Chemical Engineering Commons^™

Electrosynthesis Of A New Electroactive Poly(2,2'-Diaminophenyloxydisulfide), Yu-Zhi Su, Yan-Wen Rao, Ye Yang, Mei-Bing Chen, Yin-Ling Qiu, Yong-Hua Zhang, Ke-Cheng Gong

Journal of Electrochemistry

A new electroactive poly (2,2' diaminophenyloxydisulfide) (PDAPD) was successfully synthesized from acetonitrile(AN)/tetrahydrofuran (THF) solutions containing the supporting electrolyte (LiClO₄) and the various kinds of acids (HCl, CF₃COOH, CCl₃COOH) on Pt electrode by consecutive cyclic voltammiry. The effects of the concentrations of supporting electrolyte (LiClO₄) and acid (HCl, CF₃COOH, CCl₃COOH) on electrodepositon of PDAPD film were investigated. The best experimental conditions for electrosynthesis of a highly electroactive conducting polymer film are that the concentrations are 0.1 mol/L and between 0.05 mol/L～0.5 mol/L,respectively for LiClO₄ and HCl.

Research Progress On Proton Exchange Membranes Of Fuel Cells, Jing-Rong Yu, Dan-Min Xing, Fu-Qiang Liu, Jian-Guo Liu, Bao-Lian Yi

Journal of Electrochemistry

The proton exchange membrane fuel cells (PEMFC) use proton exchange membranes(PEM) as their electrolytes. The performance of the PEMFC is strongly dependent on the characteristics of the PEM. In this paper, the requirements of the PEM utilized in the PEMFC were analyzed. The per-fluorinated, partially fluorinated and non-fluorinated PEM were introduced respectively. The structures, preparation, properties of the various types of PEM and their applications in the PEMFC were also discussed in detail.

The Influence Of Synthesis Conditions On The Electrochemical Properties Of Spinel Limn2O4, Jun-Feng Xu, Zhi-Yu Jiang

Journal of Electrochemistry

The electrochemical properties of spine LiMn₂O₄ synthesized via a solid state reaction were investigated. Electrolysis MnO₂(EMD), Li₂CO₃ ,LiOH and LiNO₃ were used as the initial materials. It was found that the electrochemical properties of LiMn₂O₄ were strongly influenced by the synthesis conditions. The LiMn₂O₄ sample sprepared via the reactionof EMD and LiNO₃ showed the best properties for a lithiumion intercalation reaction. The procedure includes two steps:pretreatment at 280 ℃ for 6 hours to initiate the permeation of melting LiNO₃ into the microporesof EMD …

Adsorption And Oxidation Of Methanol On Pt And Sb, S Modified Pt Electrodes Using Cyclic Voltammetry And Eqcm, Guo-Liang Chen, Sheng-Pei Chen, Heng Lin, Xing-Hong Zheng, Shi-Gang Sun

Journal of Electrochemistry

The processes of adsorption and oxidation of methanol on Pt, Pt/Sb ad and Pt/S ad electrodes were studied by using cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The results demonstrated that the oxidation of methanol depends strongly on oxidation states of electrode surface. Sb adatoms on Pt surface can adsorb oxygen at relatively low potentials, and exhibit catalytic effects for methanol oxidation. In contrast to Pt electrodes, the oxidation peak potential of methanol in this case negatively shifted to about 130 mV. In a contrary, the oxidation of S_ad atoms consumes oxygen species of Pt electrode surface. As …

Inferring Liquid Chaotic Dynamics In Bubble Columns, M. Cassanello, F. Larachi, A. Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experiments Carried Out to Study the Liquid Displacements in Bubble Columns Via the Computer Automated Radioactive Particle Tracking Technique Are Analyzed by Means of Lagrangian and Qualitative Dynamics Tools. the Lagrangian Approach Yields the Detailed Motion Sequences of the Tracer as Entrained by the Fast Ascending Bubbles or by the Liquid Flow Alongside the Column Walls. the Qualitative Dynamics Tools, on the Other Hand, Provide Prima Facie Corroboration of Chaos in Liquid Motion based on an Analysis of the Volume-Averaged Kolmogorov Entropy and the Mutual Information Function. Other Features of the Chaotic Motion, the Reconstructed Attractors and the Radial and …

