Engineering Commons^™

Optimizing Catalyst Layer Composition Of Pemfc By Orthogonal Method, Ming-Hua Wang, Xin-Jian Zhu, Guang-Yi Cao, Sheng Sui, Qing-Chun Yu, Ming-Ruo Hu, Zheng-Yu Fan

Journal of Electrochemistry

The optimal composition of catalyst layer in a PEMFC electrode was studied through orthogonal method. It was showed that the performance of hydrophilic electrodes, in which there is no PTFE in the catalyst layer, were more favorable than that of hydrophobic electrodes. According to this condition, the power density of PEMFC attained 0.37 w·cm^-2 when the Nafion loading was 1.4 mg·cm^-2, and the Pt loading was 0.4 mg·cm^-2 in the catalyst layer, using H₂ as fuel and air as oxidant both at atmospheric pressure. Additionally, the results showed that increasing Pt loading in Pt/C catalyst …

Study On Degradation Of Phenol By Electrochemical Oxidation, Yue-Li Liu, Hong-Hua Ge

Journal of Electrochemistry

Electrochemical oxidation of phenol was carried out by the Dimensionally Stable Anodes (DSA) electrode, which has been discarded as waste by alkali chloride factory. The result indicates that a good phenol removal can be obtained under certain phenol concentration by the DSA electrode. The key factor in effecting phenol removal of electrochemical oxidation is applied current density, the following factors are pH, electrolyte concentration and phenol concentration. After experiments, the optimal test conditions are 30 mA/cm², pH 10, electrolyte concentration 10 mg/L, phenol concentration 10 mg/L.67% CODcr removal and 90% absorbance removal are gained by electrochemical oxidation for …

Adsorption And Oxidation Of Phenol Electrode Processes, Bao-Cheng Wang, Yan-Ping Sun, Jin-Hua Zhu

Journal of Electrochemistry

The electrochemical behaviors of platinum electrode were studied by cyclic voltammetry in 1mol/L sulfuric acid solution and 1mol/L sulfuric acid solution contained phenol. The adsorption characteristics of phenol and the intermediat on electrode surface have been discussed. The reactive reversibility and oxidation mechanism of phenol on electrode process have been investigated.The potential of characteristic adsorption was suggested. The various products woud be formed when the electrode potential was greater than the one of characteristic adsorption.

The Study Of Green Corrosion Inhibitors For Mild Steel 907 In Natural Seawater Environment, Ping Gong, Min Du, Qing-Zhang Wang, Zhen-Jun Mu

Journal of Electrochemistry

Nine green compounds, including calcium gluconate, zinc gluconate, zinc sulfate, garlic, ACUSOL 445N, OS-15, APG, OCTA and STPP were selected according to the methods of molecule design and function groups prune. The functions of combined corrosion inhibitors mixed by the compounds mentioned above for mild steel in seawater were studied in this work using the methods of polarization curve and weight-loss.The best weight ratio and distinct synergistic effect of calcium gluconate, zinc sulfate and OCTA were studied by Latin experiment. The afgereffects of the best weight ratio corrosoin inhibitor were studied by subsection experiment. In this way, a kind of …

The Study On Carbon Nanotube-Loaded Pt Catalysts For Proton Exchange Membrane Fuel Cells, Hong Zhu, Feng-Juan Ge, Xiao-Hong Kang, Yu-Guo Yang, Yun-Hua Xu

Journal of Electrochemistry

Carbon nanotube-supported-platinum (Pt/CNTs) and carbon-supported-platinum (Pt/C) catalysts were synthesized by in-situ chemical reduction. They were analyzed using TEM and XRD, then made into electrodes to be part of assemable PEMFC for the performence tests. The resulted show that Pt clusters in both catalysts are of small particle size (about 4nm), and Pt/CNTs exhibits a higher catalytic activity than Pt/C.

