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Wave mixing spectroscopy

Description: Several new aspects of nonlinear or wave mixing spectroscopy were investigated utilizing the polarization properties of the nonlinear output field and the dependence of this field upon the occurrence of multiple resonances in the nonlinear susceptibility. First, it is shown theoretically that polarization-sensitive detection may be used to either eliminate or controllably reduce the nonresonant background in coherent anti-Stokes Raman spectroscopy, allowing weaker Raman resonances to be studied. The features of multi-resonant four-wave mixing are examined in the case of an inhomogeneously broadened medium. It is found that the linewidth of the nonlinear output narrows considerably (approaching the homogeneous width) when the quantum mechanical expressions for the doubly- and triply-resonant susceptibilities are averaged over a Doppler or strain broadened profile. Experimental studies of nonlinear processes in Pr/sup +3/:LaF/sub 3/ verify this linewidth narrowing, but indicate that this strain broadened system cannot be treated with a single broadening parameter as in the case of Doppler broadening in a gas. Several susceptibilities are measured from which are deduced dipole matrix elements and Raman polarizabilities related to the /sup 3/H/sub 4/, /sup 3/H/sub 6/, and /sup 3/P/sub 0/ levels of the praseodymium ions.
Date: August 1, 1980
Creator: Smith, R. W.
Partner: UNT Libraries Government Documents Department

Calculation of equilibria at elevated temperatures using the MINTEQ geochemical code

Description: Coefficients and equations for calculating mineral hydrolysis constants, solubility products and formation constants for 60 minerals and 57 aqueous species in the 13 component thermodynamic system K/sub 2/O-Na/sub 2/O-CaO-MgO-FeO-Al/sub 2/O/sub 3/-SiO/sub 2/-CO/sub 2/-H/sub 2/O-HF-HCl-H/sub 2/S-H/sub 2/SO/sub 4/ are presented in a format suitable for inclusion in the MINTEQ computer code. The temperature functions presented for minerals are based on the MINTEQ data base at 25/degree/C and the integration of analytical heat capacity power functions. This approach ensures that the temperature functions join smoothly with the low-temperature data base. A new subroutine, DEBYE, was added to MINTEQ that is used to calculate the theoretical Debye-Hueckel parameters A and B as a function of temperature. In addition, this subroutine also calculates a universal value of the extended Debye-Hueckel parameter, b/sub i/, as a function of temperature. The coefficients and equations provide the capability to use MINTEQ to more accurately calculate water/rock equilibrium for temperatures of up to 250/degree/C, and in dilute, low-sulfate, near neutral groundwaters to 300/degree/C. 52 refs., 1 fig., 6 tabs.
Date: December 1, 1988
Creator: Smith, R.W.
Partner: UNT Libraries Government Documents Department

Analytical studies of ancient Egyptian glass

Description: Neutron activation analysis and emission spectroscopy were used to analyze ancient Egyptian glass. The emission spectroscopic method for determining Li, Na, K, Rb, Mg, Ca, Sr, Ba, B, Al, P, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Ag, Sn, Sb, Pb, and Bi is described in the appendix. Neutron activation was used to determine Na, K, Rb, Ba, Sc, La, Ce, Eu, Lu, Hf, Th, Ta, Cr, Fe, Co, and Sb by a method described by Tobia and Sayre at the conference. (DHM)
Date: January 1, 1973
Creator: Sayre, E.V. & Smith, R.W.
Partner: UNT Libraries Government Documents Department

Under sodium viewing

Description: From IEEE ultrasonics symposium; Monterey, California, USA (5 Nov 1973). Under sodium viewing combines some standard ultrasonic techniques with some new dnta processing methods to perform ranging and imaging fanctions in the optically opaque coolant of the Liquid Metal Fast Breeder Reactor. Pulse-echo scanning methods including both B-scan and C-scan are used in conjunction with a synthesis of these methods by a technique called ISO-SCAN. by combining depth and spatial information from the B- and Cscans, ISO-SCAN produces a 3-dimensional visualization of objects submersed in liquid sodium. Special transducers have been developed to operate in sodium at temperatures up to 550 deg F. This developm ent included a process for promoting rapid wetting of the tainless steel lens of the transducer by the sodium. A lack of wetting prevents acoustic coupling between the transducer and sodium. Experiments conducted in sodium to 600 deg F have demonstrated the ability to locate and identify objects. (auth)
Date: October 1, 1973
Creator: Day, C.K. & Smith, R.W.
Partner: UNT Libraries Government Documents Department

