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Articles 1 - 19 of 19
Full-Text Articles in Engineering
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
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 …
Phase Equilibria For Iron-Rich Fe-Cu-C Alloys: 1500 To 950°C, Krishna Parameswaran, Kenneth Metz, Arthur E. Morris
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 …
21st Rocky Mountain Conference On Analytical Chemistry
21st Rocky Mountain Conference On Analytical Chemistry
Rocky Mountain Conference on Magnetic Resonance
Abstracts and meeting program from the 21st 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, July 30 - August 1, 1979.
Periodate Oxidations Of Aminoglycosides, Araxy M Deronian
Periodate Oxidations Of Aminoglycosides, Araxy M Deronian
Archived Theses and Dissertations
No abstract provided.
Curing And Flow Of Thermosetting Resins For Composite Materials Pultrusion, Howard L. Price Jr.
Curing And Flow Of Thermosetting Resins For Composite Materials Pultrusion, Howard L. Price Jr.
Mechanical & Aerospace Engineering Theses & Dissertations
Fibrous composite materials for mechanical and structural applications often are expensive due to high labor costs. One economical way of making composites is pultrusion, a manufacturing process in which resin-impregnated fibers are pulled at a constant speed through a heated die which shapes the resin-fiber mass and cures the resin. Most of the work which has been done on the process has been of an empirical nature, with limited understanding of the process principles. Most of the experience with pultrusion has been gained with polyester resins and glass fibers. Very little experience has been gained with higher performance, more costly …
Hidrometalurjide Yeni, Fathi Habashi
Hidrometalurjide Yeni, Fathi Habashi
Fathi Habashi
Turkish translation of F. Habashi, “Recent Advances in Hydrometallurgy,” Proceedings International Mineral Processing Congress, Warsaw, 1979, edited by J. Laskowski, published by Elsevier, pp. 902–935
Generation Of Horizontally Polarized Shear Waves In Ferromagnetic Materials Using Magnetostrictively Coupled Meander‐Coil Electromagnetic Transducers, R. Bruce Thompson
Generation Of Horizontally Polarized Shear Waves In Ferromagnetic Materials Using Magnetostrictively Coupled Meander‐Coil Electromagnetic Transducers, R. Bruce Thompson
R. Bruce Thompson
A new electromagnetic transducer configuration is described for generating horizontally polarized shear (SH) waves in ferromagnetic materials. The transducer consists of a meander coil and static bias magnetic field parallel to the coil elements. This configuration generates no ultrasonic waves in a nonmagnetic metal since the induced eddy currents are parallel to the bias field and the driving Lorentz forces vanish. However, the configuration provides coupling to SH waves in ferromagnetic materials through magnetostrictive effects. Experimental measurements of the variation of transduction efficiency with bias field in nickel and 4130 steel plate are presented and compared to the efficiency obtained …
An Elastic‐Wave Ellipsometer For Measurement Of Material Property Variations, R. Bruce Thompson
An Elastic‐Wave Ellipsometer For Measurement Of Material Property Variations, R. Bruce Thompson
R. Bruce Thompson
Electromagnetic‐acoustic transducers (EMAT’s) can excite and detect elastic shear waves with electronically controlled elliptical polarizations. These can be used to construct an ellipsometer for precise measurement of mechanical properties of solids, in analogy to devices presently used in optical studies. The elastic‐wave case differs from the optical case in two important ways. Longitudinal as well as transverse waves will, in general, exist, and the propagation medium, as well as the surfaces, play an important role in determining the system response. A device is described which is designed to avoid the former mode conversion effects on thin plates. The results of …
A Feasibility Analysis Of A Directly Sun-Pumped Carbon Dioxide Laser In Space, Seiichi Morimoto
A Feasibility Analysis Of A Directly Sun-Pumped Carbon Dioxide Laser In Space, Seiichi Morimoto
Dissertations and Theses
The possibility of using sunlight to pump a CW carbon dioxide laser has been analyzed. Such a laser could be of interest for such applications as space communication and power transmission. In order to optically pump CO2 using sunlight, the intense vibrational-rotational absorption bands of CO2 in the 4.3 micron spectral region would have to be utilized. The total pumping power from sunlight can be calculated from the known data of the solar spectral irradiance outside the atmosphere and the infrared absorption by carbon dioxide at 4.3 microns. The pumping power is proportional to the collector area of …
Nonlinear Anelasticity And The Martensitic Transformation, Manfred Wuttig, Tetsuro Suzuki
Nonlinear Anelasticity And The Martensitic Transformation, Manfred Wuttig, Tetsuro Suzuki
Materials Science and Engineering Faculty Research & Creative Works
Zener's model of a standard linear solid is extended to include nonlinearities characteristic of metals and alloys in the vicinity of a martensitic transformation. The equation of motion of a nonlinear anelastic solid is derived and solved using van der Pol's method. The characteristics of the solutions indicate that auto-oscillations of finite amplitude can be excited externally. It is proposed that the streaming oscillations represent the beat between the external excitation and the auto-oscillation. © 1979.
