Analysis of Potential Benefits and Costs of Updating the Commercial Building Energy Code in Iowa (open access)

Analysis of Potential Benefits and Costs of Updating the Commercial Building Energy Code in Iowa

The state of Iowa is considering adpoting ASHRAE 90.1-1999 as its commercial building energy code. In an effort to evaluate whether or not this is an appropraite code for the state, the potential benefits and costs of adopting this standard are considered. Both qualitative and quantitative benefits are assessed. The energy simulation and economic results suggest that adopting ASHRAE 90.1-1999 would provide postitive net benefits to the state relative to the building and design requirements currently in place.
Date: September 7, 2002
Creator: Cort, Katherine A.; Belzer, David B.; Richman, Eric E. & Winiarski, David W.
Object Type: Report
System: The UNT Digital Library
Photon Colliders (open access)

Photon Colliders

A photon collider interaction region has the possibility of expanding the physics reach of a future TeV scale electron-positron collider. A survey of ongoing efforts to design the required lasers and optics to create a photon collider is presented in this paper.
Date: October 7, 2002
Creator: Gronberg, J.
Object Type: Article
System: The UNT Digital Library
Solid-State Heat-Capacity-Laser Review (open access)

Solid-State Heat-Capacity-Laser Review

We describe our recent progress in the area of solid-state heat-capacity-lasers (SSHCL). In particular, we examine the physics of heat-capacity operation of a solid state laser and give the present technology status of our 10 kW flashlamp-pumped laser The current status of work leading to a diode-pumped Nd:GGG HCL is also described.
Date: May 7, 2002
Creator: Rotter, M D & Dane, C B
Object Type: Article
System: The UNT Digital Library
Strong Earthquake Motion Estimates for Three Sites on the U.C. San Diego Campus (open access)

Strong Earthquake Motion Estimates for Three Sites on the U.C. San Diego Campus

The approach of the Campus Earthquake Program (CEP) is to combine the substantial expertise that exists within the UC system in geology, seismology, and geotechnical engineering, to estimate the earthquake strong motion exposure of UC facilities. These estimates draw upon recent advances in hazard assessment, seismic wave propagation modeling in rocks and soils, and dynamic soil testing. The UC campuses currently chosen for application of our integrated methodology are Riverside, San Diego, and Santa Barbara. The procedure starts with the identification of possible earthquake sources in the region and the determination of the most critical fault(s) related to earthquake exposure of the campus. Combined geological, geophysical, and geotechnical studies are then conducted to characterize each campus with specific focus on the location of particular target buildings of special interest to the campus administrators. We drill, sample, and geophysically log deep boreholes next to the target structure, to provide direct in-situ measurements of subsurface material properties, and to install uphole and downhole 3-component seismic sensors capable of recording both weak and strong motions. The boreholes provide access below the soil layers, to deeper materials that have relatively high seismic shear-wave velocities. Analyses of conjugate downhole and uphole records provide a basis …
Date: May 7, 2002
Creator: Day, S.; Doroudian, M.; Elgamal, A.; Gonzales, S.; Heuze, F.; Lai, T. et al.
Object Type: Report
System: The UNT Digital Library
A Picosecond 14.7 nm X-Ray Laser for Probing Matter Undergoing Rapid Changes (open access)

