Chemical Engineering Commons^™

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 …

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 …

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 …

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 …

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 …

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 …

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.

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 …

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 …

Development In The Petroleum Sub-Sector And Their Impacts On Nigerian Economy., I. P. Ojinnaka

Bullion

The development of the petroleum industry has had both negative and positive impacts on the Nigerian economy. Two schools of thought can be examined. First, that positive impacts outweigh the negative, and secondly, the inverse. The paper will examined the impacts and analyzed the positive ones. From the approach of the study it is clear that the petroleum industry has had both negative and positive impacts on the Nigerian economy. Nigeria without petroleum could be like any other country without oil or gas, that is, import dependent. However, Nigeria with oil is the best thing that could have happened to …

Comparison Of Charged Sheets And Corrected 3-D Ewald Calculations Of Long-Range Forces In Slab Geometry Electrolyte Systems With Solvent Molecules, Richard L. Rowley, Paul S. Crozier, Eckhard Spoht, Douglas Henderson

Faculty Publications

Two methods of calculating long-range intermolecular potentials are compared for an approximately 3 M aqueous electrolyte solution confined between two charged surfaces. We investigate the ionic density profiles using the charged-sheets method and the corrected three-dimensional (3D) Ewald method at two different system sizes and also compare the Coulomb forces directly. The corrected 3D Ewald method is recommended for the calculation of long-range potentials in systems of this nature because it is less system size dependent than the charged sheets method and the resultant forces are more consistent with periodic boundaries. However, the charged-sheets method for estimating long-range potentials in …

Calibration Of Optical Digital Fragmentation Measuring Systems, Norbert H. Maerz, Wei Zhou

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Optical granulometry systems like WipFrag are required to measure fragments in situ. That is to say, the fragments are in piles where sorting takes place, where fragments are partially overlapped, and where fines may not be seen because they fall in and behind the coarser fragments, or where the fines are simply too small to be seen. As a result, optical systems tend typically to overestimate the size of the distribution, and underestimate the variability of the distribution. The wider the size distribution being measured, the more severe the problem is. This paper presents the results of a study that …

The Impact And Fate Of Aqueous Sodium Nitrate On Hydrocarbon Flames, Ann Marie Flynn

Dissertations

This study examined the impact and fate of sodium (fed as an aqueous nitrate solution) in fuel-rich methane/air and methane/methyl chloride/air flames as a function of equivalence ratios that experienced diffusion of air from the surroundings. The flames were stabilized on a slotted, uncooled burner. The data set was divided into profiles of relative sodium atom concentrations, temperatures, and selected stable species concentrations. The flames were simulated using a modified version of the Sandia FORTRAN program for modeling steady laminar one-dimensional premixed flames complete with detailed mechanisms. The results showed that maximum sodium atom concentration in the flame is decreased …

Endotoxin Removal From Protein Solutions By Immobilized Metal Ion Affinity Chromatography, Yun Kang

Dissertations

In the biotechnology/pharmaceutical industry, the removal of endotoxins from final protein product has always been a challenge. A novel method for endotoxin removal from protein solutions, immobilized metal (ion) affinity chromatography (IMAC) has been developed in this study. Fe³⁺ was charged to a chelating gel that contains iminodiacetic acid (IDA). The IDA- Fe³⁺ IMAC column was exploited to remove endotoxin from protein solutions. This method involves the adsorption of the endotoxin on IMAC column. More than 99% endotoxin is removed and protein yield is higher than 90%. IDA-Fe³⁺ IMAC has proved to be an economical and efficient …

Fluidization And Soot Filtration In A Rotating Fluidized Bed, Gui-Hua Qian

Dissertations

A horizontal rotating fluidized bed (RFB) has been investigated for the removal of soot from diesel engine exhaust. This requires necessitating an understanding of the nature of fluidization, particle mixing and filtration in the RFB.

In an RFB, particles are subject to a centrifugal force which can be much larger than the force of gravity. Therefore the Geldart classification for conventional fluidized beds must be modified for rotating fluidized beds. A theoretical analysis shows that group A particles (minimum bubbling velocity U_mb > minimum fluidization velocity U_mf can shift to group B U_mb = U_mf and group …

An Integrated Membrane-Based Chromatographic Process For Biomolecule Isolation And Purification, Xiaoping Dai

Dissertations

Biomolecules obtained from fermentation and cell-culture processes are present in low concentrations in a complex medium/broth. For intracellular products, cells are first harvested. Subsequently, cell lysis and homogenization are undertaken to produce a homogenate. The biomolecules are next separated from the cell debris by lysate clarification. For extracellular products, the biomolecules are separated from the whole cells by clarification. The overall yield is reduced with each additional step. As the cost of bioseparation process accounts for 50-80% of the final product cost, innovations in and improvement of bio-downstream processing are greatly needed.

