Advances in Materials Science and Engineering http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. A Study on the Effect of the Contact Point and the Contact Force of a Glass Fiber under End-Face Polishing Process Thu, 02 Jul 2015 08:58:54 +0000 http://www.hindawi.com/journals/amse/2015/825238/ The offset between the center lines of the polished end-face and the fiber core has a significant effect on coupling efficiency. The initial contact point and the contact force are two of the most important parameters that induce the offset. This study proposes an image assistant method to find the initial contact point and a mathematical model to estimate the contact force when fabricating the double-variable-curvature end-face of single mode glass fiber. The repeatability of finding the initial contact point via the vision assistant program is 0.3 μm. Based on the assumption of a large deflection, a mathematical model is developed to study the relationship between the contact force and the displacement of the lapping film. In order to verify the feasibility of the mathematical model, experiments, as well as DEFORM simulations, are carried out. The results show that the contact forces are alomst linearly proportional to the feed amounts of the lapping film and the errors are less than 9%. By using the method developed in this study, the offset between the grinding end-face and the center line of the fiber core is within 0.15 to 0.35 μm. Ying-Chien Tsai, Guang-Miao Huang, Shin-Wei Cheng, Cheng-An Hsu, and Innchyn Her Copyright © 2015 Ying-Chien Tsai et al. All rights reserved. Simulation-Based Optimization of Cure Cycle of Large Area Compression Molding for LED Silicone Lens Wed, 01 Jul 2015 09:08:53 +0000 http://www.hindawi.com/journals/amse/2015/573076/ Three-dimensional heat transfer-curing simulation was performed for the curing process by introducing a large area compression molding for simultaneous forming and mass production for the lens and encapsulants in the LED molding process. A dynamic cure kinetics model for the silicone resin was adopted and cure model and analysis result were validated and compared through a temperature measurement experiment for cylinder geometry with cure model. The temperature deviation between each lens cavity could be reduced by implementing a simulation model on the large area compression mold and by optimizing the location of heat source. A two-step cure cycle was constructed to reduce excessive reaction peak at the initial stage and cycle time. An optimum cure cycle that could reduce cycle time by more than 29% compared to a one-step cure cycle by adjusting dwell temperature, heating rate, and dwell time was proposed. It was thus confirmed that an optimization of large area LED lens molding process was possible by using the present experiment and the finite element method. Min-Jae Song, Kwon-Hee Kim, Seok-Kwan Hong, Jeong-Won Lee, Jeong-Yeon Park, Gil-Sang Yoon, and Heung-Kyu Kim Copyright © 2015 Min-Jae Song et al. All rights reserved. The Microstructure and Thermal Conductivity of Pressureless Infiltrated Composites Containing Electroless Nickel Platings Mon, 29 Jun 2015 11:32:51 +0000 http://www.hindawi.com/journals/amse/2015/351780/ A nickel (Ni) coating was deposited on the surface of silicon carbide particles () through electroless plating and we characterized the morphology and phase structure of the coating and the pressureless infiltrated composites. The effect of Ni coatings on the thermal conductivity of the composites was examined and analyzed with three-dimensional video microscope, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction microscope (XRD), and finite-element. The results show that a continuous and uniform coating with a certain thickness (around 3.5 μm) can be formed on the surface of . With the addition of the Ni layer, there are some intermetallics Ni3Al but no interfacial carbide Al4C3, which improves the wettability and the thermal conductivity of the composites. The experiments and simulations both show that Ni coatings do not substantially decrease the overall thermal conductivity of the composite, although the thermal conductivity of Ni itself is lower than Al and SiC by a factor of 1. Aihua Zou, Xianliang Zhou, Xiaozhen Hua, Duosheng Li, and Kaiyang Wu Copyright © 2015 Aihua Zou et al. All rights reserved. Equal Channel Angular Extrusion Simulation of High-Nb Containing β-γ TiAl Alloys Mon, 29 Jun 2015 09:42:39 +0000 http://www.hindawi.com/journals/amse/2015/285170/ TiAl alloys containing high Nb are significantly promising for high-temperature structural applications in