Engineering Science and Materials Commons^™

Research Progresses In Polymeric Proton Exchange Membranes For Fuel Cells, Xu-Po Liu, Yun-Feng Zhang, Shao-Feng Deng, De-Li Wang, Han-Song Cheng

Journal of Electrochemistry

Proton exchange membrane (PEM) is one of the key components in PEM fuel cells, which possesses the function of separating the cathode and anode, affording proton transport channels and preventing fuel permeability. The property of PEM significantly influences the performance and service life of fuel cells. Nowadays, the commercially used Nafion membranes have the shortcomings of serious fuel permeability, low proton conductivity at elevated temperature and high price, which limits the rapid development of PEM fuel cells. Therefore, it seems to be urgent to develop novel PEMs with low cost and good comprehensive properties. Polymeric proton exchange membrane is an …

Research Progresses In Ni-Co-Mn/Al Ternary Concentration Gradient Cathode Materials For Li-Ion Batteries, Chun-Fang Zhang, Wen-Gao Zhao, Shi-Yao Zheng, Yi-Xiao Li, Zheng-Liang Gong, Zhong-Ru Zhang, Yong Yang

Journal of Electrochemistry

Nickel-rich ternary materials with large reversible capacity as well as high operating voltage are considered as the most promising candidate for next generation lithium-ion batteries (LIBs). However, the inferior cycle stability and thermal stability have limited their widely commercial applications. Concentration gradient design of Ni-Co-Mn/Al ternary concentration gradient materials have been extensively studied in the past decade, which can ensure high cycle capacity while maintaining excellent cycle stability. In this paper, the latest research progresses in Ni-Co-Mn/Al ternary concentration gradient materials for LIBs are reviewed. Firstly, we summarize the different synthesis methods of ternary concentration-gradient materials, especially focusing on the …

Effect Of Nitrogen Content In Catalyst Precursor On Activity Of Fen/C Catalyst For Oxygen Reduction Reaction, Zhi Yang, Ya-Yun Shen, E Zhou, Cheng-Ling Wei, Hao-Li Qin, Juan Tian

Journal of Electrochemistry

Non-noble metal catalysts with high activity and low cost have attracted increasing interest as potential catalysts for oxygen reduction reaction (ORR) to replace Pt-based catalysts. In this paper, the effect of nitrogen content in catalyst precursor on ORR activity of FeN/C catalyst was investigated by X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET) surface area and pore size distribution measurements, transmission electron microscope (TEM), thermogravimetric analysis (TGA), and rotating disk electrode (RDE) techniques. The results show that the most active catalyst was obtained by pyrolysis in argon at 1050 °C with a catalyst precursor containing 20wt% 1,10-phenanthroline, 1wt% Fe and Black Pearl 2000. …

Challenges In The Activity And Stability Of Pt-Based Catalysts Toward Orr, Tuo Zhao, Er-Gui Luo, Xian Wang, Jun-Jie Ge, Chang-Peng Liu, Wei Xing

Journal of Electrochemistry

The development of highly efficient oxygen reduction reaction (ORR) catalysts is the key to the commercialization of fuel cells, where the sluggish ORR reaction rate needs to be overcome by adjusting the intermediates adsorption energies on the catalytic surfaces. To-date, platinum (Pt)-based materials are the-state-of-the-art catalysts in terms of both activity and stability in ORR, making them the preferred choice for commercial applications. However, the high cost of Pt-based catalysts limits their widespread use, leading to massive effects paid in reducing Pt loading, improving catalyst activity and stability. This article illustrates the challenges in the ORR reaction and introduces the …

Preparation And Electrocatalytic Performance Of Nico2O4/Ni Foam For Hydrogen Peroxide Electrooxidation, Wei-Wei Chen, Fei-Fan Zhang, Jia-Liang Du, Yi Wang, Chun-Lin Zhao, Kai Zhu, Dian-Xue Cao, Gui-Ling Wang

