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Articles 61 - 90 of 138
Full-Text Articles in Chemical Engineering
P2: Image Analysis And Quantification Of 3d Cancer Cell Migration, Stephen Hong, Alexander Roth
P2: Image Analysis And Quantification Of 3d Cancer Cell Migration, Stephen Hong, Alexander Roth
Undergraduate Research Posters 2017
Metastatic tumors are known for their ability to migrate toward circulatory apparatus and detach from the primary tumor. Generally, metastasis is quantified in vitro using migration assays that are normally measured in two dimensions (2D). Threedimensional (3D) migration assays can better mimic cancers by providing similar microenvironments to those observed in vivo. Imaging 3D cell cultures requires multiple 2D images stacked along a Z-axis; however, imaged cells would be in-focus at varied z-positions at different time points due to the characteristics of cell migration. Our goal in this study was to analyze in-focus cell images and quantify cell migration in …
P1: Dispersion And Characterization Of Boron Nitride Nanotubes Stabilized By Dna, Camerin Mcdonald
P1: Dispersion And Characterization Of Boron Nitride Nanotubes Stabilized By Dna, Camerin Mcdonald
Undergraduate Research Posters 2017
Boron nitride nanotubes (BNNTs) are newly emerging nanomaterials with extraordinary mechanical properties as well as thermal and chemical stability. There have been growing interests in both fundamental studies and technological development of BNNTs such as protective coatings for high temperature and hazardous environments due to recent success in large scale synthesis of BNNTs. In this work, various DNA sequences were utilized to stabilize aqueous dispersions of BNNTs. First, we determined the optimum mass ratio of 1:1 for BNNTs:DNA using (GT)20 by UV-vis absorbance measurements. Second, the DNA length effect on the dispersion yield of BNNTs was investigated using sequences (GT)3, …
Response Of A Doublet To A Nearby Dc Electrode Of Uniform Potential, Christopher L. Wirth, Sri Harsha Nuthalapati
Response Of A Doublet To A Nearby Dc Electrode Of Uniform Potential, Christopher L. Wirth, Sri Harsha Nuthalapati
Chemical & Biomedical Engineering Faculty Publications
The electric-field-assisted directed assembly of spherical colloidal particles near an electrode has been studied for nearly three decades. Recently, focus has shifted to the electric-field-assisted assembly and propulsion of nonspherical (i.e., anisotropic) particles. This paper describes calculations and results for a doublet of asymmetric ζ potential and size responding to a dc electric field. The doublet experienced a net vertical force that depended on both the asymmetry in ζ potential and lobe size. In addition, the doublet experienced a net lateral force perpendicular to the applied electric field. The lateral force depended on the difference in ζ potential of the …
Methodological Considerations Of Electron Spin Resonance Spin Trapping Techniques For Measuring Reactive Oxygen Species Generated From Metal Oxide Nanomaterials, Min Sook Jeong, Kyeong-Nam Yu, Hyun Hoon Chung, Soo Jin Park, Ah Young Lee, Mi Ryoung Song, Myung-Haing Cho, Jun Sung Kim
Methodological Considerations Of Electron Spin Resonance Spin Trapping Techniques For Measuring Reactive Oxygen Species Generated From Metal Oxide Nanomaterials, Min Sook Jeong, Kyeong-Nam Yu, Hyun Hoon Chung, Soo Jin Park, Ah Young Lee, Mi Ryoung Song, Myung-Haing Cho, Jun Sung Kim
Chemical & Biomedical Engineering Faculty Publications
