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Articles 22921 - 22950 of 27397

Full-Text Articles in Engineering

Study Conditions Of Aluminum Billets For Relationship Between Precipitated Phases And Homogenizing Temperature With Different Cooling Methods, U Phongsophitanan, M Polboon, N Chumchery Jul 2011

Study Conditions Of Aluminum Billets For Relationship Between Precipitated Phases And Homogenizing Temperature With Different Cooling Methods, U Phongsophitanan, M Polboon, N Chumchery

Journal of Metals, Materials and Minerals

In producing cast aluminum billets for using in extruded profile production, homogenization is one of the significant steps of the process. This project examined a suitable homogenizing temperature for usage in manufacturing besides common condition. Computerized fluid dynamics and image analysis solution were techniques to identify the relationship between the area fraction of precipitated phases and homogenizing temperature with different cooling methods. Temperature gradient pattern revealed that soaking temperatures at 575C and 565C are suitable conditions to be used in manufacturing. Furthermore, area fraction calculation showed that the area fractions of precipitated phases of each cooling method were not significantly …

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Synthesis And Catalytic Property Of Flaked Spindle-Like Cuo Nanocrystals, Jian-Feng Fan, Li-Qing Li, Yu-Feng Huang, Lou-Zhen Fan May 2011

Synthesis And Catalytic Property Of Flaked Spindle-Like Cuo Nanocrystals, Jian-Feng Fan, Li-Qing Li, Yu-Feng Huang, Lou-Zhen Fan

Journal of Electrochemistry

A simple and efficient electrochemical route was developed for the synthesis of flaked spindle-like CuO nanocrystals using aqueous electrolyte and Cu sacrificial anode (graphite as the cathode) in an undivided cell at a constant potential mode under room temperature. The morphologies, structure and component of CuO nanocrystals obtained were characterized by SEM, XRD, respectively. Flaked spindle-like CuO nanocrystals were successfully used to modify a GC electrode to detect H2O2 with cyclic voltammetry (CV) and amperometric (AC).The results showed that products were pure monoclinic CuO nanocrystals. The linear range for the determination of hydrogen peroxide is from 1.0 …

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Detection Of Acute Promyelocytic Leukemia Pml/Rarî± Fusion Gene Using Graphene Modified Glassy Carbon Electrode, Zhi-Xian Lian, Guang-Xian Zhong, Kun Wang, Ai-Lin Liu, Xin-Hua Lin, Yuan-Zhong Chen May 2011

Detection Of Acute Promyelocytic Leukemia Pml/Rarî± Fusion Gene Using Graphene Modified Glassy Carbon Electrode, Zhi-Xian Lian, Guang-Xian Zhong, Kun Wang, Ai-Lin Liu, Xin-Hua Lin, Yuan-Zhong Chen

Journal of Electrochemistry

A graphene modified glassy carbon electrode (GCE) was prepared by electrochemical reduction of graphite oxide fixed on the surface of GCE. Then, the amino-group modified probe of acute promyelocytic leukemia (APL) PML/RARα fusion gene fragment was immobilized onto surface of the graphene modified GCE by coupling activating agent. With methylene blue (MB) as a novel electrochemical indicator, artificial APL PML/RARα fusion gene fragment was measured by differential pulse voltammetry (DPV). The result indicated graphene nanomaterial showed good sensitization on the signal of MB. The relationship between the reduction peak current of MB and the concentration of complementary strand was linear …

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Influence Of Tert-Butylpyridine On The Band Energetics Of Nanostructured Tio2 Electrodes And The Photoelectrochemical Properties Of Dye-Seneitized Electrodes, Shu-Ming Yang, Ji-Chao Wang, Hui-Zhi Kou, Hong-Bin Xue, Hong-Jun Wang, Yu-Ling Guo May 2011

Influence Of Tert-Butylpyridine On The Band Energetics Of Nanostructured Tio2 Electrodes And The Photoelectrochemical Properties Of Dye-Seneitized Electrodes, Shu-Ming Yang, Ji-Chao Wang, Hui-Zhi Kou, Hong-Bin Xue, Hong-Jun Wang, Yu-Ling Guo

