Resource Type

149 Matching Results

Results open in a new window/tab.

DOE'S geothermal division: A period of transition (open access)

DOE'S geothermal division: A period of transition

The transition that the Department of Energy's geothemal research program is undergoing is discussed. This transitional period began last year and will continue at least through final implementation of the Department's reorganization and downsizing. Current and recently completed R&D programs are reviewed. New initiatives are outlined. The foci and direction of the Division's activities of particular interest to the geothermal research community are addressed.
Date: January 24, 1996
Creator: Jelacic, Allan J. & Reed, Marshall
System: The UNT Digital Library
Proposed empirical gas geothermometer using multidimensional approach (open access)

Proposed empirical gas geothermometer using multidimensional approach

Several formulas of surface gas geothermometer have been developed to utilize in geothermal exploration, i.e. by D'Amore and Panichi (1980) and by Darling and Talbot (1992). This paper presents an empirical gas geothermometer formula using multidimensional approach. The formula was derived from 37 selected chemical data of the 5 production wells from the Awibengkok Geothermal Volcanic Field in West Java. Seven components, i.e., gas volume percentage, CO<sub>2</sub>, H<sub>2</sub>S, CH<sub>4</sub>, H<sub>2</sub>, N<sub>2</sub>, and NH<sub>3</sub>, from these data are utilize to developed three model equations which represent relationship between temperature and gas compositions. These formulas are then tested by several fumarolic chemical data from Sibual-buali Area (North Sumatera) and from Ringgit Area (South Sumatera). Preliminary result indicated that gas volume percentage, H<sub>2</sub>S and CO<sub>2</sub> concentrations have a significant role in term of gas geothermometer. Further verification is currently in progress.
Date: January 24, 1996
Creator: Supranto; Sudjatmiko; Toha, Budianto; Wintolo, Djoko & Alhamid, Idrus
System: The UNT Digital Library
Geothermal reservoir technology research at the DOE Idaho Operations Office (open access)

Geothermal reservoir technology research at the DOE Idaho Operations Office

Geothermal reservoir technology research projects managed at the Department of Energy Idaho Falls Operations office (DOE-ID) account for a large portion of the Department of Energy funding for reservoir technology research (approximately 7 million dollars in FY-95). DOE-ID managed projects include industry coupled geothermal exploration drilling, cooperative research projects initiated through the Geothermal Technology Organization (GTO), and other geothermal reservoir technology research projects. A solicitation for cost-shared industry coupled drilling has been completed and one zward has been made in FY-95. Another solicitation for industry coupled drilling may be conducted in the spring of 1996. A separate geothermal research technology research, development and demonstration solicitation will result in multiple year awards over the next 2 years. The goals of these solicitations are to ensure competition for federal money and to get the Government and the geothermal industry the most useful information for their research dollars.
Date: January 24, 1996
Creator: Creed, Bob
System: The UNT Digital Library
Geothermal field's interaction with geophysical fields of another nature (open access)

Geothermal field's interaction with geophysical fields of another nature

The energy balance of active lithosphere zones is to a large extent determined by nonstationary interaction of mechanical (elastic and hydrodynamic), thermal, electromagnetic, and gravitational geophysical fields. Seismic disturbances of electromagnetic and temperature fields, repeatedly observed before earthquakes are a striking manifestation of this interaction (Sec. 1). Technological processes of exploitation of hydrothermal deposits are determined by the interaction of hydrodynamical and temperature field (Sec. 2). These “fast” interactions (with the characteristic time scale from seconds to years) take place against the background of “slow” thermomechanical interactions (time scale of Myears), the latter determining the formation of regional geothermal fields (Sec. 3).
Date: January 24, 1996
Creator: Novik, Oleg B.; Mikhailovskaya, Irina B.; Repin, Dmitry G. & Yershov, Sergey V.
System: The UNT Digital Library
Transient analysis of the 1991 Hijiori Shallow Reservoir Circulation Test (open access)