Non-Repressing Carbon Sources For Alcohol Oxidase (Aoxi) Promoter Of Pichia Pastoris, Mehmet İnan, Michael M. Meagher

Papers in Biochemical Engineering

The growth of Pichia pastoris in a mixture of either glycerol or glucose and methanol follows a diauxic growth, with C1, utilizing enzymes being repressed. Therefore, these carbon sources can not be used as a mixture with methanol to simultaneously grow P. pastoris and induce C1, utilizing enzymes, especially in shake flask cultures of AOX-deficient P. pastoris. Among the alternative carbon sources tested, alanine, sorbitol, mannitol and trehalose, did not repress β-gal production when methanol was used as an inducer in mut- strain of P. pastoris. Our results show that either one of alanine, sorbitol, …

Taylor Cone And Jetting From Liquid Droplets In Electrospinning Of Nanofibers, Alexander L. Yarin, S Koombhongse, Darrell Hyson Reneker

College of Polymer Science and Polymer Engineering

Sessile and pendant droplets of polymer solutions acquire stable shapes when they are electrically charged by applying an electrical potential difference between the droplet and a flat plate, if the potential is not too large. These stable shapes result only from equilibrium of the electric forces and surface tension in the cases of inviscid, Newtonian, and viscoelastic liquids. In liquids with a nonrelaxing elastic force, that force also affects the shapes. It is widely assumed that when the critical potential phi (0*) has been reached and any further increase will destroy the equilibrium, the liquid body acquires a conical shape …

Monte Carlo Simulations Of Peptide Adsorption On Solid Surfaces (Monte Carlo Simulations Of Peptide Adsorption), D. Song, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Monte Carlo (MC) simulations of a short peptide in bulk water and at charged and neutral surfaces were performed. To pursue the objective of finding whether or not the water structure around the peptide changes upon adsorption and how these changes affect the orientation of the peptide at the surface, the water structure around the peptide in the bulk and at charged and neutral surfaces were compared by analyzing the pair correlation functions (PCFs) between selected groups in the peptide and the surrounding water. In general, evidence was obtained that water is not homogeneously distributed over the peptide surface.

Silica-Based Membrane Sorbent For Heavy Metal Sequestration, Dibakar Bhattacharyya, Stephen M. Ritchie, Leonidas G. Bachas, Jamie A. Hestekin, Subhas K. Sikdar

Chemical and Materials Engineering Faculty Patents

An apparatus providing for metal ion/nitrate entrapment comprises a chemically activated, microfiltration, composite polymer and silica-based membrane including a polyamino acid attached thereto through reaction of a terminal amine group of the polyamino acid with the membrane. A method for preparing such a chemically activated or polyamino acid functionalized membrane includes the steps of permeating the silica-based membrane with a solution of silane and a solvent so as to react methoxy groups of the silane with silanol groups of the membrane to incorporate epoxide groups and attaching a polyamino acid to the membrane by reacting a terminal amine group of …

Characteristics And Sequence Of Phosphoglycolate Phosphatase From A Eukaryotic Green Alga Chlamydomonas Reinhardtii, Tarlan G. Mamedov, Kensaku Suzuki, Kenji Miura, Ken-Ichi Kucho, Hideya Fukuzawa

Papers in Biochemical Engineering

Phosphoglycolate phosphatase (PGPase), a key en¬zyme of photorespiration in photosynthetic organisms, was purified from Chlamydomonas reinhardtii. The en¬zyme was an ~65-kDa homodimer with a pI value of 5.1 composed of ~32-kDa subunits not connected by any S–S bridges. It was also highly specific for phosphoglycolate with a Km value of 140 μM and an optimal pH between 8 and 9. The activity was strongly inhibited by CaCl2, and it recovered competitively following the addition of MgCl2 or EGTA. A mobility shift was observed in SDS-polyacrylamide gel electrophoresis by the addition of CaCl2, indicating that the enzyme binds to Ca2+ . …

