bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis and Simulation of a High Step-Up DC-DC Converter for Renewable Energy System Applications
Authors: Khwan-On Sudarat , Vatcharasukpo Sopida
Published: July 2015

This paper proposes a new step-up DC-DC converter topology with a high voltage conversion ratio for renewable system applications. The desired high voltage gain and satisfactory performance can be achieved by employing only a single power switch with simple control technique. The proposed converter can be used to step up the low voltage generated from renewable energy sources, such as solar photovoltaic modules, to the high level of the dc bus voltage, obtaining low-to-high voltage conversion ratios of approximately 30 times without adopting extremely large duty cycle. Employing the proposed converter the low input voltage (20-50Vdc) can be boosted up to the high output voltage level about 600Vdc at the dc-link bus required for the three-phase inverter feeding the three-phase motor drive system. In this paper, the proposed converter configuration with only one active power switch is presented. The operating principleincluding analysis of the steady-state performance characteristics under continuous conduction mode (CCM) operating conditions is described. In addition, the control strategy is developed in order to obtain the satisfactory output voltage regulation. Finally, simulation results are shown to demonstrate the effectiveness of the proposed converter with its control strategy to achievehigh step-up conversion ratios under different operating conditions.
The Testing System of Precise Motion Transmission Chains Based on Virtual Instrument
Authors: Ma Jin Ping , Chen Wei , Zhong Jian
Published: July 2015

This paper mainly adopts the virtual instrument to realize the test on the accuracy of precise transmission chains, and a precise transmission testing system has been developed. The system based on the LABVIEW software can realize data acquisition, signal processing and display of results, meanwhile,it can dynamically analyze the precision of the transmission chain. The results of the actual measurements show that the testing system can accurately and rapidly measure the precision index, furthermore, it has the characteristics of high accuracy, good real-time performance, flexible operation, easy to modify the measurement program. the system can not only be used in signal measurement and analysis, but also can automatically record and store data. What is more, it can real-time display dynamic precision and transmission error curve of precise transmission chain , It is Suitable for the precision measurement and error analysis of high precision transmission chains (such as harmonic gears, planetary gears and so on) ,and has a good application value in this field.
Development of Shaking Table for Rapid Detection System of Microorganisms
Authors: Wang Hao Dong , Sun Yi Hong , Chen Jing Chun
Published: July 2015

Shaking table is an important component in rapid detection system of microorganisms. Based on the discussion regarding the advantage and shortage of the shaking table, this paper proposed a simple, reliable, and low-cost automatic shaking table. Three mechanisms were discussed with the achievement of reciprocating motion: slide-crank mechanism, follower-cam mechanism, and incomplete gear mechanism. The three mechanisms were compared in mechanical motion pair, motion form, component design, and manufacturing process. The slide-crank mechanism was finally determined. To overcome the strong oscillation of the liquid in the test tube along a single direction, this paper improved the slider-crank mechanism, and whose trajectory was modified into an irregular circle.
Study Based on MATLAB Edge Detection Operator in Extracting Out-of-Gauge Goods Contour
Authors: Qiao Mu , Han Mei , Chen Chao
Published: July 2015

In the process of railway out-of-gauge goods transportation, it is of great significance to guarantee the safety of railway transportation by measuring out-of-gauge goods counter accurately. This paper introduces the acquisition of out of gauge goods image using CCD technology and extracting out-of-gauge goods counter based on MATLAB operator edge detection algorithm. In order to determine the high quality edge detection operator and lay the foundation of measuring out-of-gauge goods counter, three types of operator to extract contour were compared and analyzed at the same time.
Smartphone Based Classification System for Indoor Navigation
Authors: Aljeroudi Yazan , Legowo Ari , Sulaeman Erwin
Published: July 2015

This paper introduces a smartphone-based classification system for an indoor environment of a walking person. The system relies only on smartphone inertial data and it can be considered as a smartphone-based aiding system for an indoor navigation. In addition, it does not need pre-installing of wireless network in the environment or heavily tuning process before the navigation run. Therefore, this system can be used as an aiding block where the person wants to localize himself in an indoor environment starting from known navigations point. This system categorizes person navigation in indoor environment into three types of classes: walking straight, turning right, and turning left. There is an ELM (Extreme Learning Machine)-Based neural network for deciding the class of the current navigation action. The evaluation measure shows that the best performance is obtained with the Radial Basis Function (RBF) as the activation function of the neural network. Also, the obtained accuracy rates up to 95%.
Development of Methods and Algorithms to Identify Real-Time Features of the Time-Frequency Characteristics of Electromagnetic Radiation in the Digital Data Radio Receiver
Authors: Kalyaev Anatoly , Korovin Iakov , Khisamutdinov Maxim , Kalyaev Igor
Published: July 2015

The main objective of the work is the development of methods, algorithms and software to identify real-time features of the time-frequency characteristics of electromagnetic radiation in the digital data radio receiver different wavelength ranges.
Development of a Process Analysis System Oriented to Discrete Manufacturing Industry
Authors: Sun Jia Kun , Yin Fu Peng , Yang Chao Ying
Published: July 2015

