Engineering Commons^™

Electrochemical Oxidization Of Herring Sperm Dna And Its Interaction With Histone, Juan Xu, Gui-Ping Huang, Hong Li, Wei Zhu

Journal of Electrochemistry

The voltammetric behavior of herring sperm DNA at glassy carbon electrode and its interaction with histone have been investigated by using cyclic voltammetry,differential pulse voltammetry,and fluorescence measurement.In the potential range of 0.20 V to 1.25 V,it is found that an irreversible oxidative peak is exhibited in acid solution,but in the neutral or alkaline solution two oxidative peaks are observed.Oxidative peak potential values show a negative shift with increasing pH via a slope of-57 mV·pH-1 and a linear relation with DNA concentration in the range of 0.45 to 8.20 mmol·L^-1.In the presence of histone,the oxidative peak current of DNA …

Eiectro-Oxidation Of Methanol On Pdnio/C Catalyst In Alkaline Medium, Mei-Li Wang, Lin Sang, Cheng-De Huang

Journal of Electrochemistry

The electro-oxidation of methanol in alkaline electrolyte at in-house synthesized PdNiO/C and Pd/C catalysts and the effect of heat treatment on the structure and performance of catalysts were studied by cyclic voltammetry,chronoamperometry,chronopotentiometry and X-ray diffraction methods.It is shown that when the reduction temperature is 70℃ and the ratio between Pd and Ni is 8∶2,The PdNiO/C catalyst presents a highest activity for methanol electrooxidation.Calcining can increase the particle size and crystallinity of catalysts,but decrease the dispersion and activity of catalysts, too.Besides,the NiO is disengaged from Pd lattice by heat-treatment.The optimal PdNiO/C catalyst shows higher catalytic activity and much better poisoning resistance …

Preparation And Properties Of High Capacity Lifepo4, Jun Li, Gui-Tang Lai, Hui-Min Huang, Da-Guang Li, Xin-De Xia

Journal of Electrochemistry

Carbon-doped LiFePO₄/C and pure phase LiFePO₄ cathode materials were prepared by liquid-state precipitation reaction. The results of XRD, SEM, elemental analysis,FTIR and A.C.impedance tests show that the samples have had olivine structure and a 3.4V discharge platform.The tapped density of LiFePO₄/C sample could reach 1.46g/cm³, the initiate discharge capacity is 144.6mAh/g at 0.1C,which remained capacity is 93.2% after 20 cycles. The first discharge capacity is 133.5mAh/g at 1C and the capacity decreased 8.76% after 20 cycles.

Electrochemical Behavor Of Zinc-Indium Alloy Electrodes In Concentrated Alkaline Solution, Zhi-Lin Wang, Xiao-Ge Zhang, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

The electrochemical behavior of zinc-indium alloy electrodes in 35%KOH solutions has been investigated by electrochemical methods including the potentiodynamic polarization and discharge measurements under constant current density.The results indicate that the anodic current density and passive current density increase after the indium addition.The discharge measurement shows that the addition of indium shortens the time to passive state for the Zn alloy compared to pure zinc at a large discharge conditions,that is the addition of indium may enhance the electrochemical activity of Zn alloy electrodes.It is found that the anodic dissolution of zinc-indium alloy electrodes in the concentrated KOH solution occurs …

Study On The Corrosion Of Chlorine Condenser By Electrochemical Method, Bin Xiang, Wen Chen, Wen-Zhang Huang, Shao-Hua Xing, Sheng-Tao Zhang

Journal of Electrochemistry

Corrosion of condenser is very seriously in chlorine-alkali industry,which could lead to fatal disaster.The most commonly used material in low pressure condenser includes steel of 16MnR,10#,and welding rod of J507.Electrochemical analysis of the three materials in 29.9%(by mass) calcium chloride(CaCl₂) solution was carried out.The corrosion current density icorr and impedance parameters of the three materials in 29.9% CaCl₂ solution were estimated separately.The result showed that in the tripartite phase regions where the 10# seamless tube and 16MnR armor plate were jointed by welding,the weld was firstly eroded and suggested that the chlorine condenser should be examined and …

Determination Of Malathion Based On Carbon Nanotubes Modified Electrode Incorporating Acetylcholinesterase, Lu Zhang, Yao-Dong Zhang, Hong-Lan Qi

Journal of Electrochemistry

A biosensor for determination of organophosphorus pesticide based on the acetylcholinesterase and multi-wall carbon nanotubes modified electrode is fabricated.Under the optimal conditions,the chronoamperometric current at +0.70V(vs.SCE) increased linearly with the concentration of malathion in the range from 6.0×10^-10 to 6.0×10^-9 mol·L^-1 with a detection limit of 1.0×10^-10 mol·L^-1.The recoveries of malathion in lake water is 97% to 105% determinated by this method.

