Engineering Commons^™

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 …

A Management Training Model For Engineers In Saudi Arabia, Majid Al-Kassabi

Doctoral Dissertations

“Great economic growth has occurred in Saudi Arabia in the last decade creating overwhelming demands for professionally trained people. The emerging Saudi professionals are mostly engineers who have been put in managerial positions without the benefit of managerial training.

Objectives of this research were 1) To identify the skills needed by engineers to become managers; 2) To identify problems and constraints inherent in management training programs; 3) To identify the impact of a model training program on the individual; and 4) The impact of a model training program on the firm.

A training program was implemented using an experimental group …

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 …}

Numerical Simulation Of Mixing Processes In Two-Dimensional Channel Flows, Milan Karel Straka

Doctoral Dissertations

"Recently, considerable interest has arisen in the numerical simulation of laminar and turbulent transport phenomena. More knowledge in this field is needed to improve predictions of heat and mass transfer processes in a variety of technical fields.

In this work a new computationally efficient transport model is developed. It consists of partially parabolized time-dependent equations of motion, continuity, and concentration of nonconservative species. Pertinent equations are solved numerically for both laminar and turbulent flow.

Results of calculations of laminar flow in the entry region of a parallel-plate channel agree well with the work of other authors. For turbulent flows, the …

Kinetics And Reactor Design In The Pyrolysis Of Tar Sands, Charles Arthur Lechner

Doctoral Dissertations

"Data from the thermal decomposition of bitumen from Utah tar sands was obtained and analysed with both isothermal and non-isothermal chemical reaction models. The use of a power rate law to describe the complex kinetics of pyrolysis gave agreement with the experimental data that was approximate, but adequate for design purposes. The results indicated a reaction rate that was second order in bitumen content, with an activation energy of about 17 to 20 kcal/gmol.

Data for the boiling point distribution of the products was consistent with a change of mechanism from vaporization to pyrolysis as the samples are heated. Higher …