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in subjects: "37 Inorganic, Organic, Physical And Analytical Chemistry"  
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Detailed Comparison of Blast Effects in Air and Vacuum

Description: Although blast mitigation is most often achieved with solid shielding, ambient gas pressure can also affect the coupling of shock waves to solid targets. In this work the role of air as an energy transfer medium was examined experimentally by subjecting identical large-area rectangular witness plates to short-range blast effects in air and vacuum ({approx}50 mtorr) at 25 C. The expanding reactant front of 3 kg C4 charges was observed by fast camera to be cylindrically symmetric in both air and … more
Date: July 26, 2007
Creator: Tringe, J W; Molitoris, J D; Garza, R G; Andreski, H G; Batteux, J D; Lauderbach, L M et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Image Resolution in Scanning Transmission Electron Microscopy

Description: Digital images captured with electron microscopes are corrupted by two fundamental effects: shot noise resulting from electron counting statistics and blur resulting from the nonzero width of the focused electron beam. The generic problem of computationally undoing these effects is called image reconstruction and for decades has proved to be one of the most challenging and important problems in imaging science. This proposal concerned the application of the Pixon method, the highest-performance… more
Date: June 26, 2008
Creator: Pennycook, S. J. & Lupini, A.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Fast Prediction of HCCI and PCCI Combustion with an Artificial Neural Network-Based Chemical Kinetic Model

Description: We have added the capability to look at in-cylinder fuel distributions using a previously developed ignition model within a fluid mechanics code (KIVA3V) that uses an artificial neural network (ANN) to predict ignition (The combined code: KIVA3V-ANN). KIVA3V-ANN was originally developed and validated for analysis of Homogeneous Charge Compression Ignition (HCCI) combustion, but it is also applicable to the more difficult problem of Premixed Charge Compression Ignition (PCCI) combustion. PCCI co… more
Date: September 26, 2007
Creator: Piggott, W. T.; Aceves, S. M.; Flowers, D. L. & Chen, J. Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Threshold Studies on TNT, Composition B, and C-4 Explosives Using the Steven Impact Test

Description: Steven Impact Tests were performed at low velocity on the explosives TNT, Comp B, and C-4 in attempts to obtain a threshold for reaction. A 76 mm helium driven gas gun was used to accelerate the Steven Test projectiles up to approximately 200 m/s in attempts to react (ignite) the explosive samples. Blast overpressure gauges, acoustic microphones, standard video and high-speed photography were used to characterize the level of any high explosive reaction violence. No bulk reactions were observed… more
Date: September 26, 2005
Creator: Vandersall, K S; Switzer, L L & Garcia, F
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Calibration of Chemical Kinetic Models Using Simulations of Small-Scale Cookoff Experiments

Description: Establishing safe handling limits for explosives in elevated temperature environments is a difficult problem that often requires extensive simulation. The largest influence on predicting thermal cookoff safety lies in the chemical kinetic model used in these simulations, and these kinetic model reaction sequences often contain multiple steps. Several small-scale cookoff experiments, notably Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), One-Dimensional Time-to-Explos… more
Date: February 26, 2008
Creator: Wemhoff, A P; Becker, R C & Burnham, A K
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Method to prepare Semtex

Description: This procedure requires the binder and uncoated RDX be prepared in separate steps, see Figure 1: (1) The binder and dye are mixed by agitation with a water-insoluble organic solvent (e.g., toluene), I; (2) The RDX/PETN is agitated thoroughly with water, II; (3) The binder solution I is added to the RDX/water mixture at II with thorough mixing to form a slurry III; (4) In the next step the solvent is distilled off at IV leaving resulting granules; (5) The next step is followed by filtration at V… more
Date: November 26, 2006
Creator: Alcaraz, A. & Dougan, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Final Scientific Report

Description: Viscosities of water, nitrogen and carbon dioxide have been measured at elevated pressures and temperatures in the diamond-anvil cell. A strong correlation between viscosity and entropy has been confirmed.
Date: June 26, 2009
Creator: Abramson, Evan
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Bioforensics: Characterization of biological weapons agents by NanoSIMS

Description: The anthrax attacks of Fall 2001 highlight the need to develop forensic methods based on multiple identifiers to determine the origin of biological weapons agents. Genetic typing methods (i.e., DNA and RNA-based) provide one attribution technology, but genetic information alone is not usually sufficient to determine the provenance of the material. Non-genetic identifiers, including elemental and isotopic signatures, provide complementary information that can be used to identify the means, geogr… more
Date: February 26, 2007
Creator: Weber, P K; Ghosal, S; Leighton, T J; Wheeler, K E & Hutcheon, I D
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Evaluating GC/MS Performance

