Engineering Commons^™

Prediction Of Paper Color: A Process Simulation Approach, Mayank Chaturvedi

Masters Theses

A simulation model was developed for a dye mixing process and for the prediction of the optical properties of the paper. The model was integrated with the MAPPS (Modular Analysis of Pulp and Paper Systems) simulation software package. The model was validated using dyed handsheets made in a laboratory and dyed paper made on a pilot papermachine. Validation comprised of prediction of the optical properties of the handsheets and the machine-made paper which contained various combinations of three non-fluorescent dyes. Sheet reflectances were predicted at 20 nanometer intervals for discrete light wavelength range of 400 to 700 nanometers and verified …

Non-Linear Finite Element Analysis Of Reinforced Concrete Beams, Wael Mohamed El-Dessouki

Archived Theses and Dissertations

No abstract provided.

Stimulation Of Amorphizing Reactions In Co-Si Multi-Layers, Jeanne K. Jackson

Opportunities for Undergraduate Research Experience Program (OURE)

Co-Si multi-layer specimens do not normally amorphize. To possibly stimulate amorphization, Ti was added by evaporation and the specimens were annealed at 300 and 400 degrees Celsius. The results showed that amorphization occurred at 400 degrees Celsius in the presence of Ti, but did not occur at 300 degrees Celsius. Further research would be necessary to conclude whether the amorphization was stimulated by the addition of Ti or the temperature increase.

Cyclodextrin Stationary Phases For The Gas-Solid Chromatographic Separation Of Hydrocarbons, Chris A. Monge

Opportunities for Undergraduate Research Experience Program (OURE)

Cyclodextrin, bonded to silica gel and used as a gas-solid chromatographic stationary phase provides a practical and efficient means for separating a wide variety of C₁-C₇ hydrocarbons at ambient to elevated temperatures. Conditioning the columns at high temperature (300°C) for several hours increased efficiency and resolution. The adsorption of these light hydrocarbons involves a multiple retention mechanism. Evaluation of the columns and an analogous silica gel column with hydrocarbon standards is reported. Capacity factors and chromatograms are presented for these GSC stationary phases.

Optimization Of Sodium Carbonate-Sodium Hydroxide Pulping Of Wheat Straw For Corrugating Medium Production, Irmak Yayin

Masters Theses

This study's primary objective was to present sodium carbonate pulping as an alternative to soda or lime pulping of wheat straw for corrugating medium production. If sodium carbonate pulping is comparable with soda pulping in terms of strength properties, it could be the preference of choice because the recovery of sodium carbonate is simpler requiring less capital investment. The two strength properties that were optimized with respect to total chemical charge, cooking time, and sodium hydroxide fraction in the cooking liquor were Concora crush resistance and STFI compressive strength. These are the two most important strength properties for the end …

Materially Nonlinear Finite Element Analyses Of Trusses And Slab-On-Grade Problems, Moayyad Moh'd Al-Nasra

Civil & Environmental Engineering Theses & Dissertations

The overall approach is to employ the finite-element method along with specified material models to account for material nonlinearity. This study includes two different applications: truss structures and slabs-on-grade.

Procedures for materially nonlinear analysis of truss structures, which apply for both determinate and indeterminate cases are proposed. The proposed procedures are simple and can handle a variety of different stress-strain functions, and the applied load does not have to be incremental. Proposed procedures results are verified with the output of NASTRAN.

A finite-element model for slab-on-grade is introduced. The concrete slab is represented by eight-node brick elements, and the joints …

Transfer Function Models And Control Of A Flexible Structure Using Piezoelectric Laminates, Joseph A. Colvin

Mechanical & Aerospace Engineering Theses & Dissertations

The development of piezoelectric polymer films has generated a great deal of excitement in the structural controls community because they are lightweight, durable, distributed in nature and have broad band frequency characteristics. The flurry of research inspired by piezoelectric films has primarily been dedicated to using them as distributed sensors, and to a lesser extent, as distributed actuators.

Active damping of structural vibrations using piezoelectric polymer films as sensors and actuators has primarily been directed toward taking advantage of their distributed nature and employing various types of distributed control theory. This approach does not easily yield insight into the dynamics …

Method For Making Reshapable Articles Containing Lignocellulose Utilizing Polyisocyanate Resins, Bernard C. Sun

Michigan Tech Patents

Reshapable composite material and/or articles formed from lignocellulose-containing materials and having improved strength and water resistance characteristics are made by applying about 7 to about 100 weight % of a polyisocyanate resin to fibers and/or fiber bundles of a lignocellulose-containing material. The resulting mixture or furnish is compression molded to form a composite material and/or article of the desired shape and dimensions.

