Social Security reform: evaluating current proposals. Latest results of the EBRI-SSASIM2 policy simulation model.

Science.gov (United States)

Copeland, C; VanDerhei, J; Salisbury, D L

1999-06-01

The present Social Security program has been shown to be financially unsustainable in the future without modification to the current program. The purpose of this Issue Brief, EBRI's fourth in a series on Social Security reform, is threefold: to illustrate new features of the EBRI-SSASIM2 policy simulation model not available in earlier EBRI publications, to expand quantitative analysis to specific proposals, and to evaluate the uncertainty involved in proposals that rely on equity investment. This analysis compares the Gregg/Breaux-Kolbe/Stenholm (GB-KS) and Moynihan/Kerrey proposals with three generic or "traditional" reforms: increasing taxes, reducing benefits, and/or increasing the retirement age. Both proposals would create individual accounts by "carving out" funds from current Social Security payroll taxes. This analysis also examines other proposed changes that would "add on" to existing Social Security funds through the use of general revenue transfers and/or investment in the equities market. President Clinton has proposed a general revenue transfer and the collective investment of some of the OASDI trust fund assets in equities. Reps. Archer and Shaw have proposed a general revenue tax credit to establish individual accounts that would be invested partially in the equities markets. When comparing Social Security reform proposals that would specifically alter benefit levels, the Moynihan/Kerrey bill compares quite favorably with the other proposals in both benefit levels and payback ratios, when individuals elect to use the individual account option. In contrast, the GB-KS bills do not compare quite as favorably for their benefit levels, but do compare favorably in terms of payback ratios. An important comparison in these bills is the administrative costs of managing the individual accounts, since benefits can be lowered by up to 23 percent when going from the assumed low to high administrative costs. Moreover, allowing individuals to decide whether to

Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol

Directory of Open Access Journals (Sweden)

Radon Katja

2010-05-01

Full Text Available Abstract Background The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result, observed differences in exposure levels between study populations may not reflect real exposure differences but may be in part, or wholly due to methodological differences. Methods The aim of this paper is to develop a study protocol for future personal RF-EMF exposure studies based on experience drawn from previous research. Using the current knowledge base, we propose procedures for the measurement of personal exposure to RF-EMF, data collection, data management and analysis, and methods for the selection and instruction of study participants. Results We have identified two basic types of personal RF-EMF measurement studies: population surveys and microenvironmental measurements. In the case of a population survey, the unit of observation is the individual and a randomly selected representative sample of the population is needed to obtain reliable results. For microenvironmental measurements, study participants are selected in order to represent typical behaviours in different microenvironments. These two study types require different methods and procedures. Conclusion Applying our proposed common core procedures in future personal measurement studies will allow direct comparisons of personal RF-EMF exposures in different populations and study areas.

Neutral currents and parity breakdown in atomic transitions: three proposed experiments

International Nuclear Information System (INIS)

Bloom, S.D.

1976-01-01

This paper describes three proposed experiments for observing the breakdown of parity in atomic transitions due to the exchange of neutral, parity-violating currents arising from some of the new gauge models (e.g., the Weinberg model) for the weak interaction. The experiments are based on exploiting a suggestion, by Bouchiat and Bouchiat, that modern laser technology be utilized to produce intense, monochromatic, and polarized photon beams with which to excite forbidden atomic transitions of the basic form parallel ns 1 / 2 broken bracket → parallel n's 1 / 2 broken bracket. The asymmetries (of the order of 10 -4 ) in the de-exitation processes then signal the presence of the parity-violating components due to the neutral currents. In all three experiments suggested here, the use of multiple (uncollimated)atomic beams as targets forms a basic part, and their advantages over a temperature-equilibrium vapor are described. The first experiment uses 55 Cs atomic beams as a target; the second uses 37 Rb in conjunction with a superstrong magnetic field (approximately 80 kG); the third uses 81 Tl and requires frequency doubling of the exciting laser beam. All three experiments appear to be quite feasible, and, given the requisite equipment (much of which is or soon will be commercially available), they could yield definitive results in a period of a few months

Health effects of water-borne radon: review of a proposed study. Final report

International Nuclear Information System (INIS)

1986-01-01

The Science Advisory Board's Radiation Advisory Committee was requested to review the scientific merit of a proposal to conduct an epidemiological study of radon in indoor air. The Board accepted the request and formed a Radioepidemiology Subcommittee which responded to two overriding scientific issues: Can further epidemiological study contribute to an understanding of the risks of lung cancer associated with household exposures. The Subcommittee concludes that scientific uncertainties in current epidemiological studies (chiefly studies of uranium miners) could be further reduced through direct investigations of the domestic population. Is the proposed study under review by the Office of Research and Development, entitled Health Effects of Waterborne Radon, appropriately designed to address the risk. For reasons cited in the attached report, the Subcommittee concludes that it is not appropriately designed

Study of Co-Current and Counter-Current Gas-Liquid Two-Phase Flow Through Packed Bed in Microgravity

Science.gov (United States)

Revankar, Shripad T.

2002-11-01

The main goal of the project is to obtain new experimental data and development of models on the co-current and counter-current gas-liquid two-phase flow through a packed bed in microgravity and characterize the flow regime transition, pressure drop, void and interfacial area distribution, and liquid hold up. Experimental data will be obtained for earth gravity and microgravity conditions. Models will be developed for the prediction of flow regime transition, void fraction distribution and interfacial area concentration, which are key parameters to characterize the packed bed performance. Thus the specific objectives of the proposed research are to: (1) Develop experiments for the study of the gas liquid two-phase flow through the packed bed with three different flow combinations: co-current down flow, co-current upflow and counter current flow. (2) Develop pore scale and bed scale two-phase instrumentation for measurement of flow regime transition, void distribution and gas-liquid interfacial area concentration in the packed bed. (3) Obtain database on flow regime transition, pressure drop, void distribution, interfacial area concentration and liquid hold up as a function of bed characteristics such as bed particle size, porosity, and liquid properties such as viscosity and surface tension. (4) Develop mathematical model for flow regime transition, void fraction distribution and interfacial area concentration for co-current gas-liquid flow through the porous bed in gravity and micro gravity conditions.(4) Develop mathematical model for the flooding phenomena in counter-current gas-liquid flow through the porous bed in gravity and micro gravity conditions. The present proposal addresses the most important topic of HEDS-specific microgravity fluid physics research identified by NASA 's one of the strategic enterprises, OBPR Enterprise. The proposed project is well defined and makes efficient use of the ground-based parabolic flight research aircraft facility. The

Regional economic effects of current and proposed management alternatives for Arrowwood National Wildlife Refuge

Science.gov (United States)

Koontz, Lynne; Lambert, Heather

2005-01-01

The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a Refuge and provide long range guidance and management direction to achieve Refuge purposes. Arrowwood National Wildlife Refuge (NWR), located along the James River in east central North Dakota, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for Arrowwood NWR must contain an analysis of expected effects associated with current and proposed Refuge management strategies.

Regional economic impacts of current and proposed management alternatives for Charles M. Russell National Wildlife Refuge

Science.gov (United States)

Koontz, Lynne; Sexton, Natalie; Ishizaki, Asuka; Ritten, John

2013-01-01

The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a refuge and provide long-range guidance and management direction to achieve refuge purposes. Charles M. Russell (CMR) National Wildlife Refuge, located in north-central Montana, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for the Refuge must contain an analysis of expected effects associated with current and proposed refuge-management strategies. For refuge CCP planning, an economic analysis provides a means of estimating how current management (No Action Alternative) and proposed management activities (Alternatives) affect the local economy. This type of analysis provides two critical pieces of information: (1) it illustrates a refuge’s contribution to the local community; and (2) it can help in determining whether economic effects are or are not a real concern in choosing among management alternatives. It is important to note that the economic value of a refuge encompasses more than just the impacts on the regional economy. Refuges also provide substantial nonmarket values (values for items not exchanged in established markets) such as maintaining endangered species, preserving wetlands, educating future generations, and adding stability to the ecosystem (Carver and Caudill, 2007). However, quantifying these types of nonmarket values is beyond the scope of this study. This report first presents a description of the local community and economy near the Refuge. Next, the methods used to conduct a regional economic impact analysis are described. An analysis of the final CCP management strategies that could affect stakeholders and residents and the local economy is then presented. The refuge management activities of economic concern in this analysis are:

Cognitive-behavior therapy for problem gambling: a critique of current treatments and proposed new unified approach.

Science.gov (United States)

Tolchard, Barry

2017-06-01

There is evidence supporting the use of cognitive-behavioral therapy (CBT) in the treatment of problem gambling. Despite this, little is known about how CBT works and which particular approach is most effective. This paper aims to synthesize the evidence for current CBT and propose a more unified approach to treatment. A literature review and narrative synthesis of the current research evidence of CBT for the treatment of problem gambling was conducted, focusing on the underlying mechanisms within the treatment approach. Several CBT approaches were critiqued. These can be divided into forms of exposure therapy (including aversion techniques, systematic desensitization and other behavioral experiments) those focusing on cognitive restructuring techniques (such as reinforcement of nongambling activity, use of diaries, motivational enhancement and audio-playback techniques and third wave techniques including mindfulness. Findings, in relation to the treatment actions, from this synthesis are reported. The debate surrounding the treatment of problem gambling has been conducted as an either/or rather than a both/and discourse. This paper proposes a new, unified approach to the treatment of problem gambling that incorporates the best elements of both exposure and cognitive restructuring techniques, alongside the use of techniques borrowed from mindfulness and other CBT approaches.

Study of a piezoelectric transformer-based DC/DC converter with a cooling system and current-doubler rectifier

International Nuclear Information System (INIS)

Su, Yu-Hao; Liu, Yuan-Ping; Wu, Wen-Jong; Lee, Chih-Kung; Vasic, Dejan; Costa, Francois

2013-01-01

The objective of this study was to increase the output current and power in a piezoelectric transformer (PT)-based DC/DC converter by using a cooling system. It is known that the output current of a PT is limited by temperature build-up because of losses, especially when driving at high vibration velocity. Although connecting different inductive circuits at the PT secondary terminal can increase the output current, the root cause of the temperature build-up problem has not yet been solved. This paper presents a study of a PT with cooling system in a DC/DC converter with a commonly used full-bridge rectifier and current-doubler rectifier. The advantages and disadvantages of the proposed technique were investigated. A theoretical–phenomenological model was developed to explain the relationship between the losses and the temperature rise. It will be shown that the vibration velocity as well as heat generation increases the losses. In our design, the maximum output current capacity can increase by 100% when the temperature of operation of the PT is kept below 55 ° C. The study comprises a theoretical part and experimental proof-of-concept demonstration of the proposed design method. (paper)

Study on classical and excess eddy currents losses of Terfenol-D

Energy Technology Data Exchange (ETDEWEB)

Talebian, Soheil; Hojjat, Yousef [Department of Mechanical Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Ghodsi, Mojtaba [Department of Mechanical and Industrial Engineering, Sultan Qaboos University, Muscat (Oman); Karafi, Mohammad Reza [Department of Mechanical Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

2015-08-15

In the present paper, classical and excess eddy currents losses of Terfenol-D are studied and effects of magnetic field frequency, peak of magnetic flux density and diameter of Terfenol-D on the eddy currents losses are investigated. To provide reliable data for the purpose of the paper, an experimental laboratory is fabricated and used to obtain major and minor hysteresis loops of Terfenol-D at different frequencies. In theoretical study, initially an analytical model based on uniform distribution of magnetic flux is developed which yields to calculation of classical eddy currents losses. Then, another eddy currents model based on non-uniform distribution of magnetic flux and nonlinear diffusion of electromagnetic fields is presented. The difference between output values of the two models is identified as excess eddy currents losses. Obtained results show that the values of excess losses are generally larger than classical losses and applying just classical model leads to wrong calculation of actual value of eddy currents losses. For the results obtained from two above models, empirical models with respect to the magnetic field frequency and the peak value of magnetic flux density are achieved which can predict the eddy currents losses precisely. To validate the empirical relations, experiments are repeated at a new frequency and values of power losses calculated from analytical equations are compared with the predicted values of the empirical models. The results point towards possibility to use the obtained empirical relations in order to calculate the classical and excess eddy currents losses of Terfenol-D at the frequencies below 200 Hz and different values of magnetic flux density. - Highlights: • Classical eddy currents loss of Terfenol-D is studied using Maxwell's laws. • Excess eddy currents loss of Terfenol-D is studied using Mayergoyz nonlinear model. • Effects of Terfenol-D geometry on the eddy currents losses are investigated. • Power

Intervention studies to foster resilience - A systematic review and proposal for a resilience framework in future intervention studies.

Science.gov (United States)

Chmitorz, A; Kunzler, A; Helmreich, I; Tüscher, O; Kalisch, R; Kubiak, T; Wessa, M; Lieb, K

2018-02-01

Psychological resilience refers to the phenomenon that many people are able to adapt to the challenges of life and maintain mental health despite exposure to adversity. This has stimulated research on training programs to foster psychological resilience. We evaluated concepts, methods and designs of 43 randomized controlled trials published between 1979 and 2014 which assessed the efficacy of such training programs and propose standards for future intervention research based on recent developments in the field. We found that concepts, methods and designs in current resilience intervention studies are of limited use to properly assess efficacy of interventions to foster resilience. Major problems are the use of definitions of resilience as trait or a composite of resilience factors, the use of unsuited assessment instruments, and inappropriate study designs. To overcome these challenges, we propose 1) an outcome-oriented definition of resilience, 2) an outcome-oriented assessment of resilience as change in mental health in relation to stressor load, and 3) methodological standards for suitable study designs of future intervention studies. Our proposals may contribute to an improved quality of resilience intervention studies and may stimulate further progress in this growing research field. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

CMOS current controlled fully balanced current conveyor

International Nuclear Information System (INIS)

Wang Chunhua; Zhang Qiujing; Liu Haiguang

2009-01-01

This paper presents a current controlled fully balanced second-generation current conveyor circuit (CF-BCCII). The proposed circuit has the traits of fully balanced architecture, and its X-Y terminals are current controllable. Based on the CFBCCII, two biquadratic universal filters are also proposed as its applications. The CFBCCII circuits and the two filters were fabricated with chartered 0.35-μm CMOS technology; with ±1.65 V power supply voltage, the total power consumption of the CFBCCII circuit is 3.6 mW. Comparisons between measured and HSpice simulation results are also given.

Study of non inductive current generation in a plasma

International Nuclear Information System (INIS)

Rax, J.M.

1987-01-01

The problem of non-thermal bremsstrahlung during lower hybrid current drive is considered. The proposed method shows the role of the Compton effects at low frequencies and allows us to establish the link between the emitted power and the absorbed power at high frequency. The non-thermal emission is considered as a kinematical mode conversion between the absorbed radio-frequency mode and the emitted X ray photons. The fast electrons diagnostics and the ways to reach the wave structure are shown. Kinetic and electromagnetic problems concerning current generation are described. The plasma properties and diagnostics in the case of a non inductive current generation are discussed [fr

Primary energy use for heating in the Swedish building sector-Current trends and proposed target

International Nuclear Information System (INIS)

Johansson, P.; Nylander, A.; Johnsson, F.

2007-01-01

One goal of the Swedish energy policy is to reduce the amount of electricity used for heating in the building sector. This means to reduce the primary energy used for heating which in this paper is analyzed in the context of various heating technologies and CO 2 emissions. The analysis is applied to a region in Sweden (southern Sweden) for which detailed information on the energy infrastructure (the capital stock of the buildings and heating systems together with geographical variations in heat intensity) is available from a previous work [Johansson, P., Nylander, A., Johnsson, F., 2005. Electricity dependency and CO 2 emissions from heating in the Swedish building sector-current trends in conflict with governmental policy? Energy policy] and which is large enough to be assumed representative for Sweden as a whole. The detailed mapping of the energy infrastructure allows a good estimate on the rate at which the energy system can be expected to be replaced with respect to economical lifetime of the capital stock (the year 2025 in this case). Two scenarios are investigated; a target scenario for which energy savings are employed (e.g. improving climate shell in buildings) and oil and most of the electricity used for heating purposes are phased out and a second for which the current trend in the heating market continues. In the target scenario it is shown that although only applying commercially competitive heating technologies, it is possible to achieve a 47% reduction in primary energy use for heating with a 34% decrease in heat demand together with significant reduction in CO 2 emissions. However, the scenario which continues the current trends on the heating market instead yields an increase (of about 10%) in primary energy use (reduction in conversion efficiency) of the heating system of the region over the period studied, in spite of a slight decrease in heat demand (9%, mainly due to energy efficiency measures) as well as in CO 2 emissions. In light of the

A study of some political problems considering current geographical analytical parameters

Directory of Open Access Journals (Sweden)

Héctor Adolfo Dupuy

2008-01-01

Full Text Available This paper intends to study some of the main problems presented, on different scales, by current politics, considering the spatial implications as well as various parameters offered lately by the geographical science. The proposal is supported by the theoretical bases developed from Emmanuel Wallerstein and Peter Taylor's statement about a world system structured as a world economy, based on the capitalist mode of production. Conversely, it attempts to provide a theoretical explanation for the dynamics experienced by the territories upon thee basis of such world system's mechanics. According to these assumptions, an analysis is proposed of some of the main phenomena resulting from the previous analysis and its spatial implications, such as the current power relations in the system, the subsistence of traditional power factors (Nation-states, ethnically based cultural configurations and the appearance of new ones (the forming of transnational blocs and associations, new social movements, new forms of local participation, the importance of hegemonic and counter-hegemonic discourses in the construction of symbolic representations and of the mass media in such processes or the new cultural identity and hybridization chart from population mobility.

Proposed shake table studies for NAPP containment

International Nuclear Information System (INIS)

Akolkar, P.M.; Khuddus, M.A.

1975-01-01

The proposal for shake table studies on model of containment structure of Narora Atomic Power Project is discussed. The physical characteristics such as the dimensions, connection details of the containment with the internal structure and the dynamic interaction between the two have been described. The dynamic scale factors obtained through similitude requirements and dimensional analysis have been presented and the modelling aspects and the choice of model material and scale have been discussed. The proposed type of tests, necessary measurement and instrumentation have been mentioned. The limitations imposed by similitude requirements on model studies are brought out and the usefulness of the results of the proposed tests in the dynamic design of the containment have been covered. (author)

Regional economic effects of current and proposed management alternatives for Sand Lake National Wildlife Refuge

Science.gov (United States)

Koontz, Lynne; Lambert, Heather

2005-01-01

The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a Refuge and provide long range guidance and management direction to achieve Refuge purposes. Sand Lake National Wildlife Refuge (NWR), located 27 miles northeast of Aberdeen, South Dakota, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for Sand Lake NWR must contain an analysis of expected effects associated with current and proposed Refuge management strategies.

Soft commutated direct current motor [summary of proposed paper

Energy Technology Data Exchange (ETDEWEB)

Hsu, John S.

1998-10-22

A novel soft commutated direct current (DC) motor is introduced. The current of the commutated coil is intentionally drained before the brush disconnects the coil. This prevents the spark generation that normally occurs in conventional DC motors. A similar principle can be applied for DC generators.

Current status of regional hydrogeological studies and numerical simulations on geological disposal

International Nuclear Information System (INIS)

Nakao, Shinsuke; Kikuchi, Tsuneo; Ishido, Tsuneo

2004-01-01

Current status of regional hydrogeological studies on geological disposal including hydrogeological modeling using numerical simulators is reviewed in this report. A regional scale and boundary conditions of numerical models are summarized mainly from the results of the RHS (regional hydrogeological study) project conducted by Japan Nuclear Cycle Development Institute (JNC) in the Tono area. We also refer to the current conceptual modes of hydrology and numerical models of unsaturated zone flow at Yucca Mountain, Nevada, which is the arid site proposed for consideration as the United States' first underground high-level radioactive waste repository. Understanding behavior of a freshwater-saltwater transition zone seems to play a key role in the hydrogeological modeling in a coastal region. Technical features of a numerical simulator as a tool for geothermal reservoir modeling is also briefly described. (author)

Nuclear regulations: current status and proposed initiatives

International Nuclear Information System (INIS)

Domondon, D.B.; Valdezco, E.M.; Mateo, A.J.; Parami, V.K.

1996-01-01

The science Act of 1958 created the Philippine Atomic Energy Commission, presently known as the Philippine Nuclear Research Institute (PNRI), under the Department of Science and Technology (DOST). The PNRI is tasked with the dual role of promotion and control of the peaceful applications of atomic energy. To carry its mandate of regulation and control on the use of raioisotopes in various fields, the PNRI had promulgated and issued specific regulations known as the Code of PNRI regulations. This paper summarizes the activities undertaken by PNRI in the continuing process of review and subsequent revisions of the Code of PNRI regulations and related guidance documents. It highlights proposed modifications in the present regulations in an attempt to adopt the new international basic safety standards, the practical problems and related issues attendant to the implementation of these new standards, among others. In line with the overall objective of PNRI to ensure the safe application of nuclear energy and radiation technology in various fields, the institute conducted a series of regulatory information conferences to provide an opportunity for members of the regulatory staff of the PNRI and licenses to discuss safety initiatives and regulatory issues. This paper will also provide an in-depth assessment of the lessons learned from these conferences which were conducted by sector or by specific applications for a more focused approach, e.g. radiopharmaceuticals, industrial radiography, research, among others. Licensees' feedback on the PNRI regulatory process are presented as part of the overall objective of enhancing the operational experiences of the licensing, review and evaluation group as well as that of inspection, enforcement and compliance. Several proposed initiatives for consideration of the PNRI to further strengthen its regulatory functions are also briefly outlined. (author)

The next GUM and its proposals: a comparison study

Science.gov (United States)

Damasceno, J. C.; Couto, P. R. G.

2018-03-01

The Guide to the Expression of Uncertainty in Measurement (GUM) is currently under revision. New proposals for its implementation were circulated in the form of a draft document. Two of the main changes are explored in this work using a Brinell hardness model example. Changes in the evaluation of uncertainty for repeated indications and in the construction of coverage intervals are compared with the classic GUM and with Monte Carlo simulation method.

An appraisal of current regulations and recommendations in relation to proposals for the use of X-ray optics equipment

International Nuclear Information System (INIS)

Weatherley, E.G.

1984-01-01

Current regulatory requirements for the use of x-ray optics equipment in factories are compared with the 19-year-old Guidance Notes for their use in research and teaching establishments. The difficulties in drafting new legislation to cater for both areas of use are discussed and the proposed regulations and approved code of practice having a direct bearing on x-ray optics equipment are reviewed. Comment is made concerning the proposed Health and Safety Executive document, ''Radiation Safety in the use of X-ray Optics Equipment, which will give practical advice and guidance on cost effective methods of achieving the regulatory objectives. The costs involved are unlikely to be significant for the majority of users and implementation of the proposed legislation should not restrict the use of x-ray optics equipment. (author)

High-current railgap studies

Science.gov (United States)

Druce, R.; Gordon, L.; Hofer, W.; Wilson, M.

1983-06-01

Characteristics of a 40-kV, 750-kA, multichannel rail gap are presented. The gap is a three electrode, field distortion triggered design, with a total switch inductance of less than 10 nH. At maximum ratings, the gap typically switches 10 C per shot, at 700 kA, with a jitter of less than 2 ns. Channel evolution and current division were studied on image converter streak photographs. Transient gas pressure measurements were made to investigate the arc generated shocks and to detect single channel failure. Channel current sharing and simultaneity are described and their effects on the switch inductance in the channel current sharing and erosion measurements are discussed.

Regional economic analysis of current and proposed management alternatives for Rappahannock River Valley National Wildlife Refuge

Science.gov (United States)

Koontz, Lynne; Sexton, Natalie; Donovan, Ryan

2009-01-01

The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan. The Comprehensive Conservation Plan must describe the desired future conditions of a refuge and provide long-range guidance and management direction to achieve refuge purposes. The Rappahannock River Valley National Wildlife Refuge (refuge) is in the process of developing a range of management goals, objectives, and strategies for the Comprehensive Conservation Plan. The Comprehensive Conservation Plan for the refuge must contain an analysis of expected effects associated with current and proposed refuge management strategies. The purpose of this study was to assess the regional economic implications associated with draft Comprehensive Conservation Plan management strategies. Special interest groups and local residents often criticize a change in refuge management, especially if there is a perceived negative impact to the local economy. Having objective data on economic impacts may show that these fears are overstated. Quite often, the extent of economic benefits a refuge provides to a local community is not fully recognized, yet at the same time the effects of negative changes is overstated. Spending associated with refuge recreational activities, such as wildlife viewing and hunting, can generate considerable tourist activity for surrounding communities. Additionally, refuge personnel typically spend considerable amounts of money purchasing supplies in local stores, repairing equipment and purchasing fuel at the local service stations, and reside and spend their salaries in the local community. For refuge Comprehensive Conservation Plan planning, a regional economic assessment provides a means of estimating how current management (no action alternative) and proposed management activities (alternatives) could affect the local economy. This type of analysis provides two critical pieces of

Experimental study of neoclassical currents

International Nuclear Information System (INIS)

Zarnstorff, M.C.; Prager, S.C.

1985-05-01

A detailed experimental study is presented of the bootstrap and Pfirsch-Schlueter currents that are predicted by neoclassical transport theory. In a toroidal octupole, on magnetic surfaces within the separatrix, the observed parallel plasma currents are in excellent quantitative agreement with neoclassical theory with regard to the spatial structure (along a magnetic surface), collisionality dependence and toroidal magnetic field dependence. On magnetic surfaces outside the separatrix, the ion portion of the parallel current is in agreement with neoclassical theory but the electron parallel current is observed to obtain a unidirectional component which deviates from and exceeds the theoretical prediction

High-current railgap studies

Energy Technology Data Exchange (ETDEWEB)

Druce, R.; Gordon, L.; Hofer, W.; Wilson, M.

1983-06-03

Characteristics of a 40-kV, 750-kA, multichannel rail gap are presented. The gap is a three electrode, field-distortion-triggered design, with a total switch inductance of less than 10 nH. At maximum ratings, the gap typically switches 10 C per shot, at 700 kA, with a jitter of less than 2 ns. Image-converter streak photographs were used to study channel evolution and current division. Transient gas-pressure measurements were made to investigate the arc generated shocks and to detect single channel failure. Channel current sharing and simultaneity are described and their effects on the switch inductance and lifetime are discussed. Lifetime tests of the rail gap were performed. Degradation in the channel current-sharing and erosion measurements are discussed.

A numerical study on the feasibility evaluation of a hybrid type superconducting fault current limiter applying thyristors

Energy Technology Data Exchange (ETDEWEB)

Nam, Seok Ho; Lee, Woo Seung; Lee, Ji Ho; Hwang, Young Jin; Ko, Tae Kuk [Yonsei University, Seoul (Korea, Republic of)

2013-12-15

Smart fault current controller (SFCC) proposed in our previous work consists of a power converter, a high temperature superconducting (HTS) DC reactor, thyristors, and a control unit [1]. SFCC can limit and control the current by adjusting firing angles of thyristors when a fault occurs. SFCC has complex structure because the HTS DC reactor generates the loss under AC. To use the DC reactor under AC, rectifier that consists of four thyristors is needed and it increases internal resistance of SFCC. For this reason, authors propose a hybrid type superconducting fault current limiter (SFCL). The hybrid type SFCL proposed in this paper consists of a non-inductive superconducting coil and two thyristors. To verify the feasibility of the proposed hybrid type SFCL, simulations about the interaction of the superconducting coil and thyristors are conducted when fault current flows in the superconducting coil. Authors expect that the hybrid type SFCL can control the magnitude of the fault current by adjusting the firing angles of thyristors after the superconducting coil limits the fault current at first peak.

A numerical study on the feasibility evaluation of a hybrid type superconducting fault current limiter applying thyristors

International Nuclear Information System (INIS)

Nam, Seok Ho; Lee, Woo Seung; Lee, Ji Ho; Hwang, Young Jin; Ko, Tae Kuk

2013-01-01

Smart fault current controller (SFCC) proposed in our previous work consists of a power converter, a high temperature superconducting (HTS) DC reactor, thyristors, and a control unit [1]. SFCC can limit and control the current by adjusting firing angles of thyristors when a fault occurs. SFCC has complex structure because the HTS DC reactor generates the loss under AC. To use the DC reactor under AC, rectifier that consists of four thyristors is needed and it increases internal resistance of SFCC. For this reason, authors propose a hybrid type superconducting fault current limiter (SFCL). The hybrid type SFCL proposed in this paper consists of a non-inductive superconducting coil and two thyristors. To verify the feasibility of the proposed hybrid type SFCL, simulations about the interaction of the superconducting coil and thyristors are conducted when fault current flows in the superconducting coil. Authors expect that the hybrid type SFCL can control the magnitude of the fault current by adjusting the firing angles of thyristors after the superconducting coil limits the fault current at first peak.

Emendation of the family Chlamydiaceae: proposal of a single genus, Chlamydia, to include all currently recognized species.

Science.gov (United States)

Sachse, Konrad; Bavoil, Patrik M; Kaltenboeck, Bernhard; Stephens, Richard S; Kuo, Cho-Chou; Rosselló-Móra, Ramon; Horn, Matthias

2015-03-01

The family Chlamydiaceae (order Chlamydiales, phylum Chlamydiae) comprises important, obligate intracellular bacterial pathogens of humans and animals. Subdivision of the family into the two genera Chlamydia and Chlamydophila has been discussed controversially during the past decade. Here, we have revisited the current classification in the light of recent genomic data and in the context of the unique biological properties of these microorganisms. We conclude that neither generally used 16S rRNA sequence identity cut-off values nor parameters based on genomic similarity consistently separate the two genera. Notably, no easily recognizable phenotype such as host preference or tissue tropism is available that would support a subdivision. In addition, the genus Chlamydophila is currently not well accepted and not used by a majority of research groups in the field. Therefore, we propose the classification of all 11 currently recognized Chlamydiaceae species in a single genus, the genus Chlamydia. Finally, we provide emended descriptions of the family Chlamydiaceae, the genus Chlamydia, as well as the species Chlamydia abortus, Chlamydia caviae and Chlamydia felis. Copyright © 2015 Elsevier GmbH. All rights reserved.

Counter-current extraction studies for the recovery of neptunium by the Purex process. Part I

Energy Technology Data Exchange (ETDEWEB)

Srinivasan, N.; Nadkarni, M. N.; Kumar, S. V.; Kartha, P. K.S.; Sonavane, R. R.; Ramaniah, M. V.; Patil, S. K.

1974-07-01

It is proposed to recover neptunium-237, along with uranium and plutonium, during the fuel reprocessing in the PREFRE plant at Tarapur. Counter-current extraction studies, relevant to the code contamination (HA) and partitioning (IA) cycles of the purex process, were carried out to arrive at suitable chemical flowsheet conditions which would enable the co-extraction of neptunium along with uranium and plutonium. The results of the studies carried out using a laboratory mixer-settler unit and synthetic mixtures of neptunium and uranium are reported here. Based on these results, the chemical flowsheet conditions are proposed for the co-extraction of neptunium even if it exists as Np(V) in the aqueous feed solution. (auth)

A renormalization group study of persistent current in a quasiperiodic ring

Energy Technology Data Exchange (ETDEWEB)

Dutta, Paramita [Theoretical Condensed Matter Physics Division, Saha Institute of Nuclear Physics, Sector-I, Block-AF, Bidhannagar, Kolkata-700 064 (India); Maiti, Santanu K., E-mail: santanu.maiti@isical.ac.in [Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata-700 108 (India); Karmakar, S.N. [Theoretical Condensed Matter Physics Division, Saha Institute of Nuclear Physics, Sector-I, Block-AF, Bidhannagar, Kolkata-700 064 (India)

2014-04-01

We propose a real-space renormalization group approach for evaluating persistent current in a multi-channel quasiperiodic Fibonacci tight-binding ring based on a Green's function formalism. Unlike the traditional methods, the present scheme provides a powerful tool for the theoretical description of persistent current with a very high degree of accuracy in large periodic and quasiperiodic rings, even in the micron scale range, which emphasizes the merit of this work.

Measurement technology of RF interference current in high current system

Science.gov (United States)

Zhao, Zhihua; Li, Jianxuan; Zhang, Xiangming; Zhang, Lei

2018-06-01

Current probe is a detection method commonly used in electromagnetic compatibility. With the development of power electronics technology, the power level of power conversion devices is constantly increasing, and the power current of the electric energy conversion device in the electromagnetic launch system can reach 10kA. Current probe conventionally used in EMC (electromagnetic compatibility) detection cannot meet the test requirements on high current system due to the magnetic saturation problem. The conventional high current sensor is also not suitable for the RF (Radio Frequency) interference current measurement in high current power device due to the high noise level in the output of active amplifier. In this paper, a passive flexible current probe based on Rogowski coil and matching resistance is proposed that can withstand high current and has low noise level, to solve the measurement problems of interference current in high current power converter. And both differential mode and common mode current detection can be easily carried out with the proposed probe because of the probe's flexible structure.

The "Taller de Prácticas Docentes" [Teaching Practice Workshop], a Role-Playing-Based Proposal for Higher Dance Studies

Science.gov (United States)

Torregrosa Salcedo, Elvira; Roig-Vila, Rosabel; Blasco Mira, Josefa Eugenia

2017-01-01

This study focuses on current developments in Higher Dance Studies in Spain. The proposal for a "Taller de Prácticas Docentes" [Teaching Practice Workshop,or TPD by its Spanish acronym] carried out at the Higher Dance Conservatory of Alicante (Spain) and implemented as a pilot experience at this centrebecame our research point of…

Current-current interaction picture for proton-proton scattering

International Nuclear Information System (INIS)

Clarke, D.J.; Lo, S.Y.

1979-01-01

The authors propose that color current - color current interaction is reponsible for small angle elastic proton proton scattering at asymptotic energy. Excellent fits are obtained for all data above 12 GeV/c which covers twelve orders of magnitude

Proposal for a race-track microtron with high peak current

NARCIS (Netherlands)

Ernst, G.J.; Haselhoff, E.H.; Witteman, W.J.; Botman, J.I.M.; van Genderen, W.; Hagedoorn, H.L.; van der Heide, J.A.; Kleeven, W.J.G.M.

1989-01-01

In order to obtain high gain in a free electron laser a high-quality electron beam with high peak current is required. It is well-known that a microtron is able to produce a high-quality beam having low emittance and small energy spread (1%). Because a circular microtron has a limited high-current

A study of different types of current mirrors using polysilicon TFTs

International Nuclear Information System (INIS)

Pappas, I; Nalpantidis, L; Kalenteridis, V; Siskos, S; Dimitriadis, C A; Hatzopoulos, A A

2005-01-01

Polysilicon thin-film technology has become of great interest due to the demand for large area electronic devices. Active matrix liquid crystal displays (AMLCDs) and active matrix organic light emitting displays (AMOLEDs) are among the fields where polysilicon thin-film transistors (poly-Si TFTs) are most commonly used. Such devices, generally, require analog signal processing. This fact makes the performance of basic analog blocks, such as current mirrors implemented with poly-Si TFTs, crucial. This paper examines the performance of various current mirror designs through simulation. Finally, a novel design of a current mirror is proposed aimed to be used in low voltage applications

A Study of Frequency Mixing Approaches for Eddy Current Testing of Steam Generator Tubes

International Nuclear Information System (INIS)

Jung, Hee Jun; Song, Sung Jin; Kim, Chang Hwan; Kim, Dae Kwang

2009-01-01

The multifrequency eddy current testing(ECT) have been proposed various frequency mixing algorithms. In this study, we compare these approaches to frequency mixing of ECT signals from steam generator tubes; time-domain optimization, discrete cosine transform-domain optimization. Specifically, in this study, two different frequency mixing algorithms, a time-domain optimization method and a discrete cosine transform(DCT) optimization method, are investigated using the experimental signals captured from the ASME standard tube. The DCT domain optimization method is computationally fast but produces larger amount of residue.

New insights from direct monitoring of turbidity currents; and a proposal for co-ordinating international efforts at a series of global "turbidity current test sites"

Science.gov (United States)

Talling, Peter

2015-04-01

Turbidity currents, and other types of submarine sediment density flow, arguably redistribute more sediment across the surface of the Earth than any other flow process. It is now over 60 years since the seminal publication of Kuenen and Migliorini (1950) in which they made the link between sequences of graded bedding and turbidity currents. The deposits of submarine sediment density flows have been described in numerous locations worldwide, and this might lead to the view that these flows are well understood. However, it is sobering to note quite how few direct measurements we have from these submarine flows in action. Sediment concentration is the critical parameter controlling such flows, yet it has never been measured directly for flows that reach and build submarine fans. How then do we know what type of flow to model in flume tanks, or which assumptions to use to formulate numerical simulations or analytical models? It is proposed here that international efforts are needed for an initiative to monitor active turbidity currents at a series of 'test sites' where flows occur frequently. The flows evolve significantly, such that source to sink data are needed. We also need to directly monitor flows in different settings with variable triggering factors and flow path morphologies because their character can vary significantly. Such work should integrate numerical and physical modelling with the collection of field observations in order to understand the significance of field observations. Such an international initiative also needs to include coring of deposits to link flow processes to deposit character, because in most global locations flow behaviour must be inferred from deposits alone. Collection of seismic datasets is also crucial for understanding the larger-scale evolution and resulting architecture of these systems, and to link with studies of subsurface reservoirs. Test site datasets should thus include a wide range of data types, not just from direct flow

Electromigration failures under bidirectional current stress

Science.gov (United States)

Tao, Jiang; Cheung, Nathan W.; Hu, Chenming

1998-01-01

Electromigration failure under DC stress has been studied for more than 30 years, and the methodologies for accelerated DC testing and design rules have been well established in the IC industry. However, the electromigration behavior and design rules under time-varying current stress are still unclear. In CMOS circuits, as many interconnects carry pulsed-DC (local VCC and VSS lines) and bidirectional AC current (clock and signal lines), it is essential to assess the reliability of metallization systems under these conditions. Failure mechanisms of different metallization systems (Al-Si, Al-Cu, Cu, TiN/Al-alloy/TiN, etc.) and different metallization structures (via, plug and interconnect) under AC current stress in a wide frequency range (from mHz to 500 MHz) has been study in this paper. Based on these experimental results, a damage healing model is developed, and electromigration design rules are proposed. It shows that in the circuit operating frequency range, the "design-rule current" is the time-average current. The pure AC component of the current only contributes to self-heating, while the average (DC component) current contributes to electromigration. To ensure longer thermal-migration lifetime under high frequency AC stress, an additional design rule is proposed to limit the temperature rise due to self-joule heating.

Flexible Compensation of Voltage and Current Unbalance and Harmonics in Microgrids

DEFF Research Database (Denmark)

Mousazadeh, Seyyed Yousef; Jalilian, Alireza; Savaghebi, Mehdi

2017-01-01

In recent years, the harmonics and unbalance problem endanger the voltage and current quality of power systems due to increasing usage of nonlinear and unbalance loads. Using DG interfacing inverters is proposed for voltage or current compensation. In this paper, a flexible control method...... is proposed to compensate voltage and current unbalance and harmonics using the Distributed Generation (DG) interfacing inverters. This method is applicable to both grid-connected and islanded microgrids. In the proposed method, not only the proper control of active and reactive powers can be achieved......) frame. An extensive simulation study has been performed and the results demonstrate the effectiveness of the proposed control scheme. The results show that depending on the compensation mode, the harmonics and unbalance compensation of DGs’ output current, MG’s injected current to the grid as well...

Comparative study of microcontroller controlled four-wire voltage and current source shunt active power filters

Energy Technology Data Exchange (ETDEWEB)

Pettersson, S.

2009-07-01

During the past two decades, active power filters have increasingly grown their popularity as a viable method for improving electric power quality. The main reasons for this have been the advent of fast self-commutating solid-state devices, the progression of digital technology and the improved sensor technology. Four-wire active power filters provide an efficient solution for improving the quality of supply in grounded three-phase systems or three-phase systems with neutral conductors, which are commonly used for powering residential, office and public buildings. Four-wire active power filters are applicable in compensating current harmonics, reactive power, neutral current and load phase imbalance.This thesis presents a comparative study of microcontroller controlled four-wire voltage and current source shunt active power filters. The study includes two voltage source topologies and a current source topology with two different dc-link energy storage structures, which are compared on the basis of their filtering properties, filtering performance and efficiency. The obtained results are used for determining the suitability of current source technology for four-wire active power filtering and finding the most viable four-wire shunt active power filter topology. One commonly recognized disadvantage of the current source active power filter has always been the bulky dc-link inductor. To reduce the size of the dc-link inductor, an alternative dc-link structure for current source active power filters was introduced in the late 80's. The hybrid energy storage consists of both inductive and capacitive energy storage elements, two diodes and two controllable semiconductor switching devices. Since the capacitive element is used as a main storage unit, the inductance of the dc-link inductor can be considerably reduced. However, the original dc current control method proposed is not able to utilize the full potential of the hybrid energy storage and the inductance

Study of eddy current power loss from outer-winding coils of a magnetic position sensor

International Nuclear Information System (INIS)

Liu, C.-P.; Lin, T.-K.; Chang, Y.-H.; Yu, C.-S.; Wu, K.-T.; Wang, S.-J.; Ying, T.-F.; Huang, D.-R.

2000-01-01

The present analysis is concerned with eddy current power loss of a magnetic position sensor, which arises from a non-uniform flux linkage distribution between magnetic material and position sensor. In the paper, a magnetic position sensor system is simplified to be an outer-winding coil along the axial direction of a low carbon steel bar, and developed a numerical model to compute the electrical characteristics by an excited current source. According to the simulated and measured data in this proposed model from 2.52 to 11.37 Oes, eddy current power losses of conducting material have a variation of 6.1% and 9.77%, respectively. Finally, the phases of waveform of the induced output voltage will also be obtained in the conducting material, and have a variation of 3.68% obtained by using the current source in the proposed model

Study of eddy current power loss from outer-winding coils of a magnetic position sensor

CERN Document Server

Liu, C P; Chang, Y H; Yu, C S; Wu, K T; Wang, S J; Ying, T F; Huang, D R

2000-01-01

The present analysis is concerned with eddy current power loss of a magnetic position sensor, which arises from a non-uniform flux linkage distribution between magnetic material and position sensor. In the paper, a magnetic position sensor system is simplified to be an outer-winding coil along the axial direction of a low carbon steel bar, and developed a numerical model to compute the electrical characteristics by an excited current source. According to the simulated and measured data in this proposed model from 2.52 to 11.37 Oes, eddy current power losses of conducting material have a variation of 6.1% and 9.77%, respectively. Finally, the phases of waveform of the induced output voltage will also be obtained in the conducting material, and have a variation of 3.68% obtained by using the current source in the proposed model.

Frequency-Controlled Current-Fed Resonant Converter with No Input Ripple Current

Directory of Open Access Journals (Sweden)

Bor-Ren Lin

2018-02-01

Full Text Available This paper studies a frequency-controlled current-fed resonant circuit. The adopted direct current (DC-to-DC converter contains two boost circuits and a resonant circuit on the primary side. First, two boost circuits are connected in parallel to achieve voltage step-up and reduce input ripple current by using interleaved pulse-width modulation. Therefore, the size and current rating of boost inductors are decreased in the proposed converter. Second, the boost voltage is connected to the resonant circuit to realize the mechanism of the zero-voltage switching of all active switches and zero-current switching of all diodes. Two boost circuits and a resonant circuit use the same power devices in order to lessen the switch counts. The voltage doubler topology is adopted on the secondary side (high-voltage side. Therefore, the voltage rating of diodes on the high-voltage side is clamped at output voltage. The feasibility of the studied circuit is confirmed by the experimental tests with a 1 kW prototype circuit.

Balanced Current Control Strategy for Current Source Rectifier Stage of Indirect Matrix Converter under Unbalanced Grid Voltage Conditions

Directory of Open Access Journals (Sweden)

Yeongsu Bak

2016-12-01

Full Text Available This paper proposes a balanced current control strategy for the current source rectifier (CSR stage of an indirect matrix converter (IMC under unbalanced grid voltage conditions. If the three-phase grid connected to the voltage source inverter (VSI of the IMC has unbalanced voltage conditions, it affects the currents of the CSR stage and VSI stage, and the currents are distorted. Above all, the distorted currents of the CSR stage cause instability in the overall system, which can affect the life span of the system. Therefore, in this paper, a control strategy for balanced currents in the CSR stage is proposed. To achieve balanced currents in the CSR stage, the VSI stage should receive DC power without ripple components from the CSR stage. This is implemented by controlling the currents in the VSI stage. Therefore, the proposed control strategy decouples the positive and negative phase-sequence components existing in the unbalanced voltages and currents of the VSI stage. Using the proposed control strategy under unbalanced grid voltage conditions, the stability and life span of the overall system can be improved. The effectiveness of the proposed control strategy is verified by simulation and experimental results.

Simulation study and experimental results for detection and classification of the transient capacitor inrush current using discrete wavelet transform and artificial intelligence

Directory of Open Access Journals (Sweden)

Patcharoen Theerasak

2018-04-01

Full Text Available This paper describes the combination of discrete wavelet transforms (DWT and artificial intelligence (AI, which are efficient techniques to identify the type of inrush current, analyze the origin and possible cause on the capacitor bank switching. The experiment setup used to verify the proposed techniques can be detected and classified the transient inrush current from normal capacitor rated current. The discrete wavelet transforms are used to detect and classify the inrush current. Then, output from wavelet is acted as input of fuzzy inference system for discriminating the type of switching transient inrush current. The proposed technique shows enhanced performance with a discrimination accuracy of 90.57%. Both simulation study and experimental results are quite satisfactory with providing the high accuracy and reliability which can be developed and implemented into a numerical overcurrent (50/51 and unbalanced current (60C protection relay for an application of shunt capacitor bank protection in the future.

Simulation study and experimental results for detection and classification of the transient capacitor inrush current using discrete wavelet transform and artificial intelligence

Science.gov (United States)

Patcharoen, Theerasak; Yoomak, Suntiti; Ngaopitakkul, Atthapol; Pothisarn, Chaichan

2018-04-01

This paper describes the combination of discrete wavelet transforms (DWT) and artificial intelligence (AI), which are efficient techniques to identify the type of inrush current, analyze the origin and possible cause on the capacitor bank switching. The experiment setup used to verify the proposed techniques can be detected and classified the transient inrush current from normal capacitor rated current. The discrete wavelet transforms are used to detect and classify the inrush current. Then, output from wavelet is acted as input of fuzzy inference system for discriminating the type of switching transient inrush current. The proposed technique shows enhanced performance with a discrimination accuracy of 90.57%. Both simulation study and experimental results are quite satisfactory with providing the high accuracy and reliability which can be developed and implemented into a numerical overcurrent (50/51) and unbalanced current (60C) protection relay for an application of shunt capacitor bank protection in the future.

76 FR 5580 - Eagle Crest Energy Company; Notice of Applicant-Proposed Water Pipeline Route for the Proposed...

Science.gov (United States)

2011-02-01

... Energy Company; Notice of Applicant-Proposed Water Pipeline Route for the Proposed Eagle Mountain Pumped... Hydroelectric Project (Eagle Mountain Project). This notice describes the water supply pipeline route proposed... property that would be crossed by the proposed water supply pipeline. We are currently soliciting comments...

Study of structure of HTS coated conductor with ferromagnetic substrate having low AC transport current loss using FEM

International Nuclear Information System (INIS)

Miyagi, D.; Amadutsumi, Y.; Takahashi, N.; Tsukamoto, O.

