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Full-Text Articles in Engineering

Application Of Advanced Biomechanical Methods In Studying Low Back Pain – Recent Development In Estimation Of Lower Back Loads And Large-Array Surface Electromyography And Findings, Babak Bazrgari, Ting Xia Jul 2017

Application Of Advanced Biomechanical Methods In Studying Low Back Pain – Recent Development In Estimation Of Lower Back Loads And Large-Array Surface Electromyography And Findings, Babak Bazrgari, Ting Xia

Biomedical Engineering Faculty Publications

Low back pain (LBP) is a major public health problem and the leading disabling musculoskeletal disorder globally. A number of biomechanical methods using kinematic, kinetic and/or neuromuscular approaches have been used to study LBP. In this narrative review, we report recent developments in two biomechanical methods: estimation of lower back loads and large-array surface electromyography (LA-SEMG) and the findings associated with LBP. The ability to estimate lower back loads is very important for the prevention and the management of work-related low back injuries based on the mechanical loading model as one category of LBP classification. The methods used for estimation …


Comparison Between Single Loading–Unloading Indentation And Continuous Stiffness Indentation, Yun-Fei Jia, Yuan-Yuan Cui, Fu-Zhen Xuan, Fuqian Yang Jul 2017

Comparison Between Single Loading–Unloading Indentation And Continuous Stiffness Indentation, Yun-Fei Jia, Yuan-Yuan Cui, Fu-Zhen Xuan, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Experiments are performed on fused silica, Si, and duplex stainless steel to examine whether the CSM (continuous stiffness indentation) method will provide approximately the “same” results of contact modulus and indentation hardness as those measured from the quasi-static single loading–unloading indentation. The experimental results show that the elastic modulus measured by the CSM method is compatible with that by the quasi-static loading–unloading method for hard materials, while there exists a percentage difference of ∼21.3% between the smallest value and the largest vale of the measured indentation hardnesses from the CSM method for fused silica and a percentage difference of ∼15.3% …


Maximizing Operating Room Performance Using Portfolio Selection, Vivek Reddy Gunna, Amin Abedini, Wei Li Jul 2017

Maximizing Operating Room Performance Using Portfolio Selection, Vivek Reddy Gunna, Amin Abedini, Wei Li

Mechanical Engineering Faculty Publications

The operating room (OR) is responsible for most hospital admissions and is one of the most cost and work intensive areas in the hospital. From recent trends, we observe an ironic parallel increase among expenditure and waiting time. Therefore, improving OR scheduling has become obligatory, particularly in terms of patient flow and benefit. Most of the hospitals rely on average patient arrivals and processing times in OR planning. But in practice, variations in arrivals and processing times causes high instability in OR performance. Our model of optimization provides OR schedules maximizing patient flow and benefit at a fixed level of …


An Optimization Model For Operating Room Scheduling To Reduce Blocking Across The Perioperative Process, Amin Abedini, Wei Li, Honghan Ye Jul 2017

An Optimization Model For Operating Room Scheduling To Reduce Blocking Across The Perioperative Process, Amin Abedini, Wei Li, Honghan Ye

Mechanical Engineering Faculty Publications

Operating room (OR) scheduling is important. Because of increasing demand for surgical services, hospitals must provide high quality care more efficiently with limited resources. When constructing the OR schedule, it is necessary to consider the availability of downstream resources, such as intensive care unit (ICU) and post anaesthesia care unit (PACU). The unavailability of downstream resources causes blockings between every two consecutive stages. In this paper we address the master surgical schedule (MSS) problem in order to minimize blockings between two consecutive stages. First, we present a blocking minimization (BM) model for the MSS by using integer programming, based on …


Multiple Attributes Decision Fusion For Wireless Sensor Networks Based On Intuitionistic Fuzzy Set, Zhenjiang Zhang, Ziqi Hao, Sherali Zeadally, Jing Zhang, Bowen Han, Han-Chieh Chao Jul 2017

