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Full-Text Articles in Physical Sciences and Mathematics

Mössbauer-Effect Studies Of The Phase Transitions In Antiferroelectric Pbzro₃ And Ferroelectric Pbti₀.₀₂Zr₀.₈O₃, James P. Canner, C. M. Yagnik, Robert Gerson, William Joseph James Nov 1971

Mössbauer-Effect Studies Of The Phase Transitions In Antiferroelectric Pbzro₃ And Ferroelectric Pbti₀.₀₂Zr₀.₈O₃, James P. Canner, C. M. Yagnik, Robert Gerson, William Joseph James

Physics Faculty Research & Creative Works

The Mössbauer spectra were studied for the antiferroelectric compound PbZrO3 and for the closely related ferroelectric PbTi0.2Zr0.8O3. In both cases, a substitution of 5-mol% BiFeO3 was made to permit the Mössbauer measurements. Little difference was found in the isomer shift in these compounds, whether they were in the ferroelectric, antiferroelectric, or cubic state, indicating that the bonding character is not affected by the transitions among the states. There was a pronounced and approximately equivalent dip in the recoil-free fraction at the Curie points of both the antiferroelectric and ferroelectric materials, associated with …


Noble Gases Anomalies In Terrestrial Ores And Meteorites, B. Srinivasan Jan 1971

Noble Gases Anomalies In Terrestrial Ores And Meteorites, B. Srinivasan

Doctoral Dissertations

"Analyses of the content and isotopic composition of xenon and krypton in terrestiral ores containing tellurium, selenium or iodine resulted in the following conclusions: 1. The double beta-decay half-life for ¹³⁰Te is 2.51 x 10²¹ years from analysis of tellurobismuthite from Boliden, Sweden and 2.83 x 10²¹ years from analysis of tellurides from Kalgoorlie, Australia. 2. The ratio of the double beta-decay half-life of ¹²⁸Te relative to that of ¹³⁰Te is ≥ 108 and ≥ 293 for Boliden tellurobismuthite and Kalgoorlie tellurides, respectively. 3. Selenium minerals and tellurium ores containing selenium exhibit ⁸²Kr excess attributed to the double beta-decay of …


Anodic Dissolution Of Beryllium In Anhydrous Media, William Joseph James, Martin E. Straumanis Jan 1971

Anodic Dissolution Of Beryllium In Anhydrous Media, William Joseph James, Martin E. Straumanis

Chemistry Faculty Research & Creative Works

No abstract provided.


The Oxidative Decarboxylation Of Polyaminocarboxylic Acids - Ii. A Comparative Kinetic Study Of The Oxidation Of Nta, Edta, Cdta And Dtpa With Cerium(Iv) In Sulfuric Acid Media, Samir B. Hanna, Rita Hessley, William H. Webb, William R. Carroll Jan 1971

The Oxidative Decarboxylation Of Polyaminocarboxylic Acids - Ii. A Comparative Kinetic Study Of The Oxidation Of Nta, Edta, Cdta And Dtpa With Cerium(Iv) In Sulfuric Acid Media, Samir B. Hanna, Rita Hessley, William H. Webb, William R. Carroll

Chemistry Faculty Research & Creative Works

The rates of oxidation of four chelating agents, NTA, EDTA, CDTA, and DTPA with Ce(IV), in sulfuric acid media, were determined spectrophotometrically by a stopped-flow technique. The reductive ability is in the order CDTA > EDTA > DTPA > NTA. The influence of varying the acidity of the medium was studied, and in each case a maximum in the rate constant vs. [H+] plot was observed. A possible interpretation of the reactivities and the influence of acidity is advanced. © 1971 Springer-Verlag.


The Effects Of Divalent Metal Ions On The Micellar Properties Of Sodium Dodecyl Sulfate, Michael U. Oko, Raymond L. Venable Jan 1971

The Effects Of Divalent Metal Ions On The Micellar Properties Of Sodium Dodecyl Sulfate, Michael U. Oko, Raymond L. Venable

Chemistry Faculty Research & Creative Works

Critical micelle concentrations and micellar molecular weights have been determined for sodium dodecyl sulfate in the presence of nitrates of copper, lead, zinc, and magnesium and critical micelle concentrations have been determined with sodium nitrate and silver nitrate as the added electrolytes. The thickness of the ionic atmosphere at the critical micelle concentration has been found to be 34.1 Å with no electrolyte present and 33.6 Å with 9.66 x 10-6 M sodium or silver nitrate and was found to increase upon addition of the 2:1 electrolytes. This is explained in terms of molecular and ionic interactions. Micellar molecular weights …


Mass Fraction And The Isotopic Anomalies Of Xenon And Krypton In Ordinary Chondrites, Edward W. Hennecke Jan 1971

Mass Fraction And The Isotopic Anomalies Of Xenon And Krypton In Ordinary Chondrites, Edward W. Hennecke

