Advances in Materials Science and Engineering The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Electrical Characterization of Sol-Gel Derived TiO2 Film on c-Si Substrate by Admittance Measurement Wed, 20 Aug 2014 10:38:48 +0000 Transport and storage properties of sol-gel synthesized, namely, dip coating technique, titanium dioxide (TiO2) thin film over crystalline silicon (c-Si), has been investigated by means of current-voltage (I-V) and admittance analysis within different ambient. Considering the work function of anatase TiO2 film, determined by both FTIR and TG/DTA analysis, silver (Ag) as front metal electrode was chosen to hinder a barrier for charge carriers. Electrical analysis implied that Ag/TiO2/c-Si structure was actually constituted by Ag/TiO2/native silicon dioxide (SiO2)/c-Si [SIS] structure, in which SiO2 layer was identified by FTIR analysis. Consequently, the electrical features of the film were interpreted in terms of SIS diode that is capable of explaining C-V features. Ayşe Evrim Saatci and Orhan Özdemir Copyright © 2014 Ayşe Evrim Saatci and Orhan Özdemir. All rights reserved. Experimental Study on Thermal Performance of Externally Insulated Walls of Intermittent Air-Conditioned Rooms in Summer in Hot Summer and Cold Winter Region, China Wed, 20 Aug 2014 08:55:21 +0000 Now requirements for the thermal performance of building walls are based on the assumption that heat flux transfers in one direction through the wall. However, in Hot Summer and Cold Winter Region of China, the direction of heat flow in the wall not only changes with the seasons, but also changes in the same period of using. In this paper, dynamic thermal process of externally insulated walls in different air-conditioner’s running state in summer in Chongqing, China, was tested. The distribution characteristics of the outdoor and indoor air temperature and the surface and inner temperatures of the wall were analyzed and demonstrated. Based on the unsteady-state heat transfer theory, the study calculated and analyzed the distribution characteristics of the direction of the heat flux in the thermal process. Also the characteristics of insulation and heat preservation for walls under different air-conditioner’s running state were analyzed. It is shown that, in any air-conditioner’s running state, the direction of the heat flux through the wall is obviously dynamically changing. There is obvious difference in the thermal performance needs of the wall; that is, it has strong demand for thermal insulation in daytime and strong demand for heat dissipation during night time in summer. Yong Ding, Lu Xu, Baizhan Li, and Xiaoqing Liu Copyright © 2014 Yong Ding et al. All rights reserved. Study of Interface Charge Densities for ZrO2 and HfO2 Based Metal-Oxide-Semiconductor Devices Wed, 20 Aug 2014 06:28:59 +0000 A thickness-dependent interfacial distribution of oxide charges for thin metal oxide semiconductor (MOS) structures using high-k materials ZrO2 and HfO2 has been methodically investigated. The interface charge densities are analyzed using capacitance-voltage (C-V) method and also conductance (G-V) method. It indicates that, by reducing the effective oxide thickness (EOT), the interface charge densities () increases linearly. For the same EOT, has been found for the materials to be of the order of 1012 cm−2 eV−1 and it is originated to be in good agreement with published fabrication results at p-type doping level of  cm−3. Numerical calculations and solutions are performed by MATLAB and device simulation is done by ATLAS. N. P. Maity, Reshmi Maity, R. K. Thapa, and S. Baishya Copyright © 2014 N. P. Maity et al. All rights reserved. Membrane Material-Based Rigid Solar Array Design and Thermal Simulation for Stratospheric Airships Tue, 19 Aug 2014 11:45:04 +0000 In order to improve effective utilization of rigid solar array used in stratospheric airships here, the flexible connection design and light laminated design were introduced to rigid solar array. Based on the analysis of the design scheme, firstly, the equivalent coefficient of thermal conductivity was calculated by the theoretical formula. Subsequently, the temperature variation characteristics of the solar cell module were accurately modeled and simulated by using Computational Fluid Dynamics (CFD) software. Compared