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Measurement of Cross Sections for b Jet Production in Events with a Z Boson in p-anti-p Collisions at s**(1/2) = 1.96-TeV (open access)

Measurement of Cross Sections for b Jet Production in Events with a Z Boson in p-anti-p Collisions at s**(1/2) = 1.96-TeV

A measurement of the b jet production cross section is presented for events containing a Z boson produced in p{bar p} collisions at {radical}s = 1.96 TeV, using data corresponding to an integrated luminosity of 2 fb{sup -1} collected by the CDF II detector at the Tevatron. Z bosons are selected in the electron and muon decay modes. Jets are considered with transverse energy E{sub T} > 20 GeV and pseudorapidity |{eta}| < 1.5 and are identified as b jets using a secondary vertex algorithm. The ratio of the integrated Z+b jet cross section to the inclusive Z production cross section is measured to be 3.32 {+-} 0.53(stat:) {+-} 0.42(syst:) x 10{sup -3}. This ratio is also measured differentially in jet E{sub T}, jet {eta}, Z-boson transverse momentum, number of jets, and number of b jets. The predictions from leading order Monte Carlo generators and next-to-leading-order QCD calculations are found to be consistent with the measurements within experimental and theoretical uncertainties.
Date: December 1, 2008
Creator: Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D. et al.
Object Type: Article
System: The UNT Digital Library
Top Quark Mass Measurement in the Lepton plus Jets Channel Using a Modified Matrix Element Method (open access)

Top Quark Mass Measurement in the Lepton plus Jets Channel Using a Modified Matrix Element Method

The authors report a measurement of the top quark mass, m{sub t}, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. They analyze a sample corresponding to an integrated luminosity of 1.9 rfb{sup -1}. They select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. They calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. The event likelihood is a function of m{sub t} and a parameter JES that determines in situ the calibration of the jet energies. They use a neural network discriminant to distinguish signal from background events. They also apply a cut on the peak value of each event likelihood curve to reduce the contribution of background and badly reconstructed events. Using the 318 events that pass all selection criteria, they find m{sub t} = 172.7 {+-} 1.8 (stat. + JES) {+-} 1.2(syst.) GeV/c{sup 2}.
Date: December 1, 2008
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type: Article
System: The UNT Digital Library
Unexplained Excess of Electron-Like Events From a 1-GeV Neutrino Beam (open access)

Unexplained Excess of Electron-Like Events From a 1-GeV Neutrino Beam

The MiniBooNE Collaboration observes unexplained electron-like events in the reconstructed neutrino energy range from 200 to 475 MeV. With 6.46 x 10{sup 20} protons on target, 544 electron-like events are observed in this energy range, compared to an expectation of 415.2 {+-} 43.4 events, corresponding to an excess of 128.8 {+-} 20.4 {+-} 38.3 events. The shape of the excess in several kinematic variables is consistent with being due to either {nu}{sub e} and {bar {nu}}{sub e} charged-current scattering or to {nu}{sub {mu}} neutral-current scattering with a photon in the final state. No significant excess of events is observed in the reconstructed neutrino energy range from 475 to 1250 MeV, where 408 events are observed compared to an expectation of 385.9 {+-} 35.7 events.
Date: December 1, 2008
Creator: Aguilar-Arevalo, A. A.; Anderson, C. E.; Bazarko, A. O.; Brice, Stephen J.; Brown, B. C.; Bugel, L. et al.
Object Type: Article
System: The UNT Digital Library
The genome sequence of Geobacter metallireducens: features of metabolism, physiology and regulation common and dissimilar to Geobacter sulfurreducens (open access)

The genome sequence of Geobacter metallireducens: features of metabolism, physiology and regulation common and dissimilar to Geobacter sulfurreducens

