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A cold mass support system based on the use of oriented fiberglassepoxy rods in bending (open access)

A cold mass support system based on the use of oriented fiberglassepoxy rods in bending

This report describes a cold mass support system based on the use of oriented fiberglassepoxy rods in bending.
Date: July 6, 2002
Creator: Green, Michael A.; Corradi, Carol A.; LaMantia, Roberto F. & Zbasnik, Jon P.
System: The UNT Digital Library
Quantifying the Contribution of Lubrication Oil to Particulate Emissions from a Diesel Engine (open access)

Quantifying the Contribution of Lubrication Oil to Particulate Emissions from a Diesel Engine

The contribution of lubrication oil to particulate matter (PM) emissions from a Cummins B5.9 Diesel engine was measured using accelerator mass spectrometry to trace carbon isotope concentrations. The engine operated at fixed medium load (285 N-m (210 ft.lbs.) 1600 m) used 100% biodiesel fuel (B100) with a contemporary carbon-14 ({sup 14}C) concentration of 103 amol {sup 14}C/ mg C. The C concentration of the exhaust C02 and PM were 102 and 99 amol {sup 14}C/mg C, respectively. The decrease in I4C content in the PM is due to the consumption of lubrication oil which is {sup 14}C-free. Approximately 4% of the carbon in PM came from lubrication oil under these operating conditions. The slight depression in CO{sub 2} isotope content could be attributed to ambient CO{sub 2} levels and measurement uncertainty.
Date: December 6, 2002
Creator: Cheng, A. S.; Rich, D.; Dibble, R. W. & Buchholz, B. A.
System: The UNT Digital Library
20% Partial Siberian Snake in the AGS. (open access)

20% Partial Siberian Snake in the AGS.

An 11.4% partial Siberian snake was used to successfully accelerate polarized proton through a strong intrinsic depolarizing spin resonance in the AGS. No noticeable depolarization was observed. This opens up the possibility of using a 20% to 30% partial Siberian snake in the AGS to overcome all weak and strong depolarizing spin resonances. Some design and operation issues of the new partial Siberian snake are discussed.
Date: November 6, 2002
Creator: Huang, H.; Bai, M.; Brown, K. A.; Glenn, W.; Luccio, A. U.; MacKay, W. W. et al.
System: The UNT Digital Library
The interplay of matrix metalloproteinases, morphogens and growth factors is necessary for branching of mammary epithelial cells (open access)

The interplay of matrix metalloproteinases, morphogens and growth factors is necessary for branching of mammary epithelial cells

The mammary gland develops its adult form by a process referred to as branching morphogenesis. Many factors have been reported to affect this process. We have used cultured primary mammary epithelial organoids and mammary epithelial cell lines in three-dimensional collagen gels to elucidate which growth factors, matrix metalloproteinases (MMPs) and mammary morphogens interact in branching morphogenesis. Branching stimulated by stromal fibroblasts, epidermal growth factor, fibroblast growth factor 7, fibroblast growth factor 2 and hepatocyte growth factor was strongly reduced by inhibitors of MMPs, indicating the requirement of MMPs for three-dimensional growth involved in morphogenesis. Recombinant stromelysin 1/MMP-3 alone was sufficient to drive branching in the absence of growth factors in the organoids. Plasmin also stimulated branching; however, plasmin-dependent branching was abolished by both inhibitors of plasmin and MMPs, suggesting that plasmin activates MMPs. To differentiate between signals for proliferation and morphogenesis, we used a cloned mammary epithelial cell line that lacks epimorphin, an essential mammary morphogen. Both epimorphin and MMPs were required for morphogenesis, but neither was required for epithelial cell proliferation. These results provide direct evidence for a critical role of MMPs in branching in mammary epithelium and suggest that, in addition to epimorphin, MMP activity is a minimum …
Date: March 6, 2002
Creator: Simian, M.; Harail, Y.; Navre, M.; Werb, Z.; Lochter, A. & Bissell, M.J.
System: The UNT Digital Library
Transmission electron microscopy (TEM) characterization of GaN nanowires (open access)

Transmission electron microscopy (TEM) characterization of GaN nanowires

None
Date: May 6, 2002
Creator: Liliental-Weber, Z.; Gao, Y.H. & Bando, Y.
System: The UNT Digital Library
Cloud condensation nuclei spectra and polluted and clean clouds over the Indian Ocean (open access)

Cloud condensation nuclei spectra and polluted and clean clouds over the Indian Ocean

