Engineering Commons^™

Oct-Based Three Dimensional Modeling Of Stent Deployment, Pengfei Dong, David Prabhu, David L. Wilson, Hiram G. Bezerra, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Stent deployment has been widely used to treat narrowed coronary artery. Its acute outcome in terms of stent under expansion and malapposition depends on the extent and shape of calcifications. However, no clear understanding as to how to quantify or categorize the impact of calcification. We have conducted ex vivo stenting characterized by the optical coherence tomography (OCT). The goal of this work is to capture the ex vivo stent deployment and quantify the effect of calcium morphology on the stenting. A three dimensional model of calcified plaque was reconstructed from ex vivo OCT images. The crimping, balloon expansion and …

Template Induced Fabrication Of Nitrogen Doped Carbon Sheets As Electrode Materials In Supercapacitors, Tao Huang, Guang-Zhi Tao, Chong-Qing Yang, Deng Lu, Lie Ma, Dong-Qing Wu

Journal of Electrochemistry

Due to the good electrical conductivity, high specific surface area, and excellent chemical/mechanical stability, carbon nanomaterials with two-dimensional morphology have gradually become the hot topic of the research on supercapacitors. Herein, we report for the first time the fabrication of nitrogen doped carbon sheets (NCSs). In our approach, the sheet-like magnisum aluminum (MgAl) layered double hydroxide was used as the hard template, which was mixed with o-phenylene diamine and iron chloride. The following thermal treatment could render the polymerization and carbonization of o-phenylene diamine. The NCSs with ordered hexagonal architectures were formed by final etching process of the thermally treated …

Recent Advances On Carbon And Transition Metallic Compound Electrodes For High-Performance Supercapacitors, Dun Lin, Xi-Yue Zhang, Yin-Xiang Zeng, Ming-Hao Yu, Xi-Hong Lu, Ye-Xiang Tong

Journal of Electrochemistry

Supercapacitors (SCs) have stimulated intensive interests for their promising applications in electric vehicles and portable electronics, etc. Electrode material is the most important key component of SCs, which vastly determines the performance of SCs. Carbon and transition metallic compound materials have attracted considerable attention and been widely explored as electrode materials. However, the insufficient capacitance of carbon materials and unsatisfactory conductivity and cyclic stability of transition metallic compounds severely limit their implementation as robust SC electrodes. Herein, we highlight our recent efforts to boost the capacitive performance of carbon and metal oxide/nitride electrodes by rationally structural and componential design. The …

Preparation And Characterization Of Cellulose Acetate-Based Separator For Lithium-Ion Batteries, Hua-Feng Luo, Yuan-Dong Qiao

Journal of Electrochemistry

To improve the electrolyte wettability and thermal resistance of separators used for lithium-ion battery, a novel cellulose acetate (CA)-based separator is facilely prepared by non-solvent induced phase separation (NIPS) wet-process and investigated in lithium-ion batteries. Systematical investigations including morphological characterization, electrolyte wettability and thermal resistance testing were carried out. The results demonstrated that the CA-based separator exhibited well developed three-dimensional porous structures with porosity up to 65%, which is 1.5 times higher than that of PE separator. The CA separator also showed excellent electrolyte uptake (285%) and thermal stability at 150 ^oC for 30 min. Compared with the commercial …

Strategies To Enhance Energy Density For Supercapacitors, Jun-Wei Lang, Xu Zhang, Ru-Tao Wang, Xing-Bin Yan

Journal of Electrochemistry

The biggest advantage of supercapacitor lies in not only the excellent pulse and fast charging-discharging performance, but also the characteristics of long cycle life and wide operating temperature window with no pollution. However, the energy density of supercapacitor is low. In this paper, the working principle, the development status, defects and improvement method of supercapacitors are introduced. Based on the research workes of the supercapacitors with high energy density in our group, combined with the literature reports in recent years, the strategies to promote the energy density of supercarpacitors will be focused. The strategies for the enhancement of energy density …

Porous Carbon Materials Produced By Koh Activation For Supercapacitor Electrodes, Jiang-Lin Ye, Yan-Wu Zhu

Journal of Electrochemistry

Porous carbon materials with high specific surface area and excellent conductivity have wide applications in supercapacitor electrodes. Much effort has been made to synthesize and tailor the microstructures of porous carbon materials via various activation procedures (physical and chemical activations). In particular, the chemical activation using potassium hydroxide (KOH) as an activating reagent is promising because of the well-defined micropore size distribution and ultrahigh specific surface area up to 3000 m²·g^-1 of the resulting porous carbons. Based mainly on the previous works taken by the authors and collaborators in the field, we have summarized the activation mechanism …

