Engineering Commons^™

Biodiesel – Oxidation, Storage Stability And Materials Compatibility – The Brazilian R&D Experience, Eduardo Cavalcanti

Bioenergy - II: Fuels and Chemicals from Renewable Resources

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Hybrid Staged Thermolysis To Valorise Biomass, Paul J. De Wild

Bioenergy - II: Fuels and Chemicals from Renewable Resources

The need for a renewable ‘green’ chemistry is adamant because of the adverse effects of the increasing use of fossil fuels on our society, like global warming and the depletion of fossil fuel resources. Therefore, the use of ligno-cellulosic (woody) types of biomass as a renewable source for chemicals and energy is increasingly becoming important. Unfortunately, the heterogeneity of biomass presents a major obstacle to chemical utilization. The main constituents hemicellulose, cellulose and lignin are strongly interconnected by a variety of physico-chemical bonds that makes it difficult to extract individual chemicals in high yields. So an efficient and cost-effective fractionation …

Binding Studies Of Epidermal Growth Factor Receptor Targeted Compounds Using Surface Plasmon Resonance, Spandana Kankanala

Theses and Dissertations

The study of binding kinetics of proteins plays an important role in understanding molecular mechanisms that drive biological processes. The binding rate constants reflect the dynamics of the system and associated biological activity measurements of the association and dissociation rate constants make it possible to compare different interactions in a standardized manner and help elucidate a mechanistic understanding of binding events. In our study, we used Surface Plasmon Resonance (SPR) technology (Biacore) to study the binding kinetics of the antibodies EGF, Cetuximab and a candidate drug P-13 with the receptor EGFR. The candidate drug P-13 was synthesized and tested on …

Effects Of Growth Media Ph And Reaction Water Activity On The Conversion Of Acetophenone To (S)-1-Phenylethanol By Saccharomyces Cerevisiae Immobilized On Celite 635 And In Calcium Alginate, Nicholas P. Coleman, Czarena Crofcheck, Sue E. Nokes, Barbara L. Knutson

Biosystems and Agricultural Engineering Faculty Publications

Biologically catalyzed reactions often produce enantiomers of the product; however, only one configuration is desired. Reaction conditions are known to affect enantiomer ratios and reaction kinetics, but little is known regarding the effect of processing conditions on whole-cell biocatalysis. Saccharomyces cerevisiae cells were grown in batch on glucose at pH = 4, 5, and 7, and then immobilized on Celite beads or in calcium alginate beads and used as the biocatalyst for the conversion of acetophenone in hexane to (S)-1-phenylethanol at water activities of 0.37, 0.61, and 0.80. S. cerevisiae was used as a model microorganism for the whole-cell catalyzed …

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 …

Biofilm Inhibitory Coatings Formulated From Glass Polyalkenoate Cement Chemistry: An Evaluation Of Their Adhesive Nature, A. Coughlan, D. Boyd, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Researchers evaluated the adhesive nature of the biofilm inhibitory coatings formulated from glass polyalkenoate cement (GPC) chemistry with the aim to establish the novel testing modality by modifying the conventional T-peel tests. Special consideration was given to determine the resistance of a bonded assembly of two adherents having at least one adherent flexible to quantify the bond between tape and a surgical metal substrate bonded by a luting GPC. The delaminated tape surface was examined by scanning electron microscopy (SEM) with an accelerating voltage of 20 K V to determine whether failure of the bond was adhesive of cohesive in …

Theory And Computation Of Photopolymerization-Induced Phase Transition And Morphology Development In Blends Of Crystalline Polymer And Photoreactive Monomer, Pankaj Rathi, Thein Kyu

College of Polymer Science and Polymer Engineering

A hypothetical phase diagram of a crystalline polymer/photoreactive monomer mixture has been calculated on the basis of phase field (PF) free energy of crystal solidification in conjunction with Flory-Huggins (FH) free energy of liquid-liquid demixing to guide the morphology development during photopolymerization of poly(ethylene oxide)/triacrylate blend. The self-consistent solution of the combined PF-FH theory exhibits a crystalline-amorphous phase diagram showing the coexistence of solid+liquid gap bound by the liquidus and solidus lines, followed by an upper critical solution temperature at a lower temperature. When photopolymerization was triggered in the isotropic region, i.e., slightly above the crystal melting transition temperatures, the …

