Engineering Commons^™

The Effect Of Particle Properties On The Flow Characteristics Of Electrophotographic Powders, Joseph Pedano

Theses and Dissertations

The effect of particle size on the flow characteristics and tribo-electrical charge of dry electrophotographic (toner) powders was investigated. Toner samples, consisting of the same base formulation, but differing in particle size were prepared and studied using commercially available processing and analytical equipment. The effect of post-blending fumed silica into the toner was also investigated as part of this work. The results indicate that toner particle size has a strong effect on toner flow characteristics. The flowability measurements that were most affected by the particle size were the cohesiveness and compressibility properties of the toner powders. The data showed that …

Network Modeling Of The Intraparticle Convection And Diffusion Of Molecules In Porous Particles Packed In A Chromatographic Column, J. J. Meyers, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A pore network model (cubic lattice network) is constructed to represent the porous structure in a column packed with porous chromatographic particles. Expressions are developed and used to determine, through the utilization of the pore network model, the intraparticle interstitial fluid velocity and pore diffusivity of a solute as the pore connectivity, n(T), of the porous medium is varied from 2.6 to 6.0. The results show that the intraparticle interstitial velocity and the pore diffusivity increase significantly as the value of the pore connectivity, n(T), increases, and clearly indicate that the pore connectivity, n(T), plays a key role in determining …

Optimization Of Temperature-Glycerol-Ph Conditions For Fed-Batch Fermentation Process For Recombinant Hookworm (Ancylostoma Caninum) Anticoagulant Peptide (Acap-5) Production By Pichia Pastoris, Mehmet İnan, Vijay Chiruvolu, Kent M. Eskridge, George P. Vlasuk, Kenneth Dickerson, Scott Brown, Michael M. Meagher

Papers in Biochemical Engineering

This study was undertaken to determine the optimum pH, temperature and glycerol feed rate for the production of recombinant hookworm (Ancylostoma caninum) anticoagulant peptide (rAcAP-5) by Pichia pastoris using response surface methodology (RSM). A central composite design was used as an experimental design for allocation of treatment combinations in three blocks. The variables selected for study were pH, temperature and glycerol feed rate. pH was the most important variable affecting yield, specific yield and specific activity of rAcAP-5. Glycerol feed rate had a significant effect on the specific activity of rAcAP-5 (% of total secreted protein) while temperature …

Study On The Estimation And Control Of A Liquid Composite Molding Process, Dennis Sourlas, Susmito Naha, Gary Patterson, Richard Parnas

Chemical and Biochemical Engineering Faculty Research & Creative Works

An on-line nonlinear receding horizon control algortithm is employed in order to achieve setpoint tracking targets in the context of liquid composite molding processes. The robustness of this control strategy against process-model deviations is tested. Finally, recursive parameter estimation is employed as a means of actively enhancing the performance of the process control algorithm. © 1998 AACC.

The Latest World Wide Progress In Solid Oxide Fuel Cell, Yi Jiang

Journal of Electrochemistry

Solid oxide fuel cell (SOFC) is a novel, green electricity generation technology, which has been showing rapid development since 1980's. In light of its high efficiency, environmental friendly, fuel adaptability and long term stability, the Research, Development and Demonstration (RD&D) of this hype of full cell have been emphasized in a large number of developed countries. Based on the information communicated at the latest symposium on SOFC held last year in Aachen (Germany) and the knowledge gained through years of research in this field, a comprehensive review on the latest development of the tubular, this planar SOFC as well as …

A Preliminary Study Of The Synthesis Of Tin-Based Amorphous Material And Its Behavior On Lithium Intercalation, Li Liu, Han-Xi Yang, Ju-Tang Sun, Xing-Ping Ai

Journal of Electrochemistry

An amorphous lithium inserting anode material based on Tin oxide glass was synthesized by salification in solution and its properties on lithium intercalation was investigated by X ray diffraction (XRD), microelectrode voltammetry and charge discharge measurements. The results have shown that this kind of material has considerable electrochemical reversibility toward lithium intercalation deintercalation. The available discharge capacity of the material reaches 430 mAh/g with charge-discharge efficiency over 90%, showing a great potential for practical use.