Transient analysis of the 1991 Hijiori Shallow Reservoir Circulation Test

Like any dynamic system, HDR reservoirs cannot be fully characterized by their steady-state behavior. Circulation tests analysis should be performed on both the steady-state response and the transient response of HDR systems. Transient analysis allows not only estimation of critical reservoir parameters and how these parameters change with operating conditions / history, but transient analysis also aids in evaluating the feasibility of various modes of HDR system operation (base load, load following, etc.). This paper details the transient analysis of NEDO's FY 1991 Shallow Reservoir Circulation Test at the Hijiori HDR site in Japan. Reservoir fluid storage is carefully bounded through the employment of two distinct methods for calculation of the fluid storage from the observed transient response. A brief discussion is also included of the distribution of reservoir fluid storage; the relationship between pressure, reservoir stress, and apparent reservoir capacitance; and appropriate circulation test design to facilitate transient analysis.
Date: January 24, 1996
Creator: Hyodo, M.; Shinohara, N.; Takasugi, S.; Wright, C. A. & Conant, R..
System: The UNT Digital Library
Complexation of U(VI) with 1-Hydroxyethane-1,1-diphosphonicAcid (HEDPA) in Acidic to Basic Solutions (open access)

Complexation of U(VI) with 1-Hydroxyethane-1,1-diphosphonicAcid (HEDPA) in Acidic to Basic Solutions

Complexation of U(VI) with 1-hydroxyethane-1,1-diphosphonic acid (HEDPA) in acidic to basic solutions has been studied with multiple techniques. A number of 1:1 (UO{sub 2}H{sub 3}L), 1:2 (UO{sub 2}H{sub j}L{sub 2} where j = 4, 3, 2, 1, 0 and -1) and 2:2 ((UO{sub 2}){sub 2}H{sub j}L{sub 2} where j = 1, 0 and -1) complexes form, but the 1:2 complexes are the major species in a wide pH range. Thermodynamic parameters (formation constants, enthalpy and entropy of complexation) were determined by potentiometry and calorimetry. Data indicate that the complexation of U(VI) with HEDPA is exothermic, favored by the enthalpy of complexation. This is in contrast to the complexation of U(VI) with dicarboxylic acids in which the enthalpy term usually is unfavorable. Results from electrospray ionization mass spectrometry (ESI-MS) and {sup 31}P NMR have confirmed the presence of 1:1, 1:2 and 2:2 U(VI)-HEDPA complexes.
Date: January 24, 2007
Creator: Reed, W. A.; Rao, L.; Zanonato, P.; Garnov, A.; Powell, B. A. & Nash, K. L.
System: The UNT Digital Library
Metabolic reprogramming underlies cavefish muscular endurance despite loss of muscle mass and contractility (open access)

Metabolic reprogramming underlies cavefish muscular endurance despite loss of muscle mass and contractility

Article discusses the Mexican cavefish Astyanax mexicanus, has lost moderate-to-vigorous activity following cave colonization, reaching basal swim speeds ~3.7-fold slower than their river-dwelling counterpart. Collectively, the authors reveal broad skeletal muscle changes following cave colonization, displaying an adaptive skeletal muscle phenotype reminiscent to mammalian disuse and high-fat models while simultaneously maintaining a unique capacity for sustained muscle contraction via enhanced glycogen metabolism.
Date: January 24, 2023
Creator: Olsen, Luke; Levy, Michaella; Medley, J. Kyle; Hassan, Huzaifa; Miller, Brandon; Alexander, Richard et al.
System: The UNT Digital Library
Mammalian DNA Repair. Final Report (open access)

Mammalian DNA Repair. Final Report

The Gordon Research Conference (GRC) on Mammalian DNA Repair was held at Harbortown Resort, Ventura Beach, CA. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.
Date: January 24, 2003
Creator: unknown
System: The UNT Digital Library
Modeling Multiple Causes of Carcinogenesis (open access)

