37,401 research outputs found
Performance characteristics of an electric vehicle lead-acid battery pack at elevated temperatures
Discharge testing data electric car battery pack over initial electrolyte temperature variations between 27 and 55 C are presented. The tests were conducted under laboratory conditions and then compared to detailed electric vehicle simulation models. Battery discharge capacity increased with temperature for constant current discharges, and battery energy capacity increased with temperature for constant power discharges. Dynamometer tests of the electric test vehicle showed an increase in range of 25% for the higher electrolyte temperature
Survey and documentation of emerging technologies for the Satellite Power System (SPS)
The genesis of the solar power satellite (SPS) concept is reviewed historically and the original assumptions and guidelines which led to development of the SPS reference system design concept are discussed. Some guidelines are applicable to almost any SPS design, but others can be changed, leading to new and perhaps preferable systems. In order to stimulate new SPS concepts and to facilitate comparative assessment of emerging SPS technologies, one useful approach is to break the overall system into functional parts. The system functions which must be performed by any SPS concept and the interrelations between them are discussed and a systematic framework is presented for assessing the wide variety of system concepts and subsystem technologies which have been proposed. About 80 alternative SPS technologies are reviewed
A power-spectral-density computer program
Computer program simplifies and clarifies random noise vibration test results. It also varies PSD test specifications, sets up automatic equalization equipment, and calculates an exact accleration level for the random noise prior to the test
Automated attendance accounting system
An automated accounting system useful for applying data to a computer from any or all of a multiplicity of data terminals is disclosed. The system essentially includes a preselected number of data terminals which are each adapted to convert data words of decimal form to another form, i.e., binary, usable with the computer. Each data terminal may take the form of a keyboard unit having a number of depressable buttons or switches corresponding to selected data digits and/or function digits. A bank of data buffers, one of which is associated with each data terminal, is provided as a temporary storage. Data from the terminals is applied to the data buffers on a digit by digit basis for transfer via a multiplexer to the computer
Peak acceleration limiter
Device is described that limits accelerations by shutting off shaker table power very rapidly in acceleration tests. Absolute value of accelerometer signal is used to trigger electronic switch which terminates test and sounds alarm
Peak acceleration limiter for vibrational tester Patent
Electronic detection system for peak acceleration limits in vibrational testing of spacecraft component
Technology alternatives for the SPS
Emerging technologies may offer advantages over those selected for the reference design adopted for the SPS. While it is not possible to list all the technological innovations that may affect the SPS, it is feasible to develop a systematic methodology for assessing technical alternatives. This may be of value in evaluating proposed technologies and identifying high priority areas for research. Such a methodology includes involves (1) variation of guidelines; (2) analysis of system functions; (3) analysis of system sensitivity; (4) analysis of technology status and risk; and (5) external costs, problem areas, and criticisms of the SPS concept. The methodology is a first step towards the creation of a formal decision analytic framework which can support design choices and program decisions as development proceeds
Bridging the theory practice gap: an innovative approach to praxis in professional education
The notion of a ‘theorypractice gap’ in nursing has been the subject of debate for many years and is well documented in the nursing literature (Crane, 1991; Landers, 2000). McCaugherty (1991) explains the ‘gap’ using the symbolobject dichotomy as an analogy, that is the symbol such as a picture or an image is not the same as the actual object. Thus, what is taught in the classroom is not the same as that which is experienced in the clinical environment. Russell (1967) identifies the former as ‘knowledge by description’ and the latter, ‘knowledge by acquaintance’
A low-power photovoltaic system with energy storage for radio communications: Description and design methodology
A low power photovoltaic system was constructed with approximately 500 amp hours of battery energy storage to provide power to an emergency amateur radio communications center. The system can power the communications center for about 72 hours of continuous nonsun operation. Complete construction details and a design methodology algorithm are given with abundant engineering data and adequate theory to allow similar systems to be constructed, scaled up or down, with minimum design effort
A Power-spectral-density Computer Program for the Vibration Laboratory
Computer program for calculating vibration- acceleration densities along power-spectral density plots in vibration test
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