Thermodynamically Coupled Heat And Mass Flows In A Reaction-Transport System With External Resistances, Yaşar Demirel

Yaşar Demirel Publications

Considerable work has been published on mathematically coupled nonlinear differential equations by neglecting thermodynamic coupling between heat and mass flows in reaction-transport systems. The thermodynamic coupling refers that a flow occurs without or against its primary thermodynamic driving force, which may be a gradient of temperature, or chemical potential, or reaction affinity. This study presents the modeling of thermodynamically coupled heat and mass flows of two components in a reaction-transport system with external heat and mass transfer resistances. The modeling equations are based on the linear nonequilibrium thermodynamics approach by assuming that the system is in the vicinity of global …

Electrocatalytic Reduction Of Oxygen On Tungsten Carbide Electrode, Chun-An Ma, Yun Huang, Ying-Hong Zhu, Zhao-Yang Chen

Journal of Electrochemistry

Tungsten carbide(WC) catalysts were prepared by gas-solid reaction using ammonium metatungstate as precursors which were pretreated with spray drying sphere miniaturation,carbon monoxide as carrier gas and hydrogen as deoxidizing gas.The WC electrode was fabricated using WC catalyst powders and PTFE as binding agent,and characterized by XRD and SEM.Electrocatalyst behavior of WC for oxygen reduction reaction in the sulphuric acid solution was studied by steady-state voltammetry and cyclic voltammetry.The results show that the WC powders obtained were in spheric particles and the prepared WC electrode had a good electrocatalyst activity to the oxygen reduction reaction.The electrode reaction was controlled by adsorption.The …

19th International Symposium Of Fine Chemistry And Functional Polymers (Fcfp-Xix) & Iupac 5th Internaitonal Symoposium On Novel Materials And Synthesis (Nms-V), Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Electrooxidation Behaviors Of Tib2 As High Capacity Anodic Material In Neutral Aqueous Electrolytes, Ya-Dong Wang, Xian-Yong Guang, Zhi-Xin Wang, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

Titanium diborides were investigated as an anodic material for neutral aqueous batteries. It is revealed that this material shows superiorly high electrochemical activities in the neutral electrolytes. The discharge capacities observed for TiB₂ reached 1300 mAh/g at the constant current density of 50 mA/g, exceeding all the metal electrodes reported so far. The electrooxidation of this compound was found to proceed via the electrochemical dissolution of boron to form borofluoride, while titanium remained unchanged at the electrode. These results suggest a possible use of the boride compounds as a new material for constructing neutral aqueous batteries with high electrochemical …

Electrosynthesis Of 2,2-Dimethylolpropionic Acid, Hong-Yan Sun, Zhen-Hai Liang

Journal of Electrochemistry

The Ti/SnO₂+Sb₂O₄/PbO₂ electrode was prepared.The structure phase and valent state were characterized by means of XRD and XPS.The 2,2-dimethylolpropionic acid was synthesized on the Ti/SnO₂+Sb₂O₄/PbO₂ anode by direct electro-oxidation of 2,2-dimethylolpropionaldehyde.The product and crude material were analyzed by HPLC,the effects of the concentration of 2,2-dimethylolpropionaldehyde,pH,potential and reaction temperature were studied.The results showed that the optimum conditions were anode potential 1.8 V,pH=1,reaction temperature 15 ℃ and 2,2-dimethylolpropionaldehyde concentration 0.10mol/L.Under the optimum conditions,the selectivity of 36%,the current efficiency of 28% and the conversion of 58% were reached.The reported …

Synthesis,Characteristics And Electrochemical Performance Of Nano-Sized Snco/Graphite Composites As Anode For Lithium Ion Batteries, Jin-Shu Cai, Ling Huang, Fu-Sheng Ke, Shi-Gang Sun

