Engineering Science and Materials Commons^™

Electrochemical Performance Of Screen-Printed Composite Coatings Of Conducting Polymers And Carbon Nanotubes On Titanium Bipolar Plates In Aqueous Asymmetrical Supercapacitors, Xiaohang Zhou, George Z. Chen

Journal of Electrochemistry

Composites of conducting polymers (polypyrrole and polyaniline) with acid treated multi-walled carbon nanotubes were formulated into printable aqueous inks, with the aid of functional additives (benzethonium chloride as a surfactant with or without polyvinyl alcohol as a binder). The inks were screen-printed as fairly uniform coatings of various mass loading densities and areas (up to 75 mg cm^-2 and 100 cm²) on thin titanium plates (0.1 mm in thickness). These screen-printed plates were used to fabricate both unit cell and multi-cell stack of asymmetrical supercapacitors with screen-printed negative electrodes of activated carbon (pigment black) in aqueous electrolytes …

Adsorption And Electrooxidation Of Carbon Monoxide On Platinum Surfaces Modified With Sulfur, A. Mattox Mathew, W. Henney Matthew, Johnson Adam, Zou Shouzhong

Journal of Electrochemistry

Adsorbed sulfur is commonly considered as a reaction poison. However, small amounts of sulfur on platinum significantly increase the surface reactivity toward carbon monoxide (CO) electrooxidation. For the solution CO oxidation, the onset potential was shifted up to over 300 mV negative to that on S-free surface, and the extent of the negative potential shift increases with the sulfur coverage (X_s) up to about 0.6. The enhanced CO oxidation also depends on the solution pH. For the adsorbed CO, at low sulfur coverages (X_s < 0.3), the oxidation peak potential is about 40 mV negative to that of the corresponding clean Pt. However, at higher coverages, the peak potential is about 30 mV more positive. Surface-enhanced Raman spectra show that the adsorption of sulfur significantly redshifts the Pt-CO stretching frequency. These observations are explained by the weakening of the Pt-CO bond and the hindrance of CO diffusion by Sads.

Advances And Challenges Of Intermediate Temperature Solid Oxide Fuel Cells: A Concise Review, Sanping Jiang

Journal of Electrochemistry

Fuel cell is an electrochemical energy conversion device to directly convert the chemical energy of fuels to electricity. Among all types of fuel cells, solid oxide fuel cells (SOFCs) operating at intermediate temperatures of 600~800 ^oC offer an attractive option that is much more fuel flexible than low temperature fuel cells such as proton exchange membrane fuel cells, and is suitable for a wide range of applications. However, two main challenges remain towards the commercial viability and acceptance of the SOFC technologies: the cost and durability. Both are critically dependent on the process, fabrication, performance, chemical and microstructural stability …

Electrocatalytic Activity Of Palladium Nanocatalysts Supported On Carbon Nanoparticles In Formic Acid Oxidation, Jie Huang, Zhiyou Zhou, Yang Song, Xiongwu Kang, Ke Liu, Wancheng Zhou, Shaowei Chen

Journal of Electrochemistry

Palladium nanostructures were deposited onto carbon nanoparticle surface by a chemical reduction method. Transmission electron microscopic studies showed that whereas the resulting metal-carbon (Pd-CNP) nanocomposites exhibited a diameter of 20 to 30 nm, the metal components actually showed a cauliflower-like surface morphology that consisted of numerous smaller Pd nanoparticles (3 to 8 nm). Electrochemical studies showed that the effective surface area of the Pd-CNP nanoparticles was about 40% less than that of Pd black, possibly because the Pd nanoparticles were coated with a layer of carbon nanoparticles; yet, the Pd-CNP nanocomposites exhibited marked enhancement of the electrocatalytic activity in formic …

Electrocatalytic Oxidation Of Formic Acid On Pd/Ni Heterostructured Catalyst, Mingjun Ren, Liangliang Zou, Ju Chen, Ting Yuan, Qinghong Huang, Haifeng Zhang, Hui Yang, Songlin Feng

Journal of Electrochemistry

A Pd/Ni bimetallic nanostructured electrocatalyst was fabricated via a two-step reduction route. Owing to an epitaxial growth of Pd atoms on the surface of Ni nanoparticles, heterostructured Pd/Ni nanocomposites were formed and verified by high resolution transmission electron microscopy combined with energy-dispersion X-ray spectroscopy. X-ray diffraction confirmed that the as-prepared Pd/Ni nanocomposites possessed a single face-centered-cubic (fcc) Pd structure, probably due to a weaker diffraction intensity of metallic Ni and/or overlapping by that of Pd. The intrinsic catalytic activity on the Pd/Ni is higher than that on the Pd. Moreover, the durability of formic acid oxidation on the Pd/Ni was …

Kinetic Study Of Photoelectrochemical Oxidation Of Lignin Model Compounds On Tio2 Nanotubes, Min Tian, Daniel Liba, Aicheng Chen

