bluuebunny/crossref_metadata_2025 huggingface dataset:
Pile Groups Displacement Calculation Based on Mindlin Solution and Principle of Minimum Potential Energy
Authors: Fei Xiang , Zheng Yong Lai , Yang Wei Wei , Deng Shu Xin
Published: February 2014

A displacement function of a single pile among pile groups was proposed according to Mindlin solution. Using variational theory and principle of minimum potential energy and considering the relation between shear stress of soil around piles and displacement described in Randolph single pile displacement solution, the relation between soil and settlement in the tip of a pile was derived. Relation between load and displacement of a single pile among pile groups was obtained. It was compared with other examples after that. The result calculated by the method proposed here matchs closely with the result calculated by other methods.
Design of Low Carbon Footprint Alkali Activated Slag Cement Concretes for Marine Engineering Application in China
Authors: Cao Hai Lin , Krivenko Pavel V. , Weng Lu Qian , Guo Yue , Petropavlovsky O.N. , Pushkar V.I. , Kovalchuk A.Yu.
Published: February 2014

The paper covers the results of studies of the alkali activated slag cement concretes from the cements prepared under all-in-one technology to meet the requirements for concretes for marine engineering application. The compressive strength, weather resistance, biodegradability, bonding strength with steel reinforcement bar, steel reinforcement bar protection, chlorine ions diffusion parameters and resistance to corrosive exposure of 5% Na2SO4 solution were tested, which exhibit that alkali activated slag cement and concretes are very suitable for marine engineering applications.
Outsourcing of Concrete Filled Steel Tube Strengthened CFST Axial Compression Short Columns Finite Element Analysis
Authors: Wu Yang Feng , Zhang Hong Mei
Published: February 2014

A new composite strengthening method that the CFST short column was strengthened with concrete filled steel tube was presented. Through the finite element analysis of five specimens with strengthening circular concrete filled steel tube columns and a specimen without strengthening circular concrete filled steel tube to explore the impact of the outer layer of concrete strength grade, external pipe wall thickness for the ultimate bearing capacity of concrete filled steel tube columns. The results show that with the increase of the outer pipe wall thickness, double concrete filled steel tube column yield strength and ultimate strength have increased. As the outer concrete strength grade increased as the specimen bearing capacity increased. When the concrete strength grade greater than C40, the improvement of concrete strength for specimen ultimate bearing capacity is not great.
Design and Implement of Equipment Resources Management Support System Based on ExtJS Integrated Framework
Authors: Zhang Jian Jun , Liu Hu , Ni Fang Ying
Published: February 2014

With the continuous development of human society, sustainable resources has become an important issue of concern, and good resource management is an important assurance for sustainable resources. In this paper, we proposed an integrated framework base on ExtJS and SSH. SSH provides a weak coupling, easily maintainable, lightweight J2EE software development model, which can be used to build high-quality Web applications. The proposed framework can be used to build a flexible, easily extended and maintainable multi-layer Web application platforms. We developed an equipments resources management support system based on the proposed framework, and experimental results show that the efficiency of equipment resources management could be improved through using the developed management support system.
Research on Mud Pulse Signal Starting Time Extracting Algorithm in MWD
Authors: Zhang Guo Yun , Tu Bing , Zhan Teng Xi
Published: February 2014

The mud pulse signal extracting in MWD(Measurement while drilling) was a core technology in the oil drilling developing process. Determining how to accurately define the mud pulse signal starting time was a key issue affecting the decoding accuracy. This paper analyzed the transmission format of down-hole datum and transmission characteristics of mud pulse signal, using a wavelet multi-scale and related de-noising algorithm to extract mud pulse signal. On this basis, according to the characteristics of the underground encoded synchronization signal, It proposed an algorithm based on equal segmentations within a signal period to define the mud pulse signal starting time .The field tests show that the algorithm can accurately define the mud pulse signal starting time and can effectively improve the decoding accuracy and meet the requirements of engineering applications.
Research of the FEM Mesh Generation Based on Patran
Authors: Han Qian Peng , Peng Bo
Published: February 2014

Finite element method(FEM) have been widely used in modern mechanical design,mesh generation is an important part of the finite element analysis,this article discussed the process of mesh generation through two practical cases and put forward some issues we should pay more attention to.
Mining Engineering Professionals Motivated to Improve their Proficiency in English
Authors: Shen Hai Ying , Wen Shu Ming , Wang Ti Zhuan
Published: February 2014

The industrialization is progressing on the unparalleled scale, bringing an ever greater impetus to the growth of mining industry. China has had its unique pattern of developing its mining engineerin: firstly importing technologies, then studying and absorbing them, and finally achieving some innovation. Until now, China has been honored with some of mining theories taking the lead in the international mining world. As the disseminators of human civilization including advanced mining technologies, the Chinese professionals concerned are duty-bound to introduce abroad Chinas new progresses in mining engineering; that they are skillfully equipped with the four kinds of English abilities in reading, writing, listening and speaking, which is prerequisite for them to work well in foreign cooperation, has become an urgent matter to for them as well as for the authorities concerned.
Fuzzy Logic Based Closed-End Questionnaire Design
Authors: Peng Na Xin
Published: February 2014

