Advances in Materials Science and Engineering http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Resistive Switching Characteristics in TiO2/LaAlO3 Heterostructures Sandwiched in Pt Electrodes Thu, 23 Apr 2015 08:42:46 +0000 http://www.hindawi.com/journals/amse/2015/470107/ TiO2/LaAlO3 (TiO2/LAO) heterostructures have been deposited on Pt/TiO2/SiO2/Si substrates by pulsed laser deposition. Resistive switching characteristics of Pt/TiO2/LAO/Pt have been studied and discussed in comparison with those of Pt/TiO2/Pt. It is observed that the switching uniformity and the ON/OFF resistance ratio can be greatly improved by introducing the LAO layer. The observed resistive switching characteristics are discussed as a function of LAO thickness and explained by the preferential formation and rupture of conductive filaments, composed of oxygen vacancies, in the LAO layer. Yuyuan Cao, Qitao Di, Lin Zhu, Aidong Li, and Di Wu Copyright © 2015 Yuyuan Cao et al. All rights reserved. Water Vapor Sensors Based on the Swelling of Relief Gelatin Gratings Sun, 19 Apr 2015 10:59:46 +0000 http://www.hindawi.com/journals/amse/2015/584324/ We report on a novel device to measure relative humidity. The sensor is based on surface diffraction gratings made of gelatin. This material swells and shrinks according to the content of water vapor in air. By sending a light beam to the grating, diffracted orders appear. Due to the gelatin swelling or shrinking, first order intensity changes according to the relative humidity. Calibration curves relating intensity versus relative humidity have been found. The fabrication process of diffraction gratings and the testing of the prototype sensing devices are described. Sergio Calixto and Miguel V. Andres Copyright © 2015 Sergio Calixto and Miguel V. Andres. All rights reserved. Effect of the Electrolyte Temperature and the Current Density on a Layer Microhardness Generated by the Anodic Aluminium Oxidation Sun, 19 Apr 2015 09:27:16 +0000 http://www.hindawi.com/journals/amse/2015/659846/ The paper investigates the influence of the chemical composition and temperature of electrolyte, the oxidation time, voltage, and the current density on Vickers microhardness of aluminium oxide layers, at the same time. The layers were generated in the electrolytes with different concentrations of sulphuric and oxalic acids and surface current densities 1 A·dm−2, 3 A·dm−2, and 5 A·dm−2. The electrolyte temperature varied from −1.78°C to 45.78°C. The results have showed that while increasing the electrolyte temperature at the current density of 1 A·dm−2, the increase in the layer microhardness values is approximately by 66%. While simultaneously increasing the molar concentration of H2SO4 in the electrolyte, the growth rate of the microhardness value decreases. At the current density of 3 A·dm−2, by increasing the electrolyte temperature, a reduction in the microhardness of the generated layer occurs with the anodic oxidation time less than 25 min. The electrolyte temperature is not significant with the changing values of the layer microhardness at voltages less than 10.5 V. Emil Spišák, Miroslav Gombár, Ján Kmec, Alena Vagaská, Erika Fechová, Peter Michal, Ján Piteľ, and Daniel Kučerka Copyright © 2015 Emil Spišák et al. All rights reserved. Seismic Analysis of a Viscoelastic Damping Isolator Wed, 15 Apr 2015 07:01:21 +0000 http://www.hindawi.com/journals/amse/2015/280625/ Seismic prevention issues are discussed much more seriously around the world after Fukushima earthquake, Japan, April 2011, especially for those countries which are near the earthquake zone. Approximately kilograms of explosive energy will be released from a magnitude 9 earthquake. It destroys most of the unprotected infrastructure within several tens of miles in diameter from the epicenter. People can feel the earthquake even if living hundreds of miles away. This study is a seismic simulation analysis for an innovated and improved design of viscoelastic damping isolator, which can be more effectively applied to earthquake prevention and damage reduction of high-rise buildings, roads, bridges, power generation facilities, and so forth, from earthquake disaster. Solidworks graphic software is used to draw the 3D geometric model of the viscoelastic isolator. The dynamic behavior of the viscoelastic isolator through shock impact of specific earthquake loading, recorded by a seismometer, is obtained via ANSYS finite element package. The amplitude of the isolator is quickly reduced by the viscoelastic material in the device and is shown in a time response diagram. The result of this analysis can be a crucial reference when improving the design of a seismic isolator. Bo-Wun Huang, Jao-Hwa Kuang, Jung-Ge Tseng, Jyun-Cin Wang, and Yu-Xian Qiu Copyright © 2015 Bo-Wun Huang et al. All rights reserved. Fracture Characteristics Analysis of Pressured Pipeline with Crack Using Boundary Element Method Thu, 09 Apr 2015 