Multiple Attributes Decision Fusion For Wireless Sensor Networks Based On Intuitionistic Fuzzy Set, Zhenjiang Zhang, Ziqi Hao, Sherali Zeadally, Jing Zhang, Bowen Han, Han-Chieh Chao

Information Science Faculty Publications

Decision fusion is an important issue in wireless sensor networks (WSN), and intuitionistic fuzzy set (IFS) is a novel method for dealing with uncertain data. We propose a multi-attribute decision fusion model based on IFS, which includes two aspects: data distribution-based IFS construction algorithm (DDBIFCA) and the category similarity weight-based TOPSIS intuitionistic fuzzy decision algorithm (CSWBT-IFS). The DDBIFCA is an IFS construction algorithm that transforms the original attribute values into intuitionistic fuzzy measures, and the CSWBT-IFS is an intuitionistic fuzzy aggregation algorithm improved by the traditional TOPSIS algorithm, which combines intuitionistic fuzzy values of different attributes and obtains a final …


Solubility And Thermodynamic Modeling Of Carcinogenic Nitrosamines In Aqueous Amine Solvents For Co2 Capture, Jesse Thompson, Naser Matin, Kunlei Liu Jul 2017

Solubility And Thermodynamic Modeling Of Carcinogenic Nitrosamines In Aqueous Amine Solvents For Co2 Capture, Jesse Thompson, Naser Matin, Kunlei Liu

Center for Applied Energy Research Faculty and Staff Publications

A better understanding of key fundamental properties of nitrosamines, including their solubility in aqueous amine solvents, is needed to understand and accurately model the vapor-phase emission levels from operating CO2 capture systems. In this work, the first experimental Henry's volatility coefficient of a nitrosamine was obtained with a novel method using static headspace solid phase micro extraction (SPME) and gas chromatography mass spectrometry (GC/MS). The experimentally determined Henry's volatility coefficient of nitrosopyrrolidine (NPY) was found to be around 0.02 (dimensionless) at 25 °C, and falls in the range of a semi-volatile compound. A linear temperature dependency of the Henry's …


Techno-Economic Analysis Of A Secondary Air Stripper Process, J. R. Heberle, Heather Nikolic, Jesse Thompson, Kunlei Liu, Lora L. Pinkerton, David Brubaker, James C. Simpson, Song Wu, Abhoyjit S. Bhown Jul 2017

Techno-Economic Analysis Of A Secondary Air Stripper Process, J. R. Heberle, Heather Nikolic, Jesse Thompson, Kunlei Liu, Lora L. Pinkerton, David Brubaker, James C. Simpson, Song Wu, Abhoyjit S. Bhown

Center for Applied Energy Research Faculty and Staff Publications

We present results of an initial techno-economic assessment on a post-combustion CO2 capture process developed by the Center for Applied Energy Research (CAER) at the University of Kentucky using Mitsubishi Hitachi Power Systems’ H3-1 aqueous amine solvent. The analysis is based on data collected at a 0.7 MWe pilot unit combined with laboratory data and process simulations. The process adds a secondary air stripper to a conventional solvent process, which increases the cyclic loading of the solvent in two ways. First, air strips additional CO2 from the solvent downstream of the conventional steam-heated thermal stripper. This extra stripping …


Thermal Degradation Pathways Of Aqueous Diamine Co2 Capture Solvents, Jesse Thompson, Henry Richburg, Kunlei Liu Jul 2017

Thermal Degradation Pathways Of Aqueous Diamine Co2 Capture Solvents, Jesse Thompson, Henry Richburg, Kunlei Liu

Center for Applied Energy Research Faculty and Staff Publications

Diamines have shown promise as CO2 capture solvents, yet very little is known about their pathway for thermal degradation. In this study, diamine thermal degradation was quantitatively monitored in lab-scale experiments on four aqueous diamine solvents; ethylenediamine (EDA) 1,2-propanediamine (1,2-DAP), 1,3-diaminopropane (1,3-DAP) and N-methyl-1,2-ethanediamine (NMEDA), to gain a more comprehensive understanding of their degradation pathway(s). The major degradation products were identified by high resolution time-of-flight mass spectrometry (TOF-MS). Degradation pathways were proposed showing that the primary thermal degradation route for this class of amine are through carbamate formation followed by intermolecular cyclization to form an imidazolidinone or nucleophilic attack …