Customer demand is the driving force behind the development of enterprises. It is the core of mass customization production mode that access to customer demand information, analysis and management. Questionnaire is an important way to get customer demand. This paper presents a design of closed-end questionnaire about electric bicycle which has two characteristics: (1) highlighted the access to subject features of customer. (2) the numerical answers will be processed using fuzzy logic.
The Research on Grounding Pressure Distribution of Tracked Travelling Mechanism
Authors: Liu Xi Yang , Jiao Zhi Yong , Zhang Mei Yu
Published: February 2014

The grounding pressure of tracked vehicles is closely related to the overall structure of the vehicles and the ground conditions, and its distribution is more complex and changes in the different center of gravity. So in this paper, under certain assumptions, we derive the mathematical model of the grounding pressure distribution through analysis and research, which can predict the ground pressure distribution of tracked vehicles at any moment. By analyzing the tracked grounding pressure distribution, we put forward the concept of core region of track connecting with the ground, and some meaningful conclusions and formulas for the overall design of tracked vehicles.
Transient Liquid Sloshing in Partially-Filled Tank Vehicles
Authors: Zheng Xue Lian , Li Xian Sheng , Ren Yuan Yuan , Cheng Zhu Qing
Published: February 2014

To investigate the accuracy and the scope of application of the QS method in transient liquid sloshing, 3 different tanks are selected as the research object. The liquid fill level is set at 0.6 and the constant lateral acceleration changes from 0.1 g to 0.4 g. The transient liquid sloshing is simulated by FLUENT and the relevant QS results are solved at the same conditions. The mean and maximum values for transient liquid sloshing effect are compared with the corresponding QS results. It was found that the mean values in a cycle are quite close to the QS calculation results. Furthermore, the QS method can only be used when the external excitation is constant and smaller. For lateral acceleration which is constant but large, and time-variation ones, the QS method is not suitable.
A Improved Particle Swarm Optimization Algorithm for the Application with Boundary-Layer Problems of Power-Law Fluids
Authors: Zhou Jian Hui , Yue Li Xi , Lu Yan Nan
Published: February 2014

In fluid mechanics, how to solve power-law fluids in ordinary differential equations is always a concerned and difficult problem. we use generally a shooting method to tackle the boundary-layer problems under a suction/injection as well as a reverse flow boundary conditions. A improved particle swarm optimization algorithm (ISPO) is proposed for solving the parameter estimation problems of the multiple solutions in fluid mechanics. This algorithm has improved greatly in precision and the success rate. In this paper, multiple solutions can be found through changing accuracy and search coverage and multi-iterations of computer. Parameter estimation problems of the multiple solutions of ordinary differential equations are calculated, and the result has great accuracy and this method is practical.
Research on the Improvement of Technology of Low Pressure Loss and Wide Range Swirlmeter
Authors: Xie Shuang Wei , Hu Jin Min , Liang Xiao Min , You Shao Qing
Published: February 2014

This paper mainly introduces the technical parameters and the structure of low pressure loss and wide range swirlmeter. We redesigned the vortex generator of swirlmeter and changed the traditional spiral blade to linear blade. The included angle between the blade and the axis was reduced from 60 degrees to 30 degrees, which can increase the flow area and reduce the pressure loss. We converted the blade from stainless steel to the shape of isometric changed curve, and the frequency detection sensor is designed to four piezoelectric crystal sheet, the pressure loss is lower than that of spiral vortex generator. The test results show that the pressure loss of improved swirlmeter is decreased and the lower limit of measurement is reduced.
Sparse Representation De-Noising Based on Morlet Wavelet Basis and its Application for Transient Feature Extraction
Authors: Fan Wei , Zhu Z.K. , Huang Wei Guo , Cai Gai Gai
Published: February 2014

Signals with multiple transients are often encountered with much noise in engineering. The transient feature extraction has always been the key issue for signal analysis. A new signal de-noising method combining sparse representation and Morlet wavelet basis is proposed for signal de-noising and feature extraction. Simulation study concerning multiple transients signal shows the effectiveness of this method in transient feature extraction. The efficiency of this de-noising method is also verified by its application to extract fault signature for gearbox.
Finite Element Analysis of the Overturning Process of Ring-Stiffened Titanium Shperical-Cylindrica Diaphragm for Positive Expulsion Tanks
Authors: Wang Xue Ren , Wang Guang , Zhou Wei , Li Jian
Published: February 2014

The shperical-cylindrica metal diaphragm model is established to simulate with finite element analysis method in the large displacement for the elastic-plastic theory, which is based on the current research on the metal diaphragm for positive expulsion tanks. It shows that the unsteady state on the position of rolling is the main reason for the failure of the diaphragm. Based on the optimization to metal diaphragm's structure, The ring-stiffened metal diaphragm model is established to reduce the unsteady state. The simulation result concludes that the optimization can reduce the unsteady state effectively, which also provides the reference for the improving design of metal diaphragm.
Design of the Temperature and Humidity Automatically Detecting System Based on AT89S52/55
Authors: Liu Li , Yang Hui Jun
Published: February 2014

