Materials Science and Engineering Commons^™

Histar High Performance Hot-Rolled Beams, Lucien Weber

Advanced Materials for Construction of Bridges, Buildings, and Other Structures III

The construction industry is continuously looking for superior building components. Innovative production processes are, in combination with tight quality control, the keys to structural steel grades with outstanding properties. Especially the thermomechanical treatment allows for combining material properties which were formerly thought to be incompatible: high yield strength for big material thicknesses, good toughness and excellent weldability.

This paper presents the Quenching and Self-Tempering (QST) process which allows for the production of heavy hot-rolled H-beams in high strength structural steel grades with excellent weldability characteristics. The new steel grades fully comply and even exceed the requirements of the European and …

High Performance Steel For Highway Bridges, Vasant C. Mistry

Advanced Materials for Construction of Bridges, Buildings, and Other Structures III

All steels possess a combination of properties that determines how well steel performs. Strength, weldability, toughness, ductility, corrosion resistance, and formability are all important to determine how well steel performs. High-performance steel (HPS) can be defined as having an optimized balance of these properties to give maximum performance in bridge structures while remaining cost-effective.

Seismic Evaluation Of R/C Buildings Using High Performance Materials, Dimitrios Konstantinidis, Andreas J. Kappos

Advanced Materials for Construction of Bridges, Buildings, and Other Structures III

The performance of reinforced concrete (R/C) buildings made of high performance materials (HPM) in seismic areas is evaluated through the parametric analysis of twenty-two buildings designed and detailed according to the current (prEN) version of Eurocode 8, for ductility classes (DC) ''Medium'' and ''High'', in combination with the current (prEN) version of Eurocode 2. Seismic assessment of the buildings is carried out by means of nonlinear static (pushover) analysis and nonlinear dynamic (time-history) analysis.

Interface Behaviour In Frp Plates Bonded To Concrete: Experimental Tests And Theoretical Analyses, Ciro Faella , Enzo Martinelli, Emidio Nigro

Advanced Materials for Construction of Bridges, Buildings, and Other Structures III

Simplified models for simulating FRP-to-concrete interface behavior are introduced and empirical relationships are utilized for their calibration. Moreover, the results of pull-out tests on FRP-to-concrete joints are presented. They are utilized in calibrating a bilinear shear-stress-to-interface-slip relationship by means of an inverse identification procedure.

Seismic Performance Of Precast Column-Foundation Connection Assembled By Post-Tensioning, Minehiro Nishiyama, Fumio Watanabe

Advanced Materials for Construction of Bridges, Buildings, and Other Structures III

In order to develop design recommendations for column-foundation connection assembled by post-tensioning in seismic regions, cyclic loading tests were carried out on 14 test units simulating such kind of connections under earthquake loading. The tests were consisted of two series: Series A was mainly for comparison between precast reinforced and precast prestressed concrete column-foundation connections, and Series B for investigating differences between test units with grouted and ungrouted tendons. The main experimental parameter other than the above was an axial load level.

Finite-Temperature Anisotropy Of Ptco Magnets, Ralph Skomski, Arti Kashyap, David J. Sellmyer

Materials Research Science and Engineering Center: Faculty Publications

The temperature dependence of the magnetocrystalline anisotropy of PtCo and its atomic origin are investigated by first-principle and model calculations. The Pt spin moment necessary to realize the leading 5d anisotropy contribution is due to neighboring Co atoms. At finite temperatures, Co spin disorder strongly reduces the Pt moment and the anisotropy. This is in contrast to the situation encountered in 3d and 3d–4f magnets, where the atomic magnetic moments remain largely conserved, even above the Curie temperature. A consequence of the L1₀ mechanism is that theK₁ (T) curve of exhibits a negative curvature, in contrast to the …

Exchange Interactions And Curie Temperature Of Y–Co Compounds, Arti Kashyap, Ralph Skomski, Renat F. Sabiryanov, Sitaram Jaswal, David J. Sellmyer

Materials Research Science and Engineering Center: Faculty Publications

The Curie temperature of rare-earth Co intermetallics is investigated by self-consistent spin-polarized electronic-structure calculations on Y–Co compounds. The total exchange interaction of a given site with all other sites (J_o) is calculated by the linear-muffin-tin-orbital method using the local force theorem and employed to obtain mean-field Curie-temperature estimates. The theoretical predictions for YCo₃, YCo₅, and Y₂Co₁₇ are in fair agreement with the experimental Curie temperatures. For YCo₅, the variation of exchange interactions (J_ij) with distance is analyzed, and it is discussed how the presence of nonequivalent cobalt …

Thermal Properties Of La₀.₅Sr₀.₅Co₁₋ₓnixo₃-D Ceramics Using Photopyroelectric Technique, M. T. Sebastian, C. Preethy Menon, J. Philip, Robert W. Schwartz

Mechanical and Aerospace Engineering Faculty Research & Creative Works

La0.5Sr0.5Co1-xNixO3-delta (0<= x<= 0.6) ceramics were prepared using a conventional solid-state ceramic route. The thermal properties—thermal conductivity and heat capacity—of these ceramics were measured by the photopyroelectric technique. The thermal conductivity was found to increase with increasing Ni content. These materials were also found to exhibit a metallic-type variation of thermal conductivity with temperature, and no metal-insulator (M-I) transition was found to occur in any of the samples prepared by this route. However, a M-I transition was found to occur in La0.5Sr0.5CoO3-delta samples prepared by hot pressing. The difference is attributed to variations in oxygen content in the samples.

