Chemical Engineering Commons^™

Interfacial Stick-Slip Transition In Simple Shear Of Entangled Melts, Pouyan E. Boukany, Prashant Tapadia, Shi-Qing Wang

College of Polymer Science and Polymer Engineering

This article describes a systematic investigation of a discontinuous interfacial stick-slip transition (SST) in simple shear of monodisperse entangled 1,4-polybutadiene (PBD) and polyisoprene (PIP) melts with different molecular weights and architecture, using a specially designed controlled-force shear rheometer. The magnitude of the transition is found to be determined by the level of chain entanglement. Specifically, the dependence of extrapolation length b on molecular weight as b similar to M-w(3.4) and of the melt viscosity as b similar to eta is consistent with the observations based on capillary rheometric studies [X. Yang et al., Rheol. Acta 37, 415-423 (1998)]. The interfacial …

The Effects Of Tgf-Beta1 And Igf-I On The Biomechanics And Cytoskeleton Of Single Chondrocytes, Nic Leipzig

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Objective Ascertaining how mechanical forces and growth factors mediate normal and pathologic processes in single chondrocytes can aid in developing strategies for the repair and replacement of articular cartilage destroyed by injury or disease. This study examined effects of transforming growth factor-β1 (TGF-β1) and insulin-like growth factor-I (IGF-I) on the biomechanics and cytoskeleton of single zonal chondrocytes. Method Superficial and middle/deep bovine articular chondrocytes were seeded on tissue culture treated plastic for 3 and 18 h and treated with TGF-β1 (5 ng/mL), IGF-I (100 ng/mL), or a combination of TGF-β1 (5 ng/mL) + IGF-I (100 ng/mL). Single chondrocytes from all …

Designing A Nanotube Using Naturally Occurring Protein Building Blocks, Jie Zheng

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Here our goal is to carry out nanotube design using naturally occurring protein building blocks. Inspection of the protein structural database reveals the richness of the conformations of proteins, their parts, and their chemistry. Given target functional protein nanotube geometry, our strategy involves scanning a library of candidate building blocks, combinatorially assembling them into the shape and testing its stability. Since self-assembly takes place on time scales not affordable for computations, here we propose a strategy for the very first step in protein nanotube design: we map the candidate building blocks onto a planar sheet and wrap the sheet around …

Fabrication And Characterization Of Poly(Propylene Fumarate) Scaffolds With Controlled Pore Structures Using 3-Dimensional Printing And Injection Molding, Kee-Won Lee, Shanfeng Wang, Lichun Lu, Esmaiel Jabbari, Bradford L. Currier, Michael J. Yaszemski

Faculty Publications

Poly(propylene fumarate) (PPF) is an injectable, biodegradable polymer that has been used for fabricating preformed scaffolds in tissue engineering applications because of in situ crosslinking characteristics. Aiming for understanding the effects of pore structure parameters on bone tissue ingrowth, 3-dimensional (3D) PPF scaffolds with controlled pore architecture have been produced in this study from computer-aided design (CAD) models. We have created original scaffold models with 3 pore sizes (300, 600, and 900 µm) and randomly closed 0%, 10%, 20%, or 30% of total pores from the original models in 3 planes. PPF scaffolds were fabricated by a series steps involving …

Fall 2006 Che Newsletter, Department Of Chemical Engineering, Michigan Technological University

Department of Chemical Engineering Newsletters

Table of Contents

• CPM awarded First Place in Competition
• Letter from the Chair
• Sandell Recipient of Distinguished Teaching Award
• New Inductees for Chemical Engineering Distinguished Academy Honored
• New Presidential Council of Alumnae Member
• Alumni Notes
• Industrial Advisory Board
• Nam Him Retires
• Building Renovations completed
• Focus on Research

A Study Correlating Entropy Generation To Parameters Characterizing Thermal Comfort In A Conditioned Room, Sai Shrinivas Sreedharan

Mechanical & Aerospace Engineering Theses & Dissertations

Although significant advances have been made to analyze and study a room as an open thermodynamic system experiencing indoor airflow and heat exchanges with surroundings, studies incorporating entropy generation in the analysis have been sparse. This study focuses on correlating indoor thermal comfort with entropy generation, which hopefully will result in efficient utilization of energy supplied to the system. The problem that this thesis attempts to solve involves calculation of entropy production in conditioned space and its correlation to parameters that characterize thermal comfort. Thermal comfort in a conditioned space is governed by many thermal, mechanical and psychrometric parameters. The …

