bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical Property and Thermal Physical Property of Microencapsulated Phase Change Material Slurry
Authors: Zhang Yan Lai
Published: October 2011

Microencapsulated phase change material (PCM) slurry is a kind of novel heat transfer fluid called latent functionally thermal fluid. Unlike conventional (sensible) materials, when the PCM reach the temperature at which they begin phase change (its melting point), they absorb large amounts of heat with little or no temperature change. Due to this, the heat transfer ability and energy transport ability can be obviously improved. Therefore, they have many potentially important applications in some fields such as energy storage, thermal conditioning of buildings, waste heat recovery, off peak power utilization, heat pump systems, space applications. In present study, the core materials are encapsulated with membrane of synthetic material. And the core materials are composed of several kinds of n-paraffin waxes (mainly nonadecane) and the membrane is a type of melamine resin. The range of diameter of the PCM particles is distributed from 0 μm to 4.5 μm, and its average diameter is 0.74 μm. The thickness of melamine resin is about 11nm. The melting point of the PCM is about 304K. Physical properties, such as density, diameter and its distribution of microencapsulated PCM slurry are investigated. Meanwhile, the thermal physical property, apparent specific heat, is determined by a Differential Scanning Calorimeter (DSC). Also, the influence of mass concentration has been discussed.
Hot Vacuum Tribological Properties of Chromium Nitride Coatings against Austenitic Stainless Steel Type AISI 316LN and Colmonoy
Authors: Devaraju A. , Elayaperumal A. , Venugopal S. , Kailas Satish V. , Alphonsa J.
Published: October 2011

The tribological properties of Plasma Nitrided (PN) rings were examined in high vacuum environment (1.6 x 10-4bar) at 25°C, 200°C and 400°C. The high vacuum based pin on disc tribometer was used for this investigation. The two different sliders namely austenitic stainless steel type AISI 316LN (316LN) pin and Nickel based alloy coated (Colmonoy) pin have been used. The tribological parameters such as friction coefficient, wear mechanism and wear rate have been evaluated. The PN 316LN rings exhibits excellent wear resistance against 316 LN pin and Colmonoy pin at all temperatures. However, the PN 316LN ring vs Colmonoy pin pair shows better wear resistance than PN 316LN ring vs 316 LN pin pair. Whereas the untreated 316 LN ring vs 316 LN pin pair exhibits the combination strong adhesion and plastic deformation wear mechanism.
Investigating the Effects of Varying Proportions of Waxes in Wax Mix on Surface Roughness and Optimization by Taguchi Method
Authors: Katiyar Jitendra Kumar , Yadav Nikhil , Singh Nitu , Pal Vijay Kumar
Published: October 2011

In the present work, an attempt has been made to produce a wax blend which could offer a better surface finish. Experiments were conducted with different types of waxes namely paraffin wax, bees wax, montan wax, carnabua wax and ceresin wax by varying their proportions. In each case the surface roughness of wax pattern was determined. The experimental data obtained were used to optimize the quantity of the waxes to form a blend having minimum surface roughness. The effect of varying proportions of the aforesaid waxes on the surface roughness of the wax blends was investigated. Taguchi method was used to optimize the required composition of the waxes. Taguchi method has successfully suggested the required proportions of the aforesaid waxes for the blend which could offer the minimum surface roughness.
Comparison of Hybrid Rapid Mouldings for Zinc Alloy Castings
Authors: Singh Rupinder
Published: October 2011

In this work comparison of hybrid rapid moulds (prepared with three dimensional printing shells supported with dry, green and molasses sand) have been made for techno-economic analysis, for zinc (Zn) alloy shell casting. The comparison has been made on the basis of mechanical properties and dimensional accuracy. Time-temperature curves have been drawn to understand solidification of molten Zn alloy in hybrid moulds of different thicknesses. The results of study suggest that it is feasible to reduce shell wall thickness of hybrid mould cavity from recommended 12mm to 1mm. All castings prepared are consistent with the permissible range of IT grades and are acceptable as per ISO standard UNI EN 20286-1 (1995). Further green sand based hybrid prototypes at 3mm shell wall thickness, shows better dimensional accuracy and mechanical properties.
The Effects of Calcium Excess, Water Amount and Mixing Time on the Injectability of Calcium Phosphate Filling Materials
Authors: Alqap A.S.F. , Sopyan Iis , Husni M. , Athirah N.
Published: October 2011

Variation of calcium excess, water content and mixing time have been taken into the parameters of the injection test of calcium phosphate paste synthesized via low temperature hydrothermal method. The result indicated that all the parameters are very prominent to influence the material injectability possible to be fully injected out the syringe. Strict control of paste synthesizing parameters has successfully overcome poor injectability of the material.
The Critical Current of the Superconductor Having an Array of Hole with de Gennes Boundary Condition
Authors: Harsojo Harsojo
Published: October 2011

We determine the critical current density of the superconductor having an array of hole exposed under electric current and under a perpendicular magnetic field. It is assumed that the inner holes sides are accounted in the de Gennes boundary condition while outer edge is in contact with vacuum. The critical current calculation was done after solving time dependent Ginzburg-Landau equation and evaluating the electric voltage. The enhancement factor of the critical currents due to the boundary condition is discussed.
Super Accelerated Flow in Diverging Conical Pipes
Authors: Gutierrez G.J. , Villa A. López , Torres A. , Peralta S. , Vargas C. A.
Published: October 2011

