Resource Type
Partner
UNT Libraries Government Documents Department
1,639
Oklahoma Historical Society
261
UNT College of Arts and Sciences
46
UNT College of Science
29
UNT College of Engineering
12
UNT Libraries
10
UNT College of Liberal Arts & Social Sciences
7
University of North Texas
4
UNT Libraries Special Collections
3
UNT College of Information
3
8 More
Collection
Office of Scientific & Technical Information Technical Reports
1,636
The Chronicles of Oklahoma
261
UNT Scholarly Works
113
Journal of Near-Death Studies
6
Dennis Vercher Collection (The Dallas Way)
2
LGBT Collections
2
Texas State Publications
2
Abilene Library Consortium
1
D. Jack Davis Art Education Collection
1
Technical Report Archive and Image Library
1
5 More
Country
States
Decade
Month
Language
2,025 Matching Results
Results open in a new window/tab. Unexpected Results? Search the Catalog Instead.
Hydrotreating studies involving NiMo/silica-doped hydrous titanium oxide (HTO:Si)-coated alumina catalysts
For hydrotreating a petroleum-derived liquid feed at 400 C, LHSV = 2. 5 g/g{sub cat}/h, and 1500 psig hydrogen (H) pressure, both HDS and HDN activities were roughly equivalent for a name/TO:Si-coated Amocat catalyst and a commercial alumina-supported name catalyst (Amocat 1C). Superior HDN performance was exhibited by the name/TO: Si-coated Amocat catalyst at low H pressure (500 psig) and after H pressure cycling (1500-500-1500 psig) relative to Amocat 1C. Consistent with previous results obtained on a coal-derived liquid feed, the HDS/HDN results with the petroleum-derived liquid showed that the performance of the name/TO:Si-coated Amocat catalyst on an active metals weight basis exceeded the performance of Amocat 1C at all test conditions. The name/TO:Si-coated Amocat catalyst also showed potentially increased hydrogenation activity, increased resistance to deactivation, and increased yields of lower boiling point distillate fractions, although further work is needed.
Date:
July 1, 1996
Creator:
Gardner, T.J.; Miller, J.E.; McLaughlin, L.I. & Trudell, D.E.
System:
The UNT Digital Library
Ion-implantation doping in SiC and its device applications
The latest ion-implantation results on SiC are presented. The authors have performed nitrogen and phosphorus (N/P) co-implantations to obtain very high n-type carrier concentrations, Si and C bombardments for compensating n-type SiC, and V-implantation for compensating p-type SiC. They have also performed N and Al implantations directly into V-doped semi-insulating 6H-SiC substrates. Vertical p-n junction diodes were made by selective area N, P, and N/P implantations into p-type epitaxial layers grown on 6H-SiC substrates.
Date:
October 1, 1997
Creator:
Rao, M.V.; Gardner, J.; Edwards, A.; Papanicolaou, N.; Kelner, G.; Holland, O.W. et al.
System:
The UNT Digital Library
ICH antenna development on the ORNL RF Test Facility
A compact resonant loop antenna is installed on the ORNL Radio Frequency Test Facility (RFTF). Facility characteristics include a steady-state magnetic field of {approx} 0.5 T at the antenna, microwave-generated plasmas with n{sub e} {approx} 10{sup 12} cm{sup {minus}3} and T{sub e} {approx} 8 eV, and 100 kW of 25-MHz rf power. The antenna is tunable from {approximately}22--75 MHz, is designed to handle {ge}1 MW of rf power, and can be moved 5 cm with respect to the port flange. Antenna characteristics reported and discussed include the effect of magnetic field on rf voltage breakdown at the capacitor, the effects of magnetic field and plasma on rf voltage breakdown between the radiating element and the Faraday shield, the effects of graphite on Faraday shield losses, and the efficiency of coupling to the plasma. 2 refs., 4 figs.
Date:
January 1, 1987
Creator:
Gardner, W.L.; Bigelow, T.S.; Haste, G.R.; Hoffman, D.J. & Livesey, R.L.