In this research, a cyclic process integrating a …

Feasibility Study Of Rotating Fluidized Bed As A Dry Coater And Granulater, Manish Sawhney

Theses

This study is directed at enhancing our understanding of the mechanism of dry coating and granulation in a rotating fluidized bed (RFB). The main objective was to study the feasibility of the coating and granulation processes using an REB, both quantitatively and qualitatively.

A force balance and kinetic model is applied to explain the coating phenomenon and also to investigate why coating takes place in certain particle material systems and not in others. An equation for the resultant velocity with which one particle collides with another has been suggested for the rotating fluidized bed coater. A condition, which predicts whether …

Numerical Studies Of Deep Bed Filtration, Chan-Gyun Shin

Theses

Deep bed filtration is a process used to separate small solid particles suspended in a fluid by using granular solids as the collecting medium. The filter efficiency depends on many parameters such as the Reynolds number, particle drag coefficient, the ratio of the diameter of injected, and filter particles, etc.

In the present work we model the porous media flow (solution of the Navier-Stokes equations) by using a computer code developed by Dr. P. Singh and we restrict our analysis to the case of two dimensional periodic porous media. The computational domain is discretized using the finite element method. In …

Powder Microelectrode Modified With Nafion-Os(Bpy)3Â 2+ And Pvp Composite And Its Catalysis For No2- Reduction, Pei-Fang Liu, Jia-Wei Yan

Journal of Electrochemistry

The modified powder microelectrode was prepared by etching a Pt (0.1 mm diameter) disk microelectrode and filling in thus formed cavity with Nation-Os(bpy)₃²⁺/PVP composite modified carbon powder. The composite modified powder microelectrode showed cyclic voltammetric behaviors changing with the mole ratio (denoted X) of SO₃^- to Os(bpy)₃²⁺ in Nafion. When X=3, a single pair of current peaks appeared near 0.6V (vs. SCE) due to Os(bpy)₃^2+/3+ redox couple. In contrast, for X=20, a pair of additional current peaks occurred near 0.4V. Both X=3 and X=20 modified powder microelectrodes strongly catalyzed the first …

Template Synthesis And Uv-Vis Absorption Spectra Of The Nanowire Arrays Of Cadmium Chalcogenides, Shi-Min Xu, Kuan-Hong Xue, Jing-Lin Kong, Dong-Mei Sun, Yu-Ying Feng, Hai-Yan Lu, Guang-Hou Wang

Journal of Electrochemistry

The porous alumina membrane formed in the anodic oxidation of highly pure aluminum foil has attracted a great deal of attention in recent years. It can be served as a desired template to prepare nanometer scale materials due to its unique structure of discrete and cylindrical nanopores, paralleled one another, with the homogeneous size and distribution. Chalcogenide semiconductors have promising prospect in the applications of photovoltaic and photoconducting devices and have been extensively exploited for many years. Olbright and his co-workers studied experimentally and theoretically the optical nonlinearties of CdS_xSe_1-x-doped glass; Britt and Ferekides reported that …

Activated Carbon And Process For Making Same, Francis John Derbyshire, Marit Jagtoyen

Chemical and Materials Engineering Faculty Patents

A process is described for the manufacture of activated carbon in the form of a powder, as granules or as extrudates. The process includes treating a biomass feedstock, such as woods, coconut shells, fruit pits, peats, lignites and all ranks of coal with a processing agent and an activation agent. The processing agent may be a natural or synthetic monomer, oligomer, polymer or mixtures thereof capable of interacting or co-polymerizing with the biomass feedstock. The activation agent may be, for example, phosphoric acid, zinc chloride or mixtures thereof. A high surface area, high hardness extruded activated carbon may be produced …

Piezoelectric Sensors/Actuators For Use In Refractory Environments, Hendrik J. Viljoen, Barend R. Jooste

Papers in Reaction Kinetics

Disclosed is a piezoelectric system which demonstrates piezoelectric properties over a large temperature range of from room temperature to approximately 1,360 degrees Centigrade. The piezoelectric system sequentially comprises a first electrically conductive layer, a layer of Ta₂O₅) in other than a monoclinic phase, (preferably orthorhombic demonstrating small X-ray crystallographic < 0 0 1> and < 1 11 0> peaks), and a second electrically conductive layer. A preferred method of fabrication involves sputter deposition of both said layer of Ta₂O₅ and said second electrically conductive layer.