Ion-Implanting Modification Of Layered Manganese Dioxide And Its Electrochemical Performance, He-Ning Huang, Dong-Ping Lv, Xing-Kang Huang, Qi-Wei Zhang, Yong Yang

Journal of Electrochemistry

Layered MnO₂(δ-MnO₂) was prepared by thermal decomposition of potassium permanganate.Ti was ion-implanted into such δ-MnO₂ by physical techniques,forming a composite(δ-MnO₂-Ti).These materials were characterized by XRD,SEM,XPS techniques and their electrochemical proprieties were investigated.The results showed that the layered structure of δ-MnO₂ did not been destroyed after Ti ion implantation,and the implanted Ti element was mainly Ti⁴⁺ as indicated by XPS.Both of the first and the highest discharge specific capacities of the ion-implanted layered MnO₂(δ-MnO₂-Ti),compared to those of δ-MnO₂,were improved significantly.

Electrochemical Behavior And Determination Of Luteolin At A Glassy Carbon Electrode, Ai-Lin Liu, Shao-Bo Zhang, Xiao-Sha Wu, Li-Ping Li, Yang-Yuan Cao, Li-Ying Huang, Xin-Hua Lin

Journal of Electrochemistry

The electrochemical behavior of luteolin was studied by voltammetry at a glassy carbon electrode in phosphate buffer solution.The results exhibited that the well-defined redox peak of luteolin is observed and the electrode process is adsorption-controlled.The charge transfer coefficient(α) was calculated as 0.66 in phosphate buffer solution(pH 4.0).The relationships between oxidation peak current and the concentration of luteolin are linear in the range of 1.0×10^-8 ～ 5.0×10^-6 mol·L^-1 by differential pulse voltammetric method.The detection limit had been estimated as 1.0×10^-8 molL^-1.This method can be used for the determination of luteolin with satisfactory results.

Selection Of Additions In The Process Of Electrochemical Synthesizing Of K2Feo4, Wei-Hua Yang, Dong-Qin Bi, Yan Zhou, Hong-Hui Wang, Xin-Ren Lan

Journal of Electrochemistry

Some of different additions including KIO₄ was added to the anodic electrolyte for electrochemical synthesizing of K₂FeO₄,the effects of these additions on current yield were investigated.XRD and SEM were used to characterize the structure and image of K₂FeO₄.The results show that KIO₄ is a preferable addition.When the mass dosage of KIO₄ is 0.02%,electrolysis time is 1 h,the current yield is enhanced by 31.6% and the corresponding purity of the product is improved by 3.85 %.

Electrochemical Behavior Of Zinc Alloy Anode In Ca(Oh)2 Solutions Of Different Ph, Peng-Ying Ren, Ji-Quan He

Journal of Electrochemistry

The polarization curves of zinc alloy anodes in Ca(OH)₂ solutions have been measured by potentiodynamic method,and the composition of corrosion products were examined by X-ray-diffraction(XRD).The experimental results indicated that not only the electrochemical behavior of zinc alloy anodes were absolutely different in every alkaline solutions,but also many electrochemical parameters were determined,such as zero current potential(E0),the density of corrosion current(icorr),passive current density(ip),breakdown potential(Eb),and so on.There were three zero current potential when zinc alloy anodes in some Ca(OH)₂ solutions which made passive state unstable.The graphs of E-pH about zinc alloy anodes dipped in different Ca(OH)₂ solutions were drawn,and compared …

Study On Electrochemical Impedance Spectroscopy Of Carbon Steel Eroded In Methyldiethanolamine Solution, Dong-Ping Wei, Rong-Zong Hu, Dan-Mei Pan, Wei-Xiong Huang, Rui Dong