Masters Theses

"The abundance and isotopic composition of all noble gases are reported in the Wellman chondrite, and the abundance and isotopic composition of xenon and krypton are reported in the gases released by stepwise heating of the Tell and Scurry chondrites. Major changes in the isotopic composition of xenon result from the presence of radiogenic Xe¹²⁹ and from isotopic mass fractionation. The isotopic composition of trapped krypton in the different temperature fractions of the Tell and Scurry chondrites also shows the effect of isotopic fractionation, and there is a covariance in the isotopic composition of xenon with krypton in the manner …


The Thermal Accommodation Coefficients Of Helium, Neon, And Argon On Surfaces, Gerald Lee Zweerink Jan 1971

The Thermal Accommodation Coefficients Of Helium, Neon, And Argon On Surfaces, Gerald Lee Zweerink

Doctoral Dissertations

"Measurements of the accommodation coefficients of helium, neon, and argon on an ice surface at 77ºK were accomplished; Measurements of the accommodation coefficients of helium and neon on a clean tungsten surface are also reported here; These data are compared with theoretical calculations of accommodation coefficients as well as with data from other experimental studies"--Abstract, pages iii-iv.


A Measurement Of The Capture Coefficient And Of The Vapor Pressure Of Co₂ From 69ºk To 80ºk, Michel Louis Chouarain Jan 1971

A Measurement Of The Capture Coefficient And Of The Vapor Pressure Of Co₂ From 69ºk To 80ºk, Michel Louis Chouarain

Masters Theses

"The capture coefficient of CO₂ gas at 135ºK on a surface of CO₂ at temperatures between 69ºK and 80ºK is measured by means of quartz crystal microbalances. The vapor pressure of CO₂ is measured in the same range of temperature"--Abstract, page ii.


A Kinetic Study Of The Reductive Abilities Of Four Polyaminocarboxylic Acids (Edta, Cdta, Dtpa And Nta) Towards Cerium(Iv) In Perchloric Acid Media, Salem Ahmed Attiga Jan 1971

A Kinetic Study Of The Reductive Abilities Of Four Polyaminocarboxylic Acids (Edta, Cdta, Dtpa And Nta) Towards Cerium(Iv) In Perchloric Acid Media, Salem Ahmed Attiga

Masters Theses

"The reduction of Ce(IV) in HC10₄ solutions by four polyaminocarboxylic acids, which are commonly used as chelating agents, has been studied by the stopped-flow technique. The rates of reduction first increase with increasing acidity, reach maxima which are characteristic of the chelating agent and the medium, then progressively decrease with increasing the acid concentration in the media. At their maximum reactivities, trans-1,2-diaminocyclohexane tetraacetic acid (CDTA) shows the highest reductive ability; this is followed by ethylenedinitrilotetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and finally nitrilotriacetic acid (NTA). The observed maxima can be qualitatively explained in terms of a mechanism which involves unhydrolyzed …


The Halogen And Uranium Content Of Sedimentary Rocks, Tektites, Impact Glasses, And Obsidians, Victor J. Becker Jr. Jan 1971

The Halogen And Uranium Content Of Sedimentary Rocks, Tektites, Impact Glasses, And Obsidians, Victor J. Becker Jr.

Masters Theses

"The iodine and uranium concentrations in sedimentary rocks were measured by irradiating the samples in a neutron flux, radiochemically separating iodine, and ß-counting the resulting activity. The values obtained for uranium are in good agreement with previous estimates of the uranium content in sedimentary rocks. The values obtained for iodine define a distribution pattern similar to that reported for chlorine and bromine, in contrast with the distribution pattern previously reported for iodine in sedimentary rocks. The concentrations of chlorine, bromine, iodine and uranium were determined in tektites, obsidians and impact glasses by neutron activation. The uranium content found in tektites …


Mössbauer Studies Of Bifeo₃-Pbtio₃ Perovskite-Type Solid Solutions, C. M. Yagnik, Robert Gerson, William Joseph James Jan 1971

Mössbauer Studies Of Bifeo₃-Pbtio₃ Perovskite-Type Solid Solutions, C. M. Yagnik, Robert Gerson, William Joseph James

Physics Faculty Research & Creative Works

The Mössbauer spectra of the ferroelectric solid solutions (BiFeO3)x(PbTiO)1-x have been studied as a function of temperature, mainly between room temperature and 600°C, using 57Fe in the solutions as an absorber. The quadrupole splitting increased and the isomer shift decreased between x = 0.05 and x = 0.70, a range in which the solutions are tetragonal and paramagnetic, and in which the unit cell volume increases with increasing x. The isomer shift, in particular, was primarily determined by the unit cell volume. Data are presented on the internal magnetic field of the antiferromagnetic …


Conversions From Cyclohexanol: An Undergraduate Laboratory Project, Samir B. Hanna, James T. Wrobleski, Joseph T. Bohanon, Billy W. Peace Jan 1971

Conversions From Cyclohexanol: An Undergraduate Laboratory Project, Samir B. Hanna, James T. Wrobleski, Joseph T. Bohanon, Billy W. Peace

Chemistry Faculty Research & Creative Works

No abstract provided.