aerospace and automotive industries. Unfortunately the low plasticity at room temperature limits their extensive applications. To improve the plasticity, not only optimizing the opposition, but also refining grain size through equal channel angular extrusion (ECAE) is necessary. The equal channel angular extrusion simulation of Ti-44Al-8Nb-(Cr,Mn,B,Y)(at%) alloy was investigated by using the Deform-3D software. The influences of friction coefficient, extrusion velocity, and different channel angles on effective strain, damage factor, and the load on the die were analyzed. The results indicate that, with the increasing of friction coefficient, effective strain is enhanced. The extrusion velocity has little effect on the uniformity of effective strain; in contrast it has large influence on the damage factor. Thus smaller extrusion rate is more appropriate. Under the condition of different channel angles, the larger one results in the lower effective strain magnitude and better strain distribution uniformity. Lai-qi Zhang, Xiang-ling Ma, Geng-wu Ge, Yong-ming Hou, Jun-zi Zheng, and Jun-pin Lin Copyright © 2015 Lai-qi Zhang et al. All rights reserved. Multicriteria Decision Analysis in Material Design, Selection, and Manufacturing Mon, 29 Jun 2015 06:30:17 +0000 http://www.hindawi.com/journals/amse/2015/818095/ Ali Jahan, Kevin L. Edwards, Abbas S. Milani, and Marjan Bahraminasab Copyright © 2015 Ali Jahan et al. All rights reserved. Density Functional Theory Study on the Electronic Structures of Oxadiazole Based Dyes as Photosensitizer for Dye Sensitized Solar Cells Sun, 28 Jun 2015 12:39:40 +0000 http://www.hindawi.com/journals/amse/2015/286730/ The molecular structures and UV-visible absorption spectra of complex photosensitizers comprising oxadiazole isomers as the π-bridges were analyzed by density functional theory (DFT) and time-dependent DFT. The ground state and excited state oxidation potentials, HOMOs and LUMOs energy levels, and electron injection from the dyes to semiconductor TiO2 have been computed in vacuum here. The results show that all of the dyes may potentially be good photosensitizers in DSSC. To justify the simulation basis, N3 dye was also simulated under the similar conditions. Simulated absorption spectrum, HOMO, LUMO, and band gap values of N3 were compared with the experimental values. We also computed the electronic structure properties and absorption spectra of dye/(TiO2)8 systems to elucidate the electron injection efficiency at the interface. This work is expected to give proper orientation for experimental synthesis. Umer Mehmood, Ibnelwaleed A. Hussein, Khalil Harrabi, and Shakeel Ahmed Copyright © 2015 Umer Mehmood et al. All rights reserved. Atmospheric Corrosion Behavior of 2A12 Aluminum Alloy in a Tropical Marine Environment Sun, 28 Jun 2015 07:51:06 +0000 http://www.hindawi.com/journals/amse/2015/163205/ Atmospheric corrosion behavior of 2A12 aluminum alloy exposed to a tropical marine environment for 4 years was investigated. Weight loss of 2A12 alloy in the log-log coordinates can be well fitted with two linear segments, attributing to the evolution of the corrosion products. EIS results indicate that the corrosion product layer formed on the specimens exposed for 12 months or longer presents a good barrier effect. Corrosion morphology changes from pitting corrosion to severe intergranular corrosion with the extension of exposure time, resulting in the reduction of the mechanical properties. Zhongyu Cui, Xiaogang Li, Huan Zhang, Kui Xiao, Chaofang Dong, Zhiyong Liu, and Liwei Wang Copyright © 2015 Zhongyu Cui et al. All rights reserved. Piezoelectric Nanowires in Energy Harvesting Applications Thu, 25 Jun 2015 13:07:47 +0000 http://www.hindawi.com/journals/amse/2015/165631/ Recently, the nanogenerators which can convert the mechanical energy into electricity by using piezoelectric one-dimensional nanomaterials have exhibited great potential in microscale power supply and sensor systems. In this paper, we provided a comprehensive review of the research progress in the last eight years concerning the piezoelectric nanogenerators with different structures. The fundamental piezoelectric theory and typical piezoelectric materials are firstly reviewed. After that, the working mechanism, modeling, and structure design of piezoelectric nanogenerators were discussed. Then the recent progress of nanogenerators was reviewed in the structure point of views. Finally, we also discussed the potential application and future development of the piezoelectric nanogenerators. Zhao Wang, Xumin Pan, Yahua He, Yongming Hu, Haoshuang