2007-01-01

AC transport current losses of coated conductors with ferromagnetic substrates are higher than the loss calculated by the Norris equation. In order to reduce the AC transport current loss we propose in this paper a structure of the coated conductor that has wider substrate than the SC (Superconducting) layer. The current distribution and AC loss of the proposed model are analyzed by means of FEM. The AC transport current loss is reduced due to the change of current density distribution near the edge of SC layer, consequent to the high value of magnetic permeability of the ferromagnetic substrate, that is wider than the SC layer

A one-loop study of matching conditions for static-light flavor currents

Energy Technology Data Exchange (ETDEWEB)

Hesse, Dirk [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Parma Univ. (Italy); Sommer, Rainer [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Collaboration: ALPHA Collaboration

2012-11-15

Heavy Quark Effective Theory (HQET) computations of semi-leptonic decays, e.g. B{yields}{pi}l{nu}, require the knowledge of the parameters in the effective theory for all components of the heavy-light flavor currents. So far non-perturbative matching conditions have been employed only for the time component of the axial current. Here we perform a check of matching conditions for the time component of the vector current and the spatial component of the axial vector current up to one-loop order of perturbation theory and to lowest order of the 1/m-expansion. We find that the proposed observables have small higher order terms in the 1/m-series and are thus excellent candidates for a non-perturbative matching procedure.

INVESTIGATION OF PROPERTIES OF CURRENT COLLECTOR ELEMENTS AND THEIR EFFECT ON THE PERFORMANCE OF TRIBOSYSTEM «CONTACT WIRE - CURRENT COLLECTOR ELEMENT»

Directory of Open Access Journals (Sweden)

Yu. L. Bolshakov

2015-11-01

Full Text Available Purpose. The paper is devoted to the detailed analysis of interrelations at the contact point of friction pair «contact wire – current collector insert». In the work it is necessary: 1 to examine quality of manufacturing of specimens of current collector elements from different manufacturers; 2 to narrow the range of hardness for carbon inserts; 3 to develop a technique of sorting carbon current collector inserts for the structural parameters. Methodology. The executed work was based on the use of the theory of reliability of technical systems and electromechanical processes. Findings. The paper studies the interrelation at the contact point of friction pair «contact wire – current col lector insert», the connection was established between the hardness and electrical resistivity. It is proposed to narrow the range of carbon inserts hardness. The method of sorting coal collector inserts in hardness was developed, and the research has revealed the discrepancy of current collector inserts with existing regulations. It was proposed to equip the pantographs slide with current collector elements using special scheme and to develop a specialized research facility, which will be possible to conduct studies of the interaction of the friction pair «contact wire – current collector insert». Originality. In the course of the study the current collector inserts the sharp structural heterogeneity and fluctuations of the density of the material along the length of the insert were established. The dependence between hardness of inserts and electrical resistivity was established. It was analyzed and concluded about the need to reduce the values of the normal range of hardness. Based on the results of the research, the experimental dependences were obtained and proposed the method for sorting carbon current collector inserts for the structural parameters. Practical value. The obtained results of coal current collector inserts define the need to use

Impact of a proposed revision of the IESTI equation on the acute risk assessment conducted when setting maximum residue levels (MRLs) in the European Union (EU): A case study.

Science.gov (United States)

Breysse, Nicolas; Vial, Gaelle; Pattingre, Lauriane; Ossendorp, Bernadette C; Mahieu, Karin; Reich, Hermine; Rietveld, Anton; Sieke, Christian; van der Velde-Koerts, Trijntje; Sarda, Xavier

2018-06-03

Proposals to update the methodology for the international estimated short-term intake (IESTI) equations were made during an international workshop held in Geneva in 2015. Changes to several parameters of the current four IESTI equations (cases 1, 2a, 2b, and 3) were proposed. In this study, the overall impact of these proposed changes on estimates of short-term exposure was studied using the large portion data available in the European Food Safety Authority PRIMo model and the residue data submitted in the framework of the European Maximum Residue Levels (MRL) review under Article 12 of Regulation (EC) No 396/2005. Evaluation of consumer exposure using the current and proposed equations resulted in substantial differences in the exposure estimates; however, there were no significant changes regarding the number of accepted MRLs. For the different IESTI cases, the median ratio of the new versus the current equation is 1.1 for case 1, 1.4 for case 2a, 0.75 for case 2b, and 1 for case 3. The impact, expressed as a shift in the IESTI distribution profile, indicated that the 95th percentile IESTI shifted from 50% of the acute reference dose (ARfD) with the current equations to 65% of the ARfD with the proposed equations. This IESTI increase resulted in the loss of 1.2% of the MRLs (37 out of 3110) tested within this study. At the same time, the proposed equations would have allowed 0.4% of the MRLs (14 out of 3110) that were rejected with the current equations to be accepted. The commodity groups that were most impacted by these modifications are solanacea (e.g., potato, eggplant), lettuces, pulses (dry), leafy brassica (e.g., kale, Chinese cabbage), and pome fruits. The active substances that were most affected were fluazifop-p-butyl, deltamethrin, and lambda-cyhalothrin.

An analytical gate tunneling current model for MOSFETs

Energy Technology Data Exchange (ETDEWEB)

Kazerouni, Iman Abaspur, E-mail: imanabaspur@gmail.com; Hosseini, Seyed Ebrahim [Sabzevar Tarbiat Moallem University, Electrical and Computer Department (Iran, Islamic Republic of)

2012-03-15

Gate tunneling current of MOSFETs is an important factor in modeling ultra small devices. In this paper, gate tunneling in present-generation MOSFETs is studied. In the proposed model, we calculate the electron wave function at the semiconductor-oxide interface and inversion charge by treating the inversion layer as a potential well, including some simplifying assumptions. Then we compute the gate tunneling current using the calculated wave function. The proposed model results have an excellent agreement with experimental results in the literature.

Proposal on ''standardized high current solid targets for cyclotron production of diagnostic and therapeutic radionuclides''

International Nuclear Information System (INIS)

Suparman, Ibon

2000-01-01

The Center for the Development of Radioisotopes and Radiopharmaceuticals - National Nuclear Energy Agency (P2RR-BATAN) has one Cyclotron type CS-30 with maximum 30 MeV proton energy. It is used since 1990 for 201 Tl production. The main use of 201 Tl in Indonesia is for diagnosis and assessment of myocardial ischaemia, especially diagnosis of coronary artery disease, viability of the heart muscle and forecasting the outcome for patients with coronary disease. The Cyclotron facility is supported with a solid target station, two hot cells and the chemical equipment for electroplating. The yield of 201 Tl production currently achieved around 40-50%. The irradiation technique and chemical separation should be improved. We are also very interested in the development of the production of 103 Pd via 103 Rh (p,n) 103 Pd reaction. The objective of this proposal will support the main program of the National Nuclear Energy Agency (BATAN) in enhancement of health care and in providing Cyclotron produced radiopharmaceuticals for hospitals

A proposal for B-physics on current lattices

Energy Technology Data Exchange (ETDEWEB)

Blossier, B. [Paris 11 Univ., 91 - Orsay (France). Lab. de Physique Theorique; Dimopoulos, P.; Frezzotti, R. [Roma Univ., Tor Vergata (Italy). Dipt. di Fisica; INFN, Roma Tor Vergata (IT)] (and others)

2009-10-15

A method to extract B-physics parameters (b-quark mass and f{sub B}, f{sub Bs} decay constants) from currently available lattice data is presented and tested. The approach is based on the idea of constructing appropriate ratios of heavy-light meson masses and decay constants, respectively, possessing a precisely known static limit, and evaluating them at various pairs of heavy quark masses around the charm. Via a smooth interpolation in the heavy quark mass from the easily accessible charm region to the asymptotic point, B-physics parameters are computed with a few percent (statistical + systematic) error using recently produced N{sub f}=2 maximally twisted Wilson fermions data. (orig.)

A Summary of Proposed Changes to the Current ICARTT Format Standards and their Implications to Future Airborne Studies

Science.gov (United States)

Northup, E. A.; Kusterer, J.; Quam, B.; Chen, G.; Early, A. B.; Beach, A. L., III

2015-12-01

The current ICARTT file format standards were developed for the purpose of fulfilling the data management needs for the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign in 2004. The goal of the ICARTT file format was to establish a common and simple to use data file format to promote data exchange and collaboration among science teams with similar science objectives. ICARTT has been the NASA standard since 2010, and is widely used by NOAA, NSF, and international partners (DLR, FAAM). Despite its level of acceptance, there are a number of issues with the current ICARTT format, especially concerning the machine readability. To enhance usability, the ICARTT Refresh Earth Science Data Systems Working Group (ESDSWG) was established to enable a platform for atmospheric science data producers, users (e.g. modelers) and data managers to collaborate on developing criteria for this file format. Ultimately, this is a cross agency effort to improve and aggregate the metadata records being produced. After conducting a survey to identify deficiencies in the current format, we determined which are considered most important to the various communities. Numerous recommendations were made to improve upon the file format while maintaining backward compatibility. The recommendations made to date and their advantages and limitations will be discussed.

Softwareland Chronicles: A Software Development Meta-Process Proposal

Directory of Open Access Journals (Sweden)

Bolanos Sandro

2016-05-01

Full Text Available This paper presents the software development meta-process (SD-MP as a proposal to set up software projects. Within this proposal we offer conceptual elements that help solve the war of methodologies and processes in favor of an integrating viewpoint, where the main flaws associated with conventional and agile approaches are removed. Our newly developed software platform to support the meta-process is also presented together with three case studies involving projects currently in progress, where the framework proposed in SD-MP has been applied.

Tunneling current between graphene layers

OpenAIRE

Poklonski, Nikolai A.; Siahlo, Andrei I.; Vyrko, Sergey A.; Popov, Andrey M.; Lozovik, Yurii E.

2013-01-01

The physical model that allows to calculate the values of the tunneling current be-tween graphene layers is proposed. The tunneling current according to the pro-posed model is proportional to the area of tunneling transition. The calculated value of tunneling conductivity is in qualitative agreement with experimental data.

SQUID based cryogenic current comparator for measurements of the dark current of superconducting cavities

Energy Technology Data Exchange (ETDEWEB)

Vodel, W.; Nietzsche, S.; Neubert, R.; Nawrodt, R. [Friedrich Schiller Univ. Jena (Germany); Peters, A. [GSI Darmstadt (Germany); Knaack, K.; Wendt, M.; Wittenburg, K. [DESY Hamburg (Germany)

2005-07-01

The linear accelerator technology, based on super-conducting L-band (1.3 GHz) is currently under study at DESY (Hamburg, Germany). The two 10 km long main Linacs will be equipped with a total of nearly 20.000 cavities. The dark current due to the emission of electrons in these high gradient field super-conducting cavities is an unwanted particle source. A newly high performance SQUID based measurement system for detecting dark currents is proposed. It makes use of the Cryogenic Current Comparator principle and senses dark currents in the pA range with a measurement bandwidth of up to 70 kHz. The use of a cryogenic current comparator as dark current sensor has some important advantages: -) the measurement of the absolute value of the dark current, -) the non-dependence on the electron trajectories, -) the accurate absolute calibration with an additional wire loop, and -) extremely high resolution.

A hardenability test proposal

Energy Technology Data Exchange (ETDEWEB)

Murthy, N.V.S.N. [Ingersoll-Rand (I) Ltd., Bangalore (India)

1996-12-31

A new approach for hardenability evaluation and its application to heat treatable steels will be discussed. This will include an overview and deficiencies of the current methods and discussion on the necessity for a new approach. Hardenability terminology will be expanded to avoid ambiguity and over-simplification as encountered with the current system. A new hardenability definition is proposed. Hardenability specification methods are simplified and rationalized. The new hardenability evaluation system proposed here utilizes a test specimen with varying diameter as an alternative to the cylindrical Jominy hardenability test specimen and is readily applicable to the evaluation of a wide variety of steels with different cross-section sizes.

Application of digital PWM technology in current transducers

International Nuclear Information System (INIS)

Liu Huifang; Hu Zhimin; Li Rui

2012-01-01

With the development of DSP technology and mature use of PID technology,, a new program for DC or AC signal measurement is proposed. Combined with the DSP chip timer module and PID algorithm, PWM signals are generated to control the feedback circuit for the compensation current. Finally the measured current value can be obtained according to the ampere-turns compensation current and the measured current. Studies have shown that this technology enables new current transducers have high stability. (authors)

A detailed neutronics comparison of the university of Florida training reactor (UFTR) current HEU and proposed LEU cores

International Nuclear Information System (INIS)

Dionne, B.; Haghighat, A.; Yi, C.; Smith, R.; Ghita, G.; Manalo, K.; Sjoden, G.; Huh, J.; Baciak, J.; Mock, T.; Wenner, M.; Matos, J.; Stillman, J.

2006-01-01

For over 35 years, the UFTR highly-enriched core has been safely operated. As part of the Reduced Enrichment for Research and Test Reactors Program, the core is currently being converted to low-enriched uranium fuel. The analyses presented in this paper were performed to verify that, from a neutronic perspective, a proposed low-enriched core can be operated as safely and as effectively as the highly-enriched core. Detailed Monte Carlo criticality calculations are performed to determine: i) Excess reactivity for different core configurations, ii) Individual integral blade worth and shutdown margin, iii) Reactivity coefficients and kinetic parameters, and iv) Flux profiles and core six-factor formula parameters. (authors)

Study, design and manufacture eddy current probes for industry applications

International Nuclear Information System (INIS)

Nguyen Phuc; Nguyen Van Thuy; Vuong Binh Duong; Do Minh Duc; Trinh Dinh Truong; Tran Trong Duc; Do Tung Khanh; Dang Quang Trung

2016-01-01

This study is based on the studying, designing and manufacturing of eddy current probes for industry applications. The main tasks of this study include: i) Describes the overview and classification of eddy current probes (which can be classified into three categories based on the mode of operation: absolute eddy current probe, differential eddy current probe and reflect eddy current probe); ii) Describes the three methods of probe designing and manufacturing (including experimental, analytical and numerical designs); iii) Describes the designing and manufacturing of eddy current probes for industry applications, which based on experimental and analytical methods. Based on this study, we have successfully manufactured some current probes (including absolute eddy current probe, differential eddy current probe and reflect eddy current probe) for surface and tube inspections. (author)

Motion-induced eddy current thermography for high-speed inspection

Directory of Open Access Journals (Sweden)

Jianbo Wu

2017-08-01

Full Text Available This letter proposes a novel motion-induced eddy current based thermography (MIECT for high-speed inspection. In contrast to conventional eddy current thermography (ECT based on a time-varying magnetic field created by an AC coil, the motion-induced eddy current is induced by the relative motion between magnetic field and inspected objects. A rotating magnetic field created by three-phase windings is used to investigate the heating principle and feasibility of the proposed method. Firstly, based on Faraday’s law the distribution of MIEC is investigated, which is then validated by numerical simulation. Further, experimental studies are conducted to validate the proposed method by creating rotating magnetic fields at different speeds from 600 rpm to 6000 rpm, and it is verified that rotating speed will increase MIEC intensity and thereafter improve the heating efficiency. The conclusion can be preliminarily drawn that the proposed MIECT is a platform suitable for high-speed inspection.

Magneto-optical study of the intermediate state in type-I superconductors: Effects of sample shape and applied current

International Nuclear Information System (INIS)

Hoberg, Jacob

2008-01-01

The magnetic flux structures in the intermediate state of bulk, pinning-free Type-I superconductors are studied using a high resolution magneto-optical imaging technique. Unlike most previous studies, this work focuses on the pattern formation of the coexisting normal and superconducting phases in the intermediate state. The influence of various parameters such as sample shape, structure defects (pinning) and applied current are discussed in relation to two distinct topologies: flux tubes (closed topology) and laminar (open topology). Imaging and magnetization measurements performed on samples of different shapes (cones, hemispheres and slabs), show that contrary to previous beliefs, the tubular structure is the equilibrium topology, but it is unstable toward defects and flux motion. Moreover, the application of current into a sample with the geometric barrier can replace an established laminar structure with flux tubes. At very high currents, however, there exists a laminar 'stripe pattern.' Quantitative analysis of the mean tube diameter is shown to be in good agreement with the prediction proposed by Goren and Tinkham. This is the first time that this model has been confirmed experimentally. Further research into the flux tube phase shows a direct correlation with the current loop model proposed in the 1990's by Goldstein, Jackson and Dorsey. There also appears a range of flux tube density that results in a suprafroth structure, a well-formed polygonal mesh, which behaves according to the physics of foams, following standard statistical laws such as von Neumann and Lewis. The reaction of flux structures to a fast-ramped magnetic field was also studied. This provided an alignment of the structure not normally observed at slow ramp rates.

Flexible Compensation of Voltage and Current Unbalance and Harmonics in Microgrids

Directory of Open Access Journals (Sweden)

Seyyed Yousef Mousazadeh Mousavi

2017-10-01

Full Text Available In recent years, the harmonics and unbalance problems endanger the voltage and current quality of power systems, due to increasing usage of nonlinear and unbalanced loads. Use of Distributed Generation (DG-interfacing inverters is proposed for voltage or current compensation. In this paper, a flexible control method is proposed to compensate voltage and current unbalance and harmonics using the distributed generation (DG-interfacing inverters. This method is applicable to both grid-connected and islanded Microgrids (MGs. In the proposed method, not only the proper control of active and reactive powers can be achieved, but also there is flexibility in compensating the voltage or current quality problems at DG terminals or Points of Common Coupling (PCCs. This control strategy consists of active and reactive power controllers and a voltage/current quality-improvement block. The controller is designed in a stationary (αβ frame. An extensive simulation study has been performed and the results demonstrate the effectiveness of the proposed control scheme. Depending on the compensation modes, the harmonics and unbalance compensation of DG output current, MG-injected current to the grid, as well as PCC and DG voltages, can be achieved in grid-connected operation of MG while in the islanded operation, and the PCC and DG voltages compensation can be obtained through the proposed control scheme.

Beam-beam studies for the proposed SLAC/LBL/LLNL B Factory

International Nuclear Information System (INIS)

Furman, M.A.

1991-05-01

We present a summary of beam-beam dynamics studies that have been carried out to date for the proposed SLAC/LBL/LLNL B Factory. Most of the material presented here is contained in the proposal's Conceptual Design Report, although post-CDR studies are also presented. 15 refs., 6 figs., 2 tabs

AC/DC current ratio in a current superimposition variable flux reluctance machine

Science.gov (United States)

Kohara, Akira; Hirata, Katsuhiro; Niguchi, Noboru; Takahara, Kazuaki

2018-05-01

We have proposed a current superimposition variable flux reluctance machine for traction motors. The torque-speed characteristics of this machine can be controlled by increasing or decreasing the DC current. In this paper, we discuss an AC/DC current ratio in the current superimposition variable flux reluctance machine. The structure and control method are described, and the characteristics are computed using FEA in several AC/DC ratios.

Proposed Brookhaven accelerator-based neutron generator

International Nuclear Information System (INIS)

Grand, P.; Batchelor, K.; Chasman, R.; Rheaume, R.

1976-01-01

The d-Li Neutron Source concept, which includes a high-current dueteron linac, is an outgrowth of attempts made to use the BNL, 200-MeV proton linac BLIP facility to do radiation damage studies. It included a 100 mA, 30-MeV deuteron linear accelerator and a fast-flowing liquid lithium jet as the target. The latest design is not very different, except that the current is now 200 mA and the linac energy has been raised to 35 MeV. Both parameters, were changed to optimize the effectiveness of the facility with respect to flux, experimental volume and match to 14 MeV neutron-radiation-damage effects. The proposed Brookhaven Accelerator-based Neutron Generator is described with particular emphasis on the linear accelerator. The proposed facility is a practical and efficient way of producing the intense, high energy neutron beams needed for CTR material studies. The accelerator and liquid-metal technologies are well proven, state-of-the-art technologies. The fact that no new technology is required guarantees the possibility of meeting construction schedules, and more importantly, guarantees a high level of operational reliability

The ENIQ pilot study: current status

Energy Technology Data Exchange (ETDEWEB)

Lemaitre, P; Eriksen, B; Crutzen, S [European Commission, DG Joint Research Centre, Petten (Netherlands); Hansch, M [Preussische Elektrizitaets-AG (Preussenelektra), Hannover (Germany); Whittle, J [AEA Technology, Warrington (United Kingdom)

1998-11-01

A pilot study is currently being carried out by ENIQ (European Network for Inspection Qualification) in order to explore the issues involved in inspection qualification applied along the general principles of the European methodology. The components selected for the pilot study are austenitic pipe to pipe and pipe to elbows welds typical of those in BWR recirculation loops. A range of defect parameters has been defined. A suitable inspection procedure designed to find the designated defects will be applied to geometrically representative test pieces. The procedure/equipment will be qualified through open trials and technical justification. The personnel qualification will be done in a blind way. Once all features of the inspection system will have been qualified an in-service inspection will be simulated in order to test the feasibility of the qualification approach followed. In this paper the current status of this pilot study is discussed. (orig.)

Experiments with eddy currents: the eddy current brake

International Nuclear Information System (INIS)

Gonzalez, Manuel I

2004-01-01

A moderate-cost experimental setup is presented to help students to understand some qualitative and quantitative aspects of eddy currents. The setup operates like an eddy current brake, a device commonly used in heavy vehicles to dissipate kinetic energy by generating eddy currents. A set of simple experiments is proposed to measure eddy current losses and to relate them to various relevant parameters. Typical results for each of the experiments are presented, and comparisons with theoretical predictions are included. The experiments, which are devoted to first-year undergraduate students, deal also with other pedagogically relevant topics in electricity and magnetism, such as basic laws, electrical measurement techniques, the sources of the magnetic field and others

Study on model current predictive control method of PV grid- connected inverters systems with voltage sag

Science.gov (United States)

Jin, N.; Yang, F.; Shang, S. Y.; Tao, T.; Liu, J. S.

2016-08-01

According to the limitations of the LVRT technology of traditional photovoltaic inverter existed, this paper proposes a low voltage ride through (LVRT) control method based on model current predictive control (MCPC). This method can effectively improve the photovoltaic inverter output characteristics and response speed. The MCPC method of photovoltaic grid-connected inverter designed, the sum of the absolute value of the predictive current and the given current error is adopted as the cost function with the model predictive control method. According to the MCPC, the optimal space voltage vector is selected. Photovoltaic inverter has achieved automatically switches of priority active or reactive power control of two control modes according to the different operating states, which effectively improve the inverter capability of LVRT. The simulation and experimental results proves that the proposed method is correct and effective.

[Individual rights vs public health in the fight against contagious diseases: proposals to improve the current legal framework].

Science.gov (United States)

Salamero Teixidó, Laura

2016-11-01

The public health protection constitutional mandate requires public powers to protect the population from contagious diseases. This requires a legal framework that both protects public health effectively and respects individual rights and freedoms that could be undermined by the public administrations. This article analyses, from a legal perspective, the current legal framework regulating the adoption of health measures to protect public health against contagious diseases. It argues that current regulations generate legal uncertainty on the basis of the wide range of discretionary powers they give to the public administration and the lack of provisions for limiting these powers. As a result, the guarantee mechanisms (primarily judicial consent) only weakly protect the rights and freedoms of the citizens affected by health measures. To conclude, the article proposes several amendments to improve public health regulations related to contagious diseases. The purpose is to render a legal framework that offers more legal certainty, in which it is possible to protect individual rights and freedoms when measures are adopted, without sacrificing the effective protection of public health. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

A New Small Drifter for Shallow Water Basins: Application to the Study of Surface Currents in the Muggia Bay (Italy

Directory of Open Access Journals (Sweden)

Carmelo Nasello

2016-01-01

Full Text Available A new small drifter prototype for measuring current immediately below the free surface in a water basin is proposed in this paper. The drifter dimensions make it useful for shallow water applications. The drifter transmits its GPS location via GSM phone network. The drifter was used to study the trajectory of the surface current in the Muggia bay, the latter containing the industrial harbor of the city of Trieste (Italy. The analysis has been carried out under a wide variety of wind conditions. As regards the behavior of the drifter, the analysis has shown that it is well suited to detect the water current since its motion is marginally affected by the wind. The study has allowed detecting the main features of the surface circulation within the Muggia bay under different meteorological conditions. Also, the study has shown that the trajectory of the surface current within the bay is weakly affected by the Coriolis force.

Cardiovascular diseases induced by low level ionizing radiation. Current status and proposal of future directions of the biological studies

International Nuclear Information System (INIS)

Iwasaki, Toshiyasu; Nomura, Takaharu; Ishii, Keiichiro

2013-01-01

In the publication on tissue reactions of the International Commission on Radiological Protection (ICRP), the risk of cardiovascular diseases (CVD) was calculated based on linear non-threshold model, without taking account of dose-rate effect. To evaluate the validity of this estimation, we analyzed recent epidemiological and biological findings on CVD at low dose or low dose-rate. Though epidemiological data suggested that radiation would have a causal association with CVD by inducing atherosclerosis, it was limited by heterogeneity among studies, and the contribution of other pathways was also suggested. As biological mechanisms, inflammation is considered as the critical factor of radiation induced CVD. However, the inflammatory responses at low dose were inconsistent among studies, and there were few data at low dose-rate. Furthermore, because those responses were transient, it was very difficult to link them to CVD with long latency. We proposed a concept for the analysis of these long latency diseases by focusing the premonitory symptoms of CVD which could be affected by radiation. As the premonitory symptoms recruitment of white blood cells to inflamed blood vessels and/or tissues would have the highest priority to investigate. To elucidate the dose-rate effect and reflect the results on the radiological protection, it would be important to examine the premonitory symptoms after long term exposure mimicking the actual situation, such as chronic exposure or fractionated exposure of very small dose. (author)

Current measurement method for characterization of fast switching power semiconductors with Silicon Steel Current Transformer

DEFF Research Database (Denmark)

Li, Helong; Beczkowski, Szymon; Munk-Nielsen, Stig

2015-01-01

This paper proposes a novel current measurement method with Silicon Steel Current Transformer (SSCT) for the characterization of fast switching power semiconductors. First, the existing current sensors for characterization of fast switching power semiconductors are experimentally evaluated...

Study of rare earth separation by counter current electromigration

International Nuclear Information System (INIS)

Correa, Sergio Machado

1995-08-01

The counter current electromigration (CCEM) is an electrophoretic technique where the charged species migrate on an electrical field toward an electrolytic flux. Usually this electrolyte is a complexing agent and is necessary to increase the small differences between the species mobilities. A new column was developed, all made of acrylic, in a cylindrical shape. A set of experiments was carried out with the species Na + /K + , K + /Sm +3 , K + /Eu +3 and K + /Sm +3 /Eu +3 using the α-hydrox i-isobutyric acid o,01 M as the counter current electrolytic flux. From a synthetic mixture of 90% of samarium and 10% of europium was obtained the samarium ion in a purity better than 99,9% where the concentration of Eu was determined by the polarography technique. The potassium ion was used as a leading electrolyte. It was also measured the mobilities of the involved species in the α-HIBA medium. Two models are proposed, a stationary model and a dynamic one. A simulator of a simplified stationary model, prepared in FORTRAN language, was developed and tested toward experimental results. (author)

Design of a Programmable Gain, Temperature Compensated Current-Input Current-Output CMOS Logarithmic Amplifier.

Science.gov (United States)

Ming Gu; Chakrabartty, Shantanu

2014-06-01

This paper presents the design of a programmable gain, temperature compensated, current-mode CMOS logarithmic amplifier that can be used for biomedical signal processing. Unlike conventional logarithmic amplifiers that use a transimpedance technique to generate a voltage signal as a logarithmic function of the input current, the proposed approach directly produces a current output as a logarithmic function of the input current. Also, unlike a conventional transimpedance amplifier the gain of the proposed logarithmic amplifier can be programmed using floating-gate trimming circuits. The synthesis of the proposed circuit is based on the Hart's extended translinear principle which involves embedding a floating-voltage source and a linear resistive element within a translinear loop. Temperature compensation is then achieved using a translinear-based resistive cancelation technique. Measured results from prototypes fabricated in a 0.5 μm CMOS process show that the amplifier has an input dynamic range of 120 dB and a temperature sensitivity of 230 ppm/°C (27 °C- 57°C), while consuming less than 100 nW of power.

Current constrained voltage scaled reconstruction (CCVSR) algorithm for MR-EIT and its performance with different probing current patterns

International Nuclear Information System (INIS)

Birguel, Oezlem; Eyueboglu, B Murat; Ider, Y Ziya

2003-01-01

Conventional injected-current electrical impedance tomography (EIT) and magnetic resonance imaging (MRI) techniques can be combined to reconstruct high resolution true conductivity images. The magnetic flux density distribution generated by the internal current density distribution is extracted from MR phase images. This information is used to form a fine detailed conductivity image using an Ohm's law based update equation. The reconstructed conductivity image is assumed to differ from the true image by a scale factor. EIT surface potential measurements are then used to scale the reconstructed image in order to find the true conductivity values. This process is iterated until a stopping criterion is met. Several simulations are carried out for opposite and cosine current injection patterns to select the best current injection pattern for a 2D thorax model. The contrast resolution and accuracy of the proposed algorithm are also studied. In all simulation studies, realistic noise models for voltage and magnetic flux density measurements are used. It is shown that, in contrast to the conventional EIT techniques, the proposed method has the capability of reconstructing conductivity images with uniform and high spatial resolution. The spatial resolution is limited by the larger element size of the finite element mesh and twice the magnetic resonance image pixel size

18 CFR 5.11 - Potential Applicant's proposed study plan and study plan meetings.

Science.gov (United States)

2010-04-01

... study: (1) A detailed description of the study and the methodology to be used; (2) A schedule for... each study proposal and the information to be obtained; (2) Address any known resource management goals...; (4) Explain any nexus between project operations and effects (direct, indirect, and/or cumulative) on...

Improving sensitivity of residual current transformers to high frequency earth fault currents

Directory of Open Access Journals (Sweden)

Czapp Stanislaw

2017-09-01

Full Text Available For protection against electric shock in low voltage systems residual current devices are commonly used. However, their proper operation can be interfered when high frequency earth fault current occurs. Serious hazard of electrocution exists then. In order to detect such a current, it is necessary to modify parameters of residual current devices, especially the operating point of their current transformer. The authors proposed the modification in the structure of residual current devices. This modification improves sensitivity of residual current devices when high frequency earth fault current occurs. The test of the modified residual current device proved that the authors’ proposition is appropriate.

Spicy Stonehenge : Proposing a SOA Case Study

NARCIS (Netherlands)

Espinha, T.A.; Chen, C.; Zaidman, A.E.; Gross, H.G.

2012-01-01

Prepint of paper published in: ICSE Workshop on Principles of Engineering Service Oriented Systems (PESOS), 4 June 2012; doi:10.1109/PESOS.2012.6225940 Maintenance research in the context of Service Oriented Architecture (SOA) is currently lacking a suitable standard case study that can be used by

International Veterinary Epilepsy Task Force consensus proposal

DEFF Research Database (Denmark)

Bhatti, Sofie F M; De Risio, Luisa; Muñana, Karen

2015-01-01

with the initial drug is unsatisfactory, and 4) when treatment changes should be considered. In this consensus proposal, an overview is given on the aim of AED treatment, when to start long-term treatment in canine epilepsy and which veterinary AEDs are currently in use for dogs. The consensus proposal for drug...... treatment protocols, 1) is based on current published evidence-based literature, 2) considers the current legal framework of the cascade regulation for the prescription of veterinary drugs in Europe, and 3) reflects the authors' experience. With this paper it is aimed to provide a consensus...

An electron beam induced current study of gallium nitride and diamond materials

International Nuclear Information System (INIS)

Cropper, A.D.; Moore, D.J.; Scott, C.S.; Green, R.

1995-01-01

The continual need for microelectronic devices that operate under severe electronic and environmental conditions (high temperature, high frequency, high power, and radiation tolerance) has sustained research in wide bandgap semiconductor materials. The properties suggest these wide-bandgap semiconductor materials have tremendous potential for military and commercial applications. High frequency bipolar transistors and field effect transistors, diodes, and short wavelength optical devices have been proposed using these materials. Although research efforts involving the study of transport properties in Gallium Nitride (GaN) and Diamond have made significant advances, much work is still needed to improve the material quality so that the electrophysical behavior of device structures can be further understood and exploited. Electron beam induced current (EBIC) measurements can provide a method of understanding the transport properties in Gallium Nitride (GaN) and Diamond. This technique basically consists of measuring the current or voltage transient response to the drift and diffusion of carriers created by a short-duration pulse of radiation. This method differs from other experimental techniques because it is based on a fast transient electron beam probe created from a high speed, laser pulsed photoemission system

Methodological proposal for studying suicide as a complex phenomenon

Directory of Open Access Journals (Sweden)

Minayo Maria Cecília de Souza

2006-01-01

Full Text Available The authors present a methodological proposal for studying suicide and suicide attempts from a combined socio-anthropological, epidemiological, and psychosocial perspective. This interdisciplinary and complex research model simultaneously examined individual, socioeconomic, historical/cultural, and population data as few studies have succeeded to date. Considering that the present study was conducted in a specific social reality, the authors created a methodological approach to comprehend the effects of a crisis in an industrial restructuring process in a mining company town in the State of Minas Gerais, Brazil, that was associated with unusually high suicide rates. Since it referred to a small geographic area (with only 100,000 inhabitants, the research is considered an ideal case study. The authors created different strategies to trace the local epidemiological profile, adapted a psychosocial autopsy technique to elucidate suicide cases and a psychosocial harm assessment technique to comprehend suicide attempts, and conducted a local analysis of the socio-cultural context. The methods proposed here (with advantages and limitations proved productive for elucidating the study hypothesis.

Dependence of critical current on sample length analyzed by the variation of local critical current bent of BSCCO superconducting composite tape

International Nuclear Information System (INIS)

Matsubayashi, H.; Mukai, Y.; Shin, J.K.; Ochiai, S.; Okuda, H.; Osamura, K.; Otto, A.; Malozemoff, A.

2008-01-01

Using the high critical current type BSCCO composite tape fabricated at American Superconductor Corporation, the relation of overall critical current to the distribution of local critical current and the dependence of overall critical current on sample length of the bent samples were studied experimentally and analytically. The measured overall critical current was described well from the distribution of local critical current and n-value of the constituting short elements, by regarding the overall sample to be composed of local series circuits and applying the voltage summation model. Also the dependence of overall critical current on sample length could be reproduced in computer satisfactorily by the proposed simulation method

Planned and proposed pipeline regulations

International Nuclear Information System (INIS)

De Leon, C.

1992-01-01

The Research and Special Programs Administration administers the Natural Gas Pipeline Safety Act of 1968 (NGPSA) and the Hazardous Liquid Pipeline Safety Act of 1979 (HLPSA). The RSPA issues and enforces design, construction, operation and maintenance regulations for natural gas pipelines and hazardous liquid pipelines. This paper discusses a number of proposed and pending safety regulations and legislative initiatives currently being considered by the RSPA and the US Congress. Some new regulations have been enacted. The next few years will see a great deal of regulatory activity regarding natural gas and hazardous liquid pipelines, much of it resulting from legislative requirements. The office of Pipeline Safety is currently conducting a study to streamline its operations. This study is analyzing the office's business, social and technical operations with the goal of improving overall efficiency, effectiveness, productivity and job satisfaction to meet the challenges of the future

An evaluation of the proposed organisation restructuring at Kadoma city, 2015.

Science.gov (United States)

Muringazuva, A Caroline; Chirundu, Daniel; Shamu, Shepherd; Shambira, Gerald; Gombe, Notion; Juru, Tsitsi; Bangure, Donewell; Tshimanga, Mufuta

2017-01-01

Restructuring is the corporate management term for the act of reorganizing the legal, operational, or other structures of a company for the purpose of making it more profitable or better organized for its present needs. However, preparing an organization to accept and welcome any change is crucial. There is concern though over poor service delivery, untimely payment of workers, top management structure which is thought to be top heavy and employee costs taking (58%) of total expenditure. A descriptive cross sectional study was carried out. A cost benefit analysis was used to assess the cost and benefits of the proposed retrenchment exercise. A descriptive cross sectional study survey was conducted to assess the workers' perceptions towards the proposed restructuring exercise. A pretested self-administered questionnaire was used for data collection and data were analysed using EpiInfoTM (CDC 2012).Written informed consent was obtained from all study participants. Sixty nine percent of the respondents were males. The median years working for the organisation was 8 years (Q1=1; Q3=17). The total income was surpassed by expenditure with USD$11 000 and 52% of expenditures was going towards employment costs. A midyear financial review showed that 1% was channeled towards capital expenditure 2% on repairs and maintenance and employee costs accounting to 58% of all incurred expenditure. Current departmental salary budget amounted to USD 3,3million dollars. Estimated salary costs for the proposed departmental structures amount to USD 3,8 million dollars. Comparison of the current and proposed structure showed that the proposed structure costs USD$486 000 more. Projected benefits of the proposed structure aims to improve service delivery from 60%-85% . Unlike managers, lower levels workers did not want the exercise to be carried out. The proposed structure has higher costs than the current structure but with more benefits in terms of service delivery. Generally workers

Studies of current-perpendicular-to-plane magnetoresistance (CPP-MR) and current-induced magnetization switching (CIMS)

Science.gov (United States)

Kurt, Huseyin

2005-08-01

We present two CPP-MR studies of spin-valves based upon ferromagnetic/nonmagnetic/ferromagnetic (F/N/F) trilayers. We measure the spin-diffusion lengths of N = Pd, Pt, and Au at 4.2K, and both the specific resistances (sample area A times resistance R) and spin-memory-loss of N/Cu interfaces. Pd, Pt and Au are of special device interest because they give perpendicular anisotropy when sandwiching very thin Co layers. Comparing our spin-memory-loss data at Pd/Cu and Pt/Cu interfaces with older data for Nb/Cu and W/Cu gives insight into the importance of spin-orbit coupling in producing such loss. We reproduce and extend prior studies by Eid of 'magnetic activity' at the interface of Co and N-metals (or combinations of N-metals), when the other side of the N-metal contacts a superconductor (S). Our data suggest that magnetic activity may require strong spin-flipping at the N/S interface. We present five studies of a new phenomenon, CIMS, in F1/N/F2 trilayers, with F1 a thick 'polarizing' layer and F2 a thin 'switching' layer. In all prior studies of CIMS, positive current caused the magnetization of F2 to switch from parallel (P) to anti-parallel (AP) to that of F1- 'normal' switching. By judicious addition of impurities to F-metals, we are able to controllably produce both 'normal' and 'inverse' switching- where positive current switches the magnetization of F2 from AP to P to that of F1. In the samples studied, whether the switching is normal or inverse is set by the 'net polarization' produced by F1 and is independent of the properties of F2. As scattering in the bulk of F1 and F2 is essential to producing our results, these results cannot be described by ballistic models, which allow scattering only at interfaces. Most CIMS experiments use Cu as the N-layer due to its low resistivity and long spin-diffusion length. We show that Ag and Au have low enough resistivities and long enough spin-diffusion lengths to be useful alternatives to Cu for some devices. While

Rationing critical care medicine: recent studies and current trends.

Science.gov (United States)

Ward, Nicholas S

2005-12-01

This paper reviews the literature on the rationing of critical care resources. Although much has been written about the concept of rationing, there have been few scientific studies as to its prevalence. A recent meta-analysis reviewed all previously published studies on rationing access to intensive care units but little is known about practices within the intensive care unit. Much literature in the past few years has focused on the growing use of critical care resources and projections for the future. Several authors suggest there may be a crisis in financial or personnel resources if some rationing does not take place. Other papers have argued that the methods of rationing critical care previously proposed, such as limiting the care of dying patients or using cost-effectiveness analysis to determine care, may not be effective or viewed as ethical by some. Finally, several recent papers review how critical care is practiced and allocated in India and Asian countries that already practice open rationing in their health care systems. There is currently no published evidence that overt rationing is taking place in critical care medicine. There is growing evidence that in the future, the need for critical care may outstrip financial resources unless some form of rationing takes place. It is also clear from the literature that choosing how to ration critical care will be a difficult task.

Impurity study experiment proposal

International Nuclear Information System (INIS)

1975-05-01

ISX is a modest tokamak which emphasizes the production of a predictable test plasma, experimental flexibility, ease of assembly and disassembly, and good diagnostic access. Its plasma models the outer cooler layers in EPR like plasmas. In addition, provisions will be made for long discharge times which may be necessary to observe some impurity effects. These machine characteristics will enable one to study the collisional transport of impurities in the plasma, perform systematic studies of wall and limiter materials and geometries, study methods of cleaning the walls, and develop and test new diagnostic techniques. ISX will employ water-cooled copper coils to produce a maximum toroidal magnetic field of 20 kG at the plasma axis, which is 77 cm from the major axis. The plasma minor radius will be about 15 cm, and the maximum plasma current will be 100 kA which will be induced by an iron core transformer with a capability of up to 0.9 volt-sec for long discharges. An aspect ratio of five and the modest magnetic field permit a design with ample space for thick wall structures such as honeycomb walls. The ''picture frame'' toroidal field coil provides additional space, while removable coil top sections allow easy replacement of the vacuum chamber. The 72-turn toroidal field coil is grouped into 24 sections for increased access. Absence of a conducting shell and placement of the vertical field and transformer primary coils away from the plasma allow easy viewing of the plasma and good diagnostic access. (U.S.)

Proposal for constructing the energetic particle injector

International Nuclear Information System (INIS)

Ueda, M.; Ferreira, A.C.A.; Aso, Y.

1987-07-01

The construction of an electrostatic accelerator to produce an intense ion beam is proposed. The high voltage pulse to be used in the acceleration of the ions (500 kV, 1 μs) will be provided by a Marx generator. Using this pulses, a high total current proton beam (>200 KA) will be extracted from a magnetically insulated diode with an anode plasma produced by an inductive breakdown of hydrogen gas. The beam will be injected into a magnetic confinement device, a tokamak to be called ETA (Experimento Toroidal Avancado), to study heating, refueling and noninductive current generation in toroidal plasmas. (author) [pt

Reforming EIA systems: A critical review of proposals in Brazil

Energy Technology Data Exchange (ETDEWEB)

Fonseca, Alberto, E-mail: albertof@em.ufop.br [Federal University of Ouro Preto, Minas Gerais (Brazil); Sánchez, Luis Enrique [University of São Paulo, São Paulo (Brazil); Ribeiro, José Claudio Junqueira [Escola Superior Dom Helder Câmara, Belo Horizonte, Minas Gerais (Brazil)

2017-01-15

Environmental Impact Assessment (EIA) systems are under pressure in many countries, driven by a call for efficiency and streamlining. Such a phenomenon is particularly clear in Brazil, where, in the past few years, a number of influential associations put forward documents proposing significant changes to environmental licensing and impact assessment regulations. So far, there is no publicly available information about any initiative towards scrutinizing those proposals. The objective of this study was to critically review the merits and drawbacks of the changes proposed in those documents. The analysis triangulated content analysis, focus group and online survey data. The focus group included ten seasoned Brazilian EIA specialists; the survey, based on Likert-scale and open-ended questions, resulted in 322 valid responses from EIA professionals. Results show that the proposals generally agree that the current EIA system, while playing a key role in mitigating impacts and enhancing project design, needs many changes. Nonetheless, the proposals neither offered solutions to overcome political, technical and budget barriers, nor established a sense of priority of the most urgent issues. Findings from the focus group and the survey signaled that a number of proposed actions might face public outcry, and that those changes that do not depend on legislative action are more likely to be implementable. Previous studies about EIA reform focused mostly on the context of developed countries after changes had taken place. This study, while addressing the perspective of a large developing country in a “before-reform” stage, shows that capacity-building is a key requirement in EIA reform. - Highlights: • Brazil's EIA system is under strong pressure for change. • Findings corroborate ineffectiveness in current system. • There are tensions as to the best approaches to overcome problems. • Exact effects of proposals are uncertain. • Low institutional capacity can

CURRENT STUDY ON THE FUNDING SOURCES COVERAGE OF CURRENT ASSETS TO COMPANIES LISTED ON THE BUCHAREST STOCK EXCHANGE

Directory of Open Access Journals (Sweden)

Teodor HADA

2014-06-01

Full Text Available This paper presents issues about the coverage with financing sources of current assets for 64 companies listed on the Bucharest Stock Exchange. The aim of the study is to see how to calculate indicators specific to current assets and the general framework offered as whole analysis of the financing sources of current assets. The introduction of the paper presents the objective, the research methodology and the novelties brought by this study. Further on, this study shows the various views of the authors about the concept of "current assets", financing sources of current assets, the calculation of net working capital, setting the limits of the normal working capital and determining the speed of rotation. After that was done, based on the theory, a case study was performed, for companies covered in this study. Conclusions focused on determining the final data about what was detailed in the previous paragraphs.

Current-induced magnetization dynamics in nanomagnets

International Nuclear Information System (INIS)

Bertotti, G.; Serpico, C.; Mayergoyz, I.D.; Bonin, R.; D'Aquino, M.

2007-01-01

An overview is given of the various approaches that have been proposed for the interpretation of spin-transfer-driven magnetization dynamics. Models of critical currents and critical fields for switching as well as for the onset of magnetization oscillations are discussed, together with methods for the construction of field-current stability diagrams. Finally, the role of thermal fluctuations is analyzed. Particular emphasis is given to the study of uniformly magnetized nanomagnets, which represents an essential step before moving to the numerical computation of more complex micromagnetic configurations

Current-induced magnetization dynamics in nanomagnets

Energy Technology Data Exchange (ETDEWEB)

Bertotti, G. [INRIM-Istituto Nazionale di Ricerca Metrologica, Strada delle Cacce 91, 10135 Turin (Italy)]. E-mail: g.bertotti@inrim.it; Serpico, C. [Department of Electrical Engineering, Universita degli Studi Federico II, Via Claudio 21, 80125 Naples (Italy); Mayergoyz, I.D. [Department of Electrical and Computer Engineering, University of Maryland, College Park, MD 20742 (United States); Bonin, R. [INRIM-Istituto Nazionale di Ricerca Metrologica, Strada delle Cacce 91, 10135 Turin (Italy); D' Aquino, M. [Department of Electrical Engineering, Universita degli Studi Federico II, Via Claudio 21, 80125 Naples (Italy)

2007-09-15

An overview is given of the various approaches that have been proposed for the interpretation of spin-transfer-driven magnetization dynamics. Models of critical currents and critical fields for switching as well as for the onset of magnetization oscillations are discussed, together with methods for the construction of field-current stability diagrams. Finally, the role of thermal fluctuations is analyzed. Particular emphasis is given to the study of uniformly magnetized nanomagnets, which represents an essential step before moving to the numerical computation of more complex micromagnetic configurations.

A Redundancy Mechanism Design for Hall-Based Electronic Current Transformers

Directory of Open Access Journals (Sweden)

Kun-Long Chen

2017-03-01

Full Text Available Traditional current transformers (CTs suffer from DC and AC saturation and remanent magnetization in many industrial applications. Moreover, the drawbacks of traditional CTs, such as closed iron cores, bulky volume, and heavy weight, further limit the development of an intelligent power protection system. In order to compensate for these drawbacks, we proposed a novel current measurement method by using Hall sensors, which is called the Hall-effect current transformer (HCT. The existing commercial Hall sensors are electronic components, so the reliability of the HCT is normally worse than that of the traditional CT. Therefore, our study proposes a redundancy mechanism for the HCT to strengthen its reliability. With multiple sensor modules, the method has the ability to improve the accuracy of the HCT as well. Additionally, the proposed redundancy mechanism monitoring system provides a condition-based maintenance for the HCT. We verify our method with both simulations and an experimental test. The results demonstrate that the proposed HCT with a redundancy mechanism can almost achieve Class 0.2 for measuring CTs according to IEC Standard 60044-8.

Study of runaway current generation following disruptions in KSTAR

International Nuclear Information System (INIS)

Chen, Z Y; Kim, W C; Yu, Y W; England, A C; Yoo, J W; Hahn, S H; Yoon, S W; Lee, K D; Oh, Y K; Kwak, J G; Kwon, M

2013-01-01

The high fraction of runaway current conversion following disruptions has an important effect on the first wall for next-generation tokamaks. Because of the potentially severe consequences of a large full current runaway beam on the first wall in an unmitigated disruption, runaway suppression is given a high priority. The behavior of runaway currents both in spontaneous disruptions and in D 2 massive gas injection (MGI) shutdown experiments is investigated in the KSTAR tokamak. The experiments in KSTAR show that the toroidal magnetic field threshold, B T >2 T, for runaway generation is not absolute. A high fraction of runaway current conversion following spontaneous disruptions is observed at a much lower toroidal magnetic field of B T = 1.3 T. A dedicated fast valve for high-pressure gas injection with 39.7 bar is developed for the study of disruptions. A study of runaway current parameters shows that the conversion efficiency of pre-disruptive plasma currents into runaway current can reach over 80% both in spontaneous disruptions and in D 2 MGI shutdown experiments in KSTAR. (paper)

Analysis of Current Supplier Relationship Management Practices: A Solution Proposal

OpenAIRE

Gomes Campelo Filho, Eulalio

2009-01-01

The work contributes with the existing literature by investigating current SRM practices. Based on the research, the author has designed an information system framework, which provides companies with an innovative SRM solution to manage their indirect material purchasing process through an environment that supports companies entire plan-to-order activities, including functionalities such as central data management, spend data management, e-sourcing and the usual e-procurement features.