Lithium Ion Hybrid Capacitor With High Energy Density, Xian-Zhong Sun, Xiong Zhang, Kai Wang, Yan-Wei Ma

Journal of Electrochemistry

Lithium ion hybrid capacitors are electrochemical energy storage devices combining the advantages of both Li-ion battery and electrochemical capacitor. They can be extensively used in many fields. However, the commercialization of lithium ion hybrid capacitor has been encountered several problems, e.g., the device structure design, the screening of materials, the pre-lithiation process, and the interface between electrolyte and electrode, etc. This review summarizes the recent research advances in lithium ion hybrid capacitor with high energy density, including the selection of the active materials in cathode/anode and the separator, the pre-lithiation method using the three-electrode structure, the high- and low-temperature performances, …

Special Issue On Supercapacitors, Xiao-Gang Zhang

Journal of Electrochemistry

Supercapacitors (SCs) have become a new bright spot in electrochemical power source due to their high power density, long cycling life and wide operation temperature. As the high-power density energy storage devices, SCs have been widely applied in electric vehicle, modern communication, aerospace, defense, and many other emerging fields. The markets for SCs are continuously increasing. However, the commercialization of SCs suffers from a lower energy density and higher cost. Thus, one great challenge for the supercapacitor (SC) technology is to improve the energy density without sacrificing the power density and cycle life. To address this critical issue, the worldwide …

Numerical Simulation Of Multi-Phase Core-Shell Molten Metal Drop Oscillations, Kaushal Sumaria

Masters Theses

The surface tension of liquid metals is an important and scientifically interesting parameter which affects many metallurgical processes such as casting, welding and melt spinning. Conventional methods for measuring surface tension are difficult to use for molten metals above temperatures of 1000 K. Containerless methods are can be used to measure the surface tension of molten metals above 1000 K. Oscillating drop method is one such method where a levitated droplet is allowed to undergo damped oscillations. Using the Rayleigh’s theory for the oscillation of force-free inviscid spherical droplets, surface tension and viscosity of the sample can be calculated from …

Multiple Scattering Theory For Polycrystalline Materials With Strong Grain Anisotropy: Theoretical Fundamentals And Applications, Huijing He

Department of Mechanical and Materials Engineering: Faculty Publications

This work is a natural extension of the author’s previous work: “Multiple scattering theory for heterogeneous elastic continua with strong property fluctuation: theoretical fundamentals and applications” (arXiv:1706.09137 [physics.geo-ph]), which established the foundation for developing multiple scattering model for heterogeneous elastic continua with either weak or strong fluctuations in mass density and elastic stiffness. Polycrystalline material is another type of heterogeneous materials that widely exists in nature and extensively used in industry. In this work, the corresponding multiple scattering theory for polycrystalline materials with randomly oriented anisotropic crystallites is developed. To validate the theory, the theoretical results for a series of …

Floating-Gate Transistor Photodetector, Jinsong Huang, Yongbo Yuan

Department of Mechanical and Materials Engineering: Faculty Publications

A field effect transistor photodetector that can operate in room temperature includes a source electrode , a drain electrode , a channel to allow an electric current to flow between the drain and source electrodes , and a gate electrode to receive a bias voltage for controlling the current in the channel . The photodetector includes a light - absorbing mate rial that absorbs light and traps electric charges . The light absorbing material is configured to generate one or more charges upon absorbing light having a wavelength within a specified range and to hold the one or more charges …

Datumate, Purdue Ect Team

ECT Fact Sheets

Datumate is digitally transforming civil engineering processes used in construction, surveying and infrastructure inspection markets with fully automated, highly precise, cost effective and safe tools. It utilizes state-of-the-art image processing and advanced drones and camera technologies dramatically reducing the amount of time surveying crews spend in the field, speeding up construction progress checks and shortening infrastructure inspection duration, while maintaining survey grade accuracy. The intuitive, simple and automated solutions increase productivity by saving field and office time in civil engineering and inspection projects of roads, intersections, stockpile volumes, topography, piping, industrial facilities, bridges, property surveys, building facades, railways, cellular infrastructure …

