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Flood Insurance: FEMA's Rate-Setting Process Warrants Attention (open access)

Flood Insurance: FEMA's Rate-Setting Process Warrants Attention

A letter report issued by the Government Accountability Office with an abstract that begins "Questions about the financial status of the National Flood Insurance Program (NFIP) have increased since the 2005 hurricanes, which left the program with an unprecedented $17.4 billion deficit--a debt that resulted in GAO placing NFIP on its high-risk list in March 2006. Among the concerns are the subsidized rates NFIP must provide for about 25 percent of the policies, mostly for older buildings in high-risk flood zones. And although fully risk-based rates are supposed to reflect actual flood risk, concerns have been raised that they do not. This report evaluates (1) the Federal Emergency Management Agency's (FEMA) process for setting full-risk rates to determine whether it produces rates that accurately reflect the risk of flooding and (2) the process that FEMA uses to set subsidized rates and their effect on the financial condition of NFIP. To do this work, GAO evaluated the NFIP rate model, examined data from FEMA, surveyed relevant literature, and interviewed other relevant agencies and risk-modeling firms."
Date: October 31, 2008
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Defense Health Care: Additional Efforts Needed to Ensure Compliance with Personality Disorder Separation Requirements (open access)

Defense Health Care: Additional Efforts Needed to Ensure Compliance with Personality Disorder Separation Requirements

A letter report issued by the Government Accountability Office with an abstract that begins "At DOD, a personality disorder can render a servicemember unsuitable for service. GAO was required to report on personality disorder separations and examined (1) the extent that selected military installations complied with DOD's separation requirements and (2) how DOD ensures compliance with these requirements. GAO reviewed a sample of 312 servicemembers' records from four installations, representing the Army, Air Force, and Marine Corps, that had the highest or second highest number of Operation Enduring Freedom or Operation Iraqi Freedom servicemembers separated because of a personality disorder. The review is generalizable to the installations, but not to the services. GAO also reviewed 59 Navy servicemembers' records, but this review is not generalizable to the installation or the Navy because parts of the separation process could have been completed at multiple locations."
Date: October 31, 2008
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Status of GSA's Implementation of Selected Green Building Provisions of the Energy Independence and Security Act of 2007 (open access)

Status of GSA's Implementation of Selected Green Building Provisions of the Energy Independence and Security Act of 2007

Correspondence issued by the Government Accountability Office with an abstract that begins "According to the U.S. Environmental Protection Agency, buildings in the United States account for 68 percent of the nation's total electricity consumption and 39 percent of its total energy consumption. In December 2007, Congress enacted the Energy Independence and Security Act of 2007 (EISA) to, among other things, increase energy efficiency and the availability of renewable energy in federal buildings. Specifically, the act established new energy-related requirements and standards for federal buildings and for the agencies that oversee them. For example, it required the General Services Administration (GSA) to establish an Office of Federal High-Performance Green Buildings to coordinate green building information and activities within GSA and with other federal agencies. The act also required GAO to report to Congress on the implementation of certain provisions contained in EISA by October 31, 2008, and October 31, 2009. As determined in consultation with Congressional offices, this report fulfills the 2008 requirement by addressing the status of GSA's implementation of selected EISA requirements related to high-performance federal green buildings. We selected GSA as the focus of our initial report because GSA is responsible for the design, construction, operation, and maintenance …
Date: October 31, 2008
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Calendar Year 2007 Program Benefits for ENERGY STAR Labeled Products (open access)