Method For Removal Of Ammonia From Fly Ash, Jiann-Yang Hwang

Michigan Tech Patents

A method for removing ammonia and ammonia compounds from fly ash and other combustion by-products is provided. The method may be performed with raw or processed fly ash, or it may be performed in conjunction with a wet beneficiation process. The method involves mixing the ammonia-contaminated fly ash with water and then filtering and/or drying the solution to remove the ammonia and water. The method produces fly ash having an ammonia content of less than about 60-80 ppm, which allows the fly ash to be utilized in a number of applications.

The Effect Of Low Levels Of Zirconia Addition On The Mechanical Properties Of Hydroxyapatite, Mark R. Towler, I. R. Gibson

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effect of low levels of zirconia addition on the mechanical properties of hydroxyapatite was analyzed. Optimum amount of zirconia required to prevent decomposition of hydroxyapatite during sintering was determined. The particle size, morphology and surface area were measured and calcium to phosphorus ratio and trace element impurity content were determined by x-ray fluorescence. Low level addition of zirconia resulted in composites with better mechanical properties and minimum levels of decomposition.

Process For Making A Lubricating Composition, Stephen J. Miller, Gerald P. Huffman, Naresh Shah

Chemical and Materials Engineering Faculty Patents

The invention includes a process of making a lubricating oil composition including: a process for making a high VI lubricating oil composition including the steps of (1) contacting a waste plastics feed including mainly polyethylene in a pyrolysis zone at pyrolysis conditions, whereby at least a portion of the waste plastics feed is cracked, thereby forming a pyrolysis zone effluent including 1-olefins and n-paraffins; (2) passing the pyrolysis zone effluent, including a heavy fraction and a middle fraction, the pyrolysis effluent middle fraction including 1-olefins, to a separations zone; where the pyrolysis effluent heavy fraction portion is separated from the …

Institutional And Other Constraints To Non-Oil Exports., R. O. Madaki

Bullion

This paper examines the non-oil exports sector in Nigeria which had witnessed a lacklustre performance despite the several statements of government's interest in export-biased growth strategy and the establishment of several export facilitating institutions. The paper further observes that a major problem with Nigeria's non-oil export sector is that it is not predicated on the design and implementation of appropriate and coherent economic policies as there is no clear export promotion blue print in Nigeria. Consequently, the sector is facing a number of institutional and other domestic and external problems. The remaining part of the paper briefly highlight some of …

Evolutionary Polymorphic Neural Networks In Chemical Engineering Modeling, Li Gao

Dissertations

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

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

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

Dissertations

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

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

Electrode Modification Using An Unzippable Polymer Paste, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A paste is described for capping electrodes with an oxide free metal layer incorporating a solvent, an unzippable polymer and particles. The electrode could be an interconnect such as a C4 bump. A method for forming a coating and for testing integrated circuit chips is also described. The invention overcomes the problem of interconnecting Pb containing electrodes that are covered with an insulating oxide on integrated circuit chips by coating the Pb containing electrode with Au to provide an oxide free surface for testing and interconnection.

The Crystallisation Of Glasses From The Ternary Caf2-Caal2si2o8-P2 O5 System, A. Clifford, R. G. Hill, Mark R. Towler, D. J. Wood

Chemical and Biochemical Engineering Faculty Research & Creative Works

A study of glasses from the ternary system CaF₂-CaAl₂Si₂O₈-P₂O₅ has been carried out. It has been shown that glasses with low phosphorus contents and high fluorite contents crystallise to fluorite. Fluorine reduces the glass transition temperature and is also required for the formation of fluorapatite (FAP). In the absence of fluorine in the glass no apatite phase is formed. Bulk nucleation of FAP is favoured for glasses with Ca:P ratios close to the apatite stoichiometry of 1.67 and with low crosslink densities. Thermal gravimetric analysis showed significant weight losses …

Radio Frequency (Rf) Transponder (Tag) With Composite Antenna, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

An antenna composed of composite material which can be screen printed is proposed for RFID transponders and other RF communication systems.

