Effect Of Differences In The Primary Structure Of The A-Chain On The Aggregation Of Insulin Fragments,
2018
Missouri University of Science and Technology
Effect Of Differences In The Primary Structure Of The A-Chain On The Aggregation Of Insulin Fragments, Paul P. Nakka, Ke Li, Daniel Forciniti
Chemical and Biochemical Engineering Faculty Research & Creative Works
Bovine and human insulin have similar primary structures. In this article, the region of the insulin A-chain of bovine and human insulin where the amino acid composition is different was studied. Bovine insulin fragment (BIF) and human insulin fragment (HIF) were synthesized in solid-phase peptide synthesis. The effects of pH, temperature, urea, ionic strength, and stirring on the formation of fibrils were studied using a fractional factorial resolution III experimental design. Fibrillation was monitored by fluorescence and infrared spectroscopy and optical microscopy. Both fragments formed fibrils at pH 1.6 and a temperature of 60 °C. The lag time and apparent …
Membrane-Based Separation Processes For Treating High Salinity Produced Waters,
2018
University of Arkansas, Fayetteville
Membrane-Based Separation Processes For Treating High Salinity Produced Waters, Kamyar Sardari
Graduate Theses and Dissertations
Produced waters (PW) generated in the oil and gas industry within the United States often contain extreme levels of total dissolved solids (TDS). These high TDS waste streams need to be treated cost-effectively as the costs associated with the current management techniques can exceed 15 USD per barrel of discharged PW. Thermally and osmotically-driven membrane separation technologies can show promising potential for treating high TDS waste streams, as onsite low-grade waste heat may be used for their operation. In this dissertation, the application of membrane distillation (MD), forward osmosis (FO) and a hybrid FO-MD process for treating synthetic and actual …
Incorporating Germanium Oxide Into The Glass Phase Of Novel Zinc/Magnesium-Based Gpcs Designed For Bone Void Filling: Evaluating Their Physical And Mechanical Properties,
2018
Missouri University of Science andtechnology
Incorporating Germanium Oxide Into The Glass Phase Of Novel Zinc/Magnesium-Based Gpcs Designed For Bone Void Filling: Evaluating Their Physical And Mechanical Properties, Basel A. Khader, Omar Rodriguez, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
The structural role of Germanium (Ge), when substituting for Zinc (Zn) up to 8 mol % in the 0.48SiO2-0.12CaO-0.36ZnO-0.04MgO glass series, was investigated with respect to both the glass chemistry and also the properties of glass polyalkenoate cements (GPCs) manufactured from them. The Network connectivity (NC) of the glass was calculated to increase from 1.83 to 2.42 with the addition of GeO2 (0-8 mol %). Differential thermal analysis (DTA) results confirmed an increase in the glass transition temperature (Tg) of the glass series with GeO2 content. X-ray photoelectron spectroscopy (XPS) showed an increase in …
Electrocatalytic Properties Of Ni-Fe Basedalloys Toward Oxygen Evolution Reaction,
2018
Louisiana State University and Agricultural and Mechanical College
Electrocatalytic Properties Of Ni-Fe Basedalloys Toward Oxygen Evolution Reaction, Xiaodan Cui
LSU Doctoral Dissertations
In this dissertation, laser-based manufacturing was applied to develop NiFe-based alloys, with focus on their electrochemical characteristics toward oxygen evolution reaction during water electrocatalysis. The targeted electrocatalysts were designed by combining catalysis principles of absorption energy, electronic effect and geometry effect. Firstly, a one-step laser-based manufacturing method was applied to prepare a thin layer of NiFe-based electrodes with varied Ni to Fe ratios to replace high-cost noble metals as the electrocatalyst for oxygen evolution reaction (OER). Since each Ni has 0.6 d-vacancy and each Fe atom has 2.2 d-vacancies. The alloying of Ni-Fe allows electrons flowing from Ni to Fe, …
Data-Based Nonlinear Model Identification In Economic Model Predictive Control,
2018
University of Study of L’Aquila
Data-Based Nonlinear Model Identification In Economic Model Predictive Control, Laura Giuliani, Helen Durand
Chemical Engineering and Materials Science Faculty Research Publications
Many chemical/petrochemical processes in industry are not completely modeled from a first-principles perspective because of the complexity of the underlying physico-chemical phenomena and the cost of obtaining more accurate, physically relevant models. System identification methods have been utilized successfully for developing empirical, though not necessarily physical, models for advanced model-based control designs such as model predictive control (MPC) for decades. However, a fairly recent development in MPC is economic model predictive control (EMPC), which is an MPC formulated with an economics-based objective function that may operate a process in a dynamic (i.e., off steady-state) fashion, in which case the details …