System:
The UNT Digital Library
MAGNeT : Monitor for Application-Generated Network Traffic /
Over the laqt decade, network practitioners have focused on monitoring, measuring, and characterizing traffic in the network to gain insight into building critical network components (from the protocol stack to routers and switches to network interface cards). Recent research shows that additional insight can be obtained by monitoring traffic at the application level (Le,, before application-sent traffic is modulated by the protocol stack) rather than in the network (i-e., after it is modulated by the protocol stack). Consequently, this paper describes a Monitor for Application-Generated Network Traffic (MAGNeT) that captures traffic generated by the application rather than traffic in the network. MAGNeT consists of application programs as well as modifications to the standard Linux kernel. Together, these tools provide the capability of monitoring an application's network behavior and protocol state information in production systems. The use of MAGNeT will enable the research community to construct a library of real traces of application-generated traffic from which researchers can more realistically test network protocol designs and theory. MAGNeT can also be used to verify the correct operation of protocol enhancements and to troubleshoot and tune protocol implementations.
Date:
January 1, 2001
Creator:
Feng, W. C. (Wu-Chun); Hay, J. R. (Jeffrey R.) & Gardner, M. K. (Mark K.)
System:
The UNT Digital Library
MAGNET TOOLKIT: DESIGN, IMPLEMENTATION, AND EVALUATION.
The current trend in constructing high-performance computing systems is to connect a large number of machines via a fast interconnect or a large-scale network such as the Internet, This approach relies on the performance of the interconnect (or Internet) to enable Past, large-scale distributed computing. A detailed understanding of the communication traffic is required in order to optimize the operation of entire system. Network researchers traditionally monitor traffic in the network to gain the insight necessary to optimize network operations. Recent work suggests additional insight can be obtained by also monitoring trafflc at the application level. The Monitor for Application-Generated Network Traffic toolkit (MAGNeT) we describe here monitors application trallic patterns In production systems, thus enabling more highly optimized networks and interconnects for the next generation of high performance computing system. Keywords- monitor, measurement, network protocol, traffic characterization, TCP, MAGNet, traces, application-generated traffic, virtual supercomputing, network-aware applications, computational giids, high-perfomiance computing.
Date:
January 1, 2001
Creator:
Hay, J. R. (Jeffrey R.); Feng, W. C. (Wu-Chun) & Gardner, M. K. (Mark K.)
System:
The UNT Digital Library
Draft versus finished sequence data for DNA and protein diagnostic signature development
Sequencing pathogen genomes is costly, demanding careful allocation of limited sequencing resources. We built a computational Sequencing Analysis Pipeline (SAP) to guide decisions regarding the amount of genomic sequencing necessary to develop high-quality diagnostic DNA and protein signatures. SAP uses simulations to estimate the number of target genomes and close phylogenetic relatives (near neighbors, or NNs) to sequence. We use SAP to assess whether draft data is sufficient or finished sequencing is required using Marburg and variola virus sequences. Simulations indicate that intermediate to high quality draft with error rates of 10{sup -3}-10{sup -5} ({approx} 8x coverage) of target organisms is suitable for DNA signature prediction. Low quality draft with error rates of {approx} 1% (3x to 6x coverage) of target isolates is inadequate for DNA signature prediction, although low quality draft of NNs is sufficient, as long as the target genomes are of high quality. For protein signature prediction, sequencing errors in target genomes substantially reduce the detection of amino acid sequence conservation, even if the draft is of high quality. In summary, high quality draft of target and low quality draft of NNs appears to be a cost-effective investment for DNA signature prediction, but may lead to underestimation …
Date:
October 29, 2004
Creator:
Gardner, S N; Lam, M W; Smith, J R; Torres, C L & Slezak, T R
System:
The UNT Digital Library
Non-fusion applications of RF and microwave technology
The processing of materials using rf and/or microwave power is a broad area that has grown significantly in the past few years. The authors have applied rf and microwave technology in the areas of ceramic sintering, plasma processing, and waste processing. The sintering of ceramics in the frequency range of 50 MHz-28 GHz has lead to unique material characteristics compared to materials that have been sintered conventionally. It has been demonstrated that sintering can be achieved in a variety of materials, including alumina, zirconia, silicon carbide, and boron carbide. In the area of plasma processing, progress has been made in the development and understanding of high density plasma sources, including inductively coupled plasma (ICP) sources. The effects of processing conditions on the ion energy distribution at the substrate surface (a critical processing issue) have been determined for a variety of process gases. The relationship between modeling and experiment is being established. Microwave technology has also been applied to the treatment of radioactive and chemical waste. The application of microwaves to the removal of contaminated concrete has been demonstrated. Details of these programs and other potential application areas are discussed.