07:59:26 +0000 http://www.hindawi.com/journals/amse/2015/508630/ Metal materials can inevitably show deteriorated properties by the factors of stress, temperature, and environmental erosion in distinct operating environments. Without proper protection, the service life would be shortened or even deadly danger would be caused. This study aims to apply Finite Element Method and Boundary Element Method to analyzing the effects of corroded petrochemical pipes on the fatigue life and the fracture form. The research results of nondestructive testing and software analyses show that cracked oil pipes with uniform corrosion bear larger stress, mainly internal pressure, on the longitudinal direction than the circumferential direction. As a result, the maximal fatigue loading cycle of a circumferential crack is higher than that of a longitudinal one. From the growing length and depth of a crack, the final aspect ratio of crack growth appears in 2.42–3.37 and 2.71–3.42 on the circumferential and longitudinal direction, respectively. Meanwhile, the ratios of loading cycles of circumferential and longitudinal crack are 26.23 on uncorroded and 20.54 on general metal loss oil pipe. The complete crack growth and the correspondent fatigue loading cycle could be acquired to determine the service life of the oil pipe being operated as well as the successive recovery time. Han-Sung Huang Copyright © 2015 Han-Sung Huang. All rights reserved. Lead Telluride Doped with Au as a Very Promising Material for Thermoelectric Applications Tue, 07 Apr 2015 14:01:07 +0000 http://www.hindawi.com/journals/amse/2015/283782/ PbTe single crystals doped with monovalent Au or Cu were grown using the Bridgman method. Far infrared reflectivity spectra were measured at room temperature for all samples and plasma minima were registered. These experimental spectra were numerically analyzed and optical parameters were calculated. All the samples of PbTe doped with Au or Cu were of the “” type. The properties of these compositions were analyzed and compared with PbTe containing other dopants. The samples of PbTe doped with only 3.3 at% Au were the best among the PbTe + Au samples having the lowest plasma frequency and the highest mobility of free carriers-electrons, while PbTe doped with Cu was the opposite. Samples with the lowest Cu concentration of 0.23 at% Cu had the best properties. Thermal diffusivity and electronic transport properties of the same PbTe doped samples were also investigated using a photoacoustic (PA) method with the transmission detection configuration. The results obtained with the far infrared and photoacoustic characterization of PbTe doped samples were compared and discussed. Both methods confirmed that when PbTe was doped with 3.3 at% Au, thermoelectric and electrical properties of this doped semiconductor were both significantly improved, so Au as a dopant in PbTe could be used as a new high quality thermoelectric material. Pantelija M. Nikolic, Konstantinos M. Paraskevopoulos, Triantafyllia T. Zorba, Zorka Z. Vasiljevic, Eleni Pavlidou, Stevan S. Vujatovic, Vladimir Blagojevic, Obrad S. Aleksic, Aleksandar I. Bojicic, and Maria V. Nikolic Copyright © 2015 Pantelija M. Nikolic et al. All rights reserved. Bending Characteristics of Foldable Touch Display Panel with a Protection Structure Design Mon, 06 Apr 2015 11:58:07 +0000 http://www.hindawi.com/journals/amse/2015/106424/ The study proposes and demonstrates an enhancement of a touch display panel (TDP) through a polymer-based protection structure to achieve higher bendability and reliability. The bending performance of the TDP without or with the protection structure designs is addressed using three-dimensional geometry-nonlinear finite element analysis and mechanical testing. The elastic properties of the components in the TDP structure are derived from nanoindentation and uniaxial tensile/compressive testing. The calculated results are compared with each other and also against the experimental bending fatigue test data. At last, a design guideline and optimal factor setting for enhanced bending performance are sought through parametric FE analysis and Taguchi experimental design, respectively. The optimal design is compared with the original in terms of bending stress. The simulation results show that bending would create significant tensile and compressive bending stresses on the indium tin oxide/dielectric layers, which are the main cause of several commonly observed failures, such as thin film cracking and delamination, in a thin rigid film coating on a thick compliant substrate. It also turns out that a substrate with a lower stiffness has a better mechanical stability against bending stress. Hsien-Chie Cheng, Wei-Heng Xu, Wen-Hwa Chen, Pi-Hsien Wang, Kuo-Feng Chen, and Chih-Chia Chang Copyright © 2015 Hsien-Chie Cheng et al. All rights reserved. Effect of Zn/Al Layered Double Hydroxide Containing 2-Hydroxy-4-n-octoxy-benzophenone on UV