﻿<?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>Simulation of Electronic Structure of Aluminum Phosphide Nanocrystals Using Ab Initio Large Unit Cell Method</title><link>http://www.hindawi.com/journals/amse/2012/180679/</link><description>Ab initio restricted Hartree-Fock method coupled with the large unit cell method is used to determine the electronic structure and physical properties of aluminum phosphide (AlP) nanocrystals between 216 and 1000 atoms with sizes ranging up to about 3&amp;#x2009;nm in diameter. Core and surface parts with different sizes are investigated. Investigated properties include total energy, cohesive energy, energy gap, valence band width, ionicity, and degeneracy of energy levels. The oxygenated (001)-(1&amp;#x000d7;1) facet that expands with larger sizes of nanocrystals is investigated to determine the rule of the surface in nanocrystals electronic structure. Results revealed that electronic properties converge to some limit as the size of the large unit cell increases and that the 216 core atoms approaches bulk of Aluminum phosphide material in several properties. Increasing nanocrystals size also resulted in a decrease in lattice constant, increase of core cohesive energy (absolute value), increase of core energy gap, increase of core valence band width and decrease of ionicity. Valence and conduction bands are wider on the surface due to splitting and oxygen atoms. The method also shows fluctuations in the converged energy gap, valence band width and cohesive energy of core part of nanocrystals duo to shape variation.</description><Author>Hamad R. Jappor, Zeyad Adnan Saleh, and Mudar A. Abdulsattar</Author><copyright>Copyright &amp;#xa9; 2012 Hamad R. Jappor et al. All rights reserved.</copyright></item><item><title>The Comparison of Biocompatibility Properties between Ti Alloys and Fluorinated Diamond-Like Carbon Films</title><link>http://www.hindawi.com/journals/amse/2012/724126/</link><description>Titanium and titanium alloys have found several applications in the biomedical field due to their unique biocompatibility. However, there are problems associated with these materials in applications in which there is direct contact with blood, for instance, thrombogenesis and protein adsorption. Surface modification is one of the effective methods used to improve the performance of Ti and Ti alloys in these circumstances. In this study, fluorinated diamond-like carbon (F-DLC) films are chosen to take into account the biocompatible properties compared with Ti alloys. F-DLC films were prepared on NiTi substrates by a plasma-based ion implantation (PBII) technique using acetylene (C2H2) and tetrafluoromethane (CF4) as plasma sources. The structure of the films was characterized by Raman spectroscopy. The contact angle and surface energy were also measured. Protein adsorption was performed by treating the films with bovine serum albumin and fibrinogen. The electrochemical corrosion behavior was investigated in Hanks’ solution by means of a potentiodynamic polarization technique. Cytotoxicity tests were performed using MTT assay and dyed fluorescence. The results indicate that F-DLC films present their hydrophobic surfaces due to a high contact angle and low surface energy. These films can support the higher albumin-to-fibrinogen ratio as compared to Ti alloys. They tend to suppress the platelet adhesion. Furthermore, F-DLC films exhibit better corrosion resistance and less cytotoxicity on their surfaces. It can be concluded that F-DLC films can improve the biocompatibility properties of Ti alloys.</description><Author>Chavin Jongwannasiri, Nutthanun Moolsradoo, Anak Khantachawana, Pongpan Kaewtatip, and Shuichi Watanabe</Author><copyright>Copyright &amp;#xa9; 2012 Chavin Jongwannasiri et al. All rights reserved.