Engineering Commons^™

Direct Electrochemistry Of Chloroperoxidase At Gc Electrode Modified With Swnts, Hong-Xia Zhang, Xia-Qin Wu, Wen-Jing Hou, Wen Xie, Zhong-Qing Lu, Rong Wang, He-Xing Li

Journal of Electrochemistry

The chloroperoxidase(CPO) was immobilized onto the surface of SWNTs modified electrodes.The electrochemical behaviors of modified electrode have been investigated by cyclic voltammetry.The appearance of a pair of well-defined redox peaks in the CV curve indicated that SWNTs can promote the electron transfer reaction of CPO.The results of cyclic voltammetry in PBS of different pH,from 3~9,showed that the reaction of CPO on the modified electrode was with equal numbers of electron and protein.This readily prepared SWNTs modified electrode showed excellent stability and good catalysis to O₂.

Preparations Of Composite Electrodes Of Pt With HXWo3 And Catalytic Activity Toward Oxygen Reduction Reaction, Pan-Pan Guo, You-Ju Huang, Hong-Yan Yang, Wei Li, Qing-Long Zhang, Wei-Shan Li

Journal of Electrochemistry

Three composite electrodes of platinum with hydrogen tungsten bronze(H_xWO₃)were prepared by voltammetry: hydrogen tungsten bronze deposited on platinum(H_xWO₃/Pt);platinum deposited on hydrogen tungsten bronze(Pt/H_xWO₃) and codeposited platinum and hydrogen tungsten bronze(Pt-H_xWO₃).The eletro-catalytic activities of three electrodes toward oxygen reduction reaction were studied.It is found that the catalytic activity of platinum can be improved by introducing with hydrogen tungsten bronze.Among these composite electrodes Pt/H_xWO₃,and the electrode shows the best eletro-catalytic activity toward oxygen reduction reaction,hence,provides a new way for reducing loading of …

High Performance Fuel Cell Catalyst And 5kw Pemfc Stack Without Humidification At Room Temperature And Atmosphere, Xin-Fa Hu, Min Chen, Shi-Jun Liao

Journal of Electrochemistry

The Pt/C catalyst with high dispersion and high performance was prepared successfully by an organic colloidal method and small batch production(10g) of Pt/C catalyst has been realized.The particle sizes of the active components in the catalyst could be as small as 2.8 nm and the active surface area was up to 450 m²/g.A high performance membrane-electrode assembly(MEA) with surface area of 275 cm² has been prepared by using the home-made catalyst with a catalyst coated membrane method invented in the lab,and a 5 kW stack has been assembled.The stack showed working 10 h at room temperature,atmosphere and …

Ceo2/Pt Composite Electrodes And Their Catalytic Performance, Ying Fu, Zi-Dong Wei, Yong-Chao Feng, Xin-Li Ma, Ming-Jia Liao, Chao Liao, Jie Zhang, Huan Zhang

Journal of Electrochemistry

In this paper,the cerium oxide(CeO₂) nanoparticles were electrochemically deposited on a Pt electrode by potentiostatic deposition(psd) and potential pulse deposition(ppd) to form CeO₂/Pt composite electrodes,CeO₂/Pt(psd) and CeO₂/Pt(ppd).The properties of the CeO₂ were characterized by field emission scanning electron microscope(FESEM) and X-ray diffraction(XRD).The results showed that the CeO₂ nanoparticles prepared by psd and ppd were homogeneous and dense.The methanol oxidation reaction(MOR) and oxygen reduction reaction(ORR) on the Pt electrode were enhanced with the introduction of CeO₂ into Pt.In addition,the catalytic capability of the CeO₂/Pt electrode can be further …

Voltammetric Determination Of L-Cysteine At Bipyrine Bridged Copper(Ⅱ) Complex Modified Glassy Carbon Electrode, Ming-Yan Wang, Fan Yang, Sheng-Yu Zhang, Xing-You Xu, Xu-Jie Yang

