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Articles 11641 - 11670 of 14120

Full-Text Articles in Engineering

Electrically Conductive Polymeric Materials And Use Thereof, Ravi F. Saraf Nov 2000

Electrically Conductive Polymeric Materials And Use Thereof, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A polymer blend composition, capable of being made electrically conductive by application of heat having an electrically conductive upon doping polymer in undoped form; the undoped polymer is selected from the group consisting of substituted and unsubstituted polyparaphenylenevinylenes, polyanilines, polyazines, polythiophenes, poly-p-phenylene sulfides, polyfuranes, polyselenophenes, polyacetylenes filtered from soluble precursors and combinations and blends thereof, compounded and blended at a molecular scale with a dielectric polymer; wherein the dielectric polymer is selected from the group consisting of interpolymers of acrylonitrile-butadiene-styrene, acetal acrylic liquid crystal polymers, polybutylene terephthalate, polycarbonate, polyester, polyetherimide, polyethersulfone, polyethylene, polyethylene terephthalate, polyphenylene oxide, polyphenylene sulfide, polypropylene, polystyrene, …

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Electrically Conductive Polymeric Materials And Use Thereof, Ravi F. Saraf Nov 2000

Electrically Conductive Polymeric Materials And Use Thereof, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A polymer blend composition, capable of being made electrically conductive by application of heat having an electrically conductive upon doping polymer in undoped form; the undoped polymer is selected from the group consisting of substituted and unsubstituted polyparaphenylenevinylenes, polyanilines, polyazines, polythiophenes, poly-p-phenylene sulfides, polyfuranes, polyselenophenes, polyacetylenes filtered from soluble precursors and combinations and blends thereof, compounded and blended at a molecular scale with a dielectric polymer; wherein the dielectric polymer is selected from the group consisting of interpolymers of acrylonitrile-butadiene-styrene, acetal acrylic liquid crystal polymers, polybutylene terephthalate, polycarbonate, polyester, polyetherimide, polyethersulfone, polyethylene, polyethylene terephthalate, polyphenylene oxide, polyphenylene sulfide, polypropylene, polystyrene, …

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Method For Making A Heavy Wax Composition, Stephen J. Miller, Gerald P. Huffman, Naresh Shah Nov 2000

Method For Making A Heavy Wax Composition, Stephen J. Miller, Gerald P. Huffman, Naresh Shah

Chemical and Materials Engineering Faculty Patents

The invention includes a process of making a wax composition including: a process for making a heavy wax composition including the steps of (1) contacting a waste plastics feed containing primarily polyethylene in a pyrolysis zone at sub-atmospheric pressure, whereby at least a portion of the waste plastics feed is cracked, thereby forming a pyrolysis zone effluent including 1-olefins and n-paraffins; and (2) passing the pyrolysis zone effluent to a hydrotreating zone, for contacting with a hydrotreating catalyst at catalytic conditions.

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Membrane-Based Sorbent For Heavy Metal Sequestration, Dibakar Bhattacharyya, Leonidas G. Bachas, Lawrence Cullen, Jamie A. Hestekin, Subhas K. Sikdar Oct 2000

Membrane-Based Sorbent For Heavy Metal Sequestration, Dibakar Bhattacharyya, Leonidas G. Bachas, Lawrence Cullen, Jamie A. Hestekin, Subhas K. Sikdar

Chemical and Materials Engineering Faculty Patents

A process is provided for making membrane-based sorbents with enhanced binding activity that are particularly useful for heavy metal sequestration. The process includes the step of selectively hydrolyzing a polyacetylated membrane in order to deacetylated a surface layer of said membrane including the pore surfaces and expose free hydroxyl groups. This is followed by the oxidizing of the hydroxyl groups to aldehyde groups. This is then followed by the attaching of a polycarboxylic acid such as a polyamino acid, polyalkenoic acid or polypeptide to the membrane through the aldehyde groups. Preferably, the hydrolyzing step is completed under alkaline conditions and …

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Molecular Structure Of Polystyrene At Air/Polymer And Solid/Polymer Interfaces, K. S. Gautam, Alexander D. Schwab, Ali Dhinojwala, D. Zhang, S. M. Dougal, M. S. Yeganeh Oct 2000