Anion Exchange Membrane Capacitive Deionization Cells, Ayokunle Omosebi, Xin Gao, Nicolas Holubowitch, Zhiao Li, James Landon, Kunlei Liu Jul 2017

Anion Exchange Membrane Capacitive Deionization Cells, Ayokunle Omosebi, Xin Gao, Nicolas Holubowitch, Zhiao Li, James Landon, Kunlei Liu

Center for Applied Energy Research Faculty and Staff Publications

The electrochemical response of capacitive deionization (CDI) employing a single anion exchange membrane (AEM-CDI) is contrasted to conventional two-membrane CDI (MCDI) formed with complementary anion and cation exchange membranes. Pristine activated carbon cloth electrodes that possess native positive surface charge in solution were used as both anode (positive electrode) and cathode (negative electrode) in these cells. In a separate set of tests to investigate the impact of surface charge modification on deionization responses, the single and dual membrane cells were formed with asymmetric electrodes (AEM-aCDI and aMCDI) consisting of nitric acid oxidized electrodes that possess negative surface charge as the …


Solvent Degradation And Emissions From A 0.7mwe Pilot Co2 Capture System With Two-Stage Stripping, Jesse Thompson, Heather Nikolic, Megan Combs, Saloni Bhatnagar, Jonathan Pelgen, Keemia Abad, Kunlei Liu Jul 2017

Solvent Degradation And Emissions From A 0.7mwe Pilot Co2 Capture System With Two-Stage Stripping, Jesse Thompson, Heather Nikolic, Megan Combs, Saloni Bhatnagar, Jonathan Pelgen, Keemia Abad, Kunlei Liu

Center for Applied Energy Research Faculty and Staff Publications

The UKy-CAER team successfully tested an advanced 0.7 MWe post-combustion CO2 capture system on a coal-fired power plant using a heat integration process combined with two-stage stripping to enhance the CO2 absorber performance. One of the unique feature of the UKy-CAER integrated process is a two-stage stripping unit for solvent regeneration. The secondary stripper is empowered by the heat rejection from a conventional steam-heated (primary) stripper. The secondary stripper outlet stream at the commercial scale can be used as boiler secondary combustion air, consequently enriching the flue gas with CO2, resulting in less energy penalty required …


Proposal For Monitoring Concrete Painting As A Preventive Maintenance Tool (Abutments And Pier Caps), Danny Wells, Sudhir Palle, Theodore Hopwood Ii Jul 2017

Proposal For Monitoring Concrete Painting As A Preventive Maintenance Tool (Abutments And Pier Caps), Danny Wells, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Technical Assistance Report

One of the growing number of preventive bridge maintenance activities conducted by the Kentucky Transportation Cabinet (KYTC) is washing and applying thin film protective coatings to bridge abutments and piers. Previous work conducted by Kentucky Transportation Center (KTC) under KYSPR 10-406 documented increased chloride contamination of these bridge components and the need for protective coatings. KYTC Contract ID 162952 includes, among other tasks, cleaning and coating specific concrete elements of eighteen bridges in Anderson and Woodford counties (District 7). These elements are interior faces of the barrier walls, pier caps, and abutment seats. The contract was let on July 29, …


Proposed Testing Of Concrete Sealers, Danny Wells, Sudhir Palle, Theodore Hopwood Ii Jul 2017

Proposed Testing Of Concrete Sealers, Danny Wells, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Technical Assistance Report

Chlorides, in sufficient concentrations, will cause corrosion of steel reinforcement in bridge decks. Previous studies have shown that de-icing chemicals and practices used by the Kentucky Transportation Cabinet (KYTC) can result in problematic levels of chloride at steel reinforcing depths in a relatively short amount of time. With the advent of liquid applied pre-treatment deicing chemicals, testing performed in Kentucky indicate chloride levels in bridge decks at a depth of two inches have increased significantly.

