Chemical Engineering Commons^™

Study On Synthesizing Of 2-Methylbutanoic Acid By Indirect Electrooxidation, Chong-Tao Zhao, Ze-Shan Zhu

Journal of Electrochemistry

The working conditions of synthesizing 2-methylbutanoic acid by oxidizing 2-methyl-1-butanol with tetrabutylammonium hydrosulfate (TBAS) or tetrabutylammonium perchlorate (TBAP) as phase transfer catalyst in sulfuric acid Cr(Ⅵ) oxidation medium was studied. The Cr(Ⅵ) oxidation medium could be electrolytic regenerated from Cr(Ⅲ), during above oxidation reaction. Under the optinum condition, the yield of 2-methylbutanoic acid is more than 95%.

The Ac-Impedance Analysis For Pluse Oxide Film Of Aluminium Alloy, Ai-Ling Du, Xi-Cheng Ma, He-Ming Zhang

Journal of Electrochemistry

Bode diagrams for aluminum PC (abbreviated from pulse current) oxide films were first obtained by AC-impedance measurements in a wide range of frequency. The experimental results show that different kinds of electrical equivalent circuits can be used for representing PC films and DC (abbreviated from direct current) oxide films separately, the main differences between them are their porous layers, the PC films are more even with little defects.Those are also verified by SEM and V-I characteristic curve measurements.

Electrochemical Synthesis Of Fes Electrode And Its Behavior Measurement, Cong-Sheng Guan

Journal of Electrochemistry

The Potential for the electrochemical synthesis of FeS electrode has been obtained by cyclic voltammetry. FeS electrodes were synthesiaed by controlling Fe electrode at -1.0 V in LiCl-KCl-Li₂S and Li(FClI)-Li₂S melts and their behavior were measured also. The FeS electrode synthesized in molten Li(FClI)-Li₂S has the best charge and discharge properties.

Network Modeling Of The Convective Flow And Diffusion Of Molecules Adsorbing In Monoliths And In Porous Particles Packed In A Chromatographic Column, J. J. Meyers, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A cubic lattice network of interconnected pores was constructed to represent the porous structure existing in a monolith (continuous bed) or in a column packed with porous chromatographic particles. Expressions were also constructed and utilized to simulate, through the use of the pore network model, the intraparticle interstitial velocity and pore diffusivity of adsorbate molecules in porous chromatographic particles or in monoliths under retained and unretained conditions. The combined effects of steric hindrance at the entrance to the pores and frictional resistance within the pores, as well as the effects of pore size, pore connectivity, n(T), of the porous network, …

Polycrystalline Conducting Polymers And Precursors Thereof Having Adjustable Morphology And Physical Properties, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

Polycrystalline materials containing crystallies of precursors to electrically conductive polymers and electrically conductive polymers are described which have an adjustable high degree of crystallinity. The intersticial regions between the crystallites contains amorphous material containing precursors to electrically conductive polymers and/or electrically conductive polymers. The degree of crystallinity is achieved by preparing the materials under conditions which provide a high degree of mobility to the polymer molecules permitting them to associate with one another to form a crystalline state. This is preferable achieved by including additives, such as plasticizers and diluents, to the solution from which the polycrystalline material is formed. …

Bioactivities Of A Tumour Necrosis Like Factor Released By Chicken Rnacrophages, Silke Rautenschlein, Anuradha Subramanian, Jagdev M. Sharma

Papers in Biotechnology

To test for tumour necrosis-like factor (TNF) of chickens, supernatants of a lipopolysaccharide (LPS)-stimulated chicken macrophage cell line MQ-NCSU were analysed. A sequence of ion-exchange and gel-permeation chromatography was utilised to isolate TNF-like activity from the culture supernatant. The peak of TNF-like cytotoxic activity corresponded to the fractions with a nlolecular weight of 81 kDa or higher. Polyclonal anti-human TNF-a antiserum cross-reacted by Western blotting with a 17 kDa protein in the TNF-containing fraction ~ ~ n d e denaturing conditions. This result indicated that chicken TNF-like factor in the biologically active form may be a protein multimer of monomers …

Bioactivities Of A Tumour Necrosis Like Factor Released By Chicken Macrophages, Silke Rautenschlein, Anuradha Subramanian, Jagdev M. Sharma

