States

Environmental Protection: Information on the Purchase, Use, and Disposal of Engine Lubricating Oil (open access)

Environmental Protection: Information on the Purchase, Use, and Disposal of Engine Lubricating Oil

A briefing report issued by the General Accounting Office with an abstract that begins "Concerned with the time, money, and resources that the federal government expends servicing its vehicle and engine fleet, the Senate Committee on Environment and Public Works asked GAO to compile information on the government's use of engine lubricating oil. GAO was asked to determine: (1) how much engine lubricating oil the federal government bought in fiscal years 1999, 2000, and 2001; (2) what costs are incurred for the disposal and recycling of engine lubricating oil; (3) what costs are incurred for changing motor oil in military and civilian fleets; (4) what logistical implications exist for the transport of engine lubricating oil during recent military operations; and (5) what options exist for reducing purchase, maintenance, and disposal costs for engine lubricating oil. To conduct its study, GAO focused on three agencies that account for 79 percent of all non-tactical vehicles owned or leased by the U.S. government: the U.S. Postal Service (USPS), the Department of Defense (DOD), and the General Services Administration (GSA). It compiled information only on engine lubricating oil used in ground vehicles and equipment and not in aircraft and ships."
Date: January 2, 2003
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Performance and Accountability Highlights Fiscal Year 2007 (open access)

Performance and Accountability Highlights Fiscal Year 2007

Other written product issued by the Government Accountability Office with an abstract that begins "This report presents the highlights of GAO's fiscal year 2007 Performance and Accountability Report. In fiscal year 2007 we exceeded the targets for five of our six key performance measures--financial benefits, nonfinancial benefits, past recommendations implemented, new products with recommendations, and testimonies--that gauge how well we produced results and served our client, the Congress. With this level of performance we were able to achieve a return on investment for the American people of about $94 for every dollar the Congress gave us. We also met or exceeded five of the eight targets we set for our people measures--new hire rate, acceptance rate, retention rate with retirements, retention rate without retirements, and staff development. While these measures were largely similar to last year's results, we missed the performance targets for staff utilization, leadership, and organizational climate by 5, 1, and 2 percentage points, respectively, in spite of the challenges we faced internally. While supporting the Congress's oversight efforts with more than 1,200 reports and testimonies we issued during the fiscal year, in November 2006, we sent a letter to the incoming leadership of the new Congress suggesting …
Date: January 2, 2008
Creator: United States. Government Accountability Office.
Object Type: Text
System: The UNT Digital Library
Metastable Solid Solution Phases in the LiFePO4/FePO4 System (open access)

Metastable Solid Solution Phases in the LiFePO4/FePO4 System

None
Date: January 2, 2006
Creator: Chen, Guoying Chen; Song, Xiangyun & Richardson, Thomas J.
Object Type: Article
System: The UNT Digital Library
PEM Fuel Cell Freeze Durability and Cold Start Project (open access)

PEM Fuel Cell Freeze Durability and Cold Start Project

UTC has taken advantage of the unique water management opportunities inherent in micro-porous bipolar-plates to improve the cold-start performance of its polymer electrolyte fuel cells (PEFC). Diagnostic experiments were used to determine the limiting factors in micro-porous plate PEFC freeze performance and the causes of any performance decay. Alternative cell materials were evaluated for their freeze performance. Freeze-thaw cycling was also performed to determine micro-porous plate PEFC survivability. Data from these experiments has formed the basis for continuing development of advanced materials capable of supporting DOE's cold-start and durability objectives.
Date: January 2, 2008
Creator: Patterson, T. & O'Neill, Jonathan
Object Type: Report
System: The UNT Digital Library
Phase patterns of coupled oscillators with application to wireless communication (open access)

Phase patterns of coupled oscillators with application to wireless communication

Here we study the plausibility of a phase oscillators dynamical model for TDMA in wireless communication networks. We show that emerging patterns of phase locking states between oscillators can eventually oscillate in a round-robin schedule, in a similar way to models of pulse coupled oscillators designed to this end. The results open the door for new communication protocols in a continuous interacting networks of wireless communication devices.
Date: January 2, 2008
Creator: Arenas, A.
Object Type: Article
System: The UNT Digital Library
Longitudinal Stability Calculations (open access)

