1,853 Matching Results

Search Results

Advanced search parameters have been applied.

Experimental results on the two-stage, Venetian Blind, direct energy converter

Description: Some preliminary results obtained from experiments designed to test the feasibility of the Venetian Blind, direct energy-conversion concept are discussed. A two-stage unit was built and tested and found to have an overall efficiency of 65% for an energy spread of from 330 to 1000 eV. The calculated efficiency was 69% leaving a 4% discrepancy. This discrepancy seems to result from the slight transparency in the backward direction of the ribbons of the converter. (auth)
Date: February 1, 1974
Creator: Moir, R. W. & Barr, W. L.
Partner: UNT Libraries Government Documents Department

Voltage holding considerations for direct-collection units

Description: Results have been obtained from initial experiments designed to study high-voltage breakdown under conditions of importance to the design of direct- collection units. A coaxial configuration was used to mock-up critical fields near grid wires. With appropriate heat conditioning, fields as high as 9.6 x 10/ sup 5/ V/cm were maintained at the surface of a 7-mil-diam tungsten wire. This represents an enhanced field of ~10/sup 8/V/cm at whisker'' sites. Breakdown criteria are proposed for three regimes; initial, field-emission, and ultimate, which differ by the amount of prior conditioning applied to the wire. Additional considerations of importance to direct collectors such as the effect of thermionic emission and ion bombardment are discussed. (auth)
Date: December 1, 1973
Creator: Miley, G.H.
Partner: UNT Libraries Government Documents Department

Technology Development: Wireless Sensors and Controls BT0201 Review of Energy Scavenging Schemes and Recommended Order of Investigation

Description: This report reviews the characteristics of four candidate concepts that extract and convert ambient energy to provide electrical power for wireless sensors.
Date: September 1, 2004
Creator: DeSteese, John G.; Olsen, Larry C. & Schienbein, Lawrence A.
Partner: UNT Libraries Government Documents Department

Surface requirements for electrostatic direct energy converters

Description: From surface effects in controlled thermonuclear fusion devices and reactors meeting; Argonne, Illinois, USA (10 Jan 1974). There are two major electrostatic direct energy converter concepts whlch will be discussed from the point of view of the surfaces. One is the Venetian blind concept and the other is the periodic electrostatic focusing concept. They are both of the direct collector type. Fluxes of D/sup +/, T/sup +/, He/sup ++/, electrons, and x-rays are given. Design consideration due to thermionic emission, secondary electron emission, and radiation cooling are discussed. A detailed discussion is devoted to breakdown physics, the voltages and electric field strengths that can be employed, and how surface deterioration may affect voltage holding due to He/sup ++/ bombardment blistering. (auth)
Date: January 17, 1974
Creator: Moir, R.W.; Barr, W.L. & Miley, G.H.
Partner: UNT Libraries Government Documents Department

Institutional aspects of fuel-cell total-energy system: a summary survey

Description: The institutional impediments to market penetration by fuel cells are briefly discussed including the following topics: (1) ownership of fuel cell and related franchise limitations; (2) backup arrangements; (3) economic effects; (4) fuel policy; (5) regulatory proceedings; and (6) competitive response. (WHK)
Date: July 31, 1977
Partner: UNT Libraries Government Documents Department

Surface conditions in a conceptual D--T mirror reactor with direct conversion

Description: From surface effects in controlled thermonuclear fusion devices and reactors meeting; Argonne, Illinois, USA (10 Jan 1974). A conceptual D-T fusion reactor employing magnetic mirror confinement and periodic focusing electrostatic direct conversion is described with emphasis on surface conditions. (auth)
Date: January 23, 1974
Creator: Lee, J.D.
Partner: UNT Libraries Government Documents Department

Design studies of mirror machine reactors

Description: An overview is presented of a mirror fusion reactor design study. The general methodology used in the study is discussed, the reactor is described, and some design alternatives to the present approach are enumerated. The system chosen for this design study is a mirror machine with direct conversion using D- T fuel. The nominal power output is 200 MW. The coil geometry is the Yin Yang, minimum B with a vacuum mirror ratio of 3. The coil is of particular utility because of its simple conductor shapes and because the two separate conductors, by proper B-field biasing, allow the charged particles to escape preferentially through one mirror only and through a relatively small window'' of that mirror. This is necessary for direct converter economy. (auth)
Date: December 1, 1973
Creator: Werner, R.W.; Carlson, G.A.; Hovingh, J.; Lee, J.D. & Peterson, M.A.
Partner: UNT Libraries Government Documents Department

Status of the DOE Battery and Electrochemical Technology Program V

Description: The program consists of two activities, Technology Base Research (TBR) managed by the Lawrence Berkeley Laboratory (LBL) and Exploratory Technology Development and Testing (EDT) managed by the Sandia National Laboratories (SNL). The status of the Battery Energy Storage Test (BEST) Facility is presented, including the status of the batteries to be tested. ECS program contributions to the advancement of the lead-acid battery and specific examples of technology transfer from this program are given. The advances during the period December 1982 to June 1984 in the characterization and performance of the lead-acid, iron/nickel-oxide, iron/air, aluminum/air, zinc/bromide, zinc/ferricyanide, and sodium/sulfur batteries and in fuel cells for transport are summarized. Novel techniques and the application of established techniques to the study of electrode processes, especially the electrode/electrolyte interface, are described. Research with the potential of leading to improved ceramic electrolytes and positive electrode container and current-collectors for the sodium/sulfur battery is presented. Advances in the electrocatalysis of the oxygen (air) electrode and the relationship of these advances to the iron/air and aluminum/air batteries and to the fuel cell are noted. The quest for new battery couples and battery materials is reviewed. New developments in the modeling of electrochemical cell and electrode performance with the approaches to test these models are reported.
Date: June 1, 1985
Creator: Roberts, R.
Partner: UNT Libraries Government Documents Department

