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Modeling Offgas Systems for the Hanford Waste Treatment Plant (open access)

Modeling Offgas Systems for the Hanford Waste Treatment Plant

To augment steady-state design calculations, dynamic models of three offgas systems that will be used in the Waste Treatment Plant now under construction at the Hanford Site were developed using Aspen Custom Modeler{trademark}. The offgas systems modeled were those for the High Level Waste (HLW) melters, Low Activity Waste (LAW) melters and HLW Pulse Jet Ventilation (PJV) system. The models do not include offgas chemistry but only consider the two major species in the offgas stream which are air and water vapor. This is sufficient to perform material and energy balance calculations that accurately show the dynamic behavior of gas pressure, temperature, humidity and flow throughout the systems. The models are structured to perform pressure drop calculations across the various unit operations using a combination of standard engineering calculations and empirical data based correlations for specific pieces of equipment. The models include process controllers, gas ducting, control valves, exhaust fans and the offgas treatment equipment. The models were successfully used to analyze a large number of operating scenarios including both normal and off-normal conditions.
Date: September 2, 2005
Creator: Smith, Frank G., III
System: The UNT Digital Library
Polarization Smoothing on the National Ignition Facility (open access)

Polarization Smoothing on the National Ignition Facility

We have recently implemented polarization smoothing (PS) on one quad of the NIF laser. Specially cut KDP and DKDP crystals at 420 x 420 mm sizes were used to scramble the incident 351 nm laser polarization over the beam aperture. The intensity contrast deduced from the measured focal spot images for one of the NIF beams is in very good agreement with the expected contrast. KDP and DKDP crystals are known to produce considerable amount of transverse stimulated Raman scattering (SRS) when irradiated with large beams at {approx}1-2 GW/cm2. In order to measure the transverse SRS, we attached optical fibers on the side of one of the PS crystals. The KDP PS crystal showed > 1 J/cm2 side scattered SRS at irradiances of 1.2 GW/cm2. The DKDP (70% deuteration level) PS crystal showed significantly less SRS. Detailed analysis of the SRS scattering in the PS crystal is in progress.
Date: September 2, 2005
Creator: Dixit, S N; Munro, D; Murray, J R; Nostrand, M; Wegner, P J; Froula, D et al.
System: The UNT Digital Library
Direct Laser Ablation and Ionization of Solids for Chemical Analysis by Mass Spectrometry (open access)

Direct Laser Ablation and Ionization of Solids for Chemical Analysis by Mass Spectrometry

A laser ablation/ionization mass spectrometer system is described for the direct chemical analysis of solids. An Nd:YAG laser is used for ablation and ionization of the sample in a quadrupole ion trap operated in an ion-storage (IS) mode that is coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). Single pulse experiments have demonstrated simultaneous detection of up to 14 elements present in glasses in the ppm range. However, detection of the components has produced non-stoichiometric results due to difference in ionization potentials and fractionation effects. Time-of-flight secondary ionization mass spectrometry (TOF-SIMS) was used to spatially map elemental species on the surface and provide further evidence of fractionation effects. Resolution (m/Dm) of 1500 and detection limits of approximately 10 pg have been achieved with a single laser pulse. The system configuration and related operating principles for accurately measuring low concentrations of isotopes are described.
Date: September 2, 2005
Creator: Holt, J K; Nelson, E J & Klunder, G L
System: The UNT Digital Library
The Genome Sequence of the Obligately Chemolithoautotrophic, Facultatively Anaerobic Bacterium Thiobacillus Denitrificans (open access)

The Genome Sequence of the Obligately Chemolithoautotrophic, Facultatively Anaerobic Bacterium Thiobacillus Denitrificans

None
Date: September 2, 2005
Creator: Beller, H; Chain, P; Letain, T; Chakicherla, A; Larimer, F; Richardson, P et al.
System: The UNT Digital Library
Identification of isotopically primitive interplanetary dust particles: A NanoSIMS isotopic imaging study (open access)

Identification of isotopically primitive interplanetary dust particles: A NanoSIMS isotopic imaging study

