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2019

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Articles 361 - 390 of 675

Full-Text Articles in Chemical Engineering

Examination Of Flow Dynamics And Passive Cooling In An Ultra Compact Combustor, Tylor C. Rathsack Mar 2019

Examination Of Flow Dynamics And Passive Cooling In An Ultra Compact Combustor, Tylor C. Rathsack

Theses and Dissertations

The Ultra Compact Combustor (UCC) promises to greatly reduce the size of a gas turbine engine’s combustor by altering the manner in which fuel is burnt. Differing from the common axial flow combustor, the UCC utilizes a rotating flow, coaxial to the engine’s primary axis, in an outboard circumferential cavity as the primary combustion zone. The present study investigates two key UCC facets required to further this combustor design. The first area of investigation is cooling of the Hybrid Guide Vane (HGV). This UCC specific hardware acts as a combustor center body that alters the exit flow angle and acts …


Scaling Film Cooling Adiabatic Effectiveness With Mass Transfer And Thermal Experimental Techniques, Luke J. Mcnamara Mar 2019

Scaling Film Cooling Adiabatic Effectiveness With Mass Transfer And Thermal Experimental Techniques, Luke J. Mcnamara

Theses and Dissertations

With increasing engine temperatures, it is becoming more important to design effective film cooling schemes. Low temperature, large scale tests are often implemented in the design process to reduce cost and complexity. A nondimensional adiabatic effectiveness can be used as an indication of the performance of a film cooling scheme. However, the coolant flow rate must be properly scaled between the low temperature tests and engine temperatures to accurately predict film cooling effectiveness. This process is complicated by gas property variation with temperature. Tests are commonly conducted using thermal measurement techniques with infrared thermography (IR), but the use of pressure …


Tactical Missile Performance For Single And Multi-Wire Embedded Propellant Configurations With Discontinuities, Paul B. Wilson Mar 2019

Tactical Missile Performance For Single And Multi-Wire Embedded Propellant Configurations With Discontinuities, Paul B. Wilson

Theses and Dissertations

This research analyzes the performance of a nominal air-to-air tactical missile with varying configurations of wire-embedded end-burning solid propellant grains. Single and multi-wire models are developed to determine if total impulse and range is improved. Discontinuities in the wires are simulated to determine if gaps in the wire will affect overall performance. Five wire materials, seven wire diameters, and nine different break locations are tested. This research demonstrates wire discontinuities have negligible impact on performance and carbon nanotube fibers can theoretically improve total impulse by up to 25% compared to radially burning boost-phase grains while providing similar thrust outputs.


3d Printed Zeolite Monoliths For Co₂ Removal, Fateme Rezaei, Harshul V. Thakkar Mar 2019

3d Printed Zeolite Monoliths For Co₂ Removal, Fateme Rezaei, Harshul V. Thakkar

Chemical and Biochemical Engineering Faculty Research & Creative Works

Carbon dioxide (CO2) capture materials comprising one or more 3D-printed zeolite monoliths for the capture and or removal of CO2 from air or gases in enclosed compartments, including gases or mixtures of gases having less than about 5% CO2. Methods for preparing 3D-printed zeolite monoliths useful as CO2 capture materials and filters, as well as methods of removing CO2 from a gas or mixture of gases in an enclosed compartment using 3D-printed zeolite monoliths are provided.


Introducing Concept Maps In Undergraduate Thermodynamics, Jessie Lofton Mar 2019

Introducing Concept Maps In Undergraduate Thermodynamics, Jessie Lofton

ASEE IL-IN Section Conference

Concept maps, also called mind maps, are a widely utilized educational tool. While numerous studies cite the benefits of concept mapping as a tool for student learning, the use of concept maps is more common in non-engineering disciplines. This study examines student perceptions and academic performance in an undergraduate, introductory Thermodynamics course for students majoring in Mechanical Engineering. The pedagogical approach includes incorporating student-developed concept maps, as well as an interactive study tool for First Law analysis. Qualitative and quantitative results are presented. Results are limited to a single institution and a small sample size of students. Future work will …


Theoretical Investigation Of The Ring Opening Of Cyclohexane On Ir(111) And Pt(111), Kushal Ghale Mar 2019

Theoretical Investigation Of The Ring Opening Of Cyclohexane On Ir(111) And Pt(111), Kushal Ghale

