INVESTIGATION OF THE PRESENCE OF DRUGSTORE BEETLES WITHIN CELOTEX ASSEMBLIES IN RADIOACTIVE MATERIAL PACKAGINGS (open access)

INVESTIGATION OF THE PRESENCE OF DRUGSTORE BEETLES WITHIN CELOTEX ASSEMBLIES IN RADIOACTIVE MATERIAL PACKAGINGS

During normal operations at the Department of Energy's Hanford Site in Hanford, WA, drugstore beetles, (Stegobium paniceum (L.) Coleoptera: Anobiidae), were found within the fiberboard subassemblies of two 9975 Shipping Packages. Initial indications were that the beetles were feeding on the Celotex{trademark} assemblies within the package. Celotex{trademark} fiberboard is used in numerous radioactive material packages serving as both a thermal insulator and an impact absorber for both normal conditions of transport and hypothetical accident conditions. The Department of Energy's Packaging Certification Program (EM-63) directed a thorough investigation to determine if the drugstore beetles were causing damage that would be detrimental to the safety performance of the Celotex{trademark}. The Savannah River National Laboratory is conducting the investigation with entomological expertise provided by Clemson University. The two empty 9975 shipping packages were transferred to the Savannah River National Laboratory in the fall of 2007. This paper will provide details and results of the ongoing investigation.
Date: June 4, 2008
Creator: Loftin, B & Glenn Abramczyk, G
System: The UNT Digital Library
Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport (open access)

Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport

The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoretical beam current transport limits are reliable, in the absence of electrons. At the other extreme, reversing electrode biases with the solenoid transport effectively traps electrons; or, in quadrupole magnets, grounding the suppressor electrode allows electron emission from the end wall to flood the beam, in both cases producing significant degradation in the beam.
Date: June 4, 2007
Creator: Molvik, A. W.; Kireeff Covo, M.; Cohen, R.; Coleman, J.; Sharp, W.; Bieniosek, F. et al.
System: The UNT Digital Library
Electron-Cloud Build-up in the FNAL Main Injector (open access)

Electron-Cloud Build-up in the FNAL Main Injector

We present a summary on ongoing simulation results for the electron-cloud buildup in the context of the proposed FNAL Main Injector (MI) intensity upgrade [1] in a fieldfree region at the location of the RFA electron detector [2]. By combining our simulated results for the electron flux at the vacuum chamber wall with the corresponding measurements obtained with the RFA we infer that the peak secondary electron yield (SEY) {delta}{sub max} is {approx}> 1.4, and the average electron density is n{sub e} {approx}> 10{sup 10} m{sup -3} at transition energy for the specific fill pattern and beam intensities defined below. The sensitivity of our results to several variables remains to be explored in order to reach more definitive results. Effects from the electron cloud on the beam are being investigated separately [3].
Date: June 4, 2007
Creator: Furman, M. A.
System: The UNT Digital Library
Direct Observation of the Kinetically Relevant Site of CO Hydrogenation on Supported Ru Catalyst at 700 K by Time-Resolved FT-IR Spectroscopy (open access)

Direct Observation of the Kinetically Relevant Site of CO Hydrogenation on Supported Ru Catalyst at 700 K by Time-Resolved FT-IR Spectroscopy

Time-resolved FT-IR spectra of carbon monoxide hydrogenation over alumina-supported ruthenium particles were recorded on themillisecond time scale at 700 K using pulsed release of CO and a continuous flow of H2/N2 (ratio 0.067 or 0.15, 1 atm total pressure). Adsorbed carbon monoxide was detected along with gas phase products methane (3016 and 1306 cm-1), water (1900 +- 1300 cm-1), and carbon dioxide (2348 cm-1). Aside from adsorbed CO, no other surface species were observed. The rate of formation of methane is 2.5 +- 0.4 s-1 and coincides with the rate of carbon dioxide growth (3.4 +- 0.6 s-1), thus indicating that CH4 and CO2 originate from a common intermediate. The broad band of adsorbed carbon monoxide has a maximum at 2010 cm-1 at early times (36 ms) that shifts gradually to 1960 cm-1 over a period of 3 s as a result of the decreasing surface concentration of CO. Kinetic analysis of the adsorbed carbon monoxide reveals that surface sites absorbing at the high frequency end of the infrared band are temporally linked to gas phase product growth. Specifically, a (linear) CO site at 2026 cm-1 decays with a rate constant of 2.9 +- 0.1 s-1, which coincides with the …
Date: June 4, 2008
Creator: Frei, Heinz; Wasylenko, Walter & Frei, Heinz
System: The UNT Digital Library
TWO-PHASE FLOW STUDIES IN NUCLEAR POWER PLANT PRIMARY CIRCUITS USING THE THREE-DIMENSIONAL THERMAL-HYDRAULIC CODE BAGIRA. (open access)