Journal of Electrochemistry

A modified electrode has been constructed by depositing a novel copper(Ⅱ) complex 2biPy(ClO₄)₄ on the glassy carbon electrode through the method of cyclic voltammetry(CV).It was found that the modified electrode exhibited high electrocatalytic activity toward L-Cysteine oxidation with good reproducibility and high sensitivity.The peak current of semi-derivative linear scan was proportional to the concentration of L-cys in the range of 1×10^-6～3×10^-4 mol·L^-1.The detection limit was 5×10^-7 mol·L^-1.

Study On The Texturization Of C-Si Wafers By Different Kinds Of Alkaline For Heterojunction Solar Cells, Yu-Hua Dou, Yu-Qin Zhou, Mei-Fang Zhu, Shuang Song, Feng-Zhen Liu, Jin-Long Liu, Zhan-Jun Zhang

Journal of Electrochemistry

The texturization of(100) crystalline silicon(c-Si) wafer was studied by field-emission scanning electron microscope using different kinds of etchant: sodium hydroxide,sodium carbonate and tribasic sodium phosphate.By optimizing the etching parameters,the lowest values of averaged reflectance(Rav) were obtained to be 9.70% for NaOH,9.76% for Na₂CO₃ and 8.63% for Na₃PO₄·12H₂O,which is comparable to that of the wafer with textured surface covered with an anti-reflection coating of either silicon nitride or thermally grown silicon dioxide.The relation of Rav and surface morphology of textured wafer was analyzed.Moreover,special emphasis was put on the role of isopropyl alcohol(IPA) …

The Hydrothemal Synthesis Of Nanoscale Lifepo4 And Its Electrochemical Performance, Si-Min Wang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The cathode materials of LiFePO₄ were prepared via a hydrothermal reduction method using FeCl₃ as Fe source and iron as a reducing agent.The results showed that ferric salt could be reduced to ferrous salt completely under the hydrothermal condition and pure-phase LiFePO₄ was obtained based on the test results of XRD and FTIR. Carbon-coated LiFePO₄ was synthesized by pyrolysisng glucose at high temperature. The morphologies of pure LiFePO₄ displayed cluster-like while the LiFePO₄/C displayed sphere-like particles. The electrochemical test showed that the LiFePO₄/C had good rate performance,while LiFePO₄ delivered much …

Studies Of Surface Diffusion In Pemfc Electrodes, Jiang-Shui Luo, Jian Chen, Bao-Lian Yi, Chuan-Sin Cha, Hua-Min Zhang

Journal of Electrochemistry

A PEMFC electrode consisting of dual-layer catalyst layer(CL) was fabricated in this work. The outer CL was Nafion-free,while the inner CL was Nafion-bonded. The effects of Pt/C catalyst in the outer CL that did not contact with Nafion on the current generation in PEMFC electrodes were investigated. Cyclic voltammetric studies indicated that the Pt/C catalyst in the outer CL without direct contact with Nafion was still electrochemically active in taking part in the adsorption/desorption of hydrogen and the electrochemical oxidation/reduction of the oxygen-containing species occurring at the interface of "Pt/Nafion" in the inner CL. The polarization curves showed that the …

Synthesis Of The Lifepo4 By Co Reduction: Reaction Mechanism And Kinetics, Yun-Hua Chen, Yong Yang

Journal of Electrochemistry

LiFePO₄ cathode material was synthesized by CO reducing FePO₄ and LiOH precursors.The structure,morphology and electrochemical performances of such LiFePO₄ material were characterized by XRD,SEM and charge-discharge tests.It was shown that the particle size of the LiFePO₄ synthesized with 5% excess of LiOH in the precursor was about 200 nm.By carbon coating,the LiFePO₄ electrode was able to deliver a reversible capacity of 158 mAh·g^-1 at 0.1C discharge rate.Temperature-programmed X-ray diffraction was employed to monitor the reaction during the formation of LiFePO₄,and Li₃Fe₂(PO₄)₃ was found to be …