The motion of the upper free surface of a liquid column released from rest in a vertical, conical container is analyzed theoretically and experimentally. An inviscid, one-dimensional model, for a slightly expanding pipe's radius, describes how the recently reported super free fall of liquids occurs in liquids of very low viscosity. Experiments agree with the theoretical results.
Enhanced Sensitivity of Microcantilever Surface Stress Sensor
Authors: Heydari P. , Shokuhfar Ali
Published: October 2011

In this paper a novel L-shape microcantilever that is more sensitive in compare of traditional rectangular microcantilever is proposed. In traditional microcantilever surface stress sensor a slight momentum is induced by distributed area stress lead to a slight deformation. In contrast, the proposed sensor substitution the slight momentum with concentrated point force in lateral direction on the tip of the microcantilever. This lead to, mechanically amplifies of the influence of area stress and more displacement. In addition, it has been theoretically proved that proposed microcantilever sensor with same lateral area in compare with traditional microcantilever surface stress sensor can be 2 to 100 orders more sensitive. The proposed L-shape microcantilever configuration of sensor could be incorporated in most of the microfabrication processes. However in this paper we use a low cost fabrication method based on polymeric microcantilever with metal piezoresistive detection.
Comparison of Different Bearing Couples of Hip Resurfacing Prostheses: A Finite Element Study
Authors: Çilingir Ahmet Ç. , Uçar Vahdet , Çallı Ismail
Published: October 2011

Friction couples are still unsolved problems, and the optimal choice depends on the patient’s age, level of activity and functional requirements. Finite element (FE) study was performed to investigate the contact mechanics and stress/strain distribution of hip resurfacing for different bearing couples. Ceramic-ceramic or ceramic-metal bearing couples reduce adhesive wear that also reduces osteolysis. There is, however, a problem of stem fracture risk of femoral component because of brittle alumina. Stress shielding within the bone tissue, was also found to be the major concern regarding the use of ceramic as an alternative to metallic resurfacing prostheses. All these bearing couples require to be supported by clinical studies to provide surgeons an appropriate choice of bearing materials.
Experimental Study on Combustion and Pollution Characteristic of Gas Oil and Biodiesel
Authors: Bashirnezhad K. , Hosseini S. Baghdar , Moghiman A.R. , Moghiman Mohammad
Published: October 2011

The industrial development of the world has increased the demand of petroleum-based fuels sharply which are obtained from limited in certain regions of the world. As a result, most of the countries have to face energy crisis. Hence, it is necessary to look for alternative fuels which can be produced from resources available locally within the country. Lots of researches on biofuels such as alcohol, biodiesel and vegetable oils have been conducted to accelerate the development of a next generation of clean, green biofuels that can compete with fossil fuels in economics and well as performance. Biodiesel is a renewable, domestically produced fuel that has been shown to reduce particulate, hydrocarbon, and carbon monoxide emissions from combustion. In the present study an experimental investigation on emission characteristic of a liquid burner system operating on several percentage of biodiesel and gas oil is carried out. Samples of exhaust gas are analysed with Testo 350 Xl. The results show that biodiesel can lower some pollutant such as CO, CO2 and particulate matter emissions while NOx emission would increase in comparison with gas oil. They also demonstrate growth in temperature of exhaust gas with increase of percentage of biodiesel from B0 to B40. The results indicate there may be benefits to using biodiesel in industrial processes.
Synthesis and Formation Mechanism of Solid and Hollow Alumina Microspheres at the Water-Oil Interface
Authors: Zhang Liang Miao , Han Ling , Zhang Hao , Shen Shan Shan , Lu Wen Cong
Published: October 2011

NH4Al (OH) 2CO3 (AACH) hollow spheres and solid spheres were successfully synthesized with water in oil in water (W/O/W) emulsion, applying the liquid-to-liquid-phase boundary of the micellar system as a template. During the facile procedure, no high pressure, high temperature, or other complex reaction conditions were required. Transmission electric microscope (TEM) images showed that all the hollow structural products have a good spherical morphology with an average diameter of 1 μm. The as-synthesized spheres had large diameters and thin shells of about 30 nm composed of numerous small nanocrystals. In addition, the AACH product can be calcined into Al2O3 without changing its shape.
Research on Inverse Extrusion Process of High-Tin Wear-Resisting Cu-Sn-Pb-Ni Alloy
Authors: Zhou Yan Jun , Song Ke Xing , Cai Yuan Jing , Wei Jun , Zhai Guan Feng , Zhang Yan Min , Zhao Pei Feng
Published: October 2011

Based on the high-tin wear-resisting Cu-Sn-Pb-Ni Alloy which the tin content is 9~11%, the inverse extrusion plastic forming experiments in the temperature range of 800°C~ 950°C were completed. The density and hardness of alloy castings were tested and the casting mircostructure was analyzed after plastic forming, which compared with the properties and microstructures of alloy casting prepared by traditional melt casting. The results show that the density and hardness of Cu-Sn-Pb-Ni alloy casting prepared by traditional melt casting are 8.8893g/cm3 and 116HB separately, the density and hardness has increased after inverse extrusion plastic forming in different tempretures, especially at 900°C the density and hardness reached the maximum values, 9.0409g/cm3 and 139HB respectively. Compared with the as-cast microstructure is mainly obvious dendrite structure which are α solid solution and eutectoid（α+δ）, The as-extruded of alloy exhibit better propertief and its grain are obviously refined and densed. Within the range of experiments, the best inverse extrusion plastic forming tempreture is at 900°C.
Effect of Iron (III)-Doping on the Photocatalytic Activity of Titanium Dioxide Catalysts for Methylene Blue Degradation
Authors: Lin Wen Churng , Liu Rui , Yang Wein Duo
Published: October 2011

