Background Acoustic Noise Models for the IMS Hydroacoustic Stations (open access)

Background Acoustic Noise Models for the IMS Hydroacoustic Stations

None
Date: June 23, 2010
Creator: Harben, P. E. & Hauk, T. F.
Object Type: Article
System: The UNT Digital Library
Low-Intensity Nonlinear Spectral Effects in Compton Scattering (open access)

Low-Intensity Nonlinear Spectral Effects in Compton Scattering

Nonlinear effects are known to occur in Compton scattering light sources, when the laser normalized 4-potential, A = e{radical}-A{sub {mu}}A{sup {mu}}/m{sub 0}c approaches unity. In this letter, it is shown that nonlinear spectral features can appear at arbitrarily low values of A, if the fractional bandwidth of the laser pulse, {Delta}{phi}{sup -1}, is sufficiently small to satisfy A{sup 2} {Delta}{phi} {approx_equal} 1. A three dimensional analysis, based on a local plane-wave, slow-varying envelope approximation, enables the study of these effects for realistic interactions between an electron beam and a laser pulse, and their influence on high-precision Compton scattering light sources.
Date: February 23, 2010
Creator: Hartemann, F V; Albert, F; Siders, C W & Barty, C P
Object Type: Article
System: The UNT Digital Library
NANA Wind Resource Assessment Program Final Report (open access)

NANA Wind Resource Assessment Program Final Report

NANA Regional Corporation (NRC) of northwest Alaska is located in an area with abundant wind energy resources. In 2007, NRC was awarded grant DE-FG36-07GO17076 by the US Department of Energy's Tribal Energy Program for funding a Wind Resource Assessment Project (WRAP) for the NANA region. The NANA region, including Kotzebue Electric Association (KEA) and Alaska Village Electric Cooperative (AVEC) have been national leaders at developing, designing, building, and operating wind-diesel hybrid systems in Kotzebue (starting in 1996) and Selawik (2002). Promising sites for the development of new wind energy projects in the region have been identified by the WRAP, including Buckland, Deering, and the Kivalina/Red Dog Mine Port Area. Ambler, Shungnak, Kobuk, Kiana, Noorvik & Noatak were determined to have poor wind resources at sites in or very near each community. However, all five of these communities may have better wind resources atop hills or at sites with slightly higher elevations several miles away.
Date: September 23, 2010
Creator: Hermanson, Jay
Object Type: Report
System: The UNT Digital Library
Versatile device for in-situ discharge cleaning and multiple coatings of long, small diameter tubes (open access)

Versatile device for in-situ discharge cleaning and multiple coatings of long, small diameter tubes

Electron clouds, which can limit machine performance, have been observed in many accelerators including RHIC at BNL. Additional concern for the RHIC machine, whose vacuum chamber is made from relatively high resistivity 316LN stainless steel, is high wall resistivity that can result in unacceptably high ohmic heating for superconducting magnets. The high resistivity can be addressed with a copper (Cu) coating; a reduction in the secondary electron yield can be achieved with a TiN or amorphous carbon (a-C) coating. Applying such coatings in an already constructed machine is rather challenging. We have been developing a robotic plasma deposition technique for in-situ coating of long, small diameter tubes. The technique entails fabricating a device comprising of staged magnetrons mounted on a mobile mole for deposition of about 5 ?m of Cu followed by about 0.1 ?m of a-C. As a first step, a 15-cm Cu cathode magnetron was designed, fabricated, and 30-cm long samples of the RHIC pipe have been coated with 2 ?m to 5.6 ?m of copper. Deposition rates of up to 92 A/sec with an average coating rate of 30 A/sec were measured. Effects on RF resistivity is also to be measured.
Date: May 23, 2010
Creator: Hershcovitch, A.; Blaskiewicz, M.; Brennan, J. M.; Custer, A.; Erickson, M.; Liaw, C. J. et al.
Object Type: Article
System: The UNT Digital Library
Inelastic X-ray Scattering Investigations of Lattice Dynamics in SmFeAsO1-xFy Superconductors (open access)

