Engineering Commons^™

The Four-Domain Development Diagram: A Tool For Designing Development-Centered Teaching, Linda Vanasupa, Trevor S. Harding, William L. Hughes

Materials Engineering

Research in education has brought to light the complexity of the learning process, demonstrating that students' development is influenced by a myriad of cultural and social factors, as well as the environment in which learning takes place. Engineering curricula, however, are primarily focused on teaching content knowledge, often resulting in a gap between what is taught and what is learned. We propose that shifting some of the focus onto the process of learning that occurs within the student and leveraging multiple known connections from educational psychology can result in more effective engineering education. Here we define “effective” engineering education as …

Enhancing Precalculus Curricula With E-Learning: Implementation And Assessment, Janet Callahan, Seung Youn Chyung, Joanna Guild, William Clement, Joe Guarino, Doug Bullock, Cheryl Schrader

Materials Science and Engineering Faculty Publications and Presentations

During Fall semester of 2007, a semester-long, quasi-experimental study was conducted at Boise State University to investigate the effectiveness of a systematically sequenced and managed, self-paced e-learning activity on improving students’ academic performance and motivation. A total of 125 students enrolled in 3 different sections of a Precalculus class participated in the study. The e-learning activity was implemented in 2 of the 3 sections as a required homework assignment. Students enrolled in one of the 2 selected sections were all engineering majors. The 3^rd section was a control group that did not use the e-learning activity. A pre-test, measuring …

Engineering Project Laboratory Modules For An Introduction To Materials Course, Stacy Gleixner, Elliot Douglas, Olivia Graeve

Faculty Publications

The final results of curriculum development under an NSF, CCLI-EMD sponsored project, “Development of Project-Based Introductory to Materials Engineering Modules” (DUE # #0341633) is discussed. A multi-university team of faculty developed five lecture and three laboratory modules for use in Introductory to Materials courses. This course is required by most engineering programs in the U.S., with an annual enrollment of 50,000 students.1 This freshman/ sophomore class is an ideal place to excite students about their engineering majors and expose them to real world engineering problems. PRIME Modules, Project Based Resources for Introduction to Materials Engineering, utilize modern materials science and …

The Effect Of Radiation On The Electrical Properties Of Aluminum Gallium Nitride/Gallium Nitride Heterostructures, John W. Mcclory

Theses and Dissertations

AlGaN/GaN Heterojunction Field Effect Transistors (HFETs) were irradiated at low temperature and the temperature dependent changes to drain current, gate current, capacitance, and transconductance were measured. The results were compared to the charge control model of the drain current and trap-assisted tunneling model of the gate current to determine the source of the radiation-induced changes. AlGaN/GaN HFETs demonstrated threshold voltage shifts and drain current changes after irradiation. After electron and neutron irradiation applied at ~80 K, measurement of the drain current at this temperature showed an increase that saturated after 10¹³ electrons/cm² or 10¹⁰ neutrons/cm² due …

Protein Interactions With Mixed Poly(Ethylene Glycol)/Polyacrylic Acid Brushes, Zhenqing Li

All Theses

Tethered polymer chains that are grafted to a solid substrate by one chain end (polymer brushes) may be distinguished from other anchored polymer layers by the relatively high grafting densities gained. Potential uses of polymer brushes for interfacial modification to regulate interactions between proteins and substrates, such as drug delivery and protein separation, are widely recognized. Therefore, it is important to investigate interactions between proteins and surfaces modified with a polymer brush.
In this study, the 'grafting-to' method has been used to graft mixed poly(ethylene glycol) (PEG) and polyacrylic acid (PAA) brushes onto poly(glycidyl methacrylate) (PGMA)-modified silicon wafers/glass slides to …

Investigating A Natural Organic Binder As A Bitumen Substitute In Flexible Pavements, Karim Ahmed Abdel Warith

Archived Theses and Dissertations

No abstract provided.

Powder Rolling Of Cnt-Reinforced Aluminum Strips, Mostafa Abdel-Fattah El-Borady

Archived Theses and Dissertations

Multi walled carbon nanotubes (MWCNT) were added to aluminum powder (99.97% pure) to produce a composite material. Three mixing techniques were examined

1 Low energy mixing: Using a Turbula mixer with two different speeds 48 and 67 rpm.

2 High energy mixing: Using a ball mill without adding any balls in the mixing jars with two speeds 300 and 400 rpm.

3 Ball milling: Using the ball mill (with steel balls) to mix higher CNT weight fraction samples for the electrical resistivity tests.

