bluuebunny/crossref_metadata_2025 huggingface dataset:
Fuzzy Enhancement of Power System Stability Using FACTS Devices
Authors: Hamad J. , El-Bahrawy K. , Sharkawy R.
Published: October 2011

This paper investigates voltage stability of the power system during steady state and transient conditions. The voltage stability enhancement is achieved by utilizing FACTS devices at the best location of the system. The weakest bus in the system is the best location to implement shunt compensation device. In this paper, the weakest buses are identified via a fuzzy technique that utilizes two critical indices: Line Flow Index (LFI) and Voltage Profile Index (VPI) during normal and fault conditions. These indices are used to evaluate Criticality Index (CI) using Fuzzy rules, and thus, the system buses are ranked. Remedial actions are discussed to enhance the power system voltage stability by using FACTS devices (SVC and STATCOM) at the most vulnerable system buses. The results of this study show that the (STATCOM) performance is preferable to that of the (SVC) during fault conditions.
Spacecraft Adaptive Sliding Mode Attitude Tracking Control Using DGCMG
Authors: Wang Lei , Zhao Yu Shan , Shi Peng
Published: October 2011

This investigation is concerned with the non-linear multi-in-multi-out tracking control of a spacecraft with Double-gimbaled control moment gyros as actuators. An attitude dynamic model of rigid spacecraft with DGCMG and a kinematics model in terms of Modified Rodriguez parameters are given for the controller development. Then the control objective and system uncertainties in tracking problem are analyzed considering the major elements which work on the control performance such as moment of inertia change, wheel speed drift and external torque. A adaptive sliding mode controller is designed and is proved stable later in which the sliding mode control are used to compensate external torque and un-modeled dynamics while the adaptive parameters are used to estimate inertia and wheel speed on line. And a steering law of parallel mounted DGCMG is illuminated. Finally Monte Carlo simulation is carried out to prove the effectiveness of the controller.
Study of Self Phase Modulation in Chalcogenide Glass Photonic Crystal Fiber
Authors: Dabas Bhawana , Kaushal Jivesh , Rajput Monika , Sinha R. K.
Published: October 2011

In this paper, Self Phase Modulation (SPM) in chalcogenide As2Se3 glass Photonic Crystal Fiber (PCF) is numerically studied by combining the fully vectorial effective index method (FVEIM) and Split Step Fourier Method (SSFM). The FVEIM is used to calculate the variation of effective refractive index of guided mode (neff), effective area (Aeff), dispersion and non-linear coefficient (γ) with wavelength for different designs of chalcogenide As2Se3 PCF. The FVEIM solves the vector wave equations and SSFM solves non linear Schrödinger Equation (NLSE) for the different designing parameter of As2Se3 PCF. In case of Self Phase Modulation (SPM), spectral width of the obtained output pulse at d/Λ=0.7 is 1.5 times greater than width of the output pulse obtained at d/L=0.3 using SSFM. Thus we can get the desired spectral broadening just by tailoring the design parameters of the PCF.
Identification of Aerodynamic Derivatives of a Flexible Aircraft Using Output Error Method
Authors: Majeed M. , Kar Indra Narayan
Published: October 2011

A full order model of an aeroelastic aircraft has too many parameters to yield satisfactory estimates. In this paper, using simulated data, rigid body and aeroelastic derivatives are estimated in longitudinal axis for single elastic mode. The proposed approach uses an integrated model structure. It emphasizes the use of estimation techniques that have the capability to accurately determine modal characteristics in those flight test situations where the measured data is dominated by elastic effects. Output error method in time domain is applied to the simulated flight data to identify the aircraft derivatives.
Optimal Damage Detection Sensor Placement Using PSO
Authors: Abdalla M. O. , Al-Khawaldeh E.
Published: October 2011

An optimal damage detection sensor placement methodology is presented. The techniques utilize a Particle Swarm Optimization (PSO) algorithm. The proposed method is iterative in nature and it permits the use of incomplete measurements. Also, it allows diversity of damage detection algorithms to be used to generate the PSO required fitness function. However, in this work Linear Matrix Inequalities are used as the damage detection schemes. Computer simulations of a cantilevered beam will be used to demonstrate the effectiveness of the methodology.
Fuzzy Logic Based Impedance Control to Monitor on Torque under Impulsive Loading
Authors: Dizaji Mostafa Rahimi , Yazdi Mohammad Reza Hairi , Shirzi Moteaal Asadi
Published: October 2011

This paper is devoted to design a control system for robot manipulator to optimize motor torque due to external impulsive loading exerted on the manipulator. Under impulsive loading, overloading may occur in the absence of any monitoring on the torque. To avoid the overloading, impedance control is proposed as a force control strategy. Here impedance control based on force feedback of which has hit the end-effector modifies the reference trajectory. In fact, instead of resisting against impulsive loading up to extreme power of the motor, the proposed design generates small movements in the direction of impact. Therefore, the motor produces less torque in comparison to the absence of impedance control. A supervisory system assisting fuzzy logic has been used to adapt impedance controller parameters with various impact conditions. The simulation result confirms the improvement of the manipulator behavior which yields sensible reduction in motor developed torque in comparison to single PID controller.
An Architecture Analysis of ADCS for CubeSat: A Recipe for ADCS Design of ICUBE
Authors: Abbas Naqvi Najam , Xiao Han , Jun Li Yan , Raza Muhammad
Published: October 2011

