﻿<?xml version="1.0" encoding="utf-8"?><rss version="2.0"><channel><title>Advances in Materials Science and Engineering</title><link>http://www.hindawi.com</link><description>The latest articles from Hindawi Publishing Corporation</description><copyright>&amp;#169; 2012, Hindawi Publishing Corporation. All rights reserved.</copyright><item><title>Mathematical Model of Hot Metal Desulfurization by Powder Injection</title><link>http://www.hindawi.com/journals/amse/2012/969727/</link><description>Although there have been a numerous number of studies on mathematical model of hot metal desulfurization by deep injection of calcium carbide, the research field as a whole is not well integrated. This paper presents a model that takes into account the kinetics, thermodynamics, and transport processes to predict the sulfur levels in the hot metal throughout a blow. The model could be utilized to assess the influence of the treatment temperature, rate of injection, gas flow rate, and initial concentration of sulfur on the desulfurization kinetics. In the second part of this paper an analysis of the industrial data for injection of calcium carbide using this model is described. From a mathematical model that describes the characteristics of a system, it is possible to predict the behavior of the variables involved in the process, resulting in savings of time and money. Discretization is realized through the finite difference method combined with interpolation in the border domain by Taylor series.</description><Author>Yolanda Cepeda Rodríguez, Guillermo González Múzquiz, José Refugio Parga Torres, and Luciano Eliezer Ramírez Vidaurri</Author><copyright>Copyright &amp;#xa9; 2012 Yolanda Cepeda Rodr&amp;#xed;guez et al. All rights reserved.</copyright></item><item><title>Isothermal and Two-Temperature Zone Selenization of Mo Layers</title><link>http://www.hindawi.com/journals/amse/2012/345762/</link><description>Glass/Mo, Mo foil, glass/Mo/In, and glass/Mo/Cu stacked layers were selenized in closed vacuum tubes by isothermal and/or two-temperature zone annealing in Se vapors. The selenization process was studied dependent on Se vapor pressure, temperature and time. Samples were selenized from 375 to 580&amp;#x00b0;C for 30 and 60 minutes. The applied Se pressure was varied between 130 and 4.4&amp;#x022c5;103&amp;#x2009;Pa. The increase of MoSe2 film thickness was found to depend on the origin of Mo. MoSe2 thickness dL on Mo-foil was much higher than on sputtered Mo layers, and it depended linearly on time and as a power function dL~PSe1/2 on Se vapor pressure. The residual oxygen content in the formed MoSe2 layers was much lower in the two-zone selenization process. If Mo was covered with Cu or In before selenization, these were found to diffuse into formed MoSe2 layer. All the MoSe2 layers showed p-type conductivity.</description><Author>L. Kaupmees, M. Altosaar, O. Volobujeva, T. Raadik, M. Grossberg, M. Danilson, E. Mellikov, and P. Barvinschi</Author><copyright>Copyright &amp;#xa9; 2012 L. Kaupmees et al. All rights reserved.</copyright></item><item><title>Production of C3+ Olefins and Propylene from Ethanol by Zr-Modified H-ZSM-5 Zeolite Catalysts</title><link>http://www.hindawi.com/journals/amse/2012/293485/</link><description>Ethanol conversion to C3+ olefins, especially propylene, using Zr-modified H-ZSM-5 catalysts was investigated. Zr-modification to H-ZSM-5 zeolite could improve the initial yield of C3+ olefins and propylene and could reduce the initial yield of ethylene. In general, catalysts exhibiting the higher initial yield of propylene showed the steeper decrease in propylene yield as the reaction proceeded. However, Zr-modification to H-ZSM-5 could depress the decrease in propylene yield for aqueous ethanol. As cause of catalytic deactivation, carbon deposition on catalyst and framework collapse of zeolite support can be considered. The addition of water to Zr-modified H-ZSM-5 catalyst could depress carbon deposition in some degree, and, as a result, the decrease in propylene yield could be depressed.</description><Author>Megumu Inaba, Kazuhisa Murata, Isao Takahara, and Ken-ichiro Inoue</Author><copyright>Copyright &amp;#xa9; 2012 Megumu Inaba et al. All rights reserved.</copyright></item><item><title>A Thermodamage Strength Theoretical Model of Ceramic Materials Taking into Account the Effect of Residual Stress</title><link>http://www.hindawi.com/journals/amse/2012/490516/</link><description>A thermodamage strength theoretical model taking into account the effect of residual stress was established and applied to each temperature phase based on the study of effects of various physical mechanisms on the fracture strength of ultrahigh-temperature ceramics. The effects of SiC particle size, crack size, and SiC particle volume fraction on strength corresponding to different temperatures were studied in detail. This study showed that when flaw size is not large, the bigger SiC particle size results in the greater effect of tensile residual stress in the matrix grains on strength reduction, and this prediction coincides with experimental results; and the residual stress and the combined effort of particle size and crack size play important roles in controlling material strength.</description><Author>Weiguo Li, Ruzhuan Wang, Dingyu Li, and Daining Fang</Author><copyright>Copyright &amp;#xa9; 2012 Weiguo Li et al. All rights reserved.