Effect Of Dspp Al2O3 On Electrical Properties Of Polymer Electrolyte, Hai-Fen Xie, Xiao-Xiang Sun, Yi-Pin Wang, Guang-Yuan Li

Journal of Electrochemistry

The PEO-NaSCN polymer solid electrolytes by adding dispersed second phase particles (DSPP) of Al₂O₃ were studied. The characteristics of solid electrolytes and conductivity values are dependent on DSPP Al₂O₃ sizes and its contents. It was found that when the Al₂O₃ sizes are less than 1 μm, which is a criticle size, the sample conductivities were larger than those of the pure PEO-NaSCN samples and when the Al₂O₃ sizes are larger than 1 μm then the sample conductivities are less then those of the pure samples. The maximum conductivity …

The Current Fluctuations Of Carbon Steel In Nano2-Nacl Solutions, Yu-Ming Tang, Yu Zuo

Journal of Electrochemistry

The characteristics of current fluctuations of A3 carbon steel in NaNO₂-NaCl solutions were studied with potentiostatic and potentiodynamic polarization methods. The steel remained stable passivation in 0.1 mol/L NaNO₂ solution without Cl^-. After NaCl was added in to the solution, current fluctuations with a characteristic of quick increase and slow decrease occurred, indicating quick dissolution and slow re-passivation of the metastable pits. The metastable pitting may cause accumulated corrosion damage around certain area and result in observable pits. With the increase of chloride concentration, the occurring potential for metastable pits Em rised, and peak values …

Extended Hough Methodology For 3d Feature Detection, Rufus H. Cofer, Samuel Peter Kozaitis, Jihun Cha

Electrical Engineering and Computer Science Faculty Publications

In an effort to make automatically detect image features for pattern recognition, we described a 3-dimensional (3-D) Hough transform. We describe two interlocking theoretical extensions to greatly enhance the Hough transform's ability to handle finite lineal features and allow directed search for various features while balancing memory and computational complexity. We computed the 2-D Hough transform of 1-D slices of an image which results in a 2-D to 3-D transform. Features such as line segments will cluster in a particular location so that both line orientation and spatial extent can be determined. This approach allows the Hough transform to be …

Modeling The Transient Response Of A Thermosyphon, James Kirk Storey

Theses and Dissertations

Thermosyphon transient operation was numerically modeled. The numerical model presented in this work overcame the limitations of previous studies by including transient conduction in the vessel wall, shear stress between the rising vapor and the falling film in the thermosyphon, the influence of the mass in the liquid pool in the evaporator, and by using a more refined and accurate numerical grid. Unique to this model was the accounting for temporal changes in the effective length of the vapor space due to the expanding and contracting of non-condensable gases in the vapor space. The model assumed quasi-steady one-dimensional vapor flow, …

Hardware-Based Dynamic Storage Management For High-Performance And Real-Time Systems, Victor H. Lai

All Computer Science and Engineering Research

Most modern application programs depend on dynamic storage management to handle allocation and deallocation of memory. Unfortunately conventional software-based storage managers are relatively low performance due to the latency associated with accessing DRAM memory. Consequently, developers of programs with very specialized memory requirements, such a real-time systems, often choose to manage memory manually at the application-code level. This practice can greatly increase performance but it can also significantly complicate the development process. In this thesis we present the design, VHDL implementation and performance evaluation of hardware-based storage manager called the Optimized Hardware Estranged Buddy System (OHEBS). The OHEBS implements four …

Comparison Between A Hydraulic Rotary Circuit And A Small Gasoline Engine Based On Speed, Torque, And Horsepower, Erick N. Jeffers

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 Erick N. Jeffers on November 24, 2003.

The Stromal Cell-Derived Factor-1alpha/Cxcr4 Ligand-Receptor Axis Is Critical For Progenitor Survival And Migration In The Pancreas., Ayse G. Kayali, Kurt Van Gunst, Iain L. Campbell, Aleksandr Stotland, Marcie Kritzik, Guoxun Liu, Malin Flodström-Tullberg, You-Qing Zhang, Nora Sarvetnick

Journal Articles: Regenerative Medicine

The SDF-1alpha/CXCR4 ligand/chemokine receptor pair is required for appropriate patterning during ontogeny and stimulates the growth and differentiation of critical cell types. Here, we demonstrate SDF-1alpha and CXCR4 expression in fetal pancreas. We have found that SDF-1alpha and its receptor CXCR4 are expressed in islets, also CXCR4 is expressed in and around the proliferating duct epithelium of the regenerating pancreas of the interferon (IFN) gamma-nonobese diabetic mouse. We show that SDF-1alpha stimulates the phosphorylation of Akt, mitogen-activated protein kinase, and Src in pancreatic duct cells. Furthermore, migration assays indicate a stimulatory effect of SDF-1alpha on ductal cell migration. Importantly, blocking …

Airports And Loci Of Aviation: Security Guidelines For Physical Design And Modification, Ibpp Editor

International Bulletin of Political Psychology

This article provides guidelines for the design and modification of loci and aviation from a security perspective.

