Chemical Engineering Commons^™

Some Insights Into The Migration Of Double Imaginary Roots Under Small Deviation Of Two Parameters, Dina Alina Irofti, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper studies the migration of double imaginary roots of the systems’ characteristic equation when two parameters are subjected to small deviations. The proposed approach covers a wide range of models. Under the least degeneracy assumptions, we found that the local stability crossing curve has a cusp at the point that corresponds to the double root, and it divides the neighborhood of this point into an S-sector and a G-sector. When the parameters move into the G-sector, one of the roots moves to the right halfplane, and the other moves to the left half-plane. When the parameters move into the …

Raman Spectroscopy Predicts The Link Between Claw Keratin And Bone Collagen Structure In A Rodent Model Of Oestrogen Deficiency, M. Clare Caraher, Antonia Sophocleous, J. Renwick Beattie, Olive O'Driscoll, Niamh M. Cummins, Orlaith Brennan, Fergal J. O'Brien, Stuart H. Ralston, Steven E.J. Bell, Mark R. Towler, Aymen I. Idris

Chemical and Biochemical Engineering Faculty Research & Creative Works

Osteoporosis is a common disease characterized by reduced bone mass and an increased risk of fragility fractures. Low bone mineral density is known to significantly increase the risk of osteoporotic fractures; however, the majority of non-traumatic fractures occur in individuals with a bone mineral density too high to be classified as osteoporotic. Therefore, there is an urgent need to investigate aspects of bone health, other than bone mass, that can predict the risk of fracture. Here, we successfully predicted association between bone collagen and nail keratin in relation to bone loss due to oestrogen deficiency using Raman spectroscopy. Raman signal …

Nanoporous Carbon-Based Co2 Reduction Catalysts: Exploring The Combined Effects Of Surface Chemistry And Porosity, Wanlu Li

Dissertations, Theses, and Capstone Projects

For the first-time sulfur-doped, nitrogen-doped and sulfur, nitrogen-codoped nanoporous carbons were systematically studied as catalysts for CO₂ electrochemical reduction reaction (CO₂ERR). The Faradaic efficiencies (FE) of CO and CH₄ formation were calculated to evaluate the performance of these carbons. The best catalysts showed the FE of CO and CH₄ formation of 29% and 0.76%, respectively. It was found that the overall performance in CO₂ERR dramatically increased upon the reduction pretreatment of the carbons in N₂-saturated electrolyte before the CO₂ reduction process. The pretreated carbon showed the maximum FE of CO …

Kinetic Modelling And Experimental Studies For The Effects Of Fe2+ Ions On Xylan Hydrolysis With Dilute-Acid Pretreatment And Subsequent Enzymatic Hydrolysis, Hui Wei, Xiaowen Chen, Joseph Shekiro, Erik Kuhn, Wei Wang, Yun Ji, Evguenii Kozliak, Michael E. Himmel, Melvin P. Tucker

Chemical Engineering Faculty Publications

High-temperature (150–170 °C) pretreatment of lignocellulosic biomass with mineral acids is well established for xylan breakdown. Fe²⁺ is known to be a cocatalyst of this process although kinetics of its action remains unknown. The present work addresses the effect of ferrous ion concentration on sugar yield and degradation product formation from corn stover for the entire two-step treatment, including the subsequent enzymatic cellulose hydrolysis. The feedstock was impregnated with 0.5% acid and 0.75 mM iron cocatalyst, which was found to be optimal in preliminary experiments. The detailed kinetic data of acid pretreatment, with and without iron, was satisfactorily modelled …

Image-Based Modeling Of Flow Through Porous Media: Development Of Multiscale Techniques For The Pore Level, Timothy Wayne Thibodeaux

LSU Doctoral Dissertations

Increasingly, imaging technology allows porous media problems to be modeled at microscopic and sub-microscopic levels with finer resolution. However, the physical domain size required to be representative of the media prohibits comprehensive micro-scale simulation. A hybrid or multiscale approach is necessary to overcome this challenge. In this work, a technique was developed for determining the characteristic scales of porous materials, and a multiscale modeling methodology was developed to better understand the interaction/dependence of phenomena occurring at different microscopic scales. The multiscale method couples microscopic simulations at the pore and sub-pore scales. Network modeling is a common pore-scale technique which employs …

