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IEEE General Meeting Power& Energy Society

作者： R.T. Guttromson Pacific Northwest Nat. Lab. Richland WA USA

As distributed energy resource (DER) projects grow in popularity, there has been little focus on their potential to influence the dynamic stability of a transmission system. If implemented in large enough numbers, DER equipment may feasibly be leveraged to provide ancillary services such as spinning reserve, system inertia, or system stabilization. To determine the potential impacts of DER on future transmission grid stability, dynamic models of DER load combinations were created, reduced in order, and scattered throughout central and southern California within an existing western systems coordinating council (WSCC) dynamic model. Evaluation of the composite WSCC-DER dynamic model allows correlations to be drawn between various DER properties and the transmission grid stability. Key findings show that increasing DER inertia tends to destabilize the transmission system. The cause of this counterintuitive relationship requires further study but likely is related to the high impedance separating the DER from the transmission grid.

关键词： Energy resources density estimation robust algorithm Stability Laboratories USA Councils Spinning Load modeling Scattering Impedance Signal generators

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Wavelength-selectable DBR laser array inherently free from mode-hopping for high-speed switching

Wavelength-selectable DBR laser array inherently free from m...

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Optical Fiber Communication (OFC) Conference

作者： Y. Tohmori N. Fujiwara T. Kakitsuka Y. Shibata F. Kano M. Ishikawa Y. Kawaguchi H. Okamoto Y. Kondo Y. Yoshikuni NTT Photonics Laboratories Kanagawa Japan

We demonstrated inherently mode-hop-free wavelength tuning of 4.45 nm in a DBR laser with a short active-region. Dynamic characteristics on error-free operation and fast switching are confirmed. A wavelength-selectabl... 详细信息

ISBN: (纸本)1557527318

关键词： Distributed Bragg reflectors Laser tuning Laser modes Semiconductor laser arrays Optical tuning density estimation robust algorithm Photonics Error-free operation High speed optical techniques Laser transitions

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Power network planning for high penetration of dispersed energy resources. Optimal multi-criteria planning method

Power network planning for high penetration of dispersed ene...

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IEEE PES Transmission and Distribution Conference and Exposition

作者： A. Orths Otto-von-Guericke University of Magdeburg Magdeburg Germany

The conditions for power network planning in Germany have changed due to the liberalization of the energy market and the legal promotion of dispersed energy resources (DER). To meet these new requirements, an effective multi-criteria optimization method based on game theory has been developed, describing the technical-economical dependencies and the limitations caused by competition. Planning criteria such as economical, technical and operational conditions as well as reliability are considered with respect to their interaction with the energy market. To use this method, dynamic calculations concerning the behavior of DER are necessary for finding the optimal network structure. Suitable models for these simulations recently have been developed and are used during the optimization process. With this combination of the new planning method and DER-models an effective planning tool has been developed for the changed planning environment. A planning example is given to demonstrate the process and its results.

关键词： Energy resources density estimation robust algorithm Process planning Law Legal factors Game theory Power generation economics Environmental economics Legislation Cost function

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Dynamic simulation of fuel cells and microturbines integrated with a multimachine network

Dynamic simulation of fuel cells and microturbines integrate...

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Power Tech Conference

作者： A.M. Azmy I. Erlich Institute of Electrical Power Systems University of Duisburg-Essen Germany

The paper discusses aspects of dynamic modelling and simulation of fuel cell and microturbine units as a part of a multi-machine electrical network. The focus is on the consideration of a large number of units connected to different low voltage nodes. In the study, the total power generated in decentralized units reaches up to 30% of the 110 kV network demands. Therefore, it is expected that decentralized sources impact the dynamic behaviour of the high voltage network and vice versa. Hence, the investigated power system comprises also the high voltage grid and the corresponding conventional power plants supplying into this network. To evaluate the performance of the network, various disturbances are applied and the results are discussed.

关键词： Fuel cells Turbines Power system modeling density estimation robust algorithm Power system dynamics Power generation Power system reliability Power system simulation Low voltage Power system analysis computing

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Batteries for stationary standby and for stationary cycling applications part 1: standby vs. cycling - definitions and concepts

Batteries for stationary standby and for stationary cycling ...

