635 Matching Results

Search Results

Advanced search parameters have been applied.

Calibration and Testing of Sonic Stimulation Technologies

Description: In conjunction with Baker Atlas Inc. Michigan Technological University devised a system capable of recording the earth motion and pressure due to downhole and surface seismic sources. The essential elements of the system are 1) a borehole test site that will remain constant and is available all the time and for any length of time, 2) a downhole sonde that will itself remain constant and, because of its downhole digitization feature, does not require the wireline or surface recording components to remain constant, and 3) a set of procedures that ensures that the amplitude and frequency parameters of a wide range of sources can be compared with confidence. This system was used to record four seismic sources, three downhole sources and one surface source. A single activation of each of the downhole sources was not seen on time traces above the ambient noise, however, one sweep of the surface source, a small vertical vibrator, was easily seen in a time trace. One of the downhole sources was seen by means of a spike in its spectrum and a second downhole source was clearly seen after correlation and stacking. The surface vibrator produced a peak to peak particle motion signal of approximately 4.5 X 10-5 cm/sec and a peak to peak pressure of approx. 2.5 X 10-7 microPascals at a depth of 1,485 ft. Theoretical advances were made with our partner, Dr. I. Beresnev at Iowa State University. A theory has been developed to account for the behavior of oil ganglia trapped in pore throats, and their ultimate release through the additional incremental pressure associated with sonic stimulation.
Date: March 31, 2005
Creator: Turpening, Roger M. & D.Pennington, Wayne
Partner: UNT Libraries Government Documents Department

Changes in Quantitative EEG and Low Resolution Tomography Following Cranial Electrotherapy Stimulation.

Description: The effects of cranial electrotherapy stimulation (CES) on human EEG and brain current density were evaluated by quantitative electroencephalography (qEEG) and low resolution brain electromagnetic tomography (LORETA). A total of 72 research subjects were provided with a single session of CES, 38 were provided with 0.5 Hz CES while 34 were provided with 100 Hz CES. The qEEG paired t-tests revealed that in both frequencies of CES there was a significant (.05) increase in alpha relative power with concomitant decreases in delta and beta relative power. The 0.5 Hz CES decreased a wider frequency range of delta activity, while the 100 Hz CES decreased a wider frequency range of beta activity; suggesting some difference may exist in the EEG response to different frequencies of CES. The changes found in qEEG relative power were consistent with the affective and cognitive effects of CES reported in the literature, such as increased relaxation and decreased anxiety. Statistically significant changes for qEEG values other than relative power, such as coherence, amplitude asymmetry, phase lag and power ratios were also found. The LORETA paired t-tests found statistically significant (.05) increases in cortical and subcortical theta and alpha frequency current density with concomitant decreases in delta and beta current density. The effects of CES on current density varied by frequency, but did not show a differential in response based on proximity to the contacts, or structures within the brain. Statistically significant changes in current density were found in all 2394 gray matter voxels represented by LORETA, indicating a whole brain response to the CES stimulus. The qEEG and LORETA findings revealed that a single 20-minute session of CES does have a significant effect on the cortical and subcortical activity of the human brain resulting in activity consistent with decreased anxiety and increased relaxation.
Date: August 2006
Creator: Kennerly, Richard C.
Partner: UNT Libraries

Observation of multiple mechanisms for stimulating ion waves in ignition scale plasmas

Description: The laser and plasma conditions expected in ignition experiments using indirect drive inertial confinement have been studied experimentally. It has been found that there are at least three ways in which ion waves can be stimulated in these plasmas and have significant effect on the energy balance and distribution in the target. First ion waves can be stimulated by a single laser beam by the process of Stimulated Brillouin Scattering (SBS) in which an ion acoustic and a scattered electromagnetic wave grow from noise. Second, in a plasma where more than one beam intersect, ion waves can be excited at the `beat` frequency and wave number of the intersecting beams, causing the side scatter instability to be seeded, and substantial energy to be transferred between the beams [R. K. Kirkwood et. al. Phys. Re0319v. Lett. 76, 2065 (1996)]. And third, ion waves may be stimulated by the decay of electron plasma waves produced by Stimulated Raman Scattering (SRS), thereby inhibiting the SRS process [R. K. Kirkwood et. al. Phys. Rev. Lett. 77, 2706 (1996)].
Date: November 1, 1996
Creator: Kirkwood, R.K.; MacGowan, B.J. & Montgomery, D.S.
Partner: UNT Libraries Government Documents Department