Description: Evaluating the chemical background in the GC/MS system (system background) and solvent purity. This procedure will allow the analyst to verify that the GC/MS is free of chemical interferences or contamination and verify the solvent being utilized is free of interferences - Conduct a GC/MS analysis without injecting a solvent (system background) and Conduct a GC/MS analysis inject 1uL of CH2Cl2 solvent (Solvent background). GC conditions: (1) Injector Temperature (C): Injector Temperature is typ… more
Date: November 26, 2006
Creator: Alcaraz, A. & Dougan, A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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B133 Facility Screening Report (SCR)

Description: B133 is located in the southwest quadrant inside the 1 square mile site of Lawrence Livermore National Laboratory. The property is about 250 meters from the nearest boundary along Vasco Road. Building 133 is a 1 story steel framed building constructed in 1994 with stainless steel sidings. The facility covers 5,631 gross square feet of space. The building is used to house equipment to heat and cool buildings 132N and 132S. A 1380 volts electrical substation is located outside on the northeast co… more
Date: January 26, 2007
Creator: Cooper, G
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Final Technical Report: A Paradigm Shift in Chemical Processing: New Sustainable Chemistries for Low-VOC Coatings

Description: The project employed new processes to make emulsion polymers from reduced levels of petroleum-derived chemical feedstocks. Most waterborne paints contain spherical, emulsion polymer particles that serve as the film-forming binder phase. Our goal was to make emulsion polymer particles containing 30 percent feedstock that would function as effectively as commercial emulsions made from higher level feedstock. The processes developed yielded particles maintained their film formation capability and … more
Date: July 26, 2006
Creator: Smith, Kenneth F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Measurement of Cu-Doped Be Gradient Steps in Sputtered Be Capsules

Description: The purpose of this memo is to lay the groundwork for non-destructively determining the position and ultimately the concentration of Cu gradient steps in sputtered Be capsules (or Ge steps in CH capsules) by ''simple'' radiography. A second personal objective was for me to learn something about radiography, and for that reason this memo may be more detailed than necessary. Steve Haan has suggested a design for Be capsules that makes use of a gradient of Cu-doping in a sputtered Be shell. The ca… more
Date: March 26, 2004
Creator: Cook, B
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Controls of Fluid Chemistry on Fracture Growth

Description: During this two year project (the original proposal requested 3 years funding) we developed and tested a new design for a mini-bending jig for the hydrothermal atomic force microscope (HAFM) and a modified design for the HAFM itself. These new capabilities now permit study of the connection between stress and mineral dissolution and growth, as well as sub-critical crack growth (SCG). We demonstrated the successful design by imaging SCG of glass in situ, in real time in the HAFM, as a function o… more
Date: February 26, 2007
Creator: Bruton, C.; Knauss, K.; Viani, B. & Bonner, B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Gas-Expanded Liquids: Synergism of Experimental and Computational Determinations of Local Structure

Description: This project focuses on the characterization of a new class of solvent systems called gas-expanded liquids (GXLs), targeted for green-chemistry processing. The collaboration has adopted a synergistic approach combining elements of molecular dynamics (MD) simulation and spectroscopic experiments to explore the local solvent behavior that could not be studied by simulation or experiment alone. The major accomplishments from this project are: • Applied MD simulations to explore the non-uniform str… more
Date: June 26, 2007
Creator: Eckert, Charles A.; Liotta, Charles L. & Hernandez, Rigoberto
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Final Report: Ionization chemistry of high temperature molecular fluids

Description: With the advent of coupled chemical/hydrodynamic reactive flow models for high explosives, understanding detonation chemistry is of increasing importance to DNT. The accuracy of first principles detonation codes, such as CHEETAH, are dependent on an accurate representation of the species present under detonation conditions. Ionic species and non-molecular phases are not currently included coupled chemistry/hydrodynamic simulations. This LDRD will determine the prevalence of such species during … more
Date: February 26, 2007
Creator: Fried, L E
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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SINGLE-CELL LEVEL INVESTIGATION OF CYTOSKELETAL/CELLULAR RESPONSE TO EXTERNAL STIMULI

Description: A detailed understanding of the molecular mechanisms by which chemical signals control cell behavior is needed if the complex biological processes of embryogenesis, development, health and disease are to be completely understood. Yet, if we are to fully understand the molecular mechanisms controlling cell behavior, measurements at the single cell level are needed to supplement information gained from population level studies. One of the major challenges to accomplishing studies at the single ce… more
Date: February 26, 2007
Creator: Hiddessen, A L
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ALE3D Simulation of Heating and Violence in a Fast Cookoff Experiment with LX-10