Thermal Analysis Of The Vortex Tube Based Thermocycler For Fast Dna Amplification: Experimental And Two-Dimensional Numerical Results, V. Raghavan, Scott E. Whitney, Ryan J. Ebmeier, Nisha V. Padhye, Michael Nelson, Hendrik J. Viljoen, George Gogos

Hendrik J. Viljoen Publications

In this article, experimental and numerical analyses to investigate the thermal control of an innovative vortex tube based polymerase chain reaction (VT-PCR) thermocycler are described. VT-PCR is capable of rapid DNA amplification and real-time optical detection. The device rapidly cycles six 20 μl 96 bp λ-DNA samples between the PCR stages (denaturation, annealing, and elongation) for 30 cycles in approximately 6 min. Two-dimensional numerical simulations have been carried out using computational fluid dynamics (CFD) software FLUENT v.6.2.16. Experiments and CFD simulations have been carried out to measure/predict the temperature variation between the samples and within each sample. Heat transfer rate …

Evaluation And Engineering Of Saccharomyces Cerevisiae For Cellulase Expression And Growth On Insoluble Cellulose, John Mcbride

Link Foundation Energy Fellowship Reports

The conversion of cellulosic biomass into fuels and chemicals promises to be a major revolution for the United States economy, but is dependent on the advancement of low-cost conversion technology. Of the natural resources available to human societies, biomass is one of the most abundant, and is the sole sustainable source of organic fuels, chemicals, and materials [1]. Biomass derived fuels and chemicals can achieve net zero carbon emissions on a lifecycle basis, provide substantial income to rural communities, and eliminate the security issues associated with fossil resources. Cellulosic biomass (wood, grass, agricultural residues, etc.) can be produced cheaply and …

Low-Frequency Ultrasound Increases Outer Membrane Permeability Of Pseudomonas Aeruginosa, Christopher M. Runyan, John C. Carmen, Benjamin L. Beckstead, Jared L. Nelson, Richard A. Robison, William G. Pitt

Faculty Publications

Low-frequency ultrasound has been investigated as an adjuvant to antimicrobial therapy, targeted at both planktonic and biofilm (sessile) organisms. Our previous work showed that ultrasound (US) effectively enhances the bactericidal activity of certain antibiotics against planktonic cultures (Pitt et al., 1994; Rediske et al., 1999) and in vitro biofilms (Johnson et al., 1998; Qian et al., 1999) and in vivo biofilms (Carmen et al., 2004b, 2005; Rediske et al., 2000) of gram-positive and gram-negative bacteria. Ultrasound was shown to increase the transport of antibiotics through biofilms (Carmen et al., 2004a) which could account for some (or all) of the enhanced …

Magnetic Nanoparticle Supported Catalyst For Atom Transfer Radical Polymerization, Shijie Ding, Yangchuan Xing, Maciej Radosz, Youqing Shen

Chemical and Biochemical Engineering Faculty Research & Creative Works

Magnetic nanoparticles were used to support an ATRP catalyst for the polymerization of methyl methacrylate (MMA) for minimized adverse effect of catalyst support and easy catalyst separation. the nanoparticle-supported catalyst mediated a living/controlled radical polymerization of MMA as effectively as unsupported catalysts. with the addition of 22 mol % of CuBr 2, the polymer molecular weights were well-controlled with an initiator efficiency of 0.85 and polydispersity lower than 1.2. the supported catalysts could be easily separated/isolated using an external magnetic field and reused with slightly decreased activity but further improved control. the activity of the recycled catalyst was regenerated by …

Electrochemical Durability Of Carbon Nanotubes In Noncatalyzed And Catalyzed Oxidations, Liang Li, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

Noncatalyzed and catalyzed electrochemical oxidations of multiwalled carbon nanotubes (CNTs) were studied with the aim to understand their durability as catalyst support in polymer electrolyte membrane (PEM) fuel cells. Bare and Pt-deposited CNTs were investigated in 1.0 M sulfuric acid at a constant potential of 1.2 V. Carbon black (CB, Vulcan XC-72R) was also studied under the same experimental conditions. the carbons were oxidized at room temperature in the form of thin-film electrodes with time durations up to 48 h. Cyclic voltammetry was used to monitor the surface oxide redox reactions as a way to quantify the degree of surface …

Electrowetting Droplet Microfluidics On A Single Planar Surface, Christopher G. Cooney, Chao Yi Chen, Michael R. Emerling, Ali Nadim, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