A New Fabrication Process for Thin-Film Multijunction Thermal Converters

Description: Advanced thin film processing and packaging technologies are employed in the fabrication of new planar thin-film multifunction thermal converters. The processing, packaging, and design features build on experience gained from prior NIST demonstrations of thin-film converters and are optimized for improved sensitivity, bandwidth, manufacturability, and reliability.
Date: December 8, 2000
Creator: WUNSCH,THOMAS F.; KINARD,J.R.; MANGINELL,RONALD P.; SOLOMON JR.,OTIS M.; LIPE,T.E. & JUNGLING,KENNETH CORNEAL
Partner: UNT Libraries Government Documents Department

Direct energy conversion in fission reactors: A U.S. NERI project

Description: In principle, the energy released by a fission can be converted directly into electricity by using the charged fission fragments. The first theoretical treatment of direct energy conversion (DEC) appeared in the literature in 1957. Experiments were conducted over the next ten years, which identified a number of problem areas. Research declined by the late 1960's due to technical challenges that limited performance. Under the Nuclear Energy Research Initiative the authors are determining if these technical challenges can be overcome with todays technology. The authors present the basic principles of DEC reactors, review previous research, discuss problem areas in detail, and identify technological developments of the last 30 years that can overcome these obstacles. As an example, the fission electric cell must be insulated to avoid electrons crossing the cell. This insulation could be provided by a magnetic field as attempted in the early experiments. However, from work on magnetically insulated ion diodes they know how to significantly improve the field geometry. Finally, a prognosis for future development of DEC reactors will be presented .
Date: May 30, 2000
Creator: SLUTZ,STEPHEN A.; SEIDEL,DAVID B.; POLANSKY,GARY F.; ROCHAU,GARY E.; LIPINSKI,RONALD J.; BESENBRUCH,G. et al.
Partner: UNT Libraries Government Documents Department

Improving the performance of photo-electrically controlled lighting systems

Description: The ability of a photo-electrically controlled lighting system to maintain a constant total light level on a task surface by responding to changing daylight levels is affected by the control algorithm used to relate the photosensor signal to the supplied electric light level and by the placement and geometry of the photosensor. We describe the major components of a typical control system, discuss the operation of three different control algorithms, and derive expressions for each algorithm that express the total illuminance at the task as a function of the control photosensor signal. Using a specially-designed scale model, we measured the relationship between the signal generated by various ceiling-mounted control photosensors and workplane illuminance for two room geometries under real sky conditions. The measured data were used to determine the performance of systems obeying the three control algorithms under varying daylight conditions. Control systems employing the commonly-used integral reset algorithm supplied less electric light than required, failing to satisfy the control objective regardless of the control photosensor used. Systems employing an alternative, closed-loop proportional control algorithm achieved the control objective under virtually all tested conditions when operated by a ceiling-mounted photosensor shielded from direct window light.
Date: August 1, 1988
Creator: Rubinstein, F.; Ward, G. & Verderber, R.
Partner: UNT Libraries Government Documents Department

Module Utilization Committee. Final report

Description: Photovoltaic collector modules were declared surplus to the needs of the US Department of Energy. The Module Utilization Committee was formed to make appropriate disposition of the surplus modules. The final report of that committee accounts for that disposition. The membership and activities of the committee are set forth and the results of its activities are reported.
Date: March 1, 1984
Partner: UNT Libraries Government Documents Department

Reduction of photovoltaic cell reverse breakdown by a peripheral bypass diode

Description: A photovoltaic cell in a series-connected string can be forced to operate in a power-dissipation mode when the cell's short-circuit current is reduced below the string current as a result of cracking or shadowing. New techniques for significantly reducing the power dissipated are reported based on locating protection for the cell around its periphery. One approach uses a standard diode, thereby requiring processing; the other approach uses a backward diode, which requires one additional doping step. Theoretical considerations and experimental results are presented. Initial devices yield a power-dissipation reduction of more than a factor of 10 with the backward diode and over 30 for the standard diode. It is found that the standard diode requires a slight increase in cell-interconnect complexity while the backward diodes uses conventional interconnections.
Date: January 1, 1982
Creator: Cox, III, C H; Silversmith, D J & Mountain, R W
Partner: UNT Libraries Government Documents Department

Some considerations in the design of a Venetian Blind direct converter

Description: The structural design of a Venetian Blind direct converter will depend on the choice, for example, of: 1) Expander field, (2) Selective leakage, (3) Number of collector stages, (4) Method of cooling and (5) The general configuration and orientation. This note is intended to outline the major compromises that will result from the variation of parameters to fit a particular design. The relationships given are for a two-stage unit, but it is straightforward to extend them to multiple-stage units. (auth)
Date: December 15, 1975
Creator: Barr, W.L.
Partner: UNT Libraries Government Documents Department