Preparation And Optical Transmission Of The Zno Nanorod Array Films, Feng Ye, Jing-Jing Li, Tong-Tao Wang, Yong-Liang Wang, Yun Liu, Xin-Dong Wang

Journal of Electrochemistry

By using a galvaostatic electrodeposition method in the ZnCl₂ solution,the highly oriented ZnO nanorod array films have been successfully prepared on ITO substrate after the pretreatment with ZnO nanoparticles.And they were characterized by scanning electron microscope,X-ray diffraction and transmittance spectra.The results indicated that the ZnO nanorod arrays grew along(001) direction with an orientation perpendicular to the substrate.When the wavelength of incident was over 380 nm,the ZnO nanorod arrays showed high optical transmission of above 95%.Furthermore,the band gap became narrower.

Ec-Pt/Cnts Glucose Oxidative Electrode, Jia-Hua Liang, Chun-Mei Zhou, Hong-Juan Wang

Journal of Electrochemistry

A glucose oxidative electrode(GOD),EC-Pt/CNTs glucose oxidative electrode,was constructed by ethyl cellulose(EC) and Pt/CNTs.The sensitivity of the EC-Pt/CNTs GOD is 0.85 μA/mM in the concentration range of 0～4 mmol/L of glucose.After dipped in PBS(4℃) for 18 days,the activity of the EC-Pt/CNTs GOD can reach 80%.It is promising for the EC-Pt/CNTs GOD to be used to construct glucose biosensor.

Corrosion Inhibition Of Magnesium Alloy In 3.5% Nacl Medium By Tungstate, Ling-Jie Li, Zhi-Ming Yao, Jing-Lei Lei, Dong-Hai He, Sheng-Tao Zhang, Fu-Sheng Pan

Journal of Electrochemistry

Electrochemical impedance spectroscopy(EIS),Tafel polarization curves and scanning electron microscopy(SEM) were used to study the corrosion inhibition of AZ61 magnesium alloy in 3.5% NaCl medium with tungstate.Results showed that tungstate demonstrates strong inhibition to the corrosion of AZ61 magnesium alloy.At the concentration of 0.01 mol/L,tungstate has a high inhibition efficiency 75.5%.Tungstate is an anodic inhibitor that mainly inhibited the anodic reactions of magnesium alloy through forming a compact protective layer that covered the magnesium alloy surface active sites.

Electrochemical Behavior And Determination Of Paracetamol On Activated Glassy Carbon Electrode, Bao-Yu Tan, Fang Liao, Xiao-Ying He, Qing-Tao Zhu, Jun Hua, Xiao-Li Jiang

Journal of Electrochemistry

The electrochemical behavior of paracetamol(PCT) was studied at glassy carbon electrode activated by cyclic voltammetry.In HAc-NaAc buffer solution(pH=4.00),a couple of sensitive redox peaks were recorded about 0.54 V in the cyclic voltammograms.The result indicated that the process was controlled by adsorption and nearly reversible.The reaction electron and proton numbers were estimated,respectively,to be two.Excllent linearity was observed in the correlation between the oxidation peak current and the concentration of PCT in the range of 8.00×10^-6～2.00×10^-4 mol·L-1.The correlative coefficient was-0.999 18.The detection limit was 6.34×10^-6 mol·L^-1.This method can be used for the determination of PCT real …

Fabrication Of Superhydrophilic Aluminum Oxide Through Single-Step Anodic Oxidation, Qin Zhang, Qi-Ming Yin, Jia-Ming Ye, Yuan-Rong Zhu

Journal of Electrochemistry

Hydrophilic aluminum oxide is popularly used for heat exchanger of air-condition.Herein,we developed a simple method to prepare superhydrophilic aluminum oxide on the surface of aluminum through single-step electrochemical oxidization.The morphologies and water contact angles on surfaces of alumina fabricated under different electrochemical conditions were investgated.Superhydrophilic surfaces fabricated by this method have good stability and high mechanical strength with water contact angle almost 0°.Coated with low surface energy materials,superhydrophilc alumina will be converted to superhydrophobic.