The existing problems on the manufacturing process planning and management of China are introduced, a variety of manufacturing process analysis and optimization processes are integrated, product, process and technology resources are systematized, then the information model is established. The architecture of a process analysis is proposed, on the basis, a platform of process planning, management, analysis and improvement is constructed, through integration with the CAPP system, the function of process planning, analyzing and optimizing has been implemented. By application in an auto heavy plant, the desired effect of data sharing, staff collaboration, process optimization is achieved.
Parametric Study of Heat Insulation in Case of Plate Heat Exchangers
Authors: Kubín Milan , Hirš Jiří
Published: July 2015

Contribution is aimed on lost heat of plate heat exchangers to surrounding environment. Heat losses to vicinity are insignificant relative to transferred heat flow in the plate heat exchangers. This small part of the lost heat is demonstrated in parametric case study of plate heat exchanger, where is the lost part of heat energy lower than 0.50 % in ordinary cases.
Non-Newtonian Inertia Squeeze Film Characteristics in Rectangular Stepped Plates
Authors: Lin Jaw Ren , Hu Shu Ting
Published: July 2015

A study of non-Newtonian inertia squeeze film in rectangular stepped plates has been presented in this paper. Applying the momentum integral method incorporating the micro-continuum theory of non-Newtonian fluids, a non-Newtonian inertia lubrication equation is derived. It is found that the fluid inertia effects yield in a higher normal load capacity as well as a longer squeeze film time as compared to the non-Newtonian stepped squeeze film in the absence of fluid inertia forces.
Design and Development of New Type Conductor Delivery of Air-Suction Metering Device
Authors: Wang Shi Guo , Kang Jian Ming , Yan Li Min
Published: July 2015

The variation rate of seed-spaces in soil is higher and the qualification rate is lower due to the high seed releasing position of double discs furrow opener of no-tillage planter. To solve this problem, a new belt-type device for air-suction metering was designed and its main structural parameters was determined based on the cavitation time analysis of seed meter. This device integrated both transmission mechanism and seed releasing mechanism into one system, matching with the rotating speed of seed disc and the walking velocity speed of planter. The optimal parameters in relating to seeding performance were obtained by orthogonal test. When the seed releasing height is 100 mm, the rotational speed of seed disc is 30 r/min and the pressure of negative room is 3.5 kpa, the qualification rate of seed-space, the missing rate and multiple rate of seed per hill can be 98.5%, 0.48% and 1.02%, respectively.
3D Unsteady Heat Transfer in Multi-Connected Domains via LSFEM: A Case Study
Authors: Romão Estaner Claro
Published: July 2015

This paper aims in particular to do a case study of the numerical efficiency of the application of LSFEM (Least Squares Finite Element Method) in the solution of heat conduction problems in multi-connected domains. To demonstrate this study two cases (the first with exact solution for comparison of results) are presented in the same multi-connected geometry, of easy construction, to facilitate the comparison of the results of this paper with future studies of other researchers.
The Obtaining of the Intermetallic Compounds of Ni-Al System by Self-Propagating High Temperature Synthesis and Thermal Explosion
Authors: Cojocaru Mihai , Tudose Florică
Published: July 2015

The intermetallic compounds (IMC) of Ni-Al system exhibit interest both by theoretical and practical point of view: theoretically, due to particular aspects in relation to their synthesis and practically, due to their qualities that recommend them for the top industries such as, for example, the aerospace industry. In this paper are shown the results of researches on obtaining of high temperature compounds of Ni-Al system by self-propagating high temperature synthesis and thermal explosion, through the initiation of process at a temperature below the melting temperature of the easy fusible component.
Influence of the Vibrations on AlSi10Mg Casting Alloy Structure
Authors: Tierean Mircea Horia , Baltes Liana Sanda , Banea Alexandru
Published: July 2015

The goal of this paper is to analyze the influence of the mechanical vibrations during the casting on AlSi10Mg casting alloy structure. Seven samples were studied, solidified on vibrating field, using different frequencies and accelerations. After preparation, the structure was studied using optical microscope and SEM. The dimension of the Si phase was also measured. Through applying the vibrations during the crystallization, the fragmentation of the dendrites was accomplished by obtaining solid solution regions close to a spherical shape. These regions contain chemical compounds of a much smaller size than those resulting from static crystallization. The dimension of the Si phase is influenced by the presence of vibrations; increasing frequency will induce the decreasing of the Si phase size. The mathematical modelling of the frequency influence on the Si phase dimension is also presented.
The Sintering Mixed Powders Behavior of Triuranium Octoxide in Uranium Dioxide
Authors: Barbu Aurica , Cojocaru Mihai Ovidiu
Published: July 2015

The main aim of this research was to study the sintering behavior in hydrogen atmosphere of mixed powders of triuranium octoxide (U3O8) powder in dioxide uranium (UO2) powders. By cold pressing the green pellets of mixed powders of triuranium octoxide in hyper stoichiometric uranium dioxide has density over 40 % UO2 theoretical density (TD). The sintered pellets had a height diameter ratio (H / D) over one and oxygen uranium ratio (O/U) near stoichiometry of uranium dioxide (UO2). The densities of sintered pellets were up to 97% of uranium dioxide theoretical density. The proposed treatment of sintering are function of green pellets density. Increasing the proportion of triuranium octoxide leads to a decrease in the density of the sinter pellets. The pellets made by 100 % of triuranium octoxide not resist to proposed sintering treatment. The metallographic analysis show uniform grains for sinter pellets made by the 30 % mixture of triuranium octoxide in uranium dioxide. This UO2 sinter pellets are without surface defects.
Development, Microstructure and Corrosion Resistance of Al-Mg-(Si) Binary and Ternary System Samples in 5.3% NaCl Solution for Applications with Environmental Impact
Authors: Popescu Ileana Nicoleta , Enescu Maria Cristiana , Bratu Vasile , Zamfir Raluca Ioana , Stoian Elena Valentina
Published: July 2015

