bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation Research on the Compound Control System of Internal Model Add Feed-Forward Compensator
Authors: Zhang Sheng Bo
Published: July 2014

According to the characteristics of the internal model control and feed-forward control and Combining the both advantages, the compound control system of the internal model add feed-forward compensator was designed. In order to improve the dynamic performance of the control system, online identification method is adopted to establish the internal model. The designs of the internal model controller and feed-forward compensator were detailed instructions. The simulation shows that the compound control system have not only good dynamic performance, high tracking precision and strong anti-jamming capability, but also have the change of system parameters with strong robustness.
Three-Level SVPWM Inverter with Li-Ion Battery Driven for Robot Motor
Authors: Chen Sheng , Chen Chih Chen
Published: July 2014

Space vector Pulse Width Modulation (PWM) method is an advanced; computation intensive PWM method and possibly the best techniques for variable frequency drive application. Because of the constraint that the input lines must never be shorted and the output current must always be continuous, a voltage source inverter can assume only eight distinct topologies. Six out of these eight topologies produce a non-zero output voltage and are known as non-zero switching states and the remaining two topologies produce a zero output voltage and are known as zero switching states. the fluctuation in speed and torque are less when the Space Vector Modulation strategy is implemented in the vector controlled motor. Thus it can be concluded that the overall performance of a motor drive system is improved when Space Vector Modulation technique is used in robot power with the battery operated for industry application.
Meshing Efficiency of Involute Helical Gears Based on Elastohydrodynamic Lubrication
Authors: Wang Bin , Chen Xin Bo
Published: July 2014

To analyze the dynamic efficiency of helical gear during meshing process, a meshing efficiency model based on elastohydrodynamic lubrication (EHL) was established. The meshing plane between the pinion and gear was divided into seven parts in accordance to the regularity of unit load distribution. The total meshing power lose and average meshing power lose were calculated through a double integration method. The simulation results show that the method is feasible to calculate the meshing efficiency of gear pairs.
Research on Manufacturing of Blade Screw in Solid-Liquid Separator
Authors: Wang Jian Jun , Wang Ke , Wu Qiong
Published: July 2014

Blade screw propeller is used as the pushing and squeezing machine which is often used in the liquid separator for software materials. The core part of blade screw is stainless steel material with wide tooth, thin wall and other characteristics, and its processing method is different from the cylindrical surface spiral groove processing. Usually, its machining process is based on a certain forming technology to produce spiral leaf firstly, then welding leaves on the shaft. The cylindrical blade screw in test equipment adopts triangle method to calculate the blank dimensions. Variable cross section of the outer ring graph is realized by using the polar radius equation drawing in the drawing software.
Simplified Dynamics Modeling of Seat-Passenger in Vehicle Frontal Crash
Authors: Wang Yao Yuan , Lyu Zhuo Yang , Wang Liang Liang , Yan Zhen Hua
Published: July 2014

To quickly predict the performance of the seat in frontal crash during the initial stage of the seat development, in this paper a simplified coupled dynamic model of seat-passenger interaction is established according to the dynamics analysis method of Lagrange, and the fourth order Runge-Kutta method is used to resolve differential equation. Moreover, the simulation of Madymo testifies the simplified coupled dynamic model of seat-passenger interaction in frontal crash. Therefore, this model will be effective and feasible in predicting the performance of the seat in frontal crash during the initial stage of the seat development, for example, the performance of anti-submarining protection.
SINS Transfer Alignment Based on Robust SDRE Filter
Authors: Wang Da Yong , Sun Ping , Peng Jian Yi , Xu Xing Huo Gang
Published: July 2014

In order to improve the rapid response ability of the inertial navigation system mounted on the aircrafts which are onboard a ship, a novel rapid transfer alignment method of the strapdown inertial navigation system (SINS) on a rocking base is put forward.Interfering motions such as rolling, pitching, and yawing motions caused by sea waves are effectively used. Meanwhile, to remedy the effects of modeling uncertainty and adapt the nonlinear character in the error models, a robust SDRE (state-dependent Riccati equation) filter design is developed based on the infinity-norm minimization criterion. The filter presented can solve the problem that the standard Kalman filter cannot give the optimal solution when the system model and stochastic information are unknown accurately. Simulation results show that the misalignment angle error estimation can be upgraded dramatically and the new algorithm is less sensitive to uncertainty noise.
Mechanical Properties of DGEBA/Amidoamine Blend at Non-Stoichiometric Ratios
Authors: Satheesh Britto , Warrior Nick , Tshai Kim Yeow
Published: July 2014

In this paper, the effect of varying mixing ratio of Diglycidyl ether of bisphenol A (DGEBA)/aliphatic amidoamine hardener on the behavior of dynamic cure profile and mechanical properties of the resulting thermoset was investigated. Epoxy/hardener sample with a stoichiometric mixing ratio of 2:1 are tested against non-stoichiometric ratios of 3:1 and 4:1. The tensile, flexural, and hardness properties of the specimens were measured while SEM is employed to investigate the fracture surface and analyze the failure. Results showed that epoxy enriched samples (non-stoichiometric) has a much brittle behavior and the DGEBA/hardener samples tend to fail under relatively small strain.
Research on Adsorption Kinetics Models’ Fitting Values of H2O2 Oxidated Loofah Sponge on Methylene Blue
Authors: Dou Yan Han , Wang Yan Wei , Zhao Xi Hui , Wang Yue , Li Xiao Wen , Wang Min , Li Qiong , Li Qun
Published: July 2014