Inelastic X-ray Scattering Investigations of Lattice Dynamics in SmFeAsO1-xFy Superconductors

We report measurements of the phonon density of states as measured with inelastic x-ray scattering in SmFeAsO{sub 1-x}F{sub y} powders. An unexpected strong renormalization of phonon branches around 23 meV is observed as fluorine is substituted for oxygen. Phonon dispersion measurements on SmFeAsO{sub 1-x}F{sub y} single crystals allow us to identify the 21 meV A{sub 1g} in-phase (Sm,As) and the 26 meV B{sub 1g} (Fe,O) modes to be responsible for this renormalization, and may reaveal unusual electron-phonon coupling through the spin channel in iron-based superconductors.
Date: May 23, 2010
Creator: Hill, J. P.; Le Tacon, M.; Forrest, T. R.; Ruegg, Ch.; Bosak, A.; Noffsinger, J. et al.
Object Type: Article
System: The UNT Digital Library
Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine (open access)

Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine

Neighbors living near the 3 turbine, 4.5 MW Vinalhaven, Maine wind power facility, which began operations in late 2009, have complained that the noise from the turbines is unwelcome and annoying. Fox Islands Wind, the owner of the facility, hypothesized that implementing a Noise Reduced Operation (NRO) for the turbines, which effectively limits the turbines maximum rpm and power output, would reduce the sound levels produced by the turbines, and therefore might also reduce the degree to which the neighbors report being annoyed by those sounds. To test this hypothesis in a preliminary fashion, a pilot study was conducted in early 2010, the results of which are the subject of this brief report. The study included asking near-by residents - those within roughly 3000 feet - to rate the sounds and the degree to which they were annoyed by them using logs which they filled out at multiple times during the day on as many days as were possible in the 35 day study period in February and March, 2010. Meanwhile, FIW adjusted the NRO settings of the turbines in a random fashion in the evenings during the same period, but in a pattern that the respondents were not made …
Date: June 23, 2010
Creator: Hoen, Ben; Wiser, Ryan & Eckholdt, Haftan
Object Type: Report
System: The UNT Digital Library
Nuclear Power Plant Security and Vulnerabilities (open access)

Nuclear Power Plant Security and Vulnerabilities

This report discusses the physical security at nuclear power plants. The physical security of nuclear power plants and their vulnerability to deliberate acts of terrorism was elevated to a national security concern following the attacks of September 11, 2001. Since the attacks, Congress has repeatedly focused oversight and legislative attention on nuclear power plant security requirements established and enforced by the Nuclear Regulatory Commission (NRC).
Date: August 23, 2010
Creator: Holt, Mark & Andrews, Anthony
Object Type: Report
System: The UNT Digital Library
On the Mechanism of Anomalous Slip in BCC Metals (open access)

On the Mechanism of Anomalous Slip in BCC Metals

None
Date: August 23, 2010
Creator: Hsiung, L. L.
Object Type: Article
System: The UNT Digital Library
Spin dynamics simulations at AGS (open access)

Spin dynamics simulations at AGS

To preserve proton polarization through acceleration, it is important to have a correct model of the process. It has been known that with the insertion of the two helical partial Siberian snakes in the Alternating Gradient Synchrotron (AGS), the MAD model of AGS can not deal with a field map with offset orbit. The stepwise ray-tracing code Zgoubi provides a tool to represent the real electromagnetic fields in the modeling of the optics and spin dynamics for the AGS. Numerical experiments of resonance crossing, including spin dynamics in presence of the snakes and Q-jump, have been performed in AGS lattice models, using Zgoubi. This contribution reports on various results so obtained.
Date: May 23, 2010
Creator: Huang, H.; MacKay, W. W.; Meot, F. & Roser, T.
Object Type: Article
System: The UNT Digital Library
Meteorology-induced variations in the spatial behavior of summer ozone pollution in Central California (open access)

Meteorology-induced variations in the spatial behavior of summer ozone pollution in Central California

