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Me-Em Enewsbrief, March 2010, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Self-Activating Safety Mechanisms For Li-Ion Batteries, Xin-Ping Ai, Yu-Liang Cao, Han-Xi Yang

Journal of Electrochemistry

The safety concerns of LIBs are considered to be a main obstacle to their high rate or large capacity applications in electric vehicles.This paper describes briefly our research works on the development of self-activating safety mechanisms for LIBs,including redox shuttle,potential-sensitive separator,temperature-sensitive electrode,and fire-retardent electrolyte.The problems and future in this research area are also discussed.

Effects Of Different Carbon Sources On Performance Of Li3V2(Po4)3/C Composite Cathode Materials, Kai-Yuan Liu, Jian-Shu Huang, Li Yang

Journal of Electrochemistry

The monoclinic Li₃V₂(PO₄)₃ cathode materials were prepared by carbothermal reduction method,with methyl cellulose, chitosan(crab shells) or glucose anhydrous as carbon sources, respectively.The crystal structures, morphologies and the electrochemical performances were characterized by XRD, SEM and electrochemical measurement. The XRD patterns show that the samples obtained at 800 ℃ for 6 h have a pure monoclinic structure,which indicates that the carbon exists in amorphous phase. Electrochemical measurements show that the difference of carbon sources has a significant influence on the electrochemical properties of the materials. The Li₃V₂(PO₄)_{3 …}

Performance Of Sulfur-Super Conductive Carbon Black Composite In Electrolyte Mixed With Room Temperature Ionic Liquid, Bo Zhang, Si-Ting Chen, Xue-Ping Gao

Journal of Electrochemistry

The sulfur-super conductive carbon black composite was prepared as cathode material of lithium/sulfur battery.The composite was characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),and electrochemical impedance spectroscopy(EIS).The sulfur composite shows a high discharge capacity and a good cycle performance in electrolyte mixed with 50% of room temperature ionic liquid.In particular,the discharge capacity of the composite was stabilized at 483.6 mAh/g after 50 cycles.

Preparation And Characterizations Of Li3V2(Po4)3 Cathode Material For Lithium Ion Batteries, Hong Chen, Tao Jiang, Chun-Zhong Wang, Gang Chen, Ying-Jin Wei

Journal of Electrochemistry

The carbon-coated Li₃V₂(PO₄)₃ was prepared by carbothermal reduction method.The structural and morphological properties of the material were studied by X-ray diffraction,FTIR and transmission electron microscopy.The synthesized material was a pure phase of Li₃V₂(PO₄)₃,with the particle size of about 100 nm.The values of Li ion diffusion coefficient of the material in the potential window of 3.0 ～ 4.3 V were nearly 3 orders larger than those in 3.0 ～ 4.8 V.In addition,the charge-transfer resistances in 3.0 ～ 4.3 V were much smaller than those in 3.0 …

Investigation Of Ceo2 As Cathode Electrocatalyst For Direct Borohydride Fuel Cell, Xue-Min Ni, Ya-Dong Wang, Mu Pan

Journal of Electrochemistry

The performance of CeO₂ as oxygen reduction electrocatalyst in direct borohydride fuel cell was investigated.The experimental results indicate that CeO₂ shows significant electrocatalytic performance for oxygen reduction and exhibits no observed promotion effect on hydrolysis or electro-oxidation of BH₄^-.The power density of experimental one-compartment fuel cell with CeO₂ as cathode electrocatalyst can reach a 67.8 mW·cm^-2 at room temperature.

Preparation And Electrochemical Behavior Of Li4Ti5O12 Nanosheets As Anode Material For Lithium Ion Battery, Yi-Fei Wang, Yu-Feng Tang, Zheng Qiu, Li Yang

Journal of Electrochemistry

Spinel lithium titanate(Li₄Ti₅O₁₂) nanosheets with a size range of 200 ～400 nm were synthesized by hydrothermal process from the amorphous hydrous titanium oxide precursors.The as-prepared products were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The electrochemical behaviors of Li₄Ti₅O₁₂ electrode in conventional organic electrolyte and ionic liquid electrolyte were investigated by using cyclic voltammetry,galvanostatic charge-discharge and AC impedance techniques.The experimental results indicate that the as-prepared nanostructured Li₄Ti₅O₁₂,evaluated as anode material,exhibited good reversibility and cycle performance.It is expected to be a …

Synthesis Of High-Performance Lini1/3Co1/3Mn1/3O2 Cathode Materials Via Azeotropic Distillation Method, Sheng-An Xia, Li-Xia Yuan, Ze Yang, Zhao-Hui Wang, Yun-Hui Huang, Shuang Li, Wu-Xing Zhang, Ya-Bin Meng, Wei-Gong Zheng