A Picosecond 14.7 nm X-Ray Laser for Probing Matter Undergoing Rapid Changes

With laser-driven tabletop x-ray lasers now operating in the efficient saturation regime, the source characteristics of high photon flux, high monochromaticity, picosecond pulse duration, and coherence are well-matched to many applications involving the probing of matter undergoing rapid changes. We give an overview of recent experiments at the Lawrence Livermore National Laboratory (LLNL) Compact Multipulse Terawatt (COMET) laser using the picosecond 14.7 nm x-ray laser as a compact, ultrafast probe for surface analysis and for interferometry of laser-produced plasmas. The plasma density measurements for known laser conditions allow us to reliably and precisely benchmark hydrodynamics codes. In the former case, the x-ray laser ejects photo-electrons, from the valence band or shallow core-levels of the material, and are measured in a time-of-flight analyzer. Therefore, the electronic structure can be studied directly to determine the physical properties of materials undergoing rapid phase changes.
Date: October 7, 2002
Creator: Dunn, J.; Smith, R. F.; Nilsen, J.; Nelson, A. J.; Van Buuren, T. W.; Moon, S. J. et al.
Object Type: Article
System: The UNT Digital Library
Holographic Protection of Chronology in Universes of the Godel Type (open access)

Holographic Protection of Chronology in Universes of the Godel Type

We analyze the structure of supersymmetric Godel-like cosmological solutions of string theory. Just as the original four-dimensional Godel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on"phenomenological" aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Godel universes. We find that holography can serve as a chronology protection agency: The closed timelike curves are either hidden behind the holographic screen, or broken by it into causal pieces. In fact, holography in Godel universes has many features in common with de Sitter space, suggesting that Godel universes could represent a supersymmetric laboratory for addressing the conceptual puzzles of de Sitter holography. Then we initiate the investigation of"microscopic" aspects of holography of Godel universes in string theory. We show that Godel universes are T-dual to pp-waves, and use this fact to generate new Godel-like solutions of string and M-theory by T-dualizing known supersymmetric pp-wave solutions.
Date: December 7, 2002
Creator: Boyda, Edward; Ganguli, Surya; Horava, Petr & Varadarajan, Uday
Object Type: Article
System: The UNT Digital Library
HPVB and HPVZM Shaped Growth of CdZnTe, CdSe and ZnSe Crystals. (open access)

HPVB and HPVZM Shaped Growth of CdZnTe, CdSe and ZnSe Crystals.

None
Date: July 7, 2002
Creator: Kolesnikov, N. N.; James, R. B.; Berzigiarova, N. S. & Kulakov, M. P.
Object Type: Article
System: The UNT Digital Library
Filter Media Recommendation Review (open access)

Filter Media Recommendation Review

The original filter recommended by PNNL for the RASA is somewhat difficult to dissolve and has been discontinued by the manufacturer (3M) because the manufacturing process (substrate blown microfiber, or SBMF) has been superceded by a simpler process (scrim-free blown microfiber, or BMF). Several new potential filters have been evaluated by PNNL and by an independent commercial lab. A superior product has been identified which provides higher trapping efficiency, higher air flow, is easier to dissolve, and is thinner, accommodating more filters per RASA roll. This filter is recommended for all ground-based sampling, and with additional mechanical support, it could be useful for airborne sampling, as well.
Date: January 7, 2002
Creator: Thompson, Robert C.; Miley, Harry S. & Arthur, Richard J.
Object Type: Report
System: The UNT Digital Library
Photoionization of Sc2+ ions by synchrotron radiation: Highresolution measurements and absolute cross sections in the photon energyrange 23-68 eV (open access)

Photoionization of Sc2+ ions by synchrotron radiation: Highresolution measurements and absolute cross sections in the photon energyrange 23-68 eV

Cross sections for photoionization of doubly-chargedscandium ions has been measured using a merged-beams technique. Resultsare compared with the time-reversed process ofphotorecombination.
Date: October 7, 2002
Creator: Schippers, Stefan E.; Müller, A.; Ricz, S.; Bannister, M. E.; Dunn, G. H.; Schlachter, A. S. et al.
Object Type: Article
System: The UNT Digital Library
Summer Workshop: Molecular Basis, Physiology and Diversity of Microbial Adaptation (open access)

Summer Workshop: Molecular Basis, Physiology and Diversity of Microbial Adaptation

