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Magnetic Properties of Metal(II) Schiff Base Complexes

Description: Ligands prepared from various combinations of aldehydes and ketones with the appropriate aminealcohol were complexed with cupric acetate monohydrate. The complexes with O,NO or N,N,O donor atoms were synthesized to study the influences of the ligand on molecular structure, spin-spin interaction, and on the value of the exchange integral. The magnetic data indicated that of the eight Cu(II) complexes discussed, two behaved differently from known analogous compounds. Cu (benzoylacetone :ethanolamine) was compared to Cu(acac:ethanolamine), and Cu(pyrr:oaminophenol) was compared to Cu(acac:o-aminophenol). Each pair of complexes was postulated to have the same molecular structure. The synthesis and characterization of Mn(pyrr:oaminophenol) 2H2 is also discussed. The following physical data were collected and discussed: elemental analysis, melting point, molecular weight, infrared spectra, electronic spectra, and magnetic susceptibility.
Date: May 1976
Creator: Hines, Mary Katherine
Partner: UNT Libraries

Metal Carbonyl-Hydrosilane Reactions and Hydrosilation Catalysis

Description: Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a siloxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Three relevant catalytic reactions are shown. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(C0){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(I) precatalysts.
Date: April 14, 2001
Creator: Cutler, A. R.
Partner: UNT Libraries Government Documents Department

Magnetic excitations in a random exchange system Fe{sub x}Mn{sub 1-x}TiO{sub 3}

Description: In order to examine the influence of exchange frustration on spin wave excitations, inelastic neutron scattering experiments have been performed on a random exchange system Fe{sub x}Mn{sub l-x}TiO{sub 3} with x = 0.00, 0.10, 0.25 and 0.33. For all three mixed systems, the magnetic excitation spectra consist of two components: a well-defined spin wave component and a broad damped component. The latter can be well fitted to a spectral weight function for a damped harmonic oscillator.
Date: August 24, 1994
Creator: Kawano, H.; Yoshizawa, H.; Nicklow, R.M. & Ito, A.
Partner: UNT Libraries Government Documents Department

Kinetics of MN based sorbents for hot coal gas. Quarterly report, September--December 1996

Description: Manganese-based sorbents have been investigated for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot coal gases prior to its use in combined cycle turbines. Four formulations of Mn-based sorbents were tested in an ambient-pressure fixed-bed reactor to determine steady state H{sub 2}S concentrations, breakthrough times and effectiveness of the sorbent when subjected to cyclic sulfidation and regeneration testing. In a previous report, the sulfidation results were presented. Manganese-based sorbents with molar ratios > 1:1 Mn:Substrate were effective in reducing the H{sub 2}S concentration in simulated coal gases to less than 100 ppmv over five cycles. Actual breakthrough time for formulation C6-2-1100 was as high as 73% of breakthrough time based on wt% Mn in sorbent. In this report, the regeneration results will be presented. Regeneration tests determined that loaded pellets can be fully regenerated in air/steam mixture at 750{degrees}C with minimal sulfate formation. 16 refs., 9 figs., 5 tabs.
Date: December 31, 1996
Partner: UNT Libraries Government Documents Department

THE EFFECT OF Cl$sup -$ AND SO$sub 4$$sup -2$ ON THE PARAMAGNETIC RESONANCE LINE WIDTH OF Mn$sup +2$ IN AQUEOUS SOLUTION AND THE RATES OF FORMATION OF THE COMPLEX IONS

Description: The line width of one of the hynerfine components in solutions of Mn(ClO/ sub 4/)/sub 2/ containing added NaCl and Na/sub 2/SO/sub 4/ was studied from 20 to 200 deg C at 9000 Mc/sec. The chloride ion contributes littie broadening at 0.1 M below 80 deg C but considerable broadening is obtained above this temperature. The sulfate contributes broadening at all temperatures. The rates of formation of inner-sphere'' and outersphere'' complexes are discussed together with their rates of relaxation. At the lower temperatures the outersphere'' complexes primarily contribute to the broadening while at the higher temperatures the inner-sphere'' complexes also contribute. From the broadening above 80%DEC the rates of formation of the inner-sphere'' complexes are evaluated. (auth)
Date: September 23, 1963
Creator: Hayes, R.G. & Myers, R.J.
Partner: UNT Libraries Government Documents Department

