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Fabric Magic

Description: A short film examining the strengths of three Milliken-made fabric blends - nylon and wool, orlon and wool, and dacron and wool.
Date: unknown
Creator: Elwyn, Robert & Lyon, Sumner
Partner: UNT Media Library

Effect of Retting on Surface Chemistry and Mechanical Performance Interactions in Natural Fibers for High Performance Polymer Composites

Description: Sustainability through replacement of non-renewable fibers with renewable fibers is an ecological need. Impact of transportation costs from South-east Asia on the life cycle analysis of the composite is detrimental. Kenaf is an easily grown crop in America. Farm based processing involves placing the harvested crop in rivers and ponds, where retting of the fibers from the plant (separation into fibers) can take 2 weeks or more. The objective of this thesis is to analyze industrially viable processes for generating fibers and examine their synergistic impact on mechanical performance, surface topography and chemistry for functional composites. Comparison has been made with commercial and conventional retting process, including alkali retting, enzymatic retting, retting in river and pond water (retting occurs by natural microbial population) with controlled microbial retting. The resulting kenaf fibers were characterized by dynamic mechanical analysis (DMA), Raman spectroscopy (FT-Raman), Fourier transform infrared spectroscopy (FT-IR), polarized optical microscopy (POM), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) optical fluorescence microscopy, atomic force microscopy (AFM) and carbohydrate analysis. DMA results showed that pectinase and microbe treated fibers have superior viscoelastic properties compared to alkali retting. XPS, Raman, FT-IR and biochemical analysis indicated that the controlled microbial and pectinase retting was effective in removing pectin, hemicellulose and lignin. SEM, optical microscopy and AFM analysis showed the surface morphology and cross sectional architecture were preserved in pectinase retting. Experimental results showed that enzymatic retting at 48 hours and controlled microbial retting at 72 hours yield uniform and superior quality fibers compared to alkali and natural retting process. Controlled microbial retting is an inexpensive way to produce quality fibers for polymer composite reinforcement.
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Date: May 2013
Creator: Ramesh, Dinesh
Partner: UNT Libraries

Comparison of BCF-10, BCF-12, and BCF-20 Scintillating Fibers for Use in a 1-Dimensional Linear Sensor

Description: One-dimensional fiber-bundle arrays may prove useful in a number of radiation sensing applications where radiation detection over large areas is needed. Tests have been performed to evaluate the light generation and transmission characteristics of 15-meter long, 10-fiber bundles of BCF-10, BCF-12, and BCF-20 scintillating fibers (Saint Gobain) exposed to collimated gamma-ray sources. The test set-up used one R9800 (Hamamatsu) photomultiplier tube (PMT) at each end, with a high-speed waveform digitizer to collect data. Time constraints were imposed on the waveform data to perform time-of-flight analysis of the events in the fiber bundles, eliminating spurious noise pulses in the high gain PMTs and also allowing 1-dimensional localization of interactions along the lengths of the fiber bundles. This paper will present the results of these measurements including the attenuation coefficients of the two fiber types and the timing resolution (position uncertainty) possible for each fiber bundle when using the R9800 PMTs.
Date: October 1, 2012
Creator: Chichester, David L.; Watson, Scott M. & Johnson, James T.
Partner: UNT Libraries Government Documents Department

Swaged Metal Fiber-UO₂ Fuel Element: Final Report

Description: From introduction: The objectives of this program were to: study the variables of uranium dioxide, metal fibers and cladding material and determine the effects of swaging, develop thermal conductivity tests for small diameter rod-type elements, determine the thermal conductivity of various combinations of metal fibers and uranium dioxide, and select optimum combinations of the above variables to recommend for irradiation testing.
Date: January 1960
Creator: Kane, John
Partner: UNT Libraries Government Documents Department

Comparison of amplified spontaneous emission pulse cleaners for use in chirped pulse amplification front end lasers