The mixtures were packed in copper cans and rolled in a rolling machine to compact the mixture; …

Performance Of Air Breathing Direct Methanol Fuel Cell Under Ambient Condition, Jian-Guo Liu, Jun Gu, Tao Yu, Zhi-Gang Zou, T.S Zhao

Journal of Electrochemistry

The performance of the passive DMFC was systematically investigated under an ambient condition by simulating a wide range of temperature and humidity in a high-quality environmentally controlled room.The results indicated that the performance of the passive DMFC was nearly independent of ambient humidity from 30% to 90% RH and water produced in the cathode was expelled mostly from the cell in a liquid state.Compared with the humidity,the ambient temperature has a significant effect on the performance of the passive DMFC.The power density of 30 mW·cm^-2 were obtained at 40℃,while only 10 mW·cm^-2 at 10 ℃.

Structure And Property Of Molecular Self-Assembled Membrane With Zirconium Ion, Tian-De Wang, Rong Wang, Xia-Qin Wu, Zhi-Gang Guo, Wei-Wei Ji

Journal of Electrochemistry

According to the complex interaction between dodecyl phosphonate and stainless steel surface as well as the zirconium ion,the self-assembled monolayer and double-layer dodecyl phosphonate modified 304 type stainless steel electrode were prepared.The electrodes were characteristiced by static contact angles and electrochemical polarization methods.The results suggested that the double-layer modified stainless steel electrode had better corrosion inhibition effect than the monolayer modified electrode.

Electrodeposition Of Sol-Gel Imprinted Films Modified Electrode And Its Application For 3,4-Dihydroxybenzoic Acids Determination, Gui-Lin Wang, Rong Wang, Xia-Qin Wu, Zong-Rang Zhang

Journal of Electrochemistry

The sol-gel molecularly imprinted films modified glassy carbon electrode was prepared by electrodeposition of tetramethoxysilane(TMOS) and phenyltrimethoxysilane(PTMOS) with chronoamperometry in the presence of template molecules 3,4-dihydroxybenzoic acid(3,4-DHBA) followed by extraction with ethanol.The modified electrode could successfully avoid the polymerization of oxidized 3,4-DHBA and the interference of 2,4-DHBA.A linear concentration response curve was obtained from 1.0 × 10^-5 mol·L^-1 to 8.0×10^-4 mol·L^-1,with the detected concentration limit of 5.0 × 10^-6 mol·L^-1.

Carbon Nanotube Array Electrodes Based Supercapacitors With 3.5v Working Voltage, Hao Zhang, Gao-Ping Cao, Yu-Sheng Yang, Zhen-Nan Gu, Bin Xu, Wen-Feng Zhang

Journal of Electrochemistry

The carbon nanotube arrays(CNTA) were grown directly on the substrates of Ta and stainless steel by chemical vapor deposition.The button-like supercapacitors were fabricated based the CNTA electrodes.The electrochemical performance of CNTA based supercapacitors presentsed high working voltage(3.5 V),long cycle life,and good rate capability.The power and energy densities are were 928 kW·kg^-1 and 19 Wh·kg^-1,respectively(based on the mass of CNTA).

Direct Electrochemistry Of God On Glassy Carbon Electrode Modified With Mesoporous Carbon, Kun-Qi Wang, Lin Zhu, Wei Xing

Journal of Electrochemistry

Glucose oxidase(GOD) is immobilized on glassy carbon electrode mesoporous carbon by simple method.Cyclic voltammetric results indicated that on GOD of the modified electrode a quasi-reversible redox reaction took place(GCE) surface modified at a formal potential of-0.4294 V in 0.1 mol/L phosphate buffer solution(PBS)(pH 7.1).The electrochemical reaction consisted of a two-electron transfer coupled with a two-proton transfer.The GOD can completely catalyze oxidation of glucose via electron transfer intermedia of ferrocene monocarboxylic acid(FMCA) in saturated solutions with N₂.The bioactivity of GOD on the modified electrode with mesoporous carbon was obviously unattacked.

Electrochemical Performance Of C-Lifepo4 By Polyaniline Doping, Wei Wang, Li-Fang Jiao, Hua-Tang Yuan

Journal of Electrochemistry

The olivine LiFePO₄ cathode materials were synthesized using the solid state method in an inert atmosphere by doping polyaniline into the C-LiFePO₄.It was found that the electrochemical performance of polyaniline-doped C-LiFePO₄ slightly improved.At a low discharging rate(0.1C), the capability of(C-LiFePO₄)0.9(PANI)0.1 reached 164 mAh·g^-1.When the charge-discharge rate is increased to 0.5C and 1.0C,the showed capacities of 121.6 mAh·g^-1 and 110.1 mAh·g^-1 were obtained,respectively.

