bluuebunny/crossref_metadata_2025 huggingface dataset:
A Smart Access Control System Based on ARM
Authors: Tian Ying Zhong , Jin Zhi Xiang , Wang Shuai , Xu Yang , Zhang Ming
Published: April 2013

As the schools become more and more open today, how to manage the whole school is becoming a great problem. Access control system needs development to adapt the tendency. Cost saving is also need in the smart access control system. One main board communicates with several IC reader board through CANBUS is a very good idea. This system awards different authorities to people to enter one building.
Research and Simulation on the Maximum Power Tracking Control of the Wind-Light Complementary Power Generation System
Authors: Wang Gang
Published: April 2013

In view of the present problem in low efficiency of the wind-light complementary power generation system, the tracking control strategy on the system maximum power point was proposed based on the perturbation and observation method, and overall structure of wind-light complementary power generation system is introduced. The simulation study on the system maximum power control was carried out based on the MATLAB/ SIMULINK, and the results of simulation showed that the tracking control of the system maximum power point was able to be achieved and the utilization efficiency of the system energy was also improved.
Remote Access the ZigBee Sensor Network through the IP Network
Authors: Chung Chiu Chiao , Weng Wei Shiang
Published: April 2013

With the wireless communication technology and world-wide Internet, living styles have become more and more convenient and smart, especially, for the application of context-aware systems based in wireless sensor networks. Furthermore, mobile devices provide users timely information browsing and mobile data access. In this study, the ZigBee wireless sensor network combined with sensor data observed Services (Sensor data Observation Service), and PostgreSQL database systems is developed to implement a remote access ZigBee wireless sensor network through an IP Internet browser. This system includes: (a) the integration of ZigBee CC2430 sensor sensing light, humidity and temperature; (b) PostgreSQL database tools accessing data; (c) via the sensor data Observation Service (SOS ) technologies; (d) through mobile devices to master the relevant environmental information.
Application of WLAN Information Transmission and System Security Technology in the Smart Substation Network
Authors: Xu Xin , Lu Jin Xi
Published: April 2013

Since smart grid construction started, the intelligent substation network has become the hot topic. This paper combined with IEC61850 in the smart substation data sampling, analyzes the frequency and bandwidth characteristics of the wireless network for the current smart substation missing information content. It studies the application of wireless network reliability verification. The article discusses the application program from three following important respects: the WLAN design coverage, flow and load, application needs. It describes the key problems of the wireless network data sampling implement from the data sampling time. At the same time the futures application of the wireless network sampling in the smart substation is prospected.
Experiment Research of Dynamic Load Balancing Algorithm Based on Task Classification for Data Retrieval
Authors: Liu Zhuang , Dong Guang , Yang Hong Wei , Qu Guan Nan , Wang Hong Bin , Chen Lin
Published: April 2013

The core technology of load balancing is the task scheduling. Different tasks have different resource occupation rate on the server node and influence the current server load also different. This paper presents a dynamic load balancing algorithm and we design some experimental environment. We do some simulation experiments based on some reasonable assumptions and actual state of network, to evaluate our dynamic load balancing algorithm. The experimental data shows that compared with the least weighted connection scheduling algorithm, the algorithm of this paper can make full use of machine resources. The system data retrieval efficiency is also improved.
Word Segmentation Method Based on Conditional Random Fields in China's Stock Market Arbitrage Analysis: A Case Study of Shanghai a Share Market
Authors: He Henry , Che Wen Gang
Published: April 2013

In economic circles debating the efficient market hypothesis , the price volatility of the stock market, news-related is an indisputable fact . In the 21st century , information obtained through traditional media such as newspapers , television, radio may have lagged effects . This article via computer algorithm automatically in a neutral site to obtain information based on conditional random field segmentation method , word processing information , stock code search to identify the corresponding positive information , analog to the opening price bid , after open achieved a good excess returns .
Concepts of Risk in Construction Projects
Authors: Ghaffari Alireza
Published: April 2013