Chlorides, in sufficient concentrations, will cause corrosion of steel reinforcement in bridge decks. Previous studies have shown that de-icing chemicals and practices used by the …


Collection And Analysis Of 2013-2014 Travel Time Data, Mei Chen, Xu Zhang Jul 2017

Collection And Analysis Of 2013-2014 Travel Time Data, Mei Chen, Xu Zhang

Kentucky Transportation Center Research Report

This report documents the findings of Planning Study 27, Collection and Analysis of 2013-2014 Travel Time Data, which is a continuation of Planning Study 24, Analysis of Historical Travel Time Data. The main scope is to analyze newly acquired link-referenced speed data on Kentucky roads from 2013 and 2014.

Results of the analysis demonstrate the value of probe data in measuring and tracking the performance of roadways across several years. In addition, such data can help KYTC and MPOs identify bottlenecks in the network, prioritize improvement strategies, and assess the effectiveness of projects. As data collection techniques advance, …


Size And Shape Distributions Of Primary Crystallites In Titania Aggregates, Eric A. Grulke, Kazuhiro Yamamoto, Kazuhiro Kumagai, Ines Häusler, Werner Österle, Erik Ortel, Vasile-Dan Hodoroaba, Scott C. Brown, Christopher Chan, Jiwen Zheng, Kenji Yamamoto, Kouji Yashiki, Nam Woong Song, Young Heon Kim, Aleksandr B Stefaniak, D. Schwegler-Berry, Victoria A. Coleman, Åsa K. Jämting, Jan Herrmann, Toru Arakawa, Woodrow W. Burchett, Joshua W. Lambert, Arnold J. Stromberg Jul 2017

Size And Shape Distributions Of Primary Crystallites In Titania Aggregates, Eric A. Grulke, Kazuhiro Yamamoto, Kazuhiro Kumagai, Ines Häusler, Werner Österle, Erik Ortel, Vasile-Dan Hodoroaba, Scott C. Brown, Christopher Chan, Jiwen Zheng, Kenji Yamamoto, Kouji Yashiki, Nam Woong Song, Young Heon Kim, Aleksandr B Stefaniak, D. Schwegler-Berry, Victoria A. Coleman, Åsa K. Jämting, Jan Herrmann, Toru Arakawa, Woodrow W. Burchett, Joshua W. Lambert, Arnold J. Stromberg

Chemical and Materials Engineering Faculty Publications

The primary crystallite size of titania powder relates to its properties in a number of applications. Transmission electron microscopy was used in this interlaboratory comparison (ILC) to measure primary crystallite size and shape distributions for a commercial aggregated titania powder. Data of four size descriptors and two shape descriptors were evaluated across nine laboratories. Data repeatability and reproducibility was evaluated by analysis of variance. One-third of the laboratory pairs had similar size descriptor data, but 83% of the pairs had similar aspect ratio data. Scale descriptor distributions were generally unimodal and were well-described by lognormal reference models. Shape descriptor distributions …


Ionic Thermoelectric Paper, Fei Jiao, Ali Naderi, Dan Zhao, Joshua Schlueter, Maryam Shahi, Jonas Sundström, Hjalmar Granberg, Jesper Edberg, Ujwala Ail, Joseph W. Brill, Tom Lindström, Magnus Berggren, Xavier Crispin Jun 2017

Ionic Thermoelectric Paper, Fei Jiao, Ali Naderi, Dan Zhao, Joshua Schlueter, Maryam Shahi, Jonas Sundström, Hjalmar Granberg, Jesper Edberg, Ujwala Ail, Joseph W. Brill, Tom Lindström, Magnus Berggren, Xavier Crispin