Incorporating Student Reflection Into Engineering Courses, Nancy Barr

TechTalks

Critical reflection as students move through their disciplinary curriculum is one way to cultivate capacity for critical thinking. By embedding opportunities for critical reflection in disciplinary courses, educators can combine aspects of writing theory, metacognitive learning, and critical pedagogy to help students begin to frame how they will apply their skills and talents to problems effecting diverse populations. The new undergraduate ME curriculum combines applied learning and project-based learning methods in a series of four ME Practice courses. Technical communication instruction is also embedded in these courses, and the “capstone” of each course is a reflective essay. By responding to …

Space Mining Is Almost Here!, Paul Van Susant

TechTalks

When going to the Moon and Mars for extended stays with humans it is required to minimize mass by "living off the land" as soon as possible. Mining local resources and using them to produce consumables and construct simple structures can leverage launch mass to the surface of those bodies. In addition, asteroid mining will be able to provide rocket fuel to further spur economic development in CIS-Lunar space and further open up solar system activities. I am working on mining on Mars and the Moon as well as construction using local rocks.

New Concepts In Evolutionary Algorithms For Systems Architecture Optimization, Ossama Abdelkhalik

TechTalks

This talk will present recent developments in evolutionary algorithms that focus on the systems architecture optimization. One challenge in systems optimization is the variable number of design variables. Three new concepts will be presented in this talk that enable evolutionary algorithms to handle this type of problems more efficiently. The first is the biologically inspired concept of Hidden Genes that implements tags to cover/uncover genes in the variables' code, which enable handling variable number of variables in evolutionary algorithms. The second concept is a structured chromosome approach that transcripts the variables in a multi-layer code as opposed to the standard …

3d Printing Of 316l Stainless Steel And Its Effect On Microstructure And Mechanical Properties, Rawn Penn

Graduate Theses & Non-Theses

Laser powder bed fusion or 3D printing is a potential candidate for net shape forming and manufacturing complex shapes. Understanding of how various parameters affect build quality is necessary. Specimens were made from 316L stainless steel at 0°, 30°, 60°, and 90° angles measured from the build plate. Three tensile and four fatigue specimens at each angle were produced. Fracture morphology investigation was performed to determine the fracture mode of specimens at each build angle. Microstructural analysis was performed on one of each orientation. The average grain size of the samples was marginally influenced by the build angle orientation. Tensile …

Impulse, Matt Schmidt, Lora Berg, Christine Delfanian, Dave Graves, Heidi Kronaizl, Emily Weber, Micayla Standish

Impulse (Jerome J. Lohr College of Engineering Publication)

[Page] 2 Better Equipped
[Page] 4 Flashback Summer Scholars
[Page] 6 Biomedical Engineering
Ryan Mahutga is the third mechanical engineering graduate in five years to receive a prestigious National Science Foundation Graduate Research Fellowship.
Nigerian native John Asiruwa is working with associate professor Stephen Gent on a mechanical engineering project to help Sanford Health build better heart stents.
Electrical engineering graduate Bruce Lutz has selected the biomedical engineering program as a target for his future giving.
[Page] 9 Programs Accredited
[Page] 10 Fast Wheels
[Page] 12 Five Unforgettable Weeks
[Page] 14 Second in the Nation
[Page] 16 Athletes and Engineering …

The Subject Librarian Newsletter, Engineering And Computer Science, Fall 2017, Buenaventura "Ven" Basco

Libraries' Newsletters

No abstract provided.

Software For Extracting Deformation Gradient And Stress From Md Simulations: Simulations Using The Charmm Force Field, Mehrdad Negahban, Lili Zhang, Zesheng Zhang, John Jasa, Antoine Jérusalem

Department of Mechanical and Materials Engineering: Faculty Publications

Software was developed, and is provided under a general use license, to calculate continuum level deformation gradient and stress for any group of atoms in an MD simulation that uses the Charmm force fields. This software can also calculate the interaction stress applied by one group of atoms on any other group. To obtain deformation gradient and stress, the user needs to provide the selected group(s) of atoms in an atom group identification file, and provide the associated LAMMPS format files and force field parameter file. An example is included to demonstrate the use of the software.

Rice Hull Bioreactor For Recirculating Aquaculture, Marlon A. Greensword

LSU Doctoral Dissertations

The engineering of floating media biofilters has been optimized over the years. The backwashing process has made them more energy and water efficient. Likewise, moving bed bioreactors (MBBR) are gaining interest and popularity because they are relatively affordable to build. Yet, developing countries’ aquaculture production remains largely excluded from the advances made in recirculating aquaculture systems (RAS). This discrepancy is partially driven by the high costs of media such plastic beads and Kaldnes (KMT) media, commonly used in MBBR.