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IEEE General Meeting Power& Energy Society

作者： R.L. Hammond S. Everingham D. Srinivasan Arizona State University AZ USA Arizona State University USA Advanced Energy Systems Inc. USA

This paper is introductory and provides a basis for understanding the fundamental differences between the two primary applications of stationary lead-acid batteries: standby and cycling. It sets the baseline for the use of the terminology, standby (not stationary) vs. cycling, power vs. energy, and charging efficiency. Application requirements define the need for fundamentally different designs and construction for power batteries and energy batteries. A typical stand-alone remote home application is used as an example to graphically illustrate daily cycling characteristics. Factors that typically limit battery life for standby and cycling batteries are discussed. Finally, available standards for cycling applications (SCC21) and standby applications (PES/SB-SCC29) are discussed.

关键词： Batteries Fault location Energy storage Dictionaries Uninterruptible power systems Photovoltaic systems density estimation robust algorithm Terminology Emergency power supplies Power systems

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Batteries for stationary standby and for stationary cycling applications introduction

Batteries for stationary standby and for stationary cycling ...

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IEEE General Meeting Power& Energy Society

作者： G.P. Corey Sandia National Laboratories Albuquerque NM USA

The term "stationary battery" tends to conjure up many interpretations among power engineers, depending on one's perspectives on battery energy storage. The primary application that immediately comes to mind is that for standby or UPS use, but that is not the only application for stationary batteries. Currently, changes are underway where large stationary batteries are being used in grid-tied cycling applications for distributed energy resource systems. The current IEEE standards developed for standby application do not apply to these new stationary applications, but many engineers are totally unaware of the not-so-subtle differences in standby battery and cycling battery O&M requirements. The purpose of this paper is to introduce engineers are using stationary batteries in cycling applications to the differences in battery system management standards currently in use in the IEEE to preclude the improper application of standards for standby applications with those intended for cycling applications.

关键词： Batteries Standards development Power engineering and energy Energy storage Uninterruptible power systems Energy resources Automotive engineering density estimation robust algorithm Laboratories Terminology

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Probing the van der Waals atom-surface interaction in the non-zero temperature limit

Probing the van der Waals atom-surface interaction in the no...

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European Conference on Quantum Electronics (EQEC)

作者： I. Hamdi P.C. Segundo G. Dutier P. Valente H. Failache J.R.R. Leite M.-P. Gorza M. Fichet D. Bloch M. Ducloy Laboratoire de Physique des Lnsers. UMR 7538 du CNRS Université Paris 1 Villetaneuse France Laboratoire de Physique des Lasers Université Paris 13 99Av. JB Clément Yilletaneuse France Universidade Federal da Paraiba Joan Pessoa Brazil Universidad de la Republica Montevideo Uruguay Universidade Federal de Pernambuco Recife Brazil

This reports on the surface attraction exerted onto Cs(8P), as measured through the selective reflection spectroscopy (SR) technique via a one- photon excitation at 388 nm from the ground state. In a series of experiments on the Cs (6S/sub 1/2/-8P/sub 3/2/) transition in front of a sapphire surface, the accuracy in the van der Waals evaluation, and with an improved fitting method, should be on the order of 10%. Further developments, expected to be reported too, concern the fine structure component Cs (6S/sub 1/2/-8P/sub 3/2/) , along with a study of SR spectroscopy at various interfaces.

关键词： density estimation robust algorithm Atomic measurements Strontium Spectroscopy Dielectric measurements Temperature distribution Temperature sensors Reflection Surface fitting Absorption

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Are polymorphisms of the SDF1 and CCR2b genes related to the course of hepatitis C or HIV/HCV co-infection?

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DEUTSCHE MEDIZINISCHE WOCHENSCHRIFT 2002年第36期127卷 1807-1812页

作者： Woitas, RP Ahlenstiel, G Iwan, A Rockstroh, JK Brackmann, HH Kupfer, B Matz, B Offergeld, R Sauerbruch, T Spengler, U Univ Bonn Med Klin & Poliklin 1 D-53105 Bonn Germany Univ Bonn Inst Expt Hamatol & Transfus Med D-53105 Bonn Germany Univ Bonn Inst Med Mikrobiol & Immunol D-53105 Bonn Germany

