Automated detection and analysis of particle beams in laser-plasma accelerator simulations (open access)

Automated detection and analysis of particle beams in laser-plasma accelerator simulations

Numerical simulations of laser-plasma wakefield (particle) accelerators model the acceleration of electrons trapped in plasma oscillations (wakes) left behind when an intense laser pulse propagates through the plasma. The goal of these simulations is to better understand the process involved in plasma wake generation and how electrons are trapped and accelerated by the wake. Understanding of such accelerators, and their development, offer high accelerating gradients, potentially reducing size and cost of new accelerators. One operating regime of interest is where a trapped subset of electrons loads the wake and forms an isolated group of accelerated particles with low spread in momentum and position, desirable characteristics for many applications. The electrons trapped in the wake may be accelerated to high energies, the plasma gradient in the wake reaching up to a gigaelectronvolt per centimeter. High-energy electron accelerators power intense X-ray radiation to terahertz sources, and are used in many applications including medical radiotherapy and imaging. To extract information from the simulation about the quality of the beam, a typical approach is to examine plots of the entire dataset, visually determining the adequate parameters necessary to select a subset of particles, which is then further analyzed. This procedure requires laborious examination of …
Date: May 21, 2010
Creator: Ushizima, Daniela Mayumi; Geddes, Cameron G.; Cormier-Michel, Estelle; Bethel, E. Wes; Jacobsen, Janet; Prabhat et al.
System: The UNT Digital Library
Batteries: Overview of Battery Cathodes (open access)

Batteries: Overview of Battery Cathodes

The very high theoretical capacity of lithium (3829 mAh/g) provided a compelling rationale from the 1970's onward for development of rechargeable batteries employing the elemental metal as an anode. The realization that some transition metal compounds undergo reductive lithium intercalation reactions reversibly allowed use of these materials as cathodes in these devices, most notably, TiS{sub 2}. Another intercalation compound, LiCoO{sub 2}, was described shortly thereafter but, because it was produced in the discharged state, was not considered to be of interest by battery companies at the time. Due to difficulties with the rechargeability of lithium and related safety concerns, however, alternative anodes were sought. The graphite intercalation compound (GIC) LiC{sub 6} was considered an attractive candidate but the high reactivity with commonly used electrolytic solutions containing organic solvents was recognized as a significant impediment to its use. The development of electrolytes that allowed the formation of a solid electrolyte interface (SEI) on surfaces of the carbon particles was a breakthrough that enabled commercialization of Li-ion batteries. In 1990, Sony announced the first commercial batteries based on a dual Li ion intercalation system. These devices are assembled in the discharged state, so that it is convenient to employ a prelithiated cathode …
Date: July 12, 2010
Creator: Doeff, Marca M
System: The UNT Digital Library
Ch. 37, Inertial Fusion Energy Technology (open access)

Ch. 37, Inertial Fusion Energy Technology

Nuclear fission, nuclear fusion, and renewable energy (including biofuels) are the only energy sources capable of satisfying the Earth's need for power for the next century and beyond without the negative environmental impacts of fossil fuels. Substantially increasing the use of nuclear fission and renewable energy now could help reduce dependency on fossil fuels, but nuclear fusion has the potential of becoming the ultimate base-load energy source. Fusion is an attractive fuel source because it is virtually inexhaustible, widely available, and lacks proliferation concerns. It also has a greatly reduced waste impact, and no danger of runaway reactions or meltdowns. The substantial environmental, commercial, and security benefits of fusion continue to motivate the research needed to make fusion power a reality. Replicating the fusion reactions that power the sun and stars to meet Earth's energy needs has been a long-sought scientific and engineering challenge. In fact, this technological challenge is arguably the most difficult ever undertaken. Even after roughly 60 years of worldwide research, much more remains to be learned. the magnitude of the task has caused some to declare that fusion is 20 years away, and always will be. This glib criticism ignores the enormous progress that has occurred …
Date: June 9, 2010
Creator: Moses, E.
System: The UNT Digital Library
CHAPTER 5-RADIOACTIVE WASTE MANAGEMENT (open access)

