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Use Of A Segmented Electrode To Control Current Distribution In Electrochemical Systems, Barry Van Tassell 2010 CUNY City College

Use Of A Segmented Electrode To Control Current Distribution In Electrochemical Systems, Barry Van Tassell

Dissertations and Theses

"The goal of this project was to investigate the use of segmented electrodes to control the current distribution through an electrochemical cell. To achieve this goal, the project was separated into two parts, designing a scalable piece of hardware that could create a current distribution, and then using that hardware to create noticeable changes in a system by changing the current distribution within the system. Prior to building the current distribution device, a basic 3-electrode galvanostat was built in order to test its fundamental design characteristics. The design stressed a simplistic hardware, relying on software to control the current. A ...


Supercritical Carbon Dioxide Processing Of Nano - Clays And Polymer/Clay Nanocomposites, Mihai Manitiu 2010 Wayne State University

Supercritical Carbon Dioxide Processing Of Nano - Clays And Polymer/Clay Nanocomposites, Mihai Manitiu

Wayne State University Dissertations

Effective dispersion of the fillers in a polymer matrix and improvement of polymer-clay interactions are two key challenges in the field of nanocomposites. A novel processing method that utilizes the unique properties of supercritical carbon dioxide (scCO2) to disperse nano-clay and prepare a series of polymer/clay nanocomposites with enhanced properties was explored.

Significant dispersion was achieved using the scCO2 process with Cloisite 10A without the presence of an organic phase as evident by the absence of the diffraction peak in WAXD and the presence of individual tactoids that lost their parallel registry. The expanded flexible structure of the scCO2 ...


High Yield And Conversion Of Biodiesel From A Nonedible Feedstock (Pongamia Pinnata), Yogesh C. Sharma, Bhaskar Singh, John Korstad 2010 Banaras Hindu University

High Yield And Conversion Of Biodiesel From A Nonedible Feedstock (Pongamia Pinnata), Yogesh C. Sharma, Bhaskar Singh, John Korstad

College of Science and Engineering Faculty Research and Scholarship

An efficient approach has been adopted for the synthesis of biodiesel developed from karanja, a nonedible oil feedstock. A two-step reaction was followed for synthesis of biodiesel. Karanja oil possessing a high free fatty acid content was esterified with sulfuric acid, and the product obtained was further converted to fatty acid alkyl esters (biodiesel) by transesterification reactions. A moderate molar ratio of 6:1 (methanol/oil) was efficient for acid esterification with 1.5% v/v H2SO4 and 1 h of reaction time at 60 ± 0.5 °C, which resulted in reduction of FFA from 19.88 ...


Application Of An Efficient Nonconventional Heterogeneous Catalyst For Biodiesel Synthesis From Pongamia Pinnata Oil, Y. C. Sharma, Bhaskar Singh, John Korstad 2010 Banaras Hindu University

Application Of An Efficient Nonconventional Heterogeneous Catalyst For Biodiesel Synthesis From Pongamia Pinnata Oil, Y. C. Sharma, Bhaskar Singh, John Korstad

College of Science and Engineering Faculty Research and Scholarship

Recycled chicken eggshells after calcination have been used as a nonconventional heterogeneous catalyst for biodiesel synthesis from karanja oil from the pongam tree (Pongamia pinnata). The catalyst was characterized on X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and differential thermal analysis/thermogravimetric analysis (DTA/TGA). The formation of the calcium oxide phase was confirmed at 900°C after calcination. A high biodiesel yield of 95.0% and conversion of 97.4% was obtained at an 8:1 (alcohol/oil) molar ratio, 2.5 wt%catalyst, and 2.5 h reaction time at 65±°0.5C. The biodiesel conversion was ...


Catalytic Strategies Of Glycoside Hydrolases, Luis Petersen 2010 Iowa State University

Catalytic Strategies Of Glycoside Hydrolases, Luis Petersen

Graduate Theses and Dissertations

Glycoside hydrolases (GHs) are enzymes that catalyze the hydrolysis of the glycosidic bond between two carbohydrate residues or a carbohydrate unit linked to a non-carbohydrate aglycon unit. Despite years of research dedicated to GHs, there are still several mechanistic details, relevant for individual GH enzymes, that remain to be investigated. In this work, a computational analysis of the detailed mechanism of several GHs is presented. QM/MM metadynamics simulations of two glycoside hydrolases, GH8 endoglucanase and GH43 β-xylosidase, give insight into the enzymatic deconstruction of the plant cell wall, and the detailed reaction mechanism of both enzymes. In addition, an ...


