109 Matching Results

Results open in a new window/tab. Unexpected Results? Search the Catalog Instead.

Water and Wastewater Polishing Using 3M Selective Separation Remediation Cartridge Technology (open access)

Water and Wastewater Polishing Using 3M Selective Separation Remediation Cartridge Technology

3M has developed technology for selectively removing trace levels of dissolved contaminant materials from liquids using systems operating at flow rates up to 50 gallons per minute. This technology combines active particle chemistries with a particle-loaded membrane to achieve a new medium for liquid waste processing--a spiral wound filter cartridge. This technology has shown success by generating high decontamination factors and reducing contaminants to part per trillion levels. The spiral wound cartridge offers simplified installation, convenient replacement, and clean, easy disposal of a concentrated waste. By incorporating small, high surface area particles (5 to 80 microns) into a sturdy, yet porous, membrane greater removal efficiencies of even trace contaminants can be achieved at higher flow rates than with conventional column systems. In addition, the captive-particle medium prevents channeling of liquids and insures uniform flow across the sorbing particle surface. The cartridges fit into standard, commercially-available housings and whole system capital costs are substantially lower than those of column or reverse osmosis systems. Developmental work at high degrees of water polishing have included removal of mercury from contaminated wastewater, various radionuclides from process water, and organometallic species from surface water discharges. Laboratory testing and on-site demonstration data of these applications show …
Date: February 25, 2002
Creator: Hoffmann, Keith M.; Scanlan, Thomas J. & Seely, David C.
Object Type: Article
System: The UNT Digital Library
Effects of the amorphous oxide intergranular layer structure and bonding on the fracture toughness of a high purity silicon nitride (open access)

Effects of the amorphous oxide intergranular layer structure and bonding on the fracture toughness of a high purity silicon nitride

The microstructural evolution and structural characteristics and transitions in the thin grain-boundary oxide films in a silicon nitride ceramic, specifically between two adjacent grains and not the triple junctions, are investigated to find their effect on the macroscopic fracture properties. It is found that by heat treating a model Si3N4-2wt percent Y2O3 ceramic for {approx}200 hr at 1400 degrees C in air, the fracture toughness can be increased by {approx}100 percent, coincident with a change in fracture mechanism from transgranular to intergranular.
Date: November 18, 2002
Creator: Ziegler, A.; Kisielowski, C.; Hoffmann, M. J. & Ritchie, R. O.
Object Type: Article
System: The UNT Digital Library
Atomic resolution transmission electron microscopy of the intergranular structure of a Y{sub 2}O{sub 3}-silicon nitride ceramic (open access)

Atomic resolution transmission electron microscopy of the intergranular structure of a Y{sub 2}O{sub 3}-silicon nitride ceramic

High-resolution transmission electron microscopy (HRTEM) employing focus-variation phase-reconstruction methods is used to image the atomic structure of grain boundaries in a silicon nitride ceramic at a resolution of 0.8 Angstrom
Date: May 1, 2002
Creator: Ziegler, A.; Kisielowski, C.; Hoffmann, M. J. & Ritchie, R. O.
Object Type: Article
System: The UNT Digital Library
Diagnostics of discharge channels for neutralized chamber transport in heavy ion fusion (open access)

Diagnostics of discharge channels for neutralized chamber transport in heavy ion fusion

The final beam transport in the reactor chamber for heavy ion fusion in preformed plasma channels offers many attractive advantages compared to other transport modes. In the past few years, experiments at the Gesellschaft fuer Schwerionenforschung (GSI) accelerator facility have addressed the creation and investigation of discharge plasmas, designed for the transport of intense ion beams. Stable, self-standing channels of 50 cm length with currents up to 55 kA were initiated in low-pressure ammonia gas by a CO{sub 2}-laser pulse along the channel axis before the discharge is triggered. The channels were characterized by several plasma diagnostics including interferometry and spectroscopy. We also present first experiments on laser-guided intersecting discharges.
Date: May 1, 2002
Creator: Niemann, C.; Penache, D.; Tauschwitz, A.; Rosmej, F. B.; Neff, S.; Birkner, R. et al.
Object Type: Article
System: The UNT Digital Library
Disappearance of back-to-back high p {sub T} hadron correlations in central Au+Au collisions at {radical}s{sub NN} = 200 GeV (open access)

Disappearance of back-to-back high p {sub T} hadron correlations in central Au+Au collisions at {radical}s{sub NN} = 200 GeV

Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudo-rapidity range and full azimuth in Au+Au and p+p collisions at = {radical}s{sub NN} = 200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes already observed in elementary collisions. A strong back-to-back correlation exists for p+p and peripheral Au + Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.
Date: October 25, 2002
Creator: Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B. D.; Anderson, M. et al.
Object Type: Article
System: The UNT Digital Library
Kaon Production and Kaon to Pion Ratio in Au+Au Collisions at {radical}(s{sub NN})=130 GeV (open access)

Kaon Production and Kaon to Pion Ratio in Au+Au Collisions at {radical}(s{sub NN})=130 GeV

Mid-rapidity transverse mass spectra and multiplicity densities of charged and neutral kaons are reported for Au+Au collisions at {radical}s{sub NN}=130 GeV at RHIC. The spectra are exponential in transverse mass, with an inverse slope of about 280 MeV in central collisions. The multiplicity densities for these particles scale with the negative hadron pseudo-rapidity density. The charged kaon to pion ratios are K{sup +}/{pi}{sup -} = 0.161 {+-} 0.002(stat) {+-} 0.024(syst) and K{sup -}/{pi}{sup -} = 0.146 {+-} 0.002(stat) {+-} 0.022(syst) for the most central collisions. The K{sup +}/{pi}{sup -} ratio is lower than the same ratio observed at the SPS while the K{sup -}/{pi}{sup -} is higher than the SPS result. Both ratios are enhanced by about 50% relative to p+p and {bar p}+p collision data at similar energies.
Date: June 13, 2002
Creator: Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B. D.; Anderson, M. et al.
Object Type: Article
System: The UNT Digital Library
Suicide Terrorism: A Future Trend? (open access)

Suicide Terrorism: A Future Trend?

This thesis reviews the literature on “new terrorism,” to be differentiated from the “old terrorism.” The study tests two hypotheses. First, has an increase in religiously inspired terrorist groups led to an increase in terrorism's lethality? Second, does suicide bombing as a tactic explain the increased lethality of “new terrorism”? The study demonstrates three findings. First, it was found that religiously inspired terrorist groups are more lethal, though not more indiscriminate. Second, that suicide bombing has had a significant effect on the number of terrorist related fatalities. And, third, that non-religious suicide bombing is more lethal than its religious counterpart. To test these hypotheses I used Ordinary Least Squares Regression and data provided by The International Policy Institute for Counter-Terrorism.
Date: August 2002
Creator: Capell, Matthew B.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Synthesis of (plus or minus) [5-{sup 3}H] N'-Nitrosoanatabine, a tobacco-specific nitrosamine (open access)

Synthesis of (plus or minus) [5-{sup 3}H] N'-Nitrosoanatabine, a tobacco-specific nitrosamine

Tobacco-specific N'-nitrosamines (TSNA) are a unique class of systemic organ-specific carcinogens. The TSNA are formed by N-nitrosation of nicotine and of the minor tobacco alkaloids after harvesting of tobacco and during smoking. The N-nitrosation of anatabine leads to N'-nitrosoanatabine (NAT; 1-nitroso-1,2,3,4-tetrahydro-2,3'-bipyridyl) which requires in-depth assays in laboratory animals other than the rat. Furthermore, delineation of its tissue distribution and metabolism is needed for structure:activity comparisons with other TSNA and for the assessment of potential human risk from this TSNA. We have, therefore, synthesized (+)[5-3H]NAT. 5-Bromo-3-pyridine-carboxaldehyde was condensed with ethyl carbamate prior to Diels-Alder reaction with 1,4-butadiene to give the racemic anatabine ring system. Hydrolysis followed by reduction with LiAlT4 and nitrosation, led to (+)[5-3H]NAT (60 percent yield, specific activity 266 mCi/mmol, radiochemical purity of >99 percent).
Date: June 14, 2002
Creator: Desai, Dhimant; Lin, Guoying; Morimoto, Hiromi; Williams, Philip G.; El-Bayoumy, Karam & Amin, Shantu
Object Type: Article
System: The UNT Digital Library
Chemical Speciation of Inorganic Compounds under Hydrothermal Conditions (open access)

Chemical Speciation of Inorganic Compounds under Hydrothermal Conditions

Measurements of oxidation. These spectra are to the best of our knowledge the first reported in situ spectroscopic observation of homogeneous aqueous redox chemistry at temperatures beyond the critical temperature of waste. We also observed a time-dependence for the growth of the Cr(VI) XANES peak and have therefore obtained both kinetic information as well as structural information on the reactants and products at the reaction temperature. We feel that these new techniques, when employed on actual waste components will elucidate the underlying chemistry.
Date: February 21, 2002
Creator: Stern, Edward A. & Fulton, John
Object Type: Report
System: The UNT Digital Library
Non-Incineration Treatment to Reduce Benzene and VOC Emissions from Green Sand Molding Systems (open access)

