Chemical Engineering Commons^™

Evaluation Of Seal Integrity Of Flexible Food Polytrays By Destructive And Non-Destructive Techniques, William James Barlow Jr.

Masters Theses

The military has recently suffered a reduction in production capacity due to the rejection of their flexible food packaging. The rejection of these polytrays was due to sealing defects and the high standards set forth for the sealing quality. These standards set by the military were likely too conservative and until a test could be developed and optimized to quantitatively measure seal integrity, the standards will remain very high. The optimized test, whether destructive or non-destructive, must show that a particular defect, which might currently cause rejection, will not affect the quality of the items contained if passed as a …

Prediction Of Organic Droplet Behavior On A Solid Surface As Influenced By Aqueous Surfactant Solutions, Samuel Albert Morton Iii

Doctoral Dissertations

This dissertation presents a model capable of predicting equilibrium oil droplet contact angles on a solid surface immersed in surfactant solution, a thorough discussion of the effects of surfactant concentration and salt addition on contact angles, and an experimental investigation into the impact of voltage application to the solid surface on oil droplet shape in an aqueous/organic/solid system. The work contained in this dissertation resulted in five journal articles and numerous presentations.

The model applies current theories of surfactant self-assembly, the quasi-chemical approximation for solid surface adsorption, and various aqueous/organic/solid system properties to determine organic droplet contact angles. The computational …

Development Of An Accurate Toxicity Assay Using Genetically Engineered Bioluminescent Bacteria, Stacey M. Allsteadt-Barnlund

Masters Theses

Methods of developing and improving toxicity assays using genetically engineered bioluminescent bacteria PM6 and Shk1 were investigated. The EC₅₀ values for three metals (zinc, copper, and lead) were determined using these two strains and were compared with the EC₅₀ values calculated from the Microtox® assay, published inhibition to activated sludge specific oxygen uptake rate (SOUR) data (Madonii et al., 1999), and published EC₅₀ values from Microtox® for the same compounds (Kaiser and Devillers, 1994). This was done to evaluate the effectiveness of using strains PM6 and Shk1 to predict toxic effects to activated sludge as indicated by …

Development Of A Reagentless Amperometric Ethanol Biosensor Based On Yeast Alcohol Dehydrogenase And Its Coenzyme, Nad+, Coimmobilized On A Carbon Nanotubes- Modified Electrode, Justin Matthew Holland

Masters Theses

A reagentless amperometric ethanol biosensor was fabricated by modifying a glassy carbon (GC) electrode with a thin film of multi-walled carbon nanotubes (MWNTs) and depositing yeast alcohol dehydrogenase (YADH) and its coenzyme, nicotinamide adenine dinucleotide (NAD⁺), on the surface of the modified electrode. The enzyme was immobilized on the modified electrode using two techniques: adsorption and covalent attachment. Biosensors based on graphite and carbon nanofibers (CNFs) were also fabricated in a similar manner except that the enzyme was only adsorbed to the electrode surface.

The performance of the biosensors was assessed using a number of analytical techniques. Cyclic …

Molecular Dynamics Simulation Of Aqueous Electrolytes Behavior In Nanochannels, Lingchen Liao

Masters Theses

This thesis discusses the molecular dynamics simulation to determine the density distribution and diffusion coefficient of aqueous electrolytes (CaCl2, NaF, NaCl, NaBr, NaI, KCl, CsCl, RbCl) within silica nanochannels at 298K. An atomistic wall model, charged Lennard-Jones models for the ions, and the SPC/E model for water have been used. The effect of different channel radius and wall charges on divalent CaCl2 electrolytes solutions is discussed in comparison with the previously studied behavior of monovalent NaCl solutions. The comparison of (NaF, NaCl, NaBr, NaI) aqueous solutions in 1.0 nm nanochannel reveals the effects of different anion sizes. Likewise, the comparison …

Analysis And Simulation Of A Batchwise Scotch Whisky Production Process, Thomas Benton Rogers

Masters Theses

Scotch whiskey is produced in a two step distillation process that has remained relatively unchanged for decades, even centuries. The chemical composition of the whiskey is vital to its flavor and character. Much work has been done to analyze and study the final composition of different whiskies. However, to date little work has been published that studies the composition of the distillate with respect to distillation time. The goal of this work is to develop an experimental basis for study of the scotch whisky production process. Experimental data would allow us to gain a better understanding of the effects of …

Cloning And Expression Of Cytochrome P450Cam, Sirisha Chada

Masters Theses

Polyaromatic hydrocarbons (PAHs) are ubiquitously present in the environment and have deleterious affects on humans. Cytochrome P450 enzymes have been found to be useful in the biodegradation of the PAHs through an initial hydroxylation step. This makes them more water-soluble and accessible to the action of other oxidases. Cytochrome P450_cam is a model P450 enzyme that has been mutated for enabling PAH and alkane hydroxylation. P450s therefore have potential for use in commercial process for production of primary alcohols.

