Biological Applications of Cryogenic Detectors (open access)

Biological Applications of Cryogenic Detectors

High energy resolution and broadband efficiency are enabling the use of cryogenic detectors in biological research. Two areas where they have found initial application are X-ray absorption spectroscopy (XAS) and time-of-flight mass spectrometry (TOF-MS). In synchrotron-based fluorescence-detected XAS cryogenic detectors are used to examine the role of metals in biological systems by measuring their oxidation states and ligand symmetries. In time-of-flight mass spectrometry cryogenic detectors increase the sensitivity for biomolecule detection and identification for masses above {approx}50 kDa, and thus enable TOF-MS on large protein complexes or even entire viruses. More recently, cryogenic detectors have been proposed as optical sensors for fluorescence signals from biomarkers. We discuss the potential for cryogenic detectors in biological research, as well as the challenges the technology faces.
Date: December 3, 2003
Creator: Friedrich, S
Object Type: Article
System: The UNT Digital Library
Effects of electron concentration on the optical absorption edge of InN (open access)

Effects of electron concentration on the optical absorption edge of InN

None
Date: December 3, 2003
Creator: Wu, J.; Walukiewicz, W.; Li, S. X.; Armitage, R.; Ho, J. C.; Weber, E. R. et al.
Object Type: Article
System: The UNT Digital Library
Engineering surface functional groups on silica aerogel for enhanced cleanup of organics from produced water (open access)

Engineering surface functional groups on silica aerogel for enhanced cleanup of organics from produced water

None
Date: December 3, 2003
Creator: Love, A; Hanna, M L & Reynolds, J
Object Type: Article
System: The UNT Digital Library
India: Chronology of Events (open access)

India: Chronology of Events

This report provides a reverse chronology of major events involving India and India - U.S relations.
Date: December 3, 2003
Creator: Kronstadt, K. Alan
Object Type: Report
System: The UNT Digital Library
India-U.S. Relations (open access)

India-U.S. Relations

This report summarizes India-US relations from 1947 in preparation for the 2004 National elections, including information about bilateral relations, nuclear testing, separatist movements, and human rights issues.
Date: December 3, 2003
Creator: Kronstadt, K. Alan
Object Type: Report
System: The UNT Digital Library
Modeling the Reactions of Energetic Materials in the Condensed Phase (open access)

Modeling the Reactions of Energetic Materials in the Condensed Phase

High explosive (HE) materials are unique for having a strong exothermic reactivity, which has made them desirable for both military and commercial applications. Although the history of HE materials is long, condensed-phase properties are poorly understood. Understanding the condensed-phase properties of HE materials is important for determining stability and performance. Information regarding HE material properties (for example, the physical, chemical, and mechanical behaviors of the constituents in plastic-bonded explosive, or PBX, formulations) is necessary in efficiently building the next generation of explosives as the quest for more powerful energetic materials (in terms of energy per volume) moves forward. In addition, understanding the reaction mechanisms has important ramifications in disposing of such materials safely and cheaply, as there exist vast stockpiles of HE materials with corresponding contamination of earth and groundwater at these sites, as well as a military testing sites The ability to model chemical reaction processes in condensed phase energetic materials is rapidly progressing. Chemical equilibrium modeling is a mature technique with some limitations. Progress in this area continues, but is hampered by a lack of knowledge of condensed phase reaction mechanisms and rates. Atomistic modeling is much more computationally intensive, and is currently limited to very short time …
Date: December 3, 2003
Creator: Fried, L. E.; Manaa, M. R. & Lewis, J. P.
Object Type: Book
System: The UNT Digital Library
Multilayer Dielectric Gratings for Petawatt-Class Laser Systems (open access)

