Detector panels-micrometeoroid impact Patent

Development of large area micrometeoroid impact detector panel

Polarization and Extent of Maser Emission from Late-Type Stars: Support for a Plasma Turbulence Model of Maser Production

The integrated spectrum of OH emission from late-type stars is often circularly polarized, by as much as 50% in some cases. While the spectra are partially polarized, the individual maser components revealed by VLBI are much more so. Using VLBI observations of late-type stars from the literature, we show that the difference in circular polarization between main lines correlates with a difference in angular extent for a given object. This is a natural result if turbulent magnetic fields are causing the masers to be polarized via the Cook mechanism, and might serve as a good diagnostic for determining which objects should be investigated in the search for magnetic fields around evolved stars.Comment: 5 pages, 2 figs ApJL, accepte

Alaska mining and water quality

The Institute of Water Resources has sought financial assistance for some time in an attempt to initiate research relative to the impact of mining on water quality. Attempts were made as early as 1971 by Dr. Timothy Tilsworth and later by Dr. Donald Cook and Dr. Sage Murphy. These investigators anticipated growth in placer gold mining and the development of natural resources in Alaska during a period of national and environmental concern. The subsequent energy "crisis," the major increase in the price of gold on the world market, and dwindling nonrenewable resource supplies have resulted in large-scale mineral exploration in Alaska. This exploration, coupled with development of the trans-Alaska oil pipeline, has attracted considerable capital for potential investment and development in Alaska. Expected industrial growth has already started and major new projects are "just around the corner." Yet, as of 1976, no major research effort has occurred to determine the extent of or potential for water quality impacts from mining operations in Alaska. Recently a series of interdisciplinary research projects have been completed in Canada; however, the application of Canadian data to Alaskan problems is uncertain. Although, state and federal government agencies have been advised and are aware of this potential problem and lack of baseline data they have not sought out new information or rational solutions. Even now, with deadlines of Public Law 92-500 at hand, some regulatory agencies give the impression of attempting to ignore the situation. Interim limitations are proposed and permits are issued with no discernible rationale or basis. Data have not been obtained relative to the Alaskan mining operations and thus are not available for use in seeking solutions compatible with mining and environmental protection. Numbers appear to have been arbitrarily assigned to permits and water quality standards. When permits are issued, self-monitoring requirements are negligible or nonexistent. Nor have regulatory agencies demonstrated the ability or inclination to monitor mining operations or enforce permits and water quality standards. It was hoped that the project would bring together miners, environmentalists, and regulators in a cooperative effort to identify the problems and seek solutions. The investigators recognized the political sensitivity of the subject matter but proceeded optimistically. Relatively good cooperation, though not total, occurred early in the project. In April 1976, a symposium was held to exchange ideas and determine the state-of-the-art. Although the symposium had good attendance and an exchange of information occurred, the symposium itself was somewhat of a disappointment. With few exceptions, the participants aligned on one side or the other in preconceived fixed positions. Some even chose not to attend and were therefore able to avoid the issues. Little hard data was presented. Optimistically, some of the miners, environmentalists, and regulators are prepared to resolve their differences. This report, hopefully, will be of benefit to them. It is our experience that miners and environmentalists share a love of the land that is uniquely Alaska. We feel that technology is available for application to this problem for those who care about doing the job right in the "last frontier." Whether or not it will be effectively applied to protect Alaska's water resources is a question which remains unanswered.The work upon which this report is based was supported in part by funds provided by the United States Department of the Interior, Office of Water Resources Research Act of 1964, Public Law 88-379, as amended (Project A-055-ALAS)

Quasi-circular Orbits for Spinning Binary Black Holes

Using an effective potential method we examine binary black holes where the individual holes carry spin. We trace out sequences of quasi-circular orbits and locate the innermost stable circular orbit as a function of spin. At large separations, the sequences of quasi-circular orbits match well with post-Newtonian expansions, although a clear signature of the simplifying assumption of conformal flatness is seen. The position of the ISCO is found to be strongly dependent on the magnitude of the spin on each black hole. At close separations of the holes, the effective potential method breaks down. In all cases where an ISCO could be determined, we found that an apparent horizon encompassing both holes forms for separations well inside the ISCO. Nevertheless, we argue that the formation of a common horizon is still associated with the breakdown of the effective potential method.Comment: 13 pages, 10 figures, submitted to PR

Exotic Meson Decay Widths using Lattice QCD

A decay width calculation for a hybrid exotic meson h, with JPC=1-+, is presented for the channel h->pi+a1. This quenched lattice QCD simulation employs Luescher's finite box method. Operators coupling to the h and pi+a1 states are used at various levels of smearing and fuzzing, and at four quark masses. Eigenvalues of the corresponding correlation matrices yield energy spectra that determine scattering phase shifts for a discrete set of relative pi+a1 momenta. Although the phase shift data is sparse, fits to a Breit-Wigner model are attempted, resulting in a decay width of about 60 MeV when averaged over two lattice sizes.Comment: 9 pages, 8 figures, RevTex4, minor change to Fig.

Formation of molecular oxygen in ultracold O + OH reaction

We discuss the formation of molecular oxygen in ultracold collisions between hydroxyl radicals and atomic oxygen. A time-independent quantum formalism based on hyperspherical coordinates is employed for the calculations. Elastic, inelastic and reactive cross sections as well as the vibrational and rotational populations of the product O2 molecules are reported. A J-shifting approximation is used to compute the rate coefficients. At temperatures T = 10 - 100 mK for which the OH molecules have been cooled and trapped experimentally, the elastic and reactive rate coefficients are of comparable magnitude, while at colder temperatures, T < 1 mK, the formation of molecular oxygen becomes the dominant pathway. The validity of a classical capture model to describe cold collisions of OH and O is also discussed. While very good agreement is found between classical and quantum results at T=0.3 K, at higher temperatures, the quantum calculations predict a larger rate coefficient than the classical model, in agreement with experimental data for the O + OH reaction. The zero-temperature limiting value of the rate coefficient is predicted to be about 6.10^{-12} cm^3 molecule^{-1} s^{-1}, a value comparable to that of barrierless alkali-metal atom - dimer systems and about a factor of five larger than that of the tunneling dominated F + H2 reaction.Comment: 9 pages, 8 figure

Design and development of a water vapor electrolysis unit

Design and development of water vapor electrolysis unit for oxygen productio

Collisions of boosted black holes: perturbation theory prediction of gravitational radiation

We consider general relativistic Cauchy data representing two nonspinning, equal-mass black holes boosted toward each other. When the black holes are close enough to each other and their momentum is sufficiently high, an encompassing apparent horizon is present so the system can be viewed as a single, perturbed black hole. We employ gauge-invariant perturbation theory, and integrate the Zerilli equation to analyze these time-asymmetric data sets and compute gravitational wave forms and emitted energies. When coupled with a simple Newtonian analysis of the infall trajectory, we find striking agreement between the perturbation calculation of emitted energies and the results of fully general relativistic numerical simulations of time-symmetric initial data.Comment: 5 pages (RevTex 3.0 with 3 uuencoded figures), CRSR-107