Engineering Commons^™

The Effect Of Electrodes On The Thermally Stimulated Currents In Sodium Silicate Glass, Ruth Mogrovejo Cuzmar

Masters Theses

“Electrodes play an important role in the study of alkali ion motion in glasses when TSPC/TSDC techniques are used. Silver, gold and combinations of them were used in the study of Na⁺ motion in Na₂O·3SIO₂ glass. The lower temperature peak is not affected by any of these electrodes, so it is attributed to the bulk glass. A second and third peak are strongly dependent on the kind of electrode used. A gold anode is a blocking electrode, and a gold cathode, is partially blocking. There is a tendency for a space charge polarization to form when …

Sintering Of Catio₃ With The Addition Of Caco₃ And Lif, Surapol Pleekram

Masters Theses

"The densification of CaTiO₃ with the addition of 4.74, 5.90, 6.88 mol% CaCO₃ and 22 mol% LiF was investigated over the temperature range 800° to 1050°C, for sintering times ranging from 1 to 216 hours. It was found that CaCO₃ reacts with LiF and to form a liquid at a temperature of about 450°C. This liquid enhances the densification of CaTiO₃ . The densification process was followed by making weight loss, shrinkage and porosity measurements. The microstructural development was determined by scanning electron microscope examination of both fractured and polished surfaces. X-ray diffraction and DTA/TGA were …

Evaluation Of Low Temperature Properties Of Gas Oil, Dina Atef Abd El Ghaffar

Archived Theses and Dissertations

No abstract provided.

Comment On “Dielectric Properties Of Lead‐Magnesium Niobate Ceramics”, Jyoti P. Guha

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Screening Design Test For Cyclic Voltammetric Evaluation Of Zinc Sulfate Electrolyte, R. K. Singh, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

A statistical screening design program was conducted to determine the effects of certain operating parameters in the cyclic voltametric evaluation of zinc sulfate electrolyte. The variables studied included solution temperature, sulfuric acid and zinc concentrations, and scan rate. Solution temperature was found to be the most significant factor affecting the initial potential, followed by scan rate and zinc concentration. Based on screening design data, mathematical equations were developed to predict polarization behavior of addition-free zinc sulfate electrolytes. A few preliminary tests on the effect of impurities and organic additives, such as Sb(III) and glue, on potential, deposit morphology, and crystal …

Feasibility Study Of Fabricating Composite Ceramic Chamber Liners For Small Caliber Automatic Weapons, P. D. Ownby, D. V. Stewart

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

An Analysis Of Mill Sound Levels To Aid In The Control And Understanding Of The Grinding Process, Scott Douglas Morrison

Doctoral Dissertations

“An experimental study has been made to evaluate the relationships between grinding parameters and the directional sound levels emitted from the collision of the grinding media with the mill wall for a laboratory batch ball mill.

Discrete frequency and single frequency band sound pressure level measurements were performed to investigate the changes in sound levels with grind time. It was demonstrated that the reduction in sound levels with grind time observed for a narrow sized feed can be used to indicate optimum breakage rates, overall time-based particle size distribution, and ore character.

The relationships established with the discrete frequency and …

Dissolution Of Multi-Component Systems, Robin Ashley Murphy

Doctoral Dissertations

"The validity of ideal barrier layer diffusion kinetics was examined in the NaCl/KCl - glycerol and Al₂O₃-CaO-Al₂O₃-SiO₂/slag corrosion systems. Single crystals and dense polycrystalline plates of pure NaCl or KCl exhibit steady-state corrosion rates within 10%, of calculated theoretical values, while dense mixtures of the two salts corrode at rates higher than either pure material. The results are compared to the grooving phenomena of NaCl/KCl bicrystals.

Polycrystalline Al₂O₃ is shown to corrode at the same rate as single crystal sapphire at 1400°C in CaO-SiO₂-Al_{2 …}

Electrochemical Evaluation Of Zinc Electrolyte, Rajesh Kumar Singh

Doctoral Dissertations

"The polarization characteristics of acidified zinc sulfate electrolyte with varying solution chemistries were examined by cyclic voltammetry. An attempt was made to correlate the polarization results with the morphological and current efficiency data in order to develop a better understanding of the more fundamental aspects of impurity and additive behavior during the zinc electrodeposition process.