to the results of test samples, the solar cell module described here guaranteed effective output as well as good heat insulating ability, effectively improving the feasibility of the stratospheric airship design. In addition, the simulation model can effectively simulate the temperature variation characteristics of the solar cell, which, therefore, provides technical support for the engineering application. Kangwen Sun, Ming Zhu, and Qiang Liu Copyright © 2014 Kangwen Sun et al. All rights reserved. Structural, Electrical, and Ethanol-Sensing Properties of Nanoparticles Mon, 18 Aug 2014 13:04:24 +0000 The nanocrystalline () powders with orthorhombic perovskite phase were prepared by sol-gel method. The average crystallite sizes of powders are about 20 nm. The resistance and gas-sensing properties of the based sensors were investigated in the temperature range from 160 to 300°C. The results demonstrated that the resistance and response of the perovskite thick films changed with the increase of Nd content. Nguyen Thi Thuy, Dang Le Minh, Ho Truong Giang, and Nguyen Ngoc Toan Copyright © 2014 Nguyen Thi Thuy et al. All rights reserved. Transformation of Goethite to Hematite Nanocrystallines by High Energy Ball Milling Mon, 18 Aug 2014 11:20:04 +0000 α-Fe2O3 nanocrystallines were prepared by direct transformation via high energy ball milling treatment for α-FeOOH powder. X-ray diffraction, Rietveld analysis, TEM, and vibrating sample magnetometer (VSM) are used to characterize the samples obtained after several milling times. Phase identification using Rietveld analysis showed that the goethite is transformed to hematite nanocrystalline after 40 hours of milling. HRTEM confirm that the obtained phase is mostly a single-crystal structure. This result suggested that the mechanochemical reaction is an efficient way to prepare some iron oxides nanocrystallines from raw materials which are abundant in the nature. The mechanism of the formation of hematite is discussed in text. O. M. Lemine Copyright © 2014 O. M. Lemine. All rights reserved. Innovative Micro- and Nanostructured Materials and Devices for Energy Applications Wed, 13 Aug 2014 11:31:40 +0000 Luciano Mescia, Andrea Chiappini, Alessandro Massaro, and Shivakiran N. B. Bhaktha Copyright © 2014 Luciano Mescia et al. All rights reserved. The Synthesis and Physical Properties of Magnesium Borate Mineral of Admontite Synthesized from Sodium Borates Wed, 13 Aug 2014 05:59:47 +0000 Magnesium borates are significant compounds due to their advanced mechanical and thermal durability properties. This group of minerals can be used in ceramic industry, in detergent industry, and as neutron shielding material, phosphor of thermoluminescence by dint of their extraordinary specialties. In the present study, the synthesis of magnesium borate via hydrothermal method from sodium borates and physical properties of synthesized magnesium borate minerals were investigated. The characterization of the products was carried out by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies, and differential thermal analysis and thermal gravimetry (DTA/TG). The surface morphology was examined by scanning electron microscopy (SEM). B2O3 content was determined through titration. The electrical resistivity/conductivity properties of products were measured by Picoammeter Voltage Source. UV-vis spectrometer was used to investigate optical absorption characteristics of synthesized minerals in the range 200–1000 nm at room temperature. XRD results identified the synthesized borate minerals as admontite [MgO(B2O3)3·7(H2O)] with code number “01-076-0540” and mcallisterite [Mg2(B6O7(OH)6)2·9(H2O)] with code number “01-070-1902.” The FT-IR and Raman spectra of the obtained samples were similar with characteristic magnesium borate bands. The investigation of the SEM images remarked that both nano- and microscale minerals were produced. The reaction yields were between 75.1 and 98.7%. Azmi Seyhun Kipcak, Meral Yildirim, Sureyya Aydin Yuksel, Emek Moroydor Derun, and Sabriye Piskin Copyright © 2014 Azmi Seyhun Kipcak et al. All rights reserved. Production, Characterization, and Applications of Porous Materials Tue, 12 Aug 2014 05:33:56 +0000 Nikolaos Michailidis, Alexander Tsouknidas, Louis-Philippe Lefebvre, Thomas Hipke, and Naoyuki Kanetake Copyright © 2014 Nikolaos Michailidis et al. All rights reserved. A One-Dimensional Thermoelastic Problem due to a Moving Heat Source under Fractional Order Theory of Thermoelasticity Mon, 11 Aug 2014 08:04:13 +0000 The dynamic response of a one-dimensional problem for a thermoelastic rod with finite length is investigated in the context of the fractional order theory of thermoelasticity in the present work. The rod is fixed at both ends and subjected to a moving heat source. The fractional order thermoelastic coupled governing equations for the rod are formulated. Laplace transform as well as its numerical inversion is applied to solving the governing equations. The variations of the considered temperature, displacement, and stress in the rod are obtained and demonstrated graphically. The effects of time, velocity of the moving heat source, and fractional order parameter on the distributions of the considered variables are of concern and discussed in detail. Tianhu He and Ying Guo Copyright © 2014 Tianhu He and Ying Guo. All rights reserved. Influence of Styrene-Acrylic Ester Dispersion on the Early Hydration of Cement Mon, 11 Aug 2014 06:46:02 +0000 Early hydration of cement in the presence of styrene-acrylic ester (SAE) dispersion was investigated, and the hydration heat, hydration degree, and hydrates were analyzed using isothermal calorimeter, XRD, and ESEM. The results show that SAE dispersion prolongs the induction period, postpones and shortens the accelerating period, and inhibits the decelerating and stable periods of cement hydration. The hydration heat and hydration degree of cement in the presence of SAE dispersion are less than those of the control. SAE dispersion inhibits the formation of C4AH13 and thus AFt, and more SAE dispersion brings stronger influence, but it enhances the stability of AFt. AFt generation during the early hydration period is controlled gradually by the reaction of C4AH13 generation with increasing SAE dispersion, but this is controlled by the reaction of C4AH13 consumption for the control paste. Besides, SAE dispersion retards and inhibits the formation of CH and C-S-H and also changes their morphology. Ru Wang and Xiaoxin Shi Copyright © 2014 Ru Wang and Xiaoxin Shi. All rights reserved. New Trends in Energy Harvesting from Earth Long-Wave Infrared Emission Mon, 11 Aug 2014 06:43:54 +0000 A review, even if not exhaustive, on the current technologies able to harvest energy from Earth’s thermal infrared emission is reported. In particular, we discuss the role of the rectenna system on transforming the thermal energy, provided by the Sun and reemitted from the Earth, in electricity. The operating principles, efficiency limits, system design considerations, and possible technological implementations are illustrated. Peculiar features of THz and IR antennas, such as physical properties and antenna parameters, are provided. Moreover, some design guidelines for isolated antenna, rectifying diode, and antenna coupled to rectifying diode are exploited. Luciano Mescia and Alessandro Massaro Copyright © 2014 Luciano Mescia and Alessandro Massaro. All rights reserved. Structural and Morphological Properties of Nanostructured ZnO Particles Grown by Ultrasonic Spray Pyrolysis Method with Horizontal Furnace Sun, 10 Aug 2014 13:31:57 +0000 ZnO nanoparticles were synthesized in a horizontal furnace at 500°C using different zinc nitrate hexahydrate concentrations (0.01 and 0.1 M) as reactive solution by ultrasonic spray pyrolysis method. The physical-chemical properties of synthesized ZnO nanoparticles have been characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and high resolution transmission electron microscopy (HRTEM). With the TGA is has optimized the temperature at which the initial reactive (Zn(NO3)2·6H2O), is decomposed completely to give way to its corresponding oxide, ZnO. SEM revealed secondary particles with a quasispherical shape that do not change significantly with the increasing of precursor solution concentration as well as some content of the broken spheres. Increasing the precursor solution concentration leads to the increase in the average size of ZnO secondary particles from to  nm; XRD reveals the similar tendency for the crystallite size which changes from to  nm. HRTEM implies that the secondary particles are with