5,585 research outputs found
Modeling and optimization of a regenerative fuel cell system using the ASPEN process simulator
The Hydrogen-Oxygen Regenerative Fuel Cell System was identified as a key component for energy storage in support of future lunar missions. Since the H2-O2 regenerative electrochemical conversion technology has not yet been tested in space applications, it is necessary to implement predictive techniques to develop initial feasible system designs. The ASPEN simulation software furnishes a constructive medium for analyzing and for optimizing such systems. A rudimentary regenerative fuel cell system design was examined using the ASPEN simulator and this modular approach allows for easy addition of supplementary ancillary components and easy integration with life support systems. The modules included in the preliminary analyses may serve as the fundamental structure for more complicated energy storage systems
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Data-mining chess databases
This is a report on the data-mining of two chess databases, the objective being to compare their sub-7-man content with perfect play as documented in Nalimov endgame tables. Van der Heijden’s ENDGAME STUDY DATABASE IV is a definitive collection of 76,132 studies in which White should have an essentially unique route to the stipulated goal. Chessbase’s BIG DATABASE 2010 holds some 4.5 million games. Insight gained into both database content and data-mining has led to some delightful surprises and created a further agenda
Co-transport-induced instability of membrane voltage in tip-growing cells
A salient feature of stationary patterns in tip-growing cells is the key role
played by the symports and antiports, membrane proteins that translocate two
ionic species at the same time. It is shown that these co-transporters
destabilize generically the membrane voltage if the two translocated ions
diffuse differently and carry a charge of opposite (same) sign for symports
(antiports). Orders of magnitude obtained for the time and lengthscale are in
agreement with experiments. A weakly nonlinear analysis characterizes the
bifurcation
The compact far infrared emission from the young stellar object IRAS 16293-2422
High resolution far IR observations at 50 and 100 microns were made of the young stellar object (YSO), IRAS 16293-2422. The observations are part of a systematic high resolution study of nearby YSO's. The purpose is to obtain resolution in the far IR comparable to that at other wavelengths. Until recently, the high resolution that has been available in the far IR has been from either IRAS (angular resolution of approx 4 min) or the KAO using standard FIR photometry (approx 35 sec). With scanning techniques, it is possible to obtain 10 sec resolution on bright sources. Such a resolution is necessary to better determine the physical conditions of the YSO, and to compare with model of star formation. In order to better constrain the models for the source, the YSO was observed at both 50 and 100 microns on several flights in 1988 April from the KAO. Estimates are presented of the size both along the major and minor axis of the disk, as well as estimates of the dust temperature and 100 micron opacity for the YSO
1983 opinions on farm policy from leading Missouri farmers
"In March 1983, 1,600 of Missouri's leading farmers were mailed a questionnaire asking them to state their opinions about current issues in farm policy. The answers from the 745 farmers who responded are summarized in this guide sheet.* The names of farmers sent questionnaires were selected randomly from the mailing list for the extension newsletter Economic and Marketing Information for Missouri Agriculture and from a list assembled by area extension specialists. The farmers included in the March 1983 survey are believed to be representative of Missouri's leading farmers, but not of all farmers. The survey cannot be regarded as reporting for all of Missouri agriculture."--First page.Meredith M. Burks and Harold F. Breimyer (Department of Agricultural Economics College of Agriculture)New 10/83/8
Correlation Studies of Zea mays under Field Conditions
This paper is a report of statistical studies involving correlations between various growth responses of corn plants and factor data obtained in the immediately vicinity of the growing plants. Weekly growth measurements of the corn plants were obtained and these were correlated with the factor data obtained from recording instruments. 22. The relation of moisture-Thermal conductivity of oats and other grain has received little if any attention. Employing the Stiles apparatus, an attempt has been made to ascertain the specific thermal conductivity of oats, having moisture contents up to maximum absorption. The thermal conductivity of a substance is the amount of heat which will pass per unit of time through unit area of a layer of the substance of unit thickness, the opposite faces of the layer having a temperature difference of one degree. 23. Some meotic-Refinements of the paraffin technique make it possible to demonstrate critical details of meiosis. The process yields figures that are comparable to the results of the smear process. Progressive synapsis during amphitene, and the tetrad structure of the chromosome at strepsiphase can be readily demonstrated
The use of shake cultures of Neurospora for growth experiments
The use of shake cultures of Neurospora for growth experiment
On the Distribution of a Second Class Particle in the Asymmetric Simple Exclusion Process
We give an exact expression for the distribution of the position X(t) of a
single second class particle in the asymmetric simple exclusion process (ASEP)
where initially the second class particle is located at the origin and the
first class particles occupy the sites {1,2,...}
GALEX Observations of CS and OH Emission in Comet 9P/Tempel 1 During Deep Impact
GALEX observations of comet 9P/Tempel 1 using the near ultraviolet (NUV)
objective grism were made before, during and after the Deep Impact event that
occurred on 2005 July 4 at 05:52:03 UT when a 370 kg NASA spacecraft was
maneuvered into the path of the comet. The NUV channel provides usable spectral
information in a bandpass covering 2000 - 3400 A with a point source spectral
resolving power of approximately 100. The primary spectral features in this
range include solar continuum scattered from cometary dust and emissions from
OH and CS molecular bands centered near 3085 and 2575 A, respectively. In
particular, we report the only cometary CS emission detected during this event.
The observations allow the evolution of these spectral features to be tracked
over the period of the encounter. In general, the NUV emissions observed from
Tempel 1 are much fainter than those that have been observed by GALEX from
other comets. However, it is possible to derive production rates for the parent
molecules of the species detected by GALEX in Tempel 1 and to determine the
number of these molecules liberated by the impact. The derived quiescent
production rates are Q(H2O) = 6.4e27 molecules/s and Q(CS2) = 6.7e24
molecules/s, while the impact produced an additional 1.6e32 H2O molecules and
1.3e29 CS2 molecules, a similar ratio as in quiescent outgassing.Comment: 15 pages, 4 figures, accepted for publication in the Astrophysical
Journa
QUANTITATION OF HUMAN RED BLOOD CELL FIXATION BY GLUTARALDEHYDE
The uptake of glutaraldehyde by human red blood cells has been measured as a function of time by a freezing point osmometer. The rate of attachment of glutaraldehyde to the cell proteins is high over the first hour, declining to zero over a period of a few days. The number of glutaraldehyde molecules cross-linking with each hemoglobin molecule is of the order of 200, in reasonable agreement with the calculated number of attachment sites. The cell membrane is immediately highly permeable to glutaraldehyde. Selective permeability to ions is lost during fixation. Ionic equilibrium is obtained only after a few hours. An optimum fixation technique for shape preservation is suggested
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