Engineering Commons^™

Severe Corrosivity And Its Eletrochemical Mechanism Of Seawater In Xiamen Sea Area To Al-Mg Alloys, Le-Yun Lin, Yue-Hong Zhao

Journal of Electrochemistry

The surface layer seawater of different sea areas in China exhibit different corrosivity to Al-Mg alloys according to the experiment results of 16 years exposure in seawater. The seawater in Xiamen sea area possesses severe corrosivity while seawater in Qingdao possesses the mildest corrosivity to Al-Mg alloys with better regularity of corrosion behavior. The present paper illustrates by experiment data that the strongest corrosivity of Xiamen seawater to Al-Mg alloys is owing to the low salinity of the seawater and the “electrolyte effect” come from it. The 16 year corrosion data and corrosion morphology of the typical Al-Mg alloys from …

The Electroless Plating Ni-Fe-P Alloy And Its Voltammetric Behavior, Sen-Lin Wang, Hui-Huang Wu

Journal of Electrochemistry

Electroless Ni-Fe-P alloy deposition from an alkaline bath, containing sodium hypophosphite as reducer, boric acid as buffer agent and sodium citrate as complexing agent, was investigated. To increase the plating rate and to inprove the bath stability, the deposition parameters were optimized. The effects of process parameters (pH, temperature and mole ratio of [Fe²⁺]/([Ni²⁺]+[Fe²⁺]) on the plating rate and deposit composition were examined and it was found that the presence of ferrous sulfate in the bath has an inhibitory effect on the alloy deposition. As a consequence, the percentage of iron in the electroless …

The Mechanism Of Electrocatalytic Reduction Of Oxygen On Manganese Dioxide, Yu-Liang Cao, Han-Xi Yang, Xin-Ping Ai, Li-Fen Xiao

Journal of Electrochemistry

The oxygen electroreduction on the MnO₂ electrode was investigated by analysis of the polarzation properties of oxygen reduciton and its dependence on MnO₂ discharge state, in combination with the characterization of discharge intermediate and the kinetic parameters of the oxygen reduction. Based on the experimental observation and mechanistic analysis, it was suggested that the reduction of oxygen was closely related to the discharge behaviors of MnO₂. When MnO₂ was electrochimically reduced to MnOOH, it was immediately oxidized by oxygen molecules. Thus the oxygen reduction proceeds through continuous oxidation of the discharge product of MnO_{2 …}

An Electrochemical Prediction Method For Caustic Scc Of Fe-Cr-Ni Alloy, Chun-Bo Huang, Zhan-Peng Lv, Wu Yang

Journal of Electrochemistry

Stress corrosion cracking (SCC) of Fe-Cr-Ni alloy (alloy 800 M) in hot concentrated caustic solution was investigated by means of tests of C-rings under controlled potentials. The steady dissolution current densities (i_st) of the plate specimens and C-rings polarized potentiostatically were measured. The simplifed steady potentiostatical curves were drawn on the basis of i_st. The ratio R_PD measured from i_st and steady passive current density i p at low potentials (R_PD = i_st/i_p) was designed as a polarization dissolution susceptibility parameter. The parameter R_PD values of both plate …

Synthesis Of Polyunit Vapor Phase Inhibitor And Its Volatile Corrosion Inhibition Performance, Da-Quan Zhang, Li-Xin Gao, Guo-Ding Zhou

Journal of Electrochemistry

A Mannich Base derivative (BMMCH), containing two morpholinum moieties and one cyclohexylamnonium moiety, was synthesized through aminomethy1 reaction. Its configuration was verified by IR and ¹H-NMR. Its volatile rustproofing effect was appraised by volatile rustproofing sieve test and vapor inhabitability test. The result shows that BMMCH has good protection effect for carbon steel. BMMCH has lower volatility compared with dicyclohexylamnonium nitrite (DICHAN) via closed space volatile weight-loss test. The inhibition mechanism was studied by potentiodynamic polarization electrochemistry technique in ASTM simulated atmospheric water. The corrosion potential of carbon steel electrode shifted to a negative direction when BMMCH was joined …

Discussion On Factors Of Unstable 304 Stainless Steel Stress Corrosion Cracking, Xin-Sheng Zhang, Chun-Chun Xu, Gang Hu