hierarchical structure composed of primary nanosized subunits. These results showed that the precursor concentration plays an important role in the evolution on the size, stoichiometry, and morphology of ZnO nanoparticles. G. Flores-Carrasco, J. Carrillo-López, J. A. Luna-López, R. Martínez-Martínez, N. D. Espinosa-Torres, and M. E. Rabanal Copyright © 2014 G. Flores-Carrasco et al. All rights reserved. Mosaic Structure Characterization of the AlInN Layer Grown on Sapphire Substrate Sun, 10 Aug 2014 13:05:51 +0000 The 150 nm thick, (0001) orientated wurtzite-phase Al1−xInxN epitaxial layers were grown by metal organic chemical vapor deposition on GaN (2.3 µm) template/(0001) sapphire substrate. The indium (x) concentration of the Al1−xInxN epitaxial layers was changed as 0.04, 0.18, 0.20, 0.47, and 0.48. The Indium content (x), lattice parameters, and strain values in the AlInN layers were calculated from the reciprocal lattice mapping around symmetric (0002) and asymmetric (10–15) reflection of the AlInN and GaN layers. The mosaic structure characteristics of the AlInN layers, such as lateral and vertical coherence lengths, tilt and twist angle, heterogeneous strain, and dislocation densities (edge and screw type dislocations) of the AlInN epilayers, were investigated by using high-resolution X-ray diffraction measurements and with a combination of Williamson-Hall plot and the fitting of twist angles. Engin Arslan, Pakize Demirel, Huseyin Çakmak, Mustafa K. Öztürk, and Ekmel Ozbay Copyright © 2014 Engin Arslan et al. All rights reserved. Carbonation Characteristics of Alkali-Activated Blast-Furnace Slag Mortar Thu, 07 Aug 2014 10:55:35 +0000 Alkali-activated ground granulated blast-slag (AAS) is the most obvious alternative material for ordinary Portland cement (OPC). However, to use it as a structural material requires the assessment and verification of its durability. The most important factor for a durability evaluation is the degree of carbonation resistance, and AAS is known to show lower performance than OPC. A series of experiments was conducted with a view to investigate the carbonation characteristics of AAS binder. As a consequence, it was found that the major hydration product of AAS was calcium silicate hydrate (CSH), with almost no portlandite, unlike the products of OPC. After carbonation, the CSH of AAS turned into amorphous silica gel which was most likely why the compressive strength of AAS became weaker after carbonation. An increase of the activator dosage leads AAS to react more quickly and produce more CSH, increasing the compaction, compressive strength, and carbonation resistance of the microstructure. Keum-Il Song, Jin-Kyu Song, Bang Yeon Lee, and Keun-Hyeok Yang Copyright © 2014 Keum-Il Song et al. All rights reserved. Fabrication of Silver Interdigitated Electrode by a Stamp Method Thu, 07 Aug 2014 10:29:11 +0000 A stamp method was developed in this study to fabricate interdigitated electrodes (IDEs) on glass substrate from a 37.5 wt% silver ink. This method is simple and fast. A small amount of silver ink was first dripped into an IDE-patterned sponge of a stamp and then one could stamp out the desired IDE pattern made of nanosized silver colloids on a glass substrate, which was subsequently sintered at 280°C for 10 minutes to obtain the final silver IDE. Our brief study showed that when a large stamping force was used, more ink would be stamped out in the beginning and it decreased after each usage. However, if the force was too small, there would not be sufficient ink for a complete IDE. There existed therefore an optimal force to fabricate IDEs with minimal changes from sample to sample. The average dimension of an IDE when the applied force was 102 gm was roughly 403 ± 20 µm in width and 1154 ± 153 nm in height, and the average final electrical resistivity was about  Ω-cm. Kan-Sen Chou and Chia-Hsuan Lee Copyright © 2014 Kan-Sen Chou and Chia-Hsuan Lee. All rights reserved. The Effect of Bedding Structure on Mechanical Property of Coal Thu, 07 Aug 2014 10:28:17 +0000 The mechanical property of coal, influencing mining activity considerably, is significantly determined by the natural fracture distributed within coal mass. In order to study the effecting mechanism of bedding structure on mechanical property of coal, a series of