Journal of Electrochemistry

In this study, TiO₂ nanotubes were prepared via the electrochemical oxidation of titanium substrates in a non-aqueous electrolyte and their morphology and microstructures were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The photoelectrochemical oxidation of two lignin model compounds, 1-(3,4-dimethoxyphenoxy)-2-(2-methoxyphenoxy)-1,3-propanediol (DMP) and 3-hydroxy-1-(3,4-dimethoxyphenoxy)-2-(2-methoxyphenoxy)-1,3-propanone (HDM), was investigated. A new band appeared at ~304 nm during the photoelectrochemical oxidation of DMP. The rate of DMP intermediate formation was amplified with the increase of initial concentrations, while it was diminished with increased temperature. Despite the similarity in structure between HDM and DMP, there are only small increases in absorbance …

Ternary Alloy Electrocatalysts For Oxygen Reduction Reaction, Jin Luo, Lefu Yang, Binghui Chen, Chuanjian Zhong

Journal of Electrochemistry

Proton exchange membrane fuel cell represents an important electrochemical energy conversion device with many attractive features in terms of efficiency of energy conversion and minimization of environmental pollution. However, the large overpotential for oxygen reduction reaction at the cathode and the low activity, poor durability and high cost of platinum-based catalysts in the fuel cells constitute a focal point of major barriers to the commercialization of fuel cells. The development of nanostructured catalysts shows promises to addresses some of the challenging problems. The ability to engineer the composition and nanostructure of nanoalloy catalysts is important for developing active, robust and …

Quantum Dot Deposition Into Pdms And Application Onto A Solar Cell, Christopher Marcus Botros, Richard N. Savage

Master's Theses

Research to increase the efficiency of conventional solar cells is constantly underway. The goal of this work is to increase the efficiency of conventional solar cells by incorporating quantum dot (QD) nanoparticles in the absorption mechanism. The strategy is to have the QDs absorb UV and fluoresce photons in the visible region that are more readily absorbed by the cells. The outcome is that the cells have more visible photons to absorb and have increased power output. The QDs, having a CdSe core and a ZnS shell, were applied to the solar cells as follows. First, the QDs were synthesized …

An Experimental Investigation On The Trailing Edge Cooling Of Turbine Blades, Zifeng Yang, Hui Hu

Mechanical and Materials Engineering Faculty Publications

An experimental study was conducted to quantify the flow characteristics of the wall jets pertinent to trailing edge cooling of turbine blades. A high-resolution stereoscopic particle image velocimetry (PIV) system was used to conduct detailed flow field measurements to quantitatively visualize the evolution of the unsteady vortices and turbulent flow structures in the cooling wall jet streams and to quantify the dynamic mixing process between the cooling jet stream and the mainstream flows. The detailed flow field measurements were correlated with the adiabatic cooling effectiveness maps measured by using pressure sensitive paint (PSP) technique to elucidate underlying physics in order …

Energy Trapping Of Thickness-Shear And Thickness-Twist Modes In A Partially Electroded At-Cut Quartz Resonator, Huijing He, Guoquan Nie, Jinxi Liu, Jiashi Yang

Department of Mechanical and Materials Engineering: Faculty Publications

The thickness-shear and thickness-twist vibrations of a finite and partially electroded AT-cut quartz resonator are investigated. The equations of anisotropic elasticity are used with the omission of the small elastic constant c56 . An analytical solution is obtained using Fourier series from which the free vibration resonant frequencies, mode shapes, and energy trapping are calculated and examined.

Implementation Of Magnetic Resonance Elastography For The Investigation Of Traumatic Brain Injuries, Thomas Boulet

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Magnetic resonance elastography (MRE) is a potentially transformative imaging modality allowing local and non-invasive measurement of biological tissue mechanical properties. It uses a specific phase contrast MR pulse sequence to measure induced vibratory motion in soft material, from which material properties can be estimated. Compared to other imaging techniques, MRE is able to detect tissue pathology at early stages by quantifying the changes in tissue stiffness associated with diseases. In an effort to develop the technique and improve its capabilities, two inversion algorithms were written to evaluate viscoelastic properties from the measured displacements fields. The first one was based on …

Me-Em Enewsbrief, December 2012, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Product Display Versus Graphical Representation On Packaging, Joshua Galvarino

All Theses

ABSTRACT
Previous research conducted (Hurley, et al., 2012) concerning physical and graphical product visibility from the primary display panel (PDP) is limited to one product category. This research expands previous peer-reviewed research, which indicates that there is a significant difference between consumer preferences of graphical display vs. physical product display on packaging.
The shelf presence of packages showing actual product visibility versus packages showing only a graphical representation of the product was evaluated. Both shopping results and quantitative data using eye-tracking technology were collected and cross-referenced with a qualitative, post-experiment survey.
Specifically, variables of packaging within pasta, snacks, prepared frozen …

Empirically Bounding Of Space Booms With Tape Spring Hinges, Alan L. Jennings, Jonathan T. Black, Chris Allen