LSU Master's Theses

Diesel engines have higher fuel efficiency and can burn cleaner than gasoline engines. To enhance quality of diesel fuels as measured by the cetane number (CN), the removal of aromatic compounds is necessary. A potentially highly efficient approach would be to convert aromatics to saturated cycloparaffin, followed by selective ring opening to linear or branched alkanes, to increase the CN. Here the focus of the project is to study the mechanism of metal-catalyzed ring opening (RO) of cyclohexane (denoted CHA, or c-C6H12) through theoretical and computational modeling. CHA, a simplest cycloparaffin, is used as probe molecule …


String Out And Compressibility Effect On Pressure Rise In A Shut-In Well, Nicholas Henry Mar 2019

String Out And Compressibility Effect On Pressure Rise In A Shut-In Well, Nicholas Henry

LSU Master's Theses

Gas kick migration experiments were performed in a small-scale well prototype model of annular geometry to analyze the behavior of gas kicks in highly non-Newtonian fluids. The objective was to isolate and estimate the effects system compressibility and bubble string out have on the pressure build up in a situation in which a gas kick rises through a noncirculating drilling mud in a vertical well.

The experiments consisted of 2 tests. The first test measured the apparent compressibility of the liquid phase of the experiment – that phase which simulated the drilling mud in a gas kick situation. The second …


A Comprehensive Techno-Economic Framework For Shale Gas Exploitation And Distribution In The United States, Jorge Asis Charbel Chebeir Mar 2019

A Comprehensive Techno-Economic Framework For Shale Gas Exploitation And Distribution In The United States, Jorge Asis Charbel Chebeir

LSU Doctoral Dissertations

Over the past years, shale gas has turned into one of the most significant sources of energy in the United States. Technological advancements have provided the energy industry with the necessary tools to allow the economic exploitation of an enormous volume of natural gas trapped in shale formations. This has boosted the domestic gas production and generated a boom in other sectors of the economy in the country. However, major challenges are involved in the development of shale gas resources. A drastic decline of wells’ productivity, the costs involved in the gas production and distribution facets, and the volatile behavior …


Fischer–Tropsch: Product Selectivity–The Fingerprint Of Synthetic Fuels, Wilson D. Shafer, Muthu Kumaran Gnanamani, Uschi M. Graham, Jia Yang, Cornelius M. Masuku, Gary Jacobs, Burtron H. Davis Mar 2019

Fischer–Tropsch: Product Selectivity–The Fingerprint Of Synthetic Fuels, Wilson D. Shafer, Muthu Kumaran Gnanamani, Uschi M. Graham, Jia Yang, Cornelius M. Masuku, Gary Jacobs, Burtron H. Davis

Center for Applied Energy Research Faculty and Staff Publications

The bulk of the products that were synthesized from Fischer–Tropsch synthesis (FTS) is a wide range (C1–C70+) of hydrocarbons, primarily straight-chained paraffins. Additional hydrocarbon products, which can also be a majority, are linear olefins, specifically: 1-olefin, trans-2-olefin, and cis-2-olefin. Minor hydrocarbon products can include isomerized hydrocarbons, predominantly methyl-branched paraffin, cyclic hydrocarbons mainly derived from high-temperature FTS and internal olefins. Combined, these products provide 80–95% of the total products (excluding CO2) generated from syngas. A vast number of different oxygenated species, such as aldehydes, ketones, acids, and alcohols, are also embedded in this product range. …


Material And Regenerative Properties Of An Osteon-Mimetic Cortical Bone-Like Scaffold, Danial Barati, Ozan Karaman, Seyedsina Moeinzadeh, Safaa Kader, Esmaiel Jabbari Mar 2019

Material And Regenerative Properties Of An Osteon-Mimetic Cortical Bone-Like Scaffold, Danial Barati, Ozan Karaman, Seyedsina Moeinzadeh, Safaa Kader, Esmaiel Jabbari

Faculty Publications

The objective of this work was to fabricate a rigid, resorbable and osteoconductive scaffold by mimicking the hierarchical structure of the cortical bone. Aligned peptide-functionalize nanofiber microsheets were generated with calcium phosphate (CaP) content similar to that of the natural cortical bone. Next, the CaP-rich fibrous microsheets were wrapped around a microneedle to form a laminated microtube mimicking the structure of an osteon. Then, a set of the osteon-mimetic microtubes were assembled around a solid rod and the assembly was annealed to fuse the microtubes and form a shell. Next, an array of circular microholes were drilled on the outer …