Thermally Stimulated Polarization Current Technique For Measuring The Electrical Conductivity Of Vitreous Solids, Chi-Ming Hong, D. E. Day
Thermally Stimulated Polarization Current Technique For Measuring The Electrical Conductivity Of Vitreous Solids, Chi-Ming Hong, D. E. Day
Materials Science and Engineering Faculty Research & Creative Works
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 dc conductivity over the range 10−15-10−7 (Ω cm)−1 and is especially suited for conductivities <10−12 (Ω cm)−1. Polarization at the electrodes is easily detected and avoided.
Phase Equilibria In Aqueous Magnesium Chloride, Sulfate, Chromate And Phosphate Systems, Ladawan Urwongse
Phase Equilibria In Aqueous Magnesium Chloride, Sulfate, Chromate And Phosphate Systems, Ladawan Urwongse
Doctoral Dissertations
"In the first part of the present study, which is presented in Paper I, solubility of MgO in aqueous HCl solutions at 23° ± 3°C was measured and combined with analyses of neat magnesium oxychloride cements to construct an equilibrium phase diagram for the system MgO-MgCl2-H2O. Invariant liquids in equilibrium with Mg(OH)2 and 5Mg(OH)2·MgCl2·8H2O (5.1.8), with 5·1·8 and 3Mg(OH)2·MgCl2·8H2O (3·1·8), and with 3·1·8 and MgCl2·6H2O were located at 0.8 ± 0.2 MgO, 17.0 ±0.5 MgCl2; at 1.0 …
Development Of Impervious Low Thermal Expansion Petalite Bodies, Suchinda Chotipanich
Development Of Impervious Low Thermal Expansion Petalite Bodies, Suchinda Chotipanich
Masters Theses
"Impervious petalite bodies were formulated from petalite, lithium aluminosilicate frit and kaolin. Thermal expansion coefficients for selected bodies were less than 2 x 10⁻⁶ /°C(20 - 600 °C). Mineralogy and the reactions in systems containing petalite, lithium aluminosilicate frit and kaolin were observed. Silica-poor high quartz solid solution was found to be the reaction product formed from the reaction between frit and kaolin before conversion to ß-spodumene solid solution at higher temperatures. The crystallization of the ß-spodumene solid solution phases in this system did not occur at the same temperature resulting in variation in the size of the crystallites. The …
Processing Of Copper Refinery Anode Slimes, Shrirang Anant Kulkarni
Processing Of Copper Refinery Anode Slimes, Shrirang Anant Kulkarni
Masters Theses
"A study of commercial copper refinery anode slimes has been conducted to evaluate the separation of valuable metals contained in the slimes. The slimes contain substantial quantities of Ag, Sn, Au, Pb, and Cu. The values were present principally as AgCl, SnO2, Au, PbSO4, Cu and CuSO4.
A Roast-Leach-Roast-Leach (RLRL) technique solubilized up to 91 pct of the Ag and 99 pct of the Cu from raw slimes.
