Resource Type
Country
States
Decade
Year
Month
Language
11,813 Matching Results
Results open in a new window/tab.
Artificial geothermal reservoirs in hot volcanic rock
S>Some recent results from the Los Alamos program in which hydraulic fracturing is used for the recovery of geothermal energy are discussed. The location is about 4 kilometers west and south of the ring fault of the enormous Jemez Caldera in the northcentral part of New Mexico. It is shown that geothermal energy may be extracted from hot rock that does not contain circulating hot water or steam and is relatively impermeable. A fluid is pumped at high pressure into an isolated section of a wellbore. If the well is cased the pipe in this pressurized region is perforated as it is in the petroleum industry, so that the pressure may be applied to the rock, cracking it. A second well is drilled a few hundred feet away from the first. Cold water is injected through the first pipe, circulates through the crack, and hot water returns to the surface through the second pipe. Results are described and circumstances are discussed under which artiflcial geothermal reservoirs might be created in the basaltic rock of Hawaii. (MCW)
Date:
February 8, 1974
Creator:
Aamodt, R. L.
System:
The UNT Digital Library
Hydraulic fracture experiments in GT-1 and GT-2
Hydraulic fracturing experiments were conducted in granite rock, at temperatures near 100 and 150/sup 0/C, in two wells 0.785 km (2575 ft) and 1.98 km (6500 ft) deep near Los Alamos, New Mexico. No unusual difficulty was observed in fracturing crystalline rock hydraulically. The apparent surface energy (energy required to create new fracture surface by breaking the rock) was measured as 100 J/m/sup 2/. Orientation of the deeper fracture was measured as N35/sup 0/E (+-5/sup 0/). The fraction of fluid injected into the rock that could be recovered at hydrostatic surface pressure was measured. The efficiency of recovery was as high as 92 percent after the fracture impedance was lowered by ''propping'' the fracture with sand. Permeability of the rock over the face of the fracture was compatible with laboratory measurements (10/sup -7/ to 10/sup -8/ darcys). Downhole pressures required to extend the fractures were about 150 and 340 bars (2175 and 4900 psi), respectively.
Date:
February 1, 1977
Creator:
Aamodt, R. L.
System:
The UNT Digital Library
A PORTABLE BANDSAW FOR HOT CELL USE
A commercial light-weight portable bandsaw was fitted with a grip to permit it to be maneuvered remotely in a hot cell by means of a General Mills manipulator The bandsaw was supported in various positions to make cuts on typical pieces. Photographs show the saw in operation. (auth)
Date:
February 19, 1958
Creator:
Abbatiello, A. A.
System:
The UNT Digital Library
Investigating the point seismic array concept with seismic rotation measurements.
Spatially-distributed arrays of seismometers are often utilized to infer the speed and direction of incident seismic waves. Conventionally, individual seismometers of the array measure one or more orthogonal components of rectilinear particle motion (displacement, velocity, or acceleration). The present work demonstrates that measure of both the particle velocity vector and the particle rotation vector at a single point receiver yields sufficient information to discern the type (compressional or shear), speed, and direction of an incident plane seismic wave. Hence, the approach offers the intriguing possibility of dispensing with spatially-extended received arrays, with their many problematic deployment, maintenance, relocation, and post-acquisition data processing issues. This study outlines straightforward mathematical theory underlying the point seismic array concept, and implements a simple cross-correlation scanning algorithm for determining the azimuth of incident seismic waves from measured acceleration and rotation rate data. The algorithm is successfully applied to synthetic seismic data generated by an advanced finite-difference seismic wave propagation modeling algorithm. Application of the same azimuth scanning approach to data acquired at a site near Yucca Mountain, Nevada yields ambiguous, albeit encouraging, results. Practical issues associated with rotational seismometry are recognized as important, but are not addressed in this investigation.
Date:
February 1, 2009
Creator:
Abbott, Robert E. & Aldridge, David Franklin
System:
The UNT Digital Library
Evaluation of Ultra Clean Fuels from Natural Gas
ConocoPhillips, in conjunction with Nexant Inc., Penn State University, and Cummins Engine Co., joined with the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) in a cooperative agreement to perform a comprehensive study of new ultra clean fuels (UCFs) produced from remote sources of natural gas. The project study consists of three primary tasks: an environmental Life Cycle Assessment (LCA), a Market Study, and a series of Engine Tests to evaluate the potential markets for Ultra Clean Fuels. The overall objective of DOE's Ultra Clean Transportation Fuels Initiative is to develop and deploy technologies that will produce ultra-clean burning transportation fuels for the 21st century from both petroleum and non-petroleum resources. These fuels will: (1) Enable vehicles to comply with future emission requirements; (2) Be compatible with the existing liquid fuels infrastructure; (3) Enable vehicle efficiencies to be significantly increased, with concomitantly reduced CO{sub 2} emissions; (4) Be obtainable from a fossil resource, alone or in combination with other hydrocarbon materials such as refinery wastes, municipal wastes, biomass, and coal; and (5) Be competitive with current petroleum fuels. The objectives of the ConocoPhillips Ultra Clean Fuels Project are to perform a comprehensive life cycle analysis and to conduct …
Date:
February 28, 2006
Creator:
Abbott, Robert; Casey, Edward; Esen, Etop; Smith, Douglas; Burke, Bruce; Nguyen, Binh et al.