Gu, and Yu Wang Copyright © 2015 Zhao Wang et al. All rights reserved. Asphalt Concrete Mixtures: Requirements with regard to Life Cycle Assessment Thu, 25 Jun 2015 11:15:03 +0000 http://www.hindawi.com/journals/amse/2015/567238/ Design of asphalt concrete, required properties of constituent materials and their mixing ratios, is of tremendous significance and should be implemented with consideration given to the whole life cycle of those materials and the final construction. Conformity with requirements for long term performance of embedded materials is the general objective of the Life Cycle Assessment (LCA). Therefore, within the assessment, material properties need to be evaluated with consideration given to the whole service life—from the point of embedding in the construction until their disposal or recycling. The evaluation focuses on verification of conformity with criteria set for these materials and should guarantee serviceability and performance during their whole service life. Recycling and reuse of asphalt concrete should be preferred over disposal of the material. This paper presents methodology for LCA of asphalt concrete. It was created to ensure not only applicability of the materials in the initial stage, at the point of their embedding, but their suitability in terms of normatively prescribed service performance of the final construction. Methods described and results are presented in a case study for asphalt mixture AC 11; I design. Jan Mikolaj, Frantisek Schlosser, Lubos Remek, and Aurelia Chytcakova Copyright © 2015 Jan Mikolaj et al. All rights reserved. Performance Analysis of CFRP Composite Strips Confined RC Columns under Axial Compression Thu, 25 Jun 2015 08:15:38 +0000 http://www.hindawi.com/journals/amse/2015/170295/ In an attempt to mitigate the high cost of FRP composite strengthening, an experimental investigation was carried out that sought to achieve efficient and most favorable FRP strengthening using CFRP composite strips. 50 mm wide CFRP composite strips were used in two different spacings (20 mm and 40 mm) to confine columns. The test results of the column confined with smaller spacing (20 mm) showed significant restraint of axial deformation of the column and enhanced the strength capacity to a maximum of 99.20% compared to that of reference column. In contrast, the column confined by strips with larger spacing (40 mm) failed by crushing of concrete alone, which occurred even before the CFRP strips reached their ultimate strain. In addition, the embodied energy that exists in the CFRP strips could not be utilized effectively. The stress and strength enhancement ratio of this present study was compared with the previous research that has been conducted on columns confined with full wrapping. From the obtained results, it is recommended that CFRP strips with a spacing of 20 mm be used to improve the strength capacity of the RC column; in addition, this wrapping technique provides economic benefits compared to a column confined with full wrapping. J. Raja Murugadoss, Byung Jae Lee, Jin Wook Bang, G. Ganesh Prabhu, and Yun Yong Kim Copyright © 2015 J. Raja Murugadoss et al. All rights reserved. Predicting Equivalent Static Density of Fuzzy Ball Drilling Fluid by BP Artificial Neutral Network Thu, 25 Jun 2015 06:04:20 +0000 http://www.hindawi.com/journals/amse/2015/340721/ A back-propagation artificial neutral network model is built based on 220 groups of PVT experimental data to predict the equivalent static density versus depth for fuzzy ball drilling fluid which is a kind of gas-liquid two-phase material. The model is applied in the Mo80-C well located in Sichuan Province of China; the maximum relative error between calculated results and measured data is less than 2%. By comparing with the multiple regression model, the present model has a higher precision and flexibility. The equivalent static density of fuzzy ball drilling fluid from ground to the depth of 6000 m is predicted by the present model, and the results show that the equivalent static density of fuzzy ball drilling fluid will decrease slowly with the growth of depth, which indicates that the gas cores of the fuzzy balls still can exist as deep as 6000 m. Chen Yang, Zhaohong Wang, Lihui Zheng, and Dengtian Mao Copyright © 2015 Chen Yang et al. All rights reserved. A Microstructural Study of Load Distribution in Cartilage: A Comparison of Stress Relaxation versus Creep Loading Wed, 24 Jun 2015 12:34:07 +0000 http://www.hindawi.com/journals/amse/2015/952879/ The compressive response of articular cartilage has been extensively investigated and most studies