Journal of Electrochemistry

Layered LiNi_1/3Co_1/3Mn_1/3O₂ is one of the most promising alternative materials for LiCoO₂ in lithium ion batteries due to its low cost,large capacity and excellent cyclability.In this paper,LiNi_1/3Co_1/3Mn_1/3O₂ was synthesized via azeotropic distillation method with isobutyl alcohol as an azeotropic agent.The structure and surface morphology were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM),respectively.The as-prepared LiNi_1/3Co_1/3Mn_1/3O₂ shows a layered α-NaFeO₂ structure;the particles are small and uniformly distributed.As compared with the sample prepared by traditional method,the present cathode material …

Electrochemical Behavior Of Co-Ru Composite In Alkaline Solution, Su-Mei Yao, Guo-Chun Li, Xue-Ping Gao

Journal of Electrochemistry

The electrochemical properties of Ru doped cobalt hydroxides synthesized via homogeneous chemical co-precipitation were investigated in 6 mol·L^-1 KOH solution by galvanostatic charge-discharge process and cyclic voltammetry(CV).It is demonstrated that Ru doped cobalt hydroxides exhibited good capacitive characteristic and high specific capacitance.The sample with a Co/Ru molar ratio of 8 /1 shows the optimized electrochemical performance,including capacitive property and discharge capacity.The microstructure and morphology of the obtained Ru doped hydroxides were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM).The amorphous structure of ruthenium dioxide nanoparticles and single-crystal structure of Co(OH)₂ platelets were confirmed.Based on a structure analysis and …

The Electrochemical Characteristics Of Cpo-Pll/Gc Electrode, Wen Zhao, Xia-Qin Wu, Zhong-Qing Lu, Wen-Jing Hou, He-Xing Li

Journal of Electrochemistry

Poly-L-lysine(PLL) was electropolymerized onto the surface of glassy carbon(GC) electrode.1[(3-dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride(EDC) was used as a Cross-linking agent to immobilized Chloroperoxidase(CPO) onto the PLL/GC electrode.A pair of well-defined redox peaks was observed at CPO-PLL/GC electrode,which clearly suggested that PLL can promote the direct electron transfer between the CPO and the GC electrodes.The cyclic voltammetry results also showed that the electron transfer at CPO-PLL/GC is a surface adsorption-controlled quasi-reversible process,which is accompanied with proton transfer.The CPO-PLL/GC electrode exhibited a good electrochemical stability and excellently electrocatalytic activity for electrochemical reduction of O₂.

Electrochemical Corrosion Behavior Of Tio2/Ha Composite Coating On Medical Titanium In Tyrode's Physiological Solution, Li-Li Kong, Long-Xiang Lin, Rong-Gang Hu, Fan Zhang, Chang-Jian Lin

Journal of Electrochemistry

Titanium and its alloys have been widely used as medical implant materials because of their good mechanical properties and biocompatibility.However,the physiological corrosion of metal will release metal ions,resulting in toxic and side effects.In this paper,in order to improve the corrosion resistance of titanium,and to enhance its bioactivity and osseointegration,the surface modification of titamum were performed.Using eletrochemical methods Tafel polarization and electrochemical impedance spectroscopy(EIS) were applied to study the electrochemical corrosion behavior of TiO₂ /HA composite coating.It is indicated that the corrosion resistance of the prepared TiO₂ /Ti material in Tyrode's physiological solution is improved because of the enhanced …

Electrocatalytic Reduction Of L-Cystine At Pb/Nanotio2 Film Electrode, Dao-Bao Chu, Feng Wang, Ying Xiao, Xue-Jiao Zhang

Journal of Electrochemistry

The nanoporous Ti-based TiO₂ films electrodes modified with Pb particles(Pb/nanoTiO₂) were prepared by using anodization and potentiostatic electro-deposition.The optimum deposition conditions were determined by comparing with various deposition potentials and time.The SEM analyses indicated that the TiO₂ films were homogeneous nanoporous structure,and the Pb particles well dispersed on the TiO₂ films.The L-cystine electrocatalytic activity reduction on the Pb/nanoTiO₂ film electrodes was investigated by cyclic voltammetry and Chronoamperometric curves.The results showed that this type of the electrode posseses high acticity and stability.