Journal of Electrochemistry

The flat band edges (Efb) of nanostructured TiO2 electrodes in electrolyte solutions with tert-butylpyridine (TBP) of different concentrations have been determined with spectroelectrochemical technique. TBP played a role in band energetics of nanostructured TiO2 electrodes. The Efb values of -2.25, -2.46 and -2.62 V were determined in three 0.2 mol•L-1 tetrabutylammonium perchlorate (TBAP) acetonitrile electrolytes which contain 0, 0.2 and 0.4 mol•L-1 TBP respectively. The addition of Li+ ions shifted Efb positively. The Efb values of -1.12, -1.22 and -1.30 V were determined in three 0.2 mol•L-1 LiClO4 acetonitrile electrolytes which contain 0, 0.2 …

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Effects Of Additives On The Electrochemical Behaviors Of Zn Electrode In Alkaline Solutions, Shu-Na Hong, Hai-Bin Lin, Zuo-Jian Su, He-Bing Zhou, Man Liang, Wei-Shan Li May 2011

Effects Of Additives On The Electrochemical Behaviors Of Zn Electrode In Alkaline Solutions, Shu-Na Hong, Hai-Bin Lin, Zuo-Jian Su, He-Bing Zhou, Man Liang, Wei-Shan Li

Journal of Electrochemistry

Electrochemical behaviors of Zn in 3mol⋅L-1 KOH solution containing the single additive(Pb(NO3)2, SDBS) the mixed additives(Pb(NO3)2+SDBS) were investigated. The results showed that all the additives can supress the corrosion of zinc in 3mol•L-1 KOH solution. And the inhibition effeciency of the mixed additives is higher than that of any single additive.

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Preparation And Electrocatalytic Activity Of The Pt/Wc/Tio2 Composites, Chun-An Ma, Bin Yu, Mei-Qin Shi, Xiao-Ling Lang May 2011

Preparation And Electrocatalytic Activity Of The Pt/Wc/Tio2 Composites, Chun-An Ma, Bin Yu, Mei-Qin Shi, Xiao-Ling Lang

Journal of Electrochemistry

TiO2 was used as the support for preparation of Pt/WC/TiO2 composite catalyst. The composites were characterized by XRD, SEM and TEM methods. The electrocatalytical activity of Pt/WC/TiO2 composite for oxidation of methanol was investigated by cyclic voltammetry. Pt/WC/TiO2 exhibited higher activity compared with that of Pt/TiO2 and Pt/WC composite catalysts. Based on this we discussed the effects of crystal phases of TiO2 on the electrocatalytical activity of Pt/WC/TiO2 composite catalyst.

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Dft Study Of Co2 Reduction To Hydrocarbons On Cu Surfaces, Li-Hui Ou, Sheng-Li Chen May 2011

Dft Study Of Co2 Reduction To Hydrocarbons On Cu Surfaces, Li-Hui Ou, Sheng-Li Chen

Journal of Electrochemistry

CO2 reduction on Cu(111) single crystal surfaces was studied using DFT calculations on the reaction energies and the minimum energy paths. The results indicated that the possible reaction paths for CO2 reduction on Cu(111) surface are CO2(g) + H* → COOH* → (CO +OH)*, (CO + H)* → CHO*, CHO + H → CH2O* → (CH2+O)*, CH2* + 2H* → CH4 or 2CH2* → C2H4. On Cu(111) surface, the reaction rate is controlled by steps of CH2O* → (CH2 …

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Capacitance Behaviors Of Ti/Ru0.1Ti0.1Sn0.8O2 Electrodes, Hai-Yan Chen, Yan-Qun Shao, Dian Tang May 2011

Capacitance Behaviors Of Ti/Ru0.1Ti0.1Sn0.8O2 Electrodes, Hai-Yan Chen, Yan-Qun Shao, Dian Tang

Journal of Electrochemistry

Ti/Ru0.1Ti0.1Sn0.8O2 electrodes were prepared by low temperature thermal decomposition. The structural characteristics were analyzed by X-ray diffraction(XRD).The performances were tested by cyclic voltammetry and constant current charge-discharge measurements. The results show that, the structure of Ti/Ru0.1Ti0.1Sn0.8O2 belongs to small rutile phase. A high specific capacitance of 933F/g is obtained at scan rate of 20 mV/s. The cycle life test shows a 23.6% specific capacitance lost after 1000 cycles. The electrode has a good cycle stability and reversibility.