The temperature and humidity automatically detecting system based on AT89S52/55 single-chip is designed in this paper, which can realize temperature and humidity itinerant measurement of 32 points. This detecting system is made up of the single-chip system, sensor, multipath switch and signal processing, A/D conversion subsystem etc, multipath signal selection can be completed by CD4051 with CD4052, the circuit is simple and dependable.
Analysis of Driver Visual Characteristics Based on FaceLAB
Authors: Zheng Xue Lian , Li Xian Sheng , Ren Yuan Yuan , Cheng Zhu Qing , Zhao Qi Chao
Published: February 2014

Driver visual characteristics are of great importance for studying driver behavior and traffic safety. To investigate the difference of visual characteristics between skilled and fresh drivers, FaceLAB was used to collect visual data. Four drivers including male and female, skilled and fresh one were selected as the subjects. A suburbs road was chosen as the test road section and each driver drove several times on it. Based on the FaceLAB working mechanism and human eye diopter, correlation between head rotation and eye fixation point were derived and some important conclusions were drawn. For skilled drivers, they are relax at capturing traffic environment information and could obtain much more critical information in a rather large range while keeps the head constant. However, for the fresh drivers, they are much more carefully at getting visual information and the information capture process takes up much more time. Therefore, they could only get little information while keeps the head constant.
Distance-Scale Restricted SIFT Matching Method for Complicated Content & Different Scales Image Pairs
Authors: Wu Zhen Yu , Hong Hu
Published: February 2014

Scale invariant feature transform (SIFT) matching performance decreases greatly when images are in different scales with complicated content and wide-baseline. In this paper, we address this problem, and propose a simple method to improve SIFT matching. The proposed method restricts the matching searching area into much smaller and more likely region to improve matching performance. Experiments shows that the proposed method has saved up to 90% matching time and increased up to 4% in the accuracy, compared with SIFT and previously solutions which only improve the matching accuracy.
Early Image Fire-Detection Based on Maximum Margin Criterion
Authors: Yuan Jie , Hu Hai Bing , Yuan Wei , Jia Yang , Zhang Yong Ming
Published: February 2014

Nowadays as camera is applied widely, image fire detection becomes much popular. Many researchers are committed to analyze the RGB color model or even gray images. Actually they have some disadvantages. So this paper will present a new model based on Maximum Margin Criterion, a feature extraction criterion. As it is maximizing the difference of between-class scatter matrices and within-class scatter matrices, it does not depend on the nonsingularity of the within-class scatter matrix. First we will introduce the main idea and then give a mathematical description to apply the model to fire detection, with the algorithm we can calculate the result we need. At last we will put them into practice, use a database to do some experiments to present the performance of this method.
Controller Design Based on Mechatronic Model
Authors: Yue Li Xi , Zhou Jian Hui , Lu Yan Nan , Ji Chong Chong , Yu Zhi Yong
Published: February 2014

The dissertation deals with some key issues relevant to the controller design and digital design method for a newly patented high-speed parallel manipulator. Meanwhile, a Virtual Prototyping based co-simulation platform is also established according to the ADAMS and Matlab/Simulink software. In order to promote the ability that the manipulator traces the prescribed trajectory, a model based computed torque controller is described in detail, and a neural network algorithm is also used to optimize controller parameters real-timely under the consideration of systematic nonlinear, modeling error and outer disturbance. The neural network based computed torque controller increases the robustness of system dramatically.
The Stability and Efficiency of Network Structure with Joining Costs
Authors: Zhang Fan
Published: February 2014

This paper aim to study the stability and efficiency of a social and economic network in which the various elements are closely related by the network structure, while self-interested individuals can form or sever links with the network by incurring joining costs. Our novel feature is that we consider joining costs in network formation. Firstly, We also propose the concept of a stable network that is similar to the pairwise stability of Jackson and Wolinsky (1996) based on joining costs. We examine changes in the stability, efficiency and network structure. For a link model, we identify the main characteristics of stable and efficient networks. It is important to note that a stable network is not always efficient. Next, we show that the range of stable networks has been extended through the evolutionary process of developing networks with joining costs. Moreover, consistency, stability and efficiency also enhance the networks structure.
Overview of Visualization Tool as an Experimental Method in Iterative Participatory Design
Authors: Hussain Hanafizan
Published: February 2014

The purpose of this study is to define the iterative participatory design of the development for interface content. This paper will look into the usage of visualization tool that has been adopted in the interactive context. The study will also provide the process of iterative participatory design in the development of interface content using user-centered approach to find the perception of design process in human-computer interaction context. The findings from this study will indicate that the iterative participatory design is suited as experimental method in the development of knowledge life cycle. This study has intended to show how the visualization tool will be studied using the experimental method which will be leading the iterative participatory design in the development of knowledge sharing model.
An Efficient Quadratic Conversion Architecture for Real-Time Wideband DDC
Authors: Zhang Liu
Published: February 2014

This paper presents an efficient quadratic conversion architecture for real-time wideband DDC, it can move IF signal to baseband in two steps. Firstly, IF signal is moved to baseband nearby with the help of an structure based on polyphase filter, which places mixers after polyphase filters. Then, the signal is moved to baseband through conventional orthogonal frequency mixing. This presented architecture can reduce filter resources and effectively reduce the sample rate and process cost. Finally, simulation results are presented to illustrate the validity of the new structure.
Real-Time Suppression Research of Shaft-Rate Electric Field Based on the Compensated Negative Potential
Authors: Zhang Hai Peng , Chen Xin Gang , Ao Chen Yang , Sun Zhong Peng
Published: February 2014