CHAPTER 5-RADIOACTIVE WASTE MANAGEMENT

The ore pitchblende was discovered in the 1750's near Joachimstal in what is now the Czech Republic. Used as a colorant in glazes, uranium was identified in 1789 as the active ingredient by chemist Martin Klaproth. In 1896, French physicist Henri Becquerel studied uranium minerals as part of his investigations into the phenomenon of fluorescence. He discovered a strange energy emanating from the material which he dubbed 'rayons uranique.' Unable to explain the origins of this energy, he set the problem aside. About two years later, a young Polish graduate student was looking for a project for her dissertation. Marie Sklodowska Curie, working with her husband Pierre, picked up on Becquerel's work and, in the course of seeking out more information on uranium, discovered two new elements (polonium and radium) which exhibited the same phenomenon, but were even more powerful. The Curies recognized the energy, which they now called 'radioactivity,' as something very new, requiring a new interpretation, new science. This discovery led to what some view as the 'golden age of nuclear science' (1895-1945) when countries throughout Europe devoted large resources to understand the properties and potential of this material. By World War II, the potential to harness this …
Date: May 5, 2010
Creator: Marra, J.
System: The UNT Digital Library
Chapter 11. Community analysis-based methods (open access)

Chapter 11. Community analysis-based methods

Microbial communities are each a composite of populations whose presence and relative abundance in water or other environmental samples are a direct manifestation of environmental conditions, including the introduction of microbe-rich fecal material and factors promoting persistence of the microbes therein. As shown by culture-independent methods, different animal-host fecal microbial communities appear distinctive, suggesting that their community profiles can be used to differentiate fecal samples and to potentially reveal the presence of host fecal material in environmental waters. Cross-comparisons of microbial communities from different hosts also reveal relative abundances of genetic groups that can be used to distinguish sources. In increasing order of their information richness, several community analysis methods hold promise for MST applications: phospholipid fatty acid (PLFA) analysis, denaturing gradient gel electrophoresis (DGGE), terminal restriction fragment length polymorphism (TRFLP), cloning/sequencing, and PhyloChip. Specific case studies involving TRFLP and PhyloChip approaches demonstrate the ability of community-based analyses of contaminated waters to confirm a diagnosis of water quality based on host-specific marker(s). The success of community-based MST for comprehensively confirming fecal sources relies extensively upon using appropriate multivariate statistical approaches. While community-based MST is still under evaluation and development as a primary diagnostic tool, results presented herein demonstrate its promise. …
Date: May 1, 2010
Creator: Cao, Y.; Wu, C. H.; Andersen, G. L. & Holden, P. A.
System: The UNT Digital Library
Conservation Laws for Coupled Hydro-mechanical Processes in Unsaturated Porous Media: Theory and Implementation (open access)

Conservation Laws for Coupled Hydro-mechanical Processes in Unsaturated Porous Media: Theory and Implementation

We develop conservation laws for coupled hydro-mechanical processes in unsaturated porous media using three-phase continuum mixture theory. From the first law of thermodynamics, we identify energy-conjugate variables for constitutive modeling at macroscopic scale. Energy conjugate expressions identified relate a certain measure of effective stress to the deformation of the solid matrix, the degree of saturation to the matrix suction, the pressure in each constituent phase to the corresponding intrinsic volume change of this phase, and the seepage forces to the corresponding pressure gradients. We then develop strong and weak forms of boundary-value problems relevant for 3D finite element modeling of coupled hydro-mechanical processes in unsaturated porous media. The paper highlights a 3D numerical example illustrating the advances in the solution of large-scale coupled finite element systems, as well as the challenges in developing more predictive tools satisfying the basic conservation laws and the observed constitutive responses for unsaturated porous materials.
Date: February 19, 2010
Creator: Borja, R. I. & White, J. A.
System: The UNT Digital Library
Design of Genomic Signatures of Pathogen Identification & Characterization (open access)