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Preparation And Performance Of Carbon-Coated Si/C Composites, Li-Li Du, Quan-Chao Zhuang, Tao Wei, Yong-Li Cui, Zhi Sun, Shi-Gang Sun May 2011

Preparation And Performance Of Carbon-Coated Si/C Composites, Li-Li Du, Quan-Chao Zhuang, Tao Wei, Yong-Li Cui, Zhi Sun, Shi-Gang Sun

Journal of Electrochemistry

Si/C composite for lithium ion batteries was obtained by pyrolyzing and ball-milling. The microstructure and component of the composite was characterized by SEM and XRD, the electrochemical performance was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvano static charge-discharge tests. The results illustrate that the particle of Si/C composite prepared by pyrolysis exhibits inerratic morphology, uniform carbon-coating layer, good electrical conductivity, low resistance. The first intercalated-lithium capacity of the composite material is 4495 mAh/g; the first coulomb efficiency is 65.3%. From the second week the coulomb efficiency maintains 97%, and the capacity at the 100th cycle can …

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The Flip-Flop Behavior Of Acetonitrile At Au Electrode Surface Investigated By Sum Frequency Generation Vibrational Spectroscopy, Zhi Huang, Xin Tang, Gang-Hua Deng, En-Cai Zhou, Hong-Fei Wang, Yuan Guo May 2011

The Flip-Flop Behavior Of Acetonitrile At Au Electrode Surface Investigated By Sum Frequency Generation Vibrational Spectroscopy, Zhi Huang, Xin Tang, Gang-Hua Deng, En-Cai Zhou, Hong-Fei Wang, Yuan Guo

Journal of Electrochemistry

The electrochemical interface between liquid acetonitrile and polycrystal gold electrode is investigated by in situ infrared visible sum frequency generation spectroscopy (SFG-VS). The structure of acetonitrile adsorbed at polycrystal gold electrode surface is studied as a function of electrode potential. The SFG spectra of CH3 group indicate acetonitrile orients in response to the electrode potential. The SFG signal of CH3 group turns lower as the electrode potential changes from -700mV to 300mV, and vanishes around the 300mV(pzc), then becomes a negative signal above 500mV, which indicates that the orientation is predominately with the CH3 group toward the …

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Research Progress In Orthosilicates As Cathode Materials For Li-Ion Batteries, Dong-Ping Lv, Lin Wang, Yong Yang May 2011

Research Progress In Orthosilicates As Cathode Materials For Li-Ion Batteries, Dong-Ping Lv, Lin Wang, Yong Yang

Journal of Electrochemistry

Rechargeable Li-ion batteries fulfilling high-energy density, high safety, environmental friendliness, and low cost are demanded urgently for energy storage systems. Besides the structure stability arising from the strong Si-O covalent bond, environmental benignancy and low cost from the characteristics of Fe, Mn, Si elementals, orthosilicates (Li2MSiO4) show promising prospect to meet the demand of high-energy density for its two available Li+ per formula unit. Motivated by these significant advantages, Li2MSiO4 have been intensively investigated in the past few years. In the present work, we gave a review on the progress of orthosilicate research …

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Effect Of Pore Size On Pseudo-Capacitive Performance Of Nio In The Mixed Electrolyte Of Koh And Hexacyanoferrate, Wen Wu, Meng-Yan Hou, Dan-Dan Zhou, Yong-Yao Xia May 2011

Effect Of Pore Size On Pseudo-Capacitive Performance Of Nio In The Mixed Electrolyte Of Koh And Hexacyanoferrate, Wen Wu, Meng-Yan Hou, Dan-Dan Zhou, Yong-Yao Xia

Journal of Electrochemistry

In this paper, five kinds of NiO samples with different pore size distributions were synthesized .The electrochemical capacitance of the samples were characterized in 3 mol/L KOH solution with and without hexacyanoferrate addition. Electrochemical test results indicated the NiO sample with an optimum pore size of about 15 nm shows high Coulombic efficiency of the N4(NiO) electrode as the redox reaction of hexacyanoferrate ions would be limited in the pore, thus prevent ion diffusion into the bulk electrolyte solution .