We have carried out a comprehensive survey of the isotopic compositions (H, B, C, N, O, S) of a suite of interplanetary dust particles (IDPs), including both cluster and individual particles. Isotopic imaging with the NanoSIMS shows the presence of numerous discrete hotspots that are strongly enriched in {sup 15}N, including the largest {sup 15}N enrichments ({approx}1300 {per_thousand}) observed in IDPs to date. A number of the IDPs also contain larger regions with more modest enrichments in {sup 15}N, leading to average bulk N isotopic compositions that are {sup 15}N-enriched in these IDPs. Although C isotopic compositions are normal in most of the IDPs, two {sup 15}N-rich N-hotspots have correlated {sup 13}C anomalies. CN{sup -}/C{sup -} ratios suggest that most of the {sup 15}N-rich hotspots are associated with relatively N-poor carbonaceous matter, although specific carriers have not been determined. H isotopic distributions are similar to those of N: D anomalies are present both as distinct very D-rich hotspots and as larger regions with more modest enrichments. Nevertheless, H and N isotopic anomalies are not directly correlated, consistent with results from previous studies. Oxygen isotopic imaging shows the presence of abundant presolar silicate grains in the IDPs. The O isotopic compositions …
Date: September 2, 2005
Creator: Floss, C; Stadermann, F J; Bradley, J P; Dai, Z R; Bajt, S; Graham, G et al.
System: The UNT Digital Library
Advanced Control Technologies and Strategies Linking DemandResponse and Energy Efficiency (open access)

Advanced Control Technologies and Strategies Linking DemandResponse and Energy Efficiency

This paper presents a preliminary framework to describe how advanced controls can support multiple modes of operations including both energy efficiency and demand response (DR). A general description of DR, its benefits, and nationwide status is outlined. The role of energy management and control systems for DR is described. Building systems such as HVAC and lighting that utilize control technologies and strategies for energy efficiency are mapped on to DR and demand shedding strategies are developed. Past research projects are presented to provide a context for the current projects. The economic case for implementing DR from a building owner perspective is also explored.
Date: September 2, 2005
Creator: Kiliccote, Sila & Piette, Mary Ann
System: The UNT Digital Library
Enhanced K(L) ---> Pi0 Nu Anti-Nu From Direct CP Violation in B ---> K Pi With Four Generations (open access)

Enhanced K(L) ---> Pi0 Nu Anti-Nu From Direct CP Violation in B ---> K Pi With Four Generations

Recent CP violation results in B decays suggest that Z penguins may have large weak phase. This can be realized by the four generation (standard) model. Concurrently, B {yields} X{sub s}{ell}{sup +}{ell}{sup -} and B{sub s} mixing allow for sizable V*{sub t's}V{sub t'b} only if it is nearly imaginary. Such large effects in b {leftrightarrow} s transitions would affect s {leftrightarrow} d transitions, as kaon constraints would demand V{sub t'd} {ne} 0. Using {Lambda}(Z {yields} b{bar b}) to bound |V{sub t'b}|, they infer sizable |V{sub t's}| {le} |V{sub t'b}| {le} |V{sub us}|. Imposing {var_epsilon}{sub K}, K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}} and {var_epsilon}'/{var_epsilon} constraints, they find V*{sub t'd} V{sub t's} {approx} few x 10{sup -4} with large phase, enhancing K{sub L} {yields} {pi}{sup 0} {nu}{bar {nu}} to 5 x 10{sup -10} or even higher. Interestingly, {Delta}m{sub B{sub d}} and sin 2{Phi}{sub B{sub d}} are not much affected, as |V*{sub t'd} V{sub t'b} << |V*{sub td} V{sub tb}| {approx} 0.01.
Date: September 2, 2005
Creator: Hou, Wei-Shu; /Taiwan, Natl. Taiwan U. /SLAC; Nagashima, Makiko; /Taiwan, Natl. Taiwan U.; Soddu, Andrea & /Taiwan, Natl. Taiwan U. /Weizmann Inst.
System: The UNT Digital Library
Baryon Number Violation Involving Higher Generations (open access)

Baryon Number Violation Involving Higher Generations

None
Date: September 2, 2005
Creator: Hou, Wei-Shu; /Taiwan, Natl. Taiwan U. /SLAC; Nagashima, Makiko; /Taiwan, Natl. Taiwan U.; Soddu, Andrea & /Taiwan, Natl. Taiwan U. /Weizmann Inst.
System: The UNT Digital Library