Journal of Electrochemistry

The electrodes of Ni foam supported NiCo₂O₄ nanowires were prepared by hydrothermal method, followed by a thermal treatment in air, and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the NiCo₂O₄ nanowires had a diameter of about 50 nm with a length up to 3 ~ 5 μm. The catalytic performances of the Ni foam supported NiCo₂O₄ nanowires for H₂O₂ electrooxidation were studied by cyclic voltammetry and chronoamperometry. The results show that the Ni foam supported NiCo …

Manufacturing And Characterization Of Glass Fiber-Fishnet-Woven Roving And Polyester Composites, S. Sahaya Elsi, F. Michael Raj, Mary S. Prince, A. Amala Mithin Minther Singh, R. S. Jayaram

Journal of Marine Science and Technology–Taiwan

Glass fibers are imparted as reinforcement material in polyester matrix and still it act as a preferred material for the marine industry. However, it is non-biodegradable material and involves high risk during processing. In this study, new monofilament fishnets were substituted as an alternative material for glass fiber in the polyester matrix. Mechanical properties of these composite specimens such as tensile strength, flexural strength and impact resistance in accordance with ASTM, were evaluated. SEM images of various composites revealed the relations between the reinforced fishnet/glass fiber and woven roving with polyester matrix. The dynamic mechanical analysis of storage modulus, loss …

Kinematic Analysis Of Forehand Drop Shot And Long Shot Services In Table Tennis, Ibrahim Norzuria

Student Works (2020-2029)

Table tennis is one of the most widely played sports in the world. A frequent hand movement is compulsory to execute stroke than other limbs, especially the projection of racket and ball speeds,which can help to improve players’ performance. Until now, research on table tennis serving is limited. Service was assumed important in table tennis because the effective serve may allow the serving player to have advantage and control over the game. The 3D dynamic analysis is the appropriate method to analyze a sport activity such as table tennis. Therefore, the aim of research was to determine the kinematic involved …

Electromechanics Modelling Of The Effects Of Myocardial Infarction On Left Ventricular Remodelling, Chin Neng Leong

Student Works (2020-2029)

Myocardial infarction (MI) is one of the diseases with the highest mortality rate. Following MI, myocardium experiences abrupt changes in its loading condition due to the presence of infarct. In response to such changes, myocytes undergo adaptations to maintain homeostasis. However, maladaptation can happen and lead to remodelling, in which the left ventricle (LV) gradually loses its function and eventually turns into heart failure. Nevertheless, the mechanisms underlying LV remodelling are still poorly understood. In this study, a generic LV model was developed, incorporating realistic fibre orientation and excitable contracting myocardium. It was demonstrated that the developed model is capable …

Cycle-To-Cycle Flow Variations In A Square Duct With A Symmetrically Oscillating Constriction, Erica Sherman, Lori M. Lambert, Bethany White, Michael H. Krane, Timothy Wei

Department of Mechanical and Materials Engineering: Faculty Publications

Spatially and temporally resolved Digital Particle Image Velocimetry (DPIV) measurements are presented of flow complexities in a nominally two-dimensional, symmetric, duct with an oscillating constriction. The motivation for this research lies in advancing the state-of-the-art in applying integral control volume analysis to modeling unsteady internal flows. The specific target is acoustic modeling of human phonation. The integral mass and momentum equations are directly coupled to the acoustic equations and provide quantitative insight into acoustic source strengths in addition to the dynamics of the fluid-structure interactions in the glottis. In this study, a square cross-section duct was constructed with symmetric, computer …

Dual-Axis Solar Tracker, Bryan Kennedy

All Undergraduate Projects

Renewable energies, and fuels that are not fossil fuel-based, are one of the prolific topics of debate in modern society. With climate change now becoming a primary focus for scientists and innovators of today, one of the areas for the largest amount of potential and growth is that of the capturing and utilization of Solar Energy. This method involves using a mechanical system to track the progression of the sun as it traverses the sky throughout the day. A dual-axis solar tracker such as the one designed and built for this project, can follow the sun both azimuthally and in …