None
Date: September 6, 2002
Creator: Hudson, James G. & Yum, Seong Soo
System: The UNT Digital Library
Bridging the gap between building science and design studios (open access)

Bridging the gap between building science and design studios

Design studios and building science courses have been conducted independent of each other, mainly due to a lack of tools that allow quick and easy consideration of building science criteria, such as comfort and energy requirements, during the design process. Existing tools are not user-friendly and their use requires significant effort in gaining familiarity with the input requirements, understanding the modeling assumptions and interpreting the output. This paper is about the Building Design Advisor (BDA), an evolving computer-based tool intended to bridge the gap between design studios and building science considerations by addressing the above-mentioned limitations of existing tools. BDA allows automatic preparation of input files to multiple simulation tools while the user is working in a CAD environment. BDA automatically activates the relevant simulation tools when the user selects performance parameters to be computed and provides the results in a graphical form, allowing comparison of multiple design options with respect to multiple performance criteria. The paper includes considerations for the use of the BDA in the design studio and ends with a description of the current development efforts and future plans.
Date: February 6, 2002
Creator: Papamichael, Konstantinos & Pal, Vineeta
System: The UNT Digital Library
Implications of halide leaching on chlorine-36 studies at Yucca Mountain, Nevada (open access)

Implications of halide leaching on chlorine-36 studies at Yucca Mountain, Nevada

None
Date: April 6, 2002
Creator: Lu, Guoping; Sonnenthal, Eric L. & Bodvarsson, Gudmundur S.
System: The UNT Digital Library
Influence of the Sb dopant distribution on far infrared photoconductivity in Ge:Sb blocked impurity band detectors (open access)

Influence of the Sb dopant distribution on far infrared photoconductivity in Ge:Sb blocked impurity band detectors

Extended long wavelength response to {approx}200 {micro}m (50 cm{sup -1}) has been observed in Ge:Sb Blocked Impurity Band (BIB) detectors with N{sub D} {approx} 1 x 10{sup 16} cm{sup -3}. The cut-off wavelength increases from 150 {micro}m (65 cm{sup -1}) to 200 {micro}m (50 cm{sup -1}) with increasing bias. The responsivity at long wavelengths was lower than expected. This can be explained by considering the observed Sb diffusion profile in a transition region between the blocking layer and active layer. BIB modeling is presented which indicates that this Sb concentration profile increases the electric field in the transition region and reduces the field in the blocking layer. The depletion region consists partially of the transition region between the active and blocking layer, which could contribute to the reduced long wavelength response. The field spike at the interface is the likely cause of breakdown at a lower bias than expected.
Date: February 6, 2002
Creator: Bandaru, Jordana; Beeman, Jeffrey W.; Haller, Eugene E.; Samperi, Stacy & Haegel, Nancy M.
System: The UNT Digital Library
Semi-implicit spectral deferred correction methods for ordinary differential equations (open access)

Semi-implicit spectral deferred correction methods for ordinary differential equations

A semi-implicit formulation of the method of spectral deferred corrections (SISDC) for ordinary differential equations with both stiff and non-stiff terms is presented. Several modifications and variations to the original spectral deferred corrections method by Dutt, Greengard, and Rokhlin concerning the choice of integration points and the form of the correction iteration are presented. The stability and accuracy of the resulting ODE methods are explored analytically and numerically. The SISDC methods are intended to be combined with the method of lines approach to yield a flexible framework for creating higher-order semi-implicit methods for partial differential equations. A discussion and numerical examples of the SISDC method applied to advection-diffusion type equations are included. The results suggest that higher-order SISDC methods are more efficient than semi-implicit Runge-Kutta methods for moderately stiff problems in terms of accuracy per function evaluation.
Date: October 6, 2002
Creator: Minion, Michael L.
System: The UNT Digital Library
(Strange) meson interferometry at RHIC (open access)

(Strange) meson interferometry at RHIC

The authors make predictions for the kaon interferometry measurements in Au + Au collisions at the relativistic Heavy Ion Collider (RHIC). A first order phase transition from a thermalized Quark-Gluon-Plasma (QGP) to a gas of hadrons is assumed for the transport calculations. The fraction of kaons that are directly emitted from the phase boundary is considerably enhanced at large transverse momenta K{sub T} {approx} 1 GeV/c. In this kinematic region, the sensitivity of the R{sub out}/R{sub side} ratio to the QGP-properties is enlarged. The results of the 1-dimensional correlation analysis are presented. The extracted interferometry radii, depending on K{sub T}, are not unusually large and are strongly affected by finite momentum resolution effects.
Date: February 6, 2002
Creator: Soff, Sven; Bass, Steffen A.; Hardtke, David H. & Panitkin, Sergey Y.
System: The UNT Digital Library
Depths of equivalent dipole polarizability resolution for some transmitter receiver configurations (open access)