Iron-doped TiO2 photocatalyst powders were prepared by the sol–gel method and characterized by Brunauer–Emmett–Teller (BET)-specific surface area, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Ultraviolet–Visible (UV-Vis) spectroscopy. Fe3+ doping in the TiO2 decreases the crystal grain size, increases the specific surface areas of powders, extends the absorption to visible light regions (400~500 nm), and lowers the photocatalytic activity for methylene blue (MB) degradation under UV irradiation. The photocatalytic degradation of MB in water was investigated as a function of the Fe3+ content in TiO2. It was found that under the irradiation of visible light, a small amount of Fe3+ dopant in TiO22 powders could obviously enhance the photocatalytic activity. When the Fe3+ content was in the range of 0.03–0.1 mol%, the photocatalytic activity of the samples was higher than that of undoped TiO2. Appropriate content of Fe-doping is an effective means to improve the photocatalytic activity of TiO2 for MB degradation under visible light irradiation.
Preparation and Contrast of Transparent Conductive TiO2/Ag/ZnS Film by Magnetron Sputtering and Evaporation Coating Deposition
Authors: Chen Hai Feng , Zhu Jian Hua , Chen Long Jie , Qian Miao Gen
Published: October 2011

In this paper, TiO2/Ag/TiO2 and TiO2/Ag/ZnS films were prepared by evaporation coating (EC) and magnetron sputtering (MS). To test the resistance and light transmission rate to characterize the coating effect, both the size of indirect resistance that the relative thickness of the situation. By comparing the single magnetron sputtering and evaporation coating fabricated by the two transparent conductive oxide films (TCO) material conductivity and light transmission properties, determine a reasonable process. Firstly, the first layer is TiO2 film by magnetron sputtering, and then coating Ag film and ZnS film plated by evaporation, the final form of TiO2/Ag/ZnS film, which haSubscript textd much higher transmittance than TiO2/Ag/TiO2 at the same resistancSubscript texte.
Modeling and Prediction of Creep Behavior of Polypropylene Packaging Belt
Authors: Xu Zhao Yang
Published: October 2011

The short term tensile creep behaviors of polypropylene (PP) packaging belt under different stresses levels were studied through tensile creep test. The four-element model was applied to simulate the creep behaviors of the PP packaging belt. The results show that four-element model can be used to simulate the short time creep of PP packaging belt. The tensile creep behaviors of PP packaging belt have obviously correlation to the stress levels. The instantaneous elastic coefficient, delayed elastic coefficient and glutinous coefficient in Maxell model show a decreasing tendency with the increase of stress level. Based on the time-temperature-stress equivalence principle and take 15% stress level as a reference, the creep compliance master curve of 15% stress level was constructed by horizontal shift of the creep compliance curve of other stress levels, which can predict the creep behavior of PP packaging belt at the 15% stress level.
Synthesis of Polymers Containing C-N Bond Using Pd-Catalyst
Authors: Shan Wen Wen , Zhu Fang Hua , Zhang Lin
Published: October 2011

Palladium catalysis cross-coupling reaction has been widely used and played an important role in medical, new material and other fields. In this paper, we take Pd2(dba)3 as catalyst and BINAP as ligand, formulate two poly(imino ketone)s (PIKs) by C-N Cross-coupling Polycondensation. The thermal property of PIKs were tested via thermogravimetric analysis (TGA), and the result showed that PIKs possessed high thermal decomposition temperature.
Effects of Ca on Mechanical Properties of Mg-6Zn-3Al Alloy
Authors: Li Quan An , Zhang Qing , Wang Yao Gui , Zhou Wei
Published: October 2011

The effects of Ca on the mechanical properties of Mg-6Zn-3Al alloy have been investigated. The results show that the addition of 1wt.% Ca can refine the grains, improve the microstructure, cause the formation of Al2Ca phase, and enhance the mechanical properties of Mg-6Zn-3Al alloy at room temperature and 150°C.
Study on the Microstructures and Wear Resistance of ZG30 Steel Surface Layer
Authors: Wang Ai Qin , Xie Jing Pei , Wang Wen Yan , Li Ji Wen
Published: October 2011

The WC and high-Cr cast iron layer were obtained on the surface of ZG30 steel by infiltration casting process, so the surface alloying of ZG30 steel was realized. The microstructures and phase structures of penetrating layer were studied by SEM, TEM, XRD, the hardness of the test material was measured by the hardness tester, and the wear resistance was tested by wear test machine. The mechanism of alloyed layer forming was analyzed. The effects of WC contents on the wear resistance of alloyed layer were studied. The results show that the layer is dense, without pores, slag and other defects, the thickness of the alloyed layer is about 6-7mm, and the penetrating layer and matrix are metallurgical bonding. The maximum hardness of the alloyed layer surface is 820Hv. When the content of WC is 15%, the penetrating layer has the highest wear resistance which is 18.8 times as high as the matrix.
Study on Strength Reduction Method Based on Hinge Joint Concrete Block Slope Stability
Authors: Zhang Yu Qing , Mi Yong Ning , Zhao Lin , Sun Rong Hua , Zhang Ying
Published: October 2011