Molecular Structure Of Polystyrene At Air/Polymer And Solid/Polymer Interfaces, K. S. Gautam, Alexander D. Schwab, Ali Dhinojwala, D. Zhang, S. M. Dougal, M. S. Yeganeh

College of Polymer Science and Polymer Engineering

IR-visible sum-frequency generation(SFG) spectroscopy has been used in a total internal reflection geometry to study the molecular structure of polystyrene (PS) at PS/sapphire and PS/air interfaces, simultaneously. The symmetric vibrational modes of the phenyl rings dominate the SFG spectra at the PS/air interface as compared to the antisymmetric vibrational modes at the PS/sapphire interface. This indicates approximately parallel orientation of the phenyl rings at the PS/air interface while nearly perpendicular orientation at the PS/sapphire interface, with respect to the surface normal.

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Lead-Free Interconnection For Electronic Devices, Ravi F. Saraf Oct 2000

Lead-Free Interconnection For Electronic Devices, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

An electronic device that is equipped with a plurality of bonding pads positioned on the device for making electrical interconnections and electrically conductive composite bumps adhered to the bonding pads wherein the bumps are formed of a composite material consisting of a thermoplastic polymer and at least about 30 volume percent of conductive metal particles based on the total volume of the metal particles and the thermoplastic polymer. The present invention is also directed to a method of making electrical interconnections to an electronic device by pressing a plurality of composite bumps of a polymeric based material against a substrate …

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Modeling Pichia Pastoris Growth On Methanol And Optimizing The Production Of A Recombinant Protein, The Heavy-Chain Fragment C Of Botulinum Neurotoxin, Serotype A, Wenhui Zhang, Mark A. Bevins, Bradley A. Plantz, Leonard A. Smith, Michael M. Meagher Oct 2000

Modeling Pichia Pastoris Growth On Methanol And Optimizing The Production Of A Recombinant Protein, The Heavy-Chain Fragment C Of Botulinum Neurotoxin, Serotype A, Wenhui Zhang, Mark A. Bevins, Bradley A. Plantz, Leonard A. Smith, Michael M. Meagher

Papers in Biotechnology

An unstructured growth model for the recombinant methylotrophic yeast P. pastoris Mut+ expressing the heavy-chain fragment C of botulinum neurotoxin serotype A [BoNT/A(Hc)], was successfully established in quasi-steady state fed-batch fermentations with varying cell densities. The model describes the relationships between specific growth rate and methanol concentration, and the relationships between specific methanol and ammonium consump-tion rates and specific growth rate under methanol-limited growth conditions. The maximum specific growth rate (μ) determined from the model was 0.08 h−1 at a methanol concentration of 3.65 g/L, while the actual maximum μ was 0.0709 h−1. The maximum specific methanol consumption rate was …

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Theoretical Investigation On Dynamics Of Photopolymerization-Induced Phase Separation And Morphology Development In Nematic Liquid Crystal/Polymer Mixtures, Domasius Nwabunma, Hao-Wen Chiu, Thein Kyu Oct 2000

Theoretical Investigation On Dynamics Of Photopolymerization-Induced Phase Separation And Morphology Development In Nematic Liquid Crystal/Polymer Mixtures, Domasius Nwabunma, Hao-Wen Chiu, Thein Kyu

College of Polymer Science and Polymer Engineering

A theoretical investigation of the dynamics of photopolymerization-induced phase separation (PIPS) and morphology development in a nematic liquid crystal (LC) polymer network mixture has been undertaken by incorporating photopolymerization kinetics into the coupled time-dependent Ginzburg-Landau (TDGL-Model C) equations. The simulation on the spatio-temporal evolution of the coupled LC concentration and orientation order parameters reveals that both morphological and scattering patterns for the orientation order parameter initially lag behind those of the concentration order parameter. However, the two fields evolve to the same spatial topologies with the progression of time. The PIPS dynamics is characterized only by the late stage of …

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Fourier Transform Raman Spectroscopy For Process Control In The Petroleum Industry, Kent Lawson Wise Oct 2000

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 …

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Film Mass Transfer Coefficient Expressions For Electroosmotic Flows, Athanasios I. Liapis, Brian A. Grimes Sep 2000

Film Mass Transfer Coefficient Expressions For Electroosmotic Flows, Athanasios I. Liapis, Brian A. Grimes