Novel Application of Single-Well Tracer Tests to Evaluate Hydraulic Stimulation Effectiveness

Description: This paper presents a graphical method by which one can identify the number of fractures and their permeability distribution in the near-well region from single-well tracer tests. The method is an extension of tracer analysis methods developed previously to estimate flow geometry and relies on caluclating the relative fluid velocity from F-__ plots. A number of numerical examples show that high flow zones (fractures) are readily identified from the derivatives of an F-___ curve. The method can be used in evaluating well stimulation efforts by conducting a tracer test before and after the stimulation and comparing the velocity distributions.
Date: September 1, 2005
Creator: Shook, G. M. & Nalla, Gopi
Partner: UNT Libraries Government Documents Department

The Effects of Selected Auditory Stimulation upon Learning Typewriting

Description: The problem of this study was to determine the effects of typewriting practice with selected auditory stimulation on student achievement in typewriting. It included the following sub-problems: 1. Determining the extent to which typewriting practice with selected auditory stimulation affected ability to compose at the typewriter. 2. Determining the extent to which typewriting practice with selected auditory stimulation affected ability to typewrite from dictation. 3. Determining the extent to which typewriting practice with selected auditory stimulation affected ability to typewrite from copy.
Date: June 1962
Creator: Lemaster, Arthur James, 1933-
Partner: UNT Libraries

Treatment of Migraine Headache Utilizing Cerebral Electrostimulation

Description: Cerebral electrostimulation (CES) as a treatment for migraine headache was investigated. Eighteen participants recorded data on headaches for two baseline weeks. Six were assigned to each of three groups--an active treatment group receiving CES, a placebo group receiving a simulated version of CES, and a no-treatment control group placed on a waiting list during the study. The CES group evidenced a significant reduction in headache duration and intensity relative to the placebo group. The waiting list control group did as well as the CES group. A number of hypotheses were put forth in an attempt to account for the unexpected finding.
Date: December 1976
Creator: England, Ronald R.
Partner: UNT Libraries

An investigation of extrinsic laryngeal muscle responses to auditory stimulation

Description: The purpose of this study was to provide, through systematic investigation, empirical data to support or reject the assumption that auditory stimulation by discrete pitches evokes consistent muscle responses in the extrinsic laryngeal muscles. The study was an electromyographic investigation of specific upper and lower extrinsic laryngeal muscles as stimulated by two specific pitch stimuli. The responses were evoked by auditory stimulation, without vocalization.
Date: August 1985
Creator: Wallace, Jerry D. (Jerry Don)
Partner: UNT Libraries

Electrical stimulation of nerve cell networks growing on microelectrode arrays: stimulation efficiency and entrainment

Description: Presentation for the 2005 University Scholars Day at the University of North Texas discussing research on electrical stimulation of nerve cell networks growing on microelectrode arrays and stimulation efficiency and entrainment.
Date: March 31, 2005
Creator: Jain, Vivek & Gross, Guenter W.
Partner: UNT Honors College

GEOFRAC: an explosives stimulation technique for a geothermal well

Description: The first known use of explosives for stimulating a geothermal well was successfully conducted in December 1981 with a process called GEOFRAC. The 260/sup 0/C well was located at the Union Oil Company's Geysers Field in northern California. For the initial test, 364 kg of a new explosive called HITEX II was placed at a depth of 2256 meters and detonated to verify techniques. The explosive was contained in an aluminum canister to separate it from the well fluids. In the second test, 5000 kg of explosive was used representing a column length of approximately 191 meters. The explosive was detonated at a depth of 1697 meters in the same well. The results of these tests show that HITEX II can be safely emplaced and successfully detonated in a hot geothermal well without causing damage to the well bore or casing.
Date: January 1, 1982
Creator: Mumma, D.M.; McCullough, F. Jr.; Schmidt, E.W.; Pye, D.S.; Allen, W.C.; Pyle, D. et al.
Partner: UNT Libraries Government Documents Department