Cluster analysis was applied to daily 8 h ozone maxima modeled for a summer season to characterize meteorology-induced variations in the spatial distribution of ozone. Principal component analysis is employed to form a reduced dimension set to describe and interpret ozone spatial patterns. The first three principal components (PCs) capture {approx}85% of total variance, with PC1 describing a general spatial trend, and PC2 and PC3 each describing a spatial contrast. Six clusters were identified for California's San Joaquin Valley (SJV) with two low, three moderate, and one high-ozone cluster. The moderate ozone clusters are distinguished by elevated ozone levels in different parts of the valley: northern, western, and eastern, respectively. The SJV ozone clusters have stronger coupling with the San Francisco Bay area (SFB) than with the Sacramento Valley (SV). Variations in ozone spatial distributions induced by anthropogenic emission changes are small relative to the overall variations in ozone amomalies observed for the whole summer. Ozone regimes identified here are mostly determined by the direct and indirect meteorological effects. Existing measurement sites are sufficiently representative to capture ozone spatial patterns in the SFB and SV, but the western side of the SJV is under-sampled.
Date: June 23, 2010
Creator: Jin, Ling; Harley, Robert A. & Brown, Nancy J.
Object Type: Article
System: The UNT Digital Library
Results of the FY09 Enhanced DOE High Level Waste Melter Throughput Studies at SRNL (open access)

Results of the FY09 Enhanced DOE High Level Waste Melter Throughput Studies at SRNL

High-level waste (HLW) throughput (i.e., the amount of waste processed per unit time) is a function of two critical parameters: waste loading (WL) and melt rate. For the Waste Treatment and Immobilization Plant (WTP) at the Hanford Site and the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS), increasing HLW throughput would significantly reduce the overall mission life cycle costs for the Department of Energy (DOE). The objective of this task is to develop data, assess property models, and refine or develop the necessary models to support increased WL of HLW at SRS. It is a continuation of the studies initiated in FY07, but is under the specific guidance of a Task Change Request (TCR)/Work Authorization received from DOE headquarters (Project Number RV071301). Using the data generated in FY07, FY08 and historical data, two test matrices (60 glasses total) were developed at the Savannah River National Laboratory (SRNL) in order to generate data in broader compositional regions. These glasses were fabricated and characterized using chemical composition analysis, X-ray Diffraction (XRD), viscosity, liquidus temperature (TL) measurement and durability as defined by the Product Consistency Test (PCT). The results of this study are summarized below: (1) In general, the …
Date: June 23, 2010
Creator: Johnson, F. & Edwards, T.
Object Type: Report
System: The UNT Digital Library
Food Safety in the 111th Congress (open access)

Food Safety in the 111th Congress

This report discusses whether the current food safety system has the resources, authority, and structural organization to safeguard the health of American consumers, who spend more than $1 trillion on food each year. Also at issue is whether federal food safety laws, first enacted in the early 1900s, have kept pace with the significant changes that have occurred in the food production, processing, and marketing sectors since then.
Date: September 23, 2010
Creator: Johnson, Renée
Object Type: Report
System: The UNT Digital Library
Tariff Modifications: Miscellaneous Tariff Bills (open access)

Tariff Modifications: Miscellaneous Tariff Bills

Importers often request that Members of Congress introduce bills seeking to suspend or reduce tariffs on certain imports on their behalf. This report discusses the current process by which duty suspension bills and other provisions are introduced, reviewed by several government agencies and committee staff, made available for public comment, and finally included in omnibus miscellaneous trade and technical corrections bills (MTB) legislation reported out by the committees of jurisdiction.
Date: July 23, 2010
Creator: Jones, Vivian C.
Object Type: Report
System: The UNT Digital Library
U.S.-South Korea Beef Dispute: Issues and Status (open access)

U.S.-South Korea Beef Dispute: Issues and Status

This report describes the beef provisions in the Korea-U.S. Free Trade Agreement (KORUS FTA) and the separate bilateral protocols that the United States has negotiated in order to secure the lifting of South Korea's ban on U.S. beef imports, imposed after the discovery of mad cow disease in late 2003. It also summarizes U.S. beef export developments to this key market before and after the ban and since these protocols took effect; and lays out the outstanding issues on U.S. beef access that will likely need to be resolved to facilitate congressional consideration of the KORUS FTA.
Date: September 23, 2010
Creator: Jurenas, Remy & Manyin, Mark E.
Object Type: Report
System: The UNT Digital Library
Iran Sanctions (open access)

