1,838 research outputs found
Force Tests of the 4.5" Rocket, T38E3
This report covers the tests of a 2" diameter model of the
4. 5" H. E. Rocket, T38E3, to determine the force and moment coefficients and the location of the center of pressure. The tests were made in the 14" diameter working section of the High Speed Water Tunnel at the California Institute of Technology. The work was authorized by a letter of January 31, 1944, from Dr. E. H.
Colpitts, Chief of Section 6.1, National Defense Research Committee, New York City
Hydrodynamic Characteristics of the 12.75 Inch Type X10 Antisubmarine Rocket
This laboratory was requested to recommend a nose design for the 12.75-inch Antisubmarine Rocket which would give a terminal velocity of 40 feet per second. Such a nose was to have a flat face with a diameter not less than half the projectile diameter.
Two designs are submitted herein. The diagram shows their outlines together with that of the original nose. Calculations indicate that either should give a terminal velocity between 47 and 48 feet per second in sea water of 60° Fahrenheit (with 23.7 lbs. of water in discharged motor tube, 45 ft/sec if empty). These nose shapes are sufficiently different to afford considerable latitude in respect to characteristics of maximum range, ricochet, cavitation, and performance in the entry bubble.
It is unlikely that any other nose shape could further materially reduce the drag while other components remain unchanged.
The new noses have trivial effect on the cross force coefficient developed with the original nose and all have considerable static stability
Force Tests of MK 13-1 Torpedo with Suspension Bands
The purpose of the tests reported herein was to determine the effect upon hydrodynamic characteristics of two suspension bands of the same design when placed on the Mk 13-1 Torpedo with band centers spaced 14 and 30 inches and symmetrical about the center of gravity. Particular interest was in the effect upon torpedo running speed.
The tests indicated that the bands would cause a reduction of approximately 2 knots from the normal speed of 33 knots. Cavitation measurements indicated that both of the top and bottom protrusions would cavitate at normal running speeds and depths.
The effect of the bands on moment, lift, and cross force coefficients is, generally, of a minor nature
Other Orchards
Other Orchards is comprised of poems each suspect in their own way of those boundaries that might separate humans from nature, rural from urban, worker from scholar, or human from beast. Using the figure of the orchard, a kind of “false forest,” this collection studies the ways we map ourselves onto our work and the way work might inform an understanding of the self. Ultimately, these are poems that emerge from the seams of things—the shoulder of highway strewn with dead antelope, the feral apple tree lost to the woods, the farmer lost in their work, slowing becoming less and less distinguishable from the soil and fruit and birds. These poems bear necessary and tender witness to animals living and animals dying. They situate the worker as curious philosopher, daydreamer, and a student of an already-changed ecology, extolling the virtues of endurance, patience, pressing-on, adaptability. Here, the old tractor is as vital and lovely as the first blossom, the abandoned lamb as worthy of consideration as the vast, green wild
Effects of Feeding by Two Folivorous Arthropods on Susceptibility of Hybrid Poplar Clones to a Foliar Pathogen
We investigated variation in folivore-induced effects on subsequent plant suitability to a foliar pathogen. We used a leaf disk assay to expose three clones of hybrid poplar, NC11382, NE332 and NM6, to colonization by a leaf spot pathogen, Septoria musiva. Undamaged leaf disks of NE332 were the most resistant to S. musiva, followed by NM6 and NC11382, respectively. To test the effects of prior herbivory on subsequent susceptibility to this fungal pathogen, we inoculated S. musiva on leaf disks taken from leaves which had been exposed to feeding by Tetranychus mites or cottonwood leaf beetles. Prior activity by mites and cottonwood leaf beetle affected the subsequent susceptibility of clones NC 11382 and NE332 to S. musiva
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