Background: The genome sequence of Geobacter metallireducens is the second to be completed from the metal-respiring genus Geobacter, and is compared in this report to that of Geobacter sulfurreducens in order to understand their metabolic, physiological and regulatory similarities and differences. Results: The experimentally observed greater metabolic versatility of G. metallireducens versus G. sulfurreducens is borne out by the presence of more numerous genes for metabolism of organic acids including acetate, propionate, and pyruvate. Although G. metallireducens lacks a dicarboxylic acid transporter, it has acquired a second succinate dehydrogenase/fumarate reductase complex, suggesting that respiration of fumarate was important until recently in its evolutionary history. Vestiges of the molybdate (ModE) regulon of G. sulfurreducens can be detected in G. metallireducens, which has lost the global regulatory protein ModE but retained some putative ModE-binding sites and multiplied certain genes of molybdenum cofactor biosynthesis. Several enzymes of amino acid metabolism are of different origin in the two species, but significant patterns of gene organization are conserved. Whereas most Geobacteraceae are predicted to obtain biosynthetic reducing equivalents from electron transfer pathways via a ferredoxin oxidoreductase, G. metallireducens can derive them from the oxidative pentose phosphate pathway. In addition to the evidence of greater metabolic …
Date: December 1, 2008
Creator: Aklujkar, Muktak; Krushkal, Julia; DiBartolo, Genevieve; Lapidus, Alla; Land, Miriam L. & Lovley, Derek R.
Object Type: Article
System: The UNT Digital Library
Verification and Validation of TMAP7 (open access)

Verification and Validation of TMAP7

The Tritium Migration Analysis Program, Version 7 (TMAP7) code is an update of TMAP4, an earlier version that was verified and validated in support of the International Thermonuclear Experimental Reactor (ITER) program and of the intermediate version TMAP2000. It has undergone several revisions. The current one includes radioactive decay, multiple trap capability, more realistic treatment of heteronuclear molecular formation at surfaces, processes that involve surface-only species, and a number of other improvements. Prior to code utilization, it needed to be verified and validated to ensure that the code is performing as it was intended and that its predictions are consistent with physical reality. To that end, the demonstration and comparison problems cited here show that the code results agree with analytical solutions for select problems where analytical solutions are straightforward or with results from other verified and validated codes, and that actual experimental results can be accurately replicated using reasonable models with this code. These results and their documentation in this report are necessary steps in the qualification of TMAP7 for its intended service.
Date: December 1, 2008
Creator: Ambrosek, James & Ambrosek, James
Object Type: Report
System: The UNT Digital Library
Fast marching methods for the continuous traveling salesman problem (open access)

Fast marching methods for the continuous traveling salesman problem

We consider a problem in which we are given a domain, a cost function which depends on position at each point in the domain, and a subset of points ('cities') in the domain. The goal is to determine the cheapest closed path that visits each city in the domain once. This can be thought of as a version of the Traveling Salesman Problem, in which an underlying known metric determines the cost of moving through each point of the domain, but in which the actual shortest path between cities is unknown at the outset. We describe algorithms for both a heuristic and an optimal solution to this problem. The order of the heuristic algorithm is at worst case M * N logN, where M is the number of cities, and N the size of the computational mesh used to approximate the solutions to the shortest paths problems. The average runtime of the heuristic algorithm is linear in the number of cities and O(N log N) in the size N of the mesh.
Date: December 1, 2008
Creator: Andrews, J. & Sethian, J. A.
Object Type: Article
System: The UNT Digital Library
FY 2008 Infrared Photonics Final Report (open access)

FY 2008 Infrared Photonics Final Report

Through the duration of the NNSA Office of Nuclear Nonproliferation Research and development (NA-22) ITAS lifecycle project, the Infrared Photonics research has been focused on developing integrated quantum cascade (QC) laser technology to enable next-generation remote sensing designs. Our team developed the concept of the integrated QC laser transmitter and originated and promoted the vision of mid-infrared (3–12 μm) wavelength photonics. Sustained NA-22 project funding produced the QC laser transmitter that is now deployed in follow-on projects. Our team produced nationally recognized cutting-edge research in the area of infrared transparent chalcogenide photonics. Three technical staff were recruited from outside PNNL and hired to support this research. This project also supported student research at the national laboratory, including high school, undergraduate, and graduate students. This provided a derivative benefit to NA-22, PNNL, and the educational institutions through training and mentoring next-generation students in science and technology. The student support was also the catalyst to develop research collaborations with two universities that are internationally recognized for their chalcogenide glass research.
Date: December 1, 2008
Creator: Anheier, Norman C.; Bernacki, Bruce E.; Carlie, Nathan A.; Gervais, Kevin L.; Hatchell, Brian K.; Johnson, Bradley R. et al.
Object Type: Report
System: The UNT Digital Library
Oklahoma Firefighter (Oklahoma City, Okla.), Vol. 25, No. 10, Ed. 1 Monday, December 1, 2008 (open access)

