Resource Type

92 Matching Results

Results open in a new window/tab.

Introducing Name Authority into an ETD Collection (open access)

Introducing Name Authority into an ETD Collection

Article on introducing name authority into a large electronic theses and dissertations (ETD) collection.
Date: July 3, 2014
Creator: Waugh, Laura; Tarver, Hannah & Phillips, Mark Edward
System: The UNT Digital Library
Analysis of URL References in ETDs: A Case Study at the University of North Texas (open access)

Analysis of URL References in ETDs: A Case Study at the University of North Texas

Article discussing a case study at the University of North Texas (UNT) on an analysis of URL references in electronic theses and dissertations (ETDs).
Date: July 3, 2014
Creator: Phillips, Mark Edward; Alemneh, Daniel Gelaw & Reyes Ayala, Brenda
System: The UNT Digital Library
Draft Genome Sequence of Cupriavidus sp. Strain SK-3, a 4-Chlorobiphenyl- and 4-Clorobenzoic Acid-Degrading Bacterium (open access)

Draft Genome Sequence of Cupriavidus sp. Strain SK-3, a 4-Chlorobiphenyl- and 4-Clorobenzoic Acid-Degrading Bacterium

Article on the draft genome sequence of Cupriavidus sp. strain SK-3, a 4-chlorobiphenyl- and 4-clorobenzoic acid-degrading bacterium.
Date: July 3, 2014
Creator: Vilo, Claudia A.; Benedik, Michael J.; Ilori, Matthew Olusoji & Dong, Qunfeng
System: The UNT Digital Library
Removal of NOx from diesel generator exhaust by pulsed electron beams (open access)

Removal of NOx from diesel generator exhaust by pulsed electron beams

The objective of this paper is to determine the effects of electron beam pulse parameters on the utilization of the reactive free radicals for removal of NO{sub x} from diesel generator exhaust. A dose per pulse less than 1 kGy has been determined to be optimum for effective radical utilization. During each post-pulse period, the radicals are utilized in the removal of NO{sub x} in a timescale of around 100 microseconds; thus, with pulse frequencies of around 10 kHz or less, the radical concentrations remain sufficiently low to prevent any significant competition between radical-pollutant and radical-radical reactions. It is shown that a pulsed electron beam reactor, operating with a dose per pulse of less than 1 kGy/pulse and pulse repetition rate of less than 10 kHz, will have the same plasma chemistry efficiency (parts per million of removed NO{sub x} per kGy of electron beam dose) as an electron beam reactor operating with a low dose rate of 50 kGy/s in continuous mode. Ozone accumulation is a limiting factor under high pulse frequency conditions. The total dose requirement determines the optimum combination of dose per pulse and pulse frequency for both radical utilization and prevention of ozone buildup.
Date: July 3, 1997
Creator: Penetrante, B. M.
System: The UNT Digital Library
Spin physics at RHIC a new twist on the heavy ion experiments (open access)

Spin physics at RHIC a new twist on the heavy ion experiments

Operation of RHIC with two beams of highly polarized protons (70%, either longitudinal or transverse) at high luminosity ???? = 2 {circ} 10{sup 32} cm{sup -2} sec{sup -1} for two months/year will allow high statistics studies of polarization phenomena in the perturbative region of hard scattering where both QCD and ElectroWeak theory make detailed predictions for polarization effects. The collision c.m energy, {radical}s = 200 - 500 GeV, represents a new domain for the study of spin. Direct photon production win be used to measure the gluon polarization in the polarized proton. A new twist comes from W-boson production which is expected to be 100% parity violating and will thus allow measurements of flavor separated quark and antiquark (u, u, d, d) polarization distributions. Searches for parity violation in strong interaction processes such as jet and leading particle production will be a sensitive way to look for new physics beyond the standard model, one possibility being quark substructure.
Date: July 3, 1996
Creator: Tannenbaum, Michael J.
System: The UNT Digital Library
Cleanup levels for Am-241, Pu-239, U-234, U-235 & U-238 in soils at the Rocky Flats Environmental Technology Site (open access)

Cleanup levels for Am-241, Pu-239, U-234, U-235 & U-238 in soils at the Rocky Flats Environmental Technology Site

