8,744 research outputs found
Propellant material compatibility program and results
The effects of long-term (up to 10 years) contact of inert materials with earth-storable propellants were studied for the purpose of designing chemical propulsion system components that can be used for current as well as future planetary spacecraft. The primary experimental work, and results to date are reported. Investigations include the following propellants: hydrazine, hydrazine-hydrazine nitrate blends, monomethyl-hydrazine, and nitrogen tetroxide. Materials include: aluminum alloys, corrosion-resistant steels, and titanium alloys. More than 700 test specimen capsules were placed in long-term storage testing at 43 C in the special material compatibility facility. Material ratings relative to the 10-year requirement have been assigned
The monoid of queue actions
We investigate the monoid of transformations that are induced by sequences of
writing to and reading from a queue storage. We describe this monoid by means
of a confluent and terminating semi-Thue system and study some of its basic
algebraic properties, e.g., conjugacy. Moreover, we show that while several
properties concerning its rational subsets are undecidable, their uniform
membership problem is NL-complete. Furthermore, we present an algebraic
characterization of this monoid's recognizable subsets. Finally, we prove that
it is not Thurston-automatic
Hydrogen bonding in substituted nitroanilines : isolated nets in 1,3-diamino-4-nitrobenzene and continuously interwoven nets in 3,5-dinitroaniline
Peer reviewedPublisher PD
Singular value decomposition applied to compact binary coalescence gravitational-wave signals
We investigate the application of the singular value decomposition to
compact-binary, gravitational-wave data-analysis. We find that the truncated
singular value decomposition reduces the number of filters required to analyze
a given region of parameter space of compact binary coalescence waveforms by an
order of magnitude with high reconstruction accuracy. We also compute an
analytic expression for the expected signal-loss due to the singular value
decomposition truncation.Comment: 4 figures, 6 page
If Hay Mows Are Empty
Dairy cows fed plenty of silage, properly balanced with a grain mixture, will produce just as well and keep in as good condition as those fed both alfalfa hay and silage as roughage. In other words, apparently cows do not need a dry roughage along with silage
Normal growth in dairy cattle
Male calves of all the breeds studied weighed more at birth than female calves. The birth weights of female calves were as follows: Holsteins, 89 pounds; Guernseys, 65 pounds; Ayrshires, 63 pounds; and Jerseys, 50 pounds.
There was considerable variation among individuals in their live weights. Coefficients of variation ranged from above 15 percent in calves to less than 10 percent in 2-year old heifers.
The data show that the time of first freshening marks the greatest change in the rate of growth in live weight.
Very little difference can be observed in the relative rates at which animals of the different breeds approach mature size.
Mature growth values are approached most rapidly in height at withers. This measurement is not even doubled from birth to maturity.
Holsteins, Ayrshires and Jerseys are wider in relation to depth than Guernseys.
The average weight for mature Holsteins in the Iowa Experiment Station herd may be considered as 1,405 pounds; Ayrshires, 1,111 pounds; Guernseys, 1,072 pounds; and Jerseys, 950 pounds. Gestation and lactation are shown to have considerable influence upon live weight.
Late freshening heifers weigh more than heifers calving at the usual time but after freshening the weights of both groups are quite comparable
Efficiency of dairy rations containing various quantities of grain
The dairy cow is particularly well adapted for consuming and utilizing large quantities of roughages, though she responds well to grain feeding. The relative quantities of roughage and grain that should be fed are usually determined by the physiologic effects and economic efficiencies of such rations when fed to dairy cattle.
One would hardly expect high.producing cows to maintain a high yield when consuming roughage alone, because such a ration is so bulky that it prevents the intake of sufficient nutrients for maximum production. And yet, very good results have been obtained in certain areas by such a system of feeding. Then, too, the nutrients of roughage crops are usually produced at considerably less cost than those of grain crops (17) (3). Furthermore, rough. ages are more plentiful on most farms than grain crops, especially in recent years when there has been a marked increase in the production of hay and pasture crops at some sacrifice of grain production. Under these conditions the advisability of supplementing roughage rations with grain becomes a question of interest to dairy farmers
Cows Are Good Bean Market
Dairy cows will produce more butterfat on a ration in which whole (cracked) soybeans provide the protein supplement than on an ordinary ration of mixed grains which uses such a protein supplement as soybean oilmeal
Early Advanced LIGO binary neutron-star sky localization and parameter estimation
2015 will see the first observations of Advanced LIGO and the start of the
gravitational-wave (GW) advanced-detector era. One of the most promising
sources for ground-based GW detectors are binary neutron-star (BNS)
coalescences. In order to use any detections for astrophysics, we must
understand the capabilities of our parameter-estimation analysis. By simulating
the GWs from an astrophysically motivated population of BNSs, we examine the
accuracy of parameter inferences in the early advanced-detector era. We find
that sky location, which is important for electromagnetic follow-up, can be
determined rapidly (~5 s), but that sky areas may be hundreds of square
degrees. The degeneracy between component mass and spin means there is
significant uncertainty for measurements of the individual masses and spins;
however, the chirp mass is well measured (typically better than 0.1%).Comment: 4 pages, 2 figures. Published in the proceedings of Amaldi 1
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