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Investigation Of Supercapacitors Based On Polyvinyl Alcohol Hydrogel-Polymer Electrolyte, Kai-Qing Xu, Le-Qing Fan, Ji-Huai Wu, Qing Leng, Xin Zhong, Jian-Ming Lin, Miao-Liang Huang, Zhang Lan May 2011

Investigation Of Supercapacitors Based On Polyvinyl Alcohol Hydrogel-Polymer Electrolyte, Kai-Qing Xu, Le-Qing Fan, Ji-Huai Wu, Qing Leng, Xin Zhong, Jian-Ming Lin, Miao-Liang Huang, Zhang Lan

Journal of Electrochemistry

For the first time, the supercapacitor based on the hydrogel-polymer electrolyte which consisted of the cross-linking of polyvinyl alcohol-glutaraldehyde (PVA-GA) using 2-acrylamido-2-methyl propane sulfonic acid (AMPS) as solicitation reagent was assembled. The gel polymer electrolyte was characterized by FTIR and AC impedance. The maximum ionic conductivity is 1.23 mS/cm at room temperature. The electrochemical properties of the supercapacitor were investigated by cyclic voltammetry, AC impedance spectra and constant current charge-discharge curve. The results show that the specific capacitance reachs 139 F/g with AMPS of 1.0 g and 0.05 mL of 5 %(by mass) GA. And the specific capacitance still retained …

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Study On Direct Electro-Oxidation Of Anisaldehyde, Lin-Lin Wu, Ying-Hong Zhu, Shan-Shan Li, Hong-Yan Zeng, Chun-An Ma May 2011

Study On Direct Electro-Oxidation Of Anisaldehyde, Lin-Lin Wu, Ying-Hong Zhu, Shan-Shan Li, Hong-Yan Zeng, Chun-An Ma

Journal of Electrochemistry

The oxidation of anisole on Pt electrode was investigated by cyclic voltammery and constant potential electrolysis. The influence of scan rates, substrate concentration, supporting electrolytes and solvent were considered . The results show that the electro-oxidation process of anisole was irreversible. In this research the sulfuric acid was the best supporting electrolytes and acetone was the best solvent, and the process was controlled by diffusion . The product of constant potential electrolysis was charactered by GC-MS .The results show that the main products was anisaldehyde, and the selectivity was up to 66.5% when using acetone as solvent.

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Electric Vehicles And Power Batteries, Xin-Ping Ai, Han-Xi Yang May 2011

Electric Vehicles And Power Batteries, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

In retrospect of the historical development of Electric Vehicles (EV), the impact of battery technologies on the progress of EV was discussed. In consequence, it is concluded that the lack of advanced batteries was the main cause for the fluctuations of EV development and the sluggish commercialization of electric cars in the past century. After a brief introduction to the classification and the requirements of electric vehicles, the main issues of the batteries including safety, temperature range for operation and the cost as well as the effects of these factors on the applications of advanced batteries for electric vehicles were …

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Comparison Of Catalytic Performance On Different Materials Supported Pd Catalysts For Formic Acid Oxidation, Su-Dong Yang, Yan-Yu Liang, Zhu-Liang Wen, Qi-Jun Song, Xiao-Gang Zhang May 2011

Comparison Of Catalytic Performance On Different Materials Supported Pd Catalysts For Formic Acid Oxidation, Su-Dong Yang, Yan-Yu Liang, Zhu-Liang Wen, Qi-Jun Song, Xiao-Gang Zhang

Journal of Electrochemistry

Graphite oxide (GO) was prepared from by Hummers method. Then the graphene nanosheets supporting Pd catalysts were prepared by a single-step chemical reduction method. The electrocatalytic performance for formic acid oxidation of the prepared Pd/graphene composite was studied as an electrode material in comparison with the composite catalysts based on the other carbons (MWCNTs, SWCNTs, and Vulcan XC-72 carbon black). X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements indicated that the Pd nanoparticles were well dispersed on the surface of the graphene nanosheets with a small particle size. The electrocatalytic oxidation of formic acid was studied by electrochemically active …

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Anode Electrodeposition Of Ti/Mno2 Electrode And Electrocatalytic Oxidization Properties Of Phenol Degradation, Ye Chen, Wen-Li Zhao, Qing Wen May 2011

Anode Electrodeposition Of Ti/Mno2 Electrode And Electrocatalytic Oxidization Properties Of Phenol Degradation, Ye Chen, Wen-Li Zhao, Qing Wen

