62% with domestic wastewater, but doubling the anode size increases power by 12%. Volumetric power density was shown to be a linear function of cathode specific surface area (ratio of cathode surface area to reactor volume), but the impact of cathode size on power generation depended on the substrate strength (COD) and conductivity. These results demonstrate the cathode specific surface area is the most critical factor for scaling-up MFCs to obtain high power densities. © 2010 Elsevier Ltd.

  11. Laguna Verde after the extended power increase; Laguna Verde despues del aumento de potencia extendido

    Energy Technology Data Exchange (ETDEWEB)

    Herrera C, M. N.; Castaneda G, M. A.; Cardenas J, J. B.; Garcia de la C, F. M., E-mail: mitzi.herrera@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2012-10-15

    The project of extended power increase that was implemented in both units of the nuclear power plant of Laguna Verde beginning with the stage feasibility evaluation in nuclear side of the facilities, that is to say the affectation of the power increase in the equipment s, systems and components of the nuclear power plant; besides the feasibility evaluation a study cost-benefit for the rehabilitated and modernization of the equipment s, systems and components of Plant Balance was realized. Once considered technical and economically feasible the project began the engineering evaluations required to carry out the licensing of the new operation conditions, as well as beginning to the elaboration of the technical specifications purchase of the equipment s, systems and components of the Plant Balance. While on one hand was carried out the administration of the licensing of the extended power increase for other was carried out the necessary engineering to make the physical changes in the conventional side of the nuclear power plant. Once concluded the constructive stage beginning the final stage of the project, the starting-up tests, operation and performance of the Units under the new operation conditions. This work describes this last stage that contains the technical base, the realized tests and the obtained results. (Author)

  12. An Effective Distributed Model for Power System Transient Stability Analysis

    OpenAIRE

    MUTHU, B. M.; VEILUMUTHU, R.; PONNUSAMY, L.

    2011-01-01

    The modern power systems consist of many interconnected synchronous generators having different inertia constants, connected with large transmission network and ever increasing demand for power exchange. The size of the power system grows exponentially due to increase in power demand. The data required for various power system applications have been stored in different formats in a heterogeneous environment. The power system applications themselves have been developed and deployed in diff...

  13. Economic analysis of nuclear power generation

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki Dong; Choi, Young Myung; Kim, Hwa Sup; Lee, Man Ki; Moon, Kee Hwan; Kim, Seung Su; Chae, Kyu Nam

    1996-12-01

    The major contents in this study are as follows : (1) Efforts are made to examine the role of nuclear energy considering environmental regulation. An econometric model for energy demand and supply including carbon tax imposition is established. (2) Analysis for the learning effect of nuclear power plant operation is performed. The study is focused to measure the effect of technology homogeneity on the operation performance. (3) A preliminary capital cost of the KALIMER is estimated by using cost computer program, which is developed in this study. (author). 36 refs.,46 tabs., 15 figs.

  14. A Novel Elliptic Curve Scalar Multiplication Algorithm against Power Analysis

    OpenAIRE

    Hongming Liu; Yujie Zhou; Nianhao Zhu

    2013-01-01

    Nowadays, power analysis attacks are becoming more and more sophisticated. Through power analysis attacks, an attacker can obtain sensitive data stored in smart cards or other embedded devices more efficiently than with any other kind of physical attacks. Among power analysis, simple power analysis (SPA) is probably the most effective against elliptic curve cryptosystem, because an attacker can easily distinguish between point addition and point doubling in a single execution of scalar multip...

  15. Spacecraft Electrical Power System (EPS) generic analysis tools and techniques

    Science.gov (United States)

    Morris, Gladys M.; Sheppard, Mark A.

    1992-01-01

    An overview is provided of the analysis tools and techiques used in modeling the Space Station Freedom electrical power system, as well as future space vehicle power systems. The analysis capabilities of the Electrical Power System (EPS) are described and the EPS analysis tools are surveyed.

  16. Advanced Power Plant Development and Analysis Methodologies

    Energy Technology Data Exchange (ETDEWEB)

    A.D. Rao; G.S. Samuelsen; F.L. Robson; B. Washom; S.G. Berenyi

    2006-06-30

    Under the sponsorship of the U.S. Department of Energy/National Energy Technology Laboratory, a multi-disciplinary team led by the Advanced Power and Energy Program of the University of California at Irvine is defining the system engineering issues associated with the integration of key components and subsystems into advanced power plant systems with goals of achieving high efficiency and minimized environmental impact while using fossil fuels. These power plant concepts include 'Zero Emission' power plants and the 'FutureGen' H2 co-production facilities. The study is broken down into three phases. Phase 1 of this study consisted of utilizing advanced technologies that are expected to be available in the 'Vision 21' time frame such as mega scale fuel cell based hybrids. Phase 2 includes current state-of-the-art technologies and those expected to be deployed in the nearer term such as advanced gas turbines and high temperature membranes for separating gas species and advanced gasifier concepts. Phase 3 includes identification of gas turbine based cycles and engine configurations suitable to coal-based gasification applications and the conceptualization of the balance of plant technology, heat integration, and the bottoming cycle for analysis in a future study. Also included in Phase 3 is the task of acquiring/providing turbo-machinery in order to gather turbo-charger performance data that may be used to verify simulation models as well as establishing system design constraints. The results of these various investigations will serve as a guide for the U. S. Department of Energy in identifying the research areas and technologies that warrant further support.

  17. Increasing reliability of nuclear energy equipment and at nuclear power plants

    International Nuclear Information System (INIS)

    The Institute of Nuclear Energy at the Technical University in Brno cooperates with nuclear power plants in increasing their reliability. The teaching programme is briefly described. The scientific research programme of the Department of Heat and Nuclear Power Energy Equipment in the field of reliability is based on a complex systematic concept securing a high level of reliability. In 1996 the Department prepared a study dealing with the evaluation of the maintenance system in a nuclear power plant. The proposed techniques make it possible to evaluate the reliability and maintenance characteristics of any individual component in a nuclear power plant, and to monitor, record and evaluate data at any given time intervals. (M.D.)

  18. A Study on Increasing The Capacity Factor of Nuclear Power Plant in Korea

    International Nuclear Information System (INIS)

    Our estimate on generating costs of nuclear power compared with coal-fired thermal power shows that nuclear power is more economical when capacity factor exceeds 60 percent. Upgrading the plant performance in terms of capacity factor is believed most essential so as to achieve lower energy costs and to diversify the energy sources in Korea, as well. A detailed implementation plan for improving the plant capacity factor is now being developed with the plant betterment projects, considering the situation of each unit. In case of 5 percent increase of capacity factor for 9 operating plants in 1991, our preliminary estimate shows 4.68 million barrels of oil could be saved each year. It will also contribute a great deal to the economy of nation's electric power generation

  19. Increasing coal-fired power generation efficiency to reduce electric cost and environmental emissions

    International Nuclear Information System (INIS)

    New generating capacity required globally between 1993 and 2010 is estimated to be around 1500 GW, of which some two-thirds will be outside the OECD, and some 40 % in the Asian non-OECD countries. Coal is likely to account for a substantial fraction of this new generation. Today's state-of-the-art supercritical coal-fired power plant has a conversion efficiency of some 42-45 %. The capital cost increase associated with the supercritical or ultra-supercritical pulverized coal power plant compared to a conventional subcritical plant is small to negligible. The increased efficiency associated with the supercritical plant leads to an actual reduction in the total cost of electricity generated in cents/kWh, relative to a conventional plant. Despite this, the power sector continues to build subcritical plants and has no near term plans to increase the efficiency of power plants in the projects it is developing. Advanced clean coal technologies such as integrated gasification combined cycle and pressurized fluidized bed combustion will be selected for independent power projects only in very specific circumstances. Advanced clean coal plants can be operated reliably and with superior performance, and specifically that their present estimated capital costs can be reduced substantially to a point where they are competitive with state-of-the-art pulverized coal technologies. (R.P.)

  20. An ABC analysis for power generation project

    Directory of Open Access Journals (Sweden)

    Batool Hasani

    2013-07-01

    Full Text Available One of the primary concerns on performance measurement is to know how much a particular project cost. However, using traditional method on project-based products often leads to inappropriate results. In this paper, we re-examine this issue by comparing the cost of a power station construction project using ABC versus traditional method. The results of survey show that ABC method is capable of providing better estimates for overhead costs compared with traditional method. In other words, ABC method helps reduce some of the unnecessary overhead cost items and increase on some other cost components. This helps increase the relative efficiency of the system by reducing total cost of project.

  1. New Mersenne Number Transform Diffusion Power Analysis

    Directory of Open Access Journals (Sweden)

    M. F. Al-Gailani

    2011-01-01

    Full Text Available Problem statement: Due to significant developments in the processing power and parallel processing technologies, the existing encryption algorithms are increasingly susceptible to attacks, such as side-channel attacks, for example. Designing new encryption algorithms that work efficiently on different platforms and security levels to protect the transmitted data from any possible attacks is one of the most important issues in today’s information and network security. The aim is to find more secure, reliable and flexible systems that can run as a ratified standard, with reasonable computational complexity for a sufficient service time. To expand the longevity of the algorithm, it is important to be designed to work efficiently on a variety of block sizes and key lengths according to the security demand. A sensible solution is the suggested use of a parameter transform. Approach: The present study evaluates the appropriateness of the New Mersenne Number Transform for security applications by analyzing and estimating its avalanche and diffusion power. Results: The results confirm that the transform in general reflects good avalanche characteristics that are for most cases over 50% and can be up to 100%. The lower bound can be further improved by increasing the modulus and/or the transform length. Conclusion: This New Mersenne Number Transform is highly flexible and adaptable for this application. It can be involved in the design of a secure cryptosystem for the following reasons; changing a single input element makes drastic changes in the output elements and vice versa (sensitivity, provides variable block size and key length (parameterization. Has long transform length (power of two, is error free and its inverse is the same with a scale factor of (1/N which simplifies implementation of both encryption and decryption. Finally, it is appropriate for real time implementations such as fast algorithms, which can be applied to it, to speed up

  2. Conceptual Design of Solar-micro Hydro Power Plant to Increase Conversion Efficiency for Supporting Remote Tribal Community of Bangladesh

    Directory of Open Access Journals (Sweden)

    Anmona Shabnam Pranti

    2014-11-01

    Full Text Available Bangladesh is endowed with people along with limited primary energy sources and low electrification rate. Most of the hilly areas are out of the coverage of national grid where tribal people, a significant part of the country, are dwelling. The economic development of the whole country depends upon their advancement which is related to the electrification rate. Available micro hydro potential in hilly region could be a solution for this crisis if modified design is used. This paper deals with a new design of water power potential conversion efficiency increment of a micro hydro power plant to 95% from about 50% by using solar power for heating the water. In this proposed hybrid design, a parabolic reflector is considered to be used after comparative solar intensity analysis on different micro hydro power sites in Bangladesh to increase the velocity as well as the flow rate through penstock by heating the water to increase power production and efficiency. The main purpose of this concept is to supply electricity to more people, especially, remote tribal community by available renewable energy sources for economic development.

  3. Performance Analysis of Reconfigurable SRAM Cell for Low Power Applications

    Directory of Open Access Journals (Sweden)

    Dillibabu.Mannem

    2012-06-01

    Full Text Available The majority of space taken in an integrated circuit is the memory. SRAM design consists of key considerations, such as increased speed, low power and reduced layout area. A cell which is functional at the nominal supply voltage, can fail at a lower voltage. From a system perspective this leads to a higher bit-error rate with voltage scaling and limits the opportunity for power saving. While this is a serious bottleneck for SRAM arrays used for data storage. This paper presents a performance analysis of reconfigurable SRAM cell for low power application. Simulations using TSMC 0.35um technology show that the SRAM cell read & write access times are 1.53ns and 1.93ns. Mentor Graphics ELDO and EZ-wave are used for simulations.

  4. A NOVEL CONCEPT FOR REDUCING WATER USAGE AND INCREASING EFFICIENCY IN POWER GENERATION

    Energy Technology Data Exchange (ETDEWEB)

    Shiao-Hung Chiang; Guy Weismantel

    2004-03-01

    The objective of the project is to apply a unique ice thermal storage (ITS) technology to cooling the intake air to gas turbines used for power generation. In Phase I, the work includes theoretical analysis, computer simulation, engineering design and cost evaluation of this novel ITS technology. The study includes two typical gas turbines (an industrial and an aeroderivative type gas turbine) operated at two different geographic locations: Phoenix, AZ and Houston, TX. Simulation runs are performed to generate data for both power output (KW) and heat rate (Btu/KWh) as well as water recovery (acre ft/yr) in terms of intake air temperature and humidity based on weather data and turbine performance curves. Preliminary engineering design of a typical equipment arrangement for turbine inlet air-cooling operation using the ITS system is presented. A cost analysis has been performed to demonstrate the market viability of the ITS technology. When the ITS technology is applied to gas turbines, a net power gain up to 40% and a heat rate reduction as much as 7% can be achieved. In addition, a significant amount of water can be recovered (up to 200 acre-ft of water per year for a 50 MW turbine). The total cost saving is estimated to be $500,000/yr for a 50 MW gas turbine generator. These results have clearly demonstrated that the use of ITS technology to cool the intake-air to gas turbines is an efficient and cost effective means to improve the overall performance of its power generation capacity with an important added benefit of water recovery in power plant operation. Thus, further development of ITS technology for commercial applications in power generation, particularly in coal-based IGCC power plants is warranted.

  5. Increased power of resting-state gamma oscillations in autism spectrum disorder detected by routine electroencephalography

    NARCIS (Netherlands)

    van Diessen, Eric; Senders, Joeky; Jansen, Floor E.; Boersma, Maria; Bruining, Hilgo

    2015-01-01

    Experimental studies suggest that increased resting-state power of gamma oscillations is associated with autism spectrum disorder (ASD). To extend the clinical applicability of this finding, we retrospectively investigated routine electroencephalography (EEG) recordings of 19 patients with ASD and 1

  6. Analysis of future nuclear power plants competitiveness with stochastic methods

    International Nuclear Information System (INIS)

    To satisfy the increased demand it is necessary to build new electrical power plants, which could in an optimal way meet, the imposed acceptability criteria. The main criteria are potential to supply the required energy, to supply this energy with minimal (or at least acceptable) costs, to satisfy licensing requirements and be acceptable to public. The main competitors for unlimited electricity production in next few decades are fossil power plants (coal and gas) and nuclear power plants. New renewable power plants (solar, wind, biomass) are also important but due to limited energy supply potential and high costs can be only supplement to the main generating units. Large hydropower plans would be competitive under condition of existence of suitable sites for construction of such plants. The paper describes the application of a stochastic method for comparing economic parameters of future electrical power generating systems including conventional and nuclear power plants. The method is applied to establish competitive specific investment costs of future nuclear power plants when compared with combined cycle gas fired units combined with wind electricity generators using best estimated and optimistic input data. The bases for economic comparison of potential options are plant life time levelized electricity generating costs. The purpose is to assess the uncertainty of several key performance and cost of electricity produced in coal fired power plant, gas fired power plant and nuclear power plant developing probability distribution of levelized price of electricity from different Power Plants, cumulative probability of levelized price of electricity for each technology and probability distribution of cost difference between the technologies. The key parameters evaluated include: levelized electrical energy cost USD/kWh,, discount rate, interest rate for credit repayment, rate of expected increase of fuel cost, plant investment cost , fuel cost , constant annual

  7. Application of sorption heat pumps for increasing of new power sources efficiency

    Science.gov (United States)

    Vasiliev, L.; Filatova, O.; Tsitovich, A.

    2010-07-01

    In the 21st century the way to increase the efficiency of new sources of energy is directly related with extended exploration of renewable energy. This modern tendency ensures the fuel economy needs to be realized with nature protection. The increasing of new power sources efficiency (cogeneration, trigeneration systems, fuel cells, photovoltaic systems) can be performed by application of solid sorption heat pumps, regrigerators, heat and cold accumulators, heat transformers, natural gas and hydrogen storage systems and efficient heat exchangers.

  8. Overview of methods to increase dryout power in CANDU fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Groeneveld, D.C., E-mail: degroeneveld@gmail.com [Chalk River Laboratories, AECL, Chalk River (Canada); University of Ottawa, Department of Mechanical Engineering, Ottawa (Canada); Leung, L.K.H. [Chalk River Laboratories, AECL, Chalk River (Canada); Park, J.H. [Korean Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-06-15

    Highlights: • Small changes in bundle geometry can have noticeable effects on the bundle CHF. • Rod spacing devices can results in increases of over 200% in CHF. • CHF enhancement decays exponentially downstream from spacers. • CHF-enhancing bundle appendages also increase the post-CHF heat transfer. - Abstract: In CANDU reactors some degradation in the CCP (critical channel power, or power corresponding to the first occurrence of CHF in any fuel channel) will occur with time because of ageing effects such as pressure-tube diametral creep, increase in reactor inlet-header temperature, increased hydraulic resistance of feeders. To compensate for the ageing effects, various options for recovering the loss in CCP are described in this paper. They include: (i) increasing the bundle heated perimeter, (ii) optimizing the bundle configuration, (iii) optimizing core flow and flux distribution, (iv) reducing the bundle hydraulic resistance, (v) use of CHF-enhancing bundle appendages, (vi) more precise experimentation, and (vii) redefining CHF. The increase in CHF power has been quantified based on experiments on full-scale bundles and subchannel code predictions. The application of several of these CHF enhancement principles has been used in the development of the 43-rod CANFLEX bundle.

  9. Nuclear power and sustainable development. Maintaining and increasing the overall assets available to future generations

    International Nuclear Information System (INIS)

    A central goal of sustainable development is to maintain or increase the overall assets available to future generations, while minimizing consumption of finite resources and not exceeding the carrying capacities of ecosystems. The development of nuclear power broadens the natural resource base usable for energy production, increases human and man-made capital, and, when safely handled, has little impact on ecosystems. Energy is essential for sustainable development. With continuing population and economic growth, and increasing needs in the developing world, substantially greater energy demand is a given, even taking into account continuing and accelerated energy efficiency and intensity improvements. Today, nuclear power is mostly utilized in industrialized countries that have the necessary technological, institutional and financial resources. Many of the industrialized countries that are able and willing to use nuclear power are also large energy consumers. Nuclear power currently generates 16% of the world's electricity. It produces virtually no sulfur dioxide, particulates, nitrogen oxides, volatile organic compounds or greenhouse gases. Globally, nuclear power currently avoids approximately 600 million tonnes of carbon emissions annually, about the same as hydropower. The 600 MtC avoided by nuclear power equals 8% of current global greenhouse gases emissions. In the OECD countries, nuclear power has for 35 years accounted for most of the reduction in the carbon intensity per unit of delivered energy. Existing operating nuclear power plants (NPPs) for which initial capital investments are largely depreciated are also often the most cost-effective way to reduce carbon emissions from electricity generation. In fact in the United States in 2000, NPPs were the most cost-effective way to generate electricity, irrespective of avoided carbon emissions. In other countries the advantages of existing nuclear generating stations are also increasingly recognized. Interest

  10. Increase in Organization Effectiveness Using Voice Analysis: The System Approach

    Directory of Open Access Journals (Sweden)

    Lina Bartkienė

    2011-04-01

    Full Text Available The main purpose of this article is to analyze literature related to the system theory and to present the system of increase in organization effectiveness using voice analysis. The concepts of the system approach were analyzed, the definition of the system, its components and classification were discussed. Following the principles of the system theory, the system of increase in organization effectiveness using voice analysis was designed. Each element was briefly discussed, i.e. processes influencing the employee, the environment, voice analysis system, expert system, prime and final organizational effectiveness. In addition, the relations between these elements were indentified. Article in Lithuanian

  11. [Voluntary alpha-power increasing training impact on the heart rate variability].

    Science.gov (United States)

    Bazanova, O M; Balioz, N V; Muravleva, K B; Skoraia, M V

    2013-01-01

    In order to study the effect of the alpha EEG power increasing training at heart rate variability (HRV) as the index of the autonomic regulation of cognitive functions there were follow tasks: (1) to figure out the impact of biofeedback in the voluntary increasing the power in the individual high-frequency alpha-band effect on heart rate variability and related characteristics of cognitive and emotional spheres, (2) to determine the nature of the relationship between alpha activity indices and heart rate variability, depending on the alpha-frequency EEG pattern at rest (3) to examine how the individual alpha frequency EEG pattern is reflected in changes HRV as a result of biofeedback training. Psychometric indicators of cognitive performance, the characteristics of the alpha-EEG activity and heart rate variability (HRV) as LF/HF and pNN50 were recorded in 27 healthy men aged 18-34 years, before, during, and after 10 sessions of training of voluntary increase in alpha power in the individual high-frequency alpha band with eyes closed. To determine the biofeedback effect on the alpha power increasing training, data subjects are compared in 2 groups: experimental (14) with the real and the control group (13 people)--with mock biofeedback. The follow up effect of trainings was studied through month over the 10 training sessions. Results showed that alpha biofeedback training enhanced the fluency and accuracy in cognitive performance, decreased anxiety and frontal EMG, increased resting frequency, width and power in individual upper alpha range only in participants with low baseline alpha frequency. While mock biofeedback increased resting alpha power only in participants with high baseline resting alpha frequency and did change neither cognitive performance, nor HRV indices. Biofeedback training eliminated the alpha power decrease in response to arithmetic task in both with high and low alpha frequency participants and this effect was followed up over the month. Mock

  12. Power-Law Dynamics of Membrane Conductances Increase Spiking Diversity in a Hodgkin-Huxley Model

    Science.gov (United States)

    Teka, Wondimu; Stockton, David; Santamaria, Fidel

    2016-01-01

    We studied the effects of non-Markovian power-law voltage dependent conductances on the generation of action potentials and spiking patterns in a Hodgkin-Huxley model. To implement slow-adapting power-law dynamics of the gating variables of the potassium, n, and sodium, m and h, conductances we used fractional derivatives of order η≤1. The fractional derivatives were used to solve the kinetic equations of each gate. We systematically classified the properties of each gate as a function of η. We then tested if the full model could generate action potentials with the different power-law behaving gates. Finally, we studied the patterns of action potential that emerged in each case. Our results show the model produces a wide range of action potential shapes and spiking patterns in response to constant current stimulation as a function of η. In comparison with the classical model, the action potential shapes for power-law behaving potassium conductance (n gate) showed a longer peak and shallow hyperpolarization; for power-law activation of the sodium conductance (m gate), the action potentials had a sharp rise time; and for power-law inactivation of the sodium conductance (h gate) the spikes had wider peak that for low values of η replicated pituitary- and cardiac-type action potentials. With all physiological parameters fixed a wide range of spiking patterns emerged as a function of the value of the constant input current and η, such as square wave bursting, mixed mode oscillations, and pseudo-plateau potentials. Our analyses show that the intrinsic memory trace of the fractional derivative provides a negative feedback mechanism between the voltage trace and the activity of the power-law behaving gate variable. As a consequence, power-law behaving conductances result in an increase in the number of spiking patterns a neuron can generate and, we propose, expand the computational capacity of the neuron. PMID:26937967

  13. Analysis of nuclear power plant construction costs

    International Nuclear Information System (INIS)

    The objective of this report is to present the results of a statistical analysis of nuclear power plant construction costs and lead-times (where lead-time is defined as the duration of the construction period), using a sample of units that entered construction during the 1966-1977 period. For more than a decade, analysts have been attempting to understand the reasons for the divergence between predicted and actual construction costs and lead-times. More importantly, it is rapidly being recognized that the future of the nuclear power industry rests precariously on an improvement in the cost and lead-time situation. Thus, it is important to study the historical information on completed plants, not only to understand what has occurred to also to improve the ability to evaluate the economics of future plants. This requires an examination of the factors that have affected both the realized costs and lead-times and the expectations about these factors that have been formed during the construction process. 5 figs., 22 tabs

  14. Analysis of nuclear-power construction costs

    International Nuclear Information System (INIS)

    This paper discusses the use of regression analysis for estimating construction costs. The estimate is based on an historical data base and quantification of key factors considered external to project management. This technique is not intended as a replacement for detailed cost estimates but can provide information useful to the cost-estimating process and to top management interested in evaluating project management. The focus of this paper is the nuclear-power construction industry but the technique is applicable beyond this example. The approach and critical assumptions are also useful in a public-policy situation where utility commissions are evaluating construction in prudence reviews and making comparisons to other nuclear projects. 13 references, 2 figures

  15. Effects of increased microwave heating power in the stellarator TJ-K

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, Alejandro; Koehn, Alf; Ali, Ahmed; Ramisch, Mirko [Institute of Interfacial Process Engineering and Plasma Technology, University of Stuttgart, Stuttgart (Germany)

    2015-05-01

    One of the microwave heating systems at the stellarator TJ-K has been recently upgraded: a third klystron has been installed, increasing the heating power from 4 kW to 6 kW operating at 14 GHz. A phased-array antenna is used which allows to vary the injection angle by sweeping the microwave frequency in order control the coupling mechanism of the microwave to the plasma. With the two klystrons already installed, ionization degrees of α ≅ 1 have been reached. We expect that an increased heating power, by means of the third klystron put into operation, leads to an increase in the electron temperature T{sub e} only, rather than in electron density n{sub e}, and thus a decrease in the collision frequency ν{sub ei} ∝ n{sub e}T{sub e}{sup -3/2} which has an impact on heating flow damping and neoclassical properties. Parameter scans have been performed in order to characterize the new heating scenario. A radial movable Langmuir probe has been used to obtain radial profiles of the electron density and temperature. An arrangement of bolometers and an optical diode have been used to obtain the power losses by radiation. A particle and power balance model is used to obtain estimated densities and temperatures in order to compare with the experimental results.

  16. Increasing the solar cell power output by coating with transition metal-oxide nanorods

    International Nuclear Information System (INIS)

    Highlights: → Nanoparticles enhance solar cell efficiency. → Solar cell power increase by nanorod coating. → Metal-oxide nanorods are prepared in flames. → Molybdenum oxide nanorods effectively scatter light on solar cell surface. → Scattering efficiency depends on coating density. -- Abstract: Photovoltaic cells produce electric current through interactions among photons from an ambient light source and electrons in the semiconductor layer of the cell. However, much of the light incident on the panel is reflected or absorbed without inducing the photovoltaic effect. Transition metal-oxide nanoparticles, an inexpensive product of a process called flame synthesis, can cause scattering of light. Scattering can redirect photon flux, increasing the fraction of light absorbed in the thin active layer of silicon solar cells. This research aims to demonstrate that the application of transition metal-oxide nanorods to the surface of silicon solar panels can enhance the power output of the panels. Several solar panels were coated with a nanoparticle-methanol suspension, and the power outputs of the panels before and after the treatment were compared. The results demonstrate an increase in power output of up to 5% after the treatment. The presence of metal-oxide nanorods on the surface of the coated solar cells is confirmed by electron microscopy.

  17. High-level power analysis and optimization techniques

    Science.gov (United States)

    Raghunathan, Anand

    1997-12-01

    This thesis combines two ubiquitous trends in the VLSI design world--the move towards designing at higher levels of design abstraction, and the increasing importance of power consumption as a design metric. Power estimation and optimization tools are becoming an increasingly important part of design flows, driven by a variety of requirements such as prolonging battery life in portable computing and communication devices, thermal considerations and system cooling and packaging costs, reliability issues (e.g. electromigration, ground bounce, and I-R drops in the power network), and environmental concerns. This thesis presents a suite of techniques to automatically perform power analysis and optimization for designs at the architecture or register-transfer, and behavior or algorithm levels of the design hierarchy. High-level synthesis refers to the process of synthesizing, from an abstract behavioral description, a register-transfer implementation that satisfies the desired constraints. High-level synthesis tools typically perform one or more of the following tasks: transformations, module selection, clock selection, scheduling, and resource allocation and assignment (also called resource sharing or hardware sharing). High-level synthesis techniques for minimizing the area, maximizing the performance, and enhancing the testability of the synthesized designs have been investigated. This thesis presents high-level synthesis techniques that minimize power consumption in the synthesized data paths. This thesis investigates the effects of resource sharing on the power consumption in the data path, provides techniques to efficiently estimate power consumption during resource sharing, and resource sharing algorithms to minimize power consumption. The RTL circuit that is obtained from the high-level synthesis process can be further optimized for power by applying power-reducing RTL transformations. This thesis presents macro-modeling and estimation techniques for switching

  18. Measurement Error and Equating Error in Power Analysis

    Science.gov (United States)

    Phillips, Gary W.; Jiang, Tao

    2016-01-01

    Power analysis is a fundamental prerequisite for conducting scientific research. Without power analysis the researcher has no way of knowing whether the sample size is large enough to detect the effect he or she is looking for. This paper demonstrates how psychometric factors such as measurement error and equating error affect the power of…

  19. Safety analysis program for steam generators replacement and power uprate at Tihange 2 nuclear power plant

    International Nuclear Information System (INIS)

    The Belgian Tihange 2 nuclear power plant went into commercial operation in 1983 producing a thermal power of 2785 MW. Since the commissioning of the plant the steam generators U-tubes have been affected by primary stress corrosion cracking. In order to avoid further degradation of the performance and an increase in repair costs, Electrabel, the owner of the plant, decided in 1997 to replace the 3 steam generators. This decision was supported by the feasibility study performed by Tractebel Energy Engineering which demonstrated that an increase of 10% of the initial power together with a fuel cycle length of 18 months was achieved. Tractebel Energy Engineering was entrusted by Electrabel as the owner's engineer to manage the project. This paper presents the role of Tractebel Energy Engineering in this project and the safety analysis program necessary to justify the new operation point and the fuel cycle extension to 18 months re-analysis of FSAR chapter 15 accidents and verification of the capacity of the safety and auxiliary systems. The FSAR chapter 15 accidents were reanalyzed jointly by Framatome and Tractebel Energy Engineering while the systems verifications were carried out by Tractebel Energy Engineering. (author)

  20. Improved Power Saving Mechanism to Increase Unavailability Interval in IEEE 802.16e Networks

    Science.gov (United States)

    Lee, Kyunghye; Mun, Youngsong

    To manage limited energy resources efficiently, IEEE 802.16e specifies sleep mode operation. Since there can be no communication between the mobile station (MS) and the serving base station (BS) during the unavailability interval, the MS can power down its physical operation components. We propose an improved power saving mechanism (iPSM) which effectively increases the unavailability interval of Type I and Type II power saving classes (PSCs) activated in an MS. After investigating the number of frames in the unavailability interval of each Type II PSC when used with Type I PSC, the iPSM chooses the Type II PSC that yields the maximum number of frames in the unavailability interval. Performance evaluation confirms that the proposed scheme is very effective.

  1. A power flow based model for the analysis of vulnerability in power networks

    Science.gov (United States)

    Wang, Zhuoyang; Chen, Guo; Hill, David J.; Dong, Zhao Yang

    2016-10-01

    An innovative model which considers power flow, one of the most important characteristics in a power system, is proposed for the analysis of power grid vulnerability. Moreover, based on the complex network theory and the Max-Flow theorem, a new vulnerability index is presented to identify the vulnerable lines in a power grid. In addition, comparative simulations between the power flow based model and existing models are investigated on the IEEE 118-bus system. The simulation results demonstrate that the proposed model and the index are more effective in power grid vulnerability analysis.

  2. Power Quality Analysis in Off-Grid Power Platform

    OpenAIRE

    Stanislav Misak; Jindrich Stuchly; Jakub Vramba; Lukas Prokop; Marian Uher

    2014-01-01

    Research projects in the field of electrical distribution systems are moving to a new philosophy of Smart Grids, where the effort is to use the maximum possible share of power from renewable energy potential. Under this philosophy the emphasis is on energy independence, reliability and safety of operation of energy distribution system. Research in this area leads for example to developing of autonomous local microgrids with the several specific requirements. However, the problem of parameters...

  3. Increased deposition of polychlorinated biphenyls (PCBs) under an AC high-voltage power line

    Science.gov (United States)

    Öberg, Tomas; Peltola, Pasi

    2009-12-01

    There is considerable public concern regarding the potential risks to health of electromagnetic fields in general and high-voltage power lines in particular. As epidemiological findings are not supported by a clearly defined mechanism of direct magnetic field interactions with the human body, potential indirect effects are of interest. It has been suggested that an increased exposure to chemical pollutants could occur near high-voltage power lines due to formation and deposition of charged aerosols. The current study reports empirical evidence that seems to support this hypothesis. The deposition of 18 congeners of polychlorinated biphenyls (PCBs) was studied by collecting samples of pine needles under a 400 kV AC power line and at reference sites in the vicinity. Compared to the reference sites, the average deposition of PCB congeners under the power line was almost double. This difference between the two groups of samples was statistically significant. While it is premature to draw any conclusions regarding the human exposure near high-voltage power lines, the issue deserves attention and further investigations.

  4. Electric power systems analysis and control

    CERN Document Server

    Saccomanno, Fabio

    2003-01-01

    "Highly relevant and timely in scope, the book is essential reading for anyone associated with electric power systems, including students and teachers of power engineering courses, professionals in the industry, consultants, and researchers."--Jacket.

  5. An analysis of nuclear power plant operating costs

    International Nuclear Information System (INIS)

    This report presents the results of a statistical analysis of nonfuel operating costs for nuclear power plants. Most studies of the economic costs of nuclear power have focused on the rapid escalation in the cost of constructing a nuclear power plant. The present analysis found that there has also been substantial escalation in real (inflation-adjusted) nonfuel operating costs. It is important to determine the factors contributing to the escalation in operating costs, not only to understand what has occurred but also to gain insights about future trends in operating costs. There are two types of nonfuel operating costs. The first is routine operating and maintenance expenditures (O and M costs), and the second is large postoperational capital expenditures, or what is typically called ''capital additions.'' O and M costs consist mainly of expenditures on labor, and according to one recently completed study, the majoriy of employees at a nuclear power plant perform maintenance activities. It is generally thought that capital additions costs consist of large maintenance expenditures needed to keep the plants operational, and to make plant modifications (backfits) required by the Nuclear Regulatory Commission (NRC). Many discussions of nuclear power plant operating costs have not considered these capital additions costs, and a major finding of the present study is that these costs are substantial. The objective of this study was to determine why nonfuel operating costs have increased over the past decade. The statistical analysis examined a number of factors that have influenced the escalation in real nonfuel operating costs and these are discussed in this report. 4 figs, 19 tabs

  6. Future Generation Adequacy of the Hungarian Power System with Increasing Share of Res

    Directory of Open Access Journals (Sweden)

    Agnes Gerse

    2015-06-01

    Full Text Available Power generation sector is expected to undergo substantial changes in Hungary in the next years due to the decommissioning of several large units reaching the end of their lifetimes in parallel to the projected increase of renewable electricity generating capacity. In addition to the traditionally widely used deterministic adequacy assessment methods, a probabilistic approach has a great importance in case of technologies with different capacity credits. An analytical country-specific adequacy assessment model enabling the probabilistic modelling of wind power plants was developed and applied to generating capacity forecasts for Hungary. Model parameters were estimated using multi-annual production, plant availability, and hourly system demand data. Adequacy indicators obtained from the model clearly show increasing reliance on imported electricity in the absence of investments in new generating capacity.

  7. Analyzing the Impacts of Increased Wind Power on Generation Revenue Sufficiency: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qin; Wu, Hongyu; Tan, Jin; Hodge, Bri-Mathias; Li, Wanning; Luo, Cheng

    2016-08-01

    The Revenue Sufficiency Guarantee (RSG), as part of make-whole (or uplift) payments in electricity markets, is designed to recover the generation resources' offer-based production costs that are not otherwise covered by their market revenues. Increased penetrations of wind power will bring significant impacts to the RSG payments in the markets. However, literature related to this topic is sparse. This paper first reviews the industrial practices of implementing RSG in major U.S. independent system operators (ISOs) and regional transmission operators (RTOs) and then develops a general RSG calculation method. Finally, an 18-bus test system is adopted to demonstrate the impacts of increased wind power on RSG payments.

  8. Power System Transient Stability Analysis through a Homotopy Analysis Method

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shaobu; Du, Pengwei; Zhou, Ning

    2014-04-01

    As an important function of energy management systems (EMSs), online contingency analysis plays an important role in providing power system security warnings of instability. At present, N-1 contingency analysis still relies on time-consuming numerical integration. To save computational cost, the paper proposes a quasi-analytical method to evaluate transient stability through time domain periodic solutions’ frequency sensitivities against initial values. First, dynamic systems described in classical models are modified into damping free systems whose solutions are either periodic or expanded (non-convergent). Second, because the sensitivities experience sharp changes when periodic solutions vanish and turn into expanded solutions, transient stability is assessed using the sensitivity. Third, homotopy analysis is introduced to extract frequency information and evaluate the sensitivities only from initial values so that time consuming numerical integration is avoided. Finally, a simple case is presented to demonstrate application of the proposed method, and simulation results show that the proposed method is promising.

  9. Theoretical Studies of Active Power/angle Sub-matrix in Power Flow Jacobian for Power System Analysis

    Institute of Scientific and Technical Information of China (English)

    CAO Guo-yun; ZHANG Qing; CHUNG T S; CHEN Chen

    2008-01-01

    Properties of the active power/angle sub-matrix in the power flow Jacobian for power system analysis are studied. The sub-matrix is a dominant and irreducible matrix under very general conditions of power systems, so that it is invertible. Also the necessary conditions for its singularity are given. These theoretical rsuts can be used to clarify the ambiguous understanding of the sub-matrix in current literature, and also provide the theoretical foundations for the applications based on reduced power flow Jacobian. Numerical simulation on the IEEE 118-bus power system is used to illustrate our results.

  10. Power enhancement by increasing the initial array radius and wire number of tungsten Z pinches

    International Nuclear Information System (INIS)

    Tungsten wire array implosions on the 7- to 8-MA Saturn generator have been optimized using wire number and array diameter variations to produce 75±10TW of x rays with total energy outputs of 450±50kJ. By increasing the number of wires in a 12.5-mm-diam array from 24 to 70 and simultaneously decreasing the individual wire diameter from 13 to 7.5 μm, the total radiated power increased from 20±3 to 40±6TW and the x-ray pulse width decreased from 18 to 8.5 ns. In addition, a diameter scan at an implosion time of 50±5ns showed that the pulse width has a strong dependence on collapse velocity and wire thickness. For the largest diameter load of 17.5 mm with 120 5-μm-diam wires, a 4-ns pulse width with a peak power of 75±10TW was achieved: four times power gain over the 20-TW electrical power generated by the pulsed power system. Time-resolved pinhole photography confirms that the power enhancement with increased wire number is associated with the plasma achieving a tighter compression and better axial uniformity. For the higher-velocity implosions, we infer from two-dimensional radiation-magnetohydrodynamic calculations that the plasma becomes hotter and hence radiates at a higher brightness temperature. Zero- and two-dimensional load models coupled with a detailed circuit model have shown expected radial kinetic energies in the range of 100 endash 200 kJ. The total radiated energy of >400kJ in a 4 endash 20-ns FWHM pulse exceeds the total kinetic energy by more than a factor of 2. Two-dimensional, three-temperature simulations reproduce the observed trends in powers and pulse widths by using a variable initial random density perturbation. These calculations also indicate that the radiated energy is accounted for by the total work done on the plasma by the magnetic field. copyright 1997 The American Physical Society

  11. Increasing voltage of high power electric pulses by means of a pulse transformer

    Energy Technology Data Exchange (ETDEWEB)

    Vdovin, S.S.

    1985-07-01

    The production of megavolt and terawatt electric pulses is difficult and complex. A component part of this problem is increasing the voltage of power pulses of the primary generators used. The problem of increasing the voltage of these pulses can be solved by the use of pulse transformers. However, due to the great voltages and power involved, it is necessary to establish the possibility in principle of increasing voltages to several megavolts, as well as the suitability of the technical and economic characteristics of pulse transformers designed for these purposes. Calculations performed in this article indicate that with pulse lengths of over 1 microsecond, pulse transformers can yield sufficiently high voltages with very slight distortions of transformed pulse shape and power losses. The use of pulse transformers is therefore effective and expedient at pulse lengths of over 1 microsecond. At lengths of less than 0.02 microsecond, pulse transformers apparently became undesirable due to low pulse voltages, great peak distortions and low efficiency.

  12. Informed Conditioning on Clinical Covariates Increases Power in Case-Control Association Studies

    Science.gov (United States)

    Zaitlen, Noah; Lindström, Sara; Pasaniuc, Bogdan; Cornelis, Marilyn; Genovese, Giulio; Pollack, Samuela; Barton, Anne; Bickeböller, Heike; Bowden, Donald W.; Eyre, Steve; Freedman, Barry I.; Friedman, David J.; Field, John K.; Groop, Leif; Haugen, Aage; Heinrich, Joachim; Henderson, Brian E.; Hicks, Pamela J.; Hocking, Lynne J.; Kolonel, Laurence N.; Landi, Maria Teresa; Langefeld, Carl D.; Le Marchand, Loic; Meister, Michael; Morgan, Ann W.; Raji, Olaide Y.; Risch, Angela; Rosenberger, Albert; Scherf, David; Steer, Sophia; Walshaw, Martin; Waters, Kevin M.; Wilson, Anthony G.; Wordsworth, Paul; Zienolddiny, Shanbeh; Tchetgen, Eric Tchetgen; Haiman, Christopher; Hunter, David J.; Plenge, Robert M.; Worthington, Jane; Christiani, David C.; Schaumberg, Debra A.; Chasman, Daniel I.; Altshuler, David; Voight, Benjamin; Kraft, Peter; Patterson, Nick; Price, Alkes L.

    2012-01-01

    Genetic case-control association studies often include data on clinical covariates, such as body mass index (BMI), smoking status, or age, that may modify the underlying genetic risk of case or control samples. For example, in type 2 diabetes, odds ratios for established variants estimated from low–BMI cases are larger than those estimated from high–BMI cases. An unanswered question is how to use this information to maximize statistical power in case-control studies that ascertain individuals on the basis of phenotype (case-control ascertainment) or phenotype and clinical covariates (case-control-covariate ascertainment). While current approaches improve power in studies with random ascertainment, they often lose power under case-control ascertainment and fail to capture available power increases under case-control-covariate ascertainment. We show that an informed conditioning approach, based on the liability threshold model with parameters informed by external epidemiological information, fully accounts for disease prevalence and non-random ascertainment of phenotype as well as covariates and provides a substantial increase in power while maintaining a properly controlled false-positive rate. Our method outperforms standard case-control association tests with or without covariates, tests of gene x covariate interaction, and previously proposed tests for dealing with covariates in ascertained data, with especially large improvements in the case of case-control-covariate ascertainment. We investigate empirical case-control studies of type 2 diabetes, prostate cancer, lung cancer, breast cancer, rheumatoid arthritis, age-related macular degeneration, and end-stage kidney disease over a total of 89,726 samples. In these datasets, informed conditioning outperforms logistic regression for 115 of the 157 known associated variants investigated (P-value = 1×10−9). The improvement varied across diseases with a 16% median increase in χ2 test statistics and a

  13. Informed conditioning on clinical covariates increases power in case-control association studies.

    Directory of Open Access Journals (Sweden)

    Noah Zaitlen

    Full Text Available Genetic case-control association studies often include data on clinical covariates, such as body mass index (BMI, smoking status, or age, that may modify the underlying genetic risk of case or control samples. For example, in type 2 diabetes, odds ratios for established variants estimated from low-BMI cases are larger than those estimated from high-BMI cases. An unanswered question is how to use this information to maximize statistical power in case-control studies that ascertain individuals on the basis of phenotype (case-control ascertainment or phenotype and clinical covariates (case-control-covariate ascertainment. While current approaches improve power in studies with random ascertainment, they often lose power under case-control ascertainment and fail to capture available power increases under case-control-covariate ascertainment. We show that an informed conditioning approach, based on the liability threshold model with parameters informed by external epidemiological information, fully accounts for disease prevalence and non-random ascertainment of phenotype as well as covariates and provides a substantial increase in power while maintaining a properly controlled false-positive rate. Our method outperforms standard case-control association tests with or without covariates, tests of gene x covariate interaction, and previously proposed tests for dealing with covariates in ascertained data, with especially large improvements in the case of case-control-covariate ascertainment. We investigate empirical case-control studies of type 2 diabetes, prostate cancer, lung cancer, breast cancer, rheumatoid arthritis, age-related macular degeneration, and end-stage kidney disease over a total of 89,726 samples. In these datasets, informed conditioning outperforms logistic regression for 115 of the 157 known associated variants investigated (P-value = 1 × 10(-9. The improvement varied across diseases with a 16% median increase in χ(2 test statistics

  14. Optimal rate of power increase in nuclear fuel. Pellet behaviour under dynamic conditions

    International Nuclear Information System (INIS)

    A mathematical model has been worked out for the determination of the optium power escalation rate for nuclear power plants from the view-pint of fuel integrity. The model calculates the stress and strain transients in the pellet-cladding system with rapid power increase. No burnup effects are included due to the short time scale involved. An elastic solution has been transposed to a linear viscoelastic one using the correspondence principle. The cladding has however been treated under the programme assumptions as purely elastic. The fuel material has been assumed to be completely relaxed prior to the power transient. Radial cracking is included. The UO2-material distortion has been assumed to be linear viscoelastic, while the dilation is assumed as elastic. The system has been treated assuming plane strain since friction between the pellet and the cladding is large with practical burnsups, and the pellet column can be regarded as infinitely long, compared to the diameter of the pellet. The results of the calculations made show that under the above assumptions the clad stress is independent of the rate of power increase in the pellet. Scince this result is in opposition to general opinion an experimental programme was performed in order to test the results of the model. These results were confirmed. The occurance of clad failures in practice is not determined purely by clad straining. Current thought pays attention to the influence of e.g. stress-corrosion phenomena as significant. The programme reported here pays no attention such-like effects, or the effects of clad creep which could be of considerable significance with local deformations. These later effects are receiving attention in work now being initiated at the Department.(author)

  15. The Utility of Computer-Assisted Power Analysis Lab Instruction

    Science.gov (United States)

    Petrocelli, John V.

    2007-01-01

    Undergraduate students (N = 47), enrolled in 2 separate psychology research methods classes, evaluated a power analysis lab demonstration and homework assignment. Students attended 1 of 2 lectures that included a basic introduction to power analysis and sample size analysis. One lecture included a demonstration of how to use a computer-based power…

  16. Power flow analysis for DC voltage droop controlled DC microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Chaudhary, Sanjay; Dragicevic, Tomislav;

    2014-01-01

    This paper proposes a new algorithm for power flow analysis in droop controlled DC microgrids. By considering the droop control in the power flow analysis for the DC microgrid, when compared with traditional methods, more accurate analysis results can be obtained. The algorithm verification is ca...

  17. Small break LOCA analysis for Maanshan nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Jer-Cherng Kang; Shou-Chuan Chiang; Lang-Chen Wang [Taiwan Power Company, Taipei (China)

    1994-12-31

    Since 1990, Taiwan Power Company has conducted a LWR LOCA technology transfer program on RELAP5YA computer code from Yankee Atomic Electric Company (YAEC). One objective of this program is to acquire the RELAP5YA computer code from YAEC for Taipower in-house licensing analysis. The RELAP5YA is a computer program developed at YAEC for analysing the dynamic behaviour of thermal-hydraulic systems, and it can cover most of the postulated accidents and transients in light water reactor systems. In this paper, Taipower`s engineers have performed a small break loss of coolant accidents analysis for Maanshan nuclear power plant. Thais action is used to perform the licensing actions for increasing the operation margin on the steam generator tube plugging. The result is shown that the steam generator tube can be plugged slightly without a reduction in safety margins. This analysis covers a spectrum of break size for a small break LOCA. For a complete spectrum of the transient and accident analysis, the large break LOCA and the non-LOCA analysis were performed by the fuel vendor for the reload safety evaluation.