Journal of Electrochemistry

The nano-structural Sn-Co/graphite composites were prepared by chemical reduction of the alloy electroless deposition solution in graphite suspensions, and the composites were annealed at 500 ℃. The phase structure and surface morphology of the composites were measured by XRD, SEM and Raman. The results indicate that there were high dispersions and high loadings of Sn-Co nanoparticles on graphite by thermal treatment. Electrochemical lithium storage performance was studied preliminarily on the obtained samples. The graphite modified with the Sn-Co nanoparticles possessed a higher electrochemical reversible capacity than that of graphite during the charge and discharge process. The appetency between the Sn-Co …

High Utilization Aupt Nanoparticles Supported On Mwcnts For Methanol Electro-Oxidation In Alkaline Medium, Xun Guo, Dao-Jun Guo, Xin-Ping Qiu, Li-Quan Chen, Wen-Tao Zhu

Journal of Electrochemistry

We synthesized gold-platinum electrocatalysts supported on multi-walled carbon nanotubes(MWCNTs) with high utilization by a simple one-step method.A high Pt loading series of bimetallic AuPt/MWCNTs catalysts were prepared by the improved ethylene glycol reduction method,and then were compared in terms of the electrocatalytic activity for methanol electro-oxidation using cyclic voltammetry(CV) and chronoamperometry in alkaline solutions.The structure of AuPt/MWCNTs was characterized by the transmission electron microscopy(TEM),X-ray diffraction(XRD) and energy-dispersive X-ray spectroscopy(EDS).The results showed that the AuPt/MWCNTs catalysts had high Pt utilization,uniform AuPt nanoparticles size and good electrocatalytic activity for methanol electro-oxidation.The effect of Au/Pt mass ratio on electrocatalytic activity was also investigated.The …

Extraction Of Alkaloids From Opium, Keith Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

A method for extracting at least one alkaloid from opium that includes dissolving opium in a solvent, heating the dissolved opium solution, cooling the dissolved opium solution, adjusting the pH of the dissolved opium solution with at least one first weak acid, filtering the dissolved opium solution to recover a filtrate; and then separating and purifying at least one alkaloid in the filtrate. Preferably, this includes an additional step of chilling the opium solution after adjusting the pH of the dissolved opium solution with at least one first acid. The preferred method for separating and purifying at least one alkaloid …

A New Model For Aqueous Electrolyte Solutions Near The Critical Point Of Water Incorporating Aqueous Reaction Equilibria, Craig J. Peterson

Theses and Dissertations

Aqueous electrolyte solutions at temperature and pressure conditions near the critical point of water are difficult to describe using traditional equations of state based upon the excess Gibbs energy. Models based upon the residual Helmholtz energy have proven more effective. Anderko and Pitzer1 developed a residual Helmholtz energy model (AP) for aqueous electrolyte solutions in which the electrolyte is assumed to be fully associated. The model has been effectively used in describing densities and vapor-liquid equilibria for simple electrolyte systems. The model is less effective for describing enthalpic properties such as heats of dilution. Oscarson and coworkers2, 3 modified the …

Redox, Pressure And Mass Transfer Effects On Syngas Fermentation, Allyson White Frankman

Theses and Dissertations

The fermentation of syngas (a mixture of CO, CO2 and H2) to produce ethanol is of interest as an alternative fuel. Clostridium carboxidivorans, has been found to produce higher than average amounts of ethanol and butanol from CO-rich mixtures. This project sought to determine the effects of the redox level in the solution, partial pressures in the headspace and mass transfer limitations on the products obtained through fermentation of syngas. It was determined that cysteine sulfide has a greater effect on the redox level of the media used to grow bacteria, than does the gas composition. Therefore, changing gas …

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 …

Shear Banding Or Not In Entangled Dna Solutions Depending On The Level Of Entanglement, Pouyan E. Boukany, Shi-Qing Wang

College of Polymer Science and Polymer Engineering

Entangled DNA solutions are ideal as a model system to examine nonlinear shear flow behavior. Even when the number of entanglements per chain, Z, is higher than 100, the solution is still soft enough with an elastic plateau modulus under 100 Pa and is thus amenable to experimental study by commercial rotational rheometry without ambiguity and uncertainty. We have investigated nonlinear flow behavior of three entangled DNA solutions with Z=24, 60, and 156, respectively, using a combination of particle-tracking velocimetric (PTV) and conventional rheometric measurements. We explore questions such as (a) whether shear banding also occurs in moderately entangled solutions, …