Electroless-Deposition Synthesis Of Highly Active Ptru/C And Ptrusn/C As Anode Catalysts For Defc, Jing Zhu, Yi Su, Hua Ma, Fang-Yi Cheng, Zhan-Liang Tao, Jing Liang, Jun Chen

Journal of Electrochemistry

In this paper,the preparation,characterization,and ethanol electrocatalytic oxidation of Pt_0.5Ru_0.5/C and Pt_0.5Ru_0.15Sn_0.35/C electrocatalysts were reported.The electroless-deposition with sensitization-activation pretreatment was applied to prepare Pt_0.5Ru_0.5/C and Pt_0.5Ru_0.15Sn_0.35/C electrocatalysts. The XRD and TEM analyses showed that the as-prepared catalysts were composed of well-dispersed PtRu or PtRuSn nanoparticles with an average particle size of about 3 nm.The electrochemical measurements demonstrated that the as-prepared Pt_0.5Ru_0.5/C and Pt_0.5Ru_0.15Sn_0.35/C catalysts exhibited much enhanced peak current density for …

Electrocatalytic Performance Of Pt/C And Pt/Wo3/C Catalysts For Methanol Oxidation, Yuan-Yuan Chu, Bing Wu, Ya-Wen Tang, Tian-Hong Lu, Ying Gao

Journal of Electrochemistry

The catalysts of Carbon supported Pt(Pt/C) and carbon supported Pt/WO₃(Pt/WO₃/C) were prepared with liquid phase reduction method.It was found that the catalytic activity and stability of the Pt/WO₃/C catalysts were increased with the addition of WO₃.When the atomic ratio of Pt and W was 1∶1,the best electrocatalytic performance of the Pt/WO₃/C catalyst for the methanol oxidation was obtained.This is attributed to the larger electrochemical surface area of Pt/WO₃/C and the weeker adsorption of CO towards the catalyst.

Preparation And Electrochemical Capacitance Of Spherical-Like Polypyrrole Doped With Heparin Sodium, Hong-Yu Mi, Xiao-Gang Zhang, Su-Dong Yang, Xiang-Guo Ye

Journal of Electrochemistry

Spherical-like polypyrrole with an average diameter of 100 nm as the electrode material for supercapacitor was prepared by a self-assembly process with heparin sodium salt as the dopant at-10 ℃.The morphology and electrochemical properties were characterized by transmission electron microscopy(TEM),cyclic voltammetry(CV),galvanostatic charge/discharge and electrochemical impedance spectroscopy(EIS) measurements.The results showed that the polypyrrole doped with heparin sodium salt exhibited good capacitive behavior.The specific capacitance of single electrode was up to 338 F/g at 3 mA/cm².

Synthesis Of Agv3O8 As High-Capacity Of Cathode Materials For Lithium Secondary Batteries Via A Soft Chemistry Technique, Xiao-Yu Cao, Tao Li, Ling-Ling Xie, Xiang-Yang Yan, Chi-Wei Wang

Journal of Electrochemistry

The layered cathode material of AgV₃O₈ has been prepared for the lithium secondary batteries via the soft chemistry technique. The so-synthesized powders were characterized by XRD(powder X-ray diffraction), SEM(scanning electron microscope) and LPSA(laser particle size analysis). The electrochemical property was investigated by the galvanostatic discharge-charge technique. The results indicated that the particale sizes of AgV₃O₈ prepared were small in the distribution of narrow range, which leads to high discharge capacity. Among them, the material synthesized at 400 ℃ displayed the first discharge capacity of 760.5 mAh/g.

Passivation Behaviors Of Mo, W Electrodes In Mgcl2-Kcl-Nacl-Cacl2 Molten Salt For Electrolysis Of Magnesium, Ye Chen, Ke Ye

Journal of Electrochemistry

The discharge process and passivation behaviors of Mg(Ⅱ) on cathode(Mo, W) in MgCl₂-KCl-NaCl-CaCl₂ molten salt system had been investigated by means of cyclic voltammetry and chronoamperometry. The composition of molten salt was MgCl(10%) + CaCl(20%) + NaCl(60%) + KCl(10%)(by mass) and the temperature of electrolysis was 725 ℃. The deposition potential of Mo was 37 mV more negative than that of W, while the peak current was sharper than Mo according to the voltammograms at 0.05 V/s, indicating that the passivation on Mo cathode is easier than W. The formation of MgO impurities during the electrolysis could …

