3HE RECOVERY FROM A TRITIUM-AGED LANA75 SAMPLE (open access)

3HE RECOVERY FROM A TRITIUM-AGED LANA75 SAMPLE

{sup 3}He recovery is a topic of recent interest. One potential recovery source is from metal hydride materials once used to store tritium, as the decay product, {sup 3}He, is primarily trapped in the metal lattice, usually in bubbles, with such materials. In 2001, a Tritium Exposure Program (TEP) sample known as LANA75-SP1 was retired and the material was removed from the test cell and stored. Subsequently scoping temperature programmed desorption (TPD) experiments were conducted on that material to see what it might take to drive out He and residual H isotopes (the heel). Two experiments consisted of heating the sample in the presence of an excess of tin (the so-called Sn fusion experiment), and one was a simple TPD with no additives. Prior data on the so-called '21-month bed' material in the 1980's had produced {approx}21 cc of gas per gram of a LANA30 material (LaNi4.7Al0.3), with approximately 67% of that being {sup 3}He and the rest being D{sub 2} (Fig.3). However, the material had to be heated in excess of 850 C to obtain that level. Heating to less produced approximately half that amount of gas. The data also showed that {sup 3}He was released at different temperatures …
Date: December 1, 2010
Creator: Shanahan, K.
System: The UNT Digital Library
Accelerator Challenges and Opportunities for Future Neutrino Experiments (open access)

Accelerator Challenges and Opportunities for Future Neutrino Experiments

There are three types of future neutrino facilities currently under study, one based on decays of stored beta-unstable ion beams (?Beta Beams?), one based on decays of stored muon beams (?Neutrino Factory?), and one based on the decays of an intense pion beam (?Superbeam?). In this paper we discuss the challenges each design team must face and the R&D being carried out to turn those challenges into technical opportunities. A new program, the Muon Accelerator Program, has begun in the U.S. to carry out the R&D for muon-based facilities, including both the Neutrino Factory and, as its ultimate goal, a Muon Collider. The goals of this program will be briefly described.
Date: December 24, 2010
Creator: Zisman, Michael S
System: The UNT Digital Library
Adaptation of a cubic smoothing spline algortihm for multi-channel data stitching at the National Ignition Facility (open access)

Adaptation of a cubic smoothing spline algortihm for multi-channel data stitching at the National Ignition Facility

Some diagnostics at the National Ignition Facility (NIF), including the Gamma Reaction History (GRH) diagnostic, require multiple channels of data to achieve the required dynamic range. These channels need to be stitched together into a single time series, and they may have non-uniform and redundant time samples. We chose to apply the popular cubic smoothing spline technique to our stitching problem because we needed a general non-parametric method. We adapted one of the algorithms in the literature, by Hutchinson and deHoog, to our needs. The modified algorithm and the resulting code perform a cubic smoothing spline fit to multiple data channels with redundant time samples and missing data points. The data channels can have different, time-varying, zero-mean white noise characteristics. The method we employ automatically determines an optimal smoothing level by minimizing the Generalized Cross Validation (GCV) score. In order to automatically validate the smoothing level selection, the Weighted Sum-Squared Residual (WSSR) and zero-mean tests are performed on the residuals. Further, confidence intervals, both analytical and Monte Carlo, are also calculated. In this paper, we describe the derivation of our cubic smoothing spline algorithm. We outline the algorithm and test it with simulated and experimental data.
Date: December 28, 2010
Creator: Brown, C; Adcock, A; Azevedo, S; Liebman, J & Bond, E
System: The UNT Digital Library
Adjoint-Based Implicit Uncertainty Analysis for Figures of Merit in a Laser Inertial Fusion Engine (open access)

Adjoint-Based Implicit Uncertainty Analysis for Figures of Merit in a Laser Inertial Fusion Engine