Non-Incineration Treatment to Reduce Benzene and VOC Emissions from Green Sand Molding Systems

Final report describing laboratory, pilot scale and production scale evaluation of advanced oxidation systems for emissions and cost reduction in metal casting green sand systems.
Date: June 28, 2002
Creator: Cannon, Fred S. & Voigt, Robert C.
Object Type: Report
System: The UNT Digital Library
The Ranger (San Antonio, Tex.), Vol. 77, No. 6, Ed. 1 Friday, October 18, 2002 (open access)

The Ranger (San Antonio, Tex.), Vol. 77, No. 6, Ed. 1 Friday, October 18, 2002

Weekly student newspaper from San Antonio College in San Antonio, Texas that includes campus news along with advertising.
Date: October 18, 2002
Creator: San Antonio College
Object Type: Newspaper
System: The Portal to Texas History
Texas Business Today, Spring/Summer 2002 (open access)

Texas Business Today, Spring/Summer 2002

Quarterly newsletter for Texas employers describing upcoming activities, new laws affecting businesses, articles on various business-related issues, and other relevant topics.
Date: Spring 2002
Creator: Texas Workforce Commission. Office of the Commissioner Representing Employers.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Development of Novel Polymeric Materials for Gene Therapy and pH-Sensitive Drug Delivery: Modeling, Synthesis, Characterization, and Analysis (open access)

Development of Novel Polymeric Materials for Gene Therapy and pH-Sensitive Drug Delivery: Modeling, Synthesis, Characterization, and Analysis

The underlying theme of this thesis is the use of polymeric materials in bioapplications. Chapters 2-5 either develop a fundamental understanding of current materials used for bioapplications or establish protocols and procedures used in characterizing and synthesizing novel materials. In chapters 6 and 7 these principles and procedures are applied to the development of materials to be used for gene therapy and drug delivery. Chapter one is an introduction to the ideas that will be necessary to understand the subsequent chapters, as well as a literature review of these topics. Chapter two is a paper that has been published in the ''Journal of Controlled Release'' that examines the mechanism of drug release from a polymer gel, as well as experimental design suggestions for the evaluation of water soluble drug delivery systems. Chapter three is a paper that has been published in the ''Journal of Pharmaceutical Sciences'' that discusses the effect ionic salts have on properties of the polymer systems examined in chapter two. Chapter four is a paper published in the Materials Research Society Fall 2000 Symposium Series dealing with the design and synthesis of a pH-sensitive polymeric drug delivery device. Chapter five is a paper that has been published …
Date: August 27, 2002
Creator: Anderson, Brian Curtis
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Impact of beam transport method on chamber and driver design for heavy ion inertial fusion energy (open access)

Impact of beam transport method on chamber and driver design for heavy ion inertial fusion energy

In heavy ion inertial fusion energy systems, intense beams of ions must be transported from the exit of the final focus magnet system through the target chamber to hit millimeter spot sizes on the target. In this paper, we examine three different modes of beam propagation: neutralized ballistic transport, assisted pinched transport, and self-pinched transport. The status of our understanding of these three modes is summarized, and the constraints imposed by beam propagation upon the chamber environment, as well as their compatibility with various chamber and target concepts, are considered. We conclude that, on the basis of our present understanding, there is a reasonable range of parameter space where beams can propagate in thick-liquid wall, wetted-wall, and dry-wall chambers.
Date: December 1, 2002
Creator: Rose, D. V.; Welch, D. R.; Olson, C. L.; Yu, S. S.; Neff, S. & Sharp, W. M.
Object Type: Article
System: The UNT Digital Library
Alvin Sun-Advertiser (Alvin, Tex.), Vol. 111, No. 44, Ed. 1 Sunday, June 9, 2002 (open access)

Alvin Sun-Advertiser (Alvin, Tex.), Vol. 111, No. 44, Ed. 1 Sunday, June 9, 2002

Weekly newspaper from Alvin, Texas that includes local, state, and national news along with advertising.
Date: June 9, 2002
Creator: Schwind, Jim & Holton, Kathleen
Object Type: Newspaper
System: The Portal to Texas History
Vortices in dense self-assembled hole arrays. (open access)

Vortices in dense self-assembled hole arrays.

