Engineering Commons^™

Synthesis Of Platinum Nanocrystallites And Possible Electrocatalytic Properties For Methanol, Lei-Lei Lu, Bao-Zhong Du, Sha Sun, Jin-Fen Niu, Jie Zhao

Journal of Electrochemistry

Platinum nanocrystallites were synthesized by the colloidal method using oxamide as the stabilizer. The morphologies and electrocatalytic performances for methanol of platinum nanocrystallites prepared at different pH values and with different reactant ratios of precursor and stabilizer were investigated. It was found that the platinum nanocrystallites synthesized at pH=5 and with the reactant ratio of 1:20 showed the best electrocatalytic activity for methanol. The peak current density reached up to 1709 μA·cm^-2. Furthermore, the electrocatalytic activity of platinum nanocrystallites for methanol reduced significantly although the cyclic voltammograms in the blank solution were not obviously changed after exposing in …

Dynamic Lean Assessment For Takt Time Implementation, Rehab M. Ali, Ahmed M. Deif

Industrial Technology and Packaging

Increasing volatility, global competitiveness, and sales crisis all force the manufacturers to commit to the journey of world-class manufacturing performance via adopting “lean systems” to enable economic success in difficult times. Among the journey to lean, one of the hardest steps is measuring the progress of lean polices implementation especially in this highly dynamic market. This paper presents a dynamic model to evaluate the degree of leanness in manufacturing firms. The model is based on system dynamics approach and presents a “leanness score” for the manufacturing system. In addition, it examines the dynamics associated with the application of “One-piece flow” …

Impact Of Dynamic Capacity Policies On Wip Level In Mix Leveling Lean Environment, Ahmed Deif, Hoda Elmaraghy

Industrial Technology and Packaging

Balancing demand's product variety in production planning is one aspect of variety management challenge. This phenomenon is described in lean systems as mix leveling. This paper approach product mix leveling problem from a dynamic perspective. A system dynamics model is developed to explore the dynamics associated with the WIP level performance at different mix leveling policies in a lean environment. The system captures different lean tools and policies. Results showed that the best WIP performance is sensitive to both the degree of lean tools implementation as well as the capacity scalability level of the system. The presented analysis showed that …

An Integrated Approach To Assess Manufacturing Greeness Level, Ahmed H. Salen, Ahmed Deif

Industrial Technology and Packaging

This paper proposes an integrated approach for relative greenness level assessment in selected manufacturing industries at the system level. The approach builds on existing methodologies to develop a multi-layer tool box called “Greenometer” which focus on the strategic comparison for cross industries evaluation as well as tactical comparison for intra-industries. The assessment tool captures the fundamental evaluation parameters of green manufacturing namely; Environment, Energy, Resources and Economy. In addition, the Greenometer employs geometric mean method (GMM) for the strategic layer and data envelopment analysis (DEA) for the tactical layer and will be used for different selected manufacturing disciplines. The proposed …

Bifurcation Type Change Of Ac Electrostatically Actuated Mems Resonators Due To Dc Bias, Dumitru Caruntu, Kyle N. Taylor

Mechanical Engineering Faculty Publications

This paper investigates the nonlinear response of microelectromechanical system (MEMS) cantilever resonator electrostatically actuated by applying a soft alternating current (AC) voltage and an even softer direct current (DC) voltage between the resonators and a parallel fixed ground plate. The AC frequency is near natural frequency. This drives the resonator into nonlinear parametric resonance. The method ofmultiple scales (MMS) is used to solve the dimensionless differential equation of motion of the resonator and find the steady-state solutions.The reduced order model (ROM) method is used to validate the results obtained using MMS. The effect of the soft DC voltage (bias) component …

Synthesis And Characterization Of Clickable Dendrimer Hydrogels For Ocular Drug Delivery, Jingfei Tian

Theses and Dissertations

Topical medication is a standard treatment for glaucoma. However, frequent dosing makes the therapy inconvenient and patient unfriendly. There is a great need to develop new topical formulations that provide long lasting noninvasive drug release. In this thesis, novel clickable dendrimer hydrogels for anti-glaucoma drug delivery were synthesized and characterized. Polyamidoamine (PAMAM) dendrimers have been widely applied for drug delivery. The physical characteristics they possess include monodispersity, water solubility, encapsulation ability, and a large number of surface groups. Polycationic PAMAM dendrimer G3 was surface modified with alkyne-PEG5-acid and then reacted with polyethylene glycol bisazide (PEG-BA, 1100 gmol-1) through click chemistry …