uniaxial compression tests and mesoscopic tests have been conducted. The experimental results show that the distribution characteristic of calcite particles, which significantly influences the growth of cracks and the macroscopic mechanical properties of coal, is obviously affected by the bedding structure. Specifically, the uniaxial compression strength of coal sample is mainly controlled by bedding structure, and the average peak stress of specimens with axes perpendicular to the bedding planes is 20.00 MPa, which is 2.88 times the average amount of parallel ones. The test results also show a close relationship between the bedding structure and the whole deformation process under uniaxial loading. Zetian Zhang, Ru Zhang, Guo Li, Hegui Li, and Jianfeng Liu Copyright © 2014 Zetian Zhang et al. All rights reserved. Seismic Behavior of Short Concrete Columns with Prestressing Steel Wires Tue, 05 Aug 2014 08:13:40 +0000 The seismic behavior of short circular reinforced concrete columns was studied by testing seven columns retrofitted with prestressing steel wire (PSW), subjected to combined constant axial compression and lateral cyclic load. The main test parameters were configuration index of PSW, prestressing level of PSW, and axial compression ratio. An analysis and discussion of the test results including failure mode, hysteresis curves, skeleton curves, ductility, and degradation of stiffness was done. The results show that the seismic performance of the retrofitted specimens could be effectively enhanced even if the axial compression ratio of columns reached 0.81. The ductility index and the energy absorption capacity of the retrofitted specimens increase with the prestressing level of PSW. The formulas for calculating shear capacity of RC short columns strengthened with PSW were proposed which may be useful for future engineering designs and researches. Deng Zong-Cai, Jumbe R. Daud, and Li Hui Copyright © 2014 Deng Zong-Cai et al. All rights reserved. Rare Earth Doped Lanthanum Calcium Borate Polycrystalline Red Phosphors Tue, 05 Aug 2014 07:52:03 +0000 Single-phased Sm3+ doped lanthanum calcium borate (SmxLa2−xCaB10O19, SLCB, ) polycrystalline red phosphor was prepared by solid-state reaction method. The phosphor has two main excitation peaks located at 398.5 nm and 469.0 nm, which are nicely in accordance with the emitting wavelengths of commercial near-UV and blue light emitting diode chips. Under the excitation of 398.0 nm, the dominant red emission of Sm3+ in SLCB phosphor is centered at 598.0 nm corresponding to the transition of 4G5/2  6H7/2. The Eu3+ fluorescence in the red spectral region is applied as a spectroscopic probe to reveal the local site symmetry in the host lattice and, hence, Judd-Ofelt parameters of Eu3+ in the phosphor matrix are derived to be and  cm2, indicating a high asymmetrical and strong covalent environment around rare earth luminescence centers. Herein, the red phosphors are promising good candidates employed in white light emitting diodes (LEDs) illumination. H. H. Xiong, C. Zhu, X. Zhao, Z. Q. Wang, and H. Lin Copyright © 2014 H. H. Xiong et al. All rights reserved. Optical and Electrical Properties of Ag-Doped In2S3 Thin Films Prepared by Thermal Evaporation Mon, 04 Aug 2014 07:55:00 +0000 Ag-doped In2S3 (In2S3:Ag) thin films have been deposited onto glass substrates by a thermal evaporation method. Ag concentration is varied from 0 at.% to 4.78 at.%. The structural, optical, and electrical properties are characterized using X-ray diffraction (XRD), spectrophotometer, and Hall measurement system, respectively. The XRD analysis confirms the existence of In2S3 and AgIn5S8 phases. With the increase of the Ag concentration, the band gap of the films is decreased gradually from 2.82 eV to 2.69 eV and the resistivity drastically is decreased from ~103 to  Ωcm. Peijie Lin, Sile Lin, Shuying Cheng, Jing Ma, Yunfeng Lai, Haifang Zhou, and Hongjie Jia Copyright © 2014 Peijie Lin et al. All rights reserved. Material Weakening of Slip Zone Soils Induced by Water Level Fluctuation in the Ancient Landslides of Three Gorges Reservoir Mon, 04 Aug 2014 07:20:50 +0000 This experimental study investigated the effect of repeated wetting and drying on the reduction of slip zone soils taken from the Huangtupo landslide in the Three Gorges