A statistical screening design program was conducted to determine the effects of certain operating parameters on the nucleation potential of zinc from sulfate electrolyte. The variables studied included: solution temperature, H₂SO₄ and Zn concentration, and scan rate. The solution temperature was found to be the …

Mass Transport Considerations In Electrometallurgical Reactions, Jose Rolando Sami Cuzmar

Doctoral Dissertations

"The research program described is divided into three segments. In the first part, the morphology and kinetic studies of Cd²⁺ removal from ZnSO₄ solutions using Zn dust as a reducing agent are presented. In the absence of impurities, the morphology of the Cd deposit shows the formation of two-dimensional or leaf-like dendrites capable of interlocking and forming agglomerates or balls. The size and strength of the agglomerates depend on the initial Cd²⁺ concentration to Zn metal surface area ratio, the rate of Cd ²⁺ removal, and the reactor geometry. The presence of additives, like Cu²⁺ and …

The Oxidation Of Dilute Alloys Of Magnesium In Aluminium, Hollis P. Leighly, A. Alam

Materials Science and Engineering Faculty Research & Creative Works

The oxide layers developed during the oxidation of aluminum alloys containing 500 and 1000 PPM of magnesium at 850K were examined with the aid of electron spectroscopy for chemical analysis. The magnesium content of the oxide layers was relatively high because of the preferential depletion of the magnesium atoms from the base alloys. Near the outer surfaces of the oxide layers, spinel (MgAl2O4) was the predominant magnesium-bearing compound. At depth, MgO was more dominant. The preferential depletion of magnesium from the alloys injected vacancies into the material. This led to the formation of defect clusters. The presence of these defect …

Oxygen Activity Dependence Of The Defect Structure Of La-Doped Batio3, M. M. Nasrallah, Harlan U. Anderson, A. K. Agarwal, B. F. Flandermeyer

Materials Science and Engineering Faculty Research & Creative Works

A model for the behavior of donor doped BaTiO₃ as a function of oxygen activity is proposed. Thermogravimetric measurements show good agreement with the proposed model. The results show that donor-doped BaTiO₃ is stoichiometric with electronic compensation of the donor at low oxygen activity, but with increasing oxygen activity, compensation becomes ionic as excess oxygen is absorbed. The possible compensation mechanisms are discussed. © 1984 Chapman and Hall Ltd.

26th Rocky Mountain Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 26th annual meeting of the Rocky Mountain Conference, co-sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy and the Rocky Mountain Chromatography Discussion Group. Held in Denver, Colorado, August 7-8, 1984.

Oxidation-Reduction Behaviour Of La-Doped Srtio3, B. F. Flandermeyer, A. K. Agarwal, Harlan U. Anderson, M. M. Nasrallah

Materials Science and Engineering Faculty Research & Creative Works

Thermogravimetric measurements as a function of oxygen activity were performed in the temperature range of 1200 to 1400° C on a series of lanthanum SrTiO₃ compounds. A model which assumes the absorption of excess oxygen in the structure which compensates the donors by formation of cationic defects is postulated. Comparison of this model with the experimental results show reasonable agreement. © 1984 Chapman and Hall Ltd.

A Study Of The Effect Of Solids, Viscosity, And Basestock On The Development Of Blade Coated Paper Properties, Steven D. Bennett

Masters Theses

A review of literature relating coating solids to coated paper properties revealed many contradictions. Little was found relating coating viscosity to coated paper property development. A statistically designed study was conducted to evaluate the importance of solids, viscosity, and basestock on the development of blade coated paper properties. Temperature was used to control coating viscosity independently of solids. Clay-latex and calcium carbonate-latex coatings were applied to groundwood containing basestocks using a Flooded Nip blade coater. Multiple linear regression models were generated for each of the coated paper properties. Solids and basestock were most important in the models for gloss, smoothness, …

Method For Reducing Macrosegregation In Alloys, Angus Hellawell

Michigan Tech Patents

Macrosegregation in metal alloy castings and other alloys having similar solidification behavior is reduced by slowly rotating a mold or the like containing the liquid alloy about an axis at an acute angle to the vertical from the time the liquid alloy is poured into the mold until substantially all of the alloy has solidified. The mold is rotated at a speed below that which produces a centrifuging effect or causes stirring or agitation of the interdendritic liquid.