  18. Analysis of nuclear power plant component failures

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    Items are shown that have caused 90% of the nuclear unit outages and/or deratings between 1971 and 1980 and the magnitude of the problem indicated by an estimate of power replacement cost when the units are out of service or derated. The funding EPRI has provided on these specific items for R and D and technology transfer in the past and the funding planned in the future (1982 to 1986) are shown. EPRI's R and D may help the utilities on only a small part of their nuclear unit outage problems. For example, refueling is the major cause for nuclear unit outages or deratings and the steam turbine is the second major cause for nuclear unit outages; however, these two items have been ranked fairly low on the EPRI priority list for R and D funding. Other items such as nuclear safety (NRC requirements), reactor general, reactor and safety valves and piping, and reactor fuel appear to be receiving more priority than is necessary as determined by analysis of nuclear unit outage causes.

  19. Numerical analysis of phase change materials for thermal control of power battery of high power dissipations

    Science.gov (United States)

    Xia, X.; Zhang, H. Y.; Deng, Y. C.

    2016-08-01

    Solid-fluid phase change materials have been of increasing interest in various applications due to their high latent heat with minimum volume change. In this work, numerical analysis of phase change materials is carried out for the purpose of thermal control of the cylindrical power battery cells for applications in electric vehicles. Uniform heat density is applied at the battery cell, which is surrounded by phase change material (PCM) of paraffin wax type and contained in a metal housing. A two-dimensional geometry model is considered due to the model symmetry. The effects of power densities, heat transfer coefficients and onset melting temperatures are examined for the battery temperature evolution. Temperature plateaus can be observed from the present numerical analysis for the pure PCM cases, with the temperature level depending on the power densities, heat transfer coefficients, and melting temperatures. In addition, the copper foam of high thermal conductivity is inserted into the copper foam to enhance the heat transfer. In the modeling, the local thermal non-equilibrium between the metal foam and the PCM is taken into account and the temperatures for the metal foam and PCM are obtained respectively.

  20. A New Method for Increasing Output Power of a Three-Cavity Transit-Time Oscillator

    Institute of Scientific and Technical Information of China (English)

    HE Jun-Tao; ZHONG Hui-Huang; QIAN Bao-Liang; LIU Yong-Gui

    2004-01-01

    We propose a new method to increase the output power of a three-cavity transit-time oscillator (TC-TTO).Conventional transit-time effect oscillators, such as the split-cavity oscillator (SCO), super-Reltron, and TC-TTO (or double-foil SCO), etc., have a common feature that the span of any modulating cavity is uniform. The new method is to vary the three-cavity spans from uniform to nonuniform. Its configuration is called the nonuniform three-cavity transit-time oscillator (NTC-TTO). Numerical simulations show that the electron-beam is modulated more deeply in certain NTC-TTOs than that in the TC-TTO with the same whole modulating length, and the output microwave power in certain NTC-TTOs is higher than that in the TC-TTO. The experimental results are in agreement with those of the numerical simulations. The results show that the new method can increase the output power of a microwave tube based on the TC-TTO.

  1. Geometrical Methods for Power Network Analysis

    CERN Document Server

    Bellucci, Stefano; Gupta, Neeraj

    2013-01-01

    This book is a short introduction to power system planning and operation using advanced geometrical methods. The approach is based on well-known insights and techniques developed in theoretical physics in the context of Riemannian manifolds. The proof of principle and robustness of this approach is examined in the context of the IEEE 5 bus system. This work addresses applied mathematicians, theoretical physicists and power engineers interested in novel mathematical approaches to power network theory.

  2. Analysis of power system collapse risk

    International Nuclear Information System (INIS)

    In this paper are analysed the initialization events with considering different scenarios and their impact on the power system transient stability. As an initialization event is considered a short circuit at various places of power line. In each scenario are considered protection failures (backup protection), circuit-breaker failures (breaker failure relay activation). The individual states are analysed and the power system collapse risk assessed based on the simulation experiments results (Authors)

  3. Operating health analysis of electric power systems

    Science.gov (United States)

    Fotuhi-Firuzabad, Mahmud

    The required level of operating reserve to be maintained by an electric power system can be determined using both deterministic and probabilistic techniques. Despite the obvious disadvantages of deterministic approaches there is still considerable reluctance to apply probabilistic techniques due to the difficulty of interpreting a single numerical risk index and the lack of sufficient information provided by a single index. A practical way to overcome difficulties is to embed deterministic considerations in the probabilistic indices in order to monitor the system well-being. The system well-being can be designated as healthy, marginal and at risk. The concept of system well-being is examined and extended in this thesis to cover the overall area of operating reserve assessment. Operating reserve evaluation involves the two distinctly different aspects of unit commitment and the dispatch of the committed units. Unit commitment health analysis involves the determination of which unit should be committed to satisfy the operating criteria. The concepts developed for unit commitment health, margin and risk are extended in this thesis to evaluate the response well-being of a generating system. A procedure is presented to determine the optimum dispatch of the committed units to satisfy the response criteria. The impact on the response wellbeing being of variations in the margin time, required regulating margin and load forecast uncertainty are illustrated. The effects on the response well-being of rapid start units, interruptible loads and postponable outages are also illustrated. System well-being is, in general, greatly improved by interconnection with other power systems. The well-being concepts are extended to evaluate the spinning reserve requirements in interconnected systems. The interconnected system unit commitment problem is decomposed into two subproblems in which unit scheduling is performed in each isolated system followed by interconnected system evaluation

  4. Methods for Increasing Power Efficiency of Heating Furnaces Applied in Metallurgical and Mechanical Engineering Industries

    Directory of Open Access Journals (Sweden)

    M. L. German

    2011-01-01

    Full Text Available  The paper analyzes experimental data and results of balance tests of two continuous heating furnaces applied in mechanical engineering and metallurgical industries. Furnace power technological characteristics  and dependences of these characteristics on equipment productivity have been determined in the paper. The analysis has made it possible to reveal reasons of higher efficiency of a heating furnace used at BSW Rolling Mill-320 and formulate recommendations on reduction of fuel consumption in operating and designed combustion furnaces applied in mechanical engineering and metallurgical industries.

  5. 18 CFR 35.37 - Market power analysis required.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Market power analysis required. 35.37 Section 35.37 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Wholesale Sales of Electric Energy, Capacity and Ancillary Services at Market-Based Rates § 35.37...

  6. Investigation into the absorptivity change in metals with increased laser power

    DEFF Research Database (Denmark)

    Blidegn, Kristian; Olsen, Flemmming Ove

    1996-01-01

    At a first glance the low absorptivity of metals in the infrared (IR) makes the use of YAG and CO2 lasers in metal processing very inefficient. However industrial inert gas cutting abilities demonstrates that the absorptivity can reach significantly higher levels during the high power laser...... interaction. An increase which can not be explained by the increase in temperature only. The interaction between laser light and metals is a major physical phenomena in laser material processing. The Drude free electron model or simplifications like the Hagen-Rubens relation has often been used to model...... the processes.This paper discuss the need to extend the Drude mode taking into account interband transitions and anormal skin effect in order to describe in increase in absorptivity seen at high intensities. The absorption model will be used in a cut front simulation and results are compared with cutting...

  7. Investigation into the absorptivity change in Metals with increased laser Power

    DEFF Research Database (Denmark)

    Blidegn, Kristian; Olsen, Flemmming Ove

    1996-01-01

    At a first glance the low absorptivity of metals in the infrared (IR) makes the use of YAG and CO2 lasers in metal processing very inefficient. However industrial inert gas cutting abilities demonstrates that the absorptivity can reach significantly higher levels during the high power laser...... interaction. An increase which can not be explained by the increase in temperature only. The interaction between laser light and metals is a major physical phenomena in laser material processing. The Drude free electron model or simplifications like the Hagen-Rubens relation has often been used to model...... the processes.This paper discuss the need to extend the Drude model taking into account interband transitions and anormal skin effect in order to describe in increase in absorptivity seen at high intensities. The absorption model will be used in a cut front simulation and results are compared with cutting...

  8. Power system small signal stability analysis and control

    CERN Document Server

    Mondal, Debasish; Sengupta, Aparajita

    2014-01-01

    Power System Small Signal Stability Analysis and Control presents a detailed analysis of the problem of severe outages due to the sustained growth of small signal oscillations in modern interconnected power systems. The ever-expanding nature of power systems and the rapid upgrade to smart grid technologies call for the implementation of robust and optimal controls. Power systems that are forced to operate close to their stability limit have resulted in the use of control devices by utility companies to improve the performance of the transmission system against commonly occurring power system

  9. Rural Power System Load Forecast Based on Principal Component Analysis

    Institute of Scientific and Technical Information of China (English)

    Fang Jun-long; Xing Yu; Fu Yu; Xu Yang; Liu Guo-liang

    2015-01-01

    Power load forecasting accuracy related to the development of the power system. There were so many factors influencing the power load, but their effects were not the same and what factors played a leading role could not be determined empirically. Based on the analysis of the principal component, the paper forecasted the demands of power load with the method of the multivariate linear regression model prediction. Took the rural power grid load for example, the paper analyzed the impacts of different factors on power load, selected the forecast methods which were appropriate for using in this area, forecasted its 2014-2018 electricity load, and provided a reliable basis for grid planning.

  10. Multiple Sclerosis Increases Fracture Risk: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Guixian Dong

    2015-01-01

    Full Text Available Purpose. The association between multiple sclerosis (MS and fracture risk has been reported, but results of previous studies remain controversial and ambiguous. To assess the association between MS and fracture risk, a meta-analysis was performed. Method. Based on comprehensive searches of the PubMed, Embase, and Web of Science, we identified outcome data from all articles estimating the association between MS and fracture risk. The pooled risk ratios (RRs with 95% confidence intervals (CIs were calculated. Results. A significant association between MS and fracture risk was found. This result remained statistically significant when the adjusted RRs were combined. Subgroup analysis stratified by the site of fracture suggested significant associations between MS and tibia fracture risk, femur fracture risk, hip fracture risk, pelvis fracture risk, vertebrae fracture risk, and humerus fracture risk. In the subgroup analysis by gender, female MS patients had increased fracture risk. When stratified by history of drug use, use of antidepressants, hypnotics/anxiolytics, anticonvulsants, and glucocorticoids increased the risk of fracture risk in MS patients. Conclusions. This meta-analysis demonstrated that MS was significantly associated with fracture risk.

  11. Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity.

    Science.gov (United States)

    Tippett, Michael K; Cohen, Joel E

    2016-01-01

    Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from 'outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954-2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to Taylor's power law of fluctuation scaling (TL), with parameters that are consistent with multiplicative growth. Tornado-related atmospheric proxies show similar power-law scaling and multiplicative growth. Path-length-integrated tornado outbreak intensity also follows TL, but with parameters consistent with sampling variability. The observed TL power-law scaling of outbreak severity means that extreme outbreaks are more frequent than would be expected if mean and variance were independent or linearly related. PMID:26923210

  12. Security and Stability Analysis for Yunnan Power Grid with Wind Power Integration

    Directory of Open Access Journals (Sweden)

    Yinghui Qiu

    2013-12-01

    Full Text Available Wind power is sustainable, renewable and clean energy. There are abundant wind resources in Yunnan province, China. In recent years, wind power integration has developed rapidly in Yunnan province. With the first batch of the wind farm being built and a part of them going into production in Yunnan, the wind power resources will be large-scale developed and utilized in the future. Based on the wind power planning of Yunnan, the impacts of security and stability after wind power are studied in this paper. The major researches are made on the capacity analysis for accessing high-capacity wind farm, the analysis for power system voltage stability and comparison of different wind-generator model structures, thus finding out the most suitable choice for fan selection in Yunnan Power Grid.

  13. Cooling Tower Optimization A Simple Way to Generate Green Megawatts and to Increase the Efficiency of a Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Strohmer, F.

    2014-07-01

    The profitability of nuclear power plants is worldwide challenged by low electricity prices. One hand low cost shale gas is offering a low price electricity production , other hand additional taxes on fuel are reducing the operating income of nuclear power stations. The optimization of cooling towers can help to increase the efficiency and profit of a nuclear power plant. (Author)

  14. Backup Power Cost of Ownership Analysis and Incumbent Technology Comparison

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, J.; Saur, G.; Sprik, S.; Ainscough, C.

    2014-09-01

    This cost of ownership analysis identifies the factors impacting the value proposition for fuel cell backup power and presents the estimated annualized cost of ownership for fuel cell backup power systems compared with the incumbent technologies of battery and diesel generator systems. The analysis compares three different backup power technologies (diesel, battery, and fuel cell) operating in similar circumstances in four run time scenarios (8, 52, 72, and 176 hours).

  15. Analysis of Switching Noise on Power Planes

    Directory of Open Access Journals (Sweden)

    M. Ž. Stojilović

    2009-11-01

    Full Text Available Power delivery networks (PDNs in modern printed circuit boards (PCBs are usually realized using power planes. Since the planes have very low inductance, it is usually believed that such PDNs have the smallest amount of switching noise. However, in reality, the power planes can resonate. The noise at resonant frequencies can be significant and it deteriorates the PDN performance. One of the classical methods for decreasing the noise is bypassing. This paper investigates the behavior of a typical PDN and the effect that real SMD bypass capacitors produce when attached to it.

  16. Complex Network Analysis of Brazilian Power Grid

    CERN Document Server

    Martins, Gabriela C; Ribeiro, Fabiano L; Forgerini, Fabricio L

    2016-01-01

    Power Grids and other delivery networks has been attracted some attention by the network literature last decades. Despite the Power Grids dynamics has been controlled by computer systems and human operators, the static features of this type of network can be studied and analyzed. The topology of the Brazilian Power Grid (BPG) was studied in this work. We obtained the spatial structure of the BPG from the ONS (electric systems national operator), consisting of high-voltage transmission lines, generating stations and substations. The local low-voltage substations and local power delivery as well the dynamic features of the network were neglected. We analyze the complex network of the BPG and identify the main topological information, such as the mean degree, the degree distribution, the network size and the clustering coefficient to caracterize the complex network. We also detected the critical locations on the network and, therefore, the more susceptible points to lead to a cascading failure and even to a blac...

  17. Galena Electric Power A Situational Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Robert E. Chaney; Stephen G. Colt; Ronald A. Johnson; Richard W. Wiles; Gregory J. White

    2008-12-31

    The purpose of the investigation is to compare the economics of various electrical power generation options for the City of Galena. Options were assessed over a 30-year project period, beginning in 2010, and the final results were compared on the basis of residential customer electric rates ($/kWh). Galena's electric utility currently generates power using internal combustion diesel engines and generator sets. Nearby, there is an exposed coal seam, which might provide fuel for a power plant. Contributions to the energy mix might come from solar, municipal solid waste, or wood. The City has also been approached by Toshiba, Inc., as a demonstration site for a small (Model 4S) nuclear reactor power plant. The Yukon River is possibly a site for in-river turbines for hydroelectric power. This report summarizes the comparative economics of various energy supply options. This report covers: (1) thermal and electric load profiles for Galena; (2) technologies and resources available to meet or exceed those loads; (3) uses for any extra power produced by these options; (4) environmental and permitting issues and then; and (5) the overall economics of each of the primary energy options.

  18. AC Versus DC Link Comparison Based on Power Flow Analysis of a Multimachine Power System

    Directory of Open Access Journals (Sweden)

    Mohammed Abdeljalil DJEHAF

    2014-02-01

    Full Text Available Deregulation and privatization is posing new challenges on high voltage transmission and on distributions systems as well. An increasingly liberalized market will encourage trading opportunities to be identified and developed. High voltage power electronics, such as HVDC (High Voltage Direct Current and FACTS (Flexible AC Transmission Systems provide the necessary features to avoid technical problems in heavily loaded power systems; HVDC offers most advantages: it can be used for system interconnection and for control of power flow as well. The major benefit of HVDC is its incorporated ability for fault-current blocking, which is not possible with synchronous AC links. In addition, HVDC can effectively support the surrounding AC systems in case of transient fault conditions and it serves as firewall against cascading disturbances. This paper presents a comparison between HVDC link and an HVAC link in a 29 Bus multimachine system, based on load flow analysis using Newton-Raphson method for the AC link case, and sequential method for the HVDC link case.

  19. Converter Power Density Increase using Low Inductive Integrated DC-link Capacitor/Bus

    DEFF Research Database (Denmark)

    Trintis, Ionut; Franke, Toke; Rannested, Bjørn;

    2015-01-01

    The power losses in switching devices have a direct effect on the maximum converter power. For a voltage source converter, the DC-link bus has a major influence on the power loss and safe operating area of the power devices. The Power Ring Film CapacitorTM integrated with an optimized bus structu...... has a measured inductance of around 5 nH. That allows the converter to switch with low turn-off losses, and allows the safe operation at higher dc-link voltages. This paper investigates the power transfer limits of a ShowerPower® cooled power stack....

  20. Analysis of the Spectral Resolving Power in Tomographic Imaging Spectrometry

    Institute of Scientific and Technical Information of China (English)

    方俊永; 赵达尊; 蒋月娟

    2004-01-01

    From the point of view of design requirements, influence of the width of the output image of an imaging subsystem in a tomographic imaging spectrometer, namely width of the slit, the grating and the size of the CCD pixel are analyzed. For the tomographic imaging spectrometry, if the amplification ratio of the imaging subsystem is not high enough to make the whole object to be compressed within the slit, then either the slit width should be increased or the slit width kept unchanged but scanned to receive information of the object. While the width-increase method reduces the spectral resolving power and the SNR; the scanning method reduces the SNR. Analysis of the two cases and computer simulation results are given.

  1. Profitable increases in cross border transmission capacities in a European power system with large shares of renewables

    Energy Technology Data Exchange (ETDEWEB)

    Graabak, Ingeborg; Wolfgang, Ove

    2012-07-01

    This report describes analyses of profitable increases in cross border capacities in Europe in a time perspective 2030-2050 for situations with large shares of renewables in the power system. The analysis reuses a lot of the methodology from the EU 7th Framework Programme project SUSPLAN. The analyses use the EMPS model (a European model for multi-area power market simulations) and a new investment algorithm on four scenarios Red (40.1 % RES-E in 2050, traditional technologies), Yellow (54 % RES-E in 2050, traditional technologies + extra PV), Green (69 % RES-E in 2050, mainly local and regional production) and Blue (72 % RES-E in 2050, large scale production far away from demand centers). The analyses show that for the four scenarios considerable increases in cross border connections will be necessary. The capacities are in all scenarios more than doubled in 2050 compared to the system in 2010 based on profitability criteria. The result varies from about 120 000 MW in new capacities to as much as 712 700 MW dependent on the volume and location of the new renewables. The increase of transmission capacities is much higher in Blue than in the other scenarios. Blue is dominated by large scale offshore wind production and import of solar based production from Africa. The Green has the lowest CO{sub 2} emissions, a secure electricity system and the lowest electricity prices. High investments are required, but they are limited compared to a future like Blue. (Author)

  2. Stability analysis of spacecraft power systems

    Science.gov (United States)

    Halpin, S. M.; Grigsby, L. L.; Sheble, G. B.; Nelms, R. M.

    1990-01-01

    The problems in applying standard electric utility models, analyses, and algorithms to the study of the stability of spacecraft power conditioning and distribution systems are discussed. Both single-phase and three-phase systems are considered. Of particular concern are the load and generator models that are used in terrestrial power system studies, as well as the standard assumptions of load and topological balance that lead to the use of the positive sequence network. The standard assumptions regarding relative speeds of subsystem dynamic responses that are made in the classical transient stability algorithm, which forms the backbone of utility-based studies, are examined. The applicability of these assumptions to a spacecraft power system stability study is discussed in detail. In addition to the classical indirect method, the applicability of Liapunov's direct methods to the stability determination of spacecraft power systems is discussed. It is pointed out that while the proposed method uses a solution process similar to the classical algorithm, the models used for the sources, loads, and networks are, in general, more accurate. Some preliminary results are given for a linear-graph, state-variable-based modeling approach to the study of the stability of space-based power distribution networks.

  3. Summary of IEA-R1 research a reactor licensing related to its power increase from 2 to 10 MW

    International Nuclear Information System (INIS)

    This work is a summary of IEA-R1 research reactor licensing related to its power increase from 2 to 10 MW. It reports also safety requirements, fuel elements, and reactor control modifications inherent to power increase. (A.C.A.S.)

  4. Analysis of the scalability of diffraction-limited fiber lasers and amplifiers to high average power.

    Science.gov (United States)

    Dawson, Jay W; Messerly, Michael J; Beach, Raymond J; Shverdin, Miroslav Y; Stappaerts, Eddy A; Sridharan, Arun K; Pax, Paul H; Heebner, John E; Siders, Craig W; Barty, C P J

    2008-08-18

    We analyze the scalability of diffraction-limited fiber lasers considering thermal, non-linear, damage and pump coupling limits as well as fiber mode field diameter (MFD) restrictions. We derive new general relationships based upon practical considerations. Our analysis shows that if the fiber's MFD could be increased arbitrarily, 36 kW of power could be obtained with diffraction-limited quality from a fiber laser or amplifier. This power limit is determined by thermal and non-linear limits that combine to prevent further power scaling, irrespective of increases in mode size. However, limits to the scaling of the MFD may restrict fiber lasers to lower output powers. PMID:18711562

  5. Operational Modal Analysis of Wind Turbine Speed-increase Gearbox

    Directory of Open Access Journals (Sweden)

    LI Yafeng

    2013-11-01

    Full Text Available Speed increase transmission gear box is the primary vibration and noise source of wind turbine, Operational modal method was adopted to collect impact data and response data of each point based on the gearbox test model. ANSYS finite element model is established to simulate the wind turbine gearbox. Then the modal frequencies of the two methods were compared to ensure the test model is correct. The results show that operational modal method can be applied in wind turbine gearbox modal analysis and it has important guiding significance to gearbox fault diagnosis and reliability and maintainability improving.  

  6. Power spectrum analysis for optical tweezers

    DEFF Research Database (Denmark)

    Berg-Sørensen, K.; Flyvbjerg, H.

    2004-01-01

    The force exerted by an optical trap on a dielectric bead in a fluid is often found by fitting a Lorentzian to the power spectrum of Brownian motion of the bead in the trap. We present explicit functions of the experimental power spectrum that give the values of the parameters fitted, including...... error bars and correlations, for the best such chi(2) fit in a given frequency range. We use these functions to determine the information content of various parts of the power spectrum, and find, at odds with lore, much information at relatively high frequencies. Applying the method to real data, we...... the Lorentzian provides. This is achieved using old and new theory for Brownian motion in an incompressible fluid, and new results for a popular photodetection system. The trap and photodetection system are then calibrated simultaneously in a manner that makes optical tweezers a tool of precision for force...

  7. Design Analysis of a Novel Synchronous Generator for Wind Power Generation

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Higuchi

    2014-08-01

    Full Text Available A novel synchronous generator is proposed for wind power generation. The field flux is generated by the half-wave rectified excitation method. The generator does not require slip rings and brushes for field power supply, as well as permanent magnets. In this paper, the excitation method is explained, and then, the basic characteristics are calculated using the finite element method analysis. Furthermore, the generator is designed for increasing the output power and efficiency.

  8. Power-laws and spectral analysis of the Internet topology

    OpenAIRE

    Subedi, Laxmi

    2010-01-01

    In this thesis, we present the analysis on power-laws and spectral properties of the Internet topology at AS level based on Border Gateway Protocol (BGP) routing datasets collected from two repositories (Route Views and RIPE) over the period of five years. Analysis of collected datasets revealed that the two datasets have similar historical trends in the development of the Internet. Furthermore, the power-law exponents have not substantially changed over time while spectral analysis revealed ...

  9. PowerPlay: Training an Increasingly General Problem Solver by Continually Searching for the Simplest Still Unsolvable Problem.

    Science.gov (United States)

    Schmidhuber, Jürgen

    2013-01-01

    Most of computer science focuses on automatically solving given computational problems. I focus on automatically inventing or discovering problems in a way inspired by the playful behavior of animals and humans, to train a more and more general problem solver from scratch in an unsupervised fashion. Consider the infinite set of all computable descriptions of tasks with possibly computable solutions. Given a general problem-solving architecture, at any given time, the novel algorithmic framework PowerPlay (Schmidhuber, 2011) searches the space of possible pairs of new tasks and modifications of the current problem solver, until it finds a more powerful problem solver that provably solves all previously learned tasks plus the new one, while the unmodified predecessor does not. Newly invented tasks may require to achieve a wow-effect by making previously learned skills more efficient such that they require less time and space. New skills may (partially) re-use previously learned skills. The greedy search of typical PowerPlay variants uses time-optimal program search to order candidate pairs of tasks and solver modifications by their conditional computational (time and space) complexity, given the stored experience so far. The new task and its corresponding task-solving skill are those first found and validated. This biases the search toward pairs that can be described compactly and validated quickly. The computational costs of validating new tasks need not grow with task repertoire size. Standard problem solver architectures of personal computers or neural networks tend to generalize by solving numerous tasks outside the self-invented training set; PowerPlay's ongoing search for novelty keeps breaking the generalization abilities of its present solver. This is related to Gödel's sequence of increasingly powerful formal theories based on adding formerly unprovable statements to the axioms without affecting previously provable theorems. The continually increasing

  10. PowerPlay: Training an Increasingly General Problem Solver by Continually Searching for the Simplest Still Unsolvable Problem.

    Science.gov (United States)

    Schmidhuber, Jürgen

    2013-01-01

    Most of computer science focuses on automatically solving given computational problems. I focus on automatically inventing or discovering problems in a way inspired by the playful behavior of animals and humans, to train a more and more general problem solver from scratch in an unsupervised fashion. Consider the infinite set of all computable descriptions of tasks with possibly computable solutions. Given a general problem-solving architecture, at any given time, the novel algorithmic framework PowerPlay (Schmidhuber, 2011) searches the space of possible pairs of new tasks and modifications of the current problem solver, until it finds a more powerful problem solver that provably solves all previously learned tasks plus the new one, while the unmodified predecessor does not. Newly invented tasks may require to achieve a wow-effect by making previously learned skills more efficient such that they require less time and space. New skills may (partially) re-use previously learned skills. The greedy search of typical PowerPlay variants uses time-optimal program search to order candidate pairs of tasks and solver modifications by their conditional computational (time and space) complexity, given the stored experience so far. The new task and its corresponding task-solving skill are those first found and validated. This biases the search toward pairs that can be described compactly and validated quickly. The computational costs of validating new tasks need not grow with task repertoire size. Standard problem solver architectures of personal computers or neural networks tend to generalize by solving numerous tasks outside the self-invented training set; PowerPlay's ongoing search for novelty keeps breaking the generalization abilities of its present solver. This is related to Gödel's sequence of increasingly powerful formal theories based on adding formerly unprovable statements to the axioms without affecting previously provable theorems. The continually increasing

  11. Power Processing, Part 1. Electric Machinery Analysis.

    Science.gov (United States)

    Hamilton, Howard B.

    This publication was developed as a portion of a two-semester sequence commencing at either the sixth or seventh term of the undergraduate program in electrical engineering at the University of Pittsburgh. The materials of the two courses, produced by a National Science Foundation grant, are concerned with power conversion systems comprising power…

  12. Randomized block experimental designs can increase the power and reproducibility of laboratory animal experiments.

    Science.gov (United States)

    Festing, Michael F W

    2014-01-01

    Randomized block experimental designs have been widely used in agricultural and industrial research for many decades. Usually they are more powerful, have higher external validity, are less subject to bias, and produce more reproducible results than the completely randomized designs typically used in research involving laboratory animals. Reproducibility can be further increased by using time as a blocking factor. These benefits can be achieved at no extra cost. A small experiment investigating the effect of an antioxidant on the activity of a liver enzyme in four inbred mouse strains, which had two replications (blocks) separated by a period of two months, illustrates this approach. The widespread failure to use these designs more widely in research involving laboratory animals has probably led to a substantial waste of animals, money, and scientific resources and slowed down the development of new treatments for human and animal diseases.

  13. Randomized block experimental designs can increase the power and reproducibility of laboratory animal experiments.

    Science.gov (United States)

    Festing, Michael F W

    2014-01-01

    Randomized block experimental designs have been widely used in agricultural and industrial research for many decades. Usually they are more powerful, have higher external validity, are less subject to bias, and produce more reproducible results than the completely randomized designs typically used in research involving laboratory animals. Reproducibility can be further increased by using time as a blocking factor. These benefits can be achieved at no extra cost. A small experiment investigating the effect of an antioxidant on the activity of a liver enzyme in four inbred mouse strains, which had two replications (blocks) separated by a period of two months, illustrates this approach. The widespread failure to use these designs more widely in research involving laboratory animals has probably led to a substantial waste of animals, money, and scientific resources and slowed down the development of new treatments for human and animal diseases. PMID:25541548

  14. INCREASING THE FISHER INFORMATION CONTENT IN THE MATTER POWER SPECTRUM BY NONLINEAR WAVELET WIENER FILTERING

    International Nuclear Information System (INIS)

    We develop a purely mathematical tool to recover some of the information lost in the nonlinear collapse of large-scale structure. From a set of 141 simulations of dark matter density fields, we construct a nonlinear Wiener filter in order to separate Gaussian and non-Gaussian structure in wavelet space. We find that the non-Gaussian power is dominant at smaller scales, as expected from the theory of structure formation, while the Gaussian counterpart is damped by an order of magnitude on small scales. We find that it is possible to increase the Fisher information by a factor of three before reaching the translinear plateau, an effect comparable to other techniques like the linear reconstruction of the density field.

  15. Increased mortality rate and suicide in Swedish former elite male athletes in power sports.

    Science.gov (United States)

    Lindqvist, A-S; Moberg, T; Ehrnborg, C; Eriksson, B O; Fahlke, C; Rosén, T

    2014-12-01

    Physical training has been shown to reduce mortality in normal subjects, and athletes have a healthier lifestyle after their active career as compared with normal subjects. Since the 1950s, the use of anabolic androgenic steroids (AAS) has been frequent, especially in power sports. The aim of the present study was to investigate mortality, including causes of death, in former Swedish male elite athletes, active 1960-1979, in wrestling, powerlifting, Olympic lifting, and the throwing events in track and field when the suspicion of former AAS use was high. Results indicate that, during the age period of 20-50 years, there was an excess mortality of around 45%. However, when analyzing the total study period, the mortality was not increased. Mortality from suicide was increased 2-4 times among the former athletes during the period of 30-50 years of age compared with the general population of men. Mortality rate from malignancy was lower among the athletes. As the use of AAS was marked between 1960 and 1979 and was not doping-listed until 1975, it seems probable that the effect of AAS use might play a part in the observed increased mortality and suicide rate. The otherwise healthy lifestyle among the athletes might explain the low malignancy rates.

  16. Increasing biomass resource availability through supply chain analysis

    International Nuclear Information System (INIS)

    Increased inclusion of biomass in energy strategies all over the world means that greater mobilisation of biomass resources will be required to meet demand. Strategies of many EU countries assume the future use of non-EU sourced biomass. An increasing number of studies call for the UK to consider alternative options, principally to better utilise indigenous resources. This research identifies the indigenous biomass resources that demonstrate the greatest promise for the UK bioenergy sector and evaluates the extent that different supply chain drivers influence resource availability. The analysis finds that the UK's resources with greatest primary bioenergy potential are household wastes (>115 TWh by 2050), energy crops (>100 TWh by 2050) and agricultural residues (>80 TWh by 2050). The availability of biomass waste resources was found to demonstrate great promise for the bioenergy sector, although are highly susceptible to influences, most notably by the focus of adopted waste management strategies. Biomass residue resources were found to be the resource category least susceptible to influence, with relatively high near-term availability that is forecast to increase – therefore representing a potentially robust resource for the bioenergy sector. The near-term availability of UK energy crops was found to be much less significant compared to other resource categories. Energy crops represent long-term potential for the bioenergy sector, although achieving higher limits of availability will be dependent on the successful management of key influencing drivers. The research highlights that the availability of indigenous resources is largely influenced by a few key drivers, this contradicting areas of consensus of current UK bioenergy policy. - Highlights: • As global biomass demand increases, focus is placed indigenous resources. • A Biomass Resource Model is applied to analyse UK biomass supply chain dynamics. • Biomass availability is best increased

  17. Determination of the potential for utilising combined heat and power and of the target reduction of CO{sub 2} emissions, inclusive of cost analysis (increased use of combined heat and power); Ermittlung der Potenziale fuer die Anwendung der Kraft-Waerme-Kopplung und der erzielbaren Minderung der CO{sub 2}-Emissionen einschliesslich Bewertung der Kosten (Verstaerkte Nutzung der Kraft-Waerme-Kopplung)

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Manfred; Ziesing, Hans-Joachim [Deutsches Inst. fuer Wirtschaftsforschung, Berlin (Germany); Matthes, Felix Christian; Harthan, Ralph [Oeko Institut e.V., Berlin (Germany); Menzler, Gerald [VIK Verband der Industriellen Energie- und Kraftwirtschaft e.V., Essen (Germany)

    2007-07-15

    The report provides a statistical overview of CHP utilisation up to now in Germany, analyses the general economic and political conditions with a view to evaluating the competitiveness of CHP, discusses the effectiveness of the German CHP Act with respect to its contribution to meeting emissions-related goals, analyses the cost-effectiveness of investments in different types of new CHP installations, addresses mid- and longer term potential as well as impediments to the utilisation of CHP installations, presents model simulations of how CHP is expected to develop in the context of economic conditions subject to various general political conditions and makes recommendations with an eye to additional requirements and opportunities to support CHP, against the background of the findings of the analysis. (orig.)

  18. Building 865 Hypersonic Wind Tunnel Power System Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Larry X. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    This report documents the characterization and analysis of a high current power supply for the building 865 Hypersonic Wind Tunnel at Sandia National Laboratories. The system described in this report became operational in 2013, replacing the original 1968 system which employed an induction voltage regulator. This analysis and testing was completed to help the parent organization understand why an updated and redesigned power system was not delivering adequate power to resistive heater elements in the HWT. This analysis led to an improved understanding of the design and operation of the revised 2013 power supply system and identifies several reasons the revised system failed to achieve the performance of the original power supply installation. Design modifications to improve the performance of this system are discussed.

  19. Power distribution and performance analysis for wireless communication networks

    CERN Document Server

    Zhao, Dongmei

    2012-01-01

    This book provides an analysis of transmission power and network performance in different wireless communication networks. It presents the latest research and techniques for power and interference control and performance modeling in wireless communication networks with different network topologies, air interfaces, and transmission techniques. While studying the power distributions and resource management, the reader will also learn basic methodology and skills for problem formulations, can ascertain the complexity for designing radio resource management strategies in modern wireless communicat

  20. Analysis of Facial Injuries Caused by Power Tools.

    Science.gov (United States)

    Kim, Jiye; Choi, Jin-Hee; Hyun Kim, Oh; Won Kim, Sug

    2016-06-01

    The number of injuries caused by power tools is steadily increasing as more domestic woodwork is undertaken and more power tools are used recreationally. The injuries caused by the different power tools as a consequence of accidents are an issue, because they can lead to substantial costs for patients and the national insurance system. The increase in hand surgery as a consequence of the use of power tools and its economic impact, and the characteristics of the hand injuries caused by power saws have been described. In recent years, the authors have noticed that, in addition to hand injuries, facial injuries caused by power tools commonly present to the emergency room. This study aimed to review the data in relation to facial injuries caused by power saws that were gathered from patients who visited the trauma center at our hospital over the last 4 years, and to analyze the incidence and epidemiology of the facial injuries caused by power saws. The authors found that facial injuries caused by power tools have risen continually. Facial injuries caused by power tools are accidental, and they cause permanent facial disfigurements and functional disabilities. Accidents are almost inevitable in particular workplaces; however, most facial injuries could be avoided by providing sufficient operator training and by tool operators wearing suitable protective devices. The evaluation of the epidemiology and patterns of facial injuries caused by power tools in this study should provide the information required to reduce the number of accidental injuries.

  1. Characteristic Analysis and Design of Power Flow of Organizations

    Institute of Scientific and Technical Information of China (English)

    YonganZhang; HuaLiang

    2004-01-01

    This thesis has carried on comparative analysis to the power characteristic of 5 kinds of institutional framework of enterprises at first, and has carried on the survey to the domestic and international train of thought in the research about enterprise's power, then puts forward the basic contradiction in enterprises organization ("The contradictions of the complexity of management's target and people's limited reason") and essential feature ofcurrent enterprise's power ("Solidification of power"), and then has put forward new train of thought in the study of enterprise's power and organization ("flow of power"), finally has designed the way and direction that the power flowed in enterprises, Combining enterprise's life cycle theory and American scholar L.E.Greiner's model about organization development.

  2. Green Power voluntary purchases. Price elasticity and policy analysis

    International Nuclear Information System (INIS)

    Green Power schemes offer electricity from renewable energy sources to customers for a higher price than ordinary electricity. This study examines the demand characteristics of Green Power in Australia and policies which could increase its sales. A sample of 250 pooled time series and cross sectional observations was used to estimate a statistically significant elasticity of demand for Green Power with respect to price of -0.96 with a 95% confidence interval of ±68%. The wide variation in market penetration between jurisdictions and between countries for Green Power, and the low awareness of Green Power found by surveys indicate that Green Power sales could be increased by appropriate marketing and government policies. The most cost effective means to increase sales was found to be advertising campaigns although only one Australian example was found, in the state of Victoria in 2005. It was also found that full tax deductibility of the Green Power premium to residential customers, exemption from the Goods and Services Tax and a tax rebate for Green Power are all probably less cost effective for promoting sales than direct government purchase of Green Power, in terms of cost per unit of increased sales. (author)

  3. Green Power voluntary purchases: Price elasticity and policy analysis

    International Nuclear Information System (INIS)

    Green Power schemes offer electricity from renewable energy sources to customers for a higher price than ordinary electricity. This study examines the demand characteristics of Green Power in Australia and policies which could increase its sales. A sample of 250 pooled time series and cross sectional observations was used to estimate a statistically significant elasticity of demand for Green Power with respect to price of -0.96 with a 95% confidence interval of ±68%. The wide variation in market penetration between jurisdictions and between countries for Green Power, and the low awareness of Green Power found by surveys indicate that Green Power sales could be increased by appropriate marketing and government policies. The most cost effective means to increase sales was found to be advertising campaigns although only one Australian example was found, in the state of Victoria in 2005. It was also found that full tax deductibility of the Green Power premium to residential customers, exemption from the Goods and Services Tax and a tax rebate for Green Power are all probably less cost effective for promoting sales than direct government purchase of Green Power, in terms of cost per unit of increased sales.

  4. Power Analysis in Two-Level Unbalanced Designs

    Science.gov (United States)

    Konstantopoulos, Spyros

    2010-01-01

    Previous work on statistical power has discussed mainly single-level designs or 2-level balanced designs with random effects. Although balanced experiments are common, in practice balance cannot always be achieved. Work on class size is one example of unbalanced designs. This study provides methods for power analysis in 2-level unbalanced designs…

  5. Integrated analysis software for bulk power system stability

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.; Nagao, T.; Takahashi, K. [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1994-12-31

    This paper presents Central Research Inst.of Electric Power Industry - CRIEPI`s - own developed three softwares for bulk power network analysis and the user support system which arranges tremendous data necessary for these softwares with easy and high reliability. (author) 3 refs., 7 figs., 2 tabs.

  6. Performance and stability analysis of a photovoltaic power system

    Science.gov (United States)

    Merrill, W. C.; Blaha, R. J.; Pickrell, R. L.

    1978-01-01

    The performance and stability characteristics of a 10 kVA photovoltaic power system are studied using linear Bode analysis and a nonlinear analog simulation. Power conversion efficiencies, system stability, and system transient performance results are given for system operation at various levels of solar insolation. Additionally, system operation and the modeling of system components for the purpose of computer simulation are described.

  7. Improving packaging and increasing the level of integration in power electronics

    NARCIS (Netherlands)

    Popovic, J.

    2005-01-01

    The use of power electronics is growing extensively in applications such as the automotive field, lighting, power supplies, motor drives, etc. The ultimate goal is to make power electronics as transparent to the final user as possible, which means little extra cost, use of existing space and little

  8. Thermal performance analysis system based on measurement validation for nuclear power plant

    International Nuclear Information System (INIS)

    We have needs to develop a performance analysis system that can be used in nuclear power plant turbine cycle to determine whether or not to tune some equipment and when to replace the equipment. We developed NOPAS (Nuclear Operation Performance Analysis System) to aid robust performance analysis. Robustness in the performance analysis is increased by verification and validation of measured input data. We suggest new algorithm in which estimation relations for valid measurements can be obtained using correlation model between measurements and plant state. The estimation model is obtained using design data and initial acceptance measurement data of nuclear power plant. The model consists of finding most correlated state variables and mapping relations based on the model and the current state of power plant. Using this validation scheme and several adaptations from ASME PTC, we can construct more robust performance analysis system for operating nuclear power plant turbine cycle. (author)

  9. Universal Power Quality Controller Modeling and Inverters Loading Analysis

    Directory of Open Access Journals (Sweden)

    F. Gharedaghi

    2011-11-01

    Full Text Available As much as nonlinear loads and power electronics devices are more applied in power distribution systems, the importance of power quality increases. This study proposes a Universal Power Quality Conditioner (UPQC with double-converter structure. The operation principle, the algorithm of compensation reference generation, and the control method are introduced. Computer simulation and many prototype experiments are carried out to verify the operation principle and investigate the compensation characteristics of UPQC for different power quality problems. It is verified that the UPQC can effectively compensate multiple different power quality interferences originated either from the load side or from the line side. The capacity of series and shunt inverters is calculated through loading calculations of these inverters applying phasor diagram to increase the design accuracy. The results of simulation in MATLAB/SIMULINK software show that the system operates correctly.

  10. The environment power system analysis tool development program

    Science.gov (United States)

    Jongeward, Gary A.; Kuharski, Robert A.; Kennedy, Eric M.; Stevens, N. John; Putnam, Rand M.; Roche, James C.; Wilcox, Katherine G.

    1990-01-01

    The Environment Power System Analysis Tool (EPSAT) is being developed to provide space power system design engineers with an analysis tool for determining system performance of power systems in both naturally occurring and self-induced environments. The program is producing an easy to use computer aided engineering (CAE) tool general enough to provide a vehicle for technology transfer from space scientists and engineers to power system design engineers. The results of the project after two years of a three year development program are given. The EPSAT approach separates the CAE tool into three distinct functional units: a modern user interface to present information, a data dictionary interpreter to coordinate analysis; and a data base for storing system designs and results of analysis.

  11. Analysis of electric power industry restructuring

    Science.gov (United States)

    Al-Agtash, Salem Yahya

    1998-10-01

    This thesis evaluates alternative structures of the electric power industry in a competitive environment. One structure is based on the principle of creating a mandatory power pool to foster competition and manage system economics. The structure is PoolCo (pool coordination). A second structure is based on the principle of allowing independent multilateral trading and decentralized market coordination. The structure is DecCo (decentralized coordination). The criteria I use to evaluate these two structures are: economic efficiency, system reliability and freedom of choice. Economic efficiency evaluation considers strategic behavior of individual generators as well as behavioral variations of different classes of consumers. A supply-function equilibria model is characterized for deriving bidding strategies of competing generators under PoolCo. It is shown that asymmetric equilibria can exist within the capacities of generators. An augmented Lagrangian approach is introduced to solve iteratively for global optimal operations schedules. Under DecCo, the process involves solving iteratively for system operations schedules. The schedules reflect generators strategic behavior and brokers' interactions for arranging profitable trades, allocating losses and managing network congestion. In the determination of PoolCo and DecCo operations schedules, overall costs of power generation (start-up and shut-down costs and availability of hydro electric power) as well as losses and costs of transmission network are considered. For system reliability evaluation, I examine the effect of PoolCo and DecCo operating conditions on the system security. Random component failure perturbations are generated to simulate the actual system behavior. This is done using Monte Carlo simulation. Freedom of choice evaluation accounts for schemes' beneficial opportunities and capabilities to respond to consumers expressed preferences. An IEEE 24-bus test system is used to illustrate the concepts

  12. Power Law Analysis of Financial Index Dynamics

    Directory of Open Access Journals (Sweden)

    J. Tenreiro Machado

    2012-01-01

    Full Text Available Power law (PL and fractional calculus are two faces of phenomena with long memory behavior. This paper applies PL description to analyze different periods of the business cycle. With such purpose the evolution of ten important stock market indices (DAX, Dow Jones, NASDAQ, Nikkei, NYSE, S&P500, SSEC, HSI, TWII, and BSE over time is studied. An evolutionary algorithm is used for the fitting of the PL parameters. It is observed that the PL curve fitting constitutes a good tool for revealing the signal main characteristics leading to the emergence of the global financial dynamic evolution.