Study Of Electrodes Modified With Hybrid Copper Cobalt Hexacyanoferrate-Mwcnts Composites, Shan Jiang, Yun Zhang, Xiao-Yan Wang, Xiao-Fei Yao

Journal of Electrochemistry

The hybrid modified electrodes were obtained by electrochemical deposition of copper-cobalt hexacyanoferrate(CuCoHCF) /multi-walled carbon nanotubes(MWCNTs) on the surface of glassy carbon electrode.The effects of the amount of MWCNTs and composition of electrolyte on the properties of modified electrode had been researched.The copper cobalt hexacyanoferrate-MWCNTs modified electrodes show excellent electrochemical properties compared with that modified only copper-cobalt hexacyanoferrate.The CuCoHCF-MWCNTs/GCE exhibits obvious electrocatalytic activity towards oxidation of hydrogen peroxide.The oxidation peak current increased linearly with the concentration of hydrogen peroxide in the range of 3.16 × 10^-5 ～ 2.92 × 10^-3 mol· L^-1.The linear equation is given up …

Preparation And Characterization Of Sulfur/Mesoprous Carbon Composite Cathodes, Wen-Hua Zhang, Yao Chen, Xin-Ping Ai, Yu-Liang Cao

Journal of Electrochemistry

A sulfur/mesoporous carbon composite was prepared by thermally treating a mixture of sublimed sulfur and mesoporous carbon. The microstructure of the mesoporous carbon was characterized by BET analysis and X-ray diffraction(XRD). The electrochemical performance of the S/C composite as cathode materials was evaluated by the galvanostatic method. The results confirmed that the mesoporous carbon could not only greatly enhance the electrochemical activity of sulfur electrode, but also effectively confine the diffusion of dissolved polysulfides in organic electrolyte. As a result,the S/C composites showed high capacity, good cycle performance and excellent rate capability. The specific capacity of the S/C composite was …

The Synthesise Of Electron-Conducting Redox Hydrogel And Its Application In Microbial Fuel Cell, Kai-Peng Wang, Sheng-Li Chen

Journal of Electrochemistry

Efficient electron transfer between the microbe and the anode is key for the electricity generation in Microbial fuel cell(MFC).Through the modification of anode,the rate of electron transfer can be accelerated,therefore the performance of MFC can be enhanced.In this paper,we report the synthesis of a type of electronconducting and bio-compatible redox hydrogel and its application.The hydrogel consists of poly(4-vinylpyridine) as backbone and neutral red as the redox center.By immobiliazing neutral red on the backbone through covalent bond,the secondary contamination due to the soluble redox mediator to external environment can be prevented.MFCs using the hydrogel-modified carbon anode significantly exhibit shorter acclimation period,and …

Electrochemical Properties Of Ni(Oh)2 Doped By Nio, Fei-Biao Chen, Bo-Rong Wu, Wei-Feng An, Zhao-Jun Yang, Feng Wu, Shi Chen

Journal of Electrochemistry

The Ni(OH)₂ cathode material of MH/Ni was doped by NiO,which behaves as a capacitor and can improve the charge-discharge rate capacity of Ni(OH)₂.The electrochemical properties of Ni(OH)₂ was characterized by charge-discharge curves and cyclic voltammetry.The results showed that the material had the best discharge property when doped by 5% NiO,and the discharge specific capacity could reach 310.1 mAh/g at 0.2 C rate and remianed 79.5% at 3 C rate.The difference oxidation and reduction potentials between the of the battery was 164 mV when the Ni(OH)₂ was doped by 5% NiO,which showed a good cyclic property.

Studied Corrosion Behaviors Of Reinforcing Steel In Concrete By A Single-Dimensional Array Electrode, Lan-Qiang Li, Shi-Gang Dong, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

A single-dimensional array electrode was developed as a new electrochemical technique to image corrosion potential,galvanic current and polarization curves of reinforcing steel in concrete during corrosion process.Combining with the polarization behavior for each micro-electrode,the interactions between corrosion macrocell and corrosion microcell of the steel in concrete were evaluated.It was noticed that the corrosion macrocell and microcell occurred independently in difference regions at the initial stage of corrosion.The corrosion macrocell current can be in situ followed by corrosion potential imaging.The corrosion propagation of steel in concrete is closely related to the interactions between corrosion macrocell and corrosion microcell.

Electrosynthesis Of P-Aminobenzenearsenic Acid, Chun-An Ma, Qin-An Zheng, Qiang Zhou, Ying-Hua Xu

Journal of Electrochemistry

The electrochemical reduction of p-nitrophenyl arsonit acid to p-aminobenzenearsenic acid was studied using controlled-current electrolysis.The results showed that the yield of p-aminobenzenearsenic acid was determinated by the following factors:the concentrations of sulphuric acid,the amount of additive,temperature and the concentrations of p-nitrophenyl arsenic acid.The optimum electrolytic conditions were obtained to be is 10% H₂SO₄,1% NaCl,80 ℃,25 g/350 mL p-nitrophenyl arsenic acid and 10 A·dm^-2.The yield of arsanilic acid could be reached 64.7% under the optimum electrolytic conditions.

