bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature Determination of St-Al Joints during Friction Welding
Authors: Cenk Misirli , Mumin Sahin , Hilmi Kuscu
Published: February 2012

The joining of dissimilar materials is of great importance in industry. Especially, if it is used as the lightest part of the machine parts, materials such as aluminum and magnesium can be joined with steels. Friction welding is one of the methods getting higher share among the other welding methods. In the process, heat is generated by conversion of mechanical energy into thermal energy at the interface of the work pieces during rotation under pressure. Some of the advantages of friction welding are high material save, low production time and being possible of welding of parts which are made by different metals or alloys. Friction welding can also be used in order to join the components that have circular or non circular cross – sections. In this study, stainless-steel and aluminum materials which is the example material was used in the friction welding experiments. The temperature distributions are experimentally obtained in the interface of joints that is formed during friction welding of joints having same geometry. This study was made using thermocouples at different locations of joint-interface.
Antropomorphe Robot with 4 Degrees of Freedom for Didactic Use
Authors: Popescu Gheorghe , Ghimişi Stefan
Published: February 2012

The work relates to practical conceivement and achievement of mecanical and action structure of an antropomorphe industrial robot with 4 freedom degrees + gripper, conceived at “C. Brâncuşi” University – Târgu Jiu for didactical usage. The work presents cinematical chain and building solutions used for mechanical structures, actionand comand systems and speed regulate system of an industrial robot.
Bending-Torsional Flutter of a Composite Rectangular Cantilever Wing Subjected to Engine Thrust
Authors: Amoozgar Mohammad Reza , Irani Saied
Published: February 2012

The bending-torsional flutter characteristics of a cantilever composite wing subjected to engine thrust are presented. The engine thrust modeled as a follower force and the wing modeled as a two degree of freedom beam. In order to consider the spanwise and chordwise location and the properties of the engine location, the generalized function theory is used. Unsteady Theodorsen aerodynamic theory in time domain, is used. The general laminate composite theory is used for modeling the effects of the ply angles on the flutter boundary. The Ritz method is subsequently applied to convert the partial differential equations into a set of ordinary differential equations. In order to precisely consider the location of the engine Dirac delta function is used. Moreover, the numerical results are compared with the published results and excellent agreement is observed. Numerical results highlighting the effect of engine thrust on the wing instability, is presented.
Failure Process and Mechanism Analysis for the Connecting Rod of Diesel Engine
Authors: Gu Ying Kui , Hu Kang , Li Jing
Published: February 2012

The operational fault of diesel engine caused by losing the required function in running is a random phenomenon. It needs to collect a large number of fault samples and reliability data to reveal the fault occurrence rule and describe it with mathematical method. In this paper, the fault law and mechanism of the engine connecting rod were researched by the physical and chemical analysis of the fault samples. The fault reasons and the fault mechanism can be found through the analysis of the organization structure, material properties, process features, heat treatment process and other reliability information of the fault sample. It can provide scientific basis for the failure exclusion as well as the optimization and improvement of connecting rod structure.
Fluctuation-Suppression Pitch Control Strategy Study for Wind Turbine
Authors: Dong Li , Liao Ming Fu , Qin Ming , Sun Li Xiang
Published: February 2012

With the large-scale direction development of wind turbine, the vibrations of wind turbines, which are rigid-flexible coupled multi-body systems, can be easily excited. Control system can be improved to reduce the vibration amplitude and load levels. Fluctuation-suppression pitch control strategy has been improved in this paper. The reference input rotation speed, which is normally constant, is required to change with rotation acceleration in pitch control in this new control strategy. Theory and simulation show that Fluctuation-suppression pitch control (FSPC) strategy can improve the vibration characters of wind turbine and suppress rotation speed and power fluctuation, and it is also quite effective for gust situation
Global Fast Terminal Sliding Mode Control for Wind Energy Conversion System
Authors: Zhang Hu , Wang Wu
Published: February 2012

As for traditional sliding mode control (SMC) with linear sliding surface and the tracking error can’t convergent to zero in finite time, fast terminal sliding mode control (FTSMC) designed with introduction nonlinear function into sliding hyper-plane, which makes tracking error converge to zero in finite time. A global fast terminal sliding mode control (GFTSMC) was designed with SMC and FTSMC, the sliding surface of GFTSMC was designed and the control law was deduced, also the convergence time was computed and stability proved by Lyapunov theory. With simulation, the optimal sliding mode parameters was selected and applied this control strategy for wind energy conversion system (WECS), the simulation result shows this control system can realize optimal power tracking control for wind energy conversion system.
Synthesis of Al1.6667Ti(PO4)3 and its Selectivity to Li+ Exchange
Authors: Li Heng
Published: February 2012

The ion-exchanger Al1.6667Ti(PO4)3 of inverse spinel type was prepared by means of the solid state reaction crystallization method. Its ion-exchange properties for alkali ions such as saturation capacity of exchange and distribution coefficient were determined. Al1.6667Ti(PO4)3 was characterized by virtue of X-ray diffraction method. This inorganic ion-exchanger has the saturation capacity of exchange for Li+ higher than those for other alkali ions, the saturation capacity of exchange for Li+ reaches to 6.6mmol/g.
The Experimental Study on Engineering Characteristics of Improved Clay
Authors: Zhao Yu , Liu Jie , Wu Hong Juan
Published: February 2012