Photopatternable Polymeric Membranes For Optical Oxygen Sensors, Raghu Ambekar, Jongwon Park, David Henthorn, Chang-Soo Kim

Chemical and Biochemical Engineering Faculty Research & Creative Works

A new class of optical oxygen sensor that can be photopatternable by traditional UV lithography is presented. They are fabricated using photopatternable spin-on silicone (polydimethylsiloxane, PDMS) with oxygen sensitive luminescent dyes. It has a good adhesion property and can be applied on glass or on photopolymer (SU-8) without any additional surface treatments. The optimum mixture composition for patternable oxygen sensitive membranes is investigated and its optical properties are characterized. Proof-of-concepts for two applications, intensity-based oxygen sensing with SU-8 based structure and self-calibration fluidic oxygen sensor, are described. These photopatternable optical membranes will find many applications wherever small patterns of oxygen …

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 …

Temperature Influence And Heat Management Requirements Of Microalgae Cultivation In Photobioreactors, Thomas Hagen Mehlitz

Master's Theses

Microalgae are considered one of the most promising feedstocks for biofuel production for the future. The most efficient way to produce vast amounts of algal biomass is the use of closed tubular photobioreactors (PBR). The heat requirement for a given system is a major concern since the best algae growth rates are obtained between 25-30 °C, depending on the specific strain. A procedure to determine temperature influence on algal growth rates was developed for a lab-scale PBR system using the species Chlorella. A maximum growth rate of 1.44 doublings per day at 29 °C (optimal temperature) was determined. In addition, …

Precipitation Of Micro/Nanoparticles In Enhanced High Energy Dissipation Mixing Systems, Giuseppe Di Benedetto

Dissertations

Crystallization is the most common unit operation used in the pharmaceutical industry to synthesize active ingredients. Rapid development of a drug candidate is dependent on the ability to produce a desired drug substance with consistent properties, These properties include stability and purity, which are directly affected by the crystallization process and which affect, in turn, bioavailability, drug dissolution rate, drug stability, and shelf life.

The objective of this work is to produce micro/nanoparticle crystals within existent glass-lined pharmaceutical stirred-tank reactors by modifying the current reactor configuration to include features that can increase the local rate of energy dissipation in the …

Enhanced Fluidization Of Nanoparticle Agglomerates, Daniel Lepek

Dissertations

Gas fluidization of nanoparticle agglomerates has recently received much attention due to the excellent way in which these novel nanornaterials can be dispersed in a gaseous medium. Nanopowders have a very high surface area to volume ratio which allows them have unique chemical and physical properties especially at the surface. Fluidization is a popular technique for the continuous dispersal of solid materials in the fluidlike state.

Recently it has been found that nanoparticles exist in a highly agglomerate state which allow them to become fluidizable. The fluidization behavior of the nanopowders is dependent on the bulk and material properties of …

Preparation Of Nanovehicles For Targeted Drug Delivery, Anagha Avinash Bhakay

Theses

Application of nanotechnology in pharmaceutical research has opened new frontiers for drug development and its efficient delivery. In recent years, the focus of the research has been on the engineering of nano/micro-particulate structures for efficient and targeted delivery of drugs for selective and enhanced absorption. This work throws light on the preparation of biodegradable and non-toxic nanoparticulate systems for targeted drug delivery. The drug vehicles were made by two different processes namely electrostatic interactions and desolvation process. The drug carriers made by these processes were found to be in the size range of 150-200nm which is necessary for cellular uptake …

Understanding Rubber Friction In The Presence Of Water Using Sum-Frequency Generation Spectroscopy, Kumar Nanjundiah, Ping Yuan Hsu, Ali Dhinojwala