Kinetics of Mn-based sorbents for hot coal gas desulfurization. Quarterly report, December 15, 1993--March 15, 1997

Description: Manganese-based sorbents have been investigated for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot coal gases prior to its use in combined cycle turbines. Four formulations of Mn-based sorbents were tested in an ambient-pressure fixed-bed reactor to determine steady state H{sub 2}S concentrations, breakthrough times and effectiveness of the sorbent when subjected to cyclic sulfidation and regeneration testing. In previous reports, the sulfidation and regeneration results from cyclic testing done at 600{degrees}C were presented. Manganese-based sorbents, with molar ratios > 1:1 Mn:Substrate were effective in reducing the H{sub 2}S concentration in simulated coal gases to less than 100 ppmv over five cycles. Actual breakthrough time for formulation C6-2-1100 was as high as 73% of breakthrough time based on wt% Mn in sorbent. Regeneration tests determined that loaded pellets can be fully regenerated in air/steam mixture at 750{degrees}C with minimal sulfate formation. In this report, the results from cyclic crush strength tests, Sulfur profile tests and cyclic testing at 550{degrees}C and lower flowrate cyclic testing are presented. Crush strength testing done after 5 cycles showed decreases in strength from 12.6% to 57.9%. Cyclic testing at 550{degrees}C showed pre breakthrough concentrations as low as 10 ppmv. Cyclic testing done at 2 L/min and 3 L/min did not show any significant difference in pre breakthrough concentrations or capacity.
Date: March 3, 1997
Creator: Hepworth, M.T.
Partner: UNT Libraries Government Documents Department

Manganese-based sorbents for coal gas desulfurization

Description: The intent of this study is to perform a preliminary screening on a particular Mn-based sorbent, CST-939 (from Chemetals), for hot gas desulfurization. The purpose of the preliminary screening is to determine which temperature and type of coal gas this sorbent demonstrates the greatest capacity and efficiency for sulfur removal. The following conclusions were made from the data collected on the CST-939 sorbent: The sorbent efficiency and capacity are much greater at 343{degrees}C (650{degrees}F) than at 871{degrees}C (1,600{degrees}F). The sorbent efficiency and capacity are much greater in the presence of the more highly-reducing Shell gas than with the less-reducing KRW gas. The sorbent showed tremendous capacity for sulfur pickup, with actual loadings as high as 21 weight percent. Oxidative regeneration at 871{degrees}C (1,600{degrees}F) appeared to decompose sulfate; however, unusually high SO{sub 2} release during the second sulfidations and/or reductive regenerations indicated incomplete regeneration. The average crush strength of the reacted sorbent did not indicate any loss of strength as compared to the fresh sorbent. Superior sorbent performance was obtained in the presence of simulated Shell gas at 538{degrees}C (1,000{degrees}F).
Date: December 31, 1996
Creator: Gasper-Galvin, L.D.; Fisher, E.P. & Goyette, W.J.
Partner: UNT Libraries Government Documents Department

Kinetics of MN-based sorbents for hot coal gas desulfurization. Semiannual report, December 15, 1996--March 15, 1997