TWO-PHASE FLOW STUDIES IN NUCLEAR POWER PLANT PRIMARY CIRCUITS USING THE THREE-DIMENSIONAL THERMAL-HYDRAULIC CODE BAGIRA.

In this paper we present recent results of the application of the thermal-hydraulic code BAGIRA to the analysis of complex two-phase flows in nuclear power plants primary loops. In particular, we performed benchmark numerical simulation of an integral LOCA experiment performed on a test facility modeling the primary circuit of VVER-1000. In addition, we have also analyzed the flow patterns in the VVER-1000 steam generator vessel for stationary and transient operation regimes. For both of these experiments we have compared the numerical results with measured data. Finally, we demonstrate the capabilities of BAGIRA by modeling a hypothetical severe accident for a VVER-1000 type nuclear reactor. The numerical analysis, which modeled all stages of the hypothetical severe accident up to the complete ablation of the reactor cavity bottom, shows the importance of multi-dimensional flow effects.
Date: June 4, 2006
Creator: KOHURT, P. (BNL), KALINICHENKO, S.D.; KROSHILIN, A.E.; KROSHILIN, V.E. & SMIRNOV, A.V.
System: The UNT Digital Library
PERFORMANCE OF THE SAVANNAH RIVER SITE COULOMETER FOR NEPTUNIUM PROCESSACCOUNTABILITY AND NEPTUNIUM OXIDE PRODUCT CHARACTERIZATION (open access)

PERFORMANCE OF THE SAVANNAH RIVER SITE COULOMETER FOR NEPTUNIUM PROCESSACCOUNTABILITY AND NEPTUNIUM OXIDE PRODUCT CHARACTERIZATION

The Savannah River Site's (SRS) H-Area B-Line (HB-Line) nuclear facility is processing neptunium solutions for stabilization as an oxide. The oxide will eventually be reprocessed and fabricated into target material and the 237Np irradiated to produce {sup 238}Pu in support of National Aeronautics and Space Administration space program missions. As part of nuclear materials accountability, solution concentrations were measured using a high-precision controlled-potential coulometer developed and manufactured at the SRS for plutonium accountability measurements. The Savannah River Site Coulometer system and measurement methodology for plutonium meets performance standards in ISO 12183-2005, 'Controlled-Potential Coulometric Assay of Plutonium'. The Department of Energy (DOE) does not produce or supply a neptunium metal certified reference material, which makes qualifying a measurement method and determining accuracy and precision difficult. Testing and performance of the Savannah River Site Coulometer indicates that it can be used to measure neptunium process solutions and dissolved neptunium oxide without purification for material control and accountability purposes. Savannah River Site's Material Control and Accountability organization has accepted the method uncertainty for accountability and product characterization measurements.
Date: June 4, 2008
Creator: Holland, M; Patterson Nuessle, P; Sheldon Nichols, S; Joe Cordaro, J & George Reeves, G
System: The UNT Digital Library
Cyclohexene Photo-oxidation over Vanadia Catalyst Analyzed by Time Resolved ATR-FT-IR Spectroscopy (open access)

Cyclohexene Photo-oxidation over Vanadia Catalyst Analyzed by Time Resolved ATR-FT-IR Spectroscopy

