Engineering Commons^™

X-Ray Induced Electron Emission, Charles A. Aeby

Chemical and Biological Engineering ETDs

An experimental technique has been developed and successfully used in the measurement of X-Ray induced electron emission from a variety of materials including a group of significance to satellite applications. A database has been established which extends measure emission characteristics to an order of magnitude lower energies than previously available.

A Study Of The Models Describing Fines And Filler Retention By Utilizing Cationic Starch As The Retention Aid, Nen-Sen Chen

Masters Theses

Fines and filler retention under dynamic conditions was studied in this thesis work. Zeta potential of samples are also measured. Dynamic Retention/Drainage Jar and Lazer-Zee Meter were used to accomplish this work. The results have been analyzed by statistical methods. When cationic starch was utilized as a retention aid the pH affected its efficiency, probably because the charge of cationic starch was dependent on pH. This effect was detected by utilizing two-way analysis of variance to find the sources of its interactions with molecular weight and agitation rate. The mechanism was thus determined. At pH 3 and 4, charge neutralization …

Osmotic And Mean Activity Coefficients Of Libr And Lic In Methanol At 25, 35, And 45 Degrees C, Peggy Tomasula

Theses

Vapor pressure depression data of LiBr and LiCl in methanol at temperatures of 25,35, and 45°C were measured in the molality range 0.1-4.4m using a static method, where the difference in vapor pressure of the electrolytic solution is compared to that of pure methanol.

Osmotic coefficients were calculated from the vapor pressure data. This data was then correlated with both the one parameter Bromley equation and the three parameter Pitzer equation. For all systems at all temperatures, the data were better correlated by the Pitzer equation than with the Bromley equation. Mean activity coefficients of the two salts at the …

Correlation Of Thixotropic Parameters And Related Tests Of Blood From Human Subjects, Walter Fabisiak

Dissertations

The flow behavior of human blood is an important facet of the circulatory system as it affects all of the organs of the body. The rheological properties of whole blood provide a means of analyzing the flow of red cells and plasma through the microcirculation. A recently observed rheological characteristic of whole human blood is thixotropy, a time-dependent phenomenon. This phenomenon is caused mainly by the redistribution of an aggregated form of erythrocytes, known as rouleaux, and the non-aggregated, single erythrocytes. In order to further define and analyze the thixotropic properties of blood, the Huang model is used to quantitatively …

Thixotropic Properties Of Whole Human Blood, Jen An Su

Dissertations

The rheological property of whole blood from various human subjects was studied with a Weissenberg Rheogonio-meter, modified with a continuously variable speed drive. Experimental data showed a hysteresis loop in the shear stress versus the shear rate plot and a torque-decay in the shear stress versus the shearing time plot which is under a constant shear rate. The rheological equation previously developed by Huang was employed to define the thixotropic parameters of each whole blood sample based upon the recorded rheograms.

The altered thixotropic parameters for the blood from patients with open heart surgery at different clinical stages were quantitatively …

An Experimental Study Of Photopolymerization In A Continuous Stirred Tank Reactor, Songvit Setthachayanon

Theses

An experimental study was carried out on the control of CSTR by on-off regulation of light intensity for the photo-sensitized polymerization of styrene. The controllability of the reaction temperature, the advantages of operating at metastable states, and the molecular weights of the polymer formed were discussed. The influence of feed temperatures, sensitizer concentrations, and residence times on the reactor performance characteristics were also discussed. Experimental results showed that polymer formed at the metastable state had a higher average chain length and narrower molecular weight distribution than that formed at the low stable state. While increasing the residence time shifted the …

The Characterization Of The Oxygen Transfer Capabilities Of Fermentors, Joseph Stephen Adamca

Theses

A method of characterizing the oxygen mass transfer capabilities of fermentors was developed where volumetric oxygen mass transfer coefficients are obtained using a modified sulfite oxidation method in conjunction with on line digital data processing. Carboxymethylcellulose is used in the reaction media to simulate the viscosity of typical non-Newtonian fermentation broths. Using this method, instantaneous values of volumetric oxygen mass transfer coefficients can be obtained for various combinations of agitation and airflow rates in different fermentor configurations. This data is useful in the scale up or scale down of fermentors.

Data obtained using this method have revealed that for a …

Temperature Dependency Of The Group Interaction Parameters In The Agsm And Unifac Models For The Prediction Of Heats Of Mixing, Ignatius Okoronkwo Ojini

Theses

A four-parameter group-contribution model (UNIFAC) has been developed for the prediction of heats of mixing of non-electrolyte mixtures. Both the UNIFAC and AGSM models are evaluated over a wide range of temperature dependencies of the group interaction parameters. The UNIFAC model has been chosen over the AGSM model and an optimum parameter-temperature relationship has been established.

Adopting the optimum temperature dependency, group inter-action parameters have been calculated using UNIFAC for the prediction of four types of mixtures: n-Alcohols/n-Alkanes; Benzene/n-Alkanes; Nitriles/n-Alkanes; Amines/n-Alkanes.

Analysis Of Unsteady-State Heat Conduction In A Cylinder With The Finite Element Method, Richard F. Bernard

Theses

Unsteady-state heat conduction in a cylinder of finite dimensions with constant physical and thermal properties was analyzed with the finite element method. Symmetry of the cylinder and application of Newman's method reduced the problem to two independent one-dimensional problems. Finite element equations for the axial and radial dimensions were developed utilizing Galerkin's method of weighted residuals. Crank-Nicholson approximations were used for time derivatives. A computer program was written for solution of the finite element equations.

Solutions obtained were conditionally stable; dependent on the value of the ratio KΔt/ρCpl². For values of the ratio less than 1/3, errors in …

A Development Of Regression Models For Predicting Two-Phase Relative Permeability In Consolidated Rock, Mehdi Honarpour

Doctoral Dissertations

"The primary objective of this study was the development of prediction equations for the water-oil imbibition relative permeability and gas-oil drainage relative permeability from experimental data.

Laboratory relative permeability data along with the corresponding rock and fluid properties were collected, and stepwise linear regression analysis was applied. Relative permeability models were developed in terms of rock and fluid properties.

The prediction models were tested against laboratory values and previously published correlations. It was found that the models developed in this study yield results that are generally in better agreement with experimental values than the previously published correlations"--Abstract p. ii