Calendar Year 2007 Program Benefits for ENERGY STAR Labeled Products

ENERGY STAR is a voluntary energy efficiency-labeling program operated jointly by the United States Department of Energy and the United States Environmental Protection Agency (US EPA). Since the program inception in 1992, ENERGY STAR has become a leading international brand for energy efficient products. ENERGY STAR's central role in the development of regional, national, and international energy programs necessitates an open process whereby its program achievements to date as well as projected future savings are shared with committed stakeholders. Through 2007, the program saved 7.1 Quads of primary energy and avoided 128 MtC equivalent. The forecast shows that the program is expected to save 21.2 Quads of primary energy and avoid 375 MtC equivalent over the period 2008-2015. The sensitivity analysis bounds the best estimate of carbon avoided between 84 MtC and 172 MtC (1993 to 2007) and between 243 MtC and 519 MtC (2008 to 2015).
Date: October 31, 2008
Creator: Sanchez, Marla Christine; Homan, Gregory & Brown, Richard
Object Type: Report
System: The UNT Digital Library
The Effect of Terrorism on Public Confidence : An Exploratory Study. (open access)

The Effect of Terrorism on Public Confidence : An Exploratory Study.

A primary goal of terrorism is to instill a sense of fear and vulnerability in a population and to erode confidence in government and law enforcement agencies to protect citizens against future attacks. In recognition of its importance, the Department of Homeland Security includes public confidence as one of the metrics it uses to assess the consequences of terrorist attacks. Hence, several factors--including a detailed understanding of the variations in public confidence among individuals, by type of terrorist event, and as a function of time--are critical to developing this metric. In this exploratory study, a questionnaire was designed, tested, and administered to small groups of individuals to measure public confidence in the ability of federal, state, and local governments and their public safety agencies to prevent acts of terrorism. Data were collected from the groups before and after they watched mock television news broadcasts portraying a smallpox attack, a series of suicide bomber attacks, a refinery bombing, and cyber intrusions on financial institutions that resulted in identity theft and financial losses. Our findings include the following: (a) the subjects can be classified into at least three distinct groups on the basis of their baseline outlook--optimistic, pessimistic, and unaffected; (b) the …
Date: October 31, 2008
Creator: Berry, M. S.; Baldwin, T. E.; Samsa, M. E.; Ramaprasad, A. & Sciences, Decision and Information
Object Type: Report
System: The UNT Digital Library
Reliable and Repeatable Characterization of Optical Streak Cameras (open access)

Reliable and Repeatable Characterization of Optical Streak Cameras

Optical streak cameras are used as primary diagnostics for a wide range of physics and laser experiments at facilities such as the National Ignition Facility (NIF). To meet the strict accuracy requirements needed for these experiments, the systematic nonlinearities of the streak cameras (attributed to nonlinearities in the optical and electrical components that make up the streak camera system) must be characterized. In some cases the characterization information is used as a guide to help determine how experiment data should be taken. In other cases, the characterization data are applied to the raw data images to correct for the nonlinearities. In order to characterize an optical streak camera, a specific set of data is collected, where the response to defined inputs are recorded. A set of analysis software routines has been developed to extract information such as spatial resolution, dynamic range, and temporal resolution from this data set. The routines are highly automated, requiring very little user input and thus provide very reliable and repeatable results that are not subject to interpretation. An emphasis on quality control has been placed on these routines due to the high importance of the camera characterization information.
Date: October 31, 2008
Creator: Michael Charest Jr., Peter Torres III, Christopher Silbernagel, and Daniel Kalantar
Object Type: Article
System: The UNT Digital Library
Monte Carlo Simulations of High-speed, Time-gated MCP-based X-ray Detectors: Saturation Effects in DC and Pulsed Modes and Detector Dynamic Range (open access)

Monte Carlo Simulations of High-speed, Time-gated MCP-based X-ray Detectors: Saturation Effects in DC and Pulsed Modes and Detector Dynamic Range

We present here results of continued efforts to understand the performance of microchannel plate (MCP)–based, high-speed, gated, x-ray detectors. This work involves the continued improvement of a Monte Carlo simulation code to describe MCP performance coupled with experimental efforts to better characterize such detectors. Our goal is a quantitative description of MCP saturation behavior in both static and pulsed modes. We have developed a new model of charge buildup on the walls of the MCP channels and measured its effect on MCP gain. The results are compared to experimental data obtained with a short-pulse, high-intensity ultraviolet laser; these results clearly demonstrate MCP saturation behavior in both DC and pulsed modes. The simulations compare favorably to the experimental results. The dynamic range of the detectors in pulsed operation is of particular interest when fielding an MCP–based camera. By adjusting the laser flux we study the linear range of the camera. These results, too, are compared to our simulations.
Date: October 31, 2008
Creator: Craig Kruschwitz, Ming Wu, Ken Moy, Greg Rochau
Object Type: Article
System: The UNT Digital Library
Kahler Independence of the G2-MSSM (open access)