Description: Manganese-based sorbents have been investigated for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot coal gases prior to its use in combined cycle turbines. Four formulations of Mn-based sorbents were tested in an ambient-pressure fixed-bed reactor to determine steady state H{sub 2}S concentrations, breakthrough times and effectiveness of the sorbent when subjected to cyclic sulfidation and regeneration testing. In previous reports, the sulfidation and regeneration results from cyclic testing done at 600{degrees}C were presented. Manganese-based sorbents with molar ratios >1:1 Mn:substrate were effective in reducing the H{sub 2}S concentration in simulated coal gases to less than 100 ppmv over five cycles. Actual breakthrough time for formulation C6-2-1100 was as high as 73% of breakthrough time based on wt% Mn in sorbent. Regeneration tests determined that loaded pellets can be fully regenerated in air/steam mixture at 750{degrees}C with minimal sulfate formation. In this report, the results from the cyclic crush strength tests, sulfur profile test, and cyclic testing done after 5 cycles showed decreases in strength from 12.6% to 57.9%. Cyclic testing at 550{degrees}C showed pre-breakthrough concentrations as low as 10 ppmv. Cyclic testing done at 2 L/min and 3 L/min did not show any significant difference in pre-breakthrough concentrations or capacity.
Date: March 1, 1997
Creator: Hepworth, M.T.
Partner: UNT Libraries Government Documents Department

Real-Time Chord Length Analysis of Strontium and Manganese Precipitates Formed from Hanford Tank 241-AN-107 Simulant

Description: Removal of radioactive strontium and transuranic elements from Hanford Envelope C waste solutions can be accomplished by the sequential addition of sodium hydroxide, strontium nitrate, and sodium permanganate solutions. This multistep precipitation process is the baseline technology in the River Protection Project -Waste Treatment Plant (RPP-WTP) for the removal of these radioactive species from Hanford Waste Tanks. Decontamination targets are easily met using these precipitation technologies and current work in this area focuses on optimization to minimize reagent levels. Downstream treatment processes require filtration of the precipitate slurry. In order to avoid further precipitation after filtration, it is necessary to know the precipitation reaction time-scale. In addition, precipitate slurry filter flux is a primary parameter of interest to plant design personnel. Optimization of the filtration process is benefited by an understanding of the parameters that impact particle size distribution. Filter cake packing and, hence, filter flux are often sensitive to small changes in the particle size distribution. However, traditional methods of particle size analysis often are not sufficiently sensitive to develop correlations to filterability. Focused Beam Reflectance Measurements (FBRM) are a relatively new chord length analysis method with extremely high sensitivity. The method is suited for continuous monitoring of chord length distributions in the process medium. The instrument is equipped with statistical data analysis software for the identification of small shifts in the population. Reported herein are the results of FBRM analysis of strontium and manganese precipitation tests with Hanford AN-107 simulant. The objectives of the testing were to: (1) evaluate the impacts of precipitation parameters (temperature and reagent levels) upon the strontium and manganese particle chord length distributions; (2) evaluate the stability of the particles under shear; (3) determine the general time-scale of the precipitation reactions; (4) identify correlations of the chord length distribution statistics to other measured experimental ...
Date: March 18, 2004
Creator: KING, WILLIAMD
Partner: UNT Libraries Government Documents Department

SEM analysis of rock varnish chemistry: A geomorphic age discriminator

Description: Rock varnish, a manganese- and iron-rich coating commonly found on rock surfaces in arid and semiarid regions, has long been of interest as a potential age indicator. Rock varnish has been shown to be an effective medium for dating of geomorphic surfaces over a time range of several thousand to over a million years, utilizing a ratio among minor cations ((K + Ca)/Ti) for the total volume of rock varnish. We have recently, developed a technique using the scanning electron microscope (SEM) equipped with an energy dispersive x-ray analyzer (EDAX) to analyze the chemistry of rock varnish. This technique has several advantages over the earlier cation ratio technique.
Date: July 1, 1989
Creator: Harrington, C.D. & Raymond, R. Jr.
Partner: UNT Libraries Government Documents Department