Reservoir, China. The variation process of the physical property and substance composition of the slip zone soils under the wetting-drying cycles was studied through liquid and plastic limit test and X-ray diffraction test. The results indicate that (1) the shearing strength of the slip zone soil dramatically decreased after one wetting-drying cycle and then gradually decreased until reaching a relatively stable state at the fourth cycle; (2) the plasticity index of the slip zone soil varied with increasing number of cycles and a variation process opposite to that of the strength value was observed; and (3) the clay mineral content in the slip zone soil increased and the calcite and quartz contents relatively decreased with increasing number of cycles. The variations in the plasticity index of the slip zone soil, as well as the increase in its clay mineral content, play important roles in the strength reduction. The results of this study provide a foundation for revealing the deformation and damage mechanism of landslides in reservoir banks. Yu-Yong Jiao, Liang Song, Hui-Ming Tang, and Yun-An Li Copyright © 2014 Yu-Yong Jiao et al. All rights reserved. Nonlinear Finite Element Analysis of the Fluted Corrugated Sheet in the Corrugated Cardboard Wed, 23 Jul 2014 11:51:24 +0000 The choice of corrugated medium, flute size, combining adhesive, and linerboards can be varied to design a corrugated board with specific properties. In this paper, the nonlinear finite element analysis of the fluted corrugated sheet in the corrugated cardboard based on software SolidWorks2008 was investigated. The model of corrugated board with three or more flutes is reliable for stress and displacement measurement to eliminate the influence of the number of flutes in models. According to the static pressure test, with the increase of flute height or arc radius of flute, the maximum stress in the models decreased and the maximum displacement increased. However the maximum stress and maximum displacement in the models increase nonlinearly in the static pressure test with the increase of the flute angle . According to the drop test, with the increase of flute height , the maximum stress of goods on the upper board in the drop test decreased. The maximum stress of the model in the drop test decreases firstly and then increases with the increase of flute angle, and the optimal flute angle could be 60° for corrugated board. All the conclusions are consistent with experimental data or product standards. Zhiguo Zhang, Tao Qiu, Riheng Song, and Yaoyu Sun Copyright © 2014 Zhiguo Zhang et al. All rights reserved. The Research of Degradation about 1,2,4-Trichlorobenzene by the Artificial Media in Microbe Enrichment Mon, 21 Jul 2014 12:02:54 +0000 Artificial media were used to enrich microbe and improve the water resource quality; therefore trace quantity organic pollutants of 1,2,4-trichlorobenzene were biodegraded. The result of the test showed that, after domestication, the microassociation enriched in the assembled medium could remove corresponding trace quantity organic pollutants in some concentration. When the temperature was 30 degree centigrade, and the pH was between 6 and 9, the effect about the removal on trace-quantity-organic pollutants water was the best. A strain of bacteria that could degrade 1,2,4-trichlorobenzene was separated, and its degradation mechanism to 1,2,4-trichlorobenzene was studied. At the same time, the congener trace quantity organic pollutants could be biodegraded. Biofilm after domestication can effectively degrade a certain concentration range of three trichlorobenzenes and the removal effect of HRT = 7 d was better than the removal effect of HRT = 5 d. It is evident that the trace quantity organic pollutants of 1,2,4-trichlorobenzene in the source water quality from Meiliang Bay in Taihu Lake can be well degraded by enriched microbes on the artificial media. Dong-ying Xu Copyright © 2014 Dong-ying Xu. All rights reserved. Synthesis and Characterization of Acrylamide-Based Anionic Copolymer and Investigation of Solution Properties Mon, 21 Jul 2014 11:04:13 +0000 The copolymer of acrylamide (AM) and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) was synthesized through radical solution polymerization by potassium persulfate as initiator. By changing the AMPS feed