Design of Genomic Signatures of Pathogen Identification & Characterization

This chapter will address some of the many issues associated with the identification of signatures based on genomic DNA/RNA, which can be used to identify and characterize pathogens for biodefense and microbial forensic goals. For the purposes of this chapter, we define a signature as one or more strings of contiguous genomic DNA or RNA bases that are sufficient to identify a pathogenic target of interest at the desired resolution and which could be instantiated with particular detection chemistry on a particular platform. The target may be a whole organism, an individual functional mechanism (e.g., a toxin gene), or simply a nucleic acid indicative of the organism. The desired resolution will vary with each program's goals but could easily range from family to genus to species to strain to isolate. The resolution may not be taxonomically based but rather pan-mechanistic in nature: detecting virulence or antibiotic-resistance genes shared by multiple microbes. Entire industries exist around different detection chemistries and instrument platforms for identification of pathogens, and we will only briefly mention a few of the techniques that we have used at Lawrence Livermore National Laboratory (LLNL) to support our biosecurity-related work since 2000. Most nucleic acid based detection chemistries involve …
Date: February 9, 2010
Creator: Slezak, T.; Gardner, S.; Allen, J.; Vitalis, E. & Jaing, C.
System: The UNT Digital Library
Development of Glass Matrices for HLW Radioactive Wastes (open access)

Development of Glass Matrices for HLW Radioactive Wastes

Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either borosilicate glass or phosphate glass. One of the primary reasons that glass has become the most widely used immobilization media is the relative simplicity of the vitrification process, e.g. melt waste plus glass forming frit additives and cast. A second reason that glass has become widely used for HLW is that the short range order (SRO) and medium range order (MRO) found in glass atomistically bonds the radionuclides and governs the melt properties such as viscosity, resistivity, sulphate solubility. The molecular structure of glass controls contaminant/radionuclide release by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. The molecular structure is flexible and hence accounts for the flexibility of glass formulations to waste variability. Nuclear waste glasses melt between 1050-1150 C which minimizes the volatility of radioactive components such as Tc{sup 99}, Cs{sup 137}, and I{sup 129}. Nuclear waste glasses have good long term stability including irradiation resistance. Process control models based on the molecular structure of glass have been …
Date: March 18, 2010
Creator: Jantzen, Carol M.
System: The UNT Digital Library
Economic effects of projected climate change on outdoor recreation in Tennessee. (open access)

Economic effects of projected climate change on outdoor recreation in Tennessee.

Climate change projections from three General Circulation Models were used to adjust the temperature and precipitation in 2030 and 2080 in each of five ecological provinces in Tennessee to estimate the direct economic effects of the projected changes on recreation using the Tourism Climatic Index. The indirect effects on recreation were evaluated qualitatively, based on current demand for the unique values associated with current conditions. The results of the direct impact evaluation reveal that climate change will have variable effects on recreational activities in Tennessee. The magnitude and direction of the effects vary by the recreational activity involved, patterns of precipitation and temperature regimes, and specific location in Tennessee. Recreational activities such as rock climbing, winter activities independent of snow, and whitewater boating are likely to benefit from projected climate changes due to increased temperatures in the winter months. Summer-based activities such as lake recreation and camping are likely to decline with increasing seasonal temperatures. The indirect effects of climate change on recreation are likely to have a larger effect than the direct impacts of climatic variables.
Date: January 1, 2010
Creator: Hodges, Donald G.; Fogel, Jonah; Dale, Virginia H; Lannom, Karen O. & Tharp, M Lynn
System: The UNT Digital Library
Empowering Minority Communities with Health Information - ASU (open access)

Empowering Minority Communities with Health Information - ASU

Training Manual updated for United Negro College Fund Special Programs Corporation/National Library of Medicine - HBCU ACCESS Project for Alcorn State University, Natchez, Mississippi, November 12, 2010
Date: November 12, 2010
Creator: McMurray, L. and W. Templin-Branner
System: The UNT Digital Library
Empowering Minority Communities with Health Information - Howard (open access)

Empowering Minority Communities with Health Information - Howard

Training conducted as a part of the United Negro College Fund Special Programs/National Library of Medicine -HBCU ACCESS Project at Howard University, Washington, DC on November 20, 2010.
Date: November 16, 2010
Creator: McMurray, L. and R. Foster
System: The UNT Digital Library
Empowering Minority Communities with Health Information - UDC (open access)

Empowering Minority Communities with Health Information - UDC

Training update with Environmental a health focus. Training conducted as part of the United Negro College Fund Special Programs Corporation/National Library of Medicine - HBCU ACCESS Project at the University of the District of Columbia, Washington, DC on November 2, 2010.
Date: November 2, 2010
Creator: McMurray, L.; Foster, R. & Womble, and R.
System: The UNT Digital Library
Empowering Minority Communities with Health Information - WSSU (open access)

