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

Millipeds (Arthropoda: Diplopoda) of the Ark - La - Tex. VI. New Geographic Distributional Records from Select Counties of Arkansas

We continue to report, in the sixth of a series of papers, new geographic records for millipeds of the state, including noteworthy records for some taxa collected from Crowley’s Ridge in eastern Arkansas. This contribution documents 47 new co. records and includes records for 19 species within 9 families and 5 orders. More uncommon millipeds found included Okliulus carpenteri (Parajulidae), Eurymerodesmus newtonus (Eurymerodesmidae), Pseudopolydesmus minor (Polydesmidae) and undescribed species of Ethojulus (Parajulidae) and Nannaria (Xystodesmidae). Undoubtedly, additional records will be reported in the future as several gaps in the distribution of Arkansas millipeds remain

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

Flow Around XBT2D Airplane with a 2,000 Pound G.P. Bomb

Flight tests of the XBT2D-1 Airplane with 2,000 pound G. P. Bomb externally attached to the fuselage resulted in serious buffeting at critical air speeds. In a memorandum from the Bureau of Ordnance, U. S. Navy, dated 13 May, 1946, the Hydrodynamics Laboratory at the California Institute of Technology was requested to make Polarized Light Flume studies and cavitation tests on a model. The object of the tests was, originally, to obtain information helpful in eliminating such buffeting

Coccidia (Apicomplexa: Eimeriidae) of Three-toed Box Turtles, Terrapene carolina triunguis (Reptilia: Testudines), from Arkansas and Oklahoma

We collected 50 three-toed box turtles (Terrapene carolina triunguis) from 9 counties of Arkansas and 4 counties of Oklahoma, and examined their feces for coccidial parasites. Nine of 24 (38%) turtles from Arkansas and 8 of 26 (31%) from Oklahoma were found to be passing oocysts of Eimeria ornata. This represents two new geographic distributional records for this coccidian. Measurements of individual isolates of E. ornate as well as morphological characteristics are provided with comparison to its original description and to another Terrapene coccidian, Eimeria carri. In addition, we noted an adelid pseudoparasite being passed by a single T. c. triunguis from Oklahoma that likely represents a parasite of arthropods

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