Depths of equivalent dipole polarizability resolution for some transmitter receiver configurations

Equivalent dipole polarizability matrices and equivalent dipole location are a convenient way to summarize magnetic induction data arising from currents induced in isolated conductive objects. The uncertainties in polarizability estimates and in equivalent dipole location provide a quantitative measure of the performance of different configurations of transmitters and receivers. Uncertainties in equivalent dipole polarizability matrices and equivalent dipole position are estimated using a linearized inversion. For a number of systems of rectangular loop transmitters and dipole receivers sited on a horizontal grid, equivalent dipole depth is determined to 10% approximately 20% deeper, than the polarizability matrix elements can be determined to the same precision. Systems that have a lower product of rms polarizability uncertainty and square root of their number of transmitter-receiver pairs are considered more effective for their number of transmitter-receiver pairs. Among the systems studied, a system with three orthogonal transmitter loops and a three component receiver is the most effective, for objects shallower than 0.6 times the instrument siting grid spacing, yielding an rms polarizability uncertainty 0.04 times that of a single transmitter single receiver system. At intermediate depths, a system with two vertical component receivers on the diagonal of a horizontal transmitter loop is most effective …
Date: June 6, 2002
Creator: Smith, J. Torquil; Morrison, H. Frank & Becker, Alex
System: The UNT Digital Library
Laser Beam Profile Monitor Development at Bnl for Sns. (open access)

Laser Beam Profile Monitor Development at Bnl for Sns.

A beam profile monitor for H-beams based on laser photoneutralization is being developed at Brookhaven National Laboratory (BNL) for use on the Spallation Neutron Source (SNS) [l]. An H ion has a first ionization potential of 0.75eV and can be neutralized by light from a Nd:YAG laser (h=1064nm). To measure beam profiles, a narrow laser beam is passed through the ion beam neutralizing a portion of the H-beam struck by the laser. The laser trajectory is stepped across the ion beam. At each laser position, the reduction of the beam current caused by the laser is measured. A proof-of-principle experiment was done earlier at 750keV. This paper reports on measurements made on 200MeV beam at BNL and with a compact scanner prototype at Lawrence Berkeley National Lab on beam from the SNS RFQ.
Date: May 6, 2002
Creator: Connolly, R.; Cameron, P.; Cupolo, J.; Gassner, D.; Grau, M.; Kesselman, M. et al.
System: The UNT Digital Library
Preliminary Design of the Beam Loss Monitoring System for the SNS (open access)

Preliminary Design of the Beam Loss Monitoring System for the SNS

The SNS to be built at Oak Ridge National Laboratory will provide a high average intensity 1 GeV beam to produce spallation neutrons. Loss of a even small percentage of this intense beam would result in high radiation. The Beam Loss Monitor (ELM) system must detect such small, long term losses yet be capable of measuring infrequent short high losses. The large dynamic range presents special problems for the system design. Ion chambers will be used as the detectors. A detector originally designed for the FNAL Tevatron, was considered but concerns about ion collection times and low collection efficiency at high loss rates favor a new design. The requirements and design concepts of the proposed approach will be presented. Discussion of the design and testing of the ion chambers and the analog j-Point end electronics will be presented. The overall system design will be described.
Date: May 6, 2002
Creator: Witkover, R. & Gassner, D.
System: The UNT Digital Library
INSIGNIFICANCE OF RADIOTOXICITY OF SPALLATION PRODUCTS IN AN ACCELERATOR-DRIVEN TRANSMUTATION SYSTEM. (open access)

INSIGNIFICANCE OF RADIOTOXICITY OF SPALLATION PRODUCTS IN AN ACCELERATOR-DRIVEN TRANSMUTATION SYSTEM.