Risk is a part of business endeavours because of uncertainty (Flanagan and Norman 1993; Fischer and Jordan 1996). Portfolio theory and capital market theory stipulate that risk consists of two types, First, systematic risk, which cannot be controlled, emanates from external factors such as acts of God, natural disasters, market risk, interest-rate risk, and purchasing-power risk. Second, unsystematic risk, which can be controlled, relates to organization-specific factors such as business risk and financial risk(Fischer and Jordan 1996). These forms of risk are fundamental to the construction and the insurance industries.( Tah et al. 1993) . The construction project is a complex sector which characterized with low productivity, cost and time overruns and conflicts. The major challenges in construction project risk assessment which may attributed to knowledge requirements for determining the level of uncertainty and development of complex models to predict . To identifies the risk factors that influence the cost-effective management, operation, and maintenance of construction project, as well as how and when in the project life cycle the identified risk factors impact to the associated costs .The web- based tool can be used by decision -makers during the pre-planning stage of construction projects to estimate cost and duration implications of various risk occurrence scenarios, determine contingencies and prepare risk management plans . In this research the author considered all key articles in the related research streams in recent 30 years and analyzed the risk management views in order to identify key risk factors and its impact on the construction projects.
The Traits of Canonical Banach Frames Generated by Multiple Scaling Functions and Applications in Applied Materials
Authors: Gao Jing Li , Cheng Shi Hui
Published: April 2013

Frame theory has become a popular subject in scientific research during the past twenty years. In our study we use generalized multiresolution analyses in with dilation factor 4. We describe, in terms of the underlying multiresolution structure, all generalized multiresolution analyses Parseval frame wavelets all semi-orthogonal Parseval frame wavelets in . We show that there exist wavelet frame generated by two functions which have good dual wavelet frames, but for which the canonical dual wavelet frame does not consist of wavelets, according to scaling functions. That is to say, the canonical dual wavelet frame cannot be generated by the translations and dilations of a single function. Traits of tight wavelet frames are presented.
Electerochemical Study of Speek/Cloisite 15A®/TAP Membrane at Moderate Temperature for DMFC Application
Authors: Ilbeygi H. , Ismail A.F. , Nasef M.M. , Jaafar J. , Jalalvandi E. , Panahi P.
Published: April 2013

This study was to investigate the properties of the sulfonated poly(ether ether ketone) (SPEEK) nanocomposite membranes filled with Cloisite 15A® clay, in the presence of 2,4,6 triaminopyrimidine (TAP) as a compatibilizer. The membranes were prepared via solution intercalation method, before they were subjected to performance tests in the temperature range of 27 to 80 oC for comparison with Nafion® 117. The SPEEK membranes were then utilized to measure the open circuit voltage (OCV) and power density for direct methanol fuel cell (DMFC) applications in the temperature range of 27 to 60 oC. The best data obtained, among all the tested membranes, were methanol permeability of 0.52 ×10-6 cm2s-1 and proton conductivity of 47 mScm-1 with the methanol selectivity of 9.1 × 104 S.s.cm-3, even at a high temperature of 60oC.
Ammonia Gas Sensors Based on In Situ and Drop-Coated Polyaniline Nanostructures
Authors: Kebiche Houria , Debarnot D. , Merzouki A. , Poncin-Epaillard F. , Haddaoui N.
Published: April 2013

Polyaniline (PANI) nanostructures are successfully prepared and deposited by in-situ and drop-coating on glass substrates without using any template. By changing synthesis and deposition method, a new morphology of nanostructures, “the cauliflower-like structure”, is developed. These nanostructures were then tested as optical ammonia gas sensors by measuring the optical absorbance variations at 632 nm at different NH3 concentrations. The results show a strong dependence of the morphology on the deposition method. The in-situ one leads to better performances compared to the drop coated one. Protonation /deprotonation is the mechanism of interaction between NH3 molecules and PANI nanostructures.
Flow Measurements in Metal Oxide-Nanoparticle Suspensions in a Rectangular Natural Circulation Loop
Authors: Shijo Thomas , Sarun Kumar Kochunni , Sobhan Choondal Balakrishnapanicker
Published: April 2013

Natural circulation cooling systems, such as the thermosyphon loops are preferred as effective heat dissipation methods where a silent and vibration-free operation is desired in thermal control of devices and processes. Though anomalous enhancement in forced convection heat transfer coefficients have been reported for nanofluids, the effect of addition of nanoparticles to base fluids in natural convection circulation loops is not clearly understood. An experimental study is reported in this work, using aluminum oxide and copper oxide nanofluids with varying concentrations, in a thermosyphon loop. The flow velocity is arrived at from the measured pressure drop. At a nanoparticle concentration of 0.01% by volume Al2O3-water and CuO-water nanofluids shows 88.37% and 42.89% improvement in flow, respectively.
Functionalization by Acidic Treatment in the Purification of Multiwalled Carbon Nanotubes (MWCNTs)
Authors: Ahmad Mohamad Fauzi , Mazuki Adlan Akram Mohammad , Yusof Nurhalawa Md , Yahya Rosiyah , Zawawi Siti Murni M. , Mansor Nuruzatulifah Asari , Zakaria Osman
Published: April 2013