A primary purpose of computational models is to inform design decisions and, in order to make those decisions reliably, the confidence in the results of such models must be estimated. Monte Carlo neutron transport models are common tools for reactor designers. These types of models contain several sources of uncertainty that propagate onto the model predictions. Two uncertainties worthy of note are (1) experimental and evaluation uncertainties of nuclear data that inform all neutron transport models and (2) statistical counting precision, which all results of a Monte Carlo codes contain. Adjoint-based implicit uncertainty analyses allow for the consideration of any number of uncertain input quantities and their effects upon the confidence of figures of merit with only a handful of forward and adjoint transport calculations. When considering a rich set of uncertain inputs, adjoint-based methods remain hundreds of times more computationally efficient than Direct Monte-Carlo methods. The LIFE (Laser Inertial Fusion Energy) engine is a concept being developed at Lawrence Livermore National Laboratory. Various options exist for the LIFE blanket, depending on the mission of the design. The depleted uranium hybrid LIFE blanket design strives to close the fission fuel cycle without enrichment or reprocessing, while simultaneously achieving high discharge …
Date: December 3, 2010
Creator: Seifried, J. E.; Fratoni, M.; Kramer, K. J.; Latkowski, J. F.; Peterson, P. F.; Powers, J. J. et al.
System: The UNT Digital Library
Advantages of a soft protective layer for good signal-to-noise ratio proton radiographs in high debris environments (open access)

Advantages of a soft protective layer for good signal-to-noise ratio proton radiographs in high debris environments

None
Date: December 21, 2010
Creator: Le Galloudec, N. R.; Cobble, J.; Nelson, S. L.; Merwin, A.; Paudel, Y.; Shrestha, I. et al.
System: The UNT Digital Library
THE AFFECTS OF HALIDE MODIFIERS ON THE SORPTION KINETICS OF THE LI-MG-N-H SYSTEM (open access)

THE AFFECTS OF HALIDE MODIFIERS ON THE SORPTION KINETICS OF THE LI-MG-N-H SYSTEM

In this present work, the affects of different transition metal halides (TiCl{sub 3}, VCl{sub 3}, ScCl{sub 3} and NiCl{sub 2}) on the sorption properties of the 1:1 molar ratio of LiNH{sub 2} to MgH{sub 2} are investigated. The modified mixtures were found to contain LiNH{sub 2}, MgH{sub 2} and LiCl. TGA results showed that the hydrogen desorption temperature was reduced with the modifier addition in this order: TiCl{sub 3}>ScCl{sub 3}>VCl{sub 3}>NiCl{sub 2}. Ammonia release was not significantly reduced resulting in a weight loss greater than the theoretical hydrogen storage capacity of the material. The isothermal sorption kinetics of the modified systems showed little improvement after the first dehydrogenation cycle over the unmodified system but showed drastic improvement in rehydrogenation cycles. XRD and Raman spectroscopy identified the cycled material to be composed of LiH, MgH{sub 2}, Mg(NH{sub 2}){sub 2} and Mg{sub 3}N{sub 2}.
Date: December 16, 2010
Creator: Erdy, C.; Gray, J.; Lascola, R. & Anton, D.
System: The UNT Digital Library
AFFECTS OF MECHANICAL MILLING AND METAL OXIDE ADDITIVES ON SORPTION KINETICS OF 1:1 LiNH2/MgH2 MIXTURE (open access)

AFFECTS OF MECHANICAL MILLING AND METAL OXIDE ADDITIVES ON SORPTION KINETICS OF 1:1 LiNH2/MgH2 MIXTURE

The destabilized complex hydride system composed of LiNH{sub 2}:MgH{sub 2} (1:1 molar ratio) is one of the leading candidates of hydrogen storage with a reversible hydrogen storage capacity of 8.1 wt%. A low sorption enthalpy of {approx}32 kJ/mole H{sub 2} was first predicted by Alapati et al. utilizing first principle density function theory (DFT) calculations and has been subsequently confirmed empirically by Lu et al. through differential thermal analysis (DTA). This enthalpy suggests that favorable sorption kinetics should be obtainable at temperatures in the range of 160 C to 200 C. Preliminary experiments reported in the literature indicate that sorption kinetics are substantially lower than expected in this temperature range despite favorable thermodynamics. Systematic isothermal and isobaric sorption experiments were performed using a Sievert's apparatus to form a baseline data set by which to compare kinetic results over the pressure and temperature range anticipated for use of this material as a hydrogen storage media. Various material preparation methods and compositional modifications were performed in attempts to increase the kinetics while lowering the sorption temperatures. This paper outlines the results of these systematic tests and describes a number of beneficial additions which influence kinetics as well as NH{sub 3} formation.
Date: December 8, 2010
Creator: Erdy, C.; Anton, D. & Gray, J.
System: The UNT Digital Library
Aliovalent titanium substitution in layered mixed Li Ni-Mn-Co oxides for lithium battery applications (open access)