CHEMICAL DECONTAMINATION OF THE ANL-2 HIGH-PRESSURE WATER LOOP

Description: The chemical decontamination of the ANL-2 Highpressure Water Loop at the MTR is described. A mixture of sodium hydroxide and potassium permanganate was first applied to oxidize partially and loosen the magnetite corrosion film on the loop surfaces. Next, the system was treated with a solution of Versenol 120 to remove and suspend the loosened oxide film. The third chemical treatment was a mixture of sulfamic acid, HEDTA, hydrazine, and Rodine 80. After the first two chemical treatments a brown residue remained, which was presumed to be manganese dioxide. The third solution completely removed all traces of residue from the first two treatments. After a delay of one MTR fuel cycle (three weeks) due to mechanical difficulties, the loop was operated for approximately 300 hours at 420 deg F and 380 psig with excess hydrogen to passivate the loop surfaces. Approximately 70% of the corrosion film was removed from the loop surfaces as a result of the chemical decontamination. (auth)
Date: July 1, 1960
Creator: Crothers, C.C.
Partner: UNT Libraries Government Documents Department

Kinetics of Mn-based sorbents for hot coal gas desulfurization: Task 2, Exploratory experimental studies: Single pellet tests; Rate mechanism analysis. Quarterly report, June 15, 1996--September 15, 1996

Description: Currently, the Morgantown Energy Technology Center, Department of Energy (DOE/METC) is actively investigating alternative hot fuel gas desulfurization sorbents for application to the Integrated Gasification Combined Cycle (IGCC). A sorbent must be highly active towards sulfur at high temperatures and pressures, and under varying degrees of reducing atmospheres. Also, it must regenerate nearly ideally to maintain activity over numerous cycles. Furthermore, regeneration must yield a sulfur product which is economically recoverable directly or indirectly. Several metal oxides have been investigated as regenerable sorbents for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot fuel gases. MnO was shown to have an intrinsic reaction rate approximately one order of magnitude greater than the rate or reaction with either CaO or ZnO and two orders of magnitude greater than the reaction rate with V{sub 2}0{sub 3}. Manganese also shows desulfurization potential in the temperature range of 600-700{degrees}C where metal oxides currently known to be reactive with H{sub 2}S are unsatisfactorily. In response to stability difficulties of single and binary metal oxide sorbents, increasing effort is being directed towards incorporation of an inert component into sorbent formulation as witnessed by the various Zn-titanates. Primarily, the inert component increases pore structure integrity while stabilizing the active metal oxide against reduction. This report will address testing of Mn-based sorbents in an ambient pressure fixed-bed reactor. Steady-state H{sub 2}S concentrations and breakthrough times will be presented.
Date: September 11, 1996
Creator: Hepworth, M.T.
Partner: UNT Libraries Government Documents Department

Advance concepts for the conversion of syngas liquids. Quarterly report no. 6, January 1--March 31, 1996

Description: Research activities for the period January 1, 1995 to March 31, 1996 have been focused on the characterization of catalyst samples, mainly by Diffuse Reflectance Infrared Spectroscopic Techniques. These studies revealed the strong presence of hydroxyls in our synthetic metal substituted aluminophosphate (MeAPO-36) samples, the amount of which appear to vary depending on the type of metal in the framework. In this report, cases of magnesium, cobalt and manganese are highlighted and compared. The hydroxyl groups present in these samples also shows some interaction with basic probe molecules such as ammonia. Details studies are in progress.
Date: December 31, 1996
Creator: Szostak, R. & Ingram, C.
Partner: UNT Libraries Government Documents Department

Low temperature VOC combustion over manganese, cobalt and zinc AlPO{sub 4} molecular sieves. Semi-annual report-1, September 1, 1995--February 29, 1996

Description: The objective of this project is to prepare manganese, cobalt and zinc containing AlPO{sub 4} large pore molecular sieves of structure type -36 and evaluate their ability to function as successful oxidation catalysts for the removal of low levels of VOC`s from gas streams. The tasks to be accomplished are as follows: (1) To develop reliable synthesis methods that produce the large pore metal aluminophosphates containing manganese, cobalt and zinc in their framework. (2) To characterize these materials to determine phase purity and the location of the incorporated metal in the framework. Characterization will also include the nature of the active sites within the structures and the effect manganese, cobalt and zinc has on the structures` acidity. (3) To screen the material for their catalytic activity in the oxidation of hydrocarbons and aromatics. This report gives a summary of the status of the project as of 28th February 1996.
Date: June 1, 1997
Creator: Szostak, R.
Partner: UNT Libraries Government Documents Department