Magnetic Behavior Of Rare-Earth Iron-Rich Intermetallic Compounds, Dominique Givord, Remy Lemaire, William Joseph James, Jean Michel Moreau, Jayant S. Shah Jan 1971

Magnetic Behavior Of Rare-Earth Iron-Rich Intermetallic Compounds, Dominique Givord, Remy Lemaire, William Joseph James, Jean Michel Moreau, Jayant S. Shah

Chemistry Faculty Research & Creative Works

The thermal variation of lattice parameters of rare earth-transition metal intermetallic compounds rich in Fe, Co, or Ni in the temperature range of 25-900oK is studied. For the Fe compounds, negative thermal expansion is observed below their magnetic ordering temperatures regardless of the nature of substitutional ordering. For Co and Ni compounds, the thermal expansion behavior is normal. It is then concluded that for the Fe compounds, the magnetic properties are mainly determined by the Fe-Fe interatomic distances and the number of Fe nearest neighbors, whereas for Co and Ni compounds the magnetic properties are determined by the conduction electron …


Some Metal Complexes Of Dihydroxycyclobutenedione, Stewart Michael Condren Jan 1971

Some Metal Complexes Of Dihydroxycyclobutenedione, Stewart Michael Condren

Doctoral Dissertations

"This study involves an investigation of some of the physical and chemical properties of the trivalent metal squarate complexes of iron, vanadium, and indium in order to determine their structure. In this investigation studies were made of the infrared spectra, electronic spectra, x-ray diffraction powder photographs and diffractometer patterns, magnetic susceptibilities, and thermogravimetric patterns for the trihydrate, dihydrate, and anhydrous squarate complexes of vanadium(III) and iron (III) and the dihydrate squarate complex of indium(III). These studies suggest that the structures of the vanadium(III) and iron(III) squarate complexes are dimeric with hydroxyl bridges between the metal atoms. This is supported by …


The Oxidative Decarboxylation Of Aminopolycarboxylic Acids With Cerium (Iv) In Sulfuric Acid, Rita Kathleen Hessley Jan 1971

The Oxidative Decarboxylation Of Aminopolycarboxylic Acids With Cerium (Iv) In Sulfuric Acid, Rita Kathleen Hessley

Masters Theses

"The rates of oxidation of four chelating agents, NTA, EDTA CDTA, and DTPA with Ce(IV), in sulfuric acid media, were determined spectrophotometrically by a stopped-flow technique. The reductive ability is in the order CDTA>EDTA>DTPA>NTA. The influence of varying the acidity of the medium was studied, and in each case a maximum in the rate constant [H +] plot was observed. A possible interpretation of the reactivities and the influence of acidity is advanced"--Summary, page 1.


Synthesis, X-Ray Characterization, Structural And Magnetic Studies Of A New Class Of Iso-Structural Bimo₃ Compounds, Joseph Donato Bucci Jan 1971

Synthesis, X-Ray Characterization, Structural And Magnetic Studies Of A New Class Of Iso-Structural Bimo₃ Compounds, Joseph Donato Bucci

Doctoral Dissertations

"This dissertation consists of four sections. The first part is a temperature dependent X-ray study of the lattice parameters of BiFeo₃. The synthesis and subsequent X-ray characterization of BiCo₃, BiAlO₃, BiMnO₃ , BiScO₃, BiCo₁₋ₓFeₓO₃ , and BiAl₁₋ₓFeₓO₃ are reported in the second part. These compounds all crystallize in the body centered cubic (BCC) structure with a~10.2Å. Single crystal Precession and Weissenberg photographs confirmed the BCC structure. In part three, the results of the magnetic studies on BiCoO₃ and biAl.₉FE.₁ are presented. The magnetic data for BiCoO₃ are substantiated by X-ray thermal expansion studies. In the last part the compound BiCo.₉FE.₁O₃ …


Metal Salt Catalyzed Carbenoids, Billy W. Peace Jan 1971

Metal Salt Catalyzed Carbenoids, Billy W. Peace

Doctoral Dissertations

"The interaction of diazomalonic esters with olefins in the presence of homogeneous copper(I) and copper(II) catalyst has been examined as a function of olefin structure, solvent media, ionic strength, catalyst structure and catalyst concentration, using partial rate data. It has been possible to determine the fine mechanistic details of the cycloproponation, C-H insertion and "dimer" forming reactions. The initial step is displacement of a ligand from copper by diazo compound in a pre-equilibrium, loss of nitrogen in the rate determining step, return of the ligand, displacement of metal from the carbenoid by olefin, followed by collapse to products. Studies revealed …