  13. Increasing sensitivity of quasi-binary media analysis by spectral distribution of gamma-radiation albedo

    International Nuclear Information System (INIS)

    Full text: There has been suggested a method of increasing sensitivity of quasi-binary media analysis based on peculiarities of spectral distribution of gamma-radiation albedo. In quasi-binary media analysis in which there is observed close inter-connection between the effective coefficient of gamma-radiation weakening and heavy component content, it is necessary to obtain the maximum sensitivity of the analytical signal to the parameter being determined. The study showed that in certain geometrical parameters (source-detector distance, air gap between the probe and the medium surface) there is observed the spectrum displacement of the secondary radiation at the medium material composition change. The power distribution displacement of gamma-radiation albedo at the effective coefficient of gamma-radiation weakening change (the medium material composition) is explained by the adequate changing the length of free flight of primary quantum, angle characteristics of scattering and probability of photoelectric absorption of secondary radiation. The essence of the method suggested is in measuring the power corresponding to the maximum in the spectrum of the secondary radiation and the magnitude of gamma-radiation albedo. At the expense of these parameters change at the material composition of the medium analyzed variation there has been obtained the increase of the method contrast range. Depending on the type of the quasi-binary medium (coal, iron ore, carbonate raw materials) there have been determined optimal condition (primary radiation power, probe geometrical parameters) at which there is observed the maximum linear displacement of the power corresponding to the maximum in the secondary radiation spectrum and chosen the power intervals for normal magnitude of gamma-radiation albedo. The method is recommended to analyze raw and industrial materials of quasi-binary composition in which there is observed close correlation dependence between their effective atomic

  14. Analysis of TRIGA reactor thermal power calibration method

    International Nuclear Information System (INIS)

    Analysis of thermal power method of the nuclear instrumentation of the TRIGA reactor in Ljubljana is described. Thermal power calibration was performed at different power levels and at different conditions. Different heat loss processes from the reactor pool to the surrounding are considered. It is shown that the use of proper calorimetric calibration procedure and the use of heat loss corrections improve the accuracy of the measurement. To correct the position of the control rods, perturbation factors are introduced. It is shown that the use of the perturbation factors enables power readings from nuclear instrumentation with accuracy better than without corrections.(author)

  15. Increases in perinatal mortality in prefectures contaminated by the Fukushima nuclear power plant accident in Japan

    Science.gov (United States)

    Scherb, Hagen Heinrich; Mori, Kuniyoshi; Hayashi, Keiji

    2016-01-01

    Abstract Descriptive observational studies showed upward jumps in secular European perinatal mortality trends after Chernobyl. The question arises whether the Fukushima nuclear power plant accident entailed similar phenomena in Japan. For 47 prefectures representing 15.2 million births from 2001 to 2014, the Japanese government provides monthly statistics on 69,171 cases of perinatal death of the fetus or the newborn after 22 weeks of pregnancy to 7 days after birth. Employing change-point methodology for detecting alterations in longitudinal data, we analyzed time trends in perinatal mortality in the Japanese prefectures stratified by exposure to estimate and test potential increases in perinatal death proportions after Fukushima possibly associated with the earthquake, the tsunami, or the estimated radiation exposure. Areas with moderate to high levels of radiation were compared with less exposed and unaffected areas, as were highly contaminated areas hit versus untroubled by the earthquake and the tsunami. Ten months after the earthquake and tsunami and the subsequent nuclear accident, perinatal mortality in 6 severely contaminated prefectures jumped up from January 2012 onward: jump odds ratio 1.156; 95% confidence interval (1.061, 1.259), P-value 0.0009. There were slight increases in areas with moderate levels of contamination and no increases in the rest of Japan. In severely contaminated areas, the increases of perinatal mortality 10 months after Fukushima were essentially independent of the numbers of dead and missing due to the earthquake and the tsunami. Perinatal mortality in areas contaminated with radioactive substances started to increase 10 months after the nuclear accident relative to the prevailing and stable secular downward trend. These results are consistent with findings in Europe after Chernobyl. Since observational studies as the one presented here may suggest but cannot prove causality because of unknown and uncontrolled factors or

  16. Energy loss analysis of an integrated space power distribution system

    Science.gov (United States)

    Kankam, M. David; Ribeiro, P. F.

    1992-01-01

    The results of studies related to conceptual topologies of an integrated utility-like space power system are described. The system topologies are comparatively analyzed by considering their transmission energy losses as functions of mainly distribution voltage level and load composition. The analysis is expedited by use of a Distribution System Analysis and Simulation (DSAS) software. This recently developed computer program by the Electric Power Research Institute (EPRI) uses improved load models to solve the power flow within the system. However, present shortcomings of the software with regard to space applications, and incompletely defined characteristics of a space power system make the results applicable to only the fundamental trends of energy losses of the topologies studied. Accountability, such as included, for the effects of the various parameters on the system performance can constitute part of a planning tool for a space power distribution system.

  17. Reference MWA EoR Power Spectrum analysis

    Science.gov (United States)

    Hazelton, Bryna; Pober, Jonathan; Beardsley, Adam; Morales, Miguel F.; Sullivan, Ian S.; MWA Collaboration

    2015-01-01

    Observations of the Epoch of Reionization using redshifted 21cm HI emission promise to provide sensitive new cosmological constraints in the next few years. The current generation of HI EoR telescopes are targeting a statistical detection of the EoR in the power spectrum of the 21cm emission. The principal challenge lies in extracting the faint cosmological signal in the face of bright foregrounds and instrumental systematics that threaten to overwhelm it.We present the UW EoR power spectrum code, the reference code for the MWA and the first power spectrum analysis to analytically propagate the error bars through the full data analysis pipeline. We demonstrate the sensitivity of the power spectrum as a diagnostic tool for identifying subtle systematics and show power spectra of the first season of MWA observations.

  18. Utilization of graph theory in security analysis of power grid

    Directory of Open Access Journals (Sweden)

    Dalibor Válek

    2014-12-01

    Full Text Available This paper describes way how to use graph theory in security analysis. As an environment is used network of power lines and devices which are included here. Power grid is considered as a system of nodes which make together graph (network. On the simple example is applied Fiedler´s theory which is able to select the most important power lines of whole network. Components related to these lines are logicly ordered and considered by author´s modified analysis. This method has been improved and optimalized for risks related with illegal acts. Each power grid component has been connected with possible kind of attack and every of this device was gradually evaluated by five coefficients which takes values from 1 to 10. On the coefficient basis was assessed the level of risk. In the last phase the most risky power grid components have been selected. On the selected devices have been proposed security measures.

  19. Visual and Statistical Analysis of Digital Elevation Models Generated Using Idw Interpolator with Varying Powers

    Science.gov (United States)

    Asal, F. F.

    2012-07-01

    Digital elevation data obtained from different Engineering Surveying techniques is utilized in generating Digital Elevation Model (DEM), which is employed in many Engineering and Environmental applications. This data is usually in discrete point format making it necessary to utilize an interpolation approach for the creation of DEM. Quality assessment of the DEM is a vital issue controlling its use in different applications; however this assessment relies heavily on statistical methods with neglecting the visual methods. The research applies visual analysis investigation on DEMs generated using IDW interpolator of varying powers in order to examine their potential in the assessment of the effects of the variation of the IDW power on the quality of the DEMs. Real elevation data has been collected from field using total station instrument in a corrugated terrain. DEMs have been generated from the data at a unified cell size using IDW interpolator with power values ranging from one to ten. Visual analysis has been undertaken using 2D and 3D views of the DEM; in addition, statistical analysis has been performed for assessment of the validity of the visual techniques in doing such analysis. Visual analysis has shown that smoothing of the DEM decreases with the increase in the power value till the power of four; however, increasing the power more than four does not leave noticeable changes on 2D and 3D views of the DEM. The statistical analysis has supported these results where the value of the Standard Deviation (SD) of the DEM has increased with increasing the power. More specifically, changing the power from one to two has produced 36% of the total increase (the increase in SD due to changing the power from one to ten) in SD and changing to the powers of three and four has given 60% and 75% respectively. This refers to decrease in DEM smoothing with the increase in the power of the IDW. The study also has shown that applying visual methods supported by statistical

  20. Radioisotope Power System Facility shielding analysis

    International Nuclear Information System (INIS)

    A series of calculations for the Radioisotope Power System Facility have been performed. These analyses have determined the shielding required for storage, testing, and transport of 238Pu heat source modules using the Monte Carlo code MCNP3B. The source terms and the assumptions used have been verified by comparison of calculated dose rates with measured ones. This paper describes the methodology used for shielding designs and the utilization of available variance reduction techniques to improve the computational efficiency. The new version of MCNP (MCNP3B) with a repeated structure capability was used. It decreased the chance for computer model errors and greatly decreased the model setup time. 2 refs., 3 figs., 2 tabs

  1. The Photovoltaic Heat Island Effect: Larger solar power plants increase local temperatures

    Science.gov (United States)

    Barron-Gafford, Greg A.; Minor, Rebecca L.; Allen, Nathan A.; Cronin, Alex D.; Brooks, Adria E.; Pavao-Zuckerman, Mitchell A.

    2016-01-01

    While photovoltaic (PV) renewable energy production has surged, concerns remain about whether or not PV power plants induce a “heat island” (PVHI) effect, much like the increase in ambient temperatures relative to wildlands generates an Urban Heat Island effect in cities. Transitions to PV plants alter the way that incoming energy is reflected back to the atmosphere or absorbed, stored, and reradiated because PV plants change the albedo, vegetation, and structure of the terrain. Prior work on the PVHI has been mostly theoretical or based upon simulated models. Furthermore, past empirical work has been limited in scope to a single biome. Because there are still large uncertainties surrounding the potential for a PHVI effect, we examined the PVHI empirically with experiments that spanned three biomes. We found temperatures over a PV plant were regularly 3–4 °C warmer than wildlands at night, which is in direct contrast to other studies based on models that suggested that PV systems should decrease ambient temperatures. Deducing the underlying cause and scale of the PVHI effect and identifying mitigation strategies are key in supporting decision-making regarding PV development, particularly in semiarid landscapes, which are among the most likely for large-scale PV installations. PMID:27733772

  2. New Solutions For Increasing Environmental Protection During Severe Accidents At Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kulyukhin, Sergei A.; Mikheev, Nikolai B. [Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow (Russian Federation); Falkovskii, Leo N.; Reshetov, Leo A.; Zvetkova, Marianna Ya. [All-Russian Research Institute of Atomic Machine-Building, Moscow, Russia (Russian Federation); Yagodkin, Ivan V.; Osipov, Viktor P.; Skvortsov, Sergei S. [Institute of Physics and Power Engineering, Obninsk (Russian Federation); Berkovich, Viktor M.; Taranov, Gennadii S.; Grigor' ev, Mikhail M. [Institute ' Atomenergoproekt' , Moscow (Russian Federation); Meshkov, Vladimir M.; Noskov, Andrei A.; Mitrofanov, Mikhail I. [ROSENERGOATOM Concern, Moscow (Russian Federation)

    2008-07-01

    This paper reports new solutions for increasing environmental protection during severe accidents at NPPs. For NPPs with two protective shells and pressure release system such as WWER-1000 we suggest a new comprehensive, passive-mode environmental protection system of decontamination of the radioactive air-steam mixture from the containment and the inter-containment area, which includes the 'wet' stage (scrubbers, etc.), the 'dry' stage (sorption module), and also an ejector, which in a passive mode is capable of solving the multi-purpose task of decontamination of the air-steam mixture. For Russian WWER-440/230 NPPs we suggest three protection levels: 1) a jet-vortex condenser; 2) the spray system; 3) a sorption module. For modern designs of new generation NPPs, which do not provide for pressure release systems, we proposed a new passive filtering system together with the passive heat-removal system, which can be used during severe accidents in case all power supply units become unavailable. (authors)

  3. New Solutions For Increasing Environmental Protection During Severe Accidents At Nuclear Power Plants

    International Nuclear Information System (INIS)

    This paper reports new solutions for increasing environmental protection during severe accidents at NPPs. For NPPs with two protective shells and pressure release system such as WWER-1000 we suggest a new comprehensive, passive-mode environmental protection system of decontamination of the radioactive air-steam mixture from the containment and the inter-containment area, which includes the 'wet' stage (scrubbers, etc.), the 'dry' stage (sorption module), and also an ejector, which in a passive mode is capable of solving the multi-purpose task of decontamination of the air-steam mixture. For Russian WWER-440/230 NPPs we suggest three protection levels: 1) a jet-vortex condenser; 2) the spray system; 3) a sorption module. For modern designs of new generation NPPs, which do not provide for pressure release systems, we proposed a new passive filtering system together with the passive heat-removal system, which can be used during severe accidents in case all power supply units become unavailable. (authors)

  4. Economic impact analysis of independent power projects in British Columbia

    International Nuclear Information System (INIS)

    Independent power producer (IPP) projects have been active in British Columbia's (BC) regulated electricity market since the late 1980s. The 49 IPP projects developed in the province currently account for approximately 10 per cent of BC's electricity generation, and IPP development continues to expand in nearly every region. This study presented an economic impact analysis of IPP projects in BC. The economic impacts of IPP projects were divided into 2 categories: (1) existing IPP projects, and (2) potential IPP projects. The study showed that the total power potential supplied by BC IPP projects would increase from a current level of 5940 annual GWh to approximately 14,149 GWh. BC could also be generating a further 21,321 GWh of annual output to service demand domestically in addition to exporting to the United States. The value of capital investment in existing IPPs across BC was estimated at $2.8 billion. Capital investment in potential IPPs was estimated at $26.1 billion in 2009 constant dollars. Government revenues generated through the construction phase of potential IPP projects were estimated at $1.6 billion. IPP projects are expected to have a significant impact on First Nations groups, contribute to provincial energy self-sufficiency, and have little to no greenhouse gas (GHG) emissions. 25 refs., 19 tabs., 24 figs.

  5. Power system stability modelling, analysis and control

    CERN Document Server

    Sallam, Abdelhay A

    2015-01-01

    This book provides a comprehensive treatment of the subject from both a physical and mathematical perspective and covers a range of topics including modelling, computation of load flow in the transmission grid, stability analysis under both steady-state and disturbed conditions, and appropriate controls to enhance stability.

  6. Accident analysis in nuclear power plants

    International Nuclear Information System (INIS)

    The way the philosophy of Safety in Depth can be verified through the analysis of simulated accidents is shown. This can be achieved by verifying that the integrity of the protection barriers against the release of radioactivity to the environment is preserved even during accident conditions. The simulation of LOCA is focalized as an example, including a study about the associated environmental radiological consequences. (Author)

  7. Economic costs of managing of an electricity grid with increasing wind power penetration

    NARCIS (Netherlands)

    Prescott, R.; Kooten, van G.C.

    2009-01-01

    We examine the impact of policy choices, including a carbon tax, on the optimal allocation of power across different generation sources and on future investments in generating facilities. The main focus is on the Alberta power grid, as it is heavily dependent on fossil fuels and has only limited tie

  8. Increasing of Manoeuvrability of Cogeneration Combined Cycle Power Plants Owing to the Usage of Electric Boilers

    Directory of Open Access Journals (Sweden)

    S. Kachan

    2013-01-01

    Full Text Available The paper contains the results of efficiency evaluation  of using the electric boilers to improve maneuver capabilities of the cogeneration combined cycle power plants (as an example, 230 MW combined cycle unit of Minsk CHP-3 in comparison with the traditional steam-turbine units of cogeneration power plants.

  9. Burnup analysis of the power reactor, 1

    International Nuclear Information System (INIS)

    Several years of endeavors has been devoted to development of three-dimensional nuclear-thermal-hydro-dynamic simulators and research by basing the progress on the merits and demerits of the variational method, the functional approximation method, etc. As the result, the three-dimensional nuclear-thermal-hydro-dynamic code FLORA has been prepared. It has the following features. (1) The executive time is one third -- half as much as that by the convensional programs. (2) Numerical error is small when neutron spectrum mismatches. (3) In the fuels in which the distributions of Gd2O3 and enrichments are localized axially in the reactor core, three-dimensional nuclear-thermal-hydro-dynamic calculations are possible. (4) The transport kernel can be obtained by the coarse mesh method and the functional approximation method. (5) Albedo can be calculated by the two-group diffusion theory. (6) Power distribution can be obtained in the case of partial control rods inserted in the core. The course taken to the preparation, the theoretical background and example calculations with FLORA are described. The present report can be also used as a manual. (auth.)

  10. Probabilistic safety analysis of DC power supply requirements for nuclear power plants. Technical report

    International Nuclear Information System (INIS)

    A probabilistic safety assessment was performed as part of the Nuclear Regulatory Commission generic safety task A-30, Adequacy of Safety Related DC Power Supplies. Event and fault tree analysis techniques were used to determine the relative contribution of DC power related accident sequences to the total core damage probability due to shutdown cooling failures. It was found that a potentially large DC power contribution could be substantially reduced by augmenting the minimum design and operational requirements. Recommendations included (1) requiring DC power divisional independence, (2) improved test, maintenance, and surveillance, and (3) requiring core cooling capability be maintained following the loss of one DC power bus and a single failure in another system

  11. Deconstructing the power resistance relationship for squats: A joint-level analysis.

    Science.gov (United States)

    Farris, D J; Lichtwark, G A; Brown, N A T; Cresswell, A G

    2016-07-01

    Generating high leg power outputs is important for executing rapid movements. Squats are commonly used to increase leg strength and power. Therefore, it is useful to understand factors affecting power output in squatting. We aimed to deconstruct the mechanisms behind why power is maximized at certain resistances in squatting. Ten male rowers (age = 20 ± 2.2 years; height = 1.82 ± 0.03 m; mass = 86 ± 11 kg) performed maximal power squats with resistances ranging from body weight to 80% of their one repetition maximum (1RM). Three-dimensional kinematics was combined with ground reaction force (GRF) data in an inverse dynamics analysis to calculate leg joint moments and powers. System center of mass (COM) velocity and power were computed from GRF data. COM power was maximized across a range of resistances from 40% to 60% 1RM. This range was identified because a trade-off in hip and knee joint powers existed across this range, with maximal knee joint power occurring at 40% 1RM and maximal hip joint power at 60% 1RM. A non-linear system force-velocity relationship was observed that dictated large reductions in COM power below 20% 1RM and above 60% 1RM. These reductions were due to constraints on the control of the movement.

  12. Analysis of Trinity Power Metrics for Automated Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Michalenko, Ashley Christine [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-28

    This is a presentation from Los Alamos National Laboraotyr (LANL) about the analysis of trinity power metrics for automated monitoring. The following topics are covered: current monitoring efforts, motivation for analysis, tools used, the methodology, work performed during the summer, and future work planned.

  13. Power Grid Data Analysis with R and Hadoop

    Energy Technology Data Exchange (ETDEWEB)

    Hafen, Ryan P.; Gibson, Tara D.; Kleese van Dam, Kerstin; Critchlow, Terence J.

    2014-01-01

    This book chapter presents an approach to analysis of large-scale time-series sensor information based on our experience with power grid data. We use the R-Hadoop Integrated Programming Environment (RHIPE) to analyze a 2TB data set and present code and results for this analysis.

  14. Nitrogen-Based Fuels: A Power-to-Fuel-to-Power Analysis.

    Science.gov (United States)

    Grinberg Dana, Alon; Elishav, Oren; Bardow, André; Shter, Gennady E; Grader, Gideon S

    2016-07-25

    What are the fuels of the future? Seven representative carbon- and nitrogen-based fuels are evaluated on an energy basis in a power-to-fuel-to-power analysis as possible future chemical hydrogen-storage media. It is intriguing to consider that a nitrogen economy, where hydrogen obtained from water splitting is chemically stored on abundant nitrogen in the form of a nontoxic and safe nitrogen-based alternative fuel, is energetically feasible. PMID:27286557

  15. Nuclear power plant fire protection: philosophy and analysis

    International Nuclear Information System (INIS)

    This report combines a fire severity analysis technique with a fault tree methodology for assessing the importance to nuclear power plant safety of certain combinations of components and systems. Characteristics unique to fire, such as propagation induced by the failure of barriers, have been incorporated into the methodology. By applying the resulting fire analysis technique to actual conditions found in a representative nuclear power plant, it is found that some safety and nonsafety areas are both highly vulnerable to fire spread and impotant to overall safety, while other areas prove to be of marginal importance. Suggestions are made for further experimental and analytical work to supplement the fire analysis method

  16. Engineering works for increasing earthquake resistance of Hamaoka nuclear power plant

    International Nuclear Information System (INIS)

    The improvement works of the ground of outdoor piping and duct system of Hamaoka-3, one of engineering works for increasing earthquake resistance of the plant, are reported. The movable outdoor piping systems were moved. SJ method, one of the high-pressure jet mixing method, improved the ground between the duct and the unmoved light oil tank on the western side, and the environmental ground. The other places were improved by the concrete replacement works. The results of ground treated by SJ method showed the high quality of stiffness and continuity. Outline of engineering works, execution of concrete replacement works, the high-pressure jet mixing method, SJ method, the quality control and treatment of the generated mud by SJ method are reported. A seismic response analysis, execution facilities, construction planning, working diagram, improvement work conditions of three methods, and steps of SJ method are illustrated. (S.Y.)

  17. Applications of wavelet transforms for nuclear power plant signal analysis

    International Nuclear Information System (INIS)

    The safety of Nuclear Power Plants (NPPs) may be enhanced by the timely processing of information derived from multiple process signals from NPPs. The most widely used technique in signal analysis applications is the Fourier transform in the frequency domain to generate power spectral densities (PSD). However, the Fourier transform is global in nature and will obscure any non-stationary signal feature. Lately, a powerful technique called the Wavelet Transform, has been developed. This transform uses certain basis functions for representing the data in an effective manner, with capability for sub-band analysis and providing time-frequency localization as needed. This paper presents a brief overview of wavelets applied to the nuclear industry for signal processing and plant monitoring. The basic theory of Wavelets is also summarized. In order to illustrate the application of wavelet transforms data were acquired from the operating nuclear power plant Borssele in the Netherlands. The experimental data consist of various signals in the power plant and are selected from a stationary power operation. Their frequency characteristics and the mutual relations were investigated using MATLAB signal processing and wavelet toolbox for computing their PSDs and coherence functions by multi-resolution analysis. The results indicate that the sub-band PSD matches with the original signal PSD and enhances the estimation of coherence functions. The Wavelet analysis demonstrates the feasibility of application to stationary signals to provide better estimates in the frequency band of interest as compared to the classical FFT approach. (author)

  18. Power flow analysis of two coupled plates with arbitrary characteristics

    Science.gov (United States)

    Cuschieri, J. M.

    1988-01-01

    The limitation of keeping two plates identical is removed and the vibrational power input and output are evaluated for different area ratios, plate thickness ratios, and for different values of the structural damping loss factor for the source plate (plate with excitation) and the receiver plate. In performing this parametric analysis, the source plate characteristics are kept constant. The purpose of this parametric analysis is to be able to determine the most critical parameters that influence the flow of vibrational power from the source plate to the receiver plate. In the case of the structural damping parametric analysis, the influence of changes in the source plate damping is also investigated. As was done previously, results obtained from the mobility power flow approach will be compared to results obtained using a statistical energy analysis (SEA) approach. The significance of the power flow results are discussed together with a discussion and a comparison between SEA results and the mobility power flow results. Furthermore, the benefits that can be derived from using the mobility power flow approach, are also examined.

  19. The monotonic increasing relationship between average powers of CMOS VLSI circuits with and without delay and its applications

    Institute of Scientific and Technical Information of China (English)

    骆祖莹; 闵应骅; 杨士元; 李晓维

    2002-01-01

    The authors theoretically describe the monotonic increasing relationship between averagepowers of a CMOS VLSI circuit with and without delay. The power of an ideal circuit without delay, whichcan be fast computed, has been used as the evaluation criterion for the power of a practical circuit withdelay, which needs more computing time, in such fields as fast estimation for the average power and themaximum power, and fast optimization for the Iow test power. The authors propose a novel simulationapproach that uses delay-free power to compact a long input vector pair sequence into a short sequenceand then, uses the compacted one to fast simulate the average (or maximum) power for a CMOS circuit. Incomparison with the traditional simulation approach that uses an un-compacted input sequence to simu-late the average (or maximum) power, experiment results demonstrate that in the field of fast estimationfor the average power, the present approach can be 6-10 times faster without significant loss in accuracy(less than 3.5% on average), and in the field of fast estimation for the maximum power, this approach canbe 6-8 times faster without significant loss in accuracy (less than 5% on average). In the field of fast op-timization for the test power, the authors propose a novel delay-free power optimization approach for thetest power. Experiment results demonstrate that, in comparison with the approach of direct optimizationand the approach of Hamming distance optimization, this approach is of the highest optimization effi-ciency because it needs shorter time (16.84%) to obtain a better optimization effect (reducing 35.11% testpower).

  20. Nordic Power market integration : a market based approach to the price effects of increased Nordic continental power trade in the Nordic market

    OpenAIRE

    Boge, Mathias Krogh

    2012-01-01

    Based on historical market data for 2011 this thesis models estimated effects that increased Nordic-Continental power trade potential would have had on trade and on Nordic prices during this year. The model used differs from most other models used to estimate trade effects as it focuses on realized market data contrasted to the more commonly used fundamental bottom up model of the power market. The approach used in this work suggests that one extra interconnector combined with ...

  1. High-resolution Fourier transform ion cyclotron resonance mass spectrometry with increased throughput for biomolecular analysis.

    Science.gov (United States)

    Nagornov, Konstantin O; Gorshkov, Mikhail V; Kozhinov, Anton N; Tsybin, Yury O

    2014-09-16

    A multielectrode ion cyclotron resonance (ICR) cell, herein referred to as the "4X cell", for signal detection at the quadruple frequency multiple was implemented and characterized on a commercial 10 T Fourier transform ICR mass spectrometer (FT-ICR MS). Notably, with the 4X cell operating at a 10 T magnetic field we achieved a 4-fold increase in MS acquisition rate per unit of resolving power for signal detection periods typically employed in FTMS, viz., shorter than 6 s. Effectively, the obtained resolution performance represents the limit of the standard measurement principle with dipolar signal detection and FT signal processing at an equivalent magnetic field of 40 T. In other words, the achieved resolving powers are 4 times higher than those provided by 10 T FT-ICR MS with a standard ICR cell. For example, resolving powers of 170,000 and 70,000 were obtained in magnitude-mode Fourier spectra of 768 and 192 ms apodized transient signals acquired for a singly charged fluorinated phosphazine (m/z 1422) and a 19-fold charged myoglobin (MW 16.9 kDa), respectively. In peptide analysis, the baseline-resolved isotopic fine structures were obtained with as short as 768 ms transients. In intact protein analysis, the average resolving power of 340,000 across the baseline-resolved (13)C isotopic pattern of multiply charged ions of bovine serum albumin was obtained with 1.5 s transients. The dynamic range and the mass measurement accuracy of the 4X cell were found to be comparable to the ones obtained for the standard ICR cell on the same mass spectrometer. Overall, the reported results validate the advantages of signal detection at frequency multiples for increased throughput in FT-ICR MS, essential for numerous applications with time constraints, including proteomics.

  2. Thermodynamic Analysis of Combined Cycle Power Plant

    Directory of Open Access Journals (Sweden)

    A.K.Tiwari,

    2010-04-01

    Full Text Available Air Bottoming Cycle (ABC can replace the heat recovery steam generator and the steam turbine of the conventionalcombined cycle plant. The exhaust energy of the topping gas turbine of existing combine cycle is sent to gas-air heat exchange, which heats the air in the secondary gas turbine cycle. In 1980’s the ABC was proposed as an alternative for the conventional steam bottoming cycle. In spite of the cost of reducing hardware installations it could achieve a thermal efficiency of 80%. The complete thermodynamic analysis of the system has been performed by using specially designed programme, enabling the variation of main independent variables. The result shows the gain in net work output as well as efficiency of combined cycle is 35% to 68%.

  3. Statistical analysis of cascading failures in power grids

    Energy Technology Data Exchange (ETDEWEB)

    Chertkov, Michael [Los Alamos National Laboratory; Pfitzner, Rene [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory

    2010-12-01

    We introduce a new microscopic model of cascading failures in transmission power grids. This model accounts for automatic response of the grid to load fluctuations that take place on the scale of minutes, when optimum power flow adjustments and load shedding controls are unavailable. We describe extreme events, caused by load fluctuations, which cause cascading failures of loads, generators and lines. Our model is quasi-static in the causal, discrete time and sequential resolution of individual failures. The model, in its simplest realization based on the Directed Current description of the power flow problem, is tested on three standard IEEE systems consisting of 30, 39 and 118 buses. Our statistical analysis suggests a straightforward classification of cascading and islanding phases in terms of the ratios between average number of removed loads, generators and links. The analysis also demonstrates sensitivity to variations in line capacities. Future research challenges in modeling and control of cascading outages over real-world power networks are discussed.

  4. Analysis of Power Model for Linear Plasma Device

    Science.gov (United States)

    Zhang, Weiwei; Deng, Baiquan; Zuo, Haoyi; Zheng, Xianjun; Cao, Xiaogang; Xue, Xiaoyan; Ou, Wei; Cao, Zhi; Gou, Fujun

    2016-08-01

    A single cathode linear plasma device has been designed and constructed to investigate the interactions between plasma and materials at the Sichuan University. In order to further investigate the Ohmic power of the device, the output heat load on the specimen and electric potential difference (between cathode and anode) have been tested under different discharge currents. This special power distribution in the radial direction of the plasma discharge channel has also been discussed and described by some improved integral equations in this paper; it can be further simplified as P ∝ α-2 in one-parameter. Besides, we have measured the power loss of the channel under different discharge currents by the calorimetric method, calculated the effective power of the device and evaluated the performances of the plasma device through the power efficiency analysis. supported by International Thermonuclear Experimental Reactor (ITER) Program (No. 2013GB114003) and National Natural Science Foundation of China (Nos. 11275135 and 11475122)

  5. Analysis of Power Model for Linear Plasma Device

    Science.gov (United States)

    Zhang, Weiwei; Deng, Baiquan; Zuo, Haoyi; Zheng, Xianjun; Cao, Xiaogang; Xue, Xiaoyan; Ou, Wei; Cao, Zhi; Gou, Fujun

    2016-08-01

    A single cathode linear plasma device has been designed and constructed to investigate the interactions between plasma and materials at the Sichuan University. In order to further investigate the Ohmic power of the device, the output heat load on the specimen and electric potential difference (between cathode and anode) have been tested under different discharge currents. This special power distribution in the radial direction of the plasma discharge channel has also been discussed and described by some improved integral equations in this paper; it can be further simplified as P ∝ α‑2 in one-parameter. Besides, we have measured the power loss of the channel under different discharge currents by the calorimetric method, calculated the effective power of the device and evaluated the performances of the plasma device through the power efficiency analysis. supported by International Thermonuclear Experimental Reactor (ITER) Program (No. 2013GB114003) and National Natural Science Foundation of China (Nos. 11275135 and 11475122)

  6. The Murchison Widefield Array 21 cm Power Spectrum Analysis Methodology

    CERN Document Server

    Jacobs, Daniel C; Trott, C M; Dillon, Joshua S; Pindor, B; Sullivan, I S; Pober, J C; Barry, N; Beardsley, A P; Bernardi, G; Bowman, Judd D; Briggs, F; Cappallo, R J; Carroll, P; Corey, B E; de Oliveira-Costa, A; Emrich, D; Ewall-Wice, A; Feng, L; Gaensler, B M; Goeke, R; Greenhill, L J; Hewitt, J N; Hurley-Walker, N; Johnston-Hollitt, M; Kaplan, D L; Kasper, J C; Kim, H S; Kratzenberg, E; Lenc, E; Line, J; Loeb, A; Lonsdale, C J; Lynch, M J; McKinley, B; McWhirter, S R; Mitchell, D A; Morales, M F; Morgan, E; Neben, A R; Thyagarajan, N; Oberoi, D; Offringa, A R; Ord, S M; Paul, S; Prabu, T; Procopio, P; Riding, J; Rogers, A E E; Roshi, A; Shankar, N Udaya; Sethi, Shiv K; Srivani, K S; Subrahmanyan, R; Tegmark, M; Tingay, S J; Waterson, M; Wayth, R B; Webster, R L; Whitney, A R; Williams, A; Williams, C L; Wu, C; Wyithe, J S B

    2016-01-01

    We present the 21 cm power spectrum analysis approach of the Murchison Widefield Array Epoch of Reionization project. In this paper, we compare the outputs of multiple pipelines for the purpose of validating statistical limits cosmological hydrogen at redshifts between 6 and 12. Multiple, independent, data calibration and reduction pipelines are used to make power spectrum limits on a fiducial night of data. Comparing the outputs of imaging and power spectrum stages highlights differences in calibration, foreground subtraction and power spectrum calculation. The power spectra found using these different methods span a space defined by the various tradeoffs between speed, accuracy, and systematic control. Lessons learned from comparing the pipelines range from the algorithmic to the prosaically mundane; all demonstrate the many pitfalls of neglecting reproducibility. We briefly discuss the way these different methods attempt to handle the question of evaluating a significant detection in the presence of foregr...

  7. The Murchison Widefield Array 21 cm Power Spectrum Analysis Methodology

    Science.gov (United States)

    Jacobs, Daniel C.; Hazelton, B. J.; Trott, C. M.; Dillon, Joshua S.; Pindor, B.; Sullivan, I. S.; Pober, J. C.; Barry, N.; Beardsley, A. P.; Bernardi, G.; Bowman, Judd D.; Briggs, F.; Cappallo, R. J.; Carroll, P.; Corey, B. E.; de Oliveira-Costa, A.; Emrich, D.; Ewall-Wice, A.; Feng, L.; Gaensler, B. M.; Goeke, R.; Greenhill, L. J.; Hewitt, J. N.; Hurley-Walker, N.; Johnston-Hollitt, M.; Kaplan, D. L.; Kasper, J. C.; Kim, HS; Kratzenberg, E.; Lenc, E.; Line, J.; Loeb, A.; Lonsdale, C. J.; Lynch, M. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Neben, A. R.; Thyagarajan, N.; Oberoi, D.; Offringa, A. R.; Ord, S. M.; Paul, S.; Prabu, T.; Procopio, P.; Riding, J.; Rogers, A. E. E.; Roshi, A.; Udaya Shankar, N.; Sethi, Shiv K.; Srivani, K. S.; Subrahmanyan, R.; Tegmark, M.; Tingay, S. J.; Waterson, M.; Wayth, R. B.; Webster, R. L.; Whitney, A. R.; Williams, A.; Williams, C. L.; Wu, C.; Wyithe, J. S. B.

    2016-07-01

    We present the 21 cm power spectrum analysis approach of the Murchison Widefield Array Epoch of Reionization project. In this paper, we compare the outputs of multiple pipelines for the purpose of validating statistical limits cosmological hydrogen at redshifts between 6 and 12. Multiple independent data calibration and reduction pipelines are used to make power spectrum limits on a fiducial night of data. Comparing the outputs of imaging and power spectrum stages highlights differences in calibration, foreground subtraction, and power spectrum calculation. The power spectra found using these different methods span a space defined by the various tradeoffs between speed, accuracy, and systematic control. Lessons learned from comparing the pipelines range from the algorithmic to the prosaically mundane; all demonstrate the many pitfalls of neglecting reproducibility. We briefly discuss the way these different methods attempt to handle the question of evaluating a significant detection in the presence of foregrounds.

  8. Error analysis of nuclear power plant operator cognitive behavior

    International Nuclear Information System (INIS)

    Nuclear power plant is a complex human-machine system integrated with many advanced machines, electron devices and automatic controls. It demands operators to have high cognitive ability and correct analysis skill. The author divides operator's cognitive process into five stages to analysis. With this cognitive model, operator's cognitive error is analysed to get the root causes and stages that error happens. The results of the analysis serve as a basis in design of control rooms and training and evaluation of operators

  9. Increasing the resilience and security of the United States' power infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Happenny, Sean F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-08-01

    The United States' power infrastructure is aging, underfunded, and vulnerable to cyber attack. Emerging smart grid technologies may take some of the burden off of existing systems and make the grid as a whole more efficient, reliable, and secure. The Pacific Northwest National Laboratory (PNNL) is funding research into several aspects of smart grid technology and grid security, creating a software simulation tool that will allow researchers to test power infrastructure control and distribution paradigms by utilizing different smart grid technologies to determine how the grid and these technologies react under different circumstances. Understanding how these systems behave in real-world conditions will lead to new ways to make our power infrastructure more resilient and secure. Demonstrating security in embedded systems is another research area PNNL is tackling. Many of the systems controlling the U.S. critical infrastructure, such as the power grid, lack integrated security and the aging networks protecting them are becoming easier to attack.

  10. Thermo-economic analysis of a trigeneration HCPVT power plant

    Science.gov (United States)

    Selviaridis, Angelos; Burg, Brian R.; Wallerand, Anna Sophia; Maréchal, François; Michel, Bruno

    2015-09-01

    The increasing need for electricity and heat in a growing global economy must be combined with CO2 emissions reduction, in order to limit the human influence on the environment. This calls for energy-efficient and cost-competitive renewable energy systems that are able to satisfy both pressing needs. A High-Concentration Photovoltaic Thermal (HCPVT) system is a cogeneration concept that shows promising potential in delivering electricity and heat in an efficient and cost-competitive manner. This study investigates the transient behavior of the HCPVT system and presents a thermo-economic analysis of a MW-scale trigeneration (electricity, heating and cooling) power plant. Transient simulations show a fast dynamic response of the system which results in short heat-up intervals, maximizing heat recuperation throughout the day. Despite suboptimal coupling between demand and supply, partial heat utilization throughout the year and low COP of commercially available devices for the conversion of heat into cooling, the thermo-economic analysis shows promising economic behavior, with a levelized cost of electricity close to current retail prices.

  11. Increase of Power Rates Has a Big Impact on Aluminum Plants

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> An important cause for the recent adjustment ofpower rates in China is to contain the growth ofhigh-energy-consumption industries by impos-ing differentiated power rates.Therefore,as thefirst of six high-energy-consumption industries,the primary aluminum industry has receivedspecial attention.Based on the complicatedplan on adjustment of power rates currentlyavailable,it is expected that approximately800,000 tons of self-baking pot production ca-

  12. Increased power generation from primary sludge by a submersible microbial fuel cell and optimum operational conditions

    DEFF Research Database (Denmark)

    Vologni, Valentina; Kakarla, Ramesh; Angelidaki, Irini;

    2013-01-01

    sludge. In a polarization test, the maximum power density was 0.18 W/m2 at a current density of 0.8 A/m2 with an external resistor of 300 Ω. The anodic solution of the primary sludge needs to be adjusted to a pH 7 for high power generation. The modified primary sludge with an added phosphate buffer...

  13. Maximum power analysis of photovoltaic module in Ramadi city

    OpenAIRE

    Majid Shahatha Salim, Jassim Mohammed Najim, Salih Mohammed Salih

    2013-01-01

    Performance of photovoltaic (PV) module is greatly dependent on the solar irradiance, operating temperature, and shading. Solar irradiance can have a significant impact on power output of PV module and energy yield. In this paper, a maximum PV power which can be obtain in Ramadi city (100km west of Baghdad) is practically analyzed. The analysis is based on real irradiance values obtained as the first time by using Soly2 sun tracker device. Proper and adequate information on solar radiation an...

  14. Analysis and optimisation of virtual DataPower appliances

    OpenAIRE

    JANŠA, JURE

    2014-01-01

    Thesis describes the market of IBM DataPower appliances and their corresponding functionalities. We explain the benefits of these devices in the SOA (Services Oriented Architecture) environments. Case study of testing environment configuration is demonstrated on the physical XI50 and XI52 models and various configurations of virtual DataPower appliance. The analysis of the data obtained with these configurations is performed. At the end we provide the principles and guidelines for the proper ...

  15. Design and analysis of an active power factor correction circuit

    OpenAIRE

    Zhou, Zhen

    1989-01-01

    The design of an active-unity power factor correction circuit with variable-hysteresis control for off-line dc-to-dc switching power supplies is described. Design equations relating the boost inductor current ripple to the circuit components selection and circuit performance arc discussed. A computer-aided design program (CADO) is developed to give the optimal circuit components selection. A 500 watt, 300 volt experimental circuit is built to verify the simulation and analysis ...

  16. Thermodynamic analysis of CO2 capture processes for power plants

    OpenAIRE

    Biyouki, Zeinab Amrollahi

    2014-01-01

    This thesis work presents an evaluation of various processes for reducing CO2 emissions from natural-gas-fired combined cycle (NGCC) power plants. The scope of the thesis is to focus mainly on post-combustion chemical absorption for NGCC. For the post-combustion capture plant, an important interface is the steam extraction from the steam turbine in order to supply the heat for solvent regeneration. The steam extraction imposes a power production penalty. The thesis includes analysis and compa...

  17. An algebraic metric for parametric stability analysis of power systems

    OpenAIRE

    Roberts, Lewis; Champneys, Alan; De'Bell, Keith; di Bernardo, Mario

    2015-01-01

    An analytic approximation for the critical clearing time (CCT) metric is derived from direct methods for power system stability. The formula has been designed to incorporate as many features of transient stability analysis as possible such as different fault locations and different post-fault network states. The purpose of this metric is to analyse trends in stability (in terms of CCT) of power systems under the variation of a system parameter. We demonstrate the performance of this metric to...

  18. Design and Analysis of Sequential Elements for Low Power Clocking System with Low Power Techniques

    Directory of Open Access Journals (Sweden)

    S.Sasidhar Reddy

    2014-09-01

    Full Text Available This paper proposed the design of sequential elements for low power clocking system with low low power techniques for saving the power. Power consumption is a major bottleneck of system performance and is listed as one of the top three challenges in International Technology Roadmap for Semiconductor 2008. In practice, a large portion of the on chip power is consumed by the clock system which is made of the clock distribution network and flop-flops. In this paper, various design techniques for a low power clocking system are surveyed. Among them is an effective way to reduce capacity of the clock load by minimizing number of clocked transistors. To approach this, proposed a novel clocked pair shared flip-flop which reduces the number of local clocked transistors by approximately 40%. A 24% reduction of clock driving power is achieved. In addition, low swing and double edge clocking, can be easily incorporated into the new flip-flop to build clocking systems. As the feature size becomes smaller, shorter channel lengths result in increased sub-threshold leakage current through a transistor when it is off. Dual sleep and sleepy stack methods are proposed to avoid static power consumption; the flip flops are simulated using HSPICE.

  19. TRACE analysis of Phenix core response to an increase of the core inlet sodium temperature

    International Nuclear Information System (INIS)

    This work presents the analysis, using the TRACE code, of the Phenix core response to an inlet sodium temperature increase. The considered experiment was performed in the frame of the Phenix End-Of-Life (EOL) test program of the CEA, prior to the final shutdown of the reactor. It corresponds to a transient following a 40°C increase of the core inlet temperature, which leads to a power decrease of 60%. This work focuses on the first phase of the transient, prior to the reactor scram and pump trip. First, the thermal-hydraulic TRACE model of the core developed for the present analysis is described. The kinetic parameters and feedback coefficients for the point kinetic model were first derived from a 3D static neutronic ERANOS model developed in a former study. The calculated kinetic parameters were then optimized, before use, on the basis of the experimental reactivity in order to minimize the error on the power calculation. The different reactivity feedbacks taken into account include various expansion mechanisms that have been specifically implemented in TRACE for analysis of fast-neutron spectrum systems. The point kinetic model has been used to study the sensitivity of the core response to the different feedback effects. The comparison of the calculated results with the experimental data reveals the need to accurately calculate the reactivity feedback coefficients. This is because the reactor response is very sensitive to small reactivity changes. This study has enabled us to study the sensitivity of the power change to the different reactivity feedbacks and define the most important parameters. As such, it furthers the validation of the FAST code system, which is being used to gain a more in-depth understanding of SFR core behavior during accidental transients. (author)

  20. Power Budget Analysis for Waveguide-Enhanced Raman Spectroscopy.

    Science.gov (United States)

    Wang, Zilong; Pearce, Stuart J; Lin, Yung-Chun; Zervas, Michalis N; Bartlett, Philip N; Wilkinson, James S

    2016-08-01

    Waveguide-enhanced Raman spectroscopy (WERS) is emerging as an attractive alternative to plasmonic surface-enhanced Raman spectroscopy approaches as it can provide more reproducible quantitative spectra on a robust chip without the need for nanostructured plasmonic materials. Realizing portable WERS systems with high sensitivity using low-cost laser diodes and compact spectrometers requires a detailed analysis of the power budget from laser to spectrometer chip. In this paper, we describe theoretical optimization of planar waveguides for maximum Raman excitation efficiency, demonstrate WERS for toluene on a silicon process compatible high index contrast tantalum pentoxide waveguide, measure the absolute conversion efficiency from pump power to received power in an individual Raman line, and compare this with a power budget analysis of the complete system including collection with an optical fiber and interfacing to a compact spectrometer. Optimized 110 nm thick Ta2O5 waveguides on silica substrates excited at a wavelength of 637 nm are shown experimentally to yield overall system power conversion efficiency of ∼0.5 × 10(-12) from the pump power in the waveguide to the collected Raman power in the 1002 cm(-1) Raman line of toluene, in comparison with a calculated efficiency of 3.9 × 10(-12) Collection efficiency is dictated by the numerical and physical apertures of the spectral detection system but may be improved by further engineering the spatial and angular Raman scattering distributions.

  1. Environmental performance and energy analysis of nuclear power systems

    International Nuclear Information System (INIS)

    Trough this study we try to develop a useful analysis of the energy produced by nuclear power systems from environmental and energy point of view using the Life Cycle Assessment method. Life Cycle Assessment of Nuclear Power Production must include processes like extraction, fuel production, construction of waste facilities as well as operation and maintenance of nuclear power plants and waste facilities. Databases regarding nuclear power systems are not so easy to find and compare because of the variety of the nuclear power producing systems and procedures. Flows of consumables and by-products in each phase of the nuclear fuel cycle are analyzed to various degrees 'from cradle to grave'. Resource use, emissions and waste are distributed over a plausible technical life of modern nuclear power plant. Impact evaluation was made on the following impact parameters: resource use, waste, land use, noise, and the environmental impact of emissions (greenhouse gases, ozone depletion, acidification, ground level ozone, and eutrophication). We present also an energy analysis that includes a life cycle energy requirement for nuclear power plant processes and an energy comparison between several types of energy production. The results obtained are presented in tables and diagrams. From energetic point of view it is a useful way of comparing net energy yields from different ways of electricity generation. Thus, the answer to the question what system produces the best return on energy invested and generates the minimum impact can be easier obtained. (authors)

  2. Literal analysis of potential interference from satellites with the proposed pfd increase

    Energy Technology Data Exchange (ETDEWEB)

    Jeske, H.O.

    1986-01-01

    An increase in the maximum power flux-density (pfd) permitted from satelltes in the 2025 to 2300 MHz band is currently under consideration by IRAC. This analysis assumes the worst case conditions for interference to telemetry operations at the missile test ranges as a result of current and proposed satellite pfd levels. Assumptions in the analysis include the maximum permitted power flux-density with uniform energy distribution over the band of interest, polarization compatibility, and alignment of the telemetry station, the missile and the satellite. It was found that the performance of essentially all missile telemetry receiving systems may be appreciably degraded by even the lowest pfd limits currently permitted. For the higher pfd limits under consideration, degradations in the order of 40 dB are to be expected at stations with dish antennas of only five foot diameter. An increase in the size or gain of an antenna will reduce the probability of interference, because of its decreased beamwidth, but will also increase the performance degradation because of the station's increased figure of merit, G/T. For satisfactory missile telemetry operation under these conditions, the normal missile's telemetry received signal-to-noise ratio would have to be well over 40 dB to overcome satellite interference. The results of the analysis are actually independent of all receiving station parameters except the station's figure of merit, G/T. Probability of interference is not addressed because of the variation of conditions and missions of the various test ranges as well as the unknown number of satellites and their characteristics - present and future.

  3. Deterministic Safety Analysis for Nuclear Power Plants. Specific Safety Guide

    International Nuclear Information System (INIS)

    The objective of this Safety Guide is to provide harmonized guidance to designers, operators, regulators and providers of technical support on deterministic safety analysis for nuclear power plants. It provides information on the utilization of the results of such analysis for safety and reliability improvements. The Safety Guide addresses conservative, best estimate and uncertainty evaluation approaches to deterministic safety analysis and is applicable to current and future designs. Contents: 1. Introduction; 2. Grouping of initiating events and associated transients relating to plant states; 3. Deterministic safety analysis and acceptance criteria; 4. Conservative deterministic safety analysis; 5. Best estimate plus uncertainty analysis; 6. Verification and validation of computer codes; 7. Relation of deterministic safety analysis to engineering aspects of safety and probabilistic safety analysis; 8. Application of deterministic safety analysis; 9. Source term evaluation for operational states and accident conditions; References.