To reduce the impact of shaft-rate electric field (SRE) on the concealment of the ship, the ship SRE real-time suppression is proposed based on the compensated negative potential and the real-time close-loop system for the ship SRE suppression is designed and realized£¬which greatly promoted the development of ship SRE suppression technique.
Robotic Fish Technology and its Applications to Space Mechatronics
Authors: Yamamoto Ikuo , Shin Nobuhiro , Oka Taishi , Matsui Miki
Published: February 2014

The authors have developed a shark ray robotic fish based on biomimetic approaches. The paper describes the newly developed robotic fish technology and its application to mechatronics in the space. It is found that robotic fish technology creates not only new underwater robotics, but also the next generation space mechatronics for geological survey of lunar/planets and dust cleaning in the space station.
Fuzzy Predictive Control Using Particle Swarm Optimization: Application to SCARA Robot
Authors: Hadjili Mohamed Laid , Kara Kamel , Sahed Oussama Ait , Bouyanzar Jamal
Published: February 2014

In this work a fuzzy model-based predictive control (FMPC) method that uses modified particle swarm optimization (PSO) is presented. The main objective of this work is the application of this method to the control of a Selective Compliant Assembly Robot Arm (SCARA) with four degrees of freedom (4-DOF).
Design of New Intelligent Redundant Serial Bus with Isolated Driver in the Distributed Control System
Authors: Wang Ling , Mo Bo , Li Qin Hua , Mei Hong
Published: February 2014

In the distributed control system, to make sure the running of the system bus is long-term, stable and reliable, we design a new intelligent redundant serial bus as the system bus, and it will be introduced in this article. The new intelligent redundant serial bus (IRSBUS) is able to be configured into a dual redundant synchronous bus or a quadruple redundant asynchronous bus, and its redundancy is hot redundant that means two groups of the four signals are working together. We mainly design a redundant IP core, a redundant protocol and the byte format. The IP core of IRSBUS consists of the following major modules: Intelligent Signal Router, Signal Transceiver, Lines-connecting Status Detector, Synchronous Controller (Master), Synchronous Transponder (Slave), Redundant Results Decider, Interrupt Generator, Dual-port RAMs, Control and Status Registers, Master / Slave Redundant Logical Controller. The redundant protocol and byte format provide an extremely strict timing to synchronize the master-slaves and transmit the information. We show that our design allow to compare the redundant data to arrive at the correct results. It also provides a way to regroup the remaining signal lines into a system bus when one or two of the four signal lines are broken. And then it detects the lines-connection status every 100 milliseconds.
Risk Evaluation in Marine Traffic Systems Based on Fuzzy Catastrophe Theory
Authors: Qi Ji , Zheng Zhong Yi , Li Jian Min
Published: February 2014

The main purpose of MArine Traffic Safety System (MATSS) study, based on catastrophe theory, is to ensure the safety of marine traffic and reveal the essence of traffic risks, and so as to create an effective risk prediction and control mechanism. In this paper, cusp catastrophe was modeled and evolutionary path of MATSS was described. Hence, Fuzzy Catastrophe Theory was concluded. This theory combines Fuzzy Math with Catastrophe Theory and is derived from analysis of uncertainties of marine traffic, including dynamics, irreversibility and mutability. The adverse impacts of system potential function and uncertainties of outside controlling factors were minimized via developing such a theory. The marine traffic risk model was created taking perspectives of various observers into consideration accordingly. As a result, Fuzzy Catastrophe Evaluation Method was presented, which is beneficial to the system safety state evaluation and decision. In the end of the paper, the objectivity and rationality of the method was validated by MATLAB, which has broad application in marine risk prediction and control.
Superconvergence Analysis of Finite Element Method for Onlinear Klein-Gordon Equation
Authors: Shi Yu , Meng Hong Ling , Jia Qian , Shi Dong Yang
Published: February 2014

The standard finite elements of degree p over the rectangular meshes are applied to a non-linear Klein-Gordon equation. By utilizing the properties of interpolation on the element, high accuracy analysis and derivative delivery techniques with respect to time t instead of the traditional Ritz projection operator, which is an indispensable tool in the traditional finite element analysis, the supercloseproperty with order is obtained. Furthermore, the superconvergence result is derived through the postprocessing approach.
Computational Analysis of a Magnetohydrodynamic Flow in an Electrically Conducting Hairpin Duct
Authors: Xiao Xue Jiao , Kim Chang Nyung
Published: February 2014

This numerical study examines a three-dimensional liquid-metal magnetohydrodynamic flow in a hairpin-shaped electrically-conducting duct with a square cross-section under a uniform magnetic field applied perpendicular to the flow plane. Predicted is detailed information on fluid velocity, pressure, current, and electric potential in the magnetohydrodynamic duct flow. Higher velocities are observed in the side layers in the inflow and outflow channels, yielding M-shaped velocity profiles. More specifically, in the present study the axial velocity in the side layer near the partitioning wall is higher than that near the outer walls because of the current features therein. In the turning segment, a large velocity recirculation is observed at the entrance of the outflow channel caused by the flow separation, yielding complicated distributions of the electric potential and current therein. The pressure almost linearly decreases along the main flow direction, except for in the turning segment.
Research on the Aero Dynamicity of Steady Wing of Non-Parachute Terminal Sensitive Projectile
Authors: Lv Sheng Tao , Ma Xiao Dong , Liu Rong Zhong , Guo Rui
Published: February 2014