Aging Resistance of Asphalt Sun, 05 Apr 2015 13:43:21 +0000 http://www.hindawi.com/journals/amse/2015/739831/ UV radiation is a main factor to reduce the service life of asphalt pavement due to the UV aging of asphalt binder. To obtain enhanced UV aging resistance, an organic UV absorber called 2-hydroxy-4-n-octoxy-benzophenone (HNOB) had been intercalated into an inorganic UV absorber called Zn/Al layered double hydroxide (LDH) to play a combined anti-UV role in asphalt binder. Fourier transform infrared spectroscopy revealed that HNOB anions have been intercalated into the interlayer galleries of Zn/Al-LDH containing HNOB anions (Zn/Al-HNOB−-LDH). X-ray diffraction results of Zn/Al-LDH containing anions () and /styrene-butadiene-styrene (SBS) modified asphalt disclosed that asphalt molecules entered into LDH interlayer galleries to form an expanded phase structure. UV-Vis absorbance patterns showed that Zn/Al-HNOB−-LDH has a better capacity of blocking UV light due to the synergetic effect of HNOB and Zn/Al-LDH. The chemical fractions analysis, conventional physical tests, and rheological tests of SBS modified asphalt, modified asphalt, and Zn/Al-HNOB−-LDH/SBS modified asphalt before and after UV aging testified that Zn/Al-HNOB−-LDH can improve the UV aging resistance of SBS modified asphalt more significantly. Chao Peng, Jianying Yu, Jing Dai, and Jian Yin Copyright © 2015 Chao Peng et al. All rights reserved. Thermal Degradation Characteristics and Kinetics of Oxy Combustion of Corn Residues Sun, 05 Apr 2015 12:21:13 +0000 http://www.hindawi.com/journals/amse/2015/304395/ Thermogravimetric analysis was used to investigate oxy combustion of corncob and stover. The biomass samples were heated from ambient temperature to 900°C at different heating rates of 10, 30, and 50 K/min. Both biomass samples showed similar weight loss patterns with three zones, corresponding to dehydration, devolatilization, and char combustion, but displayed different degradation temperatures. Increasing heating rate was found to shift the degradation patterns to higher temperatures. Decomposition rates of cob and stover may have been influenced by their lignocellulosic composition. The kinetic parameters of the thermal degradation process were also determined and compared using the Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods. Both methods were found to give similar values and patterns of activation energy against conversion fraction. The average values were found to be in similar magnitude to those reported in the literature, around 170 and 148 kJ/mol for cob and stover, respectively. Poramate Sittisun, Nakorn Tippayawong, and Darunee Wattanasiriwech Copyright © 2015 Poramate Sittisun et al. All rights reserved. Study on Relation between Hydrodynamic Feature Size of HPAM and Pore Size of Reservoir Rock in Daqing Oilfield Mon, 30 Mar 2015 10:03:06 +0000 http://www.hindawi.com/journals/amse/2015/139284/ The flow mechanism of the injected fluid was studied by the constant pressure core displacement experiments in the paper. It is assumed under condition of the constant pressure gradient in deep formation based on the characteristic of pressure gradient distribution between the injection and production wells and the mobility of different polymer systems in deep reservoir. Moreover, the flow rate of steady stream was quantitatively analyzed and the critical flow pressure gradient of different injection parameters polymer solutions in different permeability cores was measured. The result showed that polymer hydrodynamic feature size increases with the increasing molecular weight. If the concentration of polymer solutions overlaps beyond critical concentration, then molecular chains entanglement will be occur and cause the augment of its hydrodynamic feature size. The polymer hydrodynamic feature size decreased as the salinity of the dilution water increased. When the median radius of the core pore and throat was 5–10 times of the polymer system hydrodynamic feature size, the polymer solution had a better compatibility with the microscopic pore structure of the reservoir. The estimation of polymer solutions mobility in the porous media can be used to guide the polymer displacement plan and select the optimum injection parameters. Qing Fang, Jinfeng Chen, Chunnan Lu, Dandan Yin, and Yiqiang Li Copyright © 2015 Qing Fang et al. All rights reserved. A Study of Failure Strength for Fiber-Reinforced Composite Laminates with Consideration of Interface Mon, 30 Mar 2015 06:52:15 +0000 http://www.hindawi.com/journals/amse/2015/158578/ Composite laminates can exhibit the nonlinear properties due to the fiber/matrix interface debonding and matrix plastic deformation. In this paper, by incorporating the interface stress-displacement relations between fibers and matrix, as well as the viscoplastic constitutive model for describing plastic behaviors of matrix materials, a micromechanical model is used to