have focussed largely on the directly loaded matrix. However, especially in relation to the tissue microstructure, less is known about load distribution mechanisms operating outside the directly loaded region. We have addressed this issue by using channel indentation and DIC microscopy techniques that provide visualisation of the matrix microstructural response across the regions of both direct and nondirect loading. We hypothesise that, by comparing the microstructural response following stress relaxation and creep compression, new insights can be revealed concerning the complex mechanisms of load bearing. Our results indicate that, with stress relaxation, the initial mode of stress decay appears to primarily involve relaxation of the surface layer. In the creep loading protocol, the main mode of stress release is a lateral distribution of load via the mid matrix. While these two modes of stress redistribution have a complex relationship with the zonally differentiated tissue microstructure and the depth of strain, four mechanostructural mechanisms are proposed to describe succinctly the load responses observed. Ashvin Thambyah, V. M. van Heeswijk, C. C. van Donkelaar, and Neil Broom Copyright © 2015 Ashvin Thambyah et al. All rights reserved. An Investigation into CIGS Thin-Films Solar Cell P2 Layer Scribing Depth and Width Using Different Laser Process Parameters Wed, 24 Jun 2015 07:17:11 +0000 http://www.hindawi.com/journals/amse/2015/894673/ This study will be about UV (355 nm) laser processing system as a carrier. It studied electrode insulated characteristic using laser direct forming for CIGS solar cell technology P2 layer of stainless steel. It explored the impact of this process on the way to stainless steel substrate P2 film sizes using its laser different focus position, energy density, and scanning velocities. According to the experiment results, the scribing results are straight line and larger width under minus leave perpendicularity and positive leave perpendicularity and the laser scanning velocities at 10~1000 mm/s underline width about 0.96 μm~1.07 μm. The experiment results confirm that the laser apparatus is effective when applied to a stainless steel CIGS solar cell P2 layer. Dyi-Cheng Chen, Ming-Fei Chen, and Ming-Ren Chen Copyright © 2015 Dyi-Cheng Chen et al. All rights reserved. Analysis of the Long-Term Corrosion Behavior of X80 Pipeline Steel in Acidic Red Soil Using Electrical Resistance Test Technique Tue, 23 Jun 2015 11:52:04 +0000 http://www.hindawi.com/journals/amse/2015/931761/ The long-term corrosion rate of X80 steel in an acidic red soil was monitored in situ by using a precise electrical resistance (ER) test system. The corrosion characteristics of X80 steel were examined via SEM, EDS, and XRD. The results indicated that the corrosion rate determined from ER test was very similar to that obtained from the mass loss test. The ER test technique made it possible to predict the long-term corrosion rate of steel in soil in situ. The corrosion rate of X80 steel in acidic red soil was about 0.0902 mm/a at 38 weeks, but the corrosion rate was dropped to 0.0226 mm/a after 5 years. The final corrosion product layer was composed mainly of FeOOH, γ-Fe2O3, and FeCO3. Shuaixing Wang, Daoxin Liu, Nan Du, Qing Zhao, and Jinhua Xiao Copyright © 2015 Shuaixing Wang et al. All rights reserved. Effect of Cu Addition on the Electrochemical Corrosion Performance of Ni3Al in 1.0 M H2SO4 Tue, 23 Jun 2015 07:58:32 +0000 http://www.hindawi.com/journals/amse/2015/209286/ The effect of Cu addition on the electrochemical corrosion behavior of Ni3Al intermetallic alloy was investigated by potentiodynamic polarization, open-circuit potential, linear polarization resistance, and electrochemical impedance spectroscopy in 1.0 M H2SO4 solution. Performance of the pure elements (Cu, Ni, and Al) was also evaluated. In general, Cu addition improved the corrosion resistance of Ni3Al. Electrochemical measurements show that corrosion resistance of Ni3Al-1Cu alloy is lower than that of other intermetallic alloys and pure elements (Ni, Cu, and Al) in 1.0 M H2SO4 solution at 25°C. Surface analysis showed that the Ni3Al alloys are attacked mainly through the dendritic phases, and Cu addition suppresses the density of dendritic phases. J. Porcayo-Calderon, R. A. Rodriguez-Diaz, E. Porcayo-Palafox, J. Colin, A. Molina-Ocampo, and L. Martinez-Gomez Copyright © 2015 J. Porcayo-Calderon et al. All rights reserved. The Albedo of Pervious Cement Concrete Linearly Decreases with Porosity Tue, 23 Jun 2015 06:15:30 +0000 http://www.hindawi.com/journals/amse/2015/746592/ Pervious pavements have been advocated as a potential countermeasure to the urban heat island effect. To understand if pervious pavements stay cooler than conventional pavements, the albedo of the pervious concrete must be understood. This study measured the albedo of pervious concrete with different porosity. Four Portland cement concrete mixes were casted, using designed amounts of sand to vary the porosity of the pervious concrete samples. The samples were sliced and the spectral reflectance and albedo of the sliced samples were measured and analyzed. It is found that the albedo of pervious concrete decreases linearly with the increase of the porosity. The albedo of a pervious Portland concrete varies from 0.25 to 0.35, which is 0.05~0.15 lower than the albedo of conventional cement concrete. Due to this lower albedo, it should be cautious to develop pervious concrete to battle with urban heat island unless the evaporation of pervious concrete is promoted to compensate the additional solar absorption caused by the low albedo. Rui Zhang, Guosheng Jiang, and Jia Liang Copyright © 2015 Rui Zhang et al. All rights reserved. Structure Optimization and Numerical Simulation of Nozzle for High Pressure Water Jetting Sun, 21 Jun 2015 11:51:47 +0000 http://www.hindawi.com/journals/amse/2015/732054/ Three kinds of nozzles normally used in industrial production are numerically simulated, and the structure of nozzle with the best jetting performance out of the three nozzles is optimized. The R90 nozzle displays the most optimal jetting properties, including the smooth transition of the nozzle’s inner surface. Simulation results of all sample nozzles in this study show that the helix nozzle ultimately displays the best jetting performance. Jetting velocity magnitude along and coordinates is not symmetrical for the helix nozzle. Compared to simply changing the jetting angle, revolving the jet issued from the helix nozzle creates a grinding wheel on the cleaning surface, which makes not only an impact effect but also a shearing action on the cleaning object. This particular shearing action improves the cleaning process overall and forms a wider, effective cleaning range, thus obtaining a broader jet width. Shuce Zhang, Xueheng Tao, Jinshi Lu, Xuejun Wang, and Zhenhua Zeng Copyright © 2015 Shuce Zhang et al. All rights reserved. Multicriteria Decision Analysis in Improving Quality of Design in Femoral Component of Knee Prostheses: Influence of Interface Geometry and Material Sun, 21 Jun 2015 10:13:49 +0000 http://www.hindawi.com/journals/amse/2015/693469/ Knee prostheses as medical products require careful application of quality and design tool to ensure the best performance. Therefore, quality function deployment (QFD) was proposed as a quality tool to systematically integrate consumer’s expectation to perceived needs by medical and design team and to explicitly address the translation of customer needs into engineering characteristics. In this study, full factorial design of experiment (DOE) method was accompanied by finite element analysis (FEA) to evaluate the effect of inner contours of femoral component on mechanical stability of the implant and biomechanical stresses within the implant components and adjacent bone areas with preservation of the outer contours for standard Co-Cr alloy and a promising functionally graded material (FGM). The ANOVA revealed that the inner shape of femoral component influenced the performance measures in which the angle between the distal and anterior cuts and the angle between the distal and posterior cuts were greatly influential. In the final ranking of alternatives, using multicriteria decision analysis (MCDA), the designs with FGM was ranked first over the Co-Cr femoral component, but the original design with Co-Cr material was not the best choice femoral component, among the top ranked design with the same material. Ali Jahan and Marjan Bahraminasab Copyright © 2015 Ali Jahan and Marjan Bahraminasab. All rights reserved. The Effects of Various Additive Components on the Sound Absorption Performances of Polyurethane Foams Sun, 21 Jun 2015 09:06:16 +0000 http://www.hindawi.com/journals/amse/2015/317561/ Flexible polyurethane (PU) foams comprising various additive components were synthesized to improve their acoustic performances. The purpose of this study was to investigate the effects of various additive components of the PU foams on the resultant sound absorption, which was characterized by the impedance tube technique to obtain the incident sound absorption coefficient and transmission loss. The maximum