This research article presents the architecture analysis and design of Attitude determination and control subsystem (ADCS) of the Pico-Satellites especially the CubeSat, developed and launched into the Low Earth orbit (LEO). ADCS is not a stringent requirement for all the CubeSat missions but several missions were specifically designed to test and validate the ADCS. This paper contributes in evaluating the previous ADCS of CubeSat and presents an optimal ADCS design and a recipe for any CubeSat mission and specifically for the upcoming ICUBE of the Institute of Space Technology (IST), Pakistan. The proposed ADCS for ICUBE includes GPS receiver as position sensor while magnetometer as attitude sensor and magnetic coils as the active actuators. The determination will be done by Kalman filter and LQR will be used as a controller.
Solar Energy Electric 4400 Va, 3x220 Volts, 50 Hertzs with Sliver Cells and Changeover Switch Based PLC Festo FC-34
Authors: Widodo Suprapto , Ismail Nurman
Published: October 2011

This paper present about solar energy electric with the capacity 4400voltampere, 3x220volts, 50hertzs. This capacity is assumed enough for many household, home industry, polyclinic, offices. In this case that solar panel is used “sliver cells” type because, use less silicon, more efficient, flexible, transparent, bifacial, thin. This system is build with charge controller utility to battery bank and from battery bank to 3-phase inverter. The 3-phase inverter is useful to convert direct current to 3-phase alternating current voltage. 3phase inverter used is consist of six unit of IGBT components. The output of 3-phase inverter is connected to input 3-phase stabilizer, and the output of 3-phase stabilizer is to lead to the loads. The output voltage of 3-phase stabilizer is detected and to be input to PLC (Programmable Logic Controller) Festo FC-34, because PLC to control change over-switch that the function as actuator with 5 seconds setting time, is the load supplied by solar energy electric, electric from PGL (Public Grid Line) or the electric from generator set. The alternative is ordered according with sequence of operation cost. The result of research, the output voltage from stabilizer 218.5volts, the input voltage of charge controller 56.16volts, the input voltage of inverter 48.0volts, the output voltage of inverter 205.6volts, electric current to the load 9.5amperes. If the output voltage of stabilizer less than or equal 190volts, so the PLC will actuate change over switch as the actuator to active to PGL power or to generator set power. It is found that overall system works effectively.
The Methods of Synthesis of Multilevel Circuits of Compositional Micro Program Control Units
Authors: Al Rabea Adnan I. , Alkoffash Mahmud S. , Almatarneh Feras , Alhadidi Basim
Published: October 2011

On the basis of theoretical and experimental researches the new structures and formal methods of compositional micro program control units design are proposed. It is shown that optimization of hardware in the unit of microinstructions’ addressing can be achieved by application of the methods of multilevel implementation of automata with “hardware” logic, that need adaptation to the peculiarities of compositional micro program control units. It is proposed to use the methods of the logic conditions’ encoding, the codes of the states, the codes of the operational linear chains and their classes, and also the addresses of microinstructions. The new structures and methods of design were developed for all known structures of compositional micro program control units. The proposed methods permit to decrease the amount of programmable logic devices in the automaton of addressing’s circuit from 12% to 42% in comparison with known methods of design. The analytical estimations of hardware amount as the function of characteristics of initial flow-chart have been made up. These methods permit to expand the class of synthesizable control units. The conducted researches permit to find an area of the effective application of proposed methods of design. The purpose of work is minimization of number of the large-scale integrated circuit in circuit of automatons of addressing of CMCU due to application of methods of a structural reduction. The analysis of methods of realization of algorithms of control, element basis, methods of a structural reduction, methods of synthesis and optimization of compositional micro program control units are executed, the primary goals of researches are formulated.. (Abstract)
The New Material Structure Design and Research of the GaAs-Based Resonant Tunneling Diodes
Authors: Wang Jie , Zhang Bin Zhen
Published: October 2011

Use MBE technology grew three different structures’ RTD to get a contrast test on device with different thickness of well structure’s DC character,they all grew on semi-insulating GaAs substrates, and use I-V analysis instrument tested the I-V character of the RTD in room temperature, in the test results , the PVCR of the best device was up to 7.1,VP is reduced to 0.4V ,then we analyzed the relationship between the device material structure and I-V character , this paper provided a reference for the better performance of the RTD structure design.
Wear Characteristics of Manganese Phosphate Coating with Oil Lubricant
Authors: Ilaiyavel S. , Venkatesan A. , Nallusamy N. , Sornakumar T.
Published: October 2011

Manganese Phosphate is an Industrial coating used to reduce friction and improve lubrication in sliding components. In this study, the tribology behavior of uncoated, manganese phosphate coated, Manganese Phosphate with oil lubricant AISI D2 steels was investigated. The Surface morphology of manganese phosphate coatings was examined by scanning electron microscope (SEM) and Energy dispersive X-ray Spectroscopy (EDX) .The wear tests were performed in a pin on disk apparatus as per ASTM G-99 Standard. The wear resistance of the coated steel were evaluated through pin on disc test using a sliding velocity of 0.35 m/s under normal load of 5 to35 N and controlled condition of temperature and humidity. The Coefficient of friction and wear loss were evaluated. Based on the results of the wear test, the manganese phosphate with lubricant exhibited the lowest average coefficient of friction 0.13 and the lowest wear loss 0.4 mm3 under 35 N load.
Behavior of Carbon and Nitrogen after Low Temperature Thermochemical Treatment on Austenitic and Duplex Stainless Steel
Authors: Triwiyanto A. , Hussain Patthi , Ismail M. Che
Published: October 2011

