21,938 research outputs found
Advanced high-temperature electromagnetic pump
Three phase helical, electromagnetic induction pump for use as boiler feed pump in potassium Rankine-cycle power system is described. Techniques for fabricating components of pump are discussed. Specifications of pump are analyzed
High temperature electronic requirements in aeropropulsion systems
The needs for high temperature electronic and electro-optic devices as they would be used on aircraft engines in either research and development applications, or operational applications are discussed. The conclusion reached is that the temperature at which the devices must be able to function is in the neighborhood of 500 to 600 C either for R&D or for operational applications. In R&D applications the devices must function in this temperature range when in the engine but only for a moderate period of time. On an operational engine, the reliability requirements dictate that the devices be able to be burned-in at temperatures significantly higher than those at which they will function on the engine. The major point made is that semiconductor technology must be pushed well beyond the level at which silicon will be able to function
Fabrication and test of a space power boiler feed electromagnetic pump. Part 1: Design and manufacture of pump
A three-phase helical induction electromagnetic (EM) pump has been designed and built. This pump was designed for use as the boiler-feed pump of a potassium Rankine-cycle space electric power system. The pump is constructed of high temperature materials including a T-111 duct, Hiperco 27 magnetic material, nickel clad silver conductor wire, and a completely inorganic insulation system. The pump is designed to deliver 3.25 lb/sec potassium at 1000 F with a developed head of 240 psi while being cooled by 800 F NaK. At these conditions, the overall pump efficiency is expected to be 18%
Shifting new media: from content to consultancy, from heterarchy to hierarchy
This is a detailed case history of one of London’s iconic new media companies, AMX Studios. Some of the changes in this firm, we assume, are not untypical for other firms in this sector. Particularly we want to draw attention to two transformations. The first change in AMX and in London’s new media industry more generally refers to the field of industrial relations. What can be observed is a shift from a rather heterarchical towards a more hierarchical organized new media industry, a shift from short-term project networks to long-term client dependency. The second change refers to new media products and services. We want to argue for a shift from cool content production towards consultancy and interactive communications solutions
Fabrication and test of a space power boiler feed electromagnetic pump. Part 2: Test facility and performance test
A three-phase helical induction electromagnetic pump, designed for the boiler-feed pump of a potassium Rankine-cycle space power system, was built and tested. The pump was tested over a range of potassium temperatures from 900 to 1400 F, flow rates from 0.75 to 4.85 lb/sec, developed pressures up to 340 psi, net positive suction heads (NPSH) from 1 to 22 psi, and NaK coolant temperatures from 800 to 950 F. The maximum efficiency at the pump design point of 3.25 lb/sec flow rate, 240 psi developed pressure, 1000 F potassium inlet temperature, and 800 F NaK coolant temperature was 16.3 percent. The tests also showed successful operation of the pump at an NPSH as low as 1.5 psi without cavitating
That\u27s The Time To Send For Me
https://digitalcommons.library.umaine.edu/mmb-vp/6616/thumbnail.jp
Recombination between Fusarium oxysporum telomeres and pUC ampicillin resistance gene in a transforming vector.
Transformations using certain vector/host combinations of Fusarium oxysporum have been shown to promote in vivo production of linear, autonomously replicating plasmids (Powell and Kistler, 1990, J. Bact. 172:3163-3171). The modifications to the transforming vector included: linearization of a circular plasmid, addition of putative fungal telomeres to one end of the plasmid, and duplication and translocation of the modified DNA to the other end of the plasmid. This report confirms that the putative telomere repeats (TTAGGG) from one of these fungal-modified vectors, pFOLT4R4, are also located at the ends of F. oxysporum chromosomes and indicates that these telomere sequences were added to the vector by a recombinational event
URANIUM HEXAFLUORIDE PURIFICATION
An experimental batch distillation column was used to purify UF/sub 6/ containing metal impurities. The degree of purification was determined by comparing the spectrographic analyses of the UF/sub 6/ distillate material with the original feed or pot material. Results are tabulated at 95% confidence limits. (auth
A phenomenological model of the superconducting state of the Bechgaard salts
We present a group theoretical analysis of the superconducting state of the
Bechgaard salts, e.g., (TMTSF)_2PF_6 or (TMTSF)_2ClO_6. We show that there are
eight symmetry distinct superconducting states. Of these only the (fully
gapped, even frequency, p-wave, triplet) 'polar state' is consistent with the
full range of the experiments on the Bechgaard salts. The gap of the polar
state is d(k) (psi_uk,0,0), where psi_uk may be any odd parity function that is
translationally invariant.Comment: 4 pages, no figure
Status of Outer Planet Global Reference Atmospheric Model (GRAM) Upgrades
The inability to test planetary spacecraft in the flight environment prior to a mission requires engineers to rely on ground-based testing and models of the vehicle and expected environments. One of the most widely used engineering models of the atmosphere is the Global Reference Atmospheric Model (GRAM) developed and maintained by the NASA Marshall Space Flight Center (MSFC). The NASA Science Mission Directorate (SMD) has provided funding support to upgrade the GRAMs
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