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A Thermodynamic Study Of The Germanium Sulphides, Satya Prakash Jain

Masters Theses

"The experimental determination of some of the thermodynamic properties of germanium sulphide phases was conducted by a hydrogen reduction technique. The equilibrium H₂S/H₂ ratios were determined as a function of temperature for the two phase equilibria GeS₂-GeS and GeS-Ge. A Tutwiler analysis technique was used to analyze the equilibrated gas mixture for hydrogen sulphide content.

A detailed description is given for the process and the apparatus used in performing the experiments for equilibration of H₂S/H₂ gas mixture. The methods used for the preparation of germanium sulphide phases are also discussed.

The investigation …

Preparation Of Casting Slips Containing Ferrous Powders And Alginates, Robert Eugene Newcomer

Masters Theses

"The preparation of casting slips containing ferrous powders dispersed by alginates was studied and an attempt was made to determine the mechanism by which suspension was attained. The colloidal aspects of preparing ceramic casting slips are discussed and an analogy is drawn to preparation of metallic slips suspended by alginates.

Sodium and ammonium alginates were used to suspend stainless steel and iron powders. The effect of NaOH, HC1, and various phosphate additions on the properties of slips and algin solutions was considered.

It was found that colloidal concepts can not be applied to explain observed behavior in the system studied. …

High Temperature Oxidation Of Nickel, Virgil R. Friebel

Masters Theses

"Using a sensitive volumetric technique, a study was made of the kinetics of oxidation of nickel at 1200° C. and 1300° C. Three purities of nickel were used for the investigation which was limited to the initial three hours of reaction.

The rate of oxidation of nickel followed the parabolic rate law after an initial period of deviation which lasted up to 40 minutes. No direct correlation was found between the oxide thickness and the end of the period of deviation from the parabolic rate law.

The purity of the nickel was found to have a marked effect on the …

The Effect Of The Rare Earth Elements On The Hot Workability Of Ingot Iron, L. A. Neumeier

Masters Theses

"The effect of mischmetal and rare earth oxides on the hot workability of ingot iron in the hot-short region was studied. Thirteen heats were melted in air in a basic-lined induction furnace. All heats were thoroughly deoxidized with aluminum prior to the rare earth additions. Mischmetal was added in amounts of 0.1, 0.3 and 0.5 per cent. Rare earth oxides were added in amounts of 0.1 and 0.2 per cent. Temperatures were maintained at approximately 2900°F and holding intervals between mischmetal additions and pouring at two minutes. Bars were hot rolled and swaged for hot twisting in the hot-short region. …

A Dissolution Rate Study In Hydrofluoric Acid Of Titanium And The Alpha Solid Solutions Of Oxygen In Titanium, John L. Ratliff

Masters Theses

"The dissolution mechanism of titanium in hydrofluoric acid was studied by collecting the hydrogen evolved during the dissolution reaction. A concentration range of 0.05 N to 0.50 N and a temperature range of 15°C to 45°C were employed for the determination. Values of the reaction order and energy of activation were determined for both pure titanium and the alpha solid solutions of oxygen in titanium and found to be the same within experimental limits. This indicated that the reaction giving rise to hydrogen evolution on the surfaces of both pure titanium and the TiO_x alloys was the same. The …

Imperfections In A Silicon Crystal Studied By The X-Ray And Density Method, Pierre Borgeaud

Masters Theses

"The study of imperfections in several crystals of silicon was conducted by the x-ray and density method"--Abstract, page 2.

A Thermodynamic Study Of The System Pbo-Pbs, John P. Hager

Masters Theses

"An experimental investigation was conducted in order to determine the thermodynamic and kinetic behavior of the system PbO-PbS.

The thermodynamic behavior of the system PbO-PbS was studied by measuring the P_SO₂ in argon-SO₂ mixtures equilibrated with various PbO-PbS mixtures in a recirculating-type equilibrium apparatus, and analyzing the condensed phases by means of X-ray diffraction.

The effect of temperature and PbO/PbS ratio on the rate of SO₂ evolution was investigated in order to determine the reaction mechanisms involved in the approach to equilibrium.

A sodium hydroxide, hydrogen peroxide titration technique was employed in the analysis of SO_{2 …}

A Thermodynamic Study Of Germanium Sulfides, Sham Lal Malhotra

Masters Theses

"The vapour pressure of germanium monosulfide (liquid) was determined by a boiling point method. An expression for the vapour pressure as a function of temperature was obtained and the heat of vapourization calculated. Using the heat of sublimation data obtained by other investigators, the heat of fusion was calculated.

The thermodynamic properties, change of standard free energy (Δ F°) heat content (Δ H°) and entropy (Δ S°); of germanium disulfide were determined by using an indirect method. The equilibrium H₂S/H₂O ratios are determined for the reaction:

GeS₂ (s) + 2H₂O(g) = GeO_{2 …}

The Constitution Of Magnesium-Rich Magnesium-Zirconium Alloys, Kenneth Allen Fowler

Masters Theses

"The magnesium-zirconium system has been studied to 0.8 per cent zirconium which represents the limit of solubility of zirconium in liquid magnesium at 950°C. Alloys have been prepared by two methods of alloy additions, and the results compared. Microstructural studies have been made of the alloys in the cast, extruded, and heat-treated conditions. The limit of solid solubility has been determined on the basis of resistivity and temperature coefficient of resistivity measurements, as well as by metallographic examination, with good agreement. A secondary structure resulting from precipitation of a second phase within cored regions of the alloy has been studied …

Segregation Method As Possible Process To Beneficiate Oxidized Lead Ores, Jose Molfino Tomasio

Masters Theses

"In this investigation it has been demonstrated that the Segregation Process has merit for treating oxidized lead ores.

The process comprises heating the crushed ore with salt and coal at about 750° C. to produce metallic lead attached to the carbon particles, which then is recovered by conventional flotation methods.

The quantities of sodium chloride and coal required for the best segregation of lead obtained in this work was 1.0 percent of coal and 1.0 percent of salt by weight.

Good segregation was obtained by using salt and coal as fine as 65 or 48 mesh. Segregation varied with the …