71,324 research outputs found
Fatigue failure load indicator
An indicator for recording the load at which a fatigue specimen breaks during the last cycle of a fatigue test is described. A load cell is attached to the specimen which is alternately subjected to tension and compression loads. The output of the load cell which is proportional to the load on the specimen is applied to the input of a peak detector. Each time the specimen is subjected to a compression load, means are provided for applying a positive voltage to the rest of the peak detector to reset it. During the last cycle of the tension load the peak detector measures the maximum load on the specimen. Means are provided for disconnecting the load cell from the peak detector when there is a failure in the specimen
Device for quickly sensing the amount of O2 in a combustion product gas
A sensing device comprising an O2 sensor, a pump, a compressor, and a heater is provided to quickly sense the amount of O2 in a combustion product gas. A sample of the combustion product gas is compressed to a pressure slightly above one atmosphere by the compressor. Next, the heater heats the sample between 800 C and 900 C. Next, the pump causes the sample to be flushed against the electrode located in O2 sensor 6000 to 10,000 times per second. Reference air at approximately one atmosphere is provided to the electrode of O2 sensor. Accordingly, the O2 sensor produces a voltage which is proportional to the amount of oxygen in the combustion product gas. This voltage may be used to control the amount of O2 entering into the combustion chamber which produces the combustion product gas
Curved cap corrugated sheet
The report describes a structure for a strong, lightweight corrugated sheet. The sheet is planar or curved and includes a plurality of corrugation segments, each segment being comprised of a generally U-shaped corrugation with a part-cylindrical crown and cap strip, and straight side walls and with secondary corrugations oriented at right angles to said side walls. The cap strip is bonded to the crown and the longitudinal edge of said cap strip extends beyond edge at the intersection between said crown and said side walls. The high strength relative to weight of the structure makes it desirable for use in aircraft or spacecraft
MAST flight system dynamic performance
The MAST Flight System as a test bed for large space structure control algorithms is discussed. An overview is given of the control system architecture. The actuators, the sensors, the control computer, and the baseline damping algorithm are discussed
Coherent coupling between surface plasmons and excitons in semiconductor nanocrystals
We present an experimental demonstration of strong coupling between a surface
plasmon propagating on a planar silver substrate, and the lowest excited state
of CdSe nanocrystals. Variable-angle spectroscopic ellipsometry measurements
demonstrated the formation of plasmon-exciton mixed states, characterized by a
Rabi splitting of 82 meV at room temperature. Such a coherent
interaction has the potential for the development of plasmonic non-linear
devices, and furthermore, this system is akin to those studied in cavity
quantum electrodynamics, thus offering the possibility to study the regime of
strong light-matter coupling in semiconductor nanocrystals at easily accessible
experimental conditions.Comment: 12 pages, 4 figure
Proposed fast-response oxygen monitoring and control system for the Langley 8-foot high-temperature tunnel
A fast-response oxygen monitoring and control system, based on a Y2O3-stabilized ZrO2 sensor, was developed and tested in the laboratory. The system is capable of maintaining oxygen concentration in the CH4-O2-air combustion product gases at 20.9 + or - 1.0 percent. If the oxygen concentration in the exhaust stream differs from that in normal air by 25 percent or more, an alarm signal is provided for automatic tunnel shutdown. The overall prototype system response time was reduced from about 1 sec in the original configuration to about 0.2 sec. The basis of operation and the results of laboratory tests of the system are described
Advanced Computer Dormant Reliability Study Final Report
Reliability of integrated circuits and discrete components of electronics for computer and dormant module for Minuteman
Ground pattern analysis in the Great Plains
There are no author-identified significant results in this report
FACTORS AFFECTING EFFICIENCY OF FEEDER CATTLE HEDGING IN KENTUCKY
Livestock Production/Industries,
- …