</copyright></item><item><title>Numerical Simulation for Thermal Shock Resistance of Ultra-High Temperature Ceramics Considering the Effects of Initial Stress Field</title><link>http://www.hindawi.com/journals/amse/2011/757543/</link><description>Taking the hafnium diboride ceramic as an example, the effects of heating rate, cooling rate, thermal shock initial temperature, and external constraint on the thermal shock resistance (TSR) of ultra-high temperature ceramics (UHTCs) were studied through numerical simulation in this paper. The results show that the external constraint has an approximately linear influence on the critical rupture temperature difference of UHTCs. The external constraint prepares a compressive stress field in the structure because of the predefined temperature field, and this compressive stress field relieves the tension stress in the structure when it is cooled down and then it improves the TSR of UHTCs. As the thermal shock initial temperature, a danger heating rate (or cooling rate) exists where the critical temperature difference is the lowest.</description><Author>Weiguo Li, Tianbao Cheng, Dingyu Li, and Daining Fang</Author><copyright>Copyright &amp;#xa9; 2011 Weiguo Li et al. All rights reserved.</copyright></item><item><title>Advances in Application of Natural Clay and Its Composites in Removal of Biological, Organic, and Inorganic Contaminants from Drinking Water</title><link>http://www.hindawi.com/journals/amse/2011/872531/</link><description>Natural clays are abundantly available low-cost natural resource which is nontoxic to ecosystem. Over the recent years, research on the modification of clay to increase their adsorbent capacity to remove other contaminants from drinking water other than metals is in progress. This paper reviews the recent development of natural clays and their modified forms as adsorbing agents for treating drinking water and their sources. This paper describes the versatile nature of natural clay and their ability to adsorb variety of contaminants ranging from inorganic to emerging, which are present in the drinking water. The properties and modification of the natural clay and its significance in removing a specific type of contaminant are described. The adsorbing efficiency of the natural and modified clay in the purification of drinking water, when compared to existing technologies, materials, and methods was found to be significantly higher or comparable.</description><Author>Rajani Srinivasan</Author><copyright>Copyright &amp;#xa9; 2011 Rajani Srinivasan. All rights reserved.</copyright></item><item><title>Analysis of Intergranular Precipitation in Isothermally Aged Nitrogen-Containing Austenitic Stainless Steels by an Electrochemical Method and Its Relation to Cryogenic Toughness</title><link>http://www.hindawi.com/journals/amse/2011/210209/</link><description>The precipitation process in two N-containing austenitic stainless steels, aged at temperatures between 873 and 1173&amp;#x2009;K for times from 10 to 1000&amp;#x2009;min, was analyzed by an electrochemical method based on the anodic polarization test with an electrolyte of 1&amp;#x2009;N&amp;#x2009;KOH solution. The anodic polarization curves showed the following intergranular precipitation sequence: austenite &amp;#x2192;  austenite&amp;#x2009;+&amp;#x2009;Cr23C6&amp;#x2192; austenite&amp;#x2009;+&amp;#x2009;Cr23C6&amp;#x2009;+&amp;#x2009;Cr2N. Besides, the fastest precipitation kinetics was detected in the aged steel with the highest content of nitrogen and carbon due to its higher driving force for precipitation. The higher the aging temperature, the higher volume fraction of precipitates. The precipitation fraction can be associated with the current density of the dissolution peaks of each phase. The Charpy-V-Notch impact energy of the aged specimens decreased with the increase in the volume fraction of precipitates.</description><Author>Maribel L. Saucedo-Mu&amp;#241;oz, Victor M. Lopez-Hirata, Hector J. Dorantes-Rosales, and Erika O. Avila-Davila</Author><copyright>Copyright &amp;#xa9; 2011 Maribel L. Saucedo-Mu&amp;#xf1;oz et al. All rights reserved.</copyright></item><item><title>Electrospun Nanoporous Poly(butylenes succinate-co-bytylene terephthalate) Nonwoven Mats</title><link>http://www.hindawi.com/journals/amse/2011/654360/</link><description>A traditional Chinese drug &amp;#8220;Yunnan Baiyao&amp;#8221; is used as an additive in poly(butylenes succinate-co-bytylene terephthalate) (PBST) solution, which is a kind of biodegradable aliphatic-aromatic copolyesters, to produce microspheres with nanoporosity by electrospinning; the tunable size of nanoporosity can be controlled by changing the voltage applied in the electrospinning process.</description><Author>Liang Wang, Yang-Shuai Liu, Lu-Feng Mo, Fu-Juan Liu, and Lan Xu</Author><copyright>Copyright &amp;#xa9; 2011 Liang Wang et al. All rights reserved.</copyright></item><item><title>Ultrasonic Guided Waves in Piezoelectric Layered Composite with Different Interfacial Properties</title><link>http://www.hindawi.com/journals/amse/2011/701819/</link><description>Combining the propagation model of guided waves in a multilayered piezoelectric composite with the interfacial model of rigid, slip, and weak interfaces, the generalized dispersion characteristic equations of guided waves propagating in a piezoelectric layered composite with different interfacial properties are derived. The effects of the slip, weak, and delamination interfaces in different depths on the dispersion properties of the lowest-order mode ultrasonic guided wave are analyzed. The theory would be used to characterize the interfacial properties of piezoelectric layered composite nondestructively.</description><Author>Xiao Chen</Author><copyright>Copyright &amp;#xa9; 2011 Xiao Chen. All rights reserved.</copyright></item><item><title>Thermal Stability and Tribological Performance of DLC-Si&amp;#8211;O Films</title><link>http://www.hindawi.com/journals/amse/2011/483437/</link><description>The thermal stability and tribological 