  4. Methods and tools for analysis and optimization of power plants

    Energy Technology Data Exchange (ETDEWEB)

    Assadi, Mohsen

    2000-09-01

    The most noticeable advantage of the introduction of the computer-aided tools in the field of power generation, has been the ability to study the plant's performance prior to the construction phase. The results of these studies have made it possible to change and adjust the plant layout to match the pre-defined requirements. Further development of computers in recent years has opened up for implementation of new features in the existing tools and also for the development of new tools for specific applications, like thermodynamic and economic optimization, prediction of the remaining component life time, and fault diagnostics, resulting in improvement of the plant's performance, availability and reliability. The most common tools for pre-design studies are heat and mass balance programs. Further thermodynamic and economic optimization of plant layouts, generated by the heat and mass balance programs, can be accomplished by using pinch programs, exergy analysis and thermoeconomics. Surveillance and fault diagnostics of existing systems can be performed by using tools like condition monitoring systems and artificial neural networks. The increased number of tools and their various construction and application areas make the choice of the most adequate tool for a certain application difficult. In this thesis the development of different categories of tools and techniques, and their application area are reviewed and presented. Case studies on both existing and theoretical power plant layouts have been performed using different commercially available tools to illuminate their advantages and shortcomings. The development of power plant technology and the requirements for new tools and measurement systems have been briefly reviewed. This thesis contains also programming techniques and calculation methods concerning part-load calculations using local linearization, which has been implemented in an inhouse heat and mass balance program developed by the author

  5. Mixed-signal power system emulator extension to solve unbalanced fault transient stability analysis

    OpenAIRE

    Lanz, Guillaume; Kyriakidis, Theodoras; Cherkaoui, Rachid; Kayal, Maher

    2014-01-01

    This paper presents the extension of a platform originally devoted to symmetrical transient stability analysis, into the domain of unbalanced faults. The aim of this solver is to increase the speed of dynamic stability assessment for power systems. It is based on an analog representation of the grid alongside dedicated digital resources for the simulation of the models of power network components. Using the symmetrical components theory, this platform can be adapted to handle unsymmetrical di...

  6. Remote Borehole Strainmeter Sites: Power system optimization improves data quality and increases equipment uptime

    Science.gov (United States)

    Pyatt, C.; Van Boskirk, E.; Gallaher, W.; Hodgkinson, K. M.; Henderson, D. B.; Gottlieb, M. H.; Johnson, W.; Fox, O.; Mencin, D.; Mattioli, G.

    2012-12-01

    The Earthscope Plate Boundary Observatory (PBO) Borehole strainmeter network consists of 74 sites, spanning the west coast of North America from Anza, California to Vancouver Island, British Columbia. Several instruments are installed at each site (including Gladwin Tensor Strainmeter, 3-component geophone, barometer, and rain gauge), with associated data storage and communications equipment. Selected sites also are co-located with high-precision GPS, tiltmeter, pore pressure sensor and metpack. The peak load for a site with VSAT communications is approximately 65W. Most sites are AC powered with battery backup systems. 21 sites are located in remote areas where AC power is unavailable; of these, 18 use solar panels and batteries as the primary power source. During O&M phase of PBO, two issues have brought the borehole solar sites into focus. First, most solar sites cannot continuously operate throughout the winter months because of inclement weather and local topography that blocks the solar array, which results in data loss. Second, high frequency noise is introduced into the instrument data stream by the solar charging system. Reducing noise levels at higher frequencies would decrease the detection threshold for short term transients, such as aseismic creep events, thus allowing researchers to leverage the overlap between simultaneous seismometer and strainmeter observations. Several improvements have been made to optimize the power system as well as decrease noise. TriStar TS-MPPT-60 solar controllers have been installed, which optimize solar flux by tracking and responding to the solar array maximum power point. The battery charge algorithm is designed to provide gains of up to 15% efficiency during winter months. In addition, the new solar controllers have been engineered to limit noise, and also feature remote network interfaces and data logging capability. For those sites where topography impacts the function of the solar power system, methanol fuel cells

  7. Neutronic calculations regarding the new LEU 6 x 6 fuel bundle for 14 MW TRIGA - SSR, in order to increase the reactor power up to 21 MW

    Energy Technology Data Exchange (ETDEWEB)

    Iorgulis, C.; Ciocanescu, M.; Preda, M.; Mladin, M. [Institute of Nuclear Research, Pitesti (Romania)

    1998-07-01

    In order to meet the increasing demands of terminal flux for the experimental devices which will be loaded with CANDU natural uranium pins (or clusters), is necessary to rise the reactor power up to 21 MW. In this respect we consider in our evaluations a new 6x6 TRIGA fuel bundle geometry (the actual fuel bundle contains 5x5 pins). This paper will contain a comparative analysis regarding: flux and power distribution across the 29 fuel bundles standard core, and managements patters, in order to maximize the discharge fuel burnup and core lifetime. (author)

  8. Estimation of the rate of increase in nitrogen dioxide concentrations from power plant stacks using an imaging-DOAS.

    Science.gov (United States)

    Lee, Hanlim; Kim, Young J; Lee, Chulkyu

    2009-05-01

    The emission of nitrogen compounds from power plants accounts for a significant proportion of the total emissions of nitrogen to the atmosphere. This study seeks to understand the nature of chemical reactions in the atmosphere involving nitrogen, which is important in undertaking quantitative assessments of the contribution of such reactions to local and regional air pollution. The slant column density (SCD) of power-plant-generated NO(2) was derived using imaging differential optical absorption spectroscopy (I-DOAS) with scattered sunlight as a light source. The vertical structure of NO(2) SCD from power plant stacks was simultaneously probed using a pushbroom sensor. Measured SCDs were converted to mixing ratios in calculating the rate of NO(2) increase at the center of the plume. This study presents quantitative measurements of the rate of NO(2) increase in a rising plume. An understanding of the rate of NO(2) increase is important because SO(2) and NO(x) compete for the same oxidizing radicals, and the amount of NO(x) is related to the rates of SO(2) oxidation and sulfate formation. This study is the first to directly obtain the rate of NO(2) increase in power plant plumes using the I-DOAS technique. NO(2) increase rates of 60 and 70 ppb s(-1) were observed at distances of about 45 m from the two stacks of the Pyeongtaek Power Plant, northwest South Korea. PMID:18535919

  9. Clean, renewable geothermal energy to meet the increasing power demands of the Pacific North West region

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-10-01

    Canada's most advanced geothermal project is being developed by British Columbia's Western GeoPower Corporation which holds the country's only geothermal lease issued for commercial production of electricity. The thermal reservoir at the South Meager Geothermal Project is located near Whistler, the site of the 2010 Winter Olympics. The project is expected to bring 100 MW of generating capacity on stream in 2007 and an additional 100 MW in 2009. The project has a maximum potential of 250 MW. This major geothermal site is also located 70 km from the province's main power grid which provides a direct link with the northwestern United States. This green power project offers an alternative to hydro, natural gas, coal and nuclear energy and is expected to meet the province's growing power demands. A feasibility study conducted in 2004 at a cost of C$14.5 million involved production test wells, transmission line studies and a final permitting process. The design and construction phase for 2005-2007 is expected to cost C$276 million and will involve power sales contracts; financing; steam gathering systems and well drilling; plant design and construction; transmission line design and construction; and first start up in 2007 followed by additional capacity in 2009. 2 figs.

  10. Computational component analysis techniques for high temperature power plant applications

    OpenAIRE

    Rouse, James Paul

    2014-01-01

    There is a trend in the power industry for high temperature components (such as steam pipe work) to be operated in an increasingly arduous fashion. This would involve the use of elevated steam temperatures/pressures and a greater frequency of start up/shut down cycles. Such generation strategies are being adopted due to the need for thermally efficient power supply that can match fluctuating market demands. If these generation strategies are to be implemented safely it is critical that carefu...

  11. Transient Stability Performance Analysis of Power System Using Facts Devices

    OpenAIRE

    M. Srinivasa Rao; L. Murali Mohan

    2014-01-01

    Transient stability is increasingly important for secure loading. Transient stability evaluation of large scale power systems is an extremely intricate and highly non linear problem. An important function of transient evaluation is to appraise the capability of the power system to with stand serious contingency in time, so that some emergencies or preventive control can be carried out to prevent system breakdown, the fault current so produced is diverted to the capacitor by us...

  12. Implementation of Line Stability Index for Contingency Analysis and Screening in Power Systems

    Directory of Open Access Journals (Sweden)

    Vivek Kumar

    2012-01-01

    Full Text Available Problem statement: Estimating the margin in the loadability of the power system is essential in the real time voltage stability assessment. Voltage stability is currently one of the most important research areas in the field of electrical power system. In power system operation unpredictable events is termed as contingency and may be caused by line outage in the system which could lead to entire system instability. Voltage stability analysis and contingency analysis are would be performed in a power system by evaluating the derived voltage stability index. Approach: Voltage Stability Index Lmn can be useful for estimating the distance from the current operating point to voltage collapse point. The index can either reveal the critical bus of a power system or the stability of each line connected between two buses in an interconnected network or evaluate the voltage stability margins of a system. Results: Flexible Alternating Current Transmission Systems (FACTS devices have been proposed as an effective solution for controlling power flow and regulating bus voltage in electrical power systems, resulting in an increased transfer capability, low system losses and improved stability. However to what extent the performance of FACTS devices can be brought out highly depends upon the location and the parameters of these devices. Unified Power Flow Controller (UPFC is the most promising FACTS device for power flow control. Conclusion/Recommendations: The performance of this index is presented and the effectiveness of the analyzed methods is demonstrated through simulation studies in IEEE 14 bus reliability test systems.

  13. Modeling and analysis of harmonic resonance in a power electronics based AC power system

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Chen, Zhe;

    2013-01-01

    -based analysis approach is adopted and expanded to a meshed and balanced three-phase power network. An impedance ratio derivation method is proposed based on the nodal admittance matrix. By this means, the contribution of each inverter to the system resonance modes can be easily predicted by the Nyquist...

  14. Thermodynamic, energy efficiency, and power density analysis of reverse electrodialysis power generation with natural salinity gradients.

    Science.gov (United States)

    Yip, Ngai Yin; Vermaas, David A; Nijmeijer, Kitty; Elimelech, Menachem

    2014-05-01

    Reverse electrodialysis (RED) can harness the Gibbs free energy of mixing when fresh river water flows into the sea for sustainable power generation. In this study, we carry out a thermodynamic and energy efficiency analysis of RED power generation, and assess the membrane power density. First, we present a reversible thermodynamic model for RED and verify that the theoretical maximum extractable work in a reversible RED process is identical to the Gibbs free energy of mixing. Work extraction in an irreversible process with maximized power density using a constant-resistance load is then examined to assess the energy conversion efficiency and power density. With equal volumes of seawater and river water, energy conversion efficiency of ∼ 33-44% can be obtained in RED, while the rest is lost through dissipation in the internal resistance of the ion-exchange membrane stack. We show that imperfections in the selectivity of typical ion exchange membranes (namely, co-ion transport, osmosis, and electro-osmosis) can detrimentally lower efficiency by up to 26%, with co-ion leakage being the dominant effect. Further inspection of the power density profile during RED revealed inherent ineffectiveness toward the end of the process. By judicious early discontinuation of the controlled mixing process, the overall power density performance can be considerably enhanced by up to 7-fold, without significant compromise to the energy efficiency. Additionally, membrane resistance was found to be an important factor in determining the power densities attainable. Lastly, the performance of an RED stack was examined for different membrane conductivities and intermembrane distances simulating high performance membranes and stack design. By thoughtful selection of the operating parameters, an efficiency of ∼ 37% and an overall gross power density of 3.5 W/m(2) represent the maximum performance that can potentially be achieved in a seawater-river water RED system with low

  15. Approaches and methods for econometric analysis of market power

    DEFF Research Database (Denmark)

    Perekhozhuk, Oleksandr; Glauben, Thomas; Grings, Michael;

    2016-01-01

    This study discusses two widely used approaches in the New Empirical Industrial Organization (NEIO) literature and examines the strengths and weaknesses of the Production-Theoretic Approach (PTA) and the General Identification Method (GIM) for the econometric analysis of market power in agricultu......This study discusses two widely used approaches in the New Empirical Industrial Organization (NEIO) literature and examines the strengths and weaknesses of the Production-Theoretic Approach (PTA) and the General Identification Method (GIM) for the econometric analysis of market power...... in agricultural and food markets. We provide a framework that may help researchers to evaluate and improve structural models of market power. Starting with the specification of the approaches in question, we compare published empirical studies of market power with respect to the choice of the applied approach......, functional forms, estimation methods and derived estimates of the degree of market power. Thereafter, we use our framework to evaluate several structural models based on PTA and GIM to measure oligopsony power in the Ukrainian dairy industry. The PTA-based results suggest that the estimated parameters...

  16. Does centralization increase the size of government? The effects of separation of powers and lobbying

    NARCIS (Netherlands)

    I.A. Mazza; F.A.A.M. van Winden

    2002-01-01

    Difficulties faced by the Economic and Monetary Union have strengthened the position of those who advocate a process of (further) political integration in the European Union (EU). A widespread fear is, though, that such a process would favor powerful interest groups able to lobby the EU policymakers

  17. Increased Power Capture by Rotor Speed–Dependent Yaw Control of Wind Turbines

    DEFF Research Database (Denmark)

    Kragh, Knud Abildgaard; Fleming, Paul A.; Scholbrock, Andrew K.

    2013-01-01

    When extracting energy from the wind using upwind, horizontal-axis wind turbines, a primary condition for ensuring maximum power yield is the ability to align the rotor axis with the dominating wind direction. Attempts have been made to improve the yaw alignment of wind turbines by applying advan...

  18. Increasing the Power of Instruction: Integration of Language, Literacy, and Math Across to Preschool Day

    Science.gov (United States)

    Schickedanz, Judith A.

    2008-01-01

    With many learning goals to be met, preschool teachers may wonder how to accomplish all of them. This book is intended to show teachers how to maximize the scope and power of instruction through integration across content domains and learning contexts. Focusing on language, literacy, and mathematics, the author introduces strategies to bolster…

  19. Locality-Driven Parallel Static Analysis for Power Delivery Networks

    KAUST Repository

    Zeng, Zhiyu

    2011-06-01

    Large VLSI on-chip Power Delivery Networks (PDNs) are challenging to analyze due to the sheer network complexity. In this article, a novel parallel partitioning-based PDN analysis approach is presented. We use the boundary circuit responses of each partition to divide the full grid simulation problem into a set of independent subgrid simulation problems. Instead of solving exact boundary circuit responses, a more efficient scheme is proposed to provide near-exact approximation to the boundary circuit responses by exploiting the spatial locality of the flip-chip-type power grids. This scheme is also used in a block-based iterative error reduction process to achieve fast convergence. Detailed computational cost analysis and performance modeling is carried out to determine the optimal (or near-optimal) number of partitions for parallel implementation. Through the analysis of several large power grids, the proposed approach is shown to have excellent parallel efficiency, fast convergence, and favorable scalability. Our approach can solve a 16-million-node power grid in 18 seconds on an IBM p5-575 processing node with 16 Power5+ processors, which is 18.8X faster than a state-of-the-art direct solver. © 2011 ACM.

  20. Financial risk analysis and prediction of Chinese power industry

    Energy Technology Data Exchange (ETDEWEB)

    Jin, H.; An, C. [Hebei Univ. of Technology, Tianjin (China). School of Management; Zhang, C. [Nankai Univ., Tianjin (China). School of Business

    2009-03-11

    A study of 57 Shanghai and Shenzhen power industry companies was presented. The study considered financial ratios between companies in order to determine risk factors for financial crises. Financial data from the Shanghai and Shenzhen stock markets were used to investigate power company performance from 2006 to 2008. Data from the China Center for Economic Research (CCER) were also used. Results of the study indicated that the cash-to-current debt ratio, the return on equity (ROE), net asset growth ratio, and inventory turnover presented uncorrelated and significantly varying ratios for failed power companies. The study also showed that most power companies have a high proportion of liabilities, higher debt risk, low asset turnover ratios, and negative net working capital. Results of the analysis were used to design an early warning model that used logistic regression techniques to predict risk. 7 refs., 5 tabs.

  1. Financial risk analysis and prediction of Chinese power industry

    International Nuclear Information System (INIS)

    A study of 57 Shanghai and Shenzhen power industry companies was presented. The study considered financial ratios between companies in order to determine risk factors for financial crises. Financial data from the Shanghai and Shenzhen stock markets were used to investigate power company performance from 2006 to 2008. Data from the China Center for Economic Research (CCER) were also used. Results of the study indicated that the cash-to-current debt ratio, the return on equity (ROE), net asset growth ratio, and inventory turnover presented uncorrelated and significantly varying ratios for failed power companies. The study also showed that most power companies have a high proportion of liabilities, higher debt risk, low asset turnover ratios, and negative net working capital. Results of the analysis were used to design an early warning model that used logistic regression techniques to predict risk. 7 refs., 5 tabs.

  2. Deconvolution of window effect in galaxy power spectrum analysis

    CERN Document Server

    Sato, Takahiro; Yamamoto, Kazuhiro

    2010-01-01

    We develop a new method for deconvolving the smearing effect of the survey window in the analysis of the galaxy multipole power spectra from a redshift survey. This method is based on the deconvolution theorem, and is compatible with the use of the fast Fourier transform. It is possible to measure the multipole power spectra deconvolved from the window effect efficiently. Applying this method to the luminous red galaxy sample of the Sloan Digital Sky Survey data release 7 as well as mock catalogues, we demonstrate how the method works properly. Using this deconvolution technique, the amplitude of the multipole power spectrum is corrected. Besides, the covariance matrices of the deconvolved power spectra get quite close to the diagonal form. This is also advantageous in the study of the BAO signature.

  3. Incorporation of a Wind Generator Model into a Dynamic Power Flow Analysis

    Directory of Open Access Journals (Sweden)

    Angeles-Camacho C.

    2011-07-01

    Full Text Available Wind energy is nowadays one of the most cost-effective and practical options for electric generation from renewable resources. However, increased penetration of wind generation causes the power networks to be more depend on, and vulnerable to, the varying wind speed. Modeling is a tool which can provide valuable information about the interaction between wind farms and the power network to which they are connected. This paper develops a realistic characterization of a wind generator. The wind generator model is incorporated into an algorithm to investigate its contribution to the stability of the power network in the time domain. The tool obtained is termed dynamic power flow. The wind generator model takes on account the wind speed and the reactive power consumption by induction generators. Dynamic power flow analysis is carried-out using real wind data at 10-minute time intervals collected for one meteorological station. The generation injected at one point into the network provides active power locally and is found to reduce global power losses. However, the power supplied is time-varying and causes fluctuations in voltage magnitude and power fl ows in transmission lines.

  4. The IAEA, nuclear power and sustainable development. Maintaining and increasing the overall assets available to future generations

    International Nuclear Information System (INIS)

    In the framework of one of the fundamental objectives of the IAEA mandate to enhance the contribution of nuclear technologies towards meeting the needs of Member States, the present status, all the aspects, and the future of nuclear power are reviewed. The development of nuclear power broadens the natural resource base usable for energy production, increases human and man-made capital, and when safely handled has little impact on ecosystems. This means that it could meet the central goal of sustainable development, considering that it covers maintaining or increasing the overall assets available to future generations, while minimizing consumption of finite resources and not exceeding the carrying capacities of ecosystems

  5. System analysis of power transients in advanced WDM networks

    Science.gov (United States)

    Gorinevsky, Dimitry; Farber, Gennady

    2002-06-01

    This paper considers dynamical transient effects in the physical layer of an optical circuit-switched WDM network. These transients of the average transmission power have millisecond time scales. Instead of studying detailed nonlinear dynamics of the network elements, such as optical line amplifiers, a linearized model of the dynamics around a given steady state is considered. System-level analysis in this paper uses modern control theory methods and handles nonlinearity as uncertainty. The analysis translates requirements on the network performance into the requirements to the network elements. These requirements involve a few gross measures of performance for network elements and do not depend on the circuit switching state. One such performance measure is the worst amplification gain for all harmonic disturbances of the average transmission power. Another, is cross coupling of the wavelength channel power variations. The derived requirements guarantee system-level performance for all network configurations and can be used for specifying optical components and subsystems.

  6. Analysis of DC Power Transmission Using High Tc Superconducting Cables

    Institute of Scientific and Technical Information of China (English)

    Jun-Lian Zhang; Jian-Xun Jin

    2008-01-01

    A conceptual superconducting DC cable model is designed and its magnetic fields distribution is analyzed with Ansoft/Maxwell soft. A DC Power transmission system is also studied by using the Matlab/Simulink. With the DC Line and AC Ground Fault, the system losses analysis is introduced.The analysis results mainly include the magnetic fields distribution of the HTS cable model with Ansoft/Maxwell, the system loss, the DC Line and AC Ground Fault with Matlab/Simulation.

  7. Study on accident response robot for nuclear power plant and analysis of key technologies

    International Nuclear Information System (INIS)

    With the rapid development of nuclear power industry and improving demand for nuclear safety, the demand for developing accident response robot in nuclear power plant is increasingly urgent. Firstly, design analysis for accident response robot is taken with environmental conditions in nuclear power plant. Secondly, development for response robots after Chernobyl, JCO and Fukushima accidents are reviewed, and improvements for commercial mobile robot for use in radioactive environments are summarized. Finally, some key technologies including radiation-tolerance and system reliability are analyzed in details. (authors)

  8. Attenuated Increase in Maximal Force of Rat Medial Gastrocnemius Muscle after Concurrent Peak Power and Endurance Training

    Directory of Open Access Journals (Sweden)

    Regula Furrer

    2013-01-01

    Full Text Available Improvement of muscle peak power and oxidative capacity are generally presumed to be mutually exclusive. However, this may not be valid by using fibre type-specific recruitment. Since rat medial gastrocnemius muscle (GM is composed of high and low oxidative compartments which are recruited task specifically, we hypothesised that the adaptive responses to peak power training were unaffected by additional endurance training. Thirty rats were subjected to either no training (control, peak power training (PT, or both peak power and endurance training (PET, which was performed on a treadmill 5 days per week for 6 weeks. Maximal running velocity increased 13.5% throughout the training and was similar in both training groups. Only after PT, GM maximal force was 10% higher than that of the control group. In the low oxidative compartment, mRNA levels of myostatin and MuRF-1 were higher after PT as compared to those of control and PET groups, respectively. Phospho-S6 ribosomal protein levels remained unchanged, suggesting that the elevated myostatin levels after PT did not inhibit mTOR signalling. In conclusion, even by using task-specific recruitment of the compartmentalized rat GM, additional endurance training interfered with the adaptive response of peak power training and attenuated the increase in maximal force after power training.

  9. Attenuated Increase in Maximal Force of Rat Medial Gastrocnemius Muscle after Concurrent Peak Power and Endurance Training

    Science.gov (United States)

    Furrer, Regula; Jaspers, Richard T.; Baggerman, Hein L.; Bravenboer, Nathalie; Lips, Paul; de Haan, Arnold

    2013-01-01

    Improvement of muscle peak power and oxidative capacity are generally presumed to be mutually exclusive. However, this may not be valid by using fibre type-specific recruitment. Since rat medial gastrocnemius muscle (GM) is composed of high and low oxidative compartments which are recruited task specifically, we hypothesised that the adaptive responses to peak power training were unaffected by additional endurance training. Thirty rats were subjected to either no training (control), peak power training (PT), or both peak power and endurance training (PET), which was performed on a treadmill 5 days per week for 6 weeks. Maximal running velocity increased 13.5% throughout the training and was similar in both training groups. Only after PT, GM maximal force was 10% higher than that of the control group. In the low oxidative compartment, mRNA levels of myostatin and MuRF-1 were higher after PT as compared to those of control and PET groups, respectively. Phospho-S6 ribosomal protein levels remained unchanged, suggesting that the elevated myostatin levels after PT did not inhibit mTOR signalling. In conclusion, even by using task-specific recruitment of the compartmentalized rat GM, additional endurance training interfered with the adaptive response of peak power training and attenuated the increase in maximal force after power training. PMID:23509812

  10. The Analysis of The Fault of Electrical Power Steering

    Directory of Open Access Journals (Sweden)

    Zhang Li Wen

    2016-01-01

    Full Text Available This paper analysis the common fault types of primary Electrical Power Steering system, meanwhile classify every fault. It provides the basis for further troubleshooting and maintenance. At the same time this paper propose a practical working principle of fault-tolerant, in order to make the EPS system more security and durability.

  11. PRICE DISCRIMINATION AND MARKET POWER: A THEORETICAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Olga Smirnova

    2015-07-01

    Full Text Available This paper analyzes the contemporary theoretical and empirical research in the field of impact assessment of market power and conclusions about the possibilities of the company to implement price discrimination in different market structures. The results of the analysis allow to evaluate current approaches to antitrust regulation of price discrimination.

  12. Noise analysis in bolometer detector for microwave power measurements.

    Science.gov (United States)

    Mario, Petrizzelli; Brunetti, Luciano

    2003-01-01

    A study of noise related with a thermal detector used as power standard on the 26.5-40GHz frequency band, is presented. This study starts with electromagnetic and thermal analysis, and is based on a cryogenic resistive thermometer functioning at liquid-He temperatures. In addition, the study fixes the theoretical limit of sensitivity. PMID:15916174

  13. Solar Dynamic Power System Stability Analysis and Control

    Science.gov (United States)

    Momoh, James A.; Wang, Yanchun

    1996-01-01

    The objective of this research is to conduct dynamic analysis, control design, and control performance test of solar power system. Solar power system consists of generation system and distribution network system. A bench mark system is used in this research, which includes a generator with excitation system and governor, an ac/dc converter, six DDCU's and forty-eight loads. A detailed model is used for modeling generator. Excitation system is represented by a third order model. DDCU is represented by a seventh order system. The load is modeled by the combination of constant power and constant impedance. Eigen-analysis and eigen-sensitivity analysis are used for system dynamic analysis. The effects of excitation system, governor, ac/dc converter control, and the type of load on system stability are discussed. In order to improve system transient stability, nonlinear ac/dc converter control is introduced. The direct linearization method is used for control design. The dynamic analysis results show that these controls affect system stability in different ways. The parameter coordination of controllers are recommended based on the dynamic analysis. It is concluded from the present studies that system stability is improved by the coordination of control parameters and the nonlinear ac/dc converter control stabilize system oscillation caused by the load change and system fault efficiently.

  14. Biologically relevant molecular transducer with increased computing power and iterative abilities.

    Science.gov (United States)

    Ratner, Tamar; Piran, Ron; Jonoska, Natasha; Keinan, Ehud

    2013-05-23

    As computing devices, which process data and interconvert information, transducers can encode new information and use their output for subsequent computing, offering high computational power that may be equivalent to a universal Turing machine. We report on an experimental DNA-based molecular transducer that computes iteratively and produces biologically relevant outputs. As a proof of concept, the transducer accomplished division of numbers by 3. The iterative power was demonstrated by a recursive application on an obtained output. This device reads plasmids as input and processes the information according to a predetermined algorithm, which is represented by molecular software. The device writes new information on the plasmid using hardware that comprises DNA-manipulating enzymes. The computation produces dual output: a quotient, represented by newly encoded DNA, and a remainder, represented by E. coli phenotypes. This device algorithmically manipulates genetic codes. PMID:23706637

  15. Expanding exports, increasing smog : Ontario Power Generation's and Hydro One's strategies to continue coal-fired electricity generation in Ontario

    International Nuclear Information System (INIS)

    The production of coal-fired electricity increased by approximately 150 per cent in Ontario between 1995 and 2000. As a result, the smog-causing emissions generated by the five coal-fired power plants operated by Ontario Power Generation caused an increase in smog and worsened air quality in the province as well as affecting air quality as far afield as the Atlantic provinces. Between 2002 and 2005, it is expected that the Pickering and Bruce nuclear plants will be returned to service, making the electricity generated by the coal plants surplus to Ontario's needs. Increasing this surplus are the planned natural gas generating stations. Ontario Power Generation is planning on using this surplus to export it to the United States rather than phasing out its reliance on coal. The increase in exports to the United States Northeast and Midwest is planned with Hydro One, already busy increasing its transmission capacity to the United States by 1,000 megawatt (MW). This plan involves laying 975 MW submarine cable from the Nanticoke Generating Station (operated by Ontario Power Generation) under Lake Erie to Pennsylvania, Ohio, or both states. At the moment, the exports are constrained by the government emissions limits imposed by the Ontario government on sulphur dioxide and nitrogen oxides. This constraint could be removed if Ontario Power Generation decides to pay further for pollution controls for sulphur dioxide and nitrogen oxides at its coal stations. Unfortunately, increasing the exports would also result in emissions increases for 28 other uncapped pollutants such as lead, mercury and arsenic. The author recommended that the Ontario government ban non-emergency coal-fired electricity exports to improve air quality in the province. refs., 8 figs

  16. An analysis of increasing price of gricultural products

    Institute of Scientific and Technical Information of China (English)

    王豪; 周婷婷

    2008-01-01

    @@ This report consists of following sections:at first,this report will show the content and source of the cited article,the topic of which is that price hikes for meat,eggs to affect CPI in china;Second,this part mostly presents some theories of economics which are related to the price;Third,through economic analysis,this part search for the method that solve the problem;At last,we will get the conclusion.

  17. Industry perspectives on increasing the efficiency of coal-fired power generation

    Energy Technology Data Exchange (ETDEWEB)

    Torrens, I.M. [Shell Coal International, London (United Kingdom); Stenzel, W.C.

    1997-12-31

    Independent power producers will build a substantial fraction of expected new coal-fired power generation in developing countries over the coming decades. To reduce perceived risk and obtain financing for their projects, they are currently building and plan to continue to build subcritical coal-fired plants with generating efficiency below 40%. Up-to-date engineering assessment leads to the conclusion that supercritical generating technology, capable of efficiencies of up to 45%, can produce electricity at a lower total cost than conventional plants. If such plants were built in Asia over the coming decades, the savings in carbon dioxide emissions over their lifetime would be measured in billions of tons. IPPs perceive supercritical technology as riskier and higher cost than conventional technology. The truth needs to be confirmed by discussions with additional experienced power engineering companies. Better communication among the interested parties could help to overcome the IPP perception issue. Governments working together with industry might be able to identify creative financing arrangements which can encourage the use of more efficient pulverized clean coal technologies, while awaiting the commercialization of advanced clean coal technologies like gasification combined cycle and pressurized fluidized bed combustion.

  18. Quantum heat engine power can be increased by noise-induced coherence.

    Science.gov (United States)

    Scully, Marlan O; Chapin, Kimberly R; Dorfman, Konstantin E; Kim, Moochan Barnabas; Svidzinsky, Anatoly

    2011-09-13

    Laser and photocell quantum heat engines (QHEs) are powered by thermal light and governed by the laws of quantum thermodynamics. To appreciate the deep connection between quantum mechanics and thermodynamics we need only recall that in 1901 Planck introduced the quantum of action to calculate the entropy of thermal light, and in 1905 Einstein's studies of the entropy of thermal light led him to introduce the photon. Then in 1917, he discovered stimulated emission by using detailed balance arguments. Half a century later, Scovil and Schulz-DuBois applied detailed balance ideas to show that maser photons were produced with Carnot quantum efficiency (see Fig. 1A). Furthermore, Shockley and Quiesser invoked detailed balance to obtain the efficiency of a photocell illuminated by "hot" thermal light (see Fig. 2A). To understand this detailed balance limit, we note that in the QHE, the incident light excites electrons, which can then deliver useful work to a load. However, the efficiency is limited by radiative recombination in which the excited electrons are returned to the ground state. But it has been proven that radiatively induced quantum coherence can break detailed balance and yield lasing without inversion. Here we show that noise-induced coherence enables us to break detailed balance and get more power out of a laser or photocell QHE. Surprisingly, this coherence can be induced by the same noisy (thermal) emission and absorption processes that drive the QHE (see Fig. 3A). Furthermore, this noise-induced coherence can be robust against environmental decoherence.Fig. 1.(A) Schematic of a laser pumped by hot photons at temperature T(h) (energy source, blue) and by cold photons at temperature T(c) (entropy sink, red). The laser emits photons (green) such that at threshold the laser photon energy and pump photon energy is related by Carnot efficiency (4). (B) Schematic of atoms inside the cavity. Lower level b is coupled to the excited states a and β. The laser power

  19. A Study on Management Techniques of Power Telecommunication System by Reliability Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.K.; Lee, B.S.; Woy, Y.H.; Oh, M.T.; Shin, M.T.; Kwan, O.G. [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center; Kim, K.H.; Kim, Y.H.; Lee, W.T.; Park, Y.H.; Lee, J.J.; Park, H.S.; Choi, M.C.; Kim, J. [Korea Electrotechnology Research Inst., Changwon (Korea, Republic of)

    1994-12-31

    Power telecommunication network is being increased rapidly in that expansion of power facilities according to the growth of electric power supply. The requirement of power facility and office automation and importance of communication services make it to complex and confusing to operate. And, for the sake of correspond to the change of power telecommunication network, effective operation and management is called for urgently. Therefore, the object of this study is to establish total reliability analysis system based on dependability, maintainability, cost effectiveness and replenishment for keep up reasonable reliability, support economical maintenance and reasonable planning of facility investment. And it will make effective management and administration system and schemes for total reliability improvement. (author). 44 refs., figs.

  20. Design and analysis of solar thermoelectric power generation system

    Science.gov (United States)

    Vatcharasathien, Narong; Hirunlabh, Jongjit; Khedari, Joseph; Daguenet, Michel

    2005-09-01

    This article reports on the design and performance analysis of a solar thermoelectric power generation plant (STEPG). The system considers both truncated compound parabolic collectors (CPCs) with a flat receiver and conventional flat-plate collectors, thermoelectric (TE) cooling and power generator modules and appropriate connecting pipes and control devices. The design tool uses TRNSYS IIsibat-15 program with a new component we developed for the TE modules. The main input data of the system are the specifications of TE module, the maximum hot side temperature of TE modules, and the desired power output. Examples of the design using truncated CPC and flat-plate collectors are reported and discussed for various slope angle and half-acceptance angle of CPC. To minimize system cost, seasonal adjustment of the slope angle between 0° and 30° was considered, which could give relatively high power output under Bangkok ambient condition. Two small-scale STEPGs were built. One of them uses electrical heater, whereas the other used a CPC with locally made aluminum foil reflector. Measured data showed reasonable agreement with the model outputs. TE cooling modules were found to be more appropriate. Therefore, the TRNSYS software and the developed TE component offer an extremely powerful tool for the design and performance analysis of STEPG plant.

  1. Numerical Analysis of Powder Properties in Low Power Plasma Torch

    Institute of Scientific and Technical Information of China (English)

    YAN Zhi-jun; GAO Yang; HEI Zhu-kun; AN Lian-tong

    2004-01-01

    A mathematical model was presented to describe the particle trajectory, velocity and temperature properties in the low power plasma spraying torch (3.6 kW)in which powder particles were directly injected into the region between the cathode and anode. The results show that the characteristics of the particles by low power plasma spraying are similar to that by traditional APS( Atmosphere plasma spraying) in 40 kW. The velocities of the particles increase with the increase of inlet gas flow rate, current and percentage of nitrogen and hydrogen, while the temperature of the powder increase with the decrease of the gas flow rate and with the increase of current and percentage of nitrogen and hydrogen.

  2. The increasing importance of power electronics; Die wachsende Bedeutung der Leistungselektronik. Stromerzeugung, -uebertragung und Stromverteilung sind heute ohne Silizium kaum denkbar

    Energy Technology Data Exchange (ETDEWEB)

    Baumberger, H.; Steimer, P. [ABB Schweiz AG, Turgi (Switzerland)

    2010-07-01

    This article takes a look at the importance today of silicon in power generation, power transmission and power distribution. Also, the importance of this semiconductor as an important component in systems that can increase the efficiency of power use is discussed. Various requirements placed on power electronics are examined, both in the areas of control and protection. The cooling required by such high-power semiconductors and the possibilities of realising it are discussed. Their use in the power generation area, for instance in wind power, photovoltaics and tidal power stations is reviewed, as are applications in pump-storage power stations. Along with power transmission applications, reactive power and energy storage applications are discussed. The article is rounded off with a review of the use of power electronics in consumer and industrial applications such as variable speed drives, mains voltage stabilisation and uninterruptible power supplies.

  3. Power Estimation for Gene-Longevity Association Analysis Using Concordant Twins

    DEFF Research Database (Denmark)

    Tan, Qihua; Zhao, Jing Hua; Kruse, Torben A;

    2014-01-01

    population. The genetic association study on human longevity, a complex trait that is under control of both genetic and environmental factors, has been confronted by the small sample sizes of longevity subjects which limit statistical power. Twin pairs concordant for longevity have increased probability for...... carrying beneficial genes and thus are useful samples for gene-longevity association analysis. We conducted a computer simulation to estimate the power of association study using longevity concordant twin pairs. We observed remarkable power increases in using singletons from longevity concordant twin pairs...... as cases in comparison with cases of sporadic proband. A similar power would require doubled sample sizes for fraternal twins than for identical twins who are concordant for longevity suggesting that longevity concordant identical twins are more efficient samples than fraternal twins. We also...

  4. Stochastic Modeling and Analysis of Power System with Renewable Generation

    DEFF Research Database (Denmark)

    Chen, Peiyuan

    of a substation transformer is determined by the sum of the maximum loading at individual radial feeders while assuming no generation output from local generators. However, such a deterministic analysis does not provide a realistic evaluation of system steady-state performance. A more realistic evaluation can...... be achieved through a probabilistic analysis that takes into account the stochastic behavior of wind power generation (WPG) and load demand. Such a probabilistic analysis may help network operators to cut down the cost associated with system planning. Thus, the objective of this thesis is to develop...... solution than transformer expansion in order to solve the overloading problem. In the last case, an optimal constrained load flow algorithm is proposed to determine the maximum WT capacity in the modified Støvring system when allowing reactive power control and energy curtailment of WTs, subject to voltage...

  5. Probabilistic safety analysis for the Unterweser Nuclear Power Station

    International Nuclear Information System (INIS)

    In October last year, a plant-specific probabilistic safety analysis (PSA) was conducted for the Unterweser Nuclear Power Station as part of the periodic safety review (PSR). As a living PSA, the probabilistic safety analysis was based on the first analysis conducted in 1995; its scope was extended in accordance with the 1996 PSA guideline. Besides the in-plant initiating events in the power mode, which were considered already in the 1995 PSA, the current PSA included external impacts, fires in the plant, and events occurring during plant outages as well as plant-specific data. Also findings of current research were incorporated. The results obtained show the KKU plant to enjoy a high level of safety and allow the PSA to be used alongside plant operation. (orig.)

  6. Living near nuclear power plants and thyroid cancer risk: A systematic review and meta-analysis.

    Science.gov (United States)

    Kim, Jaeyoung; Bang, Yejin; Lee, Won Jin

    2016-02-01

    There has been public concern regarding the safety of residing near nuclear power plants, and the extent of risk for thyroid cancer among adults living near nuclear power plants has not been fully explored. In the present study, a systematic review and meta-analysis of epidemiologic studies was conducted to investigate the association between living near nuclear power plants and the risk of thyroid cancer. A comprehensive literature search was performed on studies published up to March 2015 on the association between nuclear power plants and thyroid cancer risk. The summary standardized incidence ratio (SIR), standardized mortality ratio (SMR), and 95% confidence intervals (CIs) were calculated using a random-effect model of meta-analysis. Sensitivity analyses were performed by study quality. Thirteen studies were included in the meta-analysis, covering 36 nuclear power stations in 10 countries. Overall, summary estimates showed no significant increased thyroid cancer incidence or mortality among residents living near nuclear power plants (summary SIR=0.98; 95% CI 0.87-1.11, summary SMR=0.80; 95% CI 0.62-1.04). The pooled estimates did not reveal different patterns of risk by gender, exposure definition, or reference population. However, sensitivity analysis by exposure definition showed that living less than 20 km from nuclear power plants was associated with a significant increase in the risk of thyroid cancer in well-designed studies (summary OR=1.75; 95% CI 1.17-2.64). Our study does not support an association between living near nuclear power plants and risk of thyroid cancer but does support a need for well-designed future studies.

  7. Regional ozone impacts of increased natural gas use in the Texas power sector and development in the Eagle Ford shale.

    Science.gov (United States)

    Pacsi, Adam P; Kimura, Yosuke; McGaughey, Gary; McDonald-Buller, Elena C; Allen, David T

    2015-03-17

    The combined emissions and air quality impacts of electricity generation in the Texas grid and natural gas production in the Eagle Ford shale were estimated at various natural gas price points for the power sector. The increased use of natural gas in the power sector, in place of coal-fired power generation, drove reductions in average daily maximum 8 h ozone concentration of 0.6-1.3 ppb in northeastern Texas for a high ozone episode used in air quality planning. The associated increase in Eagle Ford upstream oil and gas production nitrogen oxide (NOx) emissions caused an estimated local increase, in south Texas, of 0.3-0.7 ppb in the same ozone metric. In addition, the potential ozone impacts of Eagle Ford emissions on nearby urban areas were estimated. On the basis of evidence from this work and a previous study on the Barnett shale, the combined ozone impact of increased natural gas development and use in the power sector is likely to vary regionally and must be analyzed on a case by case basis.

  8. Comprehensive physical analysis of bond wire interfaces in power modules

    DEFF Research Database (Denmark)

    Popok, Vladimir; Pedersen, Kristian Bonderup; Kristensen, Peter Kjær;

    2016-01-01

    Power modules based on insulated gate bipolar transistors have become very widely used units in energy technology. Handling large currents and high voltages at high switching frequencies leads to degradation of materials in the devices, especially at interfaces and interconnections, eventually...... causing failures. In this paper we present a review on the set of our experimental and theoretical studies allowing comprehensive physical analysis of changes in materials under active power cycling with focus on bond wire interfaces and thin metallisation layers. The developed electro-thermal and thermo...

  9. Detection of Wind Turbine Power Performance Abnormalities Using Eigenvalue Analysis

    DEFF Research Database (Denmark)

    Skrimpas, Georgios Alexandros; Sweeney, Christian Walsted; Marhadi, Kun Saptohartyadi;

    2014-01-01

    Condition monitoring of wind turbines is a field of continu- ous research and development as new turbine configurations enter into the market and new failure modes appear. Systems utilising well established techniques from the energy and in- dustry sector, such as vibration analysis...... in order to achieve better resolution and thus identify the most proba- ble root cause of the power deviation. An important aspect of the proposed technique is its independence of the power curve provided by the turbine manufacturer. It is shown that by detecting any changes of the two eigenvalues trends...

  10. Fishing power increases from technological development in the Faroe Islands longline fishery

    NARCIS (Netherlands)

    Eigaard, O.R.; Thomsen, B.; Hovgaard, H.; Nielsen, A.; Rijnsdorp, A.D.

    2011-01-01

    During an effort-regulated period from 1996 to 2002, unregistered annual increases of 0.3% of hooks fished per day were demonstrated for the Faroe Islands longline fishery. However, annual increases were higher (1.5%) during a preceding total allowable catch regulated period, thereby invalidating an

  11. Inhaled Beta2-agonist increases power output and glycolysis during sprinting in men

    DEFF Research Database (Denmark)

    Kalsen, Anders; Hostrup, Morten; Söderlund, Karin;

    2016-01-01

    PURPOSE: The aim of the present study was to investigate the effect of the beta2-agonist terbutaline (TER) on power output and muscle metabolism during maximal sprint cycling. METHODS: In a randomized double-blind crossover design, nine moderately trained men (VO2max: 4.6±0.2 L[BULLET OPERATOR......]min) conducted a 10-s cycle sprint after inhalation of either 15 mg TER or placebo (PLA). A muscle biopsy was collected before and sprint, and analyzed for metabolites. RESULTS: Mean and peak power during the sprint were 8.3±1.1 and 7.8±2.5 % higher (P.... Moreover, net rate of glycogenolysis (6.5±0.8 vs. 3.1±0.7 mmol glucosyl units kg dw s) and glycolysis (2.4±0.2 vs. 1.6±0.2 mmol glucosyl units kg dw s) were higher (Psprint, ATP was reduced in PLA (Psprint, there was no difference...

  12. Electromechanical modeling of a honeycomb core integrated vibration energy converter with increased specific power for energy harvesting applications

    Science.gov (United States)

    Chandrasekharan, Nataraj

    Innovation in integrated circuit technology along with improved manufacturing processes has resulted in considerable reduction in power consumption of electromechanical devices. Majority of these devices are currently powered by batteries. However, the issues posed by batteries, including the need for frequent battery recharge/replacement has resulted in a compelling need for alternate energy to achieve self-sufficient device operation or to supplement battery power. Vibration based energy harvesting methods through piezoelectric transduction provides with a promising potential towards replacing or supplementing battery power source. However, current piezoelectric energy harvesters generate low specific power (power-to-weight ratio) when compared to batteries that the harvesters seek to replace or supplement. In this study, the potential of integrating lightweight cellular honeycomb structures with existing piezoelectric device configurations (bimorph) to achieve higher specific power is investigated. It is shown in this study that at low excitation frequency ranges, replacing the solid continuous substrate of a conventional piezoelectric bimorph with honeycomb structures of the same material results in a significant increase in power-to-weight ratio of the piezoelectric harvester. In order to maximize the electrical response of vibration based power harvesters, the natural frequency of these harvesters is designed to match the input driving frequency. The commonly used technique of adding a tip mass is employed to lower the natural frequency (to match driving frequency) of both, solid and honeycomb substrate bimorphs. At higher excitation frequency, the natural frequency of the traditional solid substrate bimorph can only be altered (to match driving frequency) through a change in global geometric design parameters, typically achieved by increasing the thickness of the harvester. As a result, the size of the harvester is increased and can be disadvantageous

  13. Analysis of the efficiency of the Iberian power futures market

    International Nuclear Information System (INIS)

    Market efficiency is analysed for the Iberian Power Futures Market and other European Power Markets, as well as other fuel markets through evaluation of ex-post Forward Risk Premium. The equilibrium price from compulsory call auctions for distribution companies within the framework of the Iberian Power Futures Market is not optimal for remuneration purposes as it seems to be slightly upward biased. In the period considered (August 2006-July 2008), monthly futures contracts behave similarly to quarterly contracts. Average risk premia have been positive in power and natural gas markets but negative in oil and coal markets. Different hypotheses are tested regarding increasing volatility with maturity and regarding Forward Risk Premium variations (decreasing with variance of spot prices during delivery period and increasing with skewness of spot prices during delivery period). Enlarged data sets are recommended for stronger test results. Energy markets tend to show limited levels of market efficiency. Regarding the emerging Iberian Power Futures Market, price efficiency is improved with market development of all the coexistent forward contracting mechanisms and with further integration of European Regional Electricity Markets.