Journal of Electrochemistry

Corrosion behavior of carbon steel in methyldiethanolamine(MDEA) solution was investigated by Electrochemical Impedance Spectroscopy(EIS).The results were showed that the corrosion rate of carbon steel in solution containing dissolved oxygen is higher than that in solution removed of dissolved oxygen before cathodic activation.They were reversed after cathodic activation.The corrosion rate is increased at first and then decreased when the concentration of MDEA is increased in the blank solutions.In the simulated solutions containing quantities of!heat-stable salts(HSS),the corrosion rate is decreased monotonously with increase of the MDEA concentration.As anodic polarization potential is increased,the EIS of carbon steel in HSS simulated solution showed characteristics …

Preparation And Investigations On The Tio2 Nanotube Arrays For Cathodic Protection Of 316l Stainless Steel, Jing Li, Hong Yun, Chang-Jian Lin

Journal of Electrochemistry

A highly ordered TiO₂ nanotube layer was fabricated by potentiostatic anodization of pure titanium in fluorinated electrolyte solutions. The structure and composition of the as-prepared TiO₂ nanotubes were characterized by SEM and XRD.The TiO₂ nanotubes show a stronger absorption in the ultraviolet(UV) light range. The performances of photogenerated cathodic protection and the photoelectrochemical response for the TiO₂ nanotube layers under illumination and dark conditions were evaluated through the electrochemical measurements. It is found that the open-circuit potentials of 316 SS coupled with the TiO₂ nanotubes layers shift negatively under UV light irradiation(λ<380nm). It is indicated that the TiO₂ nanotubes arrays …

Research Of 2,2′-Dipyridine On Electroless Copper Plating Using Sodium Hypophosphite As Reductant, Bin Yang, Fang-Zu Yang, Ling Huang, Shu-Kai Xu, Guang-Hua Yao, Shao-Min Zhou

Journal of Electrochemistry

In the bath of the electroless copper plating using sodium hypophosphite as reductant, the effects of 2,2′-dipyridine on the deposition rate, anodic oxidation of sodium hypophosphite, cathodic reduction of copper ions, surface morphologies, structure and the existing status of the deposit components were examined. The results showed that, 2,2′-dipyridine hindered the electroless deposition.Experiments of liner sweep voltammetry (LSV) indicated that,as the addition of 2,2′-dipyridine to the electrolyte, the oxidation peak potential of sodium hypophosphite shifted to a more negative value but the peak current decreased; the reducing peak potential of copper ions moved to a more negative value whereas the …

Synthesis Of Optimal Arrays For Mimo And Diversity Systems, Britton T. Quist

Theses and Dissertations

This thesis proposes a method for determining the optimal antenna element radiation characteristics which maximize diversity gain given a specific power angular spectrum of the propagation environment. The method numerically constructs the eigenfunctions of the covariance operator for the scenario subject to constraints on the power radiated by each antenna as well as the level of supergain allowed in the solution. The optimal antenna characteristics are produced in terms of radiating current distributions along with their resulting radiation patterns. The results reveal that the optimal antennas can provide significantly more diversity gain than that provided by a simple practical design. …

Ceas E-News 11.27.2007, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Global engineering topic dominates CAViDS Vehicle Engineering Day

Trenchless Water Pipe Condition Assessment Using Artificial Neural Network, Zong Woo Geem, Chung-Li Tseng, Juhwan Kim, Cheolho Bae

Engineering Management and Systems Engineering Faculty Research & Creative Works

In order to assess the water pipe condition without excavating, artificial neural network (ANN) model was developed and applied to real-world case in South Korea. for the input in this ANN model, 11 factors such as (1) pipe material, (2) diameter, (3) pressure head, (4) inner coating, (5) outer coating, (6) electric recharge, (7) bedding condition, (8) age, (9) trench depth, (10) soil condition, and (11) number of road lanes were used; and, for the output, overall pipe condition index was derived based on 5 factors such as (1) outer corrosion, (2) crack, (3) pin hole, (4) inner corrosion, and …

Converting Traditional Materials Labs To Project-Based Learning Experiences: Aiding Students' Development Of Higher-Order Cognitive Skills, Linda Vanasupa, Katherine C. Chen, Jonathan Stolk, Richard N. Savage, Trevor S. Harding, Blair London, William L. Hughes

Materials Engineering

Against a backdrop of compelling societal needs, graduates in science and engineering now must master their disciplines and demonstrate a sophisticated level of cognitive, affective and social development. This has lead a number of national and international commissions on science and engineering to urge educators to re-think the way in which STEM disciplines are taught. We have chosen to "repackage" a traditional undergraduate materials engineering curriculum in a form designed to promote the development of higher-order cognitive skills like self-directed learning and design. Classic metallurgy experiments have been converted to project-based learning experiences where students are put in the role …