                performance of silicon- and oxygen-incorporated 
                diamond-like carbon films were investigated. The 
                DLC-Si-O films were deposited using plasma-based 
                ion implantation (PBII) method. The deposited 
                films were annealed at 400&amp;#x00B0;C, 
                600&amp;#x00B0;C, and 
                750&amp;#x00B0;C for 1 hour in vacuum, in 
                argon, and in air atmospheres. Film properties 
                were investigated using the Fourier transforms 
                infrared spectroscopy, Raman spectroscopy, energy 
                dispersive X-ray spectroscopy, and a ball-on-disk 
                friction tester. The structures of the DLC-Si-O 
                films with a low Si content 
                (&amp;#8804;25 
                at.&amp;#37;Si, 
                &amp;#8804;1 
                at.&amp;#37;O) and high Si content 
                (&amp;gt;25 
                at.&amp;#37;Si, 
                &amp;gt;1 
                at.&amp;#37;O) were not affected by the thermal 
                annealing in vacuum at 400&amp;#x00B0;C and 
                600&amp;#x00B0;C, respectively, while they 
                were affected by thermal annealing in argon and in 
                air at 400&amp;#x00B0;C. Film with 34 
                at.&amp;#37;Si and 9 at.&amp;#37;O after annealing 
                demonstrated almost constant atomic contents until 
                annealing at 600&amp;#x00B0;C in vacuum. 
                The friction coefficient of DLC-Si&amp;#8211;O films 
                with 34 at.&amp;#37;Si and 9 at.&amp;#37;O was shown to be 
                relatively stable, with a friction coefficient of 
                0.04 before annealing and 0.05 after annealing at 
                600&amp;#x00B0;C in vacuum. Moreover, the 
                low friction coefficient of film annealed at 
                600&amp;#x00B0;C in vacuum with 34 
                at.&amp;#37;Si and 9 at.&amp;#37;O was corresponded with 
                low wear rate of 1.85 
                &amp;#x00D7; 
                10-7&amp;#x2009;mm3/Nm.</description><Author>Nutthanun Moolsradoo, Shinya Abe, and Shuichi Watanabe</Author><copyright>Copyright &amp;#xa9; 2011 Nutthanun Moolsradoo et al. All rights reserved.</copyright></item><item><title>SEM and EDS Characterisation of Layering TiOx Growth onto the Cutting Tool Surface in Hard Drilling Processes of Ti-Al-V Alloys</title><link>http://www.hindawi.com/journals/amse/2011/414868/</link><description>Scanning electron microscopy (SEM) has been used to identify and analyse the secondary adhesion effect precursors formed during the dry drilling processes of Ti-6Al-4V alloy over the rake face and flute of the drilling tools. Subsequent analysis with energy dispersive spectroscopy (EDS) was enabled to distinguish its compositional characteristics. Thus, according to the EDS obtained data, a stratified multi built-up layer (MBUL) composed by TiOx is formed over the rake face of the tool. Furthermore, this multi-layer adhered allows initially the built-up edge (BUE) development close to the edge of the tool by a mechanical adhesion mechanism. In a second step, it is responsible for the formation of a thicker secondary BUL which avoids the chip flow, and it provokes the tool collapse. These mechanisms are different from those observed in the dry machining of other alloys such as steels, nickel-based alloys, or aluminium alloys.</description><Author>M. &amp;#193;lvarez, J. Salguero, J. A. S&amp;#225;nchez, M. Huerta, and M. Marcos</Author><copyright>Copyright &amp;#xa9; 2011 M. &amp;#xc1;lvarez et al. All rights reserved.</copyright></item><item><title>Modifications Caused by Enzyme-Retting and Their Effect on Composite Performance</title><link>http://www.hindawi.com/journals/amse/2011/179023/</link><description>Bethune seed flax was collected from Canada with seed removed using a stripper header and straw pulled and left in field for several weeks. Unretted straw was decorticated providing a coarse fiber bundle feedstock for enzyme treatments. Enzyme treatments using a bacterial pectinolytic enzyme with lyase activity were conducted in lab-scale reactors. Four fiber specimens were created: no retting, minimal retting, moderate retting, and full retting. Fiber characterization tests: strength, elongation, diameter, metal content, wax content, and pH were conducted with significant differences between fibers. Thermosetting vinyl ester resin was used to produce composite panels via vacuum-assisted infusion. Composite performance was evaluated using fiber bundle pull-out, tensile, impact, and interlaminar shear tests. Composite tests indicate that composite panels are largely unchanged among fiber samples. Variation in composite performance might not be realized due to poor interfacial bonding being of larger impact than the more subtle changes incurred by the enzyme treatment.</description><Author>Jonn A. Foulk, Denis Rho, Mercedes M. Alcock, Chad A. Ulven, and Shanshan Huo</Author><copyright>Copyright &amp;#xa9; 2011 Jonn A. Foulk et al. All rights reserved.