Direct Electro-Oxidation Synthesis Of D-Arabinose On Spectroscopic Graphite Electrode, Hei Wei, Huang Ying

Journal of Electrochemistry

D Arabinose synthesized by direct electro-oxidative decarboxylation of D gluconate on graphite electrode from aqueous solutions. The effects of D gluconate concentration, electrolysis potential, temperature and electrolyte composition on the current efficiency and product yield of electrosynthsis are discussed. The laboratory scale electrosynthesis was achieved with flow through cell. The optimum technology conditions for electrosynthesis were obtained with orthogonal design method. Both galvanostatic and potentionstatic conditions have been exploited, the later was found to be more effective.

Study On Electrosynthesis Of Butyl Butyrate At Conducting Oxide Anode Support On Titanium, Jun-Xiang He, Jin-Cheng Zhou, Kang-Ning Chen

Journal of Electrochemistry

Synthesis of butyl butyrate by direct electroxidation of n butyl alcohol and the electrochemical behaviors of several selected conducting oxide electrodes (Pb/PbO_2, Ti/PbO_2, i/SnO₂+Sb₂O₃/PbO₂ and Ti/SnO₂+Sb₂O₃+PdO_x/PbO₂) have been investigated. The results demonstrated that the intermediate layers of SnO₂, Sb₂O₃ and PdO_x could significantly decrease the interfacial resistance of the electrodes, and that the Ti/SnO₂+Sb₂O₃+PdO_x/PbO₂ electrode possessed better electrocatelytic performance than others.

Primary Research Of Reversible Proton Exchange Membrane Regenerative Fuel Cells, Zhi-Gang Shao, Bao-Lian Yi, Ming Han

Journal of Electrochemistry

In this paper, we report the results of our studies on regenerative proton exchange membrane fuel cell (RPEMRFC) catalysts, electrode preparation and their performances. The Pt catalyst for the oxygen electrode was replaced by 60 w%Pt + 40 w%IrO₂ which reduces polarization by 0.2 V in a polymer protone exchange membrane fuel cell. The cycle performance of RPEMRFC was found to be manly effected by the stability of the diffiusion layer of bifunctional oxygen electrode.

Gas-Viscous Liquid Behavior And Its Implications For Pressure-Relief Design, Ahmad H. Alramadneh

Doctoral Dissertations

The two-phase flow system is a multifaceted engineering task with many industrial applications. The accurate prediction of the behavior of such systems is of special importance.

This study is directed toward improving and integrating what is known about the gas-viscous liquid flow behavior during vessel depressurization, specifically, visually characterizing the top venting of saturated-viscous fluids. The experimental results are needed to improve the design methodologies for pressure-relief systems.

Lab-scale vessel depressurization experiments with initially saturated fluids were performed. In particular, a problem arose when sodium tetraborate decahydrate solution (model fluid) saturated with carbon dioxide gas is vented from a 5.3-liter …

Chromium Oxides And Lithiated Chromium Oxides. Promising Cathode Materials For Secondary Lithium Batteries, Pankaj Arora, Dong Zhang, Branko N. Popov, Ralph E. White

Faculty Publications

Chromiumoxides and lithiated chromium oxides were synthesized by thermal decompositionof chromium trioxide (CrO₃) at high temperatures and oxygen pressures.Synthesis temperature and pressure markedly affect the performance of thesecathode materials. Higher pressures lead to a higher O/Cr ratioand fewer impurities in the final product. These materials arestable intercalation hosts for lithium, and exhibit a higher capacitythan any of the prominent positive electrodes used in secondarylithium batteries. m-CrO_x has a capacity of 255 mAh/g, while m-LiCrO_xhas a capacity of 210 mAh/g, during the first discharge. Theaverage voltage of these cells is 3.0 V vs. Li/Li …

Entropy Generation In A Rectangular Packed Duct With Wall Heat Flux, Yaşar Demirel, Ramazan Kahraman