Reverse Flotation Separation Of Fluorite From Calcite: A Novel Reagent Scheme,
2018
Central South University
Reverse Flotation Separation Of Fluorite From Calcite: A Novel Reagent Scheme, Jianjun Wang, Zihan Zhou, Yuesheng Gao, Wei Sun, Yuehua Hu, Zhiyong Gao
Michigan Tech Publications, Part 1
Fluorite (CaF2), as an important strategic mineral source, is usually separated from calcite by the common froth flotation method, but this separation is still not selective enough. The development of a selective collector and/or depressant is the key to achieving high selective separation. 1-Hydroxyethylidene-1,1-diphosphonic acid (HEDP or H4L) is widely used as an environmentally friendly water treatment reagent due to its low cost and excellent anti-scaling performance in an aqueous solution. In this study, a novel reagent scheme was developed using HEDP as a fluorite depressant and sodium oleate (NaOL) as a calcite collector for the …
Diverse Lignocellulosic Feedstocks Can Achieve High Field‐Scale Ethanol Yields While Providing Flexibility For The Biorefinery And Landscape‐Level Environmental Benefits,
2018
University of Wisconsin-Madison
Diverse Lignocellulosic Feedstocks Can Achieve High Field‐Scale Ethanol Yields While Providing Flexibility For The Biorefinery And Landscape‐Level Environmental Benefits, Yaoping Zhang, Lawrence G. Oates, Jose Serate, Dan Xie, Edward Pohlman, Yury Bukhman, Rebecca Garlock Ong, Et Al.
Department of Chemical Engineering Publications
Increasing the diversity of lignocellulosic feedstocks accepted by a regional biorefinery has the potential to improve the environmental footprint of the facility; harvest,storage, and transportation logistics; and biorefinery economics. However, feedstocks can vary widely in terms of their biomass yields and quality characteristics (chemical composition, moisture content, etc.). To investigate how the diversity of potential biofuel cropping systems and feedstock supply might affect process and field‐scale ethanol yields, we processed and experimentally quantified ethanol production from five different herbaceous feedstocks: two annuals (corn stover and energy sorghum) and three perennials (switchgrass, miscanthus, and mixed prairie). The feedstocks werepretreated using ammonia …
Tio2 Assisted Photodegradation For Low Substrate Concentrations And Transition Metal Electron Scavengers,
2018
Tennessee State University
Tio2 Assisted Photodegradation For Low Substrate Concentrations And Transition Metal Electron Scavengers, Hassan A. Alsaud, Ahmed E. Abibat, Roger Painter, Lonnie Sharpe, Samuel Keith Hargrove
Mechanical and Manufacturing Engineering Faculty Research
Some contaminants of emerging concern (CECs) are known to survive conventional wastewater treatment, which introduces them back to the environment, allowing them to potentially cycle into drinking water. This is especially concerning because of the inherent ability of some CECs to induce physiological effects in humans at very low doses. Advanced oxidation processes (AOPs) such as TiO2-based photocatalysis are of great interest for addressing CECs in aqueous environments. Natural water resources often contain dissolved metal cation concentrations in excess of targeted CEC concentrations. These cations may significantly adversely impact the degradation of CECs by scavenging TiO2 surface generated electrons. Consequently, …
Rates Of Cavity Filling By Liquids,
2018
Brigham Young University - Provo
Rates Of Cavity Filling By Liquids, Dongjin Seo, Alex M. Schrader, Szu-Ying Chen, Yair Kaufman, Thomas R. Cristiani, Steven H. Page, Peter H. Koenig, Yonas Gizaw, Dong Woog Lee, Jacob N. Israelachvili
Faculty Publications
Understanding the fundamental wetting behavior of liquids on surfaces with pores or cavities provides insights into the wetting phenomena associated with rough or patterned surfaces, such as skin and fabrics, as well as the development of everyday products such as ointments and paints, and industrial applications such as enhanced oil recovery and pitting during chemical mechanical polishing. We have studied, both experimentally and theoretically, the dynamics of the transitions from the unfilled/partially filled (Cassie–Baxter) wetting state to the fully filled (Wenzel) wetting state on intrinsically hydrophilic surfaces (intrinsic water contact angle < 90°, where the Wenzel state is always the thermodynamically favorable state, while a temporary metastable Cassie–Baxter state can also exist) to determine the variables that control the rates of such transitions. We prepared silicon wafers with cylindrical cavities of different geometries and immersed them in bulk water. With bright-field and confocal fluorescence microscopy, we observed the details of, and the rates associated with, water penetration into the cavities from the bulk. We find that unconnected, reentrant cavities (i.e., cavities that open up below the surface) have the slowest cavity-filling rates, while connected or non-reentrant cavities undergo very rapid transitions. Using these unconnected, reentrant cavities, we identified the variables that affect cavity-filling rates: (i) the intrinsic contact angle, (ii) …