Cobalt-Doped Todorokite Prepared By Refluxing At Atmospheric Pressure As Lithium-Ion Battery Cathode, Rui-Qi Li, Chun-Hua Song, Chao Xu, Li-Xing Tu, Guo-Hong Qiu, Fan Liu

Journal of Electrochemistry

Cobalt-doped todorokites were prepared by refluxing at atmospheric pressure,and then charactered by X-ray diffraction(XRD),thermogravimetry(TG) and the analysis of chemical compositions.These measurements showed that all of the refluxing products were single phase of todorokites and the structure formulas were Mg_xCo_yMnO_z·nH₂O,where 0.18 ≤ x ≤ 0.22,0 ≤ y ≤ 0.24,2.10 ≤ z ≤ 2.53,and 0.35 ≤ n ≤0.73.The electrochemical characteristics of cobalt-doped todorokites were examined as lithium insertion hosts for cathodes in rechargeable lithium batteries.The first discharge capacity of undoped todorokite electrode was 211 mAh/g and the discharge capacity became 37 mAh/g after 30 …

Fabrication And Characterization Of The Ni-Scsz Composite Anodes With A Lscm-Ceo2 Catalyst Layer In Thin Film Sofc, Yun-Yun Wang, Bo Huang, Xin-Jian Zhu, Wan-Qi Hu, Qing-Chun Yu

Journal of Electrochemistry

Solid oxide full cell(SOFC) running directly on hydrocarbon fuels has attracted much attention in recent years. In this paper, a dual-layer structure anode was fabricated by tape casting and screen printing method. The addition of a LSCM-CeO₂ catalyst layer to the supported anode surface yielded better performance in ethanol fuel. The maximum power density reached 710 and 669 mW/cm² at 850 ℃ running on hydrogen gas steam and ethanol steam,respectively. No significant degradation in performance has been observed after 216 h of cell testing when the Ni-ScSZ13 anode was exposed to the ethanol steam at 700 ℃. Very …

Multiscale Transformation Field Analysis Of Progressive Damage In Fibrous Laminates, Yehia Bahei-El-Din, Ritesh Khire, Prabhat Hajela

Centre for Advanced Materials

As part of an ongoing effort to model uncertainty propagation across multiple scales in fibrous laminates, this paper presents a deterministic transformation field analysis for modeling damage progression under membrane forces and bending moments. In this approach, equivalent eigenstresses are computed in the phases and/or plies such that their respective stress components that satisfy the underlying failure criteria are reduced to zero. Superposition of the solutions found for the undamaged laminate under applied loads and under the eigenstress field provide the entire response. Failure criteria are based on stress averages in the fiber and matrix. Damage mechanisms considered are frictional …

Modified Sandwich Structures For Improved Impact Resistance Of Wind Turbine Blades, Yehia Bahei-El-Din, Mostafa Shazly, I. El-Habbal, Y. Elbahy

Centre for Advanced Materials

Wind turbine blades are susceptible to damage due to fatigue as well as impact by flying objects and parts broken off failed blades of nearby wind towers. Localized, permanent compression of the foam core and delamination of the fibrous composite face sheets are typical damage modes and can lead to progressive structural failure. Sandwich structures modified by inclusion of flexible polyurethane (PU) layers within the cross section are examined under both impact and dynamic loads. Finite element models of sandwich structures with conventional and modified designs show that sandwich designs modified with PU interlayes exhibit reduced foam core crushing and …

Me-Em 2010 Annual Report, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering Annual Reports

Table of Contents

• First Year to First Career
• Faculty & Staff
• Alumni
• Resources
• Graduates
• Publications

Luminescence Enhancement Of Cdte Nanostructures In Laf3:Ce/Cdte Nanocomposites, Mingzhen Yao, Xing Zhang, Lun Ma, Wei Chen, Alan G. Joly, Jinsong Huang, Qingwu Wang

Department of Mechanical and Materials Engineering: Faculty Publications

Radiation detection demands new scintillators with high quantum efficiency, high energy resolution, and short luminescence lifetimes. Nanocomposites consisting of quantum dots and Ce³⁺ doped nanophosphors may be able to meet these requirements. Here, we report the luminescence enhancement of LaF₃:Ce/CdTe nanocomposites which were synthesized by a wet chemistry method. CdTe quantum dots in LaF₃:Ce/CdTe nanocomposites are converted into nanowires, while in LaF₃ /CdTe nanocomposites no such conversion is observed. As a result, the CdTe luminescence in LaF₃:Ce/CdTe nanocomposites is enhanced about five times, while in LaF₃ /CdTe nanocomposites no enhancement was …