Papers in Biotechnology

To test for tumour necrosis-like factor (TNF) of chickens, supernatants of a lipopolysaccharide (LPS)-stimulated chicken macrophage cell line MQ-NCSU were analysed. A sequence of ion-exchange and gel-permeation chromatography was utilised to isolate TNF-like activity from the culture supernatant. The peak of TNF-like cytotoxic activity corresponded to the fractions with a nlolecular weight of 81 kDa or higher. Polyclonal anti-human TNF-a antiserum cross-reacted by Western blotting with a 17 kDa protein in the TNF-containing fraction ~ ~ n d e denaturing conditions. This result indicated that chicken TNF-like factor in the biologically active form may be a protein multimer of monomers …

Composite Comprising A Metal Substrate And A Corrosion Protecting Layer, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Funded Proposals

A composite comprising a metal substrate and as a corrosion protecting layer on at least one major surface of said substrate, a composition comprising a thermoset or thermoplastic polymeric matrix, and a conductive filler component, where said filler component comprises electrically conductive particles.

Particle Pressure And Marginal Stability Limits For A Homogeneous Monodisperse Gas-Fluidized Bed: Kinetic Theory And Numerical Simulations, Ashok S. Sangani, Donald L. Koch

Biomedical and Chemical Engineering - All Scholarship

A linear stability analysis is performed for the homogeneous state of a monodisperse gas-fluidized bed of spherical particles undergoing hydrodynamic interactions and solid-body collisions at small particle Reynolds number and finite Stokes number. A prerequisite for the stability analysis is the determination of the particle velocity variance which controls the particle-phase pressure. In the absence of an imposed shear, this velocity variance arises solely due to the hydrodynamic interactions among the particles. Since the uniform state of these suspensions is unstable over a wide range of values of particle volume fraction &phgr; and Stokes number St, full dynamic simulations cannot …

Parametric Study Of Unsteady-State Flow Modulation In Trickle-Bed Reactors, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

Unsteady-State Liquid Flow Modulation (Periodic Operation) Was Investigated for Hydrogenation of Alpha-Methylstyrene to Cumene in a Hexane Solvent over 0.5% Pd on Alumina Spheres. This Test Reaction Was Run under Both Gas and Liquid Reactant-Limited Conditions. It is Shown that Periodic Liquid Flow Modulation Can Alter the Supply of Liquid and Gaseous Reactants to the Catalyst and Result in Reactor Performance Different from that Obtained under Steady-State Conditions. the Effect of Key Parameters Such as Extent of Gas/liquid Limitation, Total Cycle Period, Cycle Split, and Liquid Mass Velocity Were Investigated Experimentally to Demonstrate the Cause-Effect Relationships in Periodic Operation. Performance …

Fluid Dynamic Parameters In Bubble Columns With Internals, Jinwen Chen, Fan Li, Sujatha Degaleesan, Puneet Gupta, Muthanna H. Al-Dahhan, Milorad P. Duduković, Bernard A. Toseland

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Knowledge of Gas Holdup, Liquid Recirculation and Turbulent Parameters is Important for Design and Performance Calculation of Bubble Column Reactors. Although Numerous Experimental Studies Have Been Reported on This Subject, Most Are Point Measurements Limited to Columns Without Internals Operated at Low Gas Velocities. in This Study, We Present the Results Obtained for the Gas Holdup Profiles, Time-Averaged Liquid Velocity Profiles, Turbulent Stresses and Eddy Diffusivities (Radial and Axial) Obtained in a 18″ (44 Cm) Diameter Column Without and with Internals Similar to Those Used in Industrial Scale Units (E.g., Heat Exchanger Tubes) using Both Air/water and Air/drakeoil 10 …

Comparative Hydrodynamics Study In A Bubble Column Using Computer-Automated Radioactive Particle Tracking (Carpt)/Computed Tomography (Ct) And Particle Image Velocimetry (Piv), Jinwen Chen, Abdenour Kemoun, Muthanna H. Al-Dahhan, Milorad P. Duduković, D. J. Lee, Liang Shih Fan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Hydrodynamics of a 10-Cm-Diameter Cylindrical Bubble Column at the Superficial Gas Velocity of 2, 4, and 8 Cm/s Are Investigated by Computer-Automated Radioactive Particle Tracking (CARPT), Particle Image Velocimetry (PIV), and Computed Tomography (CT). These Experimental Techniques Are Capable of Providing the Knowledge of Velocity and Holdup Fields in a Bubble Column System, Which Are Essential as the Experimental Benchmark for Modeling of Such Systems. the Flow Field of Liquid Phase, as Well as the Reynolds Stresses, Obtained by CARPT and PIV in an Air-Water System Are Compared in Detail. the Results Indicate that CARPT and PIV Complement Each …