Description: We compare various schemes for removing amplified spontaneous emission from seed laser pulses. We focus on compact schemes that are compatible with fiber laser front end systems with pulse energies in the 10nJ-1{micro}J range and pulse widths in the 100fs-10ps range. Pre-pulse contrast ratios greater than 10{sup 9} have been measured.
Date: July 2, 2007
Creator: Dawson, J.; Siders, C.; Phan, H.; Kanz, V. & Barty, C.
Partner: UNT Libraries Government Documents Department

Hemp as an Agricultural Commodity

Description: This report discusses the various industrial uses for hemp, a variety of Cannabis sativa that is of the same plant species as marijuana. It compares hemp with marijuana and discusses global production, legal status, and recent legislative activity.
Date: March 10, 2017
Creator: Johnson, Renée
Partner: UNT Libraries Government Documents Department

Remote Synchrotron Light Instrumentation Using Optical Fibers

Description: By coupling the emitted synchrotron light into an optical fiber, it is possible to transmit the signal at substantial distances from the light port, without the need to use expensive beamlines. This would be especially beneficial in all those cases when the synchrotron is situated in areas not easily access because of their location, or due to high radiation levels. Furthermore, the fiber output can be easily switched, or even shared, between different diagnostic instruments. We present the latest results on the coupling and dispersion measurements performed at the Advanced Light Source in Berkeley. In several cases, coupling synchrotron light into optical fibers can substantially facilitate the use of beam diagnostic instrumentation that measures longitudinal beam properties by detecting synchrotron radiation. It has been discussed in with some detail, how fiberoptics can bring the light at relatively large distances from the accelerator, where a variety of devices can be used to measure beam properties and parameters. Light carried on a fiber can be easily switched between instruments so that each one of them has 100% of the photons available, rather than just a fraction, when simultaneous measurements are not indispensable. From a more general point of view, once synchrotron light is coupled into the fiber, the vast array of techniques and optoelectronic devices, developed by the telecommunication industry becomes available. In this paper we present the results of our experiments at the Advanced Light Source, where we tried to assess the challenges and limitations of the coupling process and determine what level of efficiency one can typically expect to achieve.
Date: May 4, 2009
Creator: De Santis, S. & Yin, Y.
Partner: UNT Libraries Government Documents Department

The Comparison and Evaluation of Three Fiber Composite Failure Criteria

Description: Three specific failure criteria for the transversely isotropic fiber composite case will be discussed. All three use the polynomial expansion method. The three criteria are the Tsai-Wu criterion, the Hashin criterion and the Christensen criterion. All three criteria will be given in forms that admit direct and easy comparison, which has not usually been done. The central differences between these three criteria will be discussed, and steps will be taken toward the evaluation of them.
Date: February 8, 2005
Creator: Christensen, R M
Partner: UNT Libraries Government Documents Department

SBIR Final Report. Liquid Core Optical Scintillating Fibers

Description: This Phase I SBIR project focused on developing flexible scintillating liquid core optical fibers, with potential uses in high-energy calorimetry, tracking, preradiators, active targets or other fast detectors. Progress on the six tasks of the project is summarized. The technical developments involve three technology components: (1) highly flexible capillaries or tubes of relatively low n (index of refraction) to serve as cladding and liquid core containment; (2) scintillator (and clear) fluids of relatively high n to serve as a core-- these fluids must have a high light transmission and, for some applications, radiation hardness; (3) optical end plugs, plug insertion, and plug-cladding tube sealing technology to contain the core fluids in the tubes, and to transmit the light.
Date: May 16, 2000
Creator: Beetz, C.P.; Steinbeck, J. & Buerstler, R.
Partner: UNT Libraries Government Documents Department

Real-time data reorganizer for the D0 central fiber tracker trigger system at Fermilab

