Engineering Commons^™

Energy Considerations In Stock Preparation Refining Modified By Recycling, Rajendra D. Deshpande

Masters Theses

Experiments were conducted to study the effect of refining on virgin fibers as well as on recycled fibers. Interaction effects of recycling and type of treatment of virgin fibers on characteristics of secondary fiber were studied. A significant reduction in drainage properties of the furnish for both hardwood and softwood pulps were observed. This reduction in properties was found proportional to the amount of refining. It is necessary to achieve required strength properties at higher freeness values, if fibers are to be recycled. This can be done by improvement in uniformity or homogeneity of refining and by gentler and less …

Effects Of Coefficient Errors On The Performance Predictions Of A Typical Fighter At Medium Altitude, John D. Cloyd

Masters Theses

Performance prediction is one of the primary uses of wind tunnel data. Uncertainties in the tunnel data are therefore directly related to errors in performance predictions. The objective of this study was to examine the effects of aerodynamic coefficient errors on the point performance predictions for a typical fighter at medium altitude and subsonic velocity. The point performance parameters were formulated as functions of the aerodynamic coefficients. A computer program was written to calculate the selected performance parameters for 121 cases, each case representing a different combination of coefficient errors. The result was the correlation of the percentage error in …

The Relationship Of Pore Volume And Pore Size Distribution To The Development Of Gloss And Scattering Coefficient, John A. Cook

Masters Theses

This study describes in a quantitative manner the relationships between coating structure and optical properties. Gloss, scattering coefficient and void volume were measured after applying different blends of polystyrene spheres to mylar film. Each coating was modeled using large spherical particles of the same size ratios to measure pore size distribution. The coating structure followed well with theoretical packing characteristics of spheres. Optical properties were related to changes in coating structure. Scattering coefficient and gloss correlated better with pore size distribution than particle size. Gloss increased when total void volume was reduced, while the scattering coefficient decreased.

The Evaluation Of Efficiency Determination Of Screening Device (Pressure Screen) By Image Analysis, Rajeev Kumar Goyal

Masters Theses

The Omnicon 3600 image analyzer was used in the study of the evaluation of screening efficiency determination methods. It is very difficult to get a good over all contaminant mass balance across a pressure screen because of the factors involved such as sampling around a screen, time spent in collecting the samples, and possible size reduction of the contaminants by the pump and screen. The image analyzer gives the contaminant analysis in terms of the total number of particles, total area of all the particles, the mean particle area and a histogram of the contaminant size distribution. The histogram data …

Glass Formation And Properties In The Sm₂O₃·Al₂O₃·Sio₂ System, Erik M. Erbe

Masters Theses

"The purpose of this investigation was to develop a samarium containing aluminosilicate glass with properties suitable for use in the treatment of rheumatoid arthritis. Microspheres made from these compositions would be neutron activated to produce radioactive Sm-153 which has beta-particle energies suitable for treating rheumatoid arthritis as well as appropriate gamma-ray emission for nuclear imaging. The properties of Sm₂O₃ · AI₂O₃ · SiO₂ glasses containing 10 to 25 mole% Sm₂O₃ were evaluated as a function of composition. The density, refractive index, thermal expansion coefficient, and microhardness increased with increasing Sm …

An Experimental Study Of Adsorption And Variable Temperature Desorption Of Ethanol-Water, Propane-Propylene And Hydrogen Sulfide-Carbon Dioxide-Propane, Suvit Kulvaranon

Masters Theses

"An ideal adsorption only removes the desired components. Many times one or more other components are also adsorbed. If two or more components are adsorbed, an adsorption separation may not be satisfactory or may require additional separation procedures, even though one is highly preferentially adsorbed. In such cases it may be possible to get additional separation during the desorption stage by using variable temperature desorption.