Low temperature VOC combustion over manganese, Cobalt and Zinc ALPO(4) Molecular sieves. Semi-annual, March 1, 1996 - Aug. 31, 1996

Description: A functional fixed bed continuous flow catalytic reactor was constructed for conducting experiments on the catalytic destruction of VOCs using cobalt and manganese containing aluminophosphate catalysts (MeAPOs). The reactor was also interfaced to a Gas Chromatograph in order to facilitate on line product analysis. As preliminary catalytic experiments, a cobalt exchanged form of large pore zeolite Y was used as a reference catalyst for the oxidation of methylene chloride (CH{sub 2}Cl{sub 2}). At 350{degrees}C, the catalyst was effective in partial conversion of this feed stream of VOC to CO{sub 2}. Optimization of reaction conditions are currently underway in order to obtain higher conversion levels. The effect of variations in reaction conditions such as reactant flow rate, reaction temperature and catalyst compositions are currently been investigated. In the next phase of this project, the Co-exchanged Y zeolite will be substituted by the MeAPOs catalysts and the reactivities of the latter will be assessed. The potential of the MeAPOs to function as oxidation catalysts was evaluated in the liquid phase conversion of phenol to hydroquinone and catechol. The percentage conversion and product yield were significant and varied depending on the metal type and content of the molecular sieve framework. Conversion levels were also dependent on molecular sieve pore dimensions as the medium pore MeAPO-11 was more active than the larger pore MeAPO-5 or MeAPO-36.
Date: December 31, 1996
Creator: Das, K.; Sheehan, D.G. & Szostak, R.
Partner: UNT Libraries Government Documents Department

Catalytic conversion of light alkanes: Quarterly report, January 1-March 31, 1992

Description: The first Quarterly Report of 1992 on the Catalytic Conversion of Light Alkanes reviews the work done between January 1. 1992 and March 31, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products which can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon transportation fuel. During the past quarter we have continued to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. We continue to investigate three molecular environments for the active catalytic species that we are trying to generate: electron-deficient porphryinic macrocycles (PHASE I), polyoxometallates (PHASE II), and regular oxidic lattices including zeolites and related structures as well as other molecular surface structures having metal oxo groups (PHASE III).
Date: May 1, 1997
Creator: Biscardi, J.; Bowden, P.T.; Durante, V.A.; Ellis, P.E. Jr.; Gray, H.B.; Gorbey, R.G. et al.
Partner: UNT Libraries Government Documents Department

Steric and electronic effects of 1,3-disubstituted cyclopentadienyl ligands on metallocene derivatives of Cerium, Titanium, Manganese, and Iron