enhancement in the acoustic properties of the foams was obtained by adding fluorine-dichloroethane (141b) and triethanolamine. The results showed that the acoustic absorption properties of the PU foams were improved by adding 141b and triethanolamine and depended on the amount of the water, 141b, and triethanolamine. Shuming Chen, Yang Jiang, Jing Chen, and Dengfeng Wang Copyright © 2015 Shuming Chen et al. All rights reserved. Intergranular Corrosion of Low Cr Ferritic Stainless Steel 429 Evaluated by the Optimized Double Loop Electrochemical Potentiokinetic Reactivation Test Sun, 21 Jun 2015 08:52:18 +0000 http://www.hindawi.com/journals/amse/2015/716874/ Intergranular corrosion (IGC) of Nb-Ti stabilized ferritic stainless steel (FSS) 429 was investigated using the double loop electrochemical potentiokinetic reactivation (DL-EPR) test combined with the microstructure observation. The results indicated that the optimized DL-EPR test condition for FSS 429 was the solution of 0.5 M H2SO4 + 0.0001 M KSCN with a scanning rate of 100 mV/min at 30°C. Based on this condition, the specimens aging at 400–700°C for different duration were tested and a time-temperature-sensitization (TTS) curve for FSS 429 was obtained, which reveals the sensitization nose was located around 550°C. The critical value was determined to be about 3% above which IGC occurred. After aging treatment, Cr depletion zone was detected using energy dispersive spectroscopy (EDS), most possibly due to Cr segregation around intergranular TiC and NbC. Xiao-lei Li, Yi-fan Ni, Yi-ming Jiang, Jin Li, and Li Li Copyright © 2015 Xiao-lei Li et al. All rights reserved. A Fuzzy Delphi-Analytical Hierarchy Process Approach for Ranking of Effective Material Selection Criteria Sun, 21 Jun 2015 08:49:31 +0000 http://www.hindawi.com/journals/amse/2015/845346/ The ability to select the most appropriate materials for a given application is the fundamental challenge faced by a design engineer. The objective of any material selection procedure is to identify appropriate selection criteria and to obtain the most appropriate combination of criteria in conjunction with requirements. Hence, selection of material is a multicriteria decision making problem. This study investigates and evaluates critical material selection criteria in a priority framework using the fuzzy Delphi-analytical hierarchy process method to overcome all shortcomings from AHP and Delphi methods that are common in material selection problem. 75 of the most important criteria for material selection have been collected from the literature. These criteria have been questioned in automobile interior design firms in Iran for car dashboard design. This ranking method would help product designers to decide on appropriate materials in a consistent method. Results indicate that “general” criteria such as availability, quality, risk, and technology are the most important criteria from the viewpoint of Iranian car manufacturers. Other criteria such as financial, technical, social and environmental, and sensorial criteria are relatively important in subsequent ranks. Sajad Kazemi, Seyed Mahdi Homayouni, and Jay Jahangiri Copyright © 2015 Sajad Kazemi et al. All rights reserved. Green Composite Materials Sun, 21 Jun 2015 06:13:26 +0000 http://www.hindawi.com/journals/amse/2015/487416/ Hao Wang, Peter Schubel, Xiaosu Yi, Jin Zhu, Chad Ulven, and Yiping Qiu Copyright © 2015 Hao Wang et al. All rights reserved. Mechanism and Durability of Repair Systems in Polymer-Modified Cement Mortars Wed, 17 Jun 2015 13:54:06 +0000 http://www.hindawi.com/journals/amse/2015/594672/ This paper investigated the mechanism and durability of repair systems made of ordinary cement-based repair mortar and three kinds of polymer-modified repair mortars with old concrete, SBR dispersion, SAE dispersion, and SAE powder. By comparing the bonding properties of mortars before and after erosion, it was found that polymers could effectively improve the durability of the repair system and SAE powder had the best improvement. Micromorphology study of the repair mortar and the interface of repair mortar with old concrete through SEM showed that the polymer film formed from SAE powder whatever in the mortar or at the interface was dense and tough, the film formed from SAE dispersion was loose and weak, while the film formed from SBR dispersion was in between them, which explained the difference in the tensile bond strength and the durability of the repair systems. Ru Wang and Liang Zhang Copyright © 2015 Ru Wang and Liang Zhang. All rights reserved. Effect of Friction Model and Tire Maneuvering