Oxidized alkaline loofah sponge (OAL) was given by treating alkaline loofah sponge (AL) with H2O2, four classic adsorption kinetics models which were Lagergren’s pseudo-first-order, Pseudo-second-order equation, the Elovich equation and Intraparticle diffusion were applied to study how the different oxidation degrees of loofah sponge impacted on the values of fitting goodness of the above models and to determine which kind of model was the best fit of the adsorption process and adsorption mechanism. The results showed that Pseudo-second-order equation’s fitting degree was proposed to be best and adsorption mechanism was chemical adsorption by ionic bonding, at the same time, as hydrogen bonds increased, water molecules formed a barrier to impede MB diffusing into the micro-structure.
Position and the Size of Drawbeads for Sheet Metal Forming with the Finite Element Method
Authors: Sena Khemajit , Piyasin Surasith
Published: July 2014

This study aims to find a solution to improve the formability in a deep drawing process. For this purpose drawbeads were used to avoid wrinkles and ruptures. The finite element method was applied to simulate the 3D metal forming process using a die and drawbead. The drawbead amount, position, size and form were studied for their affects on the formability. 3 drawbead patterns with 3 different heights were examined. The simulation was performed for each drawbead pattern and each drawbead geometrical parameter and the failure elements were counted. The best pattern chosen was the pattern that resulted in the least failure elements.
Development of Continuous-Type Electric Furnace to Recover Metal Values from Waste Mixed Batteries
Authors: Lee Jong Moon , Lee Woo Jin , Wang Jei Pil
Published: July 2014

Continuous-type electric furnace for thermal treatment to recover metal values from waste mixed batteries was newly developed to enhance it with safe, efficient, and eco-friendly processes. Waste mixed batteries were charged continuously into the reactor and handled in the furnace at 500°C for 2 hours under argon atmosphere and they were found to be separated in side reactor with easy. The electrodic powder including valuable metals such as Mn, Ni, Co, Zn, etc. was recovered from bulk components through sieving process.
Implementation of Magnetic Damping to Reduce Chatter Amplitude and Tool Wear during Turning of Stainless Steel AISI 304
Authors: Nurul Amin A.K.M. , Mohamad Ummu Atiqah Khairiyah , Arif Muammer Din
Published: July 2014

Machine tool chatter is a type of intensive self-excited vibration of the individual components in a machine-tool-fixture-work system. Chatter affects the cutting process and may lead to negative effects concerning surface quality, cutting tool life, and machining precision. However, modern manufacturing industries and their end users demand fine surface finish, high dimensional accuracy as well as low operation costs which include the cost of tooling. Therefore, any effective damping technique, which reduces or eliminates chatter, will significantly improve tool life and will be a profitable technique to implement in the industry. This paper presents a novel chatter control method in turning of (AISI 304) stainless steel by using permanent magnets. The study compared tool wear under two different cutting conditions: normal turning and turning with magnetic damping. A specail fixture made of mild steel was designed and fabricated in order to attach a powerful neodymium permanent magnet (4500 Gauss) to the carraige of a Harrison M390 engine lathe. The arrangement ensured that the magnet was placed exactly below the tool shank. The main idea was that the magnet will provide effective damping by attracting the steel tool shank and restricting its vertical vibratory motion during cutting operations. A Kistler 50g accelerometer, placed at the bottom front end of the tool shank was used to sense vibration. The data was then collected using a Dewetron DAQ module and analyzed using Dewesoft (version 7) software in a powerful Dell workstation. Response surface methodology (RSM) in Design Expert software (version 6) was used to design the sequence of experiments needed based on three primary cutting parameters: cutting speed, feed, and depth of cut. The tool overhang was kept constant at 120 mm in order to facilitate the attachment of the magnet fixture. Analysis of the recorded vibration signals in the frequency domain indicated that significant reduction in the vibration amplitude, as much as 86%, was obtained with magnetic damping. Next tool wear was analysed and measured using a scanning electron microscope (SEM). It is found that tool wear is reduced considerably by a maximum of 87.8% with the magnetic damping method. Therefore, this new magnetic damping method can be very cost effective, in terms of vibration reduction and tool life extension, if applied to industrial turning operations of metals.
Numerical Analysis of the Galloping Character of Fan-Shaped Ice Cover Conductor
Authors: Cheng Zhi Hui , Chen You Hui , Zhang Ru Yu
Published: July 2014