Exergetic Relationship Between The Thermal Properties Of Direct Contact Membrane Distillation, D. Perdue, L. Chen, L. Schaefer Mar 2019

Exergetic Relationship Between The Thermal Properties Of Direct Contact Membrane Distillation, D. Perdue, L. Chen, L. Schaefer

Publications

Direct contact membrane distillation (DCMD) is a process that has shown promise within the field of desalination due to its less energy intensive methods and widespread applications. DCMD is a thermally driven microfiltration separation process that operates on the principle of vapor–liquid equilibrium conditions where heat and mass transfer occur simultaneously. Fundamentally, DCMD is based on a porous hydrophobic membrane separating the hot solution (feed) from the cold solution (permeate) where desalinated water condenses. The membrane interfacial temperatures determine the vapor pressure difference across the membrane. In this work, a direct simulation Monte Carlo analysis is employed to investigate how …


Use Of Penetrating Asphalt Emulsions To Address High-Void Pavement Areas, Andrew Eicher, Curt Higginbotham Mar 2019

Use Of Penetrating Asphalt Emulsions To Address High-Void Pavement Areas, Andrew Eicher, Curt Higginbotham

Purdue Road School

Longitudinal joints are high in air voids due to compaction limitations. Lowering the void content of these areas improves the durability of the pavement. Project data indicate that rapid penetrating emulsion (RPE) fills the voids beneath the surface of the pavement, reducing air and water intrusion while maintaining surface texture, whereas traditional emulsions seal the surface only. Lab tests have been developed to quantify the penetrating ability of an emulsion and resistance to water exposure. Join us for a discussion.


Controlled Anchoring Of Iron Oxide Nanoparticles On Polymeric Nanofibers: Easy Access To Core@Shell Organic-Inorganic Nanocomposites For Magneto-Scaffolds, Hussein Awada, Assala Al Samad, Danielle Laurencin, Ryan Gilbert, Xavier Dumail, Ayman El Jundi, Audrey Bethry, Rebecca Pomrenke, Christopher Johnson, Laurent Lemaire, Florence Franconi, Gautier Félix, Joulia Larionova, Yannick Guari, Benjamin Nottelet Mar 2019

Controlled Anchoring Of Iron Oxide Nanoparticles On Polymeric Nanofibers: Easy Access To Core@Shell Organic-Inorganic Nanocomposites For Magneto-Scaffolds, Hussein Awada, Assala Al Samad, Danielle Laurencin, Ryan Gilbert, Xavier Dumail, Ayman El Jundi, Audrey Bethry, Rebecca Pomrenke, Christopher Johnson, Laurent Lemaire, Florence Franconi, Gautier Félix, Joulia Larionova, Yannick Guari, Benjamin Nottelet

Chemical and Biochemical Engineering Faculty Research & Creative Works

Composites combining superparamagnetic iron oxide nanoparticles (SPIONs) and polymers are largely present in modern (bio)materials. However, although SPIONs embedded in polymer matrices are classically reported, the mechanical and degradation properties of the polymer scaffold are impacted by the SPIONs. Therefore, the controlled anchoring of SPIONs onto polymer surfaces is still a major challenge. Herein, we propose an efficient strategy for the direct and uniform anchoring of SPIONs on the surface of functionalized-polylactide (PLA) nanofibers via a simple free ligand exchange procedure to design PLA@SPIONs core@shell nanocomposites. The resulting PLA@SPIONs hybrid biomaterials are characterized by electron microscopy (scanning electron microscopy and …


Improving The Distribution And Use Of Biogas By Conversion To Methanol, Zachary Christman Mar 2019

Improving The Distribution And Use Of Biogas By Conversion To Methanol, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

In this technology review, the process of turning an average biogas into methanol will be presented. The purpose is to find a better method of transporting the energy contained within biogas so that it may be used in industry as a value added product. The first step is removal of hydrogen sulfide, a corrosive chemical that can breakdown mechanical parts. The second step is carbon capture and conversion of the biogas into hydrogen. The final step is the hydrogenation of carbon dioxide into methanol using a copper catalyst and an alcohol co-catalyst.