Qualitative and quantitative analyses of reactive oxygen species (ROS) generated on the surfaces of nanomaterials are important for understanding their toxicity and toxic mechanisms, which are in turn beneficial for manufacturing more biocompatible nanomaterials in many industrial fields. Electron spin resonance (ESR) is a useful tool for detecting ROS formation. However, using this technique without first considering the physicochemical properties of nanomaterials and proper conditions of the spin trapping agent (such as incubation time) may lead to misinterpretation of the resulting data. In this report, we suggest methodological considerations for ESR as pertains to magnetism, sample preparation and proper incubation …
Sensitivity Of Neural Stem Cell Survival, Differentiation And Neurite Outgrowth Within 3d Hydrogels To Environmental Heavy Metals, Sameera Tasneem, Kurt Farrell, Moo Yeal Lee, Chandrasekhar R. Kothapalli
Sensitivity Of Neural Stem Cell Survival, Differentiation And Neurite Outgrowth Within 3d Hydrogels To Environmental Heavy Metals, Sameera Tasneem, Kurt Farrell, Moo Yeal Lee, Chandrasekhar R. Kothapalli
Chemical & Biomedical Engineering Faculty Publications
© 2015 Elsevier Ireland Ltd. We investigated the sensitivity of embryonic murine neural stem cells exposed to 10 pM-10. μM concentrations of three heavy metals (Cd, Hg, Pb), continuously for 14 days within 3D collagen hydrogels. Critical endpoints for neurogenesis such as survival, differentiation and neurite outgrowth were assessed. Results suggest significant compromise in cell viability within the first four days at concentrations ≥10. nM, while lower concentrations induced a more delayed effect. Mercury and lead suppressed neural differentiation at as low as 10 pM concentration within 7 days, while all three metals inhibited neural and glial differentiation by day …
The Response Of An Ellipsoidal Colloid Particle In An Ac Field, Cornelius Adebowale Obasanjo
The Response Of An Ellipsoidal Colloid Particle In An Ac Field, Cornelius Adebowale Obasanjo
ETD Archive
The quest for new smart materials with engineered properties and desired functionalities has driven scientists into the domain of nanotechnology over the past 30 years. Particles with anisotropic properties as a result of their geometry, chemical patterning or surface functionality have been envisioned as building blocks for advanced materials. By tuning the anisotropic interactions engendered by anisotropic particles, one potentially could manipulate the dynamic pathways for assembly.
The work described in this thesis considers the response of an ellipsoidal colloid particle to a nearby AC electrode polarized at ~0.1 – 4 kV/m and ~0.1 – 3 kHz. The ellipsoidal particle, …
Pure And Binary Adsorption Of Methane And Nitrogen On Silicalite, Prahar S. Vaidya
Pure And Binary Adsorption Of Methane And Nitrogen On Silicalite, Prahar S. Vaidya
ETD Archive
Separation processes comprise a large portion of the activity in the chemical and petrochemical industries. For the chemical, petroleum refining, and materials processing industries as a group, separation processes are considered to be critical. Almost all the applications of chemical industries involves mixtures, so innovation in separation technology not only enhances productivity and global competitiveness of U.S. industries, but is also critical for achieving the industrial energy and waste reduction goals. Traditionally, air separation to produce nitrogen and oxygen and to separate nitrogen from methane was practiced by cryogenic distillation, which involved expensive high pressure units and large requirement of …
State Estimation Of Glucose And Insulin Dynamics, Morgan Nicholas Miller
State Estimation Of Glucose And Insulin Dynamics, Morgan Nicholas Miller
ETD Archive
Process simulation and state estimation have very important applications in chemical engineering as well as the biomedical field. Diabetes is a rapidly growing disease in the United States with 29 million people already diagnosed. The estimation of glucose and insulin concentration in patients is necessary in order to effectively treat diabetes. The Bergman Minimal Model is a popular process model that is used to simulate glucose and insulin dynamics. A simulation of this model was created based on estimated parameters for the model from historical data. This thesis investigated the estimation of glucose concentration, insulin concentration, and effect of active …