Description: Sterically demanding 1,3-disubstituted cyclopentadienyl ligands were used to modify the physical properties of the corresponding metallocenes. Sterically demanding ligands provided kinetic stabilization for trivalent cerium compounds. Tris(di-t-butylcyclopentadienyl)cerium was prepared and anion competition between halides and cyclopentadienyl groups which had complicated synthesis of the tris(cyclopentadienyl)compound was qualitatively examined. Bis(di-t-butylcyclopentadienyl)cerium methyl was prepared and its rate of decomposition, by ligand redistribution, to tris(di-t-butylcyclopentadienyl)cerium was shown to be slower than the corresponding rate for less sterically demanding ligands. Asymmetrically substituted ligands provided a symmetry label for examination of chemical exchange processes. Tris[trimethylsilyl(t-butyl)cyclopentadienyl]cerium was prepared and the rate of interconversion between the C1 and C3 isomers was examined. The enthalpy difference between the two distereomers is 7.0 kJ/mol. The sterically demanding cyclopentadienyl ligands ansa-di-t-butylcyclopentadiene (Me2Si[(Me3C)2C5H3]2), ansa-bis(trimethylsilyl)cyclopentadiene (Me2Si[(Me3Si)2C5H3]2) and tetra-t-butylfulvalene and metallocene derivatives of the ligands were prepared and their structures were examined by single crystal X-ray crystallography. The effect that substituents on the cyclopentadienyl ring have on the pi-electron system of the ligand was examined through interaction between ligand and metal orbitals. A series of 1,3-disubstituted manganocenes was prepared and their electronic states were determined by solid-state magnetic susceptibility, electron paramagnetic resonance, X-ray crystallography, and variable temperature UV-vis spectroscopy. Spin-equilibria in [(Me3C)2C5H3]2Mn and [(Me3C)(Me3Si)C5H3]2Mn were examined and indicate an enthalpy difference of 15 kJ/mol between the high-spin and low-spin forms. Cyclopentadienyl groups resistant to intramolecular oxidative addition allowed isolation of compounds susceptible to intramolecular decomposition. A kinetically stable, base-free titanocene was prepared using di-t-butylcyclopentadienyl ligands and the reactivity of the compound toward small molecules was investigated. The titanocene reacts reversibly with hydrogen to form the titanocene dihydride and the equilibrium in solution between titanocene dihydride, and titanocene and hydrogen, was examined.
Date: May 19, 2000
Creator: Sofield, C.D.
Partner: UNT Libraries Government Documents Department

Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species. Quarterly technical progress report, March 20, 1995--June 20, 1995

Description: The biological accumulation of heavy metals and cesium, strontium, and uranium in plants is discussed. The role of nutrient deficiencies and foliar treatments of manganese and iron compounds is described.
Date: December 1, 1995
Creator: Kochian, L.
Partner: UNT Libraries Government Documents Department

Scavenging of Particulate Matter in Connection With Nuclear-Powered Ships. Final Scientific Report

Description: The work carried out over a 2 1/2-yr period on the scavenging of radioactive particles which might be released by the reactor system of a nuclear- powered ship is summarized. Two types of dispersions were considered: aerosols and hydrosols. Radioactive aerosols were scavenged by heterogeneous coagulation with solid and liquid aerosols produced within the radioactive aerosol cloud. Liquid or highly hygroscopic particles, which can be classified as solid particles with liquld films on their surfaces, were found to be the most effective scavengers. A system of fine water spray and hydrolysis products of silicon tetrafluoride was found to be suitable for field application. Scavenging of radioactive cations, anions, and colloids of corrosion and fission products was studied in substitute ocean water, natural ocean water, and natural harbor water. A scavenging system composed of KMnO/sub 4/ and ferrous salts successfully removed most of the radioisotopes. Fe(OH)/sub 3/--MnO/sub 2/ hydrate adsorbed and absorbed radioactive species, thus transferring them from a liquid to a solid phase. Addition of Floc 111 to the system improved sedimentation. The KMnO/sub 4/-FeSO/sub 4/-Floc 111 system was found to bs suitable for field application. (auth)
Date: July 29, 1960
Creator: Rosinski, J.
Partner: UNT Libraries Government Documents Department

Dynamics of rock varnish formation

Description: Our studies of rock varnish from the southwestern United States suggest that the Mn-phase in rock varnish has neither the chemistry nor the crystal structure of birnessite. Rather, the Mn-rich phase is non-crystalline and contains Ba, Ca, Fe, Al, and P. Unknowns concerning the formation of this non-crystalline Mn phase must be resolved before researchers are able to define chemical parameters of rock varnish formation based upon conditions of formation of the Mn phase. 6 refs., 9 figs.
Date: January 1, 1991
Creator: Raymond, R. Jr.; Reneau, S.L.; Guthrie, G.D. Jr.; Bish, D.L. & Harrington, C.D.
Partner: UNT Libraries Government Documents Department