Effects Of Carbon Interlayer On Electrochemical Performance Of Lithium-Sulfur Cell, Jin-Peng Yu, Ming Zhang, Fei Ding, Zhi-Yuan Tang, Xing-Jiang Liu

Journal of Electrochemistry

Three kinds of conductive carbon films were prepared with Super-P (SP), KB and MWCNTs, and then the as-prepared carbon films were applied as an interlayer between a sulfur electrode and a separator for constructing a coin-type lithium-sulfur (Li-S) cell, respectively. The assessment results show that all the cells delivered the reversible capacities higher than 800 mAh·g^-1 after 40 cycles when the sulfur loading was up to 80% (by mass) in the sulfur electrode. Due to significant differences of physical properties among the carbon materials, the cell with a KB interlayer exhibited higher electrochemical polarization; the cycling performance of the …

Preparation Of Pt/H-Tio2 Catalyst With Improved Catalytic Performance For Methanol Electrooxidation, Jin Han, Zhi-You Zhou, Qiang Wang, Miao-Qiang Lv, Chi Chen, Shi-Gang Sun

Journal of Electrochemistry

White TiO₂ nanorods were synthesized by hydrothermal method with TiCl₄ as a precursor. As-synthesized TiO₂ nanorods were further subjected to high-temperature (550 ^oC) heat treatment for 2 h under H₂ atmosphere to prepare gray black hydrogen-treated TiO₂ (H-TiO₂) nanorods with oxygen vacancies and Ti³⁺ interstitial atoms. The Pt nanoparticles of 1.9 nm were supported on these two types of TiO₂ nanorods to form Pt/TiO₂ and Pt/H-TiO₂ catalysts. XRD data indicates that the crystal structure of TiO₂ was still reserved as rutile after hydrogen treatment, but the surface …

Effect Of Al-Doping In Li-Rich Material Li1.2Mn0.543Co0.078Ni0.155Al0.030O2 For Lithium-Ion Batteries, Xiao-Xi Jin, Yi-Xiao Li, Yong Yang, Zhou-Cheng Wang

Journal of Electrochemistry

The Al-doped 0.5Li₂MnO₃·0.5Li(Mn_0.4Co_0.2Ni_0.4)O₂ compounds were successfully synthesized as cathode materials for lithium-ion batteries. The pristine and Al-doped materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and laser Raman spectroscopy. The results indicated that all the prepared materials were indexed as a hexagonal structure with R-3m space group, and Al element had been introduced into lattice. When cycled at 180 mA·g^-1 (1 C-rate), the capacity retention of 4% (by mole) Al-doped 0.5Li₂MnO₃·0.5Li(Mn_0.4Co_0.2Ni …

Electrochemical Behavior Of Ionic Liquid Confined Into Nanopores Of Silica Gel Matrix, Zuo-Peng Li, Ya-Qiong Wen, Mei-Xia Wu, Yong Guo

Journal of Electrochemistry

Imidazolium Ionic liquids (ILs) nano aggregates confined into nanopores of silica gel matrices (ILs-sg) modified electrodes were prepared by sol-gel process and characterized by cyclic voltammetry. Furthermore, the amounts of 15% ~ 28% ILs-sg and nano aggregates coated with ILs silica gel (ILs/sg) were prepared and their conductivities were evaluated by performing electrochemical AC impedance measurements from 20 ^oC to 80 ^oC. The abnormal results showed that, 1) comparing with the bulk IL, the confined IL had a positive shift effect of Fc/Fc+ redox potential; 2) when IL confined into a nanospace, the electrochemical stability became poor; 3) …

Application Of Ionic Liquid Pp14Tfsi In Electrolyte Systems For Rechargeable Mg Batteries, Jin-Jie Zhu, Fei-Fei Wang, Yong-Sheng Guo, Jun Yang, Yan-Na Nuli, Jiu-Lin Wang

