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IN-VIVO DIAGNOSIS OF CHEMICALLY INDUCED MELANOMA IN AN ANIMAL MODEL USING UV-VISIBLE AND NIR ELASTIC SCATTERING SPECTROSCOPY: PRELIMINARY TESTING. (open access)

IN-VIVO DIAGNOSIS OF CHEMICALLY INDUCED MELANOMA IN AN ANIMAL MODEL USING UV-VISIBLE AND NIR ELASTIC SCATTERING SPECTROSCOPY: PRELIMINARY TESTING.

Elastic light scattering spectroscopy (ESS) has the potential to provide spectra that contain both morphological and chromophore information from tissue. We report on a preliminary study of this technique, with the hope of developing a method for diagnosis of highly-pigmented skin lesions, commonly associated with skin cancer. Four opossums were treated with dimethylbenz(a)anthracene to induce both malignant melanoma and benign pigmented lesions. Skin lesions were examined in vivo using both UV-visible and near infrared (NIR) ESS, with wavelength ranges of 330-900 nm and 900-1700 nm, respectively. Both portable systems used identical fiber-optic probe geometry throughout all of the measurements. The core diameters for illuminating and collecting fibers were 400 and 200 {micro}m, respectively, with center-to-center separation of 350 {micro}m. The probe was placed in optical contact with the tissue under investigation. Biopsies from lesions were analyzed by two standard histopathological procedures. Taking into account only the biopsied lesions, UV-visible ESS showed distinct spectral correlation for 11/13 lesions. The NIR-ESS correlated well with 12/13 lesions correctly. The results of these experiments showed that UV-visible and NIR-ESS have the potential to classify benign and malignant skin lesions, with encouraging agreement to that provided by standard histopathological examination. These initial results show potential …
Date: January 1, 2001
Creator: A'AMAR, C.; LEY, R. & AL, ET
Object Type: Article
System: The UNT Digital Library
A Super-Conducting Linac as a new Injector to the BNL-AGS (open access)

A Super-Conducting Linac as a new Injector to the BNL-AGS

N/A
Date: February 1, 2001
Creator: A., Ruggiero
Object Type: Report
System: The UNT Digital Library
Location Algorithms and Errors in Time-of-Arrival Systems (open access)

Location Algorithms and Errors in Time-of-Arrival Systems

This report describes least squares solution methods and linearized estimates of solution errors caused by data errors. These methods are applied to event locating systems which use time-of-arrival (TOA) data. Analyses are presented for algorithms that use the TOA data in a ''direct'' manner and for algorithms utilizing Time-of-arrival Squared (TSQ) methods. Location and error estimation results were applied to a ''typical'' satellite TOA detecting system. Using Monte Carlo methods, it was found that the linearized location error estimates were valid for random data errors with relatively large variances and relatively poor event/sensor geometries. In addition to least squares methods, which use an L{sub 2} norm, methods were described for L{sub 1} and L{sub {infinity}} norms. In general, these latter norms offered little improvement over least squares methods. Reduction of the location error variances can be effected by using information in addition to the TOA data themselves by adding judiciously chosen ''conditioning'' equation(s) to the least squares system. However, the added information can adversely affect the mean errors. Also, conditioned systems may offer location solutions where nonconditioned scenarios may not be solvable. Solution methods and linearized error estimates are given for ''conditioned'' systems. It was found that for significant data …
Date: September 1, 2001
Creator: AARONSON, EUGENE A.
Object Type: Report
System: The UNT Digital Library
Evolution of Stress in ScD{sub 2}/Cr Thin Films Fabricated by Evaporation and High Temperature Reaction (open access)

Evolution of Stress in ScD{sub 2}/Cr Thin Films Fabricated by Evaporation and High Temperature Reaction