Journal of Electrochemistry

Ti-base manganese dioxide (Ti/MnO2) electrode was prepared by anodically electrodeposition technology in this paper. The structure of the electrode, the microstructure of the electrode surface and the element composition of the electrode were analyzed by XRD, SEM and EDS. The preparation process parameters of the electrode were studied in detail with the help of the V~logi curve and phenol degradation curve. The Ti/MnO2 electrode was anodically electrodeposited at current density 4mA•cm-2, the Mn2 + ions concentration 0.5mol•L-1 and temperature70℃. The V~logi curve and phenol degradation curve were used to evaluate electrocatalytic oxidization properties …

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Electrochemical Studies Of Zinc Injection Into The Structure Materials Of Nuclear Power Plants, Sheng-Han Zhang, Yu Tan, Ke-Xin Liang May 2011

Electrochemical Studies Of Zinc Injection Into The Structure Materials Of Nuclear Power Plants, Sheng-Han Zhang, Yu Tan, Ke-Xin Liang

Journal of Electrochemistry

The electrochemical and semiconductor characters of oxide films formed on 304L, 316L stainless steel and alloy 600 in high temperature water with zinc addition were studied. Stress corrosion cracking and occupational radiation can be retarded effectively by zinc injection to the primary circuit of pressurized water reactor (PWR). The semiconductor characters of the materials formed by zinc injection was analyzed by Mott-Schottky curves. The surface morphology and components of the corrosion oxide layer were examined and detected by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The result reveals that the smaller crystals and the complex Zn-Cr-Ni-Fe oxide were …

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Electrochemical Capacitive Performance Of Mesoporous Carbon Based Co-Ni Oxides, Zhen-Sheng Yang, Ling-Bin Kong, Li Deng, Yong-Chun Luo, Long Kang May 2011

Electrochemical Capacitive Performance Of Mesoporous Carbon Based Co-Ni Oxides, Zhen-Sheng Yang, Ling-Bin Kong, Li Deng, Yong-Chun Luo, Long Kang

Journal of Electrochemistry

By using defects on the surface of CMK-3 served as nucleation center, Co0.25Ni0.75 oxide/C composite was successfully prepared through a simple chemical co-precipitation method. Characterization was carried by using X-ray diffraction, BET and scanning electron microscopy. Results showed that a perfect mesoporous network of interconnected nanoflakes was obtained for Co0.25Ni0.75 oxide/C composite and, this material has a less crystallization, interconnected nanoflakes network structure and a narrow mesoporous distribution at about 3~4 nm. The highly dispersed and loosely packed Co0.25Ni0.75 oxide/C composite possessed good electrochemical accessibility and fast diffusion rate of OH …

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Bs News May/June May 2011

Bs News May/June

Building Services Engineering

No abstract provided.

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Statistical Analysis When The Data Is An Image: Eliciting Student Thinking About Sampling And Variability., Margaret A. Hjalmarson, Tamara J. Moore, Robert Delmas May 2011

Statistical Analysis When The Data Is An Image: Eliciting Student Thinking About Sampling And Variability., Margaret A. Hjalmarson, Tamara J. Moore, Robert Delmas

School of Engineering Education Faculty Publications

Results of analysis of responses to a first-year undergraduate engineering activity are presented. Teams of students were asked to develop a procedure for quantifying the roughness of a surface at the nanoscale, which is typical of problems in Materials Engineering where qualities of a material need to be quantified. Thirty-five teams were selected from a large engineering course for analysis of their responses. The results indicate that engagement in the task naturally led teams to design a sampling plan, use or design measures of center and variability, and integrate those measures into a model to solve the stated problem. Team …

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The Impact Of The Taipei Port Container Terminal On The Northern Region Of Taiwan: A Computable General Equilibrium Model, Wen-Sheng Chen, Chia-Yon Chen, Feng-Chin Chen, Chun-Chu Liu Apr 2011

The Impact Of The Taipei Port Container Terminal On The Northern Region Of Taiwan: A Computable General Equilibrium Model, Wen-Sheng Chen, Chia-Yon Chen, Feng-Chin Chen, Chun-Chu Liu