The stable wing of non-parachute terminal sensitive projectile (TSP) is a plate wing with two bent angles at edges of the plate wing, thus it looks like an S. Wings of this shape slow the TSP down during its falling process which provides asymmetric forces for it. Then stable scanning motion is realized. This paper established unsteady model of the S wing of the TSP based on CFD/CSD fluid structure interaction (FSI) and analyzed the aerodynamic characteristics of both rigid wing and elastic wing. The results show that the plate which bends towards the windward has the largest deformation. The drag coefficient of the elastic wing is smaller than that of rigid wing at a smaller attack angle while bigger at a larger attack angle. The displacement of S wing increases while the incoming velocity increases and has a tiny interaction relationship with attack angle.
Analysis of Modal and Seismic Property of Oil Storage Tanks
Authors: Shi Cai Xia , Yang Wei Min
Published: February 2014

In the engineering background of 1000 cubic meters of anchored tank, the large-scale finite element software ANSYS was used to analysis of modal and transient of oil storage tanks. Completed oil tank model and carried on the modal analysis and then vibration characteristics were gained. On this basis, considering the earthquake excitation, analyzes dynamic response of the anchored tank under seismic load. Then gained the oil tank overall structure of displacement, equivalent stress, axial and circumferential stress. From images can be analyzed that the main vibration mode is multiple circumferential wave, the stress of upper tank and its seams is the largest under earthquake loading and easy to be damaged, strengthen circle should be set up. Through the simulation analysis provided powerful basis for seismic design of the vertical storage tank.
Effect of CaO Dopant on the Dielectric Properties of NiO
Authors: Syed Salim Sharifah Aishah , Mohamed Julie Juliewatty , Ahmad Zainal Arifin
Published: February 2014

CaxNi1-xO was prepared by conventional solid state reaction. The properties of undoped and CaO doped NiO ceramics have been studied. The raw mixture of CaO and NiO were ball milled for 24 hours. The samples were calcined at 1000°C for 2 hours, pressed into pellet shape at 200 MPa and sintered at 1300°C for 4 hours. The sintered samples were subjected to XRD, Scanning Electron Microscopy (SEM) and Impedance Analyzer for phase identification, microstructural observation and dielectric analysis. The grains size becomes larger with the increment of dopant amount. Enhanced dielectric constant was observed for all Ca doped NiO at the frequency range from 100 Hz to 1 MHz. The dielectric constant of sintered CaxNi1-xO
decreased with an increasing frequency. The result indicates that Ca ions have effectively changed the properties of NiO.
Numerical Modeling of Ship Composite-Based on Aluminum Casting as Alternative Materials for Ship Building
Authors: Tjahjanti Prantasi Harmi , Harmi Tjahjanti Prantasi , Panunggal Eko , Darminto Darminto , Nugroho Wibowo Harso
Published: February 2014

The structure and construction of the ship is made of aluminum alloy, generally are of wrought aluminum alloys, when experiencing fatigue failure caused by a cracked vessel structure, is a serious problem. Reviewing of 'weakness' of wrought aluminum alloys for the ship, then in this study tries to provide material alternative for ship building is composite material based on aluminum casting AlSi10Mg (b) and reinforcing material silicon carbide (SiC), which has been in-treatment with the optimum composition 15%. Analysis of numerical computation with the help of ANSYS software version 2.00 to be made numerical modeling ship to ship aluminum EN AC-AlSi10Mg (b) and ship composite EN AC-AlSi10Mg (b)+SiC*/ 15p whether the material can be applied to building ship for see the distribution of stress . The results of the stress distribution in both of model numerical of ship, its value does not exceed the stress permits (sigma 0.2) and have a factor of safety above the minimum allowable limit, so it is safe to use. The overall, in numerical modeling, the ship material aluminum and ship composite materials can be used as an alternative material for ship building, however is still needed comprehensive testing in the field.Keywords: Aluminum casting ; ship building ; composite EN AC-43100(AlSi10Mg (b))+SiC*/15p; ANSYS ver.12,0
An Investigation of Structure and Complex Impedance Behavior of Composite (1-X)BA0.5SR0.5FE11.7MN0.15TI0.15 /XLA0.7BA0.3MNO3
Authors: Repi Viktor Vekky Ronald , Manaf Azwar
Published: February 2014

We have investigated of composite (1-x)Ba0.5Sr0.5Fe11.7Mn0.15Ti0.15 / xLa0.7Ba0.3MnO3 by conventional ceramic method. The sturcture of composite and complex impedance are carried out by XRD, SEM and Impedance Spectroscopy. With changing the weight ratio from x=0; 0.3; 0.5 and x=1 the phase exhibit the composite behavior. Very interestingly, for the case of the case of weight ratio x=0.5 and 0.7 showed the complex impedance with xemicircle pattern in frequency range from 1 KHz to 1 MHz.
Characteristics of Heat Treated Al7Si-Mg-Zn - 5 wt.% SiC Squeeze Casted Composite with Variation of Mg Content for Tactical Vehicle Application
Authors: Rizkyardiani Sigma , Sofyan Bondan Tiara
Published: February 2014