For ensuring fuel consumption and pollution reduction, the researches made in the past decades considerable efforts to replacing steel with aluminum alloys in manufacturing auto bodies, or in naval transportation, because the promising weight saving. The researches consisted in general corrosion (the gravimetric index and the corrosion rate, Vcorr) and tensile tests (Rm, Rp0.2 and A5) in correlation with microstructure analysis of heat treated Al-Mg-(Si) system samples alloy, in order to obtain the best corrosion resistance and high mechanical characteristics. The Al alloys in extrusion state were solution treated at 510 – 545oC for 10-60 minutes, quenched in water 30-50o C and artificial aging at 150, 180 and 210°C at different time of aging (1, respectively 3, 7 and 11 hours). After heat treatment the obtained alloys were corroded in solution of 53g NaCl + 1000 ml distilled water and boiled in these solutions for 8, 16 respectively 24 hours. The gravimetric index was determinate by mass loss measurements for all types of heat treatment conditions. After corrosion test, samples were prepared for optical microstructural analyzing and mechanical tested. We have compared the obtained results on Al-Mg and Al-Mg-Si alloys. Were established (i) the optimum heat conditions parameters for obtaining of highest values of mechanical characteristics and corrosion resistance and also (ii) was explained the structural evolution during age (precipitation) hardening for both systems.
Choosing the Biomaterials for Hernia Mesh Fixation in Correlation with Surgical Procedure
Authors: Pariza George , Mavrodin Carmen Iuliana , Gangone Maria Eliza , Antoniac Vasile Iulian
Published: July 2015

Evolution of hernia surgery has led to polymeric biomaterials for replacement or reinforcement of the abdominal wall. Their selection, according to the structure and porosity of the material, is directly dependent on the surgical procedure used and interaction between material and abdominal viscera. The objective of the paper is to establish a protocol for the selection of hernia mesh fixation materials based on polymer structure related to the surgical procedure used. The biomaterials that promote infection should be avoided and those that do not provide a long-term mesh placement should be used in combination with other devices to compensate for this fault. In conclusion, is much better to adapt the fixation biomaterials used in clinical practice to the specific surgical procedure, given the physical and chemical characteristics of these polymers, in order to reduce the morbidity associated with this type of surgery.
Laser Welding Optimization Procedure Applied to Cobalt Alloys for Removable Partial Dentures
Authors: Ghiban Alexandru , Buzatu Mihai , Bortun Cristina Maria , Ghiban Brandusa , Serban Nicolae
Published: July 2015

Optimization of fractured or destroyed removable partial dentures realized from CoCrMo alloys are possible due to modern welding equipments. The aim of study was to offer the processing and welding optimal parameters for some long lasting prosthetic pieces. There are investigated two cobalt based alloys, used for dental applications, types CoCrMo. Laser welding equipments was a Mini Laser XXS (Orotig Italia) and the tested samples were welded in butt joint, without filler material. There are presented in comparison results concerning macro and micro structural analysis made on stereomicroscope OLYMPUS and Reichert microscope. Finally a correlation between different welding parameter values and structural features was made.
Magnetic Damping in Turning of Stainless Steel AISI 304 for the Reduction of Machining Vibration and Tool Wear
Authors: Amin A.K.M. Nurul , Arif Muammer Din , Haji Subir Siti Aminatuzzuhriyah B. , Abdullah Fawaz Mohsen
Published: July 2015

Chatter is a type of intensive self-excited vibration commonly encountered in machining. It reduces productivity and precision, and is more noticeable in the machining of difficult-to-cut alloys like hardened steel. In such cases chatter causes excessive tool wear, especially flank wear, which in turn affects the stability of the cutting edge leading to premature tool failure, poor surface finish, and unsatisfactory machining performance. Nowadays, however, the demand is for fine finish, high accuracy, and low operation costs. Therefore, any technique which significantly reduces chatter is profitable for the industry. This paper demonstrates the viability and effectiveness of a novel chatter control strategy in the turning of (AISI 304) stainless steel by using permanent bar magnets. Reduction in chatter and corresponding tool flank wear are compared from results for both undamped and magnetically damped turning using coated carbide inserts. Special fixtures and keyway were made from mild steel in order to affix the magnets on the lathe’s carriage. The two ferrite magnets (1500 Gauss each) were placed below and beside the tool shank for damping from Z and X directions, respectively. Response surface methodology (RSM) was used to design the experimental runs in terms of the three primary cutting parameters: cutting speed, feed, and depth of cut. A Kistler 50g accelerometer measured the vibrations. The data was subsequently processed using DasyLab (version 6) software. The tool wear was measured using scanning electron microscope (SEM). Results indicate that this damping setup can reduce vibration amplitude by 47.36% and tool wear by 63.85%, on average. Thus, this technique is a simple and economical way of lowering vibration and tool wear in the turning of stainless steel.
Optimization of Tool Wear Using Coupled RSM-GA Approach in Turning of Stainless Steel AISI 304 with Magnetic Damping of Tool Shank
Authors: Amin A.K.M. Nurul , Haji Subir Siti Aminatuzzuhriyah B. , Arif Muammer Din
Published: July 2015