Effects Of Digestate, Magnesium Sulfate, And Dipotassium Hydrogen Phosphate/Potassium Dihydrogen Phosphate On Microalga, Scenedesmus Dimorphus, Zhuohui Joe He
Effects Of Digestate, Magnesium Sulfate, And Dipotassium Hydrogen Phosphate/Potassium Dihydrogen Phosphate On Microalga, Scenedesmus Dimorphus, Zhuohui Joe He
ETD Archive
Digestate (D), the remaining substance after anaerobic digestion of a biodegradable feedstock, is rich in inorganic contents, which makes it a good candidate for growing algae for biofuel production. Previous studies showed digestate at around 1.25% to 1.75% (v/v) dilution is suitable for algae growth. In this study, magnesium sulfate (MgSO4) and dipotassium hydrogen phosphate/potassium dihydrogen phosphate (K-P) were added to diluted digestate growth media. Two sets of experiments were conducted in batch reactor mode to identify the digestate (D), magnesium sulfate (MgSO4) and dipotassium hydrogen phosphate/potassium dihydrogen phosphate (K-P) concentrations that would optimize the algae growth. Algae growth parameters, …
High Surface Area And Z′ In A Thermally Stable 8-Fold Polycatenated Hydrogen-Bonded Framework, Cassandra A. Zentner, Holden W.H. Lai, Joshua T. Greenfield, Ren A. Wiscons, Matthias Zeller, Charles F. Campana, Orhan Talu, Stephen A. Fitzgerald, Jesse L.C. Rowsell
High Surface Area And Z′ In A Thermally Stable 8-Fold Polycatenated Hydrogen-Bonded Framework, Cassandra A. Zentner, Holden W.H. Lai, Joshua T. Greenfield, Ren A. Wiscons, Matthias Zeller, Charles F. Campana, Orhan Talu, Stephen A. Fitzgerald, Jesse L.C. Rowsell
Chemical & Biomedical Engineering Faculty Publications
1,3,5-Tris(4-carboxyphenyl)benzene assembles into an intricate 8-fold polycatenated assembly of (6,3) hexagonal nets formed through hydrogen bonds and π-stacking. One polymorph features 56 independent molecules in the asymmetric unit, the largest Z′ reported to date. The framework is permanently porous, with a BET surface area of 1095 m2 g−1 and readily adsorbs N2, H2 and CO2.
Substrate Concentration Influences Effective Radial Diffusion Coefficient In Canine Cortical Bone, Kurt Farrell, Daniel O’Conor, Mariela Gonzalez, Caroline Androjna, Ronald J. Midura, Surendra N. Tewari, Joanne M. Belovich
Substrate Concentration Influences Effective Radial Diffusion Coefficient In Canine Cortical Bone, Kurt Farrell, Daniel O’Conor, Mariela Gonzalez, Caroline Androjna, Ronald J. Midura, Surendra N. Tewari, Joanne M. Belovich
Chemical & Biomedical Engineering Faculty Publications
Transport of nutrients and waste across osseous tissue is dependent on the dynamic micro and macrostructure of the tissue; however little quantitative data exists examining how this transport occurs across the entire tissue. Here we investigate in vitro radial diffusion across a section of canine tissue, at dimensions of several hundred microns to millimeters, specifically between several osteons connected through a porous microstructure of Volkmann's canals and canaliculi. The effective diffusion coefficient is measured by a "sample immersion" technique presented here, in which the tissue sample was immersed in solution for 18-30 h, image analysis software was used to quantify …
Evaluation Of An Inclined Gravity Settler For Microalgae Harvesting, Zhaowei Wang, Jing Hou, Dustin Bowden, Joanne M. Belovich
Evaluation Of An Inclined Gravity Settler For Microalgae Harvesting, Zhaowei Wang, Jing Hou, Dustin Bowden, Joanne M. Belovich
Chemical & Biomedical Engineering Faculty Publications