Physics and Astronomy Faculty Publications

Ionic thermoelectric materials, for example, polyelectrolytes such as polystyrene sulfonate sodium (PSSNa), constitute a new class of materials which are attracting interest because of their large Seebeck coefficient and the possibility that they could be used in ionic thermoelectric SCs (ITESCs) and field effect transistors. However, pure polyelectrolyte membranes are not robust or flexible. In this paper, the preparation of ionic thermoelectric paper using a simple, scalable and cost-effective method is described. After a composite was fabricated with nanofibrillated cellulose (NFC), the resulting NFC–PSSNa paper is flexible and mechanically robust, which is desirable if it is to be used in …


Impaired Right Ventricular Contractile Function In Childhood Obesity And Its Association With Right And Left Ventricular Changes: A Cine Dense Cardiac Magnetic Resonance Study, Linyuan Jing, Arichanah Pulenthiran, Christopher D. Nevius, Abba Mejia-Spiegeler, Jonathan D. Suever, Gregory J. Wehner, H. Lester Kirchner, Christopher M. Haggerty, Brandon K. Fornwalt Jun 2017

Impaired Right Ventricular Contractile Function In Childhood Obesity And Its Association With Right And Left Ventricular Changes: A Cine Dense Cardiac Magnetic Resonance Study, Linyuan Jing, Arichanah Pulenthiran, Christopher D. Nevius, Abba Mejia-Spiegeler, Jonathan D. Suever, Gregory J. Wehner, H. Lester Kirchner, Christopher M. Haggerty, Brandon K. Fornwalt

Biomedical Engineering Faculty Publications

Background: Pediatric obesity is a growing public health problem, which is associated with increased risk of cardiovascular disease and premature death. Left ventricular (LV) remodeling (increased myocardial mass and thickness) and contractile dysfunction (impaired longitudinal strain) have been documented in obese children, but little attention has been paid to the right ventricle (RV). We hypothesized that obese/overweight children would have evidence of RV remodeling and contractile dysfunction.

Methods: One hundred and three children, ages 8–18 years, were prospectively recruited and underwent cardiovascular magnetic resonance (CMR), including both standard cine imaging and displacement encoding with stimulated echoes (DENSE) imaging, which allowed …


Efficient Dehydration And Recovery Of Ionic Liquid After Lignocellulosic Processing Using Pervaporation, Jian Sun, Jian Shi, N. V. S. N. Murthy Konda, Dan Campos, Dajiang Liu, Stuart Nemser, Julia Shamshina, Tanmoy Dutta, Paula Berton, Gabriela Gurau, Robin D. Rogers, Blake A. Simmons, Seema Singh Jun 2017

Efficient Dehydration And Recovery Of Ionic Liquid After Lignocellulosic Processing Using Pervaporation, Jian Sun, Jian Shi, N. V. S. N. Murthy Konda, Dan Campos, Dajiang Liu, Stuart Nemser, Julia Shamshina, Tanmoy Dutta, Paula Berton, Gabriela Gurau, Robin D. Rogers, Blake A. Simmons, Seema Singh

Biosystems and Agricultural Engineering Faculty Publications

Background: Biomass pretreatment using certain ionic liquids (ILs) is very efficient, generally producing a substrate that is amenable to saccharification with fermentable sugar yields approaching theoretical limits. Although promising, several challenges must be addressed before an IL pretreatment technology can become commercially viable. One of the most significant challenges is the affordable and scalable recovery and recycle of the IL itself. Pervaporation (PV) is a highly selective and scalable membrane separation process for quantitatively recovering volatile solutes or solvents directly from non-volatile solvents that could prove more versatile for IL dehydration.