Kahler Independence of the G2-MSSM

The G{sub 2}-MSSM is a model of particle physics coupled to moduli fields with interesting phenomenology both for colliders and astrophysical experiments. In this paper we consider a more general model--whose moduli Kahler potential is a completely arbitrary G{sub 2}-holonomy Kahler potential and whose matter Kahler potential is also more general. We prove that the vacuum structure and spectrum of BSM particles is largely unchanged in this much more general class of theories. In particular, gaugino masses are still suppressed relative to the gravitino mass and moduli masses. We also consider the effects of higher order corrections to the matter Kahler potential and find a connection between the nature of the LSP and flavor effects.
Date: October 31, 2008
Creator: Acharya, Bobby S. & Bobkov, Konstantin
Object Type: Article
System: The UNT Digital Library
Production of Hydrogen for Clean and Renewable Source of Energy for Fuel Cell Vehicles (open access)

Production of Hydrogen for Clean and Renewable Source of Energy for Fuel Cell Vehicles

This was a two-year project that had two major components: 1) the demonstration of a PV-electrolysis system that has separate PV system and electrolysis unit and the hydrogen generated is to be used to power a fuel cell based vehicle; 2) the development of technologies for generation of hydrogen through photoelectrochemical process and bio-mass derived resources. Development under this project could lead to the achievement of DOE technical target related to PEC hydrogen production at low cost. The PEC part of the project is focused on the development of photoelectrochemical hydrogen generation devices and systems using thin-film silicon based solar cells. Two approaches are taken for the development of efficient and durable photoelectrochemical cells; 1) An immersion-type photoelectrochemical cells (Task 3) where the photoelectrode is immersed in electrolyte, and 2) A substrate-type photoelectrochemical cell (Task 2) where the photoelectrode is not in direct contact with electrolyte. Four tasks are being carried out: Task 1: Design and analysis of DC voltage regulation system for direct PV-to-electrolyzer power feed Task 2: Development of advanced materials for substrate-type PEC cells Task 3: Development of advanced materials for immersion-type PEC cells Task 4: Hydrogen production through conversion of biomass-derived wastes
Date: October 31, 2008
Creator: Deng, Xunming; Ingler, William B, Jr.; Abraham, Martin; Castellano, Felix; Coleman, Maria; Collins, Robert et al.
Object Type: Report
System: The UNT Digital Library
NSLS-II Control of Dynamic Aperture (open access)

NSLS-II Control of Dynamic Aperture

We have outlined how, by an intuitive approach, the on- and off-momentum dynamic aperture for a synchrotron light source can be estimated from a nonlinear system of algebraic equations for the sextupole/multipole strengths. The approach has only two free parameters: the relative weight for resonance vs. tune shift terms and the tune footprint for stable trajectories in a modern third generation synchrotron light source. In other words, we have established a control theory approach for the medium term (10{sup 3} turns) stability for a dynamic system described by a nonlinear system of ordinary differential equations. Equipped with a predictive, quantitative model for stability, we have then evaluated how to improve the control of the dynamics by analyzing and modifying the properties of the corresponding algebraic system. In particular, by changing the number- and characteristics of the parameters, i.e., we have not evaluated how the underlying (linear) optics could be improved. We have also validated our conjectures by numerical simulations with a realistic model. Presumably, our conclusions, summarized in Section 1.0, are a direct result of the presented analysis and observations.
Date: October 31, 2008
Creator: Bengtsson,J.
Object Type: Report
System: The UNT Digital Library
Flat Field Anomalies in an X-ray CCD Camera Measured Using a Manson X-ray Source (open access)