The stress of scandium dideuteride, ScD{sub 2}, thin films is investigated during each stage of vacuum processing including metal deposition via evaporation, reaction and cooldown. ScD{sub 2} films with thin Cr underlayers are fabricated on three different substrate materials: molybdenum-alumina cermet, single crystal sapphire and quartz. In all experiments, the evaporated Cr and Sc metal is relatively stress-free. However, reaction of scandium metal with deuterium at elevated temperature to form a stoichiometric dideuteride phase leads to a large compressive in-plane film stress. Compression during hydriding results from an increased atomic density compared with the as-deposited metal film. After reaction with deuterium, samples are cooled to ambient temperature, and a tensile stress develops due to mismatched coefficients of thermal expansion (CTE) of the substrate-film couple. The residual film stress and the propensity for films to crack during cooldown depends principally on the substrate material when using identical process parameters. Films deposited onto quartz substrates show evidence of stress relief during cooldown due to a large CTE misfit; this is correlated with crack nucleation and propagation within films. All ScD{sub 2} layers remain in a state of tension when cooled to 30 C. An in-situ, laser-based, wafer curvature sensor is designed and …
Date: June 1, 2001
Creator: ADAMS,DAVID P.; BROWN,LAURENCE E.; GOEKE,RONALD S.; ROMERO,JUAN A. & SILVA,ANDREW D.
Object Type: Report
System: The UNT Digital Library
EFFECTS OF IN-PLANE STRAIN ON ORBITAL ORDERING AND MAGNETISM IN LaMnO3 THIN FILM (open access)

EFFECTS OF IN-PLANE STRAIN ON ORBITAL ORDERING AND MAGNETISM IN LaMnO3 THIN FILM

None
Date: June 1, 2001
Creator: AHN, K. & MILLIS, A.
Object Type: Article
System: The UNT Digital Library
QUIET DIRECT SIMULATION OF PLASMAS (open access)

QUIET DIRECT SIMULATION OF PLASMAS

None
Date: November 1, 2001
Creator: ALBRIGHT, B. J.; DAUGHTON, W. & AL, ET
Object Type: Article
System: The UNT Digital Library
AN APPROACH TO EXTREME-SCALE SIMULATION OF NOVEL ARCHITECTURES (open access)

AN APPROACH TO EXTREME-SCALE SIMULATION OF NOVEL ARCHITECTURES

None
Date: July 1, 2001
Creator: ALEXANDER, F. J.; BERKBIGLER, K. & AL, ET
Object Type: Article
System: The UNT Digital Library
HYBRIDIZATION AND PRESSURE EFFECTS IN UTX COMPOUNDS (open access)

HYBRIDIZATION AND PRESSURE EFFECTS IN UTX COMPOUNDS

None
Date: October 1, 2001
Creator: ALSAMDI, A.; SECHOVSKY, V. & AL, ET
Object Type: Article
System: The UNT Digital Library
Cloud to CAD (open access)

Cloud to CAD

This paper documents work performed to convert scanned range data to CAD solid model representation. The work successfully developed surface fitting algorithms for quadric surfaces (e.g. plane, cone, cylinder, and sphere), and a segmentation algorithm based entirely on surface type, rather than on a differential metric like Gaussian curvature. Extraction of all CAD-required parameters for quadric surface representation was completed. Approximate face boundaries derived from the original point cloud were constructed. Work to extrapolate surfaces, compute exact edges and solid connectivity was begun, but left incomplete due to funding reductions. The surface fitting algorithms are robust in the face of noise and degenerate surface forms.
Date: May 1, 2001
Creator: AMES,ARLO L.
Object Type: Report
System: The UNT Digital Library
A PREDICTIVE MODEL OF NUCLEON-NUCLEUS SCATTERING CROSS SECTIONS (open access)

A PREDICTIVE MODEL OF NUCLEON-NUCLEUS SCATTERING CROSS SECTIONS

None
Date: August 1, 2001
Creator: AMOS, K.; DEB, P. & KARATAGLIDIS, S.
Object Type: Article
System: The UNT Digital Library
OPTIMUM ENERGY ABSORPTION OF A SHORT-PULSE LASER IN A DOPED DIELECTRIC SLAB (open access)

OPTIMUM ENERGY ABSORPTION OF A SHORT-PULSE LASER IN A DOPED DIELECTRIC SLAB

A model is used to calculate energy absorption efficiency when a short-pulse laser impinges on a dielectric slab doped with an impurity for which the electrons have a resonant line at the laser wavelength. The amount of the energy resonant absorption is due to the overlapping between laser spectrum and resonance spectrum. The energy absorption efficiency can be maximized for a certain degree of doping concentration (at a given pulselength) and also for a certain pulselength (at a given doping concentration). For a modest amount of impurity, the resonant absorption may increase the fraction of energy absorption up to tens of percent of laser energy at 100s optical cycles when the laser wavelength is tuned within 1% of the resonant line. Dimensionless parameters are constructed so that the scaling to various parameters: laser wavelength, laser pulselength, dielectric constant, slab thickness, impurity concentration, resonant linewidth, and separation between the laser wavelength and the line resonance, could easily be obtained.
Date: May 1, 2001
Creator: ANG, L.
Object Type: Article
System: The UNT Digital Library
WHITE PAPER ON PROTON - NUCLEUS COLLISONS. (open access)

WHITE PAPER ON PROTON - NUCLEUS COLLISONS.