BACKGROUND Given the small size of microalgae, and the low biomass concentrations obtained in light-limited cultures, the cost of algae harvesting is a significant barrier to commercial-scale production of biofuel from algae. A downward- flow inclined gravity settler was evaluated for its effectiveness in dewatering the microalgae Scenedesmus dimorphus and Chlorella vulgaris. RESULTS Experimental results showed that S. dimorphus can be concentrated up to 8-fold using a single settler stage, with a biomass recovery of 80%. Separation efficiency was independent of biomass concentration between 1 and 5 gdw L-1, suggesting that a two-stage sequential system of settlers may maximize biomass …
Enzyme Attached On Polymeric Micelles As A Nanoscale Reactor, Moo-Yeal Lee, Kyung-Jin Hong, Seung Pil Han, Toshio Kajiuchi
Enzyme Attached On Polymeric Micelles As A Nanoscale Reactor, Moo-Yeal Lee, Kyung-Jin Hong, Seung Pil Han, Toshio Kajiuchi
Chemical & Biomedical Engineering Faculty Publications
Similar to what lipase does, a surface-active enzyme was developed by attaching peroxidase on combshaped polymaleic anhydride-alt-1-tetradecene (PMA-TD) in a microemulsion system composed of n-butyl acetate and buffer solution, and its catalytic characteristics of polyphenol synthesis were investigated in an aqueous solution. The modified peroxidase with PMA-TD tended to form self-assembled aggregates like micelles in the aqueous solution and could be concentrated at solvent/water interfaces without unfolding of the enzyme. The efficiency of conversion of 2,4-dichlorophenol to phenolic oligomers was approximately 2-fold improved with the modified peroxidase compared to native peroxidase. The K m and V max values …
Minimal Medium For Optimal Growth And Lipid Production Of The Microalgae Scenedesmus Dimorphus, Colin Welter, Jacob Schwenk, Bahar Kanani, John Van Blargan, Joanne M. Belovich
Minimal Medium For Optimal Growth And Lipid Production Of The Microalgae Scenedesmus Dimorphus, Colin Welter, Jacob Schwenk, Bahar Kanani, John Van Blargan, Joanne M. Belovich
Chemical & Biomedical Engineering Faculty Publications
The culture of Scenedesmus dimorphus at the laboratory scale has often been in standard microalgae media, such as 3N-Basal Bold medium (3N-BB), which contains 15 different chemicals. Given the extremely tight profit margins of large-scale production of biofuel from microalgae, it is important to identify the minimally sufficient quantities of nutrients necessary to maximize lipid productivity. The individual and interactive effects of six groupings of the components of 3N-BB medium on growth rate, lipid content, and total biomass yield of S. dimorphus were determined. Trace metal and vitamin concentrations were reduced to 1/6 the level of 3N-BB medium without adversely …
Characterization Of Heterogeneous Reaction Systems By Thermal Analysis And Mathematical Modeling, Shreya Adhikari, Chuck Tillie
Characterization Of Heterogeneous Reaction Systems By Thermal Analysis And Mathematical Modeling, Shreya Adhikari, Chuck Tillie
Undergraduate Research Posters 2012
It is anticipated that this research will lead to scale-up parameters that can be used to model a laboratory-scale deposition furnace, and guide further experimentation to advance technologies for protective and conversion coatings.
The Study Of Bone Diffusion In Canine Tibia, Mariela Gonzalez-Nieves
The Study Of Bone Diffusion In Canine Tibia, Mariela Gonzalez-Nieves
Undergraduate Research Posters 2012
The provision of nutrients is imperative in order to maintain healthy bone structure. Bones are composed of dense connective tissues that are consistently reforming making it difficult for simple diffusion of large signaling molecules to occur. Fully understanding the rate at which nutrients, minerals, and waste travel throughout bone could lead to solutions to problems such as bone illnesses, breaks, and integration of prosthetics in the human body. Enhanced targeted medication delivery can be established as well.
