Engineering Commons^™

Dynamic Modeling Of Slurry Bubble Column Reactors, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Multicomponent, One-Dimensional, and Compartment-Based Dynamic Model Developed by Rados Et Al. (Catal. Today 2003, 79-80, 211-218) Has Been Used to Study the Performance of Slurry Bubble Columns Operated with Two Chemical Reaction Systems. One Reaction Causes Contraction in the Gas-Phase Volume, and the Other Causes Expansion. the Change in the Gas Flow Rate (Expansion or Contraction) Along the Reactor as a Result of the Chemical Reaction Kinetics is Accounted for by the overall Mass Balance of the Gas Phase Represented by Large and Small Bubbles. the Importance of Properly Accounting for the Change in the Gas Flow Rate Has …

Multicomponent Flow-Transport-Reaction Modeling Of Trickle Bed Reactors: Application To Unsteady State Liquid Flow Modulation, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

A One-Dimensional Reactor and Catalyst Pellet Scale Flow-Transport-Reaction Model Utilizing the Multicomponent Stefan-Maxwell Formulation for Inter- and Intraphase Transport is Developed to Simulate Unsteady State Operation in Trickle Bed Reactors. the Governing Equations and Method of Solution Are Discussed. Results Are Presented for a Model Reaction System (Hydrogenation of A-Methylstyrene) under Gas Reactant Limiting Conditions, for Liquid Flow Modulation as a Test Case of Unsteady State Operation. Model Simulations Predict that Periodic Liquid Flow Modulation Can Alter the Supply of Liquid and Gaseous Reactants to the Catalyst and Result in Reactor Performance Enhancement above that Achieved in Steady State Operation. …

Cost Effective Human Protein C Purification From Cohn Fraction Iv-1 Using Mini-Antibody., Doh Gyeuhn Ahn 1969-

Electronic Theses and Dissertations

Protein C (PC) is an important anticoagulant, antithrombotic, and antiinflammatory in blood plasma. PC deficiency can lead to severe venous thrombotic events, including lung embolism, stroke, and heart attack. In the body, PC is activated only when it is needed, and, therefore, PC does not cause bleeding problems that currently available anticoagulants may do. Purification of PC from plasma is currently done by immunoaffinity chromatography using monoclonal antibodies (Mabs), which is very expensive. Single chain variable regions (mini-Mab) with a PC binding capability, which can be produced in recombinant E. coli , were developed for PC purification. Compared to Mabs, …

Study Of Secondary Electron Emission From Niobium At Cryogenic Temperatures, Anoop George

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of this project is to study the properties of secondary electron emission from niobium samples, cleaned at the Los Alamos National Laboratory, at cryogenic temperatures to enhance existing multipacting codes with data on the samples. The predominant cause of power loss in radio-frequency superconducting accelerators cavities is multipacting. This project studies the secondary electron distribution from niobium metal due to incident primary electrons. The experiments on the niobium sample are performed in an environment close to that present in a superconducting accelerator cavity.

The experiment is performed in a vacuum chamber capable of achieving ultra high vacuum levels …

Biofilm Removal Using Bubbles And Sound, Michael R. Parini

Theses and Dissertations

Bacteria in biofilms adhere well to surfaces and are quite difficult to remove. Oral plaque is one example of a biofilm. Many researchers have studied ways to remove plaque and bacteria from surfaces. It has been found that the passage of a bubble across a surface to which bacteria has adhered can remove the bacteria from the surface. Biofilms of Streptococcus mutans were grown on glass coverslips as a simple model for oral plaque. The coverslips were mounted in a Plexiglas chamber filled with artificial saliva. A bubble stream was directed at the mounted biofilm. The velocity, gas fraction, median …

Multiphase Flow Packed-Bed Reactor Modeling: Combining Cfd And Cell Network Model, Yi Jiang, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Performance of a Multiphase Flow Packed-Bed Reactor Was Evaluated by a Mixing-Cell Network Model in Which the Cell-Scale Flow Field Information Was Provided by Multifluid CFD Modeling. Such a Sequentially Combined Modeling Approach Was Able to Show the Heterogeneity of Liquid Species Conversion in a Trickle-Bed Reactor that Has Been Confirmed by in Situ Magnetic Resonance Experiments. 1 a Conventional Plug Flow Model (PFM) and Axial Dispersion Model (ADM) Showed Either overpredicted or Underpredicted Conversion Compared with the Conversion Computed from the CFD-Cell Network Model. Preliminary Case Study Has Shown the Ability of the CFD-Cell Network Model in Assessing …