Aliovalent titanium substitution in layered mixed Li Ni-Mn-Co oxides for lithium battery applications

Improved electrochemical characteristics are observed for Li[Ni1/3Co1/3-yMyMn1/3]O2 cathode materials when M=Ti and y<0.07, compared to the baseline material, with up to 15percent increased discharge capacity.
Date: December 1, 2010
Creator: Kam, Kinson & Doeff, Marca M.
System: The UNT Digital Library
Analysis of Flow Cytometry DNA Damage Response Protein Activation Kinetics Following X-rays and High Energy Iron Nuclei Exposure (open access)

Analysis of Flow Cytometry DNA Damage Response Protein Activation Kinetics Following X-rays and High Energy Iron Nuclei Exposure

We developed a mathematical method to analyze flow cytometry data to describe the kinetics of {gamma}H2AX and pATF2 phosphorylations ensuing various qualities of low dose radiation in normal human fibroblast cells. Previously reported flow cytometry kinetic results for these DSB repair phospho-proteins revealed that distributions of intensity were highly skewed, severely limiting the detection of differences in the very low dose range. Distributional analysis reveals significant differences between control and low dose samples when distributions are compared using the Kolmogorov-Smirnov test. Radiation quality differences are found in the distribution shapes and when a nonlinear model is used to relate dose and time to the decay of the mean ratio of phosphoprotein intensities of irradiated samples to controls. We analyzed cell cycle phase and radiation quality dependent characteristic repair times and residual phospho-protein levels with these methods. Characteristic repair times for {gamma}H2AX were higher following Fe nuclei as compared to X-rays in G1 cells (4.5 {+-} 0.46 h vs 3.26 {+-} 0.76 h, respectively), and in S/G2 cells (5.51 {+-} 2.94 h vs 2.87 {+-} 0.45 h, respectively). The RBE in G1 cells for Fe nuclei relative to X-rays for {gamma}H2AX was 2.05 {+-} 0.61 and 5.02 {+-} 3.47, at 2 …
Date: December 15, 2010
Creator: Association, Universities Space Research; Chappell, Lori J.; Whalen, Mary K.; Gurai, Sheena; Ponomarev, Artem; Cucinotta, Francis A. et al.
System: The UNT Digital Library
Analysis of Off-Board Powered Thermal Preconditioning in Electric Drive Vehicles: Preprint (open access)

Analysis of Off-Board Powered Thermal Preconditioning in Electric Drive Vehicles: Preprint

Following a hot or cold thermal soak, vehicle climate control systems (air conditioning or heat) are required to quickly attain a cabin temperature comfortable to the vehicle occupants. In a plug-in hybrid electric or electric vehicle (PEV) equipped with electric climate control systems, the traction battery is the sole on-board power source. Depleting the battery for immediate climate control results in reduced charge-depleting (CD) range and additional battery wear. PEV cabin and battery thermal preconditioning using off-board power supplied by the grid or a building can mitigate the impacts of climate control. This analysis shows that climate control loads can reduce CD range up to 35%. However, cabin thermal preconditioning can increase CD range up to 19% when compared to no thermal preconditioning. In addition, this analysis shows that while battery capacity loss over time is driven by ambient temperature rather than climate control loads, concurrent battery thermal preconditioning can reduce capacity loss up to 7% by reducing pack temperature in a high ambient temperature scenario.
Date: December 1, 2010
Creator: Barnitt, R. A.; Brooker, A. D.; Ramroth, L.; Rugh , J. & Smith, K. A.
System: The UNT Digital Library
Application of Gaseous Sphere Injection Method for Modeling Under-expanded H2 Injection (open access)