Tool wear, especially flank wear, is a major concern in the manufacturing industry. Increased tool wear is caused by chatter and leads to increased surface roughness, reduced productivity and higher operating costs. It is more pronounced in the machining of difficult to cut materials such as stainless steel, tool steel, Inconel and hardened Ti alloys. Additionally, unpredictable tool wear can lead to frequent shutdowns of the machining process making it difficult for full automation. Therefore, to increase productivity and to reduce costs associated with increased and unpredictable tool wear, numerous research studies have been carried out. In this research, two permanent ferrite bar magnets of 1500 Gauss strength were used to dampen the vibration of the tool shank in the turning of stainless steel AISI 304 using titanium nitride (TiN) coated carbide inserts. Mild steel fixtures were used to place the magnets beside and below the tool shank in the carraige of a Harrison M390 engine lathe. The tool overhang was kept constant at 120 mm. A small central composite design (CCD) approach in response surface methodology (RSM) was used to model the tool wear as a response of the three primary cutting parameters: cutting speed, feed, and depth of cut. Design Expert software (version 6) was used to generate the 14 experimental runs needed to develop and verify the empirical mathematical model of tool flank wear. The resultant tool flank wear was measured using both optical and scanning electron microscopes (SEM). Finally, an empirical quadratic mathematical model of tool wear was found. This model was then used as the objective function in the optimization of tool wear using genetic algorithms (GA). The optimization results predicted that the minimum tool wear was 0.0427 mm. This prediction was subsequently validated experimentally.
Using the Desirability Function as an Effective Tool in Target Costing Model
Authors: Al Hazza Muataz Hazza F. , Konneh Mohamed , Iqbal Mohammad , Taha Assem Hatem , Hasan Muhammad H.
Published: July 2015

High speed turning (HST) is an advanced machining process that uses higher cutting speeds than those used in conventional machining. HST enables manufacturers to shorten machining times. Therefore, this approach should be followed and justified by economic study. One of the most effective tools for economic study is by developing a target-cost model to control the machining cost. The aim of this research is to develop a target costing model for high speed turning. To achieve the aim of this research, a set of experimental data was obtained in the following cutting levels: cutting speed (500-700 m/min), feed rate (1000-2000 mm/min), and depth of cut of (0.1-0.3) mm. The materials used in this research were AISI 304 stainless steel as a work piece material and coated carbide as a cutting tool. The output data was used to develop a target costing model. The desirability function has been used to optimize the model.
Effect of Tropical Climate Condition to Compressive Strength and Microstructure Properties of High Performance Fiber Reinforced Reinforced Concrete (HPFRC)
Authors: Saad Siti Asmahani , Abdul Aziz Farah Nora Aznieta , Ali Maisarah
Published: July 2015

Additional of fiber in concrete creates fiber reinforced concrete (FRC) with an improvement of the mechanical properties of the concrete. However, fiber incorporation in FRC is limited to 2% to allow normal mixing procedure. To address this issue, high performance fiber reinforced concrete (HPFRC) is introduced and it is relatively new in construction industry. Since very limited information on its capacity in tropical climate condition exposure, this research focuses on investigation of compressive strength and microstructure properties of the produced concrete in tropical climate condition. In order to complete this research, grade 80 cement slurry is used with 3%, 4% and 5% hooked-end steel fiber. Total numbers of 56 samples which are divided into 4 sets and exposed to two different curing methods namely water curing method and steam curing method at 80°C. Out of the 4 sets, 2 sets are exposed to tropical climate condition using climatic chamber at 80% relative humidity (RH) and constant temperature of 35°C for 30 days. Compression and ultrasonic pulse velocity (UPV) tests are carried out at 28 days to identify its strength as well as integrity of the concrete produced. Scanning electron microscopy (SEM) analysis is done to ascertain the microstructure properties of HPFRC. The highest compressive strength of 152.2 MPa was recorded for steam curing samples after exposed to tropical climate condition for 30 days with 5% steel fiber volume.
Compressive Behaviour of Polyarcylonitrile Fibre Reinforced Lightweight Aggregate Concrete Composite
Authors: Mo Kim Hung , Alengaram U. Johnson , Jumaat Mohd Zamin
Published: July 2015

In this paper, the effect of polyacrylonitrile (PAN) fibre addition at 0%, 0.1% and 0.2% volume fraction on the compressive behaviour such as compressive strength, residual strength upon heat exposure and compressive stress-strain relationship of lightweight oil palm shell concrete (OPSC) was investigated. OPSC with PAN fibres was found to exhibit reduced strength deterioration upon exposure to elevated temperatures of 100 °C, 200 °C and 400 °C. The strain at peak stress and the compressive ductility of OPSC were also increased with the addition of PAN fibres. Despite the reduced workability, no significant decrease in the compressive strength and saturated density of OPSC was observed in the presence of PAN fibres.
Material Removal Rate of Zirconia in Electro Discharge Micromachining
Authors: Asfana Banu , Ali Mohammad Yeakub , Mohamed Abdul Rahman , Hung Wayne N.P.
Published: July 2015