Modeling And Scale-Up Of Mixing- And Temperature-Sensitive Chemical Reactions, Gary Patterson

Chemical and Biochemical Engineering Faculty Research & Creative Works

A review of published measurements of yield for complex chemical reactions in mixed reactors of various types and methods of modeling and simulating such reactions for the purpose of reactor scale-up shows the extent of progress that has been made. Reaction kinetics for very fast competitive reactions are usually difficult and expensive to determine. Many reaction processes must be scaled up from bench- and/or pilot-scale experiments that produce yield data under various mixing conditions. the variables that strongly affect the yield results are the reaction types and their rates, feed point in the reactor, feed injection velocity and scale, mixing …

Phase-Field Modeling On Morphological Landscape Of Isotactic Polystyrene Single Crystals, Haijun Xu, Rushikesh Matkar, Thein Kyu

College of Polymer Science and Polymer Engineering

Spatio-temporal growth of isotactic polystyrene single crystals during isothermal crystallization has been investigated theoretically based on the phase field model by solving temporal evolution of a nonconserved phase order parameter coupled with a heat conduction equation. In the description of the total free energy, an asymmetric double-well local free energy density has been adopted to represent the metastable melt and the stable solid crystal. Unlike the small molecule systems, polymer crystallization rarely reaches thermodynamic equilibrium; most polymer crystals are kinetically stabilized in some metastable states. To capture various metastable polymer crystals, the phase field crystal order parameter at the solidification …

The Phosphoglycolate Phosphatase Gene And The Mutation In The Phosphoglycolate Phosphatase-Deficient Mutant (Pgp1-1) Of Chlamydomonas Reinhardtii, Kensaku Suzuki, Hidenobu Uchida, Tarlan G. Mamedov

Papers in Biochemical Engineering

The sequences of the phosphoglycolate phosphatase (PGPase) gene Pgp1 and the 5′-upstream region from Chlamydomonas reinhardtii wildtype 2137 and the pgp1-1 mutant N142 that lacks the activity of PGPase (PGP1) were determined. The comparison revealed the alteration of a G to A at position 98 relative to the start codon. This destroyed the “GT” splice donor site at the beginning of the first intron of this gene, resulting in an extension of the first exon to 49 translatable codons followed by a stop codon, containing the codons corresponding to whole transit peptide for the chloroplast stroma and the first four …

Biomass-Coal Co-Combustion: Opportunity For Affordable Renewable Energy, Larry Lin Baxter

Faculty Publications

This investigation explores the reasons for and technical challenges associated with co-combustion of biomass and coal in boilers designed for coal (mainly pulverized coal) combustion. Biomass-coal co-combustion represents a near-term, low-risk, low-cost, sustainable, renewable energy option that promises reduction in net CO2 emissions, reduction in SOx and often NOx emissions, and several societal benefits. Technical issues associated with cofiring include fuel supply, handling and storage challenges, potential increases in corrosion, decreases in overall efficiency, ash deposition issues, pollutant emissions, carbon burnout, impacts on ash marketing, impacts on SCR performance, and overall economics. Each of these issues has been investigated and …

Quality Of Common Salt In The Tanzanian Market, Kamwanya E

Tanzania Journal of Engineering and Technology (TJET)

The quality of edible salts in the Tanzanian market has been studied by comparing the levels of iodine, heavy metals, and non-metals. Among the 19 analyzed local salt samples, only two of them—Kipepeo salt (76.67 mg/kg) and Super salt (79.95 mg/kg)—met the recommended level of iodine as per TBS (Tanzania Bureau of Standards) specifications. Other brands have iodine levels below the TBS specification.