Stainless steel is widely used where corrosion resistance is importance. Stainless steel has its origin excellent corrosion resistance due to the nature of presence Cr as alloying element to form stable passive layer that protects the steel. Due to its inherent austenitic structure, this material has relatively low hardness as well as poor wear resistance which hinders a wider applicability of the material and may cause problems in existing applications. The gaseous thermochemical treatments to improve surface properties of material are typically carried out in carbon and/or nitrogen bearing gases and usually associated with temperature above 500 °C.
Low Velocity Impact Analysis on GFRP Laminates under Different Temperatures
Authors: Pazhanivel K. , Bhaskar G.B. , Arunachalam S. , Hariharan V. , Elayaperumal A.
Published: October 2011

Composite materials have a number of properties that make them attractive for use in aerospace applications. The impact behavior of fiber reinforced composite materials is much more complex than conventional metallic structures due to a number of different failure modes on the inter laminar and intra laminar level. The aim of this study is to investigate the effects of temperature and thermal residual stresses on the impact behavior and damage of glass/epoxy laminated composites. To this end, thermal stress analyses of the laminates with lay-ups [90/0/0/90] s, [90/0/45/45] s, [0/90/45/-45] s, [45/0/-45/90] s are carried out under different temperatures by using ANSYS software. Also, the impact analysis on the laminated composites was performed at the different range of impact energies under different temperatures. The specific energy values and impact parameters were obtained and compared for each type of specimens and temperatures.
Entrance Region Flow of Casson Fluid in a Circular Tube
Authors: Kandasamy A. , Pai Rekha G.
Published: October 2011

The entrance region flow of a Casson fluid in a tube has been investigated numerically without making prior assumptions on the form of velocity profile within the boundary layer region, which is determined by a cross sectional integration of the momentum differential equation for a given distance from the channel entrance. Using the macroscopic mass and momentum balance equations, the thickness of the core, the entrance length, and the pressure drop have been obtained at each cross section of the entrance region of the tube for specific values of Casson number.
The Effect of Cutting Parameters on Surface Integrity in Hard Turning
Authors: Saini Sanjeev , Ahuja Inderpreet Singh , Sharma Vishal S.
Published: October 2011

Manufacturers around the world constantly strive for lower cost solutions in order to maintain their competitiveness on machined components and manufactured goods. Globally, part quality has been found to be at acceptable levels and it continues to improve, while the pressure for part piece cost is enormous and is constantly being influenced downward by competition and buyer strategies. In machining processes, it is necessary to attain the desired surface quality in order to produce parts providing the required functioning. The surface quality is influenced by various cutting parameters (cutting speed, feed, depth of cut) and sometimes some other parameters. The objective of this paper is to review the effect of cutting parameters on surface integrity (surface roughness and residual stress) in hard turning.
Surface Plasmon Polaritons: Propagation Characteristics of Surface Plasmon Waves on Au and Ag at Optical Wavelengths
Authors: Maity Niladri Pratap , Maity Reshmi
Published: October 2011

The existence of Surface Plasmons (SPs) is possible only if the metal have a negative dielectric constant at the corresponding optical frequency. In this paper the propagation characteristics of Surface Plasmon Waves (SPWs) which exists on noble metals like gold (Au) and silver (Ag) due to the formation of Surface Plasmon Polaritons (SPPs), have been evaluated theoretically and simulated with the help of MATLAB programming language. The variation of the propagation constant (PC), the attenuation coefficient (AC) and the penetration depth (PD) inside the metals and the dielectric has been determined. It has been found that highly conducting metals Au and Ag provide a strong confinement to the SPWs at optical frequencies.
Experimental Surface Profile of Dense Granular Media in Cylindrical Couette Flow
Authors: Kumar Arkadeep
Published: October 2011

Granular materials have widespread use in the industry. The flow of granular media requires careful studies through experiments to understand the rheology of these complex materials. The present work determines the surface profile of dense granular media subjected to cylindrical Couette flow. A translation stage is used to obtain measurement of depth varying with radial distance. A depth gauge attached to the translation stage is used to measure the surface profile. Glass beads (average diameter 0.8-1 mm) and mustard seeds (average diameter 1.2-1.4 mm) are used as model granular materials. Two different Couette gaps are used (4cm and 3cm). Cylinders with smooth surfaces, as well as coated with emery paper are used. The surface profile varies with material, surface roughness of the cylinders, and the gap between the two cylinders. The comparison of the various cases has been done by graphical representation. The probable reasons for the development of such a surface profile are given.
Effect of X-Ray Computed Tomography Scanning Parameters on the Estimated Porosity of Foam Specimens
Authors: Kumar Jagadeesha , Abulrub Abdul Hadi G. , Attridge Alex , Williams Mark A.
Published: October 2011

X-Ray Computed Tomography (CT) scanning is an effective method for estimating the porosity of various engineering materials and biomedical specimens such as tissue scaffolds and bones. However, the scanning and analysis parameters play a significant role in the accuracy of the porosity value determined from CT scan. This paper presents details of an investigation carried out to understand the effect of system parameters, namely the voxel size, X-ray focal spot size and segmentation threshold, on the estimated porosity by taking an example of safety-critical foam used for impact protection applications. Different voxel resolutions and focal spot sizes are selected in a total of 12 scanning tests and the effect of segmentation threshold is analyzed on each of these tests. The study indicates that the obtained porosity value is greatly influenced by the choice of voxel size at larger spot sizes and less influenced at smaller spot sizes. The threshold also has significant effect on the porosity value, especially at larger voxel sizes.
Natural Convection in a Porous Medium Rectangular Cavity with an Applied Vertical Magnetic Field Using Lattice Boltzmann Method
Authors: Ashorynejad Hamid Reza , Farhadi Mousa , Sedighi Kurosh , Hasanpour Arman
Published: October 2011

