Collection
United States Census Map Collection
7,254
Office of Scientific & Technical Information Technical Reports
7,237
Texas State Publications
399
Texas Attorney General Opinions
260
Texas Register
102
Technical Report Archive and Image Library
66
Office of Technology Assessment
57
USGS Topographic Map Collection
50
Federal Communications Commission Record
27
Advisory Commission on Intergovernmental Relations
13
10 More
Serial/Series Title
1990 Census County Block Map
7,254
Texas Register
102
Digital Raster Graphic Topographic Maps: 7.5 Minute Series (Topographic)
39
Argonne National Laboratory Reports
34
Management data series
31
Texas Motor Vehicle Traffic Accident Summaries
30
FCC Record
27
Texas Preventable Disease News
25
PWD report
20
United States Geological Survey Reports
18
185 More
States
Decade
Year
Month
Language
15,492 Matching Results
Results open in a new window/tab.
Waste minimization study for a printed circuit board manufacturing facility in Taiwan
This paper presents a demonstration of industrial waste minimization sponsored by the Environmental Protection Administration, Taiwan, Republic of China. Waste reduction opportunities are identified and evaluated for a printed circuit board manufacturing facility in Taiwan. Plant audits were conducted on various processes, such as deburring, alkaline etching, black oxidation, desmearing, electroless copper, and copper and tin/lead plating. Specific areas in which the wastes could be minimized, such as reducing the amount of dragout and rinse water requirements in the plating and etchant lines, and on-site treatment and reuse of spent bath solutions were identified, assessed, and implemented. Jar tests on the wastewater were performed, and the results were used to improve the efficiency of the wastewater treatment plant for removal of heavy metals and reduction of sludge generation. In addition, administrative controls of hazardous wastes designed to reduce associated health and environmental hazards were recommended. 4 figs., 9 tabs.
Date:
January 1, 1990
Creator:
Chiu, Shen-yann; Huang, Hann S.; Peters, R. W.; Tsai, S. Y. (Argonne National Lab., IL (USA)); Tsai, Wen-Tien; Shieh, Shih-Shien et al.
Object Type:
Article
System:
The UNT Digital Library
A waste package strategy for regulatory compliance
This paper summarizes the strategy given in the Site Characterization Plan for demonstrating compliance with the post closure performance objectives for the waste package and the Engineered Barrier System contained in the Code of Federal Regulations. The strategy consists of the development of a conservative waste package design that will meet the regulatory requirements with sufficient margin for uncertainty using a multi-barrier approach that takes advantage of the unsaturated nature of the Yucca Mountain site. 7 refs., 1 fig.
Date:
April 1, 1990
Creator:
Stahl, D. & Cloninger, M.O.
Object Type:
Article
System:
The UNT Digital Library
Waste reduction at the Savannah River Site
The Savannah River Site (SRS) is a key installation for the production and research of nuclear materials for national defense and peace time applications and has been operating a full nuclear fuel cycle since the early 1950s. Wastes generated include high level radioactive, transuranic, low level radioactive, hazardous, mixed, sanitary, and aqueous wastes. Much progress has been made during the last several years to reduce these wastes including management systems, characterization, and technology programs. The reduction of wastes generated and the proper handling of the wastes have always been a part of the Site`s operation. This paper summarizes the current status and future plans with respect to waste reduction to waste reduction and reviews some specific examples of successful activities.
Date:
December 31, 1990
Creator:
Stevens, W. E.; Lee, R. A. & Reynolds, R. W.
Object Type:
Article
System:
The UNT Digital Library
Waste reduction at the Savannah River Site
The Savannah River Site (SRS) is a key installation for the production and research of nuclear materials for national defense and peace time applications and has been operating a full nuclear fuel cycle since the early 1950s. Wastes generated include high level radioactive, transuranic, low level radioactive, hazardous, mixed, sanitary, and aqueous wastes. Much progress has been made during the last several years to reduce these wastes including management systems, characterization, and technology programs. The reduction of wastes generated and the proper handling of the wastes have always been a part of the Site's operation. This paper summarizes the current status and future plans with respect to waste reduction to waste reduction and reviews some specific examples of successful activities.
Date:
January 1, 1990
Creator:
Stevens, W. E.; Lee, R. A. & Reynolds, R. W.