Description: We performed a computational and experimental analysis of fast cookoff of LX-10 (94.7% HMX, 5.3% Viton A) confined in a 2 kbar steel tube with reinforced end caps. A Scaled-Thermal-Explosion-eXperiment (STEX) was completed in which three radiant heaters were used to heat the vessel until ignition, resulting in a moderately violent explosion after 20.4 minutes. Thermocouple measurements showed tube temperatures as high as 340 C at ignition and LX-10 surface temperatures as high as 279 C, which i… more
Date: June 26, 2006
Creator: McClelland, M. A.; Maienschein, J. L.; Howard, W. M.; Nichols, A. L.; deHaven, M. R. & Strand, O. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Chemical Reaction Dynamics in Nanoscle Environments

Description: The major focus of the research in this program is the study of the behavior of molecular systems confined in nanoscale environments. The goal is to develop a theoretical framework for predicting how chemical reactions occur in nanoscale environments. To achieve this goal we have employed ab initio quantum chemistry, classical dynamics and quantum dynamics methods. Much of the research has focused on the behavior of molecules confined within single-walled carbon nanotubes (SWCNTs). We have also… more
Date: September 26, 2006
Creator: Goldfield, Evelyn M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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APPLICATION OF THE EMBEDDED FIBER OPTIC PROBE IN HIGH EXPLOSIVE DETONATION STUDIES: PBX-9502 AND LX-17

Description: The Embedded Fiber Optic probe directly measures detonation speed continuously in time, without the need to numerically differentiate data, and is a new tool for measuring time-dependent as well as steady detonation speed to high accuracy. It consists of a custom-design optical fiber probe embedded in high explosive. The explosive is detonated and a refractive index discontinuity is produced in the probe at the location of the detonation front by the compression of the detonation. Because this … more
Date: September 26, 2006
Creator: Hare, D; Goosman, D; Lorenz, K & Lee, E
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Heterogeneity, growing lenght scales, and universality in thedynamicsof kinetically constrained lattice gases in two dimensions

Description: We study dynamical heterogeneity and growing dynamical length scales in two kinetically constrained models, namely, the one- and two-vacancy assisted triangular lattice gases. One of the models is a strong glassformer and the other is a fragile glassformer. Both exhibit heterogeneous dynamics with broadly distributed timescales as seen in the distribution of persistence times. We show that the Stokes-Einstein relation is violated, to a greater degree in the fragile glassformer, and show how thi… more
Date: June 26, 2005
Creator: Pan, Albert P.; Garrahan, Juan P. & Chandler, David
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Removal of Radioactive Nuclides by Multi-Functional Microcapsules Enclosing Inorganic Ion-Exchangers and Organic Extractants

Description: The microcapsules enclosing two kinds of functional materials, inorganic ion-exchangers and organic extractants, were prepared by taking advantage of the high immobilization ability of alginate gel polymer. The fine powders of inorganic ion-exchanger and oil drops of extractant were kneaded with sodium alginate (NaALG) solution and the kneaded sol readily gelled in a salt solution of CaCl2, BaCl2 or HCl to form spherical gel particles. The uptake properties of various nuclides, 137Cs, 85Sr, 60C… more
Date: February 26, 2002
Creator: Mimura, H.; Akiba, K. & Onodera, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Selective Recovery of Enriched Uranium from Inorganic Wastes

Description: Uranium as U(IV) and U(VI) can be selectively recovered from liquids and sludge containing metal precipitates, inorganic salts, sand and silt fines, debris, other contaminants, and slimes, which are very difficult to de-water. Chemical processes such as fuel manufacturing and uranium mining generate enriched and natural uranium-bearing wastes. This patented Framatome ANP (FANP) uranium recovery process reduces uranium losses, significantly offsets waste disposal costs, produces a solid waste th… more
Date: February 26, 2003
Creator: Kimura, R. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Management of Spent Organic Ion-Exchange Resins by Photochemical Oxidation

Description: Management of spent ion-exchange resin waste arising from nuclear reactor operations by traditional practice of encapsulation in cement is associated with problems such as swelling and disintegration. Complete oxidation (mineralization) is an attractive alternative option. This paper reports the development of photochemical mineralization process for organic ion-exchange resins of poly (styrene-divinyl benzene) type with sulfonic acid and quaternary ammonium functional groups. It is a two-step … more
Date: February 26, 2003
Creator: Srinivas, C.; Sugilal, S. & Wattal, P. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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