Multilayer Dielectric Gratings for Petawatt-Class Laser Systems

Existing Petawatt class lasers today based on Nd:glass architectures operating at nominally 500 J, 0.5 ps use meter-scale aperture, gold-overcoated master photoresist gratings to compress the amplified chirped pulse. Many lasers operating in the >lkJ, >Ips regime are in the planning stages around the world. These will require multilayer dielectric diffraction gratings to handle larger peak powers than can be accommodated with gold gratings. Models of the electric field distribution in the solid material of these gratings suggest that high aspect-ratio structures used at high incidence angles will have better laser damage resistance. New tooling for transfer etching these submicron-grating patterns and for nondestructive critical-dimension measurement of these features on meter-scale substrates will be described.
Date: December 3, 2003
Creator: Britten, J A; Molander, W; Komashko, A M & Barty, C P J
Object Type: Article
System: The UNT Digital Library
Performance and first physics results of the SVT trigger at CDF II (open access)

Performance and first physics results of the SVT trigger at CDF II

For the first time in a hadron collider, a novel trigger processor, the Silicon Vertex Trigger (SVT), allows to select the long-lived heavy flavor particles by cutting on the track impact parameter with a precision similar to that of the offline reconstruction. Triggering on displaced tracks has enriched the B-physics program by enhancing the B yields of the lepton-based triggers and opened up full hadronic triggering at CDF. After a first commissioning period, the SVT is fully operational, performing very closely to its design capabilities. System performance and first physics results based on SVT selected data samples are presented.
Date: December 3, 2003
Creator: Vila, I.
Object Type: Article
System: The UNT Digital Library
Rebuilding the Iraqi Media: Issues for Congress (open access)

Rebuilding the Iraqi Media: Issues for Congress

This report discusses the U.S. efforts to rebuild Iraqi media after the fall of Saddam Hussein's rule.
Date: December 3, 2003
Creator: Sharp, Jeremy M.
Object Type: Report
System: The UNT Digital Library
Social Security Reform (open access)

Social Security Reform

This report provides background and analysis on social security reform. The report discusses the most recent development, the basis for the debate, specific areas of contention and reform initiatives.
Date: December 3, 2003
Creator: Kollmann, Geoffrey & Nuschler, Dawn
Object Type: Report
System: The UNT Digital Library
Testing the cosmological constant as a candidate for dark energy (open access)

Testing the cosmological constant as a candidate for dark energy

It may be difficult to single out the best model of dark energy on the basis of the existing and planned cosmological observations, because many different models can lead to similar observational consequences. However, each particular model can be studied and either found consistent with observations or ruled out. In this paper, we concentrate on the possibility to test and rule out the simplest and by far the most popular of the models of dark energy, the theory described by general relativity with positive vacuum energy (the cosmological constant). We evaluate the conditions under which this model could be ruled out by the future observations made by the Supernova/Acceleration Probe SNAP (both for supernovae and weak lensing) and by the Planck Surveyor cosmic microwave background satellite.
Date: December 3, 2003
Creator: Kratochvil, Jan; Linde, Andrei; Linder, Eric V. & Shmakova, Marina
Object Type: Article
System: The UNT Digital Library
Active Cathodes for Super-High Power Density Solid Oxide Fuel Cells Through Space Charge Effects (open access)

Active Cathodes for Super-High Power Density Solid Oxide Fuel Cells Through Space Charge Effects

This report summarizes the work done during the third quarter of the project. Effort was directed in two areas: (1) Further development of the model on the role of connectivity on ionic conductivity of porous bodies, including the role of grain boundaries, and its relationship to cathode polarization. Included indirectly through the grain boundary effect is the effect of space charge. (2) Synthesis of LSC + SDC composite cathode powders by combustion synthesis. (3) Fabrication and testing of anode-supported single cells made using synthesized LSC + ScDC composite cathodes.
Date: November 3, 2003
Creator: Virkar, Anil V.
Object Type: Report
System: The UNT Digital Library
Analyzing flow patterns in unsaturated fractured rock of YuccaMountain using an integrated modeling approach (open access)

Analyzing flow patterns in unsaturated fractured rock of YuccaMountain using an integrated modeling approach