Journal of Electrochemistry

A phenolated-based Mg salt was prepared. The mixture of THF and N-methyl-N-butyl-piperidinium bis(trifluoromethanesulfonyl)imide (PP14TFSI) serves as the mixed solvent instead of pure THF for rechargeable Mg batteries systems. This new type of electrolyte system not only has optimal reversibility of Mg, but also owns a wide electrochemical window (2.7 V vs. Mg) and high ionic conductivity (7.77 mS·cm^-1). More importantly, the addition of Ionic Liquid suppresses the volatility of THF and improves the safety of rechargeable Mg batteries. The result shows that the mixture of THF and piperidyl-based Ionic Liquid could be regarded as a good solvent candidate …

Electrodeposition Of Copper From A Choline Chloride Based Ionic Liquid, Rostom Ali M., Ziaur Rahman Md., Sankarsaha S.

Journal of Electrochemistry

The electrodeposition of copper from a solution containing copper chloride in either an ethylene glycol (EG)-choline chloride based or a urea-choline chloride based ionic liquid has been carried out onto a steel cathode by constant current and constant potential methods at room temperature. The influences of various experimental conditions on electrodeposition and the morphology of the deposited layers have been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It is shown that very smooth, shiny and dense with good adherence and bright metallic coloured copper coatings can be obtained from both EG and urea based ionic liquids at …

Electrocatalytic Oxidation Of Glycerol At The Platinum Electrode Modified With An Nd-Fe-Moo42- Cyano-Bridged Mixed Coordination Polymer, Yong-Jun Ma, Yu-Xiu Tian, Jing Liu, Min Zhou, Jing Ding, Zhi-Mei Jin, Xiang-Mei Wang

Journal of Electrochemistry

A platinum electrode decorated with the ordered Nd-Fe-MoO₄^2- cyano-bridged mixed coordination polymer was successfully prepared by electrodeposition in virtue of the lyotropic liquid crystal soft template methods, and electrocatalytic oxidation behavior of glycerol was investigated on the chemically modified electrode by cyclic voltammetry. The influences of experimental factors such as the concentrations of H⁺ and SO₄^2- in electrolytes, glycerol concentration and scan rate on the electrocatalytic activity of glycerol at the modified electrode were also studied. It indicated that the proper amount of SO₄^2- in weakly acidic electrolyte could help to improve the …

Effect Of Temperature On The Self-Humidifying Open-Cathode Proton Exchange Membrane Fuel Cell, Si-Chen Zhao, Ben Wang, Qiu-Hong Jia, Ming Han, Yu-Hong Xie

Journal of Electrochemistry

Based on the experiments about the output characteristics of a home-made temperature-controlled PEMFC system with atmospheric pressure and no external humidifying condition in different loading voltages and operating temperatures, the optimum operating temperature at different loading voltages can be obtained by tracking the output characteristics of PEMFC operating over a range of temperatures. By analyzing the fitted data the kinetic parameters are evaluated and the effect of different operating temperatures on the PEMFC performance is discussed from a view of electrode kinetics.

Fabrication And Electrochemical Properties Of Graphene-Zno Nanocomposite, Chuan-Ling Men, Wan Wang, Jun Cao

Journal of Electrochemistry

In this work, the graphene-ZnO nanocomposite was successfully synthesized through a one-step solvothermal approach, using ethylene glycol as the solvent and reducing agent. The ZnO particles could be attached to the surfaces and edges of graphene sheet. The electrochemical performance of the nanocomposite was investigated by performing cyclic voltammetry, A.C. impedance and chronopotentiometry tests in 6 mol·L^-1 KOH. The results showed that the graphene-ZnO nanocomposite exhibited a nice electrochemical specific capacitance of 115 F·g^-1 determined in cyclic voltammetry test, or 71 F·g^-1 evaluated in chronopotentiometry test and good reversible charge/discharge behavior.