Explosive stimulation of a geothermal well: GEOFRAC

Description: This paper describes the first known explosive stimulation successfully conducted in a geothermal well. Two tests were performed in a 2690-meter-(8826-ft.) deep Union Oil well at the Geysers field in Northern California in December 1981. The heat-resistant process, called GEOFRAC, uses a new unique, explosive HITEX 2, which is a nondetonable solid at room temperature. Upon melting at a temperature of 177[degrees]C (350[degrees]F), the HITEX 2 liquid becomes an explosive that can be safely heated to temperatures greater than 260[degrees]C (500[degrees]F). These unique properties of the explosive were exploited in the GEOFRAC process through the cooperative efforts of Physics International Company (PI), Rocket Research Company (RRC), Union oil Company (UO), and the university of California Los Alamos National Laboratories (LANL).
Date: July 1, 1982
Creator: Mumma, D.M. (Physics International Co., San Leandro, CA (United States))
Partner: UNT Libraries Government Documents Department

www.ceebic.org/~cleanenergyalabama

Description: The Business Innovation Center will fully participate as a member and support as fully as possible the goals of “The Alliance of Clean Energy Business Incubators” by: 1. Participating in NREL-sponsored Clean Energy Investor Forums, when possible Attended 15th Annual Growth Forum in Albany, NY, October 2003 2. Marketing our incubation services to Clean Energy Companies. October, 2002: Traveled to the University of Southern Mississippi Center for Economic and Community Development to make a presentation concerning the National Alliance of Clean Energy Incubators to the participants of the New South Economic Course. This course was attended by 65 Economic Developers, Small Business Development Center personel, and Chambers of Commerce personnel from 9 states around the South East U.S. These are people who have direct contact with entrepreneurs and can act as referrals to the Clean Energy Incubator and NREL online database, as specified in the Scope of Work
Date: January 2, 2003
Creator: Siegwald, Tom
Partner: UNT Libraries Government Documents Department

The Effect of Hypothalamic Stimulation on the Phagocytic Activity of the Reticuloendothelial System

Description: Although research has linked the central nervous system with changes in immunoresponsivity, research on the possible role of the central nervous system in altering reticuloendothelial activity is lacking. This study investigated the possible relationship between hypothalamic structures and changes in responsivity of the reticuloendothelial system. Eight male albino rats received bilateral electrode implants in the ventromedial area of the hypothalamus and, following brain stimulation, reticuloendothelial activity was assessed 3, 6, 12, 24, and 96 hours after stimulation. Brain stimulation decreased phagocytic activity of the reticuloendothelial system. These findings may increase our understanding of a possible neural mechanism underlying relationships between stress and resistance to disease states.
Date: December 1979
Creator: Lambert, Paul Louis
Partner: UNT Libraries

IFESS 2005 Special Session 5 Artifical Vision

Description: A special session on visual prostheses was held during the Annual Meeting of the International Functional Electrical Stimulation Society (IFESS), in Montreal, Canada, July 5-9, 2005. IFESS is a meeting that typically attracts researchers in implantable nerve stimulators, functional electrical stimulation, and rehabilitation. All of these areas have significant overlap with the retinal prosthesis, but these areas have decades of research behind them. The special session provided a forum for researchers with vast experience in nerve stimulation to interact with leading research in retinal and cortical visual prostheses. The grant paid for the travel and conference costs of the presenters in the session. The session was chaired by James Weiland (the PI on this grant). The session co-chair was Phil Troyk, Ph.D., from the Illinois Institute of Technology. The Department of Energy was acknowledged at the start of the session as the sponsor. The following talks were delivered: Clinical Trial of a Prototype Retinal Prosthesis James Weiland, Ph.D. Doheny Eye Institute, Los Angeles, California The U.S. Department of Energy's Artificial Sight Program Elias Greenbaum, Ph.D. Oak Ridge National Laboratory, Oak Ridge, Tennessee A 16-Channel stimulator ASIC for use in an intracortical visual prosthesis Phillip R. Troyk, Ph.D. Illinois Institute of Technology, Chicago, Illinois Two approaches to the Optic Nerve Visual Prosthesis Jean Delbeke, M.D. University Cath de Louvain, Louvain, Belgium Design and Implementation of High Power Efficiency Modules for a Cortical Visual Stimulator Mohammad Sawan, Ph.D. Ecole Polytechnique de Montreal, Montreal, Canada Remaining funds from the grant were used to support Dr. Weiland's travel to the Association for Research in Vision and Ophthalmology in May 2006, with DOE approval, where several projects, supported by the DOE artificial retina program, were presented.
Date: July 1, 2005
Creator: Weiland, J. D.; Greenbaum, E.; Delbeke, J.; Troyk, P. R. & Sawan, M.
Partner: UNT Libraries Government Documents Department

Geothermal wells: the cost benefit of fracture stimulation estimated by the GEOCOM code. Final report