The role of proton-nucleus (p-A) collisions in the study of strong interactions has a long history. It has been an important testing ground for QCD. At RHIC p-A studies have been recognized since the beginning as important elements of the program. These include so-called baseline measurements in cold nuclear matter, essential (along with p-p studies) to a systematic study of QCD at high temperatures and densities in the search for the quark gluon plasma. Also accessible is a study of QCD in the small x (parton saturation) regime, complementary to physics accessible in high-energy e-p and e-A collisions. The role of p-A physics at RHIC was reviewed and brought into sharp focus at a workshop conducted in October 2000 at BNL; the agenda is shown in Appendix 1. This document summarizes the case for p-A at RHIC during the period covered by the next Nuclear Physics Long Range Plan. In subsequent sections we cover the Physics Issues, Experiment Run Plans and Schedule, Detector Upgrade Issues, and Machine Issues & Upgrades.
Date: March 1, 2001
Creator: ARONSON,S.H. & PENG,J.C.
Object Type: Report
System: The UNT Digital Library
EFFECT OF TEMPERATURE PROFILE ON REACTION VIOLENCE IN HEATED AND SELF-IGNITED PBX-9501 (open access)

EFFECT OF TEMPERATURE PROFILE ON REACTION VIOLENCE IN HEATED AND SELF-IGNITED PBX-9501

None
Date: June 1, 2001
Creator: ASAY, B.; DICKSON, P. & AL, ET
Object Type: Article
System: The UNT Digital Library
DEVELOPMENT OF A THERMAL EQUILIBRIUM PREDICTION ALGORITHM (open access)

DEVELOPMENT OF A THERMAL EQUILIBRIUM PREDICTION ALGORITHM

None
Date: December 1, 2001
Creator: AVILES-RAMOS, C.
Object Type: Article
System: The UNT Digital Library
NOVEL GAS CLEANING/CONDITIONING FOR INTEGRATED GASIFICATION COMBINED CYCLE (open access)

NOVEL GAS CLEANING/CONDITIONING FOR INTEGRATED GASIFICATION COMBINED CYCLE

The objective of this program is to develop and evaluate novel sorbents for the Siemens Westinghouse Power Company's (SWPC's) ''Ultra-Clean Gas Cleaning Process'' for reducing to near-zero levels the sulfur- and chlorine-containing gas emissions and fine particulate matter (PM2.5) caused by fuel bound constituents found in carbonaceous materials, which are processed in Integrated Gasification Combined Cycle (IGCC) technologies.
Date: July 1, 2001
Creator: Abbasian, Javad
Object Type: Report
System: The UNT Digital Library
A High-Performance VME-Based Acquisition System for Positron Emission Mammography (open access)

A High-Performance VME-Based Acquisition System for Positron Emission Mammography

A prototype for a practical and economical breast imaging system for cancer detection is currently under development at Jefferson Lab. The latest advances in bright, fast, crystal scintillators, compact position-sensitive photomultipliers (PSPMT), and high-performance digitizing and readout electronics are being used to develop a compact imager based on Positron Emission Tomography (PET). To facilitate the performance demands of the detector as well as the high number of readout channels, the data acquisition system is built around an intelligent, self-contained, VME form-factor.
Date: November 1, 2001
Creator: Abbott, D.J.; Weisenberger, A.; Majewski, S.; Kieper, D.; Kross, B.; Popov, V. et al.
Object Type: Article
System: The UNT Digital Library
Environmental Sampling FY01 Annual Report - Understanding the Movement of Mercury in the Environmental Surrounding the INEEL (open access)

Environmental Sampling FY01 Annual Report - Understanding the Movement of Mercury in the Environmental Surrounding the INEEL

