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[News Script: Rayburn]

Description: Script from the WBAP-TV station in Fort Worth, Texas, covering a news story about House Speaker Sam Rayburn visiting Dallas, where he will be at the bedside of his sister.
Date: February 24, 1956
Creator: WBAP-TV (Television station : Fort Worth, Tex.)
Partner: UNT Libraries Special Collections

A study of the design possibilities and techniques of pounding plants into fabric and paper

Description: The problem of investigating the possibilities of direct design transfer from plant to fabric and paper was divided into two parts. The first part is concerned with the exploration of the mechanics of the transfer. The second part of the problem is concerned with the exploration of the design possibilities of the medium.
Date: August 1968
Creator: Safford, Gayle Grisham
Partner: UNT Libraries

Catalytic Properties and Mechanical Behavior of Metallic Glass Powders

Description: Lack of crystalline order and microstructural features such as grain/grain-boundary in metallic glasses results in a suite of remarkable attributes including very high strength, close to theoretical elasticity, high corrosion and wear resistance, and soft magnetic properties. By altering the morphology and tuning of composition, MGs may be transformed into high-performance catalytic materials. In this study, the catalytic properties of metallic glass powders were demonstrated in dissociating toxic organic chemicals such as AZO dye. BMG powders showed superior performance compared to state of the art crystalline iron because of their high catalytic activity, durability, and reusability. To enhance the catalytic properties, high energy mechanical milling was performed to increase the surface area and defect density. Iron-based bulk metallic glass (BMG) of composition Fe48Cr15Mo14Y2C15B6 was used because of its low cost and ability to make large surface area by high energy ball milling. AZO dye was degraded in less than 20 minutes for the 9 hours milled Fe-BMG. However, subsequent increase in ball milling time resulted in devitrification and loss of catalytic activity as measured using UV-Visible spectroscopy. Aluminum-based bulk metallic glass (Al-BMG) powder of composition Al82Fe3Ni8Y7 was synthesized by arc-melting the constituent elements followed by gas-atomization. The particle size and morphology were similar to Fe-BMG with a fully amorphous structure. A small percentage of transition metal constituents (Fe and Ni) in a mostly aluminum alloy showed high catalytic activity, with no toxic by-products and no change in surface characteristics. Al-alloy particles, being light-weight, were easily dispersed in aqueous medium and accelerated the redox reactions. The mechanism of dye dissociation was studied using Raman and Infrared (IR) spectroscopy. Breaking of -C-H- and - C-N- bonds of AZO dye was found to be the primary mechanism. Mechanical behavior of individual BMG particles was evaluated by in situ pico-indentation in a scanning electron ...
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Date: May 2017
Creator: Garrison, Seth Thomas
Partner: UNT Libraries

Evaluation of normalization methods for cDNA microarray data by k-NN classification

Description: Non-biological factors give rise to unwanted variations in cDNA microarray data. There are many normalization methods designed to remove such variations. However, to date there have been few published systematic evaluations of these techniques for removing variations arising from dye biases in the context of downstream, higher-order analytical tasks such as classification. Ten location normalization methods that adjust spatial- and/or intensity-dependent dye biases, and three scale methods that adjust scale differences were applied, individually and in combination, to five distinct, published, cancer biology-related cDNA microarray data sets. Leave-one-out cross-validation (LOOCV) classification error was employed as the quantitative end-point for assessing the effectiveness of a normalization method. In particular, a known classifier, k-nearest neighbor (k-NN), was estimated from data normalized using a given technique, and the LOOCV error rate of the ensuing model was computed. We found that k-NN classifiers are sensitive to dye biases in the data. Using NONRM and GMEDIAN as baseline methods, our results show that single-bias-removal techniques which remove either spatial-dependent dye bias (referred later as spatial effect) or intensity-dependent dye bias (referred later as intensity effect) moderately reduce LOOCV classification errors; whereas double-bias-removal techniques which remove both spatial- and intensity effect reduce LOOCV classification errors even further. Of the 41 different strategies examined, three two-step processes, IGLOESS-SLFILTERW7, ISTSPLINE-SLLOESS and IGLOESS-SLLOESS, all of which removed intensity effect globally and spatial effect locally, appear to reduce LOOCV classification errors most consistently and effectively across all data sets. We also found that the investigated scale normalization methods do not reduce LOOCV classification error. Using LOOCV error of k-NNs as the evaluation criterion, three double-bias-removal normalization strategies, IGLOESS-SLFILTERW7, ISTSPLINE-SLLOESS and IGLOESS-SLLOESS, outperform other strategies for removing spatial effect, intensity effect and scale differences from cDNA microarray data. The apparent sensitivity of k-NN LOOCV classification error to dye biases suggests that ...
Date: December 17, 2004
Creator: Wu, Wei; Xing, Eric P; Myers, Connie; Mian, Saira & Bissell, Mina J
Partner: UNT Libraries Government Documents Department