The rapid transit railway foundation bed bears the repeated dynamic load of train besides the static-load from upper structure. The engineering characteristics of improved clay, in especial the dynamic performance under repeated dynamic load or train, is the key factors to determine the improved clay can be used as roadbed fill material. In this paper, the dynamic triaxial test is adopted to imitate the repeated load of train, and the engineering characteristics of improved clay is studied such as dynamic stress plastic strain and elastic strain etc. which influence the running seriously.
The Design and Implementation of Intelligent Community Monitoring System
Authors: Wang Yu Lan , Wang Jian Xiong , Li Yao Hui
Published: February 2012

This paper designs a stable, efficient and intelligent video surveillance system, which is based on the review and analysis of the domestic and internation. And it is related research work on the basis of the intelligent security monitoring. The system is used by the Web server and database server model, and it can detect the moving object in scene of monitor. Firstly this paper analyzes the structure of server system, it uses B/S, database, ActiveX technology and is completed finally. Secondly this paper realizes the video image data in bulk storage, read, update and maintenance by using the database. The bmp format will be converted to JPG format effectively to realize the image database compression. It is valued to the video image data storage and management. Finally, the accuracy and response time can be improved in moving object detection, which is based on background subtraction method
Chemical and Structural Characterization of γ/γ′ Interfaces
Authors: Zhao Kai
Published: February 2012

More attention has been paid to the interfaces since mechanical properties of nickel-base superalloys are determined to some degree by them. The compositional transition across γ/γ′ interfaces and atomic structure of the interfaces was investigated using three-dimensional atom probe tomography and scanning transmission electron microscope equipped with high-resolution Energy Dispersive X-ray Spectrometry. Results show that no obvious segregation to the interfaces or ledges of the precipitates in the present experimental alloys has been observed. Also, adsorption of a solute to the interface was not observed. The interfaces are not flat as usually thought at an atomic scale. The interfacial thickness is about two atomic layers, i.e. 0.7 nm.
Analysis of Thermomechanical Behavior in Continuous Casting Mould and Design of Breakout Prediction System
Authors: Wang Yi , Ma Xin Jian
Published: February 2012

By measuring the surface temperature of the mould, the condition of solidified shell can be monitored by thermocouples fixed to the mould. Breakouts can be predicted and effectively avoided by monitoring the dynamic characteristics of thermocouples temperature in the casting process. A thermomechanical model was developed to analyzed the heat transfer in the mould.The breakout prediction system of continuous casting has been analyzed with consideration of the principles, model and thermocouples installation. The system has been designed and implemented in the steel plants.
Effect of Physical Properties of Manufactured Sand as Fine Aggregate in Elastic and Shrinkage Properties of Concrete and Mortar
Authors: Shanmugavadivu P.M. , Malathy R.
Published: February 2012

Common river sand is expensive due to excessive cost of transportation from natural sources. The increased sand mining affects the aquifer of the river bed and causes many environmental problems. Also large-scale depletion of these sources creates environmental problems. In such a situation the manufactured sand can be an economical alternative to river sand. Manufactured sand is defined as the residue, tailing or other non-valuable material after the extraction and the processing of rocks to form fine particles less than 4.75mm. Use of manufactured sand as a fine aggregate in concrete and mortar draws serious attention of researchers and investigators. Aggregate makes up a significant portion of concrete. The physical properties of aggregate play an important role in elastic and shrinkage properties of concrete and mortar. In this paper, the effect of manufactured sand as fine aggregate in tensile, elastic and shrinkage properties of concrete and mortar are discussed.
Load Carrying Capacity and Ductility of CFRP-Reinforced Earthquake Waste Filled Circular Steel Tube Columns
Authors: He Dong , Dong Jiang Feng , Yuan Shu Cheng , Wang Qingyuan
Published: February 2012

In order to significantly increase not only the load carrying capacity but also the ductility of the steel tube columns filled with recycled aggregate concrete from the earthquake waste, two different strengthening methods by using externally bonded of carbon fibre reinforced polymer (CFRP) to strengthened the columns was proposed. Composite columns of CFRP reinforced and steel circular steel tube columns are studied in this study. The aims were to study the contribution of the CFRP sheets applied in enhancing the load carrying capacity and ductility of the steel tube columns with different concrete type, normal concrete and recycled aggregate concrete. The results demonstrate that the ultimate load carrying capacity and ductility of the steel tube columns filled with recycled aggregate concrete can be increased satisfactorily by full wrapping and partial wrapping arrangement of CFRP sheets. Moreover, stiffness of the columns strengthened was also increased greatly due to the restraining effect offered by CFRP and the full wrapping arrangement is better than the partial wrapping arrangement in enhancing the stiffness and the load carrying capacity.
Pier Form Selection and Parameter Analysis of Reinforced Concrete Thin-Wall High Pier
Authors: Dong Xiao Mei , Wen Yan
Published: February 2012