Computer Simulation of Intergranular Stress Corrosion Cracking via Hydrogen Embrittlement

Description: Computer simulation has been applied to the investigation of intergranular stress corrosion cracking in Ni-based alloys based on a hydrogen embrittlement mechanism. The simulation employs computational modules that address (a) transport and reactions of aqueous species giving rise to hydrogen generation at the liquid-metal interface, (b) solid state transport of hydrogen via intergranular and transgranular diffusion pathways, and (c) fracture due to the embrittlement of metallic bonds by hydrogen. A key focus of the computational model development has been the role of materials microstructure (precipitate particles and grain boundaries) on hydrogen transport and embrittlement. Simulation results reveal that intergranular fracture is enhanced as grain boundaries are weakened and that microstructures with grains elongated perpendicular to the stress axis are more susceptible to cracking. The presence of intergranular precipitates may be expected to either enhance or impede cracking depending on the relative distribution of hydrogen between the grain boundaries and the precipitate-matrix interfaces. Calculations of hydrogen outgassing and in gassing demonstrate a strong effect of charging method on the fracture behavior.
Date: April 1, 2000
Creator: Smith, R.W.
Partner: UNT Libraries Government Documents Department

Compilation, evaluation, and prediction of triple-layer model constants for ions on Fe(III) and Mn(IV) hydrous oxides

Description: This report includes recommendations for further work. A brief discussion of the formulation of the Triple Layer Model (TLM) of the oxide/water interfaces is given in Section 3. Table of literature values for TLM constants are given in Section 4.0. In addition, the sources of uncertainties in the TLM constants are discussed. Equations useful for the prediction of TLM parameters are presented in Section 6.0. Summaries of experimental conditions used by the various investigators referenced in this report are given in Appendix A. 43 refs., 4 figs., 12 tabs. (JL)
Date: November 1, 1988
Creator: Smith, R.W. & Jenne, E.A.
Partner: UNT Libraries Government Documents Department

Selecting reasonable future land use scenarios

Description: This paper examines a process to help select the most reasonable future land use scenario for hazardous waste and/or low-level radioactive waste disposal sites. The process involves evaluating future land use scenarios ab applying selected criteria currently used by commercial mortgage companies to determine the feasibility of obtaining a loan for purchasing such land. The basis for the process is that only land use activities for which a loan can be obtained well be considered. To examine the process, a low-level radioactive waste site, the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory, is used as an example. The authors suggest that the process is a very precise, comprehensive, and systematic approach for determining reasonable future use of land. Implementing such a process will help enhance the planning, decisionmaking, safe management, and cleanup of present and future disposal facilities.
Date: December 31, 1995
Creator: Allred, W.E. & Smith, R.W.
Partner: UNT Libraries Government Documents Department

Thermal shock resistance and high-temperature strength of a molybdenum disilicide - aluminum oxide ceramic

Description: From Summary: "A ceramic consisting nominally of 75 percent molybdenum disilicide and 25 percent alumium oxide was investigated to determine its thermal shock characteristics and high-temperature strength properties. In a rim-quench thermal shock evaluation, the material was found to be superior to pure molybdenum disilicide. In a simulated altitude blow-out test, the material withstood an average of 2.5 cycles when quenched from 1800 degrees Fahrenheit."
Date: October 1, 1953
Creator: Maxwell, W. A. & Smith, R. W.
Partner: UNT Libraries Government Documents Department

Second-order sum- and difference-frequency generation via quadrupole transitions in atomic vapors