Urea Functionalization Of Ultrasound-Treated Biochar: A Feasible Strategy For Enhancing Heavy Metal Adsorption Capacity, Baharak Sajjadi, James William Broome, Wei Yin Chen, Daniell L. Mattern, Nosa O. Egiebor, Nathan Hammer, Cameron L. Smith Mar 2019

Urea Functionalization Of Ultrasound-Treated Biochar: A Feasible Strategy For Enhancing Heavy Metal Adsorption Capacity, Baharak Sajjadi, James William Broome, Wei Yin Chen, Daniell L. Mattern, Nosa O. Egiebor, Nathan Hammer, Cameron L. Smith

Faculty and Student Publications

© 2018 Elsevier B.V. The main objective of a series of our researches is to develop a novel acoustic-based method for activation of biochar. This study investigates the capability of biochar in adsorbing Ni(II) as a hazardous contaminant and aims at enhancing its adsorption capacity by the addition of extra nitrogen and most probably phosphorous and oxygen containing sites using an ultrasono-chemical modification mechanism. To reach this objective, biochar physically modified by low-frequency ultrasound waves (USB) was chemically treated by phosphoric acid (H3PO4) and then functionalized by urea (CO(NH2)2). Cavitation induced by ultrasound waves exfoliates and breaks apart the regular …


3,7-Dinitro-1,3,5,7-Tetraazabicyclo[3,3,1]Nonane (Dpt): An Important Intermediate In The Synthesis Route Of One Of The Most Powerful Energetic Materials (Rdx/Hmx), Hany A. Elazab, M. M. Seleet, Said M. A. Hassanein, M. A. Radwan, M. A. Sadek Mar 2019

3,7-Dinitro-1,3,5,7-Tetraazabicyclo[3,3,1]Nonane (Dpt): An Important Intermediate In The Synthesis Route Of One Of The Most Powerful Energetic Materials (Rdx/Hmx), Hany A. Elazab, M. M. Seleet, Said M. A. Hassanein, M. A. Radwan, M. A. Sadek

Chemical and Biochemical Engineering Faculty Research & Creative Works

Synthesis of Cyclotetramethylene Tetramine through the action of nitrating mixture formed of ammonium nitrate and fuming nitric acid on hexamine in presence of acetic acid, acetic anhydride and p-formaldehyde has been proven. The pathway is relatively long and Hexamine Dinitrate and Dinitro Pentamethylene Tetramine (DPT) are two of the main intermediate compounds. The former was prepared, purified, and then characterized. Conversion of this compound into the latter has been followed up experimentally. Herein, we report the Preparation of Dinitro Pentamethylene Tetramine (DPT) from Hexamine Dinitrate - as an alternative synthetic route - which is an important intermediate appears through preparation …


Effect Of Support, Preparations Methods, Ag Promotion And Nc Size On The Activity, Selectivity And Sintering Deactivation Of Supported Co Fischer-Tropsch Catalyst, Mahmood Rahmati Mar 2019

Effect Of Support, Preparations Methods, Ag Promotion And Nc Size On The Activity, Selectivity And Sintering Deactivation Of Supported Co Fischer-Tropsch Catalyst, Mahmood Rahmati

Theses and Dissertations

A series of silver-promoted, 20 wt% cobalt Fischer-Tropsch synthesis (FTS) catalysts supported on an alumina modified with 5 wt% silica were prepared using two methods: traditional incipient wetness impregnation (IWI) and a new solvent-deficient precipitation (SDP) technique. Catalysts containing silver promoter concentrations of 0.3, 0.6, 1.2, and 2.5 wt% were prepared using each of the two methods. Silver improved the reducibility of the cobalt significantly, lowering reduction temperatures by up to 100°C, and increasing the extent of reduction by up to 35%. Further, in both preparation methods, changing the silver loading altered the cobalt dispersion. The smallest Co crystallite size …


Ni/Mn3O4/Nimn2O4 Double-Shelled Hollow Spheres Embedded Into Reduced Graphene Oxide As Advanced Anodes For Sodium-Ion Batteries, Chong Yan, Hua-Ri Kou, Bo Yan, Xiao-Jing Liu, De-Jun Li, Xi-Fei Li Feb 2019

Ni/Mn3O4/Nimn2O4 Double-Shelled Hollow Spheres Embedded Into Reduced Graphene Oxide As Advanced Anodes For Sodium-Ion Batteries, Chong Yan, Hua-Ri Kou, Bo Yan, Xiao-Jing Liu, De-Jun Li, Xi-Fei Li