Date:
December 1, 1995
Creator:
Caughman, J.B.O.; Baity, F.W.; Bigelow, T.S.; Gardner, W.L.; Hoffman, D.J.; Forrester, S.C. et al.
System:
The UNT Digital Library
ORNL facilities for testing first-wall components
Future long-impulse magnetic fusion devices will have operating characteristics similar to those described in the design studies of the Tokamak Fusion Core Experiment (TFCX), the Fusion Engineering Device (FED), and the International Tokamak Reactor (INTOR). Their first-wall components (pumped limiters, divertor plates, and rf waveguide launchers with Faraday shields) will be subjected to intense bombardment by energetic particles exhausted from the plasma, including fusion products. These particles are expected to have particle energies of approx.100 eV, particle fluxes of approx.10/sup 18/ cm/sup -2/.s/sup -1/, and heat fluxes of approx.1 kW/cm/sup 2/ CW to approx.100 kW/cm/sup 2/ transient. No components are available to simultaneously handle these particle and heat fluxes, survive the resulting sputtering erosion, and remove exhaust gas without degrading plasma quality. Critical issues for research and development of first-wall components have been identified in the INTOR Activity. Test facilities are needed to qualify candidate materials and develop components. At Oak Ridge National Laboratory (ORNL), existing neutral beam and wave heating test facilities can be modified to simulate first-wall environments with heat fluxes up to 30 kW/cm/sup 2/, particle fluxes of approx.10/sup 18/ cm/sup -2/.s/sup -1/, and pulse lengths up to 30 s, within test volumes up to approx.100 L. …
Date:
January 1, 1985
Creator:
Tsai, C.C.; Becraft, W.R.; Gardner, W.L.; Haselton, H.H.; Hoffman, D.J.; Menon, M.M. et al.
System:
The UNT Digital Library
Proposal for a muSR facility at BNL
N/A
Date:
May 12, 2013
Creator:
M., Blaskiewicz; Alessi, J.; Brown, K.; Fischer, W.; Gardner, C.; Huang, H. et al.
System:
The UNT Digital Library
SUPPORTING SAFE STORAGE OF PLUTONIUM-BEARING MATERIALS THROUGH SCIENCE, ENGINEERING AND SURVEILLANCE
Reductions in the size of the U. S. nuclear weapons arsenal resulted in the need to store large quantities of plutonium-bearing metals and oxides for prolonged periods of time. To assure that the excess plutonium from the U. S. Department of Energy (DOE) sites was stored in a safe and environmentally friendly manner the plutonium-bearing materials are stabilized and packaged according to well developed criteria published as a DOE Standard. The packaged materials are stored in secure facilities and regular surveillance activities are conducted to assure continuing package integrity. The stabilization, packaging, storage and surveillance requirements were developed through extensive science and engineering activities including those related to: plutonium-environment interactions and container pressurization, corrosion and stress corrosion cracking, plutonium-container material interactions, loss of sealing capability and changes in heat transfer characteristics. This paper summarizes some of those activities and outlines ongoing science and engineering programs that assure continued safe and secure storage of the plutonium-bearing metals and oxides.
Date:
November 10, 2009
Creator:
Dunn, K.; Chandler, G.; Gardner, C.; Louthan, M. & Mcclard, J.
System:
The UNT Digital Library
Generalized emittance measurements in a beam transport line
Motivated by the need to commission 3 beam transport lines for the new AGS Booster project, we have developed a generalized emittance-measurement program; beam line specifics are entirely resident in data tables, not in program code. For instrumentation, the program requires one or more multi-wire profile monitors; one or multiple profiles are acquired from each monitor, corresponding to one or multiple tunes of the transport line. Emittances and Twiss parameters are calculated using generalized algorithms. The required matix descriptions of the beam optics are constructed by an on-line general beam modeling program. Design of the program, its algorithms, and initial experience with it will be described. 4 refs., 2 figs., 1 tab.
