108,930 research outputs found
Hot-cracking studies of Inconel 718 weld- heat-affected zones
Hot ductility tests, gas-tungsten-arc fillerless fusion tests, and circle patch-weld-restraint tests were conducted on Inconel 718 to better understand and correlate the weldability /resistance to hot cracking/ of the alloy. A correlation of the test results with composition, heat-treat condition, grain size, and microstructure was made
Cutter and stripper reduces coaxial cable connection time
Consisting of three pivoted members, this hand cutter and stripper positions to cut shielding and insulation at the right distance and depth. Coaxial cable is prepared quickly and accurately for connector attachment
Vibration exciting mechanisms induced by flow in turbomachine stages
The quasisteady computer analysis of the perturbated centrifugal impeller passage flow was reviewed. A total of 115 stage calculations were used to define the fluid damping coefficient, delta sub fluid. Results indicate that the average total damping coefficient per stage needed for stability is delta sub total 1.85
An interactive method for digitizing zone maps
A method is presented for digitizing maps that consist of zones, such as contour or climatic zone maps. A color-coded map is prepared by any convenient process. The map is then read into memory of an Image 100 computer by means of its table scanner, using colored filters. Zones are separated and stored in themes, using standard classification procedures. Thematic data are written on magnetic tape and these data, appropriately coded, are combined to make a digitized image on tape. Step-by-step procedures are given for digitization of crop moisture index maps with this procedure. In addition, a complete example of the digitization of a climatic zone map is given
Local properties of patterned vegetation: quantifying endogenous and exogenous effects
Dryland ecosystems commonly exhibit periodic bands of vegetation, thought to
form due to competition between individual plants for heterogeneously
distributed water. In this paper, we develop a Fourier method for locally
identifying the pattern wavenumber and orientation, and apply it to aerial
images from a region of vegetation patterning near Fort Stockton, Texas. We
find that the local pattern wavelength and orientation are typically coherent,
but exhibit both rapid and gradual variation driven by changes in hillslope
gradient and orientation, the potential for water accumulation, or soil type.
Endogenous pattern dynamics, when simulated for spatially homogeneous
topographic and vegetation conditions, predict pattern properties that are much
less variable than the orientation and wavelength observed in natural systems.
Our local pattern analysis, combined with ancillary datasets describing soil
and topographic variation, highlights a largely unexplored correlation between
soil depth, pattern coherence, vegetation cover and pattern wavelength. It
also, surprisingly, suggests that downslope accumulation of water may play a
role in changing vegetation pattern properties
Strain-age cracking in Rene 41 alloy
Weldability test determines the effects of material and process variables on the occurrence of strain-age cracking, and demonstrates effective and practical means for its reduction. Studies consist of tensile, impact, and stress-rupture tests
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