An Equivalent Circuit Model For Redox Flow Battery Stack, Dong-Jiang You, Hua-Min Zhang

Journal of Electrochemistry

This paper introduces an equivalent circuit model for a redox flow battery stack. The model combines the electrochemical reaction of the battery cell and the shunt current of the battery stack. An all-vanadium redox flow battery stack of 1kW rated output power is tested through transient response and self-discharge experiments. All the parameters used for the modeling are obtained. Calculated shunt current and distribution of calculated battery voltage are shown in the results. It is concluded that the impedance of the battery stack can be obtained by the experimental results of the transient response and self-discharge measurements. The capacity lose …

Phase 1 Final Report: Preamble Assisted Equalization For Aeronautical Telemetry (Paq), Michael Rice, Mohammad Saquib, Arlene Cole-Rhodes, Farzad Moazzami, Erik Perrins

Faculty Publications

This is the Phase 1 report for Preamble Assisted Equalization for Aeronautical Telemetry (PAQ).

Executive Summary:

To fully leverage the benefits of a periodically inserted preamble, the preamble is used to estimate the state of the channel. To this end the following algorithms have been developed, tested in simulation, and ported to the GPU-based real-time system:

1. The preamble detector, which scans the received samples searching for the presence of the preamble. The location of the preamble in the received samples is required to use the received samples to estimate the frequency offset, channel impulse response, and noise variance. The …

Multiscale Modeling, Reformulation, And Efficient Simulation Of Lithium-Ion Batteries, Paul Wesley Clairday Northrop

All Theses and Dissertations (ETDs)

Lithium-ion batteries are ubiquitous in modern society, ranging from relatively low-power applications, such as cell phones, to very high demand applications such as electric vehicles and grid storage. The higher power and energy density of lithium-ion batteries compared to other forms of electrochemical energy storage makes them very popular in such a wide range of applications. In order to engineer improved battery design and develop better control schemes, it is important to understand internal and external battery behavior under a variety of possible operating conditions. This can be achieved using physical experiments, but those can be costly and time consuming, …

Progress Of Mesenchymal Stem Cell Therapy For Neural And Retinal Diseases, Tsz Kin Ng, Veronica R. Fortino, Daniel Pelaez, Herman S. Cheung

Biology Faculty Articles

Complex circuitry and limited regenerative power make central nervous system (CNS) disorders the most challenging and difficult for functional repair. With elusive disease mechanisms, traditional surgical and medical interventions merely slow down the progression of the neurodegenerative diseases. However, the number of neurons still diminishes in many patients. Recently, stem cell therapy has been proposed as a viable option. Mesenchymal stem cells (MSCs), a widely-studied human adult stem cell population, have been discovered for more than 20 years. MSCs have been found all over the body and can be conveniently obtained from different accessible tissues: bone marrow, blood, and adipose …

In Situ Decomposition Of Northern Hardwood Tree Boles: Decay Rates And Nutrient Dynamics In Wood And Bark, Chris E. Johnson, Thomas G. Siccama, Ellen G. Denny, Mary Margaret Koppers, Daniel J. Vogt

Civil and Environmental Engineering - All Scholarship

The decomposition of coarse woody debris contributes to forest nutrient sustainability and carbon balances, yet few field studies have been undertaken to investigate these relationships in northern hardwood forests. We used a paired-sample approach to study the decomposition of sugar maple (Acer saccharum Marsh.), American beech (Fagus grandifolia Erhr.), and yellow birch (Betula alleghaniensis Britt.) boles at the Hubbard Brook Experimental Forest in New Hampshire. Mass loss over 16 yr followed a first-order exponential decay pattern with half-lives ranging from 4.9 to 9.4 yr in bark, and 7.3 to 10.9 yr in wood. Nitrogen and phosphorus concentrations …

Palanquin (Norimono) With Tokugawa And Ichijo Crests, Risd Museum, Melissa Carr

Channel

This elaborate palanquin, or onna norimono (“ride for a woman”), transported a bride of high social standing to the groom’s residence on their wedding day. The exterior is constructed in wood and embellished with black lacquer, gold paint, and metal fittings. Two repeated crests serve as decoration and signify that the groom descended from Tokugawa Ieyasu (1543–1616), the first military ruler, or shogun, of the Edo Period. The compact interior is embellished with an armrest and scenes from The Tale of Genji, an 11th-century masterpiece of Japanese literature, written by a noblewoman about court life. On the back wall is …

Application Of Limited Mixing In The Hele–Shaw Geometry In Fabrication Of Janus Hydrogels, Md Mahmudur Rahman