Description: A custom digital data Mixer system has been designed to reorganize, in real time, the data produced by the Fermilab D0 Scintillating Fiber Detector. The data is used for the Level 1 and Level 2 trigger generation. The Mixer System receives the data from the front-end digitization electronics over 320 Low Voltage Differential Signaling (LVDS) links running at 371 MHz. The input data is de-serialized down to 53 MHz by the LVDS receivers, clock/frame re-synchronized and multiplexed in Field Programmable Gate Arrays (FPGAs). The data is then reserialized at 371 MHz by LVDS transmitters over 320 LVDS output links and sent to the electronics responsible for Level 1 and Level 2 trigger decisions. The Mixer System processes 311 Gigabits per second of data with an input to output delay of 200 nanoseconds.
Date: December 13, 2002
Creator: Stefano Marco Rapisarda, Jamieson T Olsen and Neal George Wilcer
Partner: UNT Libraries Government Documents Department

The Structure and Properties of Carbon Fiber Based Adsorbent Monoliths

Description: Carbon fiber monoliths manufactured by a novel slurry molding process from isotropic pitch-derived fibers are being developed at ORNL for gas separation and storage applications [1]. Low density (p = 0.2 - 0,3 g/cm3) monoliths have been successfully demonstrated to have an acceptable pressure drop for gas separation applications and are currently being developed for C02/CH4 separations, whereas monoliths with densities in the range p = 0.4 - 0.6 g/cm3 have been "shown to have natural gas storage capacities of >100 VIV at 500 psi pressure and room temperature. Thermal conductivity, as a function of temperature, was measured using the LASER flash, thermal- pulse method. Another approach to minimizing the temperature gradients that develop in a storage bed is to increase the thermal conductivity of the adsorbent carbon. To this end, we have developed hybrid monoliths that contain small fractions of mesophase pitch- derived carbon fibers. Our hybrid monoliths exhibit thermal conductivities in the range 0.2-0.9 W/m.K depending on the blend and density of the monolith. In comparison, a packed bed of granular carbon at comparable density would have a thermal conductivity of approximately 0.1 W/m.K [ 1 ]. The thermal conductivities of several of the hybrid The improved thermal conductivity of our monoliths is attributed to the bonding between the fibers and the incorporation of high thermal conductivity, mesophase pitch-derived carbon fibers. These features are visible in the SEM micrograph in Fig. 4.
Date: November 6, 1998
Creator: Burchell, T.; Judkins, R.R.; Rogers, M.R. & Shaw, W.S.
Partner: UNT Libraries Government Documents Department

EFFECTS OF HETEROGENEITY ON THE STRENGTH OF 3D COMPOSITES

Description: Monte Carlo simulation interpreted with theoretical modeling is used to study the statistical failure modes in unidirectional composites consisting of a hexagonal array of elastic fibers embedded in an elastic matrix. Composite structure is idealized using the chain-of-bundles model in terms of bundles of length {delta} arranged along the fiber direction. Fibers element strengths in {delta}-bundles are taken to be Weibull distributed and Hedgepeth and Van Dyke load sharing is assumed for transverse fiber break arrays. Simulations of {delta}-bundle failure reveal two regimes. When fiber strength variability is low, the dominant failure mode is by growing clusters of fiber breaks up to instability. When this variability is high, cluster formation is suppressed by a more dispersed fiber failure mode. Corresponding to these two cases, they construct simple models that predict the strength distribution of a {delta}-bundle. Their predictions compare very favorably with simulations in the two cases.
Date: February 1, 2001
Creator: MAHESH, M.; BEYERLEIN, I. & PHOENIX, S.
Partner: UNT Libraries Government Documents Department

Anisotropic fiber alignment in composite structures

Description: High strength material composite structures are formed with oriented fibers to provide controlled anisotropic fibers. Fibers suspended in non-dilute concentrations (e.g., up to 20 volume percent for fibers having an aspect ratio of 20) in a selected medium are oriented by moving an axially spaced array of elements in the direction of desired fiber alignment. The array elements are generally perpendicular to the desired orientation. The suspension medium may also include sphere-like particles where the resulting material is a ceramic.
Date: December 31, 1992
Creator: Graham, A.L.; Mondy, L.A. & Guell, D.C.
Partner: UNT Libraries Government Documents Department

