2,417 research outputs found
Algebra Structures on Hom(C,L)
We consider the space of linear maps from a coassociative coalgebra C into a
Lie algebra L. Unless C has a cocommutative coproduct, the usual symmetry
properties of the induced bracket on Hom(C,L) fail to hold. We define the
concept of twisted domain (TD) algebras in order to recover the symmetries and
also construct a modified Chevalley-Eilenberg complex in order to define the
cohomology of such algebras
Cyclical Tests of Selected Space Shuttle TPS Metallic Materials in a Plasma Arc Tunnel. Volume 2: Appendices - Data Tabulation
Calibration data are presented for heat flux and pressure profiles, model temperature histories, and model weight and thickness changes
Cyclical tests of selected space shuttle TPS metallic materials in a plasma arc tunnel Volume 1: Description of tests and program summary
Work, concerned with cyclical thermal evaluation of selected space shuttle thermal protection system (TPS) metallic materials in a hypervelocity oxidizing atmosphere that approximated an actual entry environment, is presented. A total of 325 sample test hours were conducted on 21 super-alloy metallic samples at temperatures from 1800 to 2200 F (1256 to 1478 K) without any failures. The 4 x 4 in. (10.2 x 10.2 cm) samples were fabricated from five nickel base alloys and one cobalt base alloy. Eighteen of the samples were cycled 100 times each and the other three samples 50 times each in a test stream emanating from an 8 in. (20.3 cm) diam exit, Mach 4.6, conical nozzle. The test cycle consisted of a 10 min heat pulse to a controlled temperature followed by a 10 min cooldown period. The TD-NiCrAl and TD-NiAlY materials showed the least change in weight, thickness, and physical appearance even though they were subjected to the highest temperature environment
Space suit
A pressure suit for high altitude flights, particularly space missions is reported. The suit is designed for astronauts in the Apollo space program and may be worn both inside and outside a space vehicle, as well as on the lunar surface. It comprises an integrated assembly of inner comfort liner, intermediate pressure garment, and outer thermal protective garment with removable helmet, and gloves. The pressure garment comprises an inner convoluted sealing bladder and outer fabric restraint to which are attached a plurality of cable restraint assemblies. It provides versitility in combination with improved sealing and increased mobility for internal pressures suitable for life support in the near vacuum of outer space
Engineering Functional Quantum Algorithms
Suppose that a quantum circuit with K elementary gates is known for a unitary
matrix U, and assume that U^m is a scalar matrix for some positive integer m.
We show that a function of U can be realized on a quantum computer with at most
O(mK+m^2log m) elementary gates. The functions of U are realized by a generic
quantum circuit, which has a particularly simple structure. Among other
results, we obtain efficient circuits for the fractional Fourier transform.Comment: 4 pages, 2 figure
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