System:
The UNT Digital Library
Interated Intelligent Industrial Process Sensing and Control: Applied to and Demonstrated on Cupola Furnaces
The final goal of this project was the development of a system that is capable of controlling an industrial process effectively through the integration of information obtained through intelligent sensor fusion and intelligent control technologies. The industry of interest in this project was the metal casting industry as represented by cupola iron-melting furnaces. However, the developed technology is of generic type and hence applicable to several other industries. The system was divided into the following four major interacting components: 1. An object oriented generic architecture to integrate the developed software and hardware components @. Generic algorithms for intelligent signal analysis and sensor and model fusion 3. Development of supervisory structure for integration of intelligent sensor fusion data into the controller 4. Hardware implementation of intelligent signal analysis and fusion algorithms
Date:
February 12, 2003
Creator:
Abdelrahman, Mohamed; Haggard, roger; Mahmoud, Wagdy; Moore, Kevin; Clark, Denis; Larsen, Eric et al.
System:
The UNT Digital Library
Fermi Large Area Telescope Observations of the Cosmic-Ray Induced
We report on measurements of the cosmic-ray induced {gamma}-ray emission of Earth's atmosphere by the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. The LAT has observed the Earth during its commissioning phase and with a dedicated Earth-limb following observation in September 2008. These measurements yielded {approx} 6.4 x 10{sup 6} photons with energies > 100 MeV and {approx} 250 hours total livetime for the highest quality data selection. This allows the study of the spatial and spectral distributions of these photons with unprecedented detail. The spectrum of the emission - often referred to as Earth albedo gamma-ray emission - has a power-law shape up to 500 GeV with spectral index {Lambda} = 2.79 {+-} 0.06.
Date:
February 29, 2012
Creator:
Abdo, A. A.
System:
The UNT Digital Library
FY06 LDRD Final Report Data Intensive Computing
The goal of the data intensive LDRD was to investigate the fundamental research issues underlying the application of High Performance Computing (HPC) resources to the challenges of data intensive computing. We explored these issues through four targeted case studies derived from growing LLNL programs: high speed text processing, massive semantic graph analysis, streaming image feature extraction, and processing of streaming sensor data. The ultimate goal of this analysis was to provide scalable data management algorithms to support the development of a predictive knowledge capability consistent with the direction of Aurora.
Date:
February 13, 2007
Creator:
Abdulla, G M
System:
The UNT Digital Library
Consolidation and shear failure leading to subsidence and settlement. Final report
Subsidence and settlement are phenomena that are much more destructive than generally thought. In shallow land burials they may lead to cracking of the overburden and eventual exposure and escape of waste material. The primary causes are consolidation and cave-ins. Laboratory studies performed at Los Alamos permit us to predict settlement caused by consolidation or natural compaction of the crushed tuff overburden. We have also investigated the shear failure characteristics of crushed tuff that may lead to subsidence. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of crushed tuff. The same thing is done for bentonite/tuff mixes because some field experiments were performed using this additive (bentonite) to reduce the hydraulic conductivity of the crushed tuff. Remedial actions, i.e., means to limit the amount of settlement, are discussed. We finally discuss our field experiment, which studies the influence of subsidence on layered systems in general and on biobarriers in particular. The share of the produced cavities is compared with cavities produced by idealized voids in an idealized environment. Study of root penetration at subsidence sites gives us an indication of the remaining degree of integrity. 30 refs., 24 figs., 19 tabs.
Date:
February 1, 1986
Creator:
Abeele, W.; Nyhan, J. W.; Hakonson, T. E.; Drennon, B. J.; Lopez, E. A.; Herrera, W. J. et al.