Journal of Electrochemistry

Delicately building the unique nanocomposite with the combination of hollow structure and reduced graphene oxide (rGO) is highly desirable and still remains a great challenge in the field of energy conversion and storage. In this work, Ni/Mn3O4/NiMn2O4 double-shelled hollow spheres coated by rGO (denoted as R-NMN) have been successfully synthetized via one-step rapid solvothermal treatment followed by subsequent annealing for the first time. Served as anodes for sodium ion batteries (SIBs), the R-NMN composite containing 25wt% rGO exhibits a high discharge capacity of 187.8 mAh·g-1 after 100 cycles at 50 mA·g-1 …


Recent Developments In Surface/Interface Modulation And Structure-Performance Relationship Of Cathode Catalysts For Li-Air Batteries, Rui Gao, Jun-Kai Wang, Zhong-Bo Hu, Xiang-Feng Liu Feb 2019

Recent Developments In Surface/Interface Modulation And Structure-Performance Relationship Of Cathode Catalysts For Li-Air Batteries, Rui Gao, Jun-Kai Wang, Zhong-Bo Hu, Xiang-Feng Liu

Journal of Electrochemistry

Lithium-air battery has been considered to be one of the most promising secondary battery systems because of its high energy density. However, the sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) on the cathode, and the high overpotential, poor cycle stability and low rate capacity have severely blocked the development and application of Li-air battery. One of the effective strategies to alleviate these issues is to develop cathode catalysts for Li-air batteries. The design and development of bifunctional cathode catalysts with high activity and efficiency on both ORR and OER is highly desired for Li-air …


Synthesis Of Flower-Like Vanadium Disulfide For Lithium Storage Application, Pan Li, Jian Liu, Wei-Yi Sun, Hai-Xia Li, Zhan-Liang Tao Feb 2019

Synthesis Of Flower-Like Vanadium Disulfide For Lithium Storage Application, Pan Li, Jian Liu, Wei-Yi Sun, Hai-Xia Li, Zhan-Liang Tao

Journal of Electrochemistry

In order to improve the electrochemical properties of vanadium disulfide (VS2) as an electrode material in Li-ion battery, the flower-like VS2 was prepared by a one-step hydrothermal method with the addition of polyethylene glycol 400. The phase and morphology of the product were characterized by using X-ray diffraction and field emission scanning electron microscopy. During the growth process, it was observed that the flower-like VS2 was interspersed with several hexagonal vanadium disulfide nanosheets, which had a high specific surface area and excellent structural stability. The flower-like VS2 was used for the cathode material test in …


Carbon Capture And Synergistic Energy Storage: Performance And Uncertainty Quantification, Christopher Stephen Russell Feb 2019

Carbon Capture And Synergistic Energy Storage: Performance And Uncertainty Quantification, Christopher Stephen Russell

Theses and Dissertations

Energy use around the world will rise in the coming decades. Renewable energy sources will help meet this demand, but renewable sources suffer from intermittency, uncontrollable power supply, geographic limitations, and other issues. Many of these issues can be mitigated by introducing energy storage technologies. These technologies facilitate load following and can effectively time-shift power. This analysis compares dedicated and synergistic energy storage technologies using energy efficiency as the primary metric.
Energy storage will help renewable sources come to the grid, but fossil fuels still dominate energy sources for decades to come in nearly all projections. Carbon capture technologies can …


Cutter Elements For Drill Bits And Methods For Fabricating Same, Guodong Zhan, Biju P. Kumar, Russell C. Gilleylen, Michael D. Hughes, Xinhua Liang Feb 2019

Cutter Elements For Drill Bits And Methods For Fabricating Same, Guodong Zhan, Biju P. Kumar, Russell C. Gilleylen, Michael D. Hughes, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

A method of fabricating a PCD cutter element including a diamond table including a plurality of coated diamond particles fabricated using an atomic layer deposition (ALD) process.