Two forms of reinforced concrete pier were compared by internal force analysis and nonlinear stability analysis. According to the restriction of the stability and intensity, size optimization of the high piers’ section is calculated by means of differential coefficient. The results of the calculation and analysis indicate that the parameter optimization of the piers’ section of Long-span continuous rigid frame bridges is feasible by using the optimization model, and the results are provided to the optional design of Long-span continuous rigid frame bridges.
The Influence of Reinforced Concrete Beams Crack on Size Effect
Authors: Qin Yi
Published: February 2012

We research the influence of reinforced concrete beams crack on size effect by using the fracture Mechanics analysis method and Fracture toughness. First, the weight of three spot curved beam ,the load ,the steel bar, and the cohesive strength of breaking-down process area were superimposed of the stress intensity factor which has in the crack tip, in order to examine whether it has surpassed the fracture toughness, and judge the crack whether will be to expand. Then we went to iterative computation through increasing the load and the crack length which obtained the carrying capacity of corresponding size component, we used the Matlab programming in the entire computational process. The result shows that although the steel bar limited crack expansion of concretes beams and caused “the plasticity” characteristic, the reinforced concrete beams had the size effect phenomenon still, it did not obvious compare with the plain concrete.
Advancing Ceramics Glaze Formulation with Existing Software Technology Using Locally Available Raw Materials in Nigeria
Authors: Adelabu Oluwafemi Samuel
Published: February 2012

The application of glazes on clay-based ceramic products has been identified as one of the best form of ceramic decorations. This can be attributed to its characteristic to lend aesthetic value to ceramic products and also to render them more durable, useful and hygienic. This paper reports an investigation on the development of new ceramic glaze recipes by means of selected glaze software packages using locally available raw materials in Nigeria. For the achievement of this study, survey methods, material oxide analysis, as well as kiln firings have been used. The results established the possibility of using existing glaze software in Nigeria so as to derive new recipes from old ones by using local material analyses database. The study indicates that with recent technological solutions, local raw materials can be properly identified and maximally utilized for a nation’s industrial development and sustainable economic growth.
Experimental Study of PTFE Powder Size Impact to Mg/PTFE Pyrotechnic Composition
Authors: Chen Xin , Zhao Jun , Pan Gong Pei , Lv Hui Ping
Published: February 2012

To discover the polytetrafluoroethylene (PTFE) powder size impact to Mg/PTFE pyrotechnic composition, hot compatibility of various particle sizes of PTFE powder with spherical superfine Mg powder was studied. Safety performance of Mg/PTFE pyrotechnic composition was also researched by parameters of friction and impact sensitivity. Burning temperature and velocity were recorded and analysed. The result shows that the Mg/PTFE exothermic temperature peak floats =0.8~2.2°C, apparent activation energy alter ratio (AAEAR) =12.5%~17.8%, ignition probability due to friction sensitivity =0.32~0.48 and to impact sensitivity =0. It indicates that PTFE powder size will not inflect the safety of Mg/PTFE composition, which burns more stable with PTFE size great than 400μm. Once mass combustion velocity 2.09~3.87 g•cm-2•s-1 and linearcombustion velocity 5.02~8.13 mm•s-1, the combustion velocity will increase much by following with PTFE particle sizes decrease.
La and/or Y Doped TiO2: Facile Synthesis and Enhanced Photocatalysis
Authors: Gao Hong Tao , Liu Wen Chao
Published: February 2012

Nanocrystalline samples of titanium dioxide (TiO2) monodoped or co-doped with La and Y were prepared by a facile method, using Ti(OC4H9)4 as the precursor. All products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and UV-visible diffuse reflectance spectra (DRS), respectively. Photocatalytic activities of the products were assessed by the photocatalytic decomposition of methyl orange (MO). Both of undoped TiO2 and doped-TiO2 samples exclusively consist of primary anatase crystallites, which further form spherical aggregates with diameters ranging from 14 to 21 nm. The photocatalytic performances of rare earth (RE) element co-doped samples were much higher than that of single doped and pure TiO2 under UV-visible-light irradiation. It indicated that a strong La-Y synergistic interaction appeared to play a decisive role in driving the excellent photocatalytic performance of LYT.
A Study of the Effect of the Inertia Force of the Vanes on the Performance of the Hydraulic Vane Pump with Hypertrochoid Curve in the Inner Surface of its Stator
Authors: Ebrahimi M. , Jazayeri Seyed Ali
Published: February 2012

Performance of a fixed displacement hydraulic balance vane pump, theoretically and practically was studied by application of the hypertrochoid curve in the inner surface of its stator. In addition to improving a sealing action between pressure and suction sides of the pump, one of the important characteristics of the hypertrochoid profile is improving of the inertial reaction of the vanes in each position where these vanes have a radial movement. Then it causes a smooth sliding motion of the vanes, and hence, a higher performance of the pump while attaining a longer life of it because of decreasing vane- tip and inner surface of stator wear and decreasing of vibration, noise and high stresses.
Comparison Study of the Geomagnetically Induced Current Level of Power Grid in Different Latitude
Authors: Yang Fan , Liu Lian Guang , Li Qi , Yang Dong Mei
Published: February 2012