Pit Evolution Around The Fusion Line Of A Nicrmov Steel Welded Joint Caused By Galvanic And Stress-Assisted Coupling Corrosion, Shuo Weng, Yuhui Huang, Fuzhen Xuan, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

The corrosion of NiCrMoV steel welded joints is performed in an aqueous solution of 3.5 wt% NaCl at 180 °C in a container at a pressure of 0.8 MPa. The specimens in the shape of cylindrical tensile rods are immersed in the aqueous solution under the action of tensile stress in a range of 0 to 0.9 of the yield stress of the base metal. The experimental results suggest that there is macro-galvanic corrosion in the welded joint with the coarse-grained heat affected zone (CGHAZ) as anode due to the highest corrosion susceptibility of the CGHAZ. The CGHAZ has the …

Correlation Of Structure, Function And Protein Dynamics In Gh7 Cellobiohydrolases From Trichoderma Atroviride, T. Reesei And T. Harzianum, Anna S. Borisova, Elena V. Eneyskaya, Suvamay Jana, Silke F. Badino, Jeppe Kari, Antonella Amore, Magnus Karlsson, Henrik Hansson, Mats Sandgren, Michael E. Himmel, Peter Westh, Christina M. Payne, Anna A. Kulminskaya, Jerry Ståhlberg

Chemical and Materials Engineering Faculty Publications

Background: The ascomycete fungus Trichoderma reesei is the predominant source of enzymes for industrial conversion of lignocellulose. Its glycoside hydrolase family 7 cellobiohydrolase (GH7 CBH) TreCel7A constitutes nearly half of the enzyme cocktail by weight and is the major workhorse in the cellulose hydrolysis process. The orthologs from Trichoderma atroviride (TatCel7A) and Trichoderma harzianum (ThaCel7A) show high sequence identity with TreCel7A, ~ 80%, and represent naturally evolved combinations of cellulose-binding tunnel-enclosing loop motifs, which have been suggested to influence intrinsic cellobiohydrolase properties, such as endo-initiation, processivity, and off-rate.

Results: The TatCel7A, ThaCel7A, …

Solid Acid Catalyst Based On Single-Layer Α-Zirconium Phosphate Nanosheets For Biodiesel Production Via Esterification, Yingjie Zhou, Iman Noshadi, Hao Ding, Jingjing Liu, Richard Parnas, Abraham Clearfield, Min Xiao, Yuezhong Meng, Luyi Sun

Henry M. Rowan College of Engineering Departmental Research

In this study, a solid acid was prepared by the sulfonation of surface modified α-zirconium phosphate (ZrP) single-layer nanosheets (SO3H@ZrP), and the prepared solid acid was investigated for the esterification of oleic acid with methanol to produce biodiesel. For comparison, liquid H2SO4 and commercial Amberlyst® 15 catalyst were also evaluated for the same reaction under the same conditions. The experimental results showed that the SO3H@ZrP solid acid catalyst has a superior catalytic efficiency for the esterification reaction, as well as excellent recyclability. The SO3H@ZrP single-layer solid acid catalyst can be uniformly dispersed in the reaction media, but remains heterogeneous and …

Comparison Of Eosin And Fluorescein Conjugates For The Photoinitiation Of Cell-Compatible Polymer Coatings, Jacob L. Lilly, Anuhya Gottipati, Calvin F. Cahall, Mohamed Agoub, Brad J. Berron

Chemical and Materials Engineering Faculty Publications

Targeted photopolymerization is the basis for multiple diagnostic and cell encapsulation technologies. While eosin is used in conjunction with tertiary amines as a water-soluble photoinitiation system, eosin is not widely sold as a conjugate with antibodies and other targeting biomolecules. Here we evaluate the utility of fluorescein-labeled bioconjugates to photopolymerize targeted coatings on live cells. We show that although fluorescein conjugates absorb approximately 50% less light energy than eosin in matched photopolymerization experiments using a 530 nm LED lamp, appreciable polymer thicknesses can still be formed in cell compatible environments with fluorescein photosensitization. At low photoinitiator density, eosin allows more …