The hypothesis of half sine wave of cable galloping in span is adopted. For the problem of flabelliform iced cover conductor galloping, this paper presents a flabelliform cable galloping model of three degree-of-freedom based on D’Alembert Principle which considers the velocity coupling between air force and the cable torsional vibration. For the typical parameters of overhead line, based on the flabelliform cable galloping model of three degree-of-freedom, used the software Matlab for numerical simulation. Explore the flabelliform cable galloping characteristic of the wire on the condition of the different wind speeds, different angle of attack and span. According to the horizontal and vertical amplitude changes, determined the critical condition of transmission line dancing, and compared with the measured results are closer, according with the galloping mechanism of Nigol. It’s proved this theory is feasible, which is helpful to further study and the character of galloping.
Reasonable Choice of Motorized Spindles with HSK Tool Connection
Authors: Molodtsov Vladimir Vladimirovich , Barbin Andrey Yurevich
Published: July 2014

The article describes the problem of reasonable choice of parameters of main motion drive of modern multi-purpose machine tools. Authors propose a multi-purpose methodological model for reasonable estimation of operational capabilities of motorized spindles and efficiency of equipment usage for performing of required technological operations. Dependencies are provided considering influence of HSK connection on operational parameters of drives.
Truck Crane Hoisting Boom Reliability Analysis Based on Probabilistic and Interval Hybrid Model and Bayesian Network
Authors: Sun Qi , Xie Zheng Yi , Qu Fu Zheng
Published: July 2014

The accidents of truck crane happen frequently during working because of the structure failure of hoist boom, which result in severe economic loss and casualties. So, the method combining probabilistic and interval hybrid reliability theory with Bayesian Network is proposed to analyze the reliability of hoist boom structure. Probabilistic and interval hybrid model is built aiming at the interval variables and random variables to calculate the failure probability of hoisting boom under different conditions. Bayesian Network model is applied to calculate the importance index of different failure causes. In the end of the paper, practical example is given to illustrate the validity and efficiency of the present approach, which can provide basis for hoist boom design based on reliability.
Numerical-Experimental Comparison to Validate a Mathematical Model for the Determination of the Superplastic Material Constants
Authors: Gillo Giuliano
Published: July 2014

This paper shows a numerical-experimental comparison to validate a mathematical model which is able to determine the superplastic material constants by means of experimental tests carried out using a standard forming die geometry. In particular, the constants m, n and K for the lead-tin alloy PbSn60, for the alloy AZ31 at different forming temperatures and for the alloy AA5083 are evaluated.
Application of Simulation Technology on the Design of One Special Expandable Tubular Thread
Authors: Liu Yong Gang , Lian Zhang Hua , Li Xiao Jun , Ye Ding Peng
Published: July 2014

(minimum 200words, maximum 300-500words) The solid expandable tubular technology is one of the most important ones which play key role in 21st century’s oil drilling industry. The expandable thread connection is one of the key factor of the technology which decide the success or failure of expansion casing site construction. Finite element simulation can help analyze the feasibility effectively on expandable casing thread connection structure design and save a lot of material and financial resources. According to a special expansion casing thread which with single hook thread characteristics, metal seal cylinder and seal ring, this paper use the finite element simulation analysis method to learn the stress, strain and displacement being occurred in thread connection during the process of expansion. The finite element simulation analysis results shown that the wall thickness decreased about 0.66mm after the expansion, the maximum stress of expandable casing connection during expansion was 494 MPa which between the yield stress(ss= 380MPa) and ultimate strength(sb= 650MPa) of the casing material, the most dangerous place of thread connection was the roots of thread, there was gapless between contact surfaces of the messing thread with contact pressure during the expansion, and the rubber sealing ring kept the state with the minimum 4.64 MPa compress stress during the expansion. Through the simulation, It can come to a conclusion that the special thread structure could meet the expected connection and seal function effectively during the expansion process, which provides an important basis for the following thread processing and expansion test.
Flexible Modeling and Dynamic Design of the Auto Jack
Authors: Qiu Hai Fei , Li Shao Hai , Wu Song Lin
Published: July 2014

For evaluating the stress state of the jack more precise, the technology of flexible modeling was applied to structure design of the jack. The simulation model with rigid body of the components were set up by AutoFlex module, and the jack’s dynamic curves in static loads were acquired through flexible simulation, then the dynamic characteristic and stress state of the jack which in working process was understand. Based on that, some basis was offered for improvement and reliability design of the jack.
Conversion of Strontium Hydroxyapatite Nanopowders to Porous Scaffolds for Bone Implant Application
Authors: Mardziah Che Murad , Sopyan Iis , Hyie Koay Mei , Nik Roselina N.R.
Published: July 2014

The fabrication of Sr hydroxyapatite (HA) porous scaffolds was done by using polymeric sponge method. To prepare the porous samples, the synthesized SrHA nanopowders were mixed with distilled water and appropriate amount of dispersing agent followed by drying in the ambient air and sintering at 1300°C. The compressive strength of the materials was strongly influenced by the porosity, while there was almost no dependence on the crystallinity of the powders since XRD patterns showed high crystallinity of HA phase for all porous samples. Morphological evaluation by FESEM revealed that the SrHA scaffolds were characterized by macro-micro interconnected porosity, which replicates the morphology of the cancellous bone. Compression test on the porous scaffolds demonstrated that doping 10 mol% of strontium in HA has increased the compressive strength by a factor of two compared to the undoped HA with 1.81±0.26 MPa at 41% porosity.
Improvement of Automated Guided Vehicle Design Using Finite Element Analysis
Authors: Ahmad Shafeek , Yeong Che Fai , Su Eileen Lee Ming , Tang Swee Ho
Published: July 2014