Effect Of Pt Promotion On The Ni-Catalyzed Deoxygenation Of Tristearin To Fuel-Like Hydrocarbons, Ryan Loe, Kelsey Huff, Morgan Walli, Tonya Morgan, Dali Qian, Robert Pace, Yang Song, Mark Isaacs, Eduardo Santillan-Jimenez, Mark Crocker Feb 2019

Effect Of Pt Promotion On The Ni-Catalyzed Deoxygenation Of Tristearin To Fuel-Like Hydrocarbons, Ryan Loe, Kelsey Huff, Morgan Walli, Tonya Morgan, Dali Qian, Robert Pace, Yang Song, Mark Isaacs, Eduardo Santillan-Jimenez, Mark Crocker

Center for Applied Energy Research Faculty and Staff Publications

Pt represents an effective promoter of supported Ni catalysts in the transformation of tristearin to green diesel via decarbonylation/decarboxylation (deCOx), conversion increasing from 2% over 20% Ni/Al2O3 to 100% over 20% Ni-0.5% Pt/Al2O3 at 260 °C. Catalyst characterization reveals that the superior activity of Ni-Pt relative to Ni-only catalysts is not a result of Ni particle size effects or surface area differences, but rather stems from several other phenomena, including the improved reducibility of NiO when Pt is present. Indeed, the addition of a small amount of Pt to the supported Ni …


Near-Surface Material Phases And Microstructure Of Scandate Cathodes, Xiaotao Liu, Bernard K. Vancil, Matthew J. Beck, Thomas John Balk Feb 2019

Near-Surface Material Phases And Microstructure Of Scandate Cathodes, Xiaotao Liu, Bernard K. Vancil, Matthew J. Beck, Thomas John Balk

Chemical and Materials Engineering Faculty Publications

Scandate cathodes that were fabricated using the liquid-solid process and that exhibited excellent emission performance were characterized using complementary state-of-the-art electron microscopy techniques. Sub-micron BaAl2O4 particles were observed on the surfaces and edges of tungsten particles, as seen in cross-section samples extracted from the scandate cathode surface regions. Although several BaAl2O4 particles were observed to surround smaller Sc2O3 nanoparticles, no chemical mixing of the two oxides was detected, and in fact the distinct oxide phases were separately verified by chemical analysis and also by 3D elemental tomography. Nanobeam electron diffraction confirmed …


Characterization And Quantification Of Highly Sulfated Glycosaminoglycan Isomers By Gated-Trapped Ion Mobility Spectrometry Negative Electron Transfer Dissociation Ms/Ms, Juan Wei, Jiandong Wu, Yang Tang, Mark E. Ridgeway, Melvin A. Park, Catherine E. Costello, Joseph Zaia, Cheng Lin Feb 2019

Characterization And Quantification Of Highly Sulfated Glycosaminoglycan Isomers By Gated-Trapped Ion Mobility Spectrometry Negative Electron Transfer Dissociation Ms/Ms, Juan Wei, Jiandong Wu, Yang Tang, Mark E. Ridgeway, Melvin A. Park, Catherine E. Costello, Joseph Zaia, Cheng Lin

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glycosaminoglycans (GAGs) Play Vital Roles in Many Biological Processes and Are Naturally Present as Complex Mixtures of Polysaccharides with Tremendous Structural Heterogeneity, Including Many Structural Isomers. Mass Spectrometric Analysis of GAG Isomers, in Particular Highly Sulfated Heparin (Hep) and Heparan Sulfate (HS), is Challenging Because of their Structural Similarity and Facile Sulfo Losses during Analysis. Herein, We Show that Highly Sulfated Hep/HS Isomers May Be Resolved by Gated-Trapped Ion Mobility Spectrometry (Gated-TIMS) with Negligible Sulfo Losses. Subsequent Negative Electron Transfer Dissociation (NETD) Tandem Mass Spectrometry (MS/MS) Analysis of TIMS-Separated Hep/HS Isomers Generated Extensive Glycosidic and Cross-Ring Fragments for Confident Isomer …


The Effect Of Calcination Rate On The Structure Of Mesoporous Bioactive Glasses, Saidur Rahman, Andrew Mendonca, Adel Alhalawani, Deanna Polintan, Owen M. Clarkin, Mark R. Towler Feb 2019

The Effect Of Calcination Rate On The Structure Of Mesoporous Bioactive Glasses, Saidur Rahman, Andrew Mendonca, Adel Alhalawani, Deanna Polintan, Owen M. Clarkin, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Mesoporous bioactive glasses (MBGs) are designed to have high specific surface area. They are formulated by a sol–gel process to formulate the glass followed by calcination. This study evaluates how calcination heating rate influences the porous architecture, and thereby the specific surface area, of MBGs. MBGs of molar ratio 80:15:5 for SiO2 :CaO:P2 O 5 were calcined using both low (1 °C/min) and high (20 °C/min) heating rates, termed as L-MBG and H-MBG, respectively. The results obtained from small-angle X-ray diffraction (SAXRD) confirm that the MBGs possess 2D hexagonal (P6mm) spacing groups and wide-angle XRD confirms the amorphicity …