Chemical and Biochemical Engineering Faculty Research & Creative Works

Expressions are developed and presented that could be used to determine the film mass transfer coefficient of a solute in electroosmotic flows. In contrast to pressure-driven flows at low Reynolds numbers where the film mass transfer coefficient is independent of the linear characteristic dimension of the channel for flow, in electroosmotically driven flows at low Reynolds numbers the film mass transfer coefficient is shown to be a function of the ratio R/λ, where R is the channel radius and λ is the Debye length. This result implies that for electroosmotically driven flows in a packed bed or porous monolith with …

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Review Of: Joe Thornton, Pandora's Poison: Chlorine, Health, And A New Environmental Strategy, William Ronnenberg Jr. Sep 2000

Review Of: Joe Thornton, Pandora's Poison: Chlorine, Health, And A New Environmental Strategy, William Ronnenberg Jr.

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

Review of the book Pandora's Poison: Chlorine, Health, and a New Environmental Strategy by Joe Thornton, (M.I.T. Press 2000). Appendices, notes, references, index. LC 99-057011; ISBN 0-262-20124-0 [599 pp. $34.95 cloth, Five Cambridge Center, Cambridge MA 02142-1493] .

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Simulation Of Temperature And Stress Fields During Rcc Dam Construction, Ronaldo Luna, Yongfu Wu Sep 2000

Simulation Of Temperature And Stress Fields During Rcc Dam Construction, Ronaldo Luna, Yongfu Wu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The worldwide experience in the construction of roller-compacted concrete (RCC) dams together with the use of numerical solutions, allows the simulation of different scenarios in a computer. It is well documented that thermal control is one of the most important problems for RCC dam construction. The dam temperature changes due to the heat produced by the internal hydration of concrete and the environmental boundary conditions influencing the elastic modulus and creep properties of concrete. The construction process was simulated to study how the temperature and stress change during dam construction. The numerical methodology considers the effect of temperature on the …

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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 Aug 2000

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 …

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Nanofiltration-Based Diafiltration Process For Solvent Exchange In Pharmaceutical Manufacturing, Jignesh P. Sheth Aug 2000

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 …

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The Electro-Catalytic Oxidation Of Hcooh On Electrodeposited Pd Electrode, Quan Zhou, Cun-Zhong Zhang, Xiao-Lin Lu, Zhong-Da Wu Aug 2000

The Electro-Catalytic Oxidation Of Hcooh On Electrodeposited Pd Electrode, Quan Zhou, Cun-Zhong Zhang, Xiao-Lin Lu, Zhong-Da Wu

Journal of Electrochemistry

The coherent electroplates were prepared by electro depositing Pd on supporting materials glassy carbon. The surface morphology of the electrodes was examined by SEM. The electro oxidation of HCOOH in HClO4 solution was investigated by using cyclic voltammetry. The results show that the deposited conditions in the preparation of electrodes by electro depositing Pd affect the electrodes electro catalytic activity to the oxidation of HCOOH. The platinized Pd electrode on GC substrates using large current density is of higher catalytic activity to the oxidation of HCOOH than Pd electrode. The electro catalytic activity of PdO formed on the Pd …

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The Effect Of Anode Thickness In Sofcs With Anode Supported Ysz Film, Yi-Huang Zhang, Yi Jiang, Zi-Gui Lu, Yong-Lai Dong, Jing-Wang Yan Aug 2000

The Effect Of Anode Thickness In Sofcs With Anode Supported Ysz Film, Yi-Huang Zhang, Yi Jiang, Zi-Gui Lu, Yong-Lai Dong, Jing-Wang Yan

Journal of Electrochemistry

Solid oxide fuel cells with supported yttria stabilized zirconia electrolyte films on anode substrates of various thickness have been fabricated. The electrochemical performances of the SOFCs have been examined. The results showed that the cell performance was limited by the anodic overpotential, which is caused mainly by a concentration polarization when the anode substrate is thick. The anodic overpotential was reduced obviously as the thickness of anode substrate was decreased. As a result, the performance of the SOFC cell was improved. With a 0.5 mm anode substrate, a SOFC cell produced a power density about 0.19 W/cm2 at 800 …

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A New Method For The Preparation Of The Electrodes With Very Low Platinum Loading Used In Proton Exchange Membrane Fuel Cell, Zhi-Gang Shao, Bao-Lian Yi, Ming Han, Ya-Guang Qiao, Hao Liu, Jing-Rong Yu Aug 2000