Catalysts For Nitrogen Reduction To Ammonia,
2018
Case Western Reserve University
Catalysts For Nitrogen Reduction To Ammonia, Royce D. Duda, Julie N. Renner
Faculty Scholarship
The production of synthetic ammonia remains dependent on the energy- and capital-intensive Haber-Bosch process. Extensive research in molecular catalysis has demonstrated ammonia production from dinitrogen, albeit at low production rates. Mechanistic understanding of dinitrogen reduction to ammonia continues to be delineated through study of molecular catalyst structure, as well as through understanding the naturally occurring nitrogenase enzyme. The transition to Haber-Bosch alternatives through robust, heterogeneous catalyst surfaces remains an unsolved research challenge. Catalysts for electrochemical reduction of dinitrogen to ammonia are a specific focus of research, due to the potential to compete with the Haber-Bosch process and reduce associated carbon …
Modeling Soot Formation From Solid Complex Fuels,
2018
Brigham Young University - Provo
Modeling Soot Formation From Solid Complex Fuels, Alexander J. Josephson, Rod R. Linn, David O. Lignell
Faculty Publications
A detailed model is proposed for predicting soot formation from complex solid fuels. The proposed model resolves two particle size distributions, one for soot precursors and another for soot particles. The precursor size distribution is represented with a sectional approach while the soot particle-size distribution is represented with the method of moments and an interpolative closure method is used to resolve fractional methods. Based on established mechanisms, this model includes submodels for precursor coagulation, growth, and consumption, as well as soot nucleation, surface growth, agglomeration, and consumption. The model is validated with comparisons to experimental data for two …
Photocatalytic Carbon Dioxide Conversion To Fuel For Earth And Mars,
2018
University of South Florida
Photocatalytic Carbon Dioxide Conversion To Fuel For Earth And Mars, Anne J. Meier
USF Tampa Graduate Theses and Dissertations
As far as we know, we only have one planet to live on, with a delicate atmospheric system providing us safety and life. Global CO2 emissions continue to plague the environment of Earth, primarily due to the processing of fossil fuels, deforestation, and industrialization. There are several avenues of pursuing CO2 reutilization, each having their own benefits and limitations. Direct and indirect thermochemical approaches of CO2 conversion boast of efficient CO2 conversion rates but have limitations associated with the use of renewable hydrogen and high temperatures of operation. The work in this dissertation investigates low temperature photocatalytic CO2 conversion, a …
Texas Sour Orange Juice Used In Scaffolds For Tissue Engineering,
2018
The University of Texas Rio Grande Valley
Texas Sour Orange Juice Used In Scaffolds For Tissue Engineering, Mandana Akia, Nataly Salinas, Cristobal Rodriguez, Robert Gilkerson, Luis A. Materon, Karen Lozano
Mechanical Engineering Faculty Publications
Fine fibers of polyhydroxybutyrate (PHB), a biopolymer, were developed via a centrifugal spinning technique. The developed fibers have an average diameter of 1.8 µm. Texas sour orange juice (SOJ) was applied as a natural antibacterial agent and infiltrated within the fibrous membranes. The antibacterial activity against common Gram-positive and Gram-negative bacteria (Staphylococcus aureus and Escherichia coli, respectively) was evaluated as well as cell adhesion and viability. The PHB/SOJ scaffolds showed antibacterial activity of up to 152% and 71% against S. aureus and E. coli, respectively. The cell studies revealed a suitable environment for cell growth and cell attachment. The outcome …
Pressure Swing Adsorption Separation Of H2s/Co2/Ch4 Gas Mixtures With Molecular Sieves 4a, 5a, And 13x,
2018
Florida Institute of Technology
Pressure Swing Adsorption Separation Of H2s/Co2/Ch4 Gas Mixtures With Molecular Sieves 4a, 5a, And 13x, Howell H. Heck, Merilyn L. Hall, Rudy Dos Santos, Manolis M. Tomadakis
Mechanical and Civil Engineering Faculty Publications