</copyright></item><item><title>Experimental Study of Fiber Length and Orientation in Injection Molded Natural Fiber/Starch Acetate Composites</title><link>http://www.hindawi.com/journals/amse/2011/891940/</link><description>Composite compounds based on triethyl citrate plasticized starch acetate and hemp and flax fibers were prepared by melt processing. Plasticizer contents from 20 to 35 wt&amp;#37; and fiber contents of 10 and 40 wt&amp;#37; were used. The compounded composites were injection molded to tensile test specimens. The effect of processing, melt viscosity and fiber type on the fiber length was investigated. The lengths of fully processed fibers were determined by dissolving the matrix and measuring the length of the remaining fibers by microscope analysis. A clear reductive effect of the processing on the fiber length was noticed. A reduction of fiber length along the increasing fiber content and the decreasing plasticizer content was also detected. This reduction originated from the increasing shear forces during compounding, which again depended on the increased viscosity of the material. Hemp fibers were shown to remain longer and fibrillate more than flax fibers, leading to higher aspect ratio. Thus, the reinforcement efficiency of hemp fibers by the processing was improved, in contrast with flax fibers. In addition, the analysis of fiber dispersion and orientation showed a good dispersion of fibers in the matrix, and a predominant orientation of the fibers in the melt flow direction.</description><Author>Heidi Peltola, Bo Madsen, Roberts Joffe, and Kalle N&amp;#228;ttinen</Author><copyright>Copyright &amp;#xa9; 2011 Heidi Peltola et al. All rights reserved.</copyright></item><item><title>A Phenomenological Study on the Synergistic Role of Precious Metals in the Steam Reforming of Logistic Fuels on Bimetal-Supported Catalysts</title><link>http://www.hindawi.com/journals/amse/2011/496038/</link><description>Fuel processors are required to convert sulfur-laden logistic fuels into hydrogen-rich reformate and deliver to the fuel cell stack with little or no sulfur. Since sulfur poisons and deactivates the reforming catalyst, robust sulfur-tolerant catalysts ought to be developed. In this paper, the development, characterization and evaluation of a series of reforming catalysts containing two noble metals (with total metal loading not exceeding 1 weight percent) supported on nanoscale ceria for the steam-reforming of kerosene is reported. Due to inherent synergy, a bimetallic catalyst is superior to its monometallic analog, for the same level of loading. The choice of noble metal combination in the bimetallic formulations plays a vital and meaningful role in their performance. Presence of ruthenium and/or rhodium in formulations containing palladium showed improved sulfur tolerance and significant enhancement in their catalytic activity and stability. Rhodium was responsible for higher hydrogen yields in the logistic fuel reformate. Duration of steady hydrogen production was higher in the case of RhPd (75&amp;#x2009;h) than for RuPd (68&amp;#x2009;h); hydrogen generation was stable over the longest period (88&amp;#x2009;h) with RuRh containing no Pd. A mechanistic correlation between the characteristic role of precious metals in the presence of each other is discussed.</description><Author>Abdul-Majeed Azad and Desikan Sundararajan</Author><copyright>Copyright &amp;#xa9; 2011 Abdul-Majeed Azad and Desikan Sundararajan. All rights reserved.</copyright></item><item><title>The Electrical Characteristics of Aluminium Doped Zinc Oxide Thin Film for Humidity Sensor Applications</title><link>http://www.hindawi.com/journals/amse/2011/974906/</link><description>The electrical characteristics of aluminum (Al) doped zinc oxide (ZnO) thin film for high sensitivity humidity sensors are presented. The effects of Al doping concentration at 0&amp;#x7e;0.6 at &amp;#x25; on the Al doped ZnO thin film properties were investigated using current-voltage measurement. The optical and structural properties were characterized using photoluminescence (PL), scanning emission microscope (SEM), and X-ray diffraction (XRD). Parameter 0.6 at &amp;#x25; Aluminum doped show high sensitivity and suitable for humidity sensor. PL show an emissions band with two peaks centered at about 380&amp;#x2009;nm (ultra-violet (UV)) and 600&amp;#x2009;nm (green) in a room temperature. The length of the nanorods increases as the doping concentration increases. XRD results show the intensity of the (002) peak decreased with the increasing of doping concentration.</description><Author>N. D. Md Sin, M. Fuad Kamel, Rosalena Irma Alip, Zulfakri Mohamad, and M. Rusop</Author><copyright>Copyright &amp;#xa9; 2011 N. D. Md Sin et al. All rights reserved.</copyright></item><item><title>Effect of Induced Charge on the Passivity and Passivity Breakdown of 304LN Stainless Steels</title><link>http://www.hindawi.com/journals/amse/2011/798262/</link><description>Passivity breakdown of stainless steel by pitting in chloride environment is believed to occur at point at zero charge (pzc). So, the nature and quantity of charge on the surface plays a very important role on the breakdown of passivity, as chloride ion adsorption depends on that. In this work a DC potential was maintained between aluminium and graphite electrodes, and the aluminium electrode, in turn, was kept in the vicinity of the working electrode in the potentiostatic circuit. Both positive and negative polarity was applied on aluminium to attract or repel chloride ions in the vicinity of the working electrode. Chloride adsorption pattern on the stainless steel electrode got drastically altered due to application of DC potential on the aluminium-graphite circuit.</description><Author>Gargi Roy Chowdhury and P. K. Mitra</Author><copyright>Copyright &amp;#xa9; 2011 Gargi Roy Chowdhury and P. K. Mitra. All rights reserved.</copyright></item><item><title>The Comparison of Water Absorption Analysis between Counterrotating and Corotating Twin-Screw Extruders with Different Antioxidants Content in Wood Plastic Composites</title><link>http://www.hindawi.com/journals/amse/2011/406284/</link><description>Water absorption is a major concern for natural fibers as reinforcement in wood plastic composites (WPCs). 