Papers in Thermal Mechanics

The entropy generation due to heat transfer and friction has been calculated for fully developed, forced convection flow in a large rectangular duct, packed with spherical particles, with constant heat fluxes applied to both the top (heated) and bottom (cooled) wall. An approximate analytical expression for the velocity profile developed for packed bed with H/dp > 5 has been used together with the energy equation of fully developed flow to calculate the non isothermal temperature profiles along the flow passage. The velocity profile takes into account the increase in the velocity near the wall due to the higher voidage in this …

Magma Traps And Driving Pressure: Consequences For Pluton Shape And Emplacement In An Extensional Regime, John Patrick Hogan, Jonathan D. Price, M. Charles Gilbert

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The level of emplacement and final form of felsic and mafic igneous rocks of the Wichita Mountains Igneous Province, southwestern Oklahoma, U.S.A. Are discussed in light of magma driving pressure, lithostatic load, and crustal magma traps. Deposition of voluminous A-type rhyolites upon an eroded gabbroic substrate formed a subhorizontal strength anisotropy that acted as a crustal magma trap for subsequent rising felsic and mafic magma. Intruded along this crustal magma trap are the A-type sheet granites (length/thickness 100:1) of the Wichita Granite Group, of which the Mount Scott Granite sheet is typical, and smaller plutons of biotite bearing Roosevelt Gabbro. …

Nanofiltration With Organic Solvents And Its Possible Applications To Organic Syntheses, Jose Antonio Whu

Theses

Experimental results on the nanofiltration (NF) separation behavior of three different solvent- compatible membranes are presented for three organic solutes of molecular weights 351, 826 and 1355 in methanol; the manufacturer-specified molecular weight cut-offs (MWCO) of the membranes are 250, 400 and 700. Membranes were primarily tested at 440 psig, at different concentrations of the solutes in methanol; the effect of varying the applied pressure was also briefly explored. The solvent permeation flux and the solute rejection were time dependent for an extended initial period; the membranes had to be compacted to achieve steady-state results. Furthermore, the manufacturer-specified MWCO was …

Direct Electrochemical Reaction Of Cytochrome C At The Poly (Ethylene Oxide) Film Modified Gold Electrodes, Xiao-Gang Qu, Gong-Quan Sun, Hui Yang, Tian-Hong Lu

Journal of Electrochemistry

In this paper, the direct electrochemical reaction of cytochrome c was sudied at the poly (ethylene oxide) film modified gold electrodes. It was found the PEO is a good promoter for the electrochemical reaction of cytochrome c, and the reversibility of reaction of cytochrome c was found to depend on the molecular weight of PEO and the morphology of the PEO films.

Studies On The Electrode Kinetics Of Electrooxidation Of Mn2+, Wan-Li Hu, Tong Su, Wei Guo, Ding Zhou

Journal of Electrochemistry

The mechanism of electrooxidation of MnSO₄ on Pb Sb As alloy anode was investigated by using rotating disc electrode technique. The results shown that the conditional standard potential of Mn(Ⅲ)/Mn(Ⅱ)in 40% H₂SO₄ is 0.886 4 V.The rate controlling step of electrode process is mixed controlled by charge transfer and diffusion.

Electrooxidation Of Benzene To Benzoquinone In A Packed Bed Reactor, Xin-Sheng Zhang, Ping Ding, Ying-Chun Dai, Wei-Kang Yuan

Journal of Electrochemistry

A packed electrode reactor was used to oxidize to benzoquinone. Anode bed of the reactor has a size of 10～30 mm×450 mm×50 mm(thickness×length×width),and was packed porous lead alloy. A dispersion of benzene in 1 mol/L aqueous sulfuric acid was passed through the reactor. Current efficiency for benzoquinone generation is 62.9% at optimal operating condition: velocity of electrolyte flow, 0.19 ms ^-1 ;current, 10 A; thickness of anode bed, 10 mm, and percentage of benzene, 24%.

Study Of Proton Exchange Membrane Fuel Cells(Pemfc), Shan-Hai Ge, Bao-Lian Yi, Hong-Fen Xu, Ming Han, Zhi-Gang Shao

Journal of Electrochemistry

The electrode kinetic parameters for proton exchange membrane fuel cells(PEMFC) were investigated by measuring the relations of cell potential and current density. An experimental stack of PEMFC which can be operated at E cell =0.7V, I =0.55A/cm² steadily is presented, and the effects of electrode structure and operation conditions such as temperature, pressure, humidification, flow rate on the performance of PEMFC are discussed.