Vanadia was incorporated in the 3-dimensional mesoporous material TUD-1 with a loading of 2percent w/w vanadia. The performance in the selective photo-oxidation of liquid cyclohexene was investigated using ATR-FT-IR spectroscopy. Under continuous illumination at 458 nm a significant amount of product, i.e. cyclohexenone, was identified. This demonstrates for the first time that hydroxylated vanadia centers in mesoporous materials can be activated by visible light to induce oxidation reactions. Using the rapid scan method, a strong perturbation of the vanadyl environment could be observed in the selective oxidation process induced by a 458 nm laser pulse of 480 ms duration. This is proposed to be caused by interaction of the catalytic centre with a cyclohexenyl hydroperoxide intermediate. The restoration of the vanadyl environment could be kinetically correlated to the rate of formation of cyclohexenone, and is explained by molecular rearrangement and dissociation of the peroxide to ketone and water. The ketone diffuses away from the active center and ATR infrared probing zone, resulting in a decreasing ketone signal on the tens of seconds time scale after initiation of the photoreaction. This study demonstrates the high potential of time resolved ATR FT-IR spectroscopy for mechanistic studies of liquid phase reactions by monitoring …
Date: June 4, 2008
Creator: Frei, Heinz; Mul, Guido; Wasylenko, Walter; Hamdy, M. Sameh & Frei, Heinz
System: The UNT Digital Library
Controlled Assembly of Heterobinuclear Sites on Mesoporous Silica: Visible Light Charge-Transfer Units with Selectable Redox Properties (open access)

Controlled Assembly of Heterobinuclear Sites on Mesoporous Silica: Visible Light Charge-Transfer Units with Selectable Redox Properties

Mild synthetic methods are demonstrated for the selective assembly of oxo-bridged heterobinuclear units of the type TiOCrIII, TiOCoII, and TiOCeIII on mesoporous silica support MCM-41. One method takes advantage of the higher acidity and, hence, higher reactivity of titanol compared to silanol OH groups towards CeIII or CoII precursor. The procedure avoids the customary use of strong base. The controlled assembly of the TiOCr system exploits the selective redox reactivity of one metal towards another (TiIII precursor reacting with anchored CrVI centers). The observed selectivity for linking a metal precursor to an already anchored partner versus formation of isolated centers ranges from a factor of six (TiOCe) to complete (TiOCr, TiOCo). Evidence for oxo bridges and determination of the coordination environment of each metal centers is based on K-edge EXAFS (TiOCr), L-edge absorption spectroscopy (Ce), and XANES measurements (Co, Cr). EPR, optical, FT-Raman and FT-IR spectroscopy furnish additional details on oxidation state and coordination environment of donor and acceptor metal centers. In the case of TiOCr, the integrity of the anchored group upon calcination (350 oC) and cycling of the Cr oxidation state is demonstrated. The binuclear units possess metal-to-metal charge-transfer transitions that absorb deep in the visible region. The …
Date: June 4, 2008
Creator: Frei, Heinz; Han, Hongxian & Frei, Heinz
System: The UNT Digital Library
Emission assessment from full-scale co-combustion tests of binder- enhanced dRDF pellets and high sulfur coal at Argonne National Laboratory (open access)

Emission assessment from full-scale co-combustion tests of binder- enhanced dRDF pellets and high sulfur coal at Argonne National Laboratory

Argonne National Laboratory (ANL) and University of North Texas (UNT) research teams collected over 800 emissions and ash samples during the combustion of over 650 tons of binder enhanced densified refuse-drived fuel (b-dRDF) pellets with high sulfur coal in a spreader-stoker boiler at ANL. This full-scale test burn was conducted to validate predictions from laboratory and pilot scale test results that indicated substantial reductions of SO{sub 2}, NO{sub x} and CO{sub 2} in the flue gas, and the reduction of heavy metals and organics in the ash residue, when combusting the b-dRDF pellets with coal. Effects of varying fuel composition on performance of the boiler's spray-dryer/fabric filter emissions control system was also evaluated. This paper describes the b-dRDF pellet/coal cofiring tests, the emission and ash samples that were taken, the analyses that were conducted on these samples, and the final test results. 5 refs., 1 fig., 1 tab.
Date: June 4, 1990
Creator: Ohlsson, O. O.; Livengood, C. D. (Argonne National Lab., IL (USA)) & Daugherty, K. E. (University of North Texas, Denton, TX (USA))
System: The UNT Digital Library
Laser driven instabilities in inertial confinement fusion (open access)