Geomagnetically induced current (GIC) relates to factors such as magnetic amplitude, geotecture and structure of power grid. On the basis of geotecture, according to the geomagnetic storm data of Dec 2006, employing the plan wave method, this paper finish the calculation of GIC level of 2012 Beijing planning power gird, and compare the result to the measure data of Shanghe substation, in Yanghuai transmission system. The comparison shows that power grid is much more affected by geotecture, direction and length of transmission line, grid topology and electrical parameters in mid-low latitude area
Damage Patterns of the Hexagonal Aluminum Honeycomb Sandwich Plate Subjected to Fragment Impact
Authors: Wang Tao , Li Fang , Yu Wen Li , Wang Jin Tao , Wang Tuo
Published: February 2012

In this paper, the damage patterns of the hexagonal aluminum honeycomb sandwich plate subjected to normal and oblique impact by spherical, cylindrical and cubic fragments at different velocities are simulated using LS-DYNA code. The damage patterns of the sandwich plate and the energy loss ratio of fragment are acquired. In normal and oblique impact for different shapes of the fragment, the damage patterns of the sandwich plate include the plastic deformation, the fracture and the perforation of the face sheet and the tearing of the core or the combination of them. The curve of energy loss ratio waves with the velocity of fragment. And the peak point at the curve of energy loss ratio versus the velocity of fragment denotes the limit velocity of fragment. Furthermore, the energy loss ratios of fragments in oblique impact at the velocity of 500 m•s-1 with the angle of impact of 5°, 10°, 15° and 20° are obtained. The results denote that a fragment with large ratio of length to diameter is easy to perforate the sandwich plate both in normal and oblique impact.
Oxide Layer Modification of Mg-Al Alloy Coated by Plasma Electrolytic Oxidation Using Zirconia Particles
Authors: Choi D.Y. , Hwang J. , Lee K.M. , Shin K.R. , Ko Young Gun , Shin D.H.
Published: February 2012

The paper reported the effect of zirconia incorporation on the oxide layer modification of the valve metal such as magnesium coated by plasma electrolytic oxidation (PEO). To incorporate zirconia particles into the oxide layer, PEO coatings were carried out under AC condition in electrolytes containing zirconia powder. After PEO coatings, structure observation revealed that a number of zirconia particles were distributed uniformly throughout the oxide layer while the size and distribution of pores remained unchanged as compared to the results coated by PEO without zirconia. It was found that fine zirconia particles incorporated into the oxide layers played an important role in enhancing the anti-corrosion properties of bare metal.
A Method to Determine the Optimal Solids Content of TiO2 in DSSC Working Electrode
Authors: Tian Han Min , Chen Ai Hua , Yang Rui Xia , Duan Wen Feng , Tian Feng Lan
Published: February 2012

The way to determine the optimal solids content of TiO2 in DSSC working electrode was discussed. As a mathematical proof of the optimal conclusion extracting from the complex working mechanism of DSSCs and accidental factors, the equivalent circuit parameters of each curve are estimated corresponds to the equivalent circuit method first. And then, the trends in each parameter are analyzed. According to these trends, the optimal solids content of TiO2 are optimal identified
Effect of Rolling on Microstructure and Wear Behavior of Hot Rolled Al6061-Beryl Composites
Authors: Reddappa H.N. , Suresh K.R. , Niranjan H.B. , Satyanarayana K.G.
Published: February 2012

The present paper deals with the study of microstructure and wear characteristics of hot rolled beryl reinforced aluminium metal matrix composites (AMMCs). Al6061-beryl composites with 2, 6 and 10% of beryl were made using stir casting technique. The optical microstructure reveals the homogeneous dispersion of beryl particles in the matrix. The worn surfaces have been observed under SEM to understand the mechanism of wear. Hot rolled composites at 4500C possess higher hardness and lower specific wear rates under all loads and sliding distance studied in this investigation, when compared with cast composites.
Effect of Surface Treatment on Interfacial and Properties of Water Hyacinth Fiber Reinforced Poly(Lactic Acid) Composites
Authors: Buasri Achanai , Chaiyut Nattawut , Petsungwan Teerut , Boonyuen Yutthakarn , Moonmanee Sansana
Published: February 2012

Surface treatment of water hyacinth fiber (WHF) was investigated as a mean of improving interfacial of WHF reinforced poly (lactic acid) (PLA) composites. Fiber was treated with sodium hydroxide 15% w/v at 85 °C for 3 h. The composite materials were processed using internal melt mixer and compression molding machine. The weight content of fibervaried from 5 to 25% w/w.The mechanical and thermal properties of pure PLA and composites were compared using universal testing machine, differential scanning calorimetry (DSC) and thermogravimetricanalysis (TGA).The best mechanical properties of composite were achieved at fiber mass content of 20% w/w in this study, which showed an increase oftensile modulus by 21.6% compared to those of pure PLA. The high tensile modulus but low elongation at break indicates that this material exhibits brittle behavior. The results of TGA andDSC experiments indicated that the addition of fiber enhanced the thermal stability of the composites and WHF can act as a nucleating agent for PLA crystallites. The morphology, evaluated by scanning electron microscopy (SEM), indicated that a uniform dispersion of fiber in the PLA matrix existed. Alkali treatment of fiber increased the interfacial bonding strength and the wettability of the fiber by PLA leading to the enhancement in mechanical properties of the composites.
Experimental Study of the Compressive Performance of Life Jacket Use Polyurethane Foam for Blast Wave Protection
Authors: Li Mao Hui , Bai Chun Hua , Shi Mei Wu , Wei Yan Peng , Zhou Hong , Shen Yu Hong
Published: February 2012