Longitudinal Stability Calculations

Coupled bunch longitudinal stability in the presence of high frequency impedances is considered. A frequency domain technique is developed and compared with simulations. The frequency domain technique allows for absolute stability tests and is applied to the problem of longitudinal stability in RHIC with the new 56 MHz RF system.
Date: January 2, 2009
Creator: Blaskiewicz, M.
Object Type: Report
System: The UNT Digital Library
Sorting chromatic sextupoles for easily and effectively correcting second order chromaticity in the Relativistic Heavy Ion Collider (open access)

Sorting chromatic sextupoles for easily and effectively correcting second order chromaticity in the Relativistic Heavy Ion Collider

Based on the contributions of the chromatic sextupole families to the half-integer resonance driving terms, we discuss how to sort the chromatic sextupoles in the arcs of the Relativistic Heavy Ion Collider (RHIC) to easily and effectively correct the second order chromaticities. We propose a method with 4 knobs corresponding to 4 pairs of chromatic sextupole families to online correct the second order chromaticities. Numerical simulation justifies this method, showing that this method reduces the unbalance in the correction strengths of sextupole families and avoids the reversal of sextupole polarities. Therefore, this method yields larger dynamic apertures for the proposed RHIC 2009 100GeV polarized proton run lattices.
Date: January 2, 2009
Creator: Luo, Y.; Tepikian, S.; Fischer, W.; Robert-Demolaize, G. & Trbojevic, D.
Object Type: Report
System: The UNT Digital Library
Chemical Force Microscopy of Chemical and Biological Interactions (open access)

Chemical Force Microscopy of Chemical and Biological Interactions

Interactions between chemical functionalities define outcomes of the vast majority of important events in chemistry, biology and materials science. Chemical Force Microscopy (CFM)--a technique that uses direct chemical functionalization of AFM probes with specific functionalities--allows researchers to investigate these important interactions directly. We review the basic principles of CFM, some examples of its application, and theoretical models that provide the basis for understanding the experimental results. We also emphasize application of modern kinetic theory of non-covalent interactions strength to the analysis of CFM data.
Date: January 2, 2006
Creator: Noy, A
Object Type: Article
System: The UNT Digital Library
Multipacting Simulation Study for 56 MHz Quarter Wave Resonator using 2D Code (open access)

Multipacting Simulation Study for 56 MHz Quarter Wave Resonator using 2D Code

A beam excited 56 MHz Radio Frequency (RF) Niobium Quarter Wave Resonator (QWR) has been proposed to enhance RHIC beam luminosity and bunching. Being a RF cavity, multipacting is expected; therefore an extensive study was carried out with the Multipac 2.1 2D simulation code. The study revealed that multipacting occurs in various bands up to peak surface electric field 50 kV/m and is concentrated mostly above the beam gap and on the outer conductor. To suppress multipacting, a ripple structure was introduced to the outer conductor and the phenomenon was successfully eliminated from the cavity.
Date: January 2, 2009
Creator: Naik, D. & Ben-Zvi, Ilan
Object Type: Report
System: The UNT Digital Library
Dynamic aperture evaluation of the proposed lattices for the RHIC 2009 polarized proton run (open access)

Dynamic aperture evaluation of the proposed lattices for the RHIC 2009 polarized proton run

In the article we evaluate the dynamic apertures of the proposed lattices for the coming Relativistic Heavy Ion Collider (RHIC) 2009 polarized proton (pp) 100 GeV and 250 GeV runs. One goal of this study is to find out the appropriate {beta}* for the coming 2009 pp runs. Another goal is to study the effect of second order chromaticity correction in the RHIC pp runs.
Date: January 2, 2009
Creator: Luo, Y.; Bai, M.; Beebe-Wang, J.; Fischer, W.; Montag, C.; Robert-Demolaize, G. et al.
Object Type: Report
System: The UNT Digital Library
Comparison of Wide-Bandgap Semiconductors for Power Electronics Applications (open access)

Comparison of Wide-Bandgap Semiconductors for Power Electronics Applications

Recent developmental advances have allowed silicon (Si) semiconductor technology to approach the theoretical limits of the Si material; however, power device requirements for many applications are at a point that the present Si-based power devices cannot handle. The requirements include higher blocking voltages, switching frequencies, efficiency, and reliability. To overcome these limitations, new semiconductor materials for power device applications are needed. For high power requirements, wide-bandgap semiconductors like silicon carbide (SiC), gallium nitride (GaN), and diamond, with their superior electrical properties, are likely candidates to replace Si in the near future. This report compares wide-bandgap semiconductors with respect to their promise and applicability for power applications and predicts the future of power device semiconductor materials.
Date: January 2, 2004
Creator: Ozpineci, B.
Object Type: Report
System: The UNT Digital Library
IBS and Potential Luminosity Improvement for RHIC Operation Below Transition Energy (open access)