Laser driven instabilities in inertial confinement fusion

Parametric instabilities excited by an intense electromagnetic wave in a plasma is a fundamental topic relevant to many applications. These applications include laser fusion, heating of magnetically-confined plasmas, ionospheric modification, and even particle acceleration for high energy physics. In laser fusion, these instabilities have proven to play an essential role in the choice of laser wavelength. Characterization and control of the instabilities is an ongoing priority in laser plasma experiments. Recent progress and some important trends will be discussed. 8 figs.
Date: June 4, 1990
Creator: Kruer, W.L.
System: The UNT Digital Library
Novel plasma-based frequency upshift methods for short pulse lasers (open access)

Novel plasma-based frequency upshift methods for short pulse lasers

We discuss various novel methods of frequency upshifting short ({le} 1 picosecond) pulses of laser light. All of these methods make use of either the sudden creation of a plasma or relativistic plasma waves. The first method discussed is known as photon acceleration. This method makes use of the fact that a laser pulse moving in a plasma can be thought of as a packet of photons, each possessing an effective mass of m{sub {gamma}} = {h bar}{omega}{sub pe}/c{sup 2} and moving with the group velocity of the laser pulse. These photons experience a force acting on them when in the presence of a gradient in the plasma density. By using a relativistic plasma wave (i.e., a moving density gradient) traveling with the photons, the energy of the photons (thus the frequency) can be continuously increased. We then discuss the sudden creation of a plasma in a region where there exists an electromagnetic wave. This results in a frequency shift of the wave. A similar method is the creation of an ionization front moving near the speed of light, whereby the interaction of this plasma front with an EM wave also results in a frequency upshift of the original wave. …
Date: June 4, 1990
Creator: Wilks, S.C. (Lawrence Livermore National Lab., CA (USA)); Dawson, J.M. & Mori, W.B. (California Univ., Los Angeles, CA (USA). Dept. of Physics)
System: The UNT Digital Library
The urban perspectives of acid rain. Workshop summary (open access)

The urban perspectives of acid rain. Workshop summary

This report documents discussions held during a workshop an Urban Perspective of Acid Rain. The workshop was sponsored by the Office of the Director, National Acid Precipitation Assessment Program (NAPAP). NAPAP anticipates giving increased emphasis to the benefits in urban areas of emissions reductions. The goal of this informal, exploratory workshop was to serve as a first step towards identifying pollutant monitoring, and research and assessment needs to help answer, from an urban perspective, the two key questions posed to NAPAP by Congress: (1) what are the costs, benefits, and effectiveness of the acid rain control program, and (2) what reductions in deposition, rates are needed in order to prevent adverse effects? The workshop addressed research activities needed to respond to these questions. The discussions focused. sequentially, on data needs, data and model availability, and data and modeling gaps. The discussions concentrated on four areas of effects: human health, materials, urban forests, and visibility.
Date: June 4, 1993
Creator: Tonn, B. E.
System: The UNT Digital Library
HEGRS: Mechanical design of a high-energy, gamma-ray spectrometer (open access)

HEGRS: Mechanical design of a high-energy, gamma-ray spectrometer

A large, 3200-kg (7000-lb) gamma-ray spectrometer was designed to move in a 1500 arc with an arc accuracy of 0.50, and to move radially over a distance of 650 mm (25 in.). The entire structure is aluminum rather than steel because of the high neutron background. The two-layer support accommodates rapid, accurate positioning of the spectrometer in both the rotational and radial directions within 0.1 mm (0.004 in.). All movements and positioning are computer-controlled. The centerline deviation over the entire surface is 0.25 mm (0.0100 in.). The bottom layer, called the table, permits arc motion. The table is a baseplate consisting of two 3.6-m {times} 1.2-m (12-ft {times} 4-ft) cast-aluminum jig plates. The top layer, called the sled, is an aluminum plate 2.12-m {times} 1.22-m (83.38-in. {times} 48-in.) wide, which provides for radial motion. Due to the large mass of the spectrometer and the accurate positioning required, air pads are used to facilitate movement. Hydraulic brakes are applied when the detector is in its rest position to comply with the seismic requirements of the installation.
Date: June 4, 1993
Creator: Pedersen, K. B.
System: The UNT Digital Library
Simulating Electron Cloud Effects in Heavy-Ion Beams (open access)