Faculty Publications

Self-deploying structures seek to provide a compact launch package for large, lightweight satellite booms. One self-deploying method is a foldable tape spring. This paper examines the large scale behavior of a boom attached by a tape spring hinge during mock deployments. A boom attached by tape spring to a rigid stand was released and the boom bounced up to 60° before coming to rest (as opposed to snap-through behavior). These large amplitude bounces can cause the boom to collide with sensors, other booms or arrays causing damage or preventing full deployment. Results show the first bounce of deployment is nearly …

Vibrations Of Crystal Plates With Surface Structures For Resonator And Sensor Applications, Nan Liu

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

This dissertation is mainly on the theoretical analysis of vibrating crystal plates for acoustic wave resonator and sensor applications. The frequency and mode effects of different surface structures on either or both sides of the crystal plates are the main concerns in this dissertation. These effects are fundamental to the improvement of existing acoustic wave devices, or to the design of new acoustic wave devices, especially new sensors based on these effects.

At first, two-dimensional equations of motion for an anisotropic crystal plate with two thin films on its surfaces are derived by reduction from the three-dimensional equations of anisotropic …

The Oxidation Of Hydrogen Peroxide On Nanostructured Rhodium Microelectrodes, N. Bartlett Philip, F. Esterle Thomas

Journal of Electrochemistry

Mesoporous Rh films were deposited onto platinum microelectrodes from the H₁ lyotropic liquid crystalline phase of C₁₂EO₈ (octaethyleneglycol monododecyl ether). The electrodes show well defined voltammetry for the oxidation and the reduction of hydrogen peroxide at low concentrations (<10 mmol•L-1) with excellent stability for operation at neutral pH. Based on the hysteresis in the current and the potential dependence the oxidation of hydrogen peroxide occurs through a CEE mechanism involving Rh(OH)₃ on the mesoporous Rh electrode surface. At higher hydrogen peroxide concentrations the current reaches a plateau that is due to either saturation of the binding sites for hydrogen peroxide or limitation of the reaction due to acidification of the solution within the pores. For the thin films (below 200 nm) the hydrogen peroxide calibration curves we …

Electrochemical Synthesis Of Silver-Tetracyanoquinodimethane Nanorods At Agar Supported Water/1,2-Dichloroethane Interface, Li Huang, Yixian Wang, Michael V. Mirkin, Bin Ren, Dongping Zhan

Journal of Electrochemistry

Silver-tetracyanoquinodimethane (AgTCNQ) is an important charge transfer salt due to its high conductivity and other electronic properties. In this communication, we report the synthesis of AgTCNQ at the liquid/liquid interface. Agar was used as a gelling agent to support water/1,2-dichloroethane (DCE) interface. Silver ions were transferred from the hydrogel into DCE phase, where they combined with TCNQ^- to form AgTCNQ nanorods. The developed method can provide a new route for synthesis of functional materials based on the electrochemistry at the liquid/liquid interface.

In Situ Pm-Irras Studies Of A Floating Bilayer Lipid Membrane At Au(111) Electrode Surface, Su Zhangfei, Kycia Annia, Jay Leitch J., Lipkowski Jacek

Journal of Electrochemistry

In situ Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was used to study the structure of a DMPC + cholesterol + GM1 floating bilayer lipid membrane (fBLM) at a Au(111) surface. 1-thio-beta-D-glucose (beta-Tg) was self-assembled onto the Au electrode to increase the overall hydrophilicity of the surface. The fBLM was deposited on the beta-Tg self-assembled monolayer (SAM) using a combination of Langmuir-Blodgett/Langmuir-Schaefer (LB/LS) techniques. The carbohydrate headgroups of the GM1 molecules were physically adsorbed to the beta-Tg SAM forming a water rich cushion between the fBLM and the modified gold substrate. The PM-IRRAS spectra indicate that the DMPC molecules within …

Biaxial Bending And Lateral-Torsional Instability Of Imperfect Frp I-Beams Including Effects Of Retrofitting, Jodi Marie Knorowski

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the outcome of a theoretical and experimental study of the behavior of Fiber Reinforced Polymer (FRP) I-beams susceptible to lateral-torsional instability or when subjected to biaxial bending. Laboratory experiments involved application of vertical and horizontal static loads to a 4 x 4 x ¼ in. I-beam with various lengths, and the resulting displacement, twist, and strain were recorded. In the vertical direction, the beam was loaded from different reference load heights with respect to the shear center of the beam. The governing biaxial flexure and torsion differential equations were modified to account for the presence of initial …

Steering Adaptation In A Driving Simulator, Brian P. Moran

Undergraduate Research Posters 2012

Steering adaptation in a driving simulator occurs when participants, who possess the skills necessary to control a vehicle, modify their use of the steering controls to successfully interact with a driving simulator. This approach is sensitive to individual driving styles, as it is free of any threshold, criterion, or benchmark value and can be applied to any steering task at any driving speed.