Room temperature observation of quantum jumps of single molecule into dark states

Description: Fluctuations in the room temperature emission rate from single dye molecules which are excited with the near field scanning optical microscope reveal long (seconds) and short ({approximately} milliseconds) lived dark states.
Date: November 1, 1995
Creator: Ha, T.; Enderle, T.; Ogletree, D.F.; Selvin, P.R.; Weiss, S. & Chemla, D.S.
Partner: UNT Libraries Government Documents Department

Time-Dependent Interfacial Properties and DNAPL Mobility

Description: Interfacial properties play a major role in governing where and how dense nonaqueous phase liquids (DNAPLs) move in the subsurface. Interfacial tension and contact angle measurements were obtained for a simple, single component DNAPL (tetrachloroethene, PCE), complex laboratory DNAPLs (PCE plus Sudan IV dye), and a field DNAPL from the Savannah River Site (SRS) M-Area DNAPL (PCE, trichloroethene [TCE], and maching oils). Interfacial properties for complex DNAPLs were time-dependent, a phenomenon not observed for PCE alone. Drainage capillary pressure-saturation curves are strongly influenced by interfacial properties. Therefore time-dependence will alter the nature of DNAPL migration and penetration. Results indicate that the time-dependence of PCE with relatively high Sudan IV dye concentrations is comparable to that of the field DNAPL. Previous DNAPL mobility experiments in which the DNAPL was dyed should be reviewed to determine whether time-dependent properties influenced the resutls. Dyes appear to make DNAPL more complex, and therefore a more realistic analog for field DNAPLs than single component DNAPLs.
Date: March 10, 1999
Creator: Tuck, D.M.
Partner: UNT Libraries Government Documents Department

Nonlinear Optical Absorption and Refraction Study of Metallophthalocyanine Dyes

Description: This dissertation deals with the characterization of the nonlinear absorption and refraction of two representative metallophthalocyanine dyes: chloro aluminum phthalocyanine dissolved in methanol, referred to as CAP, and a silicon naphthalocyanine derivative dissolved in toluene, referred to as SiNc. Using the Z-scan technique, the experiments are performed on both the picosecond and nanosecond timescales at a wavelength of 0.532 μm.
Date: December 1992
Creator: Wei, Tai-Huei
Partner: UNT Libraries

Dynamical Study of Guest-Host Orientational Interaction in LiquidCrystalline Materials

Description: Guest-host interaction has long been a subject of interest in many disciplines. Emphasis is often on how a small amount of guest substance could significantly affect the properties of a host material. This thesis describe our work in studying a guest-host effect where dye-doping of liquid crystalline materials greatly enhances the optical Kerr nonlinearity of the material. The dye molecules, upon excitation and via intermolecular interaction, provides an extra torque to reorient the host molecules, leading to the enhanced optical Kerr nonlinearity. We carried out a comprehensive study on the dynamics of the photoexcited dye-doped liquid crystalline medium. Using various experimental techniques, we separately characterized the dynamical responses of the relevant molecular species present in the medium following photo-excitation, and thus were able to follow the transient process in which photo-excitation of the dye molecules exert through guest-host interaction a net torque on the host LC material, leading to the observed enhanced molecular reorientation. We also observed for the first time the enhanced reorientation in a pure liquid crystal system, where the guest population is created through photoexcitation of the host molecules themselves. Experimental results agree quantitatively with the time-dependent theory based on a mean-field model of the guest-host interaction.
Date: December 20, 2005
Creator: Truong, Thai Viet
Partner: UNT Libraries Government Documents Department

Whole Genome Amplification of DNA from Residual Cells Left By Incidental Contact

Description: Typically, the number of genetic analyses performed on a sample of DNA has been limited by the amount of starting material. For example, the small quantity of DNA obtained from the cells within a fingerprint meant that only a five to ten reactions could be performed off a single sample. We demonstrate a process wherein total genomic DNA is amplified before forensic typing analysis. The process requires as few as 8 cells and produces sufficient material for up to 20,000 subsequent PCR reactions. The technique is particularly useful to enhance current methods of latent print analysis and has been shown to be compatible with common forensic print visualization and removal techniques including dye staining and powders.
Date: November 20, 2003
Creator: Turteltaub, K; Sorensen, K; Christian, A; Williams, J & Vrankovich, G
Partner: UNT Libraries Government Documents Department