Flat Field Anomalies in an X-ray CCD Camera Measured Using a Manson X-ray Source

The Static X-ray Imager (SXI) is a diagnostic used at the National Ignition Facility (NIF) to measure the position of the X-rays produced by lasers hitting a gold foil target. The intensity distribution taken by the SXI camera during a NIF shot is used to determine how accurately NIF can aim laser beams. This is critical to proper NIF operation. Imagers are located at the top and the bottom of the NIF target chamber. The CCD chip is an X-ray sensitive silicon sensor, with a large format array (2k x 2k), 24 μm square pixels, and 15 μm thick. A multi-anode Manson X-ray source, operating up to 10kV and 10W, was used to characterize and calibrate the imagers. The output beam is heavily filtered to narrow the spectral beam width, giving a typical resolution E/ΔE≈10. The X-ray beam intensity was measured using an absolute photodiode that has accuracy better than 1% up to the Si K edge and better than 5% at higher energies. The X-ray beam provides full CCD illumination and is flat, within ±1% maximum to minimum. The spectral efficiency was measured at 10 energy bands ranging from 930 eV to 8470 eV. We observed an energy dependent …
Date: October 31, 2008
Creator: Schneider, M. J. Haugh and M. B.
Object Type: Article
System: The UNT Digital Library
Synchrotron Radiation Photoemission Spectroscopic Study of Band Offsets and Interface Self-cleaning by Atomic Layer Deposited HfO2 on In0.53Ga0.47As and In0.52Al0.48As (open access)

Synchrotron Radiation Photoemission Spectroscopic Study of Band Offsets and Interface Self-cleaning by Atomic Layer Deposited HfO2 on In0.53Ga0.47As and In0.52Al0.48As

The Synchrotron Radiation Photoemission Spectroscopic (SRPES) study was conducted to (a) investigate the surface chemistry of In{sub 0.53}Ga{sub 0.47}As and In{sub 0.52}Al{sub 0.48}As post chemical and thermal treatments, (b) construct band diagram and (c) investigate the interface property of HfO{sub 2}/In{sub 0.53}Ga{sub 0.47}As and HfO{sub 2}/In{sub 0.52}Al{sub 0.48}As. Dilute HCl and HF etch remove native oxides on In{sub 0.53}Ga{sub 0.47}As and In{sub 0.52}Al{sub 0.47}As, whereas in-situ vacuum annealing removes surface arsenic pile-up. After the atomic layer deposition of HfO{sub 2}, native oxides were considerably reduced compared to that in as-received epi-layers, strongly suggesting the self-clean mechanism. Valence and conduction band offsets are measured to be 3.37 {+-} 0.1eV, 1.80 {+-} 0.3eV for In{sub 0.53}Ga{sub 0.47}As and 3.00 {+-} 0.1eV, 1.47 {+-} 0.3eV for In{sub 0.52}Al{sub 0.47}As, respectively.
Date: October 31, 2008
Creator: Kobayashi, Masaharu; /SLAC, SSRL; Chen, P.T.; Sun, Y.; Goel, N.; Majhi, P. et al.
Object Type: Article
System: The UNT Digital Library
Characterization of Fine Particulate Matter (PM) and Secondary PM Precursor Gases in the Mexico City Metropolitan Area (open access)

Characterization of Fine Particulate Matter (PM) and Secondary PM Precursor Gases in the Mexico City Metropolitan Area