Green Electrochemistry. Examples And Challenges, Michael A. Matthews

Faculty Publications

Electrochemical methods have been proposed for synthesis of organic compounds, including conversion of CO₂. Such methods may provide a basis for environmentally friendly and sustainable methods for chemical production. Nevertheless, electrochemical syntheses are not widely utilized. Several examples of ongoing research are presented that illustrate both the opportunities as well as the challenges associated with the utilization of electrochemistry for green chemical manufacturing.

The Effect Of Ethanol And Acetate On Protein Expression In Pichia Pastoris, Mehmet İnan, Michael M. Meagher

Papers in Biochemical Engineering

Pichia pastoris is an excellent host for high-level heterologous gene expression, but there is still much interest in improving the productivity of recombinant protein production. P. pastoris produces a small amount of ethanol as a by-product during the glycerol fed-batch phase and the mixed-feed induction phase (glycerol-methanol) of high cell density fermentations, regardless of the phenotype (Mutf, Mut" or Mut-). We have investigated ethanol repression of the AOXl promoter using strains, GS115 (Mutf) and MC100-3 (Mut-), expressing an AOXI-lac2 fusion. The addition of 10 mg t1 ethanol at the start of methanol induction delayed P-galactosidase production and methanol utilization …

Expression Of A Heterologous Protein C In Mammary Tissue Of Transgenic Animals Using A Long Whey Acidic Protein Promoter , William H. Velander, Henryk Lubton, William N. Drohan, Lothar Hennighausen

Papers in Biotechnology

An isolated DNA sequence which regulates the expression of a heterologous gene composed of a mouse whey acidic protein promoter having a length of greater than about 2.4 kb extending upstream from the unique KpnI site in the mouse whey acidic protein gene is disclosed. Specifically a mouse whey acidic protein promoter of about 4.1-4.2 kb in length extending upstream from the unique KpnI site is preferred. This mouse whey acid protein promoter is operably linked to a DNA sequence encoding a heterologous polypeptide and used to prepare transgenic non-human mammals expressing the heterologous polypeptide in their milk. Particularly efficient …

Modeling The Ultraviolet Photodegradation Of Rigid Polyurethane Foams, C. R. Newman, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Before the Montreal Protocol of 1987 and the subsequent phasing-out of chlorofluorocarbons (CFCs) in industrial applications, rigid polymer foams were made using these compounds as secondary blowing agents. The CFCs remain trapped in the gaseous part of the cellular foam structure, and once discarded these foams constitute a significant reservoir for the environmental release of ozone-depleting chemicals. Environmental degradation of the foam accelerates this process. Of particular interest in this work is the degradative effect of ultraviolet (UV) light on rigid polyurethane foams. Foams were subjected to accelerated weathering conditions and then viewed with a scanning electron microscope. The thin …

Rfid Transponders With Paste Antennas And Flip-Chip Attachment, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A radio frequency transponder is provided which comprises a substrate layer, a radio frequency integrated circuit affixed to said substrate layer; and an antenna provided on said substrate layer in electrical connection with said radio frequency integrated circuit. The antenna is comprised of a conductive paste material having a resistivity of approximately 20 µΩ-cm, which is greater than the resistivity of a conventional etched copper antenna, but still sufficiently low to provide a radio frequency transponder having acceptable read range. The substrate layer further comprises a flexible organic material. The radio frequency integrated circuit is disposed in a flip-chip configuration …

Transgenic Non-Human Mammals Expressing Human Coagulation Factor Viii And Von Willebrand Factor , William H. Velander

Department of Chemical and Biomolecular Engineering: Patents

A non-human transgenic mammalian animal, as described above, contains an exogenous double stranded DNA sequence stably integrated into the genome of the animal, which comprises cis-acting regulatory units operably linked to a DNA sequence encoding human Factor VIII protein and a signal peptide, where the cis-acting regulatory units are active in mammary gland cells and the signal peptide is active in directing newly expressed Factor VIII into the milk of the animal. The promoter may be a milk protein promoter such as for whey acidic protein, casein, lactalbumin, or beta-lactoglobulin promoter. The transgenic mammals are preferably farm animals, for example, …