The Characterization Of Leadership Within Undergraduate Engineering Design Teams Through Case Study Analysis, Gary Palmer Ii

All Theses

The purpose of this research is to clearly define leadership that exists within engineering project teams. Leadership can be applicable to any field of study and is heavily researched in business management. Sources which review leadership classify this topic in reference to managerial styles, leadership types and styles, emotional intelligence, and work climate. However, there are few sources which define leadership specifically within engineering environments. The motivation of this research is driven by the absence of defining and observing consistency in engineering leadership through the research‟s experience in engineering teams. Existing leadership is defined in this research through conducting two …

Experimental And Numerical Analysis Of Fuel Cells, Abul Bashar Mahmud Hasan

LSU Doctoral Dissertations

Fuel Cells are attractive power source for use in electronic applications. Physical phenomena (water generation, saturation effect in fuel cell, poisoning, and thermal stress) are studied that governs the operation of a Proton Exchange Membrane Fuel Cell (PEMFC) and Solid Oxide Fuel cell (SOFC). Additionally, experimental studies and numerical simulations on PEMFC gas flow channel, the determination of the impact of the single channel fuel cell are presented. Furthermore, preliminary study is done for the application of APS (Air Plasma Spray) to SOFC and adhesion of anode and cathode with electrolytes for the determination of parameters involved in manufacturing the …

Antioxidant Nanoparticles As Delivery Systems, Carlos Ernesto Astete R.

LSU Doctoral Dissertations

The goal of the study was to develop antioxidant polymeric nanoparticles as a new delivery system for food and pharmaceutical applications. Natural antioxidants like alpha-tocopherol, vitamin C, and carnosine, are responsible to protect biological systems against free radicals attack. The conjugation of vitamin C-vitamin E (EC) and alpha-tocopherol-carnosine (VECAR) were performed to obtain antioxidant surfactants which were used for polymeric nanoparticle synthesis. The surfactant made of á-tocopherol (vitamin E) and ascorbic acid (vitamin C) of antioxidant properties dubbed as EC was used to make poly(lactic-co-glycolic) acid (PLGA) nanoparticles. Self-assembled EC nanostructures and PLGA-EC nanoparticles were made by nanoprecipitation, and the …

Dynamic Model Of Ecological Factors Impacting The Gulf Of Mexico Dead Zone, Jimmie Arnold Brumfield Ii

LSU Doctoral Dissertations

The industrial agriculture complex of the Mississippi River Drainage Basin has the positive effect of feeding more individuals with less land via the use of chemical nutrients, pesticides and drainage. The negative effects of the agricultural nutrient load are carried by the Mississippi River to the Gulf of Mexico. After the flood of 1927 the Flood Control Act of 1928 began changing the Mississippi River into a navigation and flood control project. While successful, the river was turned into a channel where nutrient input was discharged into the Gulf of Mexico. Nitrogen compounds discharged from the Mississippi are claimed to …

Effects Of Bondline Thickness On Nonlinear Interfacial Fracture Of Bonded Adhesive Joint, Gefu Ji

LSU Doctoral Dissertations

A number of existing and emerging industrial applications are dependent on layered substrates through adhesive bonding. The interfacial fracture of adhesively bonded structures is a critical issue for its extensive applications to a variety of modern industries. In the recent two decades, cohesive zone models (CZMs) have been receiving intensive attentions for fracture problems of adhesively bonded joints due to its fairly simple and accurate predictive ability. In CZMs the nonlinear interfacial fracture behaviors are described by the traction-separation laws (also referred to as cohesive laws). The cohesive laws represent the local constitutive behavior, instead of the global parameter, such …

Phase Change Materials For Thermal Regulation Of Building Integrated Photovoltaics, Ahmad Hassan

Doctoral

In outdoor deployed photovoltaics (PV), standard test conditions (STC) of 25 °C PV temperature, 1000 Wm-2 solar radiation intensity and 1.5 air-mass rarely prevail. PV temperature can rise 40-100 °C above STC inducing a power drop in crystalline silicon PV with a coefficient of -0.4 to -0.65 %/K above STC. Increased operating temperature also results in accelerated PV degradation due to cell delamination allowing moisture ingress. vConventional building integrated photovoltaics (BIPV) cooling techniques using passive
or active heat removal by air or water flow are limited by (i) very low heat transfer or (ii) large capital as well as maintenance …