Environmental fate and transport of the toxic air pollutant mercury (Hg) is currently a high-priority regional concern for the INEEL, and national and global concern for the U.S. Environmental Protection Agency (EPA). At the INEEL’s Idaho Nuclear Technology and Engineering Center (INTEC), significant quantities (est. 40 kg/year) of Hg may have been released over 37 years of Environmental Management’s (EM) High-Level Waste (HLW) treatment operations. The EPA is very concerned about the continued global buildup of Hg in the atmosphere and aquatic ecosystems, and has recently invested heavily in Hg research to better understand its complex environmental cycling.1,2 The Environmental Sampling work began in FY99 as a joint INEEL/U.S. Geological Survey (USGS) field research effort to (a) better understand the fate and potential impacts of Hg emissions from the INEEL’s HLW treatment operations (operational component) and (b) contribute at a national level to the scientific understanding of local, regional, and global Hg fate and transport (research component). The USGS contributed snow sampling support in the field (Water Resources Division, Salt Lake City) and laboratory analysis of all samples (Wisconsin District Mercury Research Laboratory).
Date: September 1, 2001
Creator: Abbott, Michael Lehman
Object Type: Report
System: The UNT Digital Library
Approximate ad-hoc query engine for simulation data (open access)

Approximate ad-hoc query engine for simulation data

In this paper, we describe AQSim, an ongoing effort to design and implement a system to manage terabytes of scientific simulation data. The goal of this project is to reduce data storage requirements and access times while permitting ad-hoc queries using statistical and mathematical models of the data. In order to facilitate data exchange between models based on different representations, we are evaluating using the ASCI common data model which is comprised of several layers of increasing semantic complexity. To support queries over the spatial-temporal mesh structured data we are in the process of defining and implementing a grammar for MeshSQL.
Date: February 1, 2001
Creator: Abdulla, G.; Baldwin, C.; Critchlow, T.; Kamimura, R.; Lozares, I.; Musick, R. et al.
Object Type: Article
System: The UNT Digital Library
Migration and Entrapment of DNAPLs in Heterogeneous Systems: Impact of Waste and Porous Medium Composition (open access)

Migration and Entrapment of DNAPLs in Heterogeneous Systems: Impact of Waste and Porous Medium Composition

Previously funded EMSP research efforts have been directed towards the quantification of dense nonaqueous phase liquid (DNAPL) migration and entrapment behavior in physically and chemically heterogeneous systems. This important research has demonstrated that chemical heterogeneities can have a significant influence on DNAPL fate and persistence. Previous work, however, has been limited to pure DNAPLs and well defined aqueous and solid surface chemistries. Subsurface chemical heterogeneities at many DOE sites are generally more complex as a result of the disposal of mixtures of wastes into heterogeneous subsurface environments. The research planned in this project seeks to build upon our previous research experience and expertise to explore the influence of waste and porous media composition on DNAPL migration and entrapment in the saturated zone. DNAPL mixtures and soils typical of those found across the DOE complex will be used in these studies. Many of the experimental procedures and protocols to be employed are based upon those developed under previous EMSP funding. This past work also provides the conceptual framework for characterizing and interpreting experimental results, mathematical model development, and inverse modeling protocols. Specific objectives of this research are identified below: (1) Relate measured interfacial properties for representative wastes and soils to parameters …
Date: June 1, 2001
Creator: Abriola, Linda M. & Demond, Avery H.
Object Type: Report
System: The UNT Digital Library
Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 1999 Annual Report. (open access)

Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 1999 Annual Report.

This report details the 1999 results from an ongoing project to monitor the migration behavior of wild spring/summer chinook salmon smolts in the Snake River Basin. The report also discusses trends in the cumulative data collected for this project from Oregon and Idaho streams since 1989.
Date: June 1, 2001
Creator: Achord, Stephen
Object Type: Report
System: The UNT Digital Library
Sulfur Polymer Stabilization/Solidification (Spss) Treatability of Los Alamos National Laboratory Mercury Waste. (open access)

Sulfur Polymer Stabilization/Solidification (Spss) Treatability of Los Alamos National Laboratory Mercury Waste.