Description: GEOCOM, a computer code that provides life cycle cost/benefit analysis of completion technologies applied to geothermal wells, is used to study fracture stimulation techniques. it is estimated that stimulation must increase flow by roughly tons per $100,000 in order to be cost effective. Typically, hydraulic fracturing costs $100,000 to $500,000 per well, and the attempts at stimulation to date have generally not achieved the desired flow increases. The cost effectiveness of hydraulic fracturing is considered for several geothermal reservoirs.
Date: September 1, 1983
Creator: Brown, G.L.
Partner: UNT Libraries Government Documents Department

Mapping the acid stimulation in the Beowawe geothermal field using surface electrical potentials

Description: A surface electrical potential system was fielded during the chemical stimulation of the Rossi 21-19 well in the Beowawe Geothermal Field. The technique, which measures variations in resistivity resulting from the flow of conductive fluid into the reservoir, was not only shown to be highly sensitive to the chemical treatment, but was also responsive to in situ conductive zones before any acid injection. A review of the experiment and a preliminary interpretation of the data are presented. The data provide convincing evidence that it should be possible to map the treated zone as well as the primary pretreatment in situ conductive zones.
Date: January 1, 1983
Creator: Hart, C.M.; Engi, D. & Morris, H.E.
Partner: UNT Libraries Government Documents Department

Requirements for downhole equipment used for geothermal-well stimulation. Geothermal-reservoir well-stimulation program

Description: The needs for new and improved down-hole stimulation equipment for geothermal wells are identified. The following kinds of equipment are discussed: mechanical downhole recording instruments, electric line logging tools, and downhole tools used for zone isolation.
Date: August 1, 1982
Partner: UNT Libraries Government Documents Department

Multiwell experiment: reservoir modeling analysis, Volume II

Description: This report updates an ongoing analysis by reservoir modelers at the Morgantown Energy Technology Center (METC) of well test data from the Department of Energy's Multiwell Experiment (MWX). Results of previous efforts were presented in a recent METC Technical Note (Horton 1985). Results included in this report pertain to the poststimulation well tests of Zones 3 and 4 of the Paludal Sandstone Interval and the prestimulation well tests of the Red and Yellow Zones of the Coastal Sandstone Interval. The following results were obtained by using a reservoir model and history matching procedures: (1) Post-minifracture analysis indicated that the minifracture stimulation of the Paludal Interval did not produce an induced fracture, and extreme formation damage did occur, since a 65% permeability reduction around the wellbore was estimated. The design for this minifracture was from 200 to 300 feet on each side of the wellbore; (2) Post full-scale stimulation analysis for the Paludal Interval also showed that extreme formation damage occurred during the stimulation as indicated by a 75% permeability reduction 20 feet on each side of the induced fracture. Also, an induced fracture half-length of 100 feet was determined to have occurred, as compared to a designed fracture half-length of 500 to 600 feet; and (3) Analysis of prestimulation well test data from the Coastal Interval agreed with previous well-to-well interference tests that showed extreme permeability anisotropy was not a factor for this zone. This lack of permeability anisotropy was also verified by a nitrogen injection test performed on the Coastal Red and Yellow Zones. 8 refs., 7 figs., 2 tabs.
Date: May 1, 1985
Creator: Horton, A.I.
Partner: UNT Libraries Government Documents Department

Geothermal Well Stimulation

Description: The stimulation of geothermal wells presents some new and challenging problems. Formation temperatures in the 300-600 F range can be expected. The behavior of stimulation fluids, frac proppants, and equipment at these temperatures in a hostile brine environment must be carefully evaluated before performance expectations can be determined. In order to avoid possible damage to the producing horizon of the formation, high temperature chemical compatibility between the in situ materials and the stimulation materials must be verified. Perhaps most significant of all, in geothermal wells the required techniques must be capable of bringing about the production of very large amounts of fluid. This necessity for high flow rates represents a significant departure from conventional petroleum well stimulation and demands the creation of very high near-wellbore permeability and/or fractures with very high flow conductivity.
Date: March 1, 1981
Creator: Campbell, D. A.; Morris, C. W.; Sinclair, A. R.; Hanold, R. J. & Vetter, O. J.
Partner: UNT Libraries Government Documents Department

FRACTURING FLUID CHARACTERIZATION FACILITY

Description: Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.
Date: August 1, 2000
Creator: Shah, Subhash
Partner: UNT Libraries Government Documents Department