The Effect Of Annealed Temperature On Properties Of Ru-Ir-Sn Oxide Anode Coatings, Lei Ji, Jun-Tao Wang, Li-Kun Xu, Wen-Bin Liu, Gui-Lin Xue

Journal of Electrochemistry

The anode coatings of Ru-Ir-Sn oxide were prepared by sol-gel method with different annealed temperatures.The influences of annealed temperature in properties of anode coatings were characterized by scanning electron microscope(SEM),energy dispersive X-ray detector(EDX),X-ray diffraction(XRD),potential of chlorine evolution,accelerated life,cyclic voltammetry and electrochemical impedance spectroscopy(EIS) tests.The results showed that the annealed temperature affected the morphology of coatings,while the electric quantities of cyclic voltammetry and double layer capacitances of anode coatings had a tendency to fall down and the potential of chlorine evolution and accelerated life had a tendency to increase as the annealed temperature increased.

Preparation And Photoelectrochemical Properties Of Fe-Doped Tio2 Nanotube Arrays, Jing Li, Lan Sun, Hui-Fang Zhuang, Cheng-Lin Wang, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

The Fe-doped TiO₂ nanotube arrays were fabricated in Fe(NO₃)₃-HF mixing solutions by electrochemical anodic oxidation method,and characterized by FESEM,Raman,XPS and DRS.The effect of Fe concentratiions on photoelectrochemical property of the arrays was also investigated.The diameters and lengths of Fe-doped TiO₂ nanotube arrays were 50~90 nm and about 200 nm,respectively.Compared with the undoped TiO₂ nanotube arrays,the absorption edge of Fe-doped TiO₂ nanotube arrays appeared red shifting.The more Fe content,the larger red shifting,in addition,the photocurrent of Fe-doped TiO₂ nanotube arrays increased obviously.

Cyclic Voltammetry And In Situ Ftir Studies Of Cyanide Adsorption On Nanostructured Au Film Electrode In Alkaline Solutions, Chun-Hua Zhen, Chun-Jie Fan, Shi-Gang Sun

Journal of Electrochemistry

The adsorption of cyanide(CN^-) on electrodes of nanometer scale thin film of gold supported on glassy carbon(nm-Au/GC) in alkaline solutions were investigated using cyclic voltammetry and in situ FTIR spectroscopy.It has revealed that the electrodeposited nanostructured Au thin film exhibited AIREs(abnormal infrared effects) for CN^-adsorption,which manifested 3 nonlinear IR spectral features: inversion of the direction of CN^-band,enhancement of IR absorption of adsorbed CN-species(about 39.2 folds) and increase in the FWHM(full width at half maximum) of CN^-band.

Quick Tester With Usb Interface For The Corrosion Protection Properties Of Organic Coating, Xiang-Dong Zhuo, Chang-Jian Lin

Journal of Electrochemistry

According to the principle of multiple dynamic potential scaning polarization,a quick tester with USB interface for the fast study of corrosion resistance properties of organic coating/ metal system has been developed.This tester is portable,facile,practical,and has a strong function for data collection and data treatment.It is not only suitable for the accelerated test in laboratory,but also for the quick test and evaluation to the corrosion resistance of the organic coating/metal system in industrial spots.

Electrochemical Performances Of Copper/Activated Carbon Composites, Lan-Ting Li, Qiang Xie, Wen Yan, Yan-Yan Wang, Wen-Wen Xing

Journal of Electrochemistry

The development and improvement of electrode materials can result in the enhancement of the performances of electrochemical capacitor.In this paper various copper/activated carbon composites were prepared in the presence of different amounts(from 0% to 40%) of copper nitrate from bituminous coal.Then different electrodes were prepared from copper oxide,activated carbon and copper/activated carbon composites,respectively,and were characterized by cyclic voltammetry,alternative current(AC) impedance,charge-discharge at constant current and maintenance of the self-potential.The results showed that the proper amount of copper in copper/activated carbon composites positively influenced the electrochemical performances of electrodes,and the capacitance of copper/activated carbon composites was larger than that of the total …

Preparation Of Zn-Ni Alloy Whisker By Electrochemical Method, Zhen-Hai Liang, Xi-Hua Xia

Journal of Electrochemistry

The Zn-Ni alloy whiskers were prepared by electrochemical method and were characterized by XRD, SEM and EDS methods. The results showed that Ni₅Zn₂₁ and Ni₃Zn₂₂ whiskers were obtained with the length of 2~4 μm and the diameter of 250 nm, thereby the rations of length/diameter fell between 8 and 16. The electrochemical behavior was investigated by cyclic voltammetry method simultaneously. A new method was provided on whisker preparation based on this work.