investigate the failure strength of the composites with imperfect interface bonding. Meanwhile, the classic laminate theory, which provides the relation between micro- and macroscale responses for composite laminates, is employed. Theory results show good consistency with the experimental data under unidirectional tensile conditions at both 23°C and 650°C. On this basis, the interface debonding influences on the failure strength of the [0/90]s and [0/±45/90]s composite laminates are studied. The numerical results show that all of the unidirectional (UD) laminates with imperfect interface bonding provide a sharp decrease in failure strength in the plane at 23°C. However, the decreasing is restricted in some specific region. In addition, for [0/90]s and [0/±45/90]s composite laminates, the debonding interface influences on the failure envelope can be ignored when the working temperature is increased to 650°C. Junjie Ye, Yuanying Qiu, Xuefeng Chen, Yumin He, and Zhi Zhai Copyright © 2015 Junjie Ye et al. All rights reserved. Spectroscopic Analysis of Au-Cu Alloy Nanoparticles of Various Compositions Synthesized by a Chemical Reduction Method Sun, 29 Mar 2015 13:54:57 +0000 http://www.hindawi.com/journals/amse/2015/638629/ Au-Cu alloy nanoparticles were synthesized by a chemical reduction method. Five samples having different compositions of Au and Cu (Au-Cu 3 : 1, Au-Cu 2 : 1, Au-Cu 1 : 1, Au-Cu 1 : 2, and Au-Cu 1 : 3) were prepared. The newly synthesized nanoparticles were characterized by electronic absorption, fluorescence, and X-ray diffraction spectroscopy (XRD). These alloy nanoparticles were also analyzed by SEM and TEM. The particle size was determined by SEM and TEM and calculated by Debye Scherrer’s equation as well. The results revealed that the average diameter of nanoparticles gets lowered from 80 to 65 nm as the amount of Cu is increased in alloy nanoparticles. Some physical properties were found to change with change in molar composition of Au and Cu. Most of the properties showed optimum values for Au-Cu alloy nanoparticles of 1 : 3. Cu in Au-Cu alloy caused decrease in the intensity of the emission peak and acted as a quencher. The fluorescence data was utilized for the evaluation of number of binding sites, total number of atoms in alloy nanoparticle, binding constant, and free energy of binding while morphology was deduced from SEM and TEM. Latif-ur-Rahman, Afzal Shah, Rumana Qureshi, Sher Bahadar Khan, Abdullah M. Asiri, Anwar-ul-Haq Ali Shah, Muhammad Ishaq, Mohammad Saleem Khan, Suzanne Kay Lunsford, and Muhammad Abid Zia Copyright © 2015 Latif-ur-Rahman et al. All rights reserved. A Survival Analysis on Fuel Cell Technology Patent Maintenance and Values Exploration between 1976 and 2001 Sun, 29 Mar 2015 13:02:55 +0000 http://www.hindawi.com/journals/amse/2015/387491/ Fuel cell R&D activities desirably arrive in patents; the costly maintenance fee challenges managers as well as researchers to whether or not renew existing patents. The key is, will the fuel cell patent’s value be worth renewing? Thus assessment of patent value is essential. Our study focus online searching was made available after 1976, as the initial year to conduct the patent search. Up to 2001, there are 2269 patents classified in the H01M 008/00~H01M 008/24 category, which is the category concerning fuel cell under the classification of the International Patent Classification. Effective exploitation of technology values is subject to the complementarities of organizational resources. The present study used the emerging technology of Fuel Cells as an example to show that firms may commercialize the values of technology according to their organizational resources. By aligning firms’ patenting strategies and the imparities between book values and market values this study concludes a technological ambidexterity with respect to firms’ technology development. The exploitative firms tend to file patents to defend their leadership in the product market as a result their technology is constrained within a firm’s boundaries. The results show that patent renewing decisions are consequence of firm’s constraints of complementary resources. Seng-Su Tsang, Feng-Chen Chang, and Wen-Cheng Wang Copyright © 2015 Seng-Su Tsang et al. All rights reserved. Ultrafine Resveratrol Particles: Supercritical Antisolvent Preparation and Evaluation In Vitro and In Vivo Sun, 29 Mar 2015 11:07:33 +0000 http://www.hindawi.com/journals/amse/2015/838513/ Ultrafine resveratrol (u-Res) particles were prepared through the SAS process. The orthogonal method was used to optimize the factors of the SAS process. The size of u-Res reached 0.68 μm under the optimum conditions. The characterization of the u-Res particles was tested by many analysis methods. The chemical structure of Res was unaffected by the SAS process. The degree of crystallinity of the u-Res particles greatly reduced. The purity of the u-Res particles increased