N,N’-Bis(3,5-Di-T-Butylsalicylideneimine) Propanediamine And Its Some Tetradentate Schiff Base Complexes Synthesis, Characterization And Thermal Study, Fatih Dogan, M. Ulusoy, O. F. Ozturk, I. Kaya, B. Salih

Materials Science and Engineering Faculty Research & Creative Works

Several mononuclear Co (II), Ni (II), Cu (II) and Fe (II) complexes of tetradentate salpren-type diamine, obtained from 3,5-di-tert–butyl-2-hydroxybenzaldehyde and 1,3-diaminopropane have been prepared and characterized by analytical, spectroscopic (FTIR, UV-Vis) techniques, magnetic susceptibility measurements and thermogravimetric analyses (TG). The thermodynamic and thermal properties of complexes have been investigated. For further characterization direct insertion probe-mass spectrometry (DIP-MS) was used and the fragmentation pattern and also stability of the ions were evaluated. The characterization of the end products of the decomposition was achieved by X-ray diffraction. The thermal stabilities of metal complexes of N,N’-bis(3,5-di-t-butylsalicylideneimine) propane diamine ligand (L) were found as …

Isolation Of Methyl Laurate From Coconut Oil As Raw Material For Fatty Alcohol Sulfate, Rita Arbianti, Tania Surya Utami, Astri Nugroho

Makara Journal of Technology

Isolation of Methyl Laurate from Coconut Oil as Raw Material for Fatty Alcohol Sulfate. Methyl laurate is a raw or base material for many industries, including surfactant industries. In this research, coconut oil (VCO) is transesterified with methanol to produce methyl ester, using NaOH as the catalyst. Methyl laurate is then separated by method based on the difference in melting point. This research focuses at determining the effects of some variables in transesterification on the concentration of produced methyl laurate. The variables are temperature (40 oC, 50 oC, 60 oC, 80 oC), time of transesterification reaction (0,5 hour, 1 hour, …

The Decompositioning Of Volatile-Matter Of Tanjung Enim Coal By Using Thermogravimetry Analyzer (Tga), Nukman Nukman

Makara Journal of Technology

The Decompositioning of Volatile-Matter of Tanjung Enim Coal by using Thermogravimetry Analyzer (TGA). Coal is a nature material which a kind of energy source. The decompotition of coal could analyze by heat treated using thermogravimetry analyzer. The decomposition of the volatile matter for three kinds of Tanjung Enim coal could be known. The value of activation energy that be found diference, then for Semi Anthracite, Bitumonius and Sub Bituminous Coal, the initial temperatures are 60.8 oC, 70.7 oC, 97.8oC, and the last temperatures are 893.8 oC, 832 oC, 584.6oC.

Phase Unwrapping Insar Image Using Local Energy Minimization Approach, Kusworo Adi, Tati L.R. Mengko, Andriyan B. Suksmono, Hendra Gunawan

Makara Journal of Technology

Phase Unwrapping InSAR Image Using Local Energy Minimization Approach. Reconstruction process of phase data from its cover is called Phase Unwrapping (PU). Ideally, without any noise phrase, singularity, and aliasing problems, the phase information can be unwrapped easily. However, in fact, the phase data actually always get noise disturbance and discontinuity. The PU process becomes more complicated and needs a better PU algorithm to address the problems properly. In this research, the local PU algorithm is developed using minimization of close related firstorder pixels energy approach. In this method, the energy difference between four close related pixels is counted, followed …