Two-Phase Flow Distribution In 2d Trickle-Bed Reactors, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

An Extended Discrete Cell Model (DCM), based on Minimization of Energy Dissipation Rate, is Applied to Predict Two-Phase Flow Distribution in the Two-Dimensional Trickle-Bed Reactors. the Main Advantages of DCM Are that It Can Qualitatively Capture the Experimental Observations, and Readily Distinguish between Flow Distribution in Prewetted and Non-Prewetted Beds, as Well as Reflect the Effects of Bed Structure and Inlet Liquid Distributor on Two Phase Flow Distribution. for Comparison Purpose, the Results of Liquid Distribution Obtained by DCM Are Compared with Both Computational Fluid Dynamics (CFD) Simulations and Experimental Observations in a 2D Bed. the Achieved Qualitative and Quantitative …

Method For Providing Discharge Protection Or Shielding, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Funded Proposals

Electrostatic discharge protection and electromagnetic interference shielding is provided by applying to a dielectric substrate a composition comprising a polymeric matrix and a conductive filler component. The conductive filler component comprises electrically conductive metal particles and at least one electrically conducting polymer.

Development Of A Curved Layer Lom Process For Monolithic Ceramics And Ceramic Matrix Composites, Donald A. Klosterman, Richard P. Chartoff, Nora R. Osborne, George A. Graves, Allan Lightman, Gyoowan Han, Akos Bezewredi, Stan Rodrigues, Sung Pak, Gary Kalmanovich, Leon Dodin, Song Tu

Chemical and Materials Engineering Faculty Publications

A novel rapid prototyping technology incorporating a curved layer building style was developed. The new process, based on Laminated Object Manufacturing (LOM), was designed for efficient fabrication of curved layer structures made from ceramics and fiber reinforced composites. A new LOM machine was created, referred to as Curved Layer LOM. This new machine uses ceramic tapes and fiber prepregs as feedstocks and fabricates curved structures on a curved-layer by curved-layer basis. The output of the process is a three dimensional "green" ceramic that is capable of being processed to a seamless, fully dense ceramic using traditional techniques. A detailed description …

Media Coverage Of Epa's Draft Dioxin Reassessment Report, Sharon M. Friedman, Megan A. Fitzpatrick, Brenda P. Egolf

RISK: Health, Safety & Environment (1990-2002)

Using content analysis, the authors examine the utility of news media in democratic decision making.

Biodegradation Of Thermoplastic And Hermosetting Polyesters From Z-Protected Glutamic Acid, R M. Tadros, Hossein Noureddini, Delmar C. Timm

Papers in Biomolecular Engineering

In a previous article,1 the development and molecular characterization of three polyesters from N-carbobenzyloxy-L-glutamic acid (ZGluOH) were reported. The polymers were a linear, heterochain polyester (ZGluOH and ethylene glycol), a crosslinked heterochain polyester (ZGluOH and diglycidyl ether of 1,4-butanediol), and a crosslinked, heterochain aromatic polyester (ZGluOH and diglycidyl ether of bisphenol A). In this manuscript, results of biodegradation studies are reported. The three polymers hydrolyzed to low molecular weight oligomers similar to the monomers with lipase. When exposed to a mixed culture of micro-organisms, the first two resins degraded to biomass and respiratory gases. The crosslinked heterochain aromatic polyester resisted …

Chemical Reactions And Mass Transport In Emulsion Liquid Membrane, Huifang Fan

Dissertations

Emulsion liquid membrane (ELM) systems are an important technique for wastewater cleanup. For this purpose, emulsion globules are dispersed in wastewater (external phase), each emulsion globule consisting of many tiny aqueous droplets (internal phase) enclosed in oil (membrane phase). Hazardous chemicals in the wastewater are transported into the internal droplets by mass transfer mechanisms.

Since Li first invented an ELM system in the 1960s, much research effort has been devoted to experimentally finding the optimal conditions for ELM recovery of various chemicals. Such studies would have benefited greatly from the guidance of mathematical models, especially those that provide analytical predictions. …

Fundamentals Of Dry Coating In Fluidized Bed, Rakesh Iyer

Theses

This thesis is devoted to the study of a novel dry coating method in fluidized bed - Dry Coating of Particles in Spouted bed (DCPS). The main objectives of this work were to study the feasibility of the process, both quantitatively and qualitatively, and to compare the results with coating by conventional mechanical mixing. Aerosol mechanics is applied to account for the following: 1) collision between the guest and host particles in a spouted bed (analysis of guest-host particle inertial fluid-dynamic interaction), and 2) to show how collision efficiency of guest particles with host particles affects the coating efficiency. An …

Study Of Reactive Media For Chromium Removal From Groundwater By Permeable Barriers, Hemant S. Desai

Theses

The purpose of the study was to select reduction media for application in permeable barriers for removing chromate ions from groundwater emanating from chromium refining sites in New Jersey. The high pH condition of groundwater in such sites is expected to pose limitations on the use of metallic iron (Fe⁰) as the sole reductive medium.