This presentation briefly outlines a cleanup program at a Rocky Flats site through viewgraphs and an executive summary. Exposure pathway analyses to be performed are identified, and decontamination levels are listed for open space and office worker exposure areas. The executive summary very briefly describes the technical approach, RESRAD computer code to be used for analyses, recommendations for exposure levels, and application of action levels to multiple radionuclide contamination. Determination of action levels for surface and subsurface soils, based on radiation doses, is discussed. 1 tab.
Date: July 3, 1997
Creator: Roberts, R.; Colby, B.; Brooks, L. & Slaten, S.
System: The UNT Digital Library
Fundamental limits on chemical reduction of NO{sub x} by non-thermal plasmas (open access)

Fundamental limits on chemical reduction of NO{sub x} by non-thermal plasmas

The objective of this paper is to establish the fundamental limits on the minimum electrical energy consumption that will be required to implement true chemical reduction of NOx by the plasma alone. The effect of background gas composition particularly the oxygen content on the completion between the reduction and oxidation processes will be discussed. The effect of the electron kinetic energy distribution on the radical production and subsequent chemistry will also be discussed.
Date: July 3, 1997
Creator: Penetrante, B.M., Hsiao, M.C., Merritt, B.T., Vogtlin, G.E.
System: The UNT Digital Library
Relocation of Gulf of Aqaba earthquakes using the JSOP Bulletin (open access)

Relocation of Gulf of Aqaba earthquakes using the JSOP Bulletin

Ground truth information (i.e. precise information about the hypocenter and origin time of aseismic event) is difficult to obtain in the Middle East and North Africa region. One source of ground truth we are attempting to exploit is data from local seismic networks. An electronic bulletin from the second phase of the Joint Seismic Observation Period (JSOP), with participating countries in the eastern Mediterranean region, provides a source of local network data not ordinarily available. I have used JSOP bulletin data for the period January 1996 through June 1996 to relocate over 100 earthquakes occurring in and around the Gulf of Aqaba. Fourteen of these earthquakes have picks in the bulletin for stations surrounding the Gulf (Egypt Saudi Arabia, Israel,and Jordan). The rest of the data involves picks for stations either in Israel, Jordan, and Saudi Arabia (east side and north of the Gulf) or for stations in Israel, Jordan, and Egypt (west side and north of the Gulf). The VELEST code (Joint Hypocenter Determination method) was used to calculate improved locations (over what can be obtained from single event determinations--SED with poor station configurations) for the all the earthquakes in the data set. Location differences between the JHD solution …
Date: July 3, 1997
Creator: Sweeney, J. J.
System: The UNT Digital Library
Particulate measurement issues in diesel exhausts using laser induced incandescence (open access)

Particulate measurement issues in diesel exhausts using laser induced incandescence

A number of studies in the recent past have identified Laser Induced Incandescence (LII) as a versatile technique for in-flame measurement of soot concentrations. Recently, a number of researchers have focused their attention in adapting this technique to measure particulate in diesel exhausts. However the agreement with established physical sampling techniques, such as the EPA recommended filter paper collection method, was found to be less than ideal. This paper reports the efforts to adapt this technique for diesel exhaust characterization. Many of the factors affecting LII signal were identified through computer modeling. Parameters that could not be determined through such a model were determined experimentally following a parametric study. Subsequently, LII measurements were performed in the exhaust of a modified lab burner, with conditions close to that of diesel engine exhausts. Such measurements show excellent agreement with those performed using the standard filter paper collection technique.
Date: July 3, 2000
Creator: Gupta, S. B.; Poola, R. B. & Sekar, R.
System: The UNT Digital Library
Laser ablation assisted adhesive bonding of automotive structural composites (open access)

Laser ablation assisted adhesive bonding of automotive structural composites

Laser ablation has been evaluated as a surface pretreatment prior to adhesive bonding. In prior experimental work, it was observed that when adhesively bonded, composite, single lap shear samples fail, the fracture often occurs at either the adhesive/adherend interface or in the resin rich surface layer of the composite. These two areas represent the weakest portion of the joint. Laser ablation pretreatment generates areas where the resin on the composite surface is selectively removed leaving behind exposed reinforcing fibers which are the major load bearing members of the composite. In a subsequent adhesive bonding operation, this allows portions of the fibers to be encapsulated in the adhesive while other portions of the fiber remain in the composite resin. This type of pretreatment permits fibers to bridge and reinforce the interface between adhesive and adherend. A secondary benefit is the removal of surface contaminantes by pyrolysis. Microscopic observation of laser ablated surfaces indicates a prominent, fiber rich area. Results of the mechanical evaluation indicated that the lap shear strength for laser ablated samples was significantly higher than specimens with no pretreatment or with solvent cleaning only, but were slightly lower than specimens that were mechanically roughened and cleaned with solvents prior …
Date: July 3, 1999
Creator: Boeman, R. G.; Paulauskas, F. L. & Warren, C. D.
System: The UNT Digital Library
Present and Future Automotive Composite Materials Research Efforts at DOE (open access)