Automated Guided Vehicle is a mobile robot used in various industries to transfer goods and materials from one place to another in the industrial compound such as production line and warehouses. Due to the payload it should carry, the design should be able to handle certain level of mechanical stress. The optimization study is important to assure the material and design is safe an optimum under the specified conditions before the AGV is manufactured. In this study, a conventional AGV designed previously by an AGV manufacturer to bring a payload of 70 kg is analyzed using the Finite Element Method (FEM) and SolidWorks software is used to do the FEA simulation. This paper also explain on how the factor of safety for the AGV is derived. The parameter change in this study were the thickness of the sheet metal used to build the AGV while the study output is the stress level, factor of safety and weight of the AGV.
Study on Virtual Prototype Modeling of Swing Movable Teeth Transmission
Authors: Wang Yan Fang , Zhang Qing Ping
Published: July 2014

As a new type planetary gear device, swing movable teeth transmission is used to transmit rotary motion and power between two shafts with same axis. It has compact structure, a large range of transmission ratio, strong carrying capacity and widely used. According to the principle of gear meshing, it was analyzed the principle and characteristics of the swing movable teeth transmission. Based on the structure was designed, after the entity modeling of the parts and the virtual assembly of the transmission are established, the virtual prototype modeling of swing movable teeth transmission was carried out by Solid Edge software. Virtual prototype modeling of transmission would provide the necessary for the force analysis and performance simulation.
An Approach to Recognize Machining Features for In-Process Models by Using a Hybrid Graph and Rule-Based Method
Authors: Shao Li , Bai Xiao Liang , Zhang Shu Sheng , Li Liang
Published: July 2014

A hybrid graph and rule-based method for recognizing machining features is proposed in this paper, which aims to get the machining feature in 3D in-process model construction system. Initially, the attributed adjacency graph (AAG) of the input MBD models is constructed and represented in matrix form. After that, by deleting the convex edges of the AAG, the concave sub-graphs are generated. For obtaining the volumetric features, their concave sub-graphs are matched with the feature template graphs in a pre-defined library; for those which can be generated by sweeping the edge loops, such as open pocket, closed pocket, through pocket and slot, their features are recognized by using rules. In experimental section, an example is given to illustrate the validity and effectiveness of the proposed method.
The Determination of the Three-Point Support Design of Machine Tool Based on iSIGHT
Authors: Zhao Sheng Hui , Zhu Xiao Chuang , Zhang Da Wei
Published: July 2014

In order to meet the requirements of high-precision machine tool, it has been an important factor to select an appropriate way to support the bed. By building a multidisciplinary optimization (MDO) process based on iSIGHT, this article select the deformation difference of the guides and the deformation difference of the joint surface between column and bed of the machine tool as the objective functions, and then conduct a multi-objective optimization (MOO) of the positional parameters of the three-point support. Eventually the optimization result is given and the optimal position of the three-point support is determined.
CFD Analysis of Energy Loss of Direction Control Valve in Electro-Hydraulic Systems with Inverter
Authors: Junchangpood Aphaiwong
Published: July 2014

This paper presents a new approach for reducing energy consumption coupled with force and position controls in the electro-hydraulic systems (EHS). The EHS inverter will be added for control to vary the speed of electric motor driven hydraulic pump. In addition, a single directional control valve is used to control the system parameters, which cause loss of energy. The main objective of this research is to numerically analyze the energy loss in the new control approach in the EHS with the inverter by using a simple directional control valve. The spool displacements of 4/3 hydraulic closed center directional control valve, transient flow-pressure coefficient and energy loss were simulated with computational fluid dynamics (CFD). In addition, this paper presents CFD results. The relationships of flow rate variables with time-dependent pressure drop and energy loss were addressed. The flow behaviors related with transient flow-pressure coefficients were also discussed. It is found that the loss of energy increases, depending on both the large opening spool displacement and the inlet flow variable.
Synthetic Design of High Aspect Ratio Folding Wings Based on Aeroelastic Analysis
Authors: Lv Sheng Li , Wang Cheng , Ou Yang Biao , Yang Guang Jun , Tong Xiao Yan
Published: July 2014

Finite element model of folding wings was designed in the light of structural scheme, and each part of the model used composites. Different aeroelastic analysis models were built from emission to cruise, and then the models were made the study focus on flutter analysis. The result showed the change relationship of the critical flutter speed of wings and flutter frequency with sweep angle in state of expansion process, and the change relationship of the critical flutter speed of wings and flutter frequency of folding wings with cruising altitude and cruise Mach number in state of cruise. The whole flight state was analyzed if the folding wings might flutter, and if it took place the structure optimization of wings was needed. Simulation results have a certain guiding significance for practical engineering application.
Real-Time Semi-Physical Simulation of Industry Design System Based on Virtual Reality Technology
Authors: Liu Jun , Zhang Lin Xuan , Cui Bing
Published: July 2014