This paper investigates the material removal rate (MRR) in electro discharge micromachining (micro-EDM) of zirconia. Experimental investigation is carried out with 800 μm diameter tungsten electrode with two varying parameters rotational speed and gap voltage. The MRR data are analyzed and an empirical model is developed using Design Expert software. The optimum parameters for maximum MRR are found to be 375 rpm rotational speed and 80 V gap voltage.
Effect of Temperature on the Wear Properties of Alloy Steel under Jatropha Curcas Biodiesel
Authors: Shaufe N.A. , Maleque Md Abdul , Saleh A.A. , Paruka P.
Published: July 2015

This paper presents the effect of Jatropha curcas biodiesel on the wear properties of mild steel, which was coated by preplacement of TiC particulate and melting it using a conventional TIG torch arc heat source. The aim of the study is to investigate the wear behaviour of surface modified AISI 4340 steel and the uncoated AISI 4340 steel which were performed using CSM tribometer at four different temperatures viz., 100 °C, 120 °C, 140 °C, and 160 °C, with the presence of jatropha biodiesel. At the end of the tests, wear characteristics was investigated by weight loss measurements and changes of the exposed metal surface. Surface morphology was examined by scanning electron microscope and surface profilometry. EDX analysis was performed on the samples’ surface. Results showed that wear of alloy steel increases with increasing temperature. TiC coated alloy steel showed improved wear resistance as this alloy steel demonstrated lower wear volume loss as compared to the uncoated steel in presence of jatropha biodiesel at higher temperature.
Fracture Behavior Issues in HSLA Pipeline Steels - A Review
Authors: Musa M.H.A. , Maleque Md Abdul , Ali Mohammad Yeakub , Hasan Muhammad Hasibul
Published: July 2015

The increasing demand for natural gas and oil as an important energy sources has led to rising the application of high strength low alloy steels (HSLA), which indicates continued growth of pipeline installations and the qualification of the actual pipeline network. A difficult problem to be solved for the economic and safe operation of high pressure pipelines is the control of ductile fracture propagation. As a result, the accurate estimation of the resistance to fracture and ductile fracture arrest in pressurized pipelines are important issues. Technology to ensure such control is critical for the structural integrity and safety of pipelines because the possibility of a running fracture opens-up lead to the catastrophic long-running failure of a pipeline which involve public safety and property damage and environment impact. The integrity and high reliability of pipelines depend on various factors including mechanical damage or external interference, fatigue cracks, material defects, weld cracks, improper welding, internal or external corrosion and, most of all, on the ageing of the physical state of the pipeline material and the welded joints during their prolonged use. In order to understand the current problems in the pipeline materials and to develop steels with higher strength, better toughness and weldability, this paper gives brief overview of the comprehensive of fracture behavior including crack initiation and propagation of high strength low alloy pipeline steels.
The Effects of Sliding Parameters on Dry Wear Characteristics of Ti-6Al-4V Alloy
Authors: Ndaliman Mohammed Baba , Bala Katsina Christopher , Khan Ahsan Ali , Ali Mohammad Yeakub , Abdullahi Umma , Abdulmumin Adebisi Adetayo
Published: July 2015

Titanium (Ti-6Al-4V) alloy is very attractive for many applications due to its high strength-to-weight ratio and high corrosion resistance. Even then, with these attractive properties, it has poor shear strength and surface wear properties. This study is therefore undertaken to investigate the effect of sliding parameters on the surface wear behavior of Ti-6Al-4V alloy. Pin-like specimens of the alloy were produced and subjected to sliding motion on a pin-on-disk apparatus using different speeds, loads and sliding distances. The surface and specific wear rates of the alloy were evaluated as the main output of the study. Results indicate that the most severe surface wear rate of over 0.008 mm3/sec is experienced under conditions of low disk speed (50 rpm) with high input weight (46.5 N). Higher sliding distance is also found to affect the severity of the surface wear rate. All results of specific wear rates evaluated indicate that Ti-6Al-4V alloy can be classified as a low surface wear resistance material when operated under sliding counterface.
Prediction of Crack Growth Propagation of a Super Alloy through ANN Modeling
Authors: Hasan Muhammad Hasibul , Mollik Sazib , Faizi Muataz Hazza
Published: July 2015

Linear-elastic fracture mechanics based technique was used to measure the fracture toughness in terms of K1C of a solid solution super alloy. Due to thermal fatigue and high temperature exposure for various application of Alloy 617, it was demanded to measure crack growth behaviour of this alloy. Pre-cracked compact tension (CT) specimens ware used to determine the crack growth rate (CGR) of alloy 617 by direct current potential drop (DCPD) in-situ crack monitoring technique. Artificial Neural network (ANN) statistical model computed different fracture parameters from experimental inputs by feeding information to the network. This feed-forward network calculated the threshold fracture toughness, number of cycle to failure, slope of the Paris curve for the alloy at different temperatures and load ratios. The computational model correlates and converges with the experimental results with a maximum deviation of 6%. Thus, the model is recommended for complex and stochastic application of the nickel base super alloy 617.
Conductive Polymer Composites from Polylactic Acid/Natural Rubber Filled with Carbon Black
Authors: Buys Yose Fachmi , Lokman Nor Afiza Syafina
Published: July 2015