Electrowetting refers to an electrostatically induced reduction in the contact angle of an electrically conductive liquid droplet on a surface. Most designs ground the droplet by either sandwiching the droplet with a grounding plate on top or by inserting a wire into the droplet. Washizu and others have developed systems capable of generating droplet motion without a top plate while allowing the droplet potential to float. In contrast to these designs, we demonstrate an electrowetting system in which the droplet can be electrically grounded from below using thin conductive lines on top of the dielectric layer. This alternative method of …

Influence Of Two Changes In The Composition Of An Acrylic Bone Cement On Some Of Its Properties: The Case Of Surgical Simplex® P, S. Madigan, Mark R. Towler, G. Lewis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Influence of two changes in the composition of a self-curing acrylic bone cement on some of its properties are discussed. Acrylic bone cements are widely used in orthopedic surgery for the fixation of joint prosthesis and in vertebroplasty and kyphoplasty for the stabilization and augmentation of fractured vertebrae. The cement's curing process is the result of a free-radical polymerization of a mixture of poly (methyl 1 methacrylate) [PMMA] containing powder and a liquid monomer that has methyl methacrylate (MMA) in it. It is initiated by the decomposition of benzoyl peroxide (BPO) in the powder, activated by a tertiary amine in …

The Influence Of Ultrasonic Setting On Fluoride Release From Glass Polyalkenoate Cements, N. Rushe, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effects of ultrasonic setting on fluoride release from glass polyalkenoate cements (GPC) were investigated. Cements based on two different aluminosilicate glasses that contained silica, alumina, phosphate, and strontia were used for the experiment. A series of GPCs were examined to show that increased release F^- ion occurs, regardless of GPC composition. The results show that there is a greater release of fluoride from the ultrasonically set samples than those set chemically, regardless of the chemical composition. The snap set caused by the ultrasound is likely to be due to a combination of cavitation, improved mixing of the constituents, …

Calcium And Zinc Ion Release From Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Mark R. Towler, S. Kenny, D. Boyd, T. Pembroke, M. Buggy, A. Guida, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

Calcium and zinc ion release from hydroxyapatite-zinc oxide-poly (acrylic acid) (HAZnO-PAA) composite cements into deionised water was investigated as a function of HA content, PAA concentration, PAA molecular weight and maturation time. At any given maturation time, zinc ion release was constant until the HA content was at the maximum loading (60 wt%) resulting in the cement matrix breaking up, allowing exacerbated ion release. The calcium ion release increased with increased HA content in the composite until the maximum loading where the release drops off. Up to this point, the release of both ionic species was proportional to square root …

Flow Regime Identification In A Bubble Column Based On Both Statistical And Chaotic Parameters Applied To Computed Tomography Data, Stoyan Nedeltchev, Ashfaq Shaikh, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Kolmogorov Entropy (KE) Algorithm Was Applied Successfully to Single Source Γ-Ray Computed Tomography (CT) Data Measured in a 0.162 M ID Bubble Column Equipped with a Perforated Plate Distributor (163 Holes · Ø 1.32 Mm). Dried Air Was Used as the Gas Phase and Therminol LT (ΡL = 886 Kg M-3, ΜL = 0.88 · 10-3 Pa S, Σ = 17 · 10-3 N M-1) Was Used as a Liquid Phase. Three Different Pressures, P, of 0.1, 0.4, and 1.0 MPa Were Examined. at Each Pressure the Superficial Gas Velocity, UG, Was Increased Stepwise by Steps of 0.01 Ms-1 …

Investigation On The Resistance To Electrochemical Oxidation Of Carbon Nanotubes With Various Diameters, Yu-Yan Shao, Ge-Ping Yin, Yun-Zhi Gao, Peng-Fei Shi

Journal of Electrochemistry

The resistance to electrochemical oxidation of multi-wall carbon nanotubes(CNT) with various diameters is investigated by applying a fixed potential of 1.2 V(RHE) for 120 h in 0.5 mol L^-1 H₂SO₄.The oxidation current of CNTs decreases with their diameters,but CNTs between 10~20 nm in diameter(D1020) shows the lowest oxidation current.XPS analysis shows that,after oxidation,the increase in surface oxygen for D1020 is the smallest,implying that the oxidation degree for D1020 is the lowest.The conclusion can be reached that CNTs between 10~20 nm in diameter are the most resistant to electrochemical oxidation.The difference in electrochemical stability of CNTs …

The Influence Of Pva As Disperser On Lifepo4 Synthesized By Hydrothermal Reaction, Hui-Lin Li, Hui Zhan, Yu-Hong Zhou