Carboxylic Acids Accelerate Acidic Environment-Mediated Nanoceria Dissolution, Robert A. Yokel, Matthew L. Hancock, Eric A. Grulke, Jason M. Unrine, Alan K. Dozier, Uschi M. Graham Feb 2019

Carboxylic Acids Accelerate Acidic Environment-Mediated Nanoceria Dissolution, Robert A. Yokel, Matthew L. Hancock, Eric A. Grulke, Jason M. Unrine, Alan K. Dozier, Uschi M. Graham

Pharmaceutical Sciences Faculty Publications

Ligands that accelerate nanoceria dissolution may greatly affect its fate and effects. This project assessed the carboxylic acid contribution to nanoceria dissolution in aqueous, acidic environments. Nanoceria has commercial and potential therapeutic and energy storage applications. It biotransforms in vivo. Citric acid stabilizes nanoceria during synthesis and in aqueous dispersions. In this study, citrate-stabilized nanoceria dispersions (∼4 nm average primary particle size) were loaded into dialysis cassettes whose membranes passed cerium salts but not nanoceria particles. The cassettes were immersed in iso-osmotic baths containing carboxylic acids at pH 4.5 and 37 °C, or other select agents. Cerium atom material …


On Accounting For Equipment-Control Interactions In Economic Model Predictive Control Via Process State Constraints, Helen Durand Feb 2019

On Accounting For Equipment-Control Interactions In Economic Model Predictive Control Via Process State Constraints, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Traditionally, chemical processes have been operated at steady-state; however, recent work on economic model predictive control (EMPC) has indicated that some processes may be operated in a more economically-optimal fashion under a time-varying operating policy. It is unclear how time-varying operating policies may impact process equipment, which must be investigated for safety and profit reasons. It has traditionally been considered that constraints on process states can be added to EMPC design to prevent the controller from computing control actions which create problematic operating conditions for process equipment. However, no rigorous investigation has yet been performed to analyze whether, when a …


Increasing Salt Rejection Of Polybenzimidazole Nanofiltration Membranes Via The Addition Of Immobilized And Aligned Aquaporins, Priyesh Ashokrao Wagh, Xinyi Zhang, Ryan Blood, Peter M. Kekenes-Huskey, Prasangi Rajapaksha, Yinan Wei, Isabel C. Escobar Feb 2019

Increasing Salt Rejection Of Polybenzimidazole Nanofiltration Membranes Via The Addition Of Immobilized And Aligned Aquaporins, Priyesh Ashokrao Wagh, Xinyi Zhang, Ryan Blood, Peter M. Kekenes-Huskey, Prasangi Rajapaksha, Yinan Wei, Isabel C. Escobar

Chemical and Materials Engineering Faculty Publications

Aquaporins are water channel proteins in cell membrane, highly specific for water molecules while restricting the passage of contaminants and small molecules, such as urea and boric acid. Cysteine functional groups were installed on aquaporin Z for covalent attachment to the polymer membrane matrix so that the proteins could be immobilized to the membranes and aligned in the direction of the flow. Depth profiling using x-ray photoelectron spectrometer (XPS) analysis showed the presence of functional groups corresponding to aquaporin Z modified with cysteine (Aqp-SH). Aqp-SH modified membranes showed a higher salt rejection as compared to unmodified membranes. For 2 M …


Model Predictive Automatic Control Of Sucker Rod Pump System With Simulation Case Study, Brigham Hansen, Brandon Tolbert, Cory Vernon, John Hedengren Feb 2019

Model Predictive Automatic Control Of Sucker Rod Pump System With Simulation Case Study, Brigham Hansen, Brandon Tolbert, Cory Vernon, John Hedengren

Faculty Publications

This work enables accelerated fluid recovery in oil and gas reservoirs by automatically controlling fluid height and bottomhole pressure in wells. Several literature studies show significant increase in recovered oil by determining a target bottomhole pressure but rarely consider how to control to that value. This work enables those benefits by maintaining bottomhole pressure or fluid height. Moving Horizon Estimation (MHE) determines uncertain well parameters using only common surface measurements. A Model Predictive Controller (MPC) adjusts the stroking speed of a sucker rod pump to maintain fluid height. Pump boundary conditions are simulated with Mathematical Programs with Complementarity Constraints (MPCCs) …