on Tire-Pavement Contact Stress Tue, 16 Jun 2015 12:50:33 +0000 http://www.hindawi.com/journals/amse/2015/632647/ This paper aims to simulate the effects of different friction models on tire braking. A truck radial tire (295/80R22.5) was modeled and the model was validated with tire deflection. An exponential decay friction model that considers the effect of sliding velocity on friction coefficients was adopted for analyzing braking performance. The result shows that the exponential decay friction model used for evaluating braking ability meets design requirements of antilock braking system (ABS). The tire-pavement contact stress characteristics at various driving conditions (static, free rolling, braking, camber, and cornering) were analyzed. It is found that the change of driving conditions has direct influence on tire-pavement contact stress distribution. The results provide the guidance for tire braking performance evaluation. Haichao Zhou, Guolin Wang, Yangmin Ding, Jian Yang, Chen Liang, and Jing Fu Copyright © 2015 Haichao Zhou et al. All rights reserved. Photocatalytic Performance of Carbon Monolith/TiO2 Composite Tue, 16 Jun 2015 07:14:47 +0000 http://www.hindawi.com/journals/amse/2015/803492/ The new and simple approach for deposition of catalytically active TiO2 coating on carbon monolith (CM) carrier was presented. CM photocatalysts were impregnated with TiO2 using titanium solution and thermal treatment, and their photocatalytic activity was investigated in the process of methylene blue (MB) photodegradation. For the purpose of comparison, CM composite photocatalysts were prepared by dip-coating method, which implies binder usage. The presence of TiO2 on CM carrier was confirmed by Raman spectroscopy and scanning electron microscopy. The sorption characteristics of CM and the role of adsorption in the overall process of MB removal were evaluated through amount of surface oxygen groups obtained by temperature-programmed desorption and specific surface area determined by BET method. CM has shown good adsorption properties toward MB due to high amount of surface oxygen groups and relatively high specific surface area. It was concluded that photocatalytic activity increases with CM disc thickness due to increase of MB adsorption and amount of deposited TiO2. Good photocatalytic activity achieved for samples obtained by thermal treatment is the result of better accessibility of MB solution to the TiO2 particles induced by binder absence. Marina Maletić, Marija Vukčević, Ana Kalijadis, Zoran Laušević, and Mila Laušević Copyright © 2015 Marina Maletić et al. All rights reserved. Electrochemical Properties of La2Mg17/Ni Electrodes Prepared via TiF3-Catalysed Mechanical Milling Mon, 15 Jun 2015 11:53:12 +0000 http://www.hindawi.com/journals/amse/2015/629415/ In order to improve the hydrogen storage capacity of conventional La2Mg17 electrode alloys, a nanocrystalline/amorphous-structured La2Mg17-Ni composite material was produced by high energy ball milling in the presence of TiF3. Subsequent analysis of the discharge/charge cycle performances of this electrode material revealed that its cycle stability and electrochemical capacity were greatly improved, with the latter reaching a maximum value of 787.07 mAh/g with optimisation of the TiF3 addition. Moreover, a remarkable enhancement in the reversibility of electrochemical reactions on the material’s surface was also observed. Hydrogen diffusion coefficients for the material were calculated by means of a potential step method, confirming that TiF3 markedly improves the long-range diffusion of hydrogen within the material. T. Li, Z. Liu, G. Zhang, F. Ruan, R. Guo, and J. Zhang Copyright © 2015 T. Li et al. All rights reserved. Impacts of Limestone Particle Size on the Performance of Flexible Wood Fiber Composite Floor Sun, 14 Jun 2015 07:32:10 +0000 http://www.hindawi.com/journals/amse/2015/804729/ Sustainable wood floor (WFF), produced from natural plants, is a sort of novel green and ecofriendly composite floor, which has been attracting more and more attention in the world. WFF also gives a solution of utilizations of agricultural wastes, such as bamboo mats and hemp hurd. The additive limestone powder plays key role in the performance of flexible bamboo composite floor, so, in this paper, the effects of limestone size and size distributions were investigated. The best particle size distributions of limestone are 25 wt% of 48 μm, 25 wt% of 106 μm, and 50 wt% of 160 μm. The as-obtained WFF has good elasticity, good affinity, and strong comfortableness as well as free formaldehyde