1,466 research outputs found
Rocket motor exhaust products generated by the space shuttle vehicle during its launch phase (1976 design data)
The principal chemical species emitted and/or entrained by the rocket motors of the space shuttle vehicle during the launch phase of its trajectory are considered. Results are presented for two extreme trajectories, both of which were calculated in 1976
Development of flight check-out system Final report
Flight checkout system breadboard design, construction and testin
Worldwide satellite market demand forecast
The forecast is for the years 1981 - 2000 with benchmark years at 1985, 1990 and 2000. Two typs of markets are considered for this study: Hardware (worldwide total) - satellites, earth stations and control facilities (includes replacements and spares); and non-hardware (addressable by U.S. industry) - planning, launch, turnkey systems and operations. These markets were examined for the INTELSAT System (international systems and domestic and regional systems using leased transponders) and domestic and regional systems. Forecasts were determined for six worldwide regions encompassing 185 countries using actual costs for existing equipment and engineering estimates of costs for advanced systems. Most likely (conservative growth rate estimates) and optimistic (mid range growth rate estimates) scenarios were employed for arriving at the forecasts which are presented in constant 1980 U.S. dollars. The worldwide satellite market demand forecast predicts that the market between 181 and 2000 will range from 50 billion. Approximately one-half of the world market, 20 billion, will be generated in the United States
A program for the calculation of paraboloidal-dish solar thermal power plant performance
A program capable of calculating the design-point and quasi-steady-state annual performance of a paraboloidal-concentrator solar thermal power plant without energy storage was written for a programmable calculator equipped with suitable printer. The power plant may be located at any site for which a histogram of annual direct normal insolation is available. Inputs required by the program are aperture area and the design and annual efficiencies of the concentrator; the intercept factor and apparent efficiency of the power conversion subsystem and a polynomial representation of its normalized part-load efficiency; the efficiency of the electrical generator or alternator; the efficiency of the electric power conditioning and transport subsystem; and the fractional parasitic loses for the plant. Losses to auxiliaries associated with each individual module are to be deducted when the power conversion subsystem efficiencies are calculated. Outputs provided by the program are the system design efficiency, the annualized receiver efficiency, the annualized power conversion subsystem efficiency, total annual direct normal insolation received per unit area of concentrator aperture, and the system annual efficiency
Extreme Ultraviolet Emission in the Fornax Cluster of Galaxies
We present studies of the Extreme Ultraviolet (EUV) emission in the Fornax
cluster of galaxies; a relatively nearby well-studied cluster with X-ray
emitting cluster gas and a very large radio source. We examine both the
large-scale (~size of the X-ray emitting cluster gas), and the small-scale
(<arcmin) emission.
We find that this cluster has large-scale diffuse EUV emission. However, at
the sensitivity level of the existing EUVE data, this emission is due entirely
to the low energy tail of the X-ray emitting gas. We have also examined
small-scale structures in raw EUVE images of this cluster. We find that
small-scale irregularities are present in all raw Deep Survey images as a
result of small-scale detector effects. These effects can be removed by
appropriate flat-fielding. After flat-fielding, the Fornax cluster still shows
a few significant regions of small-scale EUV enhancement. We find that these
are emission from stars and galaxies in the field. We find that at existing
levels of sensitivity, there is no excess EUV emission in the cluster on either
large or small scales.Comment: 6 pages, 3 eps figures, aastex5, Accepted to ApJ
The effects of regional insolation differences upon advanced solar thermal electric power plant performance and energy costs
The performance and cost of the 10 MWe advanced solar thermal electric power plants sited in various regions of the continental United States were determined. The regional insolation data base is discussed. A range for the forecast cost of conventional electricity by region and nationally over the next several cades are presented
The effects of regional insolation differences upon advanced solar thermal electric power plant performance and energy costs