                  This paper presents a study on the comparison analysis of water absorption between two types of twin-screw extruders, namely, counterrotating and corotating with presence of variable antioxidants content. Composites of mixed fibres between rice husk and saw dust with recycled high-density polyethylene (rHDPE) were prepared with two different extruder machines, namely, counterrotating and corotating twin screw, respectively. The contents of matrix (30&amp;#x2009;wt%) and fibres (62&amp;#x2009;wt%) were mixed with additives (8&amp;#x2009;wt%) and compounded using compounder before extruded using both of the machines. Samples were immersed in distilled water according to ASTM D 570-98. From the study, results indicated a significant difference among samples extruded by counterrotating and corotating twin-screw extruders. The counterrotating twin-screw extruder gives the smallest value of water absorption compared to corotating twin-screw extruder. This indicates that the types of screw play an important role in water uptake by improving the adhesion between natural fillers and the polymer matrix.</description><Author>Mohd Hafizuddin Ab Ghani and Sahrim Ahmad</Author><copyright>Copyright &amp;#xa9; 2011 Mohd Hafizuddin Ab Ghani and Sahrim Ahmad. All rights reserved.</copyright></item><item><title>Analysis of the Indentation Size Effect in the Microhardness Measurements in B6O</title><link>http://www.hindawi.com/journals/amse/2011/539252/</link><description>The Vickers microhardness measurements of boron suboxide (B6O) ceramics prepared by uniaxial hot-pressing was investigated at indentation test loads in the range from 0.10 to 2.0&amp;#x2009;kgf. Results from the investigation indicate that the measured microhardness exhibits an indentation load dependence. Based on the results, we present a comprehensive model intercomparison study of indentation size effects (ISEs) in the microhardness measurements of hot-pressed B6O discussed using existing models, that is, the classical Meyer&amp;#39;s law, Li and Bradt&amp;#39;s proportional specimen resistance model (PSR), the modified proportional specimen resistance model (MPSR), and Carpinteri&amp;#39;s multifractal scaling law (MFSL). The best correlation between literature-cited load-independent Vickers microhardness values, the measured values, and applied models was achieved in the case of the MPSR and the MFSL models.</description><Author>Ronald Machaka, Trevor E. Derry, Iakovos Sigalas, and Mathias Herrmann</Author><copyright>Copyright &amp;#xa9; 2011 Ronald Machaka et al. All rights reserved.</copyright></item><item><title>Near UV-Blue Excitable Green-Emitting Nanocrystalline Oxide</title><link>http://www.hindawi.com/journals/amse/2011/790517/</link><description>Green-emitting Eu-activated powders were produced by a two-stage method consisting of pressure-assisted combustion synthesis and postannealing in ammonia. The as-synthesized powders exhibited a red photoluminescence (PL) peak located at &amp;#x03BB;=616&amp;#x2009;nm when excited with &amp;#x03BB;=395&amp;#x2009;nm UV. This emission peak corresponds to the 5D0&amp;#x2192;7F2 transition in Eu3+. After annealing in ammonia, the PL emission changed to an intense broad-band peak centered at &amp;#x03BB;=500&amp;#x2009;nm, most likely produced by 4f65d1&amp;#x2192;4f7 electronic transitions in Eu2+. This green-emitting phosphor has excitation band in the near UV-blue region (&amp;#x03BB;=300&amp;#8211;450&amp;#x2009;nm). X-ray diffraction analysis reveals mainly the orthorhombic EuAlO3 and Al2O3 phases. Transmission electron microscopy observations showed that the grains are formed by faceted nanocrystals (~4&amp;#x2009;nm) of polygonal shape. The excellent excitation and emission properties make these powders very promising to be used as phosphors in UV solid-state diodes coupled to activate white-emitting lamps.</description><Author>C. E. Rodr&amp;#237;guez-Garc&amp;#237;a, N. Perea-L&amp;#243;pez, and G. A. Hirata</Author><copyright>Copyright &amp;#xa9; 2011 C. E. Rodr&amp;#xed;guez-Garc&amp;#xed;a et al. All rights reserved.</copyright></item><item><title>Experimental Study of Heat Flux Distribution of Arc Driven by AC Magnetic Field</title><link>http://www.hindawi.com/journals/amse/2011/615492/</link><description>The authors earlier developed a model to predict the heat flux distribution in an arc driven by an AC magnetic field. That theoretical model implied that the heat flux distribution depended on waveforms of the imposed AC magnetic field. Experiments were conducted in this study to validate that theoretical prediction. Theoretical calculations of heat flux distribution in the arc driven by AC magnetic field were conducted using the heat flux profile in the arc root obtained from the measurement under no magnetic field. The heat flux distributions in arcs driven by AC magnetic fields were measured by imposing two AC magnetic fields with sinusoidal and rectangular waveforms. Agreement between experimental and theoretical heat flux distributions was good. Results confirm that heat flux profiles of various types are producible by controlling the imposed magnetic flux density and its waveform.