Description: The inclusion of higher-multipole terms in the interaction of light with matter allows second-order nonlinear processes to be observed in isotropic media. These processes may be useful for both generating new wavelengths of radiation and measuring atomic or molecular quadrupole transition moments otherwise hard to determine. After a brief theoretical introduction, the experimental arrangement used to observe quadrupole sum-frequency generation is shown. Generally, the characteristics of the observed output agree with those predicted: the output shows the sharp two-photon resonance expected from the expression for chi/sup (Q)/ and the expected variation with k vector mismatch. At high densities and input powers, deviations from the simple theory occur: output falls sharply because of absorption associated with D-line resonances, two-photon saturation occurs, and third-order nonlinearities and population redistribution can cause changes in the index of refraction of the vapor which defocus the pump beams and destroy the phase matching of the output radiation. Quadrupole sum-frequency generation allows a novel and accurate measurement of quadrupole transition moments; values were found for the 3s-4d transition moment of Na. The creation of an electric dipole polarization by mixing of two pump fields, one of which is coupled to a quadrupole transition, can be described by the difference frequency polarization; chi/sup (Q/sub 1/)/ = 2.1 x 10/sup -12/ esu was found for Cs. 8 figs. (RWR)
Date: September 1, 1977
Creator: Bethune, D.; Smith, R.W. & Shen, Y.R.
Partner: UNT Libraries Government Documents Department

Development of Irradiation hardening of Unalloyed and ODS molybdenum during neurtron irradiation to low doses at 300C and 600C

Description: Unalloyed molybdenum and Oxide Dispersion Strengthened (ODS) molybdenum were irradiated at 300 C and 600 C in the high flux isotope reactor (HFIR) to neutron fluences of 0.2, 2.1, and 24.3 x 10{sup 24} n/m{sup 2} (E > 0.1 MeV), producing damage levels of 0.01, 0.1 and 1.3 Mo-dpa. Hardness measurements, electrical resistivity measurements, tensile testing, and Transmission Electron Microscopy (TEM) were used to assess the defect structure. Irradiation hardening was evident even at a damage level of 0.01 dpa resulting in a significant increase in yield stress, decrease in ductility, and elevation of the Ductile-to-Brittle Transition Temperature (DBTT). The observed size and number density of voids and loops as well as the measured irradiation hardening and electrical resistivity were found to increase sub-linearly with fluence over the range of exposure investigated. This supports the idea that the formation of the extended defects that produce irradiation hardening in molybdenum are the result of a nucleation and growth process rather than the formation of sessile defects directly from the displacement damage cascades. The formation of sessile defect clusters in the displacement cascade would be expected to result in a linear fluence dependence for the number density of defects followed by saturation at fluences less than 1-dpa. This conclusion is supported by Molecular Dynamics (MD) simulations of cascade damage which do not reveal large clusters forming directly as a result of the short-term collapse of the cascade. The finer grain size for the unalloyed Mo and ODS Mo compared to Low Carbon Arc Cast molybdenum results in slightly less irradiation hardening and slightly lower DBTT values. The unalloyed molybdenum used in this work had a low impurity interstitial content that correlates with a slightly lower void size and void number density, less irradiation hardening and lower change in electrical resistivity in this ...
Date: November 21, 2007
Creator: Cockeran, B. V. & Smith, R. W.
Partner: UNT Libraries Government Documents Department

Applications of a Small Electronic Digital Computer to Pyrometallurgical Research

Description: Report issued by the U.S. Bureau of Mines discussing the use of small digital computers for problem solving during pyrometallurgical research. As stated in the field of research, "the scope of research varies from the development of new processes to the evaluation of raw materials for existing processes. The types of calculations required range all the way from those involving attempts to determine complex mathematical relationships between physical quantities to those concerned with simple summaries and analyses of daily furnace production" (p. 2-3). This report includes tables, illustrations, and a photograph.
Date: 1960
Creator: Leary, R. J.; Smith, R. W., Jr. & Mitchel, B. J.
Partner: UNT Libraries Government Documents Department

