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Studies on the Electrolytic Reduction of Nitric Acid

Description: Report discussing the reduction of nitric acid that results from its use at the cathode for the electrolysis of uranyl nitrate. From introduction: "It is the purpose of this report to give the results of studies on the reduction of nitric acid of different concentrations, at different types of electrodes, and for various current densities in order to ascertain the effects of such changes."
Date: unknown
Creator: Hamer, Walter J.
Partner: UNT Libraries Government Documents Department

Microbial degradation of low-level radioactive waste. Volume 2, Annual report for FY 1994

Description: The Nuclear Regulatory Commission stipulates in 10 CFR 61 that disposed low-level radioactive waste (LLW) be stabilized. To provide guidance to disposal vendors and nuclear station waste generators for implementing those requirements, the NRC developed the Technical Position on Waste Form, Revision 1. That document details a specified set of recommended testing procedures and criteria, including several tests for determining the biodegradation properties of waste forms. Cement has been widely used to solidify LLW; however, the resulting waste forms are sometimes susceptible to failure due to the actions of waste constituents, stress, and environment. The purpose of this research program is to develop modified microbial degradation test procedures that will be more appropriate than the existing procedures for evaluating the effects of microbiologically influenced chemical attack on cement-solidified LLW. Groups of microorganisms indigenous to LLW disposal sites are being employed that can metabolically convert organic and inorganic substrates into organic and mineral acids. Such acids aggressively react with cement and can ultimately lead to structural failure. Results over the past year on the application of mechanisms inherent in microbially influenced degradation of cement-based material are the focus of the annual report. Data-validated evidence of the potential for microbially influenced deterioration of cement-solidified LLW and subsequent release of radionuclides has been developed during this study.
Date: August 1, 1995
Creator: Rogers, R.D.; Hamilton, M.A.; Veeh, R.H. & McConnell, J.W. Jr.
Partner: UNT Libraries Government Documents Department

Isotopic HCl transfer laser

Description: An HCl laser which uses isotopic V-V energy transfer collisions as a pumping mechanism has been demonstrated. This multiline laser, which utilized an intracavity cold gas isotope filter, increased the energy from the P/sub 1/ lines of H/sup 37/Cl while decreasng the energies of the P/sub 1/ and P/sub 2/ lines of H/sup 35/Cl. Previously unreported lines, including emission from R branch transitions, have also been observed from single-line HCl and HBr lasers.
Date: December 15, 1977
Creator: Badcock, C.C.; Hwang, W.C.; Kalsch, J.F. & Kamada, R.F.
Partner: UNT Libraries Government Documents Department

Micro-Compatibility Testing of Polysulfone

Description: Polysulfone has many useful properties, and its compatibility with other materials is of interest. It is a tough, rigid, high-strength thermoplastic that maintains its properties over a wide temperature range. It is chemically resistant to mineral acids and alkali and moderately resistant to hydrocarbon oils; however, it is not resistant to polar organic solvents such as ketones, chlorinated hydrocarbons and aromatic hydrocarbons. Micro-compatibility experiments were initiated to determine possible detrimental interactions in a sealed environment between polysulfone components and a number of other organic species.
Date: September 28, 2004
Creator: Gregg, H; Harvey, C; Maxwell, R & Vance, A
Partner: UNT Libraries Government Documents Department

Polymer Effects on Acid Generation Efficiency Using EUV and DUV Exposures

Description: Thin resist films (< 1500 {angstrom}) based on DUV chemical approaches have been demonstrated for use in EUV lithography. Resists with good sensitivity (5--6 mJ/cm{sup 2}) were observed but imaging mechanisms, in particular as they affect sensitivity, are poorly understood. To clarify mechanisms leading to photosensitivity, acid-generation efficiency at both EUV and DUV wavelengths was measured for the most promising EUV resist compositions as well as initial radiation damage experiments. In previous work, polymer composition was found to be more important in determining the relative dose to print of resists to EUV and DUV radiation than was PAG composition. Here, acid generating efficiency for several polymers upon exposure to EUV and DW are compared to gain insight into the role of the polymer and PAG in converting the incident EUV photon energy into resist images. It is shown that acid generation efficiencies at EUV do not track efficiencies measured on identical films with DUV exposures, and is attributable to polymer and polymer/PAG interactions. No particular structural feature of the polymer could be correlated to the acid generation results. Radiation damage studies showed that polymers that create acid in different yields at EUV do not show differences in radiation damage, as detected by dissolution rate changes. In addition, it is shown that no significant dissolution altering mechanisms occur with EW radiation at relevant exposure doses. The authors conclude that photospeed differences between EUV and DUV are quantitatively attributable to acid generation efficiencies for the compositions studied.
Date: May 30, 2000
Creator: Dentinger, P.
Partner: UNT Libraries Government Documents Department