</description><Author>Naomi Matsumoto, Takeo Yamamoto, Masaya Sugimoto, and Koichi Takeda</Author><copyright>Copyright &amp;#xa9; 2011 Naomi Matsumoto et al. All rights reserved.</copyright></item><item><title>Critical Analysis on the Structural and Magnetic Properties of Bulk and Nanocrystalline Cu-Fe-O</title><link>http://www.hindawi.com/journals/amse/2010/715872/</link><description>Nanocrystalline and bulk samples of &amp;#x0201c;Fe&amp;#x0201d;-doped CuO were prepared by coprecipitation and ceramic methods. Structural and compositional analyses were performed using X-ray diffraction, SEM, and EDAX. Traces of secondary phases such as CuFe2O4, Fe3O4, and &amp;#x003b1;-Fe2O3 having peaks very close to that of the host CuO were identified from the Rietveld profile analysis and the SAED pattern of bulk and nanocrystalline Cu0.98Fe0.02O samples. Vibrating Sample Magnetometer (VSM) measurements show hysteresis at 300&amp;#x02009;K for all the samples. The ferrimagnetic Neel transition temperature (TN) was found to be around 465&amp;#x000B0;C irrespective of the content of &amp;#x0201c;Fe&amp;#x0201d;, which is close to the TN value of cubic CuFe2O4. High-pressure X-Ray diffraction studies were performed on 2&amp;#x00025; &amp;#x0201c;Fe&amp;#x0201d;-doped bulk CuO using synchrotron radiation. From the absence of any strong new peaks at high pressure, it is evident that the secondary phases if present could be less than the level of detection. Cu2O, which is diamagnetic by nature, was also doped with 1&amp;#x00025; of &amp;#x0201c;Fe&amp;#x0201d; and was found to show paramagnetic behavior in contrast to the &amp;#x0201c;Fe&amp;#x0201d; doped CuO. Hence the possibility of intrinsic magnetization of &amp;#x0201c;Fe&amp;#x0201d;-doped CuO apart from the secondary phases is discussed based on the magnetization and charge state of  &amp;#x0201c;Fe&amp;#x0201d; and the host into which it is substituted.</description><Author>D. Paul Joseph, C. Venkateswaran, and R. Selva Vennila</Author><copyright>Copyright &amp;#xa9; 2010 D. Paul Joseph et al. All rights reserved.</copyright></item><item><title>Microstructure Evolution of Grade X100 Pipeline under Plastic Deformation Condition</title><link>http://www.hindawi.com/journals/amse/2010/180975/</link><description>The effects of plastic deformation on the microstructure evolution of grade X100 pipeline were investigated  by SEM, TEM and EBSD tests. The result shows that quasipolygon ferrite deforms firstly under plastic strain initial stage, then both acicular ferrite and granular bainite change remarkably with the value of plastic strain increase. When the tension stress reaches the tensile strength, microcracks nucleate around the inclusion and M/A constitute, expand with the plastic deformation increases, and finally cracks connection causes the crack penetration until the expiration. Furthermore, the microscopic orientation concentrates in {110}&amp;#x2009;&amp;#x2329;111&amp;#x0232A; direction before the deformation, while crystal orientation in {110} and {112} direction enhanced after the deformation.</description><Author>Lihua Qi, Long Yang, Jing Niu, Yaorong Feng, and Jianxun Zhang</Author><copyright>Copyright &amp;#xa9; 2010 Lihua Qi et al. All rights reserved.</copyright></item><item><title>A Phenomenological Study on the Synergistic Role of  Precious Metals in the Steam Reforming of Logistic Fuels on Trimetal-Supported Catalysts</title><link>http://www.hindawi.com/journals/amse/2010/325683/</link><description>Fuel processors are required to convert sulfur-laden logistic fuels (jet fuels, diesel, and coal) into fuel cell quality hydrogen-rich reformate with little or no sulfur for extended periods. Sulfur poisons and deactivates the reforming catalyst, therefore, sulfur-tolerant catalysts ought to be developed. In this paper, the development, characterization, and evaluation of a series of nanoscale ceria-supported reforming catalysts containing three noble metals in low concentration (1&amp;#x2009;wt&amp;#37; &amp;#x2264; total metal loading &amp;#x2264; 1.33&amp;#x2009;wt&amp;#37;) for the steam-reforming of kerosene (a JP-8 surrogate) are reported. Their performance is quantified in terms of H2 yield, tolerance towards sulfur in the fuel, and the on-stream stability and compared with that of monometal and bimetal analogs under identical conditions. Due to the inherent cooperative synergy, a trimetal catalyst was found far superior to its mono- and bimetallic analog containing same amount of the precious metal loading in terms of quality of the reformate (measured by H2 level in steady-state) as well as the catalyst longevity on-stream prior to deactivation. At the same time a mechanistic correlation between the distinct role of a given precious metal and the extent of its loading in each of the formulations and quality of the corresponding desulfurized H2-rich reformate was discovered.