This summer workshop successfully exposed beginning graduate students, research technicians from industry, and other scientists to modern concepts and experimental protocols in an area that both DOE and NSF perceived to be lacking in U.S. science. 70 students participated in this workshop over 5 summers. Each summer, 12-16 students spent 2-4 weeks at The Ohio State University covering four distinct modules through lectures, laboratory sessions, and interaction with internationally recognized eminent scientists.
Date: May 7, 2002
Creator: Tabita, F. R.
Object Type: Report
System: The UNT Digital Library
Probing dark energy with supernovae: Exploiting complementarity with the cosmic microwave background (open access)

Probing dark energy with supernovae: Exploiting complementarity with the cosmic microwave background

None
Date: August 7, 2002
Creator: Frieman, Joshua A.; Huterer, Dragan; Linder, Eric V. & Turner, Michael S.
Object Type: Article
System: The UNT Digital Library
Ammonia conversion and NOx formation in laminar coflowing nonpremixed methane-air flames (open access)

Ammonia conversion and NOx formation in laminar coflowing nonpremixed methane-air flames

This paper reports on a combined experimental and modeling investigation of NOx formation in nitrogen-diluted laminar methane diffusion flames seeded with ammonia. The methane-ammonia mixture is a surrogate for biomass fuels which contain significant fuel-bound nitrogen. The experiments use flue-gas sampling to measure the concentration of stable species in the exhaust gas, including NO, O2, CO, and CO2. The computations evolve a two-dimensional low Mach number model using a solution-adaptive projection algorithm to capture fine-scale features of the flame. The model includes detailed thermodynamics and chemical kinetics, differential diffusion, buoyancy, and radiative losses. The model shows good agreement with the measurements over the full range of experimental NH3 seeding amounts. As more NH3 is added, a greater percentage is converted to N2 rather than to NO. The simulation results are further analyzed to trace the changes in NO formation mechanisms with increasing amounts of ammonia in the fuel.
Date: January 7, 2002
Creator: Sullivan, Neal; Jensen, Anker; Glarborg, Peter; Day, Marcus S.; Grcar, Joseph F.; Bell, John B. et al.
Object Type: Article
System: The UNT Digital Library
High Frequency Electromagnetic Impedance Imaging for Vadose Zone and Groundwater Characterization (open access)

High Frequency Electromagnetic Impedance Imaging for Vadose Zone and Groundwater Characterization

Accurate description of transport pathways on the gross scale, the location of contamination, and characterization of heterogeneity within the vadose zone, are now realized as vital for proper treatment, confinement and stabilization of subsurface contamination at Department of Energy (DOE) waste sites. Electromagnetic (EM) methods are ideal for these tasks since they are directly sensitive to the amount of fluid present in porous media, as well as fluid composition. At many DOE sites it is necessary to employ lower frequency (<1 MHz) or diffusive electromagnetic fields because of the inability of ground penetrating radar (GPR) to penetrate to sufficient depths. The high frequency impedance method, which operated in the diffusive frequency range (10 Hz to 1 MHz), as well as the low end of the spectrum employed by GPR (1MHz-10 MHz), is an ideal technique to delineate and map the aforementioned targets. The method has clearly shown the potential to provide needed information on variations in subsurface saturation due to local storage tanks and perched water zones, as well as mapping geological structures related to the subsurface hydrological properties and heterogeneity within the vadose zone. Although it exhibits certain advantages over other EM methods, the impedance method comes with a …
Date: June 7, 2002
Creator: Newman, Gregory A.; Nichols, Edward; Alumbaugh, David L. & Hoversten, G. Michael
Object Type: Report
System: The UNT Digital Library
Mechanics of Bubbles in Sludges and Slurries Modeling Studies of Particulate Materials (open access)

Mechanics of Bubbles in Sludges and Slurries Modeling Studies of Particulate Materials