One of the concerns facing accelerator-driven transmutation systems (ADSs) is whether the radiotoxicity of materials produced during the transmutation process poses more of a concern than does the radiotoxicity of the spent nuclear fuel (SNF) itself. Most of the common fission products (or FPs) are emitters of beta radiation, but additionally, some of the radionuclides generated during spallation are alpha emitters. Thus, both ingestion and inhalation radiotoxicity of the materials produced during spallation could be significant. Typically, ingestion is considered to be more significant than inhalation radiotoxicity for long-term storage/disposal (such as in a repository) because the greatest potential biological hazard to humans occurs when the isotope is absorbed in nearby ground water or brine and transported from the repository to drinking water. Nonetheless, inhalation radiotoxicity is also important to analyze in case of a breach of containment inside the accelerator facility and/or for short-term (i.e., above-ground) storage concerns. Thus, this study calculated the radiotoxicity of spallation products (or SPs) from three different targets: lead-bismuth eutectic (LBE), LBE-cooled tungsten, and LBE-cooled lead.
Date: June 6, 2002
Creator: TRELLUE, HOLLY R & PITCHER, ERIC J
System: The UNT Digital Library
Lead-bismuth spallation target design of the accelerator-driven test facility (ADTF). (open access)

Lead-bismuth spallation target design of the accelerator-driven test facility (ADTF).

A design methodology for the lead-bismuth eutectic (LBE) spallation target has been developed and applied for the accelerator-driven test facility (ADTF) target. This methodology includes the target interface with the subcritical multiplier (SCM) of the ADTF and the different engineering aspects of the target design, physics, heat-transfer, hydraulics, structural, radiological, and safety analyses. Several design constrains were defined and utilized for the target design process to satisfy different engineering requirements and to minimize the time and the cost of the design development. Interface requirements with the subcritical multiplier were defined based on target performance parameters and material damage issues to enhance the lifetime of the target structure. Different structural materials were considered to define the most promising candidate based on the current database including radiation effects. The developed target design has a coaxial geometrical configuration to minimize the target footprint and it is installed vertically along the SCM axis. LBE is the target material and the target coolant with ferritic steel (HT-9 alloy) structural material. The proton beam has 8.33-mA current uniformly distributed and 8.14-cm beam radius resulting in a current density of 40 {micro}A/cm{sup 2}. The beam power is 5 MW and the proton energy is 600 MeV. The …
Date: May 6, 2002
Creator: Gohar, Y.; Finck, P.; Hanson, A.; Herceg, J.; Koploy, M.; Krajtl, L. et al.
System: The UNT Digital Library
Sucrose-mediated transcriptional regulation of sucrose symporter activity in the phloem. (open access)

Sucrose-mediated transcriptional regulation of sucrose symporter activity in the phloem.

This project was based on our discovery that sucrose acts as a signaling molecule that regulates the activity of a proton-sucrose symporter in sugar beet leaf tissue. A major objective here was determining how sucrose transporter activity is being regulated. When sucrose accumulates in the phloem sucrose transport activity drops dramatically. Western blots of plasma membrane proteins isolated from sucrose treated leaves showed that the loss of sucrose transport activity was proportional to a decline in symporter abundance, demonstrating that sucrose transport is regulated by changes in the amount of BvSUT1 protein. BvSUT1 transcript levels decreased in parallel with the loss of sucrose transport activity. Nuclear run-on experiments demonstrated that BvSUT1 gene transcription was repressed significantly in nuclei from leaves fed 100 mM exogenous sucrose, showing that sucrose-dependent modulation of BvSUT1 mRNA levels is mediated by changes in transcription. To identify which secondary messenger systems might be involved in regulating symporter activity, we used a variety of pharmacological agents to probe for a role of calcium or protein phosphorylation in sucrose signaling. In a detailed analysis, only okadaic acid altered sucrose transport activity. These results suggest a protein phosphatase is involved. We hypothesized that protein kinase inhibitors would have a …
Date: August 6, 2002
Creator: Vaughn, Matt; Harrington, Greg & Bush, Daniel R.
System: The UNT Digital Library
A web-based virtual lighting simulator (open access)

A web-based virtual lighting simulator

This paper is about a web-based ''virtual lighting simulator,'' which is intended to allow architects and lighting designers to quickly assess the effect of key parameters on the daylighting and lighting performance in various space types. The virtual lighting simulator consists of a web-based interface that allows navigation through a large database of images and data, which were generated through parametric lighting simulations. At its current form, the virtual lighting simulator has two main modules, one for daylighting and one for electric lighting. The daylighting module includes images and data for a small office space, varying most key daylighting parameters, such as window size and orientation, glazing type, surface reflectance, sky conditions, time of the year, etc. The electric lighting module includes images and data for five space types (classroom, small office, large open office, warehouse and small retail), varying key lighting parameters, such as the electric lighting system, surface reflectance, dimming/switching, etc. The computed images include perspectives and plans and are displayed in various formats to support qualitative as well as quantitative assessment. The quantitative information is in the form of iso-contour lines superimposed on the images, as well as false color images and statistical information on work plane …
Date: May 6, 2002
Creator: Papamichael, Konstantinos; Lai, Judy; Fuller, Daniel & Tariq, Tara
System: The UNT Digital Library
Towards ultrasensitive isotope trace analysis {sup 41}Ca. (open access)

Towards ultrasensitive isotope trace analysis {sup 41}Ca.