Brookhaven National Laboratory's Sulfur Polymer Stabilization/Solidification (SPSS) process was used to treat approximately 90kg of elemental mercury mixed waste from Los Alamos National Laboratory. Treatment was carried out in a series of eight batches using a 1 ft{sup 3} pilot-scale mixer, where mercury loading in each batch was 33.3 weight percent. Although leach performance is currently not regulated for amalgamated elemental mercury (Hg) mixed waste, Toxicity Characteristic Leach Procedure (TCLP) testing of SPSS treated elemental mercury waste indicates that leachability is readily reduced to below the TCLP limit of 200 ppb (regulatory requirement following treatment by retort for wastes containing > 260 ppb Hg), and with process optimization, to levels less than the stringent Universal Treatment Standard (UTS) limit of 25 ppb that is applied to waste containing < 260 ppm Hg. In addition, mercury-contaminated debris, consisting of primary glass and plastic containers, as well as assorted mercury thermometers, switches, and labware, was first reacted with SPSS components to stabilize the mercury contamination, then macroencapsulated in the molten SPSS product. This treatment was done by vigorous agitation of the sulfur polymer powder and the comminuted debris. Larger plastic and metal containers were reacted to stabilize internal mercury contamination, and then …
Date: November 1, 2001
Creator: Adams, J. W. & Kalb, P. D.
Object Type: Report
System: The UNT Digital Library
Development of Attrition Resistant Iron-Based Fischer-Tropsch Catalysts (open access)

Development of Attrition Resistant Iron-Based Fischer-Tropsch Catalysts

The Fischer-Tropsch (F-T) reaction provides a way of converting coal-derived synthesis gas (CO+H{sub 2}) to liquid fuels. Since the reaction is highly exothermic, one of the major problems in control of the reaction is heat removal. Recent work has shown that the use of slurry bubble column reactors (SBCRs) can largely solve this problem. The use of iron-based catalysts is attractive not only due to their low cost and ready availability, but also due to their high water-gas shift activity which makes it possible to use these catalysts with low H{sub 2}/CO ratios. However, a serious problem with use of Fe catalysts in a SBCR is their tendency to undergo attrition. This can cause fouling/plugging of downstream filters and equipment, makes the separation of catalyst from the oil/wax product very difficult if not impossible, and results in a steady loss of catalyst from the reactor. Recently, fundamental understanding of physical attrition is being addressed by incorporating suitable binders into the catalyst recipe. This has resulted in the preparation of a spray dried Fe-based catalyst having aps of 70 mm with high attrition resistance. This Fe-based attrition resistant, active and selective catalyst gave 95% CO conversion through 125 hours of testing …
Date: September 1, 2001
Creator: Adeyiga, Adeyinka A.
Object Type: Report
System: The UNT Digital Library
Erosive wear of selected materials for fossil energy applications (open access)

Erosive wear of selected materials for fossil energy applications

A number of materials have been evaluated to determine their erosion resistance for fossil energy applications. This is part of a larger program to study wear and corrosion at Albany Research Center. This paper will present the results for some of these materials, including FeAl, FeAl cermets, WC-Co cemented carbides, Si3N4-MoSi2, Si3N4, Stellite 6B, white cast irons and 440C steel. Trends in erosion rates due to material properties and erosive conditions will be presented. FeAl cermets performed well compared to the WC-Co cemented carbides. The interparticle spacing of the WC-Co cemented carbides correlated with the erosion rate. The erosion rate of the WC-Co cemented carbides decreased as the interparticle spacing decreased. It is important to realize that erosion resistance is not an intrinsic material property, but is a system response. A change in the wear environment can significantly alter the relative rankings of materials with respect to their wear rate. For example, at relatively low velocities, the carbides in the white cast irons are more erosion resistant than the matrix, while at higher velocities the matrix is more erosion resistant.
Date: January 1, 2001
Creator: Adler, Thomas A.; Rawers, James C.; Tylczak, Joseph H. & Hawk, Jeffrey A.
Object Type: Article
System: The UNT Digital Library
An integrated solution for secure group communication in wide-area networks (open access)

An integrated solution for secure group communication in wide-area networks

Many distributed applications require a secure reliable group communication system to provide coordination among the application components. This paper describes a secure group layer (SGL) which bundles a reliable group communication system, a group authorization and access control mechanism, and a group key agreement protocol to provide a comprehensive and practical secure group communication platform. SGL also encapsulates the standard message security services (i.e, confidentiality, authenticity and integrity). A number of challenging issues encountered in the design of SGL are brought to light and experimental results obtained with a prototype implementation are discussed.
Date: April 1, 2001
Creator: Agarwal, Deborah A.; Chevassut, Olivier; Thompson, Mary & Tsudik, Gene
Object Type: Article
System: The UNT Digital Library