This paper presents a series of modeling investigations to characterize percolation patterns in the unsaturated zone of Yucca Mountain, Nevada, a proposed underground repository site for storing high-level radioactive waste. The investigations are conducted using a modeling approach that integrates a wide variety of moisture, pneumatic, thermal, and isotopic geochemical field data into a comprehensive three-dimensional numerical model through model calibration. This integrated modeling approach, based on a dual-continuum formulation, takes into account the coupled processes of fluid and heat flow and chemical isotopic transport in Yucca Mountain's highly heterogeneous, unsaturated fractured tuffs. In particular, the model results are examined against different types of field-measured data and used to evaluate different hydrogeological conceptual models and their effects on flow patterns in the unsaturated zone. The objective of this work to provide understanding of percolation patterns and flow behavior through the unsaturated zone, which is a crucial issue in assessing repository performance.
Date: November 3, 2003
Creator: Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Pan, Lehua & Bodvarsson,Gudmundur S.
Object Type: Article
System: The UNT Digital Library
Biologically-Induced Micropitting of Alloy 22, a Candidate Nuclear Waste Packaging Material (open access)

Biologically-Induced Micropitting of Alloy 22, a Candidate Nuclear Waste Packaging Material

The effects of potential microbiologically influenced corrosion (MIC) on candidate packaging materials for nuclear waste containment are being assessed. Coupons of Alloy 22, the outer barrier candidate for waste packaging, were exposed to a simulated, saturated repository environment (or microcosm) consisting of crushed rock (tuff) from the Yucca Mountain repository site and a continual flow of simulated groundwater for periods up to five years at room temperature and 30 C. Coupons were incubated with YM tuff under both sterile and non-sterile conditions. Surfacial analysis by scanning electron microscopy of the biotically-incubated coupons show development of both submicron-sized pinholes and pores; these features were not present on either sterile or untreated control coupons. Room temperature, biotically-incubated coupons show a wide distribution of pores covering the coupon surface, while coupons incubated at 30 C show the pores restricted to polishing ridges.
Date: November 3, 2003
Creator: Martin, S; Carrillo, C & Horn, J
Object Type: Article
System: The UNT Digital Library
The CDF-II tau physics program triggers, tau ID and preliminary results (open access)

The CDF-II tau physics program triggers, tau ID and preliminary results

The study of processes containing {tau} leptons in the final state will play an important role at Tevatron Run II. Such final states will be relevant both for electroweak studies and measurements as well as in searches for physics beyond the Standard Model. The present paper discusses the physics opportunities and challenges related to the implementation of new set of triggers able to select events containing tau candidates in the final state. They illustrate, in particular, the physics capabilities for a variety of new physics scenarios such as supersymmetry (SUSY), SUSY with Rp-parity violation, with Bilinear parity violation or models with the violation of lepton flavor. Finally, they present the first Run II results obtained using some of the described tau triggers.
Date: November 3, 2003
Creator: al., C. Pagliarone et
Object Type: Article
System: The UNT Digital Library
Characterize Framework for Igneous Activity at Yucca Mountain, Nevada (open access)

Characterize Framework for Igneous Activity at Yucca Mountain, Nevada

None
Date: November 3, 2003
Creator: Perry, F.; Youngs, R. & Vogt, T.
Object Type: Report
System: The UNT Digital Library
Comparison of States' Highway Construction Costs (open access)

Comparison of States' Highway Construction Costs

Correspondence issued by the General Accounting Office with an abstract that begins "We are reporting to Congress on whether Federal Highway Administration (FHWA) data can help transportation stakeholders understand how states' costs to build, reconstruct, and maintain federally financed highways, roads, and bridges (termed "constructing highways" for this report) compare. Durig our review, we became aware of significant issues regarding the quality of the data that FHWA collects and reports, a topic also discussed in this report."
Date: November 3, 2003
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Confirmed results of the 248Cm(48Ca,4n)292116 experiment (open access)

Confirmed results of the 248Cm(48Ca,4n)292116 experiment

The results of a detailed analysis performed on the data obtained in the {sup 248}Cm({sup 48}Ca,4n){sup 292}116 reaction is presented. This analysis is independent of the original data analysis performed in Dubna in which three separate decay chains were found. Each decay chain began with an evaporation residue followed by three {alpha} decays and ended in a spontaneous fission event, all correlated in time and position. The analysis presented confirms that the three events are present in the data. A summary of the three events will be given as well as a description of the analysis performed.
Date: November 3, 2003
Creator: Patin, J B; Moody, K J; Stoyer, M A; Wild, J F; Shaughnessy, D A & Stoyer, N J
Object Type: Report
System: The UNT Digital Library
Elastic and Poroelastic Analysis of Thomsen Parameters for Seismic Waves in Finely Layered VTI Media (open access)