Reasonable reduction kinetics was achieved using iron at pH < 9.2. Several pH lowering media were investigated and were found to have either very slow or very fast dissolution kinetics, which rendered them impractical for use in passive permeable barriers. Two other media, namely: pyrite and siderite minerals have shown promising results, but fell short of achieving the required performance. Detailed investigation of interfacial processes in a batch reactor have shown that the addition of a small amount of a neutral salt can significantly improve chromate reduction kinetics, even at high pH conditions around 10.9.

The formation of passivating layers, which can slowdown the reaction significantly, was found to be important at high pH conditions. It is recommended that an injection system be used with the reactive barrier to …

Thermodynamic And Kinetic Analysis On Cl.+Rci -- Cl2+R.Reactions, Ch3cjo+O2= Products And Cjcho+O2= Products, Jongwoo Lee

Theses

Thermodynamic Parameters, ΔH°_f(298), S°₍₂₉₈₎ and Cp(T) are evaluated for C₁ and C₂ chlorocarbon molecules and radicals. These thermodynamic properties are used in evaluation and comparison of R.+ Cl₂ => R-Cl + Cl. (defined forward direction) reaction rate constants from the kinetics literature. Data from some 20 reactions in the literature show linearity on a plot of Ea_fwd vs. ΔH_rxn,fwd, yielding a slope of (0.38 ± 0.04) and intercept of (10.10 ± 0.77) kcal/mole. Thermodynamic properties (ΔH°₍₂₉₈₎, S°₍₂₉₈₎ and Cp(T) from 300 to 1500 K) for reactants, adducts, transition …

Oxidation And Adsorption Of Deoxyribonucleic Acid At Highly Ordered Pyrolytic Graphite And Glass Carbon Electrode, Jian-Zhang Zhou, Ling-Ling Wu, Jin Luo, Zhong-Hua Lin

Journal of Electrochemistry

It is shown that calf thymus DNA (CT DNA) can be adsorbed at highly ordered pyrolytic graphite (HOPG) electrode and detected by differential pulse voltammetry (DPV) and electrochemical atomic force microscopy (ECAFM). It is found that controlled potential pre-polarization influences largely the adsorption of dsDNA while it has little influence on ssDNA. It is demonstrated that ECAFM is useful to exploit adsorption of DNA at HOPGE. The pattern of adsorption of DNA at HOPG electrode that fits best with the experimental data is proposed. The results aslo shows that UV/Vis reflection spectroscopy, which has not been used in studying electrochemical …

Influence Of Ptfe And Nafion On The Utilization Efficiency Of Pt/C Catalyst In Pemfc, Xiao-Liang Cheng, Bao-Lian Yi, Jing-Xin Zhang, Ming Han, Ya-Guang Qiao

Journal of Electrochemistry

With cycling voltammetry curve(C-V), TEM and SEM photographs, the influence of PTFE and Nafion on the platinum utilization in catalyst layer of PEMFC was investigated. The results show that in gas diffusion electrode, the blocking effect of PTFE in the platinum utilization is not pronunced. In the thin-film catalyst layer, the electron conduct of the catalyst was blocked by the nafion solid and this caused the decrease of platinum utilization. With the increase of the nafion content in the catalyst layer, both platinum utilization and the electron conductivity decreased in the catalyst layer. Because the molecule size of nafion is …

Method Of Coupling Ligands Onto Supports And Products Produced Therefrom , William H. Velander, Anuradha Subramanian

Department of Chemical and Biomolecular Engineering: Patents

A method is disclosed for coupling a ligand within a porous support. The method involves mixing ligand and porous support under conditions sufficient to suppress coupling conditions of the ligand to the porous support while enhancing the relative rate of diffusion, to the rate of reaction, of the ligand into and within the porous support, and then altering the conditions to enhance rapid coupling of the ligand within the porous support. The alteration from diffusion conditions to coupling conditions involves a change in the reaction solution of pH, ionic strength, temperature, coupling competitor, such that a relatively lower Thiele Modulus …

Method Of Coupling Ligands Onto Supports And Products Produced Therefrom , William H. Velander