  14. Exergetic analysis of a solar thermal power system with PCM storage

    International Nuclear Information System (INIS)

    Highlights: • Exergy efficiency of parabolic trough system is 10% while energy efficiency is 30%. • Overall exergy efficiency can increase up to 30% using PCM with the solar collector. • PCM with higher melting point temperature give higher exergy efficiency of the system. - Abstract: Exergy analysis has become an important tool for thermodynamic assessment of power generation systems. In the present study, thermodynamic performance (energy and exergy) analysis is performed for a solar thermal power plant located in Shiraz, Iran. In addition, a computational exergy analysis is performed to show the possible improvement of this power plant integrating with Phase Change Material (PCM) storage. Consequently, it is found that overall energy efficiency without PCM storage is about 30% while the exergy efficiency is about 10%. However, about 30% overall exergy efficiency can be achieved for the case of using PCM storage along with the solar collector

  15. Increasing the reliability of power semiconductors using DAB-substrates; Steigerung der Zuverlaessigkeit von Leistungshalbleitern durch Verwendung von DAB-Substraten

    Energy Technology Data Exchange (ETDEWEB)

    Grieger, F.; Lindemann, A. [Magdeburg Univ. (Germany); Boettge, B.; Klengel, S.; Petzold, M. [Fraunhofer IWM, Halle an der Saale (Germany)

    2012-07-01

    Besides power electronic loads, power electronic sources for decentralised generation have established in the grid. In the smart grid, the use of power electronics will even increase because of the introduction of more HVDC transmission lines and the necessity to control power flows. This paper deals with direct aluminium bonded (DAB) substrates which can serve as carriers of power electronic components with further increased reliability as desirable for long-term usage in the smart grid. (orig.)

  16. Scaling range of power laws that originate from fluctuation analysis

    Science.gov (United States)

    Grech, Dariusz; Mazur, Zygmunt

    2013-05-01

    We extend our previous study of scaling range properties performed for detrended fluctuation analysis (DFA) [Physica A0378-437110.1016/j.physa.2013.01.049 392, 2384 (2013)] to other techniques of fluctuation analysis (FA). The new technique, called modified detrended moving average analysis (MDMA), is introduced, and its scaling range properties are examined and compared with those of detrended moving average analysis (DMA) and DFA. It is shown that contrary to DFA, DMA and MDMA techniques exhibit power law dependence of the scaling range with respect to the length of the searched signal and with respect to the accuracy R2 of the fit to the considered scaling law imposed by DMA or MDMA methods. This power law dependence is satisfied for both uncorrelated and autocorrelated data. We find also a simple generalization of this power law relation for series with a different level of autocorrelations measured in terms of the Hurst exponent. Basic relations between scaling ranges for different techniques are also discussed. Our findings should be particularly useful for local FA in, e.g., econophysics, finances, or physiology, where the huge number of short time series has to be examined at once and wherever the preliminary check of the scaling range regime for each of the series separately is neither effective nor possible.

  17. Exergy analysis and optimization of Dieng single-flash geothermal power plant

    International Nuclear Information System (INIS)

    Highlights: • We analyze the exergy simulation of the geothermal power plant in Dieng, Indonesia. • We also optimize the power plant to consider the improvement of power output. • The total available exergy of the geothermal fluid is estimated to be 59.52 MW. • It is found that the second law efficiency of the power plant is 36.48%. • With optimization, the power output increases by lowering the separator pressure. - Abstract: Exergy analysis and optimization of a single-flash geothermal power plant are conducted by developing a mathematical model that is applied to the Dieng geothermal power plant in Indonesia. Calculations are conducted by using the Engineering Equation Solver (EES) code using methods based on the laws of thermodynamics. The exergy flow and efficiency are computed at several plant components, including the separator, turbine, condenser, and for the whole power plant. The exergy of the geothermal fluid that is discharged from the production wells is estimated to be 59.52 MW. This amount of fluid produces 21.71 MW of electricity from the power plant overall, with second law efficiency to be 36.48%. There is a considerable amount of waste brine, amounting to 17.98% (10.70 MW) of the total available exergy, which is disposed of in the plant’s reservoir. The optimization of the plant is carried out by adjusting the separator pressure. The results show that a slight increase of 20 kW in the output power can be attained by lowering the separator pressure to 9 bar from 10 bar. The Grassmann diagram shows the exergy losses at each component in the power plant. The turbine and separator losses are 7.51 MW (12.62%) and 8.04 MW (13.5%), respectively, while the cooling tower has an exergy loss of 2.62 MW (4.40%). The total condenser loss is 5.8 MW (9.75%)

  18. Dynamic Analysis & Characterization of Conventional Hydraulic Power Supply Units

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Bech, Michael Møller; Liedhegener, Michael;

    2016-01-01

    Hydraulic power units operated as constant supply pres-sure systems remain to be widely used in the industry, to supply valve controlled hydraulic drives etc., where the hydraulic power units are constituted by variable pumps with mechanical outlet pressure control, driven by induction motors...... such that limited impact on the drive dynamics is observed. Such ideal properties however, are not necessarily present in industrial hydraulic applications for various reasons, with the most common being large volumes of supply lines. Long supply lines, hence large supply line volumes, between the sup-ply system...... with internal pi-lot supply are used. This paper is concerned with the analysis and characterization of the coupled pump-induction motor dy-namics, confined to hydraulic power units constituted by an axial piston pump with mechanical outlet pressure control, driven by an induction motor operated at grid...

  19. Betweenness as a Tool of Vulnerability Analysis of Power System

    Science.gov (United States)

    Rout, Gyanendra Kumar; Chowdhury, Tamalika; Chanda, Chandan Kumar

    2016-06-01

    Complex network theory finds its application in analysis of power grid as both share some common characteristics. By using this theory finding critical elements in power network can be achieved. As vulnerabilities of elements of the network decide the vulnerability of the total network, in this paper, vulnerability of each element is studied using two complex network models—betweenness centrality and extended betweenness. The betweenness centrality considers only topological structure of power system whereas extended betweenness is based on both topological and physical properties of the system. In the latter case, some of the electrical properties such as electrical distance, line flow limits, transmission capacities of lines and PTDF matrix are included. The standard IEEE 57 bus system has been studied based upon the above mentioned indices and following conclusions have been discussed.

  20. Core thermal hydraulic analysis for TNR power uprating

    International Nuclear Information System (INIS)

    This paper presents preliminary results of a study undertaken to investigate the possibility of raising the power of the Tajura Nuclear Research Reactor (TNRR) from 10 to 20 MWt keeping the same core configuration and with minimum changes in the primary cooling circuit. The study was carried out for a fresh core, with compact load (16 assemblies) under normal operation conditions. A computer program, TAJT, was used to simulate the core and perform the necessary thermal hydraulic analysis. The results obtained show that the reactor power could be raised to 15 MWt safely and with no changes in the primary cooling circuit. To raise the power to 20 MWt will require changes in the core configuration and primary circuit

  1. Thermodynamic analysis of Thermophotovoltaic Efficiency and Power Density Tradeoffs

    Energy Technology Data Exchange (ETDEWEB)

    P.F. Baldasara; J.E. Reynolds; G.W. Charache; D.M. DePoy; C.T. Ballinger; T. Donovan; J.M. Borrego

    2000-02-22

    This report presents an assessment of the efficiency and power density limitations of thermophotovoltaic (TPV) energy conversion systems for both ideal (radiative-limited) and practical (defect-limited) systems. Thermodynamics is integrated into the unique process physics of TPV conversion, and used to define the intrinsic tradeoff between power density and efficiency. The results of the analysis reveal that the selection of diode bandgap sets a limit on achievable efficiency well below the traditional Carnot level. In addition it is shown that filter performance dominates diode performance in any practical TPV system and determines the optimum bandgap for a given radiator temperature. It is demonstrated that for a given radiator temperature, lower bandgap diodes enable both higher efficiency and power density when spectral control limitations are included. The goal of this work is to provide a better understanding of the basic system limitations that will enable successful long-term development of TPV energy conversion technology.

  2. Software and codes for analysis of concentrating solar power technologies.

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Clifford Kuofei

    2008-12-01

    This report presents a review and evaluation of software and codes that have been used to support Sandia National Laboratories concentrating solar power (CSP) program. Additional software packages developed by other institutions and companies that can potentially improve Sandia's analysis capabilities in the CSP program are also evaluated. The software and codes are grouped according to specific CSP technologies: power tower systems, linear concentrator systems, and dish/engine systems. A description of each code is presented with regard to each specific CSP technology, along with details regarding availability, maintenance, and references. A summary of all the codes is then presented with recommendations regarding the use and retention of the codes. A description of probabilistic methods for uncertainty and sensitivity analyses of concentrating solar power technologies is also provided.

  3. Sensitivity of Transient Phenomena Analysis of the Francis Turbine Power Plants

    OpenAIRE

    Viktor Iliev; Bojan Ivljanin

    2015-01-01

    The accurate definition of the transient phenomena of the hydroelectric power plant (HPP) and its units, taking into account various aspects of operation is an essential requirement for design, performances and control of HPPs. Numerical analysis of transient phenomena, such as increase of the rotational speed (runaway) of the units, increase of the pressure (turbine inlet head) in the hydraulic system (water hammer) and water level oscillation in the surge tank is presented. The ...

  4. Drivers for the Value of Demand Response under Increased Levels of Wind and Solar Power; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Hale, Elaine

    2015-07-30

    Demand response may be a valuable flexible resource for low-carbon electric power grids. However, there are as many types of possible demand response as there are ways to use electricity, making demand response difficult to study at scale in realistic settings. This talk reviews our state of knowledge regarding the potential value of demand response in several example systems as a function of increasing levels of wind and solar power, sometimes drawing on the analogy between demand response and storage. Overall, we find demand response to be promising, but its potential value is very system dependent. Furthermore, demand response, like storage, can easily saturate ancillary service markets.

  5. Development of an Axial Flux MEMS BLDC Micromotor with Increased Efficiency and Power Density

    Directory of Open Access Journals (Sweden)

    Xiaofeng Ding

    2015-06-01

    Full Text Available This paper presents a rigorous design and optimization of an axial flux microelectromechanical systems (MEMS brushless dc (BLDC micromotor with dual rotor improving both efficiency and power density with an external diameter of only around 10 mm. The stator is made of two layers of windings by MEMS technology. The rotor is developed by film permanent magnets assembled over the rotor yoke. The characteristics of the MEMS micromotor are analyzed and modeled through a 3-D magnetic equivalent circuit (MEC taking the leakage flux and fringing effect into account. Such a model yields a relatively accurate prediction of the flux in the air gap, back electromotive force (EMF and electromagnetic torque, whilst being computationally efficient. Based on 3-D MEC model the multi-objective firefly algorithm (MOFA is developed for the optimal design of this special machine. Both 3-D finite element (FE simulation and experiments are employed to validate the MEC model and MOFA optimization design.

  6. Thermodynamic analysis of an idealised solar tower thermal power plant

    International Nuclear Information System (INIS)

    In the real solar tower thermal power system, it is widely acknowledged that the thermodynamic irreversibility, such as convective and radiative loss on tower receiver, and thermal resistance in heat exchangers, is unavoidable. With above factors in mind, this paper presents an ideal model of the solar tower thermal power system to analyze the influence of various parameters on thermal and exergy conversion efficiencies, including receiver working temperature, concentration ratio, endoreversible heat engine efficiency and so forth. And therefore the variation of maximum thermal conversion efficiency in terms of concentration ratio and endoreversible heat engine efficiency could be theoretically obtained. The results indicate that raising the receiver working temperature could initially increase both thermal and exergy conversion efficiencies until an optimum temperature is reached. The optimum temperature would also increase with the concentration ratio. Additionally, the concentration ratio has a positive effect on the thermal conversion efficiency: increasing the concentration ratio could raise the conversion efficiency until the concentration ratio is extremely high, after which there will be a slow drop. Lastly, the endoreversible engine efficiency also has significant influence on the thermal conversion efficiency, it will increase the thermal conversion efficiency until it reaches the maximum and optimum value, and then the conversion efficiency will drop dramatically. - Highlights: • Built an idealized thermodynamic model for solar tower thermal power plants. • Analyze the influence of various parameters on thermal and exergy efficiencies. • The optimum temperature would increase with the concentration ratio. • The endoreversible engine efficiency would have an optimum value

  7. Knowledge brokerage - potential for increased capacities and shared power in impact assessment

    International Nuclear Information System (INIS)

    Constructive and collaborative planning theory has exposed the perceived limitations of public participation in impact assessment. At strategic levels of assessment the established norm can be misleading and practice is illusive. For example, debates on SEA effectiveness recognize insufficiencies, but are often based on questionable premises. The authors of this paper argue that public participation in strategic assessment requires new forms of information and engagement, consistent with the complexity of the issues at these levels and that strategic assessments can act as knowledge brokerage instruments with the potential to generate more participative environments and attitudes. The paper explores barriers and limitations, as well as the role of knowledge brokerage in stimulating the engagement of the public, through learning-oriented processes and responsibility sharing in more participative models of governance. The paper concludes with a discussion on building and inter-change of knowledge, towards creative solutions to identified problems, stimulating learning processes, largely beyond simple information transfer mechanisms through consultative processes. The paper argues fundamentally for the need to conceive strategic assessments as learning platforms and design knowledge brokerage opportunities explicitly as a means to enhance learning processes and power sharing in IA. - Highlights: ► Debates on SEA recognize insufficiencies on public participation ► We propose new forms of engagement consistent with complex situations at strategic levels of decision-making ► Constructive and collaborative planning theories help explain how different actors acquire knowledge and the value of knowledge exchange ► Strategic assessments can act as knowledge brokerage instruments ► The paper argues for strategic assessments as learning platforms as a means to enhance learning processes and power sharing in IA.

  8. A literal analysis of potential interference from satellites with the proposed pfd increase

    Science.gov (United States)

    Jeske, Harold O.

    In this paper, an increase of 16 dB above current power flux density (pfd) limits for ITU Radio Regulations is proposed. The results of an analysis are reviewed which assumed worst case conditions for interference with telemetry operations at missile test ranges due to current and proposed satellite pfd levels. It was found that the performance of essentially all missile telemetry receiving systems may be appreciably degraded by even the lowest pfd limits currently permitted. For the higher pfd limits under consideration, degradation on the order of 40 dB is to be expected at stations with dish antennas only five feet in diameter. For satisfactory telemetry operation, the normal missile's telemetry received SNR would have to be well over 40 dB to overcome satellite interference. Several practical recommendations are made for missile and satellite telemetry to coexist in the 2200-2290 MHz band.

  9. Harmonic Analysis of Boolean Networks: Determinative Power and Perturbations

    CERN Document Server

    Heckel, Reinhard; Bossert, Martin

    2011-01-01

    Consider a large Boolean network with a feed forward structure. Given a probability distribution for the inputs, can one find-possibly small-collections of input nodes that determine the states of most other nodes in the network? To identify these nodes, a notion that quantifies the determinative power of an input over states in the network is needed. We argue that the mutual information (MI) between a subset of the inputs X = {X_1, ..., X_n} of node i and the function f_i(X)$ associated with node i quantifies the determinative power of this subset of inputs over node i. To study the relation of determinative power to sensitivity to perturbations, we relate the MI to measures of perturbations, such as the influence of a variable, in terms of inequalities. The result shows that, maybe surprisingly, an input that has large influence does not necessarily have large determinative power. The main tool for the analysis is Fourier analysis of Boolean functions. Whether a function is sensitive to perturbations or not...

  10. Cooperative genome-wide analysis shows increased homozygosity in early onset Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Javier Simón-Sánchez

    Full Text Available Parkinson's disease (PD occurs in both familial and sporadic forms, and both monogenic and complex genetic factors have been identified. Early onset PD (EOPD is particularly associated with autosomal recessive (AR mutations, and three genes, PARK2, PARK7 and PINK1, have been found to carry mutations leading to AR disease. Since mutations in these genes account for less than 10% of EOPD patients, we hypothesized that further recessive genetic factors are involved in this disorder, which may appear in extended runs of homozygosity.We carried out genome wide SNP genotyping to look for extended runs of homozygosity (ROHs in 1,445 EOPD cases and 6,987 controls. Logistic regression analyses showed an increased level of genomic homozygosity in EOPD cases compared to controls. These differences are larger for ROH of 9 Mb and above, where there is a more than three-fold increase in the proportion of cases carrying a ROH. These differences are not explained by occult recessive mutations at existing loci. Controlling for genome wide homozygosity in logistic regression analyses increased the differences between cases and controls, indicating that in EOPD cases ROHs do not simply relate to genome wide measures of inbreeding. Homozygosity at a locus on chromosome19p13.3 was identified as being more common in EOPD cases as compared to controls. Sequencing analysis of genes and predicted transcripts within this locus failed to identify a novel mutation causing EOPD in our cohort.There is an increased rate of genome wide homozygosity in EOPD, as measured by an increase in ROHs. These ROHs are a signature of inbreeding and do not necessarily harbour disease-causing genetic variants. Although there might be other regions of interest apart from chromosome 19p13.3, we lack the power to detect them with this analysis.

  11. Power Quality Analysis Using Bilinear Time-Frequency Distributions

    Directory of Open Access Journals (Sweden)

    Sha'ameri AhmadZuri

    2010-01-01

    Full Text Available Abstract Bilinear time-frequency distributions (TFDs are powerful techniques that offer good time and frequency resolution of time-frequency representation (TFR. It is very appropriate to analyze power quality signals which consist of nonstationary and multi-frequency components. However, the TFDs suffer from interference because of cross-terms. Many TFDs have been implemented, and there is no fixed window or kernel that can remove the cross-terms for all types of signals. In this paper, the bilinear TFDs are implemented to analyze power quality signals such as smooth-windowed Wigner-Ville distribution (SWWVD, Choi-Williams distribution (CWD, B-distribution (BD, and modified B-distribution (MBD. The power quality signals focused are swell, sag, interruption, harmonic, interharmonic, and transient based on IEEE Std, 1159-1995. A set of performance measures is defined and used to compare the TFRs. It shows that SWWVD presents the best performance and is selected for power quality signal analysis. Thus, an adaptive optimal kernel SWWVD is designed to determine the separable kernel automatically from the input signal.

  12. A long-term analysis of pumped hydro storage to firm wind power

    International Nuclear Information System (INIS)

    Highlights: • This is a long term generation analysis of a high wind power system. • A high CO2 and fossil fuel price is closest to Ireland’s EU ETS 2020 target. • New pumped storage to firm wind is limited unless strong market costs exist. • Reserve for wind power show that ancillary services are relevant for balancing. - Abstract: Although pumped hydro storage is seen as a strategic key asset by grid operators, financing it is complicated in new liberalised markets. It could be argued that the optimum generation portfolio is now determined by the economic viability of generators based on a short to medium term return on investment. This has meant that capital intensive projects such as pumped hydro storage are less attractive for wholesale electricity companies because the payback periods are too long. In tandem a significant amount of wind power has entered the generation mix, which has resulted in operating and planning integration issues due to wind’s inherent uncertain, varying spatial and temporal nature. These integration issues can be overcome using fast acting gas peaking plant or energy storage. Most analysis of wind power integration using storage to date has used stochastic optimisation for power system balancing or arbitrage modelling to examine techno-economic viability. In this research a deterministic dynamic programming long term generation expansion model is employed to optimise the generation mix, total system costs and total carbon dioxide emissions, and unlike other studies calculates reserve to firm wind power. The key finding of this study is that the incentive to build capital-intensive pumped hydro storage to firm wind power is limited unless exogenous market costs come very strongly into play. Furthermore it was demonstrated that reserve increases with increasing wind power showing the importance of ancillary services in future power systems

  13. Human factor analysis and preventive countermeasures in nuclear power plant

    International Nuclear Information System (INIS)

    Based on the human error analysis theory and the characteristics of maintenance in a nuclear power plant, human factors of maintenance in NPP are divided into three different areas: human, technology, and organization. Which is defined as individual factors, including psychological factors, physiological characteristics, health status, level of knowledge and interpersonal skills; The technical factors including technology, equipment, tools, working order, etc.; The organizational factors including management, information exchange, education, working environment, team building and leadership management,etc The analysis found that organizational factors can directly or indirectly affect the behavior of staff and technical factors, is the most basic human error factor. Based on this nuclear power plant to reduce human error and measures the response. (authors)

  14. Exergy Analysis of Combined Cycle Power Plant: NTPC Dadri, India

    Directory of Open Access Journals (Sweden)

    Arvind Kumar Tiwari

    2012-12-01

    Full Text Available The aim of the present paper is to exergy analysis of combined Brayton/Rankine power cycle of NTPC Dadri India. Theoretical exergy analysis is carried out for different components of dadri combined cycle power plant which consists of a gas turbine unit, heat recovery steam generator without extra fuel consumption and steam turbine unit. The results pinpoint that more exergy losses occurred in the gas turbine combustion chamber. Its reached 35% of the total exergy losses while the exergy losses in other plant components are between 7% -21% of the total exergy losses at 1400o C turbine inlet temperature and pressure ratio 10 .This paper also considered the effect of the pressure ratio, turbine inlet temperature, pressure drop in combustion chamber and heat recovery steam generator on the exergy losses in the plant, there are a clear effects in the exergy losses when changing pressure ratio, turbine inlet temperature.

  15. ANALYSIS OF THE METHOD FOR COMPENSATIVE POWER IN THE ELECTRICITY SUPPLY NETWORKS BASED ON PORTABLE ELECTRIC POWER STATION

    OpenAIRE

    Karamnov, A.

    2006-01-01

    In this paper we consider a base technology for compensating the reactive power in electricity supply networks based on portable electric power stations (e.g. bank of capacitors, synchronous motors, barier-layer statistical reactive power source). Analysis of advantages and disadvantages for considered engineering solutions is performed.

  16. 福清核电1、2号机组增大应急给水箱容积安全分析%Safety Analysis on the Volume Increase of Auxiliary Water Tank for Number One and Two Units of Fuqing Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    佟立丽; 邵舸; 顾健; 薛峻峰; 彭建平; 王志强

    2013-01-01

    When main feed water system or start-up feed water system is unavailable, auxiliary feed water system, as Engineered Safety Facility (ESF), provides water for Steam Generators (SG) to remove the stored and decay heat from the reactor core. In order to improve the safety of Nuclear Power Plants (NPPs) and increase operational flexibility, the water inventory of the auxiliary feed water tank is increased in the number one and two units of Fuqing NPP. The model of the NPP is built based on mechanical safety analytical code, and conservative assumptions are used in the calculation. Three typical accident sequences, such as loss of main feed water, loss of offsite power in category Ⅱ accident, and main feed water line break in category IV, are selected to analyze whether or not the inventory in auxiliary water tank after improvement satisfies the relevant requirements in RCC-R The results show that auxiliary water inventory of 713m3 is needed for loss of main feed water accident, auxiliary water inventory of 723m3 is needed for loss of offsite power accident, and auxiliary water inventory of 799m3 is needed for main feed water line break accident. The inventory in auxiliary water tank after improvement satisfies the requirements for category Ⅱ and Ⅳ accidents. The safety of NPP is improved due to the inventory redundancy and a time window is also provided for the operators to perform related accident procedures.%辅助给水系统(ASG)作为专设安全设施在主给水或启动给水不可用时向蒸汽发生器供水,以导出堆芯余热.为了提高电厂安全性,增加运行灵活性,福清核电1、2号机组对应急给水箱的有效容积进行了增加.本文采用机理性安全分析程序,建立核电厂分析模型,在计算过程中采用保守假设条件,选取Ⅱ类工况下正常给水丧失事故,厂外电丧失事故,Ⅳ类工况下主给水管道破裂事故3条典型事故序列,分析改进后的应急给水箱容量是否满足压水

  17. Nuclear power and the public: analysis of collected survey research

    Energy Technology Data Exchange (ETDEWEB)

    Melber, B.D.; Nealey, S.M.; Hammersla, J.; Rankin, W.L.

    1977-11-01

    This executive summary highlights the major findings of a comprehensive synthesis and analysis of over 100 existing surveys dealing with public attitudes toward nuclear power issues. Questions of immediate policy relevance to the nuclear debate are posed and answered on the basis of these major findings. For each issue area, those sections of the report in which more-detailed discussion and presentation of relevant data may be found are indicated.

  18. Nuclear power and the public: analysis of collected survey research

    International Nuclear Information System (INIS)

    This executive summary highlights the major findings of a comprehensive synthesis and analysis of over 100 existing surveys dealing with public attitudes toward nuclear power issues. Questions of immediate policy relevance to the nuclear debate are posed and answered on the basis of these major findings. For each issue area, those sections of the report in which more-detailed discussion and presentation of relevant data may be found are indicated

  19. Employing Power Graph Analysis to Facilitate Modeling Molecular Interaction Networks

    Directory of Open Access Journals (Sweden)

    Momchil Nenov

    2015-04-01

    Full Text Available Mathematical modeling is used to explore and understand complex systems ranging from weather patterns to social networks to gene-expression regulatory mechanisms. There is an upper limit to the amount of details that can be reflected in a model imposed by finite computational resources. Thus, there are methods to reduce the complexity of the modeled system to its most significant parameters. We discuss the suitability of clustering techniques, in particular Power Graph Analysis as an intermediate step of modeling.

  20. Rerouting end-face-TIR capable rays to significantly increase evanescent wave signal power

    Institute of Scientific and Technical Information of China (English)

    Jianjun Ma; Yasser Chiniforooshan; Huacai Chen; Jiahua Chen; Wojtek J. Bock; Andrea Cusano

    2011-01-01

    The critical findings associated with end-face total internal reflection (TIR) phenomemon we proved before are reported. In particular, these findings reveal that the end-face-TIR capable rays experience enormous mode mixing when encountering a roughened end face. As a result, 94% of the overall detectable power is contributed by this effect. With a smooth fiber end face, this figure is mere 52%. We interpret the mechanism behind these unusual phenomena and its significance for the performance enhancement of fiber optic evanescent wave sensor.%@@ The critical findings associated with end-face total internal reflection (TIR) phenomemon we proved before are reported, In particular, these findings reveal that the end-face-TIR capable rays experience enormous mode mixing when encountering a roughened end face.As a result, 94Vo of the overall detectable poweris contributed by this effect.With a smooth fiber end face, this figure is mere 52%.We interpret the mechanism behind these unusual phenomena and its significance for the performance enhancement of fiber optic evanescent wave sensor.

  1. Jacobian integration method increases the statistical power to measure gray matter atrophy in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Kunio Nakamura

    2014-01-01

    Full Text Available Gray matter atrophy provides important insights into neurodegeneration in multiple sclerosis (MS and can be used as a marker of neuroprotection in clinical trials. Jacobian integration is a method for measuring volume change that uses integration of the local Jacobian determinants of the nonlinear deformation field registering two images, and is a promising tool for measuring gray matter atrophy. Our main objective was to compare the statistical power of the Jacobian integration method to commonly used methods in terms of the sample size required to detect a treatment effect on gray matter atrophy. We used multi-center longitudinal data from relapsing–remitting MS patients and evaluated combinations of cross-sectional and longitudinal pre-processing with SIENAX/FSL, SPM, and FreeSurfer, as well as the Jacobian integration method. The Jacobian integration method outperformed these other commonly used methods, reducing the required sample size by a factor of 4–5. The results demonstrate the advantage of using the Jacobian integration method to assess neuroprotection in MS clinical trials.

  2. Some aspects of increasing the quality of personnel training for nuclear power plants in Czechoslovakia

    International Nuclear Information System (INIS)

    Nuclear power plant personnel in Czechoslovakia is subject to periodical training in accordance with the Unified System of Nuclear Facility Personnel Training. This training is the responsibility of the Educational and Training Centre of the Nuclear Plant Research Institute in Trnava. Nuclear plant personnel is divided into 7 groups as follows: A - supervisory technical-administrative management staff; B - selected operating personnel such as shift supervisors, unit supervisors, reactor operators and secondary circuit operators; C - engineering-technical personnel of technical and maintenance departments; D - managing shift-operating staff; E - workers at technical plant departments; F - operational shift workers and servicemen; and G - maintenance personnel. These groups are respected in the training, which includes basic training, re-training and additional training. The basic training comprises 8 stages: general theoretical education; specialized theoretical education; on-the-job training in a plant designated for training; training on a simulator (group B); preparing for and taking final examinations for the certificate; doubling in the NPP designated for training (groups B, D, F); preparation in the NPP of future employment; preparing for and taking the state examination for obtaining the license (group B). Details of the management of the training process, experience gained during the implementation of the training and challenges for future improvement of the system are outlined. (P.A.)

  3. Method for Increasing the Efficiency of Automatic Fire Extinguish System at Objects Of Power

    Directory of Open Access Journals (Sweden)

    Dmitrienko Margarita

    2015-01-01

    Full Text Available Operation of energy facilities requires compliance with all safety standards, and especially fire safety. Emergency situations that arise when operated the power equipment damage not only the objects of the technosphere but also the environment. In recent years, can be noted a trend of quite intensive development of technological bases of technology water mist fire extinguishing. Using the methods of optical panoramic imaging PIV, IPI and the method of high-speed video recording were performed the experimental studies of the characteristics of evaporation of large single water droplets as they pass through the flames of oil and oil products with varying parameters of the processes (the initial size of 2–6 mm, the rate of 2–4 m/s and the temperature of water drops 290–300 K, the temperature of the combustion products 185–2073 K. Was established decisive influence droplet size, velocities at which droplets enter the gaseous medium, the initial water temperature on heating rate and evaporation of droplets in a stream of high-temperature combustion products.

  4. Analysis of electrical tree propagation in XLPE power cable insulation

    Science.gov (United States)

    Bao, Minghui; Yin, Xiaogen; He, Junjia

    2011-04-01

    Electrical treeing is one of the major breakdown mechanisms for solid dielectrics subjected to high electrical stress. In this paper, the characteristics of electrical tree growth in XLPE samples have been investigated. XLPE samples are obtained from a commercial XLPE power cable, in which electrical trees have been grown from pin to plane in the frequency range of 4000-10,000 Hz, voltage range of 4-10 kV, and the distances between electrodes of 1 and 2 mm. Images of trees and their growing processes were taken by a CCD camera. The fractal dimensions of electric trees were obtained by using a simple box-counting technique. The results show that the tree growth rate and fractal dimension was bigger when the frequency or voltage was higher, or the distance between electrodes was smaller. Contrary to our expectation, it has been found that when the distance between electrodes changed from 1 to 2 mm, the required voltage of the similar electrical trees decreased only 1or 2 kV. In order to evaluate the difficulties of electrical tree propagation in different conditions, a simple energy threshold analysis method has been proposed. The threshold energy, which presents the minimum energy that a charge carrier in the well at the top of the tree should have to make the tree grow, has been computed considering the length of electrical tree, the fractal dimension, and the growth time. The computed results indicate that when one of the three parameters of voltage, frequency, and local electric field increase, the trends of energy threshold can be split into 3 regions.

  5. Analysis of debt leveraging in private power projects

    International Nuclear Information System (INIS)

    As private power (non-utility generation) has grown to become a significant part of the electricity system, increasing concern about its financial implications has arisen. In many cases, the source of this concern has been the substantial reliance of these projects on debt financing. This study examines debt leveraging in private power projects. The policy debate on these issues has typically been conducted at a high level of generality. Critics of the private power industry assert that high debt leveraging confers an unfair competitive advantage by lowering the cost of capital, and that this leveraging is only possible because risks are shifted to the utility. Further, debt leveraging is claimed to be a threat to reliability. On the opposite side, it is argued that debt leveraging imposes costs and obligations not home by utilities, and so there is no financial advantage. The private producers also argue that on balance more risk is shifted away from utilities than to them, and that incentives for reliability are strong. In this study we examine the project finance mechanisms used in private power lending in detail, relying on a sample of actual loan documents. This review and its findings should be relevant to the further evolution of this debate. State regulatory commissions are likely to be interested in it, and Federal legislation to amend the Public Utility Holding Company Act (PUHCA) could require states to consider the implications of debt leveraging in relation to their oversight of utility power purchase programs

  6. Analysis of debt leveraging in private power projects

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, E.P. (Lawrence Berkeley Lab., CA (United States)); Meal, M.; Doerrer, S.; Morse, S. (Morse, Richard, Weisenmiller Associates, Inc., Oakland, CA (United States))

    1992-08-01

    As private power has grown to become a significant part of the electricity system, increasing concern about its financial implications has arisen. In many cases, the source of this concern has been the substantial reliance of these projects on debt financing. This study examines debt leveraging in private power projects. The policy debate on these issues has typically been conducted at a high level of generality. Critics of the private power industry assert that high debt leveraging confers an unfair competitive advantage by lowering the cost of capital. This leveraging is only possible because risks are shifted to the utility. Further, debt leveraging is claimed to be a threat to reliability. On the opposite side, it is argued that debt leveraging imposes costs and obligations not borne by utilities, and so there is no financial advantage. The private producers also argue that on balance more risk is shifted away from utilities than to them, and that incentives for reliability are strong. In this study we examine the project finance mechanisms used in private power lending in detail, relying on a sample of actual loan documents. This review and its findings should be relevant to the further evolution of this debate. State regulatory commissions are likely to be interested in it, and Federal legislation to amend the Public Utility Holding Company Act (PUHCA) could require states to consider the implications of debt leveraging in relation to their oversight of utility power purchase programs.

  7. Power Spectrum Analysis of Three-Dimensional Redshift Surveys

    CERN Document Server

    Feldman, H A; Peacock, J A; Feldman, Hume A.; Kaiser, Nick; Peacock, John A.

    1994-01-01

    We develop a general method for power spectrum analysis of three dimensional redshift surveys. We present rigorous analytical estimates for the statistical uncertainty in the power and we are able to derive a rigorous optimal weighting scheme under the reasonable (and largely empirically verified) assumption that the long wavelength Fourier components are Gaussian distributed. We apply the formalism to the updated 1-in-6 QDOT IRAS redshift survey, and compare our results to data from other probes: APM angular correlations; the CfA and the Berkeley 1.2Jy IRAS redshift surveys. Our results bear out and further quantify the impression from e.g.\\ counts-in-cells analysis that there is extra power on large scales as compared to the standard CDM model with $\\Omega h\\simeq 0.5$. We apply likelihood analysis using the CDM spectrum with $\\Omega h$ as a free parameter as a phenomenological family of models; we find the best fitting parameters in redshift space and transform the results to real space. Finally, we calcul...

  8. COMPARATIVE ANALYSIS OF EV-MOGA AND GODLIKE MULTIOBJECTIVE EVOLUTIONARY ALGORITHMS FOR RISK BASED OPTIMAL POWER SCHEDULING OF A VIRTUAL POWER PLANT

    Directory of Open Access Journals (Sweden)

    Mahesh S. Narkhede

    2015-01-01

    Full Text Available An attempt has been made in this article to compare the performances of two multiobjective evolutionary algorithms namely ev-MOGA and GODLIKE. The performances of both are evaluated on risk based optimal power scheduling of virtual power plant. The risk based scheduling is proposed as a conflicting bi objective optimization problem with increased number of durations of day. Both the algorithms are elaborated in detail. Results based on the performance analysis are depicted at the end.

  9. A performance analysis of solar chimney thermal power systems

    Directory of Open Access Journals (Sweden)

    Al-Dabbas Awwad Mohammed

    2011-01-01

    Full Text Available The objective of this study was to evaluate the solar chimney performance theoretically (techno-economic. A mathematical model was developed to estimate the following parameter: Power output, Pressure drop across the turbine, the max chimney height, Airflow temperature, and the overall efficiency of solar chimney. The mathematical model was validated with experimental data from the prototype in Manzanares power. It can be concluded that the differential pressure of collector-chimney transition section in the system, is increase with the increase of solar radiation intensity. The specific system costs are between 2000 Eur/kW and 5000 Eur/kW depending on the system size, system concept and storage size. Hence, a 50 MWe solar thermal power plant will cost 100-250 Eur million. At very good sites, today’s solar thermal power plants can generate electricity in the range of 0.15 Eur/kWh, and series production could soon bring down these costs below 0.10 Eur /kWh.

  10. Intervention analysis of power plant impact on fish populations

    International Nuclear Information System (INIS)

    Intervention analysis was applied to 10 yr (years 1973-1982) of field fish abundance data at the D. C. Cook Nuclear Power Plant, southeastern Lake Michigan. Three log-transformed catch series, comprising monthly observations, were examined for each combination of two species (alewife, Alosa pseudoharenga, or yellow perch, Perca flavescens) and gear (trawl or gill net): catch at the plant discharged transect, catch at the reference transect, and the ratio of plant catch to reference catch. Time series separated by age groups were examined. Based on intervention analysis, no change in the abundance of fish populations could be attributed to plant operation. Additionally, a modification of the intervention analysis technique was applied to investigate trends in abundance at both the plant discharge and reference transects. Significant declines were detected for abundance of alewife adults at both of the transects. Results of the trend analysis support the contention that the alewives have undergone a lakewide decrease in abundance during the 1970s

  11. Bifurcation Analysis of a DC-DC Bidirectional Power Converter Operating with Constant Power Loads

    Science.gov (United States)

    Cristiano, Rony; Pagano, Daniel J.; Benadero, Luis; Ponce, Enrique

    Direct current (DC) microgrids (MGs) are an emergent option to satisfy new demands for power quality and integration of renewable resources in electrical distribution systems. This work addresses the large-signal stability analysis of a DC-DC bidirectional converter (DBC) connected to a storage device in an islanding MG. This converter is responsible for controlling the balance of power (load demand and generation) under constant power loads (CPLs). In order to control the DC bus voltage through a DBC, we propose a robust sliding mode control (SMC) based on a washout filter. Dynamical systems techniques are exploited to assess the quality of this switching control strategy. In this sense, a bifurcation analysis is performed to study the nonlinear stability of a reduced model of this system. The appearance of different bifurcations when load parameters and control gains are changed is studied in detail. In the specific case of Teixeira Singularity (TS) bifurcation, some experimental results are provided, confirming the mathematical predictions. Both a deeper insight in the dynamic behavior of the controlled system and valuable design criteria are obtained.

  12. Large scale exchange of balancing power between Norway and Europe: analysis of impacts

    Energy Technology Data Exchange (ETDEWEB)

    Graabak, Ingeborg; Skjelbred, Hans Ivar

    2012-07-01

    This report is from at study in Centre for environmental design of renewable energy (CEDREN). (The objective of the analysis is to show the impacts on the European power system if Norwegian hydropower is used for large-scale balancing. A special focus in on possible reductions of the CO{sub 2} emissions. A scenario methodology is used to explore different future developments of the power systems. The analysis is performed by the EMPS-model. All expected impacts on the European power system where observed: the Norwegian hydro power system worked as a pump-storage, the surplus in the production, the rationing of the demand and the CO{sub 2} emissions from the European power production were reduced. However, this report must mainly be regarded as preliminary analysis of the impacts of Norway as a 'green battery' for Europe. The work has given increased insight in necessary improvements in the design of the cases for analysis, the use og the EMPS as well as the implementation of the model before it is possible to finally quantify the impacts. The work will be brought further in other projects. (Author)

  13. Westinghouse FREY calculations: excessive load increase, boron dilution, and rod withdrawal at power. Final report

    International Nuclear Information System (INIS)

    The purpose of this investigation was to execute three sample problems with the FREY Code (a transient analysis code for fuel rods), to document the problems, and to discuss the results. Three ANSI Condition II overpower transients were evaluated. Problem inputs were generated from reactor system models and fuel rod parameters. FREY results were compared to results from a Westinghouse fuel rod modeling code. FREY results for fuel temperatures in general display the correct trend with time during the transients. FREY temperature results are lower than the values obtained from the Westinghouse code. These differences were found to have been principally due to differences in the calculated gap conductance values

  14. Thermoeconomic analysis of a power/water cogeneration plant

    International Nuclear Information System (INIS)

    Cogeneration plants for simultaneous production of water and electricity are widely used in the Arabian Gulf region. They have proven to be more thermodynamically efficient and economically feasible than single purpose power generation and water production plants. Yet, there is no standard or universally applied methodology for determining unit cost of electric power generation and desalinated water production by dual purpose plants. A comprehensive literature survey to critically assess and evaluate different methods for cost application in power/water cogeneration plants is reported in this paper. Based on this analysis, an in-depth thermoeconomic study is carried out on a selected power/water cogeneration plant that employs a regenerative Rankine cycle. The system incorporates a boiler, back pressure turbine (supplying steam to two MSF distillers), a deaerator and two feed water heaters. The turbine generation is rated at 118 MW, while MSF distiller is rated at 7.7 MIGD at a top brine temperature of 105 deg. C. An appropriate costing procedure based on the available energy accounting method which divides benefits of the cogeneration configuration equitably between electricity generation and water production is used to determine the unit costs of electricity and water. Capital charges of common equipment such as the boiler, deaerator and feed water heaters as well as boiler fuel costs are distributed between power generated and desalinated water according to available energy consumption of the major subsystems. A detailed sensitivity analysis was performed to examine the impact of the variation of fuel cost, load and availability factors in addition to capital recovery factor on electricity and water production costs

  15. Increasing the power of FiR 1 TRIGA reactor by a factor of 2 1/2

    International Nuclear Information System (INIS)

    An early domestic reactor engineering project was increasing the neutron flux of the Triga Mark II reactor in Otaniemi by a factor of 2 1/2, thirty-five years ago. The thermal power of the facility was increased from 100 kW to 250 kW by modifications made in the fuel loading, control rods, control and protection systems, radiation shielding structures and in the heat removal system. This improved the efficiency of the plant and reduced time requirements in proportion for physical research, isotope production and medical irradiations. Experimental runs were made at 318 kW power, and the final approval inspection for continuous operation at 250 kW was completed on August 3, 1967. (author)

  16. Cascaded gain fibers for increasing output power and the stimulated Brillouin scattering threshold of narrow linewidth fiber Raman amplifiers.

    Science.gov (United States)

    Nagel, J A; Temyanko, V; Dobler, J T; Likhachev, M E; Bubnov, M M; Dianov, E M; Peyghambarian, N

    2016-05-20

    We show both experimentally and theoretically a method to increase the stimulated Brillouin scattering (SBS) threshold and output power of narrow linewidth fiber Raman amplifiers. This method employs two or more fibers with varying concentrations of the Raman gain material dopant such as GeO2 or P2O5 in silicate-based glasses. These fibers are then cascaded to form an amplifier gain stage, disrupting the buildup of SBS that normally occurs in single continuous fibers. The numerical model shown is applicable to arbitrary amplifier systems for gain stage optimization and increased power scaling. We give experimental results for phosphosilicate fibers that agree well with simulation predictions that support the numerical model used. PMID:27411133

  17. Fault tree based reliability analysis for digital reactor power control system of nuclear power plant

    International Nuclear Information System (INIS)

    Fault tree method is used for reliability analysis for reactor power control system, including uncertainty analysis and sensitive analysis. 'loss of regulation accident' top event and 'loss of effective control' top event are defined, corresponding fault tree are constructed, and contribution of hardware failure and software failure to system safety are calculated. It points out that common mode failures of software, actuator, sensor and operator's response have significant influence to system reliability in 'loss of regulation accident'; software common mode failure and operators' response have significant contribution to system reliability in 'loss of efficient control accident'. (authors)

  18. Merger market power analysis: Pacific Enterprises and Enova Corporation

    International Nuclear Information System (INIS)

    The Pacific Enterprises - Enova (PE-Enova) merger may be viewed as an example of the new breed of gas and power 'convergence' mergers. The merger involved the combination of a large gas distribution utility and a contiguous gas and electric utility located in Southern California. As with most mergers, the PE-Enova merger was proposed to federal and state regulators as an opportunity to achieve ratepayer savings. However, the merger also presented an issue of vertical market power involving the substantial electric generation capacity served by Southern California Gas Company (SoCalGas) and its potential impact on electric market prices, and the associated revenues for generation assets owned by San Diego Gas and Electric (SDGandE). In order for the merger to proceed, the approval of at least five separate State and federal regulators would be required. Although much of the attention of state regulators, proponents, and intervenors surrounded the division of synergy savings between ratepayers and shareholders, the analysis of the potential for market power abuse was extensive. Intervenors presented numerous complex arguments regarding the potential adverse effects of the merger on competition. In particular, intervenors argued that the combined company would manipulate its storage and transport operations to influence the delivered price of gas to California generators, and therefore, the price of power in the wholesale electric market. The arguments surrounding the existence and impacts of market power in this case are of interest in the understanding the nature and complexity of factors that may be considered in evaluating mergers. The proceeding also provides insight into how regulators are grappling with market power issues associated with convergence mergers, and weigh merger costs and benefits

  19. Analysis of chinese Power Market in 2007 and Its Forecast

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Power supply and demand in January-September, 2007 Since 2007, the national economy developed continuously, showing a situation of rapid growth, more optimized structure, increased efficiency and improvement of people's livelihood. In the first three quarters, GDP achieved 16.6043 trillion Yuan, and its year-on-year growth rate was 11.5%; the growth rate was 0.7 percentage points higher than that of the previous year.

  20. Analysis of Highly Wind Power Integrated Power System model performance during Critical Weather conditions

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Sørensen, Poul Ejnar;

    2014-01-01

    . For this purpose, the power system model has been developed that represents the relevant dynamic features of power plants and compensates for power imbalances caused by the forecasting error during critical weather conditions. The regulating power plan, as an input time series for the developed power system model......Secure power system operation of a highly wind power integrated power system is always at risk during critical weather conditions, e.g. in extreme high winds. The risk is even higher when 50% of the total electricity consumption has to be supplied by wind power, as the case for the future Danish......, is provided by the hour-ahead power balancing model, i.e. Simulation power Balancing model (SimBa. The regulating power plan is prepared from day-ahead power production plan and hour-ahead wind power forecast. The wind power (forecasts and available) are provided by the Correlated Wind power fluctuations (Cor...

  1. Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity

    OpenAIRE

    Tippett, Michael K.; Cohen, Joel E.

    2016-01-01

    Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from ‘outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954–2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to...

  2. The Environment-Power System Analysis Tool development program. [for spacecraft power supplies

    Science.gov (United States)

    Jongeward, Gary A.; Kuharski, Robert A.; Kennedy, Eric M.; Wilcox, Katherine G.; Stevens, N. John; Putnam, Rand M.; Roche, James C.

    1989-01-01

    The Environment Power System Analysis Tool (EPSAT) is being developed to provide engineers with the ability to assess the effects of a broad range of environmental interactions on space power systems. A unique user-interface-data-dictionary code architecture oversees a collection of existing and future environmental modeling codes (e.g., neutral density) and physical interaction models (e.g., sheath ionization). The user-interface presents the engineer with tables, graphs, and plots which, under supervision of the data dictionary, are automatically updated in response to parameter change. EPSAT thus provides the engineer with a comprehensive and responsive environmental assessment tool and the scientist with a framework into which new environmental or physical models can be easily incorporated.

  3. Power

    OpenAIRE

    Samuel Bowles; Herbert Gintis

    2007-01-01

    We consider the exercise of power in competitive markets for goods, labour and credit. We offer a definition of power and show that if contracts are incomplete it may be exercised either in Pareto-improving ways or to the disadvantage of those without power. Contrasting conceptions of power including bargaining power, market power, and consumer sovereignty are considered. Because the exercise of power may alter prices and other aspects of exchanges, abstracting from power may miss essential a...

  4. Analysis of the Thermonuclear Instability including Low-Power ICRH Minority Heating in IGNITOR

    CERN Document Server

    Cardinali, Alessandro

    2014-01-01

    The nonlinear thermal balance equation for classical plasma in a toroidal geometry is analytically and numerically investigated including ICRH power. The determination of the equilibrium temperature and the analysis of the stability of the solution are performed by solving the energy balance equation that includes the transport relations obtained by the kinetic theory. An estimation of the confinement time is also provided. We show that the ICRH heating in the IGNITOR experiment, among other applications, is expected to stabilize the power of the thermonuclear burning by automatic regulation of the RF coupled power. Here a scenario is considered where IGNITOR is led to operate in a slightly sub-critical regime by adding a small fraction of ${}^3He$ to the nominal 50-50 Deuterium-Tritium mixture. The difference between power lost and alpha heating is compensated by additional ICRH heating, which should be able to increase the global plasma temperature via collisions between ${}^3He$ minority and the background...