Controlled-Stress Large-Area Pulsed Laser Deposition Of Yttria Stabilized Zirconia, Paul C. Rounsavall

Theses and Dissertations

The US Air Force has need of parabolic-shaped membrane mirrors for surveillance satellites. The current polymer membrane technology has been unable to overcome shape deformation problems caused by intrinsic stresses from the membrane casting and mounting processes. One proposed solution was to coat the membrane mirrors with a stressed coating to compensate for shape deformations. Thus, the research presented in this dissertation produced controlled-stress large-area pulsed laser deposition (PLD) grown thin films on polymer substrates and investigated optical time-of-flight (TOF) sensor systems and Raman spectroscopy for control for the PLD process with respect to thin film stress. Initially, the PLD-grown …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Fourth Quarterly Report 06/01/2003-08/30/2003, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Annual Report -Phase Ii 09/01/2002-08/30/2003, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …

Synthesis And Electrochemical Properties Of K2Feo4, Ning Zhou, Shi-Hai Ye, Yong-Long Wang, Xue-Ping Gao, Dong-Feng Lin, Zuo-Xiang Zhou, De-Ying Song

Journal of Electrochemistry

The K₂FeO₄ used for new positive electrode materials was prepared. The primary batteries were used in different concentration of electrolyte and different currents. In 9 mol/L KOH , the capacity was the best. The higher the concentration of electrolyte, the lower the electric potential was. When the batteries discharged in 0.4 C , the capacity reached 521.3 mAh/g. By XRD, we gave the reasonable explanations for the discharge products of K₂FeO₄. Possible mechanism of discharge is discussed.

Corrosion Fatigue And Dynamic Strain Aging Of Duplex Stainless Steel In Aqueous Solution, Chuan-Ming Tseng, I-Hsuang Lo, Wen-Ta Tsai

Journal of Electrochemistry

The corrosion fatigue and dynamic strain aging behaviors of 22%Cr duplex stainless steel (DSS) in sodium chloride solutions were investigated. Austenitic 316L SS and ferrtic 430 SS were also used in this study for a comparison. The experimental results showed that no stress corrosion cracking (SCC) occurred in all these SSs tested in 3.5wt% NaCl solution at 80 ℃. However, dynamic strain aging (DSA) occurred in 316L austenitic SS and 22%Cr DSS during slow strain rate testing (SSRT) in this solution.The occurrence of DSA was dependent on solution temperature,strain rate and the presence of austenitic phase. The corrosion rate of …

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 …

Influence Of Marine Organisms Upon Corrosion Of Steel Piling Systems, Jiunn-Shyong Luo, Cliff Rau, Kuei-Ching Chen

Journal of Electrochemistry

To study the influence of marine organisms upon corrosion of ASTM A36 steel piling sysems, specimens were immersed in both natural and synthetic seawater. Electrochemical techniques such as linear polarization resistance and electrochemical impedance scan(EIS) were applied to evaluate corrosion of the steel. The results indicated that attachment of marine organisms to form fouling layers on the steel surface reduced general corrosion, but localized corrosion occurred underneath marine organisms. An equivalent circuit model was established to simulate attachment of marine organisms upon carbon carbon steel surfaces.

Comparison Of Thermal Cyclic Oxidation Of The Pvd Ni-Al And Hvof-Mcraly Coatings, J-T Chang, C-H Yeh, J-L He, K-C Chen

Journal of Electrochemistry

A PVD process-cathodic arc plasma ion plating was used to deposit Ni-Al films on Inconel 600 superalloy. The oxidation behaviors of PVD Ni-Al coating and the thermal sprayed CoCrAlY coatings were revealed and compared by performing cyclic thermal oxidation test at 1100 ℃ to evaluate its feasibility. Experimental results showed that the films with different compositions of Ni₆₂Al₃₈, Ni₆₃Al₃₇ and Ni₆₉Al₃₁ could be obtained when using Ni₅₂Al₄₈, Ni₆₀Al₄₀ and Ni₇₀Al₃₀ as targets, respectively. During the cyclic thermal oxidation test, the …

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 …

Effect Of Heat Laminating Aggregation Status Of Polymer Lithium-Ion Battery Cathode On Battery Performance, Ming-Gang Jin, Quan-Feng Dong, Ming-Sen Zheng, Li Huang, Hui-Qun Cai, Jin-Qua You, Zu-Geng Lin

Journal of Electrochemistry

Multi-layer heat laminated polymer lithium ion battery was made, the effect of temperature of cathode laminating on battry performance was also investigated. It was discovered that suitable temperature of cathode laminating is critical to battery performance and is a key parameter to manufacture process control of polymer lithium ion battery.