Department of Chemical and Biomolecular Engineering: Patents

A method is disclosed for coupling a ligand within a porous support. The method involves mixing ligand and porous support under conditions sufficient to suppress coupling conditions of the ligand to the porous support while enhancing the relative rate of diffusion, to the rate of reaction, of the ligand into and within the porous support, and then altering the conditions to enhance rapid coupling of the ligand within the porous support. The alteration from diffusion conditions to coupling conditions involves a change in the reaction solution of pH, ionic strength, temperature, coupling competitor, such that a relatively lower Thiele Modulus …

Reversal Flow In Fixed-Bed Reactors Operating Under Reaction-Regeneration Cycles, Daniel O. Borio, Noemi S. Schbib, Jorge E. Gatica

Chemical & Biomedical Engineering Faculty Publications

The unsteady state simulation of a set of industrial fixed-bed reactors is presented. The catalytic dehydrogenation of 1-butene into 1-3-butadiene is selected as case study. These reactors operate under reaction-regeneration cycles. Each stage of the process, i.e., dehydrogenation (deactivation by coking), steam purge, oxidative regeneration and evacuation, is simulated by means of the corresponding dynamic model. The kinetic parameters used in the dehydrogenation and regeneration stages for a Cr₂O₃/Al₂O₃ catalyst are taken from the literature. The performance of the reactors is investigated for two different operation modes: conventional …

Ultrasonic Enhancement Of Antibiotic Action On Escherichia Coli Biofilms: An In Vivo Model, Andrea M. Rediske, Beverly L. Roeder, Maren K. Brown, Jared L. Nelson, Rachel L. Robison, David O. Draper, G. Bruce Schaalje, Richard A. Robison, William G. Pitt

Faculty Publications

Biofilm infections are a common complication of prosthetic devices in humans. Previous in vitro research has determined that low-frequency ultrasound combined with aminoglycoside antibiotics is an effective method of killing biofilms. We report the development of an in vivo model to determine if ultrasound enhances antibiotic action. Two 24-h-old Escherichia coli (ATCC 10798) biofilms grown on polyethylene disks were implanted subcutaneously on the backs of New Zealand White female rabbits, one on each side of the spine. Low-frequency (28.48-kHz) and low-power-density (100- and 300-mW/cm2) continuous ultrasound treatment was applied for 24 h with and without systemic administration of gentamicin. The …

Direct Chip Attach For Low Alpha Emission Interconnect System, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

An interconnect system that has low alpha particle emission characteristics for use in an electronic device includes a semiconductor chip that has an upper surface and spaced apart electrically resistive bumps positioned on conductive regions of the upper surface, the electrically resistive bumps are made of a composite material of a polymer and metal particles, and a substrate that has conductive regions bonded to the electrically resistive bumps in a bonding process wherein the electrically resistive bumps convert to electrically conductive bumps after the bonding process.

Preparation And Surface Studies Of Negative Electron Affinity Semiconductors Photocathodes, Khaled A. Elamrawi

Electrical & Computer Engineering Theses & Dissertations

Fabrication of high quantum efficiency, long lifetime negative electron affinity photocathodes is important for applications such as photomultipliers, image intensifiers, electron beam lithography, electron microscopy, and polarized electron sources. The surface cleanliness of the III-V semiconductor photocathode is crucial in obtaining high photosensitivity.

GaAs(100) and InP(100) photocathodes are prepared by atomic hydrogen cleaning. The cleaning effect on the photocathode performance is discussed. The surface degradation mechanisms which reduce the photocathode lifetime are presented. The photocathode surface cleanliness, structure, and morphology are studied using reflection high-energy electron diffraction (RHEED).

Quantum efficiencies of ∼14% and 8% are obtained for GaAs and InP, …

Spatio-Temporal Growth Of Nematic Domains In Liquid Crystal Polymer Mixtures, Hao-Wen Chiu, Thein Kyu

College of Polymer Science and Polymer Engineering

Dynamics of phase separation and morphology development in mixtures of a low molar mass liquid crystal (LC) and a polymer have been investigated theoretically in comparison with experimental results. In the theoretical model, the combined free-energy densities of Flory-Huggins theory for isotropic mixing and Maier-Saupe theory for nematic ordering have been incorporated into the time-dependent Ginzburg-Landau equation (type C). The temporal evolution of the structure factor and the emergence of phase-separated liquid crystal domains have been simulated on the basis of an explicit central difference method based on a square lattice (128 x 128) with a periodic boundary condition. Of …