Protein And Oil Recoveries From Enzyme-Assisted Aqueous Extraction Of Soybeans And Sunflower Seed, Kerry Alan Campbell 2010 Iowa State University

Protein And Oil Recoveries From Enzyme-Assisted Aqueous Extraction Of Soybeans And Sunflower Seed, Kerry Alan Campbell

Graduate Theses and Dissertations

Aqueous extraction processing (AEP) of soybeans has the potential to achieve oil extraction yields comparable to hexane extraction without the environmental or safety concerns associated with hexane. The economic viability of this novel process depends upon maximizing the yield of free oil as well the development of a cost effective, high yielding method of recovering protein values in the aqueous by-product.

In order to direct strategies for yield improvement, mechanisms of AEP were studied by microscopic observation of extracted residual solids coupled with yield measurements and mathematical modeling. The nature of the oil-confining matrix varied depending on physical treatment of ...


Development Of A Sorbent For Carbon Dioxide, Dursun Can Ozcan 2010 Iowa State University

Development Of A Sorbent For Carbon Dioxide, Dursun Can Ozcan

Graduate Theses and Dissertations

The reversible absorption of CO2 by CaO at high temperature is a promising method for capturing and removing CO2 from a hot gas stream. The main challenge facing the use of this method is the deterioration of CO2 absorption capacity when the method is applied over a large number of CO2 absorption/desorption cycles. Although various techniques have been proposed for improving the cyclic stability and performance of calcium based sorbents, a cost effective method is still needed for industrial applications. Therefore, two promising methods for improving the cyclic stability were selected for further investigation. One method is to optimize ...


Structures, Kinetics, And Modeling Of Glycoside Hydrolase Family 44 Endoglucanases From Clostridium Acetobutylicum And Ruminococcus Flavefaciens Fd-1, Christopher Donald Warner 2010 Iowa State University

Structures, Kinetics, And Modeling Of Glycoside Hydrolase Family 44 Endoglucanases From Clostridium Acetobutylicum And Ruminococcus Flavefaciens Fd-1, Christopher Donald Warner

Graduate Theses and Dissertations

Glycoside hydrolases (GH) are enzymes that hydrolyze glycosidic bonds between carbohydrates. Family 44 contains endo- and xylo- glucanases capable of hydrolyzing cellulose and hemicelluose. Two members produced by Clostridium acetobutylicum and Ruminococcus flavefaciens FD-1 are the subjects of characterization work in this dissertation.

The EG from Clostridium acetobutylicum was characterized both structurally and kinetically. Crystallization and x-ray diffraction to 2.2-y resolution revealed a TIM barrel-like structure with additional ψ-loop and β-sandwich folds. The EG hydrolyzes cellotetraose and larger cellooligosaccharides, as well as carboxymethylcellulose and xylan at approximately the same rates. It converts lichenan to oligosaccharides of intermediate size and ...


A Comrehensive Model Study For Flash Nanoprecipitation: Computational Fluid Dynamics, Micro- Particle Image Velocimetry, And Population Balance Modeling, Janine Chungyin Cheng 2010 Iowa State University

A Comrehensive Model Study For Flash Nanoprecipitation: Computational Fluid Dynamics, Micro- Particle Image Velocimetry, And Population Balance Modeling, Janine Chungyin Cheng

Graduate Theses and Dissertations

A model study has been conducted for Flash Nanoprecipitation(FNP)) - a novel approach to produce functional nanoparticles. A mixing study has been conducted in a custom-designed microscale multi-inlet vortex reactor (MIVR) and a scalar mixing model was validated against experimental data. A microPIV experiment was conducted to further validate the turbulent model. A population balance equation (PBE) has been proposed to model the FNP process. It was furthermore, integrated into a computational fluid dynamics (CFD) simulation of to yield conditions comparable to the real experimental settings. In coping with the complicated aggregation model in the CFD code, a new numerical ...


Acid Catalyzed Carbohydrate Degradation And Dehydration, Basak Cinlar 2010 Iowa State University

Acid Catalyzed Carbohydrate Degradation And Dehydration, Basak Cinlar

Graduate Theses and Dissertations

Facile commercial production of versatile polyfunctional compounds from biomass constitutes a great challenge for establishing a sustainable chemical industry. One such example is the production of furfural and hydroxymethyl furfural via dehydration of pentoses and hexoses. Identified as primary building blocks in polymer industry, their massive production is highly desired, yet suffers from several problems, such as feedstock availability, low product yields due to excessive side reactions and lack of an industrially feasible heterogeneous catalyst.

