Engineering Commons^™

Recycling Of Aluminium, Nayera Abdel Mossawer Shahin

Archived Theses and Dissertations

No abstract provided.

Characteristics Of The Background Emission Spectrum From A Miniature Inductively-Coupled Plasma, Richard N. Savage, G. M. Hieftje

Materials Engineering

The spectral characteristics of the background radiation emitted by a miniature inductively-coupled plasma (i.c.p.) are carefully examined and methods for reducing undesirable features discussed. The complex nature of the background emission spectrum for the mini-i.c.p. indicates that careful line selection criteria and background correction procedures should be employed. Extending the torch coolant tube to the bottom of the region being observed in the plasma proved to be the most effective method for reducing undesirable spectral band features. Acute changes in background emission levels with r.f. power and nebulizer gas flow rates emphasize the need for careful control of these parameters …

Model For Evaporation Of A Grain‐Boundary Phase, Manfred Wuttig, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The surface profile which develops in the vicinity of a grain boundary precipitate in the course of evaporation is calculated. It is shown that the presence of the grain boundary precipitate affects the profile significantly if the product of the width of the grain boundary precipitate and the ratio of the evaporation rates of the unperturbed surface and the grain boundary precipitate is larger than one. Copyright © 1981, Wiley Blackwell. All rights reserved

Structure And Properties Of Neodymium Chromite, David Charles Hitchcock

Masters Theses

"Pure, accepton and Al doped NdCrO₃ were prepared by an organo-metallic process.

The crystal structure and lattice parameters were determined by x-ray diffraction. All compositions were orthorhombic Pbnm.

Pellets were pressed from powders of each composition and sintered to high density in a reducing atmosphere. When a small amount of Fe was substituted for Cr, the powder could be sintered in air.

Electrical conductivity for acceptor doped NdCrO₃ varied from about 1 (ohm cm)^-1 at room temperature to about 10 (ohm cm)^-1 at 900°C, about two orders of magnitude higher than the electrical conductivity of the …

Plastic Deformation And Fracture Of Two-Phase Alloys Under Compressive Loading, Abla Mahmoud Zayed

Archived Theses and Dissertations

No abstract provided.

Autooscillations In Zinc, Manfred Wuttig, Alex Aning, Tetsuro Suzuki

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Slip Dislocation Formation During Continuous Wave Laser Annealing Of Silicon, Helmut Baumgart

Electrical & Computer Engineering Faculty Publications

High-voltage electron microscopy (HVEM) has been used for the investigation of the defect structure in cw laser-annealed silicon. We report for the first time a (HVEM) analysis of the formation processes involved in the nucleation and glide of slip dislocations during epitaxial regrowth by cw laser annealing of ion-implantation damaged silicon layers. Based on the combined optical and HVEM observations a model of the dislocation generation and glide processes is presented.

The Inert Gas Effect On The Rate Of Evaporation Of Zinc And Cadmium, P. C.S. Wu, Thomas J. O'Keefe, Fred Kisslinger

Materials Science and Engineering Faculty Research & Creative Works

An experimental study has been made to investigate the effect of argon and helium on the rate of evaporation of zinc and cadmium under one atmosphere pressure at temperatures ranging from 500 to 850°C. The experimental results were compared with the maximum rates calculated using the effusion formula as well as with values obtained using two different types of equations based on kinetic theory, diffusion theory, and empirical data. Equations have been derived for expressing the rate of evaporation of zinc and cadmium in both argon and helium as functions of temperature of the liquid zinc and cadmium. It was …

Magnetic Properties Of Iron Rich Calcium Silicate Glasses And Their Aluminium Composites, Sylvia Menassa

Archived Theses and Dissertations

No abstract provided.

Kentucky Building Code 1980, Kentucky Library Research Collections

Research Collections

Kentucky Building Code (KBC) is the official referenced standards to ensure that a building is constructed in accordance with the approved construction documents.

22nd Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Abstracts and meeting program from the 22nd annual meeting of the Rocky Mountain Conference on Analytical Chemistry, 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 10-14, 1980.

Evaluation Of Zinc Sulphate Electrolytes Containing Certain Impurities And Additives By Cyclic Voltammetry, D. R. Fosnacht, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

The polarization characteristics of acid zinc sulphate electrolytes containing various amounts of germanium and cobalt were examined by cyclic voltammetry. The effects of zinc and acid concentration, temperature, and surface preparation were also investigated. Small concentrations of impurities are shown to cause measurable changes in polarization behavior. Levels as low as 0.02 mgl-1 Ge and 0.1 mgl-1 Co can be detected using this technique. The actual mechanism of impurity behavior is more clearly delineated using this technique and evaluation of the data from these tests indicate that germanium and cobalt form local galvanic cells. The results of these short-term tests …

Mechanical Properties And Microstructure Examinations Of Aluminium-Steel Composites, Mervet Ibrahim Shenouda

Archived Theses and Dissertations

No abstract provided.