The performance and cost of four 10 MWe advanced solar thermal electric power plants sited in various regions of the continental United States was studied. Each region has different insolation characteristics which result in varying collector field areas, plant performance, capital costs and energy costs. The regional variation in solar plant performance was assessed in relation to the expected rise in the future cost of residential and commercial electricity supplied by conventional utility power systems in the same regions. A discussion of the regional insolation data base is presented along with a description of the solar systems performance and costs. A range for the forecast cost of conventional electricity by region and nationally over the next several decades is given
OGO-6 gas-surface energy transfer experiment
The kinetic energy flux of the upper atmosphere was analyzed using OGO-6 data. Energy transfer between 10 microwatts/sq cm and 0.1 W/sq cm was measured by short-term frequency changes of temperature-sensitive quartz crystals used in the energy transfer probe. The condition of the surfaces was continuously monitored by a quartz crystal microbalance to determine the effect surface contamination had on energy accommodation. Results are given on the computer analysis and laboratory tests performed to optimize the operation of the energy transfer probe. Data are also given on the bombardment of OGO-6 surfaces by high energy particles. The thermoelectrically-cooled quartz crystal microbalance is described in terms of its development and applications
Radiation mechanisms and geometry of Cygnus X-1 in the soft state
We present X-ray/gamma-ray spectra of Cyg X-1 observed during the transition
from the hard to the soft state and in the soft state by ASCA, RXTE and OSSE in
1996 May and June. The spectra consist of a dominant soft component below ~2
keV and a power-law-like continuum extending to at least ~800 keV. We interpret
them as emission from an optically-thick, cold accretion disc and from an
optically-thin, non-thermal corona above the disc. A fraction f ~ 0.6 of total
available power is dissipated in the corona. We model the soft component by
multi-colour blackbody disc emission taking into account the torque-free
inner-boundary condition. If the disc extends down to the minimum stable orbit,
the ASCA/RXTE data yield the most probable black hole mass of about 10 solar
masses and an accretion rate about 0.5 L_E/c^2, locating Cyg X-1 in the soft
state in the upper part of the stable, gas-pressure dominated, accretion-disc
solution branch. The spectrum of the corona is well modelled by repeated
Compton scattering of seed photons from the disc off electrons with a hybrid,
thermal/non-thermal distribution. The electron distribution can be
characterized by a Maxwellian with an equilibrium temperature of kT ~ 30--50
keV and a Thomson optical depth of ~0.3 and a quasi-power-law tail. The
compactness of the corona is between 2 and 7, and a presence of a significant
population of electron-positron pairs is ruled out. We find strong signatures
of Compton reflection from a cold and ionized medium, presumably an accretion
disc, with an apparent reflector solid angle ~0.5--0.7. The reflected continuum
is accompanied by a broad iron K-alpha line.Comment: 18 pages, 12 figures, 2 landscape tables in a separate file. Accepted
to MNRA
Development and application of rice starch based edible coating to improve the postharvest storage potential and quality of plum fruit (<i>Prunus salicina</i>)
The study investigated the possibility of enhancing the shelf life of plum fruit coated with rice starch-ι-carrageenan (RS-ι-car) composite coating blended with sucrose fatty acid esters (FAEs). Film solution (starch 3%, carrageenan 1.5% and FAEs 2%) was prepared by mixing the ingredients and properties of stand-alone films (physical, mechanical, barrier and surface morphology) were studied before applying the coating on fruit surface. Fruit were stored at 20 °C for 3 weeks and analyzed for weight loss, ethylene production, respiration rate, color change, firmness, and titratable acidity (TA) and soluble solid content (SSC). Surface morphology of stand-alone film and fruit surface (after applying on the plum fruit) was studied using scanning electron microscopy (SEM). Phytochemical analysis was performed during the storage period and total phenolic content (TPC), total antioxidant capacity (TAC), flavonoid content (FC) and free radical scavenging activity were determined. The rice starch composite coating was shown to be effective in reducing both weight loss (WL) and respiration rate and inhibiting the endogenous ethylene production when compared to the uncoated control fruit stored at room temperature (p < 0.05). TPC, TAC, FC and free radical scavenging activity was unaffected in the coated fruit throughout the storage period (p < 0.05). The findings reported in this study indicate that the RS-ι-car-FAEs coating prolongs the shelf life and maintains the overall quality of plum fruit during storage and could potentially be commercialized as a new edible coating for the plum fruit industry
- …