Compositional analysis technique for HNS/Kel-F 800

Description: A compositional analysis procedure for the plastic-bonded explosive consisting of HNS and Kel-F 800 is presented. The Kel-F is determined gravimetrically after extraction of the HNS with fuming nitric acid. The HNS content is calculated by difference.
Date: August 1, 1980
Creator: Sandoval, J.
Partner: UNT Libraries Government Documents Department

Uranium from phosphate ores

Description: The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant.
Date: January 1, 1983
Creator: Hurst, F.J.
Partner: UNT Libraries Government Documents Department

Waste acid recycling via diffusion dialysis

Description: Inorganic acids are commonly used for surface cleaning and finishing of metals. The acids become unuseable due to contamination with metals or diluted and weakened. Diffusion dialysis has become a way to recover the useable acid and allow separation of the metals for recovery and sale to refineries. This technique is made possible by the use of membranes that are strong enough to withstand low ph and have long service life.
Date: May 26, 1995
Creator: Steffani, C.
Partner: UNT Libraries Government Documents Department

Numerical simulation to study the feasibility of using CO2 as a stimulation agent for enhanced geothermal systems

Description: A major concern in the development of enhanced geothermal systems (EGS) is achieving and maintaining adequate injectivity, while avoiding the development of preferential short-circuiting flow paths such as those caused by thermally-induced stress cracking. Past researches have tended to focus primarily on thermal and hydraulic stimulation. Recent studies suggest that chemical stimulation may improve the performance of EGS reservoirs. Geothermal injection wells are often drilled into formations containing reactive minerals such as calcite. Injecting aqueous chemical agents such as mineral acids, could be effective for mineral dissolution and porosity enhancement at distances of several meters around a well. An alternative to treatment with strong acids is the use of supercritical (SC) CO{sub 2} as stimulation agent for an aqueous-based EGS. Reactive transport modeling is used to investigate the effectiveness of this method. We used the thermal condition and mineralogical composition from a well of Desert Peak EGS site, to examine ways in which mixtures of water and CO{sub 2} can be injected to enhance porosity.
Date: November 15, 2009
Creator: Xu, T.; Zhang, W. & Pruess, K.
Partner: UNT Libraries Government Documents Department

Ab initio potential surface calculations for the H + H/sub 2/O and H + HF hydrogen atom exchange reactions

Description: The calculations reveal that the H + H/sub 2/O and H + HF exchange reactions are both characterized by a large energy barrier (on the order of 20 to 30 kcal/mole) and a transition state possessing significant Rydberg 3s character on the central atom. The presence of high energy barriers means that both exchange reactions will be extremely slow except at very high temperatures.
Date: January 1, 1976
Creator: Wadt, W. R. & Winter, N. W.
Partner: UNT Libraries Government Documents Department

Far infrared chemical lasers. Technical progress report No. 3, August 1, 1976--July 31, 1977. [HCN]