from 98.5% to 99.2% during the SAS process. The u-Res particles had greater saturation solubility and dissolution rate than the raw-Res (r-Res) particles. The radical scavenging activity and bioavailability of the u-Res in vivo were 1.9 times of the r-Res. Kunlun Wang, Xiuhua Zhao, Yuangang Zu, Jialei Li, Xiaonan Zhang, Wei Sun, and Xinyang Yu Copyright © 2015 Kunlun Wang et al. All rights reserved. The Study for Saving Energy and Optimization of LED Street Light Heat Sink Design Thu, 26 Mar 2015 12:23:01 +0000 http://www.hindawi.com/journals/amse/2015/418214/ LED lamps are characterized by high energy efficiency, high luminance, and long lifespans. However, the heat radiation problem caused by the extra high power shortens the lifespan and reduces the luminous efficiency of such lamps. This study introduced the development of a novel cooling fin structure for LED lamps and compared its performance with those of commercially available products. The objective of the design was to reduce the maximum temperature and temperature difference on the fin, the amount of aluminum required for fin manufacturing, and CO2 emissions to save energy. The study employed the Taguchi method for experiment planning and used gray relational analysis and principal component analysis to determine the optimal parameter combination for cooling fins. The results showed that the maximum temperature on the fin surface dropped by 2.62°C in environments without forced convection, which indicated improved lighting efficiency. Furthermore, the amount of aluminum used per unit volume for fins was reduced by 15%, which effectively reduced CO2 emissions during the manufacturing process. Chi-Chang Hsieh and Yan-Huei Li Copyright © 2015 Chi-Chang Hsieh and Yan-Huei Li. All rights reserved. Effect of NaNO2 and C6H15NO3 Synergistic Admixtures on Steel-Rebar Corrosion in Concrete Immersed in Aggressive Environments Thu, 26 Mar 2015 11:56:54 +0000 http://www.hindawi.com/journals/amse/2015/540395/ This paper studies effect of different combinations of NaNO2 (sodium nitrite) and C6H15NO3 (triethanolamine (TEA)), as synergistic admixtures in concrete immersed in NaCl and in H2SO4 test environments, on the corrosion of the concrete reinforcing steel (rebar). Although statistically analysed electrochemical test results confirmed NaNO2 effectiveness, synergistic combinations of 4 g NaNO2 + 4 g C6H15NO3 in NaCl medium and of 2 g NaNO2 + 6 g C6H15NO3 in H2SO4 medium were also highly effective at inhibiting rebar corrosion. Synergistic parameter analyses showed that the effective synergistic admixtures that inhibited concrete steel-rebar corrosion in their respective medium were the NaNO2 and C6H15NO3 combinations that exhibited synergistic interactions of cooperative adsorption on steel-rebar. These support the suitability of requisite concentration of triethanolamine as additive admixture with sodium nitrite for steel-rebar corrosion mitigation, which is potent with reduced environmental effects, in concrete immersed in NaCl and in H2SO4 corrosive media. Joshua Olusegun Okeniyi, Abimbola Patricia Idowu Popoola, Cleophas Akintoye Loto, Olugbenga Adeshola Omotosho, Stanley Okechukwu Okpala, and Idemudia Joshua Ambrose Copyright © 2015 Joshua Olusegun Okeniyi et al. All rights reserved. The Experimental Studies on Behavior of Ultrahigh-Performance Concrete Confined by Hybrid Fiber-Reinforced Polymer Tubes Thu, 26 Mar 2015 07:39:15 +0000 http://www.hindawi.com/journals/amse/2015/201289/ This paper conducts axial compression test of ultrahigh performance concrete- (UHPC-) filled hybrid FRP (HFRP) tubes, using the alternating hybrid technology to improve the deformation capacity of FRP tube and measure the axial compressive responses of ultimate strength, strains, and stress-strain curve of confined specimens. The test results show that the local rupture of HFRP tubes did not lead to explosive failure of UHPC cylinder, and its ductility is better than that of UHPC confined by only one type of FRP tube; HFRP tube can effectively improve the compressive strength and ultimate strain of UHPC specimens; the stress-strain curves divide into three distinct regions: linear phase, transition phase, and linear strengthening phase. None of the models provided a reasonable prediction for strength and strain of HFRP-confined UHPC specimen; therefore, a new ultimate strength and strain perdition model considering the confinement effectiveness of different hybrid FRP series was proposed. The new proposed model presented the best fitting results. The stress-strain responses predicted by the existing models are all below the experimental curves; therefore, a new three-stage constitutive model was proposed, which relatively fits the test curves better than the existing models. Zong-cai Deng and Jiu-ling Qu Copyright © 2015 Zong-cai Deng and Jiu-ling Qu. All rights reserved. Evaluation of Sintering Behavior of Premix Al-Zn-Mg-Cu Alloy Powder