  5. Increasing the Discriminatory Power of DEA Using Shannon’s Entropy

    Directory of Open Access Journals (Sweden)

    Qiwei Xie

    2014-03-01

    Full Text Available In many data envelopment analysis (DEA applications, the analyst always confronts the difficulty that the selected data set is not suitable to apply traditional DEA models for their poor discrimination. This paper presents an approach using Shannon’s entropy to improve the discrimination of traditional DEA models. In this approach, DEA efficiencies are first calculated for all possible variable subsets and analyzed using Shannon’s entropy theory to calculate the degree of the importance of each subset in the performance measurement, then we combine the obtained efficiencies and the degrees of importance to generate a comprehensive efficiency score (CES, which can observably improve the discrimination of traditional DEA models. Finally, the proposed approach has been applied to some data sets from the prior DEA literature.

  6. Steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Fang, Jiakun; Liu, Jinghua;

    2016-01-01

    Nowadays, the electric power system and natural gas network are becoming increasingly coupled and interdependent. A harmonized integration of natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables in terms of system...... flexibility. This work focuses on the steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion. A unified energy flow formulation is developed to describe the nodal balance and branch flow in both systems and it is solved with the Newton...... series of wind power and power load are used to investigate the mitigation effect of the integrated energy system. At last, the effect of wind power and power demand on the output of Power to Gas (P2G) and gas-fired power generation (GPG) has also been investigated....

  7. Analysis of competition and market power in the wholesale electricity market in India

    International Nuclear Information System (INIS)

    The electricity reforms were initiated in India with the objective of promoting competition in the electricity market. In order to promote competition, the Electricity Act 2003 was enacted and various policy initiatives were taken by the Government of India. Central Electricity Regulatory Commission (CERC) also facilitated competition through the regulatory framework of availability based tariff, Indian Electricity Grid Code, open access in inter-state transmission, inter-state trading and power exchanges. Despite these initiatives, electricity prices increased in the Wholesale Electricity Market in India (WEMI). This paper analyses the market structure and competitiveness in the WEMI. There are, of course, various potential reasons for the rise in the electricity price. This paper seeks to investigate, if market power was one of the reasons for increase in market prices. Concentration ratio, Herfindahl-Hirschman index, Supply Margin Assessment, and Residual Supply Index have been used to measure market power. This paper also uses the price-cost mark-up to examine, if exercise of market power led to higher margins. The analysis suggests that market power of firms may be part of the reason for the increase in electricity prices in WEMI. The study suggests various measures to increase competition in the WEMI.

  8. Analysis of engineering cycles power, refrigerating and gas liquefaction plant

    CERN Document Server

    Haywood, R W

    1991-01-01

    Extensively revised, updated and expanded, the fourth edition of this popular text provides a rigorous analytical treatment of modern energy conversion plant. Notable for both its theoretical and practical treatment of conventional and nuclear power plant, and its studies of refrigerating and gas-liquefaction plant. This fourth edition now includes material on topics of increasing concern in the fields of energy 'saving' and reduction of environmental pollution. This increased coverage deals specifically with the following areas: CHP (cogeneration) plant, studies of both gas and coal burning p

  9. Modus operandi for maximizing energy efficiency and increasing permeate flux of community scale solar powered reverse osmosis systems

    International Nuclear Information System (INIS)

    Highlights: • Experimental data on energy efficient photovoltaic powered reverse osmosis system. • Synergetic management of electrical, thermal and hydraulic energies. • Use of reflectors, heat exchanger and turgo turbine. - Abstract: Photovoltaic powered reverse osmosis systems can only be made cost effective if they are made highly energy efficient. In this work we describe a protocol to maximize energy efficiency and increase permeate flux in a fully integrated installation of such a system. The improved system consisted of (i) photovoltaic array fitted with suitably positioned and aligned North–South V-trough reflectors to enhance power output from the array; (ii) direct contact heat exchanger fitted on the rear of the photovoltaic modules for active cooling of the same while safeguarding the terminals from short-circuit and corrosion; (iii) use of reverse osmosis feed water as heat exchange medium while taking due care to limit the temperature rise of feed water; (iv) enhancing permeate flux through the rise in feed water temperature; (v) turgo-turbine for conversion of hydraulic energy in reverse osmosis reject water into mechanical energy to provide part of the energy to replace booster pump utilized in the reverse osmosis unit. The V-trough reflectors onto the photovoltaic modules with thermal energy recovery system brought about an increase in power output of 40% and the synergistic effect of (i)–(iv) gave rise to total permeate volume boost of 59%. Integration of (v) resulted in 56% and 26% saving of electrical power when the reverse osmosis plant was operated by battery bank and direct photovoltaic array respectively

  10. Power plant selection in a carbon constrained world the TERA (technoeconomic environmental risk analysis)

    Institute of Scientific and Technical Information of China (English)

    Stephen Ogaji; Pericles Pilidis; Vishal Sethi

    2009-01-01

    There is an increasing concern that current trends of consumption of natural resources cannot continue. It is imperative that major targeted investments are made into economical and reliable environment friendly propulsion and power solutions. Many novel and promising concepts are being proposed. The selection of the best candidates to pursue for investment becomes a very difficult choice.A detailed TERA (techno-economic environmental risk analysis) framework is described here to quantify risks and to compare and rank competing schemes on a formal and consistent basis. This technique is based on detailed and rigorous thermodynamic representations of power plants. A layer of environment, economic, weather and other models to describe the appropriate local conditions is superimposed to this.The outcome is a techno-economic environmental risk analysis framework with appropriate detail of each power plant as applied to the appropriate conditions. The results for each concept can then be compared and contrasted to make appropriate selections.

  11. Probabilistic methods in nuclear power plant component ageing analysis

    International Nuclear Information System (INIS)

    The nuclear power plant ageing research is aimed to ensure that the plant safety and reliability are maintained at a desired level through the designed, and possibly extended lifetime. In ageing studies, the reliability of components, systems and structures is evaluated taking into account the possible time- dependent decrease in reliability. The results of analyses can be used in the evaluation of the remaining lifetime of components and in the development of preventive maintenance, testing and replacement programmes. The report discusses the use of probabilistic models in the evaluations of the ageing of nuclear power plant components. The principles of nuclear power plant ageing studies are described and examples of ageing management programmes in foreign countries are given. The use of time-dependent probabilistic models to evaluate the ageing of various components and structures is described and the application of models is demonstrated with two case studies. In the case study of motor- operated closing valves the analysis are based on failure data obtained from a power plant. In the second example, the environmentally assisted crack growth is modelled with a computer code developed in United States, and the applicability of the model is evaluated on the basis of operating experience

  12. Information or prices, which is most powerful in increasing consumer demand for organic vegetables?

    DEFF Research Database (Denmark)

    Smed, Sinne; Andersen, Laura Mørch

    2012-01-01

    to prices. “New” consumers can be persuaded to buy organic vegetables by providing information about the negative health effects of consuming conventional vegetables since it increases the probability of an organic purchase. Once consumers have entered the organic marked for vegetables, information......Based on a unique and very detailed panel dataset covering consumption of organically and conventionally produced vegetables in the years 2005 - 2007, we examine the effects of information about positive health effects of consuming organic vegetables and information about negative health effects...... of consuming conventional vegetables on demand for organic foods for six different segments of Danish households. Three of these segments are positive towards organics whereas the remaining three segments are negative or indifferent. Using the double hurdle model we estimate partial effects of both directly...

  13. Error analysis of short term wind power prediction models

    International Nuclear Information System (INIS)

    The integration of wind farms in power networks has become an important problem. This is because the electricity produced cannot be preserved because of the high cost of storage and electricity production must follow market demand. Short-long-range wind forecasting over different lengths/periods of time is becoming an important process for the management of wind farms. Time series modelling of wind speeds is based upon the valid assumption that all the causative factors are implicitly accounted for in the sequence of occurrence of the process itself. Hence time series modelling is equivalent to physical modelling. Auto Regressive Moving Average (ARMA) models, which perform a linear mapping between inputs and outputs, and Artificial Neural Networks (ANNs) and Adaptive Neuro-Fuzzy Inference Systems (ANFIS), which perform a non-linear mapping, provide a robust approach to wind power prediction. In this work, these models are developed in order to forecast power production of a wind farm with three wind turbines, using real load data and comparing different time prediction periods. This comparative analysis takes in the first time, various forecasting methods, time horizons and a deep performance analysis focused upon the normalised mean error and the statistical distribution hereof in order to evaluate error distribution within a narrower curve and therefore forecasting methods whereby it is more improbable to make errors in prediction. (author)

  14. Error analysis of short term wind power prediction models

    Energy Technology Data Exchange (ETDEWEB)

    De Giorgi, Maria Grazia; Ficarella, Antonio; Tarantino, Marco [Dipartimento di Ingegneria dell' Innovazione, Universita del Salento, Via per Monteroni, 73100 Lecce (Italy)

    2011-04-15

    The integration of wind farms in power networks has become an important problem. This is because the electricity produced cannot be preserved because of the high cost of storage and electricity production must follow market demand. Short-long-range wind forecasting over different lengths/periods of time is becoming an important process for the management of wind farms. Time series modelling of wind speeds is based upon the valid assumption that all the causative factors are implicitly accounted for in the sequence of occurrence of the process itself. Hence time series modelling is equivalent to physical modelling. Auto Regressive Moving Average (ARMA) models, which perform a linear mapping between inputs and outputs, and Artificial Neural Networks (ANNs) and Adaptive Neuro-Fuzzy Inference Systems (ANFIS), which perform a non-linear mapping, provide a robust approach to wind power prediction. In this work, these models are developed in order to forecast power production of a wind farm with three wind turbines, using real load data and comparing different time prediction periods. This comparative analysis takes in the first time, various forecasting methods, time horizons and a deep performance analysis focused upon the normalised mean error and the statistical distribution hereof in order to evaluate error distribution within a narrower curve and therefore forecasting methods whereby it is more improbable to make errors in prediction. (author)

  15. Analysis of Maisotsenko open gas turbine power cycle with a detailed air saturator model

    International Nuclear Information System (INIS)

    Highlights: • Developed an accurate air saturator model. • Performed sensitivity analysis for Maisotsenko gas turbine cycle (MGTC). • Performed comparative analysis for MGTC and simple gas turbine with reheat (SGTR) and humid air turbine (HAT). • MGTC has higher efficiency and specific work output with at high compressor pressure ratio. • Optimum air saturator water mass flow rate is calculated. - Abstract: With ever increasing cost of fossil fuels and natural gas, the improvement in gas turbine power cycle efficiency is needed due to the tremendous savings in fuel consumption. Water/steam injection is considered as one of the most popular power augmentation techniques because of its significant impact on the gas turbine performance. One of the recently suggested evaporative gas turbine cycles is the Maisotsenko open cycle for gas turbine power generation. In this paper, detailed thermodynamic analysis of this cycle is investigated with a thorough air saturator model. A comparative analysis is carried out to signify the advantages and disadvantages of Maisotsenko gas turbine cycle (MGTC) as compared with humid air gas turbine cycles. MGTC performance is evaluated based on a simple recuperated gas turbine cycle. In addition, sensitivity analysis is performed to investigate the effect of different operating parameters on the overall cycle performance. Finally, integrating an air saturator instead of a conventional heat exchanger in recuperated gas turbine cycles enhances the power plant performance such that an efficiency enhancement of 7% points and net specific work output augmentation of 44.4% are obtained

  16. The Power of Three: Coral Reefs, Seagrasses and Mangroves Protect Coastal Regions and Increase Their Resilience.

    Science.gov (United States)

    Guannel, Greg; Arkema, Katie; Ruggiero, Peter; Verutes, Gregory

    2016-01-01

    Natural habitats have the ability to protect coastal communities against the impacts of waves and storms, yet it is unclear how different habitats complement each other to reduce those impacts. Here, we investigate the individual and combined coastal protection services supplied by live corals on reefs, seagrass meadows, and mangrove forests during both non-storm and storm conditions, and under present and future sea-level conditions. Using idealized profiles of fringing and barrier reefs, we quantify the services supplied by these habitats using various metrics of inundation and erosion. We find that, together, live corals, seagrasses, and mangroves supply more protection services than any individual habitat or any combination of two habitats. Specifically, we find that, while mangroves are the most effective at protecting the coast under non-storm and storm conditions, live corals and seagrasses also moderate the impact of waves and storms, thereby further reducing the vulnerability of coastal regions. Also, in addition to structural differences, the amount of service supplied by habitats in our analysis is highly dependent on the geomorphic setting, habitat location and forcing conditions: live corals in the fringing reef profile supply more protection services than seagrasses; seagrasses in the barrier reef profile supply more protection services than live corals; and seagrasses, in our simulations, can even compensate for the long-term degradation of the barrier reef. Results of this study demonstrate the importance of taking integrated and place-based approaches when quantifying and managing for the coastal protection services supplied by ecosystems.

  17. The Power of Three: Coral Reefs, Seagrasses and Mangroves Protect Coastal Regions and Increase Their Resilience.

    Science.gov (United States)

    Guannel, Greg; Arkema, Katie; Ruggiero, Peter; Verutes, Gregory

    2016-01-01

    Natural habitats have the ability to protect coastal communities against the impacts of waves and storms, yet it is unclear how different habitats complement each other to reduce those impacts. Here, we investigate the individual and combined coastal protection services supplied by live corals on reefs, seagrass meadows, and mangrove forests during both non-storm and storm conditions, and under present and future sea-level conditions. Using idealized profiles of fringing and barrier reefs, we quantify the services supplied by these habitats using various metrics of inundation and erosion. We find that, together, live corals, seagrasses, and mangroves supply more protection services than any individual habitat or any combination of two habitats. Specifically, we find that, while mangroves are the most effective at protecting the coast under non-storm and storm conditions, live corals and seagrasses also moderate the impact of waves and storms, thereby further reducing the vulnerability of coastal regions. Also, in addition to structural differences, the amount of service supplied by habitats in our analysis is highly dependent on the geomorphic setting, habitat location and forcing conditions: live corals in the fringing reef profile supply more protection services than seagrasses; seagrasses in the barrier reef profile supply more protection services than live corals; and seagrasses, in our simulations, can even compensate for the long-term degradation of the barrier reef. Results of this study demonstrate the importance of taking integrated and place-based approaches when quantifying and managing for the coastal protection services supplied by ecosystems. PMID:27409584

  18. The Power of Three: Coral Reefs, Seagrasses and Mangroves Protect Coastal Regions and Increase Their Resilience

    Science.gov (United States)

    Guannel, Greg; Arkema, Katie; Ruggiero, Peter; Verutes, Gregory

    2016-01-01

    Natural habitats have the ability to protect coastal communities against the impacts of waves and storms, yet it is unclear how different habitats complement each other to reduce those impacts. Here, we investigate the individual and combined coastal protection services supplied by live corals on reefs, seagrass meadows, and mangrove forests during both non-storm and storm conditions, and under present and future sea-level conditions. Using idealized profiles of fringing and barrier reefs, we quantify the services supplied by these habitats using various metrics of inundation and erosion. We find that, together, live corals, seagrasses, and mangroves supply more protection services than any individual habitat or any combination of two habitats. Specifically, we find that, while mangroves are the most effective at protecting the coast under non-storm and storm conditions, live corals and seagrasses also moderate the impact of waves and storms, thereby further reducing the vulnerability of coastal regions. Also, in addition to structural differences, the amount of service supplied by habitats in our analysis is highly dependent on the geomorphic setting, habitat location and forcing conditions: live corals in the fringing reef profile supply more protection services than seagrasses; seagrasses in the barrier reef profile supply more protection services than live corals; and seagrasses, in our simulations, can even compensate for the long-term degradation of the barrier reef. Results of this study demonstrate the importance of taking integrated and place-based approaches when quantifying and managing for the coastal protection services supplied by ecosystems. PMID:27409584

  19. Increasing the energy conservation awareness using the influential power of a lottery system

    Science.gov (United States)

    Nayak, Amruta Vijay

    This thesis presents an influence maximization-driven approach to promoting energy conservation awareness, with the objective to generate a competitive environment for energy consumption supervision. As consumers are typically reluctant to invest their time and effort in the activities beyond their business, an incentive-based distribution strategy is proposed to encourage consumers to actively take part in energy conservation. The key idea of the thesis lies in leveraging the consumer instincts as a driving factor for spreading positive social influence, via a smart lottery program. In the proposed framework, saving energy automatically increases the consumers' chances of winning the lottery, thereby motivating them to save more, while the smart winner selection will maximize the word-of-mouth effect of the program. The thesis collects and organizes a large body of literature in support of the claim that the spread of awareness in a social network can play a key role in the emergence of energy conscious behavior. It also reports on the findings of a survey conducted to determine the present day consumer perspective toward energy conservation and the level of influence required to motivate them to conserve more energy. Finally, a mathematical model for smart lottery winner selection is presented, and insightful observations are made concerning the properties of optimal solutions to tractable, small problem instances.

  20. The Increasing of Air and Biogas Mixer Instrument for Generating Friendly Environmental Electricity Power

    Science.gov (United States)

    Ketut Lasmi, Ni; Singarimbun, Alamta; Srigutomo, Wahyu

    2016-08-01

    The abolition of BBM Subsidize by the government causes increasing of its price, so a solution is necessary to find an alternative energy that is relatively cheap, environmentally friendly and affordable by all layers of society. Biogas is one of the renewable energy resources that are potential to be developed, especially in a farming area, because up until now, animal's excrement is not yet optimally used and it causes problem to environment. In response to this, one innovation to do is to make an instrument which is able to mix biogas and air by venture pipe using the basic theory of fluid mechanic, in order to raise the use of biogas as electricity source. Biogas conversion is done by changing fuel in benzene 5 kilowatt genset to biogas so it becomes a biogas genset. The biogas pressure is controlled when it enters the mixer instrument so that the velocity of biogas when it enters and it comes out the mixer is the same, and it will gain different pressure between biogas and air. By the pressure difference between biogas in the mixer instrument, biogas goes to the burning room so that the conversion of mechanical energy biogas to electricity will happen, and it will be applied as light and society's needs.

  1. Principal Component Analysis - A Powerful Tool in Computing Marketing Information

    Directory of Open Access Journals (Sweden)

    Constantin C.

    2014-12-01

    Full Text Available This paper is about an instrumental research regarding a powerful multivariate data analysis method which can be used by the researchers in order to obtain valuable information for decision makers that need to solve the marketing problem a company face with. The literature stresses the need to avoid the multicollinearity phenomenon in multivariate analysis and the features of Principal Component Analysis (PCA in reducing the number of variables that could be correlated with each other to a small number of principal components that are uncorrelated. In this respect, the paper presents step-by-step the process of applying the PCA in marketing research when we use a large number of variables that naturally are collinear.

  2. Analysis in environmental radioactivity around Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Woo; Han, Man Jung; Cho, Seong Won; Cho, Hong Jun; Oh, Hyeon Kyun; Lee, Jeong Min; Chang, Jae Sook [KORTIC, Taejon (Korea, Republic of)

    2003-12-15

    Twelve kinds of environmental samples such as soil, seawater, underground water, etc. around Nuclear Power Plants(NPPs) were collected. Tritium chemical analysis was tried for the samples of rain water, pine-needle, air, seawater, underground water, chinese cabbage, again of rice and milk sampled around NPPs, and surface seawater and rain water sampled over the country. Strontium in the soil that were sampled at 60 point of district in Korea were analyzed. Tritium were analyzed in 21 samples of surface seawater around the Korea peninsular that were supplied form KFRDI(National Fisheries Research and Development Institute). Sampling and chemical analysis environmental samples around Kori, Woolsung, Youngkwang, Wooljin NPPs and Taeduk science town for tritium and strontium analysis was managed according to plans. Succeed to KINS after all samples were tried.

  3. Thermodynamic analysis of the advanced zero emission power plant

    Directory of Open Access Journals (Sweden)

    Kotowicz Janusz

    2016-03-01

    Full Text Available The paper presents the structure and parameters of advanced zero emission power plant (AZEP. This concept is based on the replacement of the combustion chamber in a gas turbine by the membrane reactor. The reactor has three basic functions: (i oxygen separation from the air through the membrane, (ii combustion of the fuel, and (iii heat transfer to heat the oxygen-depleted air. In the discussed unit hot depleted air is expanded in a turbine and further feeds a bottoming steam cycle (BSC through the main heat recovery steam generator (HRSG. Flue gas leaving the membrane reactor feeds the second HRSG. The flue gas consist mainly of CO2 and water vapor, thus, CO2 separation involves only the flue gas drying. Results of the thermodynamic analysis of described power plant are presented.

  4. Thermodynamic analysis of the advanced zero emission power plant

    Science.gov (United States)

    Kotowicz, Janusz; Job, Marcin

    2016-03-01

    The paper presents the structure and parameters of advanced zero emission power plant (AZEP). This concept is based on the replacement of the combustion chamber in a gas turbine by the membrane reactor. The reactor has three basic functions: (i) oxygen separation from the air through the membrane, (ii) combustion of the fuel, and (iii) heat transfer to heat the oxygen-depleted air. In the discussed unit hot depleted air is expanded in a turbine and further feeds a bottoming steam cycle (BSC) through the main heat recovery steam generator (HRSG). Flue gas leaving the membrane reactor feeds the second HRSG. The flue gas consist mainly of CO2 and water vapor, thus, CO2 separation involves only the flue gas drying. Results of the thermodynamic analysis of described power plant are presented.

  5. An Analysis of Harmonic Mitigation to Reduce Transmission Losses in Power System

    Directory of Open Access Journals (Sweden)

    Apurva Ganguli

    2014-01-01

    Full Text Available The application of power electronics devices such as arc furnaces, adjustable speed drives, computer power supplies etc. are some typical non-linear characteristic loads used in most of the industrial applications are increasing rapidly due to improved technical devices , digital controller and flexibility in controlling the power usage. The use of the above power electronic devices in power distribution system gives rise to harmonics and reactive power disturbances. The harmonics and reactive power cause a number of undesirable effects like heating, equipment damage and electromagnetic interference effects in the power system. There are many conventional method to mitigate the harmonics but they are giving not satisfactory result To achieve a satisfactory harmonic content, the number of pulses being increased up to 48-pulses, in the present work the voltage source inverter (VSI based on 48-pulses is used; this is constituted by four three-level converters linked by four phase-shifting transformers. This device exhibits a low harmonic rate on the AC side. The 48-pulses StatCom can be utilized in high power applications without AC filters. The StatCom is used in voltage regulation mode and it can be used as compensator (Var mode. Simulation results are plotted to show the appropriateness of the proposition. A comparative study on the performances of voltage and harmonic control strategies is being used in the present work and it has been observed from simulation result that these VSI have some disadvantages such as high cost, slow response, and large size etc., during real-time implementation But by using VSI one can avail the advantages like reconfigurable hardware designs, low cost developments, selection of bit width according to applications etc. A techno-economic analysis have also being carried, that shows approximately Rs.2 lack yearly saving with pay back of 6 years approx

  6. Thermoeconomic Analysis of Advanced Solar-Fossil Combined Power Plants

    Directory of Open Access Journals (Sweden)

    Yassine Allani

    2000-12-01

    Full Text Available

    Hybrid solar thermal power plants (with parabolic trough type of solar collectors featuring gas burners and Rankine steam cycles have been successfully demonstrated by California's Solar Electric Generating System (SEGS. This system has been proven to be one of the most efficient and economical schemes to convert solar energy into electricity. Recent technological progress opens interesting prospects for advanced cycle concepts: a the ISCCS (Integrated Solar Combined Cycle System that integrates the parabolic trough into a fossil fired combined cycle, which allows a larger exergy potential of the fuel to be converted. b the HSTS (Hybrid Solar Tower System which uses high concentration optics (via a power tower generator and high temperature air receivers to drive the combined cycle power plant. In the latter case, solar energy is used at a higher exergy level as a heat source of the topping cycle. This paper presents the results of a thermoeconomic investigation of an ISCCS envisaged in Tunisia. The study is realized in two phases. In the first phase, a mixed approach, based on pinch technology principles coupled with a mathematical optimization algorithm, is used to minimize the heat transfer exergy losses in the steam generators, respecting the off design operating conditions of the steam turbine (cone law. In the second phase, an economic analysis based on the Levelized Electricity Cost (LEC approach was carried out for the configurations, which provided the best concepts during the first phase. A comparison of ISCCS with pure fossil fueled plants (CC+GT is reported for the same electrical power load. A sensitivity analysis based on the relative size of the solar field is presented.

    •  This paper was presented at the ECOS'00 Conference in Enschede, July 5-7, 2000

  7. Effects of increasing age, dosage, and duration of PTH treatment on BMD increase--a meta-analysis

    DEFF Research Database (Denmark)

    Schwarz, Peter; Jorgensen, Niklas Rye; Mosekilde, Leif;

    2012-01-01

    We studied the effects of increasing age, dosage, and duration of parathyroid hormone (PTH) treatment on changes in bone mineral density (BMD). Randomized placebo controlled trials on PTH treatment in men or women were retrieved from PubMed (1951 to present), Web of Science (1945 to present......), or Embase (1974 to present). The search date was November 16, 2010. All studies comparing PTH treatment to either placebo or antiresorptive drugs-for example, bisphosphonates or hormone replacement therapy-were included. A total of 214 studies were identified in the initial search, and 15 of these trials...... were included. By metaregression analysis, we found that the increase in spine BMD (Z-score) after PTH treatment was blunted by increasing age (R (2) = 0.27; 2p = 0.01, slope -0.023 Z-scores per year, 11 studies). By increasing PTH dosage (μg/d), spine BMD increased significantly (2p = 0...

  8. WANO-activities in supporting the operators of nuclear power plants in Bulgaria to increase the safety of the Kozloduy nuclear power plant

    International Nuclear Information System (INIS)

    On October 10, 1991 the Bulgarian government and the WANO Paris Center signed three contracts for special supportive measures. These contracts are the first important steps toward implementing a programme which was proposed with an aim toward improving the safety of older-generation Soviet nuclear reactors (WWER-230). The programme consists of a twin programme, i.e. a partnership between the French nuclear power plant of Bugey and Kozloduj, a housekeeping programme which aims toward restoring the condition of Kozloduj to the state it was in shortly after being licenced and a programme implementation unit which plans to provide assistance to the Bulgarian Community of Energy by sending in experts in the area of project and contract management. The WANO is in charge of the coordination of the project as a whole. These activities are being carried out in addition to the 'normal activities' which are carried out by WANO. Thus on the part of WANO, a significant increase in the amount of qualified personnel is required. Without a doubt, such assistance in Eastern Europe places a considerable burden on the operators of nuclear power plants in Western Europe. Dependent upon the problems which still remain to be solved, additional support programmes might be required. Yet without a doubt it is in the interest of all of us that additional serious nuclear power plant accidents be avoided world-wide. (orig./HSCH)

  9. Analysis of the Power oscillations event in Laguna Verde Nuclear Power Plant. Preliminary Report

    International Nuclear Information System (INIS)

    The event occurred at Unit 1 of Laguna Verde Nuclear Power Plant in January 24, 1995, is analyzed using the Ramona 3 B code. During this event, Unit 1 suffered power oscillation when operating previous to the transfer at high speed recirculating pumps. This phenomenon was timely detected by reactor operator who put the reactor in shut-down doing a manual Scram. Oscillations reached a maximum extent of 10.5% of nominal power from peak to peak with a frequency of 0.5 Hz. Preliminary evaluations show that the event did not endangered the fuel integrity. The results of simulating the reactor core with Ramona 3 B code show that this code is capable to moderate reactor oscillations. Nevertheless it will be necessary to perform a more detailed simulation of the event in order to prove that the code can predict the beginning of oscillations. It will be need an additional analysis which permit the identification of factors that influence the reactor stability in order to express recommendations and in this way avoid the recurrence of this kind of events. (Author)

  10. Increasing the power to detect causal associations by combining genotypic and expression data in segregating populations.

    Directory of Open Access Journals (Sweden)

    Jun Zhu

    2007-04-01

    Full Text Available To dissect common human diseases such as obesity and diabetes, a systematic approach is needed to study how genes interact with one another, and with genetic and environmental factors, to determine clinical end points or disease phenotypes. Bayesian networks provide a convenient framework for extracting relationships from noisy data and are frequently applied to large-scale data to derive causal relationships among variables of interest. Given the complexity of molecular networks underlying common human disease traits, and the fact that biological networks can change depending on environmental conditions and genetic factors, large datasets, generally involving multiple perturbations (experiments, are required to reconstruct and reliably extract information from these networks. With limited resources, the balance of coverage of multiple perturbations and multiple subjects in a single perturbation needs to be considered in the experimental design. Increasing the number of experiments, or the number of subjects in an experiment, is an expensive and time-consuming way to improve network reconstruction. Integrating multiple types of data from existing subjects might be more efficient. For example, it has recently been demonstrated that combining genotypic and gene expression data in a segregating population leads to improved network reconstruction, which in turn may lead to better predictions of the effects of experimental perturbations on any given gene. Here we simulate data based on networks reconstructed from biological data collected in a segregating mouse population and quantify the improvement in network reconstruction achieved using genotypic and gene expression data, compared with reconstruction using gene expression data alone. We demonstrate that networks reconstructed using the combined genotypic and gene expression data achieve a level of reconstruction accuracy that exceeds networks reconstructed from expression data alone, and that

  11. Sandia-Power Surety Task Force Hawaii foam analysis.

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, Annie

    2010-11-01

    The Office of Secretary of Defense (OSD) Power Surety Task Force was officially created in early 2008, after nearly two years of work in demand reduction and renewable energy technologies to support the Warfighter in Theater. The OSD Power Surety Task Force is tasked with identifying efficient energy solutions that support mission requirements. Spray foam insulation demonstrations were recently expanded beyond field structures to include military housing at Ft. Belvoir. Initial results to using the foam in both applications are favorable. This project will address the remaining key questions: (1) Can this technology help to reduce utility costs for the Installation Commander? (2) Is the foam cost effective? (3) What application differences in housing affect those key metrics? The critical need for energy solutions in Hawaii and the existing relationships among Sandia, the Department of Defense (DOD), the Department of Energy (DOE), and Forest City, make this location a logical choice for a foam demonstration. This project includes application and analysis of foam to a residential duplex at the Waikulu military community on Oahu, Hawaii, as well as reference to spray foam applied to a PACOM facility and additional foamed units on Maui, conducted during this project phase. This report concludes the analysis and describes the utilization of foam insulation at military housing in Hawaii and the subsequent data gathering and analysis.

  12. Availability Analysis of Gas Turbines Used in Power Plants

    Directory of Open Access Journals (Sweden)

    Gilberto Francisco Martha de Souza

    2009-03-01

    Full Text Available The availability of a complex system, such as a gas turbine, is strongly associated with its parts reliability and maintenance policy. That policy not only has influence on the parts’ repair time but also on the parts’ reliability affecting the system degradation and availability. This study presents a method for reliability and availability evaluation of gas turbines installed in an electric power station. The method is based on system reliability concepts, such as functional tree development, application of failure mode and effects analysis to identify critical components for improvement of system reliability, and reliability and maintainability evaluation based on a historical failure database. The method also proposes the application of Reliability Centered Maintenance concepts to improve complex system maintenance policies aimed at the reduction of unexpected failure occurrences in critical components. The method is applied to the analysis of two F series gas turbines, each with an output of 150 MW, installed in a 500 MW combined cycle power plant. The reliability and availability of the turbines are simulated based on a five-year failure database. The availability analysis shows different results for each turbine, one presenting 99% and the other 96% availability, indicating differences in their systems installation and operation.

  13. Integrated information system for analysis of nuclear power plants

    International Nuclear Information System (INIS)

    Performing complicated engineering analyses of a nuclear power plant requires storage and manipulation of a large amount of information, both data and knowledge. This information is characterized by its multidisciplinary nature, complexity, and diversity. The problems caused by inefficient and lengthy manual operations involving the data flow management within the frame-work of the safety-related analysis of a power plant can be solved by applying the computer aided engineering principles. These principles are the basis of the design of an integrated information storage system (IRIS). The basic idea is to create a computerized environment, which includes both database and functional capabilities. Consideration and analysis of the data types and required data manipulation capabilities as well as operational requirements, resulted in the choice of an object-oriented data-base management system (OODBMS) as a development platform for solving the software engineering problems. Several advantages of OODBMSs over conventional relations database systems were found of crucial importance, especially providing the necessary flexibility for different data types and extensibility potential. A detailed design of a data model is produced for the plant technical data and for the storage of analysis results. The overall system architecture was designed to assure the feasibility of integrating database capabilities with procedures and functions written in conventional algorithmic programming languages

  14. Exergy Analysis of Operating Lignite Fired Thermal Power Plant

    Directory of Open Access Journals (Sweden)

    K. Murugesan

    2009-01-01

    Full Text Available The energy assessment must be made through the energy quantity as well as the quality. But the usual energy analysisevaluates the energy generally on its quantity only. However, the exergy analysis assesses the energy on quantity as well asthe quality. The aim of the exergy analysis is to identify the magnitudes and the locations of real energy losses, in order toimprove the existing systems, processes or components. The present paper deals with an exergy analysis performed on anoperating 50MWe unit of lignite fired steam power plant at Thermal Power Station-I, Neyveli Lignite Corporation Limited,Neyveli, Tamil Nadu, India. The exergy losses occurred in the various subsystems of the plant and their components havebeen calculated using the mass, energy and exergy balance equations. The distribution of the exergy losses in several plantcomponents during the real time plant running conditions has been assessed to locate the process irreversibility. The Firstlaw efficiency (energy efficiency and the Second law efficiency (exergy efficiency of the plant have also been calculated.The comparison between the energy losses and the exergy losses of the individual components of the plant shows that themaximum energy losses of 39% occur in the condenser, whereas the maximum exergy losses of 42.73% occur in the combustor.The real losses of energy which has a scope for the improvement are given as maximum exergy losses that occurredin the combustor.

  15. Exergy costing analysis and performance evaluation of selected gas turbine power plants

    Directory of Open Access Journals (Sweden)

    S.O. Oyedepo

    2015-12-01

    Full Text Available In this study, exergy costing analysis and performance evaluation of selected gas turbine power plants in Nigeria are carried out. The results of exergy analysis confirmed that the combustion chamber is the most exergy destructive component compared to other cycle components. The exergetic efficiency of the plants was found to depend significantly on a change in gas turbine inlet temperature (GTIT. The increase in exergetic efficiency with the increase in turbine inlet temperature is limited by turbine material temperature limit. This was observed from the plant efficiency defect curve. As the turbine inlet temperature increases, the plant efficiency defect decreases to minimum value at certain GTIT (1,200 K, after which it increases with GTIT. This shows degradation in performance of gas turbine plant at high turbine inlet temperature. Exergy costing analysis shows that the combustion chamber has the greatest cost of exergy destruction compared to other components. Increasing the GTIT, both the exergy destruction and the cost of exergy destruction of this component are found to decrease. Also, from exergy costing analysis, the unit cost of electricity produced in the power plants varies from cents 1.99/kWh (N3.16/kWh to cents 5.65/kWh (N8.98/kWh.

  16. The cost of muscle power production: muscle oxygen consumption per unit work increases at low temperatures in Xenopus laevis.

    Science.gov (United States)

    Seebacher, Frank; Tallis, Jason A; James, Rob S

    2014-06-01

    Metabolic energy (ATP) supply to muscle is essential to support activity and behaviour. It is expected, therefore, that there is strong selection to maximise muscle power output for a given rate of ATP use. However, the viscosity and stiffness of muscle increases with a decrease in temperature, which means that more ATP may be required to achieve a given work output. Here, we tested the hypothesis that ATP use increases at lower temperatures for a given power output in Xenopus laevis. To account for temperature variation at different time scales, we considered the interaction between acclimation for 4 weeks (to 15 or 25°C) and acute exposure to these temperatures. Cold-acclimated frogs had greater sprint speed at 15°C than warm-acclimated animals. However, acclimation temperature did not affect isolated gastrocnemius muscle biomechanics. Isolated muscle produced greater tetanus force, and faster isometric force generation and relaxation, and generated more work loop power at 25°C than at 15°C acute test temperature. Oxygen consumption of isolated muscle at rest did not change with test temperature, but oxygen consumption while muscle was performing work was significantly higher at 15°C than at 25°C, regardless of acclimation conditions. Muscle therefore consumed significantly more oxygen at 15°C for a given work output than at 25°C, and plastic responses did not modify this thermodynamic effect. The metabolic cost of muscle performance and activity therefore increased with a decrease in temperature. To maintain activity across a range of temperature, animals must increase ATP production or face an allocation trade-off at lower temperatures. Our data demonstrate the potential energetic benefits of warming up muscle before activity, which is seen in diverse groups of animals such as bees, which warm flight muscle before take-off, and humans performing warm ups before exercise. PMID:24625645

  17. Windfarm Generation Assessment for ReliabilityAnalysis of Power Systems

    DEFF Research Database (Denmark)

    Negra, Nicola Barberis; Holmstrøm, Ole; Bak-Jensen, Birgitte;

    2007-01-01

    Due to the fast development of wind generation in the past ten years, increasing interest has been paid to techniques for assessing different aspects of power systems with a large amount of installed wind generation. One of these aspects concerns power system reliability. Windfarm modelling plays...... a significant role in this assessment and different models have been created for it, but a representation which includes all of them has not been developed yet. This paper deals with this issue. First, a list of nine influencing Factors is presented and discussed. Secondly, these Factors are included...... in a reliability model and the generation of a windfarm is evaluated by means of sequential Monte Carlo simulation. Results are used to analyse how each mentioned Factor influences the assessment, and why and when they should be included in the model....

  18. Windfarm Generation Assessment for Reliability Analysis of Power Systems

    DEFF Research Database (Denmark)

    Barberis Negra, Nicola; Bak-Jensen, Birgitte; Holmstrøm, O.;

    2007-01-01

    Due to the fast development of wind generation in the past ten years, increasing interest has been paid to techniques for assessing different aspects of power systems with a large amount of installed wind generation. One of these aspects concerns power system reliability. Windfarm modelling plays...... a significant role in this assessment and different models have been created for it, but a representation which includes all of them has not been developed yet. This paper deals with this issue. First, a list of nine influencing Factors is presented and discussed. Secondly, these Factors are included...... in a reliability model and the generation of a windfarm is evaluated by means of sequential Monte Carlo simulation. Results are used to analyse how each mentioned Factor influences the assessment, and why and when they should be included in the model....

  19. Optimum fiber tapers for increasing the power in the blue-edge of a supercontinuum - group-acceleration matching

    DEFF Research Database (Denmark)

    Sørensen, Simon Toft; Judge, Alexander; Thomsen, Carsten L.;

    2011-01-01

    We demonstrate how the gradient of the tapering in a tapered fiber can significantly affect the trapping and blueshift of dispersive waves (DWs) by a soliton. By modeling the propagation of a fundamental 10 fs soliton through tapered fibers with varying gradients, it is shown that the soliton traps...... generated in a tapered fiber and explain observations of a lack of power in the blue edge....... and blueshifts an increased fraction of the energy in its DW when the gradient is decreased. This is quantified by the group-acceleration mismatch between the soliton and DW at the entrance of the taper. These findings have direct implications for the achievable power in the blue edge of a supercontinuum...

  20. Procedure for the analysis of errors of commission during non-power modes of nuclear power plant operation

    Energy Technology Data Exchange (ETDEWEB)

    Julius, J.A.; Jorgenson, E.J.; Parry, G.W.; Mosleh, A.M

    1996-08-01

    The continued, historical occurrence of human interactions which place nuclear power plants in a condition of potentially heightened risk is of increasing interest to regulators, utility management, and industry observers alike. These Errors of Commission (EOCs), as they are often called, lead to a variety of questions such as: 'Can the event lead to a potentially dangerous condition such as core damage? By what failure mechanisms? With what frequency? What defences does the plant have to mitigate the event? Are these actions in the Probabilistic Risk Assessment (PRA) model of the plant?'. EOCs are often excluded from the bounds of a typical PRA model, yet they have the potential for being significant contributors to risk. This paper is the second of two describing procedures for the analysis of the potential for significant errors of commission. The first paper addressed operations at power while this paper describes the procedure for non-power operations. Each procedure describes a method for identifying the opportunities for error, identifying failures modes of functions, systems, or components that could arise from such errors (referred to in this paper as error expressions), and the identification of the most significant of these EOCs based on consideration of consequences, recovery potential, and likelihood.

  1. Exergy analysis of a combined heat and power plant with integrated lignocellulosic ethanol production

    DEFF Research Database (Denmark)

    Lythcke-Jørgensen, Christoffer Ernst; Haglind, Fredrik; Clausen, Lasse Røngaard

    2013-01-01

    Integrating second generation bioethanol production in combined heat and power units is expected to increase system energy efficiencies while producing sustainable fuel for the transportation sector at a competitive price. By applying exergy analysis, this study assessed the efficiency of an inte......Integrating second generation bioethanol production in combined heat and power units is expected to increase system energy efficiencies while producing sustainable fuel for the transportation sector at a competitive price. By applying exergy analysis, this study assessed the efficiency...... produces ethanol, solid biofuel, molasses, and is able to produce district heating hot water. Considering all products equally valuable, the exergy efficiency of the ethanol facility was found to be 0.790 during integrated operation with zero district heating production, and 0.852 during integrated...

  2. Development of RCM analysis software for Korean nuclear power plants

    International Nuclear Information System (INIS)

    A software called KEPCO RCM workstation (KRCM) has been developed to optimize the maintenance strategies of Korea nuclear power plants. The program modules of the KRCM were designed in a manner that combines EPRI methodologies and KEPRI analysis technique. The KRCM is being applied to the three pilot systems, chemical and volume control system, main steam system, and compressed air system of Yonggwang Units 1 and 2. In addition, the KRCM can be utilized as a tool to meet a part of the requirements of maintenance rule (MR) imposed by U.S. NRC

  3. Reliability analysis of selected systems of nuclear power unit

    International Nuclear Information System (INIS)

    The reliability analysis is discussed of selected facilities of the 440 MW nuclear power unit using the failure tree method. The first part of the paper deals with the primary circuit and analyses the possibility of a dangerous failure arising of the system of accident alarm of the first order of the WWER 440 nuclear reactor during the event of the ''outage of four and more circulating pumps''. The second part of the paper is related to the secondary circuit. It studies the causes and probabilities of the failures of functions of condensate flow pumping and control with regard to the event the ''turbogenerator failure''. (author)

  4. Power Consumption Analysis of Operating Systems for Wireless Sensor Networks

    OpenAIRE

    Rafael Lajara; José Pelegrí-Sebastiá; Perez Solano, Juan J.

    2010-01-01

    In this paper four wireless sensor network operating systems are compared in terms of power consumption. The analysis takes into account the most common operating systems-TinyOS v1.0, TinyOS v2.0, Mantis and Contiki-running on Tmote Sky and MICAz devices. With the objective of ensuring a fair evaluation, a benchmark composed of four applications has been developed, covering the most typical tasks that a Wireless Sensor Network performs. The results show the instant and average current consump...

  5. Development of RCM analysis software for Korean nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Ho; Choi, Kwang Hee; Jeong, Hyeong Jong [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A software called KEPCO RCM workstation (KRCM) has been developed to optimize the maintenance strategies of Korean nuclear power plants. The program modules of the KRCM were designed in a manner that combines EPRI methodologies and KEPRI analysis technique. The KRCM is being applied to the three pilot system, chemical and volume control system, main steam system, and compressed air system of Yonggwang Units 1 and 2. In addition, the KRCM can be utilized as a tool to meet a part of the requirements of maintenance rule (MR) imposed by U.S. NRC. 3 refs., 4 figs. (Author)

  6. Analysis of recent projections of electric power demand

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, Jr, D V

    1993-08-01

    This report reviews the changes and potential changes in the outlook for electric power demand since the publication of Review and Analysis of Electricity Supply Market Projections (B. Swezey, SERI/MR-360-3322, National Renewable Energy Laboratory). Forecasts of the following organizations were reviewed: DOE/Energy Information Administration, DOE/Policy Office, DRI/McGraw-Hill, North American Electric Reliability Council, and Gas Research Institute. Supply uncertainty was briefly reviewed to place the uncertainties of the demand outlook in perspective. Also discussed were opportunities for modular technologies, such as renewable energy technologies, to fill a potential gap in energy demand and supply.

  7. Beam instability in 980-nm power lasers: Experiment and analysis

    Science.gov (United States)

    Guthrie, James; Tan, G. L.; Ohkubo, M.; Fukushima, T.; Ikegami, Y.; Ijichi, T.; Irikawa, M.; Mand, R. S.; Xu, J. M.

    1994-12-01

    A theoretical analysis of beam instability (steering), commonly observed in high power ridge waveguide laser diodes is presented. A physical model of multiple interfering lateral modes is proposed and implemented in a two-dimensional self-consistent numerical code. It is shown that the dynamic evolution of the effective waveguide and the coherent lasing of emergent multiple lateral modes of the waveguide under high injection could lead to beam steering and knees in the fiber coupled L-I characteristics. The theory of simultaneous lasing and interaction between several lateral modes is found to be consistent with the observed back-plane radiation image.

  8. Are Public-Private Partnerships an Appropriate Governance Structure for Power Plants? A Transaction Cost Analysis

    Science.gov (United States)

    Ho, S. Ping; Hsu, Yaowen

    2015-04-01

    In order to meet the requirements of the rapid economic growth, many countries demand an increasing number of power plants to meet the increasing electricity usage. Since high capital requirements of power plants present a big issue for these countries, PPPs have been considered an alternative to provide power plant infrastructure. In particular, in emerging or developing countries, PPPs may be the fastest way to provide the infrastructure needed. However, while PPPs are a promising alternative to providing various types of infrastructure, many failed power plant PPP projects have made it evident that PPPs, under certain situations, can be very costly or even a wrong choice of governance structure. While the higher efficiency due to better pooling of resources is greatly emphasized in Public-Private Partnerships (PPPs), the embedded transaction inefficiencies are often understated or even ignored. Through the lens of Transaction Cost Economics (TCE), this paper aims to answer why and when PPPs may become a costly governance structure for power plants. Specifically, we develop a TCE-based theory of PPPs as a governance structure. This theory suggests that three major opportunism problems embedded in infrastructure PPPs are possible to cause substantial transaction costs and render PPPs a costly governance structure. The three main opportunism problems are principal-principal problem, firm's hold-up problem, and government-led hold-up problem. Moreover, project and institutional characteristics that may lead to opportunism problems are identified. Based on these characteristics, an opportunism-focused transaction cost analysis (OTCA) for PPPs as a governance structure is proposed to supplement the current practice of PPP feasibility analysis. As a part of theory development, a case study of PPP power plants is performed to evaluate the proposed theory and to illustrate how the proposed OTCA can be applied in practice. Policies and administration strategies for power

  9. Power analysis of principal components regression in genetic association studies

    Institute of Scientific and Technical Information of China (English)

    Yan-feng SHEN; Jun ZHU

    2009-01-01

    Association analysis provides an opportunity to find genetic variants underlying complex traits. A principal com-ponents regression (PCR)-based approach was shown to outperform some competing approaches. However, a limitation of this method is that the principal components (PCs) selected from single nucleotide polymorphisms (SNPs) may be unrelated to the phenotype. In this article, we investigate the theoretical properties of such a method in more detail. We first derive the exact power function of the test based on PCR, and hence clarify the relationship between the test power and the degrees of freedom (DF). Next, we extend the PCR test to a general weighted PCs test, which provides a unified framework for understanding the properties of some related statistics. We then compare the performance of these tests. We also introduce several data-driven adaptive alterna-tives to overcome difficulties in the PCR approach. Finally, we illustrate our results using simulations based on real genotype data. Simulation study shows the risk of using the unsupervised rule to determine the number of PCs, and demonstrates that there is no single uniformly powerful method for detecting genetic variants.