Method For Preparing Organic Hyponitrites, G. David Mendenhall

Michigan Tech Patents

Tertiary organic hyponitrite usable as initiators for polymerizing ethylenically unsaturated compounds are prepared by reacting an alkali metal, alkaline earth, ammonium or substituted ammonium salt of hyponitrite, such as sodium hyponitrite, with a tertiary organic halide, such as tert-butyl chloride, in the presence of one or more weak Friedel-Crafts catalysts, such as ferric or zinc chloride, and in a solution of a neutral solvent.

An Experimental And Analytical Investigation Of The Iosipescu Shear Test For Composite Materials, Barry Stuart Spigel

Mechanical & Aerospace Engineering Theses & Dissertations

Mechanical properties of composite materials under shear loading are difficult to determine. The Iosipescu Shear test, originally proposed for metals, has in recent years been applied to composites. It has the advantages of small specimen size, simple loading and a reasonably uniform shear stress in the test section.

The purpose of this work is to study the validity of the Iosipescu test method for measuring the shear modulus and shear strength of composites. Finite element analyses indicate that optimum specimen geometry and load locations depend upon the degree of orthotropy of the composite. Test results for a quasi-isotropic graphite/epoxy laminate …

X-Ray Diffraction Studies Of Amorphous Silicon, Adel Gabra I Gouda

Archived Theses and Dissertations

No abstract provided.

Tensile Properties Of Aluminium/Polypropylene Laminates, Ashraf Adib Hanna

Archived Theses and Dissertations

No abstract provided.

Method For Molding Articles Having Non-Planar Portions From Matted Wood Flakes, Bruce A. Haataja, Tauno B. Kilpela, Anders E. Lund, James F. Hamilton

Michigan Tech Patents

An article having non-planar portions, such as a pallet having a substantially flat deck member and a plurality of hollow leg members projecting integrally from the deck member, is molded as a one-piece unit from a loosely-felted, layered mat formed from a mixture of a resinous particle board binder and flake-like wood particles. The wood flakes have an average length of about 11/4 to about 6 inches, preferably about 2 to about 3 inches, an average thickness of about 0.005 to about 0.075 inch, preferably about 0.015 to about 0.025 inch, and an average width of 3 inches or less …

Assessment Of The Accuracy Of Metal Cutting In A Microcomputer Controlled Machine, Aly Mohamed Saad Ed-Din Dars

Archived Theses and Dissertations

No abstract provided.

Defect Structure Of Mg‐Doped Lacro3 Model And Thermogravimetric Measurements, B. K. Flandermeyer, M. M. Nasrallah, A. K. Agarwal, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

Chemical stability and cation stoichiometry determine the applicability of LaCrO₃ as a high‐temperature oxide electrode. A model for the behavior of acceptor‐doped LaCrO₃, as a function of oxygen activity is proposed. The model is in agreement with experimental data on Mg‐doped LaCrO₃. Stability regimes and compensation mechanisms at various oxygen activities and temperature are presented. Copyright © 1984, Wiley Blackwell. All rights reserved

Electrogalvanizing And Drawing Of Steel Wires, Thomas Joseph O'Keefe Jr.

Masters Theses

"The effects of varying current density, temperature, Zn⁺² and licorice concentrations on the morphology of the zinc deposited on steel wire have been studied and compared. The plated wires were then drawn and evaluated in terms of required drawing energy and zinc loss during processing of up to 40% reduction in area. Scanning electron microscope and X-ray diffraction were used to evaluate the electrodeposits"--Abstract, page ii.

