Adaptive optic systems promise to give diffraction limited performance to ground based telescopes operating at visible and near infrared wavelengths. However, because of the short spatial scale of atmospheric turbulence, the corrected field of view is limited to only a few arc seconds in the visible, to perhaps 10 arc seconds at L band (3.5 {mu}). A bright point source must be in this field of view as a wavefront reference, but the number density of natural stars is too small for full sky coverage at imaging wavelengths less than 3{mu}. A sufficiently bright point source can be artificially generated by a laser however, and investigations into the use of laser beacons has been proceeding for some time now. Our experiments at Livermore have concentrated on the formation of guide stars in the sodium mesospheric layer at 90 km altitude. We have also designed and built adaptive optics systems that use both artificial and natural guide stars. Experimental results to date have shown great promise for the practicality of this technique in astronomy.

Data obtained during site characterization should be useful to assess the need for remediation, to evaluate and design effective remedial plans, and to allow long-term monitoring to discern remediation effectiveness. A valuable environmental tool that incorporates this data is a model that describes groundwater and vadose zone flow and transport characteristics. Data on geology and hydrology combined with information on contaminant sources are incorporated into these conceptual models that delineate the relative significance of the various fluid migration pathways. Downstream these same models also support risk assessment, remediation design, and long-term assessment of remediation effectiveness. Consequently, the building of coherent, accurate vadose zone and groundwater models is fundamental to a successful remediation. Among the important requirements for these models is accurate knowledge of flow domain boundaries and soil characteristics. At the Hanford Site, this knowledge is obtained primarily from borehole data, which provides information only at a point. In the high energy flood and fluvial deposits found at the Hanford Site, it can, at times, be difficult to correlate lithologic horizons between boreholes. Where there is no borehole control, our understanding of the geometry of hydrogeologic boundaries and thus of fluid migration paths is limited. Surface geophysical techniques are generally …

This report very briefly discusses heavy quark symmetry.

The goal of this project is to investigate the geochemical, geological, and production parameters that control the occurrence of naturally occurring radioactive materials (NORM) in oil-and gas-field operations, Activities during the second quarter of 1993 focused on identifying field sample sites, identifying previously analyzed produced-water samples that are suitable for NORM analysis, establishing methods for analyzing radium in produced water and scale, and modifying existing geochemical modeling codes to predict radium coprecipitation with carbonate and sulfate scale on the basis of thermodynamic properties.

A low intensity radiation field is generated by the high level waste that is stored within carbon steel lined tanks at the Savannah River Site (SRS). The highest level of radiation damage to the tank walls from gamma and spontaneous neutron emissions is estimated to be less than 1.0E-6 displacements per atom (DPA) for a 100 year exposure to fresh, ``high heat`` SRS waste assuming continuous replenishment of the radionuclides. This damage level is below the limit for measurable radiation damage to the mechanical properties of carbon steel. Structural assessment of tanks for storage of high level waste may be based on nominal or code values of the mechanical properties of the steels from which the tanks were constructed.

In this quarter the design of the plant structures was completed 70%. The design philosophy of the structure economizes on the use of steel by providing supports for the hot cyclone and hot gas duct connecting the cyclone to the boiler while fulfilling the needs for platforms and walkways at the various levels necessary for operational access. Figures 1 through 6 indicate the layout of the plant structure. At the same time the structure for the Coarse Coal Silo V-2 and Limestone Silo V-4 were incorporated and completed. Following completion of the piping pressure drop calculations, pipe sizing and layout drawings, detailed drawings of the piping in different views are being prepared. The pulse combustor is used to burn fine coal particles and provide an ignition source and supplementary heat to the fluid bed. The following is a description of the components: air plenum, fine coal injectors, aerovalves, water jacket, and tailpipe inserts.

The induction of cancer by ionizing radiation is a matter of great practical importance to the nuclear industry, to national defense, to radiological medicine and to the general public. It is increasingly apparent that carcinogenesis is one of the leading dose-limiting effects of radiation exposure (Co90). Quantitative information at the cellular level is essential to an understanding of the mechanisms of radiogenic neoplastic initiation and the stages of promotion and progression to overt neoplasia. We have developed two experimental models, the rat thyroid and rat mammary clonogen transplant systems, for the quantitative study of radiation carcinogenesis at the cellular level in vivo (C185). The most important steps taken or completed during the current grant year include: (a) demonstration of the high age-dependent radiosensitivity of prepubertal rat mammary clonogens to radiogenic damage which may influence their susceptibility to neoplastic initiation, and (b) demonstration of the feasibility of using a molecular test for clonogenicity in which Simple Sequence Repeats in the DNA serve as identifying signals of the genotypic origin of the cells. We have also (c) set up a large carcinogenesis experiment to test the effect of close intercellular contact in thyroid glands in situ on promotion-progression of radiogenically initiated clonogens, …

A system-theoretic approach is proposed to investigate the feasibility of reconstructing a sound velocity profile (SVP) from acoustical hydrophone measurements. This problem is based on a state-space representation of the normal-mode propagation model. It is shown that this representation can be utilized to investigate the so-called observability of the SVP from noisy measurement data. A model-based processor is developed to extract this information and it is shown that even in cases where limited SVP information is available, the SVP can be estimated using this approach.

Weekly newsletter discussing natural resources, parks, hunting and fishing, and other information related to the outdoors in Texas.

The GEM collaboration was formed in June 1991 to develop a major detector for the SSC. The primary physics objectives of GEM are those central to the motivation for the SSC, to study high p{sub T} physics - exemplified by the search for Higgs bosons - and to search for new physics beyond the standard model. The authors present in this Technical Design Report (TDR) a detector with broad capabilities for the discovery and subsequent study of electroweak symmetry breaking, the origin of mass and flavor, and other physics requiring precise measurements of gammas, electrons, and muons - hence the name, GEM. In addition, as a design goal, they have taken care to provide the robustness needed to do the physics that requires high luminosity. Finally, good coverage and hermeticity allow the detection of missing transverse energy, E{sub T}. The GEM design emphasizes clean identification and high resolution measurement of the primary physics signatures for high p{sub T} physics. The approach is to make precise energy measurements that maximize the sensitivity to rare narrow resonances, to detect the elementary interaction products (quarks, leptons, and photons), and to build in the features required to reduce backgrounds.

The Dynamic Gas Pulse Loading (DGPL) process is an hydraulic fracturing method which uses CO{sub 2} and CO gas as a working fluid instead of a liquid. The DGPL system can be used to generate fractures for horizontal and vertical oil and gas well completions in both open hole and perforated casing. The DGPL system provides a cost effective tool for repairing near well bore permeability damage caused by inappropriate chemical treatment, migrating fines and paraffins, or slotted liners blocked by sand. Because the gas is generated from a solid propellant material by chemical reaction, no heavy equipment is required. Tremendous pump rates can be obtained. Peak pressures are naturally localized at the tool position by the tamping effect of well fluids. Thus many of the leakage and sealing problems which plague static hydrofrac processes ore completely avoided. DGPL may be effectively used before acid treatment to provide fresh pathways for the acid to reach the formation. The smaller tools may be positioned by wireline, though most Stressfrac tools are tubing conveyed.

None