Present and Future Automotive Composite Materials Research Efforts at DOE

Automobiles of the future will be forced to travel fi.uther on a tank of fuel while discharging lower levels of pollutants. Currently, the United States uses in excess of 16.4 million barrels of petroleum per day. Sixty-six percent of that petroleum is used in the transportation of people and goods. Automobiles currently account for just under two-thirds of the nation's gasoline consumptio~ and about one-third of the total United States energy usage. [1] By improving transportation related fiel efficiency, the United States can lessen the impact that emissions have on our environment and provide a cleaner environment for fiture generations. In 1992, The Department of Energy's (DOE) Office of Transportation Materials completed a comprehensive program plan entitled, The Lightweight MateriaIs (LWko Multi-Year Program Plan, for the development of technologies aimed at reducing vehicle mass [2]. This plan was followed in 1997 by the more comprehensive Office of Advanced Automotive Technologies research and development plan titled, Energy Eficient Vehicles for a Cleaner Environment [3] which outlines the department's plans for developing more efficient vehicles during the next ~een years. Both plans identi~ potential applications, technology needs, and R&D priorities. The goal of the Lightweight Materials Program is to develop materials and …
Date: July 3, 1999
Creator: Warren, C. D.
System: The UNT Digital Library
A search for coupled-bunch instability in the Fermilab Main Injector (open access)

A search for coupled-bunch instability in the Fermilab Main Injector

In the Fermilab Main Injector (MI) we are planning to double the bunch intensity from its design value by slip stacking. The accelerator consists of 18 rf cavities which operate at a harmonic number of 588. These cavities are known to have many higher ordered resonances. Longitudinal coupled-bunch instability induced by excitation of the rf cavities may be an important issue to be addressed in the intensity upgrade. Here we have carried out some simulation studies of the longitudinal coupled bunch instability to investigate bunch intensity limits. The results are presented in this paper.
Date: July 3, 2001
Creator: al., C. M. Bhat et
System: The UNT Digital Library
Space-charge effects on bunch rotation in the longitudinal phase space (open access)

Space-charge effects on bunch rotation in the longitudinal phase space

The longitudinal and transverse space-charge effects on bunch rotation in the longitudinal phase space designed to produce an intense short proton bunch are discussed. A criterion for length broadening due to space-charge modification of the rf potential is given. As for the transverse effect, the incoherent space-charge tune shifts will affect the bunch rotation unless the chromaticities are properly corrected.
Date: July 3, 2001
Creator: Ng, King-Yuen
System: The UNT Digital Library
Pbar acceleration in the MI - Tune-Up study using protons (open access)

Pbar acceleration in the MI - Tune-Up study using protons

We discuss both simulations as well as experimental studies of a potentially beneficial acceleration scheme in the MI for pbars from the Accumulator Ring or Recycler Ring. The scheme involves accepting the pbar bunches with 2.5 MHz rf structure from either of these two synchrotrons. re-bunching using 53 MHz rf system iso-adiabatically and accelerating using 53 MHz rf system from 8 GeV to 150 GeV. Further we try to coalesce the beam using the 2.5 MHz rf system. Various stages of rf manipulation are discussed and some improvements are also suggested.
Date: July 3, 2001
Creator: al., C.M. Bhat et
System: The UNT Digital Library
HVAC BESTEST: A Procedure for Testing the Ability of Whole-Building Energy Simulation Programs to Model Space Conditioning Equipment: Preprint (open access)

HVAC BESTEST: A Procedure for Testing the Ability of Whole-Building Energy Simulation Programs to Model Space Conditioning Equipment: Preprint