Oklahoma Firefighter (Oklahoma City, Okla.), Vol. 25, No. 10, Ed. 1 Monday, December 1, 2008

Monthly periodical from Oklahoma City, Oklahoma published by and for members of the Oklahoma State Firefighters Association that includes news and information along with advertising.
Date: December 1, 2008
Creator: Bain, Chris
Object Type: Journal/Magazine/Newsletter
System: The Gateway to Oklahoma History
Next Generation Nuclear Plant GAP Analysis Report (open access)

Next Generation Nuclear Plant GAP Analysis Report

As a follow-up to the phenomena identification and ranking table (PIRT) studies conducted recently by NRC on next generation nuclear plant (NGNP) safety, a study was conducted to identify the significant 'gaps' between what is needed and what is already available to adequately assess NGNP safety characteristics. The PIRT studies focused on identifying important phenomena affecting NGNP plant behavior, while the gap study gives more attention to off-normal behavior, uncertainties, and event probabilities under both normal operation and postulated accident conditions. Hence, this process also involved incorporating more detailed evaluations of accident sequences and risk assessments. This study considers thermal-fluid and neutronic behavior under both normal and postulated accident conditions, fission product transport (FPT), high-temperature metals, and graphite behavior and their effects on safety. In addition, safety issues related to coupling process heat (hydrogen production) systems to the reactor are addressed, given the limited design information currently available. Recommendations for further study, including analytical methods development and experimental needs, are presented as appropriate in each of these areas.
Date: December 1, 2008
Creator: Ball, Sydney J; Burchell, Timothy D; Corwin, William R; Fisher, Stephen Eugene; Forsberg, Charles W.; Morris, Robert Noel et al.
Object Type: Report
System: The UNT Digital Library
Evaluating hydroperiod response in carolina bay wetlands using soil physicochemical properties. (open access)

Evaluating hydroperiod response in carolina bay wetlands using soil physicochemical properties.

Abstract Carolina bays are shallow depression wetlands found in the southeastern United States that have been severely altered by human activity. The need to restore these complex and diverse systems is well established, but our limited understanding of wetland hydrologic processes in these systems hinders our ability to assess the effectiveness of bay restoration efforts. Carolina bays exhibit a wide range of moisture regimes from seasonally saturated to semipermanently inundated. Differing physicochemical properties of soils within bay interiors may control bay hydrology. However, previous efforts to establish relationships between soil characteristics and bay hydrology have been inconclusive. An assessment of soil and hydroperiod was initiated in 16 bays designated to be restored and 6 bays that were not restored (reference). Soil morphology was described, and permanent monitoring wells were installed at each site. Multiple regression analysis was used to determine relationships between the soil physicochemical characteristics and the bay hydroperiod for restored and reference bays in both pre- and postrestoration periods. A significant relationship (r2 = 0.75, p = 0.02) between prerestoration hydroperiod and clay content in the argillic horizon (Bt) of the reference bays was observed. This relationship was then used to evaluate hydroperiod change in the restored bays …
Date: December 1, 2008
Creator: Barton, Christopher, D.; Andrews, Danielle, M. & Kolka, Randall, K.
Object Type: Article
System: The UNT Digital Library
A Strategy for Nuclear Energy Research and Development (open access)

A Strategy for Nuclear Energy Research and Development

The United States is facing unprecedented challenges in climate change and energy security. President-elect Obama has called for a reduction of CO2 emissions to 1990 levels by 2020, with a further 80% reduction by 2050. Meeting these aggressive goals while gradually increasing the overall energy supply requires that all non-emitting technologies must be advanced. The development and deployment of nuclear energy can, in fact, help the United States meet several key challenges: 1) Increase the electricity generated by non-emitting sources to mitigate climate change, 2) Foster the safe and proliferation-resistant use of nuclear energy throughout the world, 3) Reduce the transportation sector’s dependence on imported fossil fuels, and 4) Reduce the demand on natural gas for process heat and hydrogen production. However, because of the scale, cost, and time horizons involved, increasing nuclear energy’s share will require a coordinated research effort—combining the efforts of industry and government, supported by innovation from the research community. This report outlines the significant nuclear energy research and development (R&D) necessary to create options that will allow government and industrial decision-makers to set policies and create nuclear energy initiatives that are decisive and sustainable. The nuclear energy R&D strategy described in this report adopts the …
Date: December 1, 2008
Creator: Bennett, Ralph G.
Object Type: Report
System: The UNT Digital Library
Science and Technology of Future Light Sources (open access)