IBS and Potential Luminosity Improvement for RHIC Operation Below Transition Energy

There is a strong interest in low-energy RHIC operations in the single-beam total energy range of 2.5-25 GeV/nucleon [1-3]. Collisions in this energy range, much of which is below nominal RHIC injection energy, will help to answer one of the key questions in the field of QeD about the existence and location of a critical point on the QCD phase diagram [4]. There have been several short test runs during 2006-2008 RHIC operations to evaluate RHIC operational challenges at these low energies [5]. Beam lifetimes observed during the test runs were limited by machine nonlinearities. This performance limit can be improved with sufficient machine tuning. The next luminosity limitation comes from transverse and longitudinal Intra-beam Scattering (IBS), and ultimately from the space-charge limit. Detailed discussion of limiting beam dynamics effects and possible luminosity improvement with electron cooling can be found in Refs. [6-8]. For low-energy RHIC operation, particle losses from the RF bucket are of particular concern since the longitudinal beam size is comparable to the existing RF bucket at low energies. However, operation below transition energy allows us to exploit an Intra-beam Scattering (IBS) feature that drives the transverse and longitudinal beam temperatures towards equilibrium by minimizing the longitudinal …
Date: January 2, 2009
Creator: Fedotov,A.
Object Type: Report
System: The UNT Digital Library
Diffusion Simulation and Lifetime Calculation at RHIC (open access)

Diffusion Simulation and Lifetime Calculation at RHIC

The beam lifetime is an important parameter for any storage ring. For protons in RHIC it is dominated by the non-linear nature of the head-on collisions that causes the particles to diffuse outside the stable area in phase space. In this report we show results from diffusion simulation and lifetime calculation for the 2006 and 2008 polarized proton runs in RHIC.
Date: January 2, 2009
Creator: Abreu,N.P.; Fischer, W.; Luo, Y. & Robert-Demolaize, G.
Object Type: Report
System: The UNT Digital Library
56 MHZ Cavity Prototype Measurements (open access)

56 MHZ Cavity Prototype Measurements

None
Date: January 2, 2009
Creator: Hahn,H. & Choi, E.
Object Type: Report
System: The UNT Digital Library
Development of dopamine receptor radiopharmaceuticals for the study of neurological and psychiatric disorders (open access)

Development of dopamine receptor radiopharmaceuticals for the study of neurological and psychiatric disorders

Our goals in this grant application are directed towards the development of radiotracers that may allow the study of the high-affinity state (functional state) of the dopamine receptors. There have been numerous reports on the presence of two inter-convertible states of these (G-protein coupled) receptors in vitro. However, there is no report that establishes the presence of these separate affinity states in vivo. We have made efforts in this direction in order to provide such direct in vivo evidence about the presence of the high affinity state. This understanding of the functional state of the receptors is of critical significance in our overall diagnosis and treatment of diseases that implicate the G-protein coupled receptors. Four specific aims have been listed in the grant application: (1). Design and syntheses of agonists (2). Radiosyntheses of agonists (3). In vitro pharmacology of agonists (4). In vivo distribution and pharmacology of labeled derivatives. We have accomplished the syntheses and radiosyntheses of three agonist radiotracers labeled with carbon-11. In vitro and in vivo pharmacological experiments have been accomplished in rats and preliminary PET studies in non-human primates have been carried out. Various accomplishments during the funded years, briefly outlined in this document, have been disseminated …
Date: January 2, 2009
Creator: Mukherjee, Dr. Jogeshwar
Object Type: Report
System: The UNT Digital Library
Effects of Booster Scraping in Polarized Proton Runs 2006 and 2008 (open access)