A New Method For The Preparation Of The Electrodes With Very Low Platinum Loading Used In Proton Exchange Membrane Fuel Cell, Zhi-Gang Shao, Bao-Lian Yi, Ming Han, Ya-Guang Qiao, Hao Liu, Jing-Rong Yu

Journal of Electrochemistry

Research and development on low platinum loading electrode is very important in reducing the cost of proton exchange membrane fuel cell(PEMFC) stack. This paper has put forward a new method to prepare the electrode of PEMFC. The pore forming substances were used in this methd. The low platinum loading electrodes (0.02 mgPt⋅cm-2) have already been prepared with the method. Compared with the traditional method, the new method is simple, cheep, and easy to scale up. The superior composition of the electrodes is catalyst: pore forming substance: Nafion= 3:3:1. The performance of a single cell using this …

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Cathodic Indirect Oxidation Of Organic Compounds(Ⅱ)——Cathodic Indirect Epoxidation Of Olefine, Xue-Ying Zhang, Bao-Qiu Cui, Deng-Ping Gu, Wei Li Aug 2000

Cathodic Indirect Oxidation Of Organic Compounds(Ⅱ)——Cathodic Indirect Epoxidation Of Olefine, Xue-Ying Zhang, Bao-Qiu Cui, Deng-Ping Gu, Wei Li

Journal of Electrochemistry

We described a novel cathodic indirect epoxidation system in which O2 was first cathodically reduced to H2O2. Then VO(acac)2 was oxidized by H2O2 homogeneously to VO(acac)2OOH which was used to epoxidize some olefine such as maleic, fumaric and crotonic acids. Many affecting factors on the current efficiency were optimized. The research will contribute to the developments of organic electrosynthesis.

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The Study On Lithiated Titanium Composite Oxides As Negative Electrode For Lithium-Ion Battery, Xiao-Yan Yang, Shou-Nan Hua, Shu-Yong Zhang Aug 2000

The Study On Lithiated Titanium Composite Oxides As Negative Electrode For Lithium-Ion Battery, Xiao-Yan Yang, Shou-Nan Hua, Shu-Yong Zhang

Journal of Electrochemistry

Lithiated titanium composite oxides Li4Ti5O12 were prepared from Li2CO3 and TiO2. The XRD results of this composite oxides indicated that the compound had a spinel structure. The electrochemical behavior of lithiated titanium composite oxides was examined. The results showed that this material had an excellent cyclic capability and reversibility for lithium insertion, and had high specific capacity: the initial discharge capacity was 300 mAh·g-1 , and the reversible capacity was 100 mAh·g-1 . The discharge plateau (about 1.5 V) and the charge plateau (about 1.6 V) were very …

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Synthesis Of Li1+XMn2O4 Cathode Material For Lithium-Ion Batteries With Solution Method, Pei-Song Liu, Sing-Quarn Liu, Qing Li, Zhao-Yong Chen, Bai-Lan Zhang, Zuo-Long Yu Aug 2000

Synthesis Of Li1+XMn2O4 Cathode Material For Lithium-Ion Batteries With Solution Method, Pei-Song Liu, Sing-Quarn Liu, Qing Li, Zhao-Yong Chen, Bai-Lan Zhang, Zuo-Long Yu

Journal of Electrochemistry

The cathode materials Li1+xMn2O4 were prepared with citric acid complexing and solution impregnating methods. Structure characterization and specific surface area test were performed by means of XRD, BET methods, the influences of calcination temperature, Li/Mn molar ratio and raw materials on the structure and electrochemical capacity of samples have beem examined. The results showed that the Li/Mn molar ratio and calcimation temperature were the key factors affecting the electrochemical capacity of cathode materias. The optimum conditions for synthesis of  Li1+xMn2O4 cathode material were 0≤x≤0.05 and calcined at 750°C. The initial …

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Fermentation Strategies For Recombinant Protein Expression In The Methylotrophic Yeast Pichia Pastoris, Wenhui Zhang, Mehmet Inan, Michael M. Meagher Aug 2000

Fermentation Strategies For Recombinant Protein Expression In The Methylotrophic Yeast Pichia Pastoris, Wenhui Zhang, Mehmet Inan, Michael M. Meagher

Papers in Biochemical Engineering

Fermentation strategies for recombinant protein production in Pichia pastoris have been investigated and are reviewed here. Characteristics of the expression system, such as phenotypes and carbon utilization, are summarized. Recently reported results such as growth model establishment, application of a methanol sensor, optimization of substrate feeding strategy, DOstat controller design, mixed feed technology, and perfusion and continuous culture are discussed in detail.