</copyright></item><item><title>Reduced Turn-On Voltage for npn Graded-Base AlGaN/GaN Heterojunction Bipolar Transistors by Thermal Treatment</title><link>http://www.hindawi.com/journals/amse/2012/654762/</link><description>A thermal treatment was employed to improve the DC performances of npn graded-base AlGaN/GaN heterojunction bipolar transistors (HBTs). Such HBTs without the thermal treatment exhibit a higher turn-on voltage of 6.45&amp;#x2009;V, a lower current gain of 0.84, and a lower collector current of 3.18 × 10-4&amp;#x2009;mA at VBE of 4.5&amp;#x2009;V. The HBTs are examined by thermal treatment with rapid thermal process (RTP) annealing at various times and various temperatures. Experimental results reveal that the HBTs with the thermal treatment exhibit a lowest turn-on voltage of 3.90&amp;#x2009;V, a highest current gain of 9.55, and highest collector current of 112.2&amp;#x2009;mA at VBE of 4.5&amp;#x2009;V. The thermal treatment brings forth the most remarkable improvements for the HBTs when the base parasitical Schottky diodes are modified.</description><Author>Shih-Wei Tan and Shih-Wen Lai</Author><copyright>Copyright &amp;#xa9; 2012 Shih-Wei Tan and Shih-Wen Lai. All rights reserved.</copyright></item><item><title>Attachment and Proliferation of Osteoblasts on Lithium-Hydroxyapatite Composites</title><link>http://www.hindawi.com/journals/amse/2012/650574/</link><description>The biocompatibility and bioactivity properties of hydroxyapatites (HAs) modified through lithium addition were investigated. Hydroxyapatites obtained from bovine bone were mixed with lithium carbonate (Li), in the proportions of 0.25, 0.50, 1.00, and 2.00&amp;#x25;&amp;#x2009;wt, and sintered at 900&amp;#xb0;, 1000&amp;#xb0;, 1100&amp;#xb0;, 1200&amp;#xb0;, and 1300&amp;#xb0;C, creating LiHA samples. The osteoblast culture behavior was assessed in the presence of these LiHA compositions. The cellular interactions were analyzed by evaluating the viability and cellular proliferation, ALP production and collagen secretion. The cytotoxic potential was investigated through measurement of apoptosis and necrosis induction. The process of cellular attachment in the presence of the product of dissolution of LiHA, was evaluated trough fluorescence analysis. The physical characteristics of these materials and their cellular interactions were examined with SEM and EDS. The results of this study indicate that the LiHA ceramics are biocompatible and have variable bioactivities, which can be tailored by different combinations of the concentration of lithium carbonate and the sintering temperature. Our findings suggest that LiHA 0.25&amp;#x25;&amp;#x2009;wt, sintered at 1300&amp;#xb0;C, combines the necessary physical and structural qualities with favorable biocompatibility characteristics, achieving a bioactivity that seems to be adequate for use as a bone implant material.</description><Author>Ana Paula M. Shainberg, Patrícia Valério, Alessandra Zonari, Faik N. Oktar, Lutfiye S. Ozyegin, Manuel Pedro F. Gra&amp;#231;a, Maria F. Leite, and Alfredo M. Goes</Author><copyright>Copyright &amp;#xa9; 2012 Ana Paula M. Shainberg et al. All rights reserved.</copyright></item><item><title>Comparison of Gelation Time and Polyalcohol Effect on Hydrogels from Domestic and Wild Silk Fibroins</title><link>http://www.hindawi.com/journals/amse/2012/819464/</link><description>Silk fibroin (SF) hydrogels were obtained from both domestic (Bombyx mori) and wild (Antheraea pernyi) silkworms from aqueous silk fibroin solutions at room temperature. The gelation time of the Antheraea pernyi (A. pernyi) SF solution was significantly shorter than that of the Bombyx mori (B. mori) SF solution. The secondary structures of the two kinds of hydrogels were also compared. In order to further reduce the gelation time, various amounts of polyethylene glycol (PEG) were blended with the silk fibroins of A. pernyi and B. mori. The gelation time of both A. pernyi SF and B. mori SF decreased with the increased amount of PEG. After freeze-drying, the hydrogels were characterized through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy. Results showed that the addition of polyalcohol did not change the main secondary structure of the hydrogels. However, the addition of polyalcohol did reduce the gelation time and triggered additional formation of &amp;#x3b2;-sheets.