Automatic adjustment of bias current for direct current superconducting quantum interference device

International Nuclear Information System (INIS)

Makie-Fukuda, K.; Hotta, M.; Okajima, K.; Kado, H.

1993-01-01

A new method of adjusting the bias current of dc superconducting quantum interference device (SQUID) is described. It is shown that the signal-to-noise ratio of a SQUID magnetometer connected in a flux-locked loop configuration is proportional to the second harmonic of the output signal from the SQUID. A circuit configuration that can automatically optimize a SQUID's bias current by measuring this second harmonic and adjusting the bias current accordingly is proposed

Proposed Sources of Coaching Efficacy: A Meta-Analysis.

Science.gov (United States)

Myers, Nicholas D; Park, Sung Eun; Ahn, Soyeon; Lee, Seungmin; Sullivan, Philip J; Feltz, Deborah L

2017-08-01

Coaching efficacy refers to the extent to which a coach believes that he or she has the capacity to affect the learning and performance of his or her athletes. The purpose of the current study was to empirically synthesize findings across the extant literature to estimate relationships between the proposed sources of coaching efficacy and each of the dimensions of coaching efficacy. A literature search yielded 20 studies and 278 effect size estimates that met the inclusion criteria. The overall relationship between the proposed sources of coaching efficacy and each dimension of coaching efficacy was positive and ranged from small to medium in size. Coach gender and level coached moderated the overall relationship between the proposed sources of coaching efficacy and each of the dimensions of coaching efficacy. Results from this meta-analysis provided some evidence for both the utility of, and possible revisions to, the conceptual model of coaching efficacy.

A Current Limiting Strategy to Improve Fault Ride-Through of Inverter Interfaced Autonomous Microgrids

DEFF Research Database (Denmark)

Sadeghkhani, Iman; Esmail Hamedani Golshan, Mohamad; Guerrero, Josep M.

2017-01-01

With high penetration of distributed energy resources (DER), fault management strategy is of great importance for the distribution network operation. The objective of this paper is to propose a current and voltage limiting strategy to enhance fault ride-through (FRT) capability of inverter...... for both four- and three-wire configurations. The proposed strategy provides high voltage and current quality during overcurrent conditions, which is necessary for sensitive loads. Several time-domain simulation studies are conducted to investigate the FRT capability of the proposed strategy against both...... asymmetrical and symmetrical faults. Moreover, the proposed method is tested on the CIGRE benchmark microgrid to demonstrate the effectiveness of the proposed limiting strategy....

A proposal to study a tracking/preshower detector for the LHC

CERN Document Server

Munday, D J; Anghinolfi, Francis; Bonino, R; Campbell, M; Fassò, A; Gildemeister, O; Heijne, Erik H M; Jarron, Pierre; Mapelli, Livio P; Pentney, J M; Poppleton, Alan; Stevenson, Graham Roger; Gössling, C; Pollmann, D; Sondermann, V; Tsesmelis, E; Clark, A G; Kienzle-Focacci, M N; Martin, M; Rosselet, L; Fretwurst, E; Lindström, G; Reich, V; Bardos, R A; Gorfine, G W; Taylor, G; Tovey, Stuart N; Stapnes, Steinar; Weidberg, A R; Lubrano, P; Pepé, M; Grayer, Geoffrey H; Sharp, P; Bakich, A M; Peak, L S; CERN. Geneva. Detector Research and Development Committee

1990-01-01

We describe a program of studies aimed at determining whether the track stub/preshower technique of electron identification can be used at the highest operating luminosities of the proposed LHC collider. The proposal covers detector and electronics developments required for the construction of a track-stub and preshower detector preceding the electromagnetic calorimeter of an LHC experiment.

Proposed artificial recharge studies in northern Qatar

Science.gov (United States)

Kimrey, J.O.

1985-01-01

The aquifer system in northern Qatar comprises a water-table aquifer in the Rus Formation which is separated by an aquitard from a partially confined aquifer in the top of the overlying Umm er Radhuma Formation. These two aquifers are composed of limestone and dolomite of Eocene and Paleocene age and contain a fragile lens of freshwater which is heavily exploited as a source of water for agricultural irrigation. Net withdrawals are greatly in excess of total recharge, and quality of ground water is declining. Use of desalinated seawater for artificial recharge has been proposed for the area. Artificial recharge, on a large scale, could stabilize the decline in ground-water quality while allowing increased withdrawals for irrigation. The proposal appears technically feasible. Recharge should be by injection to the Umm er Radhuma aquifer whose average transmissivity is about 2,000 meters squared per day (as compared to an average of about 200 meters squared per day for the Rus aquifer). Implementation of artificial recharge should be preceded by a hydrogeologic appraisal. These studies should include test drilling, conventional aquifer tests, and recharge-recovery tests at four sites in northern Qatar. (USGS)

Critical current studies of a HTS rectangular coil

Energy Technology Data Exchange (ETDEWEB)

Zhong, Z. [Department of Engineering, University of Cambridge (United Kingdom); Chudy, M., E-mail: Michal.chudy@stuba.sk [Graduate School of Technology Management, University of Pretoria (South Africa); Institute of Power and Applied Electrical Engineering, Slovak University of Technology in Bratislava (Slovakia); Ruiz, H.S. [Department of Engineering, University of Leicester, Leicester LE1 7RH (United Kingdom); Zhang, X.; Coombs, T. [Department of Engineering, University of Cambridge (United Kingdom)

2017-05-15

Highlights: • Unique square pancake coil was manufactured. • Measurements in relatively high magnetic field were performed. • Different sections of the coil were characterized. • Parts of the coil which are limiting critical current were identified. - Abstract: Nowadays, superconducting high field magnets are used in numerous applications due to their superior properties. High temperature superconductors (HTS) are usually used for production of circular pancake or racetrack coils. However different geometries of HTS coils might be required for some specific applications. In this study, the HTS coil wound on a rectangular frame was fully characterized in homogeneous DC background field. The study contains measurements of critical current angular dependencies. The critical current of the entire coil and two selected strands under different magnitudes and orientations of external magnetic fields are measured. The critical regions of the coil in different angular regimes are determined. This study brings better understanding of the in- field performance of HTS coils wound on frames with right-angles.

Numerical study of gravity currents in a channel

International Nuclear Information System (INIS)

Wang, D.

1985-01-01

A three-dimensional, primitive-equation model was used to study gravity currents produced by instantaneous releases of a buoyant fluid in a rectangular channel. Without rotation, the gravity current passes through two distinct phases: an initial adjustment phase in which the front speed is constant, and an eventual self-similar phase in which the front speed decreases with time. With rotation, the gravity current is confined to the right-hand wall, forming a coastal jet. The initial front-speed is constant; however, the front speed decreases rapidly due to strong mixing at the horizontal edge of the gravity current. Also, with rotation, part of the buoyant fluid is trapped near the source region, forming an anticyclonic vortex

Proposal for a holistic research approach to studying the implementation of IT

DEFF Research Database (Denmark)

Wit, Camilla Kølsen de

The paper is a proposal to how we can study the work process of implementing IT in radical organizational innovation projects through the use of the Critical Incident Technique (CIT).......The paper is a proposal to how we can study the work process of implementing IT in radical organizational innovation projects through the use of the Critical Incident Technique (CIT)....

Proposed use of the radio-frequency quadrupole structure to funnel high-current ion beams

International Nuclear Information System (INIS)

Stokes, R.H.; Minerbo, G.N.

1985-01-01

In this paper, we describe a new approach to funneling beams that are initially accelerated in two radio-frequency quadrupole (RFQ) accelerators. Instead of discrete optical elements, we propose to funnel within an RFQ structure, so that during the funneling process the beam is always confined by periodic transverse focusing. Beams with high space charge experience irreversible emittance growth when they emerge from a periodic focusing system. To alleviate this problem, in the proposed funneling system it should be possible to maintain the same focusing periodicity as that of the accelerators preceding the funnel. Also, instead of conventional deflection systems, we propose to use the properties of a modified RFQ structure to deflect two parallel beams toward each other and to merge them into a single final beam. 1 ref., 3 figs

Study on Application of New Approach of Fault Current Limiters in Fault Ride through Capability Improvement of DFIG Based Wind Turbine

DEFF Research Database (Denmark)

Naderi, Seyed Behzad; Davari, Pooya; Zhou, Dao

2018-01-01

Due to salient advantages, Doubly-Fed Induction Generator (DFIG) has more application in power network compared to Fixed Speed Wind Turbine. Because of employing back-to-back converters, one of the important studies regarding new grid code requirements is Fault Ride-Through (FRT) capability....... The proposed FCL can insert a controllable resistance in fault current pass to not only restrict fault current level and compensate voltage sag in the stator but also consume pre-fault output active power of the DFIG regarding wind speed variation. Simulation results and analytics are presented to prove...

A Short-Current Control Method for Constant Frequency Current-Fed Wireless Power Transfer Systems

Directory of Open Access Journals (Sweden)

Yanling Li

2017-04-01

Full Text Available Frequency drift is a serious problem in Current-Fed Wireless Power Transfer (WPT systems. When the operating frequency is drifting from the inherent Zero Voltage Switching (ZVS frequency of resonant network, large short currents will appear and damage the switches. In this paper, an inductance-dampening method is proposed to inhibit short currents and achieve constant-frequency operation. By adding a small auxiliary series inductance in the primary resonant network, short currents are greatly attenuated to a safe level. The operation principle and steady-state analysis of the system are provided. An overlapping time self-regulating circuit is designed to guarantee ZVS running. The range of auxiliary inductances is discussed and its critical value is calculated exactly. The design methodology is described and a design example is presented. Finally, a prototype is built and the experimental results verify the proposed method.

Safety and tolerability of transcranial direct current stimulation to stroke patients - A phase I current escalation study.

Science.gov (United States)

Chhatbar, Pratik Y; Chen, Rong; Deardorff, Rachael; Dellenbach, Blair; Kautz, Steven A; George, Mark S; Feng, Wuwei

A prior meta-analysis revealed that higher doses of transcranial direct current stimulation (tDCS) have a better post-stroke upper-extremity motor recovery. While this finding suggests that currents greater than the typically used 2 mA may be more efficacious, the safety and tolerability of higher currents have not been assessed in stroke patients. We aim to assess the safety and tolerability of single session of up to 4 mA in stroke patients. We adapted a traditional 3 + 3 study design with a current escalation schedule of 1»2»2.5»3»3.5»4 mA for this tDCS safety study. We administered one 30-min session of bihemispheric montage tDCS and simultaneous customary occupational therapy to patients with first-ever ischemic stroke. We assessed safety with pre-defined stopping rules and investigated tolerability through a questionnaire. Additionally, we monitored body resistance and skin temperature in real-time at the electrode contact site. Eighteen patients completed the study. The current was escalated to 4 mA without meeting the pre-defined stopping rules or causing any major safety concern. 50% of patients experienced transient skin redness without injury. No rise in temperature (range 26°C-35 °C) was noted and skin barrier function remained intact (i.e. body resistance >1 kΩ). Our phase I safety study supports that single session of bihemispheric tDCS with current up to 4 mA is safe and tolerable in stroke patients. A phase II study to further test the safety and preliminary efficacy with multi-session tDCS at 4 mA (as compared with lower current and sham stimulation) is a logical next step. ClinicalTrials.gov Identifier: NCT02763826. Copyright © 2017 Elsevier Inc. All rights reserved.

Writing a Research Proposal to The Research Council of Oman.

Science.gov (United States)

Al-Shukaili, Ahmed; Al-Maniri, Abdullah

2017-05-01

Writing a research proposal can be a challenging task for young researchers. This article explains how to write a strong research proposal to apply for funding, specifically, a proposal for The Research Council (TRC) of Oman. Three different research proposal application forms are currently used in TRC, including Open Research Grant (ORG), Graduate Research Support Program (GRSP), and Faculty-mentored Undergraduate Research Award Program (FURAP). The application forms are filled and submitted electronically on TRC website. Each of the proposals submitted to TRC is selected through a rigorous reviewing and screening process. Novelty and originality of the research idea is the most crucial element in writing a research proposal. Performing an in-depth review of the literature will assist you to compose a good researchable question and generate a strong hypothesis. The development of a good hypothesis will offer insight into the specific objectives of a study. Research objectives should be focused, measurable, and achievable by a specific time using the most appropriate methodology. Moreover, it is essential to select a proper study design in-line with the purpose of the study and the hypothesis. Furthermore, social/economic impact and reasonable budget of proposed research are important criteria in research proposal evaluation by TRC. Finally, ethical principles should be observed before writing a research proposal involving human or animal subjects.

Writing a Research Proposal to The Research Council of Oman

Directory of Open Access Journals (Sweden)

Ahmed Al-Shukaili

2017-05-01

Full Text Available Writing a research proposal can be a challenging task for young researchers. This article explains how to write a strong research proposal to apply for funding, specifically, a proposal for The Research Council (TRC of Oman. Three different research proposal application forms are currently used in TRC, including Open Research Grant (ORG, Graduate Research Support Program (GRSP, and Faculty-mentored Undergraduate Research Award Program (FURAP. The application forms are filled and submitted electronically on TRC website. Each of the proposals submitted to TRC is selected through a rigorous reviewing and screening process. Novelty and originality of the research idea is the most crucial element in writing a research proposal. Performing an in-depth review of the literature will assist you to compose a good researchable question and generate a strong hypothesis. The development of a good hypothesis will offer insight into the specific objectives of a study. Research objectives should be focused, measurable, and achievable by a specific time using the most appropriate methodology. Moreover, it is essential to select a proper study design in-line with the purpose of the study and the hypothesis. Furthermore, social/economic impact and reasonable budget of proposed research are important criteria in research proposal evaluation by TRC. Finally, ethical principles should be observed before writing a research proposal involving human or animal subjects.

'Leak Current' correction for critical current measurement of no-insulation HTS coil

Energy Technology Data Exchange (ETDEWEB)

Song, Jung Bin [Laboratoire National des Champs Magnétiques Intenses, CNRS, Grenoble (France); Hahn, Seung Yong [Dept. of Electrical and Computer Engineering, Seoul National University, Seoul (Korea, Republic of)

2017-06-15

Discrepancy between a power supply current and an actual “spiral” coil current makes the conventional 4-probe measurement of a critical current (I{sub c}) of a no-insulation (NI) high temperature superconductor (HTS) coil inaccurate and time-consuming. This paper presents a fast and accurate approach for I{sub c} measurement of NI HTS coils. With an NI HTS coil energized at a constant ramping rate, a complete analytic expression for the spiral coil current was obtained from a first-order partial differential equation that derived from an equivalent circuit model of the NI coil. From the analytic solution, both spiral coil current and radial leak current can be obtained simultaneously, which enables fast and accurate measurement of the NI coil I{sub c}. To verify the proposed approach, an NI double-pancake (DP) coil, wound with GdBCO tapes of 6 mm × 0.1 mm, was constructed and its Ic was repeatedly measured with various ramping rates in a bath of liquid nitrogen at 77 K. The measured results agreed well with the calculated ones, which validates the proposed approach to measure I{sub c} of an NI HTS coil.

Digitizing Craft: Creative Writing Studies and New Media--A Proposal

Science.gov (United States)

Koehler, Adam

2013-01-01

This article identifies and examines a digital arm of creative writing studies and organizes that proposal into four categories through which to theorize the "craft" of creative production, each borrowed from Tim Mayers's "(Re)Writing Craft: Composition, Creative Writing, and the Future of English Studies": process, genre, author, and…

Magnetic Field of Conductive Objects as Superposition of Elementary Eddy Currents and Eddy Current Tomography

Science.gov (United States)

Sukhanov, D. Ya.; Zav'yalova, K. V.

2018-03-01

The paper represents induced currents in an electrically conductive object as a totality of elementary eddy currents. The proposed scanning method includes measurements of only one component of the secondary magnetic field. Reconstruction of the current distribution is performed by deconvolution with regularization. Numerical modeling supported by the field experiments show that this approach is of direct practical relevance.

Full-wave current conveyor precision rectifier

Directory of Open Access Journals (Sweden)

Đukić Slobodan R.

2008-01-01

Full Text Available A circuit that provides precision rectification of small signal with low temperature sensitivity for frequencies up to 100 kHz without waveform distortion is presented. It utilizes an improved second type current conveyor based on current-steering output stage and biased silicon diodes. The use of a DC current source to bias the rectifying diodes provides higher temperature stability and lower DC offset level at the output. Proposed design of the precision rectifier ensures good current transfer linearity in the range that satisfy class A of the amplifier and good voltage transfer characteristic for low level signals. Distortion during the zero crossing of the input signal is practically eliminated. Design of the proposed rectifier is realized with standard components.

Study of the tunnelling initiated leakage current through the carbon nanotube embedded gate oxide in metal oxide semiconductor structures

International Nuclear Information System (INIS)

Chakraborty, Gargi; Sarkar, C K; Lu, X B; Dai, J Y

2008-01-01

The tunnelling currents through the gate dielectric partly embedded with semiconducting single-wall carbon nanotubes in a silicon metal-oxide-semiconductor (MOS) structure have been investigated. The application of the gate voltage to such an MOS device results in the band bending at the interface of the partly embedded oxide dielectric and the surface of the silicon, initiating tunnelling through the gate oxide responsible for the gate leakage current whenever the thickness of the oxide is scaled. A model for silicon MOS structures, where carbon nanotubes are confined in a narrow layer embedded in the gate dielectric, is proposed to investigate the direct and the Fowler-Nordheim (FN) tunnelling currents of such systems. The idea of embedding such elements in the gate oxide is to assess the possibility for charge storage for memory device applications. Comparing the FN tunnelling onset voltage between the pure gate oxide and the gate oxide embedded with carbon nanotubes, it is found that the onset voltage decreases with the introduction of the nanotubes. The direct tunnelling current has also been studied at very low gate bias, for the thin oxide MOS structure which plays an important role in scaling down the MOS transistors. The FN tunnelling current has also been studied with varying nanotube diameter

Theoretical derivation of anodizing current and comparison between fitted curves and measured curves under different conditions

Science.gov (United States)

Chong, Bin; Yu, Dongliang; Jin, Rong; Wang, Yang; Li, Dongdong; Song, Ye; Gao, Mingqi; Zhu, Xufei

2015-04-01

Anodic TiO2 nanotubes have been studied extensively for many years. However, the growth kinetics still remains unclear. The systematic study of the current transient under constant anodizing voltage has not been mentioned in the original literature. Here, a derivation and its corresponding theoretical formula are proposed to overcome this challenge. In this paper, the theoretical expressions for the time dependent ionic current and electronic current are derived to explore the anodizing process of Ti. The anodizing current-time curves under different anodizing voltages and different temperatures are experimentally investigated in the anodization of Ti. Furthermore, the quantitative relationship between the thickness of the barrier layer and anodizing time, and the relationships between the ionic/electronic current and temperatures are proposed in this paper. All of the current-transient plots can be fitted consistently by the proposed theoretical expressions. Additionally, it is the first time that the coefficient A of the exponential relationship (ionic current jion = A exp(BE)) has been determined under various temperatures and voltages. And the results indicate that as temperature and voltage increase, ionic current and electronic current both increase. The temperature has a larger effect on electronic current than ionic current. These results can promote the research of kinetics from a qualitative to quantitative level.

Theoretical derivation of anodizing current and comparison between fitted curves and measured curves under different conditions.

Science.gov (United States)

Chong, Bin; Yu, Dongliang; Jin, Rong; Wang, Yang; Li, Dongdong; Song, Ye; Gao, Mingqi; Zhu, Xufei

2015-04-10

Anodic TiO2 nanotubes have been studied extensively for many years. However, the growth kinetics still remains unclear. The systematic study of the current transient under constant anodizing voltage has not been mentioned in the original literature. Here, a derivation and its corresponding theoretical formula are proposed to overcome this challenge. In this paper, the theoretical expressions for the time dependent ionic current and electronic current are derived to explore the anodizing process of Ti. The anodizing current-time curves under different anodizing voltages and different temperatures are experimentally investigated in the anodization of Ti. Furthermore, the quantitative relationship between the thickness of the barrier layer and anodizing time, and the relationships between the ionic/electronic current and temperatures are proposed in this paper. All of the current-transient plots can be fitted consistently by the proposed theoretical expressions. Additionally, it is the first time that the coefficient A of the exponential relationship (ionic current j(ion) = A exp(BE)) has been determined under various temperatures and voltages. And the results indicate that as temperature and voltage increase, ionic current and electronic current both increase. The temperature has a larger effect on electronic current than ionic current. These results can promote the research of kinetics from a qualitative to quantitative level.

Adaptive Maneuvering Frequency Method of Current Statistical Model

Institute of Scientific and Technical Information of China (English)

Wei Sun; Yongjian Yang

2017-01-01

Current statistical model(CSM) has a good performance in maneuvering target tracking. However, the fixed maneuvering frequency will deteriorate the tracking results, such as a serious dynamic delay, a slowly converging speedy and a limited precision when using Kalman filter(KF) algorithm. In this study, a new current statistical model and a new Kalman filter are proposed to improve the performance of maneuvering target tracking. The new model which employs innovation dominated subjection function to adaptively adjust maneuvering frequency has a better performance in step maneuvering target tracking, while a fluctuant phenomenon appears. As far as this problem is concerned, a new adaptive fading Kalman filter is proposed as well. In the new Kalman filter, the prediction values are amended in time by setting judgment and amendment rules,so that tracking precision and fluctuant phenomenon of the new current statistical model are improved. The results of simulation indicate the effectiveness of the new algorithm and the practical guiding significance.

Fast liner proposal

International Nuclear Information System (INIS)

Sherwood, A.R.; Freeman, B.L.; Gerwin, R.A.; Jarboe, T.R.; Krakowski, R.A.; Malone, R.C.; Marshall, J.; Miller, R.L.; Suydam, B.

1977-08-01

This is a proposal to study, both theoretically and experimentally, the possibility of making a fusion reactor by magnetically imploding a cylindrical metallic shell on a prepared plasma. The approach is characterized by the following features: (1) the nonrotating liner would be driven by an axial current, (2) the plasma would also carry an axial current that provides an azimuthal magnetic field for thermal insulation in both the radial and longitudinal directions, (3) solid end plugs would be utilized to prevent axial loss of particles, and (4) liner speeds would be in the 10 6 cm/s range. The preliminary calculations indicate (1) that the energetics are favorable (energy inputs of about 10 MJ might produce a machine in the break-even regime), (2) that radiation and heat losses could be made tolerable, (3) that alpha-particle heating could be made very effective, and (4) that Taylor instabilities in a fast liner might be harmless because of the large viscosities at high pressures. A preliminary conceptual design of the sort of fusion reactor that might result from such an approach is discussed, as are some of the relevant reactor scaling arguments

Experimental studies of 2.45 GHz ECR ion sources for the production of high intensity currents

International Nuclear Information System (INIS)

Coly, A.

2010-12-01

This thesis is the result of a collaboration between the Pantechnik company and the LPSC (Laboratory of subatomic physics and cosmology of Grenoble). It consisted in the development of a new test bench dedicated to the characterization of a 2.45 GHz ECR ion sources with the aim of the production of high currents beams for industrial purposes. Two ECR ions sources with different magnetic structures have been tested around the same RF injection system. A new 2.45 GHz ECRIS, named SPEED, featuring a dipolar magnetic field at the extraction has been designed and tested. A study of the beam extraction in the dipolar magnetic field is proposed. First tests have shown a total ionic current density of about 10 mA/cm 2 with a 900 W RF power. Tests with hydrogen plasma have shown a maximum of current on the H 2 + species. Recommendations are given to modify the magnetic structure to improve the H + production yield. The MONO1000 ion source has been tested at high RF power with a wave guide type injection system. Intense total ionic current densities have been measured up to about 95 mA/cm 2 with a diode extraction system. First results using an improved 5 electrode extraction system are presented. (author)

76 FR 64975 - Proposed Collection; Comment Request

Science.gov (United States)

2011-10-19

... examine in detail the nature of various employment and unemployment situations. II. Current Action Office... comments concerning the proposed new collection of the ``Current Population Survey (CPS) Disability... conducted at the request of the Department of Labor's Office of Disability Employment Policy. The Disability...

Assessment of current and proposed nature reserves of Mexico based on their capacity to protect geophysical features and biodiversity

Science.gov (United States)

Cantu, C.; Wright, R.G.; Scott, J.M.; Strand, Espen

2004-01-01

Mexico currently has 144 nature reserves covering approximately 9.1% of its land area. These reserves were established for a variety of reasons - often unrelated to the protection of biodiversity. In 2000 in response to a growing concern about the lack of organized conservation reserve planning to protect the important threatened biological and physical features of Mexico, the Mexican Commission for Knowledge and Use of Biodiversity (CONABIO) proposed the establishment of 151 new reserves for Mexico covering 51,429,500 ha. We compiled a GIS analysis using digital thematic maps of physical and biological features to examine how the existing and proposed reserves serve to protect the biodiversity and physical features of the country. Using a conservation target of placing a minimum of 12% of the land area of each important biophysical feature in nature reserves, we found that the 144 existing nature reserves covering 18 million ha (9% of the country) only meet that target for elevation ranges >3000 m and areas with poor soils. These mountainous areas represent less than 1% of the country. The gaps in the existing nature reserves network occur mainly at lower and intermediate elevations (<3000 m) areas with xeric, tropical, and temperate ecosystems, and high productivity soils. The areas proposed by CONABIO increase the proportion of protected lands in the country to over 27% and most of the conservation targets for geophysical features, and land cover, categories are met. Whether this area would be sufficient to maintain viable populations and ecological integrity of species and ecosystems is unknown. Even with the new reserves, low elevation coastal lands would be below the conservation target in the nature reserves. To include a representative sample of these lands would be difficult as these are the same areas where the majority of people live. ?? 2003 Elsevier Ltd. All rights reserved.

Local eddy current measurements in pulsed fields

Energy Technology Data Exchange (ETDEWEB)

Espina-Hernandez, J.H. [SEPI-Electronica, ESIME-IPN, UPALM Edif. ' Z' . Zacatenco, Mexico DF 07738 (Mexico)], E-mail: jhespina@gmail.com; Groessinger, R. [Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna (Austria); Hallen, J.M. [Departamento de Ingenieria Metalurgica, IPN-ESIQIE, UPALM Edif. 7, Zacatenco, Mexico DF 07738 (Mexico)

2008-07-15

This work presents new eddy current measurements in pulsed fields. A commercial point pick-up coil is used to detect the induction signal along the radius of Cu and Al samples with cylindrical shape and diameters between 5 and 35 mm. Local eddy current measurements were performed on the surface of conducting materials due to the small dimensions of the coil. A simple electrical circuit, used as a model, is proposed to describe the local eddy current effect in pulsed fields. The proposed model allows to calculate the phase shift angle between the signal proportional to eddy currents and the applied external field in a pulsed field magnetometer.

Eddy current analysis by BEM utilizing loop electric and surface magnetic currents as unknowns

International Nuclear Information System (INIS)

Ishibashi, Kazuhisa

2002-01-01

The surface integral equations whose unknowns are the surface electric and magnetic currents are widely used in eddy current analysis. However, when the skin depth is thick, computational error is increased especially in obtaining electromagnetic fields near the edge of the conductor. In order to obtain the electromagnetic field accurately, we propose an approach to solve surface integral equations utilizing loop electric and surface magnetic currents as unknowns. (Author)

A teaching proposal for the study of Eigenvectors and Eigenvalues

Directory of Open Access Journals (Sweden)

María José Beltrán Meneu

2017-03-01

Full Text Available In this work, we present a teaching proposal which emphasizes on visualization and physical applications in the study of eigenvectors and eigenvalues. These concepts are introduced using the notion of the moment of inertia of a rigid body and the GeoGebra software. The proposal was motivated after observing students’ difficulties when treating eigenvectors and eigenvalues from a geometric point of view. It was designed following a particular sequence of activities with the schema: exploration, introduction of concepts, structuring of knowledge and application, and considering the three worlds of mathematical thinking provided by Tall: embodied, symbolic and formal.

A Summary of Proposed Changes to the Current ICARTT Format Standards and their Implications to Future Airborne Studies

Science.gov (United States)

Northup, Emily; Benson Early, Amanda; Beach, Aubrey; Wang, Dali; Kusterer, John; Quam, Brandi; Chen, Gao

2015-01-01

The Atmospheric Science Data Center (ASDC) at NASA Langley Research Center is responsible for the ingest, archive, and distribution of NASA Earth Science data in the areas of radiation budget, clouds, aerosols, and tropospheric chemistry. The ASDC specializes in atmospheric data that is important to understanding the causes and processes of global climate change and the consequences of human activities on the climate. The ASDC currently supports more than 44 projects and has over 1,700 archived data sets, which increase daily. ASDC customers include scientists, researchers, federal, state, and local governments, academia, industry, and application users, the remote sensing community, and the general public.

Diode-Assisted Buck-Boost Current Source Inverters

DEFF Research Database (Denmark)

Gao, F.; Cai, Liang; Loh, P.C.

2007-01-01

This paper presents a couple of novel current source inverters (CSIs) with the enhanced current buckboost capability. With the unique diode-inductor network added between current source inverter circuitry and current boost elements, the proposed buck-boost current source inverters demonstrate...... uninfluenced. Lastly, all theoretical findings were verified experimentally using constructed laboratory prototypes....

A study on the influence of corona on currents and electromagnetic fields predicted by a nonlinear lightning return-stroke model

Science.gov (United States)

De Conti, Alberto; Silveira, Fernando H.; Visacro, Silvério

2014-05-01

This paper investigates the influence of corona on currents and electromagnetic fields predicted by a return-stroke model that represents the lightning channel as a nonuniform transmission line with time-varying (nonlinear) resistance. The corona model used in this paper allows the calculation of corona currents as a function of the radial electric field in the vicinity of the channel. A parametric study is presented to investigate the influence of corona parameters, such as the breakdown electric field and the critical electric field for the stable propagation of streamers, on predicted currents and electromagnetic fields. The results show that, regardless of the assumed corona parameters, the incorporation of corona into the nonuniform and nonlinear transmission line model under investigation modifies the model predictions so that they consistently reproduce most of the typical features of experimentally observed lightning electromagnetic fields and return-stroke speed profiles. In particular, it is shown that the proposed model leads to close vertical electric fields presenting waveforms, amplitudes, and decay with distance in good agreement with dart leader electric field changes measured in triggered lightning experiments. A comparison with popular engineering return-stroke models further confirms the model's ability to predict consistent electric field waveforms in the close vicinity of the channel. Some differences observed in the field amplitudes calculated with the different models can be related to the fact that current distortion, while present in the proposed model, is ultimately neglected in the considered engineering return-stroke models.

Nonlinear spin current generation in noncentrosymmetric spin-orbit coupled systems

Science.gov (United States)

Hamamoto, Keita; Ezawa, Motohiko; Kim, Kun Woo; Morimoto, Takahiro; Nagaosa, Naoto

2017-06-01

Spin current plays a central role in spintronics. In particular, finding more efficient ways to generate spin current has been an important issue and has been studied actively. For example, representative methods of spin-current generation include spin-polarized current injections from ferromagnetic metals, the spin Hall effect, and the spin battery. Here, we theoretically propose a mechanism of spin-current generation based on nonlinear phenomena. By using Boltzmann transport theory, we show that a simple application of the electric field E induces spin current proportional to E2 in noncentrosymmetric spin-orbit coupled systems. We demonstrate that the nonlinear spin current of the proposed mechanism is supported in the surface state of three-dimensional topological insulators and two-dimensional semiconductors with the Rashba and/or Dresselhaus interaction. In the latter case, the angular dependence of the nonlinear spin current can be manipulated by the direction of the electric field and by the ratio of the Rashba and Dresselhaus interactions. We find that the magnitude of the spin current largely exceeds those in the previous methods for a reasonable magnitude of the electric field. Furthermore, we show that application of ac electric fields (e.g., terahertz light) leads to the rectifying effect of the spin current, where dc spin current is generated. These findings will pave a route to manipulate the spin current in noncentrosymmetric crystals.

Modeling of the Direct Current Generator Including the Magnetic Saturation and Temperature Effects

Directory of Open Access Journals (Sweden)

Alfonso J. Mercado-Samur

2013-11-01

Full Text Available In this paper the inclusion of temperature effect on the field resistance on the direct current generator model DC1A, which is valid to stability studies is proposed. First, the linear generator model is presented, after the effect of magnetic saturation and the change in the resistance value due to temperature produced by the field current are included. The comparison of experimental results and model simulations to validate the model is used. A direct current generator model which is a better representation of the generator is obtained. Visual comparison between simulations and experimental results shows the success of the proposed model, because it presents the lowest error of the compared models. The accuracy of the proposed model is observed via Modified Normalized Sum of Squared Errors index equal to 3.8979%.

Regional absolute conductivity reconstruction using projected current density in MREIT

International Nuclear Information System (INIS)

Sajib, Saurav Z K; Kim, Hyung Joong; Woo, Eung Je; Kwon, Oh In

2012-01-01

Magnetic resonance electrical impedance tomography (MREIT) is a non-invasive technique for imaging the internal conductivity distribution in tissue within an MRI scanner, utilizing the magnetic flux density, which is introduced when a current is injected into the tissue from external electrodes. This magnetic flux alters the MRI signal, so that appropriate reconstruction can provide a map of the additional z-component of the magnetic field (B z ) as well as the internal current density distribution that created it. To extract the internal electrical properties of the subject, including the conductivity and/or the current density distribution, MREIT techniques use the relationship between the external injection current and the z-component of the magnetic flux density B = (B x , B y , B z ). The tissue studied typically contains defective regions, regions with a low MRI signal and/or low MRI signal-to-noise-ratio, due to the low density of nuclear magnetic resonance spins, short T 2 or T* 2 relaxation times, as well as regions with very low electrical conductivity, through which very little current traverses. These defective regions provide noisy B z data, which can severely degrade the overall reconstructed conductivity distribution. Injecting two independent currents through surface electrodes, this paper proposes a new direct method to reconstruct a regional absolute isotropic conductivity distribution in a region of interest (ROI) while avoiding the defective regions. First, the proposed method reconstructs the contrast of conductivity using the transversal J-substitution algorithm, which blocks the propagation of severe accumulated noise from the defective region to the ROI. Second, the proposed method reconstructs the regional projected current density using the relationships between the internal current density, which stems from a current injection on the surface, and the measured B z data. Combining the contrast conductivity distribution in the entire imaging

Reliability of Current Biokinetic and Dosimetric Models for Radionuclides: A Pilot Study

Energy Technology Data Exchange (ETDEWEB)

Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL; Meck, Robert A. [U.S. Nuclear Regulatory Commission

2008-10-01

This report describes the results of a pilot study of the reliability of the biokinetic and dosimetric models currently used by the U.S. Nuclear Regulatory Commission (NRC) as predictors of dose per unit internal or external exposure to radionuclides. The study examines the feasibility of critically evaluating the accuracy of these models for a comprehensive set of radionuclides of concern to the NRC. Each critical evaluation would include: identification of discrepancies between the models and current databases; characterization of uncertainties in model predictions of dose per unit intake or unit external exposure; characterization of variability in dose per unit intake or unit external exposure; and evaluation of prospects for development of more accurate models. Uncertainty refers here to the level of knowledge of a central value for a population, and variability refers to quantitative differences between different members of a population. This pilot study provides a critical assessment of models for selected radionuclides representing different levels of knowledge of dose per unit exposure. The main conclusions of this study are as follows: (1) To optimize the use of available NRC resources, the full study should focus on radionuclides most frequently encountered in the workplace or environment. A list of 50 radionuclides is proposed. (2) The reliability of a dose coefficient for inhalation or ingestion of a radionuclide (i.e., an estimate of dose per unit intake) may depend strongly on the specific application. Multiple characterizations of the uncertainty in a dose coefficient for inhalation or ingestion of a radionuclide may be needed for different forms of the radionuclide and different levels of information of that form available to the dose analyst. (3) A meaningful characterization of variability in dose per unit intake of a radionuclide requires detailed information on the biokinetics of the radionuclide and hence is not feasible for many infrequently

Study of Grants, new Mexico, uranium miners: current status

International Nuclear Information System (INIS)

Samet, J.M.; Morgan, M.V.; Buechley, R.W.; Key, C.R.; Valdivia, A.A.

1981-01-01

The Uranium Epidemiology Study at the University of New Mexico was initiated in 1977 with the objective of assessing health effects of uranium mining in the Grants, New Mexico, area. The planned approach was a cohort study of mortality that would capitalize on the availability of health records at the Grants Clinic. The first year's work confirmed the study's feasibility (Buechley, 1979). Subsequent efforts have focused on the health and exposure data base and comprehensive follow-up. A retrospective cohort study of early miners is in progress; a prospective cohort study of miners who began working under the current federal standard is planned. This report will summarize the current status of the Uranium Epidemiology Study

The JET project (design proposal)

International Nuclear Information System (INIS)

1976-03-01

This proposal describes a large Tokamak experiment, which aims to study plasma behavior in conditions and dimensions approaching those required in a fusion reactor. The maximum plasma minor radius (a) is 1.25m and the major radius (R 0 ) is 2.96m. An important feature is the flexibility to study, for plasma currents in the 1→3MA range, a wide range of aspect ratios (R 0 /a=2.37→5), toroidal magnetic fields (up to 3.6T), minor radii (0.6→1.25m) and elongation ratios (b/a=1→3.5). The cost of the apparatus, power supplies, plasma heating equipment and specific diagnostics is estimated as 70.1Muc (march 1975 prices, 1uc=50FB). The total construction phase cost including commissioning, buildings and staff is 135Muc. These figures include an average overall contingency of 30%. The construction time for the project is estimated at 5 years and requires 370 professional man years of effort in the construction organisation with additional effort deployed by the Associated Laboratories in such areas as diagnostics and plasma heating. This design proposal is arranged as follows: an introduction to the field of fusion research is given and relates JET to the European and international programmes; a concise summary of the design proposal describes the objectives of research with JET, and gives a brief description of the apparatus, the cost and construction schedules, the proposed experimental programme and the possible modes of operation of the device. A detailed account of the engineering design and the staff and cost estimates is presented

48 CFR 731.771 - Bid and proposal costs.

Science.gov (United States)

2010-10-01

... GENERAL CONTRACTING REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Nonprofit Organizations 731.771 Bid and proposal costs. Pending the establishment of Government-wide principles in...) below, bid and proposal costs of the current accounting period of both successful and unsuccessful bids...

Optical currents in vector fields

DEFF Research Database (Denmark)

Angelsky, O. V.; Gorsky, M. P.; Maksimyak, P. P.

2011-01-01

The influence of phase relations and the degree of mutual coherence of superimposing waves in the arrangements of twowave superposition on the characteristics of the microparticle's motion has been analyzed. The prospects of studying temporal coherence using the proposed approach are made. For th....... For the first time, we have shown experimentally the possibility of diagnostics the optical currents in liquids caused by polarization characteristics of an optical field alone, using test metallic particles of nanoscale....

MREIT experiments with 200 µA injected currents: a feasibility study using two reconstruction algorithms, SMM and harmonic BZ

International Nuclear Information System (INIS)

Arpinar, V E; Muftuler, L T; Hamamura, M J; Degirmenci, E

2012-01-01

Magnetic resonance electrical impedance tomography (MREIT) is a technique that produces images of conductivity in tissues and phantoms. In this technique, electrical currents are applied to an object and the resulting magnetic flux density is measured using magnetic resonance imaging (MRI) and the conductivity distribution is reconstructed using these MRI data. Currently, the technique is used in research environments, primarily studying phantoms and animals. In order to translate MREIT to clinical applications, strict safety standards need to be established, especially for safe current limits. However, there are currently no standards for safe current limits specific to MREIT. Until such standards are established, human MREIT applications need to conform to existing electrical safety standards in medical instrumentation, such as IEC601. This protocol limits patient auxiliary currents to 100 µA for low frequencies. However, published MREIT studies have utilized currents 10–400 times larger than this limit, bringing into question whether the clinical applications of MREIT are attainable under current standards. In this study, we investigated the feasibility of MREIT to accurately reconstruct the relative conductivity of a simple agarose phantom using 200 µA total injected current and tested the performance of two MREIT reconstruction algorithms. These reconstruction algorithms used are the iterative sensitivity matrix method (SMM) by Ider and Birgul (1998 Elektrik 6 215–25) with Tikhonov regularization and the harmonic B Z proposed by Oh et al (2003 Magn. Reason. Med. 50 875–8). The reconstruction techniques were tested at both 200 µA and 5 mA injected currents to investigate their noise sensitivity at low and high current conditions. It should be noted that 200 µA total injected current into a cylindrical phantom generates only 14.7 µA current in imaging slice. Similarly, 5 mA total injected current results in 367 µA in imaging slice. Total acquisition

Quantum electrodynamics with compensating current

Energy Technology Data Exchange (ETDEWEB)

Bechler, A [Warsaw Univ. (Poland). Instytut Fizyki Teoretycznej

1974-01-01

A formulation of quantum electrodynamics is proposed in which all the propagators and field operators are gauge invariant. It is based on an old idea of Heisenberg and Euler which consists in the introduction of the linear integrals of potentials as arguments of the exponential functions. This method is generalized by an introduction of the so-called ''compensating currents'', which ensure local, i.e. in every point of space-time, charge conservation. The linear integral method is a particular case of that proposed in this paper. As the starting point we use quantum electrodynamics with a non-zero, small photon mass (Proca theory). It is shown that, due to the presence of the compensating current, the theory is fully renormalizable in Hilbert space with positive definite scalar product. The problem of the definition of the current operator is also briefly discussed.

Three-axis orthogonal transceiver coil for eddy current sounding

Science.gov (United States)

Sukhanov, D.; Zavyalova, K.; Goncharik, M.

2017-08-01

We propose the new structure of three-axis transceiver magnetic-induction coil for eddy current probing. Due to the orientation of the coils, the direct signal from the transmitting coil to the receiving coil is minimized, which provided a high dynamic range. Sensitivity in all directions is provided by combining coils of different orientations. Numerical simulation and experimental studies of such a system have been carried out and confirmed the applicability of the proposed method and the mathematical model.

Study of current instabilities in high resistivity gallium arsenide

International Nuclear Information System (INIS)

Barraud, A.

1968-01-01

We have shown the existence and made a study of the current oscillations produced in high-resistivity gallium arsenide by a strong electric field. The oscillations are associated with the slow travelling of a region of high electrical field across the whole sample. An experimental study of the properties of these instabilities has made it possible for us to distinguish this phenomenon from the Gunn effect, from acoustic-electric effects and from contact effects. In order to account for this type of instability, a differential trapping mechanism involving repulsive impurities is proposed; this mechanism can reduce the concentration of charge carriers in the conduction band at strong electrical fields and can lead to the production of a high-field domain. By developing this model qualitatively we have been able to account for all the properties of high-resistance gallium arsenide crystals subjected to a strong electrical field: increase of the Hall constant, existence of a voltage threshold for these oscillations, production of domains of high field, low rate of propagation of these domains, and finally the possibility of inverting the direction of the propagation of the domain without destroying the latter. A quantitative development of the model makes it possible to calculate the various characteristic parameters of these instabilities. Comparison with experiment shows that there is a good agreement, the small deviations coming especially from the lack of knowledge concerning transport properties in gallium arsenide subjected to high fields. From a study of this model, it appears that the instability phenomenon can occur over a wide range of repulsive centre concentrations, and also for a large range of resistivities. This is the reason why it appears systematically in gallium arsenide of medium and high resistivity. (authors) [fr

Spin-polarized current generated by magneto-electrical gating

International Nuclear Information System (INIS)

Ma Minjie; Jalil, Mansoor Bin Abdul; Tan, Seng Ghee

2012-01-01

We theoretically study spin-polarized current through a single electron tunneling transistor (SETT), in which a quantum dot (QD) is coupled to non-magnetic source and drain electrodes via tunnel junctions, and gated by a ferromagnetic (FM) electrode. The I–V characteristics of the device are investigated for both spin and charge currents, based on the non-equilibrium Green's function formalism. The FM electrode generates a magnetic field, which causes a Zeeman spin-splitting of the energy levels in the QD. By tuning the size of the Zeeman splitting and the source–drain bias, a fully spin-polarized current is generated. Additionally, by modulating the electrical gate bias, one can effect a complete switch of the polarization of the tunneling current from spin-up to spin-down current, or vice versa. - Highlights: ► The spin polarized transport through a single electron tunneling transistor is systematically studied. ► The study is based on Keldysh non-equilibrium Green's function and equation of motion method. ► A fully spin polarized current is observed. ► We propose to reverse current polarization by the means of gate voltage modulation. ► This device can be used as a bi-polarization current generator.

Temperature dependence of the current in Schottky-barrier source-gated transistors

Science.gov (United States)

Sporea, R. A.; Overy, M.; Shannon, J. M.; Silva, S. R. P.

2015-05-01

The temperature dependence of the drain current is an important parameter in thin-film transistors. In this paper, we propose that in source-gated transistors (SGTs), this temperature dependence can be controlled and tuned by varying the length of the source electrode. SGTs comprise a reverse biased potential barrier at the source which controls the current. As a result, a large activation energy for the drain current may be present which, although useful in specific temperature sensing applications, is in general deleterious in many circuit functions. With support from numerical simulations with Silvaco Atlas, we describe how increasing the length of the source electrode can be used to reduce the activation energy of SGT drain current, while maintaining the defining characteristics of SGTs: low saturation voltage, high output impedance in saturation, and tolerance to geometry variations. In this study, we apply the dual current injection modes to obtain drain currents with high and low activation energies and propose mechanisms for their exploitation in future large-area integrated circuit designs.

Current Situation, Determinants, and Solutions to Drug Shortages in Shaanxi Province, China: A Qualitative Study.

Science.gov (United States)

Yang, Caijun; Wu, Lina; Cai, Wenfang; Zhu, Wenwen; Shen, Qian; Li, Zongjie; Fang, Yu

2016-01-01

Drug shortages were a complex global problem. The aim of this study was to analyze, characterize, and assess the drug shortages, and identify possible solutions in Shaanxi Province, western China. A qualitative methodological approach was conducted during May-June 2015 and December 2015-January 2016. Semi-structured interviews were performed to gather information from representatives of hospital pharmacists, wholesalers, pharmaceutical producers, and local health authorities. Thirty participants took part in the study. Eight traditional Chinese medicines and 87 types of biologicals and chemicals were reported to be in short supply. Most were essential medicines. Five main determinants of drug shortages were detected: too low prices, too low market demands, Good Manufacturing Practice (GMP) issues, materials issues, and approval issues for imported drugs. Five different solutions were proposed by the participants: 1) let the market decide the drug price; 2) establish an information platform; 3) establish a reserve system; 4) enhance the communication among the three parties in the supply chain; and 5) improve hospital inventory management. Western China was currently experiencing a serious drug shortage. Numerous reasons for the shortage were identified. Most drug shortages in China were currently because of "too low prices." To solve this problem, all of the stakeholders, especially the government, needed to participate in managing the drug shortages.