Object Type:
Article
System:
The UNT Digital Library
Waste segregation procedures and benefits
Segregation is a critical first step in handling hazardous and radioactive materials to minimize the generation of regulated wastes. In addition, segregation can significantly reduce the complexity and the total cost of managing waste. Procedures at Sandia National Laboratories, Albuquerque require that wastes be segregated, first, by waste type (acids, solvents, low level radioactive, mixed, classified, etc.). Higher level segregation requirements, currently under development, are aimed at enhancing the possibilities for recovery, recycle and reapplication; reducing waste volumes; reducing waste disposal costs, and facilitating packaging storage, shipping and disposal. 2 tabs.
Date:
January 1, 1990
Creator:
Fish, Jim D.; Massey, Charles D. & Ward, Stephen J.
Object Type:
Article
System:
The UNT Digital Library
Waste storage in the vadose zone affected by water vapor condensation and leaching
One of the major concerns associated with waste storage in the vadose zone is that toxic materials may somehow be leached and transported by advecting water down to the water table and reach the accessible environment through either a well or discharge to a river. Consequently, care is taken to provide barriers over and around the storage sites to reduce contact between infiltrating water and the buried waste form. In some cases, it is important to consider the intrusion of water vapor as well as water in the liquid phase. Water vapor diffuses through porous material along vapor pressure gradients. A slightly low temperature, or the presence of water-soluble components in the waste, favors water condensation resulting in leaching of the waste form and advection of water-soluble components to the water table. A simple analysis is presented that allows one to estimate the rate of vapor condensation as a function of waste composition and backfill materials. An example using a waste form surrounded by concrete and gravel layers is presented. The use of thermal gradients to offset condensation effects of water-soluble components in the waste form is discussed. Thermal gradients may be controlled by design factors that alter the atmospheric …
Date:
August 1, 1990
Creator:
Cary, J. W.; Gee, G. W. & Whyatt, G. A.
Object Type:
Article
System:
The UNT Digital Library
Water and UV degradable lactic acid polymers
A water and UV light degradable copolymer of monomers of lactic acid and a modifying monomer selected from the class consisting of ethylene and polyethylane glycols (PVB 6/22/90), propylene and and polypropylene (PVB 6/22/90) glycols, P-dioxanone, 1, 5 dioxepan-2-one, 1,4 -oxathialan-2-one, 1,4-dioxide and mixtures thereof. These copolymers are useful for waste disposal and agricultural purposes. Also disclosed is a water degradable blend of polylactic acid or modified polylactic acid and high molecular weight polyethylene oxide wherein the high molecular weight polyethylene oxide is present in the range of from about 2% by weight to about 50% by weight, suitable for films. A method of applying an active material selected from the class of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof to an agricultural site is also disclosed.
Date:
June 26, 1990
Creator:
Bonsignore, P. V. & Coleman, R. D.
Object Type:
Patent
System:
The UNT Digital Library
Water potential and starvation stress in deep subsurface microorganisms
Nine intact core samples, collected aseptically from depths of 10--436 m near the Savannah River Plant in South Carolina, were tested for water potential, microbial numbers, and microbial activity. Although all samples were collected from below the water table, two samples (a Pee Dee clay from 238 m and a Middendorf clay from 324 m) showed unsaturated conditions ({minus}2.7 and {minus}2.1 MPa, respectively). Both of these samples had very low numbers of culturable cells, low microbial biomass (ATP assay), and low microbial activities (measured as respiration), suggesting that low metric waterpotentials in these strata are limiting factors to microorganisms. An Acinetobacter sp. isolated from the 324 m depth was found to maintain viability under starvation conditions in sterilized aquifer material, even when subjected to severe desiccation ({minus}22 MPa). A Pseudomonas sp., with the ability to oxidize thiosulfate to sulfate, was isolated from the 378 m Middendorf clay sample. This organism survived nutrient deprivation reasonably well; however, the presence of thiosulfate appeared to interfere with its normal ability to maintain viability by endogenous metabolism. Cells cultured in the presence of thiosulfate did not undergo dwarfing and cell viability declines. These are two examples of indigenous subsurface microorganisms, each with different adaptations …
Date:
December 31, 1990
Creator:
Kieft, Thomas L.; Rosacker, Laurie L.; Willcox, David & Franklin, Abraham J.