Synthesis And Electrochemical Characteristics Of Li[Li(0.167)Mn(0.583)Ni(0.25)]O2 Cathode Material, Ling-Yan Yu, Wei-Hua Qiu, Fang Lian, Jia-Yuan Huang, Xao-Li Kang, Wei Liu

Journal of Electrochemistry

The cathode material of Li[Li_0.167Mn_0.583Ni_0.25]O₂ was synthesized by low-heat solid state reaction.The results of XRD and FESEM indicated that the powders of the material were well crystallized with the uniform diameters ranging from 60 nm to 100 nm and could be indexed as α-NaFeO₂ structure(R3-m space). Galvanostatic charge-discharge tests showed that the electrode delivered the capacity of about 120 mAh/g with good cyclability when cycled in 2.5~4.4V at 0.5C. When the cut-off potential was set up to 4.6V, the cathode delivered much larger capacities with the maximum of 234 mAh/g. It was …

The Effect Of Vibratory Milling On The Powder Properties Of Zinc Oxide Varistors, Maura Kelleher, M.S.J. Hashmi

Articles

The formation of powders from multi-elemental oxides for the subsequent formation of a green and sintered compact body is a major processing operation in the manufacture of ZnO varistors. The physical and chemical properties of the metal oxides are crucial not only for the formation of a varistor component with optimum microstructure and thus electrical characteristics but also for avoiding the introduction of flaws and reduced yield during subsequent manufacturing stages. The effect of vibratory milling using cylindrical zirconia media on the physical and chemical properties of the mixed multi-elemental oxide additives of a commercial ZnO varistor formulation was studied. …

Improving Steel Cleanliness Through Slag Refining, Sarina Bao, Xinhua Wang, Lifeng Zhang, Shufeng Yang, Kent D. Peaslee

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Optical Properties Of Colloidal Core/Shell Nanocrystals, Abhishek Joshi

Electrical Engineering Undergraduate Honors Theses

Recently, colloidal core/shell nanocrystals have found use in several applications such as solar cells, light emitting diodes, fluorescent dies, etc. In this thesis, optical properties of colloidal CdSe/ZnS core/shell nanocrystals were studied. The samples were prepared such that the nanocrystals were embedded in a UV curable resin. Once the samples were cured, they were placed in different spectrophotometers to measure the absorbance and the photoluminescence (PL) spectrum. The effect on the absorbance and PL spectra was investigated by using nanocrystal samples of different quantum dot sizes and by changing the temperature of the samples. It was found that the energy …

Tribological And Antiwear Mechanisms Of Fluorinated Zinc Dialkyl Dithiophosphate In Comparison To Zinc Dialkyl Dithiophosphate In Engine Oils, Ramoun Mourhatch

Material Science and Engineering Dissertations - Archive

Tribofilms generated in wear tests using lubricants containing fluorinated ZDDP and ZDDP were studied. Fluorinated ZDDP demonstrated superior wear performance compared to ZDDP under tribological conditions even at lower phosphorus levels. Chemical properties and the molecular structure of the fluorinated ZDDP were examined and presented in a previous companion study by Parekh and Aswath [1] using techniques such as NMR and DSC while this study examines the tribological behavior of this compound and the characteristics of the tribofilms formed by it. Ball on cylinder tribological tests were conducted with lubricants containing this new fluorinated thiophosphate compound and compared to lubricants …

A Study Of The Antiwear Behavior And Oxidation Stability Of Fluorinated Zinc Dialkyl Dithio Phosphate In The Presence Of Antioxidants, Anuradha Somayaji

Material Science and Engineering Dissertations - Archive

The antiwear additive Zinc dialkyl dithio phosphate (ZDDP) is one of the most important components of engine-oil additives and a major source of phosphorus. Phosphorus plays a crucial part in mitigating engine wear, yet has been proven harmful to modern catalytic converters. Progressive regulatory caps on phosphorus content in automotive lubricants have led to widespread efforts to reduce its levels. A new fluorinated ZDDP (F-ZDDP) complex developed at the University of Texas at Arlington has found to breakdown at lower temperatures compared to ZDDP and has showed better wear performance than ZDDP alone. This would allow the possibility of further …