We present a study of the upper critical field and pinning strength from the resistivity and magnetization of a Nb film containing a dense array of 45 nm diameter holes on a hexagonal lattice with a spacing of 101 nm. The holes were formed by self-assembly in anodic aluminum oxide (AAO) using an electrochemical procedure. Confinement effects and Little-Parks oscillations are seen above 6 K, and strong pinning with matching field effects is seen below 6 K. Above the first matching field interstitial vortices coexist with vortices trapped in the hole array. Pinning in the Nb films with hole arrays is enhanced by two orders of magnitude over that in continuous Nb films. At low temperature, flux avalanches are observed and imaged using the magneto-optical Faraday effect.
Date: October 9, 2002
Creator: Crabtree, G. W.; Welp, U.; Xiao, Z. L.; Jiang, J. S.; Vlasko-Vlasov, V. K.; Bader, S. D. et al.
Object Type: Article
System: The UNT Digital Library
Carbon-Hydrogen Bond Activation by Titanium Imido Complexes. Computational Evidence for the Role of Alkane Adducts in Selective C-H Activation (open access)

Carbon-Hydrogen Bond Activation by Titanium Imido Complexes. Computational Evidence for the Role of Alkane Adducts in Selective C-H Activation

This article reports calculations that probe the role of R (hydrocarbon) and R' (ligand substituent) effects on the reaction coordinate for C-H activation.
Date: January 19, 2002
Creator: Cundari, Thomas R., 1964-; Klinckman, Thomas R. & Wolczanski, Peter T.
Object Type: Article
System: The UNT Digital Library
The Cuero Record (Cuero, Tex.), Vol. 108, No. 50, Ed. 1 Wednesday, December 11, 2002 (open access)

The Cuero Record (Cuero, Tex.), Vol. 108, No. 50, Ed. 1 Wednesday, December 11, 2002

Weekly newspaper from Cuero, Texas that includes local, state, and national news along with advertising.
Date: December 11, 2002
Creator: Rea, Glenn
Object Type: Newspaper
System: The Portal to Texas History
Family Land Heritage Registry, Volume 17, 2002 (open access)

Family Land Heritage Registry, Volume 17, 2002

Book commemorating Family Land Heritage Day with descriptions of the honorees for 2002 -- including important dates, people, and biographical information -- with related information.
Date: March 15, 2002
Creator: Texas. Department of Agriculture.
Object Type: Report
System: The Portal to Texas History
Texas State Historical Association One Hundred and Sixth Annual Meeting, 2002 (open access)

Texas State Historical Association One Hundred and Sixth Annual Meeting, 2002

Program for the 106th annual meeting of the Texas State Historical Association, held in Corpus Christi, Texas, including a list of sessions for the meeting and related information about the organization and conference.
Date: March 2002
Creator: Texas State Historical Association
Object Type: Pamphlet
System: The Portal to Texas History
Correlations between spatially resolved Raman shifts and dislocation density in GaN films (open access)

Correlations between spatially resolved Raman shifts and dislocation density in GaN films

None
Date: July 31, 2002
Creator: Nootz, G.; Schulte, A.; Chernyak, L.; Osinsky, A.; Jasinski, J.; Benamara, M. et al.
Object Type: Article
System: The UNT Digital Library
Symmetry-Breaking Transitions in RECuAs2-xPx (RE=Sm, Gd, Ho, and Er) (open access)

Symmetry-Breaking Transitions in RECuAs2-xPx (RE=Sm, Gd, Ho, and Er)

None
Date: May 30, 2002
Creator: Mozharivskyj, Yurij
Object Type: Thesis or Dissertation
System: The UNT Digital Library
SIAM Conference on Geometric Design and Computing. Final Technical Report (open access)

SIAM Conference on Geometric Design and Computing. Final Technical Report

The SIAM Conference on Geometric Design and Computing attracted 164 domestic and international researchers, from academia, industry, and government. It provided a stimulating forum in which to learn about the latest developments, to discuss exciting new research directions, and to forge stronger ties between theory and applications. Final Report
Date: March 11, 2002
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Magnetization reversal in magnetostatically coupled dot arrays. (open access)

Magnetization reversal in magnetostatically coupled dot arrays.

None
Date: January 15, 2002
Creator: Shima, H.; Guslienko, K.-Y.; Novosad, V.; Otani, Y. & Fukamichi, K.
Object Type: Article
System: The UNT Digital Library