Results: We evaluated a commercially available PV system for …


Method Of Inhibiting Nitrosation Of An Aqueous Amine Solution Used In A Process Of Removing Carbon Dioxide From A Flue Gas, Joseph Eugene Remias, Payal Chandan, Kunlei Liu Jun 2017

Method Of Inhibiting Nitrosation Of An Aqueous Amine Solution Used In A Process Of Removing Carbon Dioxide From A Flue Gas, Joseph Eugene Remias, Payal Chandan, Kunlei Liu

Center for Applied Energy Research Faculty Patents

A method is provided for inhibiting nitrosation of an aqueous amine solution used in a process of removing carbon dioxide from a flue gas. That method includes a step of adding an effective amount of an antioxidant to the aqueous amine solution being circulated between an absorber and a stripper of a carbon dioxide capture system.


Benefits From Constructability Reviews, Nikiforos Stamatiadis, Roy Sturgill, Kiriakos Amiridis Jun 2017

Benefits From Constructability Reviews, Nikiforos Stamatiadis, Roy Sturgill, Kiriakos Amiridis

Civil Engineering Faculty Publications

Constructability review is a process used during project design to infuse construction knowledge into the design process. There is industry impetus encouraging early construction involvement in project development. State transportation agencies often have to abide by legislation restricting these procurement methods leaving construability review as the only opportunity for early construction involvement. Staffing and budgetary constraints lead to state transportation agencies being very cautious in the practices and processes they implement that seemingly lie outside the main missions of project development and delivery. Without straightforward and documented savings of constructability review processes, these methods may also be eliminated. After streamlining …


Development Of A Methodology To Determine Antibiotic Concentrations In Water Samples Using High-Pressure Liquid Chromatography, Tahnee Qualls, Carmen T. Agouridis, Manish Kulshrestha Jun 2017

Development Of A Methodology To Determine Antibiotic Concentrations In Water Samples Using High-Pressure Liquid Chromatography, Tahnee Qualls, Carmen T. Agouridis, Manish Kulshrestha

Biosystems and Agricultural Engineering Faculty Publications

Antibiotic concentrations are typically measured using solid-phase extraction along with liquid chromatography, but this process is not practical due to a large number of man hours involved. The use of a lyophilizer with high-pressure liquid chromatography (HPLC) is an accurate and cost-effective method of analyzing antibiotics in water samples. An initial antibiotic analysis methodology was developed with the goal of concentrating antibiotics in water samples for greater detection; however, it was observed that the methodology required additional refinement to improve accuracy, particularly when manure was present in the water samples. Based on prior tetracycline antibiotic research, we hypothesized that sample …


Multilayer Concentrated Windings For Axial Flux Pm Machines, Vandana Rallabandi, Narges Taran, Dan M. Ionel Jun 2017

Multilayer Concentrated Windings For Axial Flux Pm Machines, Vandana Rallabandi, Narges Taran, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Coreless axial flux machines are of interest because of the absence of stator core losses and cogging torque. These machines generally employ concentrated windings. One of the challenges with such a winding is that the torque producing MMF component that corresponds to the fundamental of the magnet excitation is accompanied by substantial asynchronous components. These harmonics cause losses in the rotor core and magnets, which can become significant at high speeds. This paper proposes a new multilayer winding arrangement to eliminate the non-torque producing MMF components. This winding is applied to a 12-coil 16-pole coreless axial flux machine. The efficacy …


Improved Bridge Joint Materials And Design Details, Theodore Hopwood Ii, Christopher W. Van Dyke, Sudhir Palle Jun 2017

Improved Bridge Joint Materials And Design Details, Theodore Hopwood Ii, Christopher W. Van Dyke, Sudhir Palle

Kentucky Transportation Center Research Report

Expansion joints accommodate bridge movements that result from factors such as thermal expansion and contraction, concrete shrinkage, creep effects, live loading, settlement of the foundation and substructure, and environmental stressors. Expansion joints fall into two categories — open joints and closed joints. Open joints contain gaps that facilitate the passage of water and debris runoff through bridge joints. Flexible or stiff troughs are generally installed beneath open joints to direct runoff away from bridge elements. Closed joints produce a watertight seal that inhibits water, debris, and deicing materials from passing through bridge joints and remaining in contact with underlying bridge …