The Evaluation Of Aviation Security And Security Incidents, Ibpp Editor

International Bulletin of Political Psychology

This article describes several difficulties in evaluating the efficacy of aviation security policies, programs, strategies, and tactics.

Riser Design For Green Sand And Ductile Iron Castings, K. Michael Kuebler

Graduate Research Papers

Shrinkage defects in ductile iron riser contacts has long been one of the most frustrating defects to eliminate for the foundry engineer. While process variation can definitively contribute to the occurrence of these defects most can be prevented if the risers are properly designed and/or applied to the castings to be fed. There are several proven methods for the designing risers some of which go back over 40 years ago. There are also new methods available today with the advancements of simulation software. Four of these riser design methods were evaluated for their ability to produce an internally sound casting …

Bomb-Pulse Chlorine-36 At The Proposed Yucca Mountain Repository Horizon: An Investigation Of Previous Conflicting Results And Collection Of New Data, Klaus J. Stetzenbach, Fred Phillips, Drew Coleman, Don Baepler, Amy J. Smiecinski

Publications (YM)

Previous studies by scientists at Los Alamos National Laboratory (LANL) and the United States Geological Survey (USGS) quantified ³⁶Cl/Cl to test for the presence of fast pathways at the proposed Yucca Mountain high-level nuclear waste repository. The goal of these studies was to determine whether or not fluids containing bomb-pulse ³⁶Cl/Cl traveled along fast travel pathways and reached the repository horizon, however, the two groups followed somewhat different procedures and produced conflicting results. The objective of this study is to attempt to determine the cause of the conflicting results and to obtain additional data to determine whether or …

Canal Velocity Indexing At Colorado River Indian Tribes (Crit) Irrigation Project In Parker, Arizona Using The Sontek Argonaut Sl, Stuart W. Styles, Mark Niblack, Beau J. Freeman

BioResource and Agricultural Engineering

An index velocity rating was developed for a SonTek/YSI Argonaut Side-Looking (SL) ultrasonic Doppler flow meter installed in the Main Canal of the Colorado River Indian Tribes (CRIT) Irrigation Project in Parker, Arizona. Velocity data collected concurrently with the ultrasonic flow meter and conventional current meter were compared using linear regression techniques. The rating equation for this installation provides a reasonably accurate means of computing discharge. This project was completed by the Irrigation Training and Research Center (ITRC), California Polytechnic State University, San Luis Obispo, working under a technical assistance contract for the Water Conservation Office, United States Bureau of …

Robust Pi Controller Design Satisfying Sensitivity And Uncertainty Specifications, O. Yaniv, Mark L. Nagurka

Mechanical Engineering Faculty Research and Publications

This paper presents a control design method for determining proportional-integral-type controllers satisfying specifications on gain margin, phase margin, and an upper bound on the (complementary) sensitivity for a finite set of plants. The approach can be applied to plants that are stable or unstable, plants given by a model or measured data, and plants of any order, including plants with delays. The algorithm is efficient and fast, and as such can be used in near real-time to determine controller parameters (for online modification of the plant model including its uncertainty and/or the specifications). The method gives an optimal controller for …

Thermodynamic Determination Of The Cation Distribution In Nixmn1-Γ-Xfe2+Γo4 Ferrites, Qiangmin Wei, Brian W. Robertson

Department of Mechanical and Materials Engineering: Faculty Publications

The cation distribution in the spinel ferrite system NixMn1-γ-xFe2+γO4 (x = 0, 0.25, 0.5, 0.75 and γ = 0.137) has been calculated analytically in complete form as a function of thermodynamic parameters. A generalized theoretical framework based on the O’Neill–Navrotsky model and Newton methods was used to solve a multicomponent system for up to 10 cation species. The relationship between the cation distribution and composition is given. The results are shown to agree with the available experimental results.

Slides: Encana, John Moran

Workshop on Directional Drilling in the Rocky Mountain Region (November 13)

Presenter: John Moran, Reservoir Engineer, Encana Oil & Gas

23 slides

Abstract: For companies doing directional drilling, what are the direct and indirect costs and benefits? When is it economical and what factors does industry take into account in making the decision to utilize directional drilling?

Notes From The Directional Drilling Workshop, University Of Colorado Boulder. Natural Resources Law Center

Workshop on Directional Drilling in the Rocky Mountain Region (November 13)

20 pages

"These notes were taken by one of our law students attending the workshop. They are not a verbatim transcript and they were not supplied by, and may not have been reviewed by, the speakers. There may be errors or gaps in the notes and for these we apologize in advance. Where the speaker provided an abstract of their talk, these are included and noted as such."