Description: Laser oscillation at 337 and 311 ..mu..m has been obtained from HCN molecules prepared in vibrationally excited states by the reaction between cyanogen radicals and hydrogen molecules. It has likewise been observed in HCN raised to an electronically excited state by flash photolysis. The characteristics of the pulsed output are quite different in the two cases and beginnings have been made on experiments to probe the pumping and energy transfer kinetics. The rate determining step is not the reaction rate, but rather some relaxation process that eventually channels the excitation into the upper lasing state of one quantum each of CN stretch and bend. Detailed studies of the relative intensities of pure rotational lasing in OH and OD have been made. The rotational inversions are produced by rare gas-aided, adiabatic energy conversion from vibrational to rotational excitation. The process is rapid in comparison to rotational collisional relaxation. Using transfer parameters from the ''information theoretic'' analysis (R. D. Levine) computations have been made which reproduce the results in detail, providing support for the pumping mechanism proposed, and the applicability of the theory. Preliminary work on NH (from the HN/sub 3/ photolysis) has opened up extremely interesting questions concerning the electronic states of the nascent molecules and the subsequently lasing molecules. Pure rotational laser action in at least two states (one singlet and one triplet) has been measured.
Date: August 1, 1977
Creator: Robinson, D. W.
Partner: UNT Libraries Government Documents Department

ESTIMATION OF THE TEMPERATURE RISE OF A MCU ACID STREAM PIPE IN NEAR PROXIMITY TO A SLUDGE STREAM PIPE

Description: Effluent streams from the Modular Caustic-Side Solvent Extraction Unit (MCU) will transfer to the tank farms and to the Defense Waste Processing Facility (DWPF). These streams will contain entrained solvent. A significant portion of the Strip Effluent (SE) pipeline (i.e., acid stream containing Isopar{reg_sign} L residues) length is within one inch of a sludge stream. Personnel envisioned the sludge stream temperature may reach 100 C during operation. The nearby SE stream may receive heat from the sludge stream and reach temperatures that may lead to flammability issues once the contents of the SE stream discharge into a larger reservoir. To this end, personnel used correlations from the literature to estimate the maximum temperature rise the SE stream may experience if the nearby sludge stream reaches boiling temperature. Several calculation methods were used to determine the temperature rise of the SE stream. One method considered a heat balance equation under steady state that employed correlation functions to estimate heat transfer rate. This method showed the maximum temperature of the acid stream (SE) may exceed 45 C when the nearby sludge stream is 80 C or higher. A second method used an effectiveness calculation used to predict the heat transfer rate in single pass heat exchanger. By envisioning the acid and sludge pipes as a parallel flow pipe-to-pipe heat exchanger, this method provides a conservative estimation of the maximum temperature rise. Assuming the contact area (i.e., the area over which the heat transfer occurs) is the whole pipe area, the results found by this method nearly matched the results found with the previous calculation method. It is recommended that the sludge stream be maintained below 80 C to minimize a flammable vapor hazard from occurring.
Date: July 12, 2007
Creator: Fondeur, F; Michael Poirier, M & Samuel Fink, S
Partner: UNT Libraries Government Documents Department

Catalytic Deprotection of Acetals In Strongly Basic Solution Usinga Self-Assembled Supramolecular 'Nanozyme'

Description: Acetals are among the most commonly used protecting groups for aldehydes and ketones in organic synthesis due to their ease of installation and resistance to cleavage in neutral or basic solution.[1] The common methods for hydrolyzing acetals almost always involve the use of either Broensted acid or Lewis acid catalysts.[2] Usually aqueous acids or organic solutions acidified with organic or inorganic acids have been used for reconversion of the acetal functionality to the corresponding carbonyl group; however, recently a number of reports have documented a variety of strategies for acetal cleavage under mild conditions. These include the use of Lewis acids such as bismuth(III)[3] or cerium(IV),[4, 5] functionalized silica gel, such as silica sulfuric acid[6] or silica-supported pyridinium p-toluene sulfonate,[7] or the use of silicon-based reagents such as TESOTf-2,6-Lutidine.[8] Despite these mild reagents, all of the above conditions require either added acid or overall acidic media. Marko and co-workers recently reported the first example of acetal deprotection under mildly basic conditions using catalytic cerium ammonium nitrate at pH 8 in a water-acetonitrile solution.[5] Also recently, Rao and co-workers described a purely aqueous system at neutral pH for the deprotection of acetals using {beta}-cyclodextrin as the catalyst.[9] Herein, we report the hydrolysis of acetals in strongly basic aqueous solution using a self-assembled supramolecular host as the catalyst. During the last decade, we have used metal-ligand interactions for the formation of well-defined supramolecular assemblies with the stoichiometry M{sub 4}L{sub 6}6 (M = Ga{sup III} (1 refers to K{sub 12}[Ga{sub 4}L{sub 6}]), Al{sup III}, In{sup III}, Fe{sup III}, Ti{sup IV}, or Ge{sup IV}, L = N,N{prime}-bis(2,3-dihydroxybenzoyl)-1,5-diaminonaphthalene) (Figure 1).[10] The metal ions occupy the vertices of the tetrahedron and the bisbidentate catecholamide ligands span the edges. The strong mechanical coupling of the ligands transfers the chirality from one metal center to the other, thereby ...
Date: July 26, 2007
Creator: Pluth, Michael D.; Bergman, Robert G. & Raymond, Kenneth N.
Partner: UNT Libraries Government Documents Department