X-Ray Diffraction Data for Aromatic, Hydroaromatic, and Tetrahedral Structures of Carbon

Description: From Abstract: "A brief theoretical introduction of the Debye interference function is given, and an outline is made of the treatment of experimental data so that the experimental interference function can be obtained. This study is part of the investigations of the fundamental structure of coals and cokes by the Federal Bureau of Mines. X-ray diffraction is a very powerful tool in studying structure."
Date: unknown
Creator: Ergun, Sabri; Donaldson, W. F. & Smith, R. W., Jr.
Partner: UNT Libraries Government Documents Department

Novel microorganism for selective separation of coal from ash and pyrite; First quarterly technical progress report, September 1, 1993--November 30, 1993

Description: This report summarizes the progress made during the first quarter of the research project entitled ``A Novel Microorganism for Selective Separation of Coal from Ash and Pyrite,`` DOE Grant No. DE-FG22-93PC93215. The objective of this project is to study the effectiveness of a novel hydrophobic microorganism, Mycobacterium phlei (M. phlei), for the selective flocculation of coal from pyrite and ash-forming minerals. During the reporting period, three different coal samples: Illinois No. 6 coal, Kentucky No. 9 coal and Pittsburgh No. 8 coal, were collected to be used in the investigation. The microorganism, M. phlei, was obtained as freeze-dried cultures and the growth characteristics of the bacteria were studied. Scanning electron microphotographs revealed that M. phlei cells are coccal in shape and are approximately 1 {mu}m in diameter. Electrokinetic measurements showed that the Illinois No. 6 and Pittsburgh No. 8 coal samples had an isoelectric point (IEP) around pH 6 whereas M. phlei had an IEP around pH 1.5. Electrokinetic measurements of the ruptured microorganisms exhibited an increase in IEP. The increase in IEP of the ruputured cells was due to the release of fatty acids and polar groups from the cell membrane.
Date: December 31, 1993
Creator: Misra, M.; Smith, R.W. & Raichur, A.M.
Partner: UNT Libraries Government Documents Department

Novel microorganism for selective separation of coal from ash and pyrite. Seventh quarterly technical progress report, April 1, 1995--June 30, 1995

Description: The selective separation of pyrite and ash-forming minerals from coal can be accomplished by flotation, agglomeration and selective flocculation. The methods currently used for selective flocculation of coals include addition of natural or synthetic polymeric flocculants along with precise pH control. In some cases, these flocculants are nonselective or work imperfectly. It is known that many highly charged planktonic algae and bacteria will adhere to certain solid surfaces if the charge or hydrophobic interaction between the organism and the solids are favorable for adhesion. The resultant microorganism-mineral entities, if formed, can flocculate and can be separated. In addition, many living organisms produce extracellular biopolymers that can also cause flocculation. The microorganism, M. phlei, has the properties of being both highly charged and highly hydrophobic. The aim of the present investigation is to study the effectiveness of M. phlei and biopolymers derived from the organism for selective flocculation and separation of fine coal from pyrite and ash.
Date: December 31, 1996
Creator: Misra, M.; Smith, R.W. & Raichur, A.M.
Partner: UNT Libraries Government Documents Department

Novel microorganism for selective separation of coal from ash and pyrite. Sixth quarterly technical progress report, January 1, 1995--March 31, 1995

Description: The objective of this research project is to study the effectiveness of a novel hydrophobic microorganism, Mycobacterium phlei (M. phlei), for the selective flocculation of coal from pyrite and ash forming minerals. During the reporting period, the flocculation efficiencies of Illinois No. 6 and KY No. 9 coal in the presence of whole and ruptured cells of M. phlei were studied. The effect of synthetic flocculants were also studied for comparison at selected pH values. Results showed that the whole cells of M. phlei can flocculate coal very effectively and rapidly for both the coal samples. However, with ruptured cells of M. phlei the flocculation efficiency is significantly less which can be attributed to the loss of extracellular surfactants during rupturing. Separation of flocs using column flotation was studied for both the coal samples in the acidic pH range. Results indicated that excellent rejection of pyritic sulfur and ash could be obtained with a high combustible recovery. DLVO calculations were performed for all the minerals used in this study to calculate the interaction energies in the presence of whole cells and ruptured cells of M. phlei. A minimum in interaction energy is observed between coal and whole cells of M. phlei at pH 4 which is probably responsible for the higher adhesion and flocculation efficiencies at the pH. However, with ruptured cells the interaction energy increases thus decreasing the amount of M. phlei cells adhering to the surface.
Date: August 1, 1995
Creator: Misra, M.; Smith, R.W. & Raichur, A.M.
Partner: UNT Libraries Government Documents Department