Influence Of Ash Deposit Chemistry And Structure On Physical And Transport Properties, Larry Lin Baxter 8507091

Faculty Publications

Boiler ash deposits generated during combustion of coal, biomass, black liquor, and energetic materials affect both the net plant efficiency and operating strategy of essentially all boilers. Such deposits decrease convective and radiative heat exchange with boiler heat transfer surfaces. In many cases, even a small amount of ash on a surface decreases local heat transfer rates by factors of three or more. Apart from their impact on heat transfer, ash deposits in boilers represent potential operational problems and boiler maintenance issues, including plugging, tube wastage (erosion and corrosion), and structural damage. This report relates the chemistry and microstructural properties …

Electronic Package Comprising A Substrate And A Semiconductor Device Bonded Thereto, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A composition containing a polymeric matrix and a conductive filler component is provided. The conductive filler component comprises conductive particles and a polymer selected from the group consisting of substituted and unsubstituted polyanilines, substituted and unsubstituted polyparaphenylenevinylenes, substituted and unsubstituted polythiophenes, substituted and unsubstituted polyazines, substituted and unsubstituted polyparaphenylenes, substituted and unsubstituted polyfuranes, substituted and unsubstituted polypyrroles, substituted and unsubstituted polyselenophene, substituted and unsubstituted poly-p-phenylene sulfides and substituted and unsubstituted polyacetylenes, and mixtures thereof, and copolymers thereof. The compositions of the present invention are useful as adhesives for interconnecting a semiconductor chip to a substrate

Electronic Package Comprising A Substrate And A Semiconductor Device Bonded Thereto, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A composition containing a polymeric matrix and a conductive filler component is provided. The conductive filler component comprises conductive particles and a polymer selected from the group consisting of substituted and unsubstituted polyanilines, substituted and unsubstituted polyparaphenylenevinylenes, substituted and unsubstituted polythiophenes, substituted and unsubstituted polyazines, substituted and unsubstituted polyparaphenylenes, substituted and unsubstituted polyfuranes, substituted and unsubstituted polypyrroles, substituted and unsubstituted polyselenophene, substituted and unsubstituted poly-p-phenylene sulfides and substituted and unsubstituted polyacetylenes, and mixtures thereof, and copolymers thereof. The compositions of the present invention are useful as adhesives for interconnecting a semiconductor chip to a substrate

Design Considerations For A Three-Phase Fluidized-Bed Bioreactor, S Manyele

Tanzania Journal of Engineering and Technology (TJET)

The design Of a three-phase fluidized bed bioreactor using novel biomass support for industrial wastewater treatment is reported in this paper. A column of 0.20 m diameter with variable height up to 6.60 m equipped with a foam breaker tank was designed, commissioned and operated. A novel biomass support, KMTR support, has been used Separate gas and liquid feeding systems were designed to facilitate proper bioreactor operation. A flat distriburor plate with 4 mm holes- diameter was desined A study on the hydrodynamic properties of the three-phase fluidized bed bioreactor revealed high values of bed expansion and air hold-ups. Purification …

Use Of Dissolved Oxygen Concentration Probes In Biological Wastewater Treatment Plants, S Manyele

Tanzania Journal of Engineering and Technology (TJET)

A study on use Of dissolved oxygen probes (DOP) for measurement Of oxygen concentration in warer and wastewater treatment is presented. The principles Of operation, design considerations and selection criteria for Two types of probes, viz. galvanic and polarographic, are discussed Use of polarographic probes in n rhree-phase fluidized bed bioreactor and in laboratory experiments is presented and discussed. The effect of airflow rate and treatment time on dissolved oxygen concentration was found to be significant. It was found that polarographic probes are important equipment in determining the pollution of the industrial effluents. Finally, the use of the DOC probes …

Removal Of Volatile Organic Compound (Voc) Vapors In Biotrickling Filters : Process Modeling And Validation With Chlorinated Aromatic Compounds, Christos J. Mpanias

Dissertations

This study dealt with the removal of vapors of volatile organic compounds from airstreams in biotrickling filters (BTFs). A detailed general model was developed for describing the process under steady-state conditions. The model accounts for mass transfer between phases (air, liquid, biofilm) and biodegradation of pollutants in the biofilm. It also accounts for potential kinetic interactions among pollutants as well as potential process limitations by oxygen availability.

