Degree Department

44 Matching Results

Results open in a new window/tab.

Spectrum Management: Public Safety and the Transition to Digital Television (open access)

Spectrum Management: Public Safety and the Transition to Digital Television

None
Date: November 24, 2003
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Investigation of Ti-doped NaAlH4 by solid-state NMR (open access)

Investigation of Ti-doped NaAlH4 by solid-state NMR

In recent years, the development of Ti-doped NaAlH{sub 4} as a hydrogen storage material has gained attention because of its large weight percentage of hydrogen ({approx}5%) compared to traditional interstitial hydrides. The addition of transition-metal dopants, in the form of Ti-halides, such as TiCl{sub 3}, dramatically improves the kinetics of the absorption and desorption of hydrogen from NaAlH{sub 4}. However, the role that Ti plays in enhancing the absorption and desorption of H{sub 2} is still unknown. In the present study, {sup 27}Al, {sup 23}Na, and {sup 1}H MAS (Magic Angle Spinning) NMR (Nuclear Magnetic Resonance) has been performed to understand the titanium speciation in Ti-doped NaAlH{sub 4}. All experiments were performed on a sample of crushed single crystals exposed to Ti during growth, a sample of solvent-mixed 4TiCl{sub 3} + 112NaAlH{sub 4}, a reacted sample of solvent-mixed TiCl{sub 3} + {sup 3}NaAlH{sub 4} with THF, and a reacted sample of ball-milled TiCl3 + 3NaAlH{sub 4}. The {sup 27}Al MAS NMR has shown differences in compound formation between solvent-mixed TiCl{sub 3} + 3NaAlH{sub 4} with THF and the mechanically ball-milled TiCl{sub 3} + 3NaAlH{sub 4}. {sup 27}Al MAS NMR of the mechanically ball-milled mixture of fully-reacted TiCl{sub 3} + 3NaAlH{sub …
Date: November 24, 2003
Creator: Maxwell, R; Majzoub, E & Herberg, J
Object Type: Article
System: The UNT Digital Library
ALE3D Model Predictions and Experimental Analysis of the Cookoff Response of Comp B* (open access)

ALE3D Model Predictions and Experimental Analysis of the Cookoff Response of Comp B*

ALE3D simulations are presented for the thermal explosion of Comp B (RDX,TNT) in a Scaled Thermal Explosion Experiment (STEX). Candidate models and numerical strategies are being tested using the ALE3D code which simulates the coupled thermal, mechanical, and chemical behavior during heating, ignition, and explosion. The mechanical behavior of the solid constituents is represented by a Steinberg-Guinan model while polynomial and gamma-law expressions are used for the equation of state of the solid and gas species, respectively. A gamma-law model is employed for the air in gaps, and a mixed material model is used for the interface between air and explosive. A three-step chemical kinetics model is used for each of the RDX and TNT reaction sequences during the heating and ignition phases, and a pressure-dependent deflagration model is employed during the rapid expansion. Parameters for the three-step kinetics model are specified using measurements of the One-Dimensional-Time-to-Explosion (ODTX), while measurements for burn rate are employed to determine parameters in the burn front model. We compare model predictions to measurements for temperature fields, ignition temperature, and tube wall strain during the heating, ignition, and explosive phases.
Date: November 24, 2003
Creator: Maienschein, J. L.; McClelland, M. A.; Wardell, J. F.; Reaugh, J. E.; Nichols, A. L. & Tran, T. D.
Object Type: Article
System: The UNT Digital Library

Ensemble: 2003-11-24 – Chamber Orchestra

Orchestra concert performed at the UNT College of Music Concert Hall. Conducted by Mee-Ah Lo, Eun Young Park, and Stacy Weill in partial fulfillment of the Master of Music (MM) degree. Conducted by Ai Kuang Sun in partial fulfillment of the Doctor of Musical Arts (DMA) degree.
Date: November 24, 2003
Creator: University of North Texas. Chamber Orchestra.
Object Type: Sound
System: The UNT Digital Library
Oral History Interview with Jack C. Henthorn, November 24, 2003 transcript

Oral History Interview with Jack C. Henthorn, November 24, 2003

The National Museum of the Pacific War presents an oral interview with Jack C. Henthorn. Henthorn joined the Army Air Forces in March 1944. He was sent to gunnery school and describes how he was trained as a ball turret gunner. Henthorn was sent to England as a part of a B-24 crew to serve with the 564th Bomb Squadron, 389th Bomb Group. He briefly mentions having Jimmy Stewart as a commanding officer. Henthorn discusses getting an infection from a cut and how he was treated. He describes participating in four missions just before the end of the war. Henthorn details the trip back to the US. He was discharged soon after his return, but remained in the reserves.
Date: November 24, 2003
Creator: Henthorn, Jack C.
Object Type: Sound
System: The Portal to Texas History
Evolution of technetium speciation in reducing grout (open access)

