253 research outputs found
Recommended from our members
Report of Investigations No. 133 Three-Dimensional Ground-Water Modeling in Depositional Systems, Wilcox Group, Oakwood Salt Dome Area, East Texas
UT Librarie
Recommended from our members
Siting a Low-Level Radioactive Waste Disposal Facility in Texas Volume Four- Geologic and Hydrologic Investigations of State of Texas and University of Texas Lands
The Bureau of Economic Geology, The University of Texas at Austin, conducted preliminary investigations of the geology and hydrology of 5 areas in Culberson and Hudspeth Counties, Texas, selected by the Texas Low-Level Radioactive Waste Disposal Authority as potential sites for a low-level radioactive waste repository. This report discusses the results of those studies.
Two areas in Culberson County, Texas, Site S-15 and Block 46 and adjacent regions, were investigated. The Permian Castile Formation underlies all of Site S-15 and the eastern half of Block 46. The Castile Formation displays evidence of extensive solution and local collapse and appears to contain a complex system of karst features and underground solution channels. The western half of Block 46 is underlain by the Permian Bell Canyon Formation, consisting of interbeds of sandstone and limestone. Both the Castile and subjacent Bell Canyon Formations contain prominent joint systems and local areas of normal faults. Surficial deposits are commonly composed of detritus derived from local formations and appear to be both porous and permeable.
The groundwater flow in both areas is governed by karst dissolution and collapse features. The chemical and isotopic composition of groundwater indicates active recharge through the thin unsaturated zone combined with older water flowing from the west. Residence time of groundwater in the aquifers is relatively short, and numerous springs discharge from the shallow groundwater table.Bureau of Economic Geolog
Recommended from our members
Geologic and Hydrologic Studies of Sites Hu1A and Hu1B in Hudspeth County, Texas
The Bureau of Economic Geology, The University of Texas at Austin, conducted preliminary investigations of the geology and hydrology of northern Hudspeth County for the Texas Low-Level Radioactive Waste Disposal Authority. The Authority had previously identified two sites, HU1A and HU1B, as possible sites for an above-ground disposal facility for low-level radioactive wastes.
Regional and site-specific investigations were conducted to characterize the geology and hydrology of HU1A and HU1B. The two sites are underlain by different bedrock lithologies covered by alluvium, which necessitated drilling for site-specific investigations. Because of the lack of exposed bedrock, studies of the regional geologic setting were used to infer the probable nature of the bedrock geologic environment at each site. Hydrologic studies were predominantly regional because of the limited data available at either site and the availability of water-level data and water samples from previously drilled wells in the region.Bureau of Economic Geolog
Recommended from our members
Hydrogeology and Hydrochemistry of the Falls City Uranium Mine Tailings Remedial Action Project, Karnes County, Texas
Oxidized uranium ore deposits were discovered in the Deweesville sandstone (also referred to as the Stones Switch; Bunker and MacKallor [1973]) in the Falls City region in the 1950s. Uranium was mined and milled in the small community of Deweesville by Susquehanna-Western, Inc. (SWI) from April 1961 to August 1973. Tailings composed of sediment residue from the sulfuric acid milling process and residual sulfuric acid solutions were disposed of in six ponds on the outcrop of the Deweesville, within the mined-out uranium pits in the Deweesville, and on the outcrop of the Conquista, creating a set of large tailings impoundments (figs. 1.1 and 1.2). From 1978 to 1982 Solution Engineering, Inc. (SEI) conducted a secondary recovery of the remaining uranium in the tailings piles by in situ leaching. In 1984, the ponds on top of two of the tailings piles were spray evaporated and a clay cap was placed over the piles to prevent additional percolation of water through the piles and into the underlying aquifers. Acidic tailings solutions have been recharging the underlying aquifers since initial tailings disposal and may still be leaking into these aquifers.