Pressure swing adsorption experiments were carried out for the separation of equimolar mixtures of carbon dioxide and methane containing small amounts of hydrogen sulfide, utilizing 4A, 5A, and 13X molecular sieves. High-purity methane of zero or nearly zero hydrogen sulfide concentration was produced in the adsorption stage with 13X and 5A sieves, at high product recovery rates; high-purity carbon dioxide was obtained with the same sieves in the desorption stage. Zeolite 4A was found capable of raising considerably the hydrogen sulfide concentration in the accumulated desorption product (vs. the adsorption feed) at high recovery rates too. Adsorption selectivity values derived …
Methods And Systems For Identifying A Particle Using Dielectrophoresis,
2018
Michigan Technological University
Methods And Systems For Identifying A Particle Using Dielectrophoresis, Adrienne Minerick, Jeana Collins, Kaela M. Leonard, Tayloria N.G. Adams
Michigan Tech Patents
A system for identifying a particle. The system includes a microfluidic device; a microelectrode array including a plurality of electrodes, the microelectrode array disposed within the microfluidic device; a plurality of particles suspended in a solution and delivered to the microelectrode array using the microfluidic device; a signal generator operatively coupled to the microelectrode array; a particle detector adjacent to the microelectrode array; and a controller in operative communication with the signal generator and the particle detector. The controller is configured to apply an oscillating voltage signal to the microelectrode array between a low frequency and a high frequency at …
Hydrogels For Cell Delivery,
2018
University of South Carolina
Hydrogels For Cell Delivery, Esmaiel Jabbari
Faculty Publications
No abstract provided.
Properties Of Matter,
2018
University of Arkansas, Fayetteville
Properties Of Matter, Mike Jackson, Holly Haney
High School Lesson Plans
Students will investigate the relationship(s) between thermal and electrical properties of matter. First, students will use a multimeter and temperature probe to investigate the relationship between electrical resistance and temperature of an electrical resistor composed of metals. They will then graph collected data to analyze the relationship and draw a conclusion as to their relationship. They will then perform the same investigation on a thermal resistor made of a semiconducting substance and analyze that collected data. Finally, using ClaimEvidence-Reasoning (CER) structure, students will use their experimental evidence to state the similarities and differences between the electro-thermal properties of metals and …
What Can I Do As A Student To Make A Positive Impact On The Environment?,
2018
University of Arkansas, Fayetteville
What Can I Do As A Student To Make A Positive Impact On The Environment?, Tammy Guthrie, Greg Herzig, Kathy Prophet, Cassie Kautzer
Middle School Lesson Plans
Students discover ways they can make a positive impact on the environment.
Gekko Optimization Suite,
2018
Brigham Young University
Gekko Optimization Suite, Logan Beal, Daniel Hill, Ronald Abraham Martin, John Hedengren
Faculty Publications
This paper introduces GEKKO as an optimization suite for Python. GEKKO specializes in dynamic optimization problems for mixed-integer, nonlinear, and differential algebraic equations (DAE) problems. By blending the approaches of typical algebraic modeling languages (AML) and optimal control packages, GEKKO greatly facilitates the development and application of tools such as nonlinear model predicative control (NMPC), real-time optimization (RTO), moving horizon estimation (MHE), and dynamic simulation. GEKKO is an object-oriented Python library that offers model construction, analysis tools, and visualization of simulation and optimization. In a single package, GEKKO provides model reduction, an object-oriented library for data reconciliation/model predictive control, and …
Homogeneous Reaction Kinetics Of Carbohydrates With Viologen Catalysts For Biofuel Cell Applications,
2018
Brigham Young University
Homogeneous Reaction Kinetics Of Carbohydrates With Viologen Catalysts For Biofuel Cell Applications, Hilary Bingham
Theses and Dissertations
Energy usage is continually on the rise and significant efforts are being extended to provide more renewable energy. One area of exploration is the development of fuel cells, which includes biofuel cells that can extract energy from carbohydrates obtained from biomass. Recently, viologen catalysts have been shown to enhance reaction rates of energy extraction and improve carbohydrate conversion efficiencies. However, characterizing the effects of process parameters such as pH, reactant concentrations, and carbohydrate exposure time to buffer solutions with a rigorous model is lacking. This thesis characterizes the homogeneous reaction between carbohydrates and a methyl viologen catalyst to provide insights …