release. Hongcheng He, Jinling Nie, and Jing Wang Copyright © 2015 Hongcheng He et al. All rights reserved. Characterization of Waste Material Derived Willemite-Based Glass-Ceramics Doped with Erbium Tue, 09 Jun 2015 17:12:14 +0000 http://www.hindawi.com/journals/amse/2015/953659/ We reported, for the first time, to the best of our knowledge, the production of erbium doped willemite-based glass-ceramic using waste material. In this work, a willemite-based glass-ceramic was prepared from waste material to obtain excellent crystallinity and then doped with trivalent erbium (Er3+) to yield ([(ZnO)0.5(SLS)0.5]1−x[Er2O3]x) final composition where  wt%. The samples were sintered at various temperatures (500–1100°C) to study the effects of sintering temperatures on microstructure and physical properties of the samples. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) were used to determine structural changes and functional groups in the samples, respectively. Field-emission scanning electron microscopy (FE-SEM) equipped with energy dispersive X-ray was used to observe surface morphology and to detect presence of elements in the samples. Findings showed that average grain size of the Er3+ doped glass-ceramic sample increased as a function of the sintering temperature and the optimum temperature was 900°C. G. V. Sarrigani, H. J. Quah, W. F. Lim, K. A. Matori, N. S. Mohd Razali, A. Kharazmi, M. Hashim, and H. R. Bahari Copyright © 2015 G. V. Sarrigani et al. All rights reserved. Impact of Layer-by-Layer Self-Assembly Clay-Based Nanocoating on Flame Retardant Properties of Sisal Fiber Cellulose Microcrystals Tue, 09 Jun 2015 14:24:22 +0000 http://www.hindawi.com/journals/amse/2015/691290/ The renewable cationic polyelectrolyte chitosan (CH) and anionic nanomontmorillonite (MMT) layers were alternately deposited on the surface of sisal fiber cellulose microcrystals (SFCM) via layer-by-layer (LBL) self-assembly method. The structure and properties of the composites were characterized by zeta potential, thermal gravimetric analysis (TGA), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectrometer (FTIR), microcalorimeter (MCC), and so forth. The zeta potential results show that the cellulose microcrystalline surface charge reversed due to the adsorption of CH and MMT nanoplatelets during multilayer deposition. MMT characteristic diffraction peaks appear in XRD patterns of SFCM(CH/MMT)5 and SFCM(CH/MMT)10 composites. Additionally, FESEM reveals that the SFCM(CH/MMT)10 surface is covered with a layer of material containing Si, which has been verified by elemental analysis. TGA results show that the initial decomposition (weight loss of 5%) temperature of SFCM(CH/MMT)5 is increased by 4°C compared to that of pure SFCM. On the other hand, carbon residue percentage of SFCM(CH/MMT)10 is 25.1%, higher than that of pure SFCM (5.4%) by 19.7%. Eventually, it is testified by MCC measurement that CH/MMT coating can significantly reinforce the flame retardant performance of SFCM. Chun Wei, Sihua Zeng, Yuyuan Tan, Wu Wang, Jian Lv, and Hongxia Liu Copyright © 2015 Chun Wei et al. All rights reserved. Development of a Zero-Cement Binder Using Slag, Fly Ash, and Rice Husk Ash with Chemical Activator Tue, 09 Jun 2015 08:31:31 +0000 http://www.hindawi.com/journals/amse/2015/247065/ The increasing demand and consumption of cement have necessitated the use of slag, fly ash, rice husk ash (RHA), and so forth as a supplement of cement in concrete construction. The aim of the study is to develop a zero-cement binder (Z-Cem) using slag, fly ash, and RHA combined with chemical activator. NaOH, Ca(OH)2, and KOH were used in varying weights and molar concentrations. Z-Cem was tested for its consistency, setting time, flow, compressive strength, XRD, SEM, and FTIR. The consistency and setting time of the Z-Cem paste increase with increasing RHA content. The Z-Cem mortar requires more superplasticizer to maintain a constant flow of % compared with OPC. The compressive strength of the Z-Cem mortar is significantly influenced by the amounts, types, and molar concentration of the activators. The Z-Cem mortar achieves a compressive strength of 42–44 MPa at 28 days with 5% NaOH or at 2.5 molar concentrations. The FTIR results reveal that molecules in the Z-Cem mortar have a silica-hydrate (Si-H) bond with sodium or other inorganic metals (i.e., sodium/calcium-silica-hydrate-alumina gel). Therefore, Z-Cem could be developed using the aforementioned materials with the chemical activator. M. R. Karim, M. F. M. Zain, M. Jamil, and F. C. Lai Copyright © 2015 M. R. Karim et al. All rights reserved.