Engineering Commons^™

A Molecular Investigation Of Absorption Onto Mineral Pigments, Brian J. Ninness

Electronic Theses and Dissertations

Pigment suspensions are important in several processes such as ceramics, paints, inks, and coatings. In the wet state, pigments are combined with a variety of chemical species such as polymers, surfactants, and polyelectrolytes which produce a complex colloidal system. The adsorption, desorption, and redistribution of these species at the pigment - aqueous solution interface can have an impact on the behavior in both the wet state or its final dried state. The goal of this work is to establish a molecular picture of the adsorption properties of these pigmented systems. A novel in situ infrared technique has been developed which …

Characterization Of Chitosan Films For Cell Culture Applications, Michael Katalinich

Electronic Theses and Dissertations

Chitosan (β-(l,4)-2-amino-2-deoxy-D-glucose) is a naturally occurring, abundant biopolymer exhibiting desirable biomaterial properties of biodegradability, low toxicity and good biocompatibility. These properties indicate the suitability of chitosan as a surface for mammalian cell growth. The goal of this thesis is to explore the potential for using chitosan as a surface for NIH 3T3 fibroblast attachment and growth. '4 standard, reproducible film-formation technique, based on other researchers techniques was established. The reproducibility of this technique. through characterization of the physical and chemical properties of these films, was good. The attachment and growth of NIH 3T3 fibroblasts on chitosan films and controls was …

The Relationship Between Rheology, Application Method, And Final Coating Structure, Basant Galal Dimetry

Electronic Theses and Dissertations

Paper is coated to improve the printability and the visual properties. The factors that determine the coating structure are important because the structure determines the physical, optical, and printing properties. This work focuses on determining a relationship between the rheological properties of the coating, the application method, and the final coating structure. Coatings with different polymers and pigments were characterized in terms of steady shear and viscoelastic properties. These coatings were applied onto plastic film and paper with a laboratory rod coater, a spray coater, and a high-speed blade coater. The final coating structure after drying was characterized in terms …

Evolutionary Polymorphic Neural Networks In Chemical Engineering Modeling, Li Gao

Dissertations

Evolutionary Polymorphic Neural Network (EPNN) is a novel approach to modeling chemical, biochemical and physical processes. This approach has its basis in modern artificial intelligence, especially neural networks and evolutionary computing. EPNN can perform networked symbolic regressions for input-output data, while providing information about both the structure and complexity of a process during its own evolution.

In this work three different processes are modeled: 1. A dynamic neutralization process. 2. An aqueous two-phase system. 3. Reduction of a biodegradation model. In all three cases, EPNN shows better or at least equal performances over published data than traditional thermodynamics /transport or …

Modeling And Experimental Validation Of A Single-Feed Semi-Batch Precipitation Process, Ernesto Uehara-Nagamine

Dissertations

Crystallization is a widely practiced unit operation throughout the chemical and pharmaceutical process industries. Despite its widespread application, crystallization still suffers a disproportionate number of process difficulties due to the complexity of the steps involved in the process. In particular, the final characteristics of the product are strongly affected by the mixing conditions during the process. The development of a validated modeling approach would be highly valuable for the successful prediction of the crystal characteristics under differing mixing conditions.

In the present work, the single-feed semi-batch precipitation process of barium sulfate in a stirred tank was experimentally studied and numerically …

The Influence Of Fiber Swelling On Paper Wetting, Sedef Akinli-Kocak

Electronic Theses and Dissertations

The water uptake behavior of fibers, especially those at the surface of paper, influences printing and coating operations. The dynamic water uptake behavior of the surface fibers may determine the initial consolidation of the coating at the surface and the penetration of coating into the paper, but clear studies on this topic have not been reported in the literature. Four different fiber types and seven different paper sheets were investigated in the present study. The three different fiber types were prepared by carboxymethylation of softwood kraft pulp thereby producing pulps with different water uptake values. The fiber length and water …

Influence Of Viscoelasticity On The Nano-Micromechanical Behavior Of Latex Films And Pigmented Coatings, Manish Giri