Journal of Electrochemistry

The 304 stainless steels were stretched at low temperatures to get different martensite phase transformation. Ferrmagnetometer was used to measure the martensite phase content. It was found that the dislocation density of 304 stainless sted was increased unavoidably with increase of deformation. Transmission electron microscope (TEM) was used to study the distribution of the dislocation. The influence of microstructure change on SCC of 304 stainless steel was discussed by slow strain rate testing (SSRT) in 42% MgCl₂ boiling solution,metallurgical microscope and scanning electron microscope (SEM).The results showed that martensite phase and dislocation flaw act together on the SCC susceptibility …

The Technique Of Rare-Earth Conversion Coatings On Aluminum Alloy, Jun-Tao Wang, Jian-Hua Wu, Guang-Zhang Chen

Journal of Electrochemistry

The orthogonal design was used to screen the film_forming technique on LY12 aluminum alloy using quadrivalent cerium salt, and the corrosion-resistance performance of the coating was studied. The results revealed that: after LY12 aluminum alloy was treated by cerium salt, its pitting potential shifts to positive direction while the corrosion potential slightly decreases, showing that the alloy becomes less sensitive to pitting corrosion was greatly improved, comparable to that after chromate treatment; in addition, by combining the results of electrochemical measurements with surface analysis, the mechanism of corrosion-resistance on the race-earth conversion coating of the aluminum alloy was also discussed.

Day 5. Friday, August 15, 2003: Rocky Mountain National Park, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

1 page.

Contains references.

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 5/16/03- 8/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

Two activities are proposed in this Phase I task: the development of a systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model is the start of an integrated approach to the analysis of the materials separations associated with the AAA Program. A second portion of the project is to streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral …

Development Of A Systems Engineering Model Of The Chemical Separations Process, Yitung Chen, Sean Hsieh, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

The AFCI program is developing technology for the transmutation of nuclear waste to address many of the long-term disposal issues. An integral part of this program is the proposed chemical separations scheme.

Nearly all issues related to risks to future generations arising from long-term disposal of such spent nuclear fuel is attributable to about 2% of its content. Such 2% is made up primarily of plutonium, neptunium, americium, and curium (the transuranic elements) and long-lived isotopes of iodine and technetium created as products from the fission process in power reactors. When transuranics are removed from discharged fuel destined for disposal, …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 5/16/03- 8/15/03, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

The analysis of mold filling and solidification continues with progress being made for the consideration of these two features within one model. Analysis of the induction heating process of an Induction Skull Melter (ISM) is under study. Efforts are underway to validate the modeling procedure and specific comparisons are being made to previously published work. Few detailed modeling results have been reported by other researchers, making the validations an important part of the overall modeling process. Skin heating depths, power deposition rates, and other process parameters are being evaluated for use in upcoming furnace design simulations. Efforts are beginning on …

Day 4. Thursday, August 14, 2003: Hayden Power Plant, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

5 pages (includes color illustrations and maps).

Contains references.

Day 4. Thursday, August 14, 2003: Trapper Mine, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

8 pages (includes some color illustrations).

Contains references.

Day 3. Wednesday, August 13, 2003: Oil Shale, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

8 pages.

Contains references.

Day 3. Wednesday, August 13, 2003: Travel To Grand Junction, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

5 pages (includes color illustration and map).

Contains references.

Day 3. Wednesday, August 13, 2003: Lighthawk Flyover, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

11 pages (includes some color illustrations and maps).

Contains references.

Day 3. Wednesday, August 13, 2003: Coalbed Methane Development, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

10 pages (includes color illustrations and maps).

Day 2. Tuesday, August 12, 2003: Delta Montrose Energy, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

1 page.

Contains references.

Day 2. Tuesday, August 12, 2003: Valley Oil And Gas Development, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

1 page.

Contains references.

Day 2. Tuesday, August 12, 2003: Roan Plateau Proposed Wilderness Area, Roan Plateau

Energy Field Tour 2003 (August 11-16)

4 pages (includes color illustration).

Contains references.

Day 1. Monday, August 11, 2003: National Renewable Energy Lab, National Energy Renewable Laboratory

Energy Field Tour 2003 (August 11-16)

8 pages (includes illustrations).

Contains references.

Agenda: Energy Field Tour 2003, University Of Colorado Boulder. Natural Resources Law Center

Energy Field Tour 2003 (August 11-16)

Congressional staff tour held August 11-16, 2003

Summary: Binder of assorted articles, maps, brochures and other materials prepared for participants of the tour

Contents:

MONDAY, AUGUST 11, 2003: BLUE SPRUCE PEAKER PLANT: University of Colorado Natural Resources Law Center : congressional staff tour of Blue Spruce Energy Center / Peggy Duxbury -- 'Power Struggle', National Journal, June 27, 2003 / Margaret Kritz -- 'Calpine's Blue Spruce Energy Center begins commercial operation', Calpine press release, April 17, 2003 -- NATIONAL RENEWABLE ENERGY LAB: NREL at a glance -- NREL technologies -- SHOSHONE HYDROELECTRIC PLANT: 'River District Board supports spring Shoshone call …

Day 1. Monday, August 11, 2003: Shoshone Hydroelectric Plant, Glenwood Canyon, Shoshone Hydroelectric Plant

Energy Field Tour 2003 (August 11-16)

3 pages.

