23,217 research outputs found
Replaceable filters and cones for flared-tubing connectors
Connector is modified by machining the cone from one end before the fitting is bored to accommodate a metallic-filament type of slip-in filter. Thus, when surface of the cone is damaged, only the cone needs replacement
Portable remote laser sensor for methane leak detection
A portable laser system for remote detection of methane gas leaks and concentrations is disclosed. The system transmitter includes first and second lasers, tuned respectively to a wavelength coincident with a strong absorption line of methane and a reference wavelength which is weakly absorbed by methane gas. The system receiver includes a spherical mirror for collecting the reflected laser radiation and focusing the collected radiation through a narrowband optical filter onto an optial detector. The filter is tuned to the wavelength of the two lasers, and rejects background noise. The output of the optical detector is processed by a lock-in detector synchronized to the chopper, and which measures the difference between the first wavelength signal and the reference wavelength signal
Summary of the electromagnetic compatibility evaluation of the proposed satellite power system
The effects of the proposed solar power satellite (SPS) operations on electronic equipment and systems by fundamental, harmonic, and intermodulation component emissions from the orbital station; and the fundamental, harmonic, and structural intermodulation emissions from the rectenna site were evaluated. The coupling and affects interactions affecting a wide spectrum of electronic equipment are considered. The primary EMC tasking areas are each discussed separately
Using ACIS on the Chandra X-ray Observatory as a particle radiation monitor
The Advanced CCD Imaging Spectrometer (ACIS) is one of two focal-plane
instruments on the Chandra X-ray Observatory. During initial radiation-belt
passes, the exposed ACIS suffered significant radiation damage from trapped
soft protons scattering off the x-ray telescope's mirrors. The primary effect
of this damage was to increase the charge-transfer inefficiency (CTI) of the
ACIS 8 front-illuminated CCDs. Subsequently, the Chandra team implemented
procedures to remove the ACIS from the telescope's focus during high-radiation
events: planned protection during radiation-belt transits; autonomous
protection triggered by an on-board radiation monitor; and manual intervention
based upon assessment of space-weather conditions. However, as Chandra's
multilayer insulation ages, elevated temperatures have reduced the
effectiveness of the on-board radiation monitor for autonomous protection. Here
we investigate using the ACIS CCDs themselves as a radiation monitor. We
explore the 10-year database to evaluate the CCDs' response to particle
radiation and to compare this response with other radiation data and
environment models.Comment: 10 pages, 5 figures. To appear in Proc. SPIE vol. 773
Metal-Assisted Hydrolysis Reactions Involving Lipids: A Review
This report covers major advances in the use of metal ions and complexes to hydrolyze ester and phosphate ester lipid bonds. These metal-based Lewis acids have been investigated as catalysts to isolate fatty acids from biological sources, as probes to study phospholipid bilayer properties, as tools to examine signal transduction pathways, and as lead compounds toward the discovery of therapeutic agents. Metal ions that accelerate phosphate ester hydrolysis under mild conditions of temperature and pH may have the potential to mimic phospholipase activity in biochemical applications
Multidimensional integrable systems and deformations of Lie algebra homomorphisms
We use deformations of Lie algebra homomorphisms to construct deformations of
dispersionless integrable systems arising as symmetry reductions of
anti--self--dual Yang--Mills equations with a gauge group Diff.Comment: 14 pages. An example of a reduction to the Beltrami equation added.
New title. Final version, published in JM
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