Thu, 26 Mar 2015 07:33:39 +0000 http://www.hindawi.com/journals/amse/2015/987687/ Sintering of light aluminium alloys powder has been investigated as a way to substitute steels in automotive and aerospace industries. Premix Al-5.5Zn-2.5Mg-0.5Cu composite powder called Alumix 431D was analyzed in this research. Sintering was carried out under ultra high purity nitrogen gas and before reaching sintering temperature, green samples were delubricated at 400°C for 30 min. The powder possesses high sinterability by reaching 96% relative density at 580°C sintering temperature. Formation of liquid phase seems to support achieving high sintering density. Optimum mechanical properties also were obtained under those conditions. T6 heat treatment was done to improve the mechanical properties by formation of precipitation strengthening, and MgZn2 appears to be dominant strengthening precipitate. X-ray diffraction, optical microscopy, and SEM-EDS were used to characterize powder, and sintered and heat treated samples. Haris Rudianto, Gwang Joo Jang, Sang Sun Yang, Yong Jin Kim, and Ivo Dlouhy Copyright © 2015 Haris Rudianto et al. All rights reserved. Novel Approaches in Designing Natural/Synthetic Materials for Environmental Applications Wed, 25 Mar 2015 12:22:03 +0000 http://www.hindawi.com/journals/amse/2015/820854/ George Z. Kyzas, Saeid Azizian, and Margaritis Kostoglou Copyright © 2015 George Z. Kyzas et al. All rights reserved. A Nonlinear Creep Model of Rock Salt and Its Numerical Implement in FLAC3D Wed, 25 Mar 2015 12:08:31 +0000 http://www.hindawi.com/journals/amse/2015/285158/ Creep characteristics are integral mechanical properties of rock salt and are related to both long-term stability and security of rock salt repository. Rock salt creep properties are studied in this paper through employing combined methods of theoretical analysis and numerical simulation with a nonlinear creep model and the secondary development in FLAC3D software. A numerical simulation of multistage loading creep was developed with the model and resulting calculations were found consequently to coincide with previously tested data. Xinrong Liu, Xin Yang, and Junbao Wang Copyright © 2015 Xinrong Liu et al. All rights reserved. Size Effects in Residual Stress Formation during Quenching of Cylinders Made of Hot-Work Tool Steel Wed, 25 Mar 2015 09:42:40 +0000 http://www.hindawi.com/journals/amse/2015/678056/ The present work investigates the residual stress formation and the evolution of phase fractions during the quenching process of cylindrical specimens of different sizes. The cylinders are made of hot-work tool steel grade X36CrMoV5-1. A phase transformation kinetic model in combination with a thermomechanical model is used to describe the quenching process. Two phase transformations are considered for developing a modelling scheme: the austenite-to-martensite transformation and the austenite-to-bainite transformation. The focus lies on the complex austenite-to-bainite transformation which can be observed at low cooling rates. For an appropriate description of the phase transformation behaviour nucleation and growth of bainite are taken into account. The thermomechanical model contains thermophysical data and flow curves for each phase. Transformation induced plasticity (TRIP) is modelled by considering phase dependent Greenwood-Johnson parameters for martensite and bainite, respectively. The influence of component size on residual stress formation is investigated by the finite element package Abaqus. Finally, for one cylinder size the simulation results are validated by X-ray stress measurements. Manuel Schemmel, Petri Prevedel, Ronald Schöngrundner, Werner Ecker, and Thomas Antretter Copyright © 2015 Manuel Schemmel et al. All rights reserved. Experimental Study on the Feasibility of Using Water Glass and Aluminum Sulfate to Treat Complications in High Liquid Limit Soil Subgrade Tue, 24 Mar 2015 13:50:38 +0000 http://www.hindawi.com/journals/amse/2015/457978/ The feasibility of using water glass and aluminum sulfate to treat high liquid limit soil subgrade diseases is studied through laboratory experiments, and the following results were observed. After improving the high liquid limit clay with water glass and aluminum sulfate, the liquid limit decreases, the plastic limit increases, and the plasticity index decreases. Compared with untreated soil, the clay content of the improved soil decreases, while the silt and coarse contents increase. The absolute and relative expansion rates of the improved soil are both lower than those of the untreated soil. With the same number of dry and wet cycles, the decreased degrees of cohesion and internal friction angle of the improved soil are, respectively, one-half and one-third of those of the untreated soil. After three dry and wet cycles, the California bearing ratio (CBR) of the untreated soil does not meet the requirements of specifications. However, after