Comparative studies of two multi-walled carbon nanotubes (MWCNT) from different manufacturers were reported. The purification and functionalization of commercial multiwall carbon nanotubes were investigated. MWCNTs were treated with boiling concentrated HNO3 under a reflux condenser for 2 hours at 100 °C in order to purify and oxidize the raw material. The oxidized MWCNTs were rinsed with deionized water until stabilization of the filtrate pH. The measurement technique was by thermogravimetric analysis (TGA) for thermal analysis decomposition products. Meanwhile, the chemical shifted in MWCNTs can be determined by using Raman Spectroscopy.
Advanced Thermoelectric Materials in Electrical and Electronic Applications
Authors: Tiwari Pratibha , Gupta Nishu , Gupta K.M.
Published: April 2013

Thermoelectric materials are a novel class of materials having unique characteristics. They are Seebeck and Peltier effect materials and are used as thermocouples, for thermoelectric cooling of microelectronic products, as thermoelectric converter for energy conservation etc. Due to their versatility of behaviour, they are now used as construction materials for microelectronic equipment, wireless sensors also. This paper aims at elaborating the development of such materials by compiling the recent and ongoing researches. In this regard, the research developments of some newer materials by other investigators have been presented here. Brief details of the development of thermoelectric generation, thermoelectric cooling, thermoelectric power generator for wearable systems, nano-thermocouple, thermoelectric Peltier microcoolers etc. are presented. In these elaborations, it is shown by the respective investigators that these TE materials can be effectively used in heavily doped semiconductor, thin films, quantum well etc.
The Recent Advances of Research on Memristor and Memristive Characteristic Devices
Authors: Li Mi , Deng Hong , Wei Min , Qiu Wen Wen , Yao Jian Qiang , Deng Xue Ran , Gao Qiu Lei , Jiang Ji Tian , Wen Guang Jun
Published: April 2013

As a circuit element, memristor behaves like a nonlinear resistor with memory. It is demonstrated as the fourth fundamental circuit element in addition to resistor, capacitor and inductor. This paper summarized the main progress in this field, such as, the development of models and mechanism, the selection of new materials, the experimental results, and the similarities and differences of unipolar and bipolar Resistive Switching Characteristics
S/N Ratio Analysis of Tribological Behavior of SiCp Reinforced Al2124 Based Metal Matrix Composite
Authors: Şahin Y. , Öksüz K. Emre
Published: April 2013

Al2124-20wt.% SiCp composites were prepared by powder metallurgy (PM) method and investigated the tribological behavior of MMCs. S/N ratio analysis and analysis of variance (ANOVA) were employed to investigate which design parameters significantly affected the wear of the composites. The hardness of the matrix alloy increased from 44.2 HRB up to 87 HRB when reinforced with SiC particles. The ANOVA results showed that the hardness exerted the greatest effect on the wear, followed by the abrasive size.
Effect of Welding Speed on CO2 Laser Beam Welded Aluminum-Magnesium Alloy 5083 in H321 Condition
Authors: Subbaiah K. , Manivasagam Geetha , Shanmugarajan B. , Rao S.R. Koteswara
Published: April 2013

Laser beam welding of aluminum alloys is expected to offer good mechanical properties of welded joints. In this experimental work reported, CO2 laser beam welding at 3.5 kW incident power was conducted autogenously on 5 mm thick 5083-H321 aluminum alloy plates at different welding speeds. The mechanical properties and microstructural characteristics of the welds are evaluated through tensile tests, micro-hardness tests, optical microscopy and scanning electron microscopy (SEM). Both yield stress and tensile strength of the laser beam welded joint at the optimum welding speed were 88 % of base metal values. Experimental results indicate that the tensile strength and hardness of laser beam welds are affected by the variation of the intermetallic compounds.
Numerical Evaluation of Steel Columns Stability under Various Cases of Thermal Loads
Authors: Almasri Amin H. , Alayan Hesham H.
Published: April 2013