Energy Analysis Of Bio-Ethanol Dehydration Using Pervaporative Processes, Michel Elia Kahwaji Janho
Energy Analysis Of Bio-Ethanol Dehydration Using Pervaporative Processes, Michel Elia Kahwaji Janho
Undergraduate Research Posters 2012
Environmental effects and health hazards posed by fossil-fuel based technologies complemented by changes in the global economy have increased the demand for “cleaner” and more efficient technologies. Developments in technologies that rely on renewable or synthetic resources have therefore become more relevant in today’s economy and current industrial outlook. This study focuses on a critical assessment of pervaporation as a dehydration technique in the production of ethanol from sugar-cane. Energy demands of various separation schemes using this technique are evaluated.
A Direct Sampling Particle Filter From Approximate Conditional Density Function Supported On Constrained State Space, Sridhar Ungarala
A Direct Sampling Particle Filter From Approximate Conditional Density Function Supported On Constrained State Space, Sridhar Ungarala
Chemical & Biomedical Engineering Faculty Publications
Constraints on the state vector must be taken into account in the state estimation problem. Recently, acceptance/rejection and projection methods are proposed in the particle filter framework for constraining the particles. A weighted least squares formulation is used for constraining samples in unscented and ensemble Kalman filters. In this paper, direct sampling from an approximate conditional probability density function (pdf) is proposed. It is obtained by approximating the a priori pdf as a Gaussian. The support of the conditional density is a subset of the intersection of two supports, the 3-sigma bounds of the priori Gaussian and the constrained state …
Doug Ruthven And Jorg Karger: Their Individual And Collective Contributions To The Field Of Zeolite Science And Engineering, Dhananjai B. Shah
Doug Ruthven And Jorg Karger: Their Individual And Collective Contributions To The Field Of Zeolite Science And Engineering, Dhananjai B. Shah
Chemical & Biomedical Engineering Faculty Publications
Prof. Doug Ruthven and Prof. Jörg Kärger are two giants in the field of zeolite science and engineering. Over their academic careers encompassing almost forty years each, they have contributed significantly to the advancement of fundamental understanding of adsorption and diffusion in zeolites as well as their industrial applications. The author, in the beginning of his academic career, had an opportunity to spend two years as a post-doctoral fellow in Prof. Ruthven’s laboratory at the University of New Brunswick (1975–1977). This experience actually motivated me to spend my academic career in working in the field of zeolite adsorption and …
Lipids And Collagen Matrix Restrict The Hydraulic Permeability Within The Porous Compartment Of Adult Cortical Bone, Demin Wen, Caroline Androjna, Amit Vasanji, Joanne M. Belovich, Ronald J. Midura
Lipids And Collagen Matrix Restrict The Hydraulic Permeability Within The Porous Compartment Of Adult Cortical Bone, Demin Wen, Caroline Androjna, Amit Vasanji, Joanne M. Belovich, Ronald J. Midura
Chemical & Biomedical Engineering Faculty Publications
In vivo the hydraulic permeability of cortical bone influences the transport of nutrients, waste products and signaling molecules, thus influencing the metabolic functions of osteocytes and osteoblasts. In the current study two hypotheses were tested: the presence of (1) lipids and (2) collagen matrix in the porous compartment of cortical bone restricts its permeability. Our approach was to measure the radial permeability of adult canine cortical bone before and after extracting lipids with acetone-methanol, and before and after digesting collagen with bacterial collagenase. Our results showed that the permeability of adult canine cortical bone was below 4.0 × 10 …
Computing Arrival Cost Parameters In Moving Horizon Estimation Using Sampling Based Filters, Sridhar Ungarala
Computing Arrival Cost Parameters In Moving Horizon Estimation Using Sampling Based Filters, Sridhar Ungarala
Chemical & Biomedical Engineering Faculty Publications