</description><Author>Abdul-Majeed Azad and Desikan Sundararajan</Author><copyright>Copyright &amp;#xa9; 2010 Abdul-Majeed Azad and Desikan Sundararajan. All rights reserved.</copyright></item><item><title>Performance of Sprayed Fiber Reinforced Polymer Strengthened Timber Beams</title><link>http://www.hindawi.com/journals/amse/2010/498378/</link><description>A study was carried out to investigate the use of Sprayed Fiber Reinforced Polymer (SFRP) for retrofit of timber beams. A total of 10-full scale specimens were tested. Two different timber preservatives and two different bonding agents were investigated. Strengthening was characterized using load deflection diagrams. Results indicate that it is possible to enhance load-carrying capacity and energy absorption characteristics using the technique of SFRP. Of the two types of preservatives investigated, the technique appears to be more effective for the case of creosote-treated specimens, where up to a 51&amp;#37; improvement in load-carrying capacity and a 460&amp;#37; increase in the energy absorption capacity were noted. Effectiveness of the bonding agent used was dependent on the type of preservative the specimen had been treated with.</description><Author>S. Talukdar and N. Banthia</Author><copyright>Copyright &amp;#xa9; 2010 S. Talukdar and N. Banthia. All rights reserved.</copyright></item><item><title>Parameters Expediting the Thermal Conversion of Ba-Exchanged Zeolite A to Monoclinic Celsian</title><link>http://www.hindawi.com/journals/amse/2010/683429/</link><description>Four samples of Ba-exchanged zeolite A, bearing small residual amounts of Na (0.27, 0.43, 0.58, and 0.74&amp;#x2009;meq/g), were thermally treated in the temperature range 200&amp;#8211;1500&amp;#x2218;C for times up to 28 hours. The same samples were pressed at 30 and 60&amp;#x2009;MPa to form cylindrical pellets which were thermally treated at 1300&amp;#x2218;C for 5 hours. All materials were characterized by room temperature XRD. The sequence of thermal transformations that Ba-exchanged zeolite A undergoes (zeolite &amp;#x2192; amorphous phase &amp;#x2192; hexacelsian &amp;#x2192; monoclinic celsian) and the strong mineralizing action developed by Na are confirmed. Pressing the Ba-exchanged zeolite A powder-like samples to obtain cylindrical pellets is found to expedite the sluggish final phase transition hexacelsian &amp;#x2192; monoclinic celsian. The optimum residual Na content of Ba-exchanged zeolite A for transformation into monoclinic celsian is assessed to be between 0.27 and 0.43&amp;#x2009;meq/g.</description><Author>A. Marocco, M. Pansini, G. Dell'Agli, and S. Esposito</Author><copyright>Copyright &amp;#xa9; 2010 A. Marocco et al. All rights reserved.</copyright></item><item><title>Sintering Behavior, Microstructure, and Mechanical Properties: A Comparison among Pressureless Sintered Ultra-Refractory Carbides</title><link>http://www.hindawi.com/journals/amse/2010/835018/</link><description>Nearly fully dense carbides of zirconium, hafnium, and tantalum were obtained by pressureless sintering at 1950&amp;#xB0;C with the addition of 5&amp;#8211;20&amp;#x2009;vol&amp;#37; of MoSi2. Increasing the amount of sintering aid, the final density increased too, thanks to the formation of small amounts of liquid phase constituted by M-Mo-Si-O-C, where M is either Zr, Hf, or Ta. The matrices of the composites obtained with the standard procedure showed faceted squared grains; when an ultrasonication step was introduced in the powder treatment, the grains were more rounded and no exaggerated grains growth occurred. Other secondary phases observed in the microstructure were SiC and mixed silicides of the transition metals. Among the three carbides prepared by pressurless sintering, TaC-based composites had the highest mechanical properties at room temperature (strength 590 MPa, Young&amp;#39;s modulus 480 GPa, toughness 3.8 
MPa&amp;#x22C5;m1/2). HfC-based materials showed the highest sinterability (in terms of final density versus amount of sintering aid) and the highest high-temperature strength (300 MPa at 1500&amp;#x2009;
   &amp;#xB0;C).</description><Author>Laura Silvestroni and Diletta Sciti</Author><copyright>Copyright &amp;#x00A9; 2010 Laura Silvestroni and Diletta Sciti. All rights reserved.</copyright></item><item><title>Cutting Force in Stone Machining by Diamond Disk</title><link>http://www.hindawi.com/journals/amse/2010/631437/</link><description>Stone machining by diamond disk is a widespread process to manufacture standard products, such as tiles, slabs, and kerbs. Cutting force and energy may be used to monitor stone machining. Empirical models are required to guide the selection of cutting conditions. In this paper, the effects of cutting conditions on cutting force and cutting energy are related to the shape of the idealized chip thickness. The empirical models developed in this paper can be used to predict the variation of the cutting energy. Therefore these models can be used to guide the selection of cutting conditions. The chip generation and removal process has been quantified with the intention of assisting both the toolmaker and the stonemason in optimising the tool composition and cutting process parameters, respectively.