Slope protection is to ensure the safety of River embankment important infrastructure projects.the actual project--the Bird Island Park in Shenyang, an example of hinge joint concrete block revetment,Using the FLAC analysis software, and the finite difference method percolation theory to calculate the 29° slope angle the role of a 45kg block under the action of Slope stability safety factor,Further discussed in detail the different blocks of different slope and slope stability on the role of the quality factor of safety effects, and draw the best slope and block quality portfolio, which is the slope of reference designs and applications.
Study on State Recognition of ASCE Benchmark FEM Based on Lyapunov Exponent Spectrum Entropy
Authors: Yang Jian Xi , Zhou Jian Ting , Han Feng Qing
Published: October 2011

In this paper, ASCE Benchmark Finite Element Model was established and analyzed. Also, The MLI(the max Lyapunov Index) and LISE(Lyapunov Index Spectrum Entropy) has made to recognize state of the FEM using non-linear theory and chaos time sequence. The results show that MLI and LISE are sensitive with the structure state, and the structure system is chaotic.
Design and Optimization of the Deposition Baffle Shape for Magnetron Sputtering
Authors: Chen Hai Feng , Zhu Jian Hua , Sun Ye Zhen , Qian Miao Gen
Published: October 2011

This resistance by tests to simulate the sputtering thickness distribution and the relative value, we try to reduce the degree of uneven thickness by designing baffle shape for the coating equipment. In view of the structural characteristics of the device and the deposition of complex principles, theory and practice there are still some gaps, according to the measured data (resistance value) to be constantly revised to optimize and baffle design to achieve greater uniformity of product thickness. For example, to meet the resistivity greater than or equal 9.6 Ω and the average transmittance above 80%, TiO2/Ag/TiO2film fully met the requirements of practical applications by applying improved baffle. Concluding remarks are stated at the end of the abstract text. Based on the use of a simple baffle design and improvement, we had achieved good results in mastering the sputtering parameters.
Superplastic Behavior and Constitutive Equation of AZ31B Magnesium Alloy
Authors: Chen Fu Xiao , Chen Xiang Zhen , Sun Fu Tao
Published: October 2011

To study the superplasticity of AZ31B magnesium alloy, hot compression tests were performed in forming temperature range from 280°C to 440°C and strain rate range from 0.001s-1 to 0.1s-1. The influence of deformation strain rate and forming temperature on flow stress was also analyzed detailed. It was shown that the flow stress of AZ31B was very sensitive to formpng temperature and stain rate, and was decreased with deformation temperature increasing, and was increased with stain rate increasing. However, no significant change of flow stress was observed at the temperature of 440°C and the strain rate below 0.01s-1. The activation energy of AZ31B in superplastic deformation was 141.6KJ•mol-1 and its constitutive equation was established also.
Numerical Study on the Relationship of the Axis Orientation of Deeply Buried Circular Tunnel and the Direction of Horizontal In Situ Stress
Authors: Wang Jun Qi
Published: October 2011

Deeply buried tunnels usually lie in high stress fields, whose horizontal stress which is not uniform is far larger than vertical stress, and their stability is dominated by the original in-situ stresses. With three-dimensional nonlinear finite element method, the axis orientation effects of tunnel on the displacement and stability of two types of surrounding rocks are studied systematically for one water diversion project. The tunnel lies in different original stress fields whose maximum horizontal principal stress is parallel with or perpendicular to the axis and lies in different kinds of rocks. The numerical analysis results show that the plastic zones develop in side wall of tunnel mostly when the horizontal maximum principal stress is parallel with the tunnel axis while the plastic zones distribute in the top and bottom of tunnel when the horizontal maximum principal stress is perpendicular to the tunnel axis. It is concluded that the principle of tunnel axis should be parallel with horizontal maximum principal stress regulated by the “specification for design of hydraulic tunnel” is not available for the stability of tunnel always.
Study on Corrosion Resistance of High-Entropy Alloys NiCoCrFeMnCuC in Medium Acid Liquid
Authors: Liu Ze , Zeng Jian Min , Zhan Hai Hong
Published: October 2011

High-entropy alloy of NiCoCrFeMnCuC were made by vacuum non-consumable arc furnace in the present work. The crystal structure of NiCoCrFeMnCuC was analyzed by XRD. The corrosion resistance of NiCoCrFeMnCuC in 10%HNO3-3%HF, 10%H2SO4, 5%HCl and 10%HF was investigated, respectively with weight loss experiment. The results show that main intermetallics of the alloy are CoCx, FeNi3 and Fe3Mn7. The NiCoCrFeMnCuC has simple crystal structures with face-centered cubic crystal structure FCC and Quartet and has excellent corrosion resistance in some medium acid liquids.
Effect of Microstructure on CTOD of Welded Joints for Offshore High-Strength Steel
Authors: Niu Li Na , Miao Zhang Mu , Ma Tao , Chen Gang
Published: October 2011