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Determination Of The Intraparticle Electroosmotic Volumetric Flow-Rate, Velocity And Peclet Number In Capillary Electrochromatography From Pore Network Theory, B. A. Grimes, J. J. Meyers, Athanasios I. Liapis Aug 2000

Determination Of The Intraparticle Electroosmotic Volumetric Flow-Rate, Velocity And Peclet Number In Capillary Electrochromatography From Pore Network Theory, B. A. Grimes, J. J. Meyers, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

The results obtained from the pore network model employed in this work, clearly show that the magnitudes of the intraparticle electroosmotic volumetric flowrate, Q(intrap), and velocity, < v (intrap,x) >, in the pores of the charged porous silica particles considered in this study are greater than zero. The intraparticle Peclet number, Pe(intra), of a solute in these charged porous silica particles would be greater than zero, and, in fact, the magnitude of the intraparticle Peclet number, Pe(intrap), of lysozyme is greater than unity for all the values of the pore connectivity, n(T), of the intraparticle pores and of the applied electric potential difference …

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Membrane-Based Sorbent For Heavy Metal Sequestration, Dibakar Bhattacharyya, Leonidas G. Bachas, Lawrence Cullen, Jamie A. Hestekin, Subhas K. Sikdar Aug 2000

Membrane-Based Sorbent For Heavy Metal Sequestration, Dibakar Bhattacharyya, Leonidas G. Bachas, Lawrence Cullen, Jamie A. Hestekin, Subhas K. Sikdar

Chemical and Materials Engineering Faculty Patents

A process is provided for making membrane-based sorbents with enhanced binding activity that are particularly useful for heavy metal sequestration. The process includes the step of selectively hydrolyzing a polyacetylated membrane in order to deacetylate a surface layer of said membrane and expose free hydroxyl groups. This is followed by the oxidizing of the hydroxyl groups to aldehyde groups. This is then followed by the attaching of a polycarboxylic acid such as a polyamino acid, polyalkenoic acid or polypeptide to the membrane through the aldehyde groups. Preferably, the hydrolyzing step is completed under alkaline conditions and the oxidizing step is …

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Micro Goniometer For Scanning Microscopy, Ravi F. Saraf Aug 2000

Micro Goniometer For Scanning Microscopy, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A goniometer for performing scanning probe microscopy on a substrate surface is disclosed. The goniometer has a cantilever, having a cantilevered end and a supported end and a tip disposed at the cantilevered end of the cantilever. The goniometer also has a block disposed at the supported end of the cantilever. The block has at least one pair of piezoelectric layers, a pair of electrodes disposed about each individual piezoelectric layer such that varying a potential difference applied between the individual electrodes of a pair of electrodes causes the corresponding piezoelectric layer to deform, and a first insulating material disposed …

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Enhanced Adhesion Between A Vapor Deposited Metal And An Organic Polymer Surface Exhibiting Tailored Morphology, Ravi F. Saraf Aug 2000

Enhanced Adhesion Between A Vapor Deposited Metal And An Organic Polymer Surface Exhibiting Tailored Morphology, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

Enhanced adhesion between a vapor deposited metal and an organic polymer surface is achieved without utilizing any intermediate surface preparatory steps. The morphology of the polymer surface is tailored to produce mounds and dimples on the surface which leads to a mechanically tougher, interdigitated metal/polymer interface. In the preferred embodiment, a solution of a solvent or solvent system and two or more polymer precursors or polymers or combinations thereof are cast in a film on a substrate and heated to spontaneously form a rough surface due to phase separation. The surface topography of such a film consists of characteristic mounds …

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Facile Sol-Gel Synthesis Of Porous Silicas Using Poly(Propylene)Imine Dendrimers As Templates, Gustavo F. Larsen, Edgar Lotero, Manuel Marquez Aug 2000

Facile Sol-Gel Synthesis Of Porous Silicas Using Poly(Propylene)Imine Dendrimers As Templates, Gustavo F. Larsen, Edgar Lotero, Manuel Marquez