The general model was experimentally validated using mono-chlorobenzene (m-CB) and ortho-dichlorobenzene (o-DCB) as model compounds either alone or in mixture with each other. Before BTF experiments were undertaken, a systematic kinetic study was …

Modelling Of In-Situ Bioremediation With Emphasis On Inhibitory Kinetics And Biomass Growth, Dilip Kumar Mandal

Dissertations

This thesis was motivated by the need for better engineering tools to predict the extent of contaminant plume migration in the saturated zone. The principal result was a mathematical model analogous to a catalytic packed-bed reactor, in which the subsurface was considered to be composed (conceptually) of soil aggregates (the "catalyst" particles, in which biodegradation, diffusion, and sorption take place), and a mobile phase (groundwater) passing around the aggregates, in which convection, axial diffusion, and mass transfer from the aggregates take place.

The modelling emphasis was on a more detailed exposition of the biokinetics of the system (including an inhibitory …

Rheological Characterization Of Unmodified And Chemically Modified Poly (Ethylene Terephthalate) Resins, Jorge Quintans

Theses

Intrinsic viscosity (IV) has often been misused for estimating both melt viscosity and elasticity of poly(ethylene terephthalate) (PET). A rheological study was conducted to determine the variations between a virgin unmodified PET and a recycled and chemically modified PET, both having a reported nominal IV of 0.95.

The modified material had a larger melt viscosity (capillary and dynamic) than the virgin material (by an average of 61%). The extrudate swell, a better indicator of melt elasticity, of the modified was more than 110% greater than that of the unmodified material. Activation energies for melt viscosity and extrudate swell were found …

An Experimental Study On Removal Cadmium From Wastewater By Emulsion Liquid Membrane, Jing-Chi Shiu

Theses

Research was conducted on cadmium, a heavy metal pollutant, extraction out of wastewater by means of an emulsion liquid membrane system. The emulsion liquid membrane was made of a carrier (di(2-ethylhexyl) phosphoric acid), a surfactant (ECA 4360J), and a stripping agent (sulfuric acid). The effects of using the following parameters on the membrane to optimize the operating conditions were investigated: type of buffer solutions, initial external phase pH, initial cadmium concentration, internal sulfuric acid concentration, impeller stirring speed, carrier concentration, surfactant concentration, and selectivity between cadmium and sodium ion.

The best performance for the system presented in this thesis was: …

In-Situ Raman Spectroscopic Study Of The Oxidation And Reduction Of Ag Electrode In Na2So4, Yan-Xia Chen, Kai-Qi Huang, Zhong-Qun Tian

Journal of Electrochemistry

In-situ Raman spectroscopy combined with cyclic voltammogram measurements was used to investigate formation of oxygen species at Ag electrode surfaces during the oxidation and reduction process in 0.1 mol/L Na₂SO₄ solution. The time dependent Raman spectra show that at potentials positive of 0.2 V, adsorption of oxygen atom occurs, while at the potentials positive of 0.4 V, some oxygen atoms migrate into subsurface of the Ag electrode and the other form strongly bound oxygen on the surface through chemical bond. At the same potentials, part of the silver atoms are oxidized and form Ag₂SO_{4 …}

Studies Of Surface Alloy As High Efficient Electrocatalyst For Glyoxylic Acid Synthesis, Sheng-Pei Chen, Sheng-Qing Xia, Shi-Gang Sun

Journal of Electrochemistry

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Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A simple process for card assembly by Direct Chip Attachment (DCA) uses electrically conductive adhesives. Two methods create the same intermediate wafer product with a layer of insulative thermoplastic and conductive thermoplastic bumps. After sawing or dicing the wafer to form the chips, the chips are adhered to chip carriers with conductive pads which match the conductive thermoplastic bumps, using heat and pressure. Chips may be easily removed and replaced using heat.