Slides: Directional Drilling: The Promise And The Peril, Alfred W. Eustes Iii

Workshop on Directional Drilling in the Rocky Mountain Region (November 13)

Presenter: Dr. Bill Eustes, Ph.D., P.E., Department of Petroleum Engineering, Colorado School of Mines, Golden, CO

63 slides

Abstract: What is it, where can it be done and how does it fit into full field development for oil and gas? This segment will set the foundation and bring everyone up to a basic level of understanding of the technology of directional drilling.

Slides: Untitled [British Petroleum], Rusty Riese

Workshop on Directional Drilling in the Rocky Mountain Region (November 13)

Presenter: Dr. Rusty Riese, Consulting Geologist, BP American Production Co.

6 slides

Abstract: For companies doing directional drilling, what are the direct and indirect costs and benefits? When is it economical and what factors does industry take into account in making the decision to utilize directional drilling?

Slides: Untitled [Western Resource Advocates], Mike Chiropolos

Workshop on Directional Drilling in the Rocky Mountain Region (November 13)

Presenter: Mike Chiropolos, Attorney, Western Resource Advocates

10 slides

Abstract: What are the environmental considerations involved with directional drilling? How should the NEPA analysis take this technology into account? When should it be analyzed as an alternative to conventional vertical drilling?

Slides: Untitled [Colorado Attorney General's Office], Carol Harmon

Workshop on Directional Drilling in the Rocky Mountain Region (November 13)

Presenter: Carol Harmon, Colorado Attorney General's Office

8 slides

Abstract: When does the State require directional drilling? Can landowners require it in Surface Use Agreements? What does Colorado's version of the accommodation doctrine mean for directional drilling?

Infrastructure For Performance Tuning Mpi Applications, Kathryn Marie Mohror

Dissertations and Theses

Clusters of workstations are becoming increasingly popular as a low-budget alternative for supercomputing power. In these systems, message-passing is often used to allow the separate nodes to act as a single computing machine. Programmers of such systems face a daunting challenge in understanding the performance bottlenecks of their applications. This is largely due to the vast amount of performance data that is collected, and the time and expertise necessary to use traditional parallel performance tools to analyze that data.

The goal of this project is to increase the level of performance tool support for message-passing application programmers on clusters of …

Thermodynamic Property Prediction For Solid Organic Compounds Based On Molecular Structure, Benjamin T. Goodman

Theses and Dissertations

A knowledge of thermophysical properties is necessary for the design of all process units. Reliable property prediction methods are essential because reliable experimental data are often not available due to concerns about measurement difficulty, cost, scarcity, safety, or environment. In particular, there is a lack of prediction methods for solid properties. Predicted property values can also be used to fill holes in property databases to understand more fully compound characteristics. This work is a comprehensive analysis of the prediction methods available for five commonly needed solid properties. Where satisfactory methods are available, recommendations are made; where methods are unsatisfactory in …

Preliminary Assessment Of Experimental Sophomore Ee Courses, James G. Harris, Kena Burke

Electrical Engineering

In academic year 2001-2002, an experimental yearlong sequence of courses was taught to EE and CPE majors that replaced the traditional circuits and electronics sequence of required courses. The experimental sequence consisted of three quarters, with the first quarter devoted to digital signal processing, and the next two quarters formed from an integrated approach to circuits and electronics. The two sections of students who took the experimental course now are taking the junior year required courses in their major. An assessment is being made to compare the experimental students with a cohort of traditional students. Preliminary results are given for …

An Examination Of The Relationship Between Academic Dishonesty And Professional Behavior, Trevor S. Harding, Honor J. Passow, Donald D. Carpenter, Cynthia J. Finelli

Materials Engineering

A number of recent studies have found correlations between academic dishonesty in higher education and unethical behavior in the work settings. However, these studies have not explored the causal relationship between the underlying factors that lead to this dishonesty. This realization, and apparently high levels of cheating among engineering students, has lead us to a research hypothesis that decision making patterns about academic cheating among engineering students are positively correlated with those individuals' decision making patterns about work place ethics and responsibility. To test our hypothesis, we have developed an exploratory survey that asks questions about the respondent's decisions during …

Motivation And Aviation As A Terrorism Target, Ibpp Editor

International Bulletin of Political Psychology

This article describes the content and dynamics of terrorist motivation towards targeting aviation.