Electronic Theses and Dissertations

Nan0 to microscale deformation behavior of different carboxylated styrene-butadiene co- polymer Latexes were investigated using a commercial nanoindentation device. The latexes dif- fered primarily in their glass transition temperature (T_g). The bulk dynamic rheological properties, as determined from a rheometer, dictate the axismmetric deformation behavior of the latexes. Results from dynamic tests performed on latexes were analyzed using the theories in contact and fracture mechanics. Two theories of linear viscoelastic fracture mechanics (LVEFM) were employed to model the adhesion hysteresis (loading-unloading cycle) curves to obtain meaningful cohesive zone (fracture process zone) parameters and a stress intensity functional ( …

An Investigation Of Centrifugal Blood-Cell Separation, Timothy Edward Roche

Dissertations

This dissertation investigated the centrifugal, batch separation of whole blood into subpopulations of red blood cells (erythrocytes) and white blood cells (leukocytes). Separations took place in a custom-built centrifuge (using a seal-less, anti-twisting feed/withdrawal system) containing, a 25-ml capacity separation chamber. The blood separation chamber had dart-shaped geometry in the radial plane and a constant depth in the axial direction. Separation experiments were performed on whole bovine blood at varying hematocrit, centrifuge speed, and batch duration. A small, companion study of whole human blood separation runs also were conducted; they concentrated on batch duration effect and achieved superior separations.

A …

An Experimental Study Of Dry Particle Coating : Devices, Operating Parameters And Applications, Michelle Ramlakhan Mohan

Dissertations

Dry particle coating, which mechanically coats fine guest particles onto the surfaces of larger host particles, without binders or solvents, is investigated. Several systems of host and guest particles are coated in different devices to study various aspects of dry particle coating. The devices used are Magnetically Assisted Impaction Coating (MAIC) device, Mechanofusion, and the Hybridizer.

MAIC is used to coat fine SiO₂ guest particles onto the surface of larger cornstarch and cellulose host particles. This is done to simultaneously improve the flowability of the host particles, as well as reduce their hydrophilicity. Dry particle coating is used to …

Immobilized Liquid Membranes For Facilitated Transport And Gas Separation, Anjaneya Sarma Kovvali

Dissertations

Separation and purification of gas mixtures is a major area of activity in chemical engineering. Gas separation using facilitated transport membranes has been the subject of considerable research for many years. Immobilized liquid membranes (ILMs) are an important class of facilitated transport membranes. Despite their potential to provide superior performance, they could not achieve commercial success so far due to their instability. Recent research addressed the issue of stability of ILMs by replacing water as the solvent successfully with glycerol. In the present thesis, the relevance of glycerol as an ideal solvent for developing stable ILMs is demonstrated using the …

Microporous Polymeric Membranes Via Melt Processing, Chaiya Chandavasu

Dissertations

Novel ultraporous and microporous membranes from immiscible polymer blends were produced via melt processing and post-extrusion treatments. Polystyrene (PS)/polypropylene (PP) and poly(ethylene terephthalate) (PET)/polypropylene (PP) blend systems with different rheological properties were studied. The blends were first compounded in an intermeshing co-rotating twin-screw extruder and subsequently extruded through a sheet die to obtain the precursor films. These were post treated by uniaxial or biaxial deformation (100-500%) with respect to original dimensions to induce a microporous structure. The porosity is induced by drawing the precursor film at a temperature below the glass transition temperature (T_g) of the minor …

Structures, Intramolecular Rotation Barriers, And Thermodynamic Properties Of Methane And Ethylene Carbons Bonding To Two Unsaturated Groups : Ethylene, Acetylene, Phenyl And Carbonyl, Manish H. Gurbani

Theses

Enthalpy, ΔH_f°₂₉₈, entropy, S°₂₉₈ and heat capacities C_p(T) (300 ≤ T/K ≤ 1500) are determined for Methane, bi-phenyl (CCB2H2); Methane, phenyl-vinyl (CCBCDH2);Toluene, 1-formyl (CCBCOH2), Propyne, 3-phenyl (CCBCTH2); 1,4-pentadiene (CCD2H2); Propene, 3-formyl (CCDCOH2); Methane, di-formyl (CCO2H2); Propyne, 3-formyl (CCOCTH2); Methane, di-ethynl (CCT2H2); Ethene, bi-phenyl (CDCB2); 1,4 Butadiene, 3-phenyl (CDCBCD); Ethene, I-ethynl-l-phenyl (CDCBCT); 1,4 Butadiene,3-vinyl (CDCD2); 1,4 Butadiene, 2-ethynl (CDCDCT) and Ethene, 1,1di-ethynl(CDCT2) using density functional B3LYP/6-31G(d) calculation method. Molecular structures and vibration frequencies are determined at the B3LYP/6-31G(d) density functional calculation level. Evaluation of data from the isodesmic reactions results in ΔH_f° …

