Effective potential for nonrelativistic non-Abelian Chern-Simons matter system in constant background fields

We present the effective potential for nonrelativistic matter coupled to non-Abelian Chern-Simons gauge fields. We perform the calculation using a functional method in constant background fields to satisfy Gauss's law and to simplify the computation. Both the quantum gauge and matter fields are integrated over. The gauge fixing is achieved with an $R_\xi$-gauge in the $\xi\to 0$ limit. Divergences appearing in the matter sector are regulated via operator regularization. We find no corrections to the Chern-Simons coupling constant and the system experiences conformal symmetry breaking to one-loop order except at the known value of self-duality. These results agree with previous analysis of the non-Abelian Aharonov-Bohm scattering.Comment: 17 pages in Tex (phyzzx), UdeM-LPN-TH-94-200, CRM-219

Micromagnetic simulations of sweep-rate dependent coercivity in perpendicular recording media

The results of micromagnetic simulations are presented which examine the impact of thermal fluctuations on sweep rate dependent coercivities of both single-layer and exchange-coupled-composite (ECC) perpendicular magnetic recording media. M-H loops are calculated at four temperatures and sweep rates spanning five decades with fields applied normal to the plane and at 45 degrees. The impact of interactions between grains is evaluated. The results indicate a significantly weaker sweep-rate dependence for ECC media suggesting more robustness to long-term thermal effects. Fitting the modeled results to Sharrock-like scaling proposed by Feng and Visscher [J. Appl. Phys. 95, 7043 (2004)] is successful only in the case of single-layer media with the field normal to the plane.Comment: 7 pages, 14 figure

Design, development and evaluation of Stanford/Ames Extra-Vehicular Activity (EVA) prehensors

A summary is given of progress to date on work proposed in 1983 and continued in 1985, including design iterations on three different types of manually powered prehensors, construction of functional mockups of each and culminating in detailed drawings and specifications for suit-compatible sealed units for testing under realistic conditions

Design, development and evaluation of Stanford/Ames EVA prehensors

Space Station operations and maintenance are expected to make unprecedented demands on astronaut EVA. With Space Station expected to operate with an 8 to 10 psi atmosphere (4 psi for Shuttle operations), the effectivness of pressurized gloves is called into doubt at the same time that EVA activity levels are to be increased. To address the need for more frequent and complex EVA missions and also to extend the dexterity, duration, and safety of EVA astronauts, NASA Ames and Stanford University have an ongoing cooperative agreement to explore and compare alternatives. This is the final Stanford/Ames report on manually powered Prehensors, each of which consists of a shroud forming a pressure enclosure around the astronaut's hand, and a linkage system to transfer the motions and forces of the hand to mechanical digits attached to the shroud. All prehensors are intended for attachment to a standard wrist coupling, as found on the AX-5 hard suit prototype, so that realistic tests can be performed under normal and reduced gravity as simulated by water flotation

Effect of Desiccation, pH, Heat, and Ultraviolet Irradiation on Viability of \u3ci\u3eBaculovirus penaei\u3c/i\u3e

Tolerance of Baculovirus penaei virus to desiccation, pH, heat, and ultraviolet irradiation (uv), as well as its survival in 32 ppt sea water, was investigated using larval Penaeus vannamei in a bioassay. Test shrimp were sampled from 36 to 264 hr after food-borne exposure to treated B. penaei and examined for patent infections (polyhedral inclusion bodies detectable in fresh preparations of hepatopancreas) with light microscopy. B. penaei was completely inactivated within 30 min after exposure to pH 3, whereas exposure to pH 11 extended the prepatency period (period before infection is apparent) but did not inactivate the virus. B. penaei was inactivated by 10-min exposures to temperatures of 60–90°C. Ultraviolet irradiation for 40 min at a wavelength of 254 nm when B. penaei was 5 cm from the light source inactivated the virus (measured as a cumulative uv dosage of 7.08 × 106 μW ⋅ sec/cm2). Desiccation for 48 hr also inactivated the virus, and that method is the most practical to halt or prevent infections in some aquaculture facilities. B. penaei free from its host survived 32 ppt sea water at 22°C for 7 days and at 5°C for at least 14 days

Gauge Invariance in Chern-Simons Systems

We show explicitly that the question of gauge invariance of the effective potential in standard scalar electrodynamics remains unchanged despite the introduction of the Chern-Simons term. The result does not depend on the presence of the Maxwell term in the Chern-Simons territory.Comment: 10 pages, Plain Tex, DF/UFPB-14/9

Monolithic InP-Based Grating Spectrometer for Wavelength-Division Multiplexed Systems at 1.5 μm

A monolithic InP-based grating spectrometer for use in wavelength-division multiplexed systems at 1.5 μm is reported. The spectrometer uses a single etched reflective focusing diffraction grating and resolves >50 channels at 1 nm spacing with a ~0.3nm channel width and at least 19dB channel isolation. Operation is essentially of the state of the input polarisation