Science and Technology of Future Light Sources

Many of the important challenges facing humanity, including developing alternative sources of energy and improving health, are being addressed by advances that demand the improved understanding and control of matter. While the visualization, exploration, and manipulation of macroscopic matter have long been technological goals, scientific developments in the twentieth century have focused attention on understanding matter on the atomic scale through the underlying framework of quantum mechanics. Of special interest is matter that consists of natural or artificial nanoscale building blocks defined either by atomic structural arrangements or by electron or spin formations created by collective correlation effects. The essence of the challenge to the scientific community has been expressed in five grand challenges for directing matter and energy recently formulated by the Basic Energy Sciences Advisory Committee [1]. These challenges focus on increasing our understanding of, and ultimately control of, matter at the level of atoms, electrons. and spins, as illustrated in Figure 1.1, and serve the entire range of science from advanced materials to life sciences. Meeting these challenges will require new tools that extend our reach into regions of higher spatial, temporal, and energy resolution. X-rays with energies above 10 keV offer capabilities extending beyond the nanoworld …
Date: December 1, 2008
Creator: Bergmann, Uwe; Corlett, John; Dierker, Steve; Falcone, Roger; Galayda, John; Gibson, Murray et al.
Object Type: Report
System: The UNT Digital Library
Hydrogen and oxygen adsorption stoichiometries on silica supported ruthenium nanoparticles (open access)

Hydrogen and oxygen adsorption stoichiometries on silica supported ruthenium nanoparticles

Treatment under H{sub 2} at 300 C of Ru(COD)(COT) dispersed on silica yields 2 nm ruthenium nanoparticles, [Ru{sub p}/SiO{sub 2}], according to EXAFS, HRTEM and XPS. H{sub 2} adsorption measurements on [Ru{sub p}/SiO{sub 2}] in the absence of O{sub 2} show that Ru particles adsorb up to ca. 2 H per surface ruthenium atoms (2H/Ru{sub s}) on various samples; this technique can therefore be used to measure the dispersion of Ru particles. In contrast, O{sub 2} adsorption on [Ru{sub p}/SiO{sub 2}] leads to a partial oxidation of the bulk at 25 C, to RuO{sub 2} at 200 C and to sintering upon further reduction under H{sub 2}, showing that O{sub 2} adsorption cannot be used to measure the dispersion of Ru particles.
Date: December 1, 2008
Creator: Berthoud, Romain; Delichere, Pierre; Gajan, David; Lukens, Wayne; Pelzer, Katrin; Basset, Jean-Marie et al.
Object Type: Article
System: The UNT Digital Library
Technology Transfer and Commercialization Annual Report 2008 (open access)

Technology Transfer and Commercialization Annual Report 2008

The Idaho National Laboratory (INL) is a Department of Energy (DOE) multi-program national laboratory that conducts research and development in all DOE mission areas. Like all other federal laboratories, INL has a statutory, technology transfer mission to make its capabilities and technologies available to all federal agencies, to state and local governments, and to universities and industry. To fulfill this mission, INL encourages its scientific, engineering, and technical staff to disclose new inventions and creations to ensure the resulting intellectual property is captured, protected, and made available to others who might benefit from it. As part of the mission, intellectual property is licensed to industrial partners for commercialization, creating jobs and delivering the benefits of federally funded technology to consumers. In other cases, unique capabilities are made available to other federal agencies or to regional small businesses to solve specific technical challenges. In other interactions, INL employees work cooperatively with researchers and other technical staff of our partners to further develop emerging technologies. This report is a catalog of selected INL technology transfer and commercialization transactions during this past year. The size and diversity of INL technical resources, coupled with the large number of relationships with other organizations, virtually ensures …
Date: December 1, 2008
Creator: Blacker, Michelle R.
Object Type: Report
System: The UNT Digital Library
GUTs on Compact Type IIB Orientifolds (open access)