The Pb-Sn separation was investigated using the following hydrometallurgical techniques: 1) DETA (diethylene triamine) leaching; 2) NaOH leaching; 3) (NH4)2CO3 leaching; …
Pelletizing Of A Lead Sinter Machine Feed, Hung-Yang Tsai
Pelletizing Of A Lead Sinter Machine Feed, Hung-Yang Tsai
Masters Theses
"A typical lead sinter machine feed can be pelletized in a drum pelletizer using tap water as a binding liquid. The green pellets produced have return sinter as cores, and an outer layer of new material and fluxes. The moisture content of the pellets produced is about 5%. The pelletizing procedure developed used raw materials from the Amax Lead Smelter, with only a minor amount of feed preparation. The importance of proper moisture control, use of binders, method of adding moisture, speed of pelletizing drum, etc. were investigated. The stability of pellets under extreme storage conditions was also determined"--page ii.
A Metallurgical Evaluation Of The Mi Vida Prospect: A Mixed Copper Sulfide-Carbonate Ore Body, Sells, Pima County, Arizona, Kevin Michael Kenney
A Metallurgical Evaluation Of The Mi Vida Prospect: A Mixed Copper Sulfide-Carbonate Ore Body, Sells, Pima County, Arizona, Kevin Michael Kenney
Masters Theses
"A copper-prospect in south-central Arizona has been evaluated on a metallurgical basis. Primary chalcocite and secondary covellite, plus the copper oxides malachite and brochantite, constitute the economic mineralization. The deposit outcrops as a steeply dipping (70°SW), intensely brecciated, copper-bearing quartz vein with discontinuous lenticular ore shoots.
Acid leaching techniques alone and in conjunction with froth flotation utilizing four copper oxide specific collectors were used to evaluate the amenability of this ore to processing. Direct acid leaching was examined and found to be ineffective. Removal of the chalcocite by froth flotation with xanthate was easy and gave better results to subsequent …
Molybdenum Stability In Coal Slags At 1400⁰C: Corrosion Properties For Mhd Electrode Applications., Kenton Brian Wright
Molybdenum Stability In Coal Slags At 1400⁰C: Corrosion Properties For Mhd Electrode Applications., Kenton Brian Wright
Masters Theses
"Molten coal slag corrosion studies conducted on molybdenum at 1400°C used static and stirred slag experiments and electrical current experiments to parallel electrode conditions of slagging duct MHD generators. Crucibles containing molybdenum and slag were exposed to combustion-type gases in a tube furnace. Carbon monoxide-carbon dioxide gas mixtures controlled oxygen partial pressures at selected values between 10-11 and 10-3 atm. Metallograph and microprobe examination of polished sample sections defined corrosion characteristics.
At 1400°C, molybdenum metal is stable below 10-9 atm oxygen pressure. Molybdenum dioxide is stable at higher pressure, but volatile molybdenum trioxides prevent formation of stable …
Boehmite-Bonded High-Alumina Refractories, Gerhard H. Schiroky
Boehmite-Bonded High-Alumina Refractories, Gerhard H. Schiroky
Masters Theses
"High-alumina refractories (99+ % Al₂O₃) were produced by pressing a mixture of 70% tabular alumina and 30% reactive alumina and autoclaving in saturated steam at 1.4 MPa (200 psia)/194 °C to 3.4 MPa (500 psia)/242 °C for 12 to 96 h. Autoclaving converted the reactive alumina to boehmite which acted as the bond phase. At room temperature the MOR ranged up to 37 MPa depending upon boehmite content. The hot-MOR decreased steadily with increasing temperature, but was still 8 MPa at 1400 °C which exceeds that of comparable cement-bonded or conventionally fired high-alumina refractories. The estimated autoclaving costs are lower …
Recovery Of Lead From Lead Smelter Mattes, Cheng-Ping Chang
Recovery Of Lead From Lead Smelter Mattes, Cheng-Ping Chang
Masters Theses
"A by-product of lead smelting is a matte which consists mostly of lead and copper sulfides. Experiments were conducted to determine the feasibility of removing lead from molten matte by adding iron as a reducing agent. The effectiveness of iron at 1000 and 1100°C was a function of matte composition, but not of temperature except near iron saturation. The lead content of matte could be decreased to as low as 9.0 to 11.6 wt pct (2.3 to 3.0 at. pct) at 1000°C, depending on composition. The effect of oxygen in the matte on lead recovery from iron-saturated mattes was also …