A graphite based STT-RAM cell with reduction in switching current

International Nuclear Information System (INIS)

Varghani, Ali; Peiravi, Ali

2015-01-01

Spin Transfer Torque Random Access Memory (STT-RAM) is a serious candidate for “universal memory” because of its non-volatility, fast access time, high density, good scalability, high endurance and relatively low power dissipation. However, problems with low write speed and large write current are important existing challenges in STT-RAM design and there is a tradeoff between them and data retention time. In this study, a novel STT-RAM cell structure which uses perfect graphite based Magnetic Tunnel Junction (MTJ) is proposed. First, the cross-section of the structure is selected to be an ellipse of 45 nm and 180 nm dimensions and a six-layer graphite is used as tunnel barrier. By passing a lateral current with a short pulse width (before applying STT current and independent of it) through four middle graphene layers of the tunnel barrier, a 27% reduction in the amplitude of the switching current (for fast switching time of 2 ns) or a 58% reduction in its pulse width is achieved without any reduction in data retention time. Finally, the effect of downscaling of technology on the proposed structure is evaluated. A reduction of 31.6% and 9% in switching current is achieved for 90 and 22 nm cell width respectively by passing sufficient current (100 µA with 0.1 ns pulse width) through the tunnel barrier. Simulations are done using Object Oriented Micro Magnetic Framework (OOMMF). - Highlights: • A new STT-RAM cell structure which uses perfect graphite based MTJ is proposed. • The amplitude of the switching current or its pulsewidth can be reduced without any sacrifice of data retention time. • The proposed design is down-scalable from 90 nm to 22 nm. • Micromagnetic simulations are done with OOMMF

Disturbed flow mediated modulation of shear forces on endothelial plane: A proposed model for studying endothelium around atherosclerotic plaques

Science.gov (United States)

Balaguru, Uma Maheswari; Sundaresan, Lakshmikirupa; Manivannan, Jeganathan; Majunathan, Reji; Mani, Krishnapriya; Swaminathan, Akila; Venkatesan, Saravanakumar; Kasiviswanathan, Dharanibalan; Chatterjee, Suvro

2016-06-01

Disturbed fluid flow or modulated shear stress is associated with vascular conditions such as atherosclerosis, thrombosis, and aneurysm. In vitro simulation of the fluid flow around the plaque micro-environment remains a challenging approach. Currently available models have limitations such as complications in protocols, high cost, incompetence of co-culture and not being suitable for massive expression studies. Hence, the present study aimed to develop a simple, versatile model based on Computational Fluid Dynamics (CFD) simulation. Current observations of CFD have shown the regions of modulated shear stress by the disturbed fluid flow. To execute and validate the model in real sense, cell morphology, cytoskeletal arrangement, cell death, reactive oxygen species (ROS) profile, nitric oxide production and disturbed flow markers under the above condition were assessed. Endothelium at disturbed flow region which had been exposed to low shear stress and swirling flow pattern showed morphological and expression similarities with the pathological disturbed flow environment reported previously. Altogether, the proposed model can serve as a platform to simulate the real time micro-environment of disturbed flow associated with eccentric plaque shapes and the possibilities of studying its downstream events.

Buck-Boost Current-Source Inverters With Diode-Inductor Network

DEFF Research Database (Denmark)

Gao, Feng; Liang, Chao; Loh, Poh Chiang

2009-01-01

This paper presents a number of novel currentsource inverters (CSIs) with enhanced current buck-boost capability. By adding a unique diode-inductor network between the inverter circuitry and current-boost elements, the proposed buck-boost CSIs demonstrate a doubling of current-boost capability......, as compared with other recently reported buck-boost CSIs. For controlling the proposed CSIs, two modulation schemes are designed for achieving either optimized harmonic performance or minimized commutation count without influencing the inverter current buck-boost gain. These theoretical findings were...

Energy management study: A proposed case of government building

International Nuclear Information System (INIS)

Tahir, Mohamad Zamhari; Nawi, Mohd Nasrun Mohd; Baharum, Mohd Faizal

2015-01-01

Align with the current needs of the sustainable and green technology in Malaysian construction industry, this research is conducted to seek and identify opportunities to better manage energy use including the process of understand when, where, and how energy is used in a building. The purpose of this research is to provide a best practice guideline as a practical tool to assist construction industry in Malaysia to improve the energy efficiency of the office building during the post-production by reviewing the current practice of the building operation and maintenance in order to optimum the usage and reduce the amount of energy input into the building. Therefore, this paper will review the concept of maintenance management, current issue in energy management, and on how the research process will be conducted. There are several process involves and focuses on technical and management techniques such as energy metering, tracing, harvesting, and auditing based on the case study that will be accomplish soon. Accordingly, a case study is appropriate to be selected as a strategic research approach in which involves an empirical investigation of a particular contemporary phenomenon within its real life context using multiple sources of evidence for the data collection process. A Government office building will be selected as an appropriate case study for this research. In the end of this research, it will recommend a strategic approach or model in a specific guideline for enabling energy-efficient operation and maintenance in the office building

Energy management study: A proposed case of government building

Science.gov (United States)

Tahir, Mohamad Zamhari; Nawi, Mohd Nasrun Mohd; Baharum, Mohd Faizal

2015-05-01

Align with the current needs of the sustainable and green technology in Malaysian construction industry, this research is conducted to seek and identify opportunities to better manage energy use including the process of understand when, where, and how energy is used in a building. The purpose of this research is to provide a best practice guideline as a practical tool to assist construction industry in Malaysia to improve the energy efficiency of the office building during the post-production by reviewing the current practice of the building operation and maintenance in order to optimum the usage and reduce the amount of energy input into the building. Therefore, this paper will review the concept of maintenance management, current issue in energy management, and on how the research process will be conducted. There are several process involves and focuses on technical and management techniques such as energy metering, tracing, harvesting, and auditing based on the case study that will be accomplish soon. Accordingly, a case study is appropriate to be selected as a strategic research approach in which involves an empirical investigation of a particular contemporary phenomenon within its real life context using multiple sources of evidence for the data collection process. A Government office building will be selected as an appropriate case study for this research. In the end of this research, it will recommend a strategic approach or model in a specific guideline for enabling energy-efficient operation and maintenance in the office building.

Energy management study: A proposed case of government building

Energy Technology Data Exchange (ETDEWEB)

Tahir, Mohamad Zamhari; Nawi, Mohd Nasrun Mohd [School of Technology Management and Logistics, Universiti Utara Malaysia, 06010 Sintok, Kedah (Malaysia); Baharum, Mohd Faizal [School of Building, Housing and Planning, Universiti Sains Malaysia, 11800 Penang (Malaysia)

2015-05-15

Align with the current needs of the sustainable and green technology in Malaysian construction industry, this research is conducted to seek and identify opportunities to better manage energy use including the process of understand when, where, and how energy is used in a building. The purpose of this research is to provide a best practice guideline as a practical tool to assist construction industry in Malaysia to improve the energy efficiency of the office building during the post-production by reviewing the current practice of the building operation and maintenance in order to optimum the usage and reduce the amount of energy input into the building. Therefore, this paper will review the concept of maintenance management, current issue in energy management, and on how the research process will be conducted. There are several process involves and focuses on technical and management techniques such as energy metering, tracing, harvesting, and auditing based on the case study that will be accomplish soon. Accordingly, a case study is appropriate to be selected as a strategic research approach in which involves an empirical investigation of a particular contemporary phenomenon within its real life context using multiple sources of evidence for the data collection process. A Government office building will be selected as an appropriate case study for this research. In the end of this research, it will recommend a strategic approach or model in a specific guideline for enabling energy-efficient operation and maintenance in the office building.

Current and proposed revisions, changes, and modifications to American codes and standards to address packaging, handling, and transportation of radioactive materials and how they relate to comparable international regulations

International Nuclear Information System (INIS)

Borter, W.H.; Froehlich, C.H.

2004-01-01

This paper addresses current and proposed revisions, additions, and modifications to American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) (i.e., ''ASMEthe Code'') Section III, Division 3 and American National Standards Institute (ANSI)/ASME N14.6. It provides insight into the ongoing processes of the associated committees and highlights important revisions, changes, and modifications to this Code and Standard. The ASME Code has developed and issued Division 3 to address items associated with the transportation and storage of radioactive materials. It currently only addresses ''General Requirements'' in Subsections WA and ''Class TP (Type B) Containments'' (Transportation Packages) in Subsection WB, but is in the process of adding a new Subsection WC to address ''Class SC'' (Storage Containments). ANSI/ASME Standard N14.6 which interacts with components constructed to Division 3 by addressinges special lifting devices for radioactive material shipping containers. This Standard is in the process of a complete re-write. This Code and Standard can be classified as ''dynamic'' in that their committees meet at least four times a year to evaluate proposed modifications and additions that reflect current safety practices in the nuclear industry. These evaluations include the possible addition of new materials, fabrication processes, examination methods, and testing requirements. An overview of this ongoing process is presented in this paper along with highlights of the more important proposed revisions, changes, and modifications and how they relate to United States (US) and international regulations and guidance like International Atomic Energy Agency (IAEA) Requirement No. TS-R-1

Fault Ride-through Capability Enhancement of Voltage Source Converter-High Voltage Direct Current Systems with Bridge Type Fault Current Limiters

Directory of Open Access Journals (Sweden)

Md Shafiul Alam

2017-11-01

Full Text Available This paper proposes the use of bridge type fault current limiters (BFCLs as a potential solution to reduce the impact of fault disturbance on voltage source converter-based high voltage DC (VSC-HVDC systems. Since VSC-HVDC systems are vulnerable to faults, it is essential to enhance the fault ride-through (FRT capability with auxiliary control devices like BFCLs. BFCL controllers have been developed to limit the fault current during the inception of system disturbances. Real and reactive power controllers for the VSC-HVDC have been developed based on current control mode. DC link voltage control has been achieved by a feedback mechanism such that net power exchange with DC link capacitor is zero. A grid-connected VSC-HVDC system and a wind farm integrated VSC-HVDC system along with the proposed BFCL and associated controllers have been implemented in a real time digital simulator (RTDS. Symmetrical three phase as well as different types of unsymmetrical faults have been applied in the systems in order to show the effectiveness of the proposed BFCL solution. DC link voltage fluctuation, machine speed and active power oscillation have been greatly suppressed with the proposed BFCL. Another significant feature of this work is that the performance of the proposed BFCL in VSC-HVDC systems is compared to that of series dynamic braking resistor (SDBR. Comparative results show that the proposed BFCL is superior over SDBR in limiting fault current as well as improving system fault ride through (FRT capability.

ADAP: A Divorce Assessment Proposal.

Science.gov (United States)

Ferreiro, Beverly Webster; And Others

1986-01-01

Proposed guidelines for mental health clinicians in assessing clients' divorce-related concerns. Current empirical information on factors affecting individual and family adjustment after divorce is organized into a practical format for clinical application. Details a comprehensive assessment that will help the clinician to understand the client's…

Accelerated failure time regression for backward recurrence times and current durations

DEFF Research Database (Denmark)

Keiding, N; Fine, J P; Hansen, O H

2011-01-01

Backward recurrence times in stationary renewal processes and current durations in dynamic populations observed at a cross-section may yield estimates of underlying interarrival times or survival distributions under suitable stationarity assumptions. Regression models have been proposed for these......Backward recurrence times in stationary renewal processes and current durations in dynamic populations observed at a cross-section may yield estimates of underlying interarrival times or survival distributions under suitable stationarity assumptions. Regression models have been proposed...... for these situations, but accelerated failure time models have the particularly attractive feature that they are preserved when going from the backward recurrence times to the underlying survival distribution of interest. This simple fact has recently been noticed in a sociological context and is here illustrated...... by a study of current duration of time to pregnancy...

Design Studies for a High Current Bunching System for CLIC Test Facility (CTF3) Drive Beam

CERN Document Server

Thiery, Y.; Le Duff, J.

2000-01-01

A bunching system is proposed for the initial stage of CTF3 which consists of one (two) 3 GHz prebunchers and one 3 GHz travelling wave (TW) buncher with variable phase velocities. The electron beam is emitted from a 140 KV DC gun. Since the macropulse beam current (3.5 A) at the exit of the TW buncher is rather high, inside the TW buncher one has to take the beam loading effect into consideration. By using PARMELA, it is shown numerically that the bunching system can provide the bunches whose properties satisfy the design requirement of CTF3. The 0.8 m long TW buncher working at 2pi/3 mode has two phase velocities, 0.75 and 1. The dimensions of the caities in the two phase velocity regions are proposed considering the beam loading effect. The transient beam loading effect and the multibunch transverse instabilities are studied numerically, and it is concluded that higher order mode couplers should be installed in the TW buncher with the loaded quality factor of the dipole mode lower than 80.

Leadership during Crisis: Threat Identifcation and Solution Proposal

Directory of Open Access Journals (Sweden)

Lukáš Mazánek

2016-01-01

Full Text Available Purpose of the article: In the current dynamic market environment, companies are vulnerable to many problems of different character, which could result into a real business crisis. The submitted study summarizes possible approaches to leading through crisis situation. Therefore proposal of solutions which tools leader could use during crisis was made. Purpose of this study is to create theoretical background for the future research, in the field of application right leadership concept during crisis. Methodology/methods: For the purpose of the illustration possible threats which can lead to a business crisis was chosen the Ishikawa diagram. Next up review of scientific publication focused on leadership during crisis was made. With emphasis especially on research studies published in last 10 years in the Leadership Quarterly Journal. These results was precisely analyzed and then the most useful informations synthesized into proposed solutions. Scientific aim: The aim of this study, is to identify possible threats which could be a source of corporate crises. Subsequently propose solutions within the competence of corporate leader, how to prevent those threats or lower the intensity of crisis which already occur Findings: Proposed solutions was found in the field of HR leadership, crisis communication, leader´s behavior connected with leadership style used during crisis and increasing effectivity of leading crisis team. The application of mentioned approaches, contribute to preparedness on the possible negative future development and reduce the intensity of crisis, which has already af-fected the corporation. Conclusions: The contribution of this study is creation of synoptic overview of corporate threats and proposal of corresponding solutions of those. The implication is to summarize results from previous empirical studies to create enough theoretic foundation for the future research.

Current and Voltage Mode Multiphase Sinusoidal Oscillators Using CBTAs

Directory of Open Access Journals (Sweden)

M. Sagbas

2013-04-01

Full Text Available Current-mode (CM and voltage-mode (VM multiphase sinusoidal oscillator (MSO structures using current backward transconductance amplifier (CBTA are proposed. The proposed oscillators can generate n current or voltage signals (n being even or odd equally spaced in phase. n+1 CBTAs, n grounded capacitors and a grounded resistor are used for nth-state oscillator. The oscillation frequency can be independently controlled through transconductance (gm of the CBTAs which are adjustable via their bias currents. The effects caused by the non-ideality of the CBTA on the oscillation frequency and condition have been analyzed. The performance of the proposed circuits is demonstrated on third-stage and fifth-stage MSOs by using PSPICE simulations based on the 0.25 µm TSMC level-7 CMOS technology parameters.

Proportional-Integral-Resonant AC Current Controller

Directory of Open Access Journals (Sweden)

STOJIC, D.

2017-02-01

Full Text Available In this paper an improved stationary-frame AC current controller based on the proportional-integral-resonant control action (PIR is proposed. Namely, the novel two-parameter PIR controller is applied in the stationary-frame AC current control, accompanied by the corresponding parameter-tuning procedure. In this way, the proportional-resonant (PR controller, common in the stationary-frame AC current control, is extended by the integral (I action in order to enable the AC current DC component tracking, and, also, to enable the DC disturbance compensation, caused by the voltage source inverter (VSI nonidealities and by nonlinear loads. The proposed controller parameter-tuning procedure is based on the three-phase back-EMF-type load, which corresponds to a wide range of AC power converter applications, such as AC motor drives, uninterruptible power supplies, and active filters. While the PIR controllers commonly have three parameters, the novel controller has two. Also, the provided parameter-tuning procedure needs only one parameter to be tuned in relation to the load and power converter model parameters, since the second controller parameter is directly derived from the required controller bandwidth value. The dynamic performance of the proposed controller is verified by means of simulation and experimental runs.

The JET Project (Design proposal)

International Nuclear Information System (INIS)

1976-01-01

This proposal describes a large Tokamak experiment, which aims to study plasma behavior in conditions and dimensions approaching those required in a fusion reactor. The maximum plasma minor radius (a) is 1.25 m and the major radius R 0 is 2.96 m. An important feature is the flexibility to study, for plasma currents in the 1→3 MA range, a wide range of aspect ratios R 0 /a=2.37→5), toroidal magnetic fields (up to 3.6T), minor radii (0.6→1.25 m) and elongation ratios (b/a=1→3.5). The cost of the apparatus, power supplies, plasma heating equipment and specific diagnostics is estimated as 70.1 Muc (March 1975 prices, 1 uc=50 FB). The total construction phase cost including commissioning, buildings and staff is 135 Muc. These figures include an average overall contingency of 30%. The construction time for the project is estimated at 5 years and requires 370 professional man years of effort in the construction organisation with additional effort deployed by the Associated Laboratories in such areas as diagnostics and plasma heating. This design proposal is arranged as follows: The preface gives an introduction to the field of fusion research and relates JET to the European and international programmes. Chapter I is a concise summary of the design proposal, it describes the objectives of research with JET, and gives a brief description of: the apparatus; the cost and construction schedules; the proposed experimental programme and the possible modes of operation of the device. A detailed account of the project is given in the rest of the report of which Chapters IV and VII comprise the engineering design and the staff and cost estimates respectively

Review of proposed kaon factory facilities

International Nuclear Information System (INIS)

Macek, R.J.

1985-01-01

A number of proton accelerator facilities, popularly called ''Kaon Factories,'' have been proposed to extend the intensity frontier from about 1 GeV to higher energies in the range of 15 to 45 GeV. Seven proposed facilities - LAMPF II, TRIUMF II, SIN II, AGS II, KEK, MUNICH, and KYOTO - are reviewed with emphasis on capabilities of the experimental facilities. Costs and the choice of energy and current are also discussed. 7 refs., 29 figs., 7 tabs

Neutron induced current pulses in fission chambers

International Nuclear Information System (INIS)

Taboas, A.L.; Buck, W.L.

1978-01-01

The mechanism of neutron induced current pulse generation in fission chambers is discussed. By application of the calculated detector transfer function to proposed detector current pulse shapes, and by comparison with actually observed detector output voltage pulses, a credible, semi-empirical, trapezoidal pulse shape of chamber current is obtained

Three proposals for revitalising the European Union

Directory of Open Access Journals (Sweden)

Mario Tonveronachi

2016-12-01

Full Text Available Widespread perception that convergence on the current set of rules is not capable of producing convergence on results, or anyway generally better results, has increased the socio-political fragmentation inside the European Union. The result has been an increasing demand for a partial re-nationalisation of sovereign powers, whose physiology comes from the necessity of higher national flexibility. Asking how feasible changes in the current set of rules could accommodate the increased demand of national flexibility, the paper focuses on the euro area and proposes to revise the monetary operations of the European Central Bank, current fiscal rules, and the financial regulatory approach. The proposed new design is based on the premise that no changes in the Treaty on the Functioning of the European Union are possible at the moment, even though a minimum political convergence is necessary. If successfully implemented, the proposal would contribute to give a viable perspective to the design of the Economic and Monetary Union, capable of attracting those EU non-euro area countries that consider the mismanagement of the recent crisis and of its after-effects reason enough for resisting further losses of sovereignty. JEL: E52, E62, F33, F36, F45, G28

Oscillating field current drive for reversed field pinch discharges

International Nuclear Information System (INIS)

Schoenberg, K.F.; Gribble, R.F.; Baker, D.A.

1984-06-01

Oscillating Field Current Drive (OFCD), also known as F-THETA pumping, is a steady-state current-drive technique proposed for the Reversed Field Pinch (RFP). Unlike other current-drive techniques, which employ high-technology, invasive, and power intensive schemes using radio frequency or neutral particle injection, F-THETA pumping entails driving the toroidal and poloidal magnetic field circuits with low-frequency (audio) oscillating voltage sources. Current drive by this technique is a consequence of the strong nonlinear plasma coupling in the RFP. Because of its low frequency and efficient plasma coupling, F-THETA pumping shows excellent promise as a reactor-relevant current-drive technique. A conceptual and computational study of this concept, including its experimental and reactor relevance, is explored in this paper

PACMan to Help Sort Hubble Proposals

Science.gov (United States)

Kohler, Susanna

2017-04-01

Every year, astronomers submit over a thousand proposals requesting time on the Hubble Space Telescope (HST). Currently, humans must sort through each of these proposals by hand before sending them off for review. Could this burden be shifted to computers?A Problem of VolumeAstronomer Molly Peeples gathered stats on the HST submissions sent in last week for the upcoming HST Cycle 25 (the deadline was Friday night), relative to previous years. This years proposal round broke the record, with over 1200 proposals submitted in total for Cycle 25. [Molly Peeples]Each proposal cycle for HST time attracts on the order of 1100 proposals accounting for far more HST time than is available. The proposals are therefore carefully reviewed by around 150 international members of the astronomy community during a six-month process to select those with the highest scientific merit.Ideally, each proposal will be read by reviewers that have scientific expertise relevant to the proposal topic: if a proposal requests HST time to study star formation, for instance, then the reviewers assigned to it should have research expertise in star formation.How does this matching of proposals to reviewers occur? The current method relies on self-reported categorization of the submitted proposals. This is unreliable, however; proposals are often mis-categorized by submitters due to misunderstanding or ambiguous cases.As a result, the Science Policies Group at the Space Telescope Science Institute (STScI) which oversees the review of HST proposals must go through each of the proposals by hand and re-categorize them. The proposals are then matched to reviewers with self-declared expertise in the same category.With the number of HST proposals on the rise and the expectation that the upcoming James Webb Space Telescope (JWST) will elicit even more proposals for time than Hubble scientists at STScI and NASA are now asking: could the human hours necessary for this task be spared? Could a computer program

Variable speed DFIG wind energy system for power generation and harmonic current mitigation

Energy Technology Data Exchange (ETDEWEB)

Gaillard, A.; Saadate, S. [Groupe de Recherche en Electrotechnique et Electronique de Nancy, Nancy Universite - Universite Henri Poincare Nancy 1, BP239, 54506 Vandoeuvre les Nancy Cedex (France); Poure, P. [Laboratoire d' Instrumentation Electronique de Nancy, Nancy Universite - Universite Henri Poincare Nancy 1, BP239, 54506 Vandoeuvre les Nancy Cedex (France); Machmoum, M. [IREENA, 37 Boulevard de l' Universite, BP 406, 44602 Saint-Nazaire Cedex (France)

2009-06-15

This paper presents a novel approach for simultaneous power generation and harmonic current mitigation using variable speed WECS with DFIG. A new control strategy is proposed to upgrade the DFIG control to achieve simultaneously a green active and reactive power source with active filtering capability. To ensure high filtering performance, we studied an improved harmonic isolator in the time-domain, based on a new high selectivity filter developed in our laboratory. We examined two solutions for harmonic current mitigation: first, by compensating the whole harmonic component of the grid currents or second, by selective isolation of the predominant harmonic currents to ensure active filtering of the 5th and 7th harmonics. Simulation results for a 3 MW WECS with DFIG confirm the effectiveness and the performance of the two proposed approaches. (author)

A simulation-based proposed high-k heterostructure AlGaAs/Si junctionless n-type tunnel FET

International Nuclear Information System (INIS)

Rahi Shiromani Balmukund; Asthana Pranav; Ghosh Bahniman

2014-01-01

We propose a heterostructure junctionless tunnel field effect transistor (HJL-TFET) using AlGaAs/Si. In the proposed HJL-TFET, low band gap silicon is used in the source side and higher band gap AlGaAs in the drain side. The whole AlGaAs/Si region is heavily doped n-type. The proposed HJL-TFET uses two isolated gates (named gate, gate1) with two different work functions (gate = 4.2 eV, gate1 = 5.2 eV respectively). The 2-D nature of HJL-TFET current flow is studied. The proposed structure is simulated in Silvaco with different gate dielectric materials. This structure exhibits a high on current in the range of 1.4 × 10 −6 A/μm, the off current remains as low as 9.1 × 10 −14 A/μm. So I ON /I OFF ratio of ≃ 10 8 is achieved. Point subthreshold swing has also been reduced to a value of ≃ 41 mV/decade for TiO 2 gate material. (semiconductor devices)

Current generation by minority-species heating

International Nuclear Information System (INIS)

Fisch, N.J.

1981-01-01

It is proposed that electric currents be generated from the preferential heating of ions travelling in one direction but with no net momentum injected into the system. This can be accomplished with, for example, travelling waves in a two-ion-species plasma. The current can be generated efficiently enough for the scheme to be of interest in maintaining steady-state toroidal currents in a reactor. (author)

Current generation by minority species heating

International Nuclear Information System (INIS)

Fisch, N.J.

1980-07-01

It is proposed that electric currents be generated from the preferential heating of ions traveling in one direction but with no net momentum injected into the system. This can be accomplished with, for example, traveling waves in a two-ion-species plasma. The current can be generated efficiently enough for the scheme to be of interest in maintaining steady-state toroidal currents in a reactor

Assessing the EC ILUC proposal. Dutch national ILUC Impact Assessment

Energy Technology Data Exchange (ETDEWEB)

Peters, D.; Toop, G.; Van den Bos, A.; Spoettle, M.

2013-04-15

Indirect Land Use Change (ILUC) is the effect that when existing agricultural land producing food is used for biofuel feedstock production, food production is reduced and this reduction is partially compensated by the conversion of non-agricultural land into new cropland elsewhere. ILUC can have a negative impact on the GHG performance of biofuels and can lead to loss of biodiversity. ILUC, its quantification and possible policy measures have been debated in the EU since 2008. The final legislative text to be negotiated on the basis of the ILUC proposal is likely to have a profound impact on the current EU biofuels market but especially on its future development. This report assesses the legal soundness and factual basis of the proposal. It also assesses the policy risks, effectiveness of, and economic consequences resulting from the four most important proposed measures. Alternative scenarios are explored for each of the proposed measures. The report starts with a description of the Dutch biofuels market as the current situation and future perspective of this market is naturally of specific concern for Dutch negotiators in Brussels. This report takes the IFPRI (International Food Policy Research Institute) 2011 modelling study as a starting point when assessing the ILUC impacts of EU biofuels. The IFPRI study modelling results assign high ILUC emissions to conventional biodiesel and assigns much lower ILUC emissions to conventional ethanol. The study does not model ILUC effects of advanced biofuels. The Dutch biofuels market is dominated by biodiesel, of which a large share is double counting. Following the IFPRI 2011 ILUC modelling, this means that a high share of biofuels with a high ILUC risk are supplied to the market but also a high share of advanced, double counting biofuels with a low to medium ILUC risk. The Netherlands hosts a relatively large oilseed crushing and biofuel production industry, of which an important share consists of advanced biofuel

Implicit and Explicit Self-Esteem in Current, Remitted, Recovered, and Comorbid Depression and Anxiety Disorders: The NESDA Study

Science.gov (United States)

van Tuijl, Lonneke A.; Glashouwer, Klaske A.; Bockting, Claudi L. H.; Tendeiro, Jorge N.; Penninx, Brenda W. J. H.; de Jong, Peter J.

2016-01-01

Background Dual processing models of psychopathology emphasize the relevance of differentiating between deliberative self-evaluative processes (explicit self-esteem; ESE) and automatically-elicited affective self-associations (implicit self-esteem; ISE). It has been proposed that both low ESE and ISE would be involved in major depressive disorder (MDD) and anxiety disorders (AD). Further, it has been hypothesized that MDD and AD may result in a low ISE “scar” that may contribute to recurrence after remission. However, the available evidence provides no straightforward support for the relevance of low ISE in MDD/AD, and studies testing the relevance of discrepant SE even showed that especially high ISE combined with low ESE is predictive of the development of internalizing symptoms. However, these earlier findings have been limited by small sample sizes, poorly defined groups in terms of comorbidity and phase of the disorders, and by using inadequate indices of discrepant SE. Therefore, this study tested further the proposed role of ISE and discrepant SE in a large-scale study allowing for stricter differentiation between groups and phase of disorder. Method In the context of the Netherlands Study of Depression and Anxiety (NESDA), we selected participants with current MDD (n = 60), AD (n = 111), and comorbid MDD/AD (n = 71), remitted MDD (n = 41), AD (n = 29), and comorbid MDD/AD (n = 14), recovered MDD (n = 136) and AD (n = 98), and never MDD or AD controls (n = 382). The Implicit Association Test was used to index ISE and the Rosenberg Self-Esteem Scale indexed ESE. Results Controls reported higher ESE than all other groups, and current comorbid MDD/AD had lower ESE than all other clinical groups. ISE was only lower than controls in current comorbid AD/MDD. Discrepant self-esteem (difference between ISE and ESE) was not associated with disorder status once controlling for ESE. Limitations Cross-sectional design limits causal inferences. Conclusion Findings

Implicit and Explicit Self-Esteem in Current, Remitted, Recovered, and Comorbid Depression and Anxiety Disorders: The NESDA Study.

Directory of Open Access Journals (Sweden)

Lonneke A van Tuijl

Full Text Available Dual processing models of psychopathology emphasize the relevance of differentiating between deliberative self-evaluative processes (explicit self-esteem; ESE and automatically-elicited affective self-associations (implicit self-esteem; ISE. It has been proposed that both low ESE and ISE would be involved in major depressive disorder (MDD and anxiety disorders (AD. Further, it has been hypothesized that MDD and AD may result in a low ISE "scar" that may contribute to recurrence after remission. However, the available evidence provides no straightforward support for the relevance of low ISE in MDD/AD, and studies testing the relevance of discrepant SE even showed that especially high ISE combined with low ESE is predictive of the development of internalizing symptoms. However, these earlier findings have been limited by small sample sizes, poorly defined groups in terms of comorbidity and phase of the disorders, and by using inadequate indices of discrepant SE. Therefore, this study tested further the proposed role of ISE and discrepant SE in a large-scale study allowing for stricter differentiation between groups and phase of disorder.In the context of the Netherlands Study of Depression and Anxiety (NESDA, we selected participants with current MDD (n = 60, AD (n = 111, and comorbid MDD/AD (n = 71, remitted MDD (n = 41, AD (n = 29, and comorbid MDD/AD (n = 14, recovered MDD (n = 136 and AD (n = 98, and never MDD or AD controls (n = 382. The Implicit Association Test was used to index ISE and the Rosenberg Self-Esteem Scale indexed ESE.Controls reported higher ESE than all other groups, and current comorbid MDD/AD had lower ESE than all other clinical groups. ISE was only lower than controls in current comorbid AD/MDD. Discrepant self-esteem (difference between ISE and ESE was not associated with disorder status once controlling for ESE.Cross-sectional design limits causal inferences.Findings suggest a prominent role for ESE in MDD and AD, while

Implicit and Explicit Self-Esteem in Current, Remitted, Recovered, and Comorbid Depression and Anxiety Disorders: The NESDA Study.

Science.gov (United States)

van Tuijl, Lonneke A; Glashouwer, Klaske A; Bockting, Claudi L H; Tendeiro, Jorge N; Penninx, Brenda W J H; de Jong, Peter J

2016-01-01

Dual processing models of psychopathology emphasize the relevance of differentiating between deliberative self-evaluative processes (explicit self-esteem; ESE) and automatically-elicited affective self-associations (implicit self-esteem; ISE). It has been proposed that both low ESE and ISE would be involved in major depressive disorder (MDD) and anxiety disorders (AD). Further, it has been hypothesized that MDD and AD may result in a low ISE "scar" that may contribute to recurrence after remission. However, the available evidence provides no straightforward support for the relevance of low ISE in MDD/AD, and studies testing the relevance of discrepant SE even showed that especially high ISE combined with low ESE is predictive of the development of internalizing symptoms. However, these earlier findings have been limited by small sample sizes, poorly defined groups in terms of comorbidity and phase of the disorders, and by using inadequate indices of discrepant SE. Therefore, this study tested further the proposed role of ISE and discrepant SE in a large-scale study allowing for stricter differentiation between groups and phase of disorder. In the context of the Netherlands Study of Depression and Anxiety (NESDA), we selected participants with current MDD (n = 60), AD (n = 111), and comorbid MDD/AD (n = 71), remitted MDD (n = 41), AD (n = 29), and comorbid MDD/AD (n = 14), recovered MDD (n = 136) and AD (n = 98), and never MDD or AD controls (n = 382). The Implicit Association Test was used to index ISE and the Rosenberg Self-Esteem Scale indexed ESE. Controls reported higher ESE than all other groups, and current comorbid MDD/AD had lower ESE than all other clinical groups. ISE was only lower than controls in current comorbid AD/MDD. Discrepant self-esteem (difference between ISE and ESE) was not associated with disorder status once controlling for ESE. Cross-sectional design limits causal inferences. Findings suggest a prominent role for ESE in MDD and AD, while

An Experimental Study on the Darrieus-Savonius Turbine for the Tidal Current Power Generation

Science.gov (United States)

Kyozuka, Yusaku

The Darrieus turbine is popular for tidal current power generation in Japan. It is simple in structure with straight wings rotating around a vertical axis, so that it has no directionality against the motion of tidal flow which changes its direction twice a day. However, there is one defect in the Darrieus turbine; its small starting torque. Once it stops, a Darrieus turbine is hard to re-start until a fairly fast current is exerted on it. To improve the starting torque of the Darrieus turbine used for tidal power generation, a hybrid turbine, composed of a Darrieus turbine and a Savonius rotor is proposed. Hydrodynamic characteristics of a semi-circular section used for the Savonius bucket were measured in a wind tunnel. The torque of a two bucket Savonius rotor was measured in a circulating water channel, where four different configurations of the bucket were compared. A combined Darrieus and Savonius turbine was tested in the circulating water channel, where the effect of the attaching angle between Darrieus wing and Savonius rotor was studied. Finally, power generation experiments using a 48 pole electric generator were conducted in a towing tank and the power coefficients were compared with the results of experiments obtained in the circulating water channel.

A novel algorithm for discrimination between inrush current and internal faults in power transformer differential protection based on discrete wavelet transform

Energy Technology Data Exchange (ETDEWEB)

Eldin, A.A. Hossam; Refaey, M.A. [Electrical Engineering Department, Alexandria University, Alexandria (Egypt)

2011-01-15

This paper proposes a novel methodology for transformer differential protection, based on wave shape recognition of the discriminating criterion extracted of the instantaneous differential currents. Discrete wavelet transform has been applied to the differential currents due to internal fault and inrush currents. The diagnosis criterion is based on median absolute deviation (MAD) of wavelet coefficients over a specified frequency band. The proposed algorithm is examined using various simulated inrush and internal fault current cases on a power transformer that has been modeled using electromagnetic transients program EMTDC software. Results of evaluation study show that, proposed wavelet based differential protection scheme can discriminate internal faults from inrush currents. (author)

Dynamic modelling and robust current control of wind-turbine driven DFIG during external AC voltage dip

Institute of Scientific and Technical Information of China (English)

HU Jia-bing; HE Yi-kang

2006-01-01

Doubly-FedInduction Generator (DFIG), with vector control applied, is widely used in Variable-Speed ConstantFrequency (VSCF) windenergy generation system and shows good performance in maximum wind energy capture. But in two traditional vector control schemes, the equivalent stator magnetizing current is considered invariant in order to simplify the rotor current inner-loop controller. The two schemes can perform very well when the grid is in normal condition. However, when grid disturbance such as grid voltage dip or swell fault occurs, the control performance worsens, the rotor over current occurs and the Fault Ride-Through (FRT) capability of the DFIG wind energy generation system gets seriously deteriorated. An accurate DFIG model was used to deeply investigate the deficiency of the traditional vector control. The improved control schemes of two typical traditional vector control schemes used in DFIG were proposed, and simulation study of the proposed and traditional control schemes, with robust rotor current control using Internal Model Control (IMC) method, was carried out. The validity of the proposed modified schemes to control the rotor current and to improve the FRT capability of the DFIG wind energy generation system was proved by the comparison study.

76 FR 64368 - Notice of Submission of Proposed Information Collection to OMB Homelessness Prevention Study

Science.gov (United States)

2011-10-18

... Proposed Information Collection to OMB Homelessness Prevention Study AGENCY: Office of Policy Development... Homelessness Prevention Study. The proposed information collection was approved under emergency review (OMB...) has submitted to OMB a request to extend approval for information collection for the Homelessness...

Minimum component high frequency current mode rectifier | Sampe ...

African Journals Online (AJOL)

In this paper a current mode full wave rectifier circuit is proposed. The current mode rectifier circuit is implemented utilizing a floating current source (FCS) as an active element. The minimum component full wave rectifier utilizes only a single floating current source, two diodes and two grounded resistors. The extremely ...

A proposed programme for energy risk research

International Nuclear Information System (INIS)

1979-01-01

The report consists of two parts. Part I presents an overview of technological risk management, noting major contributions and current research needs. Part II details a proposed program of energy research, including discussions of some seven recommended projects. The proposed energy risk research program addresses two basic problem areas: improving the management of energy risks and energy risk communication and public response. Specific recommended projects are given for each. (Auth.)

Study Proposal

African Journals Online (AJOL)

MATHEMATICS DEPARTMENT

This cross sectional study design on mathematical syllabi at preparatory levels of the high schools was to ... Technology, Computer Science and Applied Sciences. It is studied of ..... For example, Jimma University Medical faculty students ...

Nanoinformatics workshop report: Current resources, community needs, and the proposal of a collaborative framework for data sharing and information integration.

Science.gov (United States)

Harper, Stacey L; Hutchison, James E; Baker, Nathan; Ostraat, Michele; Tinkle, Sally; Steevens, Jeffrey; Hoover, Mark D; Adamick, Jessica; Rajan, Krishna; Gaheen, Sharon; Cohen, Yoram; Nel, Andre; Cachau, Raul E; Tuominen, Mark

2013-01-01

The quantity of information on nanomaterial properties and behavior continues to grow rapidly. Without a concerted effort to collect, organize and mine disparate information coming out of current research efforts, the value and effective use of this information will be limited at best. Data will not be translated to knowledge. At worst, erroneous conclusions will be drawn and future research may be misdirected. Nanoinformatics can be a powerful approach to enhance the value of global information in nanoscience and nanotechnology. Much progress has been made through grassroots efforts in nanoinformatics resulting in a multitude of resources and tools for nanoscience researchers. In 2012, the nanoinformatics community believed it was important to critically evaluate and refine currently available nanoinformatics approaches in order to best inform the science and support the future of predictive nanotechnology. The Greener Nano 2012: Nanoinformatics Tools and Resources Workshop brought together informatics groups with materials scientists active in nanoscience research to evaluate and reflect on the tools and resources that have recently emerged in support of predictive nanotechnology. The workshop goals were to establish a better understanding of current nanoinformatics approaches and to clearly define immediate and projected informatics infrastructure needs of the nanotechnology community. The theme of nanotechnology environmental health and safety (nanoEHS) was used to provide real-world, concrete examples on how informatics can be utilized to advance our knowledge and guide nanoscience. The benefit here is that the same properties that impact the performance of products could also be the properties that inform EHS. From a decision management standpoint, the dual use of such data should be considered a priority. Key outcomes include a proposed collaborative framework for data collection, data sharing and information integration.

Nanoinformatics workshop report: current resources, community needs and the proposal of a collaborative framework for data sharing and information integration

International Nuclear Information System (INIS)

Harper, Stacey L; Hutchison, James E; Baker, Nathan; Ostraat, Michele; Tinkle, Sally; Steevens, Jeffrey; Hoover, Mark D; Adamick, Jessica; Rajan, Krishna; Gaheen, Sharon; Cohen, Yoram; Nel, Andre; Cachau, Raul E; Tuominen, Mark

2013-01-01

The quantity of information on nanomaterial properties and behavior continues to grow rapidly. Without a concerted effort to collect, organize and mine disparate information coming out of current research efforts, the value and effective use of this information will be limited at best. Data will not be translated to knowledge. At worst, erroneous conclusions will be drawn and future research may be misdirected. Nanoinformatics can be a powerful approach to enhance the value of global information in nanoscience and nanotechnology. Much progress has been made through grassroots efforts in nanoinformatics resulting in a multitude of resources and tools for nanoscience researchers. In 2012, the nanoinformatics community believed it was important to critically evaluate and refine currently available nanoinformatics approaches in order to best inform the science and support the future of predictive nanotechnology. The Greener Nano 2012: Nanoinformatics Tools and Resources Workshop brought together informatics groups with materials scientists active in nanoscience research to evaluate and reflect on the tools and resources that have recently emerged in support of predictive nanotechnology. The workshop goals were to establish a better understanding of current nanoinformatics approaches and to clearly define immediate and projected informatics infrastructure needs of the nanotechnology community. The theme of nanotechnology environmental health and safety (nanoEHS) was used to provide real-world, concrete examples on how informatics can be utilized to advance our knowledge and guide nanoscience. The benefit here is that the same properties that impact the performance of products could also be the properties that inform EHS. From a decision management standpoint, the dual use of such data should be considered a priority. Key outcomes include a proposed collaborative framework for data collection, data sharing and information integration. (paper)

Proposal for the momentum-resolved and time-resolved optical measurement of the current distribution in semiconductors.

Science.gov (United States)

Liu, Jiang-Tao; Su, Fu-Hai; Deng, Xin-Hua; Wang, Hai

2012-05-21

The two-color optical coherence absorption spectrum (QUIC-AB) of semiconductors in the presence of a charge current is investigated. We find that the QUIC-AB depends strongly not only on the amplitude of the electron current but also on the direction of the electron current. Thus, the amplitude and the angular distribution of current in semiconductors can be detected directly in real time with the QUIC-AB.

Multiscale Study of Currents Affected by Topography

Science.gov (United States)

2015-09-30

1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Multiscale Study of Currents Affected by Topography ...the effects of topography on the ocean general and regional circulation with a focus on the wide range of scales of interactions. The small-scale...details of the topography and the waves, eddies, drag, and turbulence it generates (at spatial scales ranging from meters to mesoscale) interact in the

Natural current profiles in tokamaks

International Nuclear Information System (INIS)

Biskamp, D.

1986-01-01

It is proposed that a certain class of equilibrium, which follow from an elementary variational principle, are the natural current profiles in tokamaks, to which actual discharge profiles tend to relax. (orig.)

Agricultural market access proposals in the Doha round : Dutch agro-food interests

NARCIS (Netherlands)

Kuiper, M.H.; Banse, M.A.H.

2007-01-01

This report analyses the impact of market access proposals tabled in the current WTO Doha round. The first part of the study assesses the 'bite' of tariff reductions by comparing border prices of Dutch products with those of imports before and after implementing tariff reductions. The second part of

Numerical modeling of transformer inrush currents

Energy Technology Data Exchange (ETDEWEB)

Cardelli, E. [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy); Faba, A., E-mail: faba@unipg.it [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy)

2014-02-15

This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.

Strain-assisted current-induced magnetization reversal in magnetic tunnel junctions: A micromagnetic study with phase-field microelasticity

International Nuclear Information System (INIS)

Huang, H. B.; Hu, J. M.; Yang, T. N.; Chen, L. Q.; Ma, X. Q.

2014-01-01

Effect of substrate misfit strain on current-induced in-plane magnetization reversal in CoFeB-MgO based magnetic tunnel junctions is investigated by combining micromagnetic simulations with phase-field microelasticity theory. It is found that the critical current density for in-plane magnetization reversal decreases dramatically with an increasing substrate strain, since the effective elastic field can drag the magnetization to one of the four in-plane diagonal directions. A potential strain-assisted multilevel bit spin transfer magnetization switching device using substrate misfit strain is also proposed.

Studies and Proposals for an Automatic Crystal Control System

CERN Document Server

Drobychev, Gleb; Khruschinsky, A A; Korzhik, Mikhail; Missevitch, Oleg; Oriboni, André; Peigneux, Jean-Pierre; Schneegans, Marc

1997-01-01

This document presents the status of the studies for an Automatic Crystal Control System ( ACCOS) performed since autumn 1995 for the CMS collaboration. Evaluation of a startstop method for light yield, light uniformity and decay time measurements of PbWO4 crystals is presented, as well as the first results obtained with a compact double-beam spectrophotometer for transverse transmission. Various overall schemes are proposed for an integrated set-up including crystal dimension measurement. The initial financial evaluationperformed is also given.

Automatic J–A Model Parameter Tuning Algorithm for High Accuracy Inrush Current Simulation

Directory of Open Access Journals (Sweden)

Xishan Wen

2017-04-01

Full Text Available Inrush current simulation plays an important role in many tasks of the power system, such as power transformer protection. However, the accuracy of the inrush current simulation can hardly be ensured. In this paper, a Jiles–Atherton (J–A theory based model is proposed to simulate the inrush current of power transformers. The characteristics of the inrush current curve are analyzed and results show that the entire inrush current curve can be well featured by the crest value of the first two cycles. With comprehensive consideration of both of the features of the inrush current curve and the J–A parameters, an automatic J–A parameter estimation algorithm is proposed. The proposed algorithm can obtain more reasonable J–A parameters, which improve the accuracy of simulation. Experimental results have verified the efficiency of the proposed algorithm.

Temperature Insensitive Current-Mode Four Quadrant Multiplier Using Single CFCTA

Directory of Open Access Journals (Sweden)

Tuntrakool Sunti

2017-01-01

Full Text Available A four quadrant multiplier of two current input signals using active building block, namely current follower cascaded transconductance amplifier (CFCTA is presented in this paper. The proposed multiplier consists of only single CFCTA without the use of any passive element. The presented circuit has low impedance at current input node and high impedance at current output node which is convenient for cascading in current mode circuit without the need of current buffer circuits. The output current can multiply two input currents with temperature insensitivity. Moreover, the magnitude of output current can be controlled electronically via DC bias current. With only single active building block, the presented multiplier is suitable for integrated circuit implementation for analog signal processing. Simulation results from a PSpice program are presented in order to demonstrate the multiplier proposed here.

Current research projects on traffic conflicts technique studies.

NARCIS (Netherlands)

Hondel, M. van den & and Kraay, J.H.

1979-01-01

A review of current research concerning the development, evaluation and use of the traffic conflicts technique is presented. The 32 studies, selected from the IRRD data base, are listed alphabetically by names of countries and under countries by names of research organizations. The IRRD descriptions

An Overview of the Current State of Women’s Leadership in Higher Education in Saudi Arabia and a Proposal for Future Research Directions

Directory of Open Access Journals (Sweden)

Azzah Alsubaie

2017-10-01

Full Text Available Despite the predominance of perspectives on women’s leadership, which consistently emphasize the underrepresentation of women in virtually every sphere of political and economic life in countries around the world, very little is known about women’s leadership, especially in higher education, in the Kingdom of Saudi Arabia (KSA. This has resulted in a gap in the literature, since higher education is one area of employment where Saudi women have made progress, and in spite of complex social, religious, cultural and organisational barriers, some have broken through the glass ceiling into higher education leadership. One goal of this paper is to highlight, through a synthesis of existing literature, the current state of women’s higher education leadership in Saudi Arabia. The second goal of this paper is to propose new directions for future research to address the current dearth of empirical work on women’s leadership in higher education in Saudi Arabia. This may be relevant to other regions of the Middle East and elsewhere.

The impact of endorsing Spitzer's proposed criteria for PTSD in the forthcoming DSM-V on male and female Veterans.

Science.gov (United States)

Miller, Lyndsey N; Chard, Kathleen M; Schumm, Jeremiah A; O'Brien, Carol

2011-06-01

This study explored differences between Spitzer's proposed model of posttraumatic stress disorder (PTSD) and the current DSM-IV diagnostic classification scheme in 353 Veterans. The majority of Veterans (89%) diagnosed with PTSD as specified in the DSM-IV also met Spitzer's proposed criteria. Veterans who met both DSM-IV and Spitzer's proposed criteria had significantly higher Clinician Administered PTSD Scale severity scores than Veterans only meeting DSM-IV criteria. Logistic regression indicated that being African American and having no comorbid diagnosis of major depressive disorder or history of a substance use disorder were found to predict those Veterans who met current, but not proposed criteria. These findings have important implications regarding proposed changes to the diagnostic classification criteria for PTSD in the forthcoming DSM-V. Copyright © 2011 Elsevier Ltd. All rights reserved.