</description><Author>Huijing Zhao, Siyong Xiong, Mingzhong Li, Qiang Zhang, and Guiyang Liu</Author><copyright>Copyright &amp;#xa9; 2012 Huijing Zhao et al. All rights reserved.</copyright></item><item><title>Stress Corrosion Cracking of Steel and Aluminum in Sodium Hydroxide: Field Failure and Laboratory Test</title><link>http://www.hindawi.com/journals/amse/2012/235028/</link><description>Through an investigation of the field failure analysis and laboratory experiment, a study on (stress corrosion cracking) SCC behavior of steel and aluminum was performed. All samples were extracted from known operating conditions from the field failures. Similar but accelerated laboratory test was subsequently conducted in such a way as to mimic the field failures. The crack depth and behavior of the SCC were then analyzed after the laboratory test and the mechanism of stress corrosion cracking was studied. The results show that for the same given stress relative to ultimate tensile strength, the susceptibility to SCC is greatly influenced by heat treatment. Furthermore, it was also concluded that when expressed relative to the (ultimate tensile strength) UTS, aluminum has similar level of SCC susceptibility to that of steel, although with respect to the same absolute value of applied stress, aluminum is more susceptible to SCC in sodium hydroxide environment than steel.</description><Author>Y. Prawoto, K. Sumeru, and W. B. Wan Nik</Author><copyright>Copyright &amp;#xa9; 2012 Y. Prawoto et al. All rights reserved.</copyright></item><item><title>Synthesis and Characterization of Nickel-Alumina Composites from Recycled Nickel Powder</title><link>http://www.hindawi.com/journals/amse/2012/395612/</link><description>The recycling of metallic waste to create more valuable materials and their valorization into upgraded metal-based composites constitutes an important field of study. The composite industry nowadays considers environmental improvements as important as other properties of the materials. In the present paper, nickel powder was recycled from ferrous scrap, a low-cost and largely available material, by an effective hydrometallurgical recovery process. Then, this recycled powder was successfully used along with particulate &amp;#x3b1;-alumina to prepare oblong nickel-based composite specimens with ceramic reinforcement loadings ranging from 0 to 30&amp;#x2009;wt.% by applying powder processing manufacturing techniques including cold isostatic pressing (CIP) and sintering. The microstructures obtained were characterized, the specimens were subjected to three-point bend tests, and their fracture behaviour was evaluated. By increasing the % ceramic reinforcement content, density clearly decreases while strengthening is achieved, thus leading to development of lightweight and enhanced oblong nickel-alumina composites. The composite microstructure, and particularly the metal-ceramic interface bonding, has a strong impact on fracture behaviour upon external loading.</description><Author>V. G. Karayannis and A. K. Moutsatsou</Author><copyright>Copyright &amp;#xa9; 2012 V. G. Karayannis and A. K. Moutsatsou. All rights reserved.</copyright></item><item><title>The Effect of Ultrasonic Treatment on Thermal Stability of the Cured Epoxy/Layered Silicate Nanocomposite</title><link>http://www.hindawi.com/journals/amse/2012/789815/</link><description>The effect of ultrasonic treatment on thermal stability of binary systems containing epoxy and organic chemically modified montmorillonite (Cloisite 30B) was studied. Differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and wide angle X-ray diffraction (WAXD) analysis were utilized. The mixing of epoxy and Cloisite 30B nanocomposites was performed by mechanical stirring, followed by 1 or 3-hour ultrasonic treatment, and polyetheramine as the curing agent. Both XRD and TEM analyses confirmed that the intercalation of Cloisite 30B was achieved. The d0 spacings for silicate in cured sample prepared at 1- and 3-hour duration of ultrasonic treatment were about 21 and 18&amp;#x2009;Å, respectively. This shows that shorter duration or ultrasonic treatment may be preferable to achieve higher d0 spacing of clay. This may be attributed to the increase in viscosity as homopolymerization process occurred, which restricts silicate dispersion. The 1-hour sonicated samples seem to be more thermally stable during the glass transition, but less stable during thermal decomposition process.