Effects of Booster Scraping in Polarized Proton Runs 2006 and 2008

Effects of the Booster vertical scraping on the RHIC beam polarization, the RHIC beam emittance, and on the Booster to AGS transfer efficiency and AGS transmission as well, are further studied. In [1], the strong dependence of the RHIC beam polarization and emittance on bunch intensity in proton run 2008 (pp08) is compared with the proton run 2006 (pp06), where the dependence is much weaker. The setting in the AGS Booster, mainly the vertical scraping, is suspected to having played a role in the different patterns in the two runs. In this note, we further study the effects of the Booster vertical scraping on the RHIC beam polarization, and on the RHIC beam emittance as well. With the improvement of the RHIC bunch intensity in mind, the Booster scraping effects on the Booster to AGS transfer (BtA) efficiency and the AGS transmission are also studied. For simplicity and to be more useful, only the RHIC fills after the one-week shutdown in pp06 and the fills using the AGS User 2 in pp08 are shown. For these fills, the machine settings in AGS are similar in pp06 and pp08 runs. Furthermore, this setting might be used for next polarized proton run, …
Date: January 2, 2009
Creator: Zhang, S. Y.; Ahrens, L.; Huang, H. & Zeno, K.
Object Type: Report
System: The UNT Digital Library
Cryogenic and Crysostat System for the 56 MHZ SRF Cavity (open access)

Cryogenic and Crysostat System for the 56 MHZ SRF Cavity

This report addresses the cryogenic and cryostat system for the 56 MHZ SRF Cavity
Date: January 2, 2009
Creator: Than,R.
Object Type: Report
System: The UNT Digital Library
The PEP-II Project: Low-Energy Ring Design and Project Status (open access)

The PEP-II Project: Low-Energy Ring Design and Project Status

We describe the present status of the PEP-II project. The project comprises four major systems: Injector, High-Energy Ring (HER), Low-Energy Ring (LER), and Interaction Region (IR). We focus in detail on the design of the LER, as its parameters and requirements are most closely related to those required for the Beijing Tau-Charm Factory rings. The PEP-II LER is a high-current, 3.1-GeV positron ring mounted above the 9-GeV HER. The LER uses a wiggler located in one of its six straight sections to provide emittance control and additional damping. We describe the rather complicated IR, which must transport the LER beam into the plane of the HER, focus it to a common beam size, and separate the beams after the head-on collisions. Both permanent magnet and conventional electromagnets are used in this area. The LER lattice has now adopted a simplified non-interleaved sextupole correction scheme that has reduced the required number of sextupoles substantially. We describe the LER vacuum system, one of the most challenging subsystems in PEP-II. It employs several technologies. In the arcs, aluminum extrusions and titanium sublimation pumps are employed; the straight sections use stainless steel chambers with lumped ion pumps. In the wiggler area, an extended copper …
Date: January 2, 2006
Creator: Zisman, Michael S.
Object Type: Report
System: The UNT Digital Library
Solid Solution Lithium Alloy Cermet Anodes (open access)

Solid Solution Lithium Alloy Cermet Anodes

None
Date: January 2, 2006
Creator: Richardson, Thomas J. & Chen, Guoying
Object Type: Article
System: The UNT Digital Library
Energy Scaling of Spin Tune due to RHIC Snakes (open access)

Energy Scaling of Spin Tune due to RHIC Snakes

For a ring like RHIC with two full Siberian snakes on opposite sides of the ring, the spin tune for a flat orbit will be 1/2 if the snake rotation axes are perpendicular, {Delta}{phi} = {phi}{sub 9}-{phi}{sub 3} = {pi}/2. Here {phi}{sup 9} and {phi}{sub 3} are respectively the direction of the rotation axes of the 9 o'clock and 3 o'clock snakes relative to the design trajectory as shown in Figure 1. If the two snakes are slightly detuned by the same amount such that the rotation axes are no longer perpendicular, then the deviation of the closed-orbit spin tune {nu}{sub 0} from 1/2 is given by {Delta}{nu}{sub 0} {approx_equal} ({Delta}{mu}){sup 2}/4{pi} cosG{gamma}{pi} - 2{Delta}{phi}/{pi} {approx_equal} 2{Delta}{phi}/180{sup o} with G{gamma} at a half integer, and where {Delta}{mu} is the deviation of snake rotation angle from 180{sup o}. It should be noted that there is a sign ambiguity in {Delta}{mu}{sub 0} since a spin tune of 0.495 is also a spin tune of 0.505, depending on the direction taken along the stable spin axis. In order to understand the effect of energy scaling on the snake axis direction, I have integrated the trajectory and spin rotation through a model of a …
Date: January 2, 2009
Creator: MacKay, W. W.
Object Type: Report
System: The UNT Digital Library
iTOUGH2-IFC: An Integrated Flow Code in Support of Nagra's Probabilistic Safety Assessment:--User's Guide and Model Description (open access)

iTOUGH2-IFC: An Integrated Flow Code in Support of Nagra's Probabilistic Safety Assessment:--User's Guide and Model Description