This dissertation evaluates the usability and profitability of rice hulls (RH), an abundant by-product in many developing nations, as a sinking …

Thermo-Stability And Active Site Structure Of Fe/N/C Electrocatalyst For Oxygen Reduction Reaction, Chi Chen, Yu-Jiao Lai, Zhi-You Zhou, Xin-Sheng Zhang, Shi-Gang Sun

Journal of Electrochemistry

The development of Fe/N/C electrocatalyst for oxygen reduction reaction (ORR) is vital for the large-scale applications of proton exchange membrane fuel cells. Understanding the active site structure will contribute to the rational design of highly active catalysts. In this study, the as-prepared Fe/N/C catalyst based on poly-m-phenylenediamine (PmPDA-FeN_x/C) catalyst with the high ORR activity was subjected to the high-temperature heat treatment again at 1000 ~1500 ^oC. The degradation of in the ORR activity of PmPDA-FeN_x/C by with various heat treatments was correlated to the change of elemental compositions, chemical states and textural properties. As the …

Electric Current Induced Flow And Electrocapillary Deformation Of Liquid Wood Alloy In Naoh Aqueous Solution, Guo-Di Zhang, Qiao-Li Lin, Jian-Hong Cheng, Rui Cao

Journal of Electrochemistry

The phenomena of the electric current induced flow and electrocapillary deformation for a liquid Wood alloy in a NaOH electrolyte were studied. Electrocapillary behaviors for the liquid Wood alloy in NaOH electrolytes by applying external low voltages were investigated. The electrode reaction (redox reaction) induced the formation or removing removal of an oxide film, and further caused the drop deformation by decreasing or increasing an interfacial tension. The same polar charge in the electric double layer would also decrease the interfacial tension. In order to maintain the stability of system, the contact area of the interface would be expanded, and …

Effects Of Surface Modification Modes On Proton-Over-Vanadium Ion Selectivity Of Nafion®Membrane For Application In Vanadium Redox Flow Battery, Qing-Long Tan, Hai-Ning Wang, Shan-Fu Lu, Da-Wei Liang, Chun-Xiao Wu, Yan Xiang

Journal of Electrochemistry

The effect of surface modification modes on proton-over-vanadium ion selectivity was studied by spin-coating chitosan-Phosphotungstic Acid (PWA) as a single or double layer on Nafion membrane surface. To suppress the vanadium ions permeation through the Nafion? membrane in a vanadium redox flow battery (VRFB), the single surface-modified Nafion membrane (Nafion/chitosan-PWA)S and double surface-modified Nafion membrane (Nafion/chitosan-PWA)D demonstrated a 89.9% and 92.7% reduction of vanadium ion permeability in comparison with pristine Nafion, respectively. The (Nafion/chitosan-PWA)D exhibited betterhigher selectivity between proton and vanadium ions than the (Nafion/chitosan-PWA)S at the same layer thickness. Furthermore, the columbic efficiency for the VRFB single cell based …

Density Functional Investigation On Cathode/Electrolyte Interface In Solid-State Lithium Batteries, Xuelong Wang, Ruijuan Xiao, Yong Xiang, Hong Li, Liquan Chen

Journal of Electrochemistry

The rapidly expanding application of lithium ion batteries stimulates research interest on energy storage devices with higher energy density, better safety and faster charge/discharge speed. All-solid-state lithium batteries have been considered as promising candidates because of their fewer side reactions and better safety compared with conventional lithium-ion batteries with organic liquid electrolytes. Looking for well-matched electrode/electrolyte interfaces is one of the keys to ensuring good comprehensive performance of solid-state lithium batteries. In this report, with the aid of first-principles simulations, the local structure and lithium ions transportation properties of electrolyte surfaces and cathode/electrolyte interfaces are investigated. The β-Li₃PS …

A New Type Carbon Composited Molybdenum Doped Vanadium Oxide Nanowires As A Cathode Material For Sodium Ion Batteries, Guang-Rui Zhang, Li-Qiang Hu, Bao-Zhu Zhang

Journal of Electrochemistry

In recent years, the development of lithium ion batteries (LIBs) has been limited due to the insufficient lithium resource and increasing cost. As a promising candidate, sodium ion batteries (SIBs) with the similar electrochemical mechanism and lower cost than LIBs are developing rapidly. However, as a result of the larger radius of Na⁺ compared with Li⁺, the crystalline structures of the most electrode materials are damaged severely during the intercalation of Na⁺, which limits the electrochemical properties of SIBs. Thus, developing new types of electrode materials for SIBs is particularly important. Among the cathode materials, …