Optical properties of fluids in microfabricated channels

Description: Microfabricated channels are widely thought to be the key to realizing chemical analysis on a microscopic scale. Chemical and biological information in the microchannels is often probed with optical techniques such as fluorescence, Raman and absorption spectroscopy. However, the optical effects of a microchannel are not well characterized. For example, it is important to understand the optics of the channel in order to optimize optical coupling efficiency. The authors consider various designs for enhancing the sensitivity of fluorescence detection in a microchannel.
Date: March 1, 1997
Creator: French, T.; Gourley, P.L. & McDonald, A.E.
Partner: UNT Libraries Government Documents Department

Discussion of DNAPL Migration through a Fractured Perching Layer

Description: The visualization study of 1,1,1-trichloroethane (TCA) infiltration described by Stephens et al. (1998) was an elegant design, clearly demonstrating DNAPL behavior encountering a fractured perched layer. I question, however, their interpretation, stated in both abstract and conclusions, that rapid DNAPL penetration of the fracture was "in contrast to existing mathematical solutions of hydrostatic initial conditions and full saturation below the fracture." I also have a comment regarding the experimental conditions.
Date: January 13, 1999
Creator: Tuck, D.M.
Partner: UNT Libraries Government Documents Department

Characterization of fluid transport in microscale structures

Description: A new tool for imaging both scalar transport and velocity fields in liquid flows through microscale structures is described. The technique employs an ultraviolet laser pulse to write a pattern into the flow by uncaging a fluorescent dye. This is followed, at selected time delays, by flood illumination with a pulse of visible light which excites the uncaged dye. The resulting fluorescence image collected onto a sensitive CCD camera. The instrument is designed as an oil immersion microscope to minimize the beam steering effects. The caged fluorescent dye is seeded in trace quantities throughout the active fluid, thus images with high contrast and minimal distortion due to any molecular diffusion history can be obtained at any point within the microchannel by selectivity activating the dye in the immediate region of interest. The author reports images of pressure- and electrokinetically-driven steady flow within round cross section capillaries having micron scale inner diameters. The author also demonstrates the ability to recover the velocity profile from a time sequence of these scalar images by direct inversion of the conserved scalar advection-convection equation.
Date: January 1, 1998
Creator: Paul, P.H.
Partner: UNT Libraries Government Documents Department

1995 and 1996 Upper Three Runs Dye Study Data Analyses

Description: This report presents an analysis of dye tracer studies conducted on Upper Three Runs. The revised STREAM code was used to analyze these studies and derive a stream velocity and a dispersion coefficient for use in aqueous transport models. These models will be used to facilitate the establishment of aqueous effluent limits and provide contaminant transport information to emergency management in the event of a release.
Date: June 1998
Creator: Chen, K. F.
Partner: UNT Libraries Government Documents Department

Analysis of Dyes Extracted from Millimeter-Size Nylon Fibers by Micellar Electrokinetic Chromatography

Description: The Learning Objective is to present to the forensic community a potential qualitative/quantitative method for trace-fiber color comparisons using micellar electrokinetic chromatography (MEKC). Developing a means of analyzing extracted dye constituents from millimeter-size nylon fiber samples was the objective of this research initiative. Aside from ascertaining fiber type, color evaluation and source comparison of trace-fiber evidence plays a critical role in forensic-fiber examinations. Literally thousands of dyes exist to date, including both natural and synthetic compounds. Typically a three-color-dye combination is employed to affect a given color on fiber material. The result of this practice leads to a significant number of potential dye combinations capable of producing a similar color and shade. Since a typical forensic fiber sample is 2 mm or less in length, an ideal forensic dye analysis would qualitatively and quantitatively identify the extracted dye constituents from a sample size of 1 mm or smaller. The goal of this research was to develop an analytical method for comparing individual dye constituents from trace-fiber evidence with dyes extracted from a suspected source, while preserving as much of the original evidence as possible.
Date: July 30, 2001
Creator: Lewis, L.A.
Partner: UNT Libraries Government Documents Department

Pollutant dispersion in a large indoor space: Part 2 -Computational Fluid Dynamics (CFD) predictions and comparison with ascale model experiment for isothermal flow