</description><Author>N. Y. Yuhana, S. Ahmad, and A. R. Shamsul Bahri</Author><copyright>Copyright &amp;#xa9; 2012 N. Y. Yuhana et al. All rights reserved.</copyright></item><item><title>Effects of Aging Temperature on Moisture Absorption of Perforated GFRP</title><link>http://www.hindawi.com/journals/amse/2012/303014/</link><description>This paper examines the effects of aging on the flexural stiffness and bending loading
capacity of a perforated glass fiber-reinforced epoxy composite subjected to combined
moisture and elevated temperature. Specimens, in the configuration of one-quarter of a
perforated GFRP tube, were aged in 60% humidity and temperatures of 40, 60, and 80&amp;#x000b0;C,
respectively. Moisture absorptions of the specimens were measured during the aging
process, and bending tests were conducted on the specimens after aging. The SEM
images were also captured to further examine the effects of the moisture absorption on
the aged specimens. The results indicated that the increase in the aging temperature reduced the diffusion
coefficient, thus inducing more moisture absorption by the composite and in turn causing more reduction in composite’s flexural stiffness and bending capacity. Moreover, the ability of Fick’s equation for predicting the moisture absorption rate in such perforated thin-walled composite configuration at various moisture contents and temperatures was also assessed. A semiempirical equation was developed and proposed by which the reduction of the stiffness in the perforated aged GFRP structures
could be predicted.</description><Author>Shiva Eslami, Fathollah Taheri-Behrooz, and Farid Taheri</Author><copyright>Copyright &amp;#xa9; 2012 Shiva Eslami et al. All rights reserved.</copyright></item><item><title>Electrical Properties of a  CeO2-Bi2O3 Mix System Elaborated at 600&amp;#xb0;C</title><link>http://www.hindawi.com/journals/amse/2012/452383/</link><description>The electrical conduction of a series of polycristalline [(1&amp;#x2212;x)CeO2&amp;#x22c5;x/2Bi2O3] samples has been analyzed using electrical impedance spectroscopy, in the temperature range 25 to 750&amp;#x2218;C. Samples have been prepared via a coprecipitation route followed by a pyrolysis process at 600&amp;#x2218;C. For compositions x&amp;#x02264;0.20, Ce1&amp;#x02212;xBixO2&amp;#x02212;x/2 solid solutions, with fluorite cubic structure, are obtained. In the composition range 0.30&amp;#x02264;x&amp;#x02264;1, the system is biphasic with coexistence of cubic and tetragonal structures. To interpret the Nyquist representations of electrical analyses, various impedance models including constant phase elements and Warburg impedances have been used. In the biphasic range (0.30&amp;#x02264;x&amp;#x02264;0.7), the conductivity variation might be related to the increasing fraction of two tetragonal &amp;#x03B2;&amp;#x02032; and &amp;#x03B2;-Bi2O3 phases. The stabilization of the tetragonal phase coexisting with substituted ceria close to composition  x=0.7 is associated with a high conduction of the mix system CeO2-Bi2O3.</description><Author>Lamia Bourja, Bahcine Bakiz, Abdeljalil Benlhachemi, Mohamed Ezahri, Sylvie Villain, Claude Favotto, and Jean-Raymond Gavarri</Author><copyright>Copyright &amp;#xa9; 2012 Lamia Bourja et al. All rights reserved.