The Hanford Site has 177 underground waste storage tanks that are known to retain and release bubbles composed of flammable gases. Characterizing and understanding the behavior of these bubbles is important for the safety issues associated with the flammable gases for both ongoing waste storage and future waste-retrieval operations. The retained bubbles are known to respond to small barometric pressure changes, though in a complex manner with unusual hysteresis occurring in some tanks in the relationship between bubble volume and pressure, or V-P hysteresis. With careful analysis, information on the volume of retained gas and the interactions of the waste and the bubbles can be determined.
Date: January 7, 2002
Creator: Gauglitz, Phillip A.; Terrones, Guillermo; Muller, Susan J.; Denn, Morton M. & Rossen, William R.
Object Type: Report
System: The UNT Digital Library
Final report (open access)

Final report

This grant was a continuation of research conducted at the University of Florida under Grant No. DE-FG05-91ER45462 in which we investigated the energy bandgap shifts produced in semiconductor quantum dots of sizes between 1.5 and 40 nm. The investigated semiconductors consisted of a series of Column 2-6 compounds (CdS, CdSe, CdTe) and pure Column IV elements (Si and Ge). It is well-known of course that the 2-6 semiconductors possess a direct-gap electronic structure, while the Column IV elements possess an indirect-gap structure. The investigation showed a major difference in quantum confinement behavior between the two sets of semiconductors. This difference is essentially associated with the change in bandgap energy resulting from size confinement. In the direct-gap semiconductors, the change in energy (blue shift) saturates when the crystals approach 2-3 nm in diameter. This limits the observed shift in energy to less than 1 eV above the bulk value. In the indirect-gap semiconductors, the energy shift does not show any sign of saturation and in fact, we produced Si and Ge nanocrystals with absorption edges in the UV. The reason for this difference has not been determined and will require additional experimental and theoretical studies. In our work, we suggest, but …
Date: August 7, 2002
Creator: Simmons, Joseph H. & Bukowski, Tracie J.
Object Type: Report
System: The UNT Digital Library
Determining size-specific emission factors for environmental tobacco smoke particles (open access)

Determining size-specific emission factors for environmental tobacco smoke particles

Because size is a major controlling factor for indoor airborne particle behavior, human particle exposure assessments will benefit from improved knowledge of size-specific particle emissions. We report a method of inferring size-specific mass emission factors for indoor sources that makes use of an indoor aerosol dynamics model, measured particle concentration time series data, and an optimization routine. This approach provides--in addition to estimates of the emissions size distribution and integrated emission factors--estimates of deposition rate, an enhanced understanding of particle dynamics, and information about model performance. We applied the method to size-specific environmental tobacco smoke (ETS) particle concentrations measured every minute with an 8-channel optical particle counter (PMS-LASAIR; 0.1-2+ micrometer diameters) and every 10 or 30 min with a 34-channel differential mobility particle sizer (TSI-DMPS; 0.01-1+ micrometer diameters) after a single cigarette or cigar was machine-smoked inside a low air-exchange-rate 20 m{sup 3} chamber. The aerosol dynamics model provided good fits to observed concentrations when using optimized values of mass emission rate and deposition rate for each particle size range as input. Small discrepancies observed in the first 1-2 hours after smoking are likely due to the effect of particle evaporation, a process neglected by the model. Size-specific ETS particle …
Date: July 7, 2002
Creator: Klepeis, Neil E.; Apte, Michael G.; Gundel, Lara A.; Sextro, Richard G. & Nazaroff, William W.
Object Type: Article
System: The UNT Digital Library
KTeV results: Re(e'/e) and rare decay results (open access)