Analyzing Concrete Beam Design: Verifying Predictions In T&Ee Classrooms, Andrew J. Hughes, Chris Merrill

Educational Leadership & Technology Faculty Publications

Design is often accepted as a fundamental aspect of engineering (Dym, et al., 2005). The design process is frequently portrayed as a set of steps. However, the design process is more complex than just a set of steps in a relatively fixed process. The complex nature of design, design thinking, questioning, and decision-making is exactly what technology and engineering classrooms are well suited to address. When addressing the question—“Why is technology and engineering education (T&EE) so important?”—the authors believe T&EE’s importance relates to our discipline’s ability to solve complex problems by balancing theory and practice in engaging hands-on learning scenarios …

Adjustable Short Throw Shifter (Asts), Joshua Franklin

All Undergraduate Projects

Every manual transmission vehicle has a shift lever for changing gears. The problem is that the shifting linkage is setup up for one kind of driving. Numerous vehicles have multiple settings for the suspension to adapt to varying driving scenarios (i.e. cruising, sport, track). No vehicle currently has an adjustable short throw shifter (ASTS) that can accommodate drag racing, drifting, sports car racing, rallying, off-roading, or casual driving. The design of the ASTS solves this problem by moving the central axis of rotation of the shifter up two inches, permitting the adjustment of the shifting throw between 20 and 40%. …

Inexpensive Fluid Flow Visualization In A Microfluidic Channel Experiment Overview, Maoling Chu

Bridges: A Journal of Student Research

Flow visualization is vital to describe the motion of a fluid in microfluidic channels. This paper summarizes and lists systems based on two common visualization technique categories: particle-based techniques and scalar-based techniques. For this experiment, microfluidic channels were created using PDMS (polydimethylsiloxane). Based on our results and many fabrication trials, it was difficult to say whether this experiment was easy or inexpensive. If the first channel made by the researchers had successfully worked, it would have been clear that utilizing PDMS to fabricate a microfluidic channel for flow visualization was cheap and easy. However, no fully successful microfluidic chips were …

Using Mechanics Of A Double Pendulum To Maximize Sport Performance, Heston Neal

Bridges: A Journal of Student Research

Sports have developed over time into an entire industry from the children who grow up playing sports to the professional players that fans love to watch. Because all sports involve movements of the human body, a bio-mechanical system, these movements may be modeled with mathematics and physics. Specifically, the sports of golf, tennis, and baseball can use the concepts of a double pendulum to maximize sport performance. The double pendulum model is applied to these sports by making the arm one pendulum and the club, racquet, or bat the second pendulum. A good understanding of the mechanics of a double …

The Thermal And Mechanical Characteristics Of Lithiated Peo Lagp Composite Electrolytes, Jacob Michael Denney

Browse all Theses and Dissertations

Lithium-ion batteries are part of a multibillion-dollar industry that strives to meet the demands for an increasingly advanced technological future. Flexible batteries can be easily adapted from emerging novel wearable electronics to electrical vehicles and advanced solar panels. Solid-state batteries can greatly reduce the risk of fire or leaking hazardous materials due to puncture. For the development of solid-state flexible lithium based batteries polymer-ceramic composites are attractive electrolyte candidates because of their combined properties, such as electrical, thermal and mechanical properties, that not only overcome limitations from the base materials but may also render some enhanced performances resulting from the …

Hierarchical Mechanisms Of Lateral Interactions In High- Performance Fibers, Taylor A, Stockdale, Daniel P. Cole, Jeffrey M. Staniszewski, Michael R. Roenbeck, Dimitry Papkov, Steve R. Lustig, Youris A. Dzenis, Kenneth E. Strawhecker