Gustavo Larsen Publications

Commercially available poly(propylene)imine (DAB-Am-32 and DAB-Am-64) dendrimers were used as single-molecule templates to tailor the porosity of silicas via a nonacidic sol-gel method. X-ray diffraction on both the as-prepared (oven-dried at 373 K) and the calcined (833 K) materials revealed that modest contraction took place on template removal and that the cavities created did not achieve three-dimensional ordering under the current synthesis conditions. Transmission electron microscopy of “Pt-stained” samples supported this picture. A modified Horvath–Kawazoe analysis of the argon adsorption isotherms indicated that DAB-Am-64 is a much more effective template than DAB-Am-32. Pyrolysis and oxidation protocols for template removal are …

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High Efficiency Separation Of Microbial Aggregates Using Capillary Electrophoresis, J. M. Schneiderheinze, Daniel W. Armstrong, G. Schulte, David J. Westenberg Aug 2000

High Efficiency Separation Of Microbial Aggregates Using Capillary Electrophoresis, J. M. Schneiderheinze, Daniel W. Armstrong, G. Schulte, David J. Westenberg

Chemistry Faculty Research & Creative Works

Recent advances in the technique of capillary electrophoresis have demonstrated fast, highly efficient separation of mixtures of intact microbes. This paper describes the application of this technique for the separation of microbial aggregates of Micrococcus luteus, Saccharomyces cerevisiae, or Alcaligenes faecalis. The aggregates of these microbes were resolved into several highly efficient peaks with analysis times under 10 min and efficiencies approaching 1 000 000 plates m-1 in some cases. A reproducible relationship was found between the electrophoretic mobility and the aggregation number or size of the cluster under a given set of experimental conditions. Often, cellular aggregation was reversible …

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Information Models For Planning And Scheduling Of Chemical Processes, Neil L. Book, Vivek Bhatnagar Jul 2000

Information Models For Planning And Scheduling Of Chemical Processes, Neil L. Book, Vivek Bhatnagar

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Process Data Exchange Institute (pdXi) has developed an information model for process engineering data. The pdxi information model is designed to facilitate the storage and exchange of steady-state process engineering data. Batch and real-time operating data can be stored and exchanged using the pdXi model as snapshots (data that characterizes the process at a specific point in time). Snapshots are an inefficient method for storing and exchanging batch and real-time data. Also, snapshots do not contain data that describe the processes that occur between snapshots. Sharma and Book modified the basic structure of the pdXi information model to make …

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Inherently Safer Analysis Of The Attainable Region Process For The Adiabatic Oxidation Of Sulfur Dioxide, Neil L. Book, Venkata U.B. Challagulla Jul 2000

Inherently Safer Analysis Of The Attainable Region Process For The Adiabatic Oxidation Of Sulfur Dioxide, Neil L. Book, Venkata U.B. Challagulla

Chemical and Biochemical Engineering Faculty Research & Creative Works

The attainable region (AR) method is used to obtain the optimal design and operating conditions for the adiabatic oxidation of sulfur dioxide to sulfur trioxide. The optimum process layout for this exothermic, catalytic, reversible reaction is a complex interconnection of reactors that achieves a conversion in excess of the equilibrium value for a single adiabatic reactor. The complex design obtained from the AR method is technically and economically superior to a single adiabatic reactor, but it is inferior from a safety perspective as a result of its complex interconnections and its high preheat temperature. The strategies of inherently safer design …

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A Multiscale, Bayesian And Error-In-Variables Approach For Linear Dynamic Data Rectification, Sridhar Ungarala, Bhavik R. Bakshi Jul 2000

A Multiscale, Bayesian And Error-In-Variables Approach For Linear Dynamic Data Rectification, Sridhar Ungarala, Bhavik R. Bakshi

Chemical & Biomedical Engineering Faculty Publications

A multiscale approach to data rectification is proposed for data containing features with different time and frequency localization. Noisy data are decomposed into contributions at multiple scales and a Bayesian optimization problem is solved to rectify the wavelet coefficients at each scale. A linear dynamic model is used to constrain the optimization problem, which facilitates an error-in variables (EIV) formulation and reconciles all measured variables. Time-scale recursive algorithms are obtained by propagating the prior with temporal and scale models. The multi-scale Kalman filter is a special case of the proposed Bayesian EIV approach.

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