Journal of Marine Science and Technology–Taiwan

There are some primary modelling tools, including econometric forecasting models, fixed price input-output (I-O) multi-sector models, social accounting matrix (SAM) and computable general equilibrium (CGE) models, used to analyse regional economic issues. CGE models combine the advantages of econometric, I-O models and SAM, strengthening the theoretical basis of the modelling effort and thus enabling more precise policy analysis. Current CGE literature includes models used to analyse international trade, tax reform, energy and environment issues. However, application of this technique on a regional scale is rare in the scientific literature. In this paper, a small regional computable general equilibrium model is …

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Aerodynamic Performance And Shedding Characteristics On A Swept-Back Wing, Shun-Chang Yen Apr 2011

Aerodynamic Performance And Shedding Characteristics On A Swept-Back Wing, Shun-Chang Yen

Journal of Marine Science and Technology–Taiwan

A NACA 0012 finite swept-back wing with a sweep-back angle of 15° was utilized to investigate the effects of angle of attack (α) and the chord Reynolds number (Rec) on the vortex shedding and aerodynamic coefficients. A hot-wire anemometer was applied to measure the vortex-shedding frequency. The projected Strouhal number (Std) at various angles of attack was determined and discussed. The relationship between Std and α is regressed as: Std = -0.0008 α + 0.209, for 22° < α < 90°. Four characteristic surface-flow patterns: separation bubble, leading-edge bubble, bubble burst, and turbulent separation were classified by changing α and Re. The behavior of surface-flow structures significantly affects the lift, drag, and moment coefficients. The lift coefficient (CL) increases with α in the separation bubble and leading-edge bubble regimes. The maximum increase rate of CL with respect to α (d(CL)/dα) is 1.52 π/rad. Occurring in the leadingedge bubble regime. However, the maximum increase rate of drag coefficient (CD) with respect to α (d(CD)/dα) is 0.49 π/rad. Occurring in the bubble-burst regime. The steep-drop of moment coefficient at stall in the unswept-wings is not observed in the swept-back wings.

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Hydrogen Absorption/Desorption In A Metal Hydride Reactor Accounting For Varied Effective Thermal Conductivity, Chih-Yuan Wang, Hwa-Chong Tien, San-Der Chyou, Nang-Nong Huang, Shing-Hoa Wang Apr 2011

Hydrogen Absorption/Desorption In A Metal Hydride Reactor Accounting For Varied Effective Thermal Conductivity, Chih-Yuan Wang, Hwa-Chong Tien, San-Der Chyou, Nang-Nong Huang, Shing-Hoa Wang

Journal of Marine Science and Technology–Taiwan

This paper investigates the effect of varied effective thermal conductivity on the hydrogen absorption/desorption in a metal hydride (MH) reactor. The effective thermal conductivity of a metal hydride bed was measured by performing steady-state experiment and then compared with the results obtained by employing an existing model. Good agreement was found. Next, numerical simulation on the performance of hydrogen absorption/desorption of the MH reactor was conducted by assuming either varied or constant effective thermal conductivity. Corresponding hydrogen absorption/desorption experiment was performed for comparison. It was found that numerical simulation accounting for varied effective thermal conductivity agrees with the experimental data …

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Dislocation Substructures Of Interstitial-Free Steel Subjected To Low Cycle Fatigue At Various Strain Amplitude, Shih-Wei Mao, Wen-Chun Lo, Hsing-Lu Huang, New-Jin Ho Apr 2011

Dislocation Substructures Of Interstitial-Free Steel Subjected To Low Cycle Fatigue At Various Strain Amplitude, Shih-Wei Mao, Wen-Chun Lo, Hsing-Lu Huang, New-Jin Ho

Journal of Marine Science and Technology–Taiwan

The aim of this wok is to study the fatigue properties in relation to the microstructures of interstitial-free (IF) steel, a representative of body center cubic (BCC) materials, subjected to low cycle periodic stress. In order to compare the grain size effect on dislocation development, we used samples of two distinctive grain sizes, 70 µm and 210 µm, prepared by different thermo-mechanical processes. We found (1) there was an initial softening when the stain amplitude was lower than 1.6% and the microstructure of the fatigued samples are cellular independent of the grain sizes and the amplitude of strain. (2) A …

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Zener-Stroh Crack Problem In A Finite Plate, Yizhou Chen Apr 2011

Zener-Stroh Crack Problem In A Finite Plate, Yizhou Chen

Journal of Marine Science and Technology–Taiwan

In this paper, a Zener-Stroh crack problem in a finite plate is studied. By using the principle of superposition, the original problem is converted into a Zener-Stroh crack problem in an infinite plate and a usual Griffith crack problem in a finite plate. The former problem has a solution in a closed form. The latter problem can be solved by using EEVM (eigenfunction expansion variational method). Finally, numerical examples for evaluating the stress intensity factors at crack tips are presented.