Several hydrogeologic investigations have been conducted to assess whether there has been groundwater contamination from the tailings. Early studies were conducted by Turk, Kehle and Associates (1976), and Ford, Bacon & Davis Utah (1978, 1981). Each of these studies included only minor investigations of the hydrogeology and hydrochemistry of the site and, in general, underestimated the extent of contamination from the site. Investigations conducted by the U.S. Department of Energy (DOE) from 1985 to 1991 have since revealed the true extent of contamination (U.S. Department of Energy, 1991).Bureau of Economic Geolog
Plant Mol Biol
Proteomic studies have addressed the composition of plant chloroplast ribosomes and 70S ribosomes from the unicellular organism Chlamydomonas reinhardtii But comprehensive characterization of cytoplasmic 80S ribosomes from higher plants has been lacking. We have used two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) to analyse the cytoplasmic 80S ribosomes from the model flowering plant Arabidopsis thaliana. Of the 80 ribosomal protein families predicted to comprise the cytoplasmic 80S ribosome, we have confirmed the presence of 61; specifically, 27 (84%) of the small 40S subunit and 34 (71%) of the large 60S subunit. Nearly half (45%) of the ribosomal proteins identified are represented by two or more distinct spots in the 2-DE gel indicating that these proteins are either post-translationally modified or present as different isoforms. Consistently, MS-based protein identification revealed that at least one-third (34%) of the identified ribosomal protein families showed expression of two or more family members. In addition, we have identified a number of non-ribosomal proteins that co-migrate with the plant 80S ribosomes during gradient centrifugation suggesting their possible association with the 80S ribosomes. Among them, RACK1 has recently been proposed to be a ribosome-associated protein that promotes efficient translation in yeast. The study, thus provides the basis for further investigation into the function of the other identified non-ribosomal proteins as well as the biological meaning of the various ribosomal protein isoforms
Proteome analysis of Arabidopsis thaliana by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionisation-time of flight mass spectrometry
In the present study we show results of a large-scale proteome analysis of the recently sequenced plant Arabidopsis thaliana. On the basis of a previously published sequential protein extraction protocol, we prepared protein extracts from eight different A. thaliana tissues (primary leaf, leaf, stem, silique, seedling, seed, root, and inflorescence) and analysed these by two-dimensional gel electrophoresis. A total of 6000 protein spots, from three of these tissues, namely primary leaf, silique and seedling, were excised and the contained proteins were analysed by matrix assisted laser desorption/ionisation time of flight mass spectrometry peptide mass fingerprinting. This resulted in the identification of the proteins contained in 2943 spots, which were found to be products of 663 different genes. In this report we present and discuss the methodological and biological results of our plant proteome analysis
Recommended from our members
Preliminary Investigation of the Geology and Hydrology of the Laska Siding Area, Hudspeth County, Texas
The Bureau of Economic Geology, The University of Texas at Austin, at the request of the Texas Low-Level Radioactive Waste Disposal Authority, conducted a preliminary investigation of the geology and hydrology of the Laska Siding area in Hudspeth County, Texas. This area is being evaluated as a potential site for a low-level radioactive waste repository to be built on State-owned lands in Trans-Pecos Texas.
The Laska Siding site lies about 9 miles (14.5 km) west of the town of Sierra Blanca. The site was selected for this study because of the presence of previously mapped low-permeability sediments of the Hueco Formation, its relatively low-relief topography, and the probable great thickness of the unsaturated zone in the vicinity. The site is also attractive for a repository because of its proximity and access to a major highway and a railroad.