In order to develop environmentally friendly conductive polymer composites, polylactic acid (PLA) was melt blended with natural rubber (NR), with addition of carbon black (CB) as the conductive filler. It was found that the PLA/NR blends were immiscible, and the sea-island and co-continuous morphological structures were observed at PLA/NR with ratio of 80/20 vol% and 60/40 vol% respectively. Addition of CB to 60/40 PLA/NR matrix, brought the composites to become electrically conductive at CB content of 2 phr. It was also found that the impact strength of PLA/NR/CB composite is better than that of the neat PLA.
Crush Zone Morphology of Epoxy-Glass Fiber-Aluminium Composite Columnar Tube due to Longitudinal Crushing Force
Authors: Paruka Perowansa , Mat Yasin Mohd Hafizil , Mamat Rizalman , Maleque Md Abdul , Md Shah Md Kamal
Published: July 2015

Epoxy–glass fiber–aluminium composite may be of interest for energy absorption application due to their improved crashworthiness. In the current study, the hybrid–composite columnar tube specimen has been fabricated by a hand lay–up method using epoxy–glass fiber with aluminium columnar tube as a core material. An experimental quasi–static crush test has been performed on the specimen under axial loading. The post–crushing of composite lay–up configuration was observed during and after interaction of the axial loading with the specimen. The result of crush morphology analysis on final mode of failure of the specimen was carried out using SEM and showed combination of several failure modes such as matrix–fiber interfacial fracture, fiber breakage and hackles. However, the main failure mode is brittle type fracture comprising transverse shearing and splaying modes.
Effect of Electron Beam Radiation on Water Absorption of Hybrid Kenaf-Glass Unsaturated Polyester Composite
Authors: Maleque Md Abdul , Atiqah A. , Fazal M. , Iqbal M.M. , Paruka Perowansa
Published: July 2015

This paper presents the effect of electron beam radiation on water absorption of kenaf-glass (KG) mat reinforced unsaturated polyester (UPE) hybrid composite which has been compounded using sheet molding compound (SMC) process. Hybrid synthetic and natural fiber composite materials are attractive structural materials because of natural fibers resource and their lower cost making their study a relevant research area today. In the present study, the fabricated hybrid composites were subjected to a dose of electron beam radiation of 75 kGy. Furthermore, fourier transform infra-red (FTIR) analysis was carried out on irradiated hybrid kenaf-glass reinforced UPE composite. It was found that the effect of electron beam radiation increases the impact strength and water uptake significantly.Water absorption values were found to be increased with the increasing of kenaf fiber loading for non-irradiated hybrid KG-UPE composite.
Mechanical Properties of Kenaf Core Sandwich Panel Toughened with Modified Epoxy
Authors: Hasnidawani J.N. , Hassan Noor Azlina , Norita H. , Halim Zahurin , Zuraida A.
Published: July 2015

Kenaf-core sandwich panels were prepared by hand lay-up method with the optimum characteristics. The aim of this study is to determine the effects of modified epoxy on the mechanical properties of the sandwich panel. Mechanical test such as flexural, drop impact and tensile test were performed to investigate the optimum system of kenaf-core sandwich panel within 0-5wt% of kenaf fiber content. It revealed that the optimum loading of kenaf fiber was at 3wt%. Furthermore, this system was studied with the incorporation of liquid natural rubber (LNR) as impact modifier. All tests have been carried out according to the ASTM 365, C297, C393, and D1736. Each final data point is an average value that has been obtained based on a statistical sampling of four specimens. The main element of core structure is kenaf and the skin used in this study is aluminium type 1100. According to compression, flatwise tensile, three point bending and drop impact tests, 3wt% of LNR content exhibit as an excellent impact modifier, in modifying the mechanical properties due to rubber toughening. In addition of too much liquid natural rubber more than 5wt% was substantially interrupted the system.
Morphology and Mechanical Properties of MIM Feedstock Using TPNR Backbone Binder
Authors: Norita Hassan , Ahmad Sahrim , Muhamad N. , Omar Mohd Afian , Hassan Noor Azlina
Published: July 2015

This study has examined the effects of using TPNR backbone polymer on the morphology and mechanical properties of the metal injection moulding feedstock 316L stainless steel with paraffin wax (PW) and palm stearin (PS) respectively as the main binder and stearic acid as a lubricant during mixing and injection moulding process. Tensile behaviour indicates that the green sample of feedstock PW/TPNR/SA system gives higher value compared to PS/TPNR/SA system. Morphology studies showed that green samples of PS/TPNR/SA exhibited brittleness fracture compared to PW/TPNR/SA system.
The Effect of Etchant Concentration and Temperature on Surface Finish of Silicon Wafer Thinning
Authors: Safaruddin M.A. , Shahar S.F.M. , Jaafar I.H.
Published: July 2015