Determination of optimal electrode positions for transcranial direct current stimulation (tDCS)

International Nuclear Information System (INIS)

Im, Chang-Hwan; Jung, Hui-Hun; Choi, Jung-Do; Lee, Soo Yeol; Jung, Ki-Young

2008-01-01

The present study introduces a new approach to determining optimal electrode positions in transcranial direct current stimulation (tDCS). Electric field and 3D conduction current density were analyzed using 3D finite element method (FEM) formulated for a dc conduction problem. The electrode positions for minimal current injection were optimized by changing the Cartesian coordinate system into the spherical coordinate system and applying the (2+6) evolution strategy (ES) algorithm. Preliminary simulation studies applied to a standard three-layer head model demonstrated that the proposed approach is promising in enhancing the performance of tDCS. (note)

Determination of optimal electrode positions for transcranial direct current stimulation (tDCS)

Energy Technology Data Exchange (ETDEWEB)

Im, Chang-Hwan; Jung, Hui-Hun; Choi, Jung-Do [Department of Biomedical Engineering, Yonsei University, Wonju, 220-710 (Korea, Republic of); Lee, Soo Yeol [Department of Biomedical Engineering, Kyung Hee University, Suwon (Korea, Republic of); Jung, Ki-Young [Korea University Medical Center, Korea University College of Medicine, Seoul (Korea, Republic of)], E-mail: ich@yonsei.ac.kr

2008-06-07

The present study introduces a new approach to determining optimal electrode positions in transcranial direct current stimulation (tDCS). Electric field and 3D conduction current density were analyzed using 3D finite element method (FEM) formulated for a dc conduction problem. The electrode positions for minimal current injection were optimized by changing the Cartesian coordinate system into the spherical coordinate system and applying the (2+6) evolution strategy (ES) algorithm. Preliminary simulation studies applied to a standard three-layer head model demonstrated that the proposed approach is promising in enhancing the performance of tDCS. (note)

High current polarized electron source

Science.gov (United States)

Suleiman, R.; Adderley, P.; Grames, J.; Hansknecht, J.; Poelker, M.; Stutzman, M.

2018-05-01

Jefferson Lab operates two DC high voltage GaAs photoguns with compact inverted insulators. One photogun provides the polarized electron beam at the Continuous Electron Beam Accelerator Facility (CEBAF) up to 200 µA. The other gun is used for high average current photocathode lifetime studies at a dedicated test facility up to 4 mA of polarized beam and 10 mA of un-polarized beam. GaAs-based photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed facilities that must operate in excess of tens of mA of polarized average current. This contribution describes techniques to maintain good vacuum while delivering high beam currents, and techniques that minimize damage due to ion bombardment, the dominant mechanism that reduces photocathode yield. Advantages of higher DC voltage include reduced space-charge emittance growth and the potential for better photocathode lifetime. Highlights of R&D to improve the performance of polarized electron sources and prolong the lifetime of strained-superlattice GaAs are presented.

A STUDY ABOUT CELL ACTIVITY ON ANODIZED Ti-6Al-4V BY MEANS OF PULSED CURRENT

Directory of Open Access Journals (Sweden)

LUANA M. R. VASCONCELLOS

2017-05-01

Full Text Available Titanium and some of its alloys exhibit excellent anti-corrosive and biocompatibility properties due to rapid formation of a passive film on their surfaces when exposed to the atmosphere. However, such materials presentpoor osteoindutive properties. Surfaces modified via anodization are being proposed in this study to promote a chemical interaction between implants and bone cells. For this purpose, samples in Ti-6Al-4V alloy discs were anodized in a phosphoric acid solution using pulsed current for being applied in orthopaedic implants. The pulsed current is based on duty cycle (DC, which was supplied by a square wave pulse rectifier at 100 Hz and maximum tension of 30 V. A scanning electron microscope was used to obtain images of the anodized surfaces, thus revealing the presence of uniformly distributed pores over the entire surface, measuring approximately 2 m in diameter. Osteogenic cells grown on the surface of the control and anodized samples were assayed for cytotoxicity and mineralized matrix formation. The anodized surfaces presented a higher rate of viable cells after 10 days, as well as a higher amount of nodules (p = 0.05. In conclusion, these results suggest that the nanotopography promoted by anodization using pulsed current induces beneficial modulatory effects on osteoblastic cells.

Feasibility of the current-duration approach to studying human fecundity

DEFF Research Database (Denmark)

Slama, Rémy; Ducot, Béatrice; Carstensen, Lisbeth

2006-01-01

of unprotected intercourse was defined for 69 women (5.7%). An additional 15 women (1.2%) were planning to start trying to become pregnant within the next 6 months. Parametric methods allowed, based on current duration of unprotected intercourse, estimation of fecundity as if the couples had been followed...... up (current-duration design). To illustrate the feasibility of the current-duration design, we contacted a random sample of 1204 French women age 18 to 44 years in 2004 and recruited those who were currently having unprotected sexual intercourse. The current duration since the beginning...... prospectively. The estimated proportion of couples not pregnant after 12 months of unprotected intercourse was 34% (95% confidence interval [CI] = 15-54%). The accelerated-failure time model allows study of the influence of environmental factors on fecundity. As an illustration, tobacco smoking by the woman...

Writing a Research Proposal to The Research Council of Oman

OpenAIRE

Al-Shukaili, Ahmed; Al-Maniri, Abdullah

2017-01-01

Writing a research proposal can be a challenging task for young researchers. This article explains how to write a strong research proposal to apply for funding, specifically, a proposal for The Research Council (TRC) of Oman. Three different research proposal application forms are currently used in TRC, including Open Research Grant (ORG), Graduate Research Support Program (GRSP), and Faculty-mentored Undergraduate Research Award Program (FURAP). The application forms are filled and submitted...

Current source converter based D-STATCOM for voltage sag mitigation

Directory of Open Access Journals (Sweden)

Singh Moirangthem Deben

2015-01-01

Full Text Available This paper presents a novel method of realizing one of the custom power controllers, the distribution static synchronous compensator (D-STATCOM using current source converter (CSC topology. Almost all the custom power controllers such as dynamic voltage restorer (DVR, unified power quality conditioner (UPQC including D-STATCOM are generally designed and implemented by using voltage source converters (VSC and not much research publications with CSC based approach has been reported over the last one decade. Since the D-STATCOM is a current injection device, its performance can be improved when realized by a current-source converter which can generate a controllable current directly at its output terminals and offers many advantageous features. In this paper, an attempt has been made to study the performance of a CSC based D-STATCOM suitable for use in the power distribution system in order to mitigate voltage sag and improve power quality. The proposed model uses a three leg CSC whose switching strategy is based on sinusoidal pulse width modulation (SPWM. The model has been simulated in the Matlab/Simulink environment. The results of the simulation runs under steady state and dynamic load perturbation provide excellent voltage and current waveforms that support the justification of the proposed model.

Operating tokamaks with steady-state toroidal current

International Nuclear Information System (INIS)

Fisch, N.J.

1981-04-01

Continuous operation of a tokamak requires, among other things, a means of continuously providing the toroidal current. Various methods have been proposed to provide this current including methods which utilize radio-frequency waves in any of several frequency regimes. Here we elaborate on the prospects of incorporating these current-drive techniques in tokamak reactors, concentrating on the theoretical minimization of the power requirements

Study the topology of Branciari metric space via the structure proposed by Csaszar

Directory of Open Access Journals (Sweden)

Dong ZHANG

2017-06-01

Full Text Available In this paper, we topologically study the generalized metric space proposed by Branciari [3] via the weak structure proposed by Cs´asz´ar [9, 10], and compare convergent sequences in several different senses. We also introduce the concepts of available points and unavailable points on such structures. Besides, we define the continuous function on structures and investigate further characterizations of continuous functions.

International collaborative study for the calibration of proposed International Standards for thromboplastin, rabbit, plain and for thromboplastin, recombinant, human, plain

DEFF Research Database (Denmark)

van den Besselaar, A M H P; Chantarangkul, V; Angeloni, F

2018-01-01

BACKGROUND: The availability of International Standards for thromboplastin is essential for the calibration of routine reagents and hence the calculation of the International Normalized Ratio (INR). Stocks of the current 4(th) International Standards are running low. Candidate replacement materia......) international standard (rTF/09). The candidate materials have been accepted by WHO as the 5(th) International Standards for thromboplastin, rabbit plain, and thromboplastin, recombinant, human, plain. This article is protected by copyright. All rights reserved.......BACKGROUND: The availability of International Standards for thromboplastin is essential for the calibration of routine reagents and hence the calculation of the International Normalized Ratio (INR). Stocks of the current 4(th) International Standards are running low. Candidate replacement materials...... have been prepared. This report describes the calibration of the proposed 5(th) International Standards for thromboplastin, rabbit, plain (coded RBT/16) and for thromboplastin, recombinant, human, plain (coded rTF/16). METHODS: An international collaborative study was carried out for the assignment...

Chronostratigraphy and geochronology: A proposed realignment

NARCIS (Netherlands)

Zalasiewicz, J.; Cita, M.B.; Hilgen, F.; Pratt, B.R.; Strasser, A.; Thierry, J.; Weissert, H.

2013-01-01

We propose a realignment of the terms geochronology and chronostratigraphy that brings them broadly into line with current use, while simultaneously resolving the debate over whether the Geological Time Scale should have a “single” or “dual” hierarchy of units: Both parallel sets of units are

Design of the power supply system for the plasma current modulation on J-TEXT tokamak

Energy Technology Data Exchange (ETDEWEB)

Zhang, M.; Shao, J.; Ma, S.X., E-mail: mashaoxiang@hust.edu.cn; Liang, X.; Yu, K.X.; Pan, Y.

2016-10-15

Highlights: • A modification scheme of heating field power supply system for plasma current modulation. • High-power fast control power supply with multilevel cascade circuit. • Restraining circulating current with coupled inductors in cyclic symmetric structure. - Abstract: In order to further study the influence of current modulation parameters on suppressing tearing instability, the plasma current should be modulated in a wider range. So a modification scheme is designed to improve the performance of ohmic heating power supply system on J-TEXT tokamak. A multilevel cascade circuit with carrier phase-shifted PWM technique has been proposed. Coupled inductors are connected in the form of cyclic symmetry to restrain the circulating current caused by multiple paralleled branches. The simulation proves this proposed current modulation power supply system matches output requirement and achieves good current sharing effect. Finally, a prototype is designed, and the experiment results can verify the correctness of the simulation model well.

New digital reference current generation for shunt active power filter under distorted voltage conditions

Energy Technology Data Exchange (ETDEWEB)

Abdusalam, Mohamed; Karimi, Shahram; Saadate, Shahrokh [Groupe de Recherche en Electrotechnique et Electronique de Nancy (GREEN), CNRS UMR 7037 (France); Poure, Philippe [Laboratoire d' Instrumentation Electronique de Nancy (LIEN), EA 3440, Universite Henri Poincare - Nancy Universite, B.P. 239, 54506 Vandoeuvre les Nancy Cedex (France)

2009-05-15

In this paper, a new reference current computation method suitable for shunt active power filter control under distorted voltage conditions is proposed. The active power filter control is based on the use of self-tuning filters (STF) for the reference current generation and on a modulated hysteresis current controller. This active filter is intended for harmonic compensation of a diode rectifier feeding a RL load under distorted voltage conditions. The study of the active filter control is divided in two parts. The first one deals with the harmonic isolator which generates the harmonic reference currents and is experimentally implemented in a DS1104 card of a DSPACE prototyping system. The second part focuses on the generation of the switching pattern of the inverter by using a modulated hysteresis current controller, implemented in an analogue card. The use of STF instead of classical extraction filters allows extracting directly the voltage and current fundamental components in the {alpha}-{beta} axis without phase locked loop (PLL). The performances are good even under distorted voltage conditions. First, the effectiveness of the new proposed method is mathematically studied and verified by computer simulation. Then, experimental results are presented using a DSPACE system associated with the analogue current controller for a real shunt active power filter. (author)

Spin-current diode with a ferromagnetic semiconductor

International Nuclear Information System (INIS)

Sun, Qing-Feng; Xie, X. C.

2015-01-01

Diode is a key device in electronics: the charge current can flow through the device under a forward bias, while almost no current flows under a reverse bias. Here, we propose a corresponding device in spintronics: the spin-current diode, in which the forward spin current is large but the reversed one is negligible. We show that the lead/ferromagnetic quantum dot/lead system and the lead/ferromagnetic semiconductor/lead junction can work as spin-current diodes. The spin-current diode, a low dissipation device, may have important applications in spintronics, as the conventional charge-current diode does in electronics

Study program for constant current capacitor charging method

Energy Technology Data Exchange (ETDEWEB)

Pugh, C.

1978-10-04

The objective of the study program was to determine the best method of charging 20,000 to 132,000 microfarads of capacitance to 22 kVdc in 14 to 15 sec. Component costs, sizes, weights, line current graphs, copies of calculations and manufacturer's data are included.

Return on investment (ROI) proposal preparation guide

International Nuclear Information System (INIS)

BOOM, R.J.

1999-01-01

Section I: Background Return on Investment (ROI) Proposal Preparation Guide-- Over $1.9M is available to fund fiscal year (FY) 2000 waste minimization projects on the Hanford Site. This money was allocated by the US. Department of Energy Headquarters (DOE-HQ). The U.S. Department of Energy, Richland Operations (RL) and the U.S. Department of Energy, Office of River Protection (ORP) are currently seeking pollution prevention proposals from across the Hanford Site that provide a high return-on-investment (ROI) by reducing waste and associated management costs. Purpose of ROI Training The ROI Proposal Preparation Guide is a tool to assist Hanford waste generators in preparing ROI proposal forms for submittal to RL for funding. The guide describes the requirements for submitting an ROI proposal and provides examples of completed ROI forms. The intent is to assist waste generators in identifying projects that meet the criteria, provide information necessary to complete the ROI forms, and submit a proposal that is eligible to receive funding. This guide accompanies the one-hour training workshop on how to prepare and submit an ROI proposal

Classifying insulin regimens--difficulties and proposal for comprehensive new definitions.

Science.gov (United States)

Neu, A; Lange, K; Barrett, T; Cameron, F; Dorchy, H; Hoey, H; Jarosz-Chobot, P; Mortensen, H B; Robert, J-J; Robertson, K; de Beaufort, C

2015-09-01

Modern insulin regimens for the treatment of type 1 diabetes are highly individualized. The concept of an individually tailored medicine accounts for a broad variety of different insulin regimens applied. Despite clear recommendations for insulin management in children and adolescents with type 1 diabetes there is little distinctiveness about concepts and the nomenclature is confusing. Even among experts similar terms are used for different strategies. The aim of our review--based on the experiences of the Hvidoere Study Group (HSG)--is to propose comprehensive definitions for current insulin regimens reflecting current diabetes management in childhood and adolescence. The HSG--founded in 1994--is an international group representing 24 highly experienced pediatric diabetes centers, from Europe, Japan, North America and Australia. Different benchmarking studies of the HSG revealed a broad variety of insulin regimens applied in each center, respectively. Furthermore, the understanding of insulin regimens has been persistently different between the centers since more than 20 yr. Not even the terms 'conventional' and 'intensified therapy' were used consistently among all members. Besides the concepts 'conventional' and 'intensified', several other terms for the characterization of insulin regimens are in use: Basal Bolus Concept (BBC), multiple daily injections (MDI), and flexible insulin therapy (FIT) are most frequently used, although none of these expressions is clearly or consistently defined. The proposed new classification for insulin management will be comprehensive, simple, and catchy. Currently available terms were included. This classification may offer the opportunity to compare therapeutic strategies without the currently existing confusion on the insulin regimen. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Antiresonance induced spin-polarized current generation

Science.gov (United States)

Yin, Sun; Min, Wen-Jing; Gao, Kun; Xie, Shi-Jie; Liu, De-Sheng

2011-12-01

According to the one-dimensional antiresonance effect (Wang X R, Wang Y and Sun Z Z 2003 Phys. Rev. B 65 193402), we propose a possible spin-polarized current generation device. Our proposed model consists of one chain and an impurity coupling to the chain. The energy level of the impurity can be occupied by an electron with a specific spin, and the electron with such a spin is blocked because of the antiresonance effect. Based on this phenomenon our model can generate the spin-polarized current flowing through the chain due to different polarization rates. On the other hand, the device can also be used to measure the generated spin accumulation. Our model is feasible with today's technology.

Cryogenic current comparators for precise ion beam current measurements

International Nuclear Information System (INIS)

Kurian, Febin

2015-01-01

The planned Facility for Antiproton and Ion Research (FAIR) at GSI has to cope with a wide range of beam intensities in its high-energy beam transport systems and in the storage rings. To meet the requirements of a non-intercepting intensity measurement down to nA range, it is planned to install a number of Cryogenic Current Comparator (CCC) units at different locations in the FAIR beamlines. In this work, the first CCC system for intensity measurement of heavy ion beams, which was developed at GSI, was re-commissioned and upgraded to be used as a 'GSI - CCC prototype' for extensive optimization and development of an improved CCC for FAIR. After installation of a new SQUID sensor and related electronics, as well as implementation of improved data acquisition components, successful beam current measurements were performed at a SIS18 extraction line. The measured intensity values were compared with those of a Secondary Electron Monitor (SEM). Furthermore, the spill-structure of a slowly extracted beam was measured and analyzed, investigating its improvement due to bunching during the slow-extraction process. Due to the extreme sensitivity of the superconducting sensor, the determined intensity values as well as the adjustment of the system for optimal performance are strongly influenced by the numerous noise sources of the accelerators environment. For this reason, detailed studies of different effects caused by noise have been carried out, which are presented together with proposals to reduce them. Similarly, studies were performed to increase the dynamic range and overcome slew rate limitations, the results of which are illustrated and discussed as well. By combining the various optimizations and characterizations of the GSI CCC prototype with the experiences made during beam operation, criteria for a more efficient CCC System could be worked out, which are presented in this work. The details of this new design are worked out with respect to the

Five-Level Current-Source Inverters With Buck–Boost and Inductive-Current Balancing Capabilities

DEFF Research Database (Denmark)

Gao, Feng; Loh, Poh Chiang; Blaabjerg, Frede

2010-01-01

This paper presents new five-level current-source inverters (CSIs) with voltage/current buck–boost capability, unlike existing five-level CSIs where only voltage–boost operation is supported. The proposed inverters attain self-inductive-currentbalancing per switching cycle at their dc front ends...... without having to include additional balancing hardware or complex control manipulation. The inverters can conveniently be controlled by using the well-established phase-shifted carrier modulation scheme with only two additional linear references and a mapping logic table needed. Existing modulators can...

Evaluation of a proposed optimization method for discrete-event simulation models

Directory of Open Access Journals (Sweden)

Alexandre Ferreira de Pinho

2012-12-01

Full Text Available Optimization methods combined with computer-based simulation have been utilized in a wide range of manufacturing applications. However, in terms of current technology, these methods exhibit low performance levels which are only able to manipulate a single decision variable at a time. Thus, the objective of this article is to evaluate a proposed optimization method for discrete-event simulation models based on genetic algorithms which exhibits more efficiency in relation to computational time when compared to software packages on the market. It should be emphasized that the variable's response quality will not be altered; that is, the proposed method will maintain the solutions' effectiveness. Thus, the study draws a comparison between the proposed method and that of a simulation instrument already available on the market and has been examined in academic literature. Conclusions are presented, confirming the proposed optimization method's efficiency.

Molecular Dynamics Study of the Separation Behavior at the Interface between PVDF Binder and Copper Current Collector

Directory of Open Access Journals (Sweden)

Seungjun Lee

2016-01-01

Full Text Available In Li-ion batteries, the mechanical strengths at the interfaces of binder/particle and binder/current collector play an important role in maintaining the mechanical integrity of the composite electrode. In this work, the separation behaviors between polyvinylidene fluoride (PVDF binders and copper current collectors are studied in the opening and sliding modes using molecular dynamics (MD simulations. The simulation shows that the separation occurs inside the PVDF rather than at the interface due to the strong adhesion between PVDF and copper. This fracture behavior is different from the behavior of the PVDF/graphite basal plane that shows a clear separation at the interface. The results suggest that the adhesion strength of the PVDF/copper is stronger than that of the PVDF/graphite basal plane. The methodology used in MD simulation can directly evaluate the adhesion strength at the interfaces of various materials between binders, substrates, and particles at the atomic scales. The proposed method can therefore provide a guideline for the design of the electrode in order to enhance the mechanical integrity for better battery performance.

Study of the Weak Charged Hadronic Current in b Decays

CERN Document Server

Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alpat, B; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Antreasyan, D; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banicz, K; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Borgia, B; Boucham, A; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Buytenhuijs, A O; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Caria, M; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chan, A; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Choi, M T; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; De Boeck, H; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dorne, I; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Fernández, D; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Janssen, H; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kuijten, H; Kunin, A; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee Jae Sik; Lee, K Y; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lieb, E H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Morganti, S; Moulik, T; Mount, R; Müller, S; Muheim, F; Nagy, E; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nippe, A; Nisati, A; Nowak, H; Opitz, H; Organtini, G; Ostonen, R; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Rahal-Callot, G; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riemers, B C; Riles, K; Rind, O; Ro, S; Robohm, A; Rodin, J; Rodríguez-Calonge, F J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Rykaczewski, H; Salicio, J; Sánchez, E; Santocchia, A; Sarakinos, M E; Sarkar, S; Sassowsky, M; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Sens, Johannes C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F

1997-01-01

Charged and neutral particle multiplicities of jets associated with identified semileptonic and hadronic b decays are studied. The observed differences between these jets are used to determine the inclusive properties of the weak charged hadronic current. The average charged particle multiplicity of the weak charged hadronic current in b decays is measured for the first time to be 2.69$\\pm$0.07(stat.)$\\pm$0.14(syst.). This result is in good agreement with the JETSET hadronization model of the weak charged hadronic current if 40$\\pm$17\\% of the produced mesons are light--flavored tensor (L=1) mesons. This level of tensor meson production is consistent with the measurement of the $\\pi^0$ multiplicity in the weak charged hadronic current in b decays. \\end{abstract}

Modeling of HVDC System to Improve Estimation of Transient DC Current and Voltages for AC Line-to-Ground Fault—An Actual Case Study in Korea

Directory of Open Access Journals (Sweden)

Dohoon Kwon

2017-10-01

Full Text Available A new modeling method for high voltage direct current (HVDC systems and associated controllers is presented for the power system simulator for engineering (PSS/E simulation environment. The aim is to improve the estimation of the transient DC voltage and current in the event of an AC line-to-ground fault. The proposed method consists primary of three interconnected modules for (a equation conversion; (b control-mode selection; and (c DC-line modeling. Simulation case studies were carried out using PSS/E and a power systems computer aided design/electromagnetic transients including DC (PSCAD/EMTDC model of the Jeju– Haenam HVDC system in Korea. The simulation results are compared with actual operational data and the PSCAD/EMTDC simulation results for an HVDC system during single-phase and three-phase line-to-ground faults, respectively. These comparisons show that the proposed PSS/E modeling method results in the improved estimation of the dynamic variation in the DC voltage and current in the event of an AC network fault, with significant gains in computational efficiency, making it suitable for real-time analysis of HVDC systems.

A pre-heating method based on sinusoidal alternating current for lithium-ion battery

Science.gov (United States)

Fan, Wentao; Sun, Fengchun; Guo, Shanshan

2018-04-01

In this paper, a method of low temperature pre-heating of sinusoidal alternating current (SAC) is proposed. Generally, the lower the frequency of the AC current, the higher the heat generation rate. Yet at low frequency, there is a risk of lithium-ion deposition during the half cycle of charging. This study develops a temperature-adaptive, deposition-free AC pre-heating method. a equivalent electric circuit(EEC) model is established to predict the heat generation rate and temperature status, whose parameters are calibrated from the EIS impedance measurements. The effects of current frequency and amplitude on the heating effect are investigated respectively. A multistep temperature-adaptive amplitude strategy is proposed and the cell can be heated from -20°C to 5°C within 509s at 100Hz frequency with this method.

Revisiting Antipsychotic-induced Akathisia: Current Issues and Prospective Challenges

Science.gov (United States)

Salem, Haitham; Nagpal, Caesa; Pigott, Teresa; Teixeira, Antonio Lucio

2017-01-01

Background: Akathisia continues to be a significant challenge in current neurological and psychiatric practice. Prompt and accurate detection is often difficult and there is a lack of consensus concerning the neurobiological basis of akathisia. No definitive treatment has been established for akathisia despite numerous preclinical and clinical studies. Method: We reviewed antipsychotic-induced akathisia including its clinical presentation, proposed underlying pathophysiology, current and under investigation therapeutic strategies. Conclusion: Despite the initial promise that second generation antipsychotics would be devoid of akathisia effects, this has not been confirmed. Currently, there are limited therapeutic options for the clinical practice and the evidence supporting the most widely used treatments (beta blockers, anticholinergic drugs) is still absent or inconsistent. PMID:27928948

Eddy current examination of the nuclear fuel elements with aluminum 1100-F cladding of IPR-R1 research reactor: An initial study

International Nuclear Information System (INIS)

Silva, Roger F. da; Silva Júnior, Silvério F. da; Frade, Rangel T.; Rodrigues, Juliano S.

2017-01-01

Tubes of aluminum 1100-F as well as tubes of AISI 304 stainless steel are used as cladding of the fuel elements of TRIGA IPR-R1 nuclear research reactor. Usually, these tubes are inspected by means of visual test and sipping test. The visual test allows the detection of changes occurred at the external fuel elements surface, such as those promoted by corrosion processes. However, this test method cannot be used for detection of internal discontinuities at the tube walls. Sipping test allows the detection of fuel elements whose cladding has failed, but it is not able to determine the place where the discontinuity is located. On the other hand, eddy current testing, an electromagnetic nondestructive test method, allows the detection of discontinuities and monitoring their growth. In previous works, the application of eddy current testing to evaluate the AISI 304 cladding fuel elements of TRIGA IPR-R1 was studied. In this paper, it is proposed an initial study about the use of eddy current testing for detection and characterization of discontinuities in the aluminum 1100-F fuel elements cladding. The study includes the development of probes and the design and manufacture of reference standards. (author)

Eddy current examination of the nuclear fuel elements with aluminum 1100-F cladding of IPR-R1 research reactor: An initial study

Energy Technology Data Exchange (ETDEWEB)

Silva, Roger F. da; Silva Júnior, Silvério F. da; Frade, Rangel T. [Centro de Desenvolvimento da Tecnologia Nucelar (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Rodrigues, Juliano S., E-mail: rfs@cdtn.br, E-mail: silvasf@cdtn.br, E-mail: rtf@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

2017-07-01

Tubes of aluminum 1100-F as well as tubes of AISI 304 stainless steel are used as cladding of the fuel elements of TRIGA IPR-R1 nuclear research reactor. Usually, these tubes are inspected by means of visual test and sipping test. The visual test allows the detection of changes occurred at the external fuel elements surface, such as those promoted by corrosion processes. However, this test method cannot be used for detection of internal discontinuities at the tube walls. Sipping test allows the detection of fuel elements whose cladding has failed, but it is not able to determine the place where the discontinuity is located. On the other hand, eddy current testing, an electromagnetic nondestructive test method, allows the detection of discontinuities and monitoring their growth. In previous works, the application of eddy current testing to evaluate the AISI 304 cladding fuel elements of TRIGA IPR-R1 was studied. In this paper, it is proposed an initial study about the use of eddy current testing for detection and characterization of discontinuities in the aluminum 1100-F fuel elements cladding. The study includes the development of probes and the design and manufacture of reference standards. (author)

An adaptable walking-skid for seabed ROV under strong current disturbance

Science.gov (United States)

Si, Jianting; Chin, Chengsiong

2014-09-01

This paper proposed a new concept of an adaptable multi-legged skid design for retro-fitting to a remotely-operated vehicle (ROV) during high tidal current underwater pipeline inspection. The sole reliance on propeller-driven propulsion for ROV is replaced with a proposed low cost biomimetic solution in the form of an attachable hexapod walking skid. The advantage of this adaptable walking skid is the high stability in positioning and endurances to strong current on the seabed environment. The computer simulation flow studies using Solidworks Flow Simulation shown that the skid attachment in different compensation postures caused at least four times increase in overall drag, and negative lift forces on the seabed ROV to achieve a better maneuvering and station keeping under the high current condition (from 0.5 m/s to 5.0 m/s). A graphical user interface is designed to interact with the user during robot-in-the-loop testing and kinematics simulation in the pool.

Programmable, very low noise current source

Science.gov (United States)

Scandurra, G.; Cannatà, G.; Giusi, G.; Ciofi, C.

2014-12-01

We propose a new approach for the realization of very low noise programmable current sources mainly intended for application in the field of low frequency noise measurements. The design is based on a low noise Junction Field Effect Transistor (JFET) acting as a high impedance current source and programmability is obtained by resorting to a low noise, programmable floating voltage source that allows to set the sourced current at the desired value. The floating voltage source is obtained by exploiting the properties of a standard photovoltaic MOSFET driver. Proper filtering and a control network employing super-capacitors allow to reduce the low frequency output noise to that due to the low noise JFET down to frequencies as low as 100 mHz while allowing, at the same time, to set the desired current by means of a standard DA converter with an accuracy better than 1%. A prototype of the system capable of supplying currents from a few hundreds of μA up to a few mA demonstrates the effectiveness of the approach we propose. When delivering a DC current of about 2 mA, the power spectral density of the current fluctuations at the output is found to be less than 25 pA/√Hz at 100 mHz and less than 6 pA/√Hz for f > 1 Hz, resulting in an RMS noise in the bandwidth from 0.1 to 10 Hz of less than 14 pA.

Remote sub-wavelength focusing of ultrasonically activated Lorentz current

Science.gov (United States)

Rekhi, Angad S.; Arbabian, Amin

2017-04-01

We propose the use of a combination of ultrasonic and magnetic fields in conductive media for the creation of RF electrical current via the Lorentz force, in order to achieve current generation with extreme sub-wavelength resolution at large depth. We demonstrate the modeling, generation, and measurement of Lorentz current in a conductive solution and show that this current can be localized at a distance of 13 cm from the ultrasonic source to a region about three orders of magnitude smaller than the corresponding wavelength of electromagnetic waves at the same operation frequency. Our results exhibit greater depth, tighter localization, and closer agreement with prediction than previous work on the measurement of Lorentz current in a solution of homogeneous conductivity. The proposed method of RF current excitation overcomes the trade-off between focusing and propagation that is fundamental in the use of RF electromagnetic excitation alone and has the potential to improve localization and depth of operation for RF current-based biomedical applications.

Feasibility study of a large-scale tuned mass damper with eddy current damping mechanism

Science.gov (United States)

Wang, Zhihao; Chen, Zhengqing; Wang, Jianhui

2012-09-01

Tuned mass dampers (TMDs) have been widely used in recent years to mitigate structural vibration. However, the damping mechanisms employed in the TMDs are mostly based on viscous dampers, which have several well-known disadvantages, such as oil leakage and difficult adjustment of damping ratio for an operating TMD. Alternatively, eddy current damping (ECD) that does not require any contact with the main structure is a potential solution. This paper discusses the design, analysis, manufacture and testing of a large-scale horizontal TMD based on ECD. First, the theoretical model of ECD is formulated, then one large-scale horizontal TMD using ECD is constructed, and finally performance tests of the TMD are conducted. The test results show that the proposed TMD has a very low intrinsic damping ratio, while the damping ratio due to ECD is the dominant damping source, which can be as large as 15% in a proper configuration. In addition, the damping ratios estimated with the theoretical model are roughly consistent with those identified from the test results, and the source of this error is investigated. Moreover, it is demonstrated that the damping ratio in the proposed TMD can be easily adjusted by varying the air gap between permanent magnets and conductive plates. In view of practical applications, possible improvements and feasibility considerations for the proposed TMD are then discussed. It is confirmed that the proposed TMD with ECD is reliable and feasible for use in structural vibration control.

77 FR 48993 - Proposed Collection; Comment Request; The Sister Study: A Prospective Study of the Genetic and...

Science.gov (United States)

2012-08-15

... Genetic and Environmental Risk Factors for Breast Cancer SUMMARY: In compliance with the requirement of... proposed data collection projects, the National Institute of Environmental Health Sciences (NIEHS), the... Sister Study: A Prospective Study of the Genetic and Environmental Risk Factors for Breast Cancer. Type...

Music-Evoked Emotions—Current Studies

Science.gov (United States)

Schaefer, Hans-Eckhardt

2017-01-01

The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields. PMID:29225563

Family medicine practice in Saudi Arabia: The current situation and Proposed Strategic Directions Plan 2020.

Science.gov (United States)

Al-Khaldi, Yahia M; Al-Ghamdi, Essam A; Al-Mogbil, Tariq I; Al-Khashan, Hesham I

2017-01-01

The objectives of this study were to assess the current situation of the teaching and training of undergraduate and postgraduate programs in family medicine in KSA, assess the current practice of family medicine, and draw a roadmap to achieve Saudi vision 2020. This study was conducted with the support and collaboration of the Primary Health Care Department of the Ministry of Health, Saudi Arabia, and World Health Organization (EMRO) in November 2015. Based on the literature review of previous studies conducted for similar purposes, relevant questionnaires were developed. These consisted of four forms, each of which was directed at a different authority to achieve the above-mentioned objectives. Data of all questionnaires were coded, entered, and analyzed using SPSS version 16. There are 2282 primary health-care centers (PHCCs), 60% of which are in rural areas. More than half of the PHCCs have a laboratory and more than one-third have a Radiology Department. Out of the 6107 physicians, 636 are family physicians (10%). All medical colleges have a family medicine department with a total staff of 170 medical teachers. Thirteen departments run family medicine courses of 4-8 weeks' duration for students. Fourteen colleges have internship programs in family medicine and four colleges have postgraduate centers for family medicine (27%). There are 95 training centers for Saudi Board (Saudi Board of Family Medicine [SBFM]) and 68 centers for Saudi Diploma (Saudi Diploma of Family Medicine [SDFM]). The total number of trainers was 241, while the total trainees were 756 in SBFM and 137 in SDFM. This survey showed that there is a shortage of qualified family physicians in all health sectors in Saudi Arabia as a result of the lack of a strategic plan for the training of family physicians. A national strategic plan with specific objectives and an explicit budget are necessary to deal with this shortage and improve the quality of health-care services at PHCCs.

Study of longshore current equations for currents in Visakhapatnam beach

Digital Repository Service at National Institute of Oceanography (India)

Chandramohan, P.; Rao, T.V.N.

Longshore currents were measured along the Visakhapatnam Beach, Andhra Pradesh, India at weekly intervals from March 1978 to March 1979. Visual observations on breaker characteristics were also made during this period. Using modified Longuet...

An analysis of pharmaceutical experience with decades of rat carcinogenicity testing: support for a proposal to modify current regulatory guidelines.

Science.gov (United States)

Sistare, Frank D; Morton, Daniel; Alden, Carl; Christensen, Joel; Keller, Douglas; Jonghe, Sandra De; Storer, Richard D; Reddy, M Vijayaraj; Kraynak, Andrew; Trela, Bruce; Bienvenu, Jean-Guy; Bjurström, Sivert; Bosmans, Vanessa; Brewster, David; Colman, Karyn; Dominick, Mark; Evans, John; Hailey, James R; Kinter, Lewis; Liu, Matt; Mahrt, Charles; Marien, Dirk; Myer, James; Perry, Richard; Potenta, Daniel; Roth, Arthur; Sherratt, Philip; Singer, Thomas; Slim, Rabih; Soper, Keith; Fransson-Steen, Ronny; Stoltz, James; Turner, Oliver; Turnquist, Susan; van Heerden, Marjolein; Woicke, Jochen; DeGeorge, Joseph J

2011-06-01

Data collected from 182 marketed and nonmarketed pharmaceuticals demonstrate that there is little value gained in conducting a rat two-year carcinogenicity study for compounds that lack: (1) histopathologic risk factors for rat neoplasia in chronic toxicology studies, (2) evidence of hormonal perturbation, and (3) positive genetic toxicology results. Using a single positive result among these three criteria as a test for outcome in the two-year study, fifty-two of sixty-six rat tumorigens were correctly identified, yielding 79% test sensitivity. When all three criteria were negative, sixty-two of seventy-six pharmaceuticals (82%) were correctly predicted to be rat noncarcinogens. The fourteen rat false negatives had two-year study findings of questionable human relevance. Applying these criteria to eighty-six additional chemicals identified by the International Agency for Research on Cancer as likely human carcinogens and to drugs withdrawn from the market for carcinogenicity concerns confirmed their sensitivity for predicting rat carcinogenicity outcome. These analyses support a proposal to refine regulatory criteria for conducting a two-year rat study to be based on assessment of histopathologic findings from a rat six-month study, evidence of hormonal perturbation, genetic toxicology results, and the findings of a six-month transgenic mouse carcinogenicity study. This proposed decision paradigm has the potential to eliminate over 40% of rat two-year testing on new pharmaceuticals without compromise to patient safety.

High current vacuum closing switch

International Nuclear Information System (INIS)

Dolgachev, G.I.; Maslennikov, D.D.; Romanov, A.S.; Ushakov, A.G.

2005-01-01

The paper proposes a powerful pulsed closing vacuum switch for high current commutation consisting of series of the vacuum diodes with near 1 mm gaps having closing time determined by the gaps shortening with the near-electrode plasmas [ru

Output Current Ripple Reduction Algorithms for Home Energy Storage Systems

Directory of Open Access Journals (Sweden)

Jin-Hyuk Park

2013-10-01

Full Text Available This paper proposes an output current ripple reduction algorithm using a proportional-integral (PI controller for an energy storage system (ESS. In single-phase systems, the DC/AC inverter has a second-order harmonic at twice the grid frequency of a DC-link voltage caused by pulsation of the DC-link voltage. The output current of a DC/DC converter has a ripple component because of the ripple of the DC-link voltage. The second-order harmonic adversely affects the battery lifetime. The proposed algorithm has an advantage of reducing the second-order harmonic of the output current in the variable frequency system. The proposed algorithm is verified from the PSIM simulation and experiment with the 3 kW ESS model.

Modelling and analysis of the transformer current resonance in dual active bridge converters

DEFF Research Database (Denmark)

Qin, Zian; Shen, Zhan; Blaabjerg, Frede

2017-01-01

Due to the parasitic capacitances of the transformer and inductor in Dual Active Bridge (DAB) converters, resonance happens in the transformer currents. This high frequency resonant current flowing into the full bridges will worsen their soft-switching performance and thereby reduce its efficiency....... In order to study the generation mechanism of this current resonance, the impedance of the transformer and inductor with parasitic components is modelled in this digest. Then, based on the impedance model, an approach is proposed to mitigate the current resonance. Finally, both the impedance model...

78 FR 48636 - Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for...

Science.gov (United States)

2013-08-09

... collection related to the proposed rule, ``Current Good Manufacturing Practice and Hazard Analysis and Risk... period. These two proposals are related to the proposed rule ``Current Good Manufacturing Practice and... final extension of the comment period for the ``Current Good Manufacturing Practice and Hazard Analysis...

An optimization design proposal of automated guided vehicles for mixed type transportation in hospital environments.

Science.gov (United States)

González, Domingo; Romero, Luis; Espinosa, María Del Mar; Domínguez, Manuel

2017-01-01

The aim of this paper is to present an optimization proposal in the automated guided vehicles design used in hospital logistics, as well as to analyze the impact of its implementation in a real environment. This proposal is based on the design of those elements that would allow the vehicles to deliver an extra cart by the towing method. So, the proposal intention is to improve the productivity and the performance of the current vehicles by using a transportation method of combined carts. The study has been developed following concurrent engineering premises from three different viewpoints. First, the sequence of operations has been described, and second, a proposal of design of the equipment has been undertaken. Finally, the impact of the proposal has been analyzed according to real data from the Hospital Universitario Rio Hortega in Valladolid (Spain). In this particular case, by the implementation of the analyzed proposal in the hospital a reduction of over 35% of the current time of use can be achieved. This result may allow adding new tasks to the vehicles, and according to this, both a new kind of vehicle and a specific module can be developed in order to get a better performance.

An optimization design proposal of automated guided vehicles for mixed type transportation in hospital environments.

Directory of Open Access Journals (Sweden)

Domingo González

Full Text Available The aim of this paper is to present an optimization proposal in the automated guided vehicles design used in hospital logistics, as well as to analyze the impact of its implementation in a real environment.This proposal is based on the design of those elements that would allow the vehicles to deliver an extra cart by the towing method. So, the proposal intention is to improve the productivity and the performance of the current vehicles by using a transportation method of combined carts.The study has been developed following concurrent engineering premises from three different viewpoints. First, the sequence of operations has been described, and second, a proposal of design of the equipment has been undertaken. Finally, the impact of the proposal has been analyzed according to real data from the Hospital Universitario Rio Hortega in Valladolid (Spain. In this particular case, by the implementation of the analyzed proposal in the hospital a reduction of over 35% of the current time of use can be achieved. This result may allow adding new tasks to the vehicles, and according to this, both a new kind of vehicle and a specific module can be developed in order to get a better performance.

Theory of current-drive in plasmas

International Nuclear Information System (INIS)

Fisch, N.J.

1986-12-01

The continuous operation of a tokamak fusion reactor requires, among other things, a means of providing continuous toroidal current. Such operation is preferred to the conventional pulsed operation, where the plasma current is induced by a time-varying magnetic field. A variety of methods has been proposed to provide continuous current, including methods which utilize particle beams or radio frequency waves in any of several frequency regimes. Currents as large as half a mega-amp have now been produced in the laboratory by such means, and experimentation in these techniques has now involved major tokamak facilities worldwide

Study of leakage current behaviour on artificially polluted surface of ceramic insulator

International Nuclear Information System (INIS)

Subba Reddy, B.; Nagabhushana, G.R.

2003-01-01

This paper presents the results of the study concerning to the leakage current behaviour on artificially polluted ceramic insulator surface. From the present study it was observed that there is a reasonably well-defined inception of current i.e. scintillations at a finite voltage. The corresponding voltages for extinction of the current are in the range of 0.8 kV to 2.1 kV. Obviously, the dry band formed in the immediate vicinity of the pin prevents smooth current flow as the voltage rises from zero. Only when the voltage is adequate it causes a flashover of the dray band and current starts flowing. As is common in similar current extinction phenomena, here also, the extinction voltages are significantly lower than the inception voltages. Further, the voltage-current curves invariably show hysteresis-the leakage currents are lower in the reducing portion of the voltage. This is obviously due to drying of the wet pollutant layer thereby increasing its resistance. It is believed that this is the first time that such a direct quantitative evidence of drying in individual half cycles is experimentally visualized

A unified grid current control for grid-interactive DG inverters in microgrids

DEFF Research Database (Denmark)

Wang, Xiongfei; Loh, Poh Chiang; Blaabjerg, Frede

2015-01-01

This paper proposes a unified grid current control for grid-interactive distributed generation inverters. In the approach, the grid-side current, instead of inverter-side current, is controlled as an inner loop, while the filter capacitor voltage is indirectly regulated through a virtual admittan...... locus analyses in the discrete z-domain are performed for elaborating the controller design. Simulations and experimental results demonstrate the performances of the proposed approach.......This paper proposes a unified grid current control for grid-interactive distributed generation inverters. In the approach, the grid-side current, instead of inverter-side current, is controlled as an inner loop, while the filter capacitor voltage is indirectly regulated through a virtual admittance...... in the outer loop. It, therefore, provides several superior features over traditional control schemes: 1) high-quality grid current in the grid-connected mode, 2) inherent derivative-less virtual output impedance control, and 3) the unified active damping for both grid-connected and islanded operations. Root...

Assessment of environmental impact of HVDC power lines in terms of corona currents

International Nuclear Information System (INIS)

Tikhodeev, N.N.

1997-01-01

Corona loss measurements were made on a HVDC power transmission line to evaluate current density. Ion currents were obtained from unipolar and bipolar 400 to 1000 kV DC test lines. A numerical solution was proposed for assessing the maximum current density of unipolar corona currents near the lines. A larger ground clearance of line conductors was proposed as being the most effective way of lowering the current density. 11 refs., 2 tabs., 4 figs

Post-tensioning tendon force loss detection using low power pulsed eddy current measurement

Science.gov (United States)

Kim, Ji-Min; Lee, Jun; Sohn, Hoon

2018-04-01

In the field of bridge engineering, pre-fabrication of a bridge member and its construction in site have been issued and studied, which achieves improved quality and rapid construction. For integration of those pre-fabricated segments into a structural member (i.e., a concrete slab, girder and pier), post-tensioning (PT) technique is adopted utilizing a high-strength steel tendon, and an effective investigation of the remaining PT tendon force is essential to assure an overall structural integrity. This study proposes a pulsed eddy current based tendon force loss detection system. A compact eddy current sensor is designed to be installed on the surface of an anchor holding a steel PT tendon. The intensity of the induced eddy current varies with PT tendon force alteration due to the magnetostriction effect of a ferromagnetic material. The advantages of the proposed system are as follows: (1) low power consumption, (2) rapid inspection, and (3) simple installation. Its performance was validated experimentally in a full-scale lab test of a 3.3-m long, 15.2-mm diameter mono-tendon that was tensioned using a universal testing machine. Tendon force was controlled from 20 to 180 kN with 20 kN interval, and eddy current responses were measured and analyzed at each force condition. The proposed damage index and the amount of force loss of PT tendon were monotonically related, and an excessive loss as much as 30 % of an initially-introduced tendon force was successfully predicted.

Considerations on ECFH current drive and bootstrap current for W VII-X

International Nuclear Information System (INIS)

Gasparino, U.; Maassberg, H.

1988-01-01

Low shear is the characteristic of all proposed Wendelstein VII-X configurations. To avoid low harmonic rational numbers within the rotational transform profile, the current contribution to the rotational transform, Δt a α I/B, should be typically less than 10%. This leads to an upper limit of 50 kA (at B = 2.5 T) for the tolerable net toroidal current. A considerable net toroidal current (bootstrap current) is expected by neoclassical theory in the plateau and the low-collisionality regimes. Both radial transport as well as the bootstrap current densities depend sensitively on the magnetic configuration (see A. Montvai, this workshop). In case of an axisymmetric configuration with dimension and plasma parameters as predicted for the high- regime of WVII-X ( ∼ 5%), this current (∼ 0.5/1 MA) would dominate the rotational transform profile. This requires a reduction of magnitude of the bootstrap current to some % of the value of an equivalent tokamak. This reduction must act on the current profile itself and should not be merely obtained by having two channels of currents of different sign at different radii. Due to the possibility of controlling absorbed power and driven current profiles, electron cyclotron waves are a natural candidate for current profile control. Linear calculations show the possibility to drive a counteracting current with a profile similar to the bootstrap one. For ∼ 5% conditions, however, the optimium current drive efficiency (η ∼ 10 kA per MW) is far too low to make ECF-current drive suitable

Regression analysis of informative current status data with the additive hazards model.

Science.gov (United States)

Zhao, Shishun; Hu, Tao; Ma, Ling; Wang, Peijie; Sun, Jianguo

2015-04-01

This paper discusses regression analysis of current status failure time data arising from the additive hazards model in the presence of informative censoring. Many methods have been developed for regression analysis of current status data under various regression models if the censoring is noninformative, and also there exists a large literature on parametric analysis of informative current status data in the context of tumorgenicity experiments. In this paper, a semiparametric maximum likelihood estimation procedure is presented and in the method, the copula model is employed to describe the relationship between the failure time of interest and the censoring time. Furthermore, I-splines are used to approximate the nonparametric functions involved and the asymptotic consistency and normality of the proposed estimators are established. A simulation study is conducted and indicates that the proposed approach works well for practical situations. An illustrative example is also provided.

Ethical dilemma and moral distress: proposed new NANDA diagnoses.

