51,280 research outputs found
Air sampler collects and protects minute particles
Air ejector impactor sampler collects and protects samples of particles greater than 0.1 micron in diameter. In operation, it causes impaction of particle-laden air onto several collection surfaces within a collection cylinder. When not operating, the collector cylinder is maintained in a retracted state within a protective envelope
Apparatus for sampling particulates in gases
A device for sampling particulates in gases is described. The device is used to obtain samples of the upper atmosphere. The equipment used a common source of gas pressure to provide the driving gas of an air ejector pump. The sample collection cylinder has many slit impactors running longitudinally on the outer surface of a cylinder and terminating just short of each end of the cylinder
Gas ion laser construction for electrically isolating the pressure gauge thereof
The valve and the pressure gauge of a gas ion laser were electrically insulated from the laser discharge path by connecting them in series with the cathode of the laser. The laser cathode can be grounded and preferably is a cold cathode although a hot cathode may be used instead. The cold cathode was provided with a central aperture to which was connected both the pressure gauge and the gas pressure reservoir through the valve. This will effectively prevent electric discharges from passing either to the pressure gauge or the valve which would otherwise destroy the pressure gauge
AIS Investigation of Agricultural Monocultures
Airborne Imaging Spectrometer (AIS) data were acquired over an agricultural area in eastern San Joaquin County, California in July, 1984. Cover type information was subsequently collected for all fields along this flight line. The lack of detailed ground data on individual fields, however, limited AIS data analysis to a qualitative comparison of the spectral reflectance curves for a total of nine cover types. Based on this analysis, it appears that cover types with a positive slope in the 1550 to 1700 nm region have a higher spectral response in the 1200 to 1300 nm region compared to those cover types with a negative slope in the 1550 to 1700 nm region. Within cover type, spectral variability was also found to be greater than that between cover types. Given the lack of additional field data, the reason for these differences is a matter of speculation
Bicategories of spans as cartesian bicategories
Bicategories of spans are characterized as cartesian bicategories in which
every comonad has an Eilenberg-Moore ob ject and every left adjoint arrow is
comonadic
Apollo 16 mission report. Supplement 2: Service Propulsion system final flight evaluation
The Apollo 16 Mission was the sixteenth in a series of flights using Apollo flight hardware and included the fifth lunar landing of the Apollo Program. The Apollo 16 Mission utilized CSM 113 which was equipped with SPS Engine S/N 66 (Injector S/N 137). The engine configuration and expected performance characteristics are presented. Since previous flight results of the SPS have consistently shown the existence of a negative mixture ratio shift, SPS Engine S/N 66 was reorificed to increase the mixture ratio for this mission. The propellant unbalance for the two major engine firings is compared with the predicted unbalance. Although the unbalance at the end of the TEI burn is significantly different than the predicted unbalance, the propellant mixture ratio was well within limits. The SPS performed six burns during the mission, with a total burn duration of 575.3 seconds. The ignition time, burn duration and velocity gain for each of the six SPS burns are reported
A Coronal Hole's Effects on CME Shock Morphology in the Inner Heliosphere
We use STEREO imagery to study the morphology of a shock driven by a fast
coronal mass ejection (CME) launched from the Sun on 2011 March 7. The source
region of the CME is located just to the east of a coronal hole. The CME ejecta
is deflected away from the hole, in contrast with the shock, which readily
expands into the fast outflow from the coronal hole. The result is a CME with
ejecta not well centered within the shock surrounding it. The shock shape
inferred from the imaging is compared with in situ data at 1 AU, where the
shock is observed near Earth by the Wind spacecraft, and at STEREO-A. Shock
normals computed from the in situ data are consistent with the shock morphology
inferred from imaging.Comment: to appear in The Astrophysical Journa
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