Underwater blast injury is a common war injury during combat around islands or fighting for beachhead, and is also ordinary in underwater engineering construction blast. Adding an extra underwater blast wave protection layer and Integration with life jacket is a reasonable protection measure. Four different low mass density closed cell polyurethane foams used in life jacket have been tested by quasi-static material testing machine, and the dynamic mechanical behavior at strain rates of 10-3～10-1s-1 has been analyzed. The yield strength has been tested with Split Hopkinson Pressure Bar. Experimental results show that the compressive performance of the polyurethane foam is sensitive to the strain rates. The polyurethane foams’ yield strength shows rising trend along with strain rates increase. Under the condition of the plateau yield strength below human’s allowable pressure, the energy absorption performance of the polyurethane foams has been analyzed and in contrast.
Fabrication and Mechanical Properties of ZrO2/Ni Functionally Graded Materials
Authors: El-Wazery M.S. , El-Desouky A.R. , Hamed O.A. , Mansour N.A. , Hassan A.A.
Published: February 2012

The microstructure and mechanical properties of ZrO2/Ni functionally graded materials (FGMs) fabricated by powder metallurgy technique were investigated experimentally. The relative density of non-graded composite and functionally graded materials (FGM) was also measured. Microscopic examination exhibits that the material composition and microstructure of the FGMs vary gradually. The distributions of mechanical properties in the FGMs are obtained from the mechanical testing of homogeneous composite samples with different volume fractions of Ni. The results show that the elastic modulus and the bending strength decreases with increasing the nickel content from 0 to 50 % Ni, this is mainly affected by the weakly bonded ceramic/metal interface. Also, it was found that the fracture toughness and the elastic modulus in the FGMs are higher than that of the all non-graded composite.
Ferroelectricity of PZT-Based Thin Films Doped with Mn and Nb
Authors: Zhang Tao , Ma Hong Wei , Liu Jie , Zhang Peng Li , Liu Ping
Published: February 2012

The ternary compound thin films doped with Mn and Nb, Pb(Mn1/3,Nb2/3)O3-PbZrO3- PbTiO3(PMnN-PZ-PT), with the same ratio of PZ/PT=52:48(PZT(52/48)) are fabricated on the heterostructure substrates of SrRuO3(SRO)/Pt(111)/Ti/SiO2/Si(100) by the radio frequency (RF) magnetron sputtering system, in which the quench method is used for the post heat treatments. The ternary compound films exhibit polycrystal phase combined with (001), (101) and (111) orientations with the 6% mole percent mixing ratio of PMnN, in which the (111) directions are the main orientations for non-mixed PZT(52/48) films and 6% mole percent PMnN mixing PZT(52/48) films(6%PMnN-94%PZT(52/48)), and so both of them are epitaxially grown on Silicon substrates with the (111) orientation. The ferroelectricities of the films are studied by the Sawyer Tower circuit, and the results show that the mixing of PMnN seriously improves the ferroelectricities of PZT(52/48), in which the 6% mixed PZT films own the rest polarization intensity , the saturation polarization intensity and the coercive electric-field intensity =139 kV/cm which are distinctly larger than the non-mixed PZT(52/48) films
Germanium Adsorption on SrTiO3 (001) 2×1 Surface: A Density Functional Theory Study
Authors: Wang Jun Jie , Lefebvre Isabelle
Published: February 2012

Integrating germanium on Si is one of the major challenges of epitaxial growth and presents important applicative interest. Recently, SrTiO3 was adopted as a buffer layer to accommodate the mismatch between Ge and Si. Germanium can take its bulk lattice parameter as soon as the growth begins without threading defects on SrTiO3 surface. However, the details of Ge adsorption on SrTiO3 surface are not clear. In present work, the electronic structures of Ge deposited on the SrTiO3 (001) 2×1 Double Layer (DL) TiO2 surfaces were investigated by means of density functional theory calculations. Several stable adsorption sites are identified. It is found that the germanium adsorption shows site selectivity and causes noticeable surface distortion. The charge transfer from germanium atom to surface contributes to the formation of strong Ge-O bondings and surface metallization.
Nucleation and Growth of Cr7C3 of Brazing Diamond with Ni-Cr Alloy in Protective Atmosphere Furnace
Authors: Lu Jin Bin , Meng Pu , Zhao Bin , Liu Jian Jun
Published: February 2012

Mono-crystal diamond was brazed with Ni-Cr alloy in protective atmosphere furnace, SEM and XRD were used to analyze the carbides on the surface of diamond and the phases of diamond after brazing, respectively. The results show that the diamond brazed in protective atmosphere furnace can realize high strength connection; the diamond has clear edges and complete morphology after brazing. On the surface of diamond, the arrangement of Cr3C2 is regular, the growth direction of Cr3C2 has a certain orientation relationship with the (111) crystal plane of diamond, all the Cr7C3 nucleates and grows on the surface of Cr3C2, finally, the inner layer is regular arrangement Cr3C2 and the external layer is Cr7C3.
Effects of Cu on Microstructure, Mechanical Properties and Damping Capacity of As-Cast Mg-3%Ni Alloy
Authors: Chen Shu Qun , Dong Xuan Pu , Xiong Xiao Qing , Ma Rong , Fan Zi Tian
Published: February 2012