Realizing Full Coverage Of Stable Perovskite Film By Modified Anti-Solvent Process, Long Ji, Ting Zhang, Yafei Wang, Peng Zhang, Detao Liu, Zhi David Chen, Shibin Li May 2017

Realizing Full Coverage Of Stable Perovskite Film By Modified Anti-Solvent Process, Long Ji, Ting Zhang, Yafei Wang, Peng Zhang, Detao Liu, Zhi David Chen, Shibin Li

Electrical and Computer Engineering Faculty Publications

Lead-free solution-processed solid-state photovoltaic devices based on formamidinium tin triiodide (FASnI3) and cesium tin triiodide (CsSnI3) perovskite semiconductor as the light harvester are reported. In this letter, we used solvent engineering and anti-solvent dripping method to fabricate perovskite films. SnCl2 was used as an inhibitor of Sn4+ in FASnI3 precursor solution. We obtained the best films under the function of toluene or chlorobenzene in anti-solvent dripping method and monitored the oxidation of FASnI3 films in air. We chose SnF2 as an additive of CsSnI3 precursor solution to prevent the oxidation …


Desulfination By 2′-Hydroxybiphenyl-2-Sulfinate Desulfinase Proceeds Via Electrophilic Aromatic Substitution By The Cysteine-27 Proton, Inacrist Geronimo, Shawn R. Nigam, Christina M. Payne May 2017

Desulfination By 2′-Hydroxybiphenyl-2-Sulfinate Desulfinase Proceeds Via Electrophilic Aromatic Substitution By The Cysteine-27 Proton, Inacrist Geronimo, Shawn R. Nigam, Christina M. Payne

Chemical and Materials Engineering Faculty Publications

Biodesulfurization is an attractive option for enzymatically removing sulfur from the recalcitrant thiophenic derivatives that comprise the majority of organosulfur compounds remaining in hydrotreated petroleum products. Desulfurization in the bacteria Rhodococcus erythropolis follows a four-step pathway culminating in C–S bond cleavage in the 2′-hydroxybiphenyl-2-sulfinate (HBPS) intermediate to yield 2-hydroxybiphenyl and bisulfite. The reaction, catalyzed by 2′-hydroxybiphenyl-2-sulfinate desulfinase (DszB), is the rate-limiting step and also the least understood, as experimental evidence points to a mechanism unlike that of other desulfinases. On the basis of structural and biochemical evidence, two possible mechanisms have been proposed: nucleophilic addition and electrophilic aromatic substitution. Density …


Pore Functionalized Pvdf Membranes With In-Situ Synthesized Metal Nanoparticles: Material Characterization, And Toxic Organic Degradation, Hongyi Wan, Nicolas J. Briot, Anthony Saad, Lindell E. Ormsbee, Dibakar Bhattacharyya May 2017

Pore Functionalized Pvdf Membranes With In-Situ Synthesized Metal Nanoparticles: Material Characterization, And Toxic Organic Degradation, Hongyi Wan, Nicolas J. Briot, Anthony Saad, Lindell E. Ormsbee, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

Functionalized PVDF membrane platforms were developed for environmentally benign in-situ nanostructured Fe/Pd synthesis and remediation of chlorinated organic compounds. To prevent leaching and aggregation, nanoparticle catalysts were integrated into membrane domains functionalized with poly (acrylic acid). Nanoparticles of 16–19 nm were observed inside the membrane pores by using focused ion beam (FIB). This technique prevents mechanical deformation of the membrane, compared to the normal SEM preparation methods, thus providing a clean, smooth surface for nanoparticles characterization. This allowed quantification of nanoparticle properties (size and distribution) versus depth underneath the membrane surface (0–20 μm). The results showed that nanoparticles were uniformly …


Real-Time Atomistic Observation Of Structural Phase Transformations In Individual Hafnia Nanorods, Bethany M. Hudak, Sean W. Depner, Gregory R. Waetzig, Anjana Talapatra, Raymundo Arroyave, Sarbajit Banerjee, Beth S. Guiton May 2017