being cured for seven days and being subjected to three dry and wet cycles, the CBR of the improved soil, with 4% water glass solution and 0.4% aluminum sulfate, meets the requirements of specifications. Wen-hui Zhang, Hua-wen Zheng, Jia-wei Qi, and Bao-tian Wang Copyright © 2015 Wen-hui Zhang et al. All rights reserved. Earth Materials and Environmental Applications Tue, 24 Mar 2015 08:52:14 +0000 http://www.hindawi.com/journals/amse/2015/404561/ Zhaohui Li, Hanlie Hong, and Guocheng Lv Copyright © 2015 Zhaohui Li et al. All rights reserved. Research on Wetting-Drying Cycles’ Effect on the Physical and Mechanical Properties of Expansive Soil Improved by OTAC-KCl Mon, 23 Mar 2015 13:32:52 +0000 http://www.hindawi.com/journals/amse/2015/304276/ Expansive soil experiences periodic swelling and shrinkage during the alternate wet and dry environments, which will result in severe damage to the slope stability. In this study, a promising modifier OTAC-KCl is introduced, which has a good diffusivity and is soluble in water or other solvents easily. Firstly, a reasonable combination of ameliorant 0.3% STAC and 3% KCl is chosen referring to the free swell test. Then, the best curing period, 14 days, is gotten from UCS tests. The effect of wetting and drying cycles on engineering properties of expansive soil improved by OTAC-KCl admixtures after 14-day curing is also studied accordingly. Both treated and untreated expansive soil samples are prepared for the cyclic wetting-drying tests which mainly include cyclic swelling potential and cyclic strength tests. Experimental results show that the swelling potential of expansive soil samples stabilized with OTAC-KCl is suppressed efficiently, and the untreated soil specimens will collapse when immersed in water while the treated specimens keep in good conditions. Moreover, expansive soil samples modified with 0.3% OTAC + 3% KCl show enough durability on the swelling ability, shear strength, and unconfined compressive strength, which means, that both the physical and the mechanical properties of stabilized expansive soil have been improved effectively. Bao-tian Wang, Can-hong Zhang, Xue-lian Qiu, En-yue Ji, and Wen-hui Zhang Copyright © 2015 Bao-tian Wang et al. All rights reserved. Dissolution Behavior of Cellulose in IL + DMSO Solvent: Effect of Alkyl Length in Imidazolium Cation on Cellulose Dissolution Mon, 23 Mar 2015 13:16:28 +0000 http://www.hindawi.com/journals/amse/2015/406470/ Four cellulose solvents including [C2mim][CH3COO] + DMSO, [C4mim][CH3COO] + DMSO, [C6mim][CH3COO] + DMSO, and [C8mim][CH3COO] + DMSO were prepared by adding dimethyl sulfoxide DMSO in 1-ethyl-3-methylimidazolium acetate [C2mim][CH3COO], 1-butyl-3-methylimidazolium acetate [C4mim][CH3COO], 1-hexyl-3-methylimidazolium acetate [C6mim][CH3COO], and 1-octyl-3-methylimidazolium acetate [C8mim][CH3COO], respectively. The solubilities of cellulose in these solvents were determined at 25°C. The effect of the alkyl chain length in imidazolium cation on cellulose solubility was investigated. With increasing alkyl chain length in imidazolium cation, the solubility of cellulose increases, but further increase in alkyl chain length results in decreases in cellulose. Airong Xu, Lili Cao, Bingjun Wang, and Junying Ma Copyright © 2015 Airong Xu et al. All rights reserved. Preparation and Characterization of Barite/TiO2 Composite Particles Mon, 23 Mar 2015 12:35:43 +0000 http://www.hindawi.com/journals/amse/2015/878594/ To make full use of barite mineral and obtain a kind of composite particles material which has the property of both barite and TiO2, the composite particles material with TiO2 coated on the surface of barite particle was prepared by the method of TiOSO4 solution chemical hydrolysis and precipitation to form hydrolysis composite, removing the impurities of hydrolysis composite, drying, and calcination in this study. The results were evaluated by the covering power of composites. Composite structure and properties were characterized by means of XRD, SEM, FTIR, and XPS. The results showed that the surface of barite had been coated with rutile TiO2 uniformly and compactly and the hiding power value and oil absorption value of the composite powder were 18.50 g/m2 and 15.5 g/100 g, respectively, which had similar pigment performances to TiO2. The results also showed that it was mainly the strong chemical bond between barite and TiO2 that combined them firmly in barite/TiO2 composite particle (B/TCP). Hong Zhou, Mengmeng Wang, Hao Ding, and Gaoxiang Du Copyright © 2015 Hong Zhou et al. All rights reserved. Triaxial Test and Mechanical Analysis of Rock-Soil Aggregate Sampled from Natural Sliding Mass Mon, 23 Mar 2015 11:28:07 +0000 http://www.hindawi.com/journals/amse/2015/238095/ Rock-soil aggregate, as a specific geomaterial, exhibits complicated mechanical behavior. The rock-soil aggregate sampled from the deep layer of sliding mass at Jinpingzi area of Wudongde