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

It is widely accepted that cells behave differently responding to the stiffness of their extracellular matrix (ECM). Such observations were made by culturing cells on hydrogel substrates of tunable stiffness. However, it was recently proposed that cells may sense how strongly they are tethered to ECM, not the local stiffness of ECM. To investigate both hypotheses, we developed a method to fabricate Janus polyacrylamide (PAAM) gels. We squeeze two drops of different concentrations in the Hele-Shaw geometry to generate radial Stokes flow. When the drops coalesce, limited mixing occurs at the interface due to the narrow confinement, and diffusion normal …

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• CEIT Golf Tournament a success
• Dr. A. Mitra receives national recognition

Damage Mapping Of Powdery Mildew In Winter Wheat With High-Resolution Satellite Image, Lin Yuan, Jingcheng Zhang, Yeyin Shi, Chenwei Nie, Liguang Wei, Jihua Wang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Powdery mildew, caused by the fungus Blumeria graminis, is a major winter wheat disease in China. Accurate delineation of powdery mildew infestations is necessary for site-specific disease management. In this study, high-resolution multispectral imagery of a 25 km2 typical outbreak site in Shaanxi, China, taken by a newly-launched satellite, SPOT-6, was analyzed for mapping powdery mildew disease. Two regions with high representation were selected for conducting a field survey of powdery mildew. Three supervised classification methods—artificial neural network, mahalanobis distance, and maximum likelihood classifier—were implemented and compared for their performance on disease detection. The accuracy assessment showed that the ANN …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Dr. Mitra of Mechanical Engineering Receives National Recognition

A New Spatio-Temporal Data Mining Method And Its Application To Reservoir System Operation, Abhinaya Mohan

School of Computing: Dissertations, Theses, and Student Research

This thesis develops a spatio-temporal data mining method for uncertain water reservoir data. The goal of the data mining method is to learn from a history human reservoir operations in order to derive an automated controller for a reservoir system. Spatio-temporal data mining is a challenging task due to the reasons: (1) spatio-temporal datasets are usually much larger than spatial data sets, (2) many common spatial techniques are unable to deal with objects that change location, size or shape, and (3) complex and often non-linear spatio-temporal relationships cannot be separated into pure spatial and pure temporal relationships.

Support Vector Machines …

The Santa Clara, 2014-04-24, Santa Clara University

The Santa Clara

No abstract provided.

Identification Of Curriculum Content For A Renewable Energy Graduate Degree Program, John R. Haugherty

Morehead State Theses and Dissertations

A Thesis Presented to the Faculty of the College of Science and Technology Morehead State University in Partial Fulfillment of the Requirements for the Degree Master of Science by John R. Haughery on April 24, 2014.

Power Side-Channel Dac Implementations For Xilinx Fpgas, Daniel Chase Savory

Theses and Dissertations

This thesis presents a novel power side-channel DAC (PS-DAC) which is constructed from user-controllable short circuits in FPGAs and which manipulate overall system power through dynamic power dissipation. Alternately, similar PS-DACs are created using shift-register primitives(SRL16E) which manipulate system power through switching logic, for means of comparison with short-circuit-based PS-DACs. PS-DACs are created of various sizes using both short-circuit-based and shift-register-based methods. These PS-DACs are characterized in terms of output linearity,monotonicity, and frequency distortion. Applications explored in this thesis which use PS-DAC technology include a Simple Power Analysis (SPA) side-channel transmitter, and a frequency watermarking application. These applications serve as …

Characterization Of Extraction Methods To Recover Phenolic-Rich Antioxidants From Blue Green Algae (Spirulina) Using Response Surface Approaches, Ahmad Salamatullah

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Blue green algae (spirulina) is a dietary system that is widely consumed as a whole food or as a supplement in many Asian countries where populations are mostly unaffected by many of the diseases currently afflicting western societies, such as cancer, heart disease and arthiritis. Indeed, spirulina is a rich source of antioxidants with the phenolic compounds playing a significant role. As components of a complex dietary system, phenolic compounds can act alone or through synergistic mechanisms to impart a greater biologic effect than can be elicited by a sum of the individual parts. Therefore, an understanding of the antioxidative …