Object Type:
Article
System:
The UNT Digital Library
Water Potential and Starvation Stress in Deep Subsurface Microorganisms
Nine intact core samples, collected aseptically from depths of 10--436 m near the Savannah River Plant in South Carolina, were tested for water potential, microbial numbers, and microbial activity. Although all samples were collected from below the water table, two samples (a Pee Dee clay from 238 m and a Middendorf clay from 324 m) showed unsaturated conditions ({minus}2.7 and {minus}2.1 MPa, respectively). Both of these samples had very low numbers of culturable cells, low microbial biomass (ATP assay), and low microbial activities (measured as respiration), suggesting that low metric waterpotentials in these strata are limiting factors to microorganisms. An Acinetobacter sp. isolated from the 324 m depth was found to maintain viability under starvation conditions in sterilized aquifer material, even when subjected to severe desiccation ({minus}22 MPa). A Pseudomonas sp., with the ability to oxidize thiosulfate to sulfate, was isolated from the 378 m Middendorf clay sample. This organism survived nutrient deprivation reasonably well; however, the presence of thiosulfate appeared to interfere with its normal ability to maintain viability by endogenous metabolism. Cells cultured in the presence of thiosulfate did not undergo dwarfing and cell viability declines. These are two examples of indigenous subsurface microorganisms, each with different adaptations …
Date:
January 1, 1990
Creator:
Kieft, Thomas L.; Rosacker, Laurie L.; Willcox, David & Franklin, Abraham J.
Object Type:
Article
System:
The UNT Digital Library
Water quality investigation of Kingston Fossil Plant dry ash stacking
Changing to a dry ash disposal systems at Kingston Fossil Plant (KFP) raises several water quality issues. The first is that removing the fly ash from the ash pond could alter the characteristics of the ash pond discharge to the river. The second concerns proper disposal of the runoff and possibly leachate from the dry ash stack. The third is that dry ash stacking might change the potential for groundwater contamination at the KFP. This report addresses each of these issues. The effects on the ash pond and its discharge are described first. The report is intended to provide reference material to TVA staff in preparation of environmental review documents for new ash disposal areas at Kingston. Although the investigation was directed toward analysis of dry stacking, considerations for other disposal options are also discussed. This report was reviewed in draft form under the title Assessment of Kingston Fossil Plant Dry Ash Stacking on the Ash Pond and Groundwater Quality.'' 11 refs., 3 figs., 18 tabs.
Date:
April 1, 1990
Creator:
Bohac, C.E.
Object Type:
Report
System:
The UNT Digital Library
Water resources review: Ocoee reservoirs, 1990
Tennessee Valley Authority (TVA) is preparing a series of reports to make technical information on individual TVA reservoirs readily accessible. These reports provide a summary of reservoir purpose and operation; physical characteristics of the reservoir and watershed; water quality conditions; aquatic biological conditions; and designated, actual and potential uses of the reservoir and impairments of those use. This reservoir status report addressed the three Ocoee Reservoirs in Polk County, Tennessee.
Date:
August 1, 1990
Creator:
Cox, J. P.
Object Type:
Report
System:
The UNT Digital Library
Water resources review: Wheeler Reservoir, 1990
Protection and enhancement of water quality is essential for attaining the full complement of beneficial uses of TVA reservoirs. The responsibility for improving and protecting TVA reservoir water quality is shared by various federal, state, and local agencies, as well as the thousands of corporations and property owners whose individual decisions affect water quality. TVA's role in this shared responsibility includes collecting and evaluating water resources data, disseminating water resources information, and acting as a catalyst to bring together agencies and individuals that have a responsibility or vested interest in correcting problems that have been identified. This report is one in a series of status reports that will be prepared for each of TVA's reservoirs. The purpose of this status report is to provide an up-to-date overview of the characteristics and conditions of Wheeler Reservoir, including: reservoir purposes and operation; physical characteristics of the reservoir and the watershed; water quality conditions: aquatic biological conditions: designated, actual, and potential uses of the reservoir and impairments of those uses; ongoing or planned reservoir management activities. Information and data presented here are form the most recent reports, publications, and original data available. 21 refs., 8 figs., 29 tabs.
Date:
September 1, 1990
Creator:
Wallus, Robert & Cox, Janice P.
Object Type:
Report
System:
The UNT Digital Library
Water Science and Technology Board annual report 1989
This report summarizes the activities of the Water Science and Technology Board (WSTB) and its subgroups during 1989, it seventh year of existence. It describes current and recently completed projects, new activities scheduled to begin in 1990, and plans for the future. The report also includes information on Board and committee memberships, program operational features, and reports produced during the past several years. This annual report is an introduction to the WSTB and its program for the year. 4 figs.