REVIEW OF ALTERNATIVE ENHANCED CHEMICAL CLEANING OPTIONS FOR SRS WASTE TANKS

Description: A literature review was conducted to support the Task Technical and Quality Assurance Plan for Alternative Enhanced Chemical Cleaning (AECC) for sludge heel removal funded as part of the EM-21 Engineering and Technology program. The goal was to identify potential technologies or enhancements to the baseline oxalic acid cleaning process for chemically dissolving or mobilizing Savannah River Site (SRS) sludge heels. The issues with the potentially large volume of oxalate solids generated from the baseline process have driven an effort to find an improved or enhanced chemical cleaning technology for the tank heels. This literature review builds on a previous review conducted in 2003. A team was charged with evaluating the information in these reviews and developing recommendations of alternative technologies to pursue. The new information in this report supports the conclusion of the previous review that oxalic acid remains the chemical cleaning agent of choice for dissolving the metal oxides and hydroxides found in sludge heels in carbon steel tanks. The potential negative impact of large volumes of sodium oxalate on downstream processes indicates that the amount of oxalic acid used for chemical cleaning needs to be minimized as much as possible or the oxalic acid must be destroyed prior to pH adjustment in the receipt tank. The most straightforward way of minimizing the volume of oxalic acid needed for chemical cleaning is through more effective mechanical cleaning. Using a mineral acid to adjust the pH of the sludge prior to adding oxalic acid may also help to minimize the volume of oxalic acid used in chemical cleaning. If minimization of oxalic acid proves insufficient in reducing the volume of oxalate salts, several methods were found that could be used for oxalic acid destruction. For some waste tank heels, another acid or even caustic treatment (or pretreatment) might be ...
Date: August 1, 2009
Creator: Hay, M. & Koopman, D.
Partner: UNT Libraries Government Documents Department

A process for separating acid-sugar mixtures using ion exclusion chromatography

Description: Work using a low-temperature concentrated sulfuric acid hydrolysis process to convert the cellulosic fraction of corn stover to monomeric sugars demonstrated the high conversion efficiencies possible with that process. The TVA work also confirmed the need for a cost-effective acid-sugar separation process. A preparative-scale ion-exclusion chromatography (IEC) system was designed, constructed, and tested with a variety of synthetic solutions and actual hydrolyzates. Although significant dispersion was observed initially, design changes were effective in minimizing this phenomenon. Data collected during the operation of the preparative-scale system were used in the design and construction of an IEC miniplant capable of processing larger volumes of synthetic solutions or hydrolyzates and in the design of an extraction-assisted IEC system. The data were also used to assess the viability of a continuous feed IEC system. This paper includes a discussion of the IEC process, provides overall material balances for various IEC process scenarios, and presents a discussion on process economics.
Date: October 1, 1994
Creator: Hester, R. D.; Hartfield, S. W. & Farina, G. E.
Partner: UNT Libraries Government Documents Department

Staff exchange with Viatex-Recovery Systems, Inc.. Final project report

Description: The purpose of this industrial staff exchange is to assist the license, Viatec, Inc., in commercializing the Waste Acid Detoxification and Reclamation (WADR) process system. The process system was developed at the Pacific Northwest Laboratory (PNL) which is a DOE national laboratory. The objective of the activity is to establish a successful local business to design, build, and manufacture WARD process systems.
Date: March 1, 1994
Creator: Jones, E. O. & Kensington, K. L.
Partner: UNT Libraries Government Documents Department