Journal of Electrochemistry

LiFePO₄ was synthesized by means of hydrothermal reaction,in which PVA acts as disperser and glucose as carbon source. The samples were characterized by X-ray diffraction, scanning electron microscopy and electrochemical measurement. SEM results show that the sample is homogeneously composed of grains with a particle size of ca.200nm. In the charge/discharge test, the products exhibited a 3.45V discharge voltage plateau and a maximum specific capacity of 140mAh/g. After 40 cycles, its capacity only declined by 2.1%. Besides these, the mechanism for the influence of the particle size and carbon coating on the electrochemical property of LiFePO₄ material was …

Electrochemical Behavior Of Electrolytic Manganese Dioxide In Mgso4 Solution, Dan-Mei Yu, Yu-Jun Si, Chang-Guo Chen, Yu-Ping Liu, Yan Liu

Journal of Electrochemistry

The rechargeability and crystal structure changing of electrolytic manganese dioxide(EMD) in MgSO₄ electrolyte were investigated by cyclic voltammetry,galvanostatic charge/discharge and X-ray diffraction.The results have shown that the EMD has good rechargeability;after several initial cycles,the charge and discharge became stability;after discharge,the γ-MnO₂ structure of EMD was changed,the production was reversible and could be recharged to γ-MnO₂ structure again which ensured the rechargeability of EMD.

Calcined Temperatures Influence On Synthesis And Electrochemistry Charactarization Of Li[Ni0.475Mn0.475Co0.05]O2 For Li-Ion Batteries, Li-Qin Wang, Li-Fang Jiao, Hua-Tang Yuan, Yong-Mei Wang

Journal of Electrochemistry

Layered Li[Ni_0.475Mn_0.475Co_0.05]O₂ materials have been prepared by a solid-state pyrolysis method.Experiments of XRD,SEM,cyclic voltammetry and charge/discharge cycling were carried out.It can be learned that when calclined at 800 ℃,the sample showed the highest first discharge capacity of 178.8 mAh·g^-1 at a current density of 20 mA/g in the voltage range 2.3~4.6 V

Immobilization Of Cytochrome C On The Surface Of Single-Wall Carbon Nanotube And Its Direct Electron Transfer And Electrocatalysis, Ya-Jing Yin, Ya-Fen Lv, Ping Wu, Pan Du, Yan-Mao Shi, Chen-Xin Cai

Journal of Electrochemistry

Cytochrome c(Cyto c) was immobilized on the surface of the single-wall carbon nanotube(SWNT) by using the method of adsorption.Infrared spectroscopy indicated that the Cyto c remained in its original structure and did not undergo structural change after its immobilization on the SWNT.The direct electrochemistry of cyto c,which was adsorbed on the surface of the SWNT,was studied by cyclic voltammetry.The voltammetric results demonstrated that the SWNT had promoting effects on the direct electron transfer of Cyto c and also indicated that the immobilized Cyto c retained its bioelectrocatalytic activity to the reduction of H₂O₂.This modified electrode might …

Investigation Of The Direct Electrochemical Reduction Of Cr2O3 Powder In Molten Cacl2 By A Metallic Cavity Electrode, Guo-Hong Qiu, Di-Hua Wang, Xian-Bo Jin, Xiao-Hong Hu, Zheng Chen

Journal of Electrochemistry

A metallic cavity electrode is used for further investigation of the electrochemical behaviour of Cr₂O₃ powder in molten CaCl₂(Na: ~0.02% by mass,Mg: < 0.005% by mass) at 900 ℃.The Cr₂O₃ powder reduction mechanism was confirmed in line with EDX and SEM analysis of the potentiostatic electrolysis products.The correlations between the particle size of metallised product and the electrolysis potential,or electrolysis time were analysed.

Studies On Synthesis And Electrochemical Performance Of LiXNi1/3Mn1/3Co1/3O2 As Cathode Material For Lithium Ion Batteries, Xiao-Jian Guo, Jie Li, Yi-Xiao Li, Yong Yang

Journal of Electrochemistry

A series of LiNi_1/3Mn_1/3Co_1/3O₂ were synthesized by a combined hydroxides coprecipitation and calcination method.Effects of synthesizing temperature of coprecipitations and the Li∶M ratios on structure and electrochemical performance of the materials were studied.The results showed that materials synthesized with coprecipitation at room temperature(~20 ~(o)C) delivered the best electrochemical performance.Another series of cathode materials Li_XNi_1/3Mn_1/3Co_1/3O₂ with different Li∶M ratios were synthesized with this method.The results showed that sintering at high temperature could cause loss of LiOH,thus more LiOH should be added.It is demonstrated that Li …