ratio from 10 to 70%, and keeping other reaction conditions constant, different copolymers were synthesized. The techniques of Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H- 13C-NMR) spectroscopy were used for identification of functional groups and confirmation of copolymers’ structure. Intrinsic and apparent viscosity of samples were measured in aqueous sodium chloride solution under standard conditions. The anionic degree of copolymers was determined by back titration method and by 13C-NMR spectroscopy. Molecular weight of copolymers was determined by the Mark-Houwink relationship. The measured molecular weight of samples showed that we have acquired a high molecular weight product. The effect of different range of shear rates on solution viscosity was evaluated. The copolymer solutions showed non-Newtonian shear thinning behavior. The performance of copolymers with respect to shear resistance and molecular weight was evaluated from industry application standpoint. H. Jamshidi and A. Rabiee Copyright © 2014 H. Jamshidi and A. Rabiee. All rights reserved. Comprehensive Analysis of Fault Diagnosis Methods for Aluminum Electrolytic Control System Mon, 21 Jul 2014 08:22:24 +0000 This paper established the fault diagnosis system of aluminum electrolysis, according to the characteristics of the faults in aluminum electrolysis. This system includes two subsystems; one is process fault subsystem and the other is fault subsystem. Process fault subsystem includes the subneural network layer and decision fusion layer. Decision fusion neural network verifies the diagnosis result of the subneural network by the information transferring over the network and gives the decision of fault synthetically. EMD algorithm is used for data preprocessing of current signal in stator of the fault subsystem. Wavelet decomposition is used to extract feature on current signal in the stator; then, the system inputs the feature to the rough neural network for fault diagnosis and fault classification. The rough neural network gives the results of fault diagnosis. The simulation results verify the feasibility of the method. Jie-jia Li, Xiao-yan Han, Peng Zhou, Xiao-yu Sun, and Na Chang Copyright © 2014 Jie-jia Li et al. All rights reserved. Smooth Particle Hydrodynamics Simulation of Micro-Cup-Extrusion Using a Graphit-ic Coating Mon, 21 Jul 2014 08:05:13 +0000 Microextrusion is becoming increasingly important for the manufacturing of microcomponents. However, this reduction in scale to a microlevel means that the influence of friction and the need for suitable lubrication are greatly increased. This study therefore looks at the use of a low-friction and highly wear resistant Graphit-ic coating on the mold-forming section of a microextrusion mold, this coating being applied by a closed-field unbalanced magnetron sputter ion plating technique. A microcup of CuZn33 brass alloy was then extruded, with a wall thickness of 0.45 mm, outside diameter of 2.9 mm, and an internal diameter of 2 mm. The experimental results in which extrusion uses the mold coating with Graphit-ic film are compared against the experimental results in which extrusion uses the mold uncoating with Graphit-ic film. This showed that the load was decreased a lot and the self-lubricating solid coating facilitates a smooth extrusion process. As the extrusion rate was quite high, smoothed particle hydrodynamics method simulations of the extrusion process were conducted, these being then compared with the experimental results. These result showed that the SPH simulation can be applied to show the deformation of materials and predict the load trend. Li Shi-Cheng, Chen Ze-Zhong, Zheng Jie, and Wang Dong-Feng Copyright © 2014 Li Shi-Cheng et al. All rights reserved. Fabrication of Upconverting Hybrid Nanoparticles for Near-Infrared Light Triggered Drug Release Mon, 21 Jul 2014 00:00:00 +0000 Low tissue penetration and harmful effects of (ultraviolet) UV or visible light on normal tissue limit exploiting nanocarriers for the application of light-controlled drug release. Two strategies may solve the problem: one is to improve the sensitivity of the nanocarriers to light to decrease the radiation time; the other one is using more friendly light as the trigger. In this work, we fabricated a core-shell hybrid nanoparticle with an