GUTs on Compact Type IIB Orientifolds

We systematically analyze globally consistent SU(5) GUT models on intersecting D7-branes in genuine Calabi-Yau orientifolds with O3- and O7-planes. Beyond the well-known tadpole and K-theory cancellation conditions there exist a number of additional subtle but quite restrictive constraints. For the realization of SU(5) GUTs with gauge symmetry breaking via U(1)Y flux we present two classes of suitable Calabi-Yau manifolds defined via del Pezzo transitions of the elliptically fibred hypersurface P{sub 1,1,1,6,9}[18] and of the Quintic P{sub 1,1,1,1,1}[5], respectively. To define an orientifold projection we classify all involutions on del Pezzo surfaces. We work out the model building prospects of these geometries and present five globally consistent string GUT models in detail, including a 3-generation SU(5) model with no exotics whatsoever. We also realize other phenomenological features such as the 10 10 5{sub H} Yukawa coupling and comment on the possibility of moduli stabilization, where we find an entire new set of so-called swiss-cheese type Calabi-Yau manifolds. It is expected that both the general constrained structure and the concrete models lift to F-theory vacua on compact Calabi-Yau fourfolds.
Date: December 1, 2008
Creator: Blumenhagen, Ralph; Braun, Volker; Grimm, Thomas W. & Weigand, Timo
Object Type: Report
System: The UNT Digital Library
A search for resonant Z pair production (open access)

A search for resonant Z pair production

I describe a search for anomalous production of Z pairs through a new massive resonance X in 2.5-2.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV using the CDFII Detector at the Fermilab Tevatron. I reconstruct Z pairs through their decays to electrons, muons, and quarks. To achieve perhaps the most efficient lepton reconstruction ever used at CDF, I apply a thorough understanding of the detector and new reconstruction software heavily revised for this purpose. In particular, I have designed and employ new general-purpose algorithms for tracking at large {eta} in order to increase muon acceptance. Upon analyzing the unblinded signal samples, I observe no X {yields} ZZ candidates and set upper limits on the production cross section using a Kaluza-Klein graviton-like acceptance.
Date: December 1, 2008
Creator: Boveia, Antonio
Object Type: Thesis or Dissertation
System: The UNT Digital Library
HyPro: A Financial Tool for Simulating Hydrogen Infrastructure Development, Final Report (open access)

HyPro: A Financial Tool for Simulating Hydrogen Infrastructure Development, Final Report

This report summarizes a multi-year Directed Technologies Inc. (DTI) project to study the build-out of hydrogen production facilities during the transition from gasoline internal combustion engine vehicle to hydrogen fuel cell vehicles. The primary objectives of the project are to develop an enhanced understanding of hydrogen production issues during the transition period (out to 2050) and to develop recommendations for the DOE on areas of further study. These objectives are achieved by conducting economic and scenario analysis to predict how industry would provide the hydrogen production, delivery and dispensing capabilities necessary to satisfy increased hydrogen demand. The primary tool used for the analysis is a custom created MatLab simulation tool entitled HyPro (short for Hydrogen Production). This report describes the calculation methodology used in HyPro, the baseline assumptions, the results of the baseline analysis and several corollary studies. The appendices of this report included a complete listing of model assumptions (capital costs, efficiencies, feedstock prices, delivery distances, etc.) and a step-by-step manual on the specific operation of the HyPro program. This study was made possible with funding from the U.S. Department of Energy (DOE).
Date: December 1, 2008
Creator: Brian D. James, Peter O. Schmidt, Julie Perez
Object Type: Report
System: The UNT Digital Library

Getting the Word Out: Diesel Exhaust Fluid (DEF) Locator, Mapping Tools, and Outreach Activities

Presentation covers diesel exhaust fluid resources on the Alternative Fuels and Advanced Vehicles Data Center.
Date: December 1, 2008
Creator: Brodt-Giles, Debbie
Object Type: Presentation
System: The UNT Digital Library
Head-Tail Modes for Strong Space Charge (open access)

Head-Tail Modes for Strong Space Charge

Head-tail modes are described here for the space charge tune shift significantly exceeding the synchrotron tune. General equation for the modes is derived. Spatial shapes of the modes, their frequencies, and coherent growth rates are explored. The Landau damping rates are also found. Suppression of the transverse mode coupling instability by the space charge is explained.
Date: December 1, 2008
Creator: Burov, Alexey
Object Type: Article
System: The UNT Digital Library
Transverse Instabilities of Coasting Beams with Space Charge (open access)