KTeV results: Re(e'/e) and rare decay results

The KTeV physics program encompasses many goals including a precision measurement of the direct CP violation parameter Re({epsilon}{prime}/{epsilon}) in K{sub S,L} {yields} {pi}{pi} decays, and studies of rare neutral kaon decays. The KTeV detector collected data during the Fermilab fixed-target runs of 1996-97 and 1999. This article focuses on the precision measurement of the direct CP violation parameter Re({epsilon}{prime}/{epsilon}) using the 1996-97 data set. In addition, measurements of the neutral kaon parameters {tau}{sub s}, {Delta}m, {phi}{sub {+-}}, {Delta}{phi} from that data set and a new measurement of the branching fraction of K{sub L} {yields} e{sup +}e{sup -} {mu}{sup +}{mu}{sup -} from the 1997 and 1999 data also are presented.
Date: October 7, 2002
Creator: Whitmore, Juliana
Object Type: Article
System: The UNT Digital Library
Busted Butte Phase 2: Introduction and Analytical Modeling of Nonreactive Tracer and Lithium Breakthrough (open access)

Busted Butte Phase 2: Introduction and Analytical Modeling of Nonreactive Tracer and Lithium Breakthrough

The Busted Butte Unsaturated-Zone Transport Test Facility is located approximately 8 km southeast of Yucca Mountain, and was designed to address uncertainties associated with flow and transport in the UZ site-process models for Yucca Mountain. Busted Butte Phase 2 consisted of a 10m x 10m x 7m test block. From July 1988 through October 2000, complex tracer mixtures were injected continuously at 77 discrete points located along eight parallel 10-m boreholes arranged in two horizontal planes. In August 1999, iodide was added to the tracer mixture to explore the effects of initial hydraulic transients. During the course of the experiment, porewater samples were collected at regular intervals using sorbing-paper collection pads, emplaced into fifteen horizontal and inclined 10-m collection boreholes, oriented perpendicular to the injection boreholes. Potential travel distances ranged from 20 cm to over 500 cm. Nonreactive tracer and weakly sorbing lithium breakthrough was observed at most of the collection points during the injection period. Following termination of injection, approximately 800 rock samples were collected using overcore and mineback techniques, and analyzed for tracer concentration. Rock analyses are discussed in a subsequent paper. To complement complex 3-dimensional finite-element modeling of the entire block, bromide, iodide, and lithium breakthrough onto …
Date: October 7, 2002
Creator: Turin, H. J. & Soll, W. E.
Object Type: Report
System: The UNT Digital Library
Computer-aided analysis of eddy current rotating probe data. (open access)

Computer-aided analysis of eddy current rotating probe data.

Eddy current (EC) estimate of flaw size obtained from inservice inspection is often the primary means of assessing the structural integrity of steam generator tubes. Reliable prediction of failure pressure and leak rate in tubes with complex cracking requires more detailed information about the geometry and extent of degradation than is generally available from conventional bobbin coil examinations. High-resolution inspections with EC rotating probes are thus carried out on selected regions of tubing to provide the more extensive nondestructive evaluation (NDE) information that is needed to better assess flaw size and distribution. Interpretation of signals from complex cracking that are often distorted by coherent and incoherent noise can be a challenging NDE task. Studies at Argonne National Laboratory have demonstrated that computer-aided data analysis can be used for more accurate and efficient processing of the large amounts of data collected by such probes. The basic structure of a rule-based multiparameter data analysis algorithm is described in this paper. Multiple-frequency inspection data from a standard rotating pancake coil were used for the analyses. The codes were implemented as MATLAB scripts and provide, as the final outcome, profiles of flaw depth in a section of tube. Graphical user interface tools were devised …
Date: March 7, 2002
Creator: Bakhtiari, S.; Park, J. Y.; Kupperman, D. S. & Shack, W. J.
Object Type: Article
System: The UNT Digital Library
Review of North American Neutrino Factory R and D (open access)

Review of North American Neutrino Factory R and D

We report here on the R and D program of the U.S. Neutrino Factory and Muon Collider Collaboration. Our effort includes work on targetry, muon ionization cooling, simulation work, and development of superconducting RF cavities. In addition, we are involved in the international effort toward a Muon Ionization Cooling Experiment (MICE). Recent activities in all these areas will be described.
Date: October 7, 2002
Creator: Zisman, Michael S. & Collaboration, Neutrino Factory and Muon Collider
Object Type: Article
System: The UNT Digital Library
Effect of Temperature and Electrolyte Composition on the Susceptibility of Alloy 22 to Localized Corrosion (open access)