Science.gov (United States)

Kopala, Beverly; Burkhart, Lisa

2005-01-01

To propose two NANDA diagnoses--ethical dilemma and moral distress--and to distinguish between the NANDA diagnosis decisional conflict and the proposed nursing diagnosis of ethical dilemma. Journal articles, books, and focus group research findings. Moral/ethical situations exist in health care. Nurses' experiences of ethical dilemmas and moral distress are extrapolated to the types and categories of ethical dilemmas and moral distress that patients experience and are used as the basis for development of two new nursing diagnoses. The two proposed NANDA diagnoses fill a void in current standardized terminology. It is important that nurses have the ability to diagnose ethical or moral situations in health care. Currently, NANDA does not offer a means to document this important phenomenon. The creation of two sets of nursing diagnoses, ethical dilemma and moral distress, will enable nurses to recognize and track nursing care related to ethical or moral situations.

Experimental performance study of a proposed desiccant based air conditioning system.

Science.gov (United States)

Bassuoni, M M

2014-01-01

An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system.

Current Control of Grid Converters Connected with Series AC Capacitor

DEFF Research Database (Denmark)

Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

2015-01-01

The series ac capacitor has recently been used with the transformerless grid-connected converters in the distribution power grids. The capacitive characteristic of the resulting series LC filter restricts the use of conventional synchronous integral or stationary resonant current controllers. Thus...... this paper proposes a fourth-order resonant controller in the stationary frame, which guarantees a zero steady-state current tracking error for the grid converters with series LC filter. This method is then implemented in a three-phase experimental system for verification, where the current harmonics below...... the LC filter resonance frequency are effectively eliminated. Experimental results confirm the validity of the proposed current control scheme....

78 FR 41926 - Proposed Information Collection Request; Comment Request; Performance Evaluation Studies on...

Science.gov (United States)

2013-07-12

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OECA-2013-0413; FRL--9832-8] Proposed Information Collection Request; Comment Request; Performance Evaluation Studies on Wastewater Laboratories (Renewal); EPA... request (ICR), ``Performance Evaluation Studies on Wastewater Laboratories'' (EPA ICR No. 0234.11, OMB...

Cathodal Transcranial Direct Current Stimulation Improves Focal Hand Dystonia in Musicians: A Two-Case Study

Directory of Open Access Journals (Sweden)

Sara Marceglia

2017-09-01

Full Text Available Focal hand dystonia (FHD in musicians is a movement disorder causing abnormal movements and irregularities in playing. Since weak electrical currents applied to the brain induce persistent excitability changes in humans, cathodal tDCS was proposed as a possible non-invasive approach for modulating cortical excitability in patients with FHD. However, the optimal targets and modalities have still to be determined. In this pilot study, we delivered cathodal (2 mA, anodal (2 mA and sham tDCS over the motor areas bilaterally for 20 min daily for five consecutive days in two musicians with FHD. After cathodal tDCS, both patients reported a sensation of general wellness and improved symptoms of FHD. In conclusion, our pilot results suggest that cathodal tDCS delivered bilaterally over motor-premotor (M-PM cortex for 5 consecutive days may be effective in improving symptoms in FHD.

MREIT experiments with 200 µA injected currents: a feasibility study using two reconstruction algorithms, SMM and harmonic B(Z).

Science.gov (United States)

Arpinar, V E; Hamamura, M J; Degirmenci, E; Muftuler, L T

2012-07-07

Magnetic resonance electrical impedance tomography (MREIT) is a technique that produces images of conductivity in tissues and phantoms. In this technique, electrical currents are applied to an object and the resulting magnetic flux density is measured using magnetic resonance imaging (MRI) and the conductivity distribution is reconstructed using these MRI data. Currently, the technique is used in research environments, primarily studying phantoms and animals. In order to translate MREIT to clinical applications, strict safety standards need to be established, especially for safe current limits. However, there are currently no standards for safe current limits specific to MREIT. Until such standards are established, human MREIT applications need to conform to existing electrical safety standards in medical instrumentation, such as IEC601. This protocol limits patient auxiliary currents to 100 µA for low frequencies. However, published MREIT studies have utilized currents 10-400 times larger than this limit, bringing into question whether the clinical applications of MREIT are attainable under current standards. In this study, we investigated the feasibility of MREIT to accurately reconstruct the relative conductivity of a simple agarose phantom using 200 µA total injected current and tested the performance of two MREIT reconstruction algorithms. These reconstruction algorithms used are the iterative sensitivity matrix method (SMM) by Ider and Birgul (1998 Elektrik 6 215-25) with Tikhonov regularization and the harmonic B(Z) proposed by Oh et al (2003 Magn. Reason. Med. 50 875-8). The reconstruction techniques were tested at both 200 µA and 5 mA injected currents to investigate their noise sensitivity at low and high current conditions. It should be noted that 200 µA total injected current into a cylindrical phantom generates only 14.7 µA current in imaging slice. Similarly, 5 mA total injected current results in 367 µA in imaging slice. Total

Mitigation of grid-current distortion for LCL-filtered grid-connected voltage-source inverter with inverter-side current control

DEFF Research Database (Denmark)

Xin, Zhen; Mattavelli, Paolo; Yao, WenLi

2017-01-01

Due to the low inductance of an LCL-filter, the grid current generated by an LCL-filtered Voltage Source Inverter (VSI) is sensitive to low-order grid-voltage harmonics. This issue is especially tough for the control system with Inverter Current Feedback (ICF), because the grid-current harmonics...... can freely flow into the filter capacitor without control. To cope with this issue, this paper develops an approach for the ICF control system to suppress the grid-current harmonics without adding extra sensors. The proposed method applies harmonic controllers and feedforward scheme simultaneously...

Case Study: Applying the Theory of Planned Behavior as Interventions to Increase Sponsored Project Proposal Submissions from Liberal Arts Faculty

Science.gov (United States)

Hartmann, Anita

2011-01-01

In the current economic climate, many colleges and universities face similar challenges: the need to increase external sponsorship for research activities and the need to benefit from additional indirect cost recovery. Preparing funding proposals for submission to sponsors is a faculty behavior that can be modified by applying behavioral theory to…

A Phase Current Reconstruction Approach for Three-Phase Permanent-Magnet Synchronous Motor Drive

Directory of Open Access Journals (Sweden)

Hao Yan

2016-10-01

Full Text Available Three-phase permanent-magnet synchronous motors (PMSMs are widely used in renewable energy applications such as wind power generation, tidal energy and electric vehicles owing to their merits such as high efficiency, high precision and high reliability. To reduce the cost and volume of the drive system, techniques of reconstructing three-phase current using a single current sensor have been reported for three-phase alternating current (AC control system using the power converts. In existing studies, the reconstruction precision is largely influenced by reconstructing dead zones on the Space Vector Pulse Width Modulation (SVPWM plane, which requires other algorithms to compensate either by modifying PWM modulation or by phase-shifting of the PWM signal. In this paper, a novel extended phase current reconstruction approach for PMSM drive is proposed. Six novel installation positions are obtained by analyzing the sampling results of the current paths between each two power switches. By arranging the single current sensor at these positions, the single current sensor is sampled during zero voltage vectors (ZVV without modifying the PWM signals. This proposed method can reconstruct the three-phase currents without any complex algorithms and is available in the sector boundary region and low modulation region. Finally, this method is validated by experiments.

Metering error quantification under voltage and current waveform distortion

Science.gov (United States)

Wang, Tao; Wang, Jia; Xie, Zhi; Zhang, Ran

2017-09-01

With integration of more and more renewable energies and distortion loads into power grid, the voltage and current waveform distortion results in metering error in the smart meters. Because of the negative effects on the metering accuracy and fairness, it is an important subject to study energy metering combined error. In this paper, after the comparing between metering theoretical value and real recorded value under different meter modes for linear and nonlinear loads, a quantification method of metering mode error is proposed under waveform distortion. Based on the metering and time-division multiplier principles, a quantification method of metering accuracy error is proposed also. Analyzing the mode error and accuracy error, a comprehensive error analysis method is presented which is suitable for new energy and nonlinear loads. The proposed method has been proved by simulation.

Adaptive slope compensation for high bandwidth digital current mode controller

DEFF Research Database (Denmark)

Taeed, Fazel; Nymand, Morten

2015-01-01

An adaptive slope compensation method for digital current mode control of dc-dc converters is proposed in this paper. The compensation slope is used for stabilizing the inner current loop in peak current mode control. In this method, the compensation slope is adapted with the variations...... in converter duty cycle. The adaptive slope compensation provides optimum controller operation in term of bandwidth over wide range of operating points. In this paper operation principle of the controller is discussed. The proposed controller is implemented in an FPGA to control a 100 W buck converter...

Thyristor based short circuit current injection in isolated grids

OpenAIRE

Hoff, Bjarte; Sharma, Pawan; Østrem, Trond

2017-01-01

This paper proposes a thyristor based short circuit current injector for providing short circuit current in isolated and weak grids, where sufficient fault current to trigger circuit breakers may not be available. This will allow the use of conventional miniature circuit breakers, which requires high fault current for instantaneous tripping. The method has been validated through experiments.

Adaptation of superconducting fault current limiter to high-speed reclosing

International Nuclear Information System (INIS)

Koyama, T.; Yanabu, S.

2009-01-01

Using a high temperature superconductor, we constructed and tested a model superconducting fault current limiter (SFCL). The superconductor might break in some cases because of its excessive generation of heat. Therefore, it is desirable to interrupt early the current that flows to superconductor. So, we proposed the SFCL using an electromagnetic repulsion switch which is composed of a superconductor, a vacuum interrupter and a by-pass coil, and its structure is simple. Duration that the current flow in the superconductor can be easily minimized to the level of less than 0.5 cycle using this equipment. On the other hand, the fault current is also easily limited by large reactance of the parallel coil. There is duty of high-speed reclosing after interrupting fault current in the electric power system. After the fault current is interrupted, the back-up breaker is re-closed within 350 ms. So, the electromagnetic repulsion switch should return to former state and the superconductor should be recovered to superconducting state before high-speed reclosing. Then, we proposed the SFCL using an electromagnetic repulsion switch which employs our new reclosing function. We also studied recovery time of the superconductor, because superconductor should be recovered to superconducting state within 350 ms. In this paper, the recovery time characteristics of the superconducting wire were investigated. Also, we combined the superconductor with the electromagnetic repulsion switch, and we did performance test. As a result, a high-speed reclosing within 350 ms was proven to be possible.

Decentralised control method for DC microgrids with improved current sharing accuracy

DEFF Research Database (Denmark)

Yang, Jie; Jin, Xinmin; Wu, Xuezhi

2017-01-01

A decentralised control method that deals with current sharing issues in dc microgrids (MGs) is proposed in this study. The proposed method is formulated in terms of ‘modified global indicator’ concept, which was originally proposed to improve reactive power sharing in ac MGs. In this work......, the ‘modified global indicator’ concept is extended to coordinate dc MGs, which aims to preserve the main features offered by decentralised control methods such as no need of communication links, central controller or knowledge of the microgrid topology and parameters. This global indicator is inserted between...... a shunt virtual resistance. The operation under multiple dc-buses is also included in order to enhance the applicability of the proposed controller. A detailed mathematical model including the effect of network mismatches is derived for analysis of the stability of the proposed controller. The feasibility...

Multispacecraft current estimates at swarm

DEFF Research Database (Denmark)

Dunlop, M. W.; Yang, Y.-Y.; Yang, J.-Y.

2015-01-01

During the first several months of the three-spacecraft Swarm mission all three spacecraft camerepeatedly into close alignment, providing an ideal opportunity for validating the proposed dual-spacecraftmethod for estimating current density from the Swarm magnetic field data. Two of the Swarm...

Distributed Cooperative Current-Sharing Control of Parallel Chargers Using Feedback Linearization

Directory of Open Access Journals (Sweden)

Jiangang Liu

2014-01-01

Full Text Available We propose a distributed current-sharing scheme to address the output current imbalance problem for the parallel chargers in the energy storage type light rail vehicle system. By treating the parallel chargers as a group of agents with output information sharing through communication network, the current-sharing control problem is recast as the consensus tracking problem of multiagents. To facilitate the design, input-output feedback linearization is first applied to transform the nonidentical nonlinear charging system model into the first-order integrator. Then, a general saturation function is introduced to design the cooperative current-sharing control law which can guarantee the boundedness of the proposed control. The cooperative stability of the closed-loop system under fixed and dynamic communication topologies is rigorously proved with the aid of Lyapunov function and LaSalle invariant principle. Simulation using a multicharging test system further illustrates that the output currents of parallel chargers are balanced using the proposed control.

A Comparative Study of Voltage, Peak Current and Dual Current Mode Control Methods for Noninverting Buck-Boost Converter

Directory of Open Access Journals (Sweden)

M. Č. Bošković

2016-06-01

Full Text Available This paper presents a comparison of voltage mode control (VMC and two current mode control (CMC methods of noninverting buck-boost converter. The converter control-to-output transfer function, line-to-output transfer function and the output impedance are obtained for all methods by averaging converter equations over one switching period and applying small-signal linearization. The obtained results are required for the design procedure of feedback compensator to keep a system stable and robust. A comparative study of VMC, peak current mode control (PCMC and dual-current mode control (DCMC is performed. Performance evaluation of the closed-loop system with obtained compensator between these methods is performed via numerical simulations.

CURRENT-VOLTAGE CURVES FOR TREATING EFFLUENT CONTAINING HEDP: DETERMINATION OF THE LIMITING CURRENT

Directory of Open Access Journals (Sweden)

T. Scarazzato

2015-12-01

Full Text Available Abstract Membrane separation techniques have been explored for treating industrial effluents to allow water reuse and component recovery. In an electrodialysis system, concentration polarization causes undesirable alterations in the ionic transportation mechanism. The graphic construction of the current voltage curve is proposed for establishing the value of the limiting current density applied to the cell. The aim of this work was to determine the limiting current density in an electrodialysis bench stack, the function of which was the treatment of an electroplating effluent containing HEDP. For this, a system with five compartments was used with a working solution simulating the rinse waters of HEDP-based baths. The results demonstrated correlation between the regions defined by theory and the experimental data.

Ultra-low-power, class-AB, CMOS four-quadrant current multiplier

NARCIS (Netherlands)

Sawigun, C.; Serdijn, W.A.

2009-01-01

A class-AB four-quadrant current multiplier constituted by a class-AB current amplifier and a current splitter which can handle input signals in excess of ten times the bias current is presented. The proposed circuit operation is based on the exponential characteristic of BJTs or subthreshold

Experimental and analytical study on vibration control effects of eddy-current tuned mass dampers under seismic excitations

Science.gov (United States)

Lu, Zheng; Huang, Biao; Zhang, Qi; Lu, Xilin

2018-05-01

Eddy-current tuned mass dampers (EC-TMDs) are non-contacting passive control devices and are developed on the basis of conventional tuned mass dampers. They comprise a solid mass, a stiffness element, and a damping element, wherein the damping mechanism originates from eddy currents. By relative motion between a non-magnetic conductive metal and a permanent magnet in a dynamic system, a time-varying magnetic field is induced in the conductor, thereby generating eddy currents. The eddy currents induce a magnetic field with opposite polarity, causing repulsive forces, i.e., damping forces. This technology can overcome the drawbacks of conventional tuned mass dampers, such as limited service life, deterioration of mechanical properties, and undesired additional stiffness. The experimental and analytical study of this system installed on a multi-degree-of-freedom structure is presented in this paper. A series of shaking table tests were conducted on a five-story steel-frame model with/without an EC-TMD to evaluate the effectiveness and performance of the EC-TMD in suppressing the vibration of the model under seismic excitations. The experimental results show that the EC-TMD can effectively reduce the displacement response, acceleration response, interstory drift ratio, and maximum strain of the columns under different earthquake excitations. Moreover, an analytical method was proposed on the basis of electromagnetic and structural dynamic theories. A comparison between the test and simulation results shows that the simulation method can be used to estimate the response of structures with an EC-TMD under earthquake excitations with acceptable accuracy.

Proposed Doctrine Based Structure of the Armored Reconnaissance Squadron

Science.gov (United States)

2017-06-09

squadron. A new structure was proposed based on the deduced required capabilities, utilizing organizational theory and current army practices. This...squadron, which now puts greater emphasis on this analysis to link structure to doctrinally based task. Organizational Theory Since earliest...expect to find capability based discourse; there is a lack of proposed structure based on capability, task or equipment . The Armour Bulletin serves

Fokker-Planck modeling of current penetration during electron cyclotron current drive

International Nuclear Information System (INIS)

Merkulov, A.; Westerhof, E.; Schueller, F. C.

2007-01-01

The current penetration during electron cyclotron current drive (ECCD) on the resistive time scale is studied with a Fokker-Planck simulation, which includes a model for the magnetic diffusion that determines the parallel electric field evolution. The existence of the synergy between the inductive electric field and EC driven current complicates the process of the current penetration and invalidates the standard method of calculation in which Ohm's law is simply approximated by j-j cd =σE. Here it is proposed to obtain at every time step a self-consistent approximation to the plasma resistivity from the Fokker-Planck code, which is then used in a concurrent calculation of the magnetic diffusion equation in order to obtain the inductive electric field at the next time step. A series of Fokker-Planck calculations including a self-consistent evolution of the inductive electric field has been performed. Both the ECCD power and the electron density have been varied, thus varying the well known nonlinearity parameter for ECCD P rf [MW/m -3 ]/n e 2 [10 19 m -3 ] [R. W. Harvey et al., Phys. Rev. Lett 62, 426 (1989)]. This parameter turns out also to be a good predictor of the synergetic effects. The results are then compared with the standard method of calculations of the current penetration using a transport code. At low values of the Harvey parameter, the standard method is in quantitative agreement with Fokker-Planck calculations. However, at high values of the Harvey parameter, synergy between ECCD and E parallel is found. In the case of cocurrent drive, this synergy leads to the generation of large amounts of nonthermal electrons and a concomitant increase of the electrical conductivity and current penetration time. In the case of countercurrent drive, the ECCD efficiency is suppressed by the synergy with E parallel while only a small amount of nonthermal electrons is produced

Realization of Electronically Controllable Current-mode Square-rooting Circuit Based on MO-CFTA

OpenAIRE

P. Silapan; C. Chanapromma; T. Worachak

2011-01-01

This article proposes a current-mode square-rooting circuit using current follower transconductance amplifier (CTFA). The amplitude of the output current can be electronically controlled via input bias current with wide input dynamic range. The proposed circuit consists of only single CFTA. Without any matching conditions and external passive elements, the circuit is then appropriate for an IC architecture. The magnitude of the output signal is temperature-insensitive. Th...

A Novel Programmable CMOS Fuzzifiers Using Voltage-to-Current Converter Circuit

Directory of Open Access Journals (Sweden)

K. P. Abdulla

2012-01-01

Full Text Available This paper presents a new voltage-input, current-output programmable membership function generator circuit (MFC using CMOS technology. It employs a voltage-to-current converter to provide the required current bias for the membership function circuit. The proposed MFC has several advantageous features. This MFC can be reconfigured to perform triangular, trapezoidal, S-shape, Z-Shape, and Gaussian membership forms. This membership function can be programmed in terms of its width, slope, and its center locations in its universe of discourses. The easily adjustable characteristics of the proposed circuit and its accuracy make it suitable for embedded system and industrial control applications. The proposed MFC is designed using the spice software, and simulation results are obtained.

Study on a linear relationship between limited pressure difference and coil current of on/off valve and its influential factors.

Science.gov (United States)

Zhang, Junzhi; Lv, Chen; Yue, Xiaowei; Li, Yutong; Yuan, Ye

2014-01-01

On/off solenoid valves with PWM control are widely used in all types of vehicle electro-hydraulic control systems respecting to their desirable properties of reliable, low cost and fast acting. However, it can hardly achieve a linear hydraulic modulation by using on/off valves mainly due to the nonlinear behaviors of valve dynamics and fluid, which affects the control accuracy significantly. In this paper, a linear relationship between limited pressure difference and coil current of an on/off valve in its critical closed state is proposed and illustrated, which has a great potential to be applied to improve hydraulic control performance. The hydraulic braking system of case study is modeled. The linear correspondence between limited pressure difference and coil current of the inlet valve is simulated and further verified experimentally. Based on validated simulation models, the impacts of key parameters are researched. The limited pressure difference affected by environmental temperatures is experimentally studied, and the amended linear relation is given according to the test data. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Performance of different metrics proposed to CIE TC 1-91

NARCIS (Netherlands)

Bhusal, P.; Dangol, R.

2017-01-01

The main aim of the article is to find out the performance of different metrics proposed to CIE TC 1-91. Currently, six different indexes have been proposed to CIE TC 1-91: Colour Quality Scale (CQS), Feeling of Contrast Index (FCI), Memory colour rendering index (MCRI), Preference of skin (PS),

Subminiature eddy current transducers for studying boride coatings

Science.gov (United States)

Dmitriev, S. F.; Ishkov, A. V.; Malikov, V. N.; Sagalakov, A. M.

2016-07-01

Strengthening of parts and units of machines, increased reliability and longer service life is an important task of modern mechanical engineering. The main objects of study in the work were selected steel 65G and 50HGA, wear-resistant boride coatings ternary system Fe-B-Fe n B which were investigated by scanning electron microscopy and eddy-current nondestructive methods.

Comparative study on current trading system and online trading: the ...

African Journals Online (AJOL)

Comparative study on current trading system and online trading: the case of ... of online trading and factors affecting its feasibility of implementation in ECX. ... The study found that there is significant capacity problem with major skills gap with ...

ACCOUNTING AND AUDIT OPERATIONS ON CURRENT ACCOUNT

Directory of Open Access Journals (Sweden)

Koblyanska Olena

2018-03-01

Full Text Available Introduction. The article is devoted to theoretical, methodical and practical issues of accounting and auditing of operations on the current account. The purpose of the study is to deepen and consolidate the theoretical and practical knowledge of the issues of accounting and auditing of operations on the current account, identify practical problems with the implementation of the methodology and organization of accounting and auditing of operations on the current account and develop recommendations for the elimination of deficiencies and improve the accounting and auditing. Results. The issue of the relevance of proper accounting and audit of transactions on the current account in the bank is considered. The research of typical operations on the current account was carried out with using of the method of their reflection in the account on practical examples. Features of the audit of transactions on the current account are examined, the procedure for its implementation is presented, and types of abuses and violations that occur while performing operations on the current account are identified. The legal regulation of accounting, analysis and control of operations with cash on current accounts is considered. The problem issues related to the organization and conducting of the audit of funds in the accounts of the bank are analyzed, as well as the directions of their solution are determined. The proposals for determining the sequence of actions of the auditor during the check of cash flow on accounts in the bank are provided. Conclusions. The questions about theoretical, methodological and practical issues of accounting and auditing of operations on the current account in the bank. A study of typical operations with cash on the current account was carried out with the use of the method of their reflection in the accounts and the features of the auditing of cash on the account.

Current measurement studies around the Cesme Peninsula (Turkey)

International Nuclear Information System (INIS)

Taspinar, N.

1989-04-01

In order to design coastal structures and marine vehicles safely, it is required to know current climate which shows the variation of the current characteristics with time. There are a wide variety of current meters designed to measure water flow today. Each current meter is capable of recording the influence of mooring arrangement. Here we describe sea water temperatures, salinities and current velocities at offshore of Akburun, Tatlicak Burnu, Kalem Burnu and Kizil Burun areas in Cesme Peninsula 27 August, 1986 to 19 November, 1986. At the end of the investigations, measured significant maximum and average current velocities have been routinely analysed with micro-computers and also the percentages of current velocity have been calculated. (author). 8 refs, 6 figs, 4 tabs

The Effect of IT Integration on Supply Chain Agility Towards Market Performance (A Proposed Study

Directory of Open Access Journals (Sweden)

Shaghayegh Maleki Far

2017-06-01

Full Text Available Aim/Purpose\t: An important objective of any firm is escalation of its performance and the achievement of competitive advantages. Supply chain agility plays a prominent role to enhance the level of firm’s performance. Moreover, information technology (IT plays a foundational role in supply chain management practices. Hence, this study proposes the relationship between IT integration as the competency of IT and firm’s market performance both directly and through mediating role of supply chain agility. Background:\tMany studies have been done to date on the impact of supply chain agility on overall firm’s performance. However, the effect of an agile supply chain on firm’s market performance per se needs to be studied. Furthermore, there is a gap in the literature about the effect of IT competency such as IT integration on firm’s market performance both directly and through mediating role of supply chain agility. Recommendation for Researchers: The first direction this study gives to researchers is to consider the different factors which have significant effect on the agility of supply chain, particularly the IT related ones. The second direction is about the study on the effect of IT competencies and supply chain agility on each category of firm’s performance separately instead of considering it as a one construct. Impact on Society\t: Although this is a conceptual study, it can highlight the importance of IT competency not only in our daily life, but also in our businesses and industries. Future Research:\tThis study only proposes some relationships based on theory and literature. Future researchers can test these proposed relationships in different contexts and compare the results. Furthermore, this study proposes the relationships for large manufacturing sector in developing countries. The model could be tested for SMEs as well. In addition, the proposed theoretical model in this study might be tested in both developing as well as

A proposed clinical research support career pathway for noninvestigators.

Science.gov (United States)

Smith, Sheree; Gullick, Janice; Ballard, Jacqueline; Perry, Lin

2018-03-08

To discuss the international experience of clinical research support for noninvestigator roles and to propose a new pathway for Australia, to promote a sustainable research support workforce capable of delivering high-quality clinical research. Noninvestigator research support roles are currently characterized by an ad hoc approach to training, with limited role delineation and perceived professional isolation with implications for study completion rates and participant safety. A focused approach to developing and implementing research support pathways has improved patient recruitment, study completion, job satisfaction, and research governance. The Queensland and New South Wales state-based Nurses' Awards, the Australian Qualifications Framework, and a University Professional (Research) Staff Award. Research nurses in the clinical environment improve study coordination, adherence to study protocol, patient safety, and clinical care. A career pathway that guides education and outlines position descriptions and skill sets would enhance development of the research support workforce. This pathway could contribute to changing the patient outcomes through coordination and study completion of high-quality research. A wide consultative approach is required to determine a cost-effective and feasible approach to implementation and evaluation of the proposed pathway. © 2018 John Wiley & Sons Australia, Ltd.

Model for ICRF fast wave current drive in self-consistent MHD equilibria

International Nuclear Information System (INIS)

Bonoli, P.T.; Englade, R.C.; Porkolab, M.; Fenstermacher, M.E.

1993-01-01

Recently, a model for fast wave current drive in the ion cyclotron radio frequency (ICRF) range was incorporated into the current drive and MHD equilibrium code ACCOME. The ACCOME model combines a free boundary solution of the Grad Shafranov equation with the calculation of driven currents due to neutral beam injection, lower hybrid (LH) waves, bootstrap effects, and ICRF fast waves. The equilibrium and current drive packages iterate between each other to obtain an MHD equilibrium which is consistent with the profiles of driven current density. The ICRF current drive package combines a toroidal full-wave code (FISIC) with a parameterization of the current drive efficiency obtained from an adjoint solution of the Fokker Planck equation. The electron absorption calculation in the full-wave code properly accounts for the combined effects of electron Landau damping (ELD) and transit time magnetic pumping (TTMP), assuming a Maxwellian (or bi-Maxwellian) electron distribution function. Furthermore, the current drive efficiency includes the effects of particle trapping, momentum conserving corrections to the background Fokker Planck collision operator, and toroidally induced variations in the parallel wavenumbers of the injected ICRF waves. This model has been used to carry out detailed studies of advanced physics scenarios in the proposed Tokamak Physics Experiment (TPX). Results are shown, for example, which demonstrate the possibility of achieving stable equilibria at high beta and high bootstrap current fraction in TPX. Model results are also shown for the proposed ITER device

Circulation-based Modeling of Gravity Currents

Science.gov (United States)

Meiburg, E. H.; Borden, Z.

2013-05-01

Atmospheric and oceanic flows driven by predominantly horizontal density differences, such as sea breezes, thunderstorm outflows, powder snow avalanches, and turbidity currents, are frequently modeled as gravity currents. Efforts to develop simplified models of such currents date back to von Karman (1940), who considered a two-dimensional gravity current in an inviscid, irrotational and infinitely deep ambient. Benjamin (1968) presented an alternative model, focusing on the inviscid, irrotational flow past a gravity current in a finite-depth channel. More recently, Shin et al. (2004) proposed a model for gravity currents generated by partial-depth lock releases, considering a control volume that encompasses both fronts. All of the above models, in addition to the conservation of mass and horizontal momentum, invoke Bernoulli's law along some specific streamline in the flow field, in order to obtain a closed system of equations that can be solved for the front velocity as function of the current height. More recent computational investigations based on the Navier-Stokes equations, on the other hand, reproduce the dynamics of gravity currents based on the conservation of mass and momentum alone. We propose that it should therefore be possible to formulate a fundamental gravity current model without invoking Bernoulli's law. The talk will show that the front velocity of gravity currents can indeed be predicted as a function of their height from mass and momentum considerations alone, by considering the evolution of interfacial vorticity. This approach does not require information on the pressure field and therefore avoids the need for an energy closure argument such as those invoked by the earlier models. Predictions by the new theory are shown to be in close agreement with direct numerical simulation results. References Von Karman, T. 1940 The engineer grapples with nonlinear problems, Bull. Am. Math Soc. 46, 615-683. Benjamin, T.B. 1968 Gravity currents and related

A comparative study on the property determination of metal matrix composites using ultrasonic and eddy current techniques

International Nuclear Information System (INIS)

Jeong, Hyun Jo

1997-01-01

Ultrasonic and eddy current methods were developed for the quantitative determination of material properties in particulate reinforced metal matrix composites. The proposed techniques employed measurements of ultrasonic velocity and eddy current conductivity, together with theoretical models which relate the effective anisotropic properties of the composites to their microstructures. The approach was used for a wide range of SiC particulate reinforced Al matrix(SiC p /Al) composites to estimate the particulate volume fractions of the composites. The SiC p volume fraction was calculated by coupling the measured velocity and conductivity with their corresponding model predictions. Both methods were shown to be reliable in determining the reinforcement volume fractions. However, the ultrasonic method was found to be better than the eddy current method, since the electrical conductivity was sensitive to the presence of intermetallic compounds formed during processing stage.

77 FR 71404 - Intent To Prepare an Environmental Impact Statement for the Proposed Flood Risk Management Study...

Science.gov (United States)

2012-11-30

... Environmental Impact Statement for the Proposed Flood Risk Management Study for the Blanchard River Watershed... the subject Flood Risk Management Study. The Buffalo District of the U.S. Army Corps of Engineers... with the proposed Flood Risk Management Study in the Blanchard River Watershed including the...

A Current-Fed Isolated Bidirectional DC-DC Converter

DEFF Research Database (Denmark)

Sun, Xiaofeng; Wu, Xiaoying; Shen, Yanfeng

2017-01-01

This paper proposes a current-fed isolated bidirectional DC-DC converter (CF-IBDC) which has the advantages of wide input voltage range, low input current ripple, low conduction losses, and soft switching over the full operating range. Compared with conventional CF-IBDCs, the voltage spikes...

Proposal and analysis of the benchmark problem suite for reactor physics study of LWR next generation fuels

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-10-01

In order to investigate the calculation accuracy of the nuclear characteristics of LWR next generation fuels, the Research Committee on Reactor Physics organized by JAERI has established the Working Party on Reactor Physics for LWR Next Generation Fuels. The next generation fuels mean the ones aiming for further extended burn-up such as 70 GWd/t over the current design. The Working Party has proposed six benchmark problems, which consists of pin-cell, PWR fuel assembly and BWR fuel assembly geometries loaded with uranium and MOX fuels, respectively. The specifications of the benchmark problem neglect some of the current limitations such as 5 wt% {sup 235}U to achieve the above-mentioned target. Eleven organizations in the Working Party have carried out the analyses of the benchmark problems. As a result, status of accuracy with the current data and method and some problems to be solved in the future were clarified. In this report, details of the benchmark problems, result by each organization, and their comparisons are presented. (author)

77 FR 16541 - Notice of Proposed Information Collection Requests; Office of Planning, Evaluation and Policy...

Science.gov (United States)

2012-03-21

...). Grants are made to Institutions of Higher Education that have entered into consortium arrangements with... DEPARTMENT OF EDUCATION Notice of Proposed Information Collection Requests; Office of Planning, Evaluation and Policy Development; Case Studies of Current and Former Grantees of the Title III National...

A fault-tolerant strategy based on SMC for current-controlled converters

Science.gov (United States)

Azer, Peter M.; Marei, Mostafa I.; Sattar, Ahmed A.

2018-05-01

The sliding mode control (SMC) is used to control variable structure systems such as power electronics converters. This paper presents a fault-tolerant strategy based on the SMC for current-controlled AC-DC converters. The proposed SMC is based on three sliding surfaces for the three legs of the AC-DC converter. Two sliding surfaces are assigned to control the phase currents since the input three-phase currents are balanced. Hence, the third sliding surface is considered as an extra degree of freedom which is utilised to control the neutral voltage. This action is utilised to enhance the performance of the converter during open-switch faults. The proposed fault-tolerant strategy is based on allocating the sliding surface of the faulty leg to control the neutral voltage. Consequently, the current waveform is improved. The behaviour of the current-controlled converter during different types of open-switch faults is analysed. Double switch faults include three cases: two upper switch fault; upper and lower switch fault at different legs; and two switches of the same leg. The dynamic performance of the proposed system is evaluated during healthy and open-switch fault operations. Simulation results exhibit the various merits of the proposed SMC-based fault-tolerant strategy.

Lower hybrid wave accessibility as a means for current profile control

International Nuclear Information System (INIS)

Briffod, G.; Gormezano, C.; Parlange, F.; Van Houtte, D.

1986-01-01

Powerful ICRH experiments on JET and Neutral Beam Injection of various species on TFTR have recently confirmed the insensitivity of the temperature and safety factor profile shapes to the heating profile and the important role played by the sawtooth activity on the overall performances. In order to overcome these limitations, we propose in this paper, in a Tokamak operating at constant plasma current: to control the resistive part of the current by driving an H.F. current by Lower Hybrid Wave. To act on the current profile, with the constraint that q(o) > 1 by controlling the wave penetration. Constant plasma current Tokamak discharges in which a part of the current is driven by L.H.W. have been extensively studied on PETULA and this mode of operation has proven to be very efficient in stabilizing the sawtooth and M.H.D. activity

Interface currents in topological superconductor–ferromagnet heterostructures

International Nuclear Information System (INIS)

Brydon, P M R; Timm, Carsten; Schnyder, Andreas P

2013-01-01

We propose the existence of a substantial charge current parallel to the interface between a noncentrosymmetric superconductor and a metallic ferromagnet. Our analysis focuses upon two complementary orbital-angular-momentum pairing states of the superconductor, exemplifying topologically nontrivial states which are gapped and gapless in the bulk, respectively. Utilizing a quasiclassical scattering theory, we derive an expression for the interface current in terms of Andreev reflection coefficients. Performing a systematic study of the current, we find stark qualitative differences between the gapped and gapless superconductors, which reflect the very different underlying topological properties. For the fully gapped superconductor, there is a sharp drop in the zero-temperature current as the system is tuned from a topologically nontrivial to a trivial phase. We explain this in terms of the sudden disappearance of the contribution to the current from the subgap edge states at the topological transition. The current in the gapless superconductor is characterized by a dramatic enhancement at low temperatures, and exhibits a singular dependence on the exchange-field strength in the ferromagnetic metal at zero temperature. This is caused by the energy shift of the strongly spin-polarized nondegenerate zero-energy flat bands due to their coupling to the exchange field. We argue that the interface current provides a novel test of the topology of the superconductor, and discuss prospects for the experimental verification of our predictions. (paper)

The qualitative research proposal

Directory of Open Access Journals (Sweden)

H Klopper

2008-09-01

Full Text Available Qualitative research in the health sciences has had to overcome many prejudices and a number of misunderstandings, but today qualitative research is as acceptable as quantitative research designs and is widely funded and published. Writing the proposal of a qualitative study, however, can be a challenging feat, due to the emergent nature of the qualitative research design and the description of the methodology as a process. Even today, many sub-standard proposals at post-graduate evaluation committees and application proposals to be considered for funding are still seen. This problem has led the researcher to develop a framework to guide the qualitative researcher in writing the proposal of a qualitative study based on the following research questions: (i What is the process of writing a qualitative research proposal? and (ii What does the structure and layout of a qualitative proposal look like? The purpose of this article is to discuss the process of writing the qualitative research proposal, as well as describe the structure and layout of a qualitative research proposal. The process of writing a qualitative research proposal is discussed with regards to the most important questions that need to be answered in your research proposal with consideration of the guidelines of being practical, being persuasive, making broader links, aiming for crystal clarity and planning before you write. While the structure of the qualitative research proposal is discussed with regards to the key sections of the proposal, namely the cover page, abstract, introduction, review of the literature, research problem and research questions, research purpose and objectives, research paradigm, research design, research method, ethical considerations, dissemination plan, budget and appendices.

76 FR 81959 - Notice of Proposed Information Collection: Comment Request; Homelessness Prevention Study Site...

Science.gov (United States)

2011-12-29

... Information Collection: Comment Request; Homelessness Prevention Study Site Visits AGENCY: Office of the Chief.... This Notice also lists the following information: Title of Proposal: Homelessness Prevention Study Site... of the Paperwork Reduction Act requirements associated with HUD's Homelessness Prevention Study Site...

A Circulating Current Suppression Method for Parallel Connected Voltage-Source-Inverters (VSI) with Common DC and AC Buses

DEFF Research Database (Denmark)

Wei, Baoze; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

2016-01-01

This paper describes a theoretical with experiment study on a control strategy for the parallel operation of threephase voltage source inverters (VSI), to be applied to uninterruptible power systems (UPS). A circulating current suppression strategy for parallel VSIs is proposed in this paper based...... on circulating current control loops used to modify the reference currents by compensating the error currents among parallel inverters. Both of the cross and zero-sequence circulating currents are considered. The proposed method is coordinated together with droop and virtual impedance control. In this paper......, droop control is used to generate the reference voltage of each inverter, and the virtual impedance is used to fix the output impedance of the inverters. In addition, a secondary control is used in order to recover the voltage deviation caused by the virtual impedance. And the auxiliary current control...

Systematic analysis of ocular trauma by a new proposed ocular trauma classification

Directory of Open Access Journals (Sweden)

Bhartendu Shukla

2017-01-01

Full Text Available Purpose: The current classification of ocular trauma does not incorporate adnexal trauma, injuries that are attributable to a nonmechanical cause and destructive globe injuries. This study proposes a new classification system of ocular trauma which is broader-based to allow for the classification of a wider range of ocular injuries not covered by the current classification. Methods: A clinic-based cross-sectional study to validate the proposed classification. We analyzed 535 cases of ocular injury from January 1, 2012 to February 28, 2012 over a 4-year period in an eye hospital in central India using our proposed classification system and compared it with conventional classification. Results: The new classification system allowed for classification of all 535 cases of ocular injury. The conventional classification was only able to classify 364 of the 535 trauma cases. Injuries involving the adnexa, nonmechanical injuries and destructive globe injuries could not be classified by the conventional classification, thus missing about 33% of cases. Conclusions: Our classification system shows an improvement over existing ocular trauma classification as it allows for the classification of all type of ocular injuries and will allow for better and specific prognostication. This system has the potential to aid communication between physicians and result in better patient care. It can also provide a more authentic, wide spectrum of ocular injuries in correlation with etiology. By including adnexal injuries and nonmechanical injuries, we have been able to classify all 535 cases of trauma. Otherwise, about 30% of cases would have been excluded from the study.

Simulative research on reverse current in magnetically insulated coaxial diode

Directory of Open Access Journals (Sweden)

Danni Zhu

2017-10-01

Full Text Available The reverse current tends to occur in the transition region of the guiding magnetic field in a magnetically insulated coaxial diode (MICD. Influence of the guiding magnetic field on characteristics of the MICD especially on the reverse current is studied by the particle-in-cell (PIC simulation in this paper. The reverse current is confirmed to be irrelevant with the guiding magnetic field strength. However, the reverse current is clarified quantitatively to depend on the electric and magnetic field distribution in the upstream of the cathode tip. As the MICD has been widely employed in microwave tubes, a simple approach to suppress the reverse current on the premise of little change of the original diode is valuable and thus proposed. The optimum matching point between the cathode and the magnetic field is selected in consideration of the entrance depth tolerance, the diode impedance discrepancy and the reverse current coefficient.

Study of complex resistivity measurement using current and potential waveform data; Denryu to den`i hakei data wo riyoshita fukusohi teiko sokutei no kento

Energy Technology Data Exchange (ETDEWEB)

Shima, H; Sakurai, K; Yamashita, Y [OYO Corp., Tokyo (Japan)

1997-10-22

This paper proposes a measurement method for complex resistivity using both current and potential waveforms. This method was applied to actual data. Especially, chargeability was discussed among complex resistivities. A method was proposed for determining the complex resistivity. At first, digital measurements of both current and potential waveforms were conducted. For the potential waveform, zero-order self-potential was canceled. Then, the FFT technique was applied to both current and potential waveforms, to determine both current and potential in the frequency domain. Hereafter, complex resistivity was determined through simple division. Since the inductive coupling was observed at higher frequencies, it was difficult to apply Cole-Cole model, simply. However, the inductive coupling could be removed using proper sampling frequency. Thus, a proper Cole-Cole dispersion curve could be obtained. Using this Cole-Cole dispersion curve, new chargeability could be defined. A linear relation between this chargeability and the ordinary time domain chargeability was made clear. 4 refs., 10 figs.

A Modified Droop Control Method for Parallel-Connected Current Source Inverters

DEFF Research Database (Denmark)

Wei, Baoze; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

2016-01-01

In this paper, a novel control method was proposed for current source inverters under the grid-connected working mode. The control scheme is based on a modified droop control method, with an additional current reference signal that will be generated instead of the voltage reference. Hence......, there is only a current control loop with droop control in the whole control scheme without voltage control loop. So it is very suitable for grid-connected current source inverter which will simplify the design of the control scheme and combine the advantage of droop control. The parallel configuration...... is widely used to acquire high power demand, but the circulating current problem is a key issue that should be considered. In this paper, a simulation based on parallel current source inverters using the proposed control scheme is provided. Simulation results showed that a good circulating current...

Studies of Polar Current Systems Using the IMS Scandinavian Magnetometer Array

Science.gov (United States)

Untiedt, J.; Baumjohann, W.

1993-09-01

As a contribution to the International Magnetospheric Study (IMS, 1976 1979) a two-dimensional array of 42 temporary magnetometer stations was run in Scandinavia, supplementary to the permanent observatories and concentrated in the northern part of the region. This effort aimed at the time-dependent (periods above about 100 s) determination of the two-dimensional structure of substorm-related magnetic fields at the Earth's surface with highest reasonable spatial resolution (about 100 km, corresponding to the height of the ionosphere) near the footpoints of field-aligned electric currents that couple the disturbed magnetosphere to the ionosphere at auroral latitudes. It has been of particular advantage for cooperative studies that not only simultaneous data were available from all-sky cameras, riometers, balloons, rockets, and satellites, but also from the STARE radar facility yielding colocated two-dimensional ionospheric electric field distributions. In many cases it therefore was possible to infer the three-dimensional regional structure of substorm-related ionospheric current systems. The first part of this review outlines the basic relationships and methods that have been used or have been developed for such studies. The second short part presents typical equivalent current patterns observed by the magnetometer array in the course of substorms. Finally we review main results of studies that have been based on the magnetometer array observations and on additional data, omitting studies on geomagnetic pulsations. These studies contributed to a clarification of the nature of auroral electrojets including the Harang discontinuity and of ionospheric current systems related to auroral features such as the break-up at midnight, the westward traveling surge, eastward drifting omega bands, and spirals.

Study of single pion production in antineutrino induced charged current interactions

International Nuclear Information System (INIS)

Bolognese, Teresa.

1978-01-01

Results are presented on the exclusive charged current antineutrino production of one pion using the data of the Gargamelle propane experiment at CERN PS. The isospin structure of the charged weak current is studied as well as the energy dependence of the total cross section for π - antineutrino production, which is compared with the prediction of Adler's model [fr

Efficient spin-current injection in single-molecule magnet junctions

Directory of Open Access Journals (Sweden)

Haiqing Xie

2018-01-01

Full Text Available We study theoretically spin transport through a single-molecule magnet (SMM in the sequential and cotunneling regimes, where the SMM is weakly coupled to one ferromagnetic and one normal-metallic leads. By a master-equation approach, it is found that the spin polarization injected from the ferromagnetic lead is amplified and highly polarized spin-current can be generated, due to the exchange coupling between the transport electron and the anisotropic spin of the SMM. Moreover, the spin-current polarization can be tuned by the gate or bias voltage, and thus an efficient spin injection device based on the SMM is proposed in molecular spintronics.

Efficient spin-current injection in single-molecule magnet junctions

Science.gov (United States)

Xie, Haiqing; Xu, Fuming; Jiao, Hujun; Wang, Qiang; Liang, J.-Q.

2018-01-01

We study theoretically spin transport through a single-molecule magnet (SMM) in the sequential and cotunneling regimes, where the SMM is weakly coupled to one ferromagnetic and one normal-metallic leads. By a master-equation approach, it is found that the spin polarization injected from the ferromagnetic lead is amplified and highly polarized spin-current can be generated, due to the exchange coupling between the transport electron and the anisotropic spin of the SMM. Moreover, the spin-current polarization can be tuned by the gate or bias voltage, and thus an efficient spin injection device based on the SMM is proposed in molecular spintronics.

A Proposal of the European Association for the Study of Obesity to Improve the ICD-11 Diagnostic Criteria for Obesity Based on the Three Dimensions Etiology, Degree of Adiposity and Health Risk

Directory of Open Access Journals (Sweden)

Johannes Hebebrand

2017-07-01

Full Text Available Diagnostic criteria for complex medical conditions caused by a multitude of both genetic and environmental factors should be descriptive and avoid any attribution of causality. Furthermore, the wording used to describe a disorder should be evidence-based and avoid stigmatization of the affected individuals. Both terminology and categorizations should be readily comprehensible for healthcare professionals and guide clinical decision making. Uncertainties with respect to diagnostic issues and their implications may be addressed to direct future clinical research. In this context, the European Association of the Study of Obesity (EASO considers it an important endeavor to review the current ICD-11 Beta Draft for the definition of overweight and obesity and to propose a substantial revision. We aim to provide an overview of the key issues that we deem relevant for the discussion of the diagnostic criteria. We first discuss the current ICD-10 criteria and those proposed in the ICD 11 Beta Draft. We conclude with our own proposal for diagnostic criteria, which we believe will improve the assessment of patients with obesity in a clinically meaningful way.

A Proposal of the European Association for the Study of Obesity to Improve the ICD-11 Diagnostic Criteria for Obesity Based on the Three Dimensions Etiology, Degree of Adiposity and Health Risk

Science.gov (United States)

Hebebrand, Johannes; Holm, Jens-Christian; Woodward, Euan; Baker, Jennifer Lyn; Blaak, Ellen; Schutz, Dominique Durrer; Farpour-Lambert, Nathalie J.; Frühbeck, Gema; Halford, Jason G.C.; Lissner, Lauren; Micic, Dragan; Mullerova, Dana; Roman, Gabriela; Schindler, Karin; Toplak, Hermann; Visscher, Tommy L.S.; Yumuk, Volkan

2017-01-01

Diagnostic criteria for complex medical conditions caused by a multitude of both genetic and environmental factors should be descriptive and avoid any attribution of causality. Furthermore, the wording used to describe a disorder should be evidence-based and avoid stigmatization of the affected individuals. Both terminology and categorizations should be readily comprehensible for healthcare professionals and guide clinical decision making. Uncertainties with respect to diagnostic issues and their implications may be addressed to direct future clinical research. In this context, the European Association of the Study of Obesity (EASO) considers it an important endeavor to review the current ICD-11 Beta Draft for the definition of overweight and obesity and to propose a substantial revision. We aim to provide an overview of the key issues that we deem relevant for the discussion of the diagnostic criteria. We first discuss the current ICD-10 criteria and those proposed in the ICD 11 Beta Draft. We conclude with our own proposal for diagnostic criteria, which we believe will improve the assessment of patients with obesity in a clinically meaningful way. PMID:28738325

Quantum rings in magnetic fields and spin current generation.