hydropower plant on Yangtze River is investigated to understand its mechanical behavior. Large-scale laboratory triaxial tests are conducted considering different gradations, stone contents and confining pressures. The results show that variation of stone content and gradation considerably affects the mechanical characteristics of rock-soil aggregate. Further, the influences of stone content, and gradation variation on stress-strain curve, Mohr-Coulomb criterion based shear strength parameters, Duncan-Chang model based deformation parameters, and internal friction angle are analyzed. A modified Rowe’s stress-dilatancy equation describing the mechanical response of rock-soil aggregate is then suggested. Shuling Huang, Xiuli Ding, Yuting Zhang, and Wei Cheng Copyright © 2015 Shuling Huang et al. All rights reserved. The Application of Mechanical-Chemical Corrosion Theory in Downhole Tubing CO2 Corrosion Research Mon, 23 Mar 2015 08:35:36 +0000 http://www.hindawi.com/journals/amse/2015/296278/ Indoor simulating experiment is a main method for oil field CO2 corrosion research. Experimental parameters are very important for an accurate simulation. Based on the mechanical-chemical corrosion theory, the external load may be possible to accelerate the corrosion rate. However, the influence of N2 pressure on CO2 corrosion during the simulating experiment is negligible. Because the coupon stress induced by additional N2 pressure is very low, therefore, the N2 adding procedure can be cancelled and a more safety working space for researchers will be created. However, it does not mean that mechanical-chemical corrosion influence can be ignored. For downhole tubing, the hoop stress generated from the formation compress or liquid column internal pressure is remarkable; stress effect on corrosion has to be taken into consideration. When pit cavity especially occurred on the internal tubing surface, the stress concentration effect will induce a much higher local stress. Mechanical-chemical corrosion will become significant and more study should be performed on this topic. Peike Zhu, Wei Yan, Liyu Deng, and Jingen Deng Copyright © 2015 Peike Zhu et al. All rights reserved. Preparation of Cementitious Material Using Smelting Slag and Tailings and the Solidification and Leaching of Pb2+ Sun, 22 Mar 2015 12:33:37 +0000 http://www.hindawi.com/journals/amse/2015/352567/ The composite cementitious materials were prepared with lead-zinc tailings, lead-zinc smelting slag, and cement clinker. The effect of material ratio on the mechanical properties, the phase analysis, and microstructures were investigated. The effect of the pH and stripping time on the leaching amount of lead ion was discussed. The results show that the additive amount of the tailings should be minimized for the cementitious materials meeting the strength requirements, controlled within 10%. The leaching amount of cementitious materials remains low in a larger range of pH, which can effectively reduce the leaching of heavy metal lead. The leaching kinetics of lead ions in the three kinds of samples could be better described by the pseudo-second-model. Dan Zhang, Shiliu Shi, Chengbiao Wang, Xiaocong Yang, Lijie Guo, and Shanshan Xue Copyright © 2015 Dan Zhang et al. All rights reserved. Raw Materials Synthesis from Heavy Metal Industry Effluents with Bioremediation and Phytomining: A Biomimetic Resource Management Approach Sun, 22 Mar 2015 11:29:42 +0000 http://www.hindawi.com/journals/amse/2015/185071/ Heavy metal wastewater poses a threat to human life and causes significant environmental problems. Bioremediation provides a sustainable waste management technique that uses organisms to remove heavy metals from contaminated water through a variety of different processes. Biosorption involves the use of biomass, such as plant extracts and microorganisms (bacteria, fungi, algae, yeast), and represents a low-cost and environmentally friendly method of bioremediation and resource management. Biosorption-based biosynthesis is proposed as a means of removing heavy metals from wastewaters and soils as it aids the development of heavy metal nanoparticles that may have an application within the technology industry. Phytomining provides a further green method of managing the metal content of wastewater. These approaches represent a viable means of removing toxic chemicals from the effluent produced during the process of manufacturing, and the bioremediation process, furthermore, has the potential to save metal resources from depletion. Biomimetic resource management comprises bioremediation, biosorption, biosynthesis, phytomining, and further methods that provide innovative ways of interpreting waste and pollutants as raw materials for research and industry, inspired by materials, structures, and processes in living nature. Salmah B. Karman, S. Zaleha M. Diah, and Ille C. Gebeshuber Copyright © 2015 Salmah B. Karman et al. All rights reserved.