Composite as main materials for ballistic applications has been developed in order to reduce density which leads to lower fuel consumption and faster mobilization. Composite is required to own high hardness and high impact strength for good ballistic performance. Particulate composites Al-7Si-Mg-Zn reinforced by SiC is designed for ballistic applications due to its light weight and high hardness. Whilst the high hardness showed brittle properties, heat treatment process is applied to this composite to reduce it. This research aims to study the effect of magnesium as alloying element to composite Al-7Si-Mg-Zn reinforced by SiC particulate which applied to precipitation hardening. Composites Al-7Si-Zn-SiC with 2, 4 and 6 wt. % Mg is solution treated at 500 oC for 1 hour, followed by ageing at 200 oC. The characterization was carried out by hardness testing, microstructure observations, SEM and EDX observations, impact testing and fractographic observations. Results showed that Mg does not affect hardness of composite by precipitation hardening. Composite with 2, 4, 6 wt. % Mg had 63.83, 62.27, 62.48 HRB on its peak hardness. Mg did not become precipitate in matrix Al-7Si-Mg-Zn because of its low diffusivity in aluminium. Mg worked as wetting agent that reduces interface tension between aluminium matrix and SiC particles in order for composite to own better interface bonding. Therefore impact testing showed significant increase of impact strength with the increase of Mg content. Composite with 2, 4, 6 wt. % Mg had 2075, 3006, 3257 J/mm2 impact strength respectively
Electrochemical Behavior of Li4Ti5O12 under In Situ Process of Sintering and Surface Coating with Cassava Powder
Authors: Prihandoko Bambang , Subhan Achmad , Priyono Slamet
Published: February 2014

Anode active material Li4Ti5O12/C has an advantage to increase the life time and the ability to charge and discharge lithium batteries. An experiment was carried out to make Li4Ti5O12/C more cheaper and simple process. Preparation of Li4Ti5O12/C was carried out with stoichiometric composition of raw materials TiO2 (Merck) and LiOH.H2O (Germany) under powder metallurgy method. After mixing and calcinations cassava starch as a source of carbon black coating could be mixed under comparison 1:1 with calcinations powders. Pyrolisis process was done in - situ by the sintering process at temperature variation, i.e. 800, 850 and 900°C for 1 hour. XRD test results indicated the presence of anatase TiO2 entire sample. The best results of powder Li4Ti5O12/C with in situ process under 850°C for 1 hour had conductivity in the order of 10-4S/cm and capacity round 5mAh/g. Carbon coating of cassava starch that is well identify in the black color of sample powder and EDX analysis, gave influence on electrochemical graphics of oxidation and reduction by cyclic voltammeter. The working voltage of Li4Ti5O12/C is in general 1.55V.
Synthesis and Characterization of Bacterial Cellulose-Based Carbon Nanotube by Catalytic Graphitization
Authors: Chaldun Elsy Rahimi , Karina Myrtha , Purwasasmita Bambang Sunendar
Published: February 2014

Bacterial cellulose-based carbon nanotube has been synthesized by catalytic graphitization method. Bacterial cellulose (BS) is a source of cellulose produced from fermentation of medium by Acetobacter xylinum. Since it contains unbranch polymer linked by β-1.4 glucopyronose with hydroxil groups, BS is able to use as precursor in synthesis of carbon nanotube. Due to catalytic graphitization, chitosan served as coupling agent and dispersant of catalyst and various concentration of catalyst FeCl3.6H2O also were used. Graphitization was conducted in furnace with inert nitrogen gas atmosphere at 800°C for 2 hours. SEM-EDS were used to evaluate the morphology and semi-quantitative analysis of sample. TEM was used to determine the microstructures and crystallographic. When the chitosan was added 0.5%, its served as coupling agent and dispersant of catalyst with BS. Chitosan improved physical properties, relieved its brittleness, and caused the optical properties of BS. Catalyst of FeCl3.6H2O was used to assist the formation and growth of carbon nanotube. The amount of carbon was not affected by time aging. 0.1 M FeCl3.6H2O was the optimum concentration to produce carbon nanotube with 81, 58% the mass of carbon, plane orientation (002) (100) and the diameter of carbon nanotube is 25 nm.
Classification of Ceramic Tiles by Identifying Defect on Ceramic Tile Surface Using Local Texture Feature
Authors: Bertalya Bertalya , Prihandoko Prihandoko , Oktavina Rakhma , Febrianto Yogi
Published: February 2014

In ceramic tiles industry, the process of ceramics classification plays an important part. At present, the process of classification is carried out manually by using the human eyes observation. However, the capability of the human eyes is very limited. This condition leads to the low accuracy of the ceramic tile selection. This paper proposes a mechanism which could classify the ceramic tiles automatically using local texture feature. The result of our experiment shows a recognition rate of 76%, which means that this method can be used to classify the ceramic tiles.
Comparison of Commercially Pure Titanium Surface Hardness Improvement by Plasma Nitrocarburizing and Ion Implantation
Authors: Darmawan Agung Setyo , Siswanto Waluyo Adi , Sujitno Tjipto
Published: February 2014