This project was one of three collaborating grants funded by DOE/ASP to characterize the fine particulate matter (PM) and secondary PM precursors in the Mexico City Metropolitan Area (MCMA) during the MILAGRO Campaign. The overall effort of MCMA-2006, one of the four components, focused on i) examination of the primary emissions of fine particles and precursor gases leading to photochemical production of atmospheric oxidants and secondary aerosol particles; ii) measurement and analysis of secondary oxidants and secondary fine PM production, with particular emphasis on secondary organic aerosol (SOA), and iii) evaluation of the photochemical and meteorological processes characteristic of the Mexico City Basin. The collaborative teams pursued the goals through three main tasks: i) analyses of fine PM and secondary PM precursor gaseous species data taken during the MCMA-2002/2003 campaigns and preparation of publications; ii) planning of the MILAGRO Campaign and deployment of the instrument around the MCMA; and iii) analysis of MCMA-2006 data and publication preparation. The measurement phase of the MILAGRO Campaign was successfully completed in March 2006 with excellent participation from the international scientific community and outstanding cooperation from the Mexican government agencies and institutions. The project reported here was led by the Massachusetts Institute of Technology/Molina …
Date: October 31, 2008
Creator: Luisa T. Molina, Rainer Volkamer, Benjamin de Foy, Wenfang Lei, Miguel Zavala, Erik Velasco & Molina, Mario J.
Object Type: Report
System: The UNT Digital Library
Field Survey of Cactus Crater Storage Facility (Runit Dome) (open access)

Field Survey of Cactus Crater Storage Facility (Runit Dome)

The US Department of Energy, Office of Health and Safety (DOE/HS-10), requested that National Security Technologies, LLC, Environmental Management directorate (NSTec/EM) perform a field survey of the Cactus Crater Storage Facility (Runit Dome), similar to past surveys conducted at their request. This field survey was conducted in conjunction with a Lawrence Livermore National Laboratory (LLNL) mission on Runit Island in the Enewetak Atoll in the Republic of the Marshall Islands (RMI). The survey was strictly a visual survey, backed up by digital photos and a written description of the current condition.
Date: October 31, 2008
Creator: Douglas Miller, Terence Holland
Object Type: Report
System: The UNT Digital Library
Using Beam Echo Effect for Generation of Short-Wavelength Radiation (open access)

Using Beam Echo Effect for Generation of Short-Wavelength Radiation

We propose to use an echo effect previously observed in hadron accelerators for up-frequency conversion of density modulation in an electron beam. We show that, for generation of high harmonics, this method is much more efficient in comparison with the currently used approach. A one dimensional model of the effect is developed which allows to optimize the amplitude of the modulation for a given harmonic number.
Date: October 31, 2008
Creator: Stupakov, G.
Object Type: Article
System: The UNT Digital Library
Observation and Polarization of B->phiK1+ and phiK*2+ (open access)

Observation and Polarization of B->phiK1+ and phiK*2+

With the full BABAR data sample of 465 million B{bar B} pairs, they observe the decays B{sup {+-}} {yields} {psi}K{sub 1}(1270){sup {+-}} and B{sup {+-}} {yields} {psi}K*{sub 2}(1430){sup {+-}}. They measure the branching fractions (6.1 {+-} 1.6 {+-} 1.1) x 10{sup -6} and (8.4 {+-} 1.9 {+-} 0.9) x 10{sup -6} and the fractions of longitudinal polarization 0.46{sub -0.13-0.07}{sup +0.12+0.03} and 0.80{sub -0.10}{sup +0.09} {+-} 0.03, respectively. They also report on the B{sup {+-}} {yields} {psi}K*{sub 0}(1430){sup {+-}} decay branching fraction of (7.0 {+-} 1.3 {+-} 0.9) x 10{sup -6} and several parameters sensitive to CP violation and interference in the above three decays. Upper limits are placed on the B{sup {+-}} decay rates to final states with {psi} and K{sub 1}(1400){sup {+-}}, K*(1410){sup {+-}}, K{sub 2}(1770){sup {+-}}, or K{sub 2}(1820){sup {+-}}. Understanding the observed polarization pattern requires amplitude contributions from an uncertain source.
Date: October 31, 2008
Creator: Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
Object Type: Article
System: The UNT Digital Library
The Role of Liquid Waste Pretreatment Technologies in Solving the Doe Clean-Up Mission (open access)

The Role of Liquid Waste Pretreatment Technologies in Solving the Doe Clean-Up Mission