Modeling Multiple Causes of Carcinogenesis

An array of epidemiological results and databases on test animal indicate that risk of cancer and atherosclerosis can be up- or down-regulated by diet through a range of 200%. Other factors contribute incrementally and include the natural terrestrial environment and various human activities that jointly produce complex exposures to endotoxin-producing microorganisms, ionizing radiations, and chemicals. Ordinary personal habits and simple physical irritants have been demonstrated to affect the immune response and risk of disease. There tends to be poor statistical correlation of long-term risk with single agent exposures incurred throughout working careers. However, Agency recommendations for control of hazardous exposures to humans has been substance-specific instead of contextually realistic even though there is consistent evidence for common mechanisms of toxicological and carcinogenic action. That behavior seems to be best explained by molecular stresses from cellular oxygen metabolism and phagocytosis of antigenic invasion as well as breakdown of normal metabolic compounds associated with homeostatic- and injury-related renewal of cells. There is continually mounting evidence that marrow stroma, comprised largely of monocyte-macrophages and fibroblasts, is important to phagocytic and cytokinetic response, but the complex action of the immune process is difficult to infer from first-principle logic or biomarkers of toxic injury. The …
Date: January 24, 1999
Creator: Jones, T.D.
System: The UNT Digital Library
A 10 GHz BANDWIDTH, SINGLE TRANSIENT, DIGITIZED OSCILLOSCOPE WITH 20 GHz CAPABILITY (open access)

A 10 GHz BANDWIDTH, SINGLE TRANSIENT, DIGITIZED OSCILLOSCOPE WITH 20 GHz CAPABILITY

EG&G/EM has developed an oscilloscope with a {minus}3 dB bandwidth greater than 10 GHz. Its rolloff characteristics are such that single-transient data greater than 20 GHz may be captured. A demountable CCD camera records the oscilloscope trace and is provided with PC-compatible capture and data processing software. The capabilities of the oscilloscope, camera, and its processing software are described and examples of the system`s performance is shown.
Date: January 24, 1994
Creator: Hudson, C. L.; Kocimski, S. M.; Spector, J.; Thomas, J. B. & Woodstra, R. R.
System: The UNT Digital Library
Image Retrieval in the Industrial Environment (open access)

Image Retrieval in the Industrial Environment

The ability to manage large image databases has been a topic of growing research over the past several years. Imagery is being generated and maintained for a large variety of applications including remote sensing, art galleries, architectural and engineering design, geographic information systems, weather forecasting, medical diagnostics, and law enforcement. Content-based image retrieval (CBIR) represents a promising and cutting-edge technology that is being developed to address these needs. To date, little work has been accomplished to apply these technologies to the manufacturing environment. Imagery collected from manufacturing processes have unique characteristics that can be used in developing a manufacturing-specific CBIR approach. For example, a product image typically has an expected structure that can be characterized in terms of its redundancy, texture, geometry, or a mixture of these. Defect objects in product imagery share a number of common traits across product types and imaging modalities as well. For example, defects tend to be contiguous, randomly textured, irregularly shaped, and they disrupt the background and the expected pattern. We will present the initial results of the development of a new capability for manufacturing-specific CBIR that addresses defect analysis, product quality control, and process understanding in the manufacturing environment. Image data from the …
Date: January 24, 1999
Creator: Ferrell, R.; Karnowski, T.P. & Tobin, K.W.
System: The UNT Digital Library
Surface contamination initiated laser damage (open access)

Surface contamination initiated laser damage

We are engaged in a comprehensive effort to understand and model the initiation and growth of laser damage initiated by surface contaminants. This includes, for example, the initial absorption by the contaminant, heating and plasma generation, pressure and thermal loading of the transparent substrate, and subsequent shockwave propagation, ``splashing`` of molten material and possible spallation, optical propagation and scattering, and treatment of material fracture. The integration use of large radiation hydrodynamics codes, optical propagation codes and material strength codes enables a comprehensive view of the damage process The following picture of surface contaminant initiated laser damage is emerging from our simulations. On the entrance optical surface, small particles can ablate nearly completely. In this case, only relatively weak shockwaves are launched into the substrate, but some particulate material may be left on the surface to act as a diffraction mask and cause further absorption. Diffraction by wavelength scale scattering centers can lead to significant intensity modulation. Larger particles will not be completely vaporized. The shockwave generated in this case 1642is larger and can lead to spallation of contaminant material which then may be deposited in the substrate. A gaseous atmosphere can lead to radiation trapping with concomitant increases in temperature …
Date: January 24, 1997
Creator: Feit, M. D.; Rubenchick, A. M. & Faux, D. R.
System: The UNT Digital Library
Low level absorptance measurements and scans of high performance optical coatings for atomic vapor laser isotope separation applications (open access)