Department of Mechanical and Materials Engineering: Faculty Publications

The processing conditions used in the production of advanced polymer fibers facilitate the formation of an oriented fibrillar network that consists of structures spanning multiple length scales. The irregular nature of fiber tensile fracture surfaces suggests that their structural integrity is defined by the degree of lateral (interfacial) interactions that exist within the fiber microstructure. To date, experimental studies have quantified interfacial adhesion between nanoscale fibrils measuring 10−50 nm in width, and the global fracture energy through applying peel loads to fiber halves. However, a more in-depth evaluation of tensile fracture indicates that fiber failure typically occurs at an intermediate …

Cardiorespiratory Fitness, Balance And Walking Improvements In An Adolescent With Cerebral Palsy (Gmfcs Ii) And Autism After Motor-Assisted Elliptical Training, Guilherme Manna Cesar, Thad W. Buster, Judith M. Burnfield

Department of Mechanical and Materials Engineering: Faculty Publications

Purpose: To quantify the impact of motor-assisted elliptical (ICARE) training on cardiorespiratory fitness, balance and walking function of an adolescent with walking limitations due to cerebral palsy.

Materials and methods: A thirteen-year-old boy with hemiplegic cerebral palsy (Gross Motor Function Classification System II) and autism participated. Peak oxygen consumption (peak VO₂, primary outcome measure), oxygen cost of walking, Pediatric Balance Scale (PBS), modified Timed Up and Go (mTUG), 2-Minute Walk Test (2MWT), and gait characteristics (speed, cadence, step length, single support time) were assessed prior to and after completion of 24 sessions of moderate- to vigorous- intensity ICARE …

Three-Dimensional Characterization Of Peripapillary Retinal Pigment Epithelium-Basement Membrane Layer In Patients Following Lumbar Puncture, Junfei Tong, Pengfei Dong, Sachin Kedar, Deepta Ghate, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Purpose: To develop and test an innovative semi-automatic method for quantifying the three-dimensional morphology of the peripapillary retinal pigment epithelium-basement membrane (ppRPE/BM) layer, with application to lumbar puncture (LP) patients. Methods: Nineteen patients undergoing LP were recruited. The optic nerve head images of both eyes were acquired in 12 radial directions using optical coherence tomography (OCT) before and after LP. For each OCT image, the ppRPE/BM layer was automatically segmented with manual corrections by independent graders when necessary. The linear regression model of the ppRPE/BM layer was fitted using the least squares approach, and the ppRPE/BM layer angle was measured …

Roboticdeviceswithonboard Control And Related Systems And Devices, Shane Michael Farritor, Erik Mumm, Philip Chu, Nishant Kumar, Jason Dumpert, Yutaka Tsutano

Department of Mechanical and Materials Engineering: Faculty Publications

The embodiments disclosed herein relate to various medical device components, including components that can be incorporated into robotic and/or in vivo medical devices. Certain embodiments include various modular medical devices for in vivo medical procedures.

Role Of Interfacial Transition Zones In The Fracture Of Cu/V Nanolamellar Multilayers, Siyuan Wei, Shijian Zheng, Lifeng Zhang, Yue Liu, Jian Wang, Xianping Wang, Jiangwei Wang

Department of Mechanical and Materials Engineering: Faculty Publications

Plastic deformation and fracture behavior of Cu/V nanoscale metallic multilayers (NMMs) were systematically investigated through in situ transmission electron microscopy testing. Two different types of interfaces: sharp interfaces and interfacial transition zones (ITZs), formed in the as-fabricated Cu/V NMMs. Upon deformation, sharp interfaces and ITZs exert distinct influences on the fracture behavior of Cu/V NMMs. Sharp interfaces can impede the crack propagation by deflecting the crack propagation and blunting the crack tip, while the ITZs can induce microcracks and facilitate the fracture process. These findings shed light on the important roles of interface structures in the deformation of a broad …