Research how to realize real-time hardware in the loop (HIL) of industry design system by utilizing a variety of virtual reality (VR) hardware and software. In this paper, it introduces VR and virtual prototyping technology, and then proposes joint control and simulation based on ADAMS / Aircraft, Simulink, Flightgear three software. Moreover, the virtual scene, data gloves and real-time semi-physical simulation are analyzed and researched; finally as an example, build a real-time semi-physical simulation platform of the landing gear system for multi-wheel and multi-strut aircraft. The system can do kinematic and dynamic analysis, real-time control by visual prototyping and digital models through real-time data acquisition and co-simulation.
Research on the Static and Dynamic Characteristics of the Sliding Rail Joint Surfaces of the Fe-Based Porous Oily Material
Authors: Ma Jian Feng , Li Qiang , Wu Liang Sheng , Qu Chong Nian
Published: July 2014

The dynamic characteristics of joint interfaces have significant effect on both static and dynamic behaviors of the whole machine tool structures. A test system for identifying the unit area dynamic characteristic parameters of Fe-based joint interfaces in still and motion states were represented based on Equivalent Single Degree Of Freedom (ESDOF) system theory. Compared with the stiffness and damping parameters in stationary state, the stiffness is reduced and the damping is increased in motion. When the velocity increased, the equivalent stiffness and damping parameters of joint interface are both increased.
Slip Enhancement in Continuously Variable Transmission (CVT) by Using Adaptive Fuzzy Logic and LQR Controller
Authors: Sameh Bdran , Ma Shu Yuan , Samo Saifullah
Published: July 2014

Enhancement of fuel consumption and transmission efficiency needs a continuous improved variator performance in continuously variable transmission (CVT). This paper focuses on the improvement of a slip controller for a hydraulically actuated metal push-belt continuously variable transmission (CVT), using model for variator dynamic in the CVT. The slip control purpose is to improve the performance of variator and to increase the efficiency of CVT by determination the line pressure which generates the clamping force. The selection of slip reference-point is taken at the transition region between the micro and macro slip region to guarantee the maximum variator efficiency. The adaptive fuzzy logic control (FLC) and Linear Quadratic Regulator (LQR) controllers are applied to control the clamping force. The proposed control systems are designed to ensure the existence of a slip values within the region, which has the traction coefficient maximum value, while the load disturbances caused by suddenly changed torques in the drive lines. These approaches have potential for the CVT efficiency improvement, as compared to PID controller. The adaptive fuzzy logic control technique uses a simple group of membership functions and rules to achieve the desired control requirements of slip in CVT. Simulation results show that satisfactory slip improvement is achieved together with good robustness against suddenly changed torques. It is further revealed that all adaptive fuzzy logic control and LQR controller have a valuable effect on minimizing the slip amount and maximize the variator efficiency
Double-Acting Pneumatic-Hydraulic Pressure Amplifier Having Two-Step Liquid Pressure Output Pressure Driven by Pneumatic Cylinder with Rodless Piston
Authors: Wang Ming Di , Sun Li Ning , Zhong Kang Min
Published: July 2014

The working principle of a new kind of double-acting pneumatic-hydraulic pressure amplifier having two-step output pressure driven by the pneumatic cylinder with rodless piston is introduced. The output flux and the output pressure calculating formulae are also given out. Compared with the known single-acting pressure amplifier,the innovative pressure-amplifier is simple in structure and has much higher working efficiency. It can also output adaptive two-step liquid pressure, which is similar with the hydraulic differential connection, thus it is easy to realize move quickly in low pressure and move slowly at high pressure. This system also fits a trend of green manufacturing for using green air as transmission medium and with closed oil without leak to output pressure liquid.
Optimal Design of Voice Coil Motor for Micro Stage
Authors: Jeong Jae Heon , Kim Myeong Hyeon , Woo Si Woong , Gweon Dae Gab , Hong Dong Pyo
Published: July 2014

Micro stages have been used for various purposes on such as industry inspection, positioning technology, and manufacturing of semi-conductor etc. These micro stages have voice coil motor for actuator. The actuator has to be properly made in confined volume to generate enough force to thrust the stage. Therefore, the voice coil motor, which is actuator for the micro stage, should be optimally designed. In this paper, it is described how to design the voice coil motor in an optimal way.
Development of Vibration Simulator to Evaluate Vibration Characteristics for Railway Structure
Authors: Yoon Hyuk Jin
Published: July 2014

Vibration simulator is developed to excite the railway structure in one direction to measure the vibration and damage characteristics from the abnormal vibration in certain circumstances. The simulator consists of a base plate, a motor, several holders to fix the structure and a vibration controller. The vibration frequency can be controlled by an accurate frequency controller with 0.1Hz frequency step. The railway structure is located on the base plate which is integrated with an excitation motor. Frequency accuracy of vibration controller and amplitude level within the variable frequency range is demonstrated.
Influence of Successive Load Rejections on Water Hammer Pressure of Spiral Case in Long Diversion-Type Hydropower Station
Authors: Yu Xiao Dong , Zhang Jian , Fan Cheng Yu
Published: July 2014