Low level absorptance measurements and scans of high performance optical coatings for atomic vapor laser isotope separation applications

A surface thermal lensing and a radiometric technique was used to characterize the absorptance dependence on time, power, site, and technique of low absorptance optical multilayered coatings.
Date: January 24, 1998
Creator: Chow, R.; Taylor, J. R.; Wu, Z. L.; Krupka, R. & Yang, T.
System: The UNT Digital Library
Depth Measurement of Moving Slurry at the Wet End of a Paper Machine (open access)

Depth Measurement of Moving Slurry at the Wet End of a Paper Machine

The paper industry has long had a need to better understand and control its papermaking process upstream, specifically at the wet end in the forming section of a paper machine. A vision-based system is under development that addresses this need by automatically measuring and interpreting the pertinent paper web parameters at the wet end in real time. The wet-end characterization of the paper web by a vision system involves a four-dimensional measurement of the slurry in real time. These measurements include the two-dimensional spatial information, the intensity profile, and the depth profile. This paper describes the real-time depth profile measurement system for the high-speed moving slurry. A laser line-based measurement method is used with a high-speed programmable camera to directly measure slurry height. The camera is programmed with a profile algorithm, producing depth data at fast sampling rates. Analysis and experimentation have been conducted to optimize the system for the characteristics of the slurry and laser line image. On-line experimental results are presented.
Date: January 24, 1999
Creator: Abidi, B. R.; Goddard, J. S., Jr.; Hunt, M. A.; Sari-Sarraf, H. & Turner, J. C.
System: The UNT Digital Library
Physics beyond the standard model (open access)

Physics beyond the standard model

The author briefly summarizes the prospects for extending the understanding of physics beyond the standard model within the next five years. He interprets ``beyond the standard model'' to mean the physics of electroweak symmetry breaking, including the standard model Higgs boson. The nature of this TeV-scale new physics is perhaps the most crucial question facing high-energy physics, but one should recall (neutrino oscillations) that there is ample evidence for interesting physics in the flavour section too. In the next five years, before the LHC starts operations, the facilities available will be LEP2, HERA and the Fermilab Tevatron. He devotes a bit more time to the Tevatron as it is a new initiative for United Kingdom institutions. The Tevatron schedule now calls for data taking in Run II, using two upgraded detectors, to begin on March 1, 2001, with 2 fb{sup {minus}1} accumulated in the first two years. A nine-month shutdown will follow, to allow new silicon detector layers to be installed, and then running will resume with a goal of accumulating 15 fb{sup {minus}1} (or more) by 2006.
Date: January 24, 2000
Creator: Womersley, J.
System: The UNT Digital Library
Neutrino oscillation appearance experiment using nuclear emulsion and magnetized iron (open access)

Neutrino oscillation appearance experiment using nuclear emulsion and magnetized iron

This report describes an apparatus that could be used to measure both the identity and charge of an outgoing lepton in a charged current neutrino interaction. This capability in a massive detector would allow the most comprehensive set of neutrino oscillation physics measurements. By measuring the six observable transitions between initial and final state neutrinos, one would be able to measure all elements of the neutrino mixing matrix, as well as search for CP violation, and matter effects. If the measured matrix is not unitary, then one would also have an unambiguous determination of sterile neutrinos. Emulsion is considered as the tracking medium, and different techniques are discussed for the application of a magnetic field.
Date: January 24, 2000
Creator: Harris, D.A. & Para, A.
System: The UNT Digital Library
CP violation and rare decays (open access)

CP violation and rare decays

After a brief essay on the current state of particle physics and possible approaches to the opportunities that have presented themselves, the author summarizes the contributions to the Third Workshop on Physics and Detectors for DA{Phi}NE that deal with CP Violation and Rare Decays.
Date: January 24, 2000
Creator: Quigg, C.
System: The UNT Digital Library
High Rate Neutrino Detectors for Neutrino Factories (open access)

High Rate Neutrino Detectors for Neutrino Factories

None
Date: January 24, 2000
Creator: King, B. J.
System: The UNT Digital Library
Rotating Band Pion Production Targets for Muon Colliders and Neutrino Factories (open access)