A numerical study of the magnetohydrodynamic (MHD) flow in a square cavity filled with porous medium is presented by Lattice Boltzmann Method (LBM). The left and right vertical walls of the cavity are kept at constant but different temperatures while both the top and bottom horizontal walls are insulated. The effects of the controlling parameters involved in the heat transfer and hydrodynamic characteristics are studied in detail. The results show that heat and mass transfer mechanisms and the flow characteristics inside the enclosure depend strongly on the strength of the magnetic field and Darcy number. The average Nusselt number decreases with rising values of the Hartmann number while this increases with increasing values of the Darcy number.
Study of the Parameters in Electro-Discharge Diamond Face Grinding through Response Surface Methodology Approach
Authors: Singh Gyanendra Kumar , Yadava Vinod , Kumar Raghuvir
Published: October 2011

The present study investigates the relationship of process parameters in electro-discharge diamond face grinding (EDDFG) of tungsten carbide and cobalt composite (WC-Co). The central composite rotatable design had been utilized to plan the experiments and response surface methodology (RSM) was employed for developing experimental models. Analysis on machining characteristics of EDDFG was made based on the developed models. In this study, wheel RPM, current, pulse on-time, and duty factor are considered as input process parameters. The process performances such as material removal rate (MRR) and average surface roughness (Ra) were evaluated. Analysis of variance test had also been carried out to check the adequacy of the developed regression models. The observed optimal process parameter settings are wheel RPM of 1500, current of 6.9029 A, pulse on-time of 137. 8208 µs, and duty factor of 0.79 for achieving maximum MRR and minimum Ra; finally, the results were experimentally verified. A good agreement is observed between the results based on the RSM model and the actual experimental observations. The error between experimental and predicted values at the optimal combination of parameter settings for MRR and Ra lie within 6.18% and 12.33%, respectively.
Effect of Vanadium Contaminated Fuel on Bond Coat and Bond Coat/Top Coat Interface of Thermal Barrier Coatings
Authors: Khalid Adeel , Gasem Zuhair M.
Published: October 2011

In the present paper, an attempt has been made to discuss the degradation mechanism of bond coat and bond coat/top coat interface in thermal barrier coating system in the presence of corrosive salts such Na2SO4 and V2O5.These salts come from impurities in low grade fuel used in gas turbine industry. Salt mixture of Na2SO4 + V2O5 was prepared and applied on surface of thermal barrier coating (TBC) specimens. The specimens were exposed isothermally to 900oC for 200, 400 and 700 hours. SEM analysis revealed the formation of thermally grown oxide (TGO) in specimens sprayed with corrosive salts. Results revealed that there was no degradation of either bond coat or bond coat/top coat interface up to 200 hours of isothermal exposure .Interface cracking and spallation was observed after 400 hours of isothermal exposure owing to depletion of zirconia stabilizer i.e yttria and phase transformation of tetragonal zirconia to monoclinic zirconia.
Determining of Infrared Transition of InN Film Grown on C-Plane Sapphire by Photoreflectance
Authors: Wang Dong Po , Tu Li Wei
Published: October 2011

An InN film was grown on sapphire (c-plane) by plasma-assisted molecular beam epitaxy, and its photoluminescence at 10 K and photoreflectance (PR) spectra from 10 K to 110 K were measured. Some prominent features in the PR spectra were observed in the infrared region below 120 K. The signals become too weak to observable for temperature above 110K. Furthermore, the binding energy of InN exciton was estimated to be 9.43 meV, which is equal to kBT at 109K. Therefore, the features in the PR spectra were assigned to the A, B, and C excitonic transitions associated with the direct gap of wurtzite InN. The thus obtained energies of the A, B, and C excitonic transitions versus temperature were fitted well by Varshini’s equation. The energies of the A, B, and C excitonic transitions at room temperature obtained by the best fit of Varshni’s equation are 0.738, 0.746, and 0.764 eV, respectively.
The Study of the Properties and Function of Large Ball Mill with Liner Material
Authors: Xie Jing Pei , Li Ning Bo , Wang Wen Yan , Wang Ai Qin , Zhang Pei
Published: October 2011

In this paper, based on ctual large-scale ball mill liners working conditions, effects of different quenching temperature and tempering temperature on the Cr-Mo steel performance, optimize the best heat treatment process.The use of sophisticated electronic universal tensile testing machine, and Rockwell hardness testing machine for testing mechanical properties of steel materials were tested; Using the MMS-1G-type high-temperature high-speed Friction and wear tester, the wear properties of steel samples were studied using JSM-5610LV scanning electron microscope study of the tensile test fracture surfaces of steel and the friction and wear morphology. The results show that: For the high carbon alloy steel, of which 870 °C 620 °C tempered quenched specimen extension rate of 7.0% area reduction rate of 9.5%.
Influence of Nano-Silica on Solvent Absorption in Polypropylene Packaging
Authors: Xu Wen Cai , Li Dong Li , Fu Ya Bo , Wang Ya Jun
Published: October 2011