Based on the CTOD test, metallographic test is done. The effect of microstructure on CTOD of welded joints for offshore high-strength steel has been analyzed by SEM. The microstructure of different samples in a welding procedure and two different welding procedures are compared. From the microscopic point of view, the reasons why the toughness of the second group welded joints is better than the first group’s and why the toughness of the same group welded joints is different have been determined. And the main microstructure found in EQ70 steel welded joints is the ferrite, tempered sorbite and a small amount of pearlite. Besides some carbide particles are on the matrix of tempered sorbite. The material toughness with a small amount of acicular ferrite is better. Inclusions and pores also seriously affect the toughness of welded joints. Reducing the welding heat input appropriately can refine the grain of CGHAZ and improve toughness. But hardened microstructure may occur owing to too low welding heat input.
Effects of Process Conditions on Mechanics Properties of Micro-Foaming PP/GF Composites
Authors: Gong Wei , He Ying , Zhang Chun , Zhu Jian Hua , He Li
Published: October 2011

The microcellular foaming PP/GF composites was made under the condition of twice-open mold by using chemical foaming injection method, according to glass fiber reinforced mechanism, the effect rule of GF on mechanics properties was studied in microcellular foam PP composites. The results showed that tensile and impact strength of Micro-foam PP/GF composites by one-step method were higher than that of micro-foam PP/GF composites by two-step method, when the content of GF is 30%, the tensile and impact strength of micro-foam PP/GF composites by one-step method can reach 55.72MPa and 7.5kJ/m2respectively，one-step method can get higher strength and higher toughness micro-foam PP/GF composites.
The Numerical Study of Concrete Mesostructures’ Effect on Ballistic Responses in Penetration Problems
Authors: Xu Wei Fang , Huang Xi Cheng , Hao Zhi Ming , Wang Yang , Xia Yuan Ming , Yao Yong
Published: October 2011

In penetration problems, the heterogeneity of the concrete would affect the ballistic responses. The presented paper studied the influence by numerical method. During the analysis, the concrete was defined as “numerical concrete”, which was composed with different size aggregates randomly included in the mortar. In the numerical concrete, the ITZ (interfacial transition zone) was replaced with the connected strength (tensile strength and shear strength). Based on the validation of the mesh, the ballistic responses were studied. From the study, it was concluded that: the randomly-distributed aggregates affected the stress symmetry which changed the missile trace, which couldn’t be alternated by concrete in the homogeneous model, and that the residual velocity of the missile decreased with the increase of the connected strength of the interfaces.
Experimental Study on CFRP-Bonded Steel Plates with Thickness Reduction Using Underwater Epoxy
Authors: Chen Xiao , Kitane Yasuo , Itoh Yoshito
Published: October 2011

This paper presents a series of uniaxial loading tests on the thickness-reduced steel plates bonded with carbon fiber reinforced polymer (CFRP) strand sheets using underwater epoxy as adhesive. Four sets of material test are carried out on epoxy coupons at different curing times. Repaired performance of CFRP-bonded steel plates is investigated in terms of initial stiffness, yield strength, and failure mode of the specimens. Test results showed that the structural performance of CFRP-bonded steel plates does not reach the expected design level due to a slow curing process of epoxy adhesive in this study. The curing effects of epoxy adhesive on the repaired performance are discussed.
Evaluation of the Mechanical Properties of Copper Thin Film and Copper Bulk at the Nano-Scale by Nanoindenter
Authors: Huang Jen Ching , Weng Yung Jin
Published: October 2011

This study used the nanoindenter to perform indentation tests on copper bulk and nano copper film in order to discuss the mechanical properties of pure copper at the nano scale. This study tested 7 levels of load, ranging from 20 to 200 μN (load increment at 30 μN) for the indentation tests on copper bulk and nano copper film specimens. Results showed that the load was roughly proportional to the residual depth, in the case of flat nano copper film, while the relationship between the load and the residual depth was not significant in the case of unsmooth copper bulk. Moreover, the hardness of both the copper bulk and the nano copper film would increase along with increasing load, while the Er value change trends of both the copper bulk and the nano copper film specimens differed with increasing load.
Investigation on Mechanical Properties of Pulsed Nd:YAG Laser Welding on AISI 304 Stainless Steel to AISI 1008 Steel
Authors: Shamsudin Shazarel , Chee Yoon Phoon
Published: October 2011

Product with low cost, lightweight and enhanced mechanical properties were the main reasons welding dissimilar materials thrived by most of the industries. The laser welding technique which has high-energy density beam was found suitable of carrying this task. This paper attempts to investigate welding of AISI 304 stainless steel to AISI 1008 steel through Nd:YAG pulse laser method. The main objective of this study was to find out the weldability of these materials and investigate the mechanical properties of the welded butt joints. Peak power, pulse duration and weld speed combinations were carefully selected with the aims of producing weld with a good tensile strength, minimum heat affected zone (HAZ) and acceptable welding profile. Response surface methodology (RSM) approach was adopted as statistical design technique for tensile strength optimization. Statistical based mathematical model was developed to describe effects of each process parameters on the weld tensile strength and for response prediction within the parameter ranges. The microstructure of the weld and heat affected zones were observed via optical microscope. The results indicate the developed model can predict the response within ±9% of error from the actual values.
Rate-Dependent Behavior and Constitutive Model of Polycarbonate at Strain Rate from 10-5 to 103 S-1
Authors: Hu Wen Jun , Huang Xi Cheng , Zhang Fang Ju , Chen Cheng Jun
Published: October 2011