Application of Gaseous Sphere Injection Method for Modeling Under-expanded H2 Injection

A methodology for modeling gaseous injection has been refined and applied to recent experimental data from the literature. This approach uses a discrete phase analogy to handle gaseous injection, allowing for addition of gaseous injection to a CFD grid without needing to resolve the injector nozzle. This paper focuses on model testing to provide the basis for simulation of hydrogen direct injected internal combustion engines. The model has been updated to be more applicable to full engine simulations, and shows good agreement with experiments for jet penetration and time-dependent axial mass fraction, while available radial mass fraction data is less well predicted.
Date: December 3, 2010
Creator: Whitesides, R.; Hessel, R. P.; Flowers, D. L. & Aceves, S. M.
System: The UNT Digital Library
Automatic Fault Characterization via Abnormality-Enhanced Classification (open access)

Automatic Fault Characterization via Abnormality-Enhanced Classification

Enterprise and high-performance computing systems are growing extremely large and complex, employing hundreds to hundreds of thousands of processors and software/hardware stacks built by many people across many organizations. As the growing scale of these machines increases the frequency of faults, system complexity makes these faults difficult to detect and to diagnose. Current system management techniques, which focus primarily on efficient data access and query mechanisms, require system administrators to examine the behavior of various system services manually. Growing system complexity is making this manual process unmanageable: administrators require more effective management tools that can detect faults and help to identify their root causes. System administrators need timely notification when a fault is manifested that includes the type of fault, the time period in which it occurred and the processor on which it originated. Statistical modeling approaches can accurately characterize system behavior. However, the complex effects of system faults make these tools difficult to apply effectively. This paper investigates the application of classification and clustering algorithms to fault detection and characterization. We show experimentally that naively applying these methods achieves poor accuracy. Further, we design novel techniques that combine classification algorithms with information on the abnormality of application behavior to …
Date: December 20, 2010
Creator: Bronevetsky, G; Laguna, I & de Supinski, B R
System: The UNT Digital Library
Automatic Model Order Reduction (open access)

Automatic Model Order Reduction

None
Date: December 13, 2010
Creator: White, D. A.
System: The UNT Digital Library
Beam Conditioning for Free Electron Lasers:Consequences and Methods (open access)

Beam Conditioning for Free Electron Lasers:Consequences and Methods

The consequences of beam conditioning in four example cases [VISA, a soft x-ray free-electron laser (FEL), LCLS, and a 'Greenfield' FEL] are examined. It is shown that in emittance limited cases, proper conditioning reduces sensitivity to the transverse emittance and, furthermore, allows for stronger focusing in the undulator. Simulations show higher saturation power, with gain lengths reduced by a factor of 2 or more. The beam dynamics in a general conditioning system are studied, with 'matching conditions' derived for achieving conditioning without growth in the effective emittance. Various conditioning lattices are considered, and expressions derived for the amount of conditioning provided in each case when the matching conditions are satisfied. These results show that there is no fundamental obstacle to producing beam conditioning, and that the problem can be reduced to one of proper lattice design. Nevertheless, beam conditioning will not be easy to implement in practice.
Date: December 14, 2010
Creator: Wolski, A.; Penn, G.; Sessler, A.; Wurtele, J. & /LBL, Berkeley /UC, Berkeley, Astron. Dept.
System: The UNT Digital Library
Beyond the Standard Model Higgs Boson Searches at the Tevatron (open access)

Beyond the Standard Model Higgs Boson Searches at the Tevatron

The search for the Higgs boson is one of the main goals in High Energy Physics and one of the highest priorities at Run II of the Tevatron. There are many alternative Higgs boson models beyond the SM, including Supersymmetry (SUSY) and Fermiophobic Higgs bosons, which can actively be probed at the Tevatron, and in the absence of an excess constrained. The latest limits for several SUSY searches are presented in Section 2 and for the Fermiophobic Higgs boson searches in Section 3. More information on all these searches, along with the latest results, can be found on the CDF and D0 public results webpages. Results are presented for beyond the Standard Model Higgs boson searches using up to 4.2 fb{sup -1} of data from Run II at the Tevatron. No significant excess is observed in any of the channels so 95% confidence level limits are presented.
Date: December 1, 2010
Creator: Scanlon, Tim
System: The UNT Digital Library
Biospecimen Reporting for Improved Study Quality (open access)