College of Polymer Science and Polymer Engineering

Infrared-visible sum-frequency-generation spectroscopy (SFG) was used to study the molecular structure of water between a poly(dimethylsiloxane) (PDMS) and a sapphire substrate. The observation of SFG peaks associated with the dangling surface hydroxyl groups (3690 cm(-1)) and water bands (3000-3400 cm(-1)) indicates that the contact spot between the PDMS lens and the sapphire substrate is heterogeneous. Within the contact spot there are regions where the methyl groups of the PDMS chains are in direct contact with the surface hydroxyl groups on the sapphire substrate. In the other regions, a thin water layer is trapped between the two surfaces with spectral features …

The Developmental Effect Of Human Embryoid Bodies (Heb) Under Dynamic Culturing Conditions Using A Perfusion Based Slow Turning Lateral Vessel (Stlv) Bioreactor, Claiborne Collier

Theses and Dissertations

Human embryonic stem cells (hESCs) can provide a unique approach for novel tissue engineering applications. Previous groups have shown that hESCs can differentiate into specialized cell types through the generation of human embryoid bodies (hEBs). These multi-cellular constructs are then subjected to suspension culture for several weeks. Traditional hESC differentiation techniques have yielded non-homogeneous EBs derived in standard static cultures providing an inefficient platform for cellular viability and embryonic modeling. Here, our study aimed at systematically comparing the formation, growth, and differentiation capabilities of hESC-derived hEBs in dynamic and static suspension cultures. We used a continuous flow perfusion slow turning …

Computed Tomographic Investigation Of The Influence Of Gas Sparger Design On Gas Holdup Distribution In A Bubble Column, B. C. Ong, P. Gupta, A. Youssef, M. (Muthanna) H. Al-Dahhan, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Effect of Gas Sparger Design on the Gas Holdup Radial Profile in a Bubble Column (With a Diameter of 0.162 M) Has Been Studied using Γ-Ray Computed Tomography (CT). Six Different Configurations of Gas Spargers Were Examined, using an Air-Water System for Selected Superficial Gas Velocities from 2 Cm/s to 30 Cm/s, Covering the Homogeneous and Heterogeneous (Churn-Turbulent) Flow Regimes. Two Operating Pressures Were Used: 1 and 4 Atm. Differences Were Found between the Gas Holdup Distributions Produced by Different Spargers at Dimensionless Radii of R/R < 0.8 in the Central Region of the Column. the Cross and Single Nozzle Spargers Produced Closely Similar Gas Holdup Distributions, While the Perforated Plate Sparger Produced a Higher Gas Holdup When Compared to Other Spargers with the Same Percentage Open Area (POA). at 4 Atm, the Sparger Design Did Not Have a Significant Effect on the Gas Holdup Profiles, Compared to Atmospheric Pressure, Except for the Case of the Single-Hole Sparger, Which Was Found to Yield a Higher Gas Holdup. © 2009 American Chemical Society.

The Effect Of Sodium On The Catalytic Activity Of Zno-Al2o3/Zsm-5 And Sno-Al2o3/Zsm-5 For The Transesterification Of Vegetable Oil With Methanol, Manhoe Kim, Shuli Yan, Steven O. Salley, K.Y. Simon Ng

National Biofuels Energy Laboratory

In order to elucidate the effect of sodium on the activity of ZSM-5 supported metal oxides catalysts (ZnO-Al2O3/ZSM-5 and SnO-Al2O3/ZSM-5) for the transesterification of soybean oil with methanol, ZSM-5 supported metal oxides were prepared with and without sodium hydroxide by impregnation. The metal compositions of the ZSM-5 supported metal oxide catalysts and the metal concentrations dissolved from the catalysts to the methylester phase were measured by SEM-EDS and inductive coupled plasma spectroscopy, respectively. The catalytic activity of ZnO-Al2O3/ZSM-5 and SnO-Al2O3/ZSM-5 containing sodium did not originate from surface metal oxides sites, but from surface sodium sites or dissolved sodium leached from …

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner

Mathematics Faculty Publications

In this paper the lubrication-type dynamical model is developed of a molten, pulsed laser-irradiated metallic film. The heat transfer problem that incorporates the absorbed heat from a single beam or interfering beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the peak laser beam intensity, the film optical thickness, the Biot and …