This document describes the development and use of the Integrated Flow Code (IFC), a numerical code and related model to be used for the simulation of time-dependent, two-phase flow in the near field and geosphere of a gas-generating nuclear waste repository system located in an initially fully water-saturated claystone (Opalinus Clay) in Switzerland. The development of the code and model was supported by the Swiss National Cooperative for the Disposal of Radioactive Waste (Nagra), Wettingen, Switzerland. Gas generation (mainly H{sub 2}, but also CH{sub 4} and CO{sub 2}) may affect repository performance by (1) compromising the engineered barriers through excessive pressure build-up, (2) displacing potentially contaminated pore water, (3) releasing radioactive gases (e.g., those containing {sup 14}C and {sup 3}H), (4) changing hydrogeologic properties of the engineered barrier system and the host rock, and (5) altering the groundwater flow field and thus radionuclide migration paths. The IFC aims at providing water and gas flow fields as the basis for the subsequent radionuclide transport simulations, which are performed by the radionuclide transport code (RTC). The IFC, RTC and a waste-dissolution and near-field transport model (STMAN) are part of the Integrated Radionuclide Release Code (IRRC), which integrates all safety-relevant features, events, and …
Date: January 2, 2009
Creator: Finsterle, Stefan A.
Object Type: Report
System: The UNT Digital Library
Statistical mechanics of sum frequency generation spectroscopy for the liquid-vapor interface of dilute aqueous salt solutions (open access)

Statistical mechanics of sum frequency generation spectroscopy for the liquid-vapor interface of dilute aqueous salt solutions

We demonstrate a theoretical description of vibrational sum frequency generation (SFG) at the boundary of aqueous electrolyte solutions. This approach identifies and exploits a simple relationship between SFG lineshapes and the statistics of molecular orientation and electric field. Our computer simulations indicate that orientational averages governing SFG susceptibility do not manifest ion-specific shifts in local electric field, but instead, ion-induced polarization of subsurface layers. Counterbalancing effects are obtained for monovalent anions and cations at the same depth. Ions held at different depths induce an imbalanced polarization, suggesting that ion-specific effects can arise from weak, long ranged influence on solvent organization.
Date: January 2, 2009
Creator: Noah-Vanhoucke, Joyce; Smith, Jared D. & Geissler, Phillip L.
Object Type: Article
System: The UNT Digital Library
Superconducting Storage Cavity for RHIC (open access)

Superconducting Storage Cavity for RHIC

This document provides a top-level description of a superconducting cavity designed to store hadron beams in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. It refers to more detailed documents covering the various issues in designing, constructing and operating this cavity. The superconducting storage cavity is designed to operate at a harmonic of the bunch frequency of RHIC at a relatively low frequency of 56 MHz. The current storage cavities of RHIC operate at 197 MHz and are normal-conducting. The use of a superconducting cavity allows for a high gap voltage, over 2 MV. The combination of a high voltage and low frequency provides various advantages stemming from the resulting large longitudinal acceptance bucket.
Date: January 2, 2009
Creator: Ben-Zvi, Ilan
Object Type: Report
System: The UNT Digital Library
Water-Steel Canister Interaction and H2 Gas Pressure Buildup in aNuclear Waste Repository (open access)

Water-Steel Canister Interaction and H2 Gas Pressure Buildup in aNuclear Waste Repository

Corrosion of steel canisters, stored in a repository forspent fuel and high-level waste, leads to hydrogen gas generation in thebackfilled emplacement tunnels, which may significantly affect long-termrepository safety. Previous modeling studies used a constant H2generation rate. However, iron corrosion and H2 generation rates varywith time, depending on factors such as water chemistry, wateravailability, and water contact area. To account for these factors andfeedback mechanisms, we developed a chemistry model related to ironcorrosion, coupled with two-phase (liquid and gas) flow phenomena thatare driven by gas pressure buildup and water consumption. Resultsindicate that if H2 generation rates are dynamically calculated based ona chemistry model, the degree and extent of gas pressure buildup are muchsmaller compared to a simulation in which the coupling between flow andreactive transport mechansism is neglected.
Date: January 2, 2007
Creator: Xu, Tianfu; Senger, Rainer & Finstele, Stefan
Object Type: Article
System: The UNT Digital Library