Uni-axial quasi-static tests at strain rates 10-5, 10-4, 10-3,10-2 and 10-1 s-1 and dynamic compressive tests at strain rates 1679, 2769,5000 and 8200 s-1 have been carried out to study the mechanical behavior for polycarbonate used in the avigation industry. The stress–strain curves of polycarbonate in the strain-rate range from 10-5 to 8200 s-1 have been obtained. The effects of the strain rate on yield phenomenon and rate-dependent mechanical behavior are discussed. A plastic flow law based on the DSGZ rate-temperature-dependent constitutive model was used to describe the mechanical behavior of polycarbonate in the strain-rate range from 10-5 to 103 s-1. The results at the six strain rates are in excellent agreement with the experimental data, which illustrates that the constitutive model can describe the mechanical behavior for polycarbonate at low and high strain rates perfectly.
Three-Dimensional Viscoelastic Interactions of a Center of Dilatation with a Penny-Shaped Interfacial Crack
Authors: Sun Yu Zhou , Bian Ya Dong , Zhang Zhong Guo
Published: October 2011

This paper presents a three-dimensional viscoelastic model to study the interactions of a penny-shaped interfacial crack and a center of dilatation in the infinite viscoelastic bimaterial, which can model the rock fracture subjected to stress and thermal dilatation during some engineering process. A distinct issue associated with the present work is the incorporation of viscoelastic behavior of bimaterial. The proposed problem is first transformed into the Laplace space, and the solution in the transform space is obtained by decomposing the original problem into two auxiliary problems: (I) a center of dilatation near a bimaterial interface (no crack); and (II) a penny-shaped interfacial crack subject to internal tractions that cancel out those induced in auxiliary problem (I). The mode I, II and III stress intensity factors (SIFs) in the time domain are obtained with the inverse Laplace transform.
The Reliability Analysis of Leaf Spring Based on PDS
Authors: Huang Hui Rong , Zhu Yi Jie , Guo Jia Yuan , Zhang Hao
Published: October 2011

Abstract: A model of leaf spring composed with ten spring laminations is established by the language of APDL. The model is loaded with pre-stress, static stress and Grade B Road stress, then the results is calculated. Finally, applying the PDS unit of ANSYS, the reliability of leaf spring is worked out. As an important hanging form in the vehicle, the leaf spring is widely used in auto, besides the reliability of a car mostly depends on it. So, it is necessary to deeply study its designing method and reliability[1,2].
Analysis on Long-Span Bridge Seismic Response in Multi-Dimensional and Multi-Point Mode
Authors: Zhang Cang Hai , Dai Jun Wu
Published: October 2011

The Seismic excitation mode has been the hot and difficult topic both in engineering and academic field. This paper mainly discussed the excitation direction and the combination of excitation direction of ground motion, comparatively analyzed seismic response in four excitation mode, which including the single-track one-point incentive, single-track multi-point incentive, much-track one-point incentive, and much-track multi-point incentive, with specific project examples of large-span continuous rigid frame bridge, and get the corresponding conclusions.
A Novel Method to Fabricate Silver Chloride Films
Authors: Hsueh Hui Chung , Chang Zue Chin , You Chang Ching , Lin C. B.
Published: October 2011

Abstract: This investigation develops a novel method for fabricating silver chloride films by the heterogeneous precipitation of sodium chloride from aqueous solution and supersaturated solid-state silver nitrate out of aqueous solution. The morphology of the bottom surface of the silver chloride film thus obtained comprises numerous porous stick structures. The top surface comprises equiaxed grains, and columnar grains are observed in the cross-section.
Fish Sound Frequency Domain Analysis and Acoustic Spread Distance Experiment Research
Authors: Hu Qing Song , Chen De Hui , Wang Wei Ding , Zhang Shou Yu
Published: October 2011

Fish biological sounds reflect abundant information of its living state. It is important to systematically conduct research on the fish acoustic features. This paper designs program code based on Fast Fourier Transform (FFT) to deal with the sounds in frequency domain. By applying the program to analyze the sounds of piranha, oyster toadfish etc., the feature of main frequency is obtained and the sound features of different fishes are compared. This paper further designs the sound detection experiment about the acoustic spread distance; analyzes the sound decibel value varying trend according to the result. The different features among the fishes illustrate the sound difference. Acoustic spread detection experiment provides the fish behavior control feasible distance in the taming system design.
Control Standard of Ground Surface Settlement Induced by Running Tunnel Construction in Beijing Subway
Authors: Zhang Cheng Ping , Li Li Min , Li He , Wang Jian Chen
Published: October 2011

Ground settlement, especially the ground surface settlement induced by subway tunneling is an important issue. However, there is no an agreed standard for controlling ground surface settlement during the subway construction at present. The control standard of ground surface settlement was studied using the methods of statistical analysis and numerical simulation based on the running tunnel in Beijing subway. According to the research results, a conclusion could be obtained that the ground surface settlement can be controlled within 40 mm using the general construction measures in Beijing subway running tunnel construction, and furthermore, the settlement of 40mm will not damage the existing nearby structures and utilities including neighboring buildings, bridges and pipelines, etc. So the control valve of 40 mm is rational, which can be adopted as the control standard of ground surface settlement induced by running tunnel construction in Beijing subway.
An Overview of Recent Research Works on the Forming of Thermoplastic Composite Sheets
Authors: Suresh Sugumar , Zhu Ke
Published: October 2011