In this paper, the influence of nano-silica on adsorption behavior of solvent in polypropylene packaging is reported. A principle of reducing solvent residue in polypropylene packaging was explored through analyses of changes of crystallization behavior, polarity, and solubility parameters of nano-silica /polypropylene composites. The results showed that the value of solvent residue in modified polypropylene films was reduced about 50%. Therefore nano-silica modified polypropylene films with lower solvent adsorption are in accordance with food safety.
Influence of Refiner on the Properties and Microstucutures of High-Tin Wear-Resisting Cu-Sn-Pb-Ni Alloy
Authors: Song Ke Xing , Zhou Yan Jun , Wei Jun , Cai Yuan Jing , Zhai Guan Feng , Zhang Yan Min , Bai Ning
Published: October 2011

According to the high-tin wear-resisting Cu-Sn-Pb-Ni alloy which the tin contents are 9~11%, the alloy casting were prepared by adding 0.5% refiner in melting precess and pouring in metal mold. The density, hardness, strength and elongation of alloy castings which adding refiner in melting process or not were tested and the casting mircostructure was analyzed. The results show that the density and hardness of Cu-Sn-Pb-Ni alloy casting prepared by adding refiner in melting process are 8.9083g/cm3 and 113HB separately, the strength and elongation are 314.7MPa and 32.7% respectively, comparison with the strength and elongation of non-refiner are 252MPa and 7.3% separately, they were increased by 24.9 % and 348 % respectively. The dendrite structure which are mainly α solid solution and eutectoid（α+δ）of casting prepared by non-refiner is relatively obvious, The grain are obviously refined and the distribution of lead simple substance phase are more dispersed among the grain and grain boundary by adding refiner in melting process.
Application of Slow-Release Fertilizer with the Function of Water-Absorption and Water-Retention in Position Engineering Camouflage
Authors: Li Shao Hong , Shen Yue Guo , Shi Zhong Feng
Published: October 2011

The construction of position engineering causes a lot of naked earth slopes and rock slopes. Because the earth and rock lack of water absorption and water retention, traditional vegetation camouflage can not make it. The slow-release fertilizer with the function of water-absorption and water-retention make up it and which will be applied widely in vegetation camouflage of position engineering.
Extraction Behavior of Mercury(II) and Cadmium(II) in Ion Liquid Extraction System Using 1-Butyl-3-Methyl-Imidazolium Hexafluorophosphate and 8-Hydroxyl-Quinoline
Authors: Pan Zhong Wei , Ma Chang , Zhou Hai Long , Lian Ting , Lai Chuan Ye , Li Cheng
Published: October 2011

The extraction behavior of metal ions (Hg2+ and Cd2+, M2+) was investigated in ionic liquid (IL) extraction system using 1-butyl-3-methyl- imidazolium hexafluorophosphate ionic liquid ([Bmim]PF6) as extraction solvent and 8-hydroxyl-quinoline (HQ) as extractant. The extraction percentage of M2+ using [Bmim]PF6 was less than 5% without HQ. When sufficient HQ was included in IL phase, the extraction percentage of M2+ could be higher than 98%. The extracted species in the M2+-[Bmim]PF6-HQ system was neutral MQ2 and the recovery of M2+ extracted into [Bmim]PF6 can be achieved using 0.25 mol•L-1 HNO3 as stripping agent. [Bmim]PF6 can be recycled in the experiment.
Tensile Properties and Microstructure of ZK60 Magnesium Alloys at High Temperature
Authors: Cheng Wen Jie , Chen Fu Xiao
Published: October 2011

Using tensile test of ZK60 magnesium alloy, the superplastic flow behavior was studied. The deformation temperature was set as 280°C, 310°C,340°C, 370°C and 400°C while strain rate was 1×10-1s-1, 1×10-2s-1, 1×10-3s-1 and 1×10-4s-1. The results showed that the perfect superplastic behavior was presented at 370°C and =1×10-4s-1 and the maximum elongation could be 133.7%. The biggest factor of strain rate sensitivity was 0.62. The microstructure of the fracture was analyzed used SEM and the results showed that the main deformation mechanism of ZK60 magnesium alloy was grain boundary sliding.
Study on the Performance of a Novel Shrinkage Reducing Admixtures (SHSRA) of Concrete
Authors: Zhang Xia Hong , Li Chao , Wang Ying Fei , Wang Sheng Nian
Published: October 2011

A novel Shrinkage reducing admixture (SHSRA) has been developed. Several tests including the workability , drying shrinkage，the hydration heat and strength tests were carried out to evaluate the effect of SHSRA on the performance of the concrete specimens. The results showed that the presence of SHSRA induced a significant reduction in dry shrinkage by up to 40% after 28 days. The SHSRA could cause decreases in both hydration rate and heat release of hydration of cementing materials which can attribute to reducing the risk of cracking. Besides, no negative side effect on the concrete workability and the later strength has been observed with the addition of the SHSRA.
Improvement of Hydrogenation and Dehydrogenation Kinetics on MgH2 by the Catalytic Effect of ZrO2
Authors: Zeng Liang , Kimura Toru , Hino Satoshi , Miyaoka Hiroki , Ichikawa Takayuki , Kojima Yoshitsugu
Published: October 2011