Pre-Oxidative Amperometric Glucose Biosensor Incorporated With Carbon Nanotube And Pbo2, Hong-Lan Qi, Cheng-Xiao Zhang

Journal of Electrochemistry

A pre-oxidative amperometric glucose biosensor incorporated with carbon nanotube,ferrocenemonocarboxylic acid and PbO₂ was designed.The interferences coming from reduced substances,such as ascoribic acid and urine acid were eliminated by PbO₂.The oxidative current is linear at the potential of +0.40 V(vs.SCE) to the concentration of glucose in the range from 0.50 to 20 mmol·L^-1,and the detection limit of glucose is 0.1 mol L^-1.The relative standard deviation is 3.3% for seven successive assays at 5.0 mmol·L^-1glucose.This biosensors have been applied to determination of the glucose in serum with satisfying results.

Experimental And Modeling Investigations Of Biomass Particle Combustion, Hong Lu

Theses and Dissertations

This investigation provides a comprehensive analysis of entrained-flow biomass combustion processes. Experimental and theoretical investigations indicate how particle shape and size influence biomass combustion rates. Experimental samples include flake-like, cylinder-like, and equant (nearly spherical) shapes with similar particle masses and volumes but different surface areas. Samples of small (less than 500 µm) particles were passed through a laboratory entrained-flow reactor in a nitrogen/air atmosphere and a maximum reactor wall temperature of 1600 K, while large samples were reacted in suspension in a single particle furnace operated at similar conditions as the entrained-flow reactor. A separately developed computer and image analysis …

Porous Fiber Formation In Polymer-Solvent System Undergoing Solvent Evaporation, Pratyush Dayal, Thein Kyu

College of Polymer Science and Polymer Engineering

Temporal evolution of the fiber morphology during dry spinning has been investigated in the framework of Cahn-Hilliard equation [J. Chem. Phys. 28, 258 (1958)] pertaining to the concentration order parameter or volume fraction given by the Flory-Huggins free energy of mixing [P. J. Flory, Principles of Polymer Chemistry (Cornell University Press, Ithaca, NY, 1953), p. 672] in conjunction with the solvent evaporation rate. To guide the solvent evaporation induced phase separation, equilibrium phase diagram of the starting polymer solution was established on the basis of the Flory-Huggins free energy of mixing. The quasi-steady-state approximation has been adopted to account for …

Methane Conversion In Pulsed Corona Discharge Reactors, Morris D. Argyle, Gui-Bing Zhao, Sanil John, Ji-Jun Zhang, Linna Wang, Suresh S. Muknahallipatna, Jerry C. Hamann, John F. Ackerman, Ovid A. Plumb

Faculty Publications

This work reports the effect of capacitance, cathode material, gas flow rate and specific energy input on methane conversion, energy efficiency and product selectivity in a co-axial cylinder pulsed corona discharge reactor. Ethan and acetylene appear to be formed from dimerization of CH3 radicals and CH radicals, respectively, while ethylene is formed mainly from the dehydrogenation of ethane. At a given power input, low capacitance with high pulse frequency results in higher methane conversion and energy efficiency than operation at high capacitance with low pulse frequency. Platinum coated stainless steel cathodes slightly enhance methane conversion relative to stainless steel cathodes, …

Transgenic Fibrinogen, William H. Velander

Department of Chemical and Biomolecular Engineering: Patents

A transgenic, non-human mammalian animal is capable of expressing a heterologous gene for human or other recombinant physiologically functional fibrinogen holoprotein or individual subunit chain polypeptides thereof or a modified or fusion fibrinogen in mammary glands of the animals and secreting the expressed product into a body fluid. Methodology employing such a mammal yields recombinant physiologically functional fibrinogens, subunit chain polypeptides thereof, and modified or fusion fibrinogens.

Breakup Of Spiral And Concentric Ringed Spherulites In Polymer Crystallization, Haijun Xu, Hao-Wen Chiu, Yoshifumi Okabe, Thein Kyu

College of Polymer Science and Polymer Engineering

Recently, the breakup of spiral and concentric ringed spherulites has been observed experimentally in isothermal crystallization of poly(vinylidene fluoride) in its blends with ethylene vinyl acetate copolymer. To elucidate the phenomenon of spiral breakup in polymer spherulites, a theoretical simulation has been undertaken in the framework of the phase field model of solidification based on time-dependent Ginzburg-Landau equations (TDGL model C) pertaining to the conserved concentration and nonconserved phase field order parameters. The concentration order parameter was described in terms of the Landau-type potential, while the crystal order parameter was expressed in terms of an asymmetric double-well potential to account …

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …