Engineering Commons^™

Slides: Agricultural Resilience And Urban Growth: A Closer Look, William R. Travis

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: William R. Travis, Department of Geography, Center for Science & Technology Policy Research, CIRES, University of Colorado at Boulder

30 slides

South Burlington Vt: New Urbanist South Village, Jack Kartez, Richard Barringer

Planning

The 220 acre master plan for South Village, the largest project in the City of South Burlington’s history, encompasses multiple housing types and innovative provisions for affordable housing. It integrates housing with open space and natural resource conservation, including a major Community Supported Agriculture project developed by a nonprofit partner, the Intervale Foundation. While not a mixed-use project (that is, commercial as well as residential development), South Village nonetheless represents a qualitative change in approach for South Burlington by incorporating large-scale open space preservation as part of development and multiple housing-types in one project. The case study recounts events leading …

Routing In The Dark: Pitch Black, Nathan S. Evans

Electronic Theses and Dissertations

In many networks, such as mobile ad-hoc networks and friend-to-friend overlay networks, direct communication between nodes is limited to specific neighbors. Friendto-friend “darknet” networks have been shown to commonly have a small-world topology; while short paths exist between any pair of nodes in small-world networks, it is non-trivial to determine such paths with a distributed algorithm. Recently, Clarke and Sandberg proposed the first decentralized routing algorithm that achieves efficient routing in such small-world networks.

Herein this thesis we discuss the first independent security analysis of Clarke and Sandberg’s routing algorithm. We show that a relatively weak participating adversary can render …

Web Based Classes For Enhancement Of Prelaboratory Lectures, Tiffany Hesser, Michael Collura

Chemistry and Chemical Engineering Faculty Publications

The use of web classes, such as Tegrity Campus1, as a supplement to pre laboratory reading or a replacement for pre laboratory lectures could become a standard tool in laboratory education protocol. In classes with multiple lab sections and instructors, pre laboratory lectures can lack consistency and it can be difficult to gauge the students’ level of preparation. With the ever increasing exposure to technology, students generally prefer information in a digital and multimedia form, rather than textbook readings. Therefore, this method can prove to better prepare students prior to laboratory experiments, increasing the overall understanding of the chemical reactions …

Reconstruction Of The Upper Torso Using X-Ray Imagery, Thomas Wischgoll, Christopher Koehler

Computer Science and Engineering Faculty Publications

No abstract provided.

Store And Forward Routing For Sparse Pico-Satellite Sensor Networks With Data-Mules, Trevor Joseph Koritza

Master's Theses

Satellites are playing an increasingly important role in collecting scientific information, providing communication services, and revolutionizing navigation. Until recently satellites were large and very expensive, creating a high barrier to entry that only large corporations and government agencies could overcome. In the past few years the CubeSat project at California Polytechnic University in San Luis Obispo (Cal Poly) has worked to refine the design and launching of small, lightweight, and less expensive satellites called pico-satellites, opening space up to a wider audience. Now that Cal Poly has the launch logistics and hardware under control, a new problem has arisen. These …

Pressure-Driven Transport Of Particles Through A Converging-Diverging Microchannel, Ye Ai, Sang W. Joo, Yingtao Jiang, Xiangchun Xuan, Shizhi Qian

Mechanical Engineering Faculty Research

Pressure-driven transport of particles through a symmetric converging-diverging microchannel is studied by solving a coupled nonlinear system, which is composed of the Navier–Stokes and continuity equations using the arbitrary Lagrangian–Eulerian finite-element technique. The predicted particle translation is in good agreement with existing experimental observations. The effects of pressure gradient, particle size, channel geometry, and a particle’s initial location on the particle transport are investigated. The pressure gradient has no effect on the ratio of the translational velocity of particles through a converging-diverging channel to that in the upstream straight channel. Particles are generally accelerated in the converging region and then …

Software Quality Attribute Measurement And Analysis Based On Class Diagram Metrics, Dalia Rizk

Archived Theses and Dissertations

Software quality measurement lies at the heart of the quality engineering process. Quality measurement for object-oriented artifacts has become the key for ensuring high quality software. Both researchers and practitioners are interested in measuring software product quality for improvement. It has recently become more important to consider the quality of products at the early phases, especially at the design level to ensure that the coding and testing would be conducted more quickly and accurately. The research work on measuring quality at the design level progressed in a number of steps. The first step was to discover the correct set of …

Probability Density Functions For Snir In Ds-Cdma, David W. Matolak

Faculty Publications

Analytical expressions for the probability density function of block-wise signal-to-noise-plus-interference ratio for both synchronous and asynchronous direct-sequence spread spectrum code-division multiple access systems are developed, for equal average energy signals on the Gaussian and Rayleigh flat fading channels. Using the standard Gaussian approximation for multi-user interference, accurate density approximations are obtained, which agree very well with computer simulation results.

Effect Of Liquid Dispersion On Corrosion Behavior Of Metals In Gas/Liquid/Solid Multiphase Corrosion Systems, Jing Jiang, Jia Wang

Journal of Electrochemistry

Liquid dispersion,described by the parameters of gas/liquid/solid three-phase boundary(TPB) zone of dispersed liquid on a metal surface,is an important property of liquid state influencing corrosion behavior of metals in gas/liquid/solid multiphase corrosion systems.In our paper,the characterisation of cathodic oxygen reduction process in TPB zone was discussed,and a model describing the cathodic process of TPB zone was developed.On this basis,the relationship between the cathodic limiting current and the TPB parameters was studied,and the simulation results were in good agreement with the experimental data.The role of liquid dispersion in atmospheric and sandy soil corrosion systems was also simulated.

Electrodeposition Of Al On Magnesium Alloy In Ionic Liquid, Wen-Ta Tsai, Shu-You Chen, Mu-Huan Zhuang, Jeng-Kuei Chang, Yi-Wen Sun

Journal of Electrochemistry

Electrodeposition of a metallic aluminum on a magnesium alloy in acidic aluminum chloride-1-ethyl-3-methylimidazolium chloride ionic liquids(AlCl₃-EMIC) was investigated.The effects of current density and AlCl₃ content in the ionic liquid on the electrodeposition behavior were studied.The results showed that aluminum could be successfully electrodeposited on the AZ91D substrate.At-0.2 V,the ionic liquid containing 60 m/o AlCl₃ was optimum for Al electrodeposition.The current efficiency was higher if electrodeposition was performed at a lower applied current density.The existence of Al coating could caused a substantial increase in open circuit potential,reducing the susceptibility of Mg alloy to corrosion.The results of electrochemical …

Electrochemical Characteristics Of Vitaminb6 At Polybromocresol Green Modified Electrode, Jun Yao, Jiang-Yuan Li, Yang Luo

Journal of Electrochemistry

Electrochemical characteristics of VB₆ were investigated at PBG modified electrode by Cyclic voltammetry and linear sweep voltammetry.The VB₆ produced an irreversible oxidation peak at 0.978 V(Vs.SCE) in HAc-NaAc(pH=4.0) buffer solution over the potential range of 0.7 to 1.2 V.The electron number,the proton number,the transfer coefficient were determined to be 1,1 and 0.37,respectively.The oxidation peak currents of VB₆ versus its concentration showed a linear relationship in the concentration range of 1×10^-3~2×10^-5mol/L with the correlation coefficient of 0.9967 and the detection limit of 2×10^-6mol/L.The recovery was 100.06%.

Corrosion Performance Of Epoxy Coatings By Chemical Modification With Silanes, Liang Liu, Wei-Gang Ji, Ji-Ming Hu, Jian-Qing Zhang, Chu-Nan Cao

Journal of Electrochemistry

The improvement of corrosion performance of epoxy coatings by modification with "active" and "non-active" silanes is presented."Active" silanes are defined as ones having functional groups that can react with the epoxy groups in the epoxy resin,usually amino-silanes."Non-active" silanes are defined as ones not reacting with the epoxy groups,but can react with the hydroxyl groups in the epoxy backbone by the condensation reactions under the catalysis of organic tin compounds.The FTIR results showed that both the "active" and "non-active" silanes had been successfully grafted onto the epoxy resin.Electrochemical impedance spectroscopy(EIS) and accelerated corrosion test(Machu test) showed that the corrosion performance of …

Electrode Of Metallic Oxides Coated Titanium With Interlayer, Yi Tang, Li-Kun Xu, Yong-Lei Xin, Jun-Tao Wang, Ping Long

Journal of Electrochemistry

Various Ti/IrRuSn,Ti/IrTa/IrRuSn and Ti/IrTaSn/IrRuSn oxide electrodes were prepared by sol-gel method.The surface morphology and microstructure were analysed with FESEM and XRD.The electrochemical activity and stability were investigated using electrochemical technologies including chlorine and oxygen evolving potential measurements,cyclic voltammetry,accelerated life test,and alternative electrolysis.The results indicate that the electrodes with interlayers present more cracks on the surface and a little bigger average grain size,with particles of different shapes precipitated in the cracks.The electroactive sites are increased and the selectivity for the chlorine evolving reaction is enhanced,but the current efficiency for the chlorine production is somewhat lowered by the addition of different interlayers.The …

The Accelerated Test Of Simulated Atmospheric Corrosion And The Rust Evolution Of Low Carbon Steel, Jun-Hua Dong, Wei Ke

Journal of Electrochemistry

It has been set up an accelerated method of simulating to atmospheric corrosion by using wet/dry alternate test.The rust evolution rule of mass change vs time(in logarithmic coordinate) of low carbon steel under this test shows two linear sections with different slopes,in which the rust evolution transition in weight change corresponds to the compactness transition and crystallization transition during the rust layer growth.It has found that the rust evolution rule of low carbon steel in Wanning exposure site correlates to the rust evolution rule obtained by simulating the coastal atmospheric corrosion test,and the rust evolution rule of low carbon steel …

Investigation Of Electrochemical Noise In The Crevice Corrosion Of Q235 Carbon Cteel, Qian Hu, Yu-Bing Qiu, Xing-Peng Guo

Journal of Electrochemistry

The crevice corrosion behavior of Q235 carbon steels in a NaHCO₃+NaCl solution was investigated by electrochemical noise(EN) and electrochemical impedance spectroscopy(EIS).Three stages of crevice corrosion including the induction,the rapid transform and the stable development could be clearly distinguished.The characteristics of the electrochemical noise and the noise resistance Rn showed remarkable differences at each stage.The electrode area ratio(r) of outside to inside the crevice had a significant influence in the development of crevice corrosion.The time of the induction stage increased with increasing r.However,under the stable development stage of the crevice corrosion,the surface outside the crevice was at an active …

Effect Of Naphthalene Water Reducer On Corrosion Behavior Of Reinforcing Steel In Concrete, Yu-Ming Tang, Jie Zhang, Yu Zuo

Journal of Electrochemistry

The influence of naphthalene water reducer on corrosion behavior of reinforcing steel in concrete was studied by the methods of corrosion potential measurement,linear polarization and EIS test.The values of concrete resistance(Rc) and polarization resistance(Rp) of the samples with naphthalene water reducer were higher than those without naphthalene water reducer,especially in the concrete with 0.2 percent naphthalene water reducer.A suitable amount of water reducer can improve the pore structures of concrete,increase the concrete compactness and impermeability,and decrease corrosion rate of rebars in concrete.

Effect Of Electrochemical Property Of Uns J91450 Stainless Steel On Stress Corrosion Cracking In Hydrogen Sulfide Solutions, Zhi-Yong Liu, Chao-Fang Dong, Xiao-Gang Li, Li-Xian Wang

Journal of Electrochemistry

Effect of electrochemical behaviours on stress corrosion cracking(SCC) of UNS J91450 stainless steel in hydrogen sulfide environment was investigated using slow-strain-rate test(SSRT) and electchemial techniques.Results show that UNS J91540 stainless steel was susceptible to SCC in varying H₂S solutions,and the SCC susceptibility reduced with the increase of pH value.The electrochemical property plays an important role in the SCC occurrence,as a combined effect of hydrogen embritlement and anodic dissolution at SCC cracktip at open circuit potential.In the solution with a lower pH the hydrogen revolution was intensive and the cracktip anodic dissolution was weaker,however,in the higher pH solution the …

Developments Of Scanning Electrochemical Probes And Their Applications In Studying Of Localized Corrosions, Chang-Jian Lin, Yan Li, Bin Lin, Rong-Gang Hu, Min Zhang, Xiang-Dong Zhuo, Rong-Gui Du

Journal of Electrochemistry

The electrochemical inhomogeneities always exist at the interface of metal/solution,and play an important and often controlling role in localized corrosion of metals in a given environment.It is necessary to develop in situ imaging techniques for further studying the electrochemical and environmental inhomogeneities at the interface of metal/solution for the localized corrosion system.In this paper,various techniques with spatial resolution,such as scanning micro reference electrode(SMET),scanning electrochemical microscope(SECM),atomic force microscope(AFM),and scanning Kelvin probe(SKP),and their applications in corrosion studies were briefly reviewed.The chemical probes and array electrode have been developed.It was concentrated to describe our newly developed techniques of the scanning electrochemical probes,including SMET …

Preparation And Electrochemical Properties Of Layered Manganese Oxide(Li-Birnessite Type), Xing-Kang Huang, Hai-Tao Chang, Jian-Long Gan, Qing-Shun Zhang, Hong-Jun Yue, Dong-Ping Lv, Yong Yang

Journal of Electrochemistry

Layered Li-birnessite was prepared by means of oxidizing Mn²⁺ with O₂ gas in alkaline media.The as-prepared sample was characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), BET and thermogravimetric/diffenential thermal analysis(TG/DTA) techniques. The electrochemical properties of the material were also investigated. The results show that such a Li-birnessite consists of well-crystallized spherical particles with an interlayer distance of 0.70 nm. The Li-birnessite delivered a high discharge capacity of 203 mAh/g at a rate of 0.2 C(40 mA/g), and had good rate capability as well.

Electrochemical Behavior Of Mg-Li Electrodes In Nacl Solution, Lin Wu, Yan-Zhuo Lv, Xue Cao, Gui-Ling Wang, Dian-Xue Cao

Journal of Electrochemistry

The Mg-Li electrodes containing 8.5% and 14% Li were prepared using an induction melting method. Their electrochemical behavior in NaCl solution was investigated by means of potentiodynamic polarization, potentiostatic oxidation,electrochemical impedance technique and mass-loss measurements. The morphology of the electrodes after discharge was examined using scanning electron microscopy. The Mg-14Li electrode showed more negative open circuit potential and higher discharge current density than Mg-8.5Li electrode. The oxidation products of Mg-14Li loosely attached on the electrode surface and peeled off easily. The Mg-8.5Li exhibited higher utilization efficiency. Both electrodes gave higher utilization efficiencies when discharged at lower anodic potential.

Electrochemical Performance Of The Exfoliated Graphite Containing Sulfur Cathode Material For Lithium Sulfur Battery, Ke-Guo Yuan, Wei-Kun Wang, Zhong-Bao Yu, An-Bang Wang

Journal of Electrochemistry

The exfoliated graphite containing sulfur cathode material was prepared by the high temperature sulfur gas diffusion adsorption method.This cathode material could obtain an initial discharge specific capacity 972 mAh·g^-1,capacity retention ratio 78% and cycling efficiency above 80%,respectively.The exfoliated graphite containing sulfur cathode could decrease the reaction interphase charge transfer impedance,and restrain the sulfur or polysulfide shuttle phenomenon during the charge-discharge process through improving the diffusion impedance.

Effects Of Kscn On Kinetic Characters Of The Positive Couple And Performance For Vanadium Redox Flow Battery, Jian-Guo Liu, Dong Shi, Yue Men, Chuan-Wei Yan

Journal of Electrochemistry

In order to improve the reaction activity of VO²⁺/VO²⁺ and the battery performance of Vanadium redox flow battery,different concentration of potassium sulfocyanates KSCN were added into 0.1mol/L VOSO₄/ H₂SO₄ solution,and the kinetic characters of electrochemical reaction of VO²⁺/VO²⁺ was studied by CV and EIS.The results showed that the addition of KSCN could improve the oxidative peak current value of positive couple VO²⁺/VO²⁺ reaction,but had little influence in the reductive peak.The addition of KSCN decreased the impedance at 1.0 V.And the value of standard rate constant k0 …

Effect Of Impurity Cu(2+) On Oxygen Electrode In Pemfc, Xiao Jie, Jun-Bo Hou, Zhi-Gang Shao, Bao-Lian Yi

Journal of Electrochemistry

Rotating disk electrode was adopted in this paper to simulate the cathode in PEMFC.In the Cu²⁺ electrolyte,the influence of impurity Cu²⁺ on Carbon-Supported Pt Catalysts was investigated by using electrochemical measurements such as chronocoulometry,cyclic voltammetry and linear sweep.Experimental results showed that,after constant voltage at 0.49 V,the ECA of Pt/C decreased dramatically,it's perhaps under potential deposition of Cu might occur on the substrate.Meanwhile the change of ORR Tafel scope reaction is very large.It might be because oxygen adsorption sites are occupied by Cu atoms after they under potential deposit on surface of Pt/C catalyst,and the adsorption of oxygen on …

Electro-Oxidation Of Methanol On Fe-Doped Pt-Zro2/C Catalyst, Mao-Cai Lin, Dong-Dong Liu, Qing-Chun Yu, Ming-Ruo Hu, Heng-Yong Tu

Journal of Electrochemistry

The Fe-doped ZrO₂ powders were prepared by so-gel method.After that,Pt-Zr_1-xFe_xO₂/C catalysts were made by reducing platinum salts with ethylene glycol.The physical property of the catalyst was characterized by XRD and TEM.It was found that the distribution of the catalyst was narrow,the particle sizes of Pt and ZrO₂ particles were 2~4 nm and 3~7 nm,respectively.The Cyclic Voltammetry and Chronoamperometry testing indicated that the electro-catalytic activity for methanol electro-oxidation on Pt-ZrO₂/C catalyst increased when ZrO₂ was doped with Fe.And Pt-Zr_0.95Fe_0.05O₂/C catalyst showed the highest activity …

Complex Of 3-Amino-1,2,4-Triazole And Na2Wo4 As An Inhibitor For Brass Corrosion, Qun-Jie Xu, Chun-Xiang Li, Yu-Hong Ni, Guo-Ding Zhou

Journal of Electrochemistry

AC impedance and polarization methods were used to study the inhibition effect of ATA and the complex of ATA and Na₂WO₄ for brass corrosion in 3% NaCl solution.The results indicated that ATA had inhibition effect for brass corrosion.ATA showed the best inhibition effect for brass corrosion at the ATA concentration of 7.5 mg·L^-1,and the inhibition efficiency was 87.46%.At the ATA concentration of 7.5 mg·L^-1 and at the Na₂WO₄ concentration of 0.15 mg·L^-1,the complex showed optimum inhibition effect for brass corrosion,and also showed synergistic effect and the inhibition efficiency reached …

Influence Of Nano-Al2O3 Particles In Nickel Electro-Crystallization Process, Cheng-Yu Tan, Wei Hu, Hang Cui, Yu Liu

Journal of Electrochemistry

The influence of nano-Al₂O₃ particles in nickel electro-deposition on copper matrix from acid sulphate solution was studied under various potentials by using cyclic voltammetry(CV) and chronoamperometry(CA).The results show that the beginning potential of electro-deposition was about-740 mV(vs.SCE) for Ni-Al₂O₃ solution system.With the step-potential moving to the negative direction,the nucleation time of electro-deposition for Ni-Al₂O₃ solution system was shortened gradually.Compared with that of pure Ni deposition system,the nucleation time tm,corresponding to the peak current of Ni-Al₂O₃ deposition system was apparently shortened under the lower step-potential:-740~-830 mV,which indicates that Al …

Deployed Software Analysis, Madeline M. Diep

School of Computing: Dissertations, Theses, and Student Research

Profiling can offer a valuable characterization of software behavior. The richer the characterization is, the more effective the client analyses are in supporting quality assurance activities. For today's complex software, however, obtaining a rich characterization with the input provided by in-house test suites is becoming more difficult and expensive. Extending the profiling activity to deployed environments can mitigate this shortcoming by exposing more program behavior reflecting real software usage. To make profiling of deployed software plausible, however, we need to take into consideration that there are fundamental differences between the development and the deployed environments. Deployed environments allow for less …

Cybercrime And The 2012 London Olympics, Denis Edgar-Nevill

Annual ADFSL Conference on Digital Forensics, Security and Law

The London 2012 Olympics is just three years away and the clock is ticking to put in place plans get it right. The potential for cybercrime to cause harm during this event is very great; harm to national reputation, harm to the reputation to the Olympic movement, and harm to individuals competing, watching or officiating. This paper considers the need to address these risks by taking a look at what has happened in the past at sporting events and the rising wave of electronic security threats and fraud facilitated by computers at recent Olympics. The problems for law enforcement are …

Methodology For Investigating Individuals Online Social Networking Persona, Jonathan T. Rajewski

Annual ADFSL Conference on Digital Forensics, Security and Law

When investigators from either the private or public sector review digital data surrounding a case for evidentiary value, they typically conduct a systematic categorization process to identify the relevant digital devices. Armed with the proper methodology to accomplish this task, investigators can quickly recognize the appropriate digital devices for forensic processing and review. This paper purposes a methodology for investigating an individual’s online social networking persona.

Keywords: Social Networking, Web 2.0, Internet Investigations, Online Social Networking Community