Empowering Minority Communities with Health Information - WSSU

Environmental health focus with training conducted as part of the United Negro College Fund Special Programs Corporation/National Library of Medicine HBCU ACCESS Project at Winston-Salem State University, NC on November 10, 2010.
Date: November 10, 2010
Creator: McMurray, L. and W. Templin-Branner
System: The UNT Digital Library
Environmental Health Information Partnership Proceedings: March 25-26, 2010 (open access)

Environmental Health Information Partnership Proceedings: March 25-26, 2010

Proceedings of the Environmental Health Information Partnership (EnHIP) Meeting March 25-26, 2010
Date: August 1, 2010
Creator: lange, L. and R. Foster
System: The UNT Digital Library
Equal Access Initiative HIV/AIDS Information Resources from NLM (open access)

Equal Access Initiative HIV/AIDS Information Resources from NLM

The Equal Access Initiative: HIV/AIDS Information Resources from the National Library of Medicine training is designed specifically for the National Minority AIDS Council 2010 Equal Access Initiative (EAI) Computer Grants Program awardees to provide valuable health information resources from the National Library of Medicine and other reliable sources to increase awareness of the wealth of treatment information and educational materials that are available on the Internet and to improve prevention and treatment education for their clients. These resources will also meet the needs of community-based
Date: September 11, 2010
Creator: Dancy, Templin-Branner W. and N.
System: The UNT Digital Library
Establishing Natural Product Content with the Natural Radiocarbon Signature (open access)

Establishing Natural Product Content with the Natural Radiocarbon Signature

None
Date: May 7, 2010
Creator: Buchholz, B. A.; Sarachine, M. J. & Zermeno, P.
System: The UNT Digital Library
Evaluated Nuclear Data (open access)

Evaluated Nuclear Data

This chapter describes the current status of evaluated nuclear data for nuclear technology applications. We start with evaluation procedures for neutron-induced reactions focusing on incident energies from the thermal energy up to 20 MeV, though higher energies are also mentioned. This is followed by examining the status of evaluated neutron data for actinides that play dominant role in most of the applications, followed by coolants/moderators, structural materials and fission products. We then discuss neutron covariance data that characterize uncertainties and correlations. We explain how modern nuclear evaluated data libraries are validated against an extensive set of integral benchmark experiments. Afterwards, we briefly examine other data of importance for nuclear technology, including fission yields, thermal neutron scattering and decay data. A description of three major evaluated nuclear data libraries is provided, including the latest version of the US library ENDF/B-VII.0, European JEFF-3.1 and Japanese JENDL-3.3. A brief introduction is made to current web retrieval systems that allow easy access to a vast amount of up-to-date evaluated nuclear data for nuclear technology applications.
Date: October 1, 2010
Creator: Oblozinsky, P.; Oblozinsky, P.; Herman, M. & Mughabghab, S. F.
System: The UNT Digital Library
Executive Order 13514: Federal Leadership in Environmental, Energy, and Economic Performance; Comprehensive Federal Fleet Management Handbook, June 2010, Federal Energy Management Program (FEMP) (open access)

Executive Order 13514: Federal Leadership in Environmental, Energy, and Economic Performance; Comprehensive Federal Fleet Management Handbook, June 2010, Federal Energy Management Program (FEMP)

Comprehensive Federal fleet management guide offered as a companion to Executive Order 13514 Section 12 guidance.
Date: June 1, 2010
Creator: unknown
System: The UNT Digital Library
The Gut Microbiota: Ecology and Function (open access)

The Gut Microbiota: Ecology and Function

The gastrointestinal (GI) tract is teeming with an extremely abundant and diverse microbial community. The members of this community have coevolved along with their hosts over millennia. Until recently, the gut ecosystem was viewed as black box with little knowledge of who or what was there or their specific functions. Over the past decade, however, this ecosystem has become one of fastest growing research areas of focus in microbial ecology and human and animal physiology. This increased interest is largely in response to studies tying microbes in the gut to important diseases afflicting modern society, including obesity, allergies, inflammatory bowel diseases, and diabetes. Although the importance of a resident community of microorganisms in health was first hypothesized by Pasteur over a century ago (Sears, 2005), the multiplicity of physiological changes induced by commensal bacteria has only recently been recognized (Hooper et al., 2001). The term 'ecological development' was recently coined to support the idea that development of the GI tract is a product of the genetics of the host and the host's interactions with resident microbes (Hooper, 2004). The search for new therapeutic targets and disease biomarkers has escalated the need to understand the identities and functions of the microorganisms …
Date: June 1, 2010
Creator: Willing, B.P. & Jansson, J.K.
System: The UNT Digital Library
HIV/AIDS Information Resources from the National Library of Medicine-STOP (open access)