Elastic and Poroelastic Analysis of Thomsen Parameters for Seismic Waves in Finely Layered VTI Media

None
Date: November 3, 2003
Creator: Berger, E. L.
Object Type: Article
System: The UNT Digital Library
Electroweak Physics with CDF (open access)

Electroweak Physics with CDF

The CDF experiment at the Tevatron has used p{bar p} collisions at {radical}s = 1.96 TeV to perform electroweak physics measurements. A program of precision electroweak tests of SM started measuring W and Z bosons cross section using different leptonic final states, evaluating dielectron Forward-Backward Asymmetry A{sub FB} and di-boson cross section production.
Date: November 3, 2003
Creator: Sidoti, A.
Object Type: Article
System: The UNT Digital Library
FY2003 LDRD Annual Report Article (open access)

FY2003 LDRD Annual Report Article

This study proposes to deliver fundamental experimental data on the melt and phase diagrams of methane in an extended region of high pressures and temperatures. This study targets three major scientific areas: the constraint of planetary models for the outer-giant planets, discovery of exotic phases and insights for many-body intermolecular interactions of non-hard sphere and non-spherical molecules for which no reliable theory exists for these models as yet. In this study, we will adopt in situ at high pressures and temperatures by using both conventional and coherent anti-Stokes Raman spectroscopy applied to laser- or ohmic heated diamond-anvil cells. Structures of methane will be characterized by using intense, third-generation synchrotron x-ray diffraction.
Date: November 3, 2003
Creator: Park, J.; Baer, B. & Yoo, C.
Object Type: Report
System: The UNT Digital Library
Homeland Security: Protecting Airliners from Terrorist Missiles (open access)

Homeland Security: Protecting Airliners from Terrorist Missiles

This report discusses about the Homeland Security on Protecting Airliners from Terrorist Missiles where Recent events have focused attention on the threat that terrorists with shoulder fired surface-to-air missiles (SAMs) pose to commercial airliners. Most believe that no single solution exists to effectively mitigate this threat.
Date: November 3, 2003
Creator: Bolkcom, Christopher; Elias, Bartholomew & Feickert, Andrew
Object Type: Report
System: The UNT Digital Library
Integrated Urban Dispersion Modeling Capability (open access)

Integrated Urban Dispersion Modeling Capability

Numerical simulations represent a unique predictive tool for developing a detailed understanding of three-dimensional flow fields and associated concentration distributions from releases in complex urban settings (Britter and Hanna 2003). The accurate and timely prediction of the atmospheric dispersion of hazardous materials in densely populated urban areas is a critical homeland and national security need for emergency preparedness, risk assessment, and vulnerability studies. The main challenges in high-fidelity numerical modeling of urban dispersion are the accurate prediction of peak concentrations, spatial extent and temporal evolution of harmful levels of hazardous materials, and the incorporation of detailed structural geometries. Current computational tools do not include all the necessary elements to accurately represent hazardous release events in complex urban settings embedded in high-resolution terrain. Nor do they possess the computational efficiency required for many emergency response and event reconstruction applications. We are developing a new integrated urban dispersion modeling capability, able to efficiently predict dispersion in diverse urban environments for a wide range of atmospheric conditions, temporal and spatial scales, and release event scenarios. This new computational fluid dynamics capability includes adaptive mesh refinement and it can simultaneously resolve individual buildings and high-resolution terrain (including important vegetative and land-use features), treat complex …
Date: November 3, 2003
Creator: Kosovic, B & Chan, S T
Object Type: Article
System: The UNT Digital Library
International Terrorism in South Asia (open access)

International Terrorism in South Asia

None
Date: November 3, 2003
Creator: Kronstadt, K. Alan
Object Type: Report
System: The UNT Digital Library