Organic acid functional groups incorporated onto mesoporous silica offer well defined catalytic sites beside their unique textural properties and therefore could be considered as promising ...


Characterization Of Biochars Produced From Cornstovers For Soil Amendment, James W. Leeq, MIchelle Kidder, Barbara R. Evans, Sokwon Paik, A.C. Buchanan III, Charles T. Garten, Robert C. Brown 2010 Oak Ridge National Laboratory

Characterization Of Biochars Produced From Cornstovers For Soil Amendment, James W. Leeq, Michelle Kidder, Barbara R. Evans, Sokwon Paik, A.C. Buchanan Iii, Charles T. Garten, Robert C. Brown

Mechanical Engineering Publications

Through cation exchange capacity assay, nitrogen adsorption−desorption surface area measurements, scanning electron microscopic imaging, infrared spectra and elemental analyses, we characterized biochar materials produced from cornstover under two different pyrolysis conditions, fast pyrolysis at 450 °C and gasification at 700 °C. Our experimental results showed that the cation exchange capacity (CEC) of the fast-pyrolytic char is about twice as high as that of the gasification char as well as that of a standard soil sample. The CEC values correlate well with the increase in the ratios of the oxygen atoms to the carbon atoms (O:C ratios) in the ...


Experimental Study On Single Cement Fracture Exposed To Co2 Saturated Brine Under Dynamic Conditions, Tevfik Yalcinkaya 2010 Louisiana State University and Agricultural and Mechanical College

Experimental Study On Single Cement Fracture Exposed To Co2 Saturated Brine Under Dynamic Conditions, Tevfik Yalcinkaya

LSU Master's Theses

Carbon capture and storage is one of the technologies that could help reduce CO2 concentration in the atmosphere while contributing to cutback of Greenhouse Gas emissions. Depleted oil and gas fields are favorable targets for CO2 storage because existing wells can be readily used as injection wells. However, a number of abandoned wells also serve as gateway to the reservoir which should be considered in the context of effective Carbon capture and storage. Wellbore cement is a very essential element in wellbore systems that serve as a barrier between different zones in the subsurface. The fractures inside wellbore cement sheath ...


Surfactant-Induced Flow Behavior Effects In Gas Condensate Reservoirs, Bikash Deep. Saikia 2010 Louisiana State University and Agricultural and Mechanical College

Surfactant-Induced Flow Behavior Effects In Gas Condensate Reservoirs, Bikash Deep. Saikia

LSU Master's Theses

Natural gas, which accounts for a quarter of world’s energy, has been a major energy source because of its abundance and less impact on environment. With explorations at higher depth, pressure and temperature, the share of gas condensate reservoirs to global gas production is increasing. A unique production challenge associated with these reservoirs is the condensate blockage problem, which is the buildup of condensate liquid saturation around wellbore as a result of drawdown below dew point pressure. Mitigation of this problem requires in depth understanding of the multiphase flow of liquid and gas. Surfactants are well known in the ...


Processing And Conversion Of Algae To Bioethanol, Sara Katherine Kampfe 2010 College of William & Mary - Arts & Sciences

Processing And Conversion Of Algae To Bioethanol, Sara Katherine Kampfe

Dissertations, Theses, and Masters Projects

No abstract provided.


A General Approach Towards The Synthesis Of Amido-Functionalized Biodegradable Polyesters, Joseph Russell 2010 Bucknell University

A General Approach Towards The Synthesis Of Amido-Functionalized Biodegradable Polyesters, Joseph Russell

Master’s Theses

The thesis presented here describes methodologies to produce pendant group functionalized polyesters from amido-functionalized α-hydroxy acids. The synthetic methods used to produce the functionalized α-hydroxy acids are compatible with a wide array of functional groups, making this technique highly versatile. The synthesis of functionalized polyesters was investigated to develop polymers with properties that may improve the capabilities of existing biodegradable polyesters for applications in controlled release pharmaceuticals. Chemically modified a-hydroxy acids were synthesized by reacting glyoxylic acid with a primary or secondary amide. To demonstrate the utility of this reaction, fourstructurally dissimilar amide substituents were examined including 2-pyrrolidione ...