Description: This paper reports on an investigation of the adequacy of Computational fluid dynamics (CFD), using a standard Reynolds Averaged Navier Stokes (RANS) model, for predicting dispersion of neutrally buoyant gas in a large indoor space. We used CFD to predict pollutant (dye) concentration profiles in a water filled scale model of an atrium with a continuous pollutant source. Predictions from the RANS formulation are comparable to an ensemble average of independent identical experiments. Model results were compared to pollutant concentration data in a horizontal plane from experiments in a scale model atrium. Predictions were made for steady-state (fully developed) and transient (developing) pollutant concentrations. Agreement between CFD predictions and ensemble averaged experimental measurements is quantified using the ratios of CFD-predicted and experimentally measured dye concentration at a large number of points in the measurement plane. Agreement is considered good if these ratios fall between 0.5 and 2.0 at all points in the plane. The standard k-epsilon two equation turbulence model obtains this level of agreement and predicts pollutant arrival time to the measurement plane within a few seconds. These results suggest that this modeling approach is adequate for predicting isothermal pollutant transport in a large room with simple geometry.
Date: October 1, 2002
Creator: Finlayson, Elizabeth U.; Gadgil, Ashok J.; Thatcher, Tracy L. & Sextro, Richard G.
Partner: UNT Libraries Government Documents Department

Metal Ion Analysis Using Near-Infrared Dyes and the ''Laboratory-on-a-Chip''

Description: This project addresses the need for developing a highly sensitive and selective, portable radionuclide analyzer which would permit a low-cost and timely characterization of DOE remediation sites. Through the application of near-infrared fluorophore tagged macrocycles, in combination with the capillary electrophoretic separation of radionuclide and heavy metal complexes on a microchip, we propose an innovative, low cost characterization approach to gaining timely characterization data in the field. The research goals for this program are summarized as follows: (a) To synthesize a new class of near-infrared tagged macrocycles that will take advantage of the inherent metal complexation properties of the macrocycle, while fluorescing in a region of the spectrum with very little background fluorescence. (b) To characterize the fluorescence and complexation behavior of this new class of complexation agents. (c) To implement these new materials into the design of a portable monitor for radionuclide and heavy metal analytes that utilizes the ''laboratory-on-a-chip'' technology for performing capillary electrophoresis on a microchip.
Date: June 1, 1999
Creator: Collins, Greg E. & Lu, Qin, Evans III, Lawrence
Partner: UNT Libraries Government Documents Department

Magnetic Particle Process Improvement

Description: The magnetic particle testing process is performed to find linear, surface and near surface discontinuities in ferromagnetic test materials. A wet fluorescent method is used at Honeywell Federal Manufacturing & Technologies (FM&T). This method employs a liquid carrier mixed with iron oxide particles in suspension, and the particles used in the method are coated with a fluorescent dye to make them visible under a black light. The process in its current state employs the use of a tank of liquid solution of a mineral oil carrier with iron oxide particles in suspension. The change to the use of an aerosol delivery system with the same material reduces the amount of waste involved in the process while preserving the sensitivity of the testing, shortens the flowtime for the test, and saves labor and material costs.
Date: August 13, 2002
Creator: Hubert, R.R.
Partner: UNT Libraries Government Documents Department

Sorting fluorescent nanocrystals with DNA

Description: Semiconductor nanocrystals with narrow and tunable fluorescence are covalently linked to oligonucleotides. These biocompounds retain the properties of both nanocrystals and DNA. Therefore, different sequences of DNA can be coded with nanocrystals and still preserve their ability to hybridize to their complements. We report the case where four different sequences of DNA are linked to four nanocrystal samples having different colors of emission in the range of 530-640 nm. When the DNA-nanocrystal conjugates are mixed together, it is possible to sort each type of nanoparticle using hybridization on a defined micrometer -size surface containing the complementary oligonucleotide. Detection of sorting requires only a single excitation source and an epifluorescence microscope. The possibility of directing fluorescent nanocrystals towards specific biological targets and detecting them, combined with their superior photo-stability compared to organic dyes, opens the way to improved biolabeling experiments, such as gene mapping on a nanometer scale or multicolor microarray analysis.
Date: December 10, 2001
Creator: Gerion, Daniele; Parak, Wolfgang J.; Williams, Shara C.; Zanchet, Daniela; Micheel, Christine M. & Alivisatos, A. Paul
Partner: UNT Libraries Government Documents Department

Dye Sensitization of Semiconductor Particles

Description: In this project electron transfer at semiconductor liquid interfaces was examined by ultrafast time-resolved and steady-state optical techniques. The experiments primarily yielded information about the electron transfer from titanium dioxide semiconductor particles to absorbed molecules. The results show that the rate of electron transfer depends on the structure of the molecule, and the crystalline phase of the particle. These results can be qualitatively explained by Marcus theory for electron transfer.
Date: January 13, 2003
Creator: Hartland, G. V.
Partner: UNT Libraries Government Documents Department