Bending Instability Of Electrically Charged Liquid Jets Of Polymer Solutions In Electrospinning, Darrell Hyson Reneker, Alexander L. Yarin, Hao Fong, Sureeporn Koombhongse

College of Polymer Science and Polymer Engineering

Nanofibers of polymers were electrospun by creating an electrically charged jet of polymer solution at a pendent droplet. After the jet flowed away from the droplet in a nearly straight line, it bent into a complex path and other changes in shape occurred, during which electrical forces stretched and thinned it by very large ratios. After the solvent evaporated, birefringent nanofibers were left. In this article the reasons for the instability are analyzed and explained using a mathematical model. The rheological complexity of the polymer solution is included, which allows consideration of viscoelastic jets. It is shown that the longitudinal …

Single Phase Flow Modeling In Packed Beds: Discrete Cell Approach Revisited, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Discrete Cell Model (DCM), based on the Minimization of the Total Rate of Energy Dissipation, is Applied to Compute the Fluid Velocity Field in Two-Dimensional Packed Beds. the Analysis of the Individual Terms of the Energy Dissipation Rate Equation is Also Presented. the Results Obtained by DCM Are Validated Both by Comparing Them with the Solutions of Ensemble-Averaged Momentum and Mass Conservation Equations (CFDLIB Code) and by Available Experimental Results. the Differences between DCM and CFD Simulations Were Found to Be Confined to within a 10% Band over a Wide Range of Reynolds Numbers (Re' = 5-171). Thus, a …

Infrared Diode Laser Absorption Spectroscopy Measurement Of Gas Phase Radicals In C₄F Discharges For Plasma Model Validation, Karla Waters

Chemical and Biological Engineering ETDs

The etching characteristics of oxide and photoresist thin films in C₄F₈ discharges in an inductively coupled GEC Reference cell have been determined. Infrared diode laser absorption spectroscopy (IR-DLAS) measured absolute concentrations of CF_x radicals in C₄F₈ discharges and correlated their behavior to the oxide etch process. Additionally, Langmuir probe and OES data were collected to aid in characterizing the plasma and the oxide/photoresist etch processes.

A central composite design of experiment was employed. The factors were source power, chuck bias power, and total pressure. The source power varied from 200 to 500 W, …

Spatiotemporal Growth Of Faceted And Curved Single Crystals, Thein Kyu, Rujul Mehta, Hao-Wen Chiu

College of Polymer Science and Polymer Engineering

The spatiotemporal growth of single crystals in a crystalline polymer has been investigated theoretically based on a nonconserved time dependent Ginzburg-Landau equation (known as TDGL model A). In the description of the total free energy, a double-well local foe energy density signifying metastability of crystal ordering is combined with a nonlocal free energy term representing an interface gradient. The resulting nonlinear reaction diffusion equation after renormalization possesses a solitary wave property. Two-dimensional numerical calculations were performed to elucidate the faceted single crystal growth including square, rectangular, diamond-shaped, and curved single crystals. A three-dimensional simulation was also undertaken for the emergence …

Immunoaffinity Chomatography, Anuradha Subramanian

Papers in Biotechnology

Recent devclopments in recombinant DNA technology have enabled the synthesis of valuable therapeutic proteins in bacterial cells as well as in novel eucaryotic expression systems. However, the purification of proteins of interest from either the conventional sources, cell culture, or novel routes in a highly purified form necessitates the development of separation tcchniques capable of recovering proteins from these feed streams in a highly purified form (1,2). Purification of therapeutic proteins from biological sources is usually complicated by the presence of endogenous proteins (2). Purification methodologies based on ion exchange or adsorption serve as excellent prepurification steps, but they fail …

Apparatus And Method For The Generation And Use Of Ferric Ions, Donald R. Lueking, Carl C. Nesbitt

Michigan Tech Patents

An apparatus and method for the generation and use of ferric ions produced by acidophilic, chemoautotrophic bacteria.

The Character Of Ash Deposits And The Thermal Performance Of Furnaces, T. F. Wall, S. P. Bhattacharya, Larry Lin Baxter 8507091, G. Richards, J. N. Harb

Faculty Publications

The character of fireside ash deposits depend on the processes by which deposits are formed and subsequent reactions within the deposit and with furnace gases. The properties influencing furnace heat transfer, absorptivity for radiative transfer and thermal conductivity for conductive transfer are shown from many measurements to depend on this character. Illustrative trends in these properties as deposits mature and grow are presented together with their effect on furnace exit temperature and efficiency. The reflective character of initial deposits from particular coals is then considered with predictions and measurements of the spectral character of such deposits, during the first three …

Numerical Investigation Of Boundary Conditions For Moving Contact Line Problems, Sandesh Somalinga, Arijit Bose

Chemical, Biomolecular, and Materials Engineering Faculty Publications

When boundary conditions arising from the usual hydrodynamic assumptions are applied, analyses of dynamic wetting processes lead to a well-known nonintegrable stress singularity at the dynamic contact line, necessitating new ways to model this problem. In this paper, numerical simulations for a set of representative problems are used to explore the possibility of providing material boundary conditions for predictive models of inertialess moving contact line processes. The calculations reveal that up to Capillary number Ca=0.15, the velocity along an arc of radius 10L_i (L_i is an inner, microscopic length scale! from the dynamic contact line is independent of …