This paper presents the results of a simulation study of fire tests of restrained (fixed-hinged) hot rolled steel column sections subjected to axial compression in addition to constant and variable thermal loads. Finite element computer software is utilized to study steel columns stability under thermal loads using three approaches; non-linear buckling analysis, thermal structural-Load Transfer Method (LTM) analysis, and Direct Coupled Field analysis. The finite element results are in good agreement with experimental results found in literature. The Direct Coupled Field analysis is also used to study a non-uniform temperature distribution on one side of the steel column. The LTM shows the best capabilities in studying such problems compared to the other two approaches
An FEM Approach for Three-Dimensional Thermoviscoelastic Stress Analysis of Orthotropic Cylinders Made of Polymers
Authors: Ashrafi H. , Keshmiri H. , Bahadori M.R. , Shariyat M.
Published: April 2013

The objective of this study is to develop a general finite element formulation associated with an incremental adaptive procedure which established for thermoviscoelastic stress analysis of orthotropic cylinders made of polymers. This paper concerned with development of a numerical algorithm for the solution of the quasistatic initial/boundary value problems involving the linear viscoelastic media with thermal and mechanical deformations. The viscoelastic constitutive equations, represented in an integral form and involving relaxation functions, are transformed into an incremental algebraic relation. An incremental relaxation is then developed for the finite element formulation to deal with quasistatic thermoviscoelastic problems.
Crystallography and Computer Simulation of Heat Treated Co- 10 at. Pct. Cu Alloys
Authors: Mebed Abdelazim. M.
Published: April 2013

The influence of heat treatment on phase decomposition of Co-10 at. pct. Cu alloy was studied. The materials and phase compositions were studied by using energy dispersive spectrometry (EDS) and X-ray diffraction (XRD) techniques. XRD analysis showed that the samples contained Co, Cu, CuO and CoCu2O3 phases depending on the heat treatment regimes. Moreover it is found that the formation of dendrite Co phase render the spinodal decomposition even for deep long aging inside the miscibility gap. The crystal structural parameters were refined with FULLPROF program. 2-D computer simulation indicates that the morphology and the shape of the microstructure agree with experimental SEM micrographs for the Cu rich phase.
Flexural Analysis on GFRP Composites Subjected to Cyclic Gradual Load and Cyclic Impact
Authors: Pazhanivel K. , Ramadoss N. , Poyyathappan K. , Anandan P. , Bhaskar G.B.
Published: April 2013

Glass fiber reinforced polymeric (GFRP) composite laminates have been prepared by hand layup method. According to ASTM standard, the test specimens have been prepared to carry out the flexural bending tests. The specimens have been subjected to both cyclic impact load and cyclic gradual load with various frequencies prior to the flexural bending analysis. Three point bend method has been adopted to find out the flexural strength and flexural modulus. Flexural strength and modulus have been calculated from the load deflection curve obtained from the tensometer for respective specimens. The flexural bending properties of GFRP composites subjected to cyclic gradual load and cyclic impact have been compared and found that the GFRP composite materials are effective for gradual cyclic load than the cyclic impact load.
The Effects of SiC Grain Size on SiC-Based Refractory Paints
Authors: Khosravanihaghighi Ayda , Pakshir Mahmood
Published: April 2013

Refractory paints based on silicon carbide were investigated with the alkali inorganic binders. In order to optimize the β-SiC granulometric distribution, different mixture of β-SiC along with metakaolin based geopolymers were used. The alkali activator was an aqueous solution NAOH/Na2SiO3. Metakaoline dissolved and reprecipitated in alkaline condition to form geopolymer which acts like a glue to stick un-reacted Al-Si and SiC. Paints were then cured and were exposed to 900°C for 8h. In the present study various proportions of two particle size of SiC were employed and, for providing geopolymers, NaOH/Na2SiO3 as an activator and metakaolin as a raw source material were used. They were applied on the low-carbon steel substrate then characterized and compared with a monomodal of SiC up to 900°C. Due to the analysis by increasing the proportion of Nano-SiC, macrocracks has been emerged.
On the Important Mechanical Properties of Rubber-Sand
Authors: Adalier Korhan , Pamuk Ahmet
Published: April 2013

More than a billion rubber tires are discarded annually around the world. Growing piles of discarded tires create fire and environmental hazards. Current disposal methods are mostly wasteful and costly. Tires possess high tensile strength, are chemically very stable, practically non-destructible and light in weight. All of these properties make tires a potentially useful geo-material. This paper presents the results of an extensive laboratory testing study investigating the potential of using shredded tires mixed with sandy soils (rubber-sand) as lightweight fill and backfill material in road construction. The results show that rubber-sand has significant promise for use as an earthwork fill material. In addition to its engineering benefits, such use of scrap tires would significantly contribute to solving the ever-growing tire disposal problem.
The Properties of Activated Carbon Fiber Derived from Direct Activation from Oil Palm Empty Fruit Bunch Fiber
Authors: Ooi Chee Heong , Ang Chun Li , Yeoh Fei Yee
Published: April 2013

Oil palm empty fruit bunch (EFB) is an abundant agricultural waste available in Malaysia. More than two million tonnes (dry weight) of extracted oil palm fiber are estimated to be generated annually. Usually the EFB is used as boiler fuel to produce steam in the palm oil mills. EFB fiber can be used to prepare activated carbon fiber (ACF) by carbonization and activation. Conversion of EFB fiber to ACF will reduce the amount of agricultural waste produced annually and it represents a potential source of adsorbents used for adsorption. The ACF has many advantages as compared to the conventional activated carbon found in powder or granular form. These advantages include large surface area, high adsorption capacity and high rates of adsorption from the gas or liquid phase. In this study, ACF produced from EFB fiber by single step direct activation process (ACF-D) was compared against ACF produced by conventional 2-step carbonization and activation (ACF-ND). The different properties between ACFs produced were investigated. The raw EFB and ACFs were characterized by a SEM and EDS, FTIR and XRD. The results show that EFB has carbon content of 63.33 weight percentage (wt %) with oxygen content of 36.67 wt %. ACF-D was found to have a high carbon content of 93.63 wt%, with low oxygen content (5.19 wt %). ACF-ND gave a higher carbon content up to 95.68 wt% and accompanied by a lower oxygen content (3.85 wt %).
Flow Behavior in the Resin Infusion of Glass Fiber Reinforced Polymer Wind Turbine Blade
Authors: Mohd Azlan Mohd Azuan , Abdul Latif Muhamad Ridzuan , Abdullah Mohamad Zaki , Zainal Abidin Kamal Arif , Wahab Azmi Abdul
Published: April 2013

This paper presents the monitoring of resin flow during resin infusion process in the fabrication of glass fiber reinforced polymer GRP wind turbine blade (WTB). Epoxy type of resin was used as the matrix and its viscosity and gel time were determined in-house. Next, resin infusions were done to obtain the permeability of the glass fiber in different directions (longitudinal and transverse), given the specific number of layers. The fabrication of composite WTB by resin infusion was conducted with the introduction of 'moldless' setup, where both upper and lower skins are covered by flexible mould/vacuum bag without any rigid female mould. However, a wooden core is used and acts as an “inner” mould to obtain the wind turbine shape. The whole infusion process was video recorded and the flow front pattern was traced at certain time intervals to investigate the infused percentage area over time. Afterward, guided by the traces of flow patterns on grid and video observation, 3D models of resin infused at interval times are generated in a CAD software. From the models, the area infused was determined. Percentage of area infused over time was compared with the analytical plot based on Darcy's law. A good agreement was found between the experimental observation and the theoretical plot.
Effect of Sintering Conditions on Mechanical Properties and Microstructure of Titanium Alloy Produced by Metal Injection Moulding (MIM)
Authors: bin Suleiman Ahmad Muhammad Jabir , bin Abdullah Ahmad Nizam , Bin Ibrahim Rosdi , Mohamad Mazlan , Abu Kasim Noorhayaty Binti , Bin Dato’Abdul Kadir Mohammed Rafiq , Muhamad Shamsul , Itoh Yoshinori , Hanada Kotaro , Shimizu Toru
Published: April 2013