Degradation Of Waterfront Reinforced Concrete Structures At The Port Of Dar Es Salaam, I Sanga

Tanzania Journal of Engineering and Technology (TJET)

The paper summarises the results of an investigation done on piers at the Dar es Salaam Port. The problem facing these structures and marine facilities is their exposure to aggressive environmental phenomena. The paper presents an investigation of the strength and corrosion of concrete seaport piers so as to determine degradation of the reinforced concrete waterfront structures in the port of Dar es Salaam. For instance the structures at a dhow quay terminal had been in use for about 100 years. The facility was in bad condition as the concrete had been badly damaged due to corrosion. Some of the …

Ceramic Properties Of Chimala Kaolin Clay, Leonard Akwilapo

Tanzania Journal of Engineering and Technology (TJET)

The physico-chemical properties of kaolinite clays occurring in abundance near Chimala were studied with a view of finding out their suitability in sanitary ware production. The viscosity of the clay was found to be within the range acceptable in industrial application (≤ 500 cp for 70% solids), enhancing its prospects for the manufacture of slip cast shapes with satisfactory properties. The chemical composition of the clay reveals a high content of Fe₂O₃, 1.48%, which is expected to affect the translucency and colour of the finished ware. However, such quantity would not have detrimental effects in the production of sanitary ware. …

Coupling Between Lysozyme And Glycerol Dynamics: Microscopic Insights From Molecular-Dynamics Simulations, Taner E. Dirama, Gustavo A. Carri, Alexei P. Sokolov

College of Polymer Science and Polymer Engineering

We explore possible molecular mechanisms behind the coupling of protein and solvent dynamics using atomistic molecular-dynamics simulations. For this purpose, we analyze the model protein lysozyme in glycerol, a well-known protein-preserving agent. We find that the dynamics of the hydrogen bond network between the solvent molecules in the first shell and the surface residues of the protein controls the structural relaxation (dynamics) of the whole protein. Specifically, we find a power-law relationship between the relaxation time of the aforementioned hydrogen bond network and the structural relaxation time of the protein obtained from the incoherent intermediate scattering function. We demonstrate that …

Autologous Fibrinogen Purification And Concentration For Use In Fibrin Sealant, Steven M. Alston

Theses and Dissertations

Fibrinogen concentrates are used widely as a sealant during and after surgery to reduce blood loss. Commercially available fibrin sealants are made from pooled human blood, which carries the risk of blood-borne diseases, and are expensive. These concerns have brought to focus the need for autologous fibrinogen concentrates. This need has been addressed by utilizing a unique approach in which fibrinogen is precipitated from plasma with protamine. The physical properties of fibrin sealant prepared from fibrinogen precipitated with protamine were evaluated. The optimal precipitation conditions included a plasma protamine concentration of 10 mg/mL at room temperature. Under these conditions 96% …

Introducing Feedback Control To First Year Engineering Students Using Labview, Samuel Bogan Daniels, David Harding, Michael Collura

Mechanical and Industrial Engineering Faculty Publications

This paper discusses the introduction of basic feedback control concepts and applications specifically selected for first year engineering & applied science students. These activities are introduced in the second half of a first semester class that is part of a sequence of first and second year courses used to develop a strong foundation for programs in various engineering disciplines. This sequence of courses uses a Multidisciplinary Engineering Foundation Spiral¹ in the form of a four-semester sequence of engineering courses, matched closely with the development of students’ mathematical sophistication and analytical capabilities and integrated with coursework in the sciences. 1 . …

Uv-Vis -Infrared Optical And Afm Study Of Spin-Cast Chitosan Films, W H. Nosal, D. W. Thompson, Sabyasachi Sarkar, Anuradha Subramanian, John A. Woollam, L Yan

Papers in Biotechnology

Optical properties OS spin-cast chitosan films have been determined in the infrared, visible, and ultraviolet region or the spectrum ~tsing spectroscopic ellipsometry. Optical constants for the Vvis-near IR spectra from 130 to 1700 nm were determined using Cauchy dispersion forms com-bined with Lorentzian oscillator models in the absorptive shorler wavelength regions. Infrared ndex of refraction and extinction coefficients from 750 to 4000cm-' were determined using ellip-sometric data fits to dispersion models based on harmonic oscillators. This modeling determined that optical onisotropy was present and measurable over all wavelength regions of ellipsomctric data. To obtain information on the micro- and nano-scale …

Stability Of Transport And Rate Processes [Review], Yaşar Demirel

Papers in Thermal Mechanics

About fifty years ago, the Turing instability demonstrated that even simple reaction-diffusion systems might lead to spatial order and differentiation, while the Rayleigh-Bénard instability showed that the maintenance of nonequilibrium might be the source of order in fluids subjected to a thermodynamic force above a critical value. Therefore, distance from global equilibrium in the form of magnitude of a thermodynamic force emerges as another constraint of stability; some systems may enhance perturbations, and evolve to highly organized states called the dissipative structures after a critical distance on the thermodynamic branch. Although the kinetics and transport coefficients represent short-range interactions, chemical …