</description><Author>S. Turchetta</Author><copyright>Copyright &amp;#x00A9; 2010 S. Turchetta. All rights reserved.</copyright></item><item><title>Anisotropic Ferro- and Dielectric Properties of Textured  Bi4Ti3O12 Ceramics Prepared by the Solid-State Reaction Based on Multiple Calcination</title><link>http://www.hindawi.com/journals/amse/2010/398590/</link><description>The grain-oriented Bi4Ti3O12 (BIT) samples were prepared by the solid-state reaction method with a multicalcination process. The grain-oriented BIT samples exhibit anisotropic structural, ferroelectric, piezoelectric, and dielectric properties. The remanent polarization (2Pr) and the piezoelectric constant (d33) of a/b- and c-direction BIT ceramics are 49.5&amp;#x2009;&amp;#x3bc;C&amp;#x2009;cm&amp;#x2212;2, 22.2 pC N&amp;#x2212;1 and 6.7&amp;#x2009;&amp;#x3bc;C&amp;#x2009;cm&amp;#x2212;2 6.9 pC N&amp;#x2212;1, respectively. The dielectric anomalies of samples are observed around 157&amp;#x2009;K and 232&amp;#x2009;K. The dielectric anomalies at around 157 K are related to oxygen vacancies. The activation energy of the dielectric relaxation of this anomaly is estimated to be 1.36&amp;#x2009;eV. Another dielectric anomaly at around 232&amp;#x2009;K is related to polarizable domains and the viscous motion of domain walls.</description><Author>Xiangyu Mao, Wei Wang, Hui Sun, and Xiaobing Chen</Author><copyright>Copyright &amp;#x00A9; 2010 Xiangyu Mao et al. All rights reserved.</copyright></item><item><title>Deposition and Tribological Properties of Sulfur-Doped DLC Films Deposited by PBII Method</title><link>http://www.hindawi.com/journals/amse/2010/958581/</link><description>Sulfur-doped diamond-like carbon films (S-DLC) fabricated from C2H2 and SF6 mixtures were used to study the effects of sulfur content and negative pulse bias voltage on the deposition and tribological properties of films prepared by plasma-based ion implantation (PBII). The structure and relative concentration of the films were analyzed by Raman spectroscopy and Auger electron spectroscopy. Hardness and elastic modulus of films were measured by nanoindentation hardness testing. Tribological characteristics of films were performed using a ball-on-disk friction tester. The results indicate that with the increasing sulfur content, the hardness and elastic modulus decrease. Additionally, by changing the negative pulse bias voltage from 0&amp;#x2009;kV to &amp;#x2212;5&amp;#x2009;kV, the hardness and elastic modulus increase, while the friction coefficient and specific wear rate tends to decrease. Moreover, at a negative pulse bias voltage of &amp;#x2212;5&amp;#x2009;kV and flow-rate ratio of 1&amp;#x02009;:&amp;#x02009;2, there is considerable improvement in friction coefficient of 0.05 under ambient air is due to the formation of a transfer films on the interface. The decrease in the friction coefficient of films doped with 4.9 at.&amp;#37; sulfur is greater under high vacuum (0.03) than under ambient air (&amp;#62;0.1).</description><Author>Nutthanun Moolsradoo and Shuichi Watanabe</Author><copyright>Copyright &amp;#xa9; 2010 Nutthanun Moolsradoo and Shuichi Watanabe. All rights reserved.</copyright></item><item><title>Growth of  AlGaSb Compound Semiconductors on GaAs Substrate by Metalorganic Chemical Vapour Deposition</title><link>http://www.hindawi.com/journals/amse/2010/923409/</link><description>Epitaxial AlxGa1-xSb layers on GaAs substrate have been grown by atmospheric pressure metalorganic chemical vapour deposition using TMAl, TMGa, and TMSb. We report the effect of V/III flux ratio and growth temperature on growth rate, surface morphology, electrical properties, and composition analysis.  A growth rate activation energy of 0.73&amp;#x2009;eV was found. For layers grown on GaAs at 580&amp;#x2218;C and 600&amp;#x2218;C with a V/III ratio of 3 a high  quality surface morphology is typical, with a mirror-like surface and good composition control. It was found that a suitable growth temperature and V/III flux ratio was beneficial for producing good AlGaSb layers. Undoped AlGaSb grown at 580&amp;#x2218;C with a V/III flux ratio of 3 at the rate of 3.5&amp;#x2009;&amp;#x03BC;m/hour shows p-type conductivity with smooth surface morphology and its hole mobility and carrier concentration are equal to 237&amp;#x2009;cm2/V.s and 4.6&amp;#x2009;&amp;#x000D7;&amp;#x2009;1017&amp;#x2009;cm-3, respectively, at 77&amp;#x2009;K. The net hole concentration of unintentionally doped AlGaSb was found to be significantly decreased with the increased of aluminium concentration.  All samples investigated show oxide layers (Al2O3, Sb2O3, and Ga2O5) on their surfaces.  In particular the percentage of aluminium-oxide  was very high compared  with a small percentage of AlSb.  Carbon content on the surface was also very high.</description><Author>A. H. Ramelan, H. Harjana, and P. Arifin</Author><copyright>Copyright &amp;#xa9; 2010 A. H. Ramelan et al. All rights reserved.</copyright></item></channel></rss>