Date:
January 1, 1991
Creator:
Skelly, J.; Gardner, C.; Luccio, A.; Kponou, A. & Reece, K.
System:
The UNT Digital Library
When whole-genome alignments just won't work: kSNP software for alignment-free SNP discovery, phylogenetics, and annotation of microbial genomes
None
Date:
June 18, 2013
Creator:
Gardner, S N & Hall, B G
System:
The UNT Digital Library
Uniform Beam Distributions at the Target of the NSRL Beam Transfer Line
Uniform irradiation of biological or material samples with charged particle beams is desired by experimenters because it reduces radiation dose errors. In this paper we present results of uniform beams produced in the NASA SPACE RADIATION LABORATORY (NSRL) at the Brookhaven National Laboratory (BNL) by a method which was developed theoretically and was proven experimentally at BNL. A similar method which requires collimation of the beam, and also lacks the flexibility of the present method to produce beam various beam sizes at the target, was patented in the year 1988. The present method of producing uniform beam distributions on a plane transverse to the direction of the beam, is based on purely magnetic focusing of the beam and requires no collimation of the beam or any other type of beam interaction with materials. It can also generate uniform beam distributions of various sizes. The method is favorably compared with alternative methods of producing uniform beam distributions and can be applied to the whole energy spectrum of the charged particle beams that are delivered by the BNL Booster synchrotron.
Date:
June 25, 2007
Creator:
Tsoupas, N.; Ahrens, L.; Brown, K. Chiang, I-Hung, Gardner, C. J.; MacKay, W. W.; Pile, P. & Rusek, A.
System:
The UNT Digital Library
Design for the National RF Test Facility at ORNL
Conceptual and preliminary engineering design for the National RF Test Facility at Oak Ridge National Laboratory (ORNL) has been completed. The facility will comprise a single mirror configuration embodying two superconducting development coils from the ELMO Bumpy Torus Proof-of-Principle (EBT-P) program on either side of a cavity designed for full-scale antenna testing. The coils are capable of generating a 1.2-T field at the axial midpoint between the coils separated by 1.0 m. The vacuum vessel will be a stainless steel, water-cooled structure having an 85-cm-radius central cavity. The facility will have the use of a number of continuous wave (cw), radio-frequency (rf) sources at levels including 600 kW at 80 MHz and 100 kW at 28 GHz. Several plasma sources will provide a wide range of plasma environments, including densities as high as approx. 5 x 10/sup 13/ cm/sup -3/ and temperatures on the order of approx. 10 eV. Furthermore, a wide range of diagnostics will be available to the experimenter for accurate appraisal of rf testing.
Date:
January 1, 1983
Creator:
Gardner, W. L.; Hoffman, D. J.; Becraft, W. R.; Blue, C. W.; Combs, S. K.; Dagenhart, W. K. et al.
System:
The UNT Digital Library
The reaction of hydroperoxy-propyl radicals with molecular oxygen
Addition of hydroperoxy-alkyl radicals to molecular oxygen leads to chain branching in autoignition and engine knock, and in low temperature oxidation of paraffins. Rate constants and product channels for reaction of hydroperoxy-propyl radicals with O{sub 2} are estimated using thermodynamic properties, bimolecular quantum Kassel analysis and transition state theory. Thermochemistry of relevant molecules and radicals is estimated using group additivity and bond dissociation groups for radicals. Results show that rates of the hydroperoxy-propyl radical addition to O{sub 2} are near their high pressure limits at {ge} 1 atm. Main products at 1--15 atm are stabilization, reverse reaction to hydroperoxy-propyl + O{sub 2} and alkyl carbonyl + OH. Reactions of the stabilized adducts, dissociation rates and product channels are estimated using unimolecular quantum Kassel analysis, because stabilization is the most important hydroperoxy-propyl radical + O{sub 2} product channel. Below 700 K, the stabilized peroxy adducts react primarily to hydroperoxy-carbonyl + OH, products which lead to chain branching. Above 700K, the stabilized peroxy adducts react primarily to hydroperoxy-propyl radical + O{sub 2}, initial reactants, which inhibits the overall oxidation. This switchover in channels correlates well observed negative temperature coefficient behavior for propane oxidation. Rate expressions for reaction of each of the three …
Date:
December 3, 1993
Creator:
Bozzelli, J. W. & Pitz, W. J.