A Microfluidic Method To Measure Diffusion In Hydrogels, Andrew Lee Litzenberger 2010 Bucknell University

A Microfluidic Method To Measure Diffusion In Hydrogels, Andrew Lee Litzenberger

Master’s Theses

A novel microfluidic method is proposed for studying diffusion of small molecules in a hydrogel. Microfluidic devices were prepared with semi-permeable microchannels defined by crosslinked poly(ethylene glycol) (PEG). Uptake of dye molecules from aqueous solutions flowing through the microchannels was observedoptically and diffusion of the dye into the hydrogel was quantified. To complement the diffusion measurements from the microfluidic studies, nuclear magnetic resonance(NMR) characterization of the diffusion of dye in the PEG hydrogels was performed. The diffusion of small molecules in a hydrogel is relevant to applications such asdrug delivery and modeling transport for tissue-engineering applications. The diffusion ...


Data Fusion For The Problem Of Protein Sidechain Assignment, Yang Lei 2010 University of Massachusetts Amherst

Data Fusion For The Problem Of Protein Sidechain Assignment, Yang Lei

Masters Theses 1911 - February 2014

In this thesis, we study the problem of protein side chain assignment (SCA) given

multiple sources of experimental and modeling data. In particular, the mechanism

of X-ray crystallography (X-ray) is re-examined using Fourier analysis, and a novel

probabilistic model of X-ray is proposed for SCA's decision making. The relationship

between the measurements in X-ray and the desired structure is reformulated in terms

of Discrete Fourier Transform (DFT). The decision making is performed by developing

a new resolution-dependent electron density map (EDM) model and applying

Maximum Likelihood (ML) estimation, which simply reduces to the Least Squares

(LS) solution. Calculation of ...


Optimization Of Parameters And Study Of Kinetics In Lactulose Production By Lactose Isomerization Using Strong Basic Anion Exchange Resin, Arvind Nanduri 2010 Missouri University of Science and Technology

Optimization Of Parameters And Study Of Kinetics In Lactulose Production By Lactose Isomerization Using Strong Basic Anion Exchange Resin, Arvind Nanduri

Masters Theses

"In this work, an experimental design was employed to investigate the effects of different operating conditions on the isomerization of lactose to lactulose by using strong basic anion exchange resin (AMBERLITE-IRA 402). Temperature, resin/lactose mass ratio and pH were considered to be the three factors affecting the conversion of lactose. Box-Behnken design was then used to optimize the operating conditions for maximum response and also to study the various interaction and main effects of the factors. The analysis of variance (ANOVA) of the experimental data showed a high correlation coefficient R² (0.99) and a low root mean square ...


Identifying Multiple Steady States In The Design Of Reactive Distillation Processes, Thomas Karl Mills 2010 Missouri University of Science and Technology

Identifying Multiple Steady States In The Design Of Reactive Distillation Processes, Thomas Karl Mills

Doctoral Dissertations

"Global homotopy continuation is used to identify multiple steady states in ideal reactive flash and reactive distillation systems involving a reaction of the form A+B [symbol for <--> C taking place in the liquid phase. The choice of specifications has an influence on the existence of multiple solutions for both the flash and the column. For the flash, specification of the heat input or withdrawal can give rise to multiplicities while specification of the split fraction does not. Specification of one internal energy balance variable and one external material balance variable does not produce multiplicities in the column; however, specification ...


Enhanced Photorefractivity In A Polymeric Composite Photosensitized With Modified Carbon Nanotubes, Naveen Kumar Lingam 2010 Missouri University of Science and Technology

Enhanced Photorefractivity In A Polymeric Composite Photosensitized With Modified Carbon Nanotubes, Naveen Kumar Lingam

Masters Theses

"This work involves the photosensitization of photorefractive polymeric composites through the inclusion of multiwalled and singlewalled carbon nanotubes grafted to poly(N-vinyl carbazole). The photorefractive nature of the holograms gratings was established using two-beam-coupling, yielding two-beam-coupling gain coefficients approaching 80 cm⁻¹. Degenerate-four-wave-mixing experiments exhibited diffraction efficiencies as high as 60% as well as over-modulation voltages as low as ~ 40 V/µm. These notable figures of merit indicate that the grafting of the various carbon nanotubes to the poly(N-vinyl carbazole) polymer resulted in enhanced photorefractive performance. The mechanism responsible for this enhancement in photorefractive performance is investigated using a ...


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