1,234 research outputs found
Applications of the DOE/NASA wind turbine engineering information system
A statistical analysis of data obtained from the Technology and Engineering Information Systems was made. The systems analyzed consist of the following elements: (1) sensors which measure critical parameters (e.g., wind speed and direction, output power, blade loads and component vibrations); (2) remote multiplexing units (RMUs) on each wind turbine which frequency-modulate, multiplex and transmit sensor outputs; (3) on-site instrumentation to record, process and display the sensor output; and (4) statistical analysis of data. Two examples of the capabilities of these systems are presented. The first illustrates the standardized format for application of statistical analysis to each directly measured parameter. The second shows the use of a model to estimate the variability of the rotor thrust loading, which is a derived parameter
Solos do Assentamento Mato Grande - Corumbá, MS: caracterização, limitações e aptidão agrícola.
Argissolos; Cambissolos; Luvissolos; Neossolos; Planossolos; Vertissolos; Aptidão agrícola das terras; Inserção do agricultor no mercado.bitstream/item/37736/1/DOC27.pd
Solos do Assentamento Urucum - Corumbá, MS: caracterização, limitações e aptidão agrícola.
Cambissolos; Chernossolos; Luvissolos; Neossolos; Vertissolos; Aptidão agrícola das terras; Inserção do agricultor no mercado.bitstream/item/37731/1/DOC30.pd
Star cluster disruption by a supermassive black hole binary
Binary supermassive black holes (BBHs) are expected to be one of the most powerful sources of low-frequency gravitational waves (GWs) for future space-borne detectors. Prior to the GW emission stage, BBHs evolving in gas-poor nuclei shrink primarily through the slingshot ejection of stars approaching the BBH from sufficiently close distances. Here we address the possibility that the BBH shrinking rate is enhanced through the infall of a star cluster (SC) onto the BBH. We present the results of direct summation N-body simulations exploring different orbits for the SC infall, and we show that SCs reaching the BBH on non-zero angular momentum orbits (with eccentricity 0.75) fail to enhance the BBH hardening, while SCs approaching the BBH on radial orbits reduce the BBH separation by 3c 10% in less than 10 Myr, effectively shortening the BBH path towards GWs
Preliminary analysis of performance and loads data from the 2-megawatt mod-1 wind turbine generator
Preliminary test data on output power versus wind speed, rotor blade loads, system dynamic behavior, and start-stop characteristics on the Mod-1 wind turbine generator are presented. These data were analyzed statistically and are compared with design predictions of system performance and loads. To date, the Mod-1 wind turbine generator has produced up to 1.5 MW of power, with a measured power versus wind speed curve which agrees closely with design. Blade loads were measured at wind speeds up to 14 m/s and also during rapid shutdowns. Peak transient loads during the most severe shutdowns are less than the design limit loads. On the inboard blade sections, fatigue loads are approximately equal to the design cyclic loads. On the outboard blade sections, however, measured cyclic loads are significantly larger than design values, but they do not appear to exceed fatigue allowable loads as yet
Star cluster disruption by a massive black hole binary
Massive black hole binaries (BHBs) are expected to form as the result of galaxy mergers; they shrink via dynamical friction and stellar scatterings, until gravitational waves (GWs) bring them to the final coalescence. It has been argued that BHBs may stall at a parsec scale and never enter the GW stage if stars are not continuously supplied to the BHB loss cone. Here, we perform several N-body experiments to study the effect of an 8
7 104M 99 stellar cluster (SC) infalling on a parsec-scale BHB. We explore different orbital elements for the SC, and we perform runs both with and without accounting for the influence of a rigid stellar cusp (modelled as a rigid Dehnen potential). We find that the semimajor axis of the BHB shrinks by 73 10 per cent if the SC is on a nearly radial orbit; the shrinking is more efficient when a Dehnen potential is included and the orbital plane of the SC coincides with that of the BHB. In contrast, if the SC orbit has non-zero angular momentum, only few stars enter the BHB loss cone and the resulting BHB shrinking is negligible. Our results indicate that SC disruption might significantly contribute to the shrinking of a parsec-scale BHB only if the SC approaches the BHB on a nearly radial orbit
Solos do Assentamento Taquaral - Corumbá, MS: caracterização, limitações e aptidão agrícola.
Cambissolos; Chernossolos; Vertissolos; Aptidão agrícola das terras; Inserção do agricultor no mercado.bitstream/item/37733/1/DOC29.pd
Solos do Assentamento Paiolzinho, Corumbá-MS: caracterização e potencial agrícola.
Solos do Assentamento Paiolzinho; Caracterização e limitações agrícolas dos solos; Chernossolos; Vertissolos; Aptidão agrícola das terras; Inserção do agricultor no mercado.bitstream/item/37727/1/DOC32.pd
Solos do Assentamento 72, Ladário - MS: caracterização e potencial agrícola.
Solos do Assentamento 72; Caracterização e limitações agrícolas dos solos; Chernossolos; Gleissolos; Plintossolos; Vertissolos; Aptidão agrícola das terras; Inserção do agricultor no mercado.bitstream/item/81210/1/DOC34.pd
Solos do Assentamento Tamarineiro II, Corumbá - MS: caracterização e potencial agrícola.
Solos do Assentamento Tamarineiro II; Caracterização e limitações agrícolas dos solos; Chernossolos; Vertissolos; Aptidão agrícola das terras; Inserção do agricultor no mercado.bitstream/item/37726/1/DOC33.pd
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