Background and objective: Complementary to the CCR5-Delta32 mutation polymorphisms in the genes of CCR2b (CCR2b-V64 I) and stromal derived factor (SDF)-1 (SDF-1 3'A) affect the course of the human immunodeficiency virus (HIV) infection. While the CCR5-Delta32 mutation is also increased in chronic hepatitis C virus (HCV) infection it is unclear, whether the CCR2b-V64 I and the SDF-1 3'A polymorphisms also are associated with chronic HCV infection. Methods: We analyzed the frequencies of the CCR2b-V64I and SDF1-3'A mutation in patients with HIV/HCV coinfection (n = 130), HIV infection (n = 105), HCV infection (n = 153) and 112 healthy blood donors. We stratified each group into homozygous mutations, heterozygous mutations and homozygous wildtypes, respectively. The resulting subsets were compared with respect to HIV and HCV loads, CD4 and CD8 cell counts. Results: The mutant SDF1-3'A allele was found at 20.3% frequency in patients with HCV infection and at 20.4% frequency in patients with HIV/HCV coinfection, respectively. It was present in 27.1% of the patients with HIV infection and 27.9% of the healthy controls (not significant). The number of SDF-1 3'A homozygous patients was highest in patients with HIV/HCV coinfection and significantly different compared to the Hardy-Weinberg equilibrium (p = 0.010, chi(2) = 9.15). However, CD4- and CD8-cell counts or viral loads were not affected by this mutation. The frequency of the CCR2b-V64 I allele was similar in all patient groups. However, CCR2b-V64 I heterozygous patients showed HIV loads that were threefold lower than in CCR2b wildtype patients (22.9 x 10(3) vs. 6.4 x 10(3) copies/ml, not significant). Furthermore, hepatitis C viral loads were reduced roughly by 30%. Conclusion: These results suggest that the SDF1-3'A and CCR2b-V64I mutations do not affect the course of HCV and HIV/HCV infection in the same manner as does the CCR5-Delta32 mutation.

关键词： Human immunodeficiency virus infection diagnosis Human immunodeficiency virus infection drug therapy HIV Infections CXCL12 gene density estimation robust algorithm Mutation HIV Hepatitis C COL14A1 gene CD8-Positive T-Lymphocytes Patients Chemokine CXCL12

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A scissors-effect in career development of female and male medical doctors

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DEUTSCHE MEDIZINISCHE WOCHENSCHRIFT 2002年第40期127卷 2057-2062页

作者： Abele, AE Nitzsche, U Univ Erlangen Nurnberg Lehrstuhl Sozialpsychol D-91054 Erlangen Germany

Background and objective: Women are equally interested in studying medicine as men, and there is an equal proportion of female and male graduates in medicine. Women's occupational careers in medicine, however, are on the average less successful than men's. Whereas there are already many cross-sectional studies on this issue the present paper reports data of a prospective longitudinal study. Participants and methods: Participants were 139 female graduates and 172 male medical graduates. These were questioned three times, after their second "Staatsexamen", one and a half years later during their practical medical training time, and again one and a half years later within their specialized training. The questionnaires tapped performance data, occupacional self-efficacy, attitudes, goals, work satisfaction, experience of work situation, occupational development and private development. Results: There were no gender differences in grades, study duration, occupational self-efficacy and goals immediately after the exam. Experience of the work situation as well as work satisfaction did not differ, either. However, at time three female medical doctors were less often full-time employed than their male colleagues. This pertained not only to mothers but also to childless women. Full-time employed women often were singles without a partner. There were also gender differences in the expectations how occupation and family should be combined. Psychologically, women experienced a decrease in occupational self-efficacy, whereas men experienced an increase. Both equivocal female gender-role expectations and unfavorable organizational conditions of medical training are important for this development. Conclusion: The compatibility between work and family must be seen as a societal task. Otherwise many well-trained female medicine doctors will quit their jobs and as a consequence there will be a lack of doctors in the future.

关键词： physician career Self Efficacy Career Development graduate gender difference full-time employed Medicine COL14A1 gene Otolaryngologists Industrial career Female density estimation robust algorithm Job Satisfaction

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Developing a "next generation" PV inverter

Developing a "next generation" PV inverter

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Conference Record of the Twenty-Ninth IEEE Photovoltaic Specialists Conference, 2002.

作者： R.H. Bonn Sandia National Laboratories Albuquerque NM USA

The most serious reliability issue for photovoltaics (PV) is the inverter. Mean time to first failure (MTFF) is estimated to be about five years. Recent efforts to rapidly expand the production of grid-tied inverters have not resulted in improved reliability. At this time the inverter industry is uniquely positioned to develop a 'next generation' inverter that has ten-year MTFF, better performance and lower cost. The recent advents of new technologies such as DSP (digital signal processing), the growth in sales to a few hundred thousand inverters per year and the emergence of larger companies with interest in PV inverters make this possible today. At this time the Department of Energy is considering the development of a new inverter for use in distributed energy applications. This report summarizes the status of power electronics today, identifies technology issues, and identifies inverter manufacturer attributes thought to be essential for the production of a ten-year lifetime inverter.

关键词： Inverters Costs Production Digital signal processing Redundancy density estimation robust algorithm Manufacturing processes Laboratories Photovoltaic cells Marketing and sales

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