Hydrogen desorption temperature of MgH2, which was milled with 20 pieces of ZrO2 balls for 20 h, was decreased to 240 °C, although steel−ball−milled MgH2 required more than 350 °C. Moreover, the completely dehydrogenated product was able to absorb hydrogen of ~3.5 mass% even at room temperature under 1 MPa hydrogen within 5 hours. Inductively coupled plasma−atomic emission spectroscopy analysis revealed zirconium element was doped into MgH2 from the ZrO2 balls during the milling process. Therefore, it was concluded that the presence of ZrO2 improved the kinetics of the hydrogenation and dehydrogenation behaviors of MgH2.
Effect of Phosphorus Slag and Fly Ash on Anti-Corrosion Property of High Belite Cement
Authors: Liu Dong Mei
Published: October 2011

Effect of phosphorus slag and fly ash on anti-corrosion property of high belite cement has been researched in the paper. Results show that, the anti-corrosion resistance of high belite cement is obviously higher than mediate heat cement. Admixing one of phosphorus slag and fly ash or both in cement all can improve the corrosion property, but admixing fly ash has more influence. For cement mixed with phosphorus slag and fly ash, effect of the fineness and proportion of phosphorus slag on anti-corrosion coefficient K is not significant.
Influence of Porosity on Polarization in Piezoelectret Films with Regular Microstructure
Authors: Lou Ke Xing , Cao Gong Xun , You Qiong , Zhang Xiao Qing
Published: October 2011

Piezoelectret films, with a controlled ordered microstructure and various porosities, were fabricated by using a patterning-fusion bonding method. The polarization in the films with various porosities is investigation. The results show that the critical applied bias voltage for the breakdown in the inner voids is dependent on the porosity in the films. The threshold voltages for the polarization in the fabricated films with the porosities of 0, 25 and 44% are around 4000, 2000 and 2000 V, respectively. The piezoelectric d33 coefficients are enhanced by increasing the applied bias voltage during polarization.
Dynamic Characterization and Drug Release of Thermosensitive Poly(N, N-Diethylacrylamide-Co-Itaconic Acid) Copolymer Hydrogels
Authors: Li Xiao Qi , Zhang Nei Yan , Shen Yue Guo
Published: October 2011

In this study, poly(N,N-diethylacrylamide-co-itaconic acid) (P(DEA-co-IA)) copolymer hydrogels were synthesized by changing the initial DEA/IA molar ratio, N,N-methylenebisacrylamide and total monomer concentration. The thermo-sensitive and mechanical performances were optimized by altering the above parameters. In comparison with the PDEA hydrogel, the equilibrium swelling ratio (ESR) and lower critical solution temperature (LCST) of the hydrogels changed with the alternation of the above parameters. The swelling and deswelling kinetics was also studied in dital. The release behaviors of the model drug, aminophylline, are found dependent on hydrogel composition and environmental temperature, which suggests that these materials have potential application as intelligent drug carriers.
Synthesis of Lactic Acid Grafting Starch Copolymer Catalyzed with Stannous Chloride
Authors: Wang Qing Ling , Hu Ying Mo , Bian Jing
Published: October 2011

A convenient method to synthesize starch/lactic acid copolymer was studied in this work. The lactic acid grafting starch copolymer was directly prepared by reaction of cornstarch with lactic acid catalyzed with stannous chloride (SnCl2). The structure of starch/lactic acid copolymer was characterized by IR and 1H-NMR, and its morphology was seen by SEM and XRD. The effects of mass ratio between starch and lactic lacid, amount of catalyst and reaction time on the grafting degree were also studied. The result showed that the best grafting degree could reach 12.8％ with 1:6 as the mass ratio between starch and lactic acid and 1.5％ as amount of catalyst accounting for consumption of lactic acid by reaction at 90 oC for 7 h.
Nano-Crystalline Diamond Films Deposited on Copper Substrate by MPCVD Method
Authors: Li Xing Rui , Shi Xin Wei , Yao Ning , Wang Xin Chang
Published: October 2011

Nano-crystalline diamond (NCD) films with good adhesion were deposited on flexible copper substrate with Ni interlayer by Microwave Plasma Chemical Vapor Deposition (MPCVD). In this paper, two-stage method was used to improve the adhesion between the copper substrates and the diamond films. The effect of deposition time of the first stage on the morphology, crystal structure, non-diamond phase and adhesive properties of diamond films was investigated. The performance and structure of the diamond films were studied by Scanning Electron Microscope (SEM), Raman Spectroscopy (Raman) and X-Ray Diffraction (XRD). The results showed that the films were nano-crystalline diamond films positively. Impress method was used to examine the adhesion between diamond film and the substrate. When deposition time is 1.5h, the adhesion between diamond film and the copper substrate is better than the others. When it was 2.5h or longer, because the graphite layers existed as intermediate, the adherence between the diamond films and copper substrates was very poor. Therefore, the diamond films were easily peeled off from the substrates. Otherwise, the second stage called annealing process after the deposition played an important role to the adhesion. The films would be easily peeled off by curling without the annealing process.
The Effect of Bacterial Cellulose on the Mechanical and Thermal Expansion Properties of Kenaf/Polylactic Acid Composites
Authors: Sukyai Prakit , Sriroth Klana Rong , Lee Byoung Ho , Hyun Joong Kim
Published: October 2011