Fabrication of silicon (Si) wafer microfilters via focus ion beam (FIB) sputtering (milling/drilling) is planned. However, due to limitations of FIB sputtering, the wafer has to be initially thinned to a certain thickness to ensure that micron-scale through holes can be successfully manufactured. This paper reports on thinning of a silicon wafer via wet chemical etching using 15, 20, and 25% w/w potassium hydroxide (KOH) at 3 different etchant temperatures (80oC, 90oC, and 100oC). The target is to achieve 100 μm with the lowest time taken and wafer surface roughness after etching. From the experiments conducted, it was determined that KOH solution at 15% w/w concentration at 100oC produced the best result with an etch rate of 5.43 μm/min, surface roughness (Ra) of 0.12μm and thickness of 123.00μm.
Polyhydroxybutrate Filled Clamshell Biofiller: Effect of Polyvinylpyrrolidone
Authors: Othman Maizatulnisa , Yusoff Hashim Mohd , Azowa Ibrahim Nor , Khalid Khalisanni , Mohamad Souad A.
Published: July 2015

A totally green biocomposite was prepared via melt blending technique by using polyhydroxybutyrate (PHB) as a matrix, clamshells powder (CaCO3) as a reinforcing filler and polyvinylpyrrolidone (PVP) as a binder. PHB/CaCO3was fixed at 70:30 ratio and PVP weight content varied at 3, 5, 7 and 9 wt%. The properties of the biocomposite have been studied in term of mechanical properties and morphology. The results showed that incorporation of PVP increased the tensile modulus which remarkably demonstrated by the enhancement in stiffness of the biopolymer. While, elongation at break decreased in an opposite behavior. Surface morphology observation on the tensile fracture samples shows the presence of microvoids, due to binding effect of the PVP.
Characterization of Rattan Waste for Binderless Particleboard (BPB) Production
Authors: Maisarah Tajuddin , Ahmad Zuraida , Roszalia A. , Luqman M.A.
Published: July 2015

The manufacturing of furniture using rattan is becoming common nowadays, and creates high amount of waste that can be value-added into binderless particleboards (BPB). In order to determine the suitability of the rattan waste for production of BPB, characterization of rattan waste is executed and reported in this paper. The physical properties such as density and moisture content of the rattan waste, together with its morphological study and thermal analysis as well as lignin content are evaluated. It is observed that density and moisture content for rattan waste are in the range of 0.64g/cm3, and 11.3% respectively. On the other hand, the morphology of rattan stem showed that rattan waste has various diameters of vascular bundles along with wide metaxylem vessels as well as thin-walled fibres. Thermal analysis of rattan waste explicated that rattan waste went through endothermic process with peak melting point of 177.80 °C during heating. The greatest weight loss occurred at 257.03 °C. Rattan waste has high lignin content of 21.2% that obtained through Klason lignin test. These promising preliminary results show that the rattan waste is appropriate to be used as raw materials in producing BPB.
Effect of Fibre Surface Treatment on the Properties of Eco-Core Sandwich Structures
Authors: Halim Zahurin , Ahmad Zuraida , Syed Taha Syarifah Nur Adilla
Published: July 2015

The growing ecological, social and economic awareness, high rate of depletion of petroleum resources, concepts of sustainability and new environmental regulations have stimulated the search for green materials compatible with the environment. The focus of this research is to study the effect of fibre surface treatment as far as kenaf fibre composite sandwich structure is concern. The kenaf fibre is subjected to alkali treatment. Upon completion, the treated kenaf fibre is used for fabrication of composite sandwich structure by utilizing thermoset resin which is epoxy as the matrix and galvanized steel as the face skin. The sandwich structure undergone SEM for morphological study and three point bending test to identify the bending properties. Treated kenaf fibres shows improvement after the alkali treatment compared to untreated kenaf fibre in the composite sandwich structure.Keywords: Composite sandwich structures; biodegradable; kenaf fibres ; surface treatment; morphology
Hybrid Fabrication of Stainless Steel Channels for Microfluidic Application
Authors: Berestovskyi D. , Hung N.P.
Published: July 2015

This research develops a hybrid micromanufacturing technique by combining micromilling and electrochemical micropolishing to fabricate extremely smooth surface finish, high aspect ratio, and complex microchannel patterns. Milling with coated and uncoated ball-end micromills in minimum quantity lubrication is used to remove most materials to define a channel pattern. The milled channels are then electrochemically polished to required finish. A theoretical model accurately predicts surface finish in meso-scale milling, but not in micro-scale milling due to size effect. Electrochemical polishing using an acid-based electrolyte is applied to repeatedly produce stainless steel microchannels with average surface finish of 100 nm when measuring across grain boundaries and 10 nm within a single grain.
Green Polyurethane Adhesives for Wood Bonding
Authors: Amran M.A.F. , Ali Ernie Suzana
Published: July 2015

The Green polyurethane adhesive system was prepared using two types palm oil polyol having different molecular weight ~1100 (GA) and ~ 2200 (GB) respectively, 4-4-diphenylmethane diisocyanate (MDI) and nanoclay fillers via in-situ process. Adhesives were applied on both sides of two untreated wood substrate using brushing technique for lap shear test. The attached substrate then undergoes the curing process for 24 hours at room temperature with relative humidity of 50±5%. The disappearance of NCO peak in the Fourier transform infra-red (FTIR) spectrum showed that MDI has completely reacted to form PU. Contact angle measurement proved that high wetting condition obtains from green polyurethane (PU) adhesive. PU adhesive wood joint improved in shear strength with addition of 1wt% nanoclay for both green polyol.
Structural Applications and Emerging Trends of Nano- and Biocomposites: A Review
Authors: Mollik Sazib , Tariq Irum , Hasan Muhammad H
Published: July 2015