HIV/AIDS Information Resources from the National Library of Medicine-STOP

The HIV/AIDS Information Resources from the National Library of Medicine training is designed specifically for the UNCFSP HBCU Screening, Testing, Outreach, and Prevention (STOP) HIV/AIDS Program project members to provide valuable health information resources from the National Library of Medicine and other reliable sources to increase awareness of the wealth of treatment information and educational materials that are available on the Internet and to improve prevention and treatment education for their clients. These resources will also meet the needs of community-based organizations
Date: June 15, 2010
Creator: Templin-Branner, W. and N. Dancy
System: The UNT Digital Library
HIV-AIDS Information Resources from the NLM - ACIO (open access)

HIV-AIDS Information Resources from the NLM - ACIO

As the treatment and management of HIV/AIDS continues to evolve with new scientific breakthroughs, treatment discoveries, and management challenges, it is difficult for people living with HIV/AIDS and those who care for them to keep up with the latest information on HIV/AIDS screening and testing, prevention, treatment, and research. The National Library of Medicine (NLM), of the National Institutes of Health, has a wealth of health information resources freely available on the Internet to address these needs.
Date: October 1, 2010
Creator: Templin-Branner, W.
System: The UNT Digital Library
HRTEM Study of Oxide Nanoparticles in Fe-16Cr ODS Ferritic Steel Developed for Fusion Energy (open access)

HRTEM Study of Oxide Nanoparticles in Fe-16Cr ODS Ferritic Steel Developed for Fusion Energy

None
Date: June 24, 2010
Creator: Hsiung, L. L.
System: The UNT Digital Library
Hydrogeophysics (open access)

Hydrogeophysics

Developing a predictive understanding of subsurface flow and transport is complicated by the disparity of scales across which controlling hydrological properties and processes span. Conventional techniques for characterizing hydrogeological properties (such as pumping, slug, and flowmeter tests) typically rely on borehole access to the subsurface. Because their spatial extent is commonly limited to the vicinity near the wellbores, these methods often can not provide sufficient information to describe key controls on subsurface flow and transport. The field of hydrogeophysics has evolved in recent years to explore the potential that geophysical methods hold for improving the quantification of subsurface properties and processes relevant for hydrological investigations. This chapter is intended to familiarize hydrogeologists and water resource professionals with the state-of-the-art as well as existing challenges associated with hydrogeophysics. We provide a review of the key components of hydrogeophysical studies, which include: geophysical methods commonly used for shallow subsurface characterization; petrophysical relationships used to link the geophysical properties to hydrological properties and state variables; and estimation or inversion methods used to integrate hydrological and geophysical measurements in a consistent manner. We demonstrate the use of these different geophysical methods, petrophysical relationships, and estimation approaches through several field-scale case studies. Among other applications, …
Date: April 1, 2010
Creator: Hubbard, S. S. & Linde, N.
System: The UNT Digital Library
Laser Interactions in Nanomaterials Synthesis (open access)

Laser Interactions in Nanomaterials Synthesis

Laser interactions with materials have unique advantages to explore the rapid synthesis, processing, and in situ characterization of high quality and novel nanoparticles, nanotubes and nanowires. For example, laser vaporization of solids into background gases provides a wide range of processing conditions for the formation of nanomaterials by both catalyst-free and catalyst-assisted growth processes. Laser interactions with the growing nanomaterials provide remote in situ characterization of their size, structure, and composition with unprecedented temporal resolution. In this article, laser interactions involved in the synthesis of primarily carbon nanostructures are reviewed, including the catalyst-free synthesis of single-walled carbon nanohorns and quantum dots, to the catalyst-assisted growth of single and multi-walled carbon nanotubes.
Date: January 1, 2010
Creator: Geohegan, David B.; Puretzky, Alexander A.; Rouleau, Christopher M.; Jackson, Jeremy Joseph; Eres, Gyula; Xiao, Kai et al.
System: The UNT Digital Library