Permeation of chemicals through glove-box glove materials

Description: The resistance of two commercial gloves to 20 chemicals commonly used in glove boxes was studied. The chemicals were inorganic acids/bases/salts, organic acids, alcohols, glycols, halogen compounds, sulfur compounds, and hydrocarbons. The ASTM cell was used to study permeation of volatile organic compounds through protective clothing materials using air, flame ionization detector/gas chromatography; a modified version of the cell was used with isopropanol for the nonvolatile organic compounds. Permeation of inorganic compounds through the elastomers was studied using the ASTM cell with water, conductivity meter. A Teflon cell was used with HF and ammonium hydrofluoride. Results: Hypalon protects against all chemicals except trichloroethylene (TCE) and CCl{sub 4}. Acetic acid and ethanol permeated through neoprene, which also did not protect against TCE and CCl{sub 4}. Sulfuric acid dissolved neoprene in 5 h. Kerosene permeated through neoprene in 5 h. Although neoprene showed good resistance to cutting oil, TCE in cutting oil broke through in 61 min. Neoprene showed good protection against all the other chemicals with no breakthrough before 6 h.
Date: June 30, 1994
Creator: Vahdat, N,; Johnson, J. S.; Neidhardt, A.; Cheng, J. & Weitzman, D.
Partner: UNT Libraries Government Documents Department

Extraction systems for the study of dubnium

Description: The chemistry of transactinide elements (Z {ge} 104) is a topic of great interest in current nuclear chemistry research. The chemical systems that can be used in these studies are limited by the short half-lives of the isotopes and the small production rates of atoms per minute or even atoms per week. In the initial investigations, the chemistry used had to be very selective to the periodic group of interest to separate the transactinide atom from all the other unwanted nuclear reaction products, e.g., transfer products. By using the Berkeley Gas-filled Separator (BGS) as a physical pre-separator, we are able concentrate on systems that are selective between the members of the group of interest, because all other interfering products and the beam are being suppressed by the BGS [1]. We are developing suitable extraction systems for the study of element 105, dubnium. For this purpose we have studied the extraction of niobium and tantalum, the lighter homologs of dubnium, from mineral acids with different organophosphorus compounds. All studies were performed online, using short-lived niobium and tantalum produced in the {sup 124}Sn({sup 51}V,5n){sup 170}Ta and {sup 74}Se({sup 18}O,p3n){sup 88}Nb reactions. This allowed for the study of the lighter homologues at metal concentrations of 10{sup -16} M. At these low metal concentrations, the formation of polymeric species is largely prohibited. As seen in Fig. 1, by varying the extractant and the hydrochloric acid concentration from 1 to 11 M, we are able to see a difference in extraction behavior between niobium and tantalum. While the system is suitable for determining chemical differences between the lighter homologues, the extraction of tantalum from hydrochloric acid shows slow kinetics. Figure 2 shows that after 90 seconds of mixing, the system is not in equilibrium. However, experiments indicate that equilibrium is reached faster at higher acid ...
Date: September 1, 2007
Creator: Gates, J.M.; Sudowe, R.; Ali, M.N.; Calvert, M.G.; Dragojevic, I.; Ellison, P.A. et al.
Partner: UNT Libraries Government Documents Department

Detecting and quantifying lewisite degradation products in environmental samples using arsenic speciation

Description: This report describes a unique method for identifying and quantifying lewisite degradation products using arsenic (III) and arsenic (IV) speciation in solids and in solutions. Gas chromatographic methods, as well as high-performance liquid chromatographic methods are described for separation of arsenic species. Inductively coupled plasma-mass spectrographic methods are presented for the detection of arsenic.
Date: December 31, 1995
Creator: Bass, D.A.; Yaeger, J.S.; Kiely, J.T.; Crain, J.S.; Shem, L.M.; O`Neill, H.J. et al.
Partner: UNT Libraries Government Documents Department