The reinforcement of PLA matrix with natural fibers aims to generate the sustainable biocomposites. Kenaf fiber (KF) and bacterial cellulose (BC) were employed to reinforce and diminish the usage of PLA matrix. Particularly, BC is nano-cellulose which was anticipated to increased interfacial area and therefore low volume fractions of additives. That was consequently to attain mechanical property improvement. Thus, the incorporation of KF and BC reinforced PLA composites was investigated. The extrusion method was utilized and materials were mixed outside prior to adding. The specimens were examined mechanical testing, Dynamic Mechanical Analysis (DMA), Differential Scanning Calorimetry (DSC), Thermo Gravimetric Analysis (TGA) and Scanning Electron Microscopes (SEM). The mechanical study revealed that the increment of elastic modulus increased concomitantly with the augmentation of KF content. Interestingly, PLA/KF/BC sample at ratio of 60/39/1 wt.% was efficiently to maintain tensile and flexural strength comparing to 50% reduction of without BC sample with equal fiber volume. Therefore, it could recognize that mechanical properties was improved by using low amount of nano-cellulose. This would be a high aspect ratio of BC that capable to connect between PLA matrix and KF which enhanced a large contact surface and therefore excellent coherence. The temperature dependence of storage, loss and tan delta was determined by DMA. A decrease of storage modulus was consistent with increasing of temperature, result from softening of the composites. Loss modulus was increased approximately at Tg which related to storage modulus cause. In addition, the tan delta peaks of PLA and composites were around 60°C and it did not significantly shift when emerged of fiber. DSC of both composites indicated an influence of fiber on the crystallization and enthalpy. On the other hand, glass transition and melting temperature did not significantly affect. The composites exhibited a small reduction of thermal stability when examined by TGA analysis. Notwithstanding, BC showed an improvement of thermal stability of PLA/KF/BC sample at 40 wt.% total fiber content. The linkage of BC between PLA matrix and KF was monitored by SEM.
Fair-Faced Light Weight Aggregate Concrete Preparation and Durability Research
Authors: Zhou Jing , He Mu , Gu Qing Xia
Published: October 2011

Fair-faced light weight aggregate (FLWA) concrete is of good performance. There is a fluorocarbon coating on its surface. This paper studies on how vibration time influences FLWA performance and how this paint influences FLWA durability.
Evaluation on the Corrosion Resistance Improvement by Dipping to Inhibitor Solution of Galvanizing Steel
Authors: Moon Kyung Man , Lee Myung Hoon
Published: October 2011

Galvanizing method is being widely used to the numerous constructional steels such as a guard rail of high way, various types of structural steel for manufacturing ship and for some other fields etc.. However, galvanized structures inevitably may be corroded rapidly with increasing exposed time because the rate of environmental contamination is accelerating due to the rapid development of industrial society. Therefore, it is necessary to improve the corrosion resistance of the galvanizing film through various methods such as variation of chemical composition of galvanizing bath, chromate treatment and coating treatment etc.. In this study, three types of the test specimens, that is, pure galvanizing, galvalume and chromate treated steels were immersed at inhibitor solution. And the effect of inhibitor for their corrosion resistance improvement was comparatively investigated with an electrochemical method. Corrosion current density of the original galvanizing and galvalume steel exhibited the highest and lowest value respectively in seawater. However, the corrosion resistance of these samples was considerably improved by dipped to a inhibitor solution(H3PO4+ Zn(NO3)2+Q). In particular, the galvanizing steel which dipped to the inhibitor solution exhibited the lowest corrosion current density due to the best effect of corrosion resistance improvement compared to other test specimens.
Preparation, Characterization and Thermal Behavior of Copper(II) Complex with 1-(6-Hydroxynaphthalen-2-Yl)butane-1,3-Dione
Authors: Wang Dun Jia , Xu Ben Po , Kang Yan Fang
Published: October 2011

A complex of Cu(II) with 1-(6-hydroxynaphthalen-2-yl) butane-1,3-dione (HNBD) was synthesized and characterized by elemental analysis, IR, UV and TG-DTA techniques. IR spectra as well as UV-visible absorption measurements indicated that Cu(II) ion was coordinated to the HNBD ligand. The TG-DTA curves showed that the thermal decomposition for Cu(II) complex was a three-steps process. At first, the complex had a mass loss of water molecules at temperature below 134°C, then the thermal decomposition of the anhydrous complex was a two-stage process, which corresponded to the loss of two naphthol molecules and the oxidative decomposition of other organic fragments of ligand. The final decomposition product of the complex was CuO.
Preparation and Evaluation of Fe2O3/Ceramic Composites for Flue Gas Desulfurization
Authors: Min Xin , Bian Jun Jie , Zhang Shu , Li Chun Hu , Feng Li Juan
Published: October 2011

Ceramic supported ferric oxide composites were synthesized by impregnation- precipitation (I) and sol-gel (II) methods using FeSO4as a precursor. We investigated the effect of the calcination temperatures on the structure, morphology, and agglomeration of supported ferric oxide. It has been found that Fe2O3was stabilized when the as-synthesized composites were calcinated at 330-360 °C under 10% (v/v) O2/N2mixture, and the calcination temperature was chosen as 350°C . The SEM images demonstrated that for the composite I, which was prepared by method (I), Fe2O3 nanoparticles were distributed on the surface and pores of the ceramic; while for the composite II, which was synthesized by method (II), Fe2O3thin layer was covered the surface of the ceramic. EDS analysis showed 7.9% (wt) ferric oxide had been supported on the composite I and up to 13.3% (wt) ferric oxide on the composite II. XPS analysis revealed that the valence of iron was +3 on both composites. Fe2O3/ceramic composites were used as the catalysts for low temperature wet Flue Gas Desulphurization (FGD), and demonstrated higher SO2removal efficiency. Because of the excellent hydrophilicity of ceramic and high dispersibility of Fe2O3 on ceramic surface, this catalyst had high SO2removal efficiency at 60°C even at pH2O3/ceramic composites, prepared by a simple, reproducible impregnation-precipitation and sol-gel method, was an inexpensive, active catalyst for S(IV) catalytic oxidation in wet FGD process in an economical feasible temperature range.
Drug Release Behavior from a pH/Temperature Sensitive Hydrogel of Poly(N-Acryloylglycine) and Chitosan
Authors: Deng Kui Lin , Wang Shu Liang , Li Qian , Cheng Hong , Zhang Peng Fei , Gao Ting , Huang Chun Yuan , Li Chun Xiu
Published: October 2011