Discussion Of "Gas Composition, Temperature, And Pressure Measurements In A Lead Blast Furnace", Arthur E. Morris, John R. Knoepke

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Solidification Of Aluminium Alloy Ingots, Hassan Abdel Kader Abdel Salam

Archived Theses and Dissertations

No abstract provided.

The Use Of Thermal Analysis In The Identification And Characterization Of Fibers Of Forensic Interest, Ronald J. Coffey

All-Inclusive List of Electronic Theses and Dissertations

This study investigates the use of thermal analysis for the identification and characterization of fibers for forensic purposes. Fibers such as polyesters, polyacrylics, polypropylenes and nylon were investigated by Differential Thermal Analysis (D.T.A.) and Thermogravimetric Analysis (T.G.A.) to see if their resulting thermograms were characteristic of each fiber. Also, infrared analysis was performed on each fiber. In addition, such factors as heating rate and sample size along with fiber blends were studied as to their effect on thermograms. As a result of this study several important conclusions may be drawn. Although it was found that for the most part D.T.A. …

The Significance Of Peel Stresses In Cyclic Debonding, Richard A. Everett Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

One of the possible failure modes in adhesively bonded joints is cyclic debonding -- progressive separation of the adherends by cyclic failure of the adhesive bond. In this study cyclic debonding in an adhesively bonded crack-lap shear specimen has been investigated by means of a linear elastic finite-element analysis and a series of constant­ amplitude axial fatigue tests. The primary purpose of this study was to test the hypothesis that cyclic debonding is due largely to tensile peel stresses in the adhesive.

The results of this study have indicated that not all of the tensile peel stresses in the adhesive …

Autooscillations And Nonlinear Anelasticity, Manfred Wuttig, Tetsuro Suzuki

Materials Science and Engineering Faculty Research & Creative Works

In conclusion it can be stated that a novel phenomenon, a mechanical auto oscillation, has been described theoretically and shown to exist experimentally. These auto oscillations occur when a nonlinear anelastic solid is forced into large amplitude oscillations in the vicinity of a martensitic transformation. They manifest themselves as a low frequency auto modulation of the a martensitic transformation. They manifest themselves as low frequency auto modulation of the forced vibration of such a solid. © 1980.

Thermally Stimulated Polarization And Depolarization Current (Tspc/Tsdc) In Glass, Chi-Ming Hong

Doctoral Dissertations

"The feasibility of studying ionic motion in glass using thermally stimulated polarization (TSPC)/depolarization current (TSDC) techniques was investigated with 4Na₂O·96SiO₂ and 30PbO·70SiO₂ (mol%) glasses. The TSDC peaks in these glasses were dependent on glass composition and attributed to bulk polarization. The high temperature background TSPC is shown to be due to dc conductivity, whereas the TSPC/TSDC peaks in the 4Na₂O glass are attributed to shorter range Na⁺ motion.

The electrical conductivity of glasses determined by TSPC agrees well with that measured by conventional ac or dc techniques. The TSPC technique is a rapid and easy method of measuring the …

Properties Of High Alumina Refractories After Exposure To Steam/H₂ Atmospheres, David W. Lang

Masters Theses

"Selected properties of a dense fired alumina, a phosphate-bonded ramming mix, and a calcium aluminate cement-bonded castable were evaluated after exposure at 260°C and 538°C to steam/H₂ atmospheres (2.58, 5.17, and 6.89) MPa. Chemical reactions in the refractories were determined by x-ray diffraction, DTA/TGA, and changes in physical properties. The modulus of rupture (MOR) of the dense alumina decreased with increasing steam pressure and degree of saturation. The calcium aluminate cement phases in the castable were most reactive in 260°C steam and formed several hydrated phases which generally resulted in a higher MOR. The MOR of the ramming mix …

Calcium Migration In Dense Alumina Aged In Water And Physiological Media, Heidi H. Osterholm

Masters Theses

"The flexural strength and relative Ca concentration at the external surface were measured for a dense alumina aged in deionized water and Ringer's solution at 40⁰C for 60 weeks and at 80⁰C for 45 weeks. Changes in the Ca concentration at the external surface and flexural strength during aging were attributed to the dissolution of the calcium impurity believed to be present in a glass phase of unknown composition. Auger electron spectroscopy was used to investigate the relative concentration of the calcium impurity at the external and fracture surfaces of a dense alumina after in vivo exposure for 6, 12 …

Microwave Sintering Of Batio₃ Ceramics, Kurt Duane Humphrey

Masters Theses

"Barium titanate and BaTiO₃-based multilayer capacitors were sintered in a commercial microwave oven. The oven was equipped with a 2.45 GHz continuous-wave magnetron with a maximum power output of 650 watts.