Composite materials are currently being used in applications for aerospace, leisure, construction, sport, packaging and automotive industries, especially for the last mentioned application.Yet, present day trends such as a rise in interest in environmentally-friendly materials and the advancement of nanotechnology has led to the emergence of nanoand biocomposites. These materials offer comparable mechanical properties to conventional composites, with biocomposites having the added benefit of being biodegradable. This paper explores the nanoand biocomposites, focussing additionally on structural applications and emerging trends of this growing market.
Production of Carbon via Electrochemical Conversion of CO2 in Carbonates Based Molten Salt
Authors: Gakim Miron , Khong Lam Mun , Janaun Jidon , Yun Hsien Willey Liew , Siambun Nancy J.
Published: July 2015

Carbon was successfully deposited on AISI 304 stainless steel rod cathode through electrolysis process in three molten salt mixtures, namely K2CO3-Li2CO3 (mole ratio: 1:1), CaCO3-Li2CO3-LiCl (mole ratio 0.09:0.28:0.63) and CaCO3-CaCl2-KCl-LiCl (mole ratio: 0.13:0.31:0.10:0.45), under CO2 atmospheres as continuous source of carbon. The process were carried out for 1 hour at temperature range 545–585°C and electrolysis voltage of 4.0V to drive the deposition of carbon through electrochemical conversion. EDX analysis on deposited products shown carbon as dominant element (89-98%). SEM revealed carbon with Flakes and grapes aggregation shapes for different salt mixtures. The achieved current efficiency of 83.8%, 80.46% and 92.41% were found in the respective salt mixtures, and energy consumption promotes several ways for efficiency improvement on the electrochemical conversion of CO2.
Characterization and Preparation of Sago Starch (SS) Based Reinforced with Silver Nanoparticle (SNP)
Authors: Ahmad Zuraida , Ahmad Ulwi A.K. , Maisarah Tajuddin , Maisarah A.
Published: July 2015

This paper reported on the properties of sago starch (SS) films impregnated with different concentration of sliver nanoparticles (SNP) of 100, 2000, 5000 rpm with weight ratio of 1% and 10% to be used as wound healing material. The SS films were prepared through film moulding technique by mixing aqueous SNP with SS, glycerol and water at weight percentage of 6.5:3.5:90. The performance of SS-SNP films produced is studied. The morphology study shows the existence of SNP embedded in the SS particles. SNP with 2000ppm has the biggest particle width but small in particle sizes, which make the SS-SNP film of 2000ppm is superior in thickness, denser and has lower moisture content compared to other SS-SNP film with different composition. The highest water absorption occurred in the SS-SNP of 100ppm, due to the high existence of pores in the network of amylose content in starch. SNP act as particulate reinforcement in the SS film meaning higher number of ppm made the film more brittle and easy to rupture. Thus, the SS-SNP film of 5000ppm has the lowest tensile strength and modulus for tensile strength and modulus. It can be concluded that the SS-SNP film of 2000ppm is suitable to be used as wound healing material, as the addition of 2000ppm SNP inside the SS films help in improving the properties of SS-SNP film produced.
Gamma Irradiated Starch Based Hydrogel Impregnated with Silver Nanoparticle
Authors: Eslami Fayezeh , Ahmad Zuraida , Abdul Razak Nur Humairah
Published: July 2015

Hydrogel based on petroleum polymer are expensive, non-biodegradable and non-decompose which lead them to heavy waste in environment. In this paper, biopolymer is used to overcome this problem and promote environmental friendliness and biocompatible to the human skin and impregnation of silver nanoparticle (SNP) acts as anti-bacterial which needed for this application. The hydrogel is prepared by mixing the solution of sago starch with polyvinyl alcohol solution for polymeric grafting before impregnated with the SNP and finally this solution is subjected to the gamma irradiation. The irradiated starch based hydrogels is evaluated for its swelling properties, chemical functionalities and phase analysis. The hydrogels produced from this method is observed high in transparency and swelling behaviour as well as high water absorbency.
Finite Element Analysis of Tensile Test for HDPE/EPR-MMT Nanocomposite
Authors: Shaffiar N.M. , Halim M.K.A. , Anuar H. , Majid M.A.H.A.
Published: July 2015

A small amount of nanodispersed filler leads to an improvement in material properties. Montmorillonite (MMT) is one type of filler commonly used in nanocomposite material. A high density polyethylene/ethylene propylene rubber - montmorillonite (HDPE/EPR-MMT) is one of the nanocomposite material that is new to the industry. This paper investigates the strength of HDPE/EPR-MMT nanocomposite under tensile loading. The experimental results of the tensile test on the nanocomposite will be compared with the tensile simulation in the Finite Element (FE) analysis for validation. The results showed that it is validated with relatively low percentage error of 0.01 % for the ultimate tensile strength and 0.18 % for the yield strength. The ultimate tensile strength of HDPE/EPR-MMT is 14.5 MPa and the yield strength is 13.2 MPa. By using MMT as a filler, the material strength is improved. The ultimate tensile strength of HDPE/EPR without filler is 11.45 MPa and the yield strength is 10.95 MPa.