System:
The UNT Digital Library
Magnetic field measurements on ISABELLE storage ring magnets
In 1978 the magnetic field shapes of six ISABELLE prototype dipole magnets were measured in detail. All the harmonic terms that are forbidden by symmetry in dipole magnets are found to have values that are zero to within the allowed tolerances. This result indicates that the random errors in conductor placement are within tolerances and that the assembly techniques are satisfactory in this regard. However, the first allowed error term in a dipole magnet, the sextupole term, is much too large, and varies greatly from magnet to magnet resulting in field errors at the edge of the desired good field region that are 10/sup -3/ of the central field value, whereas the tolerable field errors are of the order of 10/sup -4/ of the central field value. This large sextupole term has been traced to assembly errors which yield a coil assembly which instead of being circular in cross section is racetrack shaped, with the vertical axis being 10 to 20 thousandths of an inch greater than the horizontal axis. This problem will be corrected in the future production series.
Date:
January 1, 1979
Creator:
Bleser, E.; Dahl, P.; Gardner, D.; Kaugerts, J.; McInturff, A.; Robins, K. et al.
System:
The UNT Digital Library
Observation and correction of resonance stopbands in the AGS Booster
At the design intensity of 1.5 {times} 10{sup 13} ppp, the space charge tune shift in the AGS Booster at injection has been estimated to be about 0.35. Therefore, the beam is spread over may lower order resonance lines and the stopbands have to be corrected to minimize the amplitude growth by proper compensation of the driving harmonics resulting from random errors. The observation and correction of second and third order resonance stopbands in the AGS Booster, and the establishment of a favorable operating point at high intensity are discussed.
Date:
June 1, 1993
Creator:
Gardner, C.; Shoji, Y.; Ahrens, L.; Glenn, J. W.; Lee, Y. Y.; Roser, T. et al.
System:
The UNT Digital Library
Dark Matter Constraints from a Cosmic Index of Refraction
The dark-matter candidates of particle physics invariably possess electromagnetic interactions, if only via quantum fluctuations. Taken en masse, dark matter can thus engender an index of refraction which deviates from its vacuum value. Its presence is signaled through frequency-dependent effects: the real part yields dispersive effects in propagation, and the imaginary part yields such in attenuation. We discuss theoretical constraints on the expansion of the index of refraction with frequency, the physical interpretation of the terms, and the particular observations needed to isolate its coefficients. This, with the advent of new opportunities to view gamma-ray bursts at cosmological distance scales, gives us a new probe of dark matter. As a first application we use the time delay determined from radio afterglow observations of gamma-ray bursts to limit the charge-to-mass ratio of dark matter to |{var_epsilon}|/M < 1.8 x 10{sup -5} eV{sup -1} at 95% CL.
Date:
April 1, 2009
Creator:
Gardner, Susan & Latimer, David C.
System:
The UNT Digital Library
Measurement of the Differential Cross-Sections of Inclusive, Prompt And Non-Prompt $J/\psi$ Production in Proton-Proton Collisions at $\sqrt{s}=7$ TeV
None
Date:
June 4, 2013
Creator:
Aad, Georges
System:
The UNT Digital Library
New parameterization of the E1 gamma-ray strength function
The giant dipole (GD) parameters of peak energy, width, and cross section were satisfactorily correlated for elements from V to Bi, assuming two overlapping peaks with a separation dependent on deformation. The energy dependence of the GD resonance is assumed to have a Breit-Wigner form, but with an energy-dependent width. The resulting gamma-ray strength function model is used to predict neutron capture cross sections and gamma-ray spectra for isotopes of Ta, Os, and Au. 23 references.
Date:
October 18, 1979
Creator:
Gardner, D. G. & Dietrich, F. S.