Microwave-absorbing setters made of SiC were used to offset thermal losses from the samples and allow sintering temperatures (>1325°C) to be achieved. Pure samples were pressed from commercial BaTiO₃ powder and microwave sintered to about 90% of theoretical density. Multilayer capacitors were obtained from commercial manufacturers and used in all sintering experiments. A comparison between microwave sintered material and identical samples sintered in a conventional electric furnace revealed …

The System Mgo‐Mgcl2‐H2o At 23°C, Ladawan Urwongse, Charles A. Sorrell

Materials Science and Engineering Faculty Research & Creative Works

Solubilities of MgO in aqueous HC1 solutions at 23°±3°C were measured and combined with analyses of neat magnesium oxychloride cements, cured in sealed containers, to construct an equilibrium phase diagram for the system MgO‐MgCl2‐H₂O. Specific gravities and acidities of solutions saturated with MgO and relative humidities of vapor phases over sealed samples were measured and combined with XRD data to define the compositions in equilibrium with two crystalline phases. Studies of relative reaction rates indicated that the 5–1–8 phase crystallizes more rapidly than the 3·1·8 phase and that cements near the 3·1·8 composition react rapidly with atmospheric CO …

Phase Relations In Magnesium Oxysulfate Cements, Ladawan Urwongse, Charles A. Sorrell

Materials Science and Engineering Faculty Research & Creative Works

Solubilities of MgO in H₂SO₄ solutions were measured and X‐ray analyses of over 100 neat cement samples were used to construct an isothermal phase diagram for the system MgO‐H₂SO₄‐H₂O at 23°±3°C. The phases MgO, Mg(OH)₂, 3Mg(OH)₂ MgSO₄·8H₂O (3·1·8), MgSO₄·7H₂O, MgSO₄·6H₂O, and MgSO₄·H₂O were stable at 23°C. The phases Mg(OH)₂· MgSO₄·5H₂O (1·1·5) and MgSO₄·4H₂O were observed but are considered to be metastable, resulting …

The Effect Of Shielded Metal Arc Welding Process Variables On Delta Ferrite Control In Austenitic Stainless Steel Weld Metal, Ralph Eldon Long

Dissertations and Theses @ UNI

This study was to determine the effects of shielded metal arc welding on delta ferrite in austenitic stainless steel weld metal. The two objectives of the study were to determine: (a) what variables of the SMAW process affect the delta ferrite content or Ferrite Number of austenitic stainless steel weld metal, and (b) to what extent the Ferrite Number is affected by SMAW variables.

The research design was experimental with data collected from mechanically produced weld metal using a magnetic instrument calibrated in Ferrite Numbers (FN). The electrode alloys tested were 308, 308L, 316L and 347. The sizes of electrodes …

Materials Testing And Consultancy For The Tanzanian Industry, H. Fallenbach

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Investigation Of Corrosion And Weathering Phenomena In Tropical Marine Environment, K. P. Stormer

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Computer Assisted Instruction Wood Identification Program, Dave Moyer

Graduate Research Papers

In the development of wood identification skills, certain factors are important. These include: mastery of both terminology and technique, repetitive practice experiences, and an individualized approach in both guidance and feedback to the learner. The use of the computer as a programmed instructional aid provides for an individualized approach to learning, simulated teacher-student interaction, and feedback and reinforcement to stimulate learning. The problem of this activity is to develop a computer assisted instructional program to enable the learning of techniques for identifying selected samples of hardwoods.

Phase Equilibria For Iron-Rich Fe-Cu-C Alloys: 1500 To 950°C, Krishna Parameswaran, Kenneth Metz, Arthur E. Morris

Materials Science and Engineering Faculty Research & Creative Works

Isothermal sections for the iron rich corner of the Fe-Cu-C system have been constructed at 1500, 1450, 1200, 1172, 1150, 1000, and 950°C. A ternary invariant point exists at 1172°C where an iron rich liquid, a copper rich liquid, austenite, and graphite coexist. The iron rich liquid contains 3.7 wt pct Cu and 4.0 wt pct C. The austenite contains 7.3 pct Cu and 1.6 pct C. The copper rich liquid contains 2.4 pct Fe, and apparently very little carbon. The diagrams are used to explain the phenomena of "inverse segregation" that occurs during the solidification of iron rich Fe-Cu-C …

An Experimental Study Of The Reactions Of Excited Neon Atoms In Pure Afterglow Plasmas Using Resonance Absorption Spectrometry, R. A. Sierra, J. Beverley Clark, A. J. Cunningham

Materials Science and Engineering Faculty Research & Creative Works

Resonance absorption spectrometry has been applied in a room temperature study of the reactions of excited neon atoms in pure afterglow plasmas. The pressure range 10-500 Torr was investigated. Lorentz broadened linewidths calculated using a simple classical interruption theory allowed fractional absorption signals as large as 98% to be analyzed and absolute excited-state concentrations to be determined. The first absorption studies of the decay of 1P1 excited atoms in neon afterglows are reported. Analysis of the decay profiles of the 3P2, 3P0 and 1P1 excited states allowed quenching rate coefficients for each state to be determined and the role of …