Ductile phase toughening of molybdenum disilicide by low pressure plasma spraying

Description: The low fracture toughness of MoSi{sub 2} at ambient temperature has prompted investigations into new processing methods in order to impart some degree of fracture toughness into this inherently brittle material. In the following investigation, low pressure plasma spraying was employed as a fabricating technique to produce spray-formed deposits of MoSi{sub 2} and ductile reinforced MoSi{sub 2} composites containing approximately 10 and 20 volume percent of a discontinuous tantalum lamelli reinforcement. Fracture toughness (K{sub 1C}) measurements of MoSi{sub 2} and the MoSi{sub 2}/Ta composites were done using a chevron notched 4-point bend fracture toughness test in both the as-sprayed condition and after hot isostatic pressing at 1200{degrees}C/206 MPa for 1 hour. Results from the ductile reinforced MoSi{sub 2}/Ta composites have shown fracture toughness increases on the order of 200% over the as-sprayed MoSi{sub 2}. In addition, a marked anisotropy in fracture toughness was observed in the spray-formed deposits due to the layered splat structure produced by the low pressure plasma spray process.
Date: February 1, 1992
Creator: Castro, R. G.; Rollett, A. D.; Stanek, P. W. & Smith, R. W.
Partner: UNT Libraries Government Documents Department

Novel microorganism for selective separation of coal from ash and pyrite. Second quarterly technical progress report, 1 December 1993--28 February 1994

Description: The objective of this project is to study the effectiveness of a novel hydrophobic microorganism, Mycobacterium phlei (M. phlei), for the selective flocculation of coal from pyrite and ash forming minerals. During the reporting period, the hydrophobicity of different coal samples was studied both in the presence and absence of M. phlei cells. In the absence of M. Phlei, Illinois No. 6 and Pennsylvania No. 8 exhibited higher contact angles as compared to Kentucky No. 9 coal. All the coal samples exhibited a maximum in contact angle around pH 5--7, which roughly coincides with the iso-electric point (iep) of different coals studied in this investigation. In the presence of M. phlei, maximum contact angle shifted to lower pH range of 2--3 which coincides with the iep of the M. phlei. These measurements reinforce the notion that good flocculation of coal with M. phlei can be achieved around pH 2--3. The amount of soluble fraction released during rupturing of M. phlei cells was studied as a function of sonication time. The rupturing experiments showed that the whole cells (unruptured cells) contain nearly 40% by weight of soluble fractions. Also, during the reporting period, the fabrication of the counter-current flocculation device was completed.
Date: May 1, 1994
Creator: Misra, M.; Smith, R. W. & Raichur, A. M.
Partner: UNT Libraries Government Documents Department

Transportation capabilities study of DOE-owned spent nuclear fuel

Description: This study evaluates current capabilities for transporting spent nuclear fuel owned by the US Department of Energy. Currently licensed irradiated fuel shipping packages that have the potential for shipping the spent nuclear fuel are identified and then matched against the various spent nuclear fuel types. Also included are the results of a limited investigation into other certified packages and new packages currently under development. This study is intended to support top-level planning for the disposition of the Department of Energy`s spent nuclear fuel inventory.
Date: October 1, 1994
Creator: Clark, G.L.; Johnson, R.A.; Smith, R.W.; Abbott, D.G. & Tyacke, M.J.
Partner: UNT Libraries Government Documents Department