Effect of Temperature and Electrolyte Composition on the Susceptibility of Alloy 22 to Localized Corrosion

The study of the electrochemical behavior of Alloy 22 has been carried out in various concentrated environments using different sample configurations. Comparisons were made between the electrochemical behaviors of Alloy 22 in concentrated chloride solutions, and in concentrated chloride solutions with nitrate ions (NO{sub 3}{sup -}). In other experiments, the effect of fluoride ions (F{sup -}) was investigated. These comparative studies were performed at various temperatures. The rate of corrosion was found to increase with increase in temperature. The presence of nitrate ions reduced corrosion attack on Alloy 22. F{sup -} was found to be more benign to Alloy 22 compared with chloride ions (Cl{sup -}). However a combination of F{sup -} and Cl{sup -} was found to initiate deeper crevices compared with the only Cl{sup -} in the electrolyte.
Date: October 7, 2002
Creator: Day, S.D.; Evans, K.J. & Ilevbare, G.O.
Object Type: Report
System: The UNT Digital Library
Generating Composite Overlapping Grids on CAD Geometries (open access)

Generating Composite Overlapping Grids on CAD Geometries

We describe some algorithms and tools that have been developed to generate composite overlapping grids on geometries that have been defined with computer aided design (CAD) programs. This process consists of five main steps. Starting from a description of the surfaces defining the computational domain we (1) correct errors in the CAD representation, (2) determine topology of the patched-surface, (3) build a global triangulation of the surface, (4) construct structured surface and volume grids using hyperbolic grid generation, and (5) generate the overlapping grid by determining the holes and the interpolation points. The overlapping grid generator which is used for the final step also supports the rapid generation of grids for block-structured adaptive mesh refinement and for moving grids. These algorithms have been implemented as part of the Overture object-oriented framework.
Date: February 7, 2002
Creator: Henshaw, W.D.
Object Type: Article
System: The UNT Digital Library
Low cost, compact, and high efficiency traction motor for electric and hybrid electric vehicles (open access)

Low cost, compact, and high efficiency traction motor for electric and hybrid electric vehicles

A new motor drive, the switched reluctance motor drive, has been developed for hybrid-electric vehicles. The motor drive has been designed, built and tested in the test bed at a near vehicle scale. It has been shown that the switched reluctance motor drive is more suitable for traction application than any other motor drive.
Date: October 7, 2002
Creator: Ehsani, Mark
Object Type: Report
System: The UNT Digital Library
Tank Waste Transport Stability: Summary of Slurry and Salt-Solution Studies for FY 2001 (open access)

Tank Waste Transport Stability: Summary of Slurry and Salt-Solution Studies for FY 2001

Despite over 50 years of experience in transporting radioactive tank wastes to and from equipment and tanks at the Department of Energy's Hanford, Savannah River, and Oak Ridge sites, waste slurry transfer pipelines and process piping become plugged on occasion. At Hanford, several tank farm pipelines are no longer in service because of plugs. At Savannah River, solid deposits in the outlet line of the 2H evaporator have resulted in an unplanned extended downtime. Although waste transfer criteria and guidelines intended to prevent pipeline plugging are in place, they are not always adequate. To avoid pipeline plugging in the future, other factors that are not currently embodied in the transfer criteria may need to be considered. The work summarized here is being conducted to develop a better understanding of the chemical and waste flow dynamics during waste transfer. The goal is to eliminate pipeline plugs by improving analysis and engineering tools in the field that incorporate this understanding.
Date: June 7, 2002
Creator: Welch, T. D.
Object Type: Report
System: The UNT Digital Library