The objective of this report is to describe the pretreatment solutions that allow treatment to be tailored to specific wastes, processing ahead of the completion schedules for the main treatment facilities, and reduction of technical risks associated with future processing schedules. Wastes stored at Hanford and Savannah River offer challenging scientific and engineering tasks. At both sites, space limitations confound the ability to effectively retrieve and treat the wastes. Additionally, the radiation dose to the worker operating and maintaining the radiochemical plants has a large role in establishing the desired radioactivity removal. However, the regulatory requirements to treat supernatant and saltcake tank wastes differ at the two sites. Hanford must treat and remove radioactivity from the tanks based on the TriParty Agreement and Waste Incidental to Reprocessing (WIR) documentation. These authorizing documents do not specify treatment technologies; rather, they specify endstate conditions. Dissimilarly, Waste Determinations prepared at SRS in accordance with Section 3116 of the 2005 National Defense Authorization Act along with state operating permits establish the methodology and amounts of radioactivity that must be removed and may be disposed of in South Carolina. After removal of entrained solids and site-specific radionuclides, supernatant and saltcake wastes are considered to be …
Date: October 31, 2008
Creator: Wilmarth, B. & Sheryl Bush, S.
Object Type: Report
System: The UNT Digital Library
Mechanisms of Low Dose Radiation-induced T helper Cell Function (open access)

Mechanisms of Low Dose Radiation-induced T helper Cell Function

Exposure to radiation above levels normally encountered on Earth can occur during wartime, accidents such as those at Three Mile Island and Chernobyl, and detonation of “dirty bombs” by terrorists. Relatively high levels of radiation exposure can also occur in certain occupations (low-level waste sites, nuclear power plants, nuclear medicine facilities, airline industry, and space agencies). Depression or dysfunction of the highly radiosensitive cells of the immune system can lead to serious consequences, including increased risk for infections, cancer, hypersensitivity reactions, poor wound healing, and other pathologies. The focus of this research was on the T helper (Th) subset of lymphocytes that secrete cytokines (proteins), and thus control many actions and interactions of other cell types that make up what is collectively known as the immune system. The Department of Energy (DOE) Low Dose Radiation Program is concerned with mechanisms altered by exposure to high energy photons (x- and gamma-rays), protons and electrons. This study compared, for the first time, the low-dose effects of two of these radiation forms, photons and protons, on the response of Th cells, as well as other cell types with which they communicate. The research provided insights regarding gene expression patterns and capacity to secrete …
Date: October 31, 2008
Creator: Gridley, Daila S.
Object Type: Report
System: The UNT Digital Library
The Origin of the Monochromatic Photoemission Peak in Diamondoid Monolayers (open access)

The Origin of the Monochromatic Photoemission Peak in Diamondoid Monolayers

Recent photoemission experiments have discovered a highly monochromatized secondary electron peak emitted from diamondoid self-assembled monolayers on metal substrates. New experimental data and simulation results are presented to show that a combination of negative electron affinity and strong electron-phonon scattering is responsible for this behavior. The simulation results are generated using a simple Monte Carlo transport algorithm. The simulated spectra contain the main spectral features of the measured ones.
Date: October 31, 2008
Creator: Clay, William A.; Liu, Zhi; Yang, Wanli; Fabbri, Jason D.; Dahl, Jeremy E.; Carlson, Robert M.K. et al.
Object Type: Article
System: The UNT Digital Library
Arsenic-Dominated Chemistry in the Acid Cleaning of InGaAs and InAlAs Surfaces (open access)

Arsenic-Dominated Chemistry in the Acid Cleaning of InGaAs and InAlAs Surfaces

The surface cleaning of InGaAs and InAlAs is studied using Synchrotron Radiation Photoelectron Spectroscopy. Thermal annealing at 400 C can not completely remove the native oxides from those surfaces. Elemental arsenic build-up is observed on both surfaces after acid treatment using HCl, HF or H{sub 2}SO{sub 4} solutions, which is similar to acid-cleaned GaAs surface. Cleaned InGaAs surface is oxide free but small amount of aluminum oxide remains on cleaned InAlAs surface. The common chemical reactions between III-As semiconductors and acid solutions are identified and are found to be dominated by arsenic chemistry.
Date: October 31, 2008
Creator: Sun, Y.; Pianetta, P.; Chen, P.-T.; Kobayashi, M.; Nishi, Y.; Goel, N. et al.
Object Type: Article
System: The UNT Digital Library
Shielding analysis and design of the KIPT experimental neutron source facility of Ukraine. (open access)

Shielding analysis and design of the KIPT experimental neutron source facility of Ukraine.

Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an experimental neutron source facility based on the use of an electron accelerator driven subcritical (ADS) facility [1]. The facility uses the existing electron accelerators of KIPT in Ukraine. The neutron source of the sub-critical assembly is generated from the interaction of 100 KW electron beam with a natural uranium target. The electron beam has a uniform spatial distribution and the electron energy in the range of 100 to 200 MeV, [2]. The main functions of the facility are the production of medical isotopes and the support of the Ukraine nuclear power industry. Reactor physics experiments and material performance characterization will also be carried out. The subcritical assembly is driven by neutrons generated by the electron beam interactions with the target material. A fraction of these neutrons has an energy above 50 MeV generated through the photo nuclear interactions. This neutron fraction is very small and it has an insignificant contribution to the subcritical assembly performance. However, these high energy neutrons are difficult to shield and they can be slowed down only through the inelastic …
Date: October 31, 2008
Creator: Zhong, Z.; Gohar, M. Y. A.; Naberezhnev, D. & Duo, J.
Object Type: Report
System: The UNT Digital Library
Chemical Bonding, Interfaces and Defects in Hafnium Oxide/Germanium Oxynitride Gate Stacks on Ge (100) (open access)

Chemical Bonding, Interfaces and Defects in Hafnium Oxide/Germanium Oxynitride Gate Stacks on Ge (100)

Correlations among interface properties and chemical bonding characteristics in HfO{sub 2}/GeO{sub x}N{sub y}/Ge MIS stacks were investigated using in-situ remote nitridation of the Ge (100) surface prior to HfO{sub 2} atomic layer deposition (ALD). Ultra thin ({approx}1.1 nm), thermally stable and aqueous etch-resistant GeO{sub x}N{sub y} interfaces layers that exhibited Ge core level photoelectron spectra (PES) similar to stoichiometric Ge{sub 3}N{sub 4} were synthesized. To evaluate GeO{sub x}N{sub y}/Ge interface defects, the density of interface states (D{sub it}) was extracted by the conductance method across the band gap. Forming gas annealed (FGA) samples exhibited substantially lower D{sub it} ({approx} 1 x 10{sup 12} cm{sup -2} eV{sup -1}) than did high vacuum annealed (HVA) and inert gas anneal (IGA) samples ({approx} 1x 10{sup 13} cm{sup -2} eV{sup -1}). Germanium core level photoelectron spectra from similar FGA-treated samples detected out-diffusion of germanium oxide to the HfO{sub 2} film surface and apparent modification of chemical bonding at the GeO{sub x}N{sub y}/Ge interface, which is related to the reduced D{sub it}.
Date: October 31, 2008
Creator: Oshima, Yasuhiro; /Stanford U., Materials Sci. Dept.; Sun, Yun; /SLAC, SSRL; Kuzum, Duygu; U., /Stanford et al.
Object Type: Article
System: The UNT Digital Library
Greensheet (Houston, Tex.), Vol. 39, No. 466, Ed. 1 Friday, October 31, 2008 (open access)

Greensheet (Houston, Tex.), Vol. 39, No. 466, Ed. 1 Friday, October 31, 2008

Free weekly newspaper that includes business and classified advertising.
Date: October 31, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Greensheet (Houston, Tex.), Vol. 39, No. 468, Ed. 1 Friday, October 31, 2008 (open access)

Greensheet (Houston, Tex.), Vol. 39, No. 468, Ed. 1 Friday, October 31, 2008

Free weekly newspaper that includes business and classified advertising.
Date: October 31, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History