  10. Power Analysis in Survey Research: Importance and Use for Health Educators

    Science.gov (United States)

    Price, James H.; Dake, Joseph A.; Murnan, Judy; Dimmig, Jaime; Akpanudo, Sutoidem

    2005-01-01

    This article has three purposes: to explain the two different uses of power analysis that can be used in health education research; to examine the extent to which power analysis is being used in published health education research; and to explain the implications of not using power analysis in research studies. Articles in seven leading health…

  11. 78 FR 4477 - Review of Safety Analysis Reports for Nuclear Power Plants, Introduction

    Science.gov (United States)

    2013-01-22

    ... COMMISSION Review of Safety Analysis Reports for Nuclear Power Plants, Introduction AGENCY: Nuclear... subsection to NUREG-0800, ``Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power..., Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants:...

  12. Fault Analysis of ITER Coil Power Supply System

    International Nuclear Information System (INIS)

    The ITER magnet coils are all designed using superconductors with high current carrying capability. The Toroidal Field (TF) coils operate in a steadystate mode with a current of 68 kA and discharge the stored energy in case of quench with using 9 interleaved Fast Discharge Units (FDUs). The Central Solenoid (CS) coils and Poloidal Field (PF) coils operate in a pulse mode with currents of up to 45 kA and require fast variation of currents inducing more than 10 kV during normal operation on the coil terminals using Switching Network (SN) systems (CSs, PF1 and 6) and Booster and VS converters (PF2 to 5), which are series connected to Main converters. SN and FDU systems comprise high current DC circuit breakers and resistors for generating high voltage (SN) and to dissipate magnetic energy (FDUs). High transient voltages can arise due to the switching operation of SN and FD and the characteristics of resistors and stray components of DC distribution systems. Also, faults in power supply control such as shorts or grounding faults can produce higher voltages between terminals and between terminal and ground. Therefore, the design of the coil insulation, coil terminal regions, feeders, feed throughs, pipe breaks and instrumentation must take account of these high voltages during normal and abnormal conditions. Voltage insulation level can be defined and it is necessary to test the coils at higher voltages, to be sure of reliable performance during the lifetime of operation. This paper describes the fault analysis of the TF, CS and PF coil power supply systems, taking account of the stray parameter of the power supply and switching systems and inductively coupled superconducting coil models. Resistor grounding systems are included in the simulation model and all fault conditions such as converter hardware and software faults, switching system hardware and software faults, DC short circuits and single grounding faults are simulated. The occurrence of two successive faults

  13. GNSS Spoofing Detection Based on Signal Power Measurements: Statistical Analysis

    Directory of Open Access Journals (Sweden)

    V. Dehghanian

    2012-01-01

    Full Text Available A threat to GNSS receivers is posed by a spoofing transmitter that emulates authentic signals but with randomized code phase and Doppler values over a small range. Such spoofing signals can result in large navigational solution errors that are passed onto the unsuspecting user with potentially dire consequences. An effective spoofing detection technique is developed in this paper, based on signal power measurements and that can be readily applied to present consumer grade GNSS receivers with minimal firmware changes. An extensive statistical analysis is carried out based on formulating a multihypothesis detection problem. Expressions are developed to devise a set of thresholds required for signal detection and identification. The detection processing methods developed are further manipulated to exploit incidental antenna motion arising from user interaction with a GNSS handheld receiver to further enhance the detection performance of the proposed algorithm. The statistical analysis supports the effectiveness of the proposed spoofing detection technique under various multipath conditions.

  14. TREEFINDER: a powerful graphical analysis environment for molecular phylogenetics

    Directory of Open Access Journals (Sweden)

    von Haeseler Arndt

    2004-06-01

    Full Text Available Abstract Background Most analysis programs for inferring molecular phylogenies are difficult to use, in particular for researchers with little programming experience. Results TREEFINDER is an easy-to-use integrative platform-independent analysis environment for molecular phylogenetics. In this paper the main features of TREEFINDER (version of April 2004 are described. TREEFINDER is written in ANSI C and Java and implements powerful statistical approaches for inferring gene tree and related analyzes. In addition, it provides a user-friendly graphical interface and a phylogenetic programming language. Conclusions TREEFINDER is a versatile framework for analyzing phylogenetic data across different platforms that is suited both for exploratory as well as advanced studies.

  15. Aerospace Power Systems Design and Analysis (APSDA) Tool

    Science.gov (United States)

    Truong, Long V.

    1998-01-01

    The conceptual design of space and/or planetary electrical power systems has required considerable effort. Traditionally, in the early stages of the design cycle (conceptual design), the researchers have had to thoroughly study and analyze tradeoffs between system components, hardware architectures, and operating parameters (such as frequencies) to optimize system mass, efficiency, reliability, and cost. This process could take anywhere from several months to several years (as for the former Space Station Freedom), depending on the scale of the system. Although there are many sophisticated commercial software design tools for personal computers (PC's), none of them can support or provide total system design. To meet this need, researchers at the NASA Lewis Research Center cooperated with Professor George Kusic from the University of Pittsburgh to develop a new tool to help project managers and design engineers choose the best system parameters as quickly as possible in the early design stages (in days instead of months). It is called the Aerospace Power Systems Design and Analysis (APSDA) Tool. By using this tool, users can obtain desirable system design and operating parameters such as system weight, electrical distribution efficiency, bus power, and electrical load schedule. With APSDA, a large-scale specific power system was designed in a matter of days. It is an excellent tool to help designers make tradeoffs between system components, hardware architectures, and operation parameters in the early stages of the design cycle. user interface. It operates on any PC running the MS-DOS (Microsoft Corp.) operating system, version 5.0 or later. A color monitor (EGA or VGA) and two-button mouse are required. The APSDA tool was presented at the 30th Intersociety Energy Conversion Engineering Conference (IECEC) and is being beta tested at several NASA centers. Beta test packages are available for evaluation by contacting the author.

  16. Health effects models for nuclear power plant accident consequence analysis

    International Nuclear Information System (INIS)

    The Nuclear Regulatory Commission (NRC) has sponsored several studies to identify and quantify, through the use of models, the potential health effects of accidental releases of radionuclides from nuclear power plants. The Reactor Safety Study provided the basis for most of the earlier estimates related to these health effects. Subsequent efforts by NRC-supported groups resulted in improved health effects models that were published in the report entitled open-quotes Health Effects Models for Nuclear Power Plant Consequence Analysisclose quotes, NUREG/CR-4214, 1985 and revised further in the 1989 report NUREG/CR-4214, Rev. 1, Part 2. The health effects models presented in the 1989 NUREG/CR-4214 report were developed for exposure to low-linear energy transfer (LET) (beta and gamma) radiation based on the best scientific information available at that time. Since the 1989 report was published, two addenda to that report have been prepared to (1) incorporate other scientific information related to low-LET health effects models and (2) extend the models to consider the possible health consequences of the addition of alpha-emitting radionuclides to the exposure source term. The first addendum report, entitled open-quotes Health Effects Models for Nuclear Power Plant Accident Consequence Analysis, Modifications of Models Resulting from Recent Reports on Health Effects of Ionizing Radiation, Low LET Radiation, Part 2: Scientific Bases for Health Effects Models,close quotes was published in 1991 as NUREG/CR-4214, Rev. 1, Part 2, Addendum 1. This second addendum addresses the possibility that some fraction of the accident source term from an operating nuclear power plant comprises alpha-emitting radionuclides. Consideration of chronic high-LET exposure from alpha radiation as well as acute and chronic exposure to low-LET beta and gamma radiations is a reasonable extension of the health effects model

  17. Study and Analysis of a Natural Reference Frame Current Controller for a Multi-Level H-Bridge Power Converter

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Iov, Florin; Zanchetta, P.;

    2008-01-01

    To pave the way to a sustainable energy future based on a larger share of Distributed Generation (DG), there is a clear need to prepare the European electricity system for the large-scale integration of both renewable and other distributed energy sources. Advanced power electronic converters for DG...... will be needed in order to control the power flow and to ensure proper and secure operation of this future grid with an increased level of renewable power. These power converters must be able to provide intelligent power management as well as ancillary services. This paper presents an analysis of the natural...... reference frame controller, based on proportional-resonant (PR) technique, for a multi-level H-bridge power converter for Universal and Flexible Power Management in Future Electricity Network. The proposed method is tested in terms of harmonic content in the Point of Common Coupling (PCC), voltage...

  18. Control of power sourced from a microbial fuel cell reduces its start-up time and increases bioelectrochemical activity.

    Science.gov (United States)

    Boghani, Hitesh C; Kim, Jung Rae; Dinsdale, Richard M; Guwy, Alan J; Premier, Giuliano C

    2013-07-01

    Microbial fuel cell (MFC) performance depends on the selective development of an electrogenic biofilm at an electrode. Controlled biofilm enrichment may reduce start-up time and improve subsequent power performance. The anode potential is known to affect start-up and subsequent performance in electrogenic bio-catalytic consortia. Control strategies varying electrical load through gradient based maximum power point tracking (MPPT) and transient poised anode potential followed by MPPT are compared to static ohmic loading. Three replicate H-type MFCs were used to investigate start-up strategies: (1) application of an MPPT algorithm preceded by poised-potential at the anode (+0.645 V vs Ag/AgCl); (2) MFC connected to MPPT-only; (3) static external load of 1 kΩ and 500 Ω. Active control showed a significant reduction in start-up time from 42 to 22 days, along with 3.5-fold increase in biocatalytic activity after start-up. Such active control may improve applicability by accelerating start-up and enhancing MFC power and bio-catalytic performance. PMID:23708786

  19. Sample size and power analysis in medical research

    Directory of Open Access Journals (Sweden)

    Zodpey Sanjay

    2004-03-01

    Full Text Available Among the questions that a researcher should ask when planning a study is "How large a sample do I need?" If the sample size is too small, even a well conducted study may fail to answer its research question, may fail to detect important effects or associations, or may estimate those effects or associations too imprecisely. Similarly, if the sample size is too large, the study will be more difficult and costly, and may even lead to a loss in accuracy. Hence, optimum sample size is an essential component of any research. When the estimated sample size can not be included in a study, post-hoc power analysis should be carried out. Approaches for estimating sample size and performing power analysis depend primarily on the study design and the main outcome measure of the study. There are distinct approaches for calculating sample size for different study designs and different outcome measures. Additionally, there are also different procedures for calculating sample size for two approaches of drawing statistical inference from the study results, i.e. confidence interval approach and test of significance approach. This article describes some commonly used terms, which need to be specified for a formal sample size calculation. Examples for four procedures (use of formulae, readymade tables, nomograms, and computer software, which are conventionally used for calculating sample size, are also given

  20. WORK AND POWER ANALYSIS OF THE GOLF SWING

    Directory of Open Access Journals (Sweden)

    Steven M. Nesbit

    2005-12-01

    Full Text Available A work and power (energy analysis of the golf swing is presented as a method for evaluating the mechanics of the golf swing. Two computer models were used to estimate the energy production, transfers, and conversions within the body and the golf club by employing standard methods of mechanics to calculate work of forces and torques, kinetic energies, strain energies, and power during the golf swing. A detailed model of the golf club determined the energy transfers and conversions within the club during the downswing. A full-body computer model of the golfer determined the internal work produced at the body joints during the downswing. Four diverse amateur subjects were analyzed and compared using these two models. The energy approach yielded new information on swing mechanics, determined the force and torque components that accelerated the club, illustrated which segments of the body produced work, determined the timing of internal work generation, measured swing efficiencies, calculated shaft energy storage and release, and proved that forces and range of motion were equally important in developing club head velocity. A more comprehensive description of the downswing emerged from information derived from an energy based analysis

  1. Reachability analysis based transient stability design in power systems

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Licheng; Kumar, Ratnesh; Elia, Nicola [Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50010 (United States)

    2010-09-15

    This paper provides a systematic framework to determine switching control strategies to stabilize the system after a fault if the stabilization is possible. A method to compute the stability region of a stable equilibrium point with the purpose of power system stability analysis is proposed and the validity of discrete controls in transient stability design is studied. First, a Hamilton-Jacobi-Isaas (HJI) partial differential equation (PDE) is constructed to describe the set of backward reachable states as a function of time starting from a target set of states. The backward reachable set of a stable equilibrium point is computed by numerically solving the HJI PDE backwardly in time using level set methods. This backward reachable set yields the stability region of the equilibrium point. Based on such reachability analysis, a transient stability design method is presented. The validity of a discrete control is determined by examining the stability region of the power system with the said control on. If a post-fault initial state is in the stability region of the system with a control on, the control is valid. A control strategy is provided based on the validity of controls. Finally, this method is illustrated by applying to a single machine infinite bus system with the compensation of shunt and series capacitors. (author)

  2. A nuclear power enterprise debt management system construction Based on Sanmen Nuclear Power Co., LTD, debt risk management case analysis

    International Nuclear Information System (INIS)

    Building nuclear power enterprises need huge investment , often tens of billions RMB. How to do a good job in corporate debt risk management, becoming powerful large-scale development of nuclear power ,ensuring the supply of funds and existing debt service in the process of large-scale development of nuclear power ,is an important task. In this paper, managing the company's debt is very urgent and necessary through analysis of SMNPC financing and debt structure; through the analysis of SMNPC's debt risk management , the authors would like to explore how to build up the framework of the debt management under the large-scale development of nuclear power construction . Nuclear power enterprises need to strengthen supervision mechanism and internal control,build-up and perfect all-round debt risk manage system, keep watch on debt risk in order to ensure preservation and increment of the value of state assets. (authors)

  3. Analysis and Review on Development of Power Sources in 2006

    Institute of Scientific and Technical Information of China (English)

    Wang Nan

    2007-01-01

    @@ Influenced by the rapid growing of power demand in recent years, power sources construction has been expanded fleetly in China. This article reviews the features of power sources development nationwide in 2006 and the problems that still existed in the structure of power sources. Finally,suggestions on further developing power sources are proposed.

  4. Nonlinear Analysis of Power System including FACTS and Custom Power Devices Based on Bifurcation Theory and Newton Methods

    OpenAIRE

    Segundo Ramírez, Juan

    2012-01-01

    This thesis presents the modeling of electric power systems including FACTS and Custom Power (CP) devices and their stability analysis through application of bifurcation theory, continuation methods, and Newton methods to compute the periodic steady state. The previous stability analyses of FACTS and Custom Power devices based on bifurcation theory using continuation methods neglected the harmonic distortion introduced by the voltage source converter (VSC). Besides, the network...

  5. Analysis of Loss-of-Offsite-Power Events 1998–2013

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2015-02-01

    Loss of offsite power (LOOP) can have a major negative impact on a power plant’s ability to achieve and maintain safe shutdown conditions. Risk analyses suggest that loss of all alternating current power contributes over 70% of the overall risk at some U.S. nuclear plants. LOOP event and subsequent restoration of offsite power are important inputs to plant probabilistic risk assessments. This report presents a statistical and engineering analysis of LOOP frequencies and durations at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience during calendar years 1997 through 2013. Frequencies and durations were determined for four event categories: plant-centered, switchyard-centered, grid-related, and weather-related. The emergency diesel generator failure modes considered are failure to start, failure to load and run, and failure to run more than 1 hour. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. No statistically significant trends in LOOP frequencies over the 1997–2013 period are identified. There is a possibility that a significant trend in grid-related LOOP frequency exists that is not easily detected by a simple analysis. Statistically significant increases in recovery times after grid- and switchyard-related LOOPs are identified.

  6. Advanced Thermodynamic Analysis and Evaluation of a Supercritical Power Plant

    Directory of Open Access Journals (Sweden)

    George Tsatsaronis

    2012-06-01

    Full Text Available A conventional exergy analysis can highlight the main components having high thermodynamic inefficiencies, but cannot consider the interactions among components or the true potential for the improvement of each component. By splitting the exergy destruction into endogenous/exogenous and avoidable/unavoidable parts, the advanced exergy analysis is capable of providing additional information to conventional exergy analysis for improving the design and operation of energy conversion systems. This paper presents the application of both a conventional and an advanced exergy analysis to a supercritical coal-fired power plant. The results show that the ratio of exogenous exergy destruction differs quite a lot from component to component. In general, almost 90% of the total exergy destruction within turbines comes from their endogenous parts, while that of feedwater preheaters contributes more or less 70% to their total exergy destruction. Moreover, the boiler subsystem is proven to have a large amount of exergy destruction caused by the irreversibilities within the remaining components of the overall system. It is also found that the boiler subsystem still has the largest avoidable exergy destruction; however, the enhancement efforts should focus not only on its inherent irreversibilities but also on the inefficiencies within the remaining components. A large part of the avoidable exergy destruction within feedwater preheaters is exogenous; while that of the remaining components is mostly endogenous indicating that the improvements mainly depend on advances in design and operation of the component itself.

  7. A blocked takeover in the Polish power sector: A model-based analysis

    International Nuclear Information System (INIS)

    As the President of the Office of Competition and Consumer Protection refused to approve a government initiated takeover in the Polish power sector and the Court of Competition and Consumer Protection did not make a ruling on that case, the takeover was finally prohibited. In this context, the main aim of this paper is to carry out a quantitative analysis of the impact of the takeover in question on electricity prices and quantities, consumer and producer surpluses, dead weight loss and emissions. The scope of the study covers the Polish power generation sector and the analysis was carried out for 2009. A game theory-based electricity market equilibrium model developed for Poland was applied. The model includes several country-specific conditions, such as a coal-based power generation fuel-mix, a large share of biomass co-combustion, etc. For the sake of clarity, only four scenarios are assumed. The paper concludes that the declared synergy savings did not compensate for the increase in dead weight loss and the transfer of surplus from consumers to producers caused by increased market power. - Highlights: • A takeover blocked by the President of the Office of Competition and Consumer Protection was analysed. • A game theory-based model of the Polish wholesale electricity market was applied. • The impact of the takeover on electricity prices and generation levels, surplus transfers and dead weight loss was estimated. • The results were compared with the declared synergy savings

  8. Performance analysis of monary and binary geothermal power plants operation for Ukraine conditions

    Directory of Open Access Journals (Sweden)

    Аlla Е. Denysova

    2015-03-01

    Full Text Available Every day the shortage in natural gas and coal does increase. In this respect, a great attention is paid to alternative energy sources, and geothermal electrical power generation represents one of the most cost-effective technologies. New power generation technologies using geothermal resources are ecologically clean and are close approaching to traditional ones from the efficiency point of view. This research aim is to analyze the efficiency of monary and binary geothermal power plants operation under actual conditions in Ukraine. Authors discuss prospects for the geothermal power engineering development in Ukraine and other countries. The principal thermal diagrams of monary and binary power plants are represented, as well as their operational principle considering these schemes advantages and disadvantages. Effected is an analysis of such stations performances under conditions of Ukraine. This research value and practical significance are related to the fact that for Ukraine both monary and binary geothermal power plants are very promising, but each engineering solutions should strictly follow its specific functional conditions.

  9. Analysis and Simulation of Fault Characteristics of Power Switch Failures in Distribution Electronic Power Transformers

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2013-08-01

    Full Text Available This paper presents research on the voltage and current distortion in the input stage, isolation stage and output stage of Distribution Electronic Power transformer (D-EPT after the open-circuit and short-circuit faults of its power switches. In this paper, the operational principles and the control methods for input stage, isolation stage and output stage of D-EPT, which work as a cascaded H-bridge rectifier, DC-DC converter and inverter, respectively, are introduced. Based on conclusions derived from the performance analysis of D-EPT after the faults, this paper comes up with the effects from its topology design and control scheme on the current and voltage distortion. According to the EPT fault characteristics, since the waveforms of relevant components heavily depend on the location of the faulty switch, it is very easy to locate the exact position of the faulty switch. Finally, the fault characteristics peculiar to D-EPT are analyzed, and further discussed with simulation on the Saber platform, as well as a fault location diagnosis algorithm.

  10. Parametric analysis for a new combined power and ejector-absorption refrigeration cycle

    International Nuclear Information System (INIS)

    A new combined power and ejector-absorption refrigeration cycle is proposed, which combines the Rankine cycle and the ejector-absorption refrigeration cycle, and could produce both power output and refrigeration output simultaneously. This combined cycle, which originates from the cycle proposed by authors previously, introduces an ejector between the rectifier and the condenser, and provides a performance improvement without greatly increasing the complexity of the system. A parametric analysis is conducted to evaluate the effects of the key thermodynamic parameters on the cycle performance. It is shown that heat source temperature, condenser temperature, evaporator temperature, turbine inlet pressure, turbine inlet temperature, and basic solution ammonia concentration have significant effects on the net power output, refrigeration output and exergy efficiency of the combined cycle. It is evident that the ejector can improve the performance of the combined cycle proposed by authors previously.

  11. The diagnostic value of power spectra analysis of the sleep electroencephalography in narcoleptic patients

    DEFF Research Database (Denmark)

    Christensen, Julie Anja Engelhard; Munk, Emil Gammelmark Schreiner; Peppard, Paul E.;

    2015-01-01

    Objective: Manifestations of narcolepsy with cataplexy (NC) include disturbed nocturnal sleep – hereunder sleep–wake instability, decreased latency to rapid eye movement (REM) sleep, and dissociated REM sleep events. In this study, we characterized the electroencephalography (EEG) of various sleep...... show (1) increased alpha power in REM sleep, (2) decreased sigma power in wakefulness, and (3) decreased delta power in stage N1 versus wakefulness. Sensitivity of these features ranged from 4% to 10% with specificity around 98%, and it did not vary substantially with and without treatment. Conclusions......: EEG spectral analysis of REM sleep, wake, and differences between N1 and wakefulness contain diagnostic features of NC. These traits may represent sleepiness and dissociated REM sleep in patients with NC. However, the features are not sufficient for differentiating NC from controls, and further...

  12. Using EPSAT to analyze high power systems in the space environment. [Environment Power System Analysis Tool

    Science.gov (United States)

    Kuharski, Robert A.; Jongeward, Gary A.; Wilcox, Katherine G.; Rankin, Tom R.; Roche, James C.

    1991-01-01

    The authors review the Environment Power System Analysis Tool (EPSAT) design and demonstrate its capabilities by using it to address some questions that arose in designing the SPEAR III experiment. It is shown that that the rocket body cannot be driven to large positive voltages under the constraints of this experiment. Hence, attempts to measure the effects of a highly positive rocket body in the plasma environment should not be made in this experiment. It is determined that a hollow cathode will need to draw only about 50 mA to ground the rocket body. It is shown that a relatively small amount of gas needs to be released to induce a bulk breakdown near the rocket body, and this gas release should not discharge the sphere. Therefore, the experiment provides an excellent opportunity to study the neutralization of a differential charge.

  13. Analysis of Nigeria research reactor-1 thermal power calibration methods

    Energy Technology Data Exchange (ETDEWEB)

    Agbo, Sunday Arome; Ahmed, Yusuf Aminu; Ewa, Ita Okon; Jibrin, Yahaya [Ahmadu Bello University, Zaria (Nigeria)

    2016-06-15

    This paper analyzes the accuracy of the methods used in calibrating the thermal power of Nigeria Research Reactor-1 (NIRR-1), a low-power miniature neutron source reactor located at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria. The calibration was performed at three different power levels: low power (3.6 kW), half power (15 kW), and full power (30 kW). Two methods were used in the calibration, namely, slope and heat balance methods. The thermal power obtained by the heat balance method at low power, half power, and full power was 3.7 ± 0.2 kW, 15.2 ± 1.2 kW, and 30.7 ± 2.5 kW, respectively. The thermal power obtained by the slope method at half power and full power was 15.8 ± 0.7 kW and 30.2 ± 1.5 kW, respectively. It was observed that the slope method is more accurate with deviations of 4% and 5% for calibrations at half and full power, respectively, although the linear fit (slope method) on average temperature-rising rates during the thermal power calibration procedure at low power (3.6 kW) is not fitting. As such, the slope method of power calibration is not suitable at lower power for NIRR-1.

  14. Modeling and Analysis of Harmonic Stability in an AC Power-Electronics-Based Power System

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Wu, Weimin

    2014-01-01

    This paper addresses the harmonic stability caused by the interactions among the wideband control of power converters and passive components in an AC power-electronicsbased power system. The impedance-based analytical approach is employed and expanded to a meshed and balanced threephase network w...... power system can be easily predicted through Nyquist diagrams. Time-domain simulations and experimental tests on a three-inverter-based power system are presented. The results validate the effectiveness of the theoretical approach....

  15. Mathematical Analysis of Space Radiator Segmenting for Increased Reliability and Reduced Mass

    Science.gov (United States)

    Juhasz, Albert J.

    2001-01-01

    Spacecraft for long duration deep space missions will need to be designed to survive micrometeoroid bombardment of their surfaces some of which may actually be punctured. To avoid loss of the entire mission the damage due to such punctures must be limited to small, localized areas. This is especially true for power system radiators, which necessarily feature large surface areas to reject heat at relatively low temperature to the space environment by thermal radiation. It may be intuitively obvious that if a space radiator is composed of a large number of independently operating segments, such as heat pipes, a random micrometeoroid puncture will result only in the loss of the punctured segment, and not the entire radiator. Due to the redundancy achieved by independently operating segments, the wall thickness and consequently the weight of such segments can be drastically reduced. Probability theory is used to estimate the magnitude of such weight reductions as the number of segments is increased. An analysis of relevant parameter values required for minimum mass segmented radiators is also included.

  16. A fire hazard analysis at the Ignalina nuclear power plant

    International Nuclear Information System (INIS)

    The fire hazard analysis (FHA) of the Ignalina Nuclear Power Plant (INPP) Unit no.1 was initiated during 1997 and is estimated to finalise in summer 1998. The reason for starting a FHA was a recommendation in the Safety Analysis Report and its review to prioritise a systematic FHA. Fire protection improvements had earlier been based on engineering assessments, but further improvements required a systematic FHA. It is also required by the regulator for licensing of unit no.1. In preparation of the analysis it was decided to perform a deterministic FHA to fulfil the requirements in the IAEA draft of a Safety Practice ''Preparation of Fire Hazard Analyses for Nuclear Power Plants''. As a supporting document the United States Department of Energy Reactor Core Protection Evaluation Methodology for Fires at RBMK and WWER Nuclear Power Plants (RCPEM) was agreed to be used. The assistance of the project is performed as a bilateral activity between Sweden and UK. The project management is the responsibility of the INPP. In order to transfer knowledge to the INPP project group, training activities are arranged by the western team. The project will be documented as a safety case. The project consists of parties from INPP, Sweden, UK and Russia which makes the project very dependent of good communication procedures. The most difficult problems is except from the problems with translation, the problems with different standards and lack of testing protocols of the fire protection installations and problems to set the right level of screening criteria. There is also the new dimension of making it possible to take credit for the fire brigade in the safety case, which can bring the project into difficulties. The most interesting challenges for the project are to set the most sensible safety levels in the screening phase, to handle the huge volume of rooms for survey and screening, to maintain the good exchange of fire- and nuclear safety information between all the parties involved

  17. Poisonous Weed of Insatiable Lust for Power:Theme Analysis of Macbeth

    Institute of Scientific and Technical Information of China (English)

    刘泽璞

    2014-01-01

    On the basis of an in-depth analysis of the insatiable lust of Macbeth and Lady Macbeth for power, this paper is intend-ed to reveal the theme of Macbeth: the greed for power and the corruption of power in human nature. It is argued that when Macbeth and Lady Macbeth are greedy for political power, they cannot avoid committing regicide. Once seizing the power in such an unlawful and sinister way, they abuse power. Eventually, it is their ugly inner drive for power that inevitably cause their degeneration, downfall and demise. Such a theme analysis has its practical significance for modern readers.

  18. Regression analysis of technical parameters affecting nuclear power plant performances

    International Nuclear Information System (INIS)

    Since the 80's many studies have been conducted in order to explicate good and bad performances of commercial nuclear power plants (NPPs), but yet no defined correlation has been found out to be totally representative of plant operational experience. In early works, data availability and the number of operating power stations were both limited; therefore, results showed that specific technical characteristics of NPPs were supposed to be the main causal factors for successful plant operation. Although these aspects keep on assuming a significant role, later studies and observations showed that other factors concerning management and organization of the plant could instead be predominant comparing utilities operational and economic results. Utility quality, in a word, can be used to summarize all the managerial and operational aspects that seem to be effective in determining plant performance. In this paper operational data of a consistent sample of commercial nuclear power stations, out of the total 433 operating NPPs, are analyzed, mainly focusing on the last decade operational experience. The sample consists of PWR and BWR technology, operated by utilities located in different countries, including U.S. (Japan)) (France)) (Germany)) and Finland. Multivariate regression is performed using Unit Capability Factor (UCF) as the dependent variable; this factor reflects indeed the effectiveness of plant programs and practices in maximizing the available electrical generation and consequently provides an overall indication of how well plants are operated and maintained. Aspects that may not be real causal factors but which can have a consistent impact on the UCF, as technology design, supplier, size and age, are included in the analysis as independent variables. (authors)

  19. Human Factors Considerations in New Nuclear Power Plants: Detailed Analysis.

    Energy Technology Data Exchange (ETDEWEB)

    OHara,J.; Higgins, J.; Brown, W.; Fink, R.

    2008-02-14

    This Nuclear Regulatory Commission (NRC) sponsored study has identified human-performance issues in new and advanced nuclear power plants. To identify the issues, current industry developments and trends were evaluated in the areas of reactor technology, instrumentation and control technology, human-system integration technology, and human factors engineering (HFE) methods and tools. The issues were organized into seven high-level HFE topic areas: Role of Personnel and Automation, Staffing and Training, Normal Operations Management, Disturbance and Emergency Management, Maintenance and Change Management, Plant Design and Construction, and HFE Methods and Tools. The issues where then prioritized into four categories using a 'Phenomena Identification and Ranking Table' methodology based on evaluations provided by 14 independent subject matter experts. The subject matter experts were knowledgeable in a variety of disciplines. Vendors, utilities, research organizations and regulators all participated. Twenty issues were categorized into the top priority category. This Brookhaven National Laboratory (BNL) technical report provides the detailed methodology, issue analysis, and results. A summary of the results of this study can be found in NUREG/CR-6947. The research performed for this project has identified a large number of human-performance issues for new control stations and new nuclear power plant designs. The information gathered in this project can serve as input to the development of a long-term strategy and plan for addressing human performance in these areas through regulatory research. Addressing human-performance issues will provide the technical basis from which regulatory review guidance can be developed to meet these challenges. The availability of this review guidance will help set clear expectations for how the NRC staff will evaluate new designs, reduce regulatory uncertainty, and provide a well-defined path to new nuclear power plant

  20. An Analysis of the Accuracy of Electromechanical Eigenvalue Calculations Based on Instantaneous Power Waveforms Recorded in a Power Plant

    Directory of Open Access Journals (Sweden)

    Piotr Pruski

    2013-12-01

    Full Text Available The paper presents the results of calculating the eigenvalues (associated with electromechanical phenomena of the state matrix of the Polish Power System model on the basis of analysis of simulated and measured instantaneous power disturbance waveforms of generating units in Łaziska Power Plant. The method for electromechanical eigenvalue calculations used in investigations consists in approximation of the instantaneous power swing waveforms in particular generating units with the use of the waveforms being a superposition of the modal components associated with the searched eigenvalues and their participation factors. The hybrid optimisation algorithm consisting of the genetic and gradient algorithms was used for computations.

  1. Seismic design and analysis of nuclear power plant structures

    Institute of Scientific and Technical Information of China (English)

    Pentti Varpasuo

    2013-01-01

    The seismic design and analysis of nuclear power plant (NPP) begin with the seismic hazard assessment and design ground motion development for the site.The following steps are needed for the seismic hazard assessment and design ground motion development:a.the development of regional seismo-tectonic model with seismic source areas within 500 km radius centered to the site; b.the development of strong motion prediction equations;c.logic three development for taking into account uncertainties and seismic hazard quantification; d.the development of uniform hazard response spectra for ground motion at the site; e.simulation of acceleration time histories compatible with uniform hazard response spectra.The following phase two in seismic design of NPP structures is the analysis of structural response for the design ground motion.This second phase of the process consists of the following steps:a.development of structural models of the plant buildings; b.development of the soil model underneath the plant buildings for soil-structure interaction response analysis; c.determination of in-structure response spectra for the plant buildings for the equipment response analysis.In the third phase of the seismic design and analysis the equipment is analyzed on the basis of in-structure response spectra.For this purpose the structural models of the mechanical components and piping in the plant are set up.In large 3D-structural models used today the heaviest equipment of the primary coolant circuit is included in the structural model of the reactor building.In the fourth phase the electrical equipment and automation and control equipment are seismically qualified with the aid of the in-structure spectra developed in the phase two using large three-axial shaking tables.For this purpose the smoothed envelope spectra for calculated in-structure spectra are constructed and acceleration time is fitted to these smoothed envelope spectra.

  2. Methodology for the analysis and retirement of assets: Power transformers

    Directory of Open Access Journals (Sweden)

    Gustavo Adolfo Gómez-Ramírez

    2015-09-01

    Full Text Available The following article consists of the development of a methodology of the area of the engineering of high voltage for the analysis and retirement of repaired power transformers, based on engineering criteria, in order to establish a correlation between the conditions of the transformer from several points of view: electrical, mechanical, dielectrics and thermal. Realizing an analysis of the condition of the question, there are two situations of great transcendency, first one, the international procedure are a “guide” for the acceptance of new transformers, by what they cannot be applied to the letter for repaired transformers, due to the process itself of degradation that the transformer has suffered with to happen of the years and all the factors that they were carrying to a possible repair. Second one, with base in the most recent technical literature, there have been analyzed articles, which analyze the oil dielectrics and the paper, which correlations are established between the quality of the insulating paper and the furan concentrations in the oils. To finish, great part of the investigation till now realized, it has focused in the analysis of the transformer, from the condition of the dielectric oil, so in most cases, there is not had the possibility of realizing a forensic engineering inside the transformer in operation and of being able this way, of analyzing the components of design who can compromise the integrity and operability of the same one.

  3. DESIGN AND ANALYSIS OF TURBINE BLADES IN STEAM POWER PLANT SYED

    Directory of Open Access Journals (Sweden)

    ATAUL REHAMAN BASHA

    2014-11-01

    Full Text Available The development of any country directly relates on capital energy consumption. The demand for power generation on the large scale is increasing day by day. Owing to their major contribution towards power production, thermal power plants have a vital role to play in the development of nation. Due to the scarcity of power every power plant needs to be operated at maximum level of efficiency. In case of thermal power plants this applies equally to all its auxiliaries.

  4. State estimation and transient stability analysis in power systems using artificial neural networks

    OpenAIRE

    Boozari, Mahta

    2004-01-01

    Power system state estimation and security assessment have recently become two major issues in the operation of power systems due to the increasing stress on power system networks. Utility operators must be properly informed of the operating condition or state of the power system in order to achieve a more secure and economical operation of today's complicated power systems. The state of a power system is described by a collection of voltage vectors for a given network topology and parameters...

  5. Maximum power analysis of photovoltaic module in Ramadi city

    Energy Technology Data Exchange (ETDEWEB)

    Shahatha Salim, Majid; Mohammed Najim, Jassim [College of Science, University of Anbar (Iraq); Mohammed Salih, Salih [Renewable Energy Research Center, University of Anbar (Iraq)

    2013-07-01

    Performance of photovoltaic (PV) module is greatly dependent on the solar irradiance, operating temperature, and shading. Solar irradiance can have a significant impact on power output of PV module and energy yield. In this paper, a maximum PV power which can be obtain in Ramadi city (100km west of Baghdad) is practically analyzed. The analysis is based on real irradiance values obtained as the first time by using Soly2 sun tracker device. Proper and adequate information on solar radiation and its components at a given location is very essential in the design of solar energy systems. The solar irradiance data in Ramadi city were analyzed based on the first three months of 2013. The solar irradiance data are measured on earth's surface in the campus area of Anbar University. Actual average data readings were taken from the data logger of sun tracker system, which sets to save the average readings for each two minutes and based on reading in each one second. The data are analyzed from January to the end of March-2013. Maximum daily readings and monthly average readings of solar irradiance have been analyzed to optimize the output of photovoltaic solar modules. The results show that the system sizing of PV can be reduced by 12.5% if a tracking system is used instead of fixed orientation of PV modules.

  6. Seismic margin analysis technique for nuclear power plant structures

    International Nuclear Information System (INIS)

    In general, the Seismic Probabilistic Risk Assessment (SPRA) and the Seismic Margin Assessment(SAM) are used for the evaluation of realistic seismic capacity of nuclear power plant structures. Seismic PRA is a systematic process to evaluate the seismic safety of nuclear power plant. In our country, SPRA has been used to perform the probabilistic safety assessment for the earthquake event. SMA is a simple and cost effective manner to quantify the seismic margin of individual structural elements. This study was performed to improve the reliability of SMA results and to confirm the assessment procedure. To achieve this goal, review for the current status of the techniques and procedures was performed. Two methodologies, CDFM (Conservative Deterministic Failure Margin) sponsored by NRC and FA (Fragility Analysis) sponsored by EPRI, were developed for the seismic margin review of NPP structures. FA method was originally developed for Seismic PRA. CDFM approach is more amenable to use by experienced design engineers including utility staff design engineers. In this study, detailed review on the procedures of CDFM and FA methodology was performed

  7. Maximum power analysis of photovoltaic module in Ramadi city

    Directory of Open Access Journals (Sweden)

    Majid Shahatha Salim, Jassim Mohammed Najim, Salih Mohammed Salih

    2013-01-01

    Full Text Available Performance of photovoltaic (PV module is greatly dependent on the solar irradiance, operating temperature, and shading. Solar irradiance can have a significant impact on power output of PV module and energy yield. In this paper, a maximum PV power which can be obtain in Ramadi city (100km west of Baghdad is practically analyzed. The analysis is based on real irradiance values obtained as the first time by using Soly2 sun tracker device. Proper and adequate information on solar radiation and its components at a given location is very essential in the design of solar energy systems. The solar irradiance data in Ramadi city were analyzed based on the first three months of 2013. The solar irradiance data are measured on earth's surface in the campus area of Anbar University. Actual average data readings were taken from the data logger of sun tracker system, which sets to save the average readings for each two minutes and based on reading in each one second. The data are analyzed from January to the end of March-2013. Maximum daily readings and monthly average readings of solar irradiance have been analyzed to optimize the output of photovoltaic solar modules. The results show that the system sizing of PV can be reduced by 12.5% if a tracking system is used instead of fixed orientation of PV modules.

  8. Seismic margin analysis technique for nuclear power plant structures

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jeong Moon; Choi, In Kil

    2001-04-01

    In general, the Seismic Probabilistic Risk Assessment (SPRA) and the Seismic Margin Assessment(SAM) are used for the evaluation of realistic seismic capacity of nuclear power plant structures. Seismic PRA is a systematic process to evaluate the seismic safety of nuclear power plant. In our country, SPRA has been used to perform the probabilistic safety assessment for the earthquake event. SMA is a simple and cost effective manner to quantify the seismic margin of individual structural elements. This study was performed to improve the reliability of SMA results and to confirm the assessment procedure. To achieve this goal, review for the current status of the techniques and procedures was performed. Two methodologies, CDFM (Conservative Deterministic Failure Margin) sponsored by NRC and FA (Fragility Analysis) sponsored by EPRI, were developed for the seismic margin review of NPP structures. FA method was originally developed for Seismic PRA. CDFM approach is more amenable to use by experienced design engineers including utility staff design engineers. In this study, detailed review on the procedures of CDFM and FA methodology was performed.

  9. Automotive Gas Turbine Power System-Performance Analysis Code

    Science.gov (United States)

    Juhasz, Albert J.

    1997-01-01

    An open cycle gas turbine numerical modelling code suitable for thermodynamic performance analysis (i.e. thermal efficiency, specific fuel consumption, cycle state points, working fluid flowrates etc.) of automotive and aircraft powerplant applications has been generated at the NASA Lewis Research Center's Power Technology Division. The use this code can be made available to automotive gas turbine preliminary design efforts, either in its present version, or, assuming that resources can be obtained to incorporate empirical models for component weight and packaging volume, in later version that includes the weight-volume estimator feature. The paper contains a brief discussion of the capabilities of the presently operational version of the code, including a listing of input and output parameters and actual sample output listings.

  10. Analysis of general power counting rules in effective field theory

    Science.gov (United States)

    Gavela, Belen; Jenkins, Elizabeth E.; Manohar, Aneesh V.; Merlo, Luca

    2016-09-01

    We derive the general counting rules for a quantum effective field theory (EFT) in d dimensions. The rules are valid for strongly and weakly coupled theories, and they predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. We show that the size of the cross sections is controlled by the Λ power counting of EFT, not by chiral counting, even for chiral perturbation theory (χ PT). The relation between Λ and f is generalized to d dimensions. We show that the naive dimensional analysis 4π counting is related to hbar counting. The EFT counting rules are applied to χ PT, low-energy weak interactions, Standard Model EFT and the non-trivial case of Higgs EFT.

  11. Need for a probabilistic fire analysis at nuclear power plants

    International Nuclear Information System (INIS)

    Although fire protection standards for nuclear power plants cover a wide scope and are constantly being updated, the existence of certain constraints makes it difficult to precisely evaluate plant response to different postulatable fires. These constraints involve limitations such as: - Physical obstacles which impede the implementation of standards in certain cases; - Absence of general standards which cover all the situations which could arise in practice; - Possible temporary noncompliance of safety measures owing to unforeseen circumstances; - The fact that a fire protection standard cannot possibly take into account additional damages occurring simultaneously with the fire; Based on the experience of the ASCO NPP PSA developed within the framework of the joint venture, INITEC-INYPSA-EMPRESARIOS AGRUPADOS, this paper seeks to justify the need for a probabilistic analysis to overcome the limitations detected in general application of prevailing standards. (author)

  12. Analysis of General Power Counting Rules in Effective Field Theory

    CERN Document Server

    Gavela, B M; Manohar, A V; Merlo, L

    2016-01-01

    We derive the general counting rules for a quantum effective field theory (EFT) in $\\mathsf{d}$ dimensions. The rules are valid for strongly and weakly coupled theories, and predict that all kinetic energy terms are canonically normalized. They determine the energy dependence of scattering cross sections in the range of validity of the EFT expansion. The size of cross sections is controlled by the $\\Lambda$ power counting of EFT, not by chiral counting, even for chiral perturbation theory ($\\chi$PT). The relation between $\\Lambda$ and $f$ is generalized to $\\mathsf{d}$ dimensions. We show that the naive dimensional analysis $4\\pi$ counting is related to $\\hbar$ counting. The EFT counting rules are applied to $\\chi$PT, to Standard Model EFT and to the non-trivial case of Higgs EFT, which combines the $\\Lambda$ and chiral counting rules within a single theory.

  13. Seismic reliability analysis of large electric power systems

    Institute of Scientific and Technical Information of China (English)

    何军; 李杰

    2004-01-01

    Based on the De. Morgan laws and Boolean simplification, a recursive decomposition method is introduced in this paper to identity the main exclusive safe paths and failed paths of a network. The reliability or the reliability bound of a network can be conveniently expressed as the summation of the joint probabilities of these paths. Under the multivariate normal distribution assumption, a conditioned reliability index method is developed to evaluate joint probabilities of various exclusive safe paths and failed paths, and, finally, the seismic reliability or the reliability bound of an electric power system.Examples given in thc paper show that the method is very simple and provides accurate results in the seismic reliability analysis.

  14. Theory analysis and structure optimization design of powered gait orthosis

    Directory of Open Access Journals (Sweden)

    Meng Ning

    2016-03-01

    Full Text Available Patients suffering from paraplegia are special disabled groups in society. In order to help them with lower-limb rehabilitation, a kind of power-assisted gait orthosis is designed. In consideration of the crutches that are rather necessary to keep balance when walking, the effects of crutches on analysis of mechanism cannot be ignored. Based on the gait characteristics, this gait orthosis mechanism is designed, of which the structure is optimized by genetic algorithm and the dynamical model is generated. The periodic movement of hip joints, knee joints, and ankle joints in corrected gait are achieved and the torque can be transferred to the driving force of the back motor and the pushrod according to the orthosis structure. Finally, a verification test shows this design is reasonable and practical.

  15. Throughput Analysis of Power Control B-MAC Protocol In WSN

    Directory of Open Access Journals (Sweden)

    Ramchand V

    2012-07-01

    Full Text Available This paper presents a new methodology for energy consumption of nodes and throughput analysis has been performed through simulation for B-MAC protocol in Wireless Sensor Networks. The design includes transmission power control and multi-hop transmission of frames through adjusted transmitted power level. Proposed model reduces collision with contention level notification. The proposed model has been simulated using MATLAB. The simulations reveal better results for throughput of the proposed model as compared to B-MAC protocol. In this model we have included a mechanism for node discovery to find the location of the node before transmission of data to it. This increases the throughput of the network since the position of a dislocated node has been found, that results into successful transmission of frames.However, the energy consumption of a node increases due to energy consumed in node discovery.

  16. Heat transfer and structure stress analysis of micro packaging component of high power light emitting diode

    Directory of Open Access Journals (Sweden)

    Hsu Chih-Neng

    2013-01-01

    Full Text Available This paper focuses on the heat transfer and structural stress analysis of the micro- scale packaging structure of a high-power light emitting diode. The thermal-effect and thermal-stress of light emitting diode are determined numerically. Light emitting diode is attached to the silicon substrate through the wire bonding process by using epoxy as die bond material. The silicon substrate is etched with holes at the bottom and filled with high conductivity copper material. The chip temperature and structure stress increase with input power consumption. The micro light emitting diode is mounted on the heat sink to increase the heat dissipation performance, to decrease chip temperature, to enhance the material structure reliability and safety, and to avoid structure failure as well. This paper has successfully used the finite element method to the micro-scale light emitting diode heat transfer and stress concentration at the edges through etched holes.