Steady-State Creep Deformation Of Investment Cast Near-Gamma Titanium Aluminide, D. A. Wheeler, B. London, D. E. Larsen Jr.

Materials Engineering

No Abstract.

A Response Surface Methodology Study Of Ferroelectric Memory Devices, Kevin C. Smith

Theses and Dissertations

Fatigue in ferroelectric memory devices was studied. The application of fatigue pulses to a ferroelectric sample was controlled by the RT-66 Ferroelectric Tester, a variation of the Sawyer-Tower circuit. The RT-66 also controlled data collection following the fatiguing process. Seven variables were evaluated for their potential- affect on fatigue. A sequence of fatigue tests, which varied the settings of these variables, was developed using Response Surface Methodology (RSM) experimental designs. Least-squares regression models were developed once a particular RSM set of design experiments was completed. These models were evaluated using RSM tools, and the analysis of these models allowed the …

High Temperature Alloys Synthesis By Electro-Discharge Compaction, Kenji Okazaki

Chemical and Materials Engineering Faculty Patents

A method is provided for synthesizing high temperature alloys from elemental powders. The method includes the steps of placing the elemental powders to be processed in a die. A relatively high pressure is then applied to the powders. Substantially simultaneously, an electrical discharge is applied to the powders. The discharge is of relatively high voltage and current density to provide alloying. A product fabricated by the present method is also described and claimed.

Application Of Optical Emission Diagnostics And Control Related To Semiconductor Processing, Richard N. Savage, Greg C. Viloria

Materials Engineering

This paper discusses and shows applications of optical emission spectroscopy techniques and methods to monitor plasma emissions during semiconductor processing. A brief discussion of the instrumentation that was used and the software to control the instrumentation is presented. Optical emission spectroscopy techniques discussed include chemical species identification in plasma etching, process fingerprinting, contamination detection, endpoint analysis/control, and sputter/deposition plasma monitoring.

Mixed‐Cation Oxide Powders Via Resin Intermediates Derived From A Water‐Soluble Polymer, Lone‐Wen ‐W Tai, Harlan U. Anderson, Paul A. Lessing

Materials Science and Engineering Faculty Research & Creative Works

Sub micrometer powders of complex oxides were prepared via resin intermediates based on a starch type of organic precursor. A commercially available water‐soluble starch derivative was (for the first time) used as the organic base for solution synthesis of ceramic powders. Calcination of the charred, fluffy, amorphous resins at a temperature below 600°C for 4 h yielded perovskite powders of Sr‐doped LaMnO₃ and Sr‐doped La(Fe,Co)O₃. Sr‐doped LaCrO₃ needed to be calcined above 750°C to ensure phase purity and to remove organic residue. Due to the low cost of starch derivatives, the process has the potential of …

Review Of P-Type Doped Perovskite Materials For Sofc And Other Applications, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

p-type perovskite-type oxides are candidates for use as components of high temperature fuel cells and as oxygen separation membranes. The particular properties that these applications require are reviewed. The characteristics that these oxides have which allow them to satisfy many of these requirements are discussed and a defect model presented. The status of the utilization of these oxides and of the areas which need to be addressed such as thermal expansion and sintering characteristics are reviewed. © 1992.

Effect Of Ultrasound On Acidified Brine Leaching Of Double-Kiln Treated Eaf Dust, J. A. Barrera-Godinez, Thomas J. O'Keefe, Johh L. Watson

Materials Science and Engineering Faculty Research & Creative Works

The U.S. steel industry produces approximately 500,000 tons/year of electric arc furnace (EAF) dust, which is classified as a hazardous waste. Increasing disposal costs of these dusts have encouraged studies to investigate treatment processes to render the material non-hazardous, and to possibly recover metal values. This research project was designed to examine the hydrometallurgical recovery of zinc from EAF dusts that have been treated by a double kiln fuming process. The test work consisted essentially of acidified brine leaching of the pelletized calcine to determine the influence of traditional conditions, such as acid concentration, temperature and agitation, plus the application …

Method Of Making Highly Sinterable Lanthanum Chromite Powder, Von Richards, Subhash C. Singhal

