The numerous observational indicators of instability in the radiatively-driven winds of hot stars are review briefly, followed by a summary of the present theoretical understanding of the linear instability of such winds. This provides the motivation for the hydrodynamic simulation, the major thrust of the paper. A serious approximation that must be made in order to reduce the cost of the simulations to a reasonable level--the absorption approximation for the radiation force--is discussed in some detail. The hydrodynamic methods are described briefly, and then the computational results for winds models computed in the absorption approximation are discussed. The most notable results pertain to the critical nature of the ratio v{sub th}/a of the intrinsic line width to the sound speed. When this ratio is large, only a negligible wind results; when the ratio is small, the wind executes permanent self-excited oscillations; in an intermediate range the wind is globally stable, but acts as a powerful wave amplifier. The morphology of the oscillations--strong rarefactions and reverse shocks--is described and related to Abbott's linear theory, and the possible connection to observations is mentioned. 30 refs.

Research continued on coal cleaning technologies. The work plan for this period called for the completion of the suite of gravity separation models (seven in total). Two items concerning these models were to be investigated further: (1) incorporating an Aspen Plus algorithm for converging the estimated dp of separation on the user selected dp value, and (2) evaluating methods other than interpolation by cubic spline methods for estimating Ep from a set of composite partition numbers. The water-only cyclone, fine coal jig, and concentrating spiral models were to be transferred from ICF KE to AspenTech for incorporation as system models by the end of the reporting period. Model discrimination analysis for selecting the appropriate form of an equation for generating interval partition values was slated for completion. Coding and testing of several dewatering algorithms were scheduled to take place during the work period. Models for fine coal vacuum filters, coarse and fine coal centrifuges, thickeners, and thermal dryers were to be completed during the work period. Additionally, work was expected to continue in the areas of classification, comminution, and froth flotation modeling.

We present for the first time, the self-consistent solution of the two-dimensional, time-dependent equations of radiation-hydrodynamics governing the accretion of matter onto the highly magnetized polar caps of luminous x-ray pulsars. The calculations show a structure in the accretion column very different from previous one-zone uniform models. We have included all the relevant magnetic field corrections to both the hydrodynamics and the radiative transport. We include a new theory for the diffusion and advection of both radiation energy density and photon number density. For initially uniformly accreting models with super-Eddington flows, we have uncovered evidence of strong radiation-driven outflowing optically thin radiation filled regions of the accretion column embedded in optically-thick inflowing plasma. We follow the evolution of these photon bubbles for several dynamical timescales. The development of these photon bubbles'' indicates growth times on the order of a millisecond and show fluctuations on sub-millisecond timescales in agreement with a linear stability analysis. The photon bubbles are a consequence of the effect of radiative heat flux on the internal gravity waves in the strongly magnetized atmosphere and may result in observable fluctuations in the emitted luminosity leading to luminosity dependent changes in the pulse profile. This may provide important new …

This report is a comparison of phase I and phase II results. However, it seems that the differences were due to a flowmeter. (JEF)

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.

Letter opinion issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification.

The D0 instrument air system for cryo controls has an emergency backup supply of nitrogen gas. The backup system consists of a high pressure tube trailer (38 tubes - 2400 psig MAWP), piping, valves, regulators and pressure monitoring instrumentation. The trailer is located south of DAB alongside the LN{sub 2} Dewar. Fixed piping ties to the trailer with a flex-hose. The piping follows the cryo piping bridge entering the south wall of DAB. where it passes through the pipe chase and into the cryo pump room (Rm 315). The high pressure gas is regulated down to 90 psig before tying into the compressor supplied instrument air system. Check valves are installed at the tee for the primary air and the backup N{sub 2}. Normal operating pressure for instrument air is 100-120 psig. With the backup supply pressure set to 90 psig, 'emergency air' is supplied whenever primary air pressure falls below 90 psig. There are two additional, outside connections to the system: one is a connection for repumping the trailer after a minimum backup volume is reached and the other is an auxiliary flex-hose connection for another trailer. All manual valves at system connections will be locked closed when not …

The traveler, serving as Delegate from the United States Heat Pump Center National Team, participated in the activities of the second International Energy Agency Heat Pump Center (IEA-HPC) Working Team meeting. This included a 20 minute presentation by the traveler about the Development and Activities of the IEA Heat Pump Center US National Team.'' Highlights of this meeting included development of 1991 IEA-HPC work plans including a prioritization of activities, introduction of the newly appointed IEA-HPC Advisory Board, and discussion of a new IEA Clearinghouse Network initiative. Pre-meeting discussions were held with IEA-HPC staff members which focused on US Heat Pump Center National Team contributions to the IEA-HPC Newsletter and participation in other IEA-HPC sponsored activities.

A neutron induced fission track method was successfully developed for assaying {sup 239}Pu in human urine. The technique involves means to remove potentially interfering natural uranium from the sample and reagents. The method was applied to 50 urine samples including an unknown number of spikes and controls from the Marshall Islands. 49 samples were successfully analyzed. The mean activity for the 47 samples which were not positive for {sup 239}Pu did not differ significantly from the mean for our control samples, which consisted of urines collected from six young adult Utah residents. 2 figs., 12 tabs.

Conversion of 4'-methylpropiophenone to 1-methyl-4-n-propylbenzene was accomplished in high yields. Bromination of the latter resulted in isomers of methyl-n-propyl-1-bromobenzene. Reaction of the isomers with sodium butoxide and 2-methoxybenzenethiol in presence of Pd[P(C[sub 6]H[sub 5])[sub 3]][sub 4] in 1-butanol was studied. The methylpropylbenzene was also iodinated. A decision to use iodination vs bromination will be made when more data are accumulated. 6 refs, figs.

Conversion of 4`-methylpropiophenone to 1-methyl-4-n-propylbenzene was accomplished in high yields. Bromination of the latter resulted in isomers of methyl-n-propyl-1-bromobenzene. Reaction of the isomers with sodium butoxide and 2-methoxybenzenethiol in presence of Pd[P(C{sub 6}H{sub 5}){sub 3}]{sub 4} in 1-butanol was studied. The methylpropylbenzene was also iodinated. A decision to use iodination vs bromination will be made when more data are accumulated. 6 refs, figs.

The methods used in the ALTAIR code for computing the transfer of spectral line radiation in two-dimensional axially-symmetric geometry are described. ALTAIR uses a variable-Eddington-tensor approach, in which the transfer equation of non-coherent line scattering is written in moment form, and the moments are closed with an assumed tensor relating the monochromatic pressure tensor and energy density; this Eddington tensor is obtained self-consistently using an accurate angle-dependent solution of the transfer equation. The finite element method for solving the moment system, and the discontinuous finite element method for solving the S{sub n} equation of transfer are described. Two applications of the method are discussed: line formation in uniform cylinders with different length-diameter ratios, and monochromatic transfer on an irregular x-y mesh (the Mordant test problem). 13 refs., 2 figs.

Monthly report providing tabular statistical information about motor vehicle accidents in rural areas of Texas during 1990, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.

Monthly report providing tabular statistical information about motor vehicle accidents in Texas during 1990, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.