CHEMICAL ENGINEERING DIVISION SUMMARY REPORT FOR OCTOBER, NOVEMBER, DECEMBER 1959

Description: Chemical-Metallurgical Processing. A direct-cycle pyrometallurgical fuel-processing plant is being constructed in conjunction with EBR-II. The gamma- irradiation testing of the 175-watt white fluorescent mercury vapor lamp was continued to an integrated exposure of 2 x 10/sup 9/ rad. Irradiation tests of Shell APL grease were completed, and the estimated useful life of this grease in the Air and Argon Cells is 2 and 3 years, respectively. Tests of the three - types of d-c motors used in the operating manipulator of the Argon Cell indicate an expected useful cell operating life of 2 to 3 years. Continued irradiation tests of mineralinsulated cable show no catastrophic breakdown of the electric insulation even after an accumulated gamma dose of 8.4 x 10/sup 9/ rad. The scheme currently under consideration for processing melt-refining residues involves a reduction of skull oxides by a solution of Mg in liquid Cd. Molten salt fluxes had variable effects on the rate of oxide reduction in dilute Mg systems. Work was continued on development of processes for EBR-II blanket materials. A large-scale metal-distillation unit to demonstrate metal distillation at rates up to 100 kg/hour is under construction. Two medium carbon steel thermal-convection loops were built and operated to ascertain the extent of corrosion under adverse thermal conditions. Data were obtained for the solubilities of V, Fe, and Ni in liquid Cd at temperatures from 400 to 650 deg C. Corrections were made to data on the solubility of Th in liquid Zn. Solubilities of U in Si-free Zn--Mg solutions were found to be significantly higher than when silicon was present. The peritectic temperature in the U--Cd system was found to be 474 plus or minus l deg C. The activity coefficient of U in Al at4.8% U and 686 deg C is estimated to be 1.25 x 10/sup ...
Date: February 1, 1960
Partner: UNT Libraries Government Documents Department

Far infrared spectroscopy of solids. I. Impurity states in Al$sub 2$O$sub 3$. II. Electron-hole droplets in Ge

Description: Far infrared Fourier transform spectroscopy was used to study the low lying vibronic states of Mn$sup 3+$ in Al$sub 2$O$sub 3$ and the plasma absorption of electron-hole droplets in Ge. The transmission of Mn-doped samples of Al$sub 2$O$sub 3$ was measured in the frequency range from 3 to 30 cm$sup -1$ in applied magnetic fields up to 50 kG. Absorption lines were observed due to both ground and excited state transitions. Polarization measurements established that these absorption lines were due to electric dipole transitions. Temperature dependence measurements were used to derive a level diagram for the low lying states of Mn$sup 3+$. A phenomenological model based on an electronic Hamiltonian was developed which successfully describes the data. The empirically determined trigonal field and spin-orbit quenching parameters of this model are 0.7 and 0.1 respectively. This quenching is attributed to the dynamic Jahn-- Teller interaction. The plasma absorption of small ($alpha$) electron-hole drops in Ge was measured in the frequency range from 30 to 300 cm$sup -1$. The observed absorption is in good agreement with measurements by Vavilov and other workers. A theoretical model which includes both intraband and interband contributions to the dielectric constant in the Rayleigh limit of Mie theory is used to describe the observed lineshape. Measurements of plasma absorption of large ($gamma$) drops in inhomogeneously stressed Ge were made in magnetic fields up to 50 kG. The lineshape at zero applied field was calculated in the large sphere limit of Mie theory including intraband terms and a zero-strain interband term. Qualitative agreement with experiment was obtained. The peak absorption shifted quadratically with applied magnetic field and the total plasma absorption increased. No oscillatory structure was observed in the field-dependence of the total absorption. (auth)
Date: September 12, 1975
Creator: Aurbauch, R.L.
Partner: UNT Libraries Government Documents Department