The effects of Cu addition on microstructure, mechanical properties and damping capacity of Mg-3%Ni based alloy were investigated by using tensile tests, X-ray diffraction, scanning electron microscope and dynamic mechanical analyzer. The results show that Cu addition could reduce the size of -Mg dendrites and a new binary phase Mg2Cu can be identified, which mostly distributes among the inter-dendrites in the form of typical lamellar-like eutectic microstructure and improve the mechanical properties. In low strain amplitude, with the increase of Cu addition, the damping capacities of Cu contained alloys change little, while in high strain range, the internal friction values decrease gradually with the grain refinement and increasing content of eutectic phase.
Synthesis and Characterization of Polystyrene-Graphite Nanocomposites via Surface Raft-Mediated Polymerization
Authors: Etmimi Hussein M. , Sanderson Ronald D.
Published: February 2012

The synthesis of polystyrene/GO (PS-GO) nanocomposites using the reversible addition-fragmentation chain transfer (RAFT) mediated polymerization method is described. The GO was synthesized and immobilized with a RAFT agent to afford RAFT-functionalized GO nanosheets. The RAFT-immobilized GO was used for the synthesis of PS nanocomposites in a controlled manner using miniemulsion polymerization. The moelcular weight and dispersity of the PS in the nanocomposites depended on the amount of RAFT-grafted GO in the system, in accordance with the features of the RAFT-mediated polymerization. X-ray diffraction and transmission electron microscopy analyses revealed that the nanocomposites had exfoliated morphology, even at relatively high GO content. The thermal stability and mechanical properties of the PS-GO nanocomposites were better than those of the neat PS polymer. Furthermore, the mechanical properties of the nanocomposites were dependent on the RAFT grafted GO content.
Synthesis of FeC2O4-Graphene Composites and their Application in Removal Dyes
Authors: Wu Shui Sheng , Wang Ya Ming , Jia Qing Ming , Gu Li Li , Sun Yan Lin
Published: February 2012

A well-organized composite of graphene nanosheets decorated with FeC2O4 particles was synthesized through a simple chemical precipitation method. The FeC2O4 nanoparticles obtained were 100-150 nm in size and homogeneously anchored on graphene sheets as spacers to keep the neighboring sheets separated. The FeC2O4-graphene exhbited excellent performances in absorption propties and supercapacitor make potential uses as environment and energy storage materials in future.
Synthesis of Fullerene-Acid Conjugates
Authors: Zhang Jing , Yuan Li , Zhang Ya Dong
Published: February 2012

N-substituted 3,4-fullero pyrrolidine was synthesized according to 1,3-Dipolar cycloaddition of the azomethine ylide. Aspartic acid and glutamic acid with protected α-amino and α-carboxyl groups were reacted with the activated hydroxyl group of N-substituted 3,4-fullero pyrrolidine, respectively. The products were deprotected, affording two novel fullerene α-amino acids, fullerene aspartic acid and fullerene glutamic acid. Their chemical structures were characterized by MALAI-TOF-MS, UV-Vis, FT-IR and 1HNMR. Both fullerene amino acids with a free amino group and a free carboxyl group would have unique property and potential use in medicine and biology. A novel method has been developed to synthesize fullerene conjugate. Their unique chemical structures make them very interesting for their potential use in medicine and biology.
Investigation of Deposition Parameter Effects on Energy Bandgap of Silicon Thin Film Prepared by Plasma Enhanced Chemical Vapor Deposition via Factorial Experiment
Authors: Zhao Lei , Zhao Ben Ding , Yan Bao Jun , Diao Hong Wei , Wang Wen Jing
Published: February 2012

The energy bandgap (Eg) of silicon thin film prepared by plasma enhanced chemical vapor deposition (PECVD) is greatly dependent on the deposition conditions. Although the influence of some deposition parameters on Eg has been studied individually, it is still not clear which parameter plays the most important role. Here, a 5-factor 5-level factorial experiment was designed and carried out for the deposition parameters: the flow rate of SiH4, the flow rate of H2, the plasma power, the total gas pressure, and the substrate temperature. By making main effect analysis to the influences of such 5 factors on Eg, not only the influence of each deposition parameter was obtained, but also the most critical parameters were selected out. It was found that the gas flow rate of SiH4 and the total gas pressure played the most important roles on determining Eg of silicon thin film. That is to say, in order to obtain an expected Eg for Si thin film prepared by PECVD, much attention should be paid to optimize the two parameters. However, other parameters, including the H2 flow rate, the plasma power and the substrate temperature, can be set as default values according to the experience. Thus, the optimization workload can be reduced greatly.
Tap-Changer Sliding Gear Urgent Stop Device of Main Transformer Integrated with RTU
Authors: Zhang Xi Lin , Sun Zong Tao , Xu Shu Yang
Published: February 2012

The security risks of using tap-changer of main transformer in substation to adjust remote operation and automatic sequence operation were analyzed, the tap-changer slider gear urgent stop devices of main transformers integrated into RGT were designed and developed and the functions of the system, hardware construct and software system were discussed in this paper. The vigorously developing of smart grid construction and practice application of this device are shown that the method has the urgency and effectiveness
The Effect of N2 Gas Pressure during the Rapid Thermal Process on the Structural and Morphological Properties of Cigs Films
Authors: Zhu Xiao Long , Wang Yao Ming , Li Ai Min , Zhang Lei , Huang Fu Qiang
Published: February 2012

