3,938 research outputs found
Interior noise prediction methodology: ATDAC theory and validation
The Acoustical Theory for Design of Aircraft Cabins (ATDAC) is a computer program developed to predict interior noise levels inside aircraft and to evaluate the effects of different aircraft configurations on the aircraft acoustical environment. The primary motivation for development of this program is the special interior noise problems associated with advanced turboprop (ATP) aircraft where there is a tonal, low frequency noise problem. Prediction of interior noise levels requires knowledge of the energy sources, the transmission paths, and the relationship between the energy variable and the sound pressure level. The energy sources include engine noise, both airborne and structure-borne; turbulent boundary layer noise; and interior noise sources such as air conditioner noise and auxiliary power unit noise. Since propeller and engine noise prediction programs are widely available, they are not included in ATDAC. Airborne engine noise from any prediction or measurement may be input to this program. This report describes the theory and equations implemented in the ATDAC program
Traditional Dye Yielding Plants of Firozabad, U.P., India
District Firozabad is a city of glass work and Bangles. It is also a rich source of ethnobotanical studies. Local weavers and ethnic communities use plant dyes for imparting different shades to their clothes, hands, hairs and food items. About 19 plant species belonging to 17 families of Dicots, mostly trees and herbs have been identified as traditional dye yielding plants
Management of Ashwagandha root rot disease with fungicides, biocontrol agents and botanicals
The experiment was conducted to study fungicides, biocontrol agents and botanicals for management of ashwagandha root rot disease. Ashwagandha root rot disease caused by two pathogen Fusarium solani and Rhizoctonia solani. In field trial, seed treatments with integration of fungicides, neem cake manure, neem oil and Trichoderma viride agent evaluated as seed treatments individually as well as in different combination of seed treatment and soil application of neem cake was found effective integrated treatment (ST SAAF + neem cake manure + T. viride) and soil application of neem cake manure@500g/plot showed minimum per cent root rot and maximum per cent germination and maximum yield of Ashwagandha as compared to their individual applications over the untreated control
Precise time and frequency intercomparison between NPL, India and PTB, Federal Republic of Germany via satellite symphonie-1
A time and frequency intercomparison experiment conducted using Earth stations in New Delhi, India and Raisting, FRG is described. The NPL clock was placed at New Delhi Earth Station and the Raisting Clock was calibrated with PTB/Primary standard via LORAN-C and travelling clocks. The random uncertainity of time comparisons, represented by two sample Allan Variance sigma (30 seconds), was less than 10 nanoseconds. The relative frequency difference between the NPL and Raisting Clocks, SNPL, RAIS, as measured over the 44 days period was found to be -15.7 x 10 to the -13th power. The relative frequency difference between PTB Primary Standard and Raisting Clock, SPTB, RAIS, during this period, was measured to be -22.8 x 10 to the -13th power. The relative frequency difference between NPL clock and PTB Primary Standard, SNPL, PTB, thus, is +7.1 x 10 to the -13th power. The clock rate (UTC, India) of +7.1 + or - 0.5 x 10 to the -13th power, agrees well with that obtained via VLF phase measurements over one year period and with USNO travelling clock time comparisons made in September, 1980
Nonuniversal Effects in the Homogeneous Bose Gas
Effective field theory predicts that the leading nonuniversal effects in the
homogeneous Bose gas arise from the effective range for S-wave scattering and
from an effective three-body contact interaction. We calculate the leading
nonuniversal contributions to the energy density and condensate fraction and
compare the predictions with results from diffusion Monte Carlo calculations by
Giorgini, Boronat, and Casulleras. We give a crude determination of the
strength of the three-body contact interaction for various model potentials.
Accurate determinations could be obtained from diffusion Monte Carlo
calculations of the energy density with higher statistics.Comment: 24 pages, RevTex, 5 ps figures, included with epsf.te
Annihilation Diagrams in Two-Body Nonleptonic Decays of Charmed Mesons
In the pole-dominance model for the two-body nonleptonic decays of charmed
mesons and , it is shown that the
contributions of the intermediate pseudoscalar and the axial-vector meson poles
cancel each other in the annihilation diagrams in the chiral limit. In the same
limit, the annihilation diagrams for the decays vanish
independently.Comment: 9 pages (+ 3 figures available upon request), UR-1316, ER-40685-766,
IC/93/21
Strong X-ray absorption in a BALQSO: PHL5200
We present \it {ASCA} observations of the z=1.98 prototype BALQSO: PHL5200. The source was detected in both SIS and GIS. A power-law spectrum (\alpha_E = 0.6^{+0.9}_{-0.6}) with large intrinsic absorption (N_H = 1.3^{+2.3}_{-1.1} \times 10^{23} cm^{-2}) best describes the spectrum. Excess column density over the local Galactic value is required at the 99\% confidence level. This detection suggests that, although BALQSOs are X-ray quiet, it is strong absorption in the BAL region that makes them appear faint to low energy X-ray experiments. The required intrinsic absorbing column density is two to three orders of magnitude larger than earlier estimates of column densities in BALQSOs. This implies that the BAL systems are much more highly ionized than previously thought
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