upconverting nanoparticle (UCNP) as the core and thermo- and light-responsive block copolymers as the shell to combine the two strategies together. The results indicated that the sensitivity of the block copolymer to light could be enhanced by decreasing the photolabile moieties in the polymer, and the UCNP could transfer near-infrared (NIR) light, which is more friendly to tissue and cell, to UV light to trigger the phase conversion of the block polymers in situ. Using Nile Red (NR) as the model drug, the hybrid nanoparticles were further proved to be able to act as carriers with the character of NIR triggered drug release. Ranran Zhang, Risheng Yao, Binbin Ding, Yuxin Shen, Shengwen Shui, Lei Wang, Yu Li, Xianzhu Yang, and Wei Tao Copyright © 2014 Ranran Zhang et al. All rights reserved. The Effect of Variation of Molarity of Alkali Activator and Fine Aggregate Content on the Compressive Strength of the Fly Ash: Palm Oil Fuel Ash Based Geopolymer Mortar Sun, 20 Jul 2014 06:43:36 +0000 The effect of molarity of alkali activator, manufactured sand (M-sand), and quarry dust (QD) on the compressive strength of palm oil fuel ash (POFA) and fly ash (FA) based geopolymer mortar was investigated and reported. The variable investigated includes the quantities of replacement levels of M-sand, QD, and conventional mining sand (N-sand) in two concentrated alkaline solutions; the contents of alkaline solution, water, POFA/FA ratio, and curing condition remained constant. The results show that an average of 76% of the 28-day compressive strength was found at the age of 3 days. The rate of strength development from 3 to 7 days was found between 12 and 16% and it was found much less beyond this period. The addition of 100% M-sand and QD shows insignificant strength reduction compared to mixtures with 100% N-sand. The particle angularity and texture of fine aggregates played a significant role in the strength development due to the filling and packing ability. The rough texture and surface of QD enables stronger bond between the paste and the fine aggregate. The concentration of alkaline solution increased the reaction rate and thus enhanced the development of early age strength. The use of M-sand and QD in the development of geopolymer concrete is recommended as the strength variation between these waste materials and conventional sand is not high. Iftekhair Ibnul Bashar, U. Johnson Alengaram, Mohd Zamin Jumaat, and Azizul Islam Copyright © 2014 Iftekhair Ibnul Bashar et al. All rights reserved. Characterization and Alumina Leachability of 12CaO·7Al2O3 with Different Holding Times Sun, 20 Jul 2014 00:00:00 +0000 The effect of synthesis time on phase compositions, lattice constant, average grain size, preferred orientation, and surface morphology of 12CaO·7Al2O3 synthesized at 1500°C was analyzed by XRD and SEM. The results indicate that the main phase of samples synthesized is 12CaO·7Al2O3 when holding time is over 30 min. The lattice constant increases and the preferred orientation decreases as synthesis time prolongs. The average grain size of samples is about 59 nm calculated by Scherrer formula, and it does not change with synthesis time. The synthesis time affects the micromorphology of samples greatly. There are more and bigger holes in samples synthesized for long time. The aspects mentioned above cause the alumina leaching ratio of 12CaO·7Al2O3 to increase with the prolonging of synthesis time, but the rate of increase drops. Hui-lan Sun, Bo Wang, Jian-xin Zhang, and Shu-feng Zong Copyright © 2014 Hui-lan Sun et al. All rights reserved. Investigation of Mechanical Properties and Plastic Deformation Behavior of (Ti45Cu40Zr10Ni5)100−xAlx Metallic Glasses by Nanoindentation Thu, 17 Jul 2014 12:24:19 +0000 The effect of Al addition on mechanical properties and plastic deformation behavior of (Ti45Cu40Zr10Ni5)100−xAlx (x = 0, 2, 4, 6 and 8) amorphous alloy ribbons have been investigated by nanoindentation. The hardness and elastic modulus do not simply increase with the increase of Al content. The alloy with 8 at.% Al exhibits the highest hardness and elastic modulus. The serrations or pop-in events are strongly dependent on the loading rate and alloy composition. Lanping Huang, Xuzhe Hu, TaoTao Guo, and Song Li Copyright © 2014 Lanping Huang et al. All rights reserved.