Low Loss Hybrid Waveguide Electric Field Sensor Based On Optical D-Fiber, Eric K. Johnson

Theses and Dissertations

This thesis presents the fabrication of a low loss hybrid waveguide electric field(E-field) sensor based on optical D-fiber. This novel E-field sensor is formed as part of a contiguous fiber resulting in a flexible and small cross-section device that can be embedded into electronic circuitry. The in-fiber nature of this sensor also eliminates the need for alignment and packaging that conventional sensors need. An optical fiber can detect electric fields when the core of the fiber is partially removed and replaced with an electro-optic polymer. This polymer causes a change in the index of refraction in the waveguide of the …

Space-Time Coding With Offset Modulations, N. Thomas Nelson

Theses and Dissertations

In this dissertation it is shown that the telemetry versions of Feher-patented QPSK (FQPSK-JR) and shaped offset QPSK (SOQPSK-TG) can be interpreted as both cross-correlated, trellis-coded quadrature modulation (XTCQM) and continuous phase modulation (CPM). Based on these representations, both modulations can be detected with near optimal bit error rate performance using a common detector that is formulated as either an XTCQM detector, a traditional CPM detector, or a pulse amplitude modulation (PAM) detector (due to the PAM decomposition of the CPM representations of these modulations). In addition it is shown that the complexity of the XTCQM detector for SOQPSK-TG can …

Digitally Controlled Zvs Quasi-Resonant Boost Converter With M-Type Switch, Taufik, Patrick Luther, Makbul Anwari

Electrical Engineering

This paper presents the analysis, modeling and design of zero-voltage-switching (ZVS) quasi resonant boost converter. The use of M-type switch in the topology will be described, including circuitpsilas mode of operation along with the derivations of critical voltage and current equations in each mode. Computer simulation using OrCAD Pspice and hardware development for the resonant converter with digital control will be presented. Results from both simulation and laboratory measurements to compare with theoretical analysis will be discussed.

Comparative Study Of Sinusoidal Pulse-Width And Hysteresis Modulations In Current Source Inverter, Taufik, Yat Tam, Makbul Anwari

Electrical Engineering

In this paper, modeling and comparative analysis of current source inverter (CSI) using sinusoidal pulse-width-modulation (SPWM) and hysteresis modulation (HM) will be presented. The modeling of both CSI-SPWM and CSI-HM are implemented using OrCAD Pspice. Results from the simulations will be presented along with the performance analysis of both inverters. More specifically, comparative analysis pertaining to output current regulation, harmonic contents, and transient response will be discussed. Moreover, further investigation about the effect of current THD, power factor and efficiency for balanced and unbalanced three-phase input sources with ±1%, ±3%, ±5% rms variation at the converter stage to various output …

Ceas E-News 11.20.2007, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Tues., Dec. 4, conference to showcase 42 senior engineering projects

Performance Testing An Inline Network Intrusion Detection System Using Snort, Richard Wagoner

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Richard Wagoner on November 16, 2007.

Assurance Cases For Security: The Metrics Challenge, Robin Bloomfield, Marcelo Masera, Ann K. Miller, O. Sami Saydjari, Charles B. Weinstock

Electrical and Computer Engineering Faculty Research & Creative Works

For critical systems it is important to know whether the system is trustworthy and to be able to communicate, review and debate the level of trust achieved. in the safety domain, explicit Safety Cases are increasingly required by law, regulations and standards. Yet the need to understand risks is not just a safety issue and the type of argumentation used for safety cases is not specific to safety alone. Prior workshops, beginning with one held at DSN 2004, have identified a number of technical, policy and research challenges. the focus of this workshop is on one of these challenges: metrics …

Low-Voltage Analog Cmos Architectures And Design Methods, Kent Downing Layton

Theses and Dissertations

This dissertation develops design methods and architectures which allow analog circuits to operate at VT + 2Vds,sat, the minimum supply for CMOS circuits with all transistors in the active region where Vds,sat is the drain to source saturation voltage of a MOS transistor. Techniques which meet this criteria for rail-to-rail input stages, gain enhancement stages, and output stages are discussed and developed. These techniques are used to design four fully-differential rail-to-rail amplifiers. The highest gain is shown to be attained using a drain voltage equalization (DVE) or active-bootstrapping technique which produces more than 100dB of gain in a two stage …