Electrochemistry And Electrocatalysis Of A Novel Μ-Oxamido Copper(Ⅱ) Binuclear Complex, Gui-Lian Gao, Guo-Bao Li, Qiu-Xia Yang, Xue-Lin Wang

Journal of Electrochemistry

In this paper, the cyclic voltammetric and spectroelectrochemical behaviors of μ-oxamido Copper(Ⅱ) Binuclear Complex (deCu) in PBS were studied. Cyclic voltammograms of this complex in PBS (pH=9) exhibited two reductive peaks (E_pc1 =-0.25 V, E_pc2 = -0.50 V) at hanging mercury drop electrode(HMDE), peaks at -0.50 V and -0.25 V corresponded to the reduction of ligand and copper(Ⅱ) complex, respectively. The spectroelectrochimical experiments showed that there was a new absorption band at 440 nm, and the absorption peaks at 270 nm, 280 nm red shifted to 300 nm, 310 nm under potential of -0.75 V. It was meant …

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 …

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 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 …}

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.

Semiconductor Wafer Processing System With Vertically-Stacked Process Chambers And Single-Axis Dual-Wafer Transfer System, Richard N. Savage, Frank S. Menagh, Helder R. Carvalheira, Philip A. Troiani, Dan L. Cossentine, Eric R. Vaughan, Bruce E. Mayer

Materials Engineering

A semiconductor wafer processing system including a multi-chamber module having vertically-stacked semiconductor wafer process chambers and a loadlock chamber dedicated to each semiconductor wafer process chamber. Each process chamber includes a chuck for holding a wafer during wafer processing. The multi-chamber modules may be oriented in a linear array. The system further includes an apparatus having a dual-wafer single-axis transfer arm including a monolithic arm pivotally mounted within said loadlock chamber about a single pivot axis. The apparatus is adapted to carry two wafers, one unprocessed and one processed, simultaneously between the loadlock chamber and the process chamber. A method …

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 …

Mapping Of Ecosystems In Mount Bromo Using Remote Sensing Technology, Bangun Muljo Sukojo

Makara Journal of Technology

Mapping of Ecosystems in Mount Bromo Using Remote Sensing Technology. Covered land analyses of Landsat image have been done to get ecosystem types and map in Mount Bromo region using remote sensing technology. There are nine types of ecosystems in Mount Bromo region, i.e. primary forest, secondary forest, lake, crater, sands, uncovered land, underbrush, dry-field and residence. Distribution of rock analysis has also been done by comparing the manual image interpretation with geological map. The results were coorelated with the digital image interpretation to find rock distribution map which can be useful to get the information about water reservation potencial …

Capacity Of High-Speed Powerline Communication In Vehicles, Deny Hamdani, Ery Safrianti

Makara Journal of Technology

Powerline Communication (PLC) Systems intents to use the mains network in vehicles for high-speed data transmission. Carrier frequencies in the range of MHz are required to establish data rates of some megabits per second. In this paper, typical reference channels extracted from channel measurements are presented and computation results of their capacities according to Shannon’s theorem are presented. Furthermore, the effect of limitations of frequency range and power spectral density of transmitted signal on achievable capacity is investigated. This paper outlines an assessment for theoretical channel capacity and achievable data rates of vehicular PLC transmission schemes. Finally, EMC (Electromagnetics Compatibility) …

Diffuser Optimation At Exhaust System With Catalytic Converter For 110 Cc Mopet With Fluid Flow Cfd Simulation, Tresna P. Soemardi, Ahmad Indra Siswantara, Erwin Erwin

Makara Journal of Technology

Diffuser Optimation at Exhaust System with Catalytic Converter for 110 cc Mopet with Fluid Flow CFD Simulation. CFD simulation used to get behavior of exhaust gas through catalyst, this result will be used to optimize geometry form to perform uniform stream distribution to catalyst, and CFD Simulation will used to analyze backpressure that happened at the model.

The Study On Fluorescence Characteristics Of Chlorella Spp: Ph Influence On Culture, Retno Wigajatri P., Andrianto Handojo, Hendrik Kurniawan, N. B. Prihantini

Makara Journal of Technology

The Study on Fluorescence Characteristics of Chlorella spp: pH Influence on Culture. Experiments for measuring the fluorescence characteristics of Chlorella spp. by using high stability and high repetition rate nitrogen laser of energy 5 mJ with pulse duration of 5 ns have been carried out. The results show that for a cell concentration range from 2,625 cells/ml up to 2,769,000 cells/ml, the fluorescence intensities at pada λ = 687 nm have a linear relationship with the cell concentration. It has been also found that for a 7 days old chlorella culture, the pH variation at the starting culture influenced the …