Science.gov (United States)

Cini, Michele; Bellucci, Stefano

2014-04-09

We propose three different mechanisms for pumping spin-polarized currents in a ballistic circuit using a time-dependent magnetic field acting on an asymmetrically connected quantum ring at half filling. The first mechanism works thanks to a rotating magnetic field and produces an alternating current with a partial spin polarization. The second mechanism works by rotating the ring in a constant field; like the former case, it produces an alternating charge current, but the spin current is dc. Both methods do not require a spin-orbit interaction to achieve the polarized current, but the rotating ring could be used to measure the spin-orbit interaction in the ring using characteristic oscillations. On the other hand, the last mechanism that we propose depends on the spin-orbit interaction in an essential way, and requires a time-dependent magnetic field in the plane of the ring. This arrangement can be designed to pump a purely spin current. The absence of a charge current is demonstrated analytically. Moreover, a simple formula for the current is derived and compared with the numerical results.

Proposals for new standardized general diagnostic criteria for the secondary headaches

DEFF Research Database (Denmark)

Olesen, J; Steiner, T; Bousser, M-G

2009-01-01

headache and chronic migraine. These changes made apparent a further need for broader revisions to the standard formulation of diagnostic criteria for the secondary headaches. Currently, the fourth criterion makes impossible the definitive diagnosis of a secondary headache until the underlying cause has...... propose maintaining a standard approach to the secondary headaches using a set of four criteria A, B, C and D, but we construct these so that the requirement for resolution or successful treatment is removed. The proposal for general diagnostic criteria for the secondary headaches will be entered...... classification are then foreseen for the next 10 years. Until the printing of ICHD-IIR, the printed ICHD-II criteria remain in place for all other purposes. We issue a plea to the headache community to use and study these proposed general criteria for the secondary headaches in order to provide more evidence...

A graphite based STT-RAM cell with reduction in switching current

Science.gov (United States)

Varghani, Ali; Peiravi, Ali

2015-10-01

Spin Transfer Torque Random Access Memory (STT-RAM) is a serious candidate for "universal memory" because of its non-volatility, fast access time, high density, good scalability, high endurance and relatively low power dissipation. However, problems with low write speed and large write current are important existing challenges in STT-RAM design and there is a tradeoff between them and data retention time. In this study, a novel STT-RAM cell structure which uses perfect graphite based Magnetic Tunnel Junction (MTJ) is proposed. First, the cross-section of the structure is selected to be an ellipse of 45 nm and 180 nm dimensions and a six-layer graphite is used as tunnel barrier. By passing a lateral current with a short pulse width (before applying STT current and independent of it) through four middle graphene layers of the tunnel barrier, a 27% reduction in the amplitude of the switching current (for fast switching time of 2 ns) or a 58% reduction in its pulse width is achieved without any reduction in data retention time. Finally, the effect of downscaling of technology on the proposed structure is evaluated. A reduction of 31.6% and 9% in switching current is achieved for 90 and 22 nm cell width respectively by passing sufficient current (100 μA with 0.1 ns pulse width) through the tunnel barrier. Simulations are done using Object Oriented Micro Magnetic Framework (OOMMF).

A high linearity current mode multiplier/divider with a wide dynamic range

International Nuclear Information System (INIS)

Liao Pengfei; Luo Ping; Zhang Bo; Li Zhaoji

2012-01-01

A high linearity current mode multiplier/divider (CMM/D) with a wide dynamic range is presented. The proposed CMM/D is based on the voltage—current characteristic of the diode, thus wide dynamic range is achieved. In addition, high linearity is achieved because high accuracy current mirrors are adopted and the output current is insensitive to the temperature and device parameters of the fabrication process. Furthermore, no extra bias current for all input signals is required and thus power saving is realized. With proper selection of establishing the input terminal, the proposed circuit can perform as a multifunction circuit to be operated as a multiplier/divider, without changing its topology. The proposed circuit is implemented in a 0.25 μm BCD process and the chip area is 0.26 × 0.24 mm 2 . The simulation and measurement results show that the maximum static linearity error is ±1.8% and the total harmonic distortion is 0.4% while the input current ranges from 0 to 200 μA. (semiconductor integrated circuits)

Phonosurgery of the vocal folds : a classification proposal

NARCIS (Netherlands)

Remacle, M; Friedrich, G; Dikkers, FG; de Jong, F

The Phonosurgery Committee of the European Laryngological Society (ELS) has examined the definition and technical description of phonosurgical procedures. Based on this review, the committee has proposed a working classification. The current presentation is restricted to vocal fold surgery (VFS)

Alzheimer’s Disease: Background, Current and Future Treatments

OpenAIRE

Evelyn Chou

2014-01-01

Alzheimer’s disease is a currently incurable neurodegenerative disorder, and its treatment has posed a big challenge. Proposed causes of Alzheimer’s disease include the cholinergic, amyloid and tau hypothesis. Current therapeutic treatments have been aimed at dealing with neurotransmitter imbalance. These include cholinesterase inhibitors and N-methyl D-aspartate receptor antagonists. However, current therapeutics have been unable to halt its progression. The future of Alzheimer’s disease tre...

A qualitative model for strategic analysis of organizations. Application and alternative proposal on a study case

Directory of Open Access Journals (Sweden)

Santiago Ferro Moreno

2015-12-01

Full Text Available The strategic analysis of organizations is based on the internal and external environments, in order to identify positive and negative variables and factors. The interrelation and timing of these strategic forces are essential to create alternative solutions that tend to achieve the organizational objectives.The normative prospective has theorical and methodological foundations to create a desired future and from it, be able to identify impelling and restraining forces that have influence on the particular problematic situation (go from the current situation to a better one in a certain time.The aim of this article is to analyze on a strategic way a real case with a normative-prospective model that considers the temporal dynamics of the factors impact and variables in time allowing to suggest alternative solutions.Semi-structured interviews were performed with all the employees of this case and structured observations and workshops with the commercial and general management.In consequence, with the results, the desired, current and improved situations were built. Additionally, forces were identified classified and appreciated and lastly solutions were suggested. With the proposed prospective method, alternative solutions could be constructed in order to settle temporary organizational objectives. No constraints were found to use the current method in other cases.Keywords: Strategic forces, Normative prospective, Problematic situations, Strategies

On-electrode autonomous current generator for multi-frequency EIT

International Nuclear Information System (INIS)

Jivet, I; Dragoi, B

2008-01-01

The paper presents an autonomous programmable current generator module for multi-frequency EIT systems. The module incorporates all stages from the sine wave generation with frequency and amplitude tuning, D/A converter and filter, a high output resistance voltage-to-current converter to the associated digital communication and control. The paper presents in depth the original digital quadrature signal generator and the output current generator with a high resistance. The other main blocks of the design use current practice specifications, since recent technological solutions proposed in the literature were found appropriate. The proposed signal generator circuit, characterized by a very low complexity, is analyzed in its capacity to produce multiple accurate signals up to 1 MHz in frequency. The precision output current source uses a modified current conveyor of type CCII with a high output resistance and low distortion. The output current frequency spectrum and linearity parameters obtained in the simulations are also described. The simulation results indicate a good linearity and high output resistance with an acceptable output voltage swing. The calculated performance parameters are validated with simulations, and future work for the prototype fabrication of the IC is outlined

Improvement of automatic control system for high-speed current collectors

Science.gov (United States)

Sidorov, O. A.; Goryunov, V. N.; Golubkov, A. S.

2018-01-01

The article considers the ways of regulation of pantographs to provide quality and reliability of current collection at high speeds. To assess impact of regulation was proposed integral criterion of the quality of current collection, taking into account efficiency and reliability of operation of the pantograph. The study was carried out using mathematical model of interaction of pantograph and catenary system, allowing to assess contact force and intensity of arcing at the contact zone at different movement speeds. The simulation results allowed us to estimate the efficiency of different methods of regulation of pantographs and determine the best option.

Use of high current density superconducting coils in fusion devices

International Nuclear Information System (INIS)

Green, M.A.

1979-11-01

Superconducting magnets will play an important role in fusion research in years to come. The magnets which are currently proposed for fusion research use the concept of cryostability to insure stable operation of the superconducting coils. This paper proposes the use of adiabatically stable high current density superconducting coils in some types of fusion devices. The advantages of this approach are much lower system cold mass, enhanced cryogenic safety, increased access to the plasma and lower cost

Studies of non-inductive current drive in the CDX-U tokamak

International Nuclear Information System (INIS)

Hwang, Y.S.

1993-01-01

Two types of novel, non-inductive current drive concepts for starting-up and maintaining tokamak discharges, dc-helicity injection and internally-generated pressure-driven currents, have been developed on the CDX-U tokamak. To study the equilibrium and transport of these plasmas, a full set of magnetic diagnostics was installed. By applying a finite element method and a least squares error fitting technique, internal plasma current distributions are reconstructed from the measurements. Electron density distributions were obtained from 2 mm interferometer measurements by a similar least squares error technique utilizing magnetic flux configurations obtained by the magnetic analysis. Neoclassical pressure-driven currents in ECH plasmas are modeled with the reconstructed magnetic structure, using the electron density distribution and the electron temperature profile measured by a Langmuir probe. In the dc-helicity injection scheme, the need to increase injection current and maintain plasma equilibrium restricts possible arrangements. Several injection configurations were investigated, with the best found to be outside injection with a single divertor configuration, where the cathode is placed at the low field side of the x-point. Both pressure-driven and dc-helicity injected tokamaks show the importance of plasma equilibrium in obtaining high plasma current. Programmed vertical field operation has proven to be very important in achieving high plasma current. These non-inductive current drive techniques show great potential as efficient current drive methods for future steady-state and/or long-pulse fusion reactors

Study of plasma equilibrium during the AC current reversal phase in STOR-M

International Nuclear Information System (INIS)

Xiao, C.

2002-01-01

Alternating current (AC) tokamak operation and equilibrium studies have been performed on the STOR-M tokamak. The recent experiments have achieved consistent smooth current reversal through the implementation of a hybrid digital-analog position controller and by careful density control. In order to study the plasma equilibrium during the current reversal phase with negligible rotational transform, a segmented limiter with four isolated conducting plates has been installed. The plates can be connected outside the vacuum vessel, which allows measurements of currents flowing between limiter plates. When the current reversal is smooth with zero dwell time, the hydrogen line emission level and electron density remain finite, indicating a finite particle confinement. The current from the top to the bottom limiter plate is also finite and its direction is consistent with that of the grad-B drift. The observation suggests that the limiter and other conducting structures surrounding the plasmas plays the role, during the current reversal phase of AC tokamak operation, to short out the charge separation arising from the grad-B drift and to maintain a finite particle confinement. (author)

Current superimposition variable flux reluctance motor with 8 salient poles

Science.gov (United States)

Takahara, Kazuaki; Hirata, Katsuhiro; Niguchi, Noboru; Kohara, Akira

2017-12-01

We propose a current superimposition variable flux reluctance motor for a traction motor of electric vehicles and hybrid electric vehicles, which consists of 10 salient poles in the rotor and 12 slots in the stator. However, iron losses of this motor in high rotation speed ranges is large because the number of salient poles is large. In this paper, we propose a current superimposition variable flux reluctance motor that consists of 8 salient poles and 12 slots. The characteristics of the 10-pole-12-slot and 8-pole-12-slot current superimposition variable flux reluctance motors are compared using finite element analysis under vector control.

Current superimposition variable flux reluctance motor with 8 salient poles

Directory of Open Access Journals (Sweden)

Takahara Kazuaki

2017-12-01

Full Text Available We propose a current superimposition variable flux reluctance motor for a traction motor of electric vehicles and hybrid electric vehicles, which consists of 10 salient poles in the rotor and 12 slots in the stator. However, iron losses of this motor in high rotation speed ranges is large because the number of salient poles is large. In this paper, we propose a current superimposition variable flux reluctance motor that consists of 8 salient poles and 12 slots. The characteristics of the 10-pole-12-slot and 8-pole-12-slot current superimposition variable flux reluctance motors are compared using finite element analysis under vector control.

Cloud accountability : The likely impact of the proposed EU Data Protection Regulation

NARCIS (Netherlands)

Hon, W.Kuan; Kosta, E.; Millard, Christopher; Stefanatou, D.

2014-01-01

This Working Paper considers the implications for cloud accountability of current proposals under the draft General Data Protection Regulation to modernise the EU Data Protection Directive. It makes recommendations aimed at improving the technology-neutrality of the proposals and their

Wetland Planning: Current Problems and Environmental Management Proposals at Supra-Municipal Scale (Spanish Mediterranean Coast

Directory of Open Access Journals (Sweden)

María-Teresa Sebastiá-Frasquet

2014-03-01

Full Text Available The policies that define the use and management of wetlands in Spain have undergone tremendous changes in recent decades. During the period of 1950–1980, Land Reform Plans promoted filling and draining of these areas for agricultural use. In 1986, with the incorporation of Spain to the European Union (EU, there was a sudden change of direction in these policies, which, thereafter, pursued restoring and protecting these ecosystems. This change, combined with increasing urban development and infrastructure pressures (e.g., roads, golf courses, etc., creates a conflict of uses which complicates the management of these ecosystems by local governments. This study analyzes the effectiveness of policies and management tools of important coastal wetlands at the local scale in the Valencian Community (Western Mediterranean Sea using a strengths-weaknesses-opportunities-threats (SWOT methodology. A supra-municipal model of environmental planning is proposed to enable consistent management at a regional scale. This model enhances local government’s effectiveness and it can be applied in other areas with similar problems.

[Differences between proposals for implementation of the social class concept in epidemiological studies

Science.gov (United States)

Solla

1996-07-01

This article compares different proposals for the implementation of the concept of social class and analyzes the alternatives used in each proposal, considering previous epidemiological studies on this issue and the potential of such a concept as a central category in studies on social determination in the health/disease process. Seven basic differences were identified, pertaining to the following aspects: class structure; research objective; the social class concept as a reference; the decision as to which individual has his/her occupational activity taken as defining the family's social class; the class status of the unemployed, housewives, and the retired; class status of students; and criteria for distinguishing between the "bourgeoisie", "petty bourgeoisie", "new petty bourgeoisie", and "proletariat" and whether there is a specific flow in certain population groups. Given the observed differences and underlying theoretical models, this study discusses problems related to the fact that the use of a specific concept of social class can have various implementation models.

A Digital Hysteresis Current Control for Half-Bridge Inverters with Constrained Switching Frequency

Directory of Open Access Journals (Sweden)

Triet Nguyen-Van

2017-10-01

Full Text Available This paper proposes a new robustly adaptive hysteresis current digital control algorithm for half-bridge inverters, which plays an important role in electric power, and in various applications in electronic systems. The proposed control algorithm is assumed to be implemented on a high-speed Field Programmable Gate Array (FPGA circuit, using measured data with high sampling frequency. The hysteresis current band is computed in each switching modulation period based on both the current error and the negative half switching period during the previous modulation period, in addition to the conventionally used voltages measured at computation instants. The proposed control algorithm is derived by solving the optimization problem—where the switching frequency is always constrained at below the desired constant frequency—which is not guaranteed by the conventional method. The optimization problem also keeps the output current stable around the reference, and minimizes power loss. Simulation results show good performances of the proposed algorithm compared with the conventional one.

Study of matrix converter as a current-controlled power supply in QUEST tokamak

International Nuclear Information System (INIS)

Liu, Xiaolong; Jiang, Yi; Nakamura, Kazuo

2011-01-01

Because QUEST tokamak has a divertor configuration with a higher κ and a negative n-index, a precise power supply with a rapid response is needed to control the vertical position of the plasma. A matrix converter is a direct power conversion device that uses an array of controlled bidirectional switches as the main power elements for creating a variable-output current system. This paper presents a novel three-phase to two-phase topological matrix converter as a proposed power supply that stabilizes the plasma vertical position and achieves unity input power factor. An indirect control strategy in which the matrix converter is split into a virtual rectifier stage and a virtual inverter stage is adopted. In the virtual rectifier stage, the instantaneous active power and reactive power are decoupled on the basis of system equations derived from the DQ transformation; hence, unity power factor is achieved. Space vector pulse width modulation is adopted to determine the switching time of each switch in the virtual rectifier; the output voltage of the virtual rectifier is adjusted by the virtual inverter stage to obtain the desired load current. Theoretical analyses and simulation results are provided to verify its feasibility. (author)

A Decentralized Current-Sharing Controller Endows Fast Transient Response to Parallel DC-DC Converters

DEFF Research Database (Denmark)

Wang, Haojie; Han, Minxiao; Han, Renke

2018-01-01

This paper proposes a decentralized current-sharing control strategy to endow fast transient response to paralleled DC-DC converters systems, such as DC microgrids or distributed power systems. The proposed controller consist of two main control loops: an external voltage droop control for current......-sharing proposes and an internal current loop. The external droop control loop is designed as a voltage loop with embedded virtual impedance, which avoids the use of a slow voltage loop and a separate extra virtual impedance loop that may limit the system bandwidth. The internal current loop, thanks...... and the proposed embedded-virtual-impedance based I-V droop. In order to compare the dynamic response performances between two droop controllers, their state-space models have been developed and analyzed in this paper. The results show that the dynamic response of the I-V droop control is faster than...

Study of the antineutrino-induced elastic semi-leptonic neutral current reaction

International Nuclear Information System (INIS)

Racca, C.

1978-01-01

A study of the elastic neutral current reaction antiνsub(μ)p→antiνsub(μ)p has been done using Gargamelle filled with propane and the antineutrino beam of the CERN P.S. The space-time structure of the weak neutral current is discussed, the predictions of various V-A models for the ratio of neutral to charged current elastic cross-sections Rsup(antiν) are given. The experimental set-up, the scanning criteria and the program of reconstruction are described. The background due to the contamination by the reaction np→np principally is studied. Cuts are defined to resorbe these backgrounds and corrections are made for other backgrounds and losses. The results are compared with those of the reaction antiνsub(μ)p→μ + n and the ratio Rsup(antiν) is calculated. An upper limit of this ratio is given and the results are discussed [fr

Spheromak Impedance and Current Amplification

International Nuclear Information System (INIS)

Fowler, T K; Hua, D D; Stallard, B W

2002-01-01

It is shown that high current amplification can be achieved only by injecting helicity on the timescale for reconnection, τ REC , which determines the effective impedance of the spheromak. An approximate equation for current amplification is: dI TOR 2 /dt ∼ I 2 /τ REC - I TOR 2 /τ closed where I is the gun current, I TOR is the spheromak toroidal current and τ CLOSED is the ohmic decay time of the spheromak. Achieving high current amplification, I TOR >> I, requires τ REC CLOSED . For resistive reconnection, this requires reconnection in a cold zone feeding helicity into a hot zone. Here we propose an impedance model based on these ideas in a form that can be implemented in the Corsica-based helicity transport code. The most important feature of the model is the possibility that τ REC actually increases as the spheromak temperature increases, perhaps accounting for the ''voltage sag'' observed in some experiments, and a tendency toward a constant ratio of field to current, B ∝ I, or I TOR ∼ I. Program implications are discussed

Enhancing LVRT of DFIG by Using a Superconducting Current Limiter on Rotor Circuit

Directory of Open Access Journals (Sweden)

Flávio Oliveira

2015-12-01

Full Text Available This paper have studied the dynamic of a 2.0 MW Doubly Fed Induction Generator (DFIG during a severe voltage sag. Using the dynamic model of a DFIG, it was possible to determine the current, Electromagnetic Force and flux behavior during three-phase symmetrical voltage dip. Among the technologies of wind turbines the DFIG is widely employed; however, this machine is extremely susceptible to disturbances from the grid. In order to improve DFIG Low Voltage Ride-Through (LVRT, it is proposed a novel solution, using Superconducting Current Limiter (SCL in two arrangements: one, the SCL is placed between the machine rotor and the rotor side converter (RSC, and another placed in the RSC DC-link. The proposal is validated through simulation using PSCAD™/EMTDC™ and according to requirements of specific regulations. The analysis ensure that both SCL arrangements behave likewise, and are effective in decrement the rotor currents during the disturbance.

75 FR 1608 - Proposed Information Collection; Comment Request

Science.gov (United States)

2010-01-12

..., and the impact of collection requirement on respondents can be properly assessed. Currently, the Corporation is soliciting comments concerning its proposed Stakeholder Assessment of Senior Corps RSVP...-competition beginning in 2013. Completion of the Stakeholder Assessment is required in order for RSVP grantees...

Input-parallel output-parallel (IPOP) three-level (TL) DC/DC converters with minimized capacitor ripple currents

DEFF Research Database (Denmark)

Liu, Dong; Deng, Fujin; Zhang, Qi

2016-01-01

, the component current stresses in the proposed converters are reduced. More significantly, the combination of the proposed IPOP TL circuit structure and the interleaving control strategy can largely reduce the ripple currents on the two input capacitors not only by doubling the frequencies of the ripple...... currents on two input capacitors but also by counteracting part of these ripple currents according to the operation principle of the proposed converters. Therefore, the proposed IPOP TL DC/DC converters with the interleaving control strategy can improve the performances of the converters in increasing...... the lifetimes of the input capacitors and minimizing the sizes of the input capacitors. Finally, the simulation and experimental results are presented to verify the effectiveness and feasibility of the proposed converters combined with the interleaving control strategy....

Articulated System to Analyse Digital Media (ASADM: a proposal about what and how to study online newspapers

Directory of Open Access Journals (Sweden)

Lluís Codina

2014-05-01

Full Text Available Throughout this article, we are presenting a proposal to conduct digital media studies as one of the first deliverables of an ongoing research project. This proposal, which we are calling “Articulated System to Analyse Digital Media” (ASADM: consists of a set of concepts presented through specific terminology, and of a group of articulated elements allowing to determine what we call the what (parameters and how (indicators of any future study regarding online newspapers or digital media. Thus, we obtain an operative analysis protocol as a deliverable. In between, we characterize the typical context of the sort of studies that constitute the context for our proposal.

76 FR 59706 - Proposed Collection; Comment Request; Healthy Communities Study: How Communities Shape Children's...

Science.gov (United States)

2011-09-27

... published in scientific journals and will be used for the development of future research initiatives... Request; Healthy Communities Study: How Communities Shape Children's Health (HCS) SUMMARY: Under the... control number. Proposed Collection: Title: Healthy Communities Study: How Communities Shape Children's...

Benefit analysis of proposed information systems

OpenAIRE

Besore, Mark H.

1991-01-01

Approved for public release; distribution is unlimited This thesis reviewed two different approaches to benefit analysis, benefit comparison and user satisfaction, that could be applied to the evaluation of proposed information systems which are under consideration for acquisition by the federal government. Currently the General Services Administration only recommends that present value analysis methods be used in the analysis of alternatives even though the GSA specifies...

77 FR 58510 - Proposed Information Collection; Comment Request; Current Population Survey (CPS), Annual Social...

Science.gov (United States)

2012-09-21

... various population groups. A prime statistic of interest is the classification of people in poverty and... Information Collection; Comment Request; Current Population Survey (CPS), Annual Social and Economic... conducted this supplement annually for over 50 years. The Census Bureau and the Bureau of Labor Statistics...

Perceptions of employers and unemployed youth on the proposed youth employment wage subsidy incentive in South Africa: A KwaZulu-Natal study

Directory of Open Access Journals (Sweden)

Vuyokazi N. Mtembu

2015-06-01

Full Text Available Orientation: South Africa has high levels of unemployment and severe problem of youth unemployment. This implies that the country requires a comprehensive strategy to create more jobs for the youth. Policymaking is one of the strategies that have been introduced to encourage job creation for the youth. The youth wage subsidy is just one of the strategies proposed and this article unpacks what employers and unemployed youth say and think about this policy directive. Research purpose: The main aim of the study was to determine the perceptions of unemployed South African youth and employers on the proposed youth wage subsidy incentive scheme. Motivation for the study: Youth unemployment is a very important issue and the reality is that it is a concern of every government globally. South Africa is therefore not an exception as it is a country that has been experiencing high levels of youth unemployment for the last few decades. In an attempt to curb this pressing challenge of youth unemployment, a proposal to introduce a youth wage subsidy policy was made by government; (since its mention, this idea has been met with a lot of opposing opinions from those against it and applause from those who support it. This has motivated this study to probe the perceptions of the subsidy by those who will be affected by its provisions. Method: A triangulated research approach was adopted through the administration of survey questionnaires amongst the unemployed youth and semi-structured interviews with human resource managers and specialists. A sample of unemployed youth was drawn from selected communities within KwaZulu-Natal. In addition, semi-structured interviews were conducted with human resource managers and specialists at selected organisations to determine their perceptions of the proposed scheme and any benefits or limitations they believe it might have. Non-probability sampling was used to sample 100 respondents (N = 100, 90% of whom were unemployed

Proposal of leak path passivation for InGaN solar cells to reduce the leakage current

Energy Technology Data Exchange (ETDEWEB)

Wang, Ke, E-mail: ke.wang@chiba-u.jp; Imai, Daichi; Kusakabe, Kazuhide [Center for SMART Green Innovation Research, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Yoshikawa, Akihiko, E-mail: yoshi@faculty.chiba-u.jp [Center for SMART Green Innovation Research, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Department of Information and Communication Engineering, Graduate School of Engineering, Kogakuin University, Nakano-cho, Hachioji, Tokyo 2665-1 (Japan)

2016-01-25

We propose some general ways to passivate the leak paths in InGaN solar cells and report some experimental evidences of its effectiveness. By adopting an AlOx passivation process, the photovoltaic performances of GaN pn-junctions and InGaN solar cells, grown by molecular beam epitaxy, have been significantly improved. The open circuit voltage under 1 sun illumination increases from 1.46 to 2.26 V for a GaN pn junction, and from 0.95 to 1.27 V for an InGaN solar cell, demonstrating evidence of leak path passivation (LPP) by AlOx. The proposed LPP is expected to be a realistic way to exploit the potential of thick and relaxed but defective InGaN for solar cell applications.

On current contribution to Fronsdal equations

Science.gov (United States)

Misuna, N. G.

2018-03-01

We explore a local form of second-order Vasiliev equations proposed in [arxiv:arXiv:1706.03718] and obtain an explicit expression for quadratic corrections to bosonic Fronsdal equations, generated by gauge-invariant higher-spin currents. Our analysis is performed for general phase factor, and for the case of parity-invariant theory we find the agreement with expressions for cubic vertices available in the literature. This provides an additional indication that local frame proposed in [arxiv:arXiv:1706.03718] is the proper one.

Current food classifications in epidemiological studies do not enable solid nutritional recommendations for preventing diet-related chronic diseases: the impact of food processing.

Science.gov (United States)

Fardet, Anthony; Rock, Edmond; Bassama, Joseph; Bohuon, Philippe; Prabhasankar, Pichan; Monteiro, Carlos; Moubarac, Jean-Claude; Achir, Nawel

2015-11-01

To date, observational studies in nutrition have categorized foods into groups such as dairy, cereals, fruits, and vegetables. However, the strength of the association between food groups and chronic diseases is far from convincing. In most international expert surveys, risks are most commonly scored as probable, limited, or insufficient rather than convincing. In this position paper, we hypothesize that current food classifications based on botanical or animal origins can be improved to yield solid recommendations. We propose using a food classification that employs food processes to rank foods in epidemiological studies. Indeed, food health potential results from both nutrient density and food structure (i.e., the matrix effect), both of which can potentially be positively or negatively modified by processing. For example, cereal-based foods may be more or less refined, fractionated, and recombined with added salt, sugars, and fats, yielding a panoply of products with very different nutritional values. The same is true for other food groups. Finally, we propose that from a nutritional perspective, food processing will be an important issue to consider in the coming years, particularly in terms of strengthening the links between food and health and for proposing improved nutritional recommendations or actions. © 2015 American Society for Nutrition.

A Proposal for Public and Private Partnership in Extension.

Science.gov (United States)

Krell, Rayda K; Fisher, Marc L; Steffey, Kevin L

2016-01-01

Public funding for Extension in the United States has been decreasing for many years, but farmers' need for robust information on which to make management decisions has not diminished. The current Extension funding challenges provide motivation to explore a different model for developing and delivering extension. The private sector has partnered with the public sector to fund and conduct agricultural research, but partnering on extension delivery has occurred far less frequently. The fundamental academic strength and established Extension network of the public sector combined with the ability of the private sector to encourage and deliver practical, implementable solutions has the potential to provide measurable benefits to farmers. This paper describes the current Extension climate, presents data from a survey about Extension and industry relationships, presents case studies of successful public- and private-sector extension partnerships, and proposes a framework for evaluating the state of effective partnerships. Synergistic public-private extension efforts could ensure that farmers receive the most current and balanced information available to help with their management decisions.

Studies of micromorphology and current efficiency of zinc electrodeposited from flowing chloride electrolytes

Energy Technology Data Exchange (ETDEWEB)

Mc Vay, Laura [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States); Tobias, Charles W. [Univ. of California, Berkeley, CA (United States)

1986-05-01

Results of a study of the micromorphology and current efficiency of zinc electrodeposited from flowing, acidic chloride solutions are reported. The effects of six variables were examined: flow rate, current density, zinc and hydrogen ion concentration, concentrations of nickel, iron and cadmium impurity ions, and the nature of the substrate. The development of micromorphology was studied in-situ by means of videomicrography and ex-situ by means of scanning electron microscopy. This investigation focused on the formation of grooved deposits, which are found under a wide range of deposition conditions. The major conclusions of this study are: the most important variable determining whether grooved deposits form is the interfacial concentration; large protrusions orient themselves parallel to the flow direction with the orientation starting upstream and progressing downstream; large protrusions become ridges due to growth of the highest current density portions of the electrode under mass transport control. The current efficiency was measured using EDTA titration and weight measurements. The fraction of the current taken by zinc deposition increased with zinc concentration, ranging up to 100%, and decreased with pH. The efficiency of zinc deposition was affected by the flow rate and the substrate employed. Impurities lowered the current efficiency.

78 FR 67342 - Proposed Information Collection; Comment Request

Science.gov (United States)

2013-11-12

... proposed Retired and Senior Volunteer Program Survey. The survey will be administered to a sample of current RSVP volunteers to assess the distribution of volunteers across work plans, volunteer time... volunteers by work areas to assess volunteer activity with regard to performance measurement requirements...

Examining the Proposed Disruptive Mood Dysregulation Disorder Diagnosis in Children in the Longitudinal Assessment of Manic Symptoms Study

Science.gov (United States)

Axelson, David; Findling, Robert L.; Fristad, Mary A.; Kowatch, Robert A.; Youngstrom, Eric A.; Horwitz, Sarah McCue; Arnold, L. Eugene; Frazier, Thomas W.; Ryan, Neal; Demeter, Christine; Gill, Mary Kay; Hauser-Harrington, Jessica C.; Depew, Judith; Kennedy, Shawn M.; Gron, Brittany A.; Rowles, Brieana M.; Birmaher, Boris

2013-01-01

Objective To examine the proposed disruptive mood dysregulation disorder (DMDD) diagnosis in a child psychiatric outpatient population. Evaluation of DMDD included 4 domains: clinical phenomenology, delimitation from other diagnoses, longitudinal stability, and association with parental psychiatric disorders. Method Data were obtained from 706 children aged 6–12 years who participated in the Longitudinal Assessment of Manic Symptoms (LAMS) study (sample was accrued from November 2005 to November 2008). DSM-IV criteria were used, and assessments, which included diagnostic, symptomatic, and functional measures, were performed at intake and at 12 and 24 months of follow-up. For the current post hoc analyses, a retrospective diagnosis of DMDD was constructed using items from the K-SADS-PL-W, a version of the Schedule for Affective Disorders and Schizophrenia for School-Age Children, which resulted in criteria closely matching the proposed DSM-5 criteria for DMDD. Results At intake, 26% of participants met the operational DMDD criteria. DMDD+ vs DMDD– participants had higher rates of oppositional defiant disorder (relative risk [RR] = 3.9, P conduct disorder (RR = 4.5, P oppositional defiant disorder (rate and symptom severity P values conduct disorder (rate, P disorders or in severity of inattentive, hyperactive, manic, depressive, or anxiety symptoms. Most of the participants with oppositional defiant disorder (58%) or conduct disorder (61%) met DMDD criteria, but those who were DMDD+ vs DMDD– did not differ in diagnostic comorbidity, symptom severity, or functional impairment. Over 2-year follow-up, 40% of the LAMS sample met DMDD criteria at least once, but 52% of these participants met criteria at only 1 assessment. DMDD was not associated with new onset of mood or anxiety disorders or with parental psychiatric history. Conclusions In this clinical sample, DMDD could not be delimited from oppositional defiant disorder and conduct disorder, had limited

Licensing of the proposed PBMR-SA

International Nuclear Information System (INIS)

Clapisson, G.A.; Henderson, N.R.; Hill, T.F.; Keenan, N.H.; Metcalf, P.E.; Mysenkov, A.

1997-01-01

This paper describes the preliminary criteria, which are intended to be used by the South African regulatory authority (CNS), for licensing of the ESKOM proposed - South African high temperature gas-cooled Pebble Bed Modular Reactor (PBMR-SA). The CNS intends to apply the existing CNS licensing approach together with some international design criteria used for advanced reactors as well as international experience gained from the safety evaluation of the MHTGR, THTR, etc. A major requirement to this type of reactor is that it should comply with the current CNS risk criteria and provide, as a minimum, the same degree of protection to the operator, public and environment that is required for the current generation of nuclear reactors. (author)

Hadronic currents in the infinite momentum frame

International Nuclear Information System (INIS)

Toth, K.

1975-01-01

The problem of the transformation properties of hadronic currents in the infinite momentum frame (IMF) is investigated. A general method is proposed to deal with the problem which is based upon the concept of group contraction. The two-dimensional aspects of the IMF description are studied in detail, and the current matrix elements of a three-dimensional Poincare covariant theory are reduced to those of a two-dimensional one. It is explicitlyshown that the covariance group of the two-dimensional theory may either be a 'non-relativistic' (Galilei) group, or a 'relativistic' (Poincare) one depending on the value of a parameter reminiscent of the light velocity in the three-dimensional theory. The value of this parameter cannot be determined by kinematical argument. These results offer a natural generalization of models which assume Galilean symmetry in the infinite momentum frame

Misophonia: current perspectives

Directory of Open Access Journals (Sweden)

Cavanna AE

2015-08-01

Full Text Available Andrea E Cavanna,1–3 Stefano Seri3,4 1Department of Neuropsychiatry, Birmingham and Solihull Mental Health NHS Foundation Trust and University of Birmingham, Birmingham, 2Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, 3School of Life and Health Sciences, Aston Brain Centre, Wellcome Trust Laboratory for MEG Studies, Aston University, 4Children’s Epilepsy Surgery Programme, The Birmingham Children’s Hospital NHS Foundation Trust, Birmingham, UK Abstract: Misophonia is characterized by a negative reaction to a sound with a specific pattern and meaning to a given individual. In this paper, we review the clinical features of this relatively common yet underinvestigated condition, with focus on co-occurring neurodevelopmental disorders. Currently available data on the putative pathophysiology of the condition can inform our understanding and guide the diagnostic process and treatment approach. Tinnitus retraining therapy and cognitive behavior therapy have been proposed as the most effective treatment strategies for reducing symptoms; however, current treatment algorithms should be validated in large population studies. At the present stage, competing paradigms see misophonia as a physiological state potentially inducible in any subject, an idiopathic condition (which can present with comorbid psychiatric disorders, or a symptomatic manifestation of an underlying psychiatric disorder. Agreement on the use of standardized diagnostic criteria would be an important step forward in terms of both clinical practice and scientific inquiry. Areas for future research include phenomenology, epidemiology, modulating factors, neurophysiological underpinnings, and treatment trials. Keywords: misophonia, selective sound sensitivity syndrome, hyperacusis, neurodevelopmental disorders, Tourette syndrome, obsessive-compulsive spectrum

Dynamic range of low-voltage cascode current mirrors

DEFF Research Database (Denmark)

Bruun, Erik; Shah, Peter Jivan

1995-01-01

Low-voltage cascode current mirrors are reviewed with respect to the design limitations imposed if all transistors in the mirror are required to operate in the saturation region. It is found that both a lower limit and an upper limit exist for the cascode transistor bias voltage. Further, the use....... The proposed configuration has the advantage of simplicity combined with a complete elimination of the need for fixed bias voltages or bias currents in the current mirror. A disadvantage is that it requires a higher input voltage to the current mirror...

76 FR 32992 - National Endowment for the Arts; Proposed Collection; Comment Request

Science.gov (United States)

2011-06-07

... NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES National Endowment for the Arts; Proposed Collection; Comment Request ACTION: Notice. SUMMARY: The National Endowment for the Arts (NEA), as part of.... Currently, the NEA is soliciting comments concerning the proposed information collection on the motivation...

Permanent spin currents in cavity-qubit systems

Science.gov (United States)

Kulkarni, Manas; Hein, Sven M.; Kapit, Eliot; Aron, Camille

2018-02-01

In a recent experiment [P. Roushan et al., Nat. Phys. 13, 146 (2017), 10.1038/nphys3930], a spin current in an architecture of three superconducting qubits was produced during a few microseconds by creating synthetic magnetic fields. The lifetime of the current was set by the typical dissipative mechanisms that occur in those systems. We propose a scheme for the generation of permanent currents, even in the presence of such imperfections, and scalable to larger system sizes. It relies on striking a subtle balance between multiple nonequilibrium drives and the dissipation mechanisms, in order to engineer and stimulate chiral excited states which can carry current.

Threshold current for fireball generation

Science.gov (United States)

Dijkhuis, Geert C.

1982-05-01

Fireball generation from a high-intensity circuit breaker arc is interpreted here as a quantum-mechanical phenomenon caused by severe cooling of electrode material evaporating from contact surfaces. According to the proposed mechanism, quantum effects appear in the arc plasma when the radius of one magnetic flux quantum inside solid electrode material has shrunk to one London penetration length. A formula derived for the threshold discharge current preceding fireball generation is found compatible with data reported by Silberg. This formula predicts linear scaling of the threshold current with the circuit breaker's electrode radius and concentration of conduction electrons.

Study on pulsed current cathodic protection in a simulated system

Energy Technology Data Exchange (ETDEWEB)

Yan, Milin; Li, Helin [Xi' an Jiao Tong Universitiy (China)]|[Tubular Goods Research Center of China National Petroleum Corp. (China); Qiu, Yubing; Guo, Xingpeng [Hua Zhong University of Science and Techonology (China)

2004-07-01

The pulsed current cathodic protection (PCCP) is a new cathodic protection (CP) technology and shows more advantages over the conventional DC cathodic protection (DCCP) in oil well casing system. However, little information about PCCP is reported. In this research, a simulated CP system was set up in a pool of 3.5 m x 2.0 m x 3.0 m size, in which the effects of the square wave pulsed current (SWPC) parameters (amplitude: IA, frequency: f, duty cycle: P), auxiliary anode distance (d) and media conductivity ({mu}) on the cathodic potential (E) distribution were studied, and the protection effects of PCCP and DCCP were compared. The results show that with increase of the square wave parameters (IA, f, P), the E distribution becomes more negative and the effects of each current parameter are relate closely to the cathode polarizing state. Only with suitable square wave parameters can the whole cathode be effectively protected. With increase of d and {mu}, the E distribution becomes more uniform. Compared with DCCP system, PCCP system has much more uniform E distribution, costs less average current, and gains much better protection effects. Further, the mechanism of PCCP was analyzed. (authors)

Current control of light by nonreciprocal magnetoplasmonics

Energy Technology Data Exchange (ETDEWEB)

Gong, Yongkang, E-mail: yongkang.gong@southwales.ac.uk; Li, Kang; Carver, Sara; Martinez, Juan Jose; Huang, Jungang; Copner, Nigel [Wireless and Optoelectronics Research and Innovation Centre (WORIC), Faculty of Computing, Engineering and Science, University of South Wales, Cardiff CF37 1DL (United Kingdom); Thueux, Yoann; Avlonitis, Nick [Airbus Group Innovations, Quadrant House, Celtic Springs, Coedkernew, NP10 8FZ Newport (United Kingdom)

2015-05-11

The ability to actively control light has long been a major scientific and technological goal. We proposed a scheme that allows for active control of light by utilizing the nonreciprocal magnetoplasmonic effect. As a proof of concept, we applied current signal through an ultrathin metallic film in a magneto-plasmonic multilayer and found that dynamic photonic nonreciprocity appears in magnetic-optical material layer due to the magnetic field being induced from current signal and modulates surface plasmon polaritons trapped in the metal surface and the light reflected. The proposed concept provides a possible way for the active control of light and could find potential applications such as ultrafast optoelectronic signal processing for plasmonic nanocircuit technology and ultrafast/large-aperture free-space electro-optic modulation platform for wireless laser communication technology.

Study on Nanostructures Induced by High-Current Pulsed Electron Beam

Directory of Open Access Journals (Sweden)

Bo Gao

2012-01-01

Full Text Available Four techniques using high-current pulsed electron beam (HCPEB were proposed to obtain surface nanostructure of metal and alloys. The first method involves the distribution of several fine Mg nanoparticles on the top surface of treated samples by evaporation of pure Mg with low boiling point. The second technique uses superfast heating, melting, and cooling induced by HCPEB irradiation to refine the primary phase or the second phase in alloys to nanosized uniform distributed phases in the matrix, such as the quasicrystal phase Mg30Zn60Y10 in the quasicrystal alloy Mg67Zn30Y3. The third technique involves the refinement of eutectic silicon phase in hypereutectic Al-15Si alloys to fine particles with the size of several nanometers through solid solution and precipitation refinement. Finally, in the deformation zone induced by HCPEB irradiation, the grain size can be refined to several hundred nanometers, such as the grain size of the hypereutectic Al-15Si alloys in the deformation zone, which can reach ~400 nm after HCPEB treatment for 25 pulses. Therefore, HCPEB technology is an efficient way to obtain surface nanostructure.

A Numerical Modeling for Study Marine Current in the Manado Bay, North Sulawesi

Directory of Open Access Journals (Sweden)

Parabelem Tinno Dolf Rompas

2018-02-01

Full Text Available This study is investigating about marine currents provided electrical energy through the numerical model. The objective of this study is to know the available power distributions in the Manado Bay, North Sulawesi, Indonesia. The Manado Bay was width 2200 m with 79 m of depth. In computation, we are made grids in x and y horizontal were 7 m respectively, also for z vertical of four layers. The results shown that the available power distributions in the Manado Bay at 0.1 Sv were 0.00-20.00 kW/m2 when low tide currents and when high tide currents were 0.00-105 kW/m2. The values will enable for marine currents power plant in the Manado Bay to future.

Current Mathematical Methods Used in QSAR/QSPR Studies

Directory of Open Access Journals (Sweden)

Peixun Liu

2009-04-01

Full Text Available This paper gives an overview of the mathematical methods currently used in quantitative structure-activity/property relationship (QASR/QSPR studies. Recently, the mathematical methods applied to the regression of QASR/QSPR models are developing very fast, and new methods, such as Gene Expression Programming (GEP, Project Pursuit Regression (PPR and Local Lazy Regression (LLR have appeared on the QASR/QSPR stage. At the same time, the earlier methods, including Multiple Linear Regression (MLR, Partial Least Squares (PLS, Neural Networks (NN, Support Vector Machine (SVM and so on, are being upgraded to improve their performance in QASR/QSPR studies. These new and upgraded methods and algorithms are described in detail, and their advantages and disadvantages are evaluated and discussed, to show their application potential in QASR/QSPR studies in the future.

Proposed Hydro-Quebec development plan, 1993: Proposal

International Nuclear Information System (INIS)

1992-01-01

The Quebec government now requires Hydro-Quebec to submit a development plan every three years instead of annually, in order to permit more in-depth studies and a broader consultation with interested parties. In the first of such three-year plans, a series of plan proposals is presented which was developed after a year of consultation with various groups on four fundamental matters: energy efficiency, means of generation, electro-intensive industries, and electricity exports. Options for meeting future demand at Hydro-Quebec are assessed, including the construction of new generation and transmission facilities, rehabilitation of existing facilities, improving electrical energy efficiency, and conservation strategies. These options are considered while applying the principle of sustainable development that respects the environment. Hydroelectricity will continue to be emphasized as the main source of generation since hydroelectric facilities offer distinct advantages in terms of costs, environmental impacts, and economic spinoffs. The proposed plan also presents objectives and strategies for improving the quality of service and internal operations. Financial forecasts for Hydro-Quebec are proposed which take into account the forecast changes in the utility's cost and revenue factors and its self-financing requirements. 5 figs., 15 tabs

Trend of environmental radiation protection and its current related studies

International Nuclear Information System (INIS)

Yoshida, Satoshi

2011-01-01

Reviewed are the international trend of environmental radiation protection (ERP), Japanese studies of radiation effects on environmental livings from aspects of ecosystem to molecular level, and the future view. ERP is particularly closed up toward promotion after its first involvement in the general global conference, UN Conference on Environment and Development (1992). International Commission of Radiological Protection (ICRP) has conducted such actions for the environment as establishing protection essentials for non-human species (2003), organizing Committee 5 (2005), and defining Reference Animals and Plants (2008) where Derived Consideration Reference Levels of 0.1-100 mGy/d are proposed, together with cooperative actions by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), International Atomic Energy Agency (IAEA), The Organization for Economic Co-operation and Development (OECD)/Nuclear Energy Agency (NEA) and European projects. Japanese NIRS is now enrolled in the project of Environmental Modeling for Radiation Safety-II (IAEA). Major Japanese studies of radiation effects on environmental livings have utilized killifish (medaka: Oryzias latipes), springtail, earthworm, nematode, cultured plant cell (cedar), poplar, etc. Studies of the radiation effect on microcosm consisting of 3 livings have led to establishing a model for mathematical analysis and of 8 livings, have defined 50% affect dose of 5600 Gy gamma-ray. Irradiation of gamma-ray at 1 Gy/d for 5-10 days to the soil has been shown to result in alteration of the composition of natural earth bacterial population by denaturant gradient gel electrophoresis, which being a promising tool for evaluating the alteration of soil composition and function. At molecular levels, transcriptome analysis of various cells from yeast to man, is performed after irradiation of gamma-ray, neutron, heavy particles and others to reveal radiation-induced gene expression; and Hi-CEP (high

An improved current control scheme for grid-connected DG unit based distribution system harmonic compensation

DEFF Research Database (Denmark)

He, Jinwei; Wei Li, Yun; Wang, Xiongfei

2013-01-01

In order to utilize DG unit interfacing converters to actively compensate distribution system harmonics, this paper proposes an enhanced current control approach. It seamlessly integrates system harmonic mitigation capabilities with the primary DG power generation function. As the proposed current...... controller has two well decoupled control branches to independently control fundamental and harmonic DG currents, phase-locked loops (PLL) and system harmonic component extractions can be avoided during system harmonic compensation. Moreover, a closed-loop power control scheme is also employed to derive...... the fundamental current reference. The proposed power control scheme effectively eliminates the impacts of steady-state fundamental current tracking errors in the DG units. Thus, an accurate power control is realized even when the harmonic compensation functions are activated. Experimental results from a single...

Experimental study of a high-current FEM with a broadband microwave system

Energy Technology Data Exchange (ETDEWEB)

Denisov, G.G.; Bratman, V.L.; Ginzburg, N.S. [Institute of Applied Physics, Nizhny Novgorod (Russian Federation)] [and others

1995-12-31

One of the main features of FELs and FEMs is the possibility of fast and wideband tuning of the resonant frequency of active media, which can be provided by changing the particle energy. For a frequency adjustable FEM-oscillator, a broadband microwave system, which is simply combined with an electron-optical FEM system and consists of an oversized waveguide and reflectors based on the microwave beams multiplication effect has been proposed and studied successfully in {open_quotes}cold{close_quotes} measurements. Here, the operating ability of a cavity, that includes some key elements of the broadband microwave system, was tested in the presence of an electron beam. To provide large particle oscillation velocities in a moderate undulator field and the presence of a guide magnetic field, the FEM operating regime of double resonance was chosen. In this regime the cyclotron as well as undulator resonance conditions were satisfied. The FEM-oscillator was investigated experimentally on a high-current accelerator {open_quotes}Sinus-6{close_quotes} that forms an electron beam with particle energy 500keV and pulse duration 25ns. The aperture with a diameter 2.5mm at the center of the anode allows to pass through only the central fraction of the electron beam with a current about 100A and a small spread of longitudinal velocities of the particles. Operating transverse velocity was pumped into the electron beam in the pulse plane undulator of a 2.4cm period. The cavity with a frequency near 45GHz consists of a square waveguide and two reflectors. The broadband up-stream reflector based on the multiplication effect had the power reflectivity coefficient more than 90% in the frequency band 10% for the H{sup 10} wave of the square waveguide with the maximum about 100% at a frequency 45GHz. The down-stream narrow-band Bragg reflector had the power reflection coefficient approximately 80% in the frequency band of 4% near 45GHz for the operating mode.