Contains references.

Day 1. Monday, August 11, 2003: Blue Spruce Peaker Plant, Blue Spruce Energy Center

Energy Field Tour 2003 (August 11-16)

10 pages (includes color illustrations and maps).

Contains references.

Secure Remote Control And Configuration Of Fpx Platform In Gigabit Ethernet Environment, Haoyu Song

All Computer Science and Engineering Research

Because of its flexibility and high performance, reconfigurable logic functions implemented on the Field-programmable Port Extender (FPX ) are well suited for implementing network processing such as packet classification, filtering and intrusion detection functions. This project focuses on two key aspects of the FPX system. One is providing a Gigabit Ethernet interface by designing logic for a FPGA which is located on a line card. Address Resolution Protocol (ARP) packets are handled in hardware and Ethernet frames are processed and transformed into cells suitable for standard FPX application. The other effort is to provide a secure channel to enable remote …

Revisiting The Fresnel Coefficients For Uniform Plane Wave Propagation Across A Nonchiral, Reciprocal And Chiral, Nonreciprocal Interface, Monish Ranjan Chatterjee, Sumit Nema

Electrical and Computer Engineering Faculty Publications

The problem of EM wave propagation in non-reciprocal chiral media has been studied by several investigators. In a recent approach, a dual-transform technique has been developed to study the problem of such propagation under paraxial and slow-envelope variation conditions.

In this paper, we first outline some of the results obtained using the dual transform technique for arbitrary boundary conditions within the left boundary of a semi-infinite, non-reciprocal chiral medium for a uniform plane wave, and a fundamental Gaussian-profiled beam. Next, we explore the problem of a uniform EM wave incident at an oblique angle at an interface between a reciprocal, …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics - Phase Three, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. The …

Solving Multi-Objective Multi-Constrained Optimization Problems Using Hybrid Ants System And Tabu Search, Hoong Chuin Lau, Min Kwang Lim, Wee Chong Wan, Hui Wang, Xiaotao Wu

Research Collection School Of Computing and Information Systems

Many real-world optimization problems today are multi-objective multi-constraint generalizations of NP-hard problems. A classic case we study in this paper is the Inventory Routing Problem with Time Windows (IRPTW). IRPTW considers inventory costs across multiple instances of Vehicle Routing Problem with Time Windows (VRPTW). The latter is in turn extended with time-windows constraints from the Vehicle Routing Problem (VRP), which is extended with optimal fleet size objective from the single-objective Traveling Salesman Problem (TSP). While single-objective problems like TSP are solved effectively using meta-heuristics, it is not obvious how to cope with the increasing complexity systematically as the problem is …

Learning Real-Time A* Path Planner For Sensing Closely-Spaced Targets From An Aircraft, Jason K. Howlett, Michael A. Goodrich, Timothy W. Mclain

Faculty Publications

This work develops an any-time path planner, based on the learning real-time A* (LRTA*) search, for generating flyable paths that allow an aircraft with a specified sensor footprint to sense a group of closely-spaced targets. The LRTA* algorithm searches a tree of flyable paths for the branch that accomplishes the desired objectives in the shortest distance. The tree of paths is created by assembling primitive turn and straight sections of a specified step size. The operating parameters for the LRTA* search directly influence the running time and path-length performance of the search. A modified LRTA* search is presented that terminates …

A Generic Object-Oriented Tabu Search Framework, Hoong Chuin Lau, Wee Chong Wan, Xiaomin Jia

Research Collection School Of Computing and Information Systems

Presently, most tabu search designers devise their applications without considering the potential of design and code reuse, which consequently prolong the development of subsequent applications. In this paper, we propose a software solution known as Tabu Search Framework (TSF), which is a generic C++ software framework for tabu search implementation. The framework excels in code recycling through the use of a welldesigned set of generic abstract classes that clearly define their collaborative roles in the algorithm. Additionally, the framework incorporates a centralized process and control mechanism that enhances the search with intelligence. This results in a generic framework that is …