Biospecimen Reporting for Improved Study Quality

Human biospecimens are subjected to collection, processing, and storage that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research that uses human tissues, it is crucial that information on the handling of biospecimens be reported in a thorough, accurate, and standardized manner. The Biospecimen Reporting for Improved Study Quality (BRISQ) recommendations outlined herein are intended to apply to any study in which human biospecimens are used. The purpose of reporting these details is to supply others, from researchers to regulators, with more consistent and standardized information to better evaluate, interpret, compare, and reproduce the experimental results. The BRISQ guidelines are proposed as an important and timely resource tool to strengthen communication and publications on biospecimen-related research and to help reassure patient contributors and the advocacy community that their contributions are valued and respected.
Date: December 27, 2010
Creator: Moore, Ph.D., Helen M.; Kelly, Ph.D., Andrea B.; Jewell, Ph.D., Scott D.; McShane, Ph.D., Lisa M.; Clark, M.D., Douglas P.; Greenspan, M.D., Renata et al.
System: The UNT Digital Library
A Case for the Use of 3-D Attenuation Models in Ground Motion and Seismic Hazard Assessment (open access)

A Case for the Use of 3-D Attenuation Models in Ground Motion and Seismic Hazard Assessment

None
Date: December 6, 2010
Creator: Pasyanos, M E
System: The UNT Digital Library
Challenges Surrounding the Injection and Arrival of Targets at LIFE Fusion Chamber Center (open access)

Challenges Surrounding the Injection and Arrival of Targets at LIFE Fusion Chamber Center

IFE target designers must consider several engineering requirements in addition to the physics requirements for successful target implosion. These considerations include low target cost, high manufacturing throughput, the ability of the target to survive the injection into the fusion chamber and arrive in a condition and physical position consistent with proper laser-target interaction and ease of post-implosion debris removal. This article briefly describes these considerations for the Laser Inertial Fusion-based Energy (LIFE) targets currently being designed.
Date: December 1, 2010
Creator: Miles, R.; Spaeth, M.; Manes, K.; Amendt, P.; Tabak, M.; Bond, T. et al.
System: The UNT Digital Library
CHARACTERIZATION OF MODIFIED MONOSODIUM TITANATE - AN IMPROVED SORBENT FOR STRONTIUM AND ACTINIDE SEPARATIONS (open access)

CHARACTERIZATION OF MODIFIED MONOSODIUM TITANATE - AN IMPROVED SORBENT FOR STRONTIUM AND ACTINIDE SEPARATIONS

High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 134,137}Cs, {sup 90}Sr, and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. An inorganic sorbent, monosodium titanate (MST), is currently used to remove {sup 90}Sr and alpha-emitting radionuclides, while a caustic-side solvent extraction process is used for removing {sup 134,137}Cs. A new peroxotitanate material, modified MST, or mMST, has recently been developed and has shown increased removal kinetics and capacity for {sup 90}Sr and alpha-emitting radionuclides compared to the current baseline material, MST. This paper describes recent results focused on further characterization of this material.
Date: December 21, 2010
Creator: Hobbs, D.; Taylor-Pashow, K. & Missimer, D.
System: The UNT Digital Library
CHARM 2010: Experiment summary and future charm facilities (open access)

CHARM 2010: Experiment summary and future charm facilities

The CHARM 2010 meeting had over 30 presentations of experimental results, plus additional future facilities talks just before this summary talk. Since there is not enough time to even summarize all that has been shown from experiments and to recognize all the memorable plots and results - tempting as it is to reproduce the many clean signals and data vs theory figures, the quantum correlations plots, and the D-mixing plots before and after the latest CLEO-c data is added. So, this review will give only my personal observations, exposing my prejudices and my areas of ignorance, no doubt. This overview will be at a fairly high level of abstraction - no re-showing individual plots or results. I ask the forgiveness of those who will have been slighted in this way - meaning all the presents.
Date: December 1, 2010
Creator: Appel, Jeffrey A.
System: The UNT Digital Library
Charmed Hadron Physics at BABAR (open access)

