118,795 research outputs found
Densitometer Patent
Measuring density of single and two-phase cryogenic fluids in rocket fuel tank
Multiple anode arc lamp system
A high-intensity xenon arc lamp having a plurality of separate anodes axially disposed in a symmetrical pattern which spaced a discharge gap from a common cathode is presented
Observations on the Nesting of \u3ci\u3eCrabro Tenuis\u3c/i\u3e (Hymenoptera: Sphecidae)
Three nests of Crabro tenuis were studied during June 1971-1972 in Oswego County, New York. Females constructed shallow but lengthy, multicelled nests in sand with the cells being built in clusters, sometimes in series. Females plugged the entrances with damp sand and occupied the burrows during midday. Paralyzed prey were stored head inward at the end of the burrow. The deeper cells in a cluster were excavated and provisioned first and the shallower cells built and stored later, as determined by the developmental stages of the wasps within the cells. From four to seven paralyzed, adult male flies were placed in a fully provisioned cell with their venters toward the center. Such a cell usually held only one species of fly. Provisions consisted of the suborders Brachycera and Cyclorrhapha and comprised the families Rhagionidae, Anthomyiidae and Tachinidae. An egg was affixed about equally to the left or right side of the neck of a fly and this prey was placed against or near the wall of the cell. The nesting traits of C. tenuis were compared with those of other members of the Cribrarius group, C. advena of the Advena, group, C. venator of the Tumidus group and species in the Hilaris group
Indicator providing continuous indication of the presence of a specific pollutant in air
A continuous HCl in-air indicator was developed which consists of a tube-like element with an inlet end through which a continuous stream of air containing HCl enters. The air flows downstream from the inlet end and exits the element's outlet end. Positioned between the element's inlet and outlet ends are first and second spaced apart photoelectric units, which are preferably positioned adjacent the inlet and outlet ends, respectively. Ammonia gas is injected into the air, flowing through the element, at a position between the two photoelectric units. The ammonia gas reacts with the HCl in the air to form ammonium chloride particles. The difference between the outputs of the two photoelectric units is an indication of the amount of HCl in the air stream
Range Extensions for Species of Sphecidae (Hymenoptera) in the Northeastern United States
The ranges of 10 Nearctic species of Sphecidae, Spilomena pusilla, Tachytes parvus, Solierella plenoculoides, Pison agile, Entomognathus lenapeorum, Rhopalum clavipes, Crabro hilaris, C. tenuis, Alysson conicus and Lestiphorus cockerelli, are extended in the northeastern U.S. based upon collections made in Pennsylvania and New York. The first prey record for a North American species of Lestiphorus, cockerelli, is included
Conditions driving chemical freeze-out
We propose the entropy density as the thermodynamic condition driving best
the chemical freeze-out in heavy-ion collisions. Taking its value from lattice
calculations at zero chemical potential, we find that it is excellent in
reproducing the experimentally estimated freeze-out parameters. The two
characteristic endpoints in the freeze-out diagram are reproduced as well.Comment: 8 pages, 5 eps figure
On the problems of measuring transient temperature in cryogenic fluids
Cryogenic sensor errors in measuring transient temperature in cryogenic fluid
Failure mechanisms of thermal barrier coatings exposed to elevated temperatures
The failure of a ZrO2-8%Y2O3/Ni-14% Al-0.1% Zr coating system on Rene 41 in Mach 0.3 burner rig tests was characterized. High flame and metal temperatures were employed in order to accelerate coating failure. Failure by delamination was shown to precede surface cracking or spalling. This type of failure could be duplicated by cooling down the specimen after a single long duration isothermal high temperature cycle in a burner rig or a furnace, but only if the atmosphere was oxidizing. Stresses due to thermal expansion mismatch on cooling coupled with the effects of plastic deformation of the bond coat and oxidation of the irregular bond coat are the probable life limiting factors. Heat up stresses alone could not fail the coating in the burner rig tests. Spalling eventually occurs on heat up but only after the coating has already failed through delamination
Passive Optical Sample Assembly (POSA) for STS-1 quick look post-mission report
A passively deployed array of contamination-sensitive samples was mounted and flown in the cargo bay of the space shuttle Columbia during the first orbital flight test. A similar unit was mounted in a different location in the cargo bay at Dryden Flight Research Center during the postflight operations there prior to the ferry flight return of Columbia to Kennedy Space Center. The samples in both POSA arrays were subjected to a series of optical and analytical measurements prior to delivery for installation in the cargo bay and after retrieval of the flight hardware. A quick-look summary of the results of a comparison of the series of measurements is presented
Instrument continuously measures density of flowing fluids
Electromechanical densitometer continuously measures the densities of either single-phase or two-phase flowing cryogenic fluids. Measurement is made on actual flow. The instrument operates on the principle that the mass of any vibrating system is a primary factor in determining the dynamic characteristics of the system
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