Evolution of technetium speciation in reducing grout

Cementitious waste forms (CWFs) are an important component of the strategy to immobilize high-level nuclear waste resulting from plutonium production by the U.S. Department of Energy (DOE). Technetium (99Tc) is an abundant fission product of particular concern in CWFs due to the high solubility and mobility of pertechnetate, TcO4-, the stable form of technetium in aerobic environments. CWFs can more effectively immobilize 99Tc if they contain additives that reduce mobile TcO4- to immobile Tc(IV) species. Leaching of 99Tc from reducing CWFs that contain Tc(IV) is much slower than for CWFs containing TcO4-. Previous X-ray absorption fine structure (XAFS) studies showed that the Tc(IV) species were oxidized to TcO4- in reducing grout samples prepared on a laboratory scale. Whether the oxidizer was atmospheric O2 or NO3- in the waste simulant was not determined. In actual CWFs, rapid oxidation of Tc(IV) by NO3- would be a concern, whereas oxidation by atmospheric O2 would be of less concern due to the slow diffusion and reaction of O2 with the reducing CWF. To address this uncertainty, two series of reducing grouts were prepared using TcO4- containing waste simulants with and without NO3-. In the first series of samples, the TcO4- was completely reduced using …
Date: November 24, 2003
Creator: Lukens, Wayne W.; Bucher, Jerome J.; Shuh, David K. & Edelstein,Norman M.
Object Type: Article
System: The UNT Digital Library
The Scale-Up of Large Pressurized Fluidzied Beds for Advanced Coal-Fired Power Processes (open access)

The Scale-Up of Large Pressurized Fluidzied Beds for Advanced Coal-Fired Power Processes

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor an agency thereof, nor any of the their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, A combined-cycle High Performance Power System (HIPPS) capable of overall cycle efficiencies approaching 50% has been proposed and designed by Foster Wheeler Development Corporation (FWDC). A pyrolyzer in the first stage of the HIPPS process converts a coal feedstock into fuel gas and char at an elevated pressure of 1.4 Map. (206 psia) and elevated temperature of 930 C (1700 F). The generated char serves as the feedstock for a Pulverized Coal (PC) boiler operating at atmospheric pressure, and the fuel gas is directly fired in a gas turbine. The hydrodynamic behavior of the pyrolyzer strongly influences the quality of both the fuel gas and the generated char, the energy split between the gas turbine and the steam turbine, and hence the overall efficiency of the system. By utilizing a simplified set of scaling parameters (Glicksman et al.,1993), a 4/7th labscale cold model …
Date: November 24, 2003
Creator: Glicksman, Leon R.; Louge, Michael; Younis, Hesham F.; Tan, Richard; Hyre, Mathew & Torpey, Mark
Object Type: Report
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 105, No. 215, Ed. 1 Monday, November 24, 2003 (open access)

Altus Times (Altus, Okla.), Vol. 105, No. 215, Ed. 1 Monday, November 24, 2003

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: November 24, 2003
Creator: Andrews, Mike
Object Type: Newspaper
System: The Gateway to Oklahoma History
Oral History Interview with Jack C. Henthorn, November 24, 2003 (open access)

Oral History Interview with Jack C. Henthorn, November 24, 2003

The National Museum of the Pacific War presents an oral interview with Jack C. Henthorn. Henthorn joined the Army Air Forces in March 1944. He was sent to gunnery school and describes how he was trained as a ball turret gunner. Henthorn was sent to England as a part of a B-24 crew to serve with the 564th Bomb Squadron, 389th Bomb Group. He briefly mentions having Jimmy Stewart as a commanding officer. Henthorn discusses getting an infection from a cut and how he was treated. He describes participating in four missions just before the end of the war. Henthorn details the trip back to the US. He was discharged soon after his return, but remained in the reserves.
Date: November 24, 2003
Creator: Henthorn, Jack C.
Object Type: Text
System: The Portal to Texas History
The Alvin Sun (Alvin, Tex.), Vol. 112, No. 90, Ed. 1 Monday, November 24, 2003 (open access)

The Alvin Sun (Alvin, Tex.), Vol. 112, No. 90, Ed. 1 Monday, November 24, 2003

Weekly newspaper from Alvin, Texas that includes local, state, and national news along with advertising.
Date: November 24, 2003
Creator: Schwind, Jim & Looby, Edward
Object Type: Newspaper
System: The Portal to Texas History
Wind Climate Analyses for a 61-M Tower in the Southeast (open access)

Wind Climate Analyses for a 61-M Tower in the Southeast

The Savannah River Technology Center's (SRTC) Atmospheric Technologies Group (ATG) has operated nine 61-m tower sites including the Central Climatology (CC) tower which is located near the center of the Savannah River Site (SRS) since 1985. Data from the weather instruments on this tower have provided answers to questions involving risk analyses, dose studies, forecast verifications, and wind/temperature conditions during extreme events and planned tests. Most recently, data from these towers are being used for initial and boundary conditions for computationally intensive numerical simulations using mesoscale forecasting models that are run on a three-hourly basis by ATG for SRS and the surrounding vicinity. We found that a series of wind roses based on relatively short time scales (from two weeks to one hour) were a convenient method to depict the predominant wind speeds and directions at anemometer sites in the Southeast operated by the NWS. That report also revealed some interesting spatial and temporal relationships among thirteen NWS stations in the Carolinas, Georgia, and Florida. Our study here will focus on the CC tower to show changes in the wind speed and direction distributions with height during diurnal and annual cycles. This study will concentrate on mean wind speed and …
Date: November 24, 2003
Creator: Weber, A. H.
Object Type: Article
System: The UNT Digital Library