Iran Sanctions

This report looks at the purposes and results of U.S. sanctions in Iran, which were initiated as a result of Iran's nuclear program and human rights issues. It ends by discussing future issues that Congress can consider regarding the sanctions.
Date: June 23, 2010
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library
Iran: U.S. Concerns and Policy Responses (open access)

Iran: U.S. Concerns and Policy Responses

This report discusses the reasons that Iran is considered a threat to U.S. security, including Iran's nuclear program, involvement with terrorist organizations, and involvement with neighboring countries' local governments. The report also discusses ways which the U.S. hopes to modify Iran's behavior with sanctions, and the effectiveness of these sanctions.
Date: July 23, 2010
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library
The United Arab Emirates (UAE): Issues for U.S. Policy (open access)

The United Arab Emirates (UAE): Issues for U.S. Policy

This report describes the open economy and society of the United Arab Emirates (UAE), as well as U.S. concern over proliferation of advanced technology due to said open economy and the UAE's lax export controls. This report describes these issues in relation to a recently-signed U.S.-UAE civilian nuclear agreement. It also provides a general description of the UAE's government and political structure, as well as the effects of the recent global economic downturn on the UAE in general and on the city of Dubai in particular.
Date: June 23, 2010
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library
The Carboxysome and Other Bacterial Microcompartments (open access)

The Carboxysome and Other Bacterial Microcompartments

- Carboxysomes are part of the carbon concentrating mechanism in cyanobacteria and chemoautotrophs. - Carboxysomes are a subclass of bacterial microcompartments (BMCs); BMCs can encapsulate a range of metabolic processes. - Like some viral particles, the carboxysome can be modeled as an icosahedron-in its case, having 4,000-5,000 hexameric shell subunits and 12 surface pentamers to generate curvature. - The threefold axis of symmetry of the CsoS1D protein in carboxysomes forms a pore that can open and close, allowing for selective diffusion. - Genetic modules encoding BMC shell proteins and the enzymes that they encapsulate are horizontally transferable, suggesting they enable bacteria to adapt to diverse environments.
Date: June 23, 2010
Creator: Kerfeld, Cheryl A.; Greenleaf, William B. & Kinney, James N.
Object Type: Article
System: The UNT Digital Library
Pakistan's Nuclear Weapons: Proliferation and Security Issues (open access)

Pakistan's Nuclear Weapons: Proliferation and Security Issues

This report discusses Pakistan's efforts to produce fissile material and other issues related to nuclear proliferation and improving its nuclear arsenal. It also discusses the steps Pakistan has taken to increase international confidence in its nuclear security. However, continued instability in Pakistan has caused some to question the effectiveness of its nuclear security reforms. The report addresses these issues as well, in addition to the U.S.-Pakistan relationship as it regards nuclear policy.
Date: February 23, 2010
Creator: Kerr, Paul K. & Nikitin, Mary Beth
Object Type: Report
System: The UNT Digital Library
Characteristics of Knock in Hydrogen-Oxygen-Argon SI Engine (open access)

Characteristics of Knock in Hydrogen-Oxygen-Argon SI Engine

A promising approach for improving the efficiency of internal combustion engines is to employ a working fluid with a high specific heat ratio such as the noble gas argon. Moreover, all harmful emissions are eliminated when the intake charge is composed of oxygen, nonreactive argon, and hydrogen fuel. Previous research demonstrated indicated thermal efficiencies greater than 45% at 5.5 compression ratio in engines operating with hydrogen, oxygen, and argon. However, knock limits spark advance and increasing the efficiency further. Conditions under which knock occurs in such engines differs from typical gasoline fueled engines. In-cylinder temperatures using hydrogen-oxygen-argon are higher due to the high specific heat ratio and pressures are lower because of the low compression ratio. Better understanding of knock under these conditions can lead to operating strategies that inhibit knock and allow operation closer to the knock limit. In this work we compare knock with a hydrogen, oxygen, and argon mixture to that of air-gasoline mixtures in a variable compression ratio cooperative fuels research (CFR) engine. The focus is on stability of knocking phenomena, as well as, amplitude and frequency of the resulting pressure waves.
Date: February 23, 2010
Creator: Killingsworth, Nick J.; Rapp, Vi H.; Flowers, Daniel L.; Aceves, Salvador M.; Chen, J-Y. & Dibble, Robert
Object Type: Article
System: The UNT Digital Library
Angular distribution of laser ablation plasma (open access)