Current status of studies on temperature fluctuation phenomena in LMFRs

International Nuclear Information System (INIS)

Ohshima, H.; Muramatsu, T.; Kobayashi, J.; Yamaguchi, A.

1994-01-01

This paper describes the current status of studies being performed in PNC on temperature fluctuation phenomena occurring in fast reactors. The studies concentrate on four problems: thermal stratification, thermal striping, core-plenum interaction and free surface sloshing. Both experimental and analytical approaches to reveal these phenomena and to establish design and safety evaluation methods are presented together with future works. (author)

An Analysis of Proposed and Current Regulations Concerning Lobbying Costs in Department of Defense Contracts.

Science.gov (United States)

1984-06-01

a reduction in industry participation in the defense mobilization base, and a limiting of capital available for investment in producti- vity...FAR proposals, it appears that this stratgy has b-2n successful to a large degree. Thor,-, ar , how-vr, still areas where critics believe that further...appropriations. Lobbying includes but is not limited to personal discussions or conferences, advertising , sending tel- egrams, engaging in telephonic

Current Directional Protection of Series Compensated Line Using Intelligent Classifier

Directory of Open Access Journals (Sweden)

M. Mollanezhad Heydarabadi

2016-12-01

Full Text Available Current inversion condition leads to incorrect operation of current based directional relay in power system with series compensated device. Application of the intelligent system for fault direction classification has been suggested in this paper. A new current directional protection scheme based on intelligent classifier is proposed for the series compensated line. The proposed classifier uses only half cycle of pre-fault and post fault current samples at relay location to feed the classifier. A lot of forward and backward fault simulations under different system conditions upon a transmission line with a fixed series capacitor are carried out using PSCAD/EMTDC software. The applicability of decision tree (DT, probabilistic neural network (PNN and support vector machine (SVM are investigated using simulated data under different system conditions. The performance comparison of the classifiers indicates that the SVM is a best suitable classifier for fault direction discriminating. The backward faults can be accurately distinguished from forward faults even under current inversion without require to detect of the current inversion condition.

Study and Evaluation of Current and Future Aircraft Loaders

Science.gov (United States)

1986-08-01

detonation intense Electromagnetic Pulse Eergy (DIP) is gene - rated which could seriously affect the electronic equipment. 2-105 The intense...speciality efforts, such as integrated logistics support (ILS), human factors engineering ( HFE ), and reliability, availability and m aintainability...task analyiis is outlined in detail in Appendix C: Human Fac- tors Enqineering Study and Evaluation of Current and Future Aircraft Loaders. The HFE

Natural regeneration in Iberian pines: A review of dynamic processes and proposals for management

Energy Technology Data Exchange (ETDEWEB)

Calama, R.; Manso, R.; Lucas-Borja, M.E.; Espelta, J.M.; Piqué, M.; Bravo, F.; Peso, C. del; Pardos, M.

2017-11-01

Aim of study: Designing adequate silvicultural systems for natural regeneration of a forest species requires sound knowledge of the underlying ecological subprocesses: flowering and fruiting, seed dispersal and predation, seed germination, seedling emergence and seedling survival. The main objective of the present work is to carry out a review on the current knowledge about the different subprocesses governing the regeneration process for the main Iberian Pinus species, in order to propose scientifically based management schedules. Area of study: The review focuses on the five main native Pinus species within their most representative areas in the Iberian Peninsula: Pinus nigra in Cuenca mountains, Pinus sylvestris in Sierra de Guadarrama, Pinus pinaster and Pinus pinea in the Northern Plateau and Pinus halepensis in Catalonia Material and methods: Firstly, currently available information on spatiotemporal dynamics and influential factors is introduced for each subprocess and species. Secondly, current regeneration strategies are characterized and the main bottlenecks are identified. Finally, alternative silvicultural practices proposed on the light of the previous information are presented. Main results: Different climate-mediated bottlenecks have been identified to limit natural regeneration of the Iberian pine species, with seed predation and initial seedling survival among the most influential. New approaches focusing on more gradual regeneration fellings, extended rotation periods, prevent big gaps and program fellings on mast years are presented. Research highlights: Natural regeneration of the studied species exhibit an intermittent temporal pattern, which should be aggravated under drier scenarios. More flexible management schedules should fulfil these limitations.

Natural regeneration in Iberian pines: A review of dynamic processes and proposals for management

International Nuclear Information System (INIS)

Calama, R.; Manso, R.; Lucas-Borja, M.E.; Espelta, J.M.; Piqué, M.; Bravo, F.; Peso, C. del; Pardos, M.

2017-01-01

Aim of study: Designing adequate silvicultural systems for natural regeneration of a forest species requires sound knowledge of the underlying ecological subprocesses: flowering and fruiting, seed dispersal and predation, seed germination, seedling emergence and seedling survival. The main objective of the present work is to carry out a review on the current knowledge about the different subprocesses governing the regeneration process for the main Iberian Pinus species, in order to propose scientifically based management schedules. Area of study: The review focuses on the five main native Pinus species within their most representative areas in the Iberian Peninsula: Pinus nigra in Cuenca mountains, Pinus sylvestris in Sierra de Guadarrama, Pinus pinaster and Pinus pinea in the Northern Plateau and Pinus halepensis in Catalonia Material and methods: Firstly, currently available information on spatiotemporal dynamics and influential factors is introduced for each subprocess and species. Secondly, current regeneration strategies are characterized and the main bottlenecks are identified. Finally, alternative silvicultural practices proposed on the light of the previous information are presented. Main results: Different climate-mediated bottlenecks have been identified to limit natural regeneration of the Iberian pine species, with seed predation and initial seedling survival among the most influential. New approaches focusing on more gradual regeneration fellings, extended rotation periods, prevent big gaps and program fellings on mast years are presented. Research highlights: Natural regeneration of the studied species exhibit an intermittent temporal pattern, which should be aggravated under drier scenarios. More flexible management schedules should fulfil these limitations.

APC-PC Combined Scheme in Gilbert Two State Model: Proposal and Study

Science.gov (United States)

Bulo, Yaka; Saring, Yang; Bhunia, Chandan Tilak

2017-04-01

In an automatic repeat request (ARQ) scheme, a packet is retransmitted if it gets corrupted due to transmission errors caused by the channel. However, an erroneous packet may contain both erroneous bits and correct bits and hence it may still contain useful information. The receiver may be able to combine this information from multiple erroneous copies to recover the correct packet. Packet combining (PC) is a simple and elegant scheme of error correction in transmitted packet, in which two received copies are XORed to obtain the bit location of erroneous bits. Thereafter, the packet is corrected by bit inversion of bit located as erroneous. Aggressive packet combining (APC) is a logic extension of PC primarily designed for wireless communication with objective of correcting error with low latency. PC offers higher throughput than APC, but PC does not correct double bit errors if occur in same bit location of erroneous copies of the packet. A hybrid technique is proposed to utilize the advantages of both APC and PC while attempting to remove the limitation of both. In the proposed technique, applications of APC-PC on Gilbert two state model has been studied. The simulation results show that the proposed technique offers better throughput than the conventional APC and lesser packet error rate than PC scheme.

Determining the Frequency for Load-Independent Output Current in Three-Coil Wireless Power Transfer System

Directory of Open Access Journals (Sweden)

Longzhao Sun

2015-09-01

Full Text Available Conditions for load-independent output voltage or current in two-coil wireless power transfer (WPT systems have been studied. However, analysis of load-independent output current in three-coil WPT system is still lacking in previous studies. This paper investigates the output current characteristics of a three-coil WPT system against load variations, and determines the operating frequency to achieve a constant output current. First, a three-coil WPT system is modeled by circuit theory, and the analytical expression of the root-mean-square of the output current is derived. By substituting the coupling coefficients, the quality factor, and the resonant frequency of each coil, we propose a method of calculating the frequency for load-independent output current in a three-coil WPT system, which indicates that there are two frequencies that can achieve load-independent output current. Experiments are conducted to validate these analytical results.

New Gain Controllable Resistor-less Current-mode First Order Allpass Filter and its Application

Directory of Open Access Journals (Sweden)

W. Jaikla

2012-04-01

Full Text Available New first order allpass filter (APF in current mode, constructed from 2 CCCCTAs and grounded capacitor, is presented. The current gain and phase shift can be electronically /orthogonally controlled. Low input and high output impedances are achieved which make the circuit to be easily cascaded to the current-mode circuit without additional current buffers. The operation of the proposed filter has been verified through simulation results which confirm the theoretical analysis. The application example as current-mode quadrature oscillator with non-interactive current control for both of oscillation condition and oscillation frequency is included to show the usability of the proposed filter.

A Novel DBC Layout for Current Imbalance Mitigation in SiC MOSFET Multichip Power Modules

DEFF Research Database (Denmark)

Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon

2016-01-01

This paper proposes a novel Direct Bonded Copper (DBC) layout for mitigating the current imbalance among the paralleled SiC MOSFET dies in multichip power modules. Compared to the traditional layout, the proposed DBC layout significantly reduces the circuit mismatch and current coupling effect......, which consequently improves the current sharing among the paralleled SiC MOSFET dies in power module. Mathematic analysis and circuit model of the DBC layout are presented to elaborate on the superior features of the proposed DBC layout. Simulation and experimental results further verify the theoretical...

Power demand operation - environment and potential. Proposals for main project

International Nuclear Information System (INIS)

Wathne, M.

1995-01-01

This report discusses proposals for a main project on environmental and other problems arising when hydroelectric power stations supply energy at gigawatt levels. The project aims in particular to identify environmental problems where too little is known today for proper planning of this type of operation. The proposals emphasize the consequences which cannot be adequately analysed in terms of current techniques. These techniques presuppose steady state conditions. One proposal concerns market terms for power sales. Other proposals deal with hydrological data and uncertainty, capacity of watercourses, ice and temperature, aquatic eco-systems, erosion, supersaturation of water with air, flooding and dam breaks, impact on climate, inflow of fresh water in fjords and impact on algae. 33 refs., 4 tabs

A Comparative Study of Current and Potential Users of Mobile Payment Services

Directory of Open Access Journals (Sweden)

Chanchai Phonthanukitithaworn

2016-11-01

Full Text Available Previous studies of mobile payment (m-payment services have primarily focused on a single group of adopters. This study identifies the factors that influence an individual’s intention to use m-payment services and compares groups of current users (adopters with potential users (non-adopters. A research model that reflects the behavioral intention to use m-payment services is developed and empirically tested using structural equation modeling on a data set consisting of 529 potential users and 256 current users of m-payment services in Thailand. The results show that the factors that influence current users’ intentions to use m-payment services are compatibility, subjective norms, perceived trust, and perceived cost. Subjective norms, compatibility, ease of use, and perceived risk influenced potential users’ intentions to use m-payment. Subjective norms and perceived risk had a stronger influence on potential users, while perceived cost had a stronger influence on current users, in terms of their intentions to use m-payment services. Discussions, limitations, and recommendations for future research are addressed.

A 2D finite element study on the role of material properties on eddy current losses in soft magnetic composites

Science.gov (United States)

Ren, Xiaotao; Corcolle, Romain; Daniel, Laurent

2016-02-01

The use of soft magnetic composites (SMCs) in electrical engineering applications is growing. SMCs provide an effective alternative to laminated steels because they exhibit a high permeability with low eddy current losses. Losses are a critical feature in the design of electrical machines, and it is necessary to evaluate the role of microstructure and constitutive properties of SMCs during the predesign stage. In this paper we propose a simplified finite element approach to compute eddy current losses in these materials. The computations allow to quantify the role of exciting source and material properties on eddy current losses. This analysis can later be used in the development of homogenization models for SMC. Contribution to the topical issue "Numelec 2015 - Elected submissions", edited by Adel Razek

Possible effects of a proposed high-level nuclear waste repository on consumer demand for goods and services produced in the host community. An overview of the Finnish study

International Nuclear Information System (INIS)

Koskinen, I.; Niva, M.; Timonen, P.

1998-12-01

The report provides an overview of a series of reports evaluating the possible impacts of a proposed Finnish high-level nuclear waste (HLNW) repository on consumer behavior and, subsequently, on the host community' s economy. In addition to the overview, the study consists of three parts: Report I reviews the literature on the impacts of analogous industrial facilities; Report II examines the possible reactions of industry and trade, and Report III studies the consumers' risk perceptions in relation to their consuming practices. Theoretically, this series of reports is based on previous research on risk perception, with two modifications. Report II studies products currently available on the consumer market to find out what possibilities the marketplace offers to a consumer interested in environmental risks to act according to his/her risk perception. Report III studies those everyday consuming practices on the basis of which consumers define risks. These two contexts mold the consumer reaction to risks that stem from industrial installations. The proposed HLNW repository benefits the host community in various direct and indirect ways, and may create new opportunities for developing the local economy. The proposed repository may also have negative impacts on the local economy. Food production in particular and, to a lesser extent, tourism might be affected harmfully. Consumer reaction is unlikely to be targeted at other goods produced in the proposed host communities. Under normal conditions (i.e., the repository functions as planned), consumers have fairly few possibilities to identify the products of this community without an extensive search for information, given the structure of the current food market: the proposed communities have few products with specific local identity. Also, fairly few consumers are willing to spend a substantial amount of time for studying the products and their raw materials in detail. Also, consumers are confident that they can manage

Cryogenic Current Comparator for Absolute Measurement of the Dark Current of the Superconducting Cavities for Tesla

CERN Document Server

Knaack, K; Wittenburg, K

2003-01-01

A newly high performance SQUID based measurement system for detecting dark currents, generated by superconducting cavities for TESLA is proposed. It makes use of the Cryogenic Current Comparator principle and senses dark currents in the nA range with a small signal bandwidth of 70 kHz. To reach the maximum possible energy in the TESLA project is a strong motivation to push the gradients of the superconducting cavities closer to the physical limit of 50 MV/m. The field emission of electrons (the so called dark current) of the superconducting cavities at strong fields may limit the maximum gradient. The absolute measurement of the dark current in correlation with the gradient will give a proper value to compare and classify the cavities. This contribution describes a Cryogenic Current Comparator (CCC) as an excellent and useful tool for this purpose. The most important component of the CCC is a high performance DC SQUID system which is able to measure extremely low magnetic fields, e.g. caused by the extracted ...

Multinucleon Ejection Model for Two Body Current Neutrino Interactions

Energy Technology Data Exchange (ETDEWEB)

Sobczyk, Jan T.; /Fermilab

2012-06-01

A model is proposed to describe nucleons ejected from a nucleus as a result of two-body-current neutrino interactions. The model can be easily implemented in Monte Carlo neutrino event generators. Various possibilities to measure the two-body-current contribution are discussed. The model can help identify genuine charge current quasielastic events and allow for a better determination of the systematic error on neutrino energy reconstruction in neutrino oscillation experiments.

A monograph proposing the use of canine mammary tumours as a model for the study of hereditary breast cancer susceptibility genes in humans.

Science.gov (United States)

Goebel, Katie; Merner, Nancy D

2017-05-01

Canines are excellent models for cancer studies due to their similar physiology and genomic sequence to humans, companion status and limited intra-breed heterogeneity. Due to their affliction to mammary cancers, canines can serve as powerful genetic models of hereditary breast cancers. Variants within known human breast cancer susceptibility genes only explain a fraction of familial cases. Thus, further discovery is necessary but such efforts have been thwarted by genetic heterogeneity. Reducing heterogeneity is key, and studying isolated human populations have helped in the endeavour. An alternative is to study dog pedigrees, since artificial selection has resulted in extreme homogeneity. Identifying the genetic predisposition to canine mammary tumours can translate to human discoveries - a strategy currently underutilized. To explore this potential, we reviewed published canine mammary tumour genetic studies and proposed benefits of next generation sequencing canine cohorts to facilitate moving beyond incremental advances.

A review of the quantum current standard

International Nuclear Information System (INIS)

Kaneko, Nobu-Hisa; Nakamura, Shuji; Okazaki, Yuma

2016-01-01

The electric current, voltage, and resistance standards are the most important standards related to electricity and magnetism. Of these three standards, only the ampere, which is the unit of electric current, is an International System of Units (SI) base unit. However, even with modern technology, relatively large uncertainty exists regarding the generation and measurement of current. As a result of various innovative techniques based on nanotechnology and novel materials, new types of junctions for quantum current generation and single-electron current sources have recently been proposed. These newly developed methods are also being used to investigate the consistency of the three quantum electrical effects, i.e. the Josephson, quantum Hall, and single-electron tunneling effects, which are also known as ‘the quantum metrology triangle’. This article describes recent research and related developments regarding current standards and quantum-metrology-triangle experiments. (topical review)

Improving the lattice axial vector current

International Nuclear Information System (INIS)

Horsley, R.; Perlt, H.; Schiller, A.; Zanotti, J.M.

2015-11-01

For Wilson and clover fermions traditional formulations of the axial vector current do not respect the continuum Ward identity which relates the divergence of that current to the pseudoscalar density. Here we propose to use a point-split or one-link axial vector current whose divergence exactly satisfies a lattice Ward identity, involving the pseudoscalar density and a number of irrelevant operators. We check in one-loop lattice perturbation theory with SLiNC fermion and gauge plaquette action that this is indeed the case including order O(a) effects. Including these operators the axial Ward identity remains renormalisation invariant. First preliminary results of a nonperturbative check of the Ward identity are also presented.

Experimental study of anti-tumor activity of direct current

International Nuclear Information System (INIS)

Ito, Hisao; Hashimoto, Shozo

1989-01-01

The anti-tumor activity of direct current combined with radiation was studied. The experiments were performed with fibrosarcomas (FSA, NFSA) syngenetic to C3H mice. Direct current (0.6mA, 120min) alone was effective to reduce the tumor sizes, but could not cure the tumors. When the direct current therapy (DC therapy) was combined with radiation the DC therapy following radiation was more effective than that before radiation. Using TCD 50 assay, the DC therapy enhanced the effect of a single dose of radiation with the dose-modifying factor of 1.2. However, tumor control rates by the combination therapy were more improved at the smaller doses of radiation than at the larger ones. When the single DC therapy (0.6mA, 120min) was applied immediately after the first radiation of fractionated one the combination therapy still showed the enhanced effect. However, both DC therapy and the radiation therapy were divided in three fractions, and the DC therapy (0.6mA, 40min) was applied after each radiation. Tumor growth retardation by the combination therapy was no different from that by radiation alone. This result suggests that there might be a minimum required dose of coulombs to show the effect of the combination therapy. (author)

Proposal for the study of laminar relativistic electron beam generation by a foilless diode

International Nuclear Information System (INIS)

Jones, M.E.; Thode, L.E.

1979-02-01

The continuation of an analytical and numerical study of intense relativistic electron beam generation by foilless diodes is proposed. The investigation is aimed at optimizing the diode design to produce a laminar flow

Current Food Classifications in Epidemiological Studies Do Not Enable Solid Nutritional Recommendations for Preventing Diet-Related Chronic Diseases: The Impact of Food Processing12

Science.gov (United States)

Fardet, Anthony; Rock, Edmond; Bassama, Joseph; Bohuon, Philippe; Prabhasankar, Pichan; Monteiro, Carlos; Moubarac, Jean-Claude; Achir, Nawel

2015-01-01

To date, observational studies in nutrition have categorized foods into groups such as dairy, cereals, fruits, and vegetables. However, the strength of the association between food groups and chronic diseases is far from convincing. In most international expert surveys, risks are most commonly scored as probable, limited, or insufficient rather than convincing. In this position paper, we hypothesize that current food classifications based on botanical or animal origins can be improved to yield solid recommendations. We propose using a food classification that employs food processes to rank foods in epidemiological studies. Indeed, food health potential results from both nutrient density and food structure (i.e., the matrix effect), both of which can potentially be positively or negatively modified by processing. For example, cereal-based foods may be more or less refined, fractionated, and recombined with added salt, sugars, and fats, yielding a panoply of products with very different nutritional values. The same is true for other food groups. Finally, we propose that from a nutritional perspective, food processing will be an important issue to consider in the coming years, particularly in terms of strengthening the links between food and health and for proposing improved nutritional recommendations or actions. PMID:26567188

Estimation and reduction of harmonic currents from power converters

DEFF Research Database (Denmark)

Asiminoaei, Lucian

-based method depends very much on the amount and accuracy of collected data in the development stage. The outcome of this investigation is a Harmonic Calculation Software compiled into a Graphical User Interface PC-software application, which can be applied for fast estimations of the harmonic currents...... control of the proposed topologies are given together with laboratory tests. One harmonic current mitigation solution found is to connect (two) smaller power APF's in parallel, sharing the same ac- and dc-bus. It is proven that parallel APF's may have lower passive components although other issues arises......, like circulation currents, which is removed here by common mode coils. Another harmonic solution is to use cascade connection of (two) independent APF's that cooperatively share the task of the harmonic mitigation. Two cooperative control methods are proposed called load-sharing and harmonic-sharing...

Current-type flipped-Γ-source inverters

DEFF Research Database (Denmark)

Loh, Poh Chiang; Li, Ding; Blaabjerg, Frede

2012-01-01

are of interest since they use lesser components. Their winding turns might however become too excessive for higher demanded gains. Avoiding this usual trend, a new family of current-type flipped-Γ-source inverters are proposed, whose common gain is raised by lowering, and not increasing, the winding turns...

The critical current of granular superconductor

International Nuclear Information System (INIS)

Ignat'ev, V.K.

1998-01-01

A mechanism of hyper vortex pinning in granular superconductors is proposed to describe the field dependence of the critical current density and pinning potential. The results are in a good agreement with the experiment. The model represents the peak effect and the percolation mechanism of conductivity in ceramic superconductors

Critical unpairing currents in narrow niobium films

International Nuclear Information System (INIS)

Gershenzon, M.E.; Gubankov, V.N.

1979-01-01

Investigated are the dependences of critical currents of narrow ( with the width of W=0.5-15 μm) superconducting niobium films on temperature and a magnetic field. The proposed method of film production with the width of the 1μm order and with small edge inhomogeneities ((<=500 A) permitted to realize the Ginsburg-Landau unpairing currents in the wide range of temperatures. The correct comparison with the theory showed that the unpairing currents are observed if W(< or approximately) 2delta, where delta is the effective depth of the penetration of the perpendicular magnetic field

MOS current gain cells with electronically variable gain and constant bandwidth

NARCIS (Netherlands)

Klumperink, Eric A.M.; Seevinck, Evert

1989-01-01

Two MOS current gain cells are proposed that provide linear amplification of currents supplied by several linear MOS V-I converters. The gain is electronically variable by a voltage or a current and can be made insensitive to temperature and IC processing. The gain cells have a constant

Finite-size effects on current correlation functions

Science.gov (United States)

Chen, Shunda; Zhang, Yong; Wang, Jiao; Zhao, Hong

2014-02-01

We study why the calculation of current correlation functions (CCFs) still suffers from finite-size effects even when the periodic boundary condition is taken. Two important one-dimensional, momentum-conserving systems are investigated as examples. Intriguingly, it is found that the state of a system recurs in the sense of microcanonical ensemble average, and such recurrence may result in oscillations in CCFs. Meanwhile, we find that the sound mode collisions induce an extra time decay in a current so that its correlation function decays faster (slower) in a smaller (larger) system. Based on these two unveiled mechanisms, a procedure for correctly evaluating the decay rate of a CCF is proposed, with which our analysis suggests that the global energy CCF decays as ˜t-2/3 in the diatomic hard-core gas model and in a manner close to ˜t-1/2 in the Fermi-Pasta-Ulam-β model.

Maximum Bandwidth Enhancement of Current Mirror using Series-Resistor and Dynamic Body Bias Technique

Directory of Open Access Journals (Sweden)

V. Niranjan

2014-09-01

Full Text Available This paper introduces a new approach for enhancing the bandwidth of a low voltage CMOS current mirror. The proposed approach is based on utilizing body effect in a MOS transistor by connecting its gate and bulk terminals together for signal input. This results in boosting the effective transconductance of MOS transistor along with reduction of the threshold voltage. The proposed approach does not affect the DC gain of the current mirror. We demonstrate that the proposed approach features compatibility with widely used series-resistor technique for enhancing the current mirror bandwidth and both techniques have been employed simultaneously for maximum bandwidth enhancement. An important consequence of using both techniques simultaneously is the reduction of the series-resistor value for achieving the same bandwidth. This reduction in value is very attractive because a smaller resistor results in smaller chip area and less noise. PSpice simulation results using 180 nm CMOS technology from TSMC are included to prove the unique results. The proposed current mirror operates at 1Volt consuming only 102 µW and maximum bandwidth extension ratio of 1.85 has been obtained using the proposed approach. Simulation results are in good agreement with analytical predictions.

The state of the systems of information in the companies prioritized according to the current requirementstized according to the current requirements

Directory of Open Access Journals (Sweden)

Grisel Castillo Almeida

2017-04-01

Full Text Available The necessity to maintain efficient systems of information in the prioritized companies of the territory of Pinar del Rio, Cuba, took us to carry out a diagnosis to determine the current state of the same ones and to propose group actions that congratulate the taking of decisions and the identification of the useful flows of information, to favor the organizational acting. The results of the study evidenced among other that alone 12% has an organized system of information and implemented according to the current requirements, what indicates that 88% is wasting the opportunities that offer the systems of information, also stands out the necessity to implement good practices to assure the security of the information according to the effective norms. The execution of a group of activities was approved to rise in first term the efficiency of the informative system of the study sample, with a view to continuing deepening toward the managerial intelligence.

Integrated Current Balancing Transformer for Primary Parallel Isolated Boost Converter

DEFF Research Database (Denmark)

Sen, Gökhan; Ouyang, Ziwei; Thomsen, Ole Cornelius

2011-01-01

A simple, PCB compatible integrated solution is proposed for the current balancing requirement of the primary parallel isolated boost converter (PPIBC). Input inductor and the current balancing transformer are merged into the same core, which reduces the number of components allowing a cheaper...

Proposing a project for building an e-commerce website for Ryijypalvelu-RP Oy

OpenAIRE

Sotkov, Ilya

2014-01-01

The thesis describes the development of a project proposal report for building an e-commerce website for a small textile firm based in Helsinki, Finland. The aim of the study is to determine how small businesses that are currently not highly involved in e-commerce should approach developing an e-commerce website in order to maximize the positive impact of selling on the Internet. The study combined the use of action research and qualitative research methodologies by developing a project p...

A Novel Modulation Function-Based Control of Modular Multilevel Converters for High Voltage Direct Current Transmission Systems

Directory of Open Access Journals (Sweden)

Majid Mehrasa

2016-10-01

Full Text Available In this paper, a novel modulation function-based method including analyses of the modulation index and phase is proposed for operation of modular multilevel converters (MMCs in high voltage direct current (HVDC transmission systems. The proposed modulation function-based control technique is developed based on thorough and precise analyses of all MMC voltages and currents in the a-b-c reference frame in which the alternating current (AC-side voltage is the first target to be obtained. Using the AC-side voltage, the combination of the MMC upper and lower arm voltages is achieved as the main structure of the proposed modulation function. The main contribution of this paper is to obtain two very simple new modulation functions to control MMC performance in different operating conditions. The features of the modulation function-based control technique are as follows: (1 this control technique is very simple and can be easily achieved in a-b-c reference frame without the need of using Park transformation; and (2 in addition, the inherent properties of the MMC model are considered in the proposed control technique. Considering these properties leads to constructing a control technique that is robust against MMC parameters changes and also is a very good tracking method for the components of MMC input currents. These features lead to improving the operation of MMC significantly, which can act as a rectifier in the HVDC structure. The simulation studies are conducted through MATLAB/SIMULINK software, and the results obtained verify the effectiveness of the proposed modulation function-based control technique.

New Directions in the NOAO Observing Proposal System

Science.gov (United States)

Gasson, David; Bell, Dave

For the past eight years NOAO has been refining its on-line observing proposal system. Virtually all related processes are now handled electronically. Members of the astronomical community can submit proposals through email, web form, or via the Gemini Phase I Tool. NOAO staff can use the system to do administrative tasks, scheduling, and compilation of various statistics. In addition, all information relevant to the TAC process is made available on-line, including the proposals themselves (in HTML, PDF and PostScript) and technical comments. Grades and TAC comments are entered and edited through web forms, and can be sorted and filtered according to specified criteria. Current developments include a move away from proprietary solutions, toward open standards such as SQL (in the form of the MySQL relational database system), Perl, PHP and XML.

Modelling earth current precursors in earthquake prediction

Directory of Open Access Journals (Sweden)

R. Di Maio

1997-06-01

Full Text Available This paper deals with the theory of earth current precursors of earthquake. A dilatancy-diffusion-polarization model is proposed to explain the anomalies of the electric potential, which are observed on the ground surface prior to some earthquakes. The electric polarization is believed to be the electrokinetic effect due to the invasion of fluids into new pores, which are opened inside a stressed-dilated rock body. The time and space variation of the distribution of the electric potential in a layered earth as well as in a faulted half-space is studied in detail. It results that the surface response depends on the underground conductivity distribution and on the relative disposition of the measuring dipole with respect to the buried bipole source. A field procedure based on the use of an areal layout of the recording sites is proposed, in order to obtain the most complete information on the time and space evolution of the precursory phenomena in any given seismic region.

Data Mining Activities for Bone Discipline - Current Status

Science.gov (United States)

Sibonga, J. D.; Pietrzyk, R. A.; Johnston, S. L.; Arnaud, S. B.

2008-01-01

The disciplinary goals of the Human Research Program are broadly discussed. There is a critical need to identify gaps in the evidence that would substantiate a skeletal health risk during and after spaceflight missions. As a result, data mining activities will be engaged to gather reviews of medical data and flight analog data and to propose additional measures and specific analyses. Several studies are briefly reviewed which have topics that partially address these gaps in knowledge, including bone strength recovery with recovery of bone mass density, current renal stone formation knowledge, herniated discs, and a review of bed rest studies conducted at Ames Human Research Facility.

Modulation of Current Source Inverter

Directory of Open Access Journals (Sweden)

Golam Reza Arab Markadeh

2011-04-01

Full Text Available Direct torque control with Current Source Inverter (CSI instead of voltage source inverter is so appropriate because of determining the torque of induction motor with machine current and air gap flux. In addition, Space-Vector Modulation (SVM is a more proper method for CSI because of low order harmonics reduction, lower switching frequency and easier implementation. This paper introduces the SVM method for CSI and uses the proposed inverter for vector control of an induction motor. The simulation results illustrate fast dynamic response and desirable torque and speed output. Fast and accurate response to changes of speed and load torque reference completely proves the prominence of this method.

A PIPO Boost Converter with Low Ripple and Medium Current Application

Science.gov (United States)

Bandri, S.; Sofian, A.; Ismail, F.

2018-04-01

This paper presents a Parallel Input Parallel Output (PIPO) boost converter is proposed to gain power ability of converter, and reduce current inductors. The proposed technique will distribute current for n-parallel inductor and switching component. Four parallel boost converters implement on input voltage 20.5Vdc to generate output voltage 28.8Vdc. The PIPO boost converter applied phase shift pulse width modulation which will compare with conventional PIPO boost converters by using a similar pulse for every switching component. The current ripple reduction shows an advantage PIPO boost converter then conventional boost converter. Varies loads and duty cycle will be simulated and analyzed to verify the performance of PIPO boost converter. Finally, the unbalance of current inductor is able to be verified on four area of duty cycle in less than 0.6.

Versatile current-mode universal biquadratic filter using DO-CCIIs

Science.gov (United States)

Chen, Hua-Pin

2013-07-01

In this article, a new three-input and three-output versatile current-mode universal biquadratic filter is proposed. The circuit employs three dual-output current conveyors (DO-CCIIs) as active elements together with three grounded resistors and two grounded capacitors. The proposed configuration exhibits low-input impedance and high-output impedance which is important for easy cascading in the current-mode operations. It can be used as either a single-input and three-output or three-input and two-output circuit. In the operation of single-input and three-output circuit, the lowpass, bandpass and bandreject can be realised simultaneously, while the highpass filtering response can be easily obtained by connecting appropriated output current directly without using addition stages. In the operation of three-input and two-output circuit, all five generic filtering functions can be easily realised by selecting different three input current signals. The filter permits orthogonal controllability of the quality factor and resonance angular frequency, and no component matching conditions or inverting-type input current signals are imposed. All the passive and active sensitivities are low. HSPICE simulation results based on using TSMC 0.18 µm 1P6M CMOS process technology and supply voltages ±0.9 V to verify the theoretical analysis.

Fast commutation of high current in double wire array Z-pinch loads

International Nuclear Information System (INIS)

Davis, J.; Gondarenko, N.A.; Velikovich, A.L.

1997-01-01

A dynamic model of multi-MA current commutation in a double wire array Z-pinch load is proposed and studied theoretically. Initially, the load is configured as nested concentric wire arrays, with the current driven through the outer array and imploding it. Once the outer array or the annular plasma shell formed from it approaches the inner array, the imploded plasma might penetrate through the gaps between the wires, but the azimuthal magnetic field is trapped due to both the high conductivity of the inner wires and the inductive coupling between the two parts of the array, causing a rapid switching of the total current to the inner part of the array. copyright 1997 American Institute of Physics

Hysteresis current control technique of VSI for compensation of grid-connected unbalanced loads

DEFF Research Database (Denmark)

Pouresmaeil, Edris; Akorede, Mudathir Funsho; Montesinos-Miracle, Daniel

2014-01-01

interconnection issues that usually arise as DG units connect to the electric grid. The proposed strategy, implemented in Matlab/Simulink environment in different operating scenarios, provides compensation for active, reactive, unbalanced, and harmonic current components of grid-connected nonlinear unbalanced...... resources as they connect to the exiting power grid could provoke many power quality problems on the grid side. For this reason, due considerations must be given to power generation and safe running before DG units is actually integrated into the power grid. The main aim of this paper is to address the grid...... loads. The simulation results obtained in this study demonstrate the level of accuracy of the proposed technique, which ensure a balance in the overall grid phase currents, injection of maximum available power from DG resources to the grid, improvement of the utility grid power factor, and a reduction...

Determining the Limiting Current Density of Vanadium Redox Flow Batteries

Directory of Open Access Journals (Sweden)

Jen-Yu Chen

2014-09-01

Full Text Available All-vanadium redox flow batteries (VRFBs are used as energy storage systems for intermittent renewable power sources. The performance of VRFBs depends on materials of key components and operating conditions, such as current density, electrolyte flow rate and electrolyte composition. Mass transfer overpotential is affected by the electrolyte flow rate and electrolyte composition, which is related to the limiting current density. In order to investigate the effect of operating conditions on mass transport overpotential, this study established a relationship between the limiting current density and operating conditions. First, electrolyte solutions with different states of charge were prepared and used for a single cell to obtain discharging polarization curves under various operating conditions. The experimental results were then analyzed and are discussed in this paper. Finally, this paper proposes a limiting current density as a function of operating conditions. The result helps predict the effect of operating condition on the cell performance in a mathematical model.

A Zero Input Current Ripple ZVS/ZCS Boost Converter with Boundary-Mode Control

Directory of Open Access Journals (Sweden)

Ching-Ming Lai

2014-10-01

Full Text Available In this paper, in order to achieve zero ripple conditions, the use of a ripple mirror (RM circuit for the boost converter is proposed. The operation modes are studied and steady-state analyses performed to show the merits of the proposed converter. It is found that the proposed RM circuit technique can provide much better flexibility than the two-phase interleaved boost converter for locating the zero ripple operating point in the design stage. In addition, the choice of using a boundary-mode control is mainly based on the consideration of achieving both ZVS (zero voltage switching/ZCS (zero current switching soft-switching and constant on-time control for the converter. To verify the performance of the proposed converter, a 48 V input and 200 W/200 V output prototype is constructed. Experimental results verify the effectiveness of the proposed converter.

Programmable current source for diode lasers stabilized optical fiber

International Nuclear Information System (INIS)

Gomez, J.; Camas, J.; Garcia, L.

2012-01-01

In this paper, we present the electronic design of a programmable stabilized current source. User can access to the source through a password, which, it has a database with the current and voltage operating points. This source was successfully used as current source in laser diode in optical fiber sensors. Variations in the laser current were carried out by a monitoring system and a control of the Direct Current (DC), which flowing through a How land source with amplifier. The laser current can be stabilized with an error percent of ± 1 μA from the threshold current (Ith) to its maximum operation current (Imax) in DC mode. The proposed design is reliable, cheap, and its output signal of stabilized current has high quality. (Author)

On Using Current Steering Logic in Mixed Analogue-digital Circuits

DEFF Research Database (Denmark)

Lehmann, Torsten

1998-01-01

The authors investigate power supply noise in mixed analogue-digital circuits, arising from communication between the analogue and digital parts of the circuit. Current steering techniques and proper buffering are used to show which noise currents can be reduced and which cannot. In addition......, a high-swing current steering buffer for driving analogue switches or external digital signals is proposed....

A Nineteenth-Century French Proposal to Use School Vouchers.

Science.gov (United States)

Van Vliet, W.; Smyth, J. A.

1982-01-01

In light of the current American interest in school vouchers as proposed by economist Milton Friedman, recapitulates the origins, content, and fate of an 1872 law drafted by a French parliamentary commission to establish a countrywide voucher scheme for primary schools. (NEC)

A Novel DBC Layout for Current Imbalance Mitigation in SiC MOSFET Multichip Power Modules

DEFF Research Database (Denmark)

Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon

2016-01-01

This letter proposes a novel direct bonded copper (DBC) layout for mitigating the current imbalance among the paralleled SiC MOSFET dies in multichip power modules. Compared to the traditional layout, the proposed DBC layout significantly reduces the circuit mismatch and current coupling effect...

[Social determinants of odontalgia in epidemiological studies: theoretical review and proposed conceptual model].

Science.gov (United States)

Bastos, João Luiz Dornelles; Gigante, Denise Petrucci; Peres, Karen Glazer; Nedel, Fúlvio Borges

2007-01-01

The epidemiological literature has been limited by the absence of a theoretical framework reflecting the complexity of causal mechanisms for the occurrence of health phenomena / disease conditions. In the field of oral epidemiology, such lack of theory also prevails, since dental caries the leading topic in oral research has been often studied through a biological and reductionist viewpoint. One of the most important consequences of dental caries is dental pain (odontalgia), which has received little attention in studies with sophisticated theoretical models and powerful designs to establish causal relationships. The purpose of this study is to review the scientific literature on the determinants of odontalgia and to discuss theories proposed for the explanation of the phenomenon. Conceptual models and emerging theories on the social determinants of oral health are revised, in an attempt to build up links with the bio-psychosocial pain model, proposing a more elaborate causal model for odontalgia. The framework suggests causal pathways between social structure and oral health through material, psychosocial and behavioral pathways. Aspects of the social structure are highlighted in order to relate them to odontalgia, stressing their importance in discussions of causal relationships in oral health research.

75 FR 80823 - Agency Information Collection Activities: Proposed Collection; Comment Request; Guidance for...

Science.gov (United States)

2010-12-23

... information in the ``Microbiology'' subsection of their product labeling is current or changes are needed... current information regarding susceptibility test interpretive criteria for antibacterial drug products... supplement that includes data supporting a proposed change to the microbiology information in the labeling...

Technical Notes: Notes and Proposed Guidelines on Updated ...

African Journals Online (AJOL)

In light of recent expansion in the planning and construction of major building structures as well as other infrastructures such as railways, masshousing, dams, bridges, etc, this paper reviews the extent of seismic hazard in Ethiopia and proposes a review and update of the current out-dated and - in most cases ...

Acute care patient portals: a qualitative study of stakeholder perspectives on current practices.

Science.gov (United States)

Collins, Sarah A; Rozenblum, Ronen; Leung, Wai Yin; Morrison, Constance Rc; Stade, Diana L; McNally, Kelly; Bourie, Patricia Q; Massaro, Anthony; Bokser, Seth; Dwyer, Cindy; Greysen, Ryan S; Agarwal, Priyanka; Thornton, Kevin; Dalal, Anuj K

2017-04-01

To describe current practices and stakeholder perspectives of patient portals in the acute care setting. We aimed to: (1) identify key features, (2) recognize challenges, (3) understand current practices for design, configuration, and use, and (4) propose new directions for investigation and innovation. Mixed methods including surveys, interviews, focus groups, and site visits with stakeholders at leading academic medical centers. Thematic analyses to inform development of an explanatory model and recommendations. Site surveys were administered to 5 institutions. Thirty interviews/focus groups were conducted at 4 site visits that included a total of 84 participants. Ten themes regarding content and functionality, engagement and culture, and access and security were identified, from which an explanatory model of current practices was developed. Key features included clinical data, messaging, glossary, patient education, patient personalization and family engagement tools, and tiered displays. Four actionable recommendations were identified by group consensus. Design, development, and implementation of acute care patient portals should consider: (1) providing a single integrated experience across care settings, (2) humanizing the patient-clinician relationship via personalization tools, (3) providing equitable access, and (4) creating a clear organizational mission and strategy to achieve outcomes of interest. Portals should provide a single integrated experience across the inpatient and ambulatory settings. Core functionality includes tools that facilitate communication, personalize the patient, and deliver education to advance safe, coordinated, and dignified patient-centered care. Our findings can be used to inform a "road map" for future work related to acute care patient portals. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Geometrodynamics for quarks and hadrons: the definition of currents

International Nuclear Information System (INIS)

Csikor, F.; Preparata, G.

1978-01-01

It is shown that the naive definition of the ''direct part'' of the vector and axial vector currents does not obey the necessary conservation conditions. The reasons for this failure are clarified and the precise conditions for restoring conservation are stated. Finally, an improved definition of currents is proposed and the physical interpretation is discussed

Fast and efficient STT switching in MTJ using additional transient pulse current

Science.gov (United States)

Pathak, Sachin; Cha, Jongin; Jo, Kangwook; Yoon, Hongil; Hong, Jongill

2017-06-01

We propose a profile of write pulse current-density to switch magnetization in a perpendicular magnetic tunnel junction to reduce switching time and write energy as well. Our simulated results show that an overshoot transient pulse current-density (current spike) imposed to conventional rectangular-shaped pulse current-density (main pulse) significantly improves switching speed that yields the reduction in write energy accordingly. For example, we could dramatically reduce the switching time by 80% and thereby reduce the write energy over 9% in comparison to the switching without current spike. The current spike affects the spin dynamics of the free layer and reduces the switching time mainly due to spin torque induced. On the other hand, the large Oersted field induced causes changes in spin texture. We believe our proposed write scheme can make a breakthrough in magnetic random access memory technology seeking both high speed operation and low energy consumption.

A Coordinate Control Strategy for Circulating Current Suppression in Multiparalleled Three-Phase Inverters

DEFF Research Database (Denmark)

Zhang, Xueguang; Wang, Tianyi; Wang, Xiongfei

2017-01-01

This paper addresses the zero-sequence circulating current control in the multiparalleled three-phase voltage-source inverters. The model of the zero-sequence circulating current in the N-paralleled (N ≥ 3) inverters is derived. It is shown that the circulating current is not only susceptible...... to the mismatches of circuit parameters, but it is also influenced by the interactions of circulating current controllers used by other paralleled inverters. To eliminate these adverse effects on the circulating current control loop, a coordinate control strategy for the N-paralleled inverter is proposed based...... on the zero-vector feedforward method with the space-vector pulse width modulation. Moreover, a virtual inverter method is introduced to facilitate the implementation of the proposed controller, which decouples the interactions of circulating current controllers in the paralleled inverters. Finally...

Convective effects in a regulatory and proposed fire model

International Nuclear Information System (INIS)

Wix, S.D.; Hohnstreiter, G.F.

1995-01-01

Radiation is the dominant mode of heat transfer in large fires. However, convection can be as much as 10 to 20 percent of the total heat transfer to an object in a large fire. The current radioactive material transportation packaging regulations include convection as a mode of heat transfer in the accident condition scenario. The current International Atomic Energy Agency Safety Series 6 packaging regulation states ''the convection coefficient shall be that value which the designer can justify if the package were exposed to the specified fire''. The current Title 10, Code of Federal Regulations, Part 71 (10CFR71) packaging regulation states ''when significant, convection heat input must be included on the basis of still, ambient air at 800 degrees C (1475 degrees F)''. Two questions that can arise in an analysts mind from an examination of the packaging regulations is whether convection is significant and whether convection should be included in the design analysis of a radioactive materials transportation container. The objective of this study is to examine the convective effects on an actual radioactive materials transportation package using a regulatory and a proposed thermal boundary condition

78 FR 66945 - Proposed Collection; 60-Day Comment request: Gulf Long-Term Follow-Up Study (GuLF STUDY)

Science.gov (United States)

2013-11-07

... GuLF STUDY is to investigate potential short- and long-term health effects associated with oil spill... non-Cleanup Workers Supplemental Mental Health 4,600 4 15/60 4,600 1,533 Telephone Questionnaire... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Proposed Collection; 60-Day...

Analytical drift-current threshold voltage model of long-channel double-gate MOSFETs

International Nuclear Information System (INIS)

Shih, Chun-Hsing; Wang, Jhong-Sheng

2009-01-01

This paper presents a new, physical threshold voltage model to solve the ambiguity in determining the threshold voltage of double-gate (DG) MOSFETs. To avoid the difficulties of the conventional 2ψ B model in nearly undoped DG MOSFETs, this study proposes to define the on–off switching based on the actual roles of the drift and diffusion components in the total drain current. The drift current strongly enhances beyond the threshold voltage, while the diffusion current plays a major role in the subthreshold. The threshold voltage is defined as the drift component that exceeds the diffusion counterpart. From the solutions of Poisson's equation, the drift and diffusion currents of DG MOSFETs are separately formulated to derive the analytical expressions of the threshold voltage and associated threshold current. This model provides a comprehensive description of the switching behavior of DG MOSFET devices, and offers a physical onset threshold current to determine the threshold voltage in practical extraction

Surgical options in benign parotid tumors: a proposal for classification.

Science.gov (United States)

Quer, Miquel; Vander Poorten, Vincent; Takes, Robert P; Silver, Carl E; Boedeker, Carsten C; de Bree, Remco; Rinaldo, Alessandra; Sanabria, Alvaro; Shaha, Ashok R; Pujol, Albert; Zbären, Peter; Ferlito, Alfio

2017-11-01

Different surgical options are currently available for treating benign tumors of the parotid gland, and the discussion on optimal treatment continues despite several meta-analyses. These options include more limited resections (extracapsular dissection, partial lateral parotidectomy) versus more extensive and traditional options (lateral parotid lobectomy, total parotidectomy). Different schools favor one option or another based on their experience, skills and tradition. This review provides a critical analysis of the literature regarding these options. The main limitation of all the studies is the bias of selection for different surgical approaches. For this reason, we propose a staging system that could facilitate clinical decision making and the comparison of results. We propose four categories based on the size of the tumor and its location within the parotid gland. Category I includes tumors up to 3 cm, which are mobile, close to the outer surface and close to the parotid borders. Category II includes deeper tumors up to 3 cm. Category III comprises tumors greater than 3 cm involving two levels of the parotid gland, and category IV tumors are greater than 3 cm and involve more than 2 levels. For each category and for the various pathologic types, a guideline of surgical extent is proposed. The objective of this classification is to facilitate prospective multicentric studies on surgical techniques in the treatment of benign parotid tumors and to enable the comparison of results of different clinical studies.