Transverse Instabilities of Coasting Beams with Space Charge

Transverse beam stability is strongly affected by the beam space charge. Usually it is analyzed with the rigid-beam model. However this model is only valid when a bare (not affected by the space charge) tune spread is small compared to the space charge tune shift. This condition specifies a relatively small area of parameters which, however, is the most interesting for practical applications. The Landau damping rate and the beam Schottky spectra are computed assuming that validity condition is satisfied. The results are applied to a round Gaussian beam. The stability thresholds are described by simple fits for the cases of chromatic and octupole tune spreads.
Date: December 1, 2008
Creator: Burov, Alexey & Lebedev, Valeri
Object Type: Article
System: The UNT Digital Library
The Altus Times (Altus, Okla.), Vol. 110, No. 100, Ed. 1 Monday, December 1, 2008 (open access)

The Altus Times (Altus, Okla.), Vol. 110, No. 100, Ed. 1 Monday, December 1, 2008

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: December 1, 2008
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
EMSL Contribution Plan (open access)

EMSL Contribution Plan

This Contribution Plan is EMSL’s template for achieving our vision of simultaneous excellence in all aspects of our mission as a national scientific user facility. It reflects our understanding of the long-term stewardship we must work toward to meet the scientific challenges faced by the Department of Energy (DOE) and the nation. During the next decade, we will implement the strategies contained in this Plan, working closely with the scientific community, our advisory committees, DOE’s Office of Biological and Environmental Research, and other key stakeholders. This Plan is fully aligned with the strategic plans of DOE, its Office of Science, and the Pacific Northwest National Laboratory (PNNL). We recognize that shifts in science and technology, national priorities, and resources made available through the Federal budget process create planning uncertainties and, ultimately, a highly dynamic planning environment. Accordingly, this Plan should be viewed as a living document and we continually evaluate the changing needs and opportunities posed by our stakeholders (i.e., DOE, users, staff, advisory committees), work closely with them to understand and respond to those changes, and align our strategy accordingly. This Plan is organized around two sections. Section 1 describes our vision and four strategic outcomes: 1) Scientific Innovation, …
Date: December 1, 2008
Creator: Campbell, Allison A.
Object Type: Report
System: The UNT Digital Library
Remaining Sites Verification Package for the 128-F-2, 100-F Burning Pit Waste Site, Waste Site Reclassification Form 2008-031 (open access)

Remaining Sites Verification Package for the 128-F-2, 100-F Burning Pit Waste Site, Waste Site Reclassification Form 2008-031

The 128-F-2 waste site consisted of multiple burn and debris filled pits located directly east of the 107-F Retention Basin and approximately 30.5 m east of the northeast corner of the 100-F Area perimeter road that runs along the riverbank. The burn pits were used for incinerating nonradioactive, combustible materials from 1945 to 1965. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The current site conditions achieve the remedial action objectives and the corresponding remedial action goals established in the Remaining Sites ROD. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date: December 1, 2008
Creator: Capron, J. M.
Object Type: Report
System: The UNT Digital Library
Enhanced Geothermal Systems (EGS) well construction technology evaluation report. (open access)

Enhanced Geothermal Systems (EGS) well construction technology evaluation report.

Electricity production from geothermal resources is currently based on the exploitation of hydrothermal reservoirs. Hydrothermal reservoirs possess three ingredients critical to present day commercial extraction of subsurface heat: high temperature, in-situ fluid and high permeability. Relative to the total subsurface heat resource available, hydrothermal resources are geographically and quantitatively limited. A 2006 DOE sponsored study led by MIT entitled 'The Future of Geothermal Energy' estimates the thermal resource underlying the United States at depths between 3 km and 10 km to be on the order of 14 million EJ. For comparison purposes, total U.S. energy consumption in 2005 was 100 EJ. The overwhelming majority of this resource is present in geological formations which lack either in-situ fluid, permeability or both. Economical extraction of the heat in non-hydrothermal situations is termed Enhanced or Engineered Geothermal Systems (EGS). The technologies and processes required for EGS are currently in a developmental stage. Accessing the vast thermal resource between 3 km and 10 km in particular requires a significant extension of current hydrothermal practice, where wells rarely reach 3 km in depth. This report provides an assessment of well construction technology for EGS with two primary objectives: (1) Determining the ability of existing technologies …
Date: December 1, 2008
Creator: Capuano, Louis, Jr. (Thermasource Inc.); Huh, Michael; Swanson, Robert (Thermasource Inc.); Raymond, David Wayne; Finger, John Travis; Mansure, Arthur James et al.
Object Type: Report
System: The UNT Digital Library