Preparation And Properties Of Phosphorus Oxynitride Glasses, Mary R. Reidmeyer

Masters Theses

"The preparation techniques and properties of phosphorus oxynitride glasses produced from sodium metaphosphate and nitride compounds are reported. A preliminary survey of possible nitride additives to sodium metaphosphate is presented along with an extended study of the two most promising nitrides, AIN and Mg₃N₂. Properties reported include: nitrogen content, dissolution rate in water, thermal expansion coefficient, softening point, glass transformation temperature, density, refractive index, microhardness, and infrared absorption"--Abstract, page 1.

The Role Of Boron In So32 And So43 Steels, Sunil S. Moghe

Masters Theses

"In this project study was conducted with the goal of understanding the role of boron involved in structure-toughness property relationship for SO32 and SO43 steels. For a standard heat-treatment of austenitizing (1 hr.) at 1700°F, water quenching and 1 hr. tempering at 1150°F SO32 steel (with 37 ppm B) lacked in toughness, while SO43 steel (with 2 ppm B) showed good toughness. In both steels all the boron was present in the form of "soluble boron" i.e., Fe₂₃ (B,C)₆ borocarbide. Experiments were carried out to study the effect of various heat treatment parameters on the precipitation behavior of …

Thermally Stimulated Current Studies Of Barium Titanate Capacitors, Patrick Donald Martin

Masters Theses

"Thermally stimulated polarization current (TSPC) and thermally stimulated depolarization current (TSDC) measurements were used to study sample current behavior based on the thermally activated release of trapped charges and polarization mechanisms. Samples studied included laboratory-prepared barium titanate samples (the barium to titanium ratio ranging from 0.96 to 1.04) and commercial ceramic capacitors. Both TSPC and TSDC showed the current spectra of the barium titanate samples were a function of crystal structure and the Ba/Ti ratio. The TSPC/TSDC results of the ceramic capacitors showed differences between capacitor formulations. TSPC/TSDC results also showed differences between good capacitors (physically and electrically) and capacitors …

Solid Solubility Of Sulfur In Transition Metal Oxides And Stability Of Sulfates Relevant To Roasting Processes, Zeynal Karakus

Masters Theses

"Two types of sulfur equilibration experiments were carried out in this study using either a conventional thermal gravimetric analysis (TGA) technique or a horizontal tube furnace apparatus. Samples were equilibrated with flowing SO₂-O₂ gas mixtures of either 58% SO₂ or 10% SO₂.

The types of experiments were:
1. Investigation of the extent of solid solution of sulfur in ZnO, NiO, CuO, and Fe₂O₃ over a wide range of temperature.
2. Studies of compound or solid solution formation between binary sulfate mixtures of Fe-Zn, Cu-Zn, Ni-Zn, Fe-Cr, and Cd-Zn by TGA.

The …

Ion Implantation For Improvement Of Wear Properties Of Steels, Kenneth W. Burris

Masters Theses

"Previous research on ion implantation at U.M.R. has dealt with the development of a modified Falex Lubricant Tester as a valid wear test and its use in dose curve determination. Our recent work uses Auger surface analysis and scanning electron microscopy to gather support for a model that will tie together some of the many theories proposed as to why ion-implantation improves the surface related mechanical properties of steels"--Abstract, page ii.

Dynamics Of Twinning In Natural Α-Quartz, Alexander Aning, Manfred Wuttig

Materials Science and Engineering Faculty Research & Creative Works

Finite amplitude internal friction experiments in α-quartz are described and interpreted in terms of the theory of nonlinear anelasticity. The theory predicts a linear relationship between the driving force of the excitation and the period of the auto modulation at its onset. This relation is substantiated by experiments performed with a natural α-quartz reed vibrating in flexure at resonance frequencies between 65 and 170 Hz in the temperature range of 162° and 224°C. The data suggests that Dauphiné twinning in α-quartz causes the auto modulation governed by an activation energy of 92 kJ mole. This activation energy characterizes short distance …