Rhodococcus organisms have a special mechanism for transporting the hydrophobic hydrocarbons into their cells. Cloning of the P450_cam gene …

Application Of Polymer Rheology In Melt Blowing Process And Online Rheological Sensor, Yizhong Wang

Doctoral Dissertations

Polymer rheology plays a significant role in many polymer-processing operations such as polymer extrusion, fiber spinning, and nonwovens processing. To develop real time, online process and quality control system in these operations, knowledge of polymer rheology and how the rheological properties can be determined is crucial.

In this work, rheological properties of two melt blowing grades polypropylene (PP) under different processing conditions were determined by various off line methods, which includes dynamic rheological properties, shear and elongational viscosities. The elongational viscosity was measured at different Hencky strain by using semi-hyperbolic dies developed in this research group. Good master curves were …

Integration Of Design Scales And Its Application To Multi-Component Adsorption Systems, Parag S. Adhangale

Doctoral Dissertations

Macroscopic simulations of chemical engineering unit processes provide a means of visualizing the relationship between different process variables through the use of constitutive equations such as the mass, energy and momentum balances. Molecular simulations on the other hand provide an insight into processes on the molecular scale. These simulations coupled with various concepts from statistical mechanics, are often used to study the properties of materials under a range of process conditions.

In a natural extension to these two fields, we use molecular simulations to obtain physico-chemical properties required for use in the macroscopic simulations of multi-component adsorption systems. The application …

Statistical Mechanical Models Of Adsorption And Diffusion Of Fluids In Crystalline Nanoporous Materials: Extensions To Percolation And Multicomponent Fluids, Austin M. Newman

Masters Theses

Kamat et al. has developed an analytical statistical mechanical theory that can be used to model pure component and binary liquid mixtures confined within crystalline nanoporous materials [1, 2]. The theory can be used to predict diffusivities, adsorption isotherms, and heats of adsorption as functions of temperature, pressure, and composition. The predictions obtained from this theory can then be used in macroscopic process level simulations to investigate the use of new adsorbents without conducting expensive experiments.

Kamat et al. has verified that the analytical adsorption theory can be used to model methane confined within zeolite Na-Y [3]. However, the diffusion …

Feasibility Of Using The Least Square Deconvolution Approach To Resolve Three-Person Str Dna Mixture Samples, Christopher David Lucas

Masters Theses

The feasibility of using the least-square solution method to resolve three-person mixtures of short tandem repeat deoxyribonucleic acid (STR DNA) was explored in this work. Such three-person mixtures can occur in gang rapes and other violent crimes and there is currently no suitable method for resolving these mixtures. The method evaluated in this work was named LSD-3. Simulations were conducted using the MATLAB software package to evaluate the sensitivity of correct resolution to signal perturbations as a function of the relative mass ratios of the mixture contributors. Three enhancements to the LSD-3 method were investigated; locus concatenation, reference profile incorporation, …

Separation Of Fluoride Residue Arising From Fluoride Volatility Recovery Of Uranium From Spent Nuclear Fuel, Jennifer L. Ladd-Lively

Masters Theses

The overall objective of this study was to support an alternative hybrid process to meet Advanced Fuel Cycle Initiative (AFCI) goals, using fluorination and aqueous processing techniques, for treatment of spent nuclear fuel (SNF). The specific goal was to develop a simple aqueous dissolution process to separate two high-heat fission products, cesium and strontium, from SNF fluoride residues. This separation study was based on solubility differences examined by modeling using the HSC Chemistry 5.0 and OLI Stream Analyzer 1.2 programs. HSC automatically utilizes an extensive thermochemical database, which contains enthalpy (H), entropy (S), and heat capacity (Cp) data for more …