Specific Nanoporous Geometries On Anodized Alumina Surfaces Influence Astrocyte Adhesion And Glial Fibrillary Acidic Protein Immunoreactivity Levels, D. Ganguly, C. D.L. Johnson, M. K. Gottipati, D. Rende, D. A. Borca-Tasciuc, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Electrodes implanted in the brain or spinal cord trigger the activation of resident astrocytes. In their reactive state, astrocytes surrounding the electrode form a glial scar, compromising the ability of the electrode to interface with the surrounding neural tissue. One approach to reduce the inhibiting scar tissue is to incorporate nanoarchitecture on the surface of the implanted materials to modify the astrocytic response. The incorporated nanoarchitecture changes both the surface characteristics and the material properties of the implant interface. We investigated the response of rat cortical astrocytes to nanoporous anodic aluminum oxide (AAO) surfaces. Astrocytes were seeded onto nonporous aluminum …

2017-2018 Che Newsletter, Department Of Chemical Engineering, Michigan Technological University

Department of Chemical Engineering Newsletters

Table of Contents

• Department
• Convocation
• Student News
• Faculty
• Alumni & Friends

Treatment Of Dye Wastewater Using Dehydrated Peanut Hull, Nikitha Shamirpet

ETD Archive

The release of dye waste water into environment causes harm to aquatic life when they reach drains or other water sources. They pollute the soil and causes change in cycles of plant and animal life through bio-accumulation and nutrient cycle. Dyes which form residue or precipitate causes mutations or changes in the DNA of living organisms in and around the area of release of the dye into atmosphere. In this thesis, several runs were attempted to treat the synthetically prepared dye waste water using dehydrated peanut hull. The initial dye waste water samples were all collected and checked for absorbance, …

Kinetics And Ensemble Dynamics Of Colloidal Ellipsoids Near An Ac Electrode, Jiarui Yan

ETD Archive

The manipulation of colloidal particles via applying electric fields has been studied over the past 30 years due to the unique properties associated with the fabricated colloidal crystals. Most works in this field focused on utilizing an alternating current (AC) electric field with spherical particles. However, utilizing spherical colloidal particles as building blocks for complex microstructures has been challenging. Consequently, more recent work has shifted to employing complex colloids (anisotropic in nature) as building blocks for advanced materials. In our work, the phase diagram and the kinetics of assembling colloidal polystyrene ellipsoids under an AC electric field at low frequencies …

Modeling Liver Diseases Using Hepatic Cell Microarrays, Alexander David Roth

ETD Archive

Hepatocellular carcinoma (HCC) is an invasive and aggressive cancer of the liver that arises due to chronic cirrhosis. Research into understanding HCC has focused on two-dimensional (2D) and three-dimensional (3D) technologies to simulate the liver microenvironment and use animal models to model how HCC affects the rest of the body. 3D hydrogel models are desired because they can mimic the transport behavior observed in vivo by structurally mimicking the extracellular matrix (ECM) without the ethical concerns of animal models. However, hydrogels can be toxic to cells and require optimal procedures for appropriate handling. In this study, we created 3D models …

Implementation Of A Reverse Staggered-Herringbone Microfluidic Mixer For High-Throughput Polymeric Nanoparticles Synthesis, Alexa Roberts

Undergraduate Research Posters 2018

The goal of this research is to implement and optimize the operating conditions of a microfluidic mixer to synthesize polymeric nanoparticles (NPs) in a high-throughput fashion. Using a reverse staggered-herringbone microfluidic mixer that we recently designed, the effects of experimental conditions such as flowrate and reactant composition on NP characteristics were investigated and optimized. The device design allowed for physical contact between two streams of fluids – one containing poly(lactic-co-glycolic acid; PLGA) in acetonitrile and the other deionized water, to allow for efficient mixing and NP precipitation to occur. The resulting NPs were characterized using dynamic light scattering (DLS) and …

Prediction Of Metabolism-Induced Neurotoxicity On A 384pillarplate, Rushabh Patel, Pranav Joshi, Soo-Yeon Kang, Stephen Hong, Parnian Bigdelou