Effects Of Temperature On The Nucleation And Growth Mechanism Of Pbo2 Electrodeposition, Lei Wang, Juan-Qin Xue, Li-Hua Yu, Chang-Bin Tang, Qiang Bi

Journal of Electrochemistry

In order to investigate the effects of temperature on the nucleation and growth of lead dioxide (PbO₂)， the in situ electrochemical depositions of PbO₂ were carried out on the glassy carbon electrode at different temperatures, namely, 25℃,35℃, 45℃, 55℃, and 65℃.The cyclic voltammetric curves, the time-current and the time-potential curves，SEM images and XRD patterns of the PbO₂ coatings deposited at different temperatures were obtained. The results showed that the PbO₂ underwent nucleation and grew at different temperatures. The 3D continuous nucleation mode of PbO₂ electrodeposition remained unchanged with the increase of temperature. However, the …

An Investigation Of The Synergistic Effect Between (1,3-Dioxolan-2-Ylmethyl)Triphenylphosphonium Bromide And Iodide Ion For The Corrosion Inhibition Of Zinc In Citric Acid, Saadawy M.

Journal of Electrochemistry

The effect of (1,3-Dioxolan-2-ylmethyl)-triphenylphosphonium bromide (DTPB) on the zinc corrosion in 0.5 mol·L^-1 citric acid solution was investigated at 30 ^oC using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. An ecofriendly bath was used for acid cleaning of zinc, which has not been widely used in literatures. The results showed that DTPB could serve as an effective inhibitor for the zinc corrosion in a citric acid solution with the inhibition efficiency of 98.9% at the DTPB concentration of 3×10^-3 mol·L^-1. A synergistic effect between DTPB and potassium iodide (KI) enhanced the inhibition …

Electrochemical Performance Of Sodium Difluoro(Oxalato)Borate As The Additive Of Non-Aqueous Electrolytes For Sodium-Ion Batteries, Ding Zhang, Qin Zhu, Ying Wang, Cheng-Long Zhao, Shi-Bin Liu, Shou-Dong Xu

Journal of Electrochemistry

Sodium ion battery has attracted worldwide and intensive attention recently, while the adoption of electrolyte additives has been considered as one effective strategy to promote the cell performance. Within this work sodium difluoro(oxalato)borate (NaDFOB) was prepared and adopted as an additive for the general non-aqueous electrolyte formula of 1 mol·L^-1 NaClO₄/EC/PC (Vol: Vol=1:1), and the effects of the additive concentration on ionic conductivity and oxidization decomposition voltage were investigated in detail. In addition, the cell performance evaluated by NaNi_0.5Mn_0.5O₂ as the cathode was also studied. It reveals that the …

Tetrabutylammonium Hexafluorophosphate As Flame Retardant Additive For Lithium Ion Batteries, Qing Zhao, Qian Zhang, Jing-Min Fan, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Safety issues have been attracted more and more attentions due to the wide applications of lithium ion batteries. Introducing flame retardant additives are one of the effective strategies to improve the safety of lithium-ion batteries. In this paper, the tetrabutylammonium hexafluorophosphate (TBAPF₆) as a flame retardant additive was added to the electrolyte as a flame retardant additive to enhance the safety of lithium ion batteries. The self-extinguishing time (SET) and ionic conductivities of the electrolytes with different TBAPF₆ contents were investigated. It is found that TBAPF6 dramatically reduced the flammability of the electrolyte while slightly decreasing ionic …

Influence Of Typical Anions In Seawater Environments On Corrosion Behaviors Of 5083 Aluminum Alloy, Yang-Fan Tu, Li-Ming Feng, Zhi-Gang Fang, Hai-Tao Liu, Ming-Hua Jing, Yong Guan

Journal of Electrochemistry

The interaction effects of typical anions, namely, Cl^-, HCO₃^- and SO₄^2-, presented in seawater environments on corrosion resistance behaviors of AA5083 aluminum alloy have been studied. The corrosion resistances of the 5083 aluminum alloy in different simulated seawater environments were tested by factorial analysis method. The polarization curves, the corrosion potentials, corrosion current densities and the breakdown potentials were examined in different concentrations of Cl^-, HCO₃^- and SO₄^2-.The corrosion behavior was analyzed by electrochemical impedance spectroscopy (EIS). The results showed that both Cl^-, and …