Angular distribution of laser ablation plasma

An expansion of a laser induced plasma is fundamental and important phenomena in a laser ion source. To understand the expanding direction, an array of Langmuir probes were employed. The chosen ion for the experiment was Ag{sup 1+} which was created by a second harmonics of a Nd-YAG laser. The obtained angular distribution was about {+-}10 degree. This result also indicates a proper positioning of a solenoid magnet which enhances ion beam current.
Date: May 23, 2010
Creator: Kondo, K.; Kanesue, T.; Dabrowski, R. & Okamura, M.
Object Type: Article
System: The UNT Digital Library
LIS in low power density for RHIC-EBIS (open access)

LIS in low power density for RHIC-EBIS

The Electron Beam Ion Source (EBIS) project at Brookhaven National Laboratory is a new heavy ion preinjector for Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. Laser Ion Source (LIS), which can supply many heavy ion species using solid targets, is a candidate of a primary ion source provider for RHIC-EBIS. LIS experiment with 5 Hz operation, which is required practically in RHIC-EBIS, was demonstrated to understand the beam property for long operation time. High laser power density decayed the peak current and ion yield with operation time and did not keep the surface of target flat. On the contrary, the beam in low laser power density kept the performance in long operation time.
Date: May 23, 2010
Creator: Kondo, K.; Kanesue, T.; Dabrowski, R. & Okamura, M.
Object Type: Article
System: The UNT Digital Library
DPIS for warm dense matter (open access)

DPIS for warm dense matter

Warm Dense Matter (WDM) offers an challenging problem because WDM, which is beyond ideal plasma, is in a low temperature and high density state with partially degenerate electrons and coupled ions. WDM is a common state of matter in astrophysical objects such as cores of giant planets and white dwarfs. The WDM studies require large energy deposition into a small target volume in a shorter time than the hydrodynamical time and need uniformity across the full thickness of the target. Since moderate energy ion beams ({approx} 0.3 MeV/u) can be useful tool for WDM physics, we propose WDM generation using Direct Plasma Injection Scheme (DPIS). In the DPIS, laser ion source is connected to the Radio Frequency Quadrupole (RFQ) linear accelerator directly without the beam transport line. DPIS with a realistic final focus and a linear accelerator can produce WDM.
Date: May 23, 2010
Creator: Kondo, K.; Kanesue, T.; Horioka, K. & Okamura, M.
Object Type: Article
System: The UNT Digital Library
BEAM CONTAINMENT SYSTEM FOR NSLS-II (open access)

BEAM CONTAINMENT SYSTEM FOR NSLS-II

The shielding design for the NSLS-II will provide adequate protection for the full injected beam loss in two periods of the ring around the injection point, but the remainder of the ring is shielded for lower losses of {le} 10% full beam. This will require a system to insure that beam losses don't exceed these levels for a period of time that could cause excessive radiation levels outside the shield walls. This beam containment system will measure, provide a level of control and alarm indication of the beam power losses along the beam path from the source (e-gun, linac) thru the injection system and the storage ring. This system will consist of collimators that will provide limits to (and potentially to measure) the beam miss-steering and control the loss points of the charge and monitors that will measure the average beam current losses along the beam path and alarm when this beam power loss exceeds the level set by the shielding specifications. This will require some new ideas in beam loss detection capability and collimation. The initial planning and R&D program will be presented.
Date: May 23, 2010
Creator: Kramer, S. L.; Casey, W. & Job, P. K.
Object Type: Article
System: The UNT Digital Library