Simulating Electron Cloud Effects in Heavy-Ion Beams

None
Date: June 4, 2004
Creator: Cohen, R; Friedman, A; Lund, S; Molvik, A; Azevedo, T; Vay, J et al.
System: The UNT Digital Library
Generation of Electric and Magnetic Fields During Detonation of High Explosive Charges in Boreholes (open access)

Generation of Electric and Magnetic Fields During Detonation of High Explosive Charges in Boreholes

We present experimental results of a study of electromagnetic field generation during underground detonation of high explosive charges in holes bored in sandy loam and granite. Test conditions and physico-mechanical properties of the soil exert significant influence on the parameters of electromagnetic signals generated by underground TNT charges with masses of 2 - 200 kg. The electric and magnetic field experimental data are satisfactorily described by an electric dipole model with the source embedded in a layered media.
Date: June 4, 2004
Creator: Soloviev, S. & Sweeney, J.
System: The UNT Digital Library
Development of an "Isotopic" Pulser (open access)

Development of an "Isotopic" Pulser

We have developed a pulser that is able to generate a simulated signal from a high-purity germanium (HPGe) detector for various plutonium isotopes. In this paper we describe the development of an ''isotopics'' pulser for the simulation of signals that are produced by an HPGe detector. The present pulser generates the waveforms that are produced by an HPGe detector both before and after the preamplifier. These signals have been input into a normal MCA and the result closely simulates a genuine pulse-height distribution.
Date: June 4, 2002
Creator: Luke, S. J.; Schmid, G.; Beckedahl, D.; Pohl, B. & White, G.
System: The UNT Digital Library
Spatially Continuous Mixed P2-P1 Solutions for Planar Geometry (open access)

Spatially Continuous Mixed P2-P1 Solutions for Planar Geometry

Even-order Legendre polynomial (P{sub N}) expansion approximations of the neutron transport equation have historically seen only limited practical application. Research in the last decade has resolved one of the historical theoretical objections to the use of even-order PN approximations in planar geometry, namely the ambiguity in the prescription of boundary conditions as a result of an odd number of unknowns. This research also demonstrated the P{sub 2} approximation to be more accurate than the P{sub 1} approximation in planar geometry away from boundary layers and material interfaces. Neither the P{sub 1} nor the P{sub 2} approximation is convincingly more accurate near material interfaces. This progress motivated the reexamination of the multidimensional simplified P{sub 2} (SP{sub 2}) approximation, the development of P{sub 2} approximations for planar geometry stochastic transport problems, and the examination of the P{sub 2} and SP{sub 2} approximations as a synthetic acceleration technique for the discrete ordinates equations. The major remaining objection to even-order PN approximations is that the scalar flux distributions obtained using these approximations can exhibit large spatial discontinuities at material interfaces and source discontinuities. In contrast, the odd-order PN approximations typically utilized give spatially continuous scalar flux distributions at these locations. In this paper, we …
Date: June 4, 2004
Creator: Brantley, P S
System: The UNT Digital Library
Structure and Composition of Cu Doped CdSe Nanocrystals Using Soft X-ray Absorption Spectroscopy (open access)

Structure and Composition of Cu Doped CdSe Nanocrystals Using Soft X-ray Absorption Spectroscopy

The local structure and composition of Cu ions dispersed in CdSe nanocrystals is examined using soft x-ray absorption near edge spectroscopy (XANES). Using Cu L-edge XANES and X-ray photoelectron measurements (XPS), we find that the Cu ions exist in the Cu(I) oxidation state. We also find that the observed Cu L-edge XANES signal is directly proportional to the molar percent of Cu present in our final material. Se L-edge XANES indicates changes in the Se density of states with Cu doping, due to a chemical bonding effect, and supports a statistical doping mechanism. Photoluminescence (PL) measurements indicate the Cu ions may act as deep electron traps. We show that XANES, XPS, and PL are a powerful combination of methods to study the electronic and chemical structure of dopants in nanostructured materials.
Date: June 4, 2004
Creator: Meulenberg, R W; van Buuren, T; Hanif, K M; Willey, T M; Strouse, G F & Terminello, L J
System: The UNT Digital Library
ELMs and the H-Mode Pedestal in NSTX (open access)