Moving horizon estimation (MHE) is a numerical optimization based approach to state estimation, where the joint probability density function (pdf) of a finite state trajectory is sought, which is conditioned on a moving horizon of measurements. The joint conditional pdf depends on the a priori state pdf at the start of the horizon, which is a prediction pdf based on historical data outside the horizon. When the joint pdf is maximized, the arrival cost is a penalty term based on the a priori pdf in the MHE objective function. Traditionally, the a priori pdf is assumed as …
Mechanics-Based Model For Non-Affine Swelling In Perfluorosulfonic Acid (Pfsa) Membranes, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson
Mechanics-Based Model For Non-Affine Swelling In Perfluorosulfonic Acid (Pfsa) Membranes, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson
Mechanical Engineering Faculty Publications
A mechanics-based model is developed to predict the swelling pressure in perfluorosulfonic acid (PFSA) ionomer membranes during water uptake. The PFSA membrane is represented as a two-phase system, where the water-filled hydrophilic domains are dispersed throughout the hydrophobic polymer matrix. Two representative volume elements (RVEs) are used to represent the nanostructure: (i) a spherical RVE with a spherical hydrophilic domain at the center, and (ii) a cylindrical RVE with a cylindrical hydrophilic domain. The model starts with the non-affine swelling behavior of the membrane and interprets this as a structural reorganization of the RVEs to characterize the microscopic deformation. Swelling …
Letter To The Editor, Sridhar Ungarala
Letter To The Editor, Sridhar Ungarala
Chemical & Biomedical Engineering Faculty Publications
No abstract provided.
Comments On "Robust And Reliable Estimation Via Unscented Recursive Nonlinear Dynamic Data Reconciliation", Sridhar Ungarala
Comments On "Robust And Reliable Estimation Via Unscented Recursive Nonlinear Dynamic Data Reconciliation", Sridhar Ungarala
Chemical & Biomedical Engineering Faculty Publications
No abstract provided.
The Use Of A Cell Filter For State Estimation In Closed-Loop Nmpc Of Low Dimensional Systems, Sridhar Ungarala, Keyu Li
The Use Of A Cell Filter For State Estimation In Closed-Loop Nmpc Of Low Dimensional Systems, Sridhar Ungarala, Keyu Li
Chemical & Biomedical Engineering Faculty Publications
Combining variants of the Kalman filter and moving horizon estimation (MHE) with nonlinear MPC has been studied before. The MHE is appealing due to its ability to impose constraints and demonstrated superiority over extended Kalman filter. However, nonlinear MPC based on MHE requires solutions to two back to back nonlinear programs. In this paper we propose to use the cell filter (CF) to provide state feedback to the MPC regulator. The cell filter is a piecewise constant approximation of the conditional probability density of the states, whose temporal evolution is modeled by an aggregate Markov chain. Since the CF …
Effect Of Synthesis Time And Treatment On Porosity Of Mesoporous Silica Materials, Asli Ertan, Pradeep Kodumuri, Orhan Talu, Surendra N. Tewari
Effect Of Synthesis Time And Treatment On Porosity Of Mesoporous Silica Materials, Asli Ertan, Pradeep Kodumuri, Orhan Talu, Surendra N. Tewari
Chemical & Biomedical Engineering Faculty Publications
Nitrogen adsorption at 77 K on mesoporous silica materials (MPS) with varying synthesis time and treatment conditions was investigated. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were also used to characterize the mesoporous materials. This study was performed at 6, 24 and 72-h synthesis times. It is shown that 6-h is not enough for complete formation of the MPS material and at least 24-h is necessary. The pore structure starts decaying for the 72-h synthesis time. The three-after-synthesis treatment conditions used were 1) washed, 2) washed and calcined and 3) directly calcined after synthesis. Ethanol/HCl …
Stress-Strain Behavior Of Perfluorosulfonic Acid Membranes At Various Temperatures And Humidities: Experiments And Phenomenological Modeling, Ahmet Kusoglu, Yaliang Tang, Michael Santare, Anette M. Karlsson, Simon Cleghorn, William B. Johnson