The effect of N2 gas pressure during the rapid thermal process (RTP) on the structural and morphological properties of CIGS films was investigated. The precursor was prepared by sputtering from a single quaternary CIGS target. XRD characterization demonstrated that there were two phase of CuIn0.7 Ga0.3 Se2 and Ga-rich CuInSubscript text1-xGaxSeSubscript text2 chalcopyrite structure in all of the selenized CIGS films. Too low and too high N2 gas pressure induced compact but small grain-size morphologies due to the insufficient Se supply. Furthermore, all of the samples exhibited delaminated cross-sectional morphologies. Finally, Photovoltaic devices prepared from absorbers selenized under 4 Torr N2 gas pressure resulted in efficiency of 4.8%.
The Finite Element Simulation of Lamb Wave Propagation in a Cracked Structure with Coupled Filed Elements
Authors: Tashi Samaneh , Abedian Ali , Khajehtourian Romik
Published: February 2012

Crack detection by Piezoelectric Wafer Active Sensors (PWAS) is one of the emerging methods of Non-destructive Evaluation (NDE). These sensors can assess the health state of the structure in far filed through the analyzing the high frequency Lamb wave propagation. As PWAS is the essential part of this method, simulation and modeling of these sensors and their interaction with the host structure, strongly affect the accuracy of results. In this study, unlike the previous works, in which some certain areas of the host structure were considered as a sensor and actuator, the direct simulation of electro-mechanical interaction of the PWAS and the host structure is modeled among modeling the PWAS with a FEM coupled-field element. After verification of the FEM analysis with theoretical group velocity of S0 mode, capability of the S0 mode in crack detection was examined. Different length and angles of the crack in an aluminum plate modeled. The crack growth effect was defined among a damage index by using the strain energy magnitude that received by sensor localized behind the crack. The result showed that transmitted energy from the cracks decreases as the crack length increases. In addition, as the angle crack to the sensor increases, the ability of sensor to crack detection will increase.
Development of an Efficient Haptic System for Tooth Processing
Authors: Sofronia Raluca Elena , Davidescu Arjana , Savii George Gustav
Published: February 2012

This paper focuses upon the research and development of a method for modeling human teeth. By the use of virtual reality and haptics technology an application was created, that allows dentists to prepare their next procedures or students to learn dental skills by visualizing a three-dimensional virtual human tooth and feeling real tactile sensations while touching or deforming the surface of the tooth.
Estimation and Optimization Cutting Conditions of Surface Roughness in Hard Turning Using Taguchi Approach and Artificial Neural Network
Authors: Abdullah Asaad A. , Naeem Usama J. , Xiong Cai Hua
Published: February 2012

One of the most important requirements of part manufacturing is the surface quality. This is so because the most important part is meeting the specific requirements of customers. The surface roughness is a leading indicator of the quality of the machined surface Parts. In the present work in an experimental study to achieve by application of Taguchi method to investigate the effect of three parameters, which known as cutting speeds of (45, 90, and 135 m/min), feed rate of (0.1, 0.2, and 0.3 mm/rev), and cut depth of (0.05, 0.1, and 0.15 mm) on performance measure of surface roughness (Ra). Thus to determine the optimal levels and to analyze the cutting parameter’s effect on the surface finish values by employing different method of Orthogonal array, S/N ratio, analysis of variance (ANOVA). During our work two models for prediction have been used. The first one is known as the method of regression analysis, and the second is the method of Adaptive - Neural Network (ANN) relying on practical results. The achieved results show that the estimation and prediction ability of neural networks is better than the regression analysis. Experimental results confirmed with optimal levels of the machining parameters which are clarified by using Taguchi optimization method. Also, the indicated results of the Taguchi’s method show its ability to improve the process.
Regarding the Optimization of Measurement Systems for Grinding Forces in Case of High Speed Industrial Robots
Authors: Popescu Daniel , Buzatu Stefan , Gavrila Raluca , Popescu Marian
Published: February 2012

The paper presents two measurement systems for the dynamic components of the grinding forces in case of robots that perform finishing operations. The optimization of the measurement system is performed at the force measurement captor level using a special structure elastic element within the digital command robot driving system.
Solving Load Phase Balancing Problem in LV Distribution Networks by Chaotic Simulated Annealing
Authors: Fei Chun Guo
Published: February 2012

Phase balancing problem is to make a feeder system balanced in terms of phases in low voltage (LV) distribution networks. In this paper, we investigate the use of chaotic simulated annealing (CSA) for realize phase balancing in the low voltage circuit of the distribution network. The network energy function of the CSA is constructed for objective function that defined the load balancing problem. The CSA is applied to solve the problem when load is represented in terms of current flow at the connection points. The results obtained using CSA are compared with those from a heuristic algorithm. Simulations results show that the CSA is very effective and outperforms the heuristic algorithm in terms of the maximum difference of the phase currents
Experimental Investigation of the Volatilization of Asphalts under Different Conditions
Authors: Yu Man , Wu Shao Peng , Chen Mei Zhu
Published: February 2012