Based on the theory of hydraulic transients and method of characteristics (MOC), the numerical model of hydraulic transients in water way system was established using the data of a practical hydropower station, and the probable transients were simulated. The influence of successive load rejection conditions on water hammer pressure of spiral case was analyzed. Compared with simultaneous load rejection, successive load rejection can make maximum pressure in spiral case and maximum rotating speed of runner more serious if the bifurcated pipe converging under surge tank in diversion-type hydropower station.
Valveless Pump in Closed Loop Tube System
Authors: Mahat M. Mazwan , Tharazi Izdihar , Roslan Liyana , Jasni Mohd Fakrul
Published: July 2014

This research work aims to identify the characteristic of flow in valveless impedance pump which uses acoustic impedance mismatch to drive flow. The experimental setup mainly focuses on the elastic section connected between two ends of rigid tube. Fluid flow rate resulting from the pumping mechanism were measured at different supply voltage. Meanwhile, the volume flow rate (ml / min) in the elastic tube section were also determined based upon different pinch location and width using water as a working fluid. In order to achieve these parameters quantification, the experimental test rig was designed and the set of equipments were successfully assembled. Then, the measured parameters resulting from the experiment of the impedance pump are presented in significant findings of four curves plots. It is found that the maximum flow rate occurred at voltage setting equal to 4 V. Significantly, results obtained could beneficial future design as a mimics model for novel Ventricular Assist Device use in cardiac patient as well as further explanation about the factor that influence the characteristic of valveless impedance pump.
Computer Aided Design and Manufacture of a Novel Vertical Axis Wind Turbine Rotor with Winglet
Authors: Ahmed Noor A. , Netto K.J.
Published: July 2014

In this paper the computer aided design and manufacture of a rot with winglet for performance enhancement of a vertical axis wind turbine is presented. Both computer numerical control milling and rapid prototyping have been used in the manufacture of the rotor. The rotor was then tested for performance using the large wind tunnel of the Aerodynamics laboratory of University of New South Wales. The results show substantial improvement of the rotor with the winglets installed.
Engine Performance and Emission of Emulsified Biodiesel
Authors: Aziz Amir , Yusof Ahmad Fitri , Mamat Rizalman , Azeem W.N.
Published: July 2014

An emulsion of biodiesel and water is one of the possible approaches that have been used to overcome diesel engine pollution. In this work, the performance and emission characteristics of a 4-cylinder diesel engine using pure diesel, biodiesel B20 and emulsified biodiesel were investigated. Emulsified biodiesel containing 5 % and 10 % water were utilize for the engine tests. During the experimental work, the engine was set-up at 2500 rpm and 20 % to 60 % loads. The result shows the reduction in NOx formation when the water content in emulsified biodiesel increased from 5 % to 10%. For the performance, there were no significant differences between the engine break powers measured for emulsified biodiesel containing 5% water and diesel fuel.
Analysis on Dynamic Characteristics of Closed Hydrostatic Guideway Throttled by Capillary
Authors: Zhu Xiao Chuang , Gao Wei Guo , Liu Teng , Zhao Sheng Hui , Zhang Guan Wei , Zhang Da Wei
Published: July 2014

Hydrostatic guideway is widely used in heavy and ultra-precision machine tools due to their high bearing capacity, low coefficient of friction and high capacity of precision-remaining. So it is necessary to carry on theoretical research on its dynamic characteristics. Firstly, the oil-film damping coefficient of closed hydrostatic guideway throttled by capillary is derived. Secondly, a new dynamic mathematical model, considering the oil damping effect, the extrusion effect and the volume effect, of the closed hydrostatic guideway is proposed. Thirdly, the frequency characteristics and step characteristics of it are simulated in Matlab Simulink through the transfer function. Finally, the paper investigates the influence of damping coefficient, the oil pressure, volume effect and the initial oil-film thickness on the dynamic characteristics of closed hydrostatic guideway throttled by capillary.
Analysis of the Dynamic Characteristics of the Aerostatic Journal Bearings
Authors: Xu Chun Dong , Feng Hui Hui , Wang Feng Feng
Published: July 2014

This paper investigates the dynamic characteristics of the aerostatic journal bearing, the rotation center of which is not the center of the journal length. The Finite Difference Method (FDM) and the perturbation method are employed to calculate the stiffness and damping coefficients. Results show that the coupled stiffness and damping coefficients cannot be neglected due to the rotation center being not the center of the journal length. Furthermore, with the increase of the distance between the rotation center and the center of the journal length, the coupled stiffness and damping coefficients increase.
Combined Influence of Misalignment and Orifice Diameter on the Static Performances of Hydrostatic, Water-Lubricated Journal Bearings
Authors: Feng Hui Hui , Xu Chun Dong , Wang Feng Feng
Published: July 2014

The water-lubricated bearings have gained an increasing focus to overcome the disadvantages of the oil film bearings and gas bearings. In this paper, the influences of orifice diameter in aligned and misaligned conditions on the static performance of two hydrostatic, four-recess, water-lubricated journal bearings used to support a rigid rotor, are investigated. The steady Reynolds equation for the journal bearing for the turbulent bulk flow and the film thickness expression considering tilting angles are used and numerically solved by finite difference method. Results demonstrate that the static performances, such as the quality, power loss and temperature rise are affected by the tilting angles, orifice diameter to some degree.
A Study of Water Crystal Growing Based on Dilution and Succussion Theory of Homeopathy
Authors: Hsu Yi Chu , Liang Yong Shang , Cheng Po Yuan
Published: July 2014