Hemp as an Agricultural Commodity

Description: This report discusses the various industrial uses for Hemp, a variety of Cannabis sativa and is of the same plant species as marijuana. The report compares Hemp with Marijuana and discusses global production, legal status, and recent legislative activity.
Date: March 21, 2013
Creator: Johnson, Renée
Partner: UNT Libraries Government Documents Department

Roselle: Its Culture and Uses

Description: Report discussing and promoting the cultivation of the roselle plant -- a species of hibiscus -- in the United States. Topics discussed include varieties of roselle, helpful fertilizers, harvesting practices, uses, and common diseases and insect enemies.
Date: 1907
Creator: Wester, P. J. (Peter Johnson), 1877-1931
Partner: UNT Libraries Government Documents Department

Characterization of three dimensional fiber orientation in short-fiber composites

Description: A mathematical procedure for recovering from image analysis the three dimensional nonsymmetric fiber-orientation distribution in short-fiber composites is proposed. Microphotographs from two orthogonal faces of a composite sample are needed to determine the three dimensional fiber orientation. A simple weighting function is derived to take into account the probability of intercepting fibers at varying inclination angles. The present procedure improves the previous works of other researchers in the following two aspects. First, it can obtain the single-angle fiber-orientation distribution from one micrograph in reference to the normal of the photographed surface. This distribution is often needed in predicting the mechanical and physical properties of short-fiber composites in this direction. Second, no symmetry in fiber-orientation distribution is assumed in the determination of the three dimensional fiber-orientation, which makes the present procedure more practical and versatile.
Date: May 1, 1995
Creator: Zhu, Yuntian T. & Blumenthal, W.R.
Partner: UNT Libraries Government Documents Department

MCMII and the TriP chip

Description: We describe the development of the electronics that will be used to read out the Fiber Tracker and Preshower detectors in Run IIb. This electronics is needed for operation at 132ns bunch crossing, and may provide a measurement of the z coordinate of the Fiber Tracker hits when operating at 396ns bunch crossing. Specifically, we describe the design and preliminary tests of the Trip chip, MCM IIa, MCM IIb and MCM IIc. This document also serves as a user manual for the Trip chip and the MCM.
Date: December 19, 2003
Creator: al., Juan Estrada et
Partner: UNT Libraries Government Documents Department

On the Theory of the Modulation Instability in Optical Fiber and Laser Amplifiers

Description: The modulation instability (MI) in optical fiber amplifiers and lasers with anomalous dispersion leads to CW beam breakup and the growth of multiple pulses. This can be both a detrimental effect, limiting the performance of amplifiers, and also an underlying physical mechanism in the operation of MI-based devices. Here we revisit the analytical theory of MI in fiber optical amplifiers. The results of the exact theory are compared with the previously used adiabatic approximation model, and the range of applicability of the latter is determined. The same technique is applicable to the study of spatial MI in solid state laser amplifiers and MI in non-uniform media.
Date: November 3, 2010
Creator: Rubenchik, A M; Turitsyn, S K & Fedoruk, M P
Partner: UNT Libraries Government Documents Department

Sapphire Fiber Optics Sensors for Engine Test Instrumentation

Description: This document is the final report for the Cooperative Research and Development Agreement (CRADA) between UT-Battelle and Prime Photonics, Inc. The purpose of this CRADA was to improve the properties of single crystal sapphire optical fibers for sensor applications. A reactive coating process was developed to form a magnesium aluminate spinel cladding on sapphire optical fibers. The resulting clad fiber had a numerical aperture, NA, of 0.09 as compared with 0.83 for the unclad fiber, dramatically enhancing its usefulness for sensor applications. Because the process allows one to control the diameter of the sapphire core within the fiber, it may be possible using this technology to develop waveguides that approach single-mode transmission character.
Date: September 19, 2003
Creator: Janney, MA
Partner: UNT Libraries Government Documents Department