61,492 research outputs found

    Separation nut Patent

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    Contamination free separation nut eliminating combustion products from ambient surroundings generated by squib firin

    Role of Insects and Diseases in a Jack Pine Provenance Study

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    Two jack pine plantations were established at the Cloquet Forestry Center, Cloquet, Minnesota, in 1942 and 1943, using trees originating from 22 sites in the United States and 10 in Canada. From 1945 to 1953 the incidence of attack by insects and diseases was recorded individually for all trees, and in 1980-1981 the diameter and form of both living and dead trees were recorded. There were differences in the incidence of attack by the pests and in tree response to early injury among the various seed sources. In 1980 and in 1981 there were differences in tree form resulting from insect and both living and dead pest-free trees had the best form. The diameter increases from 1955 to 1980-1981 were almost identical for all categories with the exception of the dead pest-free trees which had the smallest diameters

    Investigation of thermionic energy conversion final report, 9 jul. - 9 sep. 1962

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    Refractory ceramic oxide for thermionic diode

    Thermal performance of a photographic laboratory process: Solar Hot Water System

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    The thermal performance of a solar process hot water system is described. The system was designed to supply 22,000 liters (5,500 gallons) per day of 66 C (150 F) process water for photographic processing. The 328 sq m (3,528 sq. ft.) solar field has supplied 58% of the thermal energy for the system. Techniques used for analyzing various thermal values are given. Load and performance factors and the resulting solar contribution are discussed

    Comment on `Series expansions from the corner transfer matrix renormalization group method: the hard-squares model'

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    Earlier this year Chan extended the low-density series for the hard-squares partition function κ(z)\kappa(z) to 92 terms. Here we analyse this extended series focusing on the behaviour at the dominant singularity zdz_d which lies on on the negative fugacity axis. We find that the series has a confluent singularity of order 2 at zdz_d with exponents θ=0.83333(2)\theta=0.83333(2) and θ=1.6676(3)\theta'= 1.6676(3). We thus confirm that the exponent θ\theta has the exact value 56\frac56 as observed by Dhar.Comment: 5 pages, 1 figure, IoP macros. Expanded second and final versio

    Worldsheet Instanton Corrections to the Kaluza-Klein Monopole

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    The Kaluza-Klein monopole is a well known object in both gravity and string theory, related by T-duality to a "smeared" NS5-brane which retains the isometry around the duality circle. As the true NS5-brane solution is localized at a point on the circle, duality implies that the Kaluza-Klein monopole should show some corresponding behavior. In this paper, we express the Kaluza-Klein monopole as a gauged linear sigma model in two dimensions and show that worldsheet instantons give corrections to its geometry. These corrections can be understood as a localization in "winding space" which could be probed by strings with winding charge around the circle.Comment: 20 pages, REVTeX, v2: minor equation correctio

    Relative production rates of 6^{6}He, 9^{9}Be, 12^{12}C in astrophysical environments

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    We assume an environment of neutrons and α\alpha-particles of given density and temperature where nuclear syntheses into 6^{6}He, 9^{9}Be and 12^{12}C are possible. We investigate the resulting relative abundance as a function of density and temperature. When the relative abundance of α\alpha-particles YαY_{\alpha} is between 0.2 and 0.9, or larger than 0.9, the largest production is 9^{9}Be or 12^{12}C, respectively. When Yα<0.2Y_{\alpha}<0.2 6^{6}He is mostly frequently produced for temperatures above about 2 GK whereas the 9^{9}Be production dominates at smaller temperatures.Comment: 5 pages, 4 figure

    Dimensional reduction in a model with infinitely many absorbing states

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    Using Monte Carlo method we study a two-dimensional model with infinitely many absorbing states. Our estimation of the critical exponent beta=0.273(5) suggests that the model belongs to the (1+1) rather than (2+1) directed-percolation universality class. We also show that for a large class of absorbing states the dynamic Monte Carlo method leads to spurious dynamical transitions.Comment: 6 pages, 4 figures, Phys.Rev. E, Dec. 199

    Large boron--epoxy filament-wound pressure vessels

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    Advanced composite material used to fabricate pressure vessel is prepeg (partially cured) consisting of continuous, parallel boron filaments in epoxy resin matrix arranged to form tape. To fabricate chamber, tape is wound on form which must be removable after composite has been cured. Configuration of boron--epoxy composite pressure vessel was determined by computer program
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