ELMs and the H-Mode Pedestal in NSTX

We report on the behavior of ELMs in NBI-heated H-mode plasmas in NSTX. It is observed that the size of Type I ELMs, characterized by the change in plasma energy, decreases with increasing density, as observed at conventional aspect ratio. It is also observed that the Type I ELM size decreases as the plasma equilibrium is shifted from a symmetric double-null toward a lower single-null configuration. Type III ELMs have also been observed in NSTX, as well as a high-performance regime with small ELMs which we designate Type V. These Type V ELMs are consistent with high bootstrap current operation and density approaching Greenwald scaling. The Type V ELMs are characterized by an intermittent n=1 MHD mode rotating counter to the plasma current. Without active pumping, the density rises continuously through the Type V phase. However, efficient in-vessel pumping should allow density control, based on particle containment time estimates.
Date: June 4, 2004
Creator: Maingi, R.; Sabbagh, S.; Bush, C.; Fredrickson, E.; Menard, J.; Stutman, D. et al.
System: The UNT Digital Library
Laser Performance Operations Model (LPOM) (open access)

Laser Performance Operations Model (LPOM)

The Laser Performance Operations Model (LPOM) has been developed to provide real time predictive capabilities for the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. LPOM uses diagnostic feedback from previous NIF shots to maintain accurate energetics models for each of the 192 NIF beamlines (utilizing one CPU per laser beamline). This model is used to determine the system setpoints (initial power, waveplate attenuations, laser diagnostic settings) required for all requested NIF shots. In addition, LPOM employs optical damage models to minimize the probability that a proposed shot may damage the system. LPOM provides post-shot diagnostic reporting to support the NIF community. LPOM was deployed prior to the first main laser shots in NIF, and has since been used to set up every shot in NIF's first quad (four beamlines). Real-time adjustments of the codes energetics parameters allows the LPOM to predict total energies within 5%, and provide energy balance within the four beamlines to within 2% for shots varying from 0.5 to 26 kJ (1.053 {micro}m) per beamline. The LPOM has been a crucial tool in the commissioning of the first quad of NIF.
Date: June 4, 2004
Creator: Shaw, M; Williams, W; House, R & Haynam, C
System: The UNT Digital Library
Recent Bottomonium Results from BaBar (open access)

Recent Bottomonium Results from BaBar

Preliminary results from spectroscopic bottomonium studies of the {Upsilon}(2S) and {Upsilon} (3S) datasets collected by BABAR are presented.
Date: June 4, 2012
Creator: Fulsom, B.G.
System: The UNT Digital Library
New Results in Radiative Electroweak Penguin Decays at BaBar (open access)

New Results in Radiative Electroweak Penguin Decays at BaBar

None
Date: June 4, 2013
Creator: Flood, Kevin & /Caltech
System: The UNT Digital Library
Aerial Measuring System (AMS) Baseline Surveys for Emergency Planning (open access)

Aerial Measuring System (AMS) Baseline Surveys for Emergency Planning

Originally established in the 1960s to support the Nuclear Test Program, the AMS mission is to provide a rapid and comprehensive worldwide aerial measurement, analysis, and interpretation capability in response to a nuclear/radiological emergency. AMS provides a responsive team of individuals whose processes allow for a mission to be conducted and completed with results available within hours. This presentation slide-show reviews some of the history of the AMS, summarizes present capabilities and methods, and addresses the value of the surveys.
Date: June 4, 2012
Creator: Lyons, C
System: The UNT Digital Library
A Mixing Model for the Richtmyer-Meshkov Instability (open access)

A Mixing Model for the Richtmyer-Meshkov Instability

None
Date: June 4, 2012
Creator: Cook, A W; Weber, C; Cabot, W H & Bonazza, R
System: The UNT Digital Library