Recently, the forming of thermoplastic composite (TPC) sheets has been receiving the attention of researchers. Woven fabric TPCs have been successfully utilized in automotive, aerospace and defense industries, due to their high formability and strength. Hence, to optimize the forming process, it is essential to understand the mechanical behavior of the woven fabric and accordingly, various appropriate numerical methods are developed. A reliable simulation tool for forming is needed to obtain the optimum processing parameters, in which parts can be formed without defects, such as wrinkles. This paper explores the experimental, numerical and theoretical works conducted by many researchers to investigate the formability of TPC sheets.
The Preparation Technique of Nanometer Molybdenum Trioxide by Hydrothermal Synthesis
Authors: Li Ji Wen , Ma Yan Hua , Gong Fang Fang , Zhang Guo Shang , Xu Liu Jie , Wei Shi Zhong
Published: October 2011

The technique of hydrothermal synthesis is used to prepare nanometer molybdenum trioxide through controlling the parameters such as the acidification condition, the reaction temperature, the reaction time and so on. The technique is under high temperature and high pressure by water as the solvent. Synthesized molybdenum trioxide powder is characterized by XRD, SEM, and HRTEM. The optimal reaction time is 40h, the optimum reaction temperature is 170°C, and the optimum pH value is 1.0. The results indicate that powder has an ultrafine particle size, high purity, and narrow size distribution, good fluidity, light agglomerate and is perfect in crystal.
Study of Superconductivity of Fe-Doping DyBa2Cu3-XFexO7-δ Systems Using Positron Experiment
Authors: Xue Yun Cai , Dai Hai Yang , Xue Ren Zhong , Shi Kai , Chen Zhen Ping , Li Tao , Chen Lei Ming
Published: October 2011

The effect of Fe doping on the structure, local electron density and electronic transport properties of DyBa2Cu3-XFexO7-δ(x = 0.00- 0.30) superconductors have been investigated by X-ray diffraction (XRD), positron annihilation and other experimental methods. XRD results indicate that the compound undergoes an Orthorhombic–Tetragonal (O-T) phase transition at about x = 0.10. The electrical transport measurements show that the superconductivity was strongly suppressed by Fe doping, and the superconducting transition temperature decreases with the increase of Fe doping content. The results of local electron density calculated using positron annihilation data show that the local electron density of the systems is strongly changed by the Fe doping, and the local electron density vary noticeably at the range of O-T phase transition. From the results of local electron density and the superconductivity, it can be found that the superconducting transition temperature decreases with decreasing the local electron density. These investigations reveal that the crystal phase transition and the local electron density could strongly affect the superconductivity in the Fe doped DyBa2Cu3-XFexO7-δsystems.
Experiment for Improving the Drum Strength of Agglomerate
Authors: Wang Li Li , Ke Hai Bin , Zhang Hao
Published: October 2011

In order to improve the agglomerate drum strength, through a series of experiments study on the alkalinity and Al2O3/SiO2 and carbon content to drum strength relations. The results show that the drum strength enhances gradually along with the alkalinity increasing;when the Al2O3/SiO2 reach 0.35 and the carbon content reach 4.0%,the drum strength achieve the best.
Study on Cold-Pressing Technology for Mixture of Iron Ore and Coal
Authors: Qin Jie , Liu Gong Guo , Long Fei Hu
Published: October 2011

Operation principle of high-pressure briquetter is introduced. According to the problems arised from real production in pilot named as comprehensive utilization of vanadium-titanium magnetite, countermeasures have been proposed to solve these problems. At the base of carrying out a series of reformations on the equipments and now the high-pressure briquetter can meet the requirements of industrial production.
Research on Mechanical Properties of Separation Concrete-Filled Steel Tubes Subjected to Eccentric Compression on Non-Separation Side
Authors: Liu Xia Ping , Sun Zhuo , Huang Hai Yun , Tang Shu , Tang Chun Hui
Published: October 2011

This document deals with the whole process compression model test on 12 short columns of separation concrete-filled steel tubes (CFST) which are subjected to eccentric compression on the non-separation side. The experimental parameters include the separation ratio and the eccentricity ratio. The results show that the separation ratio and the eccentricity ratio will influence CFST components’ mechanical properties which contain the relationship of load-strain amd load-deformation, that especially embodied in the nonlinear stage. When compressed on non-separation side, the confinement of steel tubes to core concrete will be continuously weakened and the ultimate load capacity of the components will be decreased obviously with both the separation ratio and the eccentricity ratio increasing gradually. But it less serious which compare with that compressed on separation side.
Behaviors of TiN Nanoparticles in Mn18Cr2 Steel
Authors: Li Yan , Xie Jing Pei , Yu Hui Wu , Wang Wen Yan , Shao Xin Hai , Li Luo Li , Wang Ai Qin , Li Ji Wen
Published: October 2011