Electrokinetic Cha Raci'erisation Of Colloidal A-Alumina, J Ntalikwa

Tanzania Journal of Engineering and Technology (TJET)

Electrophoretic mobility (uD is an important rneasurable parameter in studying the electrokinetic properties of a colloid dispersion. This parameter is Often convened into zeta potential (C) Which piays a great role in thc description Of the stability towards aggregation Of dispersed particles. In this paper, measurements of Of colloidal a-alumina dispersed in various concentrations of electrolyte arc reported. It was observed that, the isoelectric points (the pH at which us = O) occurred at 7.52 ± 0.32, 8.05 ± 0.11 and 7,95 ± 0.18 in Naci, KCI and NaNOs respectively. The isoelectric point was observed to be a function Of …

Comparative Analysis Of Rng K-E And 'Standard' K-C Models For Fluid Flow Around A Cylinder, A Temu

Tanzania Journal of Engineering and Technology (TJET)

A two-dimensional computational scheme for simulating fluid flow around a cylinder was investigated. RNG (Re-NOrmalisation Group) and 'standard' turbulent closure models were used. simulation was implemented with assistance OfFLOW-3D computational fluid dynamics (CFD) code. The governing equation Of fluid motion, in Eulerian form, included body forces as well as surface forces. The computational model predictions for fluid velocity showed good agreement between the two models. Comparison Of the viscosities showed a large deviation from the two models, with RNG k-E model giving a better approximation. Comparison Of the velocity around the cylinder, as obtained from RNG k-c model, with approximation …

Production Of Biogas From Water Hyacinth: Effect Of Substrate Loading In Semi-Batch & Batch Operations, J Katima

Tanzania Journal of Engineering and Technology (TJET)

A study was carried out to establish the effect of substrate loading rate on the production of biogas from water hyacinth. The experiments revealed that the maximum methane yield in a batch process was 0.166 normal litre (NLVg Of volatile solids (VS) added at substrate concentration of 25 g dry mass'litre after five days of incubation. The maximum methane yield in a semi-batch process was 0.153 NWg VS added at 1.30 g VS'litre day and retention time Of 15 days.

Recyclability Of Modified Ps-Aq Pulps At Around Kappa 30, Rwaichi Minja

Tanzania Journal of Engineering and Technology (TJET)

Bleachable grade pulps prepared from Nonvegian softwood spruce chips while simulating possible alternatives of improving pulp yield by application Of polysulphide (PS) and anthraquinone (AQ) have been used in this study. The tests for recyclability were performed on hydrogen form pulps. The pulps considered were Iso- Thermal cooking (ITC) kraft pulp which was used as a reference pulp, conventional PS-AQ pulp, soda PS-AQ pulp and kraft PS-AQ pulp. The loss Of swelling ability (homification) Of the pulps, was determined by measurement of water retention value (W R V). The results showed that, PS-AQ pulps had similar or slightly better swelling …

Dislocation-Controlled Perforated Layer Phase In A Peo-B-Ps Diblock Copolymer, Lei Zhu, Ping Huang, Stephen Z. D. Cheng, Qing Ge, Roderic P. Quirk, Edwin L. Thomas, Bernard Lotz, Jean-Claude Wittmann, Benjamin S. Hsiao, Fengji Yeh, Lizhi Liu

College of Polymer Science and Polymer Engineering

Small angle x-ray analyses show that the shear-induced hexagonal perforated layer phase in a poly(ethylene oxide)-b-polystyrene diblock copolymer consists of trigonal (R3(overbar)m) twins and a hexagonal (P6(3)/mmc) structure, with trigonal twins being majority components. Transmission electron microscopy reveals that the hexagonal structure is generated through sequential intrinsic stacking faults on the second layer from a previous edge dislocation line, while the trigonal twins are formed by successive intrinsic stacking faults on neighboring layers due to the plastic deformation under mechanical shear.