Materials Science and Engineering Faculty Research & Creative Works

A highly sinterable powder consisting essentially of LaCrO.sub.3, containing from 5 weight % to 20 weight % of a chromite of dopant Ca, Sr, Co, Ba, or Mg and a coating of a chromate of dopant Ca, Sr, Co, Ba, or Mg; is made by (1) forming a solution of La, Cr, and dopant; (2) heating their solutions; (3) forming a combined solution having a desired ratio of La, Cr, and dopant and heating to reduce solvent; (4) forming a foamed mass under vacuum; (5) burning off organic components and forming a charred material; (6) grinding the charred material; (7) …

Application Of Stable Operating Criterion To Grating Tuned Strong External Feedback Semiconductor Lasers, Haiyin Sun, Malay K. Mazumder

Journal of the Arkansas Academy of Science

Stability analysis is done by applying criterion dnQ((o)/cfco>0 for grating tuned strong external feedback semiconductor lasers. The resulting stable and unstable operating ranges agree well with experiment results.

Techniques For Efficiency Calibration Of Photon Detectors For X-Rays And Low Energy Gamma Rays, Rahul Mehta

Journal of the Arkansas Academy of Science

No abstract provided.

Measurement Of The Coefficient Of Thermal Expansion Of Superconducting Thin Films Using Powder X-Ray Diffraction, Biju Chandran, R. Calvin Goforth, S. Nasrazadani

Journal of the Arkansas Academy of Science

The High Density Electronics Center (HiDEC) at the University of Arkansas, Fayetteville is developing the technology for High Temperature Superconductor Multi-Chip Modules (HTSC-MCM's). As part of this work, we are looking at the mechanical properties of HTSC materials. An important mechanical property which influences the mechanical integrity of the hybrid MCMis the coefficient of thermal expansion (CTE) of the HTSC films. As a first step in developing a procedure for the determination of the CTE of HTSC materials, the lattice parameters and the CTE of an alpha-alumina substrate have been determined by powder x-ray diffraction technique. An extension of this …

An Experimental Method For Determining Membrane Penetration, Jong W. Choi, Isao Ishibashi

Civil & Environmental Engineering Faculty Publications

A new and simple experimental method is proposed for the determination of membrane penetration due to changes of the effective confining pressure in triaxial and hollow cylinder tests. The proposed method has advantages over existing methods in that it requires neither special devices nor questionable assumptions. It only requires a series of drained isotropic compression tests in a conventional triaxial device with plastic liners. The results from the proposed method are compared to those from several existing experimental and analytical methods.

X‐Ray Powder Diffraction Structural Phase‐Transition Study Of La(Cr1‐Xmnx)O3 (X = 0 To 0.25) Using The Rietveld Method Of Analysis, Scott A. Howard, Jen‐Kuan ‐K Yau, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

The La(Cr_1‐xMn_x)O₃ (x = 0 to 0.25) system exhibited a displacive phase transformation from an orthorhombic to a rhombohedral structure at temperatures ranging from about 256°C at x= 0 to 305°C at x= 0.25. The Rietveld method of X‐ray analysis was used to determine structural characteristics and to assay phase concentrations when multiple phases were present. Indications were that the Mn ions on the B site affected the transition temperature through an ionic size effect; i.e., Mn³⁺, with a larger ionic size than Cr³⁺, increased the transition temperature while the presence …

Sme Annual Meeting. Phoenix, Usa. February 22-27, 1992, Johh L. Watson

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Solvent Extraction Reagent Entrainment Effects On Zinc Electrowinning From Waste Oxide Leach Solutions, M. Neira, Thomas J. O'Keefe, Johh L. Watson

Materials Science and Engineering Faculty Research & Creative Works

A considerable quantity of metal-containing waste oxide is generated by the primary metal industry, and under increased environmental regulation, treatment of these wastes has become viable. Hydrometallurgical processing is often appropriate and one potential treatment process for zinc oxide wastes involves leaching the oxide with an acid, purifying by a solvent extraction operation, and recovering metallic zinc by electrowinning the purified leach solution. The purification stage is frequently critical and the introduction of a solvent extraction organic reagent into the flowsheet can be detrimental to downstream processes. The object of this study was to determine the effect of organics, entrained …

Electrical Conductivity And Seebeck Coefficient Of (La, Ca) (Cr, Co)O3, R. Koc, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