Undergraduate Research Posters 2018

Metabolism of compounds including neurotoxins primarily occurs in the liver by a variety of drug-metabolizing enzymes (DMEs) followed by a series of downstream responses. Unmodified (or parent) neurotoxins are transported into human hepatocytes through several influx transporters or via passive diffusion and undergo Phase I and Phase II biotransformation by DMEs before they are cleared. Neurotoxins and their metabolites generated from human hepatocytes could potentially lead to the toxic effects on neural stem cells (NSCs) as the reactive metabolites have potential for producing reactive oxygen species (ROS), which can lead to irreversible oxidative damage to NSCs via lipid peroxidation, DNA, …

Dendrite Morphology Of Pb-5.8 Sb Alloy: Gradient Freeze Ds With Cross-Section Area Change, Michael Shannon

Undergraduate Research Posters 2018

Directional solidification (DS) is the process of solidifying a metal alloy from one end to another resulting in aligned primary dendrites which are branched tree like features. Alignment of primary dendrites along [100] direction and their uniformity and distribution along the DS length determines the mechanical properties. These properties are especially important for single crystal turbine blade applications in modern gas turbine engines. Convection during solidification plays an important role in formation of detrimental defects, such as, misaligned grains, non-uniformity of dendrites and composition inhomogeneity. In this study the microstructural evolution during “Gradient Freeze DS process”, involving an abrupt cross-section …

Effects Of Water Content And Particle Size On Yield And Reactivity Of Lignite Chars Derived From Pyrolysis And Gasification, Yong Huang, Yonggang Wang, Hao Zhou, Yaxuan Gao, Deliang Xu, Lei Bai, Shu Zhang

Faculty & Staff Scholarship

Water inside coal particles could potentially enhance the interior char–steam reactions during pyrolysis and gasification. This study aims to examine the effects of water contents on the char conversion during the pyrolysis and gasification of Shengli lignite. The ex-situ reactivities of chars were further analyzed by a thermo gravimetric analyzer (TGA). Under the pyrolysis condition, the increase in water contents has monotonically decreased the char yields only when the coal particles were small (μm). In contrast, the water in only large coal particles (0.9–2.0 mm) has clearly favored the increase in char conversion during the gasification condition where 50% steam …

Incineration Of Nanoclay Composites Leads To Byproducts With Reduced Cellular Reactivity, Alixandra Wagner, Andrew P. White, Man Chio Tang, Sushant Agarwal, Todd A. Stueckle, Yon Rojanasakul, Rakesh K. Gupta, Carasela Zoica Dinu

Faculty & Staff Scholarship

Addition of nanoclays into a polymer matrix leads to nanocomposites with enhanced properties to be used in plastics for food packaging applications. Because of the plastics’ high stored energy value, such nanocomposites make good candidates for disposal via municipal solid waste plants. However, upon disposal, increased concerns related to nanocomposites’ byproducts potential toxicity arise, especially considering that such byproducts could escape disposal filters to cause inhalation hazards. Herein, we investigated the effects that byproducts of a polymer polylactic acid-based nanocomposite containing a functionalized montmorillonite nanoclay (Cloisite 30B) could pose to human lung epithelial cells, used as a model for inhalation …

Graphene Nanoplatelets-Sericin Surface-Modified Gum Alloy For Improved Biological Response, Valentina Mitran, Valentina Dinca, Raluca Ion, Vasile D. Cojocaru, Patricia Neacsu, Cerasela Zoica Dinu, Laurentiu Rusen, Simona Brajnicov, Anca Bonciu, Maria Dinescu, Doina Raducanu, Ioan Dan

Faculty & Staff Scholarship

In this study a “Gum Metal” titanium-based alloy, Ti-31.7Nb-6.21Zr-1.4Fe-0.16O, was synthesized by melting and characterized in order to evaluate its potential for biomedical applications. The results showed that the newly developed alloy presents a very high strength, high plasticity and a low Young's modulus relative to titanium alloys currently used in medicine. For further bone implant applications, the newly synthesized alloy was surface modified with graphene nanoplatelets (GNP), sericin (SS) and graphene nanoplatelets/sericine (GNP–SS) composite films via Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The characterization of each specimen was monitored by scanning electron microscopy (SEM), atomic force microscopy (AFM), …