Validation of Building Energy Simulation Programs consists of a combination of empirical validation, analytical verification, and comparative analysis techniques (Judkoff 1988). An analytical verification and comparative diagnostic procedure was developed to test the ability of whole-building simulation programs to model the performance of unitary space-cooling equipment that is typically modeled using manufacturer design data presented as empirically derived performance maps. Field trials of the method were conducted by researchers from nations participating in the International Energy Agency (IEA) Solar Heating and Cooling (SHC) Programme Task 22, using a number of detailed hourly simulation programs from Europe and the United States, including: CA-SIS, CLIM2000, PROMETHEUS, TRNSYS-TUD, and two versions of DOE-2.1E. Analytical solutions were also developed for the test cases.
Date: July 3, 2001
Creator: Neymark, J,; Judkoff, R.; Knabe, G.; Le, H.-T.; Durig, M.; Glass, A. et al.
System: The UNT Digital Library
Recent QCD results from D0 at the Tevatron (open access)

Recent QCD results from D0 at the Tevatron

The D0 experiment at the Tevatron proton-antiproton collider accumulated a large sample of high energy jet production data during Run I (1992-1996). Presented here are measurements of the inclusive jet cross section at a center-of-mass energy {radical}s = 1800 GeV, and a ratio of central inclusive jet cross sections at two different center-of-mass energies (1800 and 630 GeV). Also included is a measure of the ratio of multijet production cross sections at the higher {radical}s: All measurements are compared to next-to-leading order QCD predictions with recent parton distribution functions (PDFs). Due to decreased statistical and systematic errors in the measurement, comparison with the theory shows that the prediction may benefit from an increased order in the calculation and from inclusion of proton-antiproton jet data in new global PDF fits.
Date: July 3, 2001
Creator: Gallas, Elizabeth
System: The UNT Digital Library
A lex-based mad parser and its applications (open access)

A lex-based mad parser and its applications

An embeddable and portable Lex-based MAD language parser has been developed. The parser consists of a front-end which reads a MAD file and keeps beam elements, beam line data and algebraic expressions in tree-like structures, and a back-end, which processes the front-end data to generate an input file or data structures compatible with user applications. Three working programs are described, namely, a MAD to C++ converter, a dynamic C++ object factory and a MAD-MARS beam line builder. Design and implementation issues are discussed.
Date: July 3, 2001
Creator: al., Oleg Krivosheev et
System: The UNT Digital Library
Real-Time Data Processing in the muon system of the D0 detector. (open access)

Real-Time Data Processing in the muon system of the D0 detector.

This paper presents a real-time application of the 16-bit fixed point Digital Signal Processors (DSPs), in the Muon System of the D0 detector located at the Fermilab Tevatron, presently the world's highest-energy hadron collider. As part of the Upgrade for a run beginning in the year 2000, the system is required to process data at an input event rate of 10 KHz without incurring significant deadtime in readout. The ADSP21csp01 processor has high I/O bandwidth, single cycle instruction execution and fast task switching support to provide efficient multisignal processing. The processor's internal memory consists of 4K words of Program Memory and 4K words of Data Memory. In addition there is an external memory of 32K words for general event buffering and 16K words of Dual port Memory for input data queuing. This DSP fulfills the requirement of the Muon subdetector systems for data readout. All error handling, buffering, formatting and transferring of the data to the various trigger levels of the data acquisition system is done in software. The algorithms developed for the system complete these tasks in about 20 {micro}s per event.
Date: July 3, 2001
Creator: Parashar, Neeti; Bardon, O.; Goodwin, R.; Hansen, S.; Hoeneisen, B.; Podstavkov, V. et al.
System: The UNT Digital Library
Double field flip cooling channel for the neutrino factory (open access)

Double field flip cooling channel for the neutrino factory

A 220 m long ionization cooling system consisting of three solenoids with two field-flip sections, is proposed as a cooling channel for the neutrino factory. The reduction of transverse emittance is achieved using 87 liquid hydrogen absorbers (30-40 cm long), and 87 (2 m long) 200 MHz linacs. The first flip is performed at relatively small magnetic field, B = 3 T, to keep the longitudinal motion under control. The field is then increased adiabatically up to 7 T and a second field flip performed. The cooler was studied and simulated in detail. Preceded by a 16 GeV proton driver, a carbon target, a mini-cooler and a buncher, the system provides about 0.082 muons per incident proton.
Date: July 3, 2001
Creator: al., Valeri Balbekov et
System: The UNT Digital Library
Implications of the Tevatron jet results on PDF (open access)