Commercially pure (cp) titanium has a relative soft hardness property. In particular usage such as sliding, the improvement of the surface hardness will be required. In this study, surface hardness improvement of cp titanium by Plasma Nitrocarburizing and Ion Implantation are compared. Plasma Nitrocarburizing processes are conducted at different elevated temperatures with different duration processes, i.e. at 350 °C for 3, 4, and 5 hours, and at 450 °C for 2, 3, and 4 hours respectively, while Ion Implantation processes are conducted at room temperature and process durations are varied as 2.3 hours, 4.7 hours, and 9.3 hours. Nitrogen ions are used to implant the material. Hardness tests are then performed on each specimen by using Micro Vickers Hardness Tester. The surface hardness number (HV) for specimens of the Plasma Nitrocarburizing processes at temperature of 350 °C for process duration of 3 hours, 4 hours, and 5 hours are 74.16, 92.25 and 94.41, respectively while those at temperature of 450 °C for duration process of 2 hours, 3 hours, and 4 hours are 103.70, 121.31 and 126.17, respectively. The processes of Ion Implantation produce the surface hardness number (HV) of 88.97, 125.51, and 130.2, for duration processes of 2.3 hours, 4.7 hours, and 9.3 hours. The process of Ion Implantation produce higher surface hardness number than the Plasma Nitrocarburizing process at temperature 350 °C but the surface hardness number is lower when compared to the Plasma Nitrocarburizing at a temperature of 450 °C. For the duration processes 4 hours and more, the process of Ion Implantation produces the same surface hardness number with the Plasma Nitrocarburizing at temperature of 450 °C.
Simulation of Metal Flow to Investigate the Application of Antilock Brake Mechanic System in Deep Drawing Process of Cup
Authors: Candra Susila , Batan I Made Londen , Pramono Agus Sigit , Pramujati Bambang
Published: February 2014

This paper presents the importance of simulation of metal flow in deep drawing process which employs an antilock brake mechanic system. Controlling the force and friction of the blank holder is imperative to assure that the sheet metal is not locked on the blank holder, and hence it flows smoothly into the die. The simulation was developed based on the material displacement, deformation and deep drawing force on flange in the radial direction, that it is controlled by blank holder with antilock brake mechanic system. The force to blank holder was applied periodically and the magnitude of force was kept constant during simulation process. In this study, the mechanical properties of the material were choses such that they equivalent to those of low carbon steel with its thickness of 0.2 mm. The diameter and the depth of the cylindrical cup-shaped product were 40 mm and 10 mm, respectively. The simulation results showed that the application of antilock brake mechanic system improves the ability to control the material flow during the drawing process, although the maximum blank holder force of 13000 N was applied. The optimum condition was found when the drawing process was performed using blank holder force of 3500 N, deep drawing force of 7000 N, friction coefficient of 0.25 and speed of punch stroke of 0.84 mm/sec. This research demonstrated that an antilock brake mechanic system can be implemented effectively to prevent cracking in deep drawing process.
The Effect of Vertical Step Block Casting to Microstructure and Mechanical Properties in Producing Thin Wall Ductile Iron
Authors: Sulamet-Ariobimo Rianti Dewi , Soedarsono Johny Wahyuadi , Nanda Is Prima
Published: February 2014

Thin wall ductile iron (TWDI) is introduced to fulfill the needs of lighter material in automotive parts that will reduce fuel consumption. Problem occurs during the production of TWDI due to the casting thickness. TWDI casting thickness classified to below 5 mm. Many designs have been made to answer the problem in producing thin wall ductile iron. Soedarsono et al established vertical step block casting design. This design based on Y-block principle that allows direct pouring of liquid metal to the mold without passing any gating system. This design will increase casting yield. The parameter of this research is pouring basin placement to study the effect of plate arrangement to filling and solidification. This research is conducted to see the effect of pouring basin placement to microstructure and mechanical properties of TWDI. The Design is made to produce 5 plates with different thickness that is 1, 2, 3, 4, and 5 mm. All of the plates arranged parallel in line. Pouring basin located in 2 ways. The first type located pouring basin above the plate of 5 mm thickness while the second one located it above the plate with 1 mm thickness. The first type coded as T4 while the second coded as T5. The moulds made from furan sand. The result shows although cold shut occurred in both pouring basin placements due to pouring discontinuity but shrinkage only formed in T5 on its plate with 1 mm thickness. Microstructure of all the plates presented nodule graphite in pearlite matrix. Carbide and skin effects also detected. Average nodularity is above 80% while the nodule count is between 614 to 1269 nodule/mm2. Most of the Brinell hardness number exceeded maximum limit given by JIS G5502 but the UTS is below the minimum limit except for 3 mm plate thickness of T5. All elongation values below the minimum standard. The results confirm that pouring basin location is important in casting design following Y-Block principle.
Resolving Individual Solute Levels of AA6061 through Multiple Sub-Ambient Temperatures Thermoelectric Power Measurements
Authors: Risanti Doty D. , van der Zwaag Sybrand
Published: February 2014

This work concentrates on assessment of the TEP change of AA6061 during isothermal aging at 177 °C and the following interrupted aging at 65 °C. The results show that the TEP is sensitive to follow the microstructural changes undergone during all aging stages. Multiple sub-ambient temperature dependences TEP of binary Al-X alloys as well as the AA6061 subjected to the above mentioned heat treatments were undertaken. The solute level of individual element of the alloy, particularly those contributing to the clustering/precipitation, can be extracted and evaluated.
Vane-Turbine as an Energy Conversion in the Propeller Slipstream of Single Screw Ship
Authors: Leksono S. , Utama I Ketut Aria Pria , Djoni Ma , Aryawan Wasis Dwi
Published: February 2014

