Chemical Engineering Commons^™

The Viscoelastic Behavior Of Pigmented Latex Coating Films, Katharina Prall

Electronic Theses and Dissertations

The mechanical properties of paper coatings are essential for use performance of coated paper (e.g. calendering, printing degradation during printing operations, pick). This study investigates the microscopic and macroscopic mechanisms that determine the viscoelastic behavior of pigmented latex coating films. Pigmented coating layers were prepared with different microstructures. This was achieved by using different pigment types and shapes (polystyrene plastic pigment - spheres, precipitated calcium carbonate - rhombs, clay - plates), and changing pigment volume concentration (PVC). Two styrene-butadiene latices with different degree of carboxylation (acidic level 0.3% and 4.5%) were evaluated to determine effect of adhesion. The viscoelastic material …

Fourier Transform Raman Spectroscopy For Process Control In The Petroleum Industry, Kent Lawson Wise

Chemistry & Biochemistry Theses & Dissertations

As early as 1950, Raman spectroscopy was proposed as a method to determine aromatics and olefins in hydrocarbon mixtures. Until recently, extensive use of Raman spectroscopy in the characterization of hydrocarbons has not been practical due to several limitations. One early limitation to Raman analysis was the absence of a high intensity and stable excitation source. This problem has been overcome with the advent of lasers. Another limitation was the presence of fluorescence in hydrocarbon fuels when excited by visible lasers. However, the development of Fourier-transform Raman spectrometers now allows Raman spectra to be collected using near-IR lasers (e.g …

Turbulent Mixing And Chemical Reaction In Baffled Stirred Tank Reactors : A Comparison Between Experiments And A Novel Micromixing-Based Computational Fluid Dynamics Model, Otute Akiti

Dissertations

The optimization of reaction processes to maximize the yield of a desired product while minimizing the formation of undesired by-products is one of the most important steps in process development for drug manufacturing or fine chemical production. In many situations the kinetics of product formation can be quite complex and involve a number of intermediate steps as well as parallel and serial reactions. This renders the systems sensitive to the operating conditions. Often, upon scale-up, a decrease in the yield of the desired product is experienced, while more undesired by-products are produced. A large number of interrelated variables influence the …

Nanofiltration-Based Diafiltration Process For Solvent Exchange In Pharmaceutical Manufacturing, Jignesh P. Sheth

Theses

Commercially available solvent stable polymeric nanofiltration membranes were used to study the nanofiltration and diafiltration operations in the context of the pharmaceutical industry. Experimental results are presented for a two-step operation involving the preconcentration of a feed solution via nanofiltration followed by the replacement of the first stage solvent with a second solvent via diafiltration in two stages. Membranes MPF-50 and MPF-60, having molecular weight cut-offs of 700 and 400 respectively, were used in the present study. A solution of erythromycin (MW 734) in ethyl acetate was preconcentrated via nanofiltration followed by replacement of ethyl acetate with methanol via batch …

The Impact And Fate Of Aqueous Sodium Nitrate On Hydrocarbon Flames, Ann Marie Flynn

Dissertations

This study examined the impact and fate of sodium (fed as an aqueous nitrate solution) in fuel-rich methane/air and methane/methyl chloride/air flames as a function of equivalence ratios that experienced diffusion of air from the surroundings. The flames were stabilized on a slotted, uncooled burner. The data set was divided into profiles of relative sodium atom concentrations, temperatures, and selected stable species concentrations. The flames were simulated using a modified version of the Sandia FORTRAN program for modeling steady laminar one-dimensional premixed flames complete with detailed mechanisms. The results showed that maximum sodium atom concentration in the flame is decreased …

Endotoxin Removal From Protein Solutions By Immobilized Metal Ion Affinity Chromatography, Yun Kang

Dissertations

In the biotechnology/pharmaceutical industry, the removal of endotoxins from final protein product has always been a challenge. A novel method for endotoxin removal from protein solutions, immobilized metal (ion) affinity chromatography (IMAC) has been developed in this study. Fe³⁺ was charged to a chelating gel that contains iminodiacetic acid (IDA). The IDA- Fe³⁺ IMAC column was exploited to remove endotoxin from protein solutions. This method involves the adsorption of the endotoxin on IMAC column. More than 99% endotoxin is removed and protein yield is higher than 90%. IDA-Fe³⁺ IMAC has proved to be an economical and efficient …

Fluidization And Soot Filtration In A Rotating Fluidized Bed, Gui-Hua Qian

Dissertations

A horizontal rotating fluidized bed (RFB) has been investigated for the removal of soot from diesel engine exhaust. This requires necessitating an understanding of the nature of fluidization, particle mixing and filtration in the RFB.