This investigation consisted of a brief study of the geology and hydrology of the site and surrounding area. The study included a reconnaissance field evaluation of the Balson sediments, mapped faults, and geomorphology, a review of water-level and chemistry data from Texas Water Commission (TWC) Central Records for local water wells, static water level measurements of water wells in the immediate vicinity of the site, and drilling of one test hole on the proposed site.Bureau of Economic Geolog
Recommended from our members
Hydrogeologic Characterization of the Saline Aquifers, East Texas Basin- Implications to Nuclear Waste Storage in East Texas salt Domes
Groundwaters in the deep aquifers (Nacatoch to Travis Peak) range in salinity from 20,000 to over 200,000 mg/L. Based on their isotopic compositions, they were originally recharged as continental meteoric waters. Recharge probably occurred predominantly during the Cretaceous time; therefore, the waters are very old. Because the basin has not been uplifted, there are no extensive recharge or discharge zones. The flanks of domes and radial faults associated with domes may function as localized discharge points. Both the water chemistry and the hydraulic pressures for the aquifers suggest that the basin can be subdivided into two major aquifer systems: (1) the upper Cretaceous aquifers (Woodbine and shallower) which are hydrostatic and (2) the deep lower Cretaceous and deeper formations (Glen Rose, Travis Peak, and older units), which are slightly overpressured. The source of sodium and chloride in the saline waters is considered to be from salt dome dissolution. Most of the dissolution occurred during the Cretaceous. Chlorine-36 analyses suggest that dome solution is not presently occurring. Salinity cross sections across individual domes do not indicate that ongoing solution is an important process. The major chemical reactions in the saline aquifers are dome dissolution, albitization, and dedolomitization. Albitization and dedolomitization are important only in the deeper formations. The high Na concentrations in the deeper aquifer system result in the alteration of plagioclase to albite and the release of Ca into solution. The increase in Ca concentrations causes a shift in the calcite/dolomite equilibrium. The increase in Mg results from dissolution of dolomite.Bureau of Economic Geolog
Declaring a Patient Brain Dead on Extracorporeal Membrane Oxygenation (ECMO): Are There Guidelines or Misconceptions
Objectives: To review the clinical practice variations and trends with declaring patients brain dead on ECMO To highlight the need for the development of consensus guidelines to assist clinicians in the accurate diagnosis of brain death in this specific patient populatio
Recommended from our members
Preliminary Evaluation of the Eagle Flat Region Hudspeth County, Texas
Preliminary evaluation of the Eagle Flat region, as designated by the Texas Legislature, indicates several areas that may have geologic and hydrologic conditions favorable for further evaluation as potential siting areas for the Texas low-level radioactive waste repository. This determination is based on a review of available data regarding surface drainage, thickness and character of alluvial fill, depth to groundwater, and apparent presence or absence of such features as late Cenozoic faults, fissures, known natural resources, and evidence of erosion. Some general siting areas have been identified that contain several sections that appear to have favorable characteristics. Examples of apparently favorable general siting areas are east of Yucca Mesa, south of Eagle Flat Mountain, and north of Little Hills. Our preliminary assessment is that, of the three areas cited above, the Yucca Mesa location should be given priority consideration. Initial flooding and drainage analysis indicates that the Yucca Mesa site includes sufficient surface areas unaffected by flooding. There are no known fissures or late Cenozoic faults. Depth to groundwater may be in excess of 500 ft, and the water quality may be poor. Shallow alluvium may be somewhat finer grained than at other settings, and the surface appears to be relatively stable and devoid of major incision by existing drainages. Although each of these characteristics needs to be investigated by further work, the most critical unanswered question is the thickness of alluvial fill. Available gravity data, including recent work by The University of Texas at El Paso, indicates that 100 ft or more of alluvial fill may be present in the area. Other areas may be present that are of equal or similar merit, but the preliminary analysis and available information suggest that the Yucca Mesa location apparently has the most favorable characteristics of those general siting areas identified currently. Smaller potential siting areas, generally about 400 to 800 acres in size, also may exist locally throughout the region where alluvial fill may be of sufficient thickness and drainage characteristics may be appropriate. These smaller potential siting areas would require additional site-specific evaluation of surface drainage characteristics before drill testing could be recommended. Any potential siting area is unique and would require site-specific evaluation activities to assess its suitability for characterization.Bureau of Economic Geolog
- …