An Atom Trap Trace Analysis (ATTA) system based on the technique of laser manipulation of neutral atoms is being developed to count individual {sup 41}Ca atoms present in natural samples with an isotopic abundance of 10{sup -15}. Trapping of all stable calcium isotopes has been demonstrated and single-atom counting has been realized. For the most abundant isotope, {sup 40}Ca (97% isotopic abundance), a magneto-optical trap (MOT) loading rate of 2 x 10{sup 10} atoms/s has been reached at the overall capture efficiency of 1 x 10{sup -4}. System improvements could increase the efficiency by at least an order of magnitude.
Date: May 6, 2002
Creator: Moore, I. D.; Bailey, K.; Lu, Z.-T.; Mueller, P.; O'Connor, T. P. & Young, L.
System: The UNT Digital Library
First Polarized Proton Collisions at RHIC. (open access)

First Polarized Proton Collisions at RHIC.

We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180{sup o} about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV.
Date: November 6, 2002
Creator: Roser, T.; Ahrens, L.; Alessi, J.; Bai, M.; Beebe-Wang, J.; Brennan, J. M. et al.
System: The UNT Digital Library
Bpm System for the Sns Ring and Transfer Lines. (open access)

Bpm System for the Sns Ring and Transfer Lines.

The Spallation Neutron Source Ring accumulates about 1060 pulses of 38mA peak current IGeV H-minus particles from the Linac thru the HEBT line, then delivers this accumulated beam in a single pulse to the mercury target via the RTBT line. Bunching frequency of beam in the HEBT line is 402.5MHz, and about 1MHz in the Ring and RTBT. Position monitor electrodes in HEBT are of the shorted stripline type, with apertures of 12cm except in the dispersive bend, where the aperture is 21cm. Ring and RTBT electrodes are open striplines, with apertures of 21, 26, 30, and 36cm. All pickups are dual plane. The electronics will be PC-based with the Analog/Digital Front End passing data and receiving control and timing thru a custom PC1 interface developed by LANL[l]. LabVIEW will be used to direct the acquisition, process the data, and transfer results via Ethernet to the EPICS control system. To handle the dynamic range required with well over 60dB variation in signal size, the Ring and RTBT electronics will employ a fast gain switching technique that will take advantage of the 300ns tail-to-head gap to provide position measurement during the entire accumulation cycle. Beam-based alignment will be utilized as part …
Date: May 6, 2002
Creator: Dawson, W. C.; Cameron, P.; Cerniglia, P.; Cupolo, J.; Degen, C.; Dellapenna, A. et al.
System: The UNT Digital Library
Coherent synchrotron radiation and microbunching in bunch compressor. (open access)

Coherent synchrotron radiation and microbunching in bunch compressor.

Coherent synchrotron radiation (CSR) is of great interest to those designing accelerators as drivers for free-electron lasers (FELs) and energy recovery linacs (ERLs). A growing body of experimental evidence indicates the potentially serious impact of CSR on beam quality as we attempt to create high-brightness, high-current electron bunches using magnetic compression techniques. It is not an over-statement to say that the success of FEL and ERL projects could well depend on how well CSR is understood in the design phase. Simulation codes typically show qualitative or rough quantitative agreement with experiments, indicating that our understanding of the physics is improving but incomplete. For example, an unexpected microbunching instability was recently discovered with the code ''elegant'' and is now the subject of intense theoretical work. This paper presents an overview of CSR issues, including recent simulation results on the CSR instability. Experimental results and issues are also discussed.
Date: September 6, 2002
Creator: Borland, M.
System: The UNT Digital Library
Current and ultimate limitations of scanning x-ray nanotomography. (open access)

Current and ultimate limitations of scanning x-ray nanotomography.

X-ray nanotomography has developed into a powerful new tool for three-dimensional structural analysis. The scanning approach offers capabilities that are competitive with full-field imaging. Current and ultimate limitations of nanotomography are examined in light of recent work.
Date: February 6, 2002
Creator: McNulty, I.
System: The UNT Digital Library