To study the possibilities of volatilization in the asphalt pavement during service process, this paper presented an experimental investigation in the laboratory-based environment by simulating the circumstances of Infrared (IR) and Ultraviolet Radiation (UV). The Vacuum (Va) condition was also conducted to discuss the possibilities of volatilization in the asphalts. The changes of asphalt mass, chemical compositions and viscosity were conducted to analyze the experimental results. All the results on the circumstance of Va, that the decrement of asphalt mass, the decrement of light components and the increment of VI values, indicated that there may exist the volatilization in the asphalt. Different trends between IR and UV with asphalts demonstrate that the volatilization is affected by asphalt species and environmental conditions. In addition, ultraviolet radiation may take a vital role on the volatilization of asphalt.
Synthesis of Barium Titanate Nanoparticles from Decomposition of Barium Titanyl Oxalate Tetrahydrate with Aid of Supercritical Water
Authors: Huang Jin Tao , Imura Tomoya , Sakamoto Norimasa
Published: February 2012

A novel process of BaTiO3 manufacture was conducted by using supercritical water. Preparation of BaTiO3 nanoparticles was investigated from decomposition of BaTiO(C2O4)2•4H2O (BTOT) with aid of supercritical water for the first time. When BTOT was exposed to supercritical water around 673 K and 30 MPa, it decomposed quickly in 5-22 seconds. The products formed strongly reply on environmental conditions. BaCO3 and TiO2 were always observed as the products in the absence of alkaline additives. BaTiO3 nanoparticles with specific surface area as high as 12~14 m2/g were able to be obtained under strong alkaline conditions, such as NaOH/COSubscript text2=2/1. It was found that environment of supercritical water was better than sub-critical conditions to obtain high quality BaTiO3 particles with fewer defects. Employment of supercritical water significantly reduced the reaction time and temperature compared to other BaTiO3 manufacture processes utilizing BTOT as precursor.
TiO2 Nanowires/Nanobelts Originating from Anodically Grown Nanotube Arrays
Authors: Tao Hai Jun , Tao Jie , Wang Tao , Bao Zuo Guo
Published: February 2012

TiO2 nanotube arrays have aroused great interest because of their enormous application in areas such as gas sensor, catalysts, biological materials, and solar cells. In this report, TiO2 nanowires/nanobelts originating from TiO2 nanotube arrays are fabricated by simple anodization of Ti foils in ethylene glycol (EG) containing 0.25wt% NH4F. From the field emission scanning electron microscopy (FE-SEM) it is observed that the morphology of the special structure is influenced by anodization voltage, water content and anodization time. In these factors, small amount of water plays a very important role in making the special nanostructure. Moreover, a possible mechanism that showed a relationship between the formation of the special structure and electric field directed chemical etch is proposed.
Investigation the Adsorption of Heavy Oil from Solution by Low-Cost Material
Authors: Al-Sultani Kadhim F.
Published: February 2012

Over the last decades, there has been increasing global concern over the public health impacts attributed to environmental pollution. Natural materials that are available in large quantities or certain waste from agricultural operations may have the potential to be used as low cost adsorbent ,widely available and are environmentally friendly after using them. Thus, rice husk RH, a commonly available waste in Iraq. RH and activated rice husk ARH (pretreated by 13M H2SO4 with 0.5 NaOH and thermally treated at573k) have been studied as sorbents for heavy oil cleanup operations in the aqueous environment (water pumped from brooks to sedimentation unit). Batch adsorption experiments were performed as a function of pH (2-10) , adsorbent dose(0.25-1g ), initial concentration (1-20g/100ml water) , agitation time (15-75min) and different temperature(298-338K),with100rpm.The maximum removal took place in the pH range of 8, adsorbent dose 1g ,initial concentration 20g/100ml water , agitation time 45 min and temperature 338k . The sorption data obtained from studies at optimized conditions have been subject to Freundlich and Langmuir isotherm studies .The data fits well to both the Freundlich and Langmuir isotherm models indicating favorable and monolayer adsorption .X-ray diffraction analysis ,which indicates that the RH and ARH mainly consist of amorphous materials .The adsorbents were characterized using FTIR . It was found that the pretreatment of rice husk increase the specific surface area and changed the functional groups , therefore leads to increase the capacity of adsorption.
Low Cycle Fatigue Behaviour of Al-Mg-Si Alloy AA6061 Processed by Equal Channel Angular Pressing
Authors: Venkatesh C.V. , Ganesh Sundara Raman S. , Uday Chakkingal
Published: February 2012

The low cycle fatigue (LCF) behaviour of aluminium-magnesium-silicon alloy AA6061 processed by equal channel angular pressing (ECAP) was studied. Solutionized specimens of the alloy were subjected to one, two and three passes of ECAP at room temperature using route Bc. Compared to the values of the solutionized material an overall increase in yield strength and ultimate tensile strength with decrease in % elongation is observed for the ECAP processed material. While the solutionized material exhibits cyclic hardening at all strain levels, the ECAP processed material shows different behaviour depending on the number of passes - stable response/cyclic softening/ softening followed by hardening. The ECAP processed material after three passes exhibit superior LCF lives at low strains presumably due to higher strength and large refinement of grains.