A Laboratory And Field Study Of The Attenuation Of Sound Intensity Using A Whistle As The Sonic Generator, Navneet Kumar

Theses

This study investigated the attenuation of sound intensity using a whistle as the sonic generator along with the detailed analysis of all the previous studies. Attenuation of sound in air studies were performed in Otto H. York Center for Environmental Engineering and Science at New Jersey Institute of Technology. Sound attenuation through air was measured by doubling the distance for each of five whistles. It was concluded that Whistle No.5 gives the highest sound intensity of 140.54 dB at a distance of 0.75 ft , the closest distance used for measurement, at a air flow rate of 7.5 SCFM. These …

Bubble Growth Behavior In Supersaturated Liquid Solutions, David Robert Cyr

Electronic Theses and Dissertations

The growth characteristics of gas bubbles in supersaturated liquid solutions were measured in preliminary experiments involving glass bottles followed by more controlled and systematic investigations using a custom designed experimental apparatus. It was proven that the presence of pre-existing gas was responsible for the bubble formation observed. Bubble growth occurred in very regular cyclical patterns at specific locations containing trapped gases. In the custom designed apparatus, liquids could be saturated with gases and supersaturated solutions made by depressurizing the system. Artificial capillaries, pre-seeded with air bubbles, behaved in a similar manner to naturally occurring sites containing pre-existing gases. The apparent …

Gloss Dynamics Of Inkjet Printers, Amol G. Shirke

Electronic Theses and Dissertations

Inkjet printing is a popular non-impact technology with widespread use in home and office applications. The basic principle involves propelling ink drops of different colors on a substrate. High quality images, near photographic quality, are now possible. The gloss of the printed substrate is an important quality attribute. Printed gloss depends on a number of characteristics of the media and the ink, but a good fundamental understanding is not available in the literature. The dependence of the gloss on the media and ink characteristics is reported in this work. The experimental results are compared with values predicted by a mathematical …

Micro-Probe For Physical And Chemical Surface Analysis, Joshua Mathews

Electronic Theses and Dissertations

Non-uniform porosity of paper and coated paper is important in printing and paper making industries. Current porosity measurements give results averaged over a large area. A new method is developed to determine local variations in porosity and surface chemistry. A measured volume of a probe liquid is applied to a hemispherical glass probe. The substrate of interest is brought into contact with the fluid drop. The resulting liquid bridge exerts a force on the probe due to surface tension forces. A video camera is used to visually correlate the physical phenomena with the force-time data. The force-time data is recorded …

The Influence Of Process Parameters On Filament Size Distribution, Saybil Nuray Ercan

Electronic Theses and Dissertations

Filaments are formed at the exit of rolling nips in some coating and printing operations. The filament size distribution can determine product quality such as gloss. The average filament size is linked to operational difficulties such as misting. The filament size distribution of various fluids and inks is characterized and compared to theoretical model. A high-speed video camera is used to visualize the exit of a rolling nip. The size distribution of the filaments is characterized with image analysis. A laboratory print tester is used with the high speed camera to characterize the size of the defects right after printing. …

Increasing The Speed And Efficiency Of Search In Fbi/Codis Dna Datadase Through Multivariate Statistical Clustering Approach And Development Of A Similarity Ranking Scheme, Puneet Yadav

Masters Theses

A new method has been developed to create and maintain a search tree-structured index to multidimensional data using naturally occurring patterns and clusters within the data, and thereby allows the implementation of efficient search and retrieval strategies in a database. This method was applied to a DNA database, which was developed by the FBI for forensic uses. A set of 10,000 DNA/STR profiles based on the STR allele probability distribution density for the Caucasians has been generated for the sixteen loci. The resulting allele distribution has been analyzed using Multivariate Statistical analysis, in specific; the Principal Component Analysis (PCA) approach …

Testing Of Semiconductor-Based Adsorption Modified Photosensitive (Samp) Sensor For Response To Toluene, Ashish Agrawal

Theses

The response of semiconductor-based adsorption modified photosensitive sensor is based on the dye-enhanced photoconductivity of a CdS semiconducting film. The change in this photoconductivity is brought about when organic molecules are sorbed onto the dye-coated surface. The response is related to the overlap in the infrared spectrum of the dye with that of the analyte.