Rotating Band Pion Production Targets for Muon Colliders and Neutrino Factories

None
Date: January 24, 2000
Creator: King, B. J.
System: The UNT Digital Library
Torsional Ratcheting Actuating System (open access)

Torsional Ratcheting Actuating System

A new type of surface micromachined ratcheting actuation system has been developed at the Microelectronics Development Laboratory at Sandia National Laboratories. The actuator uses a torsional electrostatic comb drive that is coupled to an external ring gear through a ratcheting scheme. The actuator can be operated with a single square wave, has minimal rubbing surfaces, maximizes comb finger density, and can be used for open-loop position control. The prototypes function as intended with a minimum demonstrated operating voltage of 18V. The equations of motion are developed for the torsional electrostatic comb drive. The resonant frequency, voltage vs. displacement and force delivery characteristics are predicted and compared with the fabricated device's performance.
Date: January 24, 2000
Creator: BARNES,STEPHEN MATTHEW; MILLER,SAMUEL L.; RODGERS,M. STEVEN & BITSIE,FERNANDO
System: The UNT Digital Library
Pulsed-Laser Deposition of Electronic Oxides: Superconductor and Semiconductor Applications (open access)

Pulsed-Laser Deposition of Electronic Oxides: Superconductor and Semiconductor Applications

Over the past decade, pulsed-laser deposition (PLD) has proven to be one of the most versatile and effective methods for obtaining high-quality electronic oxide thin-film materials. Much of this success can be attributed to its initial use in depositing high temperature superconducting materials. However, pulsed-laser deposition is now a leading research tool in the development of various electronic oxide thin-film technologies, In this paper, recent progress in the deposition of oxide materials on dissimilar materials for both superconductor and semiconductor applications is discussed. Recent developments in the synthesis of superconducting wires via epitaxial growth of superconducting oxides on biaxially textured metal tapes is described. In addition, efforts to integrate high-k dielectric oxides on semiconductor surfaces using pulsed-laser deposition are highlighted.
Date: January 24, 2000
Creator: Norton, D. P.; Park, C.; Lee, Y. E.; Budai, J. D.; Chisholm, M. F.; Verebelyi, D. T. et al.
System: The UNT Digital Library
Assessment of the renewable groundwater resources of Wadi El-Arish, Sinai, Egypt, by using remote sensing, digital terrain elevation, and meteorological data (open access)

Assessment of the renewable groundwater resources of Wadi El-Arish, Sinai, Egypt, by using remote sensing, digital terrain elevation, and meteorological data

The authors show that the most popular method to simulate Bose-Einstein (BE) interference effects predicts negligible correlations between identical pions originating from the hadronic decay of different W's produced in e{sup +}e{sup {minus}} {yields} W{sup +}W{sup {minus}} {yields} 4 jets at typical linear collider energies.
Date: January 24, 2000
Creator: Gheith, H. M. & Sultan, M. I.
System: The UNT Digital Library
Brief report from the Tevatron (open access)

Brief report from the Tevatron

The authors report on the B physics prospects from the Fermilab Tevatron, summarizing the B physics goals of the CDF and D0 experiments using their upgraded detectors. They discuss the time schedule for completion of the detector upgrades and summarize the current measurement of the CP violation parameter sin 2{beta} at CDF.
Date: January 24, 2000
Creator: Paulini, M.
System: The UNT Digital Library
A Split Hopkinson Bar Technique to Determine Compressive Stress-Strain Data for Rock Materials (open access)

A Split Hopkinson Bar Technique to Determine Compressive Stress-Strain Data for Rock Materials

We present a split Hopkinson pressure bar technique to obtain compressive stress-strain data for rock materials. This technique modifies the conventional split Hopkinson bar apparatus by placing a thin copper disk on the impact surface of the incident bar. When the copper disk is impacted by the striker bar, a nondispersive ramp pulse propagates in the incident bar and produces a nearly constant strain rate in a rock sample. Data from experiments with limestone show that the samples are in dynamic stress equilibrium and have constant strain rates over most of the duration of the tests. We also present analytical models that predict the time durations for sample equilibrium and constant strain rate. Model predictions are in good agreement with measurements.
Date: January 24, 2000
Creator: Frew, D. J.; Forrestal, Michael J. & Chen, W.
System: The UNT Digital Library