System:
The UNT Digital Library
Sequencing Needs for Viral Diagnostics
We built a system to guide decisions regarding the amount of genomic sequencing required to develop diagnostic DNA signatures, which are short sequences that are sufficient to uniquely identify a viral species. We used our existing DNA diagnostic signature prediction pipeline, which selects regions of a target species genome that are conserved among strains of the target (for reliability, to prevent false negatives) and unique relative to other species (for specificity, to avoid false positives). We performed simulations, based on existing sequence data, to assess the number of genome sequences of a target species and of close phylogenetic relatives (''near neighbors'') that are required to predict diagnostic signature regions that are conserved among strains of the target species and unique relative to other bacterial and viral species. For DNA viruses such as variola (smallpox), three target genomes provide sufficient guidance for selecting species-wide signatures. Three near neighbor genomes are critical for species specificity. In contrast, most RNA viruses require four target genomes and no near neighbor genomes, since lack of conservation among strains is more limiting than uniqueness. SARS and Ebola Zaire are exceptional, as additional target genomes currently do not improve predictions, but near neighbor sequences are urgently needed. …
Date:
January 26, 2004
Creator:
Gardner, S N; Lam, M; Mulakken, N J; Torres, C L; Smith, J R & Slezak, T
System:
The UNT Digital Library
High Intensity Performance of the Brookhaven AGS.
The Brookhaven AGS provides 24 GeV protons for a multi-user program of fixed-target high energy physics experiments, such as the study of extremely rare Kaon decays. Up to 7 x 10{sup 13} protons are slowly extracted over 2.2 seconds each 5.1 seconds. The muon storage ring of the g-2 experiment is supplied with bunches of 7 x 10{sup 12} protons. Since the completion of the a 1.9 GeV Booster synchrotron and installation of a new high-power rf system and transition jump system in the AGS various modes of operation have been explored to overcome space charge limits and beam instabilities at these extreme beam intensities. Experiments have been done using barrier cavities to enable accumulation of debunched beam in the AGS as a potential path to significantly higher intensities. We report on the present understanding of intensity limitations and prospects for overcoming them.
Date:
March 29, 1999
Creator:
Ahrens, L. A.; Alessi, J.; Blaskiewicz, M.; Brennan, J. M.; Brown, K.; Gardner, C. et al.
System:
The UNT Digital Library
Parameter uncertainty and model predictions: a review of Monte Carlo results
Studies of parameter variability by Monte Carlo analysis are reviewed using repeated simulations of the model with randomly selected parameter values. At the beginning of each simulation, parameter values are chosen from specific frequency distributions. This process is continued for a number of iterations sufficient to converge on an estimate of the frequency distribution of the output variables. The purpose was to explore the general properties of error propagaton in models. Testing the implicit assumptions of analytical methods and pointing out counter-intuitive results produced by the Monte Carlo approach are additional points covered.
Date:
January 1, 1979
Creator:
Gardner, R. H. & O'Neill, R. V.
System:
The UNT Digital Library
Chemical thermodynamic representations of <PuO/sub 2-x> and <U/sub 1-z/Pu/sub z/O/sub w/>
All available oxygen potential-temperature-composition data for the calcium fluorite-structure <PuO/sub 2-x/> phase were retrieved from the literature and utilized in the development of a binary solid solution representation of the phase. The data and phase relations are found to be best described by a solution of (Pu/sub 4/3/O/sub 2/) and (PuO/sub 2/) with a temperature dependent interaction energy. The fluorite-structure <U/sub 1-z/Pu/sub z/O/sub w/> is assumed to be represented by a combination of the binaries <PuO/sub 2-x/> and <UO/sub 2+-x/>, and thus treated as a solution of (Pu/sub 4/3/O/sub 2/), (PuO/sub 2/), (UO/sub 2/), and either (U/sub 2/O/sub 4/./sub 5/) or (U/sub 3/O/sub 7/). The resulting equations well reproduce the large amount of oxygen potential-temperature-composition data for the mixed oxide system, all of which were also retrieved from the literature. These models are the first that appear to display the appropriate oxygen potential-temperature-composition and phase relation behavior over the entire range of existence for the phases. 39 refs., 10 figs., 3 tabs.
Date:
January 1, 1984
Creator:
Besmann, Theodore M. & Lindemer, Terrence B.
System:
The UNT Digital Library