System:
The UNT Digital Library
Low-level integrated system test
An unusually wet season permitted us to test the integrity of our biobarrier installed in the improved or modified plots in our integrated system. Although the modified plots had a reduced water-holding capacity, they delivered leachate only at the drain installed above the biobarrier, demonstrating once more that the biobarrier is behaving successfully as a capillary barrier in rerouting the subsurface flow around the tuff beneath the biobarrier. As a result of vertical water flow impedance, more water was made available to plot vegetation, enhancing its growth dramatically. The capillary barrier theory was backed up by the tensiometer results showing saturation at the upper biobarrier interface. 11 refs., 19 figs
Date:
February 1, 1986
Creator:
Abeele, Willy; Nyhan, John; Hakonson, Tom; Drennon, Barry J.; Lopez, Edward A.; Herrera, Wilfred J. et al.
System:
The UNT Digital Library
A novel approach to highly dispersing catalytic materials in coal for gasification. Ninth quarterly report, October 1, 1991--December 31, 1991
This project seeks to develop a technique, based on coal surface properties, for highly dispersing catalysts in coal for gasification and to investigate the potential of using potassium carbonate and calcium acetate mixtures as catalysts for coal gasification. The lower cost and higher catalytic activity of the latter compound will produce economic benefits by reducing the amount of K{sub 2}CO{sub 3} required for high coal char reactivities. As was shown in previous reports, coal loading with potassium or calcium at different pHs produced CO{sub 2} gasification activities which increased in the order pH 6 > pH 10 {much_gt} pH 1. The current report shows that a similar trend was obtained when calcium and potassium were simultaneously loaded and char reaction times were less than about 75 min. Beyond this time, the coal impregnated with catalyst at pH 1 became more reactive, reaching 100% conversion after 1.5h. X-ray diffraction analysis suggest that the catalysts are well dispersed around pH 1 and 6 whereas reduced dispersion as obtained at pH 10. The reactivities are independent of the surface areas of the coals.
Date:
February 10, 1992
Creator:
Abotsi, G. M. K. & Bota, K. B.
System:
The UNT Digital Library
A novel approach to highly dispersing catalytic materials in coal for gasification
This project seeks to develop a technique, based on coal surface properties, for highly dispersing catalysts in coal for gasification and to investigate the potential of using potassium carbonate and calcium acetate mixtures as catalysts for coal gasification. The lower cost and higher catalytic activity of the latter compound will produce economic benefits by reducing the amount of K{sub 2}CO{sub 3} required for high coal char reactivities. As was shown in previous reports, coal loading with potassium or calcium at different pHs produced CO{sub 2} gasification activities which increased in the order pH 6 > pH 10 {much gt} pH 1. The current report shows that a similar trend was obtained when calcium and potassium were simultaneously loaded and char reaction times were less than about 75 min. Beyond this time, the coal impregnated with catalyst at pH 1 became more reactive, reaching 100% conversion after 1.5h. X-ray diffraction analysis suggest that the catalysts are well dispersed around pH 1 and 6 whereas reduced dispersion as obtained at pH 10. The reactivities are independent of the surface areas of the coals.
Date:
February 10, 1992
Creator:
Abotsi, G.M.K. & Bota, K.B.
System:
The UNT Digital Library
Preliminary Safety Evaluation of the Sodium Reactor Experiment
A description is given of the Sodium Reactor Experiment (SRE) facilities and program of objectives. The hazards associated with equipment failures and malfunctions, personnel errors, natural causes, and operation are evaluated (C.J.G.)
Date:
February 19, 1954
Creator:
Abott, W. E.
System:
The UNT Digital Library
The Reaction of Glass During Gamma Irradiation in a Saturated Tuff Environment: Part 3, Long-Term Experiments at 1 X 10{Sup 4}Rad/Hour
Savannah River Laboratory 165 type glass was leached with equilibrated J-13 groundwater at 90{degree}C for times up to 182 days. These experiments were performed as part of an effort by the Nevada Nuclear Waste Storage Investigations Project to assess the importance of radiation effects on repository performance and waste glass corrosion. The gamma radiation field used in this work was 1. 0 +- 0.2 x 10{sup 4} rad/h. Glass dissolution is notably incongruent throughout the entire experimental periods and normalized releases follow the sequence Li {ge} Na {ge} B {approx_equal} U {ge} Si. The normalized leach rates of these elements, as well as the measured growth rates of the reaction layers, decreased with time. The only significant variation observed in the abundance of anions is the systematic decrease in NO{sub 3}/sup {minus}//NO{sub 2}/sup {minus}/ ratio from the starting EJ-13 groundwater to the EJ-13 blank experiments to the tuff- and glass-containing experiments. A leaching model that is consistent with the observed solution data and depth profiles is presented. The applicability and limitation of the present results in predicting the actual interactions that may occur in the NNWSI repository are discussed. 35 refs., 30 figs., 12 tabs.