Relaxation Time, Diffusion, And Viscosity Analysis Of Model Asphalt Systems Using Molecular Simulation, Liqun Zhang, Michael L. Greenfield

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Molecular dynamics simulation was used to calculate rotational relaxation time, diffusion coefficient, and zero-shear viscosity for a pure aromatic compound naphthalene and for aromatic and aliphatic components in model asphalt systems over a temperature range of 298–443 K. The model asphalt systems were chosen previously to represent real asphalt. Green–Kubo and Einstein methods were used to estimate viscosity at high temperature 443.15 K. Rotational relaxation times were calculated by nonlinear regression of orientation correlation functions to a modified Kohlrausch–Williams–Watts function. The Vogel–Fulcher–Tammann equation was used to analyze the temperature dependences of relaxation time, viscosity, and diffusion coefficient. The temperature dependences …

Mechanical Behavior And Failure Analysis Of Prosthetic Retaining Screws After Long‐Term Use In Vivo. Part 2: Metallurgical And Microhardness Analysis, Youssef S. Al Jabbari, Raymond Fournelle, Gerald J. Ziebert, Jeffrey M. Toth, Anthony Iacopino

Biomedical Engineering Faculty Research and Publications

Abstract

Purpose: This study involved testing and analyzing multiple retrieved prosthetic retaining screws after long‐term use in vivo to: (1) detect manufacturing defects that could affect in‐service behavior; (2) characterize the microstructure and alloy composition; and (3) further characterize the wear mechanism of the screw threads.

Materials and Methods: Two new (control) screws from Nobel Biocare (NB) and 18 used (in service 18–120 months) retaining screws [12 from NB and 6 from Sterngold (SG)] were: (1) metallographically examined by light microscopy and scanning electron microscopy (SEM) to determine the microstructure; (2) analyzed by energy dispersive X‐ray (EDX) microanalysis to determine …

Mechanical Behavior And Failure Analysis Of Prosthetic Retaining Screws After Long‐Term Use In Vivo. Part 1: Characterization Of Adhesive Wear And Structure Of Retaining Screws, Youssef S. Al Jabbari, Raymond Fournelle, Gerald J. Ziebert, Jeffrey M. Toth, Anthony Iacopino

Biomedical Engineering Faculty Research and Publications

Purpose: The general aim of this study and those presented in Parts 2–4 of this series was to characterize the structure, properties, wear, and fracture of prosthetic retaining screws in fixed detachable hybrid prostheses after long‐term use in vivo. This part of the overall investigation addresses whether there are differences in thread wear between the screws closest to the fulcrum and those that are farthest from the fulcrum in fixed detachable hybrid prostheses.

Materials and Methods: The total number of prosthetic retaining screws used in this study was 100 (10 new and 90 used). New screws (controls) from Nobel Biocare …

Numerical Study Of Fully Developed Laminar And Turbulent Flow Through Microchannels With Longitudinal Microstructures, Kevin B. Jeffs

Theses and Dissertations

Due to the increase of application in a number of emerging technologies, a growing amount of research has focused on the reduction of drag in microfluidic transport. A novel approach reported in the recent literature is to fabricate micro-ribs and cavities in the channel wall that are then treated with a hydrophobic coating. Such surfaces have been termed super- or ultrahydrophobic and the contact area between the flowing liquid and the solid wall is greatly reduced. Further, due to the scale of the micropatterned structures, the liquid is unable to wet the cavity and a liquid meniscus is formed between …

Ultrasonic Seaming Of Pet, Pet/Cotton Blend, And Spectra Fabrics, Renuka Kadiri Reddy

Master's Theses and Doctoral Dissertations

Ultrasonic seaming offers many advantages as an alternative for joining fabrics, such as efficiency, reduced cost, conservation of energy, and recyclability of the product.

The objective of this study was to investigate the effect of ultrasonic weld parameters – weld pressure, weld time, amplitude of vibration, seam design, and material properties – on seam efficiency and stiffness of a seam. This study also compares seam efficiency and stiffness of (a) ultrasonic seam to that of sewn seam and (b) ultrasonic seam from continuous mode of operation to that of plunge mode. Regression and analytical tests were used to analyze the …