The screw propeller of a ship generates thrust to make it moving. As a propeller rotates, it draws fluid into itself from the surrounding area (slipstream). The propeller produces two types of flow behind it, accelerated and circulated flows. Some of the energy from the ship engine is lost in the accelerated flow behind ship as a jet wash.The kinetic energy losses in the slipstream propeller captured by a turbine called the propeller-turbine system. This composed screw propeller of a vessel (the main propeller) and a vane turbine that is the area of vanes located inside the wake of the main propeller. It recovers the energy generated by the main propeller pushing water back out (which would be otherwise wasted behind the main propeller) and hopefully enhancing the efficiency of the main propeller.The influence of vane turbine on the performance breakdown of single screw ships were analyzed by using 5 (five) ships . Ship powering was calculated by using DESP Code 10 software. Thrust and power of vane turbine were calculated by applying actuator disc theory. Although the vane turbine affected speed loss of the ship, the power efficiency gained to be found always positive. Vane turbine is suitable as an energy saving device of the single screw ship.
Influence of Intermetallic Inclusion to Brittle Fracture of Electric Motor Shaft AISI 1045 under Torsion Loading
Authors: Suryadi Suryadi , Karayan Ahmad I. , Nugraha Adidjaya C. , Munir Badrul
Published: February 2014

A shaft of electric motor fin-fan cooler failed after two years operation. The inspection revealed that the v-belt attached on the electric motor loosed before the failure occurred. Visual investigation results showed the brittle fracture with less plastic deformation. Multiple crack origins observed on the edge of the shaft indicates that the more than one stress concentration generated within the shaft. Microstructure observation revealed fine grain on the edge and become coarse into the center of the shaft. The hardness test results were in good agreement to the microstructure observation where the edge are is harder than the center. Fractography using SEM revealed inclusions located within the shaft and some inclusions are clustered on the area where the cracks initiate to propagate. The presence of intermetallic inclusions was identified by microanalysis using EDS. Inclusions that are brittle in nature become stress concentrations for the operating load since its properties is close to ceramic. The presence of fine grain and inclusions on the edge of the shaft become detrimental to the shaft properties and the presence of fine grain aggravate the failure for its effect according to Hall-Petch theory.
Contribution of Galvanizing Layer to Hydrogen Induced Cracking Failure of AISI 4140 Bolt for Padeye Fixing in Marine Environment
Authors: Munir Badrul , Suryadi Suryadi , Suryo Bintang
Published: February 2014

A high strength bolt with hot dip galvanizing treatment failed shortly after being installed for two days on a padeye of mooring dolphin. The bolt was installed with increasing stress on the second day in which the value was nearly twice. Investigation results showed the bolt fractured with the nut head separated from the pin. Corroded fracture surface with brittle characteristic and no plastic deformation observed dominating the failed area. Characterization of hardness and chemical composition followed with microstructure and fractography observation on the fracture surface then conducted in order to analyze the reason for this brittle fracture occurrence. Results indicate that, while the bolt conforms to the material specification in term of chemical composition, the hardness value was high. The microstructure observation reveals a transgranular crack propagation and cleavage failure occurred. The cleavage failure was clearly observed under fractography observation using scanning electron microscope. Failed galvanize layer due to mechanical failure becomes preferential site for hydrogen evolution in marine environment, which leads to hydrogen diffusion into the matrix, thus results in hardness increase. The increasing stress during installation become detrimental to the bolt and facilitate the hydrogen induce cracking. Detrimental effect of hot dip galvanize layer is pointed out in the application of high strength material in marine environment.
Sulfuric Acid Leaching of Bangka Indonesia Ilmenite Ore and Ilmenite Decomposed by NaOH
Authors: Lalasari Latifa Hanum , Subagja Rudi , Yuwono Akhmad Herman , Firdiyono Florentinus , Harjanto Sri , Suharno Bambang
Published: February 2014

lmenite (FeO.TiO2) ore from Bangka island-Indonesia is a potential raw material for synthesizing titanium dioxide (TiO2), which can be used further as pigmen and photocatalyst. The fabrication of TiO2 particles from ilmenite can be carried out through the solvent extraction using sulfuric acid route. Therefore, the solubility of the ilmenite ore in sulfuric acid environment is one of the key factors to obtain the desired TiO2 particles. The current research is aimed at comparing the solubility of pristine Bangka ilmenite ore with that of precedingly decomposed by sodium hidroxide (NaOH) in pressurized and atmospheric reflux reactors. The dissolution of both precursors was carried out in those reactors under various temperatures of 75, 100, 125, 150 and 175°C. The results showed that the optimum dilution was achieved at 150°C. The obtained recovery of ilmenite was 88.8 % for the pressurized reactor and 75.5% for the atmospheric reflux reactor. The solubility of titanium (Ti) element increased steadily to reach a recovery of 68% at 150°C and decreased significantly afterwards. It was also found that the increase of iron (Fe) element solubility was proportional to the increase of processing temperatures.