In this study, a pH/temperature sensitive polymeric hydrogel from poly(N-acryloylglycine) and natural chitosan (PNAG-CS) was prepared via the radical polymerization. The effects of temperature and pH on the swelling behavior of PNAG-CS were systematically studied. Using caffeine as the model drug, the controlled caffeine-release from the resulting pH/temperature sensitive PNAG-CS was evaluated as functions of pH, polymer content and temperature by UV spectrophotometer.
Research on Application of Phosphorus Slag in Cement
Authors: Liu Dong Mei
Published: October 2011

The influence of phosphorus slag used as mineral additive on properties of cementing material is studied in this article. The results show that, with the content of phosphorus slag increased, the water demand of cementing material increased; the setting time prolonged; the hydration heat decreased. Under the same content of phosphorus slag, with the specific surface area of phosphorus slag increased, the water demand of cementing material decreased; the setting time shortened; but the hydration heat increased. The strengths of cementing material at 7 and 28 dates all decrease with the increase of phosphorus slag. At 90 dates, the change of strength with content of phosphorus slag is very small. The specific surface of phosphorus slag area mainly effects the early strength of cement stone.
Microstructure and Mechanical Properties of Mg-9Al-6.5Ca-3Zn-0.6Mn-XNd Alloys Prepared by Spray Forming
Authors: Zhang Guo Wei , Chen Zheng , Chen Wei , Xin Hai Ying , Zhai Jing , Guo An Zhen , Ma Li , Chen Gang
Published: October 2011

The Mg-9Al-3Zn-0.6Mn-xNd alloys, preformed with φ300mm size, has been prepared by spray forming technology under a protective atmosphere. The microstructure and mechanical properties have been investigated by XRD, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and strengths tested mechine. As a result, the precipitate phases in the alloys were the finest when the Nd content was 1% compared the alloys with the Nd content were 2% and 3%, the size of precipitation phases are between 1-2um and there are phases like Mg2Ca，Al2Ca，and MgZn2in the alloys. After extrusion, recrystallization microstructures were found in the alloys. The tensile strengths are between 400-450MPa and the yield strengths are between 350-370MPa respectively as the differences content of Nd in the alloys after heat treatment.
ADAMS-Based Braking System of a Tracked Vehicle to Optimize Mechanical Linkage Design
Authors: Sheng Long Bo , Ma Ji Sheng , Sun He Yang , Guan Shou Qiang , Zhao Wei
Published: October 2011

A certain new type of tracked vehicle has exposed the problem of insufficient braking force. Especially when tracked vehicle climbing the ramp, insufficient braking force is very harmful .The brake problem to a large extent affect the driving and mobility performance of the tracked vehicle .In this paper, using Pro/Engineer software to create braking system of a tracked vehicle mechanical linkage virtual prototype. And through the mech/pro interfaces the virtual prototype into ADAMS and is put up for dynamic analysis. On the basis of the kinematic analysis of the mechanical linkage, the link length of mechanical linkage was optimized to improve the braking force and obtain better optimization results.
Research on Technological Mineralogy of Refractory Hematite Ore
Authors: Han Xiu Li , Li Chang Cun , Liu Li Na , Yao Ming Yan , Liu Xin Fu
Published: October 2011

The characteristics of the texture, dissemination grain size, mineral composition and content of the refractory hematite ore are researched systematically. The result shows that: the ore is be of colloidal texture, complex mineral contents, fine dissemination grain size, so the ore is difficult to be separated. In order to get the idea result of processing, the ore must be ginded and concentrated stagely.
Dynamic Simulation and Test for the Valve Train Dynamics
Authors: Guan Cai Yun , Chen You Ming , Qin Wen Jie
Published: October 2011

This paper presents the development of a dynamic model of the valve train of one engine. During the parameter determination of the model, finite element method is used to calculate the contact stiffness of the cam-follower . The simulation results of the model are compared with measured data of the valve train at same speed. Excellent quantitative agreement is found between the numerical and experimental results and the validity of the dynamic model can be verified.
Static Analysis of Curved Beams with Clamped-Clamped Ends under Thermo Load
Authors: Li Xiao Fei , Cui Chun Yi , Yu De Hai
Published: October 2011

Based on the principle of thermal expansion and theory of virtual work, a class of equations for in-plane displacements at three freedom direction and internal forces in the cross-section of statically indeterminate curved beams under thermo load are derived explicitly. In the case of infinite limit of radius, these equations coincide with that of the straight beams. Compared with the results of FEM, the analytical solutions by the proposed formulae are accurate. The analytical solutions obtained in this paper would provide a scientific base for further study and design of the curved bridges.