</copyright></item><item><title>Effect of the Substrate Movement on the Optical Properties of ZnO Thin Films Deposited by Ultrasonic Spray Pyrolysis</title><link>http://www.hindawi.com/journals/amse/2012/594971/</link><description>Using a modified ultrasonic spray pyrolysis (USP) system, ZnO thin films were deposited on the substrate moved back and forth (ZO1) and rotated (ZO3) as well as fixed (ZO2) in the conventional USP technique. Prepared thin films are pure ZnO with a preferred crystalline orientation of (0 0 2) in the hexagonal wurtzite structure. Diffraction angle shift implies a decrease lattice parameter along c-axis and a-axis 0.2% and 0.3%, respectively. Maximum strain has been found for ZO1 which is about (&amp;#x2212;) 0.17%. These strain values show that presence of compressive strain due to moving substrates as depositing ZnO films. The film deposition process on the rotated quartz substrate is provided to obtain the thinner film. The grain size and root-mean- square value of roughness increase with thickness. Strong UV emission was observed at &amp;#x0223C;390&amp;#x2009;nm assigned to the band gap transition from photoluminescence measurements. Energy shifted about 39&amp;#x2009;meV for ZO3 sample with respect to that of ZO2 film deposited in conventional USP system. This behaviour is confirmed with (002) diffraction peak shifting. So, the compressed lattice will provide a wider band gap for these films. E2 phonon frequency values have not given a considerable shifting.</description><Author>Ebru Gungor and Tayyar Gungor</Author><copyright>Copyright &amp;#xa9; 2012 Ebru Gungor and Tayyar Gungor. All rights reserved.</copyright></item><item><title>Effect of PVP Intermediate Layer on the Properties of SAPO 34 Membrane</title><link>http://www.hindawi.com/journals/amse/2012/650217/</link><description>SAPO 34 zeolite membranes were prepared on a tubular mullite support. Before membrane preparation, the support surfaces were coated with seed crystals. Seeds particles were prepared by hydrothermal synthesis. Before seeding, the substrates were treated with polyvinylpyrrolidone (PVP) to orient the seeds. Both the treated and untreated supports were seeded, and membranes were synthesized on those support tubes by ex situ hydrothermal method. The PVP molecule exists in the two resonance structures. Hence the acylamino bond &amp;#x2013;N+ = C&amp;#x2013;O-&amp;#x2013; acts as intermediate linker between support surface and seed surface. Due to charge interaction, the seed crystals were anchored strongly to support surface. The synthesized membranes along with seed crystals were characterized by XRD, FESEM, and EDAX analysis. The single-gas permeation with CO2 and H2 was investigated. Up to 5 bar of feed pressure, the permselectivity of CO2 and H2 was as high as 4.2.</description><Author>Jugal K. Das, Nandini Das, and Sibdas Bandyopadhyay</Author><copyright>Copyright &amp;#xa9; 2012 Jugal K. Das et al. All rights reserved.</copyright></item><item><title>Combustion Synthesis of Fe-Incorporated SnO2 Nanoparticles Using Organometallic Precursor Combination</title><link>http://www.hindawi.com/journals/amse/2012/685754/</link><description>Synthesis of nanomaterials within flames has been demonstrated as a highly scalable and versatile approach for obtaining a variety of nanoparticles with respect to their chemistry, composition, size, morphology, and dimensionality. Its applicability can be amplified by exploring new material systems and providing further control over the particle characteristics. This study focused on iron-incorporated SnO2 nanoparticles generated using an inverse coflow diffusion flame burner that supported a near-stoichiometric methane-air combustion. A liquid organometallic precursor solution of Sn(CH3)4 and Fe(CO)5 was used to produce 11&amp;#8211;14&amp;#x2009;nm nanocrystalline particles. Synthesized particles were analyzed using TEM, XRD, and XEDS to characterize for size and composition. A flame temperature field was obtained to map particle evolution within the flame. A range of conditions and parameters were studied to specifically generate targeted particles. The study augments related research towards increasing the production potential of combustion synthesis.</description><Author>Thomas K. Barkley, Jenna E. Vastano, James R. Applegate, and Smitesh D. Bakrania</Author><copyright>Copyright &amp;#xa9; 2012 Thomas K. Barkley et al. All rights reserved.