Charmed Hadron Physics at BABAR

We present a study of the D{sup +}{pi}{sup -}, D{sup 0}{pi}{sup +}, and D*{sup +}{pi}{sup -} systems in inclusive e{sup +}e{sup -} {yields} c{bar c} interactions in a search for new excited D meson states. We use a dataset, consisting of {approx}454 fb{sup -1}, collected at center-of-mass energies near 10.58 GeV by the BABAR detector at the SLAC PEP-II asymmetric-energy collider. We observe, for the first time, candidates for the radial excitations of the D{sup 0}, D*{sup 0}, and D*{sup +}, as well as the L = 2 excited states of the D{sup 0} and D{sup +}, where L is the orbital angular momentum of the quarks.
Date: December 16, 2010
Creator: Benitez, Jose
System: The UNT Digital Library
Charmless and Penguin Decays at CDF (open access)

Charmless and Penguin Decays at CDF

Penguin transitions play a key role in the search of New Physics hints in the heavy flavor sector. During the last decade CDF has been exploring this opportunity with a rich study of two-body charmless decays of neutral B mesons into charged final-state particles. After briefly introducing the aspects of this physics peculiar to the hadron collision environment, I report on two interesting results: the first polarization measurement of the B{sub s}{sup 0} {yields} {phi}{phi} decay and the update of the B{sub (s)}{sup 0} {yields} h{sup +}h{prime}{sup -} decays analysis.
Date: December 1, 2010
Creator: Dorigo, Mirco & Collaboration, for the CDF
System: The UNT Digital Library
Climate change and forests in India: note from the guest editors (open access)

Climate change and forests in India: note from the guest editors

Forestry is one of the most important sectors in the context of climate change. It lies at the center-stage of global mitigation and adaptation efforts. Yet, it is one of the least understood sectors, especially in tropical zones, which constitute a significant portion of the global forests. Recently, there has been a growing interest in forests in addressing global climate change. The IPCC Assessment Report 4 (2007) Chapters related to forests have highlighted the limited number of studies on the impact of climate change on forests at the regional, national and sub-national level, while policy makers need information at these scales. Further, implication of projected climate change on mitigation potential of forest sector is only briefly mentioned in the IPCC report, with limited literature to support the conclusions. India is one among the top ten nations in the world in terms of forest cover. It is also sixth among the tropical countries in terms of forested area. As IPCC Assessment Report 5 work is about to be initiated soon, studies on the impact of climate change on forests as well as the mitigation potential of the forest sector, particularly at regional and national level, will be of great interest to …
Date: December 23, 2010
Creator: Ravindtranath, N.H. & Aaheim, Asbjporn
System: The UNT Digital Library
Coherent Radiation Effects in the LCLS Undulator (open access)

Coherent Radiation Effects in the LCLS Undulator

For X-ray Free-Electron Lasers such as LCLS and TESLA FEL, a change in the electron energy while amplifying the FEL radiation can shift the resonance condition out of the bandwidth of the FEL. The largest sources of energy loss is the emission of incoherent undulator radiation. Because the loss per electron depends only on the undulator parameters and the beam energy, which are fixed for a given resonant wavelength, the average energy loss can be compensated for by a fixed taper of the undulator. Coherent radiation has a strong enhancement proportional to the number of electrons in the bunch for frequencies comparable to or longer than the bunch dimension. If the emitted coherent energy becomes comparable to that of the incoherent emission, it has to be included in the taper as well. However, the coherent loss depends on the bunch charge and the applied compression scheme and a change of these parameters would require a change of the taper. This imposes a limitation on the practical operation of Free-Electron Lasers, where the taper can only be adjusted manually. In this presentation we analyze the coherent emission of undulator radiation and transition undulator radiation for LCLS, and estimate whether the resulting …
Date: December 14, 2010
Creator: Reiche, S.; /UCLA & Huang, Z.
System: The UNT Digital Library