Stress-Strain Behavior Of Perfluorosulfonic Acid Membranes At Various Temperatures And Humidities: Experiments And Phenomenological Modeling, Ahmet Kusoglu, Yaliang Tang, Michael Santare, Anette M. Karlsson, Simon Cleghorn, William B. Johnson
Mechanical Engineering Faculty Publications
The constitutive response of perfluorinated sulfonic acid (PFSA) membranes based on tensile testing is investigated, and a phenomenological constitutive model for the elastoplastic flow behavior as a function of temperature and humidity is proposed. To this end, the G'Sell–Jonas (1979, “Determination of the Plastic Behavior of Solid Polymers at Constant True Strain Rate,” J. Mater. Sci., 14, pp. 583–591) constitutive model for semicrystalline polymers is extended by incorporating, in addition to temperature, relationships between the material constants of this model and the measured relative humidity. By matching the proposed constitutive model to the experimental stress-strain data, useful material constants …
Electrodeposition Of Nickel Nanowires And Nanotubes Using Various Templates, Asli Ertan, Surendra N. Tewari, Orhan Talu
Electrodeposition Of Nickel Nanowires And Nanotubes Using Various Templates, Asli Ertan, Surendra N. Tewari, Orhan Talu
Chemical & Biomedical Engineering Faculty Publications
Nickel nanotubes and nanowires are grown by galvanostatic electrodeposition in the pores of 1000, 100, and 15 nm polycarbonate as well as in anodised alumina membranes at a current density of 10 mA cm-2. The effects of pore size, porosity, electrodeposition time, effective current density, and pore aspect ratio are investigated. Nickel nanotube structures are obtained with 1000 nm pore size polycarbonate membrane without any prior treatment method. At the early stages of electrodeposition hollow nickel nanotubes are produced and nanotubes turn into nanowires at longer depositon times. As effective current density accounting for the membrane porosity decreases, the axial …
Micromechanics Model Based On The Nanostructure Of Pfsa Membranes, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson, William B. Johnson, Simon Cleghorn
Micromechanics Model Based On The Nanostructure Of Pfsa Membranes, Ahmet Kusoglu, Michael H. Santare, Anette M. Karlsson, William B. Johnson, Simon Cleghorn
Mechanical Engineering Faculty Publications
A micromechanics model is developed to predict Young’s modulus of perfluorosulfonic acid (PFSA) membranes at various temperatures and water contents. The morphology of PFSA membranes is characterized by a two-phase structure, where hydrophilic clusters expand to hold water molecules during swelling, whereas the hydrophobic polymer network maintains the structural stability. A representative volume element (RVE) is proposed based on the descriptions for the nanostructure of PFSA membranes available in the literature. On the basis of mechanics model, we estimate Young’s modulus in tension of PFSA membranes as a function of water volume fraction for various temperatures. The results show that …
Bayesian Estimation Via Sequential Monte Carlo Sampling-Constrained Dynamic Systems, Lixin Lang, Wen-Shiang Chen, Bhavik R. Bakshi, Prem K. Goel, Sridhar Ungarala
Bayesian Estimation Via Sequential Monte Carlo Sampling-Constrained Dynamic Systems, Lixin Lang, Wen-Shiang Chen, Bhavik R. Bakshi, Prem K. Goel, Sridhar Ungarala
Chemical & Biomedical Engineering Faculty Publications
Nonlinear and non-Gaussian processes with constraints are commonly encountered in dynamic estimation problems. Methods for solving such problems either ignore the constraints or rely on crude approximations of the model or probability distributions. Such approximations may reduce the accuracy of the estimates since they often fail to capture the variety of probability distributions encountered in constrained linear and nonlinear dynamic systems. This article describes a practical approach that overcomes these shortcomings via a novel extension of sequential Monte Carlo (SMC) sampling or particle filtering. Inequality constraints are imposed by accept/reject steps in the algorithm. The proposed approach provides samples representing …