Electrical conductivity and Seebeck coefficients of (La, Ca) (Cr, Co)O₃ were measured as a function of temperature. The electrical conductivity as measured in air from 100 to 1100 °C increased with increasing Co and Ca content. The Seebeck coefficients were positive, indicating p-type conductivity. The substitution of Co for Cr significantly decreased the Seebeck coefficients, indicating that the substitution resulted in an increase in site occupancy, associated with the Co. The additional Ca substitution for La resulted in further decrease in the Seebeck coefficients, then exhibited a temperature-independent behaviour, indicating that the carrier mobility, rather than carrier concentration, was …

Effect Of Cation Substitution On The Thermal Expansion Coefficient Of Lacro3, R. Koc, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Tensile Fatigue Behaviour Of Tightly Woven Carbon/Carbon Composites, A. Ozturk, Robert E. Moore

Materials Science and Engineering Faculty Research & Creative Works

The tensile fatigue behavior of a tightly woven carbon/carbon composite was investigated as a function of stress level. Load-controlled fatigue tests were performed in tension-tension mode with a stress ratio, R, of 0.1 under ambient laboratory conditions. Results of composite behavior are discussed in terms of the relationship of the stress/strain behavior to the fatigue life of these composites as well as the effects of applied stress levels. It is shown that these composites exhibit good resistance to cyclic loading. No fatigue failures were obtained after 106 cycles when the maximum tensile load in the fatigue cycle is less than …

Grain Size Effect On The Induced Piezoelectric Properties Of 0.9pmn-0.1pt Ceramic, U. Kumar, Wayne Huebner, P. Marsh, H. Kankul, S. F. Wang, Clyde G. Oakley

Materials Science and Engineering Faculty Research & Creative Works

Lead magnesium niobate-lead titanate (Pb(Mg_1/3Nb_2/3)O₃ - PbTiO₃ (PT) solid solutions have been widely researched to produce devices that can be used in low- and high-electric-field applications. For some applications, such as medical ultrasonic transducers, it is necessary to prepare the ceramic with high density and small average grain size. The effect of grain size on the low- and high-field properties of 0.9-PMN-0.10-PT ceramics is described in the present work. To prepare highly dense ceramic, vibratory and attrition milled powders were sintered between 1000 and 1250 ⁰C. The average grain sizes of the sintered ceramics …

Development Of An Automated Ultrasonic Inspection Cell For Detecting Subsurface Discontinuities In Cast Iron, John Scott Burningham

Dissertations and Theses @ UNI

Manufacturing of value added products by companies in todays global marketplace requires the vendors to meet certain minimum standards, SAE, ASTM, ISO, etc. In a global economy, as a manufacturer for the year 2000 and beyond, preferred vendors will become ISO 9000 certified to maintain a market share of produced goods.

An automated inspection cell was developed for the inspection of cast iron ports to detect subsurface discontinuities. The cell consists of an ultrasonic flaw detector (UFD), transducer, robot, immersion tank, computer, and software. Normal beam pulse-echo ultrasonic nondestructive testing is performed on each rough casting.

Using test blocks and …

A Wear Analysis Study Of Selected Alternative Foundry Tooling Materials Using Impact Abrasion Testing, L. Fred Vondra

Dissertations and Theses @ UNI

The purpose of this study was to simulate the wear characteristics of foundry tooling using an impact abrasion test apparatus. The wear characteristic was exhibited by non-metallic materials and was measured as a function of percentage weight loss and was benchmarked against Class 30 gray iron. The research question focused on whether or not a non-metallic material exists that exhibits comparable or superior wear characteristics to Class 30 gray iron for possible consideration as tooling materials for foundry applications. The information obtained adds to knowledge and is useful to foundry professionals in making tooling decisions.

The 34 test materials were …

Crack Growth Rate Modeling Of A Titanium-Aluminide Alloy Under Thermal-Mechanical Cycling, John J. Pernot

Theses and Dissertations

In this study, a model is developed to predict crack growth rates in a titanium-aluminide alloy under thermal-mechanical fatigue (TMF). This TMF crack growth rate prediction model, which requires only isothermal data to define its parameters, is distinguished from earlier models in two ways. First, it accounts for mechanical-fatigue and environmental crack growth rate contributions while it also considers a retardation mechanism thought to be caused by creep blunting of the crack tip. This is the first study to account for such a retardation mechanism during TMF. The second uniqueness of the model is that its general form can account …