Two Element Microstrip Antenna Array With Defected Ground Structure, Fitri Yuli Zulkifli, Eko Tjipto Rahardjo, Muhamad Asvial, Djoko Hartanto

Makara Journal of Technology

Two Element Microstrip Antenna Array with Defected Ground Structure. This paper presents a two element microstrip antenna array using trapezium shape defected ground structure (DGS). The DGS is inserted in the ground plane between two elements of antenna array. Insertion of the DGS is intended to suppress the mutual coupling effect produced by antenna array. Simulation and measurement results were taken and compared between antenna array with and without DGS. Measurement results show that the antenna with DGS compared to antenna without DGS can suppress mutual coupling effect to 7.9 dB, improve the return loss to 33.29% from -30.188 dB …

Neutron Irradiation On Ss316 Material For Radioactive Endovascular Stent Production, Rohadi Awaludin, Abidin Abidin, Sriyono Sriyono

Makara Journal of Technology

Neutron Irradiation on SS316 Material for Radioactive Endovascular Stent Production. It was reported that restenosis could be prevented by radioactive endovascular stent. SS316 material of endovascular stent has been irradiated at pneumatic rabbit system of G.A. Siwabessy reactor for 5 minutes for producing radioactive stent by neutron activation. After 10 days of decay, the irradiated SS316 was measured by gamma spectrometer. The radioisotopes of 51Cr, 59Fe and 60Co were detected in the irradiated SS316 with radioactivity of 5990, 107 and 109 Bq/mg respectively. The Calculation results showed that radioisotopes of 51Cr, 59Fe and 55Fe were produced by neutron activation. The …

Physical Characteristics And Utilization Oft The Karst Beaches In Kabupaten Gunungkidul, Astrid Damayanti, Ranum Ayuningtyas

Makara Journal of Technology

Physical Characteristics and Utilization oft the Karst Beaches in Kabupaten Gunungkidul. Karsts beaches at Gunungkidul Regency (Baron, Kukup, Sepanjang, Drini, Krakal, Ngandong, and Sundak), located in south of Daerah Istimewa Yogyakarta Province, have economic potential. Even they have similarity in geological condition (genesis and morphological processes), but they have different physical characteristics. Based on result of observation environment on morphological conditions and spatial analysis method, we found the proper utilization of the beaches.

Hydrogen Absorption In Weldments Of Overlaid Claded Pressure Vessel, Ronnie Higuchi Rusli

Makara Journal of Technology

Cracks was found in type 347 stainless steel internal attachment welds of a reactor for a high temperature, and high pressure hydrogen service. One of the possible causes of cracking is low cycle fatigue cracking induced by repetition of thermal stress to embrittled weld metal. Type 347 weld metal loses its ductility by presence of sigma phase and hydrogen.

Spectral Response Surfaces And The Ringing Response Of Offshore Structures, I Ketut Suastika

Makara Journal of Technology

A method, called spectral response surface method, is proposed for the study of the ringing phenomenon of offshore structures. Newman’s results for diffraction force on a column were reformulated in terms of the frequency components of the ocean surface and their Hilbert transforms. Using a first-order reliability method together with a dynamic model for the structural response, it is straightforward to calculate the ocean surface history most likely to generate an extreme ringing response and the ringing response history.

Regulating Self-Organizing Nanostructures Via External Mechanism, Jiangyu Li, Q. G. Du, Stephen Ducharme

Stephen Ducharme Publications

Self-organizing nanostructures are ubiquitous in both natural and synthetic materials. They are not only appealing scientifically, by revealing the intrinsic atomic and molecular interactions that might be difficult to detect otherwise, but may also hold the key for the development of novel functional structures and devices. For their technological potential to be fully realized, the size, morphology, and distribution of the self-organizing nanostructures must be regulated. In this paper, we investigate the principles under which the self-organizing nanostructures can be regulated via external mechanisms. Using nanomesa and nanowell formation in polyvinylidene fluoride trifluoroethylene copolymer film as an example, we demonstrate …

Material Selection And Optimization To Mitigate 316l Stainless Steel Corrosion In A Condensate Stabilizer, Afif Saif Nasser Harhara

Theses

The United Arab Emirates (UAE) is one of the key players of the oil and gas industry of the world; with oil reserves estimated at 9% of the total world reserves, the petroleum industry is considered to be the backbone of the economy.