Implications of the Tevatron jet results on PDF

We report a new measurement of the pseudorapidity ({eta}) and transverse-energy (E{sub T}) dependence of the inclusive jet production cross section in p{bar p} collisions at {radical}s = 1:8 TeV using 95 pb{sup {minus}1} of data collected with the D0 detector at the Fermilab Tevatron. The differential cross section d{sup 2}{sigma}/(dE{sub T}d{eta}) is presented up to {vert_bar}{eta}{vert_bar} = 3, significantly extending previous measurements. The results are in good overall agreement with next-to-leading order predictions from QCD, indicate a preference for certain parton distribution functions, and provide the world's best constraint on the gluon distribution at high parton momentum fraction x.
Date: July 3, 2001
Creator: Babukhadia, Levan
System: The UNT Digital Library
Small-Scale Geothermal Power Plant Field Verification Projects (open access)

Small-Scale Geothermal Power Plant Field Verification Projects

In the spring of 2000, the National Renewable Energy Laboratory issued a Request for Proposal for the construction of small-scale (300 kilowatt [kW] to 1 megawatt [MW]) geothermal power plants in the western United States. Five projects were selected for funding. Of these five, subcontracts have been completed for three, and preliminary design work is being conducted. The three projects currently under contract represent a variety of concepts and locations: a 1-MW evaporatively enhanced, air-cooled binary-cycle plant in Nevada; a 1-MW water-cooled Kalina-cycle plant in New Mexico; and a 750-kW low-temperature flash plant in Utah. All three also incorporate direct heating: onion dehydration, heating for a fish hatchery, and greenhouse heating, respectively. These projects are expected to begin operation between April 2002 and September 2003. In each case, detailed data on performance and costs will be taken over a 3-year period.
Date: July 3, 2001
Creator: Kutscher, Chuck
System: The UNT Digital Library
High-frequency bunching and phi-delta E rotation for a muon source (open access)

High-frequency bunching and phi-delta E rotation for a muon source

A scenario for capture, bunching and rf rotation of {mu}'s from a proton source is presented. It consists of a drift section, a variable frequency {approximately} 300 {r_arrow} 180 MHz bunching section, and a fixed (or variable) frequency ({approximately}180 MHz) {phi}-{delta}E rotation section. In 1-D and 3-D simulations (SIMUCOOL and ICOOL), the overall capture performance of the system is similar to that of induction linac + buncher scenarios developed for the neutrino factory. The total rf required for the system is quite modest. Optimization procedures are described.
Date: July 3, 2001
Creator: Ginneken, David Neuffer and A. Van
System: The UNT Digital Library
Engineering, design and prototype tests of a 3.9 GHz transverse-mode superconducting cavity for a radiofrequency-separated kaon beam (open access)

Engineering, design and prototype tests of a 3.9 GHz transverse-mode superconducting cavity for a radiofrequency-separated kaon beam

A research and development program is underway to construct superconducting cavities to be used for radiofrequency separation of a Kaon beam at Fermilab. The design calls for installation of twelve 13-cell cavities operating in the 3.9 GHz transverse mode with a deflection gradient of 5 MV/m. They present the mechanical, cryogenic and vacuum design of the cavity, cryomodule, rf power coupler, cold tuner and supporting hardware. The electromagnetic design of the cavity is presented in a companion paper by Wanzenberg and McAshan. The warm tuning system (for field flatness) and the vertical test system is presented along with test results of bench measurements and cold tests on single-cell and five-cell prototypes.
Date: July 3, 2001
Creator: al., Mark S.Champion et
System: The UNT Digital Library
Pbar deceleration in the Fermilab Main Injector: Tune-Up studies with proton beam (open access)

Pbar deceleration in the Fermilab Main Injector: Tune-Up studies with proton beam

In this report we present the results of beam dynamics simulations as well as experiments with protons for deceleration from 150 GeV to 8.9 GeV in the Fermilab Main Injector (MI). The simulations are carried out on two different deceleration schemes: deceleration with a fast recovery MI cycle and with a slow recovery cycle. As a proof of principle we have carried out the first successful deceleration using proton beam in the Main Injector from the Tevatron extraction energy of 150 GeV to the Recycler injection energy of 8.9 GeV.
Date: July 3, 2001
Creator: al., C.M. Bhat et
System: The UNT Digital Library