By studying the formation of snowflakes, scientists have found that frequency data can be stored in water. Using the homeopathic principles of dilution and succussion, this study explored the relationship between aqueous information transmission and differences in the formation of water crystals. We utilized three different types of experimental solution: bali water, distilled water, and ionized water, and studied the water crystals sprouting from the resulting ice crystals. From the four significant phases of morphological change (mother tincture, 1X, 4c, and 30c), it was determined that at higher dilution ratios, crystals grown in either distilled or ionized water developed from crystallites into a single-body structure, approaching the higher energy form of straight edge hexagonals. This phenomenon demonstrates the features of coherent domains and water clusters, both of which match the homeopathic principles of energy waves and information transmission.
The Study on PCCI Mode of Diesel Engine Fueled with Methanol/Dimethyl Ether
Authors: Yan Yan , Zhang Yu Sheng
Published: July 2014

Taking into account China's abundant coal resources, methanol and DME(Dimethyl Ether) obtained from coal are good alternative fuels. The research project is to utilize the fuel of DME and methanol in diesel engines for new combustion models PCCI (Premixed Charge Compression Ignition).The tests of the PCCI mode with different boundary conditions were studied on PCCI test bench. PCCI combustion is consisted of three stages: low temperature reaction of DME, high-temperature reaction of DME and diffusion combustion reaction of methanol. DME as combustion improver should be kept relatively low concentration, and with the decrease of methanol, its concentration need to be reduced. Methanol and formaldehyde are important parts of HC emission, their volume fraction was about 70%.
A Rapid and Efficient Feature Point Detection and Matching Algorithm
Authors: Ding Xiao Ling , Zhao Qiang , Li Yi Bin , Ma Xin
Published: July 2014

In the field of computer vision research, object feature detection and matching algorithm become a hot. Aiming at SIFT algorithm and SURF algorithm cannot meet the needs of real-time application, a feature point detection and matching algorithm based on orient FAST detector and rotation BRIEF descriptor is used. The experiments demonstrate that, this method not only remains the advantages of SURF but also improves the detection speed, and it can fully applicable to the field of computer vision to detect moving targets.
Sustainable Natural Bio Composite for FDM Feedstocks
Authors: Ibrahim M. , Badrishah N.S. , Sa'ude Nasuha , Ibrahim Mohd Halim Irwan
Published: July 2014

This paper presents the development of a new Wood Plastic Composite (WPC) material for Fused Deposition Modeling (FDM) feedstocks. In this study, a biodegradable polymer matrix (POLYACTIDE, PLA) was mixed with natural wood flour (WF) by Brabender mixer, and the samples produced by injection molding machine. The effect of wood was investigated as a filler material in composite FDM feedstock and the detailed formulations of compounding ratio by weight percentage. Based on results obtained, it was found that, compounding ratio of PLA80%:WF20% has a goods result on the tensile strength and PLA60% : WF40% gave a higher value of flexural strength. An increment of 20% to 40% WF filler affected the flexural strength, and hardness results. The highly filled WF content in PLA composites increases the mechanical properties of PMC material through the injection molding process. The potential of development of a sustainable composite material will be explored as the FDM feedstocks in the rapid prototyping process.
A Comparison of Short Duration Traffic Counts Methodologies for Estimating Annual Average Daily Traffic
Authors: Ha Jung Ah
Published: July 2014

Annual average daily traffic (AADT) serves the important basic data in transportation sector. Future level of service is forecasted, based on design traffic volume. AADT is used as design traffic which is the basic traffic volume in transportation plan. But AADT is estimated using short duration traffic counts at most sites because permanent traffic counts are installed at limited sites. A various of methodologis about short duration traffic counts are used to estimate AADT. This study compared with typical short duration traffic counts methodologies in USA and Korea. Short duration traffic counts in USA typically are defined as stations where 24-hour, 48-hour of data is collected. In Korea, short duration traffic counts are collected at one day (24-hour) or two days (not two consecutive days). So this study compared among each short duration traffic counts methodology: one day (24-hour), two consecutive days (48-hour), not two consecutive days (twice per year). Short duration traffic counts surveyed twice per year is the best method to reduce AADT estimation error among analyzed methodologies. The analysis found that in case adjustment factor is applied to estimate AADT, AADT estimation error is further lowered.
Comparison of Crack Extraction Performance According to Different Edge Detectors
Authors: Cho Hyun Woo , Yoon Hyuk Jin
Published: July 2014

Edges of images contain important information such as form, size, and location of objects. Thus, edge detection is an extremely important factor in image processing. In order to detect such edges, much research has been carried out, and edge detectors such as Sobel, Prewitt, Robert, Canny, and Laplacian of Gaussian (“LoG”) are universally used. This Research compares and analyzes the crack extraction function of each edge detector to automatically detect cracks occurring in concrete structures. In order to do this, simulated crack samples of various widths and contrasts were produced and attached to concrete walls, and crack images were taken from different distances. Cracks were extracted from the images taken using edge detectors like Sobel, Prewitt, Robert, Canny, and LoG, and the crack extraction performance of the edge detectors used were compared and analyzed based on the photographed distance.
Building a Practical Anechoic Chamber for Aero-Acoustic Measurements
Authors: Ahmed Razeen F. , Yendrew Yenas , Ahmed Noor A.
Published: July 2014