Chromatographic Purification Of Mabs With Non-Affinity Supports, Anuradha Subramanian

Papers in Biotechnology

The introduction of new protein-based therapeutics such as monoclonal antibodies (MAbs), MAb-based vaccines, growth factors and plasma proteins implies the need to study, characterize, and purify. The separation step is likely to be a bottleneck and cost-effective technology will be needed to rectify it. The currently prevalent matrices for chromatographic separation of immunoglobulins (Igs) are based on Protein A or its recombinant versions (Protein G). They display excellent selectivity and specificity, but are expensive. A Protein A matrix costs $8,000 to 12,000 per L-resin. The typical production column volume is 100 L. The million-dollar matrix is far more expensive than …

Liquid Saturation And Gas-Liquid Distribution In Multiphase Monolithic Reactors, Tobias Bauer, Shaibal Roy, Ruediger Lange, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Monolith Bed is One of the Promising Catalytic Reactors for a Number of Chemical Gas-Liquid-Solid Processes. in the Present Work, Liquid Saturations for Five Different Monoliths Have Been Investigated Experimentally in a Cold-Flow Unit with a Reactor Diameter of 5.0 Cm. the Influences of Gas and Liquid Flow Rates and of the Direction of Two-Phase Flow on Liquid Saturation Were Examined. the Results Indicate that the Direction of Flow Has No Significant Influence on Liquid Saturation for Proper Gas-Liquid Distribution. the Experimental Results Are in Good Agreement with Predictions of the Drift Flux Model using the Distribution Parameter Proposed …

Single-Collector Experiments And Modeling Of Acoustically Aided Mesh Filtration, Michael T. Grossner, Donald L. Feke, Joanne M. Belovich

Chemical & Biomedical Engineering Faculty Publications

A model for the motion of particles driven by acoustic and hydrodynamic effects in the vicinity of a cylindrical collector has been previously reported. This trajectory model was developed to describe the essential physics that underlies an ultrasonically aided particle-filtration process in which a porous mesh is used to capture particles two orders of magnitude smaller than the pore size. To validate this trajectory model, experiments were performed to elucidate the detailed motion of particles in the neighborhood of a single cylindrical collector. Images of 54-μm-diameter polystyrene particles in aqueous suspension responding to acoustic and hydrodynamic forces were …

Transport Analysis And Model For The Performance Of An Ultrasonically Enhanced Filtration Process, Michael T. Grossner, Joanne M. Belovich, Donald L. Feke

Chemical & Biomedical Engineering Faculty Publications

This paper presents an analysis of a filtration technique that uses ultrasound to aid the collection of small particles (tens of microns in diameter) from suspension. In this method, particles are retained within a porous mesh that is subjected to a resonant ultrasonic field, even though the pore size of the mesh is two orders of magnitude greater than the particle diameter. The role of acoustic forces in driving the retention phenomena has previously been studied on a micro-scale, which included modeling and experimental verification of particle motion and trapping near a single element of the mesh. Here, we build …

Stable Polymer Micelle Systems As Anti-Cancer Drug Delivery Carriers, Yi Zeng

Theses and Dissertations

Several temporarily stable polymer micelle systems that might be used as ultrasonic-activated drug delivery carriers were synthesized and investigated. These polymeric micelle systems were Plurogel®, Tetronic®, poly(ethylene oxide)-b-poly(N-isopropylacrylamide) and poly(ethylene oxide)-b-poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate-lactaten). In previous work in our lab, Pruitt et al. developed a stabilized drug carrier named Plurogel® [5, 6]. Unfortunately, the rate of the successful Plurogel® synthesis was only about 30% by simply following Pruitt's process. In this work, this rate was improved to 60% by combining the process of adding 0.15 M NaCl and/or 10 µl/ml n-butanol and by preheating the solution before polymerization. Tetronics® were proved not …

The Effect Of Oxygen On Nonthermal-Plasma Reactions Of Nitrogen Oxides In Nitrogen, Morris D. Argyle, Gui-Bing Zhao, S.V.B. Janardhan Garikipati, Xudong Hu, Maciej Radosz