To study such problems, two experimental apparatus were set up, one for adsorption for ethanol and water mixtures on activated carbon and silicalite, the other for propane-propylene mixtures, and hydrogen sulfide-carbon dioxide-propane mixtures both on …

Paraffin Deposition Property Measurement Using Differential Scanning Calorimetry, Kevin Lynn Thornsberry

Masters Theses

Differential Scanning Calorimetry (DSC) has been used in past studies to identify the cloud points of diesel fuels, lube oils, jet fuels etc. and it has been assumed that its application extends to all paraffinic hydrocarbons. To verify this and to investigate the possible application of Differential Scanning Calorimetry to the production phase of the petroleum industry, the onset of wax crystallization is compared with ASTM cloud point for a number of paraffinic mixtures including a variety of crude oils. Results show cloud point can be determined for crudes using DSC. Additionally, wax content can be found on a known …

The Effect Of Phosphate Additives On Alumina, Alumina-Calcia, Alumina-Silica Refractory Castable Systems, Sukendro Widjaja

Masters Theses

The effects of the addition of phosphate chemicals to Al₂O₃, Al₂O₃-CaO, and Al₂O₃-SiO₂ systems have been studied concentrating on selected dry and fired properties. The various refractories evaluated were formulated from all alumina aggregate systems based on 1) a mix of tabular and calcined fine aluminas, 2) a combination of calcium aluminate cement bonded-tabular and calcined fine aluminas, and 3) an alumina aggregate-silica fume mixture. Specimens were vibration-cast, dried at 110°C and fired at 1450°C. It was found that each system has different property responses to different …

Processing And Characterization Of Ceramic Fiber Reinforced Porous Matrix Composites, Wen-Chiang Tu

Masters Theses

"The development of ceramic fiber reinforced ceramic matrix composites has been shown to be a promising approach for high toughness ceramic materials. The purpose of this work was to develop a new ceramic matrix composite(CMC) system based on a porous mullitic matrix reinforced with ceramic fibers. Unidirectional alligned fiber reinforced mullitic matrix composites were fabricated by a filament winding process. Prepregs were laminated and thermal processed in air. SEM fractographs of the composites were characterized and related to the observed load-deflection behaviors under 3-point flexure. The fracture surface expositions changed from extensive fiber tear-out to limited fiber pull-out as the …

Reductive Stripping Of Iron(Iii) From Di(2-Ethylhexyl) Phosphoric Acid, Byron G. Belew

Masters Theses

"Unwanted impurities, present in raw materials, are often coextracted along with desired constituents during leaching. If left unchecked, impurity levels may increase in hydrometallurgical process streams until their presence has deleterious effects upon subsequent unit processes. Due to its abundance and ease of extraction, the presence of ferric iron in solvent extraction circuits has always been a problem. The technique proposed herein constitutes a novel approach to remove iron from zinc hydrometallurgical circuits; but the principles employed may find a variety of applications.

This research investigated the reduction and stripping of ferric iron from di(2-ethylhexyl) phosphoric acid into a …

Packaging Engineering Education Qualitative Need Assessment, M. Douglas Sachs

Masters Theses

"Packaging engineering is an interdisciplinary field which has no formal degree program to support it. While there arc packaging engineers in industry, there are no packaging engineering degrees presently being offered by our nation's colleges and universities. In order to lay a foundation upon which a degree program could be based, this thesis has investigated the needs of packaging engineering education by seeking the input of the packaging industry. This qualitative comparison has been quantified, resulting in a list of prioritized classes and topics upon which a degree program could be based"--Abstract, page ii.

Behavior Of Reinforced Loess Specimens Under Triaxial Load, Mohammad Taghi Izadi

Masters Theses

"Effects of reinforcement on shear strength of a loessial (silty) soil arc studied. Unconsolidated undrained triaxial tests are performed on unreinforced and fabric reinforced soil specimens. Analyses of the test results showed that in general the shear strength of remolded loess specimens were improved substantially and increase in the shear strength was directly related to reinforcement spacing.

The mechanism of soil-reinforcement interaction and several existing analytical models are described. A modified analytical model based on enhanced confining theory is developed. This model can be used in assessing the effects of the reinforcement on shear strength of triaxial specimens. Comparison of …

Sessile Drop Studies Of Aluminum On Sapphire, Ke Wen K. Li

Masters Theses

A sessile drop technique employing a drop placement method has been used to investigate the wetting behavior and interfacial phenomena between aluminum and single crystal α-alumina. Measurements were made under a flowing mixture of H₂ and He atomsphere from 1200°C to 1600°C. Acute contact angles decreased continuously in all cases during the 8-hour experimental time. Neither the oxygen partial pressure of the flowing gas nor the orientation of the single crystal alumina substrate affected the contact angles, but the shapes of crystals grown at the substrate-metal interfaces were dependent on the orientation of the substrate surface to some extent. …