Guest Artist Recital: 2003-11-24 - The October Trio

Access: Use of this item is restricted to the UNT Community
Concert performed at UNT College of Music Recital Hall on November 24, 2003 at 8:00 pm.
Date: November 24, 2003
Creator: Clardy, Mary Karen; Hustis, Barbara & Dederich-Pejovich, Susan
Object Type: Sound
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Monday, November 24, 2003 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Monday, November 24, 2003

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: November 24, 2003
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
Fall MRS 2003: Actinides Symposium (open access)

Fall MRS 2003: Actinides Symposium

{lg_bullet} The focus was on fundamental actinide science and its role. {lg_bullet} History- none except the Nuclear Waste Management Symposia {lg_bullet} Joint Sessions- none but we are open to it in the future. {lg_bullet} Tutorials- none but we are open to it in the future. {lg_bullet} 3 days: 16 Invited talks; 36 Contributed Talks; 10 Posters
Date: November 24, 2003
Creator: Tobin, James G.
Object Type: Article
System: The UNT Digital Library
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 89, No. 64, Ed. 1 Monday, November 24, 2003 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 89, No. 64, Ed. 1 Monday, November 24, 2003

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: November 24, 2003
Creator: Broaddus, Matthew B.
Object Type: Newspaper
System: The Gateway to Oklahoma History
Effects of Elevated Radon Levels on Kanne Tritium Monitors (open access)

Effects of Elevated Radon Levels on Kanne Tritium Monitors

The Savannah River Site has used Kanne ionization chambers since the late 1950's to monitor for airborne tritium in reactor facilities. Two Kanne monitors indicated elevated airborne tritium levels while monitoring a non-ventilated room used to store tritiated liquid moderator. Subsequent air sample analysis failed to reveal the presence of airborne tritium. It was suspected that elevated radon levels caused the Kanne monitors to falsely indicate tritium activity. Two commercially available monitoring systems were used to quantify radon levels in the storage room. Measurements performed during this evaluation found that radon caused the Kanne monitors in the storage room to falsely indicate the presence of airborne tritium. A side-by-side comparison of a filtered versus an unfiltered Kanne monitor found that a high efficiency particulate filter reduced monitor response to near background under high radon conditions. It was recommended that a high efficiency filter be installed on the dedicated storage room Kanne monitor and that the room be de-posted as an Airborne Radioactivity Area. It was also found that the Kanne monitors would detect a spill from a single drum of moderator within minutes and the dose rate due to tritium exposure at 20 hours following this spill would be 4.56 …
Date: November 24, 2003
Creator: Farrell, W. E.
Object Type: Article
System: The UNT Digital Library
The Oklahoma Daily (Norman, Okla.), Vol. 87, No. 67, Ed. 1 Monday, November 24, 2003 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 87, No. 67, Ed. 1 Monday, November 24, 2003

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: November 24, 2003
Creator: King, Christopher R.
Object Type: Newspaper
System: The Gateway to Oklahoma History
Optical Properties of CdSe Nanoparticle Assemblies (open access)

Optical Properties of CdSe Nanoparticle Assemblies

We report on three-dimensional fluorescence imaging of micron-size faceted crystals precipitated from solutions of CdSe nanocrystals. Such crystals have previously been suggested to be superlattices of CdSe quantum dots [1,2]. Possible applications for these materials include their use in optical and optoelectronic devices. The micron-size crystals were grown by slow evaporation from toluene solutions of CdSe nanocrystals in the range of 3-6 nm, produced by traditional wet-chemistry techniques. By using a confocal microscope with laser illumination, three-dimensional raster-scanning and synchronized hyper-spectral detection, we have generated spatial profiles of the fluorescence emission intensity and spectrum. The fluorescence data of the micro-crystals were compared with spectra of individual nanocrystals obtained from the same solution. The results do not support the assertion that these microcrystals consist of CdSe superlattices.
Date: November 24, 2003
Creator: Huser, Thomas; Gerion, Daniele; Zaitseva, Natalia; Krol, Denise M. & Leon, F. Rafael
Object Type: Article
System: The UNT Digital Library
Perry Daily Journal (Perry, Okla.), Vol. 110, No. 218, Ed. 1 Monday, November 24, 2003 (open access)

Perry Daily Journal (Perry, Okla.), Vol. 110, No. 218, Ed. 1 Monday, November 24, 2003

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: November 24, 2003
Creator: Brown, Gloria
Object Type: Newspaper
System: The Gateway to Oklahoma History

Doctoral Recital: 2003-11-24 – Richard D. Smiley, saxophone

Recital presented at the UNT College of Music Recital Hall in partial fulfillment of the Doctor of Musical Arts (DMA) degree.
Date: November 24, 2003
Creator: Smiley, Richard D.
Object Type: Sound
System: The UNT Digital Library