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Flexural Behavior And Size Effect Of Full Scale Reinforced Lightweight Concrete Beam, Chung-Hao Wu, Yu-Cheng Kan, Chung-Ho Huang, Tsong Yen, Li-Huai Chen Apr 2011

Flexural Behavior And Size Effect Of Full Scale Reinforced Lightweight Concrete Beam, Chung-Hao Wu, Yu-Cheng Kan, Chung-Ho Huang, Tsong Yen, Li-Huai Chen

Journal of Marine Science and Technology–Taiwan

This article presents the results of experimental investigations on the size effect and the flexural behavior of full size reinforced concrete beams with lightweight aggregate and normal aggregate. The lightweight aggregate (LWA) was manufactured with fine sediments collected from the Shih-Men Reservoir in Taiwan. A total of 6 flexure beams with various reinforcement ratios (from 0.33% to 1.3%) and 6 size-effect beams with various dimensions were fabricated and tested. The designed compressive strength of concrete was 34 MPa. Test results indicated that the reinforced lightweight aggregate concrete (LWAC) beams had a similar load capacity and failure mode as those of …

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Penetration Lag Of Chloride Diffusion Through Concrete Plate Based On Advancing Model, Chih-Hsing Wang, Cho-Liang Tsai, Ching-Chang Lin Apr 2011

Penetration Lag Of Chloride Diffusion Through Concrete Plate Based On Advancing Model, Chih-Hsing Wang, Cho-Liang Tsai, Ching-Chang Lin

Journal of Marine Science and Technology–Taiwan

The solution, based on Neumann's theory, for the content distribution of a diffusion material in a semi-infinite medium is applicable for the case in which a diffusion material diffuses from one side of a plate medium to the other side. After the diffusion material reaches the other side, the penetration rate of the diffusion material is solved using Fick's diffusion law. In this study, concrete plates are manufactured and submerged individually in special containers with saltwater on one side and freshwater on the other side, and no electric charge is applied. The amount of chloride penetrating the plate is monitored. …

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Deformation Of Rolling Shutters Under Uniform Wind Pressure, Nan-Nong Huang, San-Ming Chang Apr 2011

Deformation Of Rolling Shutters Under Uniform Wind Pressure, Nan-Nong Huang, San-Ming Chang

Journal of Marine Science and Technology–Taiwan

In this study, a model is developed to analyze the structural behaviors of rolling shutters subjected to wind pressure. In the current shutter theory, the elastic properties of shutters are characterized by two bending rigidities, which can be determined from the flexural tests of slats and shutters. Close form solutions can be obtained for the deflection of shutters with two opposite simply supported edges. To assess the validity of the present theory, rolling shutters with various sizes and supporting conditions under various magnitudes of loadings are tested. It is noted that the deflections and axial displacements based on the current …

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Biodeterioration Of Coastal Concrete Structures By Macro Algae - Ulva Fasciata, Stri Hari Babu Jayakumar, Rama Saravanane, Thirumalai Sundararajan Apr 2011

Biodeterioration Of Coastal Concrete Structures By Macro Algae - Ulva Fasciata, Stri Hari Babu Jayakumar, Rama Saravanane, Thirumalai Sundararajan

Journal of Marine Science and Technology–Taiwan

Puducherry is a coastal region in India where the growth of Ulva fasciata (Delile) is very abundant on all marine structures. Though the detrimental effect of this macro algae U. fasciata is a secondary one, its effect has to be investigated. To know its effect, the basic mechanism by which U. fasciata deteriorates concrete structures has been highlighted. To ascertain its detrimental effect on coastal concrete structures, M20 grade concrete cubes were casted and immersed in the coastal area where there is abundant growth of U. fasciata. In addition laboratory simulation has been carried out. Concrete samples collected from the …

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