In an RFB, particles are subject to a centrifugal force which can be much larger than the force of gravity. Therefore the Geldart classification for conventional fluidized beds must be modified for rotating fluidized beds. A theoretical analysis shows that group A particles (minimum bubbling velocity U_mb > minimum fluidization velocity U_mf can shift to group B U_mb = U_mf and group …

An Integrated Membrane-Based Chromatographic Process For Biomolecule Isolation And Purification, Xiaoping Dai

Dissertations

Biomolecules obtained from fermentation and cell-culture processes are present in low concentrations in a complex medium/broth. For intracellular products, cells are first harvested. Subsequently, cell lysis and homogenization are undertaken to produce a homogenate. The biomolecules are next separated from the cell debris by lysate clarification. For extracellular products, the biomolecules are separated from the whole cells by clarification. The overall yield is reduced with each additional step. As the cost of bioseparation process accounts for 50-80% of the final product cost, innovations in and improvement of bio-downstream processing are greatly needed.

In this research, a cyclic process integrating a …

Numerical Studies Of Deep Bed Filtration, Chan-Gyun Shin

Theses

Deep bed filtration is a process used to separate small solid particles suspended in a fluid by using granular solids as the collecting medium. The filter efficiency depends on many parameters such as the Reynolds number, particle drag coefficient, the ratio of the diameter of injected, and filter particles, etc.

In the present work we model the porous media flow (solution of the Navier-Stokes equations) by using a computer code developed by Dr. P. Singh and we restrict our analysis to the case of two dimensional periodic porous media. The computational domain is discretized using the finite element method. In …

Feasibility Study Of Rotating Fluidized Bed As A Dry Coater And Granulater, Manish Sawhney

Theses

This study is directed at enhancing our understanding of the mechanism of dry coating and granulation in a rotating fluidized bed (RFB). The main objective was to study the feasibility of the coating and granulation processes using an REB, both quantitatively and qualitatively.

A force balance and kinetic model is applied to explain the coating phenomenon and also to investigate why coating takes place in certain particle material systems and not in others. An equation for the resultant velocity with which one particle collides with another has been suggested for the rotating fluidized bed coater. A condition, which predicts whether …

The Design Of A Chemical Plant Using Hysys Simulation Program, Michael Randolph Vaughan

Chancellor’s Honors Program Projects

No abstract provided.

In-Line Measurement Of Solibility Of Physical Blowing Agents In Thermoplastic Melts As Related To Extrusion Foaming, Qiang Zhang

Dissertations

A novel in-line method for measuring physical blowing agent solubility in thermoplastic melts in extrusion foaming equipment has been developed in this study. This method uses video microscopy in connection with a foaming extruder (single or twin-screw) to generate solubility data by observing the onset of gas bubble formation/dissolution. This method offers a number of advantages over the existing conventional methods. It can be easily used to obtain solubility data for many foamable thermoplastic-physical blowing agent systems at high pressure and temperature near actual foaming conditions. Data generated using this method could be directly used to characterize and control a …

A Study Of Sound Attenuation Using Sonic Energy Focussed At An Artificial Soil Fracture, Minhaz Bootwala

Theses

Several laws have been passed over the past two decades to control contamination and to remediate already existing contaminated sites. There are a large number of these sites and several ex-situ and in-situ techniques have been developed to decontaminate these sites. These techniques can be quite expensive, especially the ex-situ clean-up operations, and there has always been a need for cheap, quick remediation methods.

This study investigates the attenuation of sound used in the in situ remediation technique coupling Sonic Energy with Pneumatic Fracturing and Vapor Extraction. Preliminary attenuation studies were performed in the laboratory with a microphone made at …

In-Situ Frequency-Dependent Electromagnetic Sensing For Monitoring Physical And Chemical Attributes During Chemical Processing, Jeffrey David Rogozinski

Dissertations, Theses, and Masters Projects

The objective of this research was to develop an in-situ sensing technique that monitors the molecular-level response of ions and dipoles to an applied electric field in order to characterize the changes in state of a polymer resin during chemical processing. This technique needs to be capable of monitoring the reaction progress not only in the laboratory setting but also in-situ in the processing tool or reaction environment. Frequency Dependent Electromagnetic Sensing (FDEMS) was selected for this task.;This dissertation investigates the applicability of FDEMS to monitoring two types of processing methods: reactive and batch reactor. The reactive processing system examined …

Reconstitution And Characterization Of Membrane Proteins, Sarah Mia Pates

Masters Theses

“A membrane protein, cytochrome c reductase, was crystallized and examined using transmission electron microscopy. Two-dimensional crystals were prepared by two methods. In Method 1, the protein was solubilized in 50 mM Tris-Acetate (pH 6.0)/0.5 mM EDTA70.05% (w/v) Triton X-100 and reconstituted into a mixture of phosphatidylcholine and phosphatidylserine (4:1), dissolved in the same buffer. The Triton X-100 was removed from the mixture by dialysis in the presence of Bio-beads (SM-2) at approximately 25-30 °C. Method 2 was the same as Method 1, except that the vesicles were fractionated before reconstitution, and the pH and temperature for crystallization were 7.0 and …

The Dehydrochlorination Mechanism Of The Internal Allylic Chloride Structure In Poly(Vinyl Chloride), Lynda B. Payne

Dissertations, Theses, and Masters Projects

No abstract provided.

A Study Of The Aging Of Polyamide-11 Based On Molecular Weight Measurements, Yao Lin

Dissertations, Theses, and Masters Projects

No abstract provided.