</copyright></item><item><title>Self-Healing Materials Systems: Overview of Major Approaches and Recent Developed Technologies</title><link>http://www.hindawi.com/journals/amse/2012/854203/</link><description>The development of self-healing materials is now being considered for real engineering applications. Over the past few decades, there has been a huge interest in materials that can self-heal, as this property can increase  materials lifetime, reduce replacement costs, and improve product safety. Self-healing systems can be made from a variety of polymers and metallic materials. This paper reviews the main technologies currently being developed, particularly on the thermosetting composite polymeric systems. An overview of various self-healing concepts over the past decade is then presented. Finally, a perspective on future self-healing approaches using this biomimetic technique is offered. The intention is to stimulate debate and reinforce the importance of a multidisciplinary approach in this exciting field.</description><Author>B. A&amp;#239;ssa, D. Therriault, E. Haddad, and W. Jamroz</Author><copyright>Copyright &amp;#xa9; 2012 B. A&amp;#xef;ssa et al. All rights reserved.</copyright></item><item><title>Synthesis of Photochromic AgCl-Urethane Resin Composite Films</title><link>http://www.hindawi.com/journals/amse/2012/784202/</link><description>AgCl-resin photochromic composite films were prepared using AgNO3, HCl-EtOH, CuCl2 solution, and a liquid-state urethane resin as starting materials. The obtained composite films showed a photochromic property. The rate of darkening of the composite film increased after mixing with CuCl2. The AgCl particle size in the film without heat treatment was 6&amp;#8211;20&amp;#x2009;nm, and that of the heat-treated film was 25&amp;#8211;80&amp;#x2009;nm; these results were confirmed using TEM observations. The fading rate of the film without heat treatment was higher than that of the heat-treated films.</description><Author>Hidetoshi Miyazaki, Hirochi Shimoguchi, Hisao Suzuki, and Toshitaka Ota</Author><copyright>Copyright &amp;#xa9; 2012 Hidetoshi Miyazaki et al. All rights reserved.</copyright></item><item><title>Influence of Doping Concentration on Dielectric, Optical, and Morphological Properties of PMMA Thin Films</title><link>http://www.hindawi.com/journals/amse/2012/605673/</link><description>PMMA thin films were deposited by sol gel spin coating method on ITO substrates. Toluene was used as the solvent to dissolve the PMMA powder. The PMMA concentration was varied from 30 &amp;#x7e; 120&amp;#x2009;mg. The dielectric properties were measured at frequency of 0 &amp;#x7e; 100&amp;#x2009;kHz. The dielectric permittivity was in the range of 7.3 to 7.5 which decreased as the PMMA concentration increased. The dielectric loss is in the range of 0.01 &amp;#x7e; &amp;#x2013;0.01. All samples show dielectric characteristics which have dielectric loss is less than 0.05. The optical properties for thin films were measured at room temperature across 200 &amp;#x7e; 1000&amp;#x2009;nm wavelength region. All samples are highly transparent. The energy band gaps are in the range of 3.6&amp;#x2009;eV to 3.9&amp;#x2009;eV when the PMMA concentration increased. The morphologies of the samples show that all samples are uniform and the surface roughness increased as the concentration increased. From this study, it is known that, the dielectric, optical, and morphology properties were influenced by the amount of PMMA concentration in the solution.</description><Author>Lyly Nyl Ismail, Habibah Zulkefle, Sukreen Hana Herman, and Mohamad Rusop Mahmood</Author><copyright>Copyright &amp;#xa9; 2012 Lyly Nyl Ismail et al. All rights reserved.