Mn18Cr2 steel is one of austenitic deformation strengthening steel. The existing form of TiN and its influence on the austenitic structure in the steel by adding small amounts of TiN nanoparticles are discussed in this study, which may provide some advices to explore new way to strengthen high manganese steel. The microstructures of Mn18Cr2 steel added small amounts of TiN nanoparticles are observed by Transmission Electron Microscopy (TEM). The results show that TiN nanoparticles exist in austenite and there have a very good match interface between the two phases, the crystal face relationship are {220}γ//{220}N, {422}γ//{422}N, (111)γ //(200)N , orientation relationship are <110>γ// <110>N, <211>γ//<211>N, [112]γ // [011]N, moreover, the relationship of (111)γ and (200)N is not only parallel but also coherent. Meanwhile, there are many high density dislocations, a small amount of stacking faults, twins and ε-martensite in the austenite due to the role of TiN nanoparticles.
Experimental Study of High Frequency Guided Wave Inspection of Anchored Bolts
Authors: He Wen , Luo Xiao Jiang , Zhao Kui , Cheng Wang , Zhong Chun Hui
Published: October 2011

High frequency longitudinal guided waves were used to inspect the anchored rock bolts. Experiments were conducted to find the optimal frequencies for the bolt testing. A broad-band signal was excited at the top end of the bolt, and the power spectral density(PSD) analysis of the bolt end reflected waves was made. Base on that the frequency component of the bolt end reflected waves could be obtain, and the frequencies with higher power spectral density values are the optimal ones. At optimal frequencies, the guided wave attenuates more slightly than it is at other frequencies and the bolt end reflected waves can be clearly acquisitioned. Experimental results show that the optimal frequencies of guided wave in a free bolt and in an anchored bolt are quite the same, and they are mainly affected by the bolt instead of the anchor media. Conclusions can be drawn that the propagation velocities of guided wave at optimal frequencies in a free bolt are close to those in the embedded section of the bolt. As a result, the bolt length and the position of flaw in the anchored bolt can be determined by the guided wave velocity in a free bolt and the reflected wave from the bolt end and from the flaw, respectively.
Calculation and Analysis of 2-D Thermal Stress Field in Induction Motor with Compound Cage Rotor under Different Load
Authors: Cao Jun Ci , Qian Rong Chao , Li Wei Li
Published: October 2011

3kW two poles induction motor with compound cage rotor is illustrated in this paper, and 2-D thermal stress field of induction motor rotor is calculated and analyzed by finite element. Contrasting with common induction motor, induction motor with compound cage rotor has specific rotor shot shape and the bar is comprised of the upper compound material and the lower cast aluminium, which cause distribution of thermal stress is special. The motor with the rotor shot of compound material laid at single site is chosen to analyzing. The maximum thermal stress in the bar is calculated at different load, and the distribution of thermal stress in the bar is analyzed at rate load. The law of distribution of thermal stress in the bar has same reference value for designing new type of induction motor.
The Accelerated Corrosion of Elemental Sulfur for Carbon Steel in Wet H2S Environment
Authors: Zheng Shu Qi , Li Chun Yu , Chen Chang Feng
Published: October 2011

The accelerated corrosion action of sulfur for carbon steel in wet H2S environment was studied by simulating the actual serviced environment. The weight-loss method, SEM, EDS and X-ray diffraction techniques are used to analyze the corrosion rate, the structure and the composition of the corrosion production formed in the environments. The results show that sulfur aggravated the corrosion sharply in wet H2S environment.
A Study on Developing Robustness Engineering by Using Stochastic Analysis Method
Authors: Jung Dong Won , Kim Bong Chun , Kim Dong Hong , Nguyen Duc Toan
Published: October 2011

The purpose of this study is to evaluate the influence of the scatter in mechanical properties and stamping process parameters on an industrial sheet metal forming process. Based on a previously optimized forming process, a robustness analysis has been performed. The robustness analysis clearly showed production problems for the part not initially revealed by the analysis of the process that was trimmed for “optimality”. The sensitivity of the results on the variation of the parameters was evaluated. It was shown that all parts of the sheet do not react equally sensitively to the variation of the input. Zones of critical response could be identified in accordance with the zones on the actual part that showed failure in mass production. The results reveal that the common practice of performing evaluations with fixed safety margins is non-effective and hence very dangerous, or is extremely conservative and thus costly. The application of stochastic simulation methods reduces the need for wide safety margins while simultaneously increasing the reliability of the process by incorporating uncertainty into the simulation
Sheet Metal Forming Analysis of an Automotive Part Using Finite Element Simulation
Authors: Suranuntchai Surasak , Kritboonyarit Prarop
Published: October 2011

The purpose of the present research is to investigate and improve the quality of car brake booster deformed under drawing processes by using Finite Element (FE) program known as AutoForm. The materials are made from SPC270F with thickness 1.4 mm. and the initial diameter of 280 mm. The brake booster requires totally 9 production processes, including the sheet blanking, in the manufacture. Failure has found in the 4th draw in which cracking occurs at the bottom of cylinder. The material property assumed to be anisotropic, behaved according to Ludwik’s equation, and deformed rigid-plastic, which followed Hill’s yielding surface. The deformation for Forming Limit Diagram (FLD) was predicted by Keeler equation. Punch and die were assumed to be rigid during simulation. In this work, the process improvement focus mainly on the smallest change in die design which no lubricant required during the drawing processes. From the predicted results, the recommended punch diameter for the 1st draw should be extended to 111.4 mm while the new design for die’s diameter in the 1st draw is as large as 103 mm. However, punch’s height and its radius need to be varied in order to prevent the wrinkle as well. Since there is a little change in the new design while no more lubrication is required during the draw process, its can be improved in quality of finish product, cost reduction in lubricant consuming as well as the machining time to make a new punch.