Date:
February 1, 1988
Creator:
Abrajano, T. A., Jr.; Bates, J. K.; Gerding, T. J. & Ebert, W. L.
System:
The UNT Digital Library
EARLY ENTRANCE COPRODUCTION PLANT
The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site and to develop a Research, Development, and Testing Plan (RD and T) for implementation in Phase II. The objective of Phase II is to implement the RD and T as outlined in the Phase I RD and T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing plan …
Date:
February 15, 2001
Creator:
Abughazaleh, John S.; Ahmed, Mushtaq; Anand, Ashok; Anderson, John H.; Benham, Charles; Brent, Fred D. et al.
System:
The UNT Digital Library
ADVANCED COMPOSITE WIND TURBINE BLADE DESIGN BASED ON DURABILITY AND DAMAGE TOLERANCE
The objective of the program was to demonstrate and verify Certification-by-Analysis (CBA) capability for wind turbine blades made from advanced lightweight composite materials. The approach integrated durability and damage tolerance analysis with robust design and virtual testing capabilities to deliver superior, durable, low weight, low cost, long life, and reliable wind blade design. The GENOA durability and life prediction software suite was be used as the primary simulation tool. First, a micromechanics-based computational approach was used to assess the durability of composite laminates with ply drop features commonly used in wind turbine applications. Ply drops occur in composite joints and closures of wind turbine blades to reduce skin thicknesses along the blade span. They increase localized stress concentration, which may cause premature delamination failure in composite and reduced fatigue service life. Durability and damage tolerance (D&DT) were evaluated utilizing a multi-scale micro-macro progressive failure analysis (PFA) technique. PFA is finite element based and is capable of detecting all stages of material damage including initiation and propagation of delamination. It assesses multiple failure criteria and includes the effects of manufacturing anomalies (i.e., void, fiber waviness). Two different approaches have been used within PFA. The first approach is Virtual Crack Closure Technique …
Date:
February 16, 2012
Creator:
Abumeri, Galib & Abdi, Frank
System:
The UNT Digital Library
A Comprehensive Study of Surface Chemistry for Application to Engine NOx Aftertreatment
This work focuses on developing a scientific understanding of the processes associated with NO{sub x} trap operation. NO{sub x} traps are the most advanced technology for achieving future emissions standards with diesel engines. Successful development of NO{sub x} traps will allow widespread use of diesel engines in light-duty vehicles, reducing oil imports by as much as 60%. Diesel engines have a high efficiency and low maintenance that makes them the ideal choice for transportation applications. Use of diesel engines in all light-duty vehicles would reduce oil consumption in the USA by 30% and oil imports by 60%, considerably improving our energy security. For heavy trucks, there is no viable alternative to diesel engines. Only diesel engines can provide the necessary high efficiency and long life. These benefits are offset by high emission of pollutants. Diesel engines have high emissions of NO{sub x} and particulate matter. Over the last 20 years, EPA has been reducing allowable emissions from diesel engines, and NO{sub x} emissions are scheduled to be cut by a factor of 10 over the next 7 years. The target NO{sub x} emissions for year 2010 is 0.20 g/hp-hr. This value is well below 1 g/hp-hr, which has been identified …
Date:
February 19, 2004
Creator:
Aceves, S M; Piggot, T; Pitz, W; Mundy, C; Kuo, W & Havstad, M
System:
The UNT Digital Library
Thin-film characterization and flaw detection. Final report, February 1, 1993--November 31, 1997
The objectives were to determine the elastic constants of thin films deposited on substrates, to measure residual stress and to detect and characterize defects in thin film substrate configurations. There are many present and potential applications of configurations consisting of a thin film deposited on a substrate. Thin films that are deposited to improve the hardness and/or the thermal properties of surfaces were of principal interest in this work. Thin film technology does, however, also include high {Tc} superconductor films, films for magnetic recording, superlattices and films for band-gap engineering and quantum devices. The studies that were carried out on this project also have relevance to these applications. Both the film and the substrate are generally anisotropic. A line-focus acoustic microscope has been used to measure the speed of surface acoustic waves (SAW) in the thin film/substrate system. This microscope has unique advantages for measurements in anisotropic media. Analytical and numerical techniques have been employed to extract the desired information on the thin film from the measured SAW data. Results include: (1) analytical and numerical techniques for the direct problem and for inverse methods; (2) measurements of homogeneous and superlattice film constants; (3) investigation of the effect of surface roughness …
Date:
February 25, 1998
Creator:
Achenbach, J. D.
