Static force tests of a sharp leading edge delta-wing model at ambient and cryogenic temperatures with a description of the apparatus employed

A sharp leading edge delta-wing model was tested through an angle-of-attack range at Mach numbers of 0.75, 0.80, and 0.85 at both ambient and cryogenic temperatures in the Langley 1/3-meter transonic cryogenic tunnel. Total pressure was varied with total temperature in order to hold test Reynolds number constant at a given Mach number. Agreement between the aerodynamic data obtained at ambient and cryogenic temperatures indicates that flows with leading-edge vortex effects are duplicated properly at cryogenic temperatures. The test results demonstrate that accurate aerodynamic data can be obtained by using conventional force-testing techniques if suitable measures are taken to minimize temperature gradients across the balance and to keep the balance at ambient (warm) temperatures during cryogenic operation of the tunnel

Wind-tunnel roll-damping measurements of a winged space shuttle configuration in launch attitude

Ground-wind load studies were conducted on three model configurations to assess the importance of aeroelastic instabilities of erected space shuttle vehicles. Roll damping was measured on a fuselage-alone model, which had a D cross section, and a fuselage and tail surfaces in combination with either a clipped-delta wing or a low-sweep tapered wing as the primary lifting surface. The largest negative roll-damping coefficients were measured with the fuselage-alone configuration and were a function of wind azimuth. At the wind azimuths at which the wing-fuselage configuration was unstable, the negative roll-damping coefficients were a function of reduced frequency

Supersonic dynamic stability characteristics of a space shuttle orbiter

Supersonic forced-oscillation tests of a 0.0165-scale model of a modified 089B Rockwell International shuttle orbiter were conducted in a wind tunnel for several configurations over a Mach range from 1.6 to 4.63. The tests covered angles of attack up to 30 deg. The period and damping of the basic unaugmented vehicle were calculated along the entry trajectory using the measured damping results. Some parameter analysis was made with the measured dynamic derivatives. Photographs of the test configurations and test equipment are shown

Hydrogenic Spin Quantum Computing in Silicon: A Digital Approach

We suggest an architecture for quantum computing with spin-pair encoded qubits in silicon. Electron-nuclear spin-pairs are controlled by a dc magnetic field and electrode-switched on and off hyperfine interaction. This digital processing is insensitive to tuning errors and easy to model. Electron shuttling between donors enables multi-qubit logic. These hydrogenic spin qubits are transferable to nuclear spin-pairs, which have long coherence times, and electron spin-pairs, which are ideally suited for measurement and initialization. The architecture is scalable to highly parallel operation.Comment: 4 pages, 5 figures; refereed and published version with improved introductio

A nullstellensatz for sequences over F_p

Let p be a prime and let A=(a_1,...,a_l) be a sequence of nonzero elements in F_p. In this paper, we study the set of all 0-1 solutions to the equation a_1 x_1 + ... + a_l x_l = 0. We prove that whenever l >= p, this set actually characterizes A up to a nonzero multiplicative constant, which is no longer true for l < p. The critical case l=p is of particular interest. In this context, we prove that whenever l=p and A is nonconstant, the above equation has at least p-1 minimal 0-1 solutions, thus refining a theorem of Olson. The subcritical case l=p-1 is studied in detail also. Our approach is algebraic in nature and relies on the Combinatorial Nullstellensatz as well as on a Vosper type theorem.Comment: 23 page

Analysis of validation tests of the Langley pilot transonic cryogenic tunnel

A pilot transonic cryogenic pressure tunnel has recently been developed and proof tested at the NASA Langley Research Center. In addition to providing an attractive method for obtaining high Reynolds number results at moderate aerodynamic loadings and tunnel power, this unique tunnel allows the independent determination of the effects of Reynolds number, Mach number, and dynamic pressure (aeroelasticity) on the aerodynamic characteristics of the model under test. The proof of concept experimental and theoretical studies are briefly reviewed. Experimental results obtained on both two- and three-dimensional models have substantiated that cryogenic test conditions can be set accurately and that cryogenic gaseous nitrogen is a valid test medium

Alien Registration- Davenport, Bernie E. (Caribou, Aroostook County)

https://digitalmaine.com/alien_docs/26137/thumbnail.jp

A Concise Update of the Information Provided in \u3ci\u3eThe Butterflies of Southern California\u3c/i\u3e (1973) by Thomas C. Emmel and John F. Emmel

This paper’s purpose is to bring together in one resource a concise, but thorough, report on the current status of butterflies discussed in the Butterflies of Southern California by Thomas C. Emmel and John F. Emmel, published by the Natural History Museum of Los Angeles County, Los Angeles, California, United States. 1973. This update deals primarily with new species or subspecies, taxonomic matters, and new distributional information. The family order follows A Catalogue / Checklist of the Butterflies of America North of Mexico by Clifford D. Ferris, editor, published by the Lepidopterists’ Society as Memoir No. 3, 1989. Species order follows the Emmel, Emmel & Mattoon checklist for California in Systematics of Western North American Butterflies, Thomas C. Emmel, editor, Mariposa Press Gainesville, Florida, United States (pages 825-836), 1998. The area delimited as southern California here is the same as in The Butterflies of Southern California, except that all of San Luis Obispo County is included. Readers will need to research several publications to read these changes since 1973. The primary resources from which this updated information is drawn are: annual Season Summary reports published in the News of the Lepidopterists’ Society, various scientific journals (including Journal of the Lepidopterists’ Society, Bulletin of the Allyn Museum, and Journal of Research on the Lepidoptera) and articles and information reported by various researchers and observers. Much such information is found in the Systematics publication. In Systematics, there are 73 chapters written by a number of authors, with many of the chapters including information on the southern California fauna. Information for Kern County is found in Butterflies of North America 3. Butterflies of Kern and Tulare Counties, California by Ken Davenport, published as a contribution of the C. P. Gillette Museum of Arthopod Diversity, Colorado State University, Fort Collins, Colorado, United States