Real-Time Atomistic Observation Of Structural Phase Transformations In Individual Hafnia Nanorods, Bethany M. Hudak, Sean W. Depner, Gregory R. Waetzig, Anjana Talapatra, Raymundo Arroyave, Sarbajit Banerjee, Beth S. Guiton

Chemistry Faculty Publications

High-temperature phases of hafnium dioxide have exceptionally high dielectric constants and large bandgaps, but quenching them to room temperature remains a challenge. Scaling the bulk form to nanocrystals, while successful in stabilizing the tetragonal phase of isomorphous ZrO2, has produced nanorods with a twinned version of the room temperature monoclinic phase in HfO2. Here we use in situ heating in a scanning transmission electron microscope to observe the transformation of an HfO2 nanorod from monoclinic to tetragonal, with a transformation temperature suppressed by over 1000°C from bulk. When the nanorod is annealed, we observe with …


Methanol Steam Reforming: Na Doping Of Pt/Ysz Provides Fine Tuning Of Selectivity, Michela Martinelli, Gary Jacobs, Uschi M. Graham, Burtron H. Davis May 2017

Methanol Steam Reforming: Na Doping Of Pt/Ysz Provides Fine Tuning Of Selectivity, Michela Martinelli, Gary Jacobs, Uschi M. Graham, Burtron H. Davis

Center for Applied Energy Research Faculty and Staff Publications

In this work, we found that sodium doping can be used to improve CO2 selectivity for supported Pt catalyst during methanol steam reforming. These materials are usually very active in the low temperature range; however, they are characterized by high selectivity of CO, which is a poison in downstream polymer electrolyte membrane fuel cells (PEM-FC) application. With Na doping, we found that CO2 selectivity was higher than 90% when 2.5 wt.% of sodium was added to Pt/YSZ. We have speculated that the different product distribution is due to a different reaction pathway being opened for CH3OH …


Method Of Manufacturing A Semiconductor Heteroepitaxy Structure, Zhi David Chen May 2017

Method Of Manufacturing A Semiconductor Heteroepitaxy Structure, Zhi David Chen

Electrical and Computer Engineering Faculty Patents

A method of manufacturing a semiconductor structure includes the steps of depositing a layer of semiconductor oxide on a base semiconductor layer, scavenging oxygen from the layer of semiconductor oxide and recrystallizing the oxygen scavenged layer of semiconductor oxide as a semiconductor heteroepitaxy layer.


Lightweight Data Aggregation Scheme Against Internal Attackers In Smart Grid Using Elliptic Curve Cryptography, Debiao He, Sherali Zeadally, Huaqun Wang, Qin Liu May 2017

Lightweight Data Aggregation Scheme Against Internal Attackers In Smart Grid Using Elliptic Curve Cryptography, Debiao He, Sherali Zeadally, Huaqun Wang, Qin Liu

Information Science Faculty Publications

Recent advances of Internet and microelectronics technologies have led to the concept of smart grid which has been a widespread concern for industry, governments, and academia. The openness of communications in the smart grid environment makes the system vulnerable to different types of attacks. The implementation of secure communication and the protection of consumers’ privacy have become challenging issues. The data aggregation scheme is an important technique for preserving consumers’ privacy because it can stop the leakage of a specific consumer’s data. To satisfy the security requirements of practical applications, a lot of data aggregation schemes were presented over the …


Carbon Particles, Stephen M. Lipka, Christopher R. Swartz May 2017

Carbon Particles, Stephen M. Lipka, Christopher R. Swartz

Center for Applied Energy Research Faculty Patents

A composition generally includes carbon particles. The particles are prepared by dissolving a carbohydrate-based precursor in water to form a precursor solution and placing the precursor solution in a pressure vessel. The precursor solution is placed in a pressure vessel. The pressure vessel is heated to a reaction temperature to form carbon particles. The carbon particles are subjected to a chemical activation and a physical activation. The composition includes, by weight, about 5% to about 30% oxygen.