Fabrication And Mechanical Property Analysis Of A Transparent, Glass Fiber Reinforced Polymer Matrix Composite, James R. Olson

Masters Theses

"A "transparent” composite was produced by reinforcing poly(methyl methacrylate) (PMMA) with unidirectional borosilicate glass fibers. Composites with 40 volume percent fiber had a modulus of rupture of 600 MPa which is six times greater than that of pure PMMA. Young's modulus for the same composite was 18 MPA which is nine times greater than the 2 MPa measured for pure PMMA. Work of fracture was 110 kJ/m² or more than double the 45 kJ/m² required to fracture pure PMMA. The optical transmission of the composite with 30 volume percent fiber was approximately 40 percent through a 10 mm …

The Effect Of Additives On Properties Of Pfn-Pfw Dielectric Materials, Weih-Min Liao

Masters Theses

"The purpose of this study was to investigate the effect of processing and additives on the properties of the Pb(Fe_1/2Nb_1/2)O₃-PB(Fe_2/3W_1/3)O₃ solid solutions. The basic composition was 70 m% Pb(Fe_1/2Nb_1/2)O₃ and 30 m% Pb(Fe_2/3W_1/3)O₃. The additives used were MnO, PbO and ZnNbO₆. Pressed compacts were sintered over the temperature range 900'C to 1050°C for 1 to 5 hours.

The influence of processing and composition on the properties was determined by measurement of density, shrinkage, dielectric constant, dissipation factor and …

Vle For 1,3-Butadiene With 1,2-Butadiene And Propyne, Patrick J. Gripka

Masters Theses

"Vapor pressures for pure 1,3-butadiene, 1,2-butadiene and propyne and 10 binary mixtures are reported at 5, 20, 35, 50, and 65°C. An equation of state utilizing saturated vapor and liquid densities is used to correlate the experimental data. Calculated relative volatilities and saturated densities are reported for the systems 1,3-butadiene - 1,2-butadiene and 1,3-butadiene - propyne. The thermodynamic excess functions Helmholtz free energy, Gibbs free energy, entropy, enthalpy, internal energy, volume, and heat capacity are derived for the equation of state and the excess properties are reported for the two systems"--Abstract, p. iv.

Effects Of 0.5 Weight Percent Boron On Cobalt Aluminide, Kevin Thomas Slattery

Masters Theses

"A study was made on the effects of adding 0.5 weight percent boron to the ordered intermetallic Cobalt Aluninide. Thirty gram (30g) specimens were induction melted in an pure argon atmosphere and cast into a copper alloy bar mold. The addition of boron raised the modulus of rupture from 30.1 to 44.3 ksi; increased the Knoop microhardness from 543 to 693; reduced the average grain size from 190 to 70 microns; and gave a more equiaxed grain structure. X-ray diffraction detected the presence of a second phase, AlB , 12 in the material containing boron. Scanning electron micro-scopy revealed that …

Influence Of Prior Deformation On Structure And Properties Of Heat Treated Aluminum Casting Alloy, Chungwei Hsia

Masters Theses

"A1 356 alloy is extensively used for a wide variety of casting applications. The structure is composed of primary dendrites and eutectic silicon formed during the eutectic reaction. It has long been recognized that the shape of the eutectic silicon significantly affects the ductility of the alloy. Traditionally, the morphology of the silicon is changed by certain chemical and/or thermal processes to improve the ductility. Mechanically deforming the castings to "modify" the shape of silicon has been shown by this research to be an effective alternative method to improve the spheroidization rate of eutectic silicon during heat treatment. The best …

A Three-Dimensional Bistatic Radar Target Position Measurement Error Model, Robert Kenneth Lynn

Masters Theses

"The accuracy of target position measurements for an airborne bistatic radar receiver are calculated. Two methods of information measurement are utilized, both of which assume cooperative synchronization between the transmitter and receiver. Gimbal angle errors are incorporated into both methods. The size and orientation of the error ellipsoid about the true target position is found. Loci of constant circular error probable are plotted in a horizontal plane of interest"--Abstract, page ii.