This research was carried out to study the response of the sensor to a typical hydrocarbon, toluene. The sensor was tested for its response to concentrations of toluene ranging from 2.6 ppm to 200 PPM in nitrogen. The sensor was tested under non-flow conditions and …

Texture, Microstructure And Formability Of Aluminum Alloys, Xiang-Ming Cheng

University of Kentucky Doctoral Dissertations

Texture, microstructure and formability were studied in Direct Chill Cast (DC) and Strip Cast (SC) aluminum alloys with regard to crystallographic anisotropy, the Portevin-Le Chatelier effect and aging softening behavior. It was found that material properties change greatly with manufacturing processes (DC vs. SC) and chemical composition (3xxx vs. 5 xxx alloys). DC cast hot band materials are usually fully recrystallized and have strong softening textures while SC hot band materials have a rolling structure with strong deformation textures. Softening textures cause 90 earing while deformation textures result in 45 earing after deep drawing. During cold rolling, 90 earing in …

Mathematical Modeling For Fabricating A Microstructure With A Pre-Specified Geometry Using Laser -Induced Chemical Vapor Deposition, Chaoyang Zhang

Doctoral Dissertations

Laser-induced chemical vapor deposition (LCVD) is an emerging new technique with many practical applications. To optimize the system for fabricating a microstructure with a pre-specified geometry in pyrolytic LCVD, a three-dimensional mathematical model is developed for predicting temperature distributions and laser dwell times across the substrate scanned by the laser beam. A microstructure is fabricated layer by layer, and for each layer the laser beam moves from one pixel to the next. The complicated correlations among temperature distribution, deposit growth rate, and laser dwell time are investigated. A purely heterogeneous reaction is assumed and any gas-phase transport is ignored.

A …

Investigation And Characterisation Of Growth Phases Of Polycrystalline Cadmium Sulfide Thin Films Produced By The Chemical Bath Deposition Method, Peter Duncan

Theses : Honours

This research project investigates the characterisation and morphology of the growth phases of polycrystalline CdS thin films that were created using the Chemical Bath Deposition (CBD) method. One batch of CdS thin films was created by the author (group B) whilst another batch (group A) was obtained from a previous research project. In both cases, the experiments were designed such that successive slides in a set represent successive phases in the growth of these CdS thin films. Therefor analysis of the near surface for all slides in a set gave an accurate representation of conditions on the surface at the …

Electrodeposition Of Niw Alloys Into Deep Recesses, Lakshmikanth Namburi

LSU Master's Theses

Pulse electrodeposition has been investigated as a general technique for the electrodeposition of nickel-tungsten alloys in deep recesses for MEMS. Ni-W exhibits an induced codeposition mechanism, where the Ni reaction rate enhances the codeposition of W. Electrodeposition of this alloy has been achieved into recesses of 500 micron deep. The challenges that have been encountered are those related to gas evolving side reactions, local pH rises, diffusional limitations of the soluble species and long times required for filling the recesses. Electrodeposition on cylinder electrodes at different rotation rates was also carried out in order to obtain data on composition of …

Effects Of Compression Processing Parameters And Antioxidants On Molecular Degradation Of Biodegradable Poly-L-Lactide (Plla), Thomas J. Hannan Jr.

Masters Theses

The purpose of this research was to find a combination of poly (L-lactic acid), also known as poly-L-lactide or (PLLA) and antioxidants that would, together, produce a product whose degradation rate would be advantageous for use in biodegradable medical implants. Intrinsic viscosity tests were conducted on compression molded samples of PLLA that were molded at various processing parameters in order to find optimal parameters. The optimal processing parameters were found to be time 10 minutes, temperature 220°C, and pressure 1000 psi.

The molecular weight of PLLA sample was taken while pressure, time, and temperature were varied. As pressure increased, no …