The design, manufacture and installation of a practical and cost-effective anechoic chamber for aero-acoustic measurements are presented in this paper. The work was undertaken with a view to measure the aerodynamically generated noise of wind turbines under laboratory conditions. The chamber was designed to be used in conjunction with a wind tunnel. Tests were carried out to compare the reduction of noise levels from external sources with and without the chamber. The results obtained suggest a clear reduction of noise levels with different wind speeds, and as expected, resulted with higher reductions at higher wind tunnel speeds.
Oxidation of Inconel 690 Alloys at 800-1000°C in Air
Authors: Park Soon Yong , Lee Dong Bok
Published: July 2014

The Ni-based superalloy, Inconel 690, was oxidized between 800 and 1000°C for up to 300 h in air. It displayed good oxidation resistance, because the formed scales consisted primarily of Cr2O3. As the oxidation progressed, CrMn1.5O4 also formed on the surface through the ensuing outward diffusion of Mn from the alloy. Internal oxidation occurred below the scale-alloy interface along grain boundaries of the matrix.
Improving Engine Oil Properties by Dispersion of hBN/Al2O3 Nanoparticles
Authors: Abdullah Muhammad Ilman Hakimi Chua , bin Abdollah Mohd Fadzli , Amiruddin Hilmi , Tamaldin Noreffendy , Nuri Nur Rashid Mat , Hassan Masjuki , Rafeq S.A.
Published: July 2014

This paper provides oil properties study of conventional diesel engine oil enriched with hBN/Al2O3 nanoparticles. In this study, an optimal composition (0.5 vol.%) of hBN and Al2O3 nanoparticles separately dispersed in SAE 15W40 diesel engine oil by sonication technique. The oil properties were studied by measuring the Viscosity Index (VI), Total Acid Number (TAN), Total Base Number (TBN) and flash point temperature. The results reveal that the nano-oil with hBN nanoparticles could improves or at least maintain the key lubrication properties, though the TAN value is slightly increased. The results presented here may facilitate improvements in the conventional diesel engine oil performance.
Effects of UV-HEPA Air Filters on Air Quality Status inside a Public Museum in Malaysia
Authors: Ismail Marzuki , Baharuddin Nurul Hanna Attiya , Anuar Anis Syafizee , Suroto Azrin
Published: July 2014

Poor indoor air quality is a major threat towards workers since the office or office-like environment is now the workplace for the majority of the workforce in Malaysia. Workers in office buildings frequently have unexplained work-related symptoms or combinations of symptoms but evidence suggests that microbial contamination plays a part. Ultraviolet germicidal irradiation lights with high efficiency particulate air filter (UV-HEPA) are recognized for eradicating biological contaminants and capturing particles in indoor environments. Here, the effectiveness of UV-HEPA purification unit was obtained in two selected workplaces i.e. laboratory of conservation and laboratory of natural resources. Results show that there exist significance difference (P<0.05) on indoor air quality between pre-installation and post-installations of UV-HEPA filter in both selected room. Furthermore, it shows that UV-HEPA filter is effective in removing indoor air pollutants and improves the air quality. The use of UVGI lights with HEPA filter resulted in significant reduction in the concentration of microbes and respirable particulates within the ventilation systems. Keywords:indoorairquality,microbes,respirableparticulates,UV-HEPApurificationunit
Changes Process of the Shear Modulus in Gravel Bed under Horizontal Vibration Triggering
Authors: Jiang Hong Ying , Song Liang Liang , Lu Jin Bu
Published: July 2014

Based on the experimental study of response of the gravel cushion under the horizontal vibration loads, analyzed internal shear modulus changes process in the granular layer , which are the changing characteristics caused by the self-organization, particles movement and compacting degree. We simulated the response process of shear modulus in the granular layer by using the Poisson process, discussed the development of shear modulus after several vibration and established the model.
Inhibition Mechanism of Benzotriazole in Copper Chemical Mechanical Planarization
Authors: Li Jing , Lu Xin Chun , Zhang Zong Bo
Published: July 2014

During the process of chemical mechanical planarization (CMP) of copper, benzotriazole (BTA) is the most commonly used inhibitor in the slurry. Though the corrosion inhibition mechanism has been studied widely, the mechanism of BTA layer on copper surface in CMP slurries should be further investigated. In this paper, the adsorption mechanisms of BTA were studied by static corrosion tests. Besides, the surface composition was measured by XPS. Combining with CMP experiments, the material removal mechanism of copper CMP depending on pH values was investigated. It was found that the formation of passive film, consisting of Cu-BTA complex, adsorption of BTA and copper oxides, played a dominant role under acidic conditions. While the surface film composed of adsorption layer of BTA and copper oxides under alkaline conditions. The inhibition mechanism of BTA varied with pH values, resulted in corresponding changes of material removal rate and coefficients of friction.