  17. Long range prospect of the electric power demand in FY 2,000. Total demand: 8. 38 trillion KWh, annual average increase: 2. 3%

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-05

    The Agency of Natural Resources and Energy, the Ministry of International Trade and Industry held meetings of the Committee on Demand and Supply of the Electric Utility Industrial Council in October, 1987. This article is the Committee's interim report and establishes the prospect of the electric power supply and demand in Japan in FY 1995 and FY 2000. Total power demand in FY 1995 is about 7.38 trillion KWh and in FY 2000, about 8.38 trillion KWh. Average annual growth is about 2.6% during the period of FY 1995 through FY 2000. Among the above, the public demand will increase and occupy 50.2% of the total power demand in the year of 2000. The industrial demand will increase about 1.4% in terms of annual rate during the period of FY 1995 through FY 2000 due to the demand increase by new industries, etc. against continued rationalization of power utilization. The maximum electric power demand is around 163 million KW in FY 2000. The target of electric power supply in FY 2000 is 53 million KW from atomic power generation, 23 million KW from coal burning thermal power generation, 43 million KW from LNG, 21 million KW from hydro power generation and 52 million KW from oil and LPG. Hereafter, electric load leveling, more efficient electric power supply and strengthening of the basis of electric power utilization are necessary. (1 photo, 3 tabs)

  18. Transient Stability Performance Analysis of Power System Using Facts Devices

    Directory of Open Access Journals (Sweden)

    M. Srinivasa Rao

    2014-02-01

    Full Text Available Transient stability is increasingly important for secure loading. Transient stability evaluation of large scale power systems is an extremely intricate and highly non linear problem. An important function of transient evaluation is to appraise the capability of the power system to with stand serious contingency in time, so that some emergencies or preventive control can be carried out to prevent system breakdown, the fault current so produced is diverted to the capacitor by using dual-STATCOM controller, results proved that voltage is maintained nearly constant, surge currents decreased and oscillations in generator have damped and hence system stability and continuity of supply are enhanced. If for UPFC, replacing series controller with shunt controller, it works as dual STATCOM. It has advantages as series pulse controller is not required and same pulses can be given to both STATCOMs. The shunt controller is so designed to act as low impedance path for short circuit current, thereby surge currents can be diverted to VSC. A general program for transient stability studies to incorporate FACTS devices is developed using MATLAB/SIMULINK.

  19. Analysis of Chain of Events in Major Historic Power Outages

    Directory of Open Access Journals (Sweden)

    HUANG, T.

    2014-08-01

    Full Text Available Contemporary power systems are facing increasing intricate conditions that have never been considered when initially designing the infrastructure, such as malicious threats, accommodating smart grids, etc. As a consequence, blackouts albeit seldom but stubbornly keep appearing from time to time the world around, and demonstrate their devastating capability to create vast damage on both power systems and the society at large. Patterns of the blackout starting from the first triggering events to the system final status have emerged. A framework of a coding system was proposed in this paper in order to capture the common feature in the system evolution during the development of cascades. Cascades in a blackout can be tracked by a chain of events with the help of the codes. It is facile to adopt the framework to build up a knowledge base of blackouts. By applying the proposed framework to 31 selected historic blackouts, most frequent events, effects and origins are identified; the findings can provide useful information for grid designers and security experts for ranking the most imminent issues in their study.

  20. Relative power and sample size analysis on gene expression profiling data

    Directory of Open Access Journals (Sweden)

    den Dunnen JT

    2009-09-01

    Full Text Available Abstract Background With the increasing number of expression profiling technologies, researchers today are confronted with choosing the technology that has sufficient power with minimal sample size, in order to reduce cost and time. These depend on data variability, partly determined by sample type, preparation and processing. Objective measures that help experimental design, given own pilot data, are thus fundamental. Results Relative power and sample size analysis were performed on two distinct data sets. The first set consisted of Affymetrix array data derived from a nutrigenomics experiment in which weak, intermediate and strong PPARα agonists were administered to wild-type and PPARα-null mice. Our analysis confirms the hierarchy of PPARα-activating compounds previously reported and the general idea that larger effect sizes positively contribute to the average power of the experiment. A simulation experiment was performed that mimicked the effect sizes seen in the first data set. The relative power was predicted but the estimates were slightly conservative. The second, more challenging, data set describes a microarray platform comparison study using hippocampal δC-doublecortin-like kinase transgenic mice that were compared to wild-type mice, which was combined with results from Solexa/Illumina deep sequencing runs. As expected, the choice of technology greatly influences the performance of the experiment. Solexa/Illumina deep sequencing has the highest overall power followed by the microarray platforms Agilent and Affymetrix. Interestingly, Solexa/Illumina deep sequencing displays comparable power across all intensity ranges, in contrast with microarray platforms that have decreased power in the low intensity range due to background noise. This means that deep sequencing technology is especially more powerful in detecting differences in the low intensity range, compared to microarray platforms. Conclusion Power and sample size analysis

  1. Analysis of Interline Power Flow Controller (IPFC Location in Power Transmission Systems

    Directory of Open Access Journals (Sweden)

    Amir Kahyaei

    2011-07-01

    Full Text Available The Interline Power Flow Controller (IPFC is one of the latest generation Flexible AC Transmission Systems (FACTS controller used to control power flows of multiple transmission lines. The aim of this paper is investigation of the effect of location of IPFC on profile of voltage and real and reactive power flow in transmission lines in power system. This model is incorporated in Newton- Raphson (NR power flow algorithm to study the power flow control in transmission lines in which IPFC is placed. A program in MATLAB/SIMULINK has been written in order to extend conventional NR algorithm based on this model. Numerical results are carried out on a standard power system. The results without and with IPFC for various locations are compared in terms of voltages, active and reactive power flows to demonstrate the performance of the IPFC model.

  2. UPVapor: Cofrentes nuclear power plant production results analysis software

    International Nuclear Information System (INIS)

    UPVapor software version 02 has been developed for the Cofrentes nuclear power plant Data Analysis Department (Spain). It is an analysis graphical environment in which users have available all the plant variables registered in the process computer system (SIEC). In order to perform this, UPVapor software has many advanced graphic tools for work simplicity, as well as a friendly environment easy to use and with many configuration possibilities. Plant variables are classified in the same way that they are in SIEC computer and these values are taken from it through the network of Iberdrola. UPVapor can generate two different types of graphics: evolution graphs and X Y graphs. The first ones analyse the evolution up to twenty plant variables in a user's defined time period and according to historic plant files. Many tools are available: cursors, graphic configuration, mobile means, non valid data visualization ... Moreover, a particular analysis configuration can be saved, as a pre selection, giving the possibility of charging pre selection directly and developing quick monitoring of a group of preselected plant variables. In X Y graphs, it is possible to analyse a variable value against another variable in a defined time. As an option, users can filter previous data depending on a variable certain range, with the possibility of programming up to five filters. As well as the other graph, X Y graph has many configurations, saving and printing options. With UPVapor software, data analysts can save a valuable time during daily work and, as it is of easy utilization, it permits to other users to perform their own analysis without ask the analysts to develop. Besides, it can be used from any work centre with access to network framework. (Author)

  3. UPVapor: Cofrentes nuclear power plant production results analysis software

    Energy Technology Data Exchange (ETDEWEB)

    Curiel, M. [Logistica y Acondicionamientos Industriales SAU, Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain); Palomo, M. J. [ISIRYM, Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia (Spain); Baraza, A. [Iberdrola Generacion S. A., Central Nuclear Cofrentes, Carretera Almansa Requena s/n, 04662 Cofrentes, Valencia (Spain); Vaquer, J., E-mail: m.curiel@lainsa.co [TITANIA Servicios Tecnologicos SL, Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain)

    2010-10-15

    UPVapor software version 02 has been developed for the Cofrentes nuclear power plant Data Analysis Department (Spain). It is an analysis graphical environment in which users have available all the plant variables registered in the process computer system (SIEC). In order to perform this, UPVapor software has many advanced graphic tools for work simplicity, as well as a friendly environment easy to use and with many configuration possibilities. Plant variables are classified in the same way that they are in SIEC computer and these values are taken from it through the network of Iberdrola. UPVapor can generate two different types of graphics: evolution graphs and X Y graphs. The first ones analyse the evolution up to twenty plant variables in a user's defined time period and according to historic plant files. Many tools are available: cursors, graphic configuration, mobile means, non valid data visualization ... Moreover, a particular analysis configuration can be saved, as a pre selection, giving the possibility of charging pre selection directly and developing quick monitoring of a group of preselected plant variables. In X Y graphs, it is possible to analyse a variable value against another variable in a defined time. As an option, users can filter previous data depending on a variable certain range, with the possibility of programming up to five filters. As well as the other graph, X Y graph has many configurations, saving and printing options. With UPVapor software, data analysts can save a valuable time during daily work and, as it is of easy utilization, it permits to other users to perform their own analysis without ask the analysts to develop. Besides, it can be used from any work centre with access to network framework. (Author)

  4. Analysis of the contribution of wind power plants to damp power system oscillations

    OpenAIRE

    Domínguez García, José Luis

    2013-01-01

    Wind power has emerged as one of the most promising renewable energy sources. The very penetration levels of wind energy in power systems have altered several aspects of power system operation, such as system stability. Owing to the large penetration of wind power, transmission system operators (TSOs) have established special grid codes for wind farms connection. These grid codes require wind farms to provide ancillary services to the grid such as frequency and voltage regulation. In the near...

  5. Electrokinetic power generation by means of streaming potentials: a mobile-ion-drain method to increase the streaming potentials.

    Science.gov (United States)

    Yang, Jun; Lu, Fuzhi; Kostiuk, Larry W; Kwok, Daniel Y

    2005-04-01

    We show, by natural occurring phenomena of charge separation near the solid-liquid interface in microchannels, that electricity can be generated by forcing water through a ceramic rod with no moving part and emission. A single hand push on a syringe is our source of power which easily generates a streaming potential of over 20 V and a streaming current of 30 microA. By means of streaming potentials, two capacitors were charged and discharged alternatively to light-up two Light-Emitting-Diodes in every ten seconds. From our specific choice of liquid/solid pair, an efficiency of 0.8% was obtained. A mobile-ion-drain method is also demonstrated to increase the streaming potential. PMID:16004133

  6. "The Heart Truth:" Using the Power of Branding and Social Marketing to Increase Awareness of Heart Disease in Women.

    Science.gov (United States)

    Long, Terry; Taubenheim, Ann; Wayman, Jennifer; Temple, Sarah; Ruoff, Beth

    2008-03-01

    In September 2002, the National Heart, Lung, and Blood Institute launched The Heart Truth, the first federally-sponsored national campaign aimed at increasing awareness among women about their risk of heart disease. A traditional social marketing approach, including an extensive formative research phase, was used to plan, implement, and evaluate the campaign. With the creation of the Red Dress as the national symbol for women and heart disease awareness, the campaign integrated a branding strategy into its social marketing framework. The aim was to develop and promote a women's heart disease brand that would create a strong emotional connection with women. The Red Dress brand has had a powerful appeal to a wide diversity of women and has given momentum to the campaign's three-part implementation strategy of partnership development, media relations, and community action. In addition to generating its own substantial programming, The Heart Truth became a catalyst for a host of other national and local educational initiatives, both large and small. By the campaign's fifth anniversary, surveys showed that women were increasingly aware of heart disease as their leading cause of death and that the rise in awareness was associated with increased action to reduce heart disease risk.

  7. "The Heart Truth:" Using the Power of Branding and Social Marketing to Increase Awareness of Heart Disease in Women.

    Science.gov (United States)

    Long, Terry; Taubenheim, Ann; Wayman, Jennifer; Temple, Sarah; Ruoff, Beth

    2008-03-01

    In September 2002, the National Heart, Lung, and Blood Institute launched The Heart Truth, the first federally-sponsored national campaign aimed at increasing awareness among women about their risk of heart disease. A traditional social marketing approach, including an extensive formative research phase, was used to plan, implement, and evaluate the campaign. With the creation of the Red Dress as the national symbol for women and heart disease awareness, the campaign integrated a branding strategy into its social marketing framework. The aim was to develop and promote a women's heart disease brand that would create a strong emotional connection with women. The Red Dress brand has had a powerful appeal to a wide diversity of women and has given momentum to the campaign's three-part implementation strategy of partnership development, media relations, and community action. In addition to generating its own substantial programming, The Heart Truth became a catalyst for a host of other national and local educational initiatives, both large and small. By the campaign's fifth anniversary, surveys showed that women were increasingly aware of heart disease as their leading cause of death and that the rise in awareness was associated with increased action to reduce heart disease risk. PMID:19122892

  8. Comprehensive analysis of a straw-fired power plant in Vojvodina

    Directory of Open Access Journals (Sweden)

    Urošević Dragan M.

    2012-01-01

    Full Text Available In recent years, renewable energy sources have played an increasingly important role in potential energy production. The integration of renewable energy technologies into existing national energy system has therefore become a major challenge for many countries. Due to the importance of this matter, this paper deals with the comprehensive analysis for implementation of a power plant on biomass (straw. The analysis is conducted regarding several key indicators: availability of biomass, regulation, reduction of greenhouse gas emissions, location, land use, electricity price and social impacts. The analysis also includes favorable price for electricity produced from biomass relevant to national feed in tariffs. In order to demonstrate all above mentioned indicators, the region in Serbia (Province of Vojvodina with significant potential in biomass, especially in straw, is selected. The results of the analysis are validated trough environmental and social aspects. Special attention is given to identifying risks for this application.

  9. Analysis of wind power ancillary services characteristics with German 250-MW wind data

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, B.

    1999-12-09

    With the increasing availability of wind power worldwide, power fluctuations have become a concern for some utilities. Under electric industry restructuring in the US, the impact of these fluctuations will be evaluated by examining provisions and costs of ancillary services for wind power. This paper analyzes wind power in the context of ancillary services, using data from a German 250 Megawatt Wind project.

  10. Comparative Analysis of Power Plant Options for Enhanced Geothermal Systems (EGS

    Directory of Open Access Journals (Sweden)

    Mengying Li

    2014-12-01

    Full Text Available Enhanced geothermal systems (EGS extract heat from underground hot dry rock (HDR by first fracturing the HDR and then circulating a geofluid (typically water into it and bringing the heated geofluid to a power plant to generate electricity. This study focuses on analysis, examination, and comparison of leading geothermal power plant configurations with a geofluid temperature from 200 to 800 °C, and also analyzes the embodied energy of EGS surface power plants. The power generation analysis is focused on flash type cycles for using subcritical geofluid (<374 °C and expansion type cycles for using supercritical geofluid (>374 °C. Key findings of this study include: (i double-flash plants have 24.3%–29.0% higher geofluid effectiveness than single-flash ones, and 3%–10% lower specific embodied energy; (ii the expansion type plants have geofluid effectiveness > 750 kJ/kg, significantly higher than flash type plants (geofluid effectiveness < 300 kJ/kg and the specific embodied energy is lower; (iii to increase the turbine outlet vapor fraction from 0.75 to 0.90, we include superheating by geofluid but that reduces the geofluid effectiveness by 28.3%; (iv for geofluid temperatures above 650 °C, double-expansion plants have a 2% higher geofluid effectiveness and 5%–8% lower specific embodied energy than single-expansion ones.

  11. Comparative analysis of fixed and sun tracking low power PV systems considering energy consumption

    International Nuclear Information System (INIS)

    Highlights: • Photovoltaic system prototype with sun tracking. • Energy analysis of fixed and sun tracking built prototypes. • Experimental tests in different environmental conditions. • Theoretical and experimental validation of the prototype. - Abstract: Photovoltaic technology allows to directly convert solar energy into electrical energy with clear advantages: no environmental impact during operation, reliability and durability of the systems, reduced operating costs and maintenance, ability to both supply remote customers and simply connect to the electrical network. This paper evaluates the performance of two photovoltaic systems: one fixed and one equipped with a sun tracker. The objective of this research is to analyze the increase of daily produced energy by using the sun tracking system. The analysis accounts also the energy consumption of the sun tracker. An analytical approach is proposed. To validate the results through experimental tests, two alternative low power PV systems were built. Each system consists of a PV source, a MPPT (Maximum Power Point Tracker) power converter and a 12 V–40 A h electrochemical battery, which is used as electric load. The sun tracker system evidenced an important growth of power production during morning and evening

  12. Analysis of Loss-of-Offsite-Power Events 1998–2012

    Energy Technology Data Exchange (ETDEWEB)

    T. E. Wierman

    2013-10-01

    Loss of offsite power (LOOP) can have a major negative impact on a power plant’s ability to achieve and maintain safe shutdown conditions. Risk analyses performed loss of all alternating current power contributes over 70% of the overall risk at some U.S. nuclear plants. LOOP event and subsequent restoration of offsite power are important inputs to plant probabilistic risk assessments. This report presents a statistical and engineering analysis of LOOP frequencies and durations at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience from fiscal year 1998 through 2012. Frequencies and durations were determined for four event categories: plant-centered, switchyard-centered, grid-related, and weather-related. The EDG failure modes considered are failure to start, failure to load and run, and failure to run more than 1 hour. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. A statistically significant increase in industry performance was identified for plant-centered and switchyard-centered LOOP frequencies. There is no statistically significant trend in LOOP durations.

  13. Thermodynamic and exergoeconomic analysis of Çayırhan thermal power plant

    International Nuclear Information System (INIS)

    Highlights: • Thermodynamic and exergoeconomic analysis of the thermal power plant is presented. • Exergoeconomic factors of the unit groups in the power plant are analyzed. • Thermodynamic and exergoeconomic analyses are expected to be very useful for the designers. - Abstract: It is an indisputable fact that much saving could be achieved provided that the efficiency of thermal plants, which bear a huge share in the distribution of generated energy, could be increased by making certain improvements and minimize the losses. These practices as a natural consequence shall provide useful benefits to find a solution for energy problem. In the current study exergy and thermoeconomic analyses of Turkey-based Çayırhan thermal power plant have been conducted. Thermodynamic properties of the inlet and outlet points of each unit in thermal plant have been specified via EES package program. With the help of obtained thermodynamic properties, thermal and second law efficiencies of thermal power plant have been found respectively as 38% and 53%. In thermal power plant, the highest amounts of exergy losses are witnessed alternatively in; the boiler, turbine groups, condenser, heater group and pump groups. The highest amount of exergy loss costs are seen respectively in boiler, turbine group and condenser. When exergoeconomic factors are examined, the highest factor has been measured in turbine group, which is followed respectively by boiler and condenser drain pump

  14. Power Excursion Accident Analysis of Research Water Reactor

    International Nuclear Information System (INIS)

    A three-dimensional neutronic code POWEX-K has been developed, and it has been coupled with the sub-channel thermal-hydraulic core analysis code SV based on the Single Mass Velocity Model. This forms the integrated neutronic/thermal hydraulics code system POWEX-K/SV for the accident analysis. The Training and Research Reactors at Budapest University of Technology and Economics (BME-Reactor) has been taken as a reference reactor. The cross-section generation procedure based on WIMS. The code uses an implicit difference approach for both the diffusion equations and thermal-hydraulics modules, with reactivity feedback effects due to coolant and fuel temperatures. The code system was applied to analyzing power excursion accidents initiated by ramp reactivity insertion of 1.2 $. The results show that the reactor is inherently safe in case of such accidents i.e. no core melt is expected even if the safety rods do not fall into the core

  15. Power Flow Analysis of Island Business District 33KV Distribution Grid System with Real Network Simulations

    Directory of Open Access Journals (Sweden)

    Adesina, L.M

    2015-07-01

    Full Text Available The solution to power flow is one of the most important problems in electrical power systems. Traditional methods have been previously used for power flow analysis, but with prevalent drawbacks such as abnormal operating solutions and divergences in heavy loads. This paper presents power flow analysis in a power system, by modelling a typical 33kV Distribution Network, and simulating using the NEPLAN software for power flow studies. Island Business Unit’s (IBU 33kV network of Eko Electricity Distribution Plc (EKEDP for a scenario day is taken as case study in the analysis. The most important parameters of power flow analysis is utilized to find the magnitude and phase angles of the voltages at each Busbar, as well as the real and reactive power flowing through each distribution line within the network under consideration.

  16. Power

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård; Fogsgaard, Morten

    2016-01-01

    In this chapter, we will explore the dynamics of power in processes of creativity, and show its paradoxical nature as both a bridge and a barrier to creativity in organisations. Recent social psychological experimental research (Slighte, de Dreu & Nijstad, 2011) on the relation between power...... and creativity suggests that when managers give people the opportunity to gain power and explicate that there is reason to be more creative, people will show a boost in creative behaviour. Moreover, this process works best in unstable power hierarchies, which implies that power is treated as a negotiable...... and floating source for empowering people in the organisation. We will explore and discuss here the potentials, challenges and pitfalls of power in relation to creativity in the life of organisations today. The aim is to demonstrate that power struggles may be utilised as constructive sources of creativity...

  17. A homogeneous group of persons with multiple sclerosis seem to use different net joint power strategies to increase gait speed - a pilot study

    DEFF Research Database (Denmark)

    Brincks, John

    2014-01-01

    PwMS with an EDSS score median at 2.5 (Inter quartile range=1) participated. The gait patterns were analysed using 3D motion analysis at self-selected and maximum gait speed. The net joint power peaks were measured for H1-S, H2-S, H3-S, H1-F, H2-F, H3-F, K1-S, K2-S, K3-S, A1-S and A2-S...... dysfunction. Aims: This pilot study examined changes in net joint power generated or absorbed by hip flexors (H2-S, H3-S), hip extensors (H1-S), hip abductors (H1-F, H2-F, H3-F) knee extensors (K1-S, K2-S, K3-S) and ankle plantar flexors (A1-S, A2-S) bilaterally, when gait speed increased. Methods: Fourteen...... and least affected limb (from 31% to 135%;pgait speed increased (median=0.36 m/s;ppower changes between limbs. Even so, there was a trend towards larger...

  18. Strategic analysis of biomass and waste fuels for electric power generation

    International Nuclear Information System (INIS)

    Although the environmental and other benefits of using biomass and waste fuel energy to displace fossil fuels are well known, the economic realities are such that these fuels can not compete effectively in the current market without tax credits, subsidies, and other artificial measures. In 1992, EPRI initiated a strategic analysis of biomass and waste fuels and power technologies, both to develop consistent performance and cost data for the leading fuels and technologies and to identify the conditions that favor and create market pull for biomass and waste fuel energy. Using the interim results of the EPRI project, this paper compares the relative performance and cost of power generation from coal, natural gas, and biomass and waste fuels. The range of fuels includes wood, agricultural wastes, municipal solid waste, refuse-derived fuel, scrap tires, and tire-derived fuel, scrap tires, and tire-derived fuel. The power technologies include pulverized coal and natural gas/combined cycle power plants, cofiring with coal in coal-fired utility boilers, and wood gasification/combined cycle power plants. The analysis suggests that, in the near term, the highest-efficiency, lowest-cost, lowest-risk technology is cofiring with coal in industrial and utility boilers. However, this relative to fossil fuel, or the fuel user receives a tipping fee, subsidy, or emissions credit. In order to increase future use of biomass and waste fuels, a joint initiative, involving government, industry, and fuel suppliers, transporters, and users, is needed to develop low-cost and efficient energy crop production and power technology

  19. Repetitive transcranial magnetic stimulation improves consciousness disturbance in stroke patients A quantitative electroencephalography spectral power analysis

    Institute of Scientific and Technical Information of China (English)

    Ying Xie; Tong Zhang

    2012-01-01

    Repetitive transcranial magnetic stimulation is a noninvasive treatment technique that can directly alter cortical excitability and improve cerebral functional activity in unconscious patients. To investigate the effects and the electrophysiological changes of repetitive transcranial magnetic stimulation cortical treatment, 10 stroke patients with non-severe brainstem lesions and with disturbance of consciousness were treated with repetitive transcranial magnetic stimulation. A quantitative electroencephalography spectral power analysis was also performed. The absolute power in the alpha band was increased immediately after the first repetitive transcranial magnetic stimulation treatment, and the energy was reduced in the delta band. The alpha band relative power values slightly decreased at 1 day post-treatment, then increased and reached a stable level at 2 weeks post-treatment. Glasgow Coma Score and JFK Coma Recovery Scale-Revised score were improved. Relative power value in the alpha band was positively related to Glasgow Coma Score and JFK Coma Recovery Scale-Revised score. These data suggest that repetitive transcranial magnetic stimulation is a noninvasive, safe, and effective treatment technology for improving brain functional activity and promoting awakening in unconscious stroke patients.

  20. Performance analysis of a zeotropic mixture (R290/CO2) for trans-critical power cycle☆

    Institute of Scientific and Technical Information of China (English)

    Lisheng Pan; Xiaolin Wei; Weixiu Shi

    2015-01-01

    Low critical temperature limits the application of CO2 trans-critical power cycle. The binary mixture of R290/CO2 has higher critical temperature. Using mixture fluid may solve the problem that subcritical CO2 is hardly con-densed by conventional cooling water. In this article, theoretical analysis is executed to study the performance of the zeotropic mixture for trans-critical power cycle using low-grade liquid heat source with temperature of 200 °C. The results indicated that the problem that CO2 can't be condensed in power cycle by conventional cooling water can be solved by mixing R290 to CO2. Variation trend of outlet temperature of thermal oil in super-critical heater with heating pressure is determined by the composition of the mixture fluid. Gliding temperature causes the maximum outlet temperature of cooling water with the increase of mass fraction of R290. There are the maximum values for cycle thermal efficiency and net power output with the increase of supercritical heating pressure.

  1. Life cycle assessment of fossil and biomass power generation chains. An analysis carried out for ALSTOM Power Services

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Ch.

    2008-12-15

    This final report issued by the Technology Assessment Department of the Paul Scherrer Institute (PSI) reports on the results of an analysis carried out on behalf of the Alstom Power Services company. Fossil and biomass chains as well as co-combustion power plants are assessed. The general objective of this analysis is an evaluation of specific as well as overall environmental burdens resulting from these different options for electricity production. The results obtained for fuel chains including hard coal, lignite, wood, natural gas and synthetic natural gas are discussed. An overall comparison is made and the conclusions drawn from the results of the analysis are presented.

  2. Novel wave power analysis linking pressure-flow waves, wave potential, and the forward and backward components of hydraulic power.

    Science.gov (United States)

    Mynard, Jonathan P; Smolich, Joseph J

    2016-04-15

    Wave intensity analysis provides detailed insights into factors influencing hemodynamics. However, wave intensity is not a conserved quantity, so it is sensitive to diameter variations and is not distributed among branches of a junction. Moreover, the fundamental relation between waves and hydraulic power is unclear. We, therefore, propose an alternative to wave intensity called "wave power," calculated via incremental changes in pressure and flow (dPdQ) and a novel time-domain separation of hydraulic pressure power and kinetic power into forward and backward wave-related components (ΠP±and ΠQ±). Wave power has several useful properties:1) it is obtained directly from flow measurements, without requiring further calculation of velocity;2) it is a quasi-conserved quantity that may be used to study the relative distribution of waves at junctions; and3) it has the units of power (Watts). We also uncover a simple relationship between wave power and changes in ΠP±and show that wave reflection reduces transmitted power. Absolute values of ΠP±represent wave potential, a recently introduced concept that unifies steady and pulsatile aspects of hemodynamics. We show that wave potential represents the hydraulic energy potential stored in a compliant pressurized vessel, with spatial gradients producing waves that transfer this energy. These techniques and principles are verified numerically and also experimentally with pressure/flow measurements in all branches of a central bifurcation in sheep, under a wide range of hemodynamic conditions. The proposed "wave power analysis," encompassing wave power, wave potential, and wave separation of hydraulic power provides a potent time-domain approach for analyzing hemodynamics.

  3. Voltage security margin in power systems using fuzzy inference system and QV sensitivity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ceron, D.; Rios, M.; Herrera, T.; Torres, A. [Los Andes Univ., Bogota (Colombia)

    2009-07-01

    Voltage stability is a primary limiting phenomenon for different operating conditions in modern power systems. As a result of significant events related to this phenomenon, such as blackouts in large metropolitan centres around the world, there is a need to have diagnostic models for real time application. The importance of voltage collapse has increased in power systems security assessment. This paper discussed an approach to predict a security index of power systems for forecasted operating points based on a voltage security diagnostic and a modal analysis of QV sensitivity matrix in regard to the voltage stability modeling with fuzzy inference systems (ANFIS). The study involved local input variables such as active and reactive line power flows. The variables were then reduced by principal component analysis. In order to find a security index for the inference process, two methods were employed. One method utilized the loading parameter of the continuation power flow while the other method utilized a QV modal analysis criteria. The methodologies enabled the calculation of the distance from the current operation point to the collapse point. The approaches took into account different possible conditions in a day-ahead operating plan. The methodologies were then tested and validated with the RTS-96 single area and the computer times of each method were compared. Specifically, the paper presented the methodology in terms of database construction; contingency ranking; variable selection; and fuzzy inference process. The test results were also presented. It was concluded that fuzzy logic is a good identification tool based on the system behaviour data. 14 refs., 5 tabs., 5 figs.

  4. Thermal design and analysis of high power star sensors

    Directory of Open Access Journals (Sweden)

    Fan Jiang

    2015-09-01

    Full Text Available The requirement for the temperature stability is very high in the star sensors as the high precision needs for the altitude information. Thermal design and analysis thus is important for the high power star sensors and their supporters. CCD, normally with Peltier thermoelectric cooler (PTC, is the most important sensor component in the star sensors, which is also the main heat source in the star sensors suite. The major objective for the thermal design in this paper is to design a radiator to optimize the heat diffusion for CCD and PTC. The structural configuration of star sensors, the heat sources and orbit parameters were firstly introduced in this paper. The influences of the geometrical parameters and coating material characteristics of radiators on the heat diffusion were investigated by heat flux analysis. Carbon–carbon composites were then chosen to improve the thermal conductivity for the sensor supporters by studying the heat transfer path. The design is validated by simulation analysis and experiments on orbit. The satellite data show that the temperatures of three star sensors are from 17.8 °C to 19.6 °C, while the simulation results are from 18.1 °C to 20.1 °C. The temperatures of radiator are from 16.1 °C to 16.8 °C and the corresponding simulation results are from 16.0 °C to 16.5 °C. The temperature variety of each star sensor is less than 2 °C, which satisfies the design objectives.

  5. Power spectrum analysis for defect screening in integrated circuit devices

    Science.gov (United States)

    Tangyunyong, Paiboon; Cole Jr., Edward I.; Stein, David J.

    2011-12-01

    A device sample is screened for defects using its power spectrum in response to a dynamic stimulus. The device sample receives a time-varying electrical signal. The power spectrum of the device sample is measured at one of the pins of the device sample. A defect in the device sample can be identified based on results of comparing the power spectrum with one or more power spectra of the device that have a known defect status.

  6. Green Demonstrated Analysis on Structure of Our Electric Power Resource

    Institute of Scientific and Technical Information of China (English)

    YANG Jun-bao; YU Jing; CHEN Jin-jing

    2004-01-01

    According to green view and history data, the demonstrated method is applied to analyze the green rationality on the present structure of thermal, hydraulic and nuclear electric power resource; the green trend of large-scale on thermal power generating unit in our history; the distribution of between water and coal resource with the space structure of electric power installed capacity, and recommending the premise, dominance and direction of building our green electric power structure in the future.

  7. Remaining Life Analysis of Boiler Tubes on Behalf of Hoop Stresses Produced During Operation of Power Plant

    Directory of Open Access Journals (Sweden)

    Mohd. Zeeshan Gauri

    2014-07-01

    Full Text Available Boiler tube material plays an important role in efficient power generation from a fossil fuel power plant. In order to meet out the gap between fluids to increase heat available per unit mass flow of steam. Waste heat utilization phenomenon is a big challenge on fossil fuel power plants as after use of high grade coal in thermal power plants the efficiency of power plants is not at the level of required value. Clean and efficient power generation with economical aspects is the basic need of growing power generation plants to justify the quality of power and clean power generation. Life analysis technique to calculate remaining life of boiler tubes at critical zones of high temperature requires much attention and is an important hypothesis in research field. Generation of repetitive and fluctuating stress during flow of high temperature and pressure fluid require proper attention on the methodology to be used to calculate the efficiency of system and absorption efficiency of tube material. In this paper complete mathematical analysis of boiler tubes is conducted for calculation of remaining life of boiler tubes, Hoop stress values are calculated and used with mathematical tool to calculate the efficiency. Hoop stress based calculation of efficiency is more reliable and may give more accurate and practical aspects based results.

  8. Time series power flow analysis for distribution connected PV generation.

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, Robert Joseph; Quiroz, Jimmy Edward; Ellis, Abraham; Reno, Matthew J.; Smith, Jeff; Dugan, Roger

    2013-01-01

    Distributed photovoltaic (PV) projects must go through an interconnection study process before connecting to the distribution grid. These studies are intended to identify the likely impacts and mitigation alternatives. In the majority of the cases, system impacts can be ruled out or mitigation can be identified without an involved study, through a screening process or a simple supplemental review study. For some proposed projects, expensive and time-consuming interconnection studies are required. The challenges to performing the studies are twofold. First, every study scenario is potentially unique, as the studies are often highly specific to the amount of PV generation capacity that varies greatly from feeder to feeder and is often unevenly distributed along the same feeder. This can cause location-specific impacts and mitigations. The second challenge is the inherent variability in PV power output which can interact with feeder operation in complex ways, by affecting the operation of voltage regulation and protection devices. The typical simulation tools and methods in use today for distribution system planning are often not adequate to accurately assess these potential impacts. This report demonstrates how quasi-static time series (QSTS) simulation and high time-resolution data can be used to assess the potential impacts in a more comprehensive manner. The QSTS simulations are applied to a set of sample feeders with high PV deployment to illustrate the usefulness of the approach. The report describes methods that can help determine how PV affects distribution system operations. The simulation results are focused on enhancing the understanding of the underlying technical issues. The examples also highlight the steps needed to perform QSTS simulation and describe the data needed to drive the simulations. The goal of this report is to make the methodology of time series power flow analysis readily accessible to utilities and others responsible for evaluating

  9. Energy and cost analysis of small-size integrated coal gasification and syngas storage power plants

    International Nuclear Information System (INIS)

    Highlights: ► The option of syngas storage in small size coal gasification power plants is proposed. ► Syngas storage enhances flexibility and load modulation capabilities of coal gasification power plants. ► Performance and energy production costs greatly depend on the required peaking energy production. ► Solutions based on internal combustion engines perform better than solutions based on gas turbines. ► Peaking energy production costs are comparable with those of conventional peaking units. - Abstract: This study evaluates the energy and economic performance of small and medium size coal gasification power plants integrated with a syngas storage section (ICGSS). In ICGSS systems, a portion of the produced syngas is stored during periods of low energy demand and used to increase power output during periods of peaking demand, so that they can perform a load-following service and can operate in the electricity markets for energy and spinning reserve. The main energy and economic performance of ICGSS power generation plants were evaluated with reference to two different prime movers (gas turbines and internal combustion engines) and as a function of the required electrical load curve. Moreover, a preliminary economic analysis was also carried out to evaluate the peak-load energy production cost in comparison with base-load energy production cost. The results of the study show that ICGSS power plants offer considerable scope for enhancing operating flexibility and load modulation capabilities of coal gasification power plants. Plant options based on internal combustion engines performed better than options based on gas turbines.

  10. TAL Performance and Mission Analysis in a CDL Capacitor Powered Direct-Drive Configuration

    Science.gov (United States)

    Hrbud, Ivana; Rose, M. Frank; Oleson, Steve R.; Jenkins, Rhonald M.

    1999-01-01

    The goals of this research are (1) to prove the concept feasibility of a direct-drive electric propulsion system, and (2) to evaluate the performance and characteristics of a Russian TAL (Thruster with Anode Layer) operating in a long-pulse mode, powered by a capacitor-based power source developed at Space Power Institute. The TAL, designated D-55, is characterized by an external acceleration zone and is powered by a unique chemical double layer (CDL) capacitor bank with a capacitance of 4 F at a charge voltage of 400 V. Performance testing of this power supply on the TAL was conducted at NASA Lewis Research Center in Cleveland, OH. Direct thrust measurements of the TAL were obtained at CDL power levels ranging from 450 to 1750 W. The specific impulse encompassed a range from 1150 s to 2200 s, yielding thruster system efficiencies between 50 and 60%. Preliminary mission analysis of the CDL direct-drive concept and other electric propulsion options was performed for the ORACLE spacecraft in 6am/6pm and 12am/12pm, 300 km sun-synchronous orbits. The direct-drive option was competitive with the other systems by increasing available net mass between 5 and 42% and reducing two-year system wet mass between 18 and 63%. Overall, the electric propulsion power requirements for the satellite solar array were reduced between 57 and 91% depending oil the orbit evaluated The direct-drive, CDL capacitor-based concept in electric propulsion thus promises to be a highly-efficient, viable alternative for satellite operations in specific near-Earth missions.

  11. Sharing wind power forecasts in electricity markets: A numerical analysis

    DEFF Research Database (Denmark)

    Exizidis, Lazaros; Pinson, Pierre; Kazempour, Jalal;

    2016-01-01

    -ahead decisions to adjust power imbalances. This sequential market-clearing process may cope with serious operational challenges such as severe power shortage in real-time due to erroneous wind power forecasts in day-ahead market. To overcome such situations, several solutions can be considered such as adding...

  12. Analysis of North Sea Offshore Wind Power Variability

    NARCIS (Netherlands)

    Buatois, A.; Gibescu, M.; Rawn, B.G.; Van der Meijden, M.A.M.M.

    2014-01-01

    This paper evaluates, for a 2030 scenario, the impact on onshore power systems in terms of the variability of the power generated by 81 GW of offshore wind farms installed in the North Sea. Meso-scale reanalysis data are used as input for computing the hourly power production for offshore wind farms

  13. Newton-Krylov Methods in Power Flow and Contingency Analysis

    NARCIS (Netherlands)

    Idema, R.

    2012-01-01

    A power system is a system that provides for the generation, transmission, and distribution of electrical energy. Power systems are considered to be the largest and most complex man-made systems. As electrical energy is vital to our society, power systems have to satisfy the highest security and re

  14. Integrating Wind Power in Electricity Grids : an Economic Analysis

    NARCIS (Netherlands)

    Liu, J.; Kooten, van G.C.; Pitt, L.

    2005-01-01

    As a renewable energy source, wind power is gaining popularity as a favoured alternative to fossil fuel, nuclear and hydro power generation. In Europe, countries are required to achieve 15% of their energy consumption from wind by 2010 as the EU strives to meet its Kyoto obligations. Wind power is c

  15. Post-processing of polymer foam tissue scaffolds with high power ultrasound: A route to increased pore interconnectivity, pore size and fluid transport

    Energy Technology Data Exchange (ETDEWEB)

    Watson, N.J. [School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT (United Kingdom); Johal, R.K. [Division of Immunology, School of Molecular Medical Sciences, Queen' s Medical Centre, University of Nottingham, Nottingham NG7 2UH (United Kingdom); Glover, Z. [School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT (United Kingdom); Reinwald, Y.; White, L.J. [School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Ghaemmaghami, A.M. [Division of Immunology, School of Molecular Medical Sciences, Queen' s Medical Centre, University of Nottingham, Nottingham NG7 2UH (United Kingdom); Morgan, S.P. [Electrical Systems and Optics Research Division, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Rose, F.R.A.J. [School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Povey, M.J.W. [School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT (United Kingdom); Parker, N.G., E-mail: nick.parker@ncl.ac.uk [School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT (United Kingdom); School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2013-12-01

    The aim of this work is to demonstrate that the structural and fluidic properties of polymer foam tissue scaffolds, post-fabrication but prior to the introduction of cells, can be engineered via exposure to high power ultrasound. Our analysis is supported by measurements of fluid uptake during insonification and imaging of the scaffold microstructure via X-ray computed tomography, scanning electron microscopy and acoustic microscopy. The ultrasonic treatment is performed with a frequency of 30 kHz, average intensities up to 80,000 Wm{sup −2} and exposure times up to 20 h. The treatment is found to increase the mean pore size by over 10%. More striking is the improvement in fluid uptake: for scaffolds with only 40% water uptake via standard immersion techniques, we can routinely achieve full saturation of the scaffold over approximately one hour of exposure. These desirable modifications occur with negligible loss of scaffold integrity and mass, and are optimized when the ultrasound treatment is coupled to a pre-wetting stage with ethanol. Our findings suggest that high power ultrasound is highly targeted towards flow obstructions in the scaffold architecture, thereby providing an efficient means to promote pore interconnectivity and fluid transport in thick foam tissue scaffolds. - Highlights: • We expose thick PLA foam tissue scaffolds to high power ultrasound. • This treatment both accelerates and enhances the uptake of fluid into the scaffold. • It leads to significant increases in the mean pore size, pore interconnectivity and porosity. • The ultrasonic treatment is most effective when the scaffold is pre-wet with ethanol. • We demonstrate the use of acoustic microscopy to characterize the scaffold microstructure.

  16. Modifications of EEG power spectra in mesial temporal lobe during n-back tasks of increasing difficulty. A sLORETA study.

    Science.gov (United States)

    Imperatori, Claudio; Farina, Benedetto; Brunetti, Riccardo; Gnoni, Valentina; Testani, Elisa; Quintiliani, Maria I; Del Gatto, Claudia; Indraccolo, Allegra; Contardi, Anna; Speranza, Anna M; Della Marca, Giacomo

    2013-01-01

    The n-back task is widely used to investigate the neural basis of Working Memory (WM) processes. The principal aim of this study was to explore and compare the EEG power spectra during two n-back tests with different levels of difficulty (1-back vs. 3-back). Fourteen healthy subjects were enrolled (seven men and seven women, mean age 31.21 ± 7.05 years, range: 23-48). EEG was recorded while performing the N-back test, by means of 19 surface electrodes referred to joint mastoids. EEG analysis were conducted by means of the standardized Low Resolution brain Electric Tomography (sLORETA) software. The statistical comparison between EEG power spectra in the two conditions was performed using paired t-statistics on the coherence values after Fisher's z transformation available in the LORETA program package. The frequency bands considered were: delta (0.5-4 Hz); theta (4.5-7.5 Hz); alpha (8-12.5 Hz); beta (13-30 Hz); gamma (30.5-100 Hz). Significant changes occurred in the delta band: in the 3-back condition an increased delta power was localized in a brain region corresponding to the Brodmann Area (BA) 28 in the left posterior entorhinal cortex (T = 3.112; p < 0.05) and in the BA 35 in the left perirhinal cortex in the parahippocampal gyrus (T = 2.876; p < 0.05). No significant differences were observed in the right hemisphere and in the alpha, theta, beta, and gamma frequency bands. Our results indicate that the most prominent modification induced by the increased complexity of the task occur in the mesial left temporal lobe structures.

  17. Modifications of EEG Power Spectra in Mesial Temporal Lobe during n-back tasks of increasing difficulty. A sLORETA study.

    Directory of Open Access Journals (Sweden)

    Claudio eImperatori

    2013-04-01

    Full Text Available The n-back task is widely used to investigate the neural basis of Working Memory (WM processes. The principal aim of this study was to explore and compare the EEG power spectra during two n-back tests with different levels of difficulty (1-back vs 3-back.Fourteen healthy subjects were enrolled (7 men and 7 women, mean age 31.21±7.05 years, range: 23-48. EEG was recorded while performing the N-back test, by means of 19 surface electrodes referred to joint mastoids. EEG analysis were conducted by means of the standardized LOw Resolution brain Electric Tomography (sLORETA software. The statistical comparison between EEG power spectra in the two conditions was performed using paired t-statistics on the coherence values after Fisher’s z transformation available in the LORETA program package. The frequency bands considered were: delta (0.5-4 Hz; theta (4.5–7.5 Hz; alpha (8–12.5 Hz; beta (13–30 Hz; gamma (30.5–100 Hz. Significant changes occurred in the delta band: in the 3-back condition an increased delta power was localized in a brain region corresponding to the Brodmann Area (BA 28 in the left posterior entorhinal cortex (T = 3.112; p<0.05 and in the BA 35 in the left peririnhal cortex in the parahippocampal gyrus (T = 2.876; p<0.05. No significant differences were observed in the right hemisphere and in the alpha, theta, beta and gamma frequency bands. Our results indicate that the most prominent modification induced by the increased complexity of the task occur in the mesial left temporal lobe structures.

  18. Post-processing of polymer foam tissue scaffolds with high power ultrasound: A route to increased pore interconnectivity, pore size and fluid transport

    International Nuclear Information System (INIS)

    The aim of this work is to demonstrate that the structural and fluidic properties of polymer foam tissue scaffolds, post-fabrication but prior to the introduction of cells, can be engineered via exposure to high power ultrasound. Our analysis is supported by measurements of fluid uptake during insonification and imaging of the scaffold microstructure via X-ray computed tomography, scanning electron microscopy and acoustic microscopy. The ultrasonic treatment is performed with a frequency of 30 kHz, average intensities up to 80,000 Wm−2 and exposure times up to 20 h. The treatment is found to increase the mean pore size by over 10%. More striking is the improvement in fluid uptake: for scaffolds with only 40% water uptake via standard immersion techniques, we can routinely achieve full saturation of the scaffold over approximately one hour of exposure. These desirable modifications occur with negligible loss of scaffold integrity and mass, and are optimized when the ultrasound treatment is coupled to a pre-wetting stage with ethanol. Our findings suggest that high power ultrasound is highly targeted towards flow obstructions in the scaffold architecture, thereby providing an efficient means to promote pore interconnectivity and fluid transport in thick foam tissue scaffolds. - Highlights: • We expose thick PLA foam tissue scaffolds to high power ultrasound. • This treatment both accelerates and enhances the uptake of fluid into the scaffold. • It leads to significant increases in the mean pore size, pore interconnectivity and porosity. • The ultrasonic treatment is most effective when the scaffold is pre-wet with ethanol. • We demonstrate the use of acoustic microscopy to characterize the scaffold microstructure

  19. Thermodynamic analysis of a thermoelectric power generator in relation to geometric configuration device pins

    International Nuclear Information System (INIS)

    Highlights: • The influence of pin leg geometry on thermal performance of a thermoelectric device is studied. • The exponential area variation of pin legs is considered in analysis. • The influence of geometric variation on efficiency and power output is demonstrated. • It is found that increasing dimensionless geometric parameter improves the thermal efficiency of the device. • The point of maximum efficiency does not coincide with the point of the maximum device output power. - Abstract: Thermoelectric generators (TEG) are cost effective solid-state devices with low thermal efficiencies. The limitations, due to the operational temperature of the thermoelectric materials, suppress the Carnot efficiency increase of the device. Although thermoelectric generators have considerable advantages over the other renewable energy devices, low convergence efficiency of the device retains thermoelectric devices behind its competitors. In order to keep up with the competition, improvement of device efficiency becomes crucial for the practical applications. The design configuration of the device pin legs, lowering the overall thermal conductance, can improve the device efficiency. Therefore, in the present study, the influence of pin leg geometry on thermal performance of the device is formulated thermodynamically. In this case, the exponential area variation of pin legs is considered and dimensionless geometric parameter ‘a’ is introduced in analysis. The influence of dimensionless geometric parameter on efficiency and power output is demonstrated for different temperature ratios and external load resistance ratios. It is found that increasing dimensionless geometric parameter improves the thermal efficiency of the device; however, the point of maximum efficiency does not coincide with the point of the maximum device output power

  20. Power

    OpenAIRE

    Hafford-Letchfield, Trish

    2015-01-01

    This chapter looks at the concept of power in social work by focusing on what this means as a ‘professional’ and theorizes competing discourses of empowerment in social work and its key concepts, drawing in particular on the explanatory powers of critical theorist Michel Foucault (1991). The chapter problematizes the concept of power by explicitly drawing on both users’ and carers’ accounts from the literature to demonstrate different external and internal influences on the root causes of dis...