</copyright></item><item><title>Study on Burr Formation at the Top Edge  in Rectangular Groove Cutting</title><link>http://www.hindawi.com/journals/amse/2012/956208/</link><description>Previous research on burr formation in machining operations has usually been limited to the study of the rollover burr in the cutting direction. In this paper, a 3D finite element model to simulate rectangular groove cutting operation has been developed using commercial finite element software, employing experimentally determined mechanical properties at elevated strain rates and temperatures. The plastic deformation behavior and three-dimensional burr formation during rectangular groove cutting is investigated. The simulated burr profile and cutting force prove that the developed model can capture the thermo-mechanical mechanisms in rectangular groove cutting and can simulate burr development with considerable accuracy. The study concentrates on the influence of cutting parameters on burr formation which are also conducted. The results show that the feed rate and rake angle are the cutting parameters which have a major influence on burr size in the groove cutting operation. And the effect of cutting velocity and minor clearance angle in the traditional range on burr size are quite limited.</description><Author>Wen Jun Deng, Zi Chun Xie, Ping Lin, and Tong Kui Xu</Author><copyright>Copyright &amp;#xa9; 2012 Wen Jun Deng et al. All rights reserved.</copyright></item><item><title>Application of PEI-Modified Magnetic Nanoparticles as Gene Transfer Vector for the Genetic Modification of Animals</title><link>http://www.hindawi.com/journals/amse/2012/764521/</link><description>To evaluate the performance of the magnetic nanoparticles as gene transfer vector for breeding transgenic animals, we investigated a new approach to deliver green fluorescent protein (GFP) gene to porcine kidney 15 (PK-15) and porcine embryonic fibroblast (PEF) cells using PEI-modified magnetic nanoparticles as gene vector. The morphology of the nanoparticles and nanoparticle/DNA complexes was characterized using scanning electron microscopy. It was found that the surface of the particles becomes coarse and rough with increased average diameter, which implied the effective conjugating between nanoparticles with DNA. The zeta potential of nanoparticle/DNA complexes drops down from +29.4&amp;#x2009;mV to +23.1&amp;#x2009;mV comparing with pure nanoparticles. Agarose gel electrophoresis experiments show that DNA plasmids can be protected effectively against degradation of exonuclease and endonuclease. The efficiency of gene delivery was affected by the mass ratio of nanoparticle/DNA and the amount of nanoparticle/DNA complexes. We confirm that the most optimal mass ratio of nanoparticle/DNA is 1&amp;#x2009;&amp;#x2009;:&amp;#x2009;&amp;#x2009;1 by conducting a series of experiments. This work provides important experimental basis for the application of the magnetic nanoparticles on gene delivery to porcine somatic cells, which is significant for the achieving of breeding new transgenic cloned pigs by using somatic cell nuclear transfer technique.</description><Author>Jinhui Cui, Haixin Cui, Yan Wang, Changjiao Sun, Kui Li, Hongyan Ren, and Wei Du</Author><copyright>Copyright &amp;#xa9; 2012 Jinhui Cui et al. All rights reserved.</copyright></item><item><title>Lanthanum Influence on EuAlO3 Perovskite Structural Properties: Experimental and Molecular Dynamics Studies</title><link>http://www.hindawi.com/journals/amse/2012/238075/</link><description>X-ray diffraction, 27Al MAS NMR, and FTIR spectra along with results of molecular dynamics simulations were used to characterise LaxEu1&amp;#x02212;xAlO3 perovskites for x=0.3,&amp;#x2009;&amp;#x2009;0.1. Experimental and simulation results show that local changes in the perovskite-like structure can be achieved as lanthanum ions substitute europium ones. The introduction of La3+ ions in the EuAlO3 parent causes an increase in the mobility of oxygen network.</description><Author>Enrique Lima, María Elena Villafuerte-Castrejón, José Saniger, Victor Lara, Jorge E. Sánchez-Sánchez, and Luis Javier Álvarez</Author><copyright>Copyright &amp;#xa9; 2012 Enrique Lima et al. All rights reserved.</copyright></item><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></channel></rss>