Date:
January 1, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Water Science and Technology Board annual report, 1990
This report summarizes the activities of the Water Science and Technology Board (WSTB) during 1990, its eighth year of existence. It describes current and recently completed projects, new activities scheduled to begin in 1991, and plans for the future. The WSTB is intended to be a dynamic forum, a mechanism by which the board community of water science, technology, and policy professionals can help assure high-quality national water programs. As such, the Board considers out-reach and communications of much importance.
Date:
January 1, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Water Science and Technology Board annual report, 1990
This report summarizes the activities of the Water Science and Technology Board (WSTB) during 1990, its eighth year of existence. It describes current and recently completed projects, new activities scheduled to begin in 1991, and plans for the future. The WSTB is intended to be a dynamic forum, a mechanism by which the board community of water science, technology, and policy professionals can help assure high-quality national water programs. As such, the Board considers out-reach and communications of much importance.
Date:
December 31, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Water-table elevations on the Hanford Site, December 1989
The Site Characterization and Assessment Section, Environmental Sciences Department, of the Pacific Northwest Laboratory (PNL) prepares water-table maps of the Hanford Site in southeastern Washington. Water levels in selected wells open to the unconfined aquifer on the Hanford Site are measured in June and December of each year. The purpose of these measurements is to determine the changes in the configuration of the water table to assess the physical impact of waste disposal on ground-water flow. Water-level measurements can be used to construct a water-table map that represents the elevation of the water-table surface. These maps can be used to infer general directions of ground-water flow, particularly in the upper part of the aquifer. In addition to water levels measured across the Hanford Site, water levels were also measured from four specific areas within Hanford. Included are areas around the decommissioned 216-U-10 Pond (U Pond), the 216-B-3 Pond (B-Pond), the 100-N Area and the 300 Area. 17 refs., 4 figs.
Date:
June 1, 1990
Creator:
Newcomer, D.R. & McDonald, J.P.
Object Type:
Report
System:
The UNT Digital Library
A waterjet mining machine for use in room and pillar mining operations
A new mining machine is constructed for use in room and pillar mining operations. This machine uses the action of computer controlled, centrally located high pressure cutting lances to cut deep slots in a coal face. These slots stress relieve the coal ahead of the machine and outline blocks of coal. The movement forward of the machine then wedges up the lower block of coal. This wedging action is assisted by the gathering arms of the loader section of the machine, and by underlying oscillating waterjets which create a slot ahead of the loading wedge as it advances. Finally the top section of coal is brought down by the sequential advance of wedge faced roof support members, again assisted by the waterjet action from the central cutting arms. The machine is designed to overcome major disadvantages of existing room and pillar mining machines in regard to a reduction in respirable dust, the creation of an immediate roof support, and an increase in product size, with concomitant reduction in cleaning costs.
Date:
June 1, 1990
Creator:
Summers, D. A.
Object Type:
Report
System:
The UNT Digital Library
A waterjet mining machine for use in room and pillar mining operations. [Final report]
A new mining machine is constructed for use in room and pillar mining operations. This machine uses the action of computer controlled, centrally located high pressure cutting lances to cut deep slots in a coal face. These slots stress relieve the coal ahead of the machine and outline blocks of coal. The movement forward of the machine then wedges up the lower block of coal. This wedging action is assisted by the gathering arms of the loader section of the machine, and by underlying oscillating waterjets which create a slot ahead of the loading wedge as it advances. Finally the top section of coal is brought down by the sequential advance of wedge faced roof support members, again assisted by the waterjet action from the central cutting arms. The machine is designed to overcome major disadvantages of existing room and pillar mining machines in regard to a reduction in respirable dust, the creation of an immediate roof support, and an increase in product size, with concomitant reduction in cleaning costs.
Date:
June 1, 1990
Creator:
Summers, D. A.
Object Type:
Report
System:
The UNT Digital Library
Wave optics modelling of amplified spontaneous emission
A laser works by amplified spontaneous emission (ASE) of inverted atomic ions confined in an amplifier of rod-like geometry, such that ASE radiation is directed out of both ends of the rod. The forward and backward ASE waves are coupled through the population-rate equations and cause the saturation of the lasing transition (gain saturation). Diffraction of the waves in the transverse direction is responsible for the radiation pattern (angular distribution) observed on a distant screen and for the degree of spatial coherence of the radiation. Refraction of the light also occurs due to spatial gradients in the electron density. In order to describe this situation a code has been developed which numerically solves paraxial Maxwell's equations in the time and two spatial dimensions. The code uses the Peaceman-Rachford Alternating-Direction-Implicit algorithm and is benchmarked against laboratory DYE-LASER experiments. 4 refs., 1 fig.