Faculty Publications

NO is mainly converted to NO2 by chemical oxidation in the presence of oxygen. Initial selectivity analysis shows that three electron collision reactions are important for NOX evolution in O2/N2. The rate constants of these reactions decrease with increasing oxygen concentration. This is because oxygen is electronegative and hence reduces the electron concentration. The rate constant of O2 dissociation by electron collision reaction is almost two orders of magnitude higher than that of N2 dissociation. NO formation occurs predominantly through N(2D) + O2 → NO + O. The critical oxygen concentration, defined as the concentration above which the NOX formation …

Penn State University Nsf Gk-12 Project: Using Web-Based Education And Interaction With K-12 And College Freshman To Promote Science And Engineering, Elana M. Chapman, Angela D. Lueking, Robin A. Tallon, Philip H. Henning, William S. Carlsen, Daniel C. Haworth

Chemical and Biochemical Engineering Faculty Research & Creative Works

Penn State University has hosted an NSF-sponsored GK-12 Outreach project for the past five years, and has just begun the second phase of the project. The Penn State project utilizes the talents of many science and engineering graduate students as teachers, mentors and role models for the K-12 classrooms. The project focuses on developing skills of students in the areas of science, technology, engineering and mathematics through the use of Advanced Transportation Technologies. A new project component was devised and implemented-the interaction of K-12 students with college freshman via a website project. The college freshmen were asked to create a …

Risk Management For The Construction Of Power Plants In Egypt, Amir Ibrahim Abouseif

Archived Theses and Dissertations

No abstract provided.

The Effect Of Reactor Configuration On No Conversion And Energy Consumption In Non-Thermal Plasma Parallel Tube Reactors, Morris D. Argyle, Gui-Bing Zhao, S.V.B. Janardhan Garikipati, Xudong Hu, Maciej Radosz

Faculty Publications

This work shows that the configuration of a pulsed corona discharge reactor strongly affects the rate of electron collision reactions. Experiments involving the decomposition of NO in N2 were performed in a reactor in which the number or parallel reactor tubes varied from 1 to 10 at a constant pressure of 147.6 kPa and ambient temperature. A previously developed lumped model of the reactions accurately predicted the effects of varying the initial concentrations of NO (from 240ppm to 593ppm) and gas residence time (from 1.93 to 742 s). With an increasing number of parallel reactor tubes, the rate of the …

Optimization Of Sequential Purification Of Beta-Glucosidase From Tricoderma Reesei In Aqueous Two-Phase System, Shalini Gautam

Dissertations

A novel sequential technique was developed for the purification of a valuable enzyme, beta-glucosidase, from microorganism Tricoderma reesei. The fungus T. reesei produces cellulose degrading enzymes, called cellulases: beta-glucosidase, endo-glucanase and exo-glucanase and low molecular weight proteins. For specific applications, the enzyme must be separated from other contaminants. The sequential technique, that included affinity precipitation with chitosan followed by separation with an aqueous two-phase system (ATPS), was implemented for the purification of beta-glucosidase from the culture filtrate of T. reesei.

The cultivation medium (nutrient) was optimized for the production of betaglucosidase from T. reesei cell culture. Treatment of the …

Fluid-Phase Thermodynamics From Molecular-Level Properties And Interactions Based In Quantum Theory, Steven G. Arturo

Dissertations

A methodology to predict the thermodynamics of macroscopic fluid systems from quantum chemistry and statistical thermodynamics has been developed. This work extends the group-contribution concepts most utilized in chemical engineering. Computational chemistry software is used to define the geometries and electron density profiles of target molecules. Atoms in Molecules theory and associated software packages are used to calculate rigorous properties of the functional groups within molecules of interest. These properties are incorporated into an intermolecular potential energy function which describes interactions between entire molecules as a set of interactions between functional groups. This information is applied to a lattice-fluid model …

Evaluation Of Unifac Group Interaction Parameters Usijng Properties Based On Quantum Mechanical Calculations, Hansan Kim

Theses

Current group-contribution methods such as ASOG and UNIFAC are widely used for approximate estimation of mixture behavior but unable to distinguish between isomers. Atoms in Molecules (AIM) theory can solve these problems by using quantum mechanics and computational chemistry to compute atomic contributions to molecular properties and to intermolecular interactions. Rigorously defined properties available through AIM theory and new functional group definitions are used for the UNIFAC model to predict the behavior of various mixtures. Results are presented for various mixtures with nine regressed global parameters to optimize model's predictive capability. The results are also compared to analogous results for …