In one of the gas processing facilities in Abu Dhabi, UAE; a case of material failure occurred in the fractionating column twice in a cycle of less than 2 years. The materials used for the internals of the column was stainless steel 316L. The different types of stainless steel corrosion were studied with emphasis on the suspected …

Work In Progress - Attaining And Measuring Global Competency For Engineering Graduates, James Widmann, Linda Vanasupa

Materials Engineering

Downey et al. laid out a clear path of learning criteria and outcomes for global competence in their 2006 Journal of Engineering Education publication. We build on their work by integrating other disciplinary perspectives to expand upon the questions: "How can global competency be learned?", and "How can we assess it?" In this work-in-progress paper, we propose an expanded framework for global competence and identify the use of Fink's taxonomy of significant learning as a tool to consider how it can be achieved through careful design of classroom learning experiences. Drawing heavily from other models, our framework attempts to articulate …

Work In Progress - A Design Guide To Retain Female (And Male) Students In Engineering, Linda Vanasupa, Katherine C. Chen, Stacey Breitenbach, Karen R. Bangs

Materials Engineering

Despite a rich body of research on factors contributing to attrition of women during the college, women continue to be underrepresented in the graduating classes of most traditional engineering disciplines. We present our Four-Domain Development Diagram (4DDD) in an attempt to enable a systems approach to managing all the factors that contribute to retention. This diagram makes explicit the connections between the learners' response factors in the learning environment, including motivation, interest, and ultimately retention. Although we are only three years into our use of the diagrams' relationships, we have seen a lower overall net attrition rate (male and female) …

Work In Progress – Building The Survey Of Engineering Ethical Development (Seed) Instrument, Janel A. Sutkus, Donald D. Carpenter, Cynthia J. Finelli, Trevor S. Harding

Materials Engineering

When developing surveys, researchers can readily identify the concepts they intend to study, but how do they create individual survey items that will most accurately measure those concepts? Here we describe the first year of a four-year NSF project in which the E³ Team (Exploring Ethical Decision Making in Engineering) prepared to develop a national survey of the curricular and cocurricular activities, events, and experiences affecting the ethical development of engineering undergraduates. As this survey is likely to be the most comprehensive assessment of ethical development - both in content and scope - ever administered to engineering undergraduates, it …

The Psychology Of 'Ought', Trevor S. Harding

Materials Engineering

As educators, we would like to believe that we can influence the ethical growth of our students. If we are to do this, it seems worthwhile to first understand what ethical decision-making is and how it happens. For millennia, ethical decision-making has fallen within the domain of philosophy. However, recent evidence suggests that the average person does not consider ethical dilemmas in the abstract. Instead, ethical decision-making appears to be a complex dance between an individual’s rational calculus of the ethical dilemma and their emotional response to the context of the dilemma. I will present an argument that in the …

Rheological Study Of Polymer Flow Past Rough Surfaces With Slip Boundary Conditions, Anoosheh Niavarani, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

The slip phenomena in thin polymer films confined by either flat or periodically corrugated surfaces are investigated by molecular dynamics and continuum simulations. For atomically flat surfaces and weak wall-fluid interactions, the shear rate dependence of the slip length has a distinct local minimum which is followed by a rapid increase at higher shear rates. For corrugated surfaces with wavelength larger than the radius of gyration of polymer chains, the effective slip length decays monotonically with increasing corrugation amplitude. At small amplitudes, this decay is reproduced accurately by the numerical solution of the Stokes equation with constant and rate-dependent local …