System:
The UNT Digital Library
Hot dry rock reservoir characterization and modeling. Progress report, October 1, 1978-September 30, 1979. Final report
Resuls of analytical and experimental studies on hydraulic fracturing and on the characterization and modeling of hot dry rock geothermal energy reservoirs are presented. The first four Chapters are concerned with problems of thermal cracking and heat transfer, with fluid flow through large cracks, and with the stable and unstable growth of water-filled cracks under internal pressure and thermal loading. Experiments are reported, which present visually observable hydraulic fractures in transparent materials to demonstrate the interaction between hydraulic fractures and the development of thermal cracks. Seismic detection of hydraulic fractures is discussed, and a method to invert crack-scattering data is presented. Separate abstracts were prepared for each of the six chapters.
Date:
February 1, 1980
Creator:
Achenbach, J. D.; Bazant, Z. P.; Dundurs, J.; Keer, L.M.; Nemat-Nasser, S.; Mura, T. et al.
System:
The UNT Digital Library
Transmission System Performance Analysis for High-Penetration Photovoltaics
This study is an assessment of the potential impact of high levels of penetration of photovoltaic (PV) generation on transmission systems. The effort used stability simulations of a transmission system with different levels of PV generation and load.
Date:
February 1, 2008
Creator:
Achilles, S.; Schramm, S. & Bebic, J.
System:
The UNT Digital Library
Recent regulatory experience of low-Btu coal gasification. Volume III. Supporting case studies
The MITRE Corporation conducted a five-month study for the Office of Resource Applications in the Department of Energy on the regulatory requirements of low-Btu coal gasification. During this study, MITRE interviewed representatives of five current low-Btu coal gasification projects and regulatory agencies in five states. From these interviews, MITRE has sought the experience of current low-Btu coal gasification users in order to recommend actions to improve the regulatory process. This report is the third of three volumes. It contains the results of interviews conducted for each of the case studies. Volume 1 of the report contains the analysis of the case studies and recommendations to potential industrial users of low-Btu coal gasification. Volume 2 contains recommendations to regulatory agencies.
Date:
February 1, 1980
Creator:
Ackerman, E.; Hart, D.; Lethi, M.; Park, W. & Rifkin, S.
System:
The UNT Digital Library
Interactions of CO{sub 2} With Temperature and Other Climate Variables: Response of Vegetation. Final Report, September 1, 1988--August 31, 1993
The current project was initiated in 1991, and full details of the scope of the project are contained in the original proposal. that original proposal was reviewed and approved for three years funding. Progress made in 1991-92 and 1992-93 was described in annual Progress Reports and Statements of Work. This document summarizes progress made over the duration of the project, but with an emphasis on the final year`s (1993-94) results. Several of the important experiments are ongoing, to the extent that alternative funding could be arranged, and analyses of data from several of the earlier completed experiments is continuing. Therefore, this Final Report is also intermediary in nature, and additional results from this project will be reported in the open literature in the future. The overall objectives of the project were: (1) to examine experimentally, for major crop species, the interacting effects of CO{sub 2} concentration, temperature, and water availability on plant growth and development, (2) to model these interactions, and (3) to continue developing physiologically-based mechanistic models for predicting crop response to increased CO{sub 2} concentration and future global climate change.
Date:
February 1, 1995
Creator:
Acock, B. & Kimball, B. A.
System:
The UNT Digital Library
Electroweak physics: measurement of the forward-backward charge asymmetry of electron-positron pairs in p anti-p collisions at s**(1/2) = 1.96 tev
We report a measurement of the forward-backward charge asymmetry of electrons from W boson decays in p{bar p} collisions at {radical}s = 1.96 TeV using a data sample of 170 pb{sup -1} collected by the Collider Detector at Fermilab. The asymmetry is measured as a function of electron rapidity and transverse energy and provides new input on the momentum fraction dependence of the u and d quark parton distribution functions within the proton.
Date:
February 23, 2005
Creator:
Acosta, D.
System:
The UNT Digital Library
Electroweak physics: measurement of w gamma and z gamma production in pp-bar collisions at s**(1/2) = 1.96 tev
The Standard Model predictions for W{gamma} and Z{gamma} production are tested using an integrated luminosity of 200 pb{sup -1} of p{bar p} collision data collected at the Collider Detector at Fermilab. The cross sections are measured by selecting leptonic decays of the W and Z bosons, and photons with transverse energy E{sub T} > 7 GeV that are well separated from leptons. The production cross sections and kinematic distributions for the W{gamma} and Z{gamma} data are compared to SM predictions.
Date:
February 2, 2005
Creator:
Acosta, D.
System:
The UNT Digital Library