Date:
November 6, 1990
Creator:
Ritchie, B. & Garrison, J.
Object Type:
Article
System:
The UNT Digital Library
Waves in plasmas: Highlights from the past and present
To illustrate the development of some fundamental concepts in plasma waves, a number of experimental observations, going back over half a century, are reviewed. Particular attention is paid to the phenomena of dispersion, collisionfree damping, ray trajectories, amplitude transport, plasma wave echos, finite-Larmor-radius and cyclotron and cyclotron-harmonic effects, nonlocal response, and mode conversion. Also to the straight, trajectory approximation and two-level phase mixing. And to quasilinear diffusion and its relation to radiofrequency heating, current drive and induced neoclassical transport, and to stochasticity and superadiabaticity. One notes not only the constructive interplay between experiment and theory but also that major advances have come from each of the many disciplines that invoke plasma physics as a tool, including radio communication, astrophysics, controlled fusion, space physics, and basic research. 47 refs., 33 figs.
Date:
March 1, 1990
Creator:
Stix, T. H.
Object Type:
Article
System:
The UNT Digital Library
Weak scale supersymmetry
An introduction to the ideas and current state of weak scale supersymmetry is given. It is shown that LEP data on Z decays has already excluded two of the most elegant models of weak scale supersymmetry. 14 refs.
Date:
November 12, 1990
Creator:
Hall, L. J.
Object Type:
Article
System:
The UNT Digital Library
Weak turbulence theory of collisionless trapped electron driven drift instability in tokamaks
The toroidal collisionless trapped electron modes are analyzed in the weak turbulence regime treating both ions and trapped electrons nonlinearly in the presence of ion and electron temperature gradients. The spectral intensity of the density fluctuations in the nonlinearly saturated state is analytically obtained from the steady state solution of the wave-kinetic equation. Distant nonlinear interactions between low-k{sub {theta}} and high-k{sub {theta}} modes of similar frequencies via trapped electron scattering (the resonance between the beat wave and the trapped electron precession drift frequencies) suppress the low-k{sub {theta}} (k{sub {theta}}{rho}{sub s} {much lt} (L{sub n}/R){sup 1/2}) modes while close interactions via ion Compton scattering (nonlinear ion Landau damping) produce a monotonically decreasing spectrum from k{sub {theta}}{rho}{sub s} {congruent} (L{sub n}/R){sup 1/2} to k{sub {theta}}{rho}{sub s} {congruent} 1 according to an approximate power law k{sub {theta}}{sup {minus}3}. Various fluctuation amplitudes at saturation and the fluctuation-induced anomalous particle and heat fluxes are found to be smaller than the mixing length estimates. The plasma confinement is predicted to improve with higher T{sub i}/T{sub e}, more peaked density profile, larger aspect ratio, and higher plasma current. Also, a significant dependence of transport on the electron temperature gradient is found which could contribute to the rigidity …
Date:
October 1, 1990
Creator:
Hahm, T.S. & Tang, W.M.
Object Type:
Report
System:
The UNT Digital Library
Wear mechanism and wear prevention in coal-fueled diesel engines
The overall objective of this program is to develop the engine and lubricant system design approach that has the highest probability for commercial acceptance. Several specific objectives can also be identified. These objectives include: definition of the dominant wear mechanisms prevailing in coal-fueled diesel engines; definition of the specific effect of each coal-related lube oil contaminant; determination of the potential of traditional engine lubrication design approaches to either solve or mitigate the effects of the coal related lube oil contaminants; evaluation of several different design approaches aimed specifically at preventing lube oil contamination or preventing damage due to lube oil contamination; and presentation of the engine/lubricant system design determined to have the most potential. 2 figs., 3 tabs.
Date:
February 19, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Wear mechanism and wear prevention in coal-fueled diesel engines
The overall objective of this program is to develop the diesel engine and lubricant system design approach that has the highest probability for commercial acceptance. Several specific objectives can also be identified. These objectives include: Definition of the dominant wear mechanisms prevailing in coal-fueled diesel engines; Definition of the specific effect of each coal-related lube oil contaminant; Determination of the potential of traditional engine lubrication design approaches to either solve or mitigate the effects of the coal related lube oil contaminants; Evaluation of several different engine design approaches aimed specifically at preventing lube oil contamination or preventing damage due to lube oil contamination; and Presentation of the engine/lubricant system design determined to have the most potential.
Date:
June 20, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library