Metal Injection Moulding (MIM) is an efficient method for high volume production of complex shape components from powders. The purpose of this study is to determine the sintering condition of titanium alloy (Ti6Al4V) tensile shape sample. In high temperature, Ti6Al4V will react with oxygen to form of titanium oxide (TiO2) which present a problem during sintering thus affected the mechanical properties and microstructure. This reaction can be avoided either by introducing argon gases or in vacuum condition. Ti6Al4V with binder formulation consist of polyethylene (PE), paraffin wax (PW), stearic acid (SA) and palm oil derivatives; palm stearin (PS) were mixed homogenously and injected to produce green compact. The binders then are removed and sintered at 1100 °C for 8 h. During sintering, the debound part is heated, thus allowing densification of the powder into a dense solid with the elimination of pores. It was expected that the impurity gas in argon had strong effects on aspects of the densification and properties. Samples of PE/PS formulation with argon added to the sintering atmosphere, experience density of 4.375g/cm3 and tensile strength stated at 1000.100MPa compared to samples in vacuum condition which do not show any significant increment with density of 3.943g/cm3 and tensile strength at 325.976MPa. PE/PW/SA samples of vacuum condition also show no improvement in sintered properties. However with additional argon flow the density can reach until 4.359g /cm3 and 940.823MPa of tensile strength. Ti-alloy sintered in argon exhibited better densification rate than in vacuum with high strength, better elongation and lower porosity. In argon, the powder particles became interconnected signifying densification was achieved due of non-reactive properties of inert gases that prevent undesirable chemical reactions from taking place.
High Temperature Creep Behavior of Austenitic Fe-Ni-Cr Alloy
Authors: Hamzah Esah , Mudang Maureen , Khwang Jenq Ang , Adil Khattak Muhammad
Published: April 2013

Creep damage investigation was carried out in Fe-Ni-Cr alloy at 800°C, 900°C, and 983°C using rectangular section form of specimen. In all the tests conducted on this material, some creep curves showed primary stage, secondary stage and tertiary stage. The creep fracture shows ductile transgranular fracture where separation occurred at the dendrites carbide interface suggesting that the detrimental effect of creep was compounded by precipitation of carbides at matrix. The presence of cavities may be due to the difference in thermal expansion characteristics of the austenite and carbide during high temperature test. Coarsening of carbides lead to cavities formation within the dendrite and carbide interface and form cavities linkage due to formation of crack and finally cause creep fracture. Increase in creep temperature it will lead to increase in creep rate. The fracture modes of creep samples were investigated to predict the failure mode.
Effect of Ageing Treatment on the Microstructures of Ti-50.7at.%Ni Shape Memory Alloy
Authors: Hastuti Kurnia , Hamzah Esah , Hashim Jasmi
Published: April 2013

In this study, a commercial Ti-50.7at.%Ni was subjected to solution treatment at 800oC and 900oC for one hour followed by ageing at 300oC, 400oC, 500oC and 600oC for 1 hour, 2 hours and 4 hours respectively. Characterization of the material using optical microscope, XRD, FESEM and EDX has shown that the presence of Ti2Ni and Ti-rich precipitates in the as-received material remained unchanged even after heat treatment. The presence of oxygen in the air condition heat treatment has stabilized Ti2Ni since this condition causing the formation of Ti4Ni2O which is also determined as Ti2Ni due to their same crystal structure. The formation of Ti3Ni4 precipitates during ageing encouraged the establishment of R phase instead of martensite due to the depletion of Ni content in the matrix. Ageing treatment at 300oC generates two steps of R phase transformation due to the differences in Ni composition in the matrix at the grain boundary and grain interior region. However, for samples subjected to ageing at higher temperature, 400-500oC, only one step of R phase transformation occurred because Ni atomic diffusion was not forbidden in the high temperature. Hardness test performed on the samples revealed that increasing the ageing time will increase the hardness of material; however for the sample aged at 600oC, increasing the ageing time would reduce the hardness due to dissolution of Ti3Ni4 precipitaes into the matrix.
The Influence of Anode Profiles for Three Dimensions Numerical Simulation of Reinforced Concrete Corrosion Using Boundary Element Method
Authors: Ihsan M. , Fonna Syarizal , Ridha M. , Huzni Syifaul , Arrifin A.K.
Published: April 2013

The corrosion of structures is needed to be identified early to prevent any severe damage of buildings. The conventional technique such as potential mapping for diagnosing of reinforced concrete corrosion has been used widely in the field. However, the method has limitation such as less accuracy, laborious and time-consuming. This study is conducted to develop boundary element method 3 dimensions by considering polarization curves of anode and cathode for corrosion simulation and analyzed the influences of anode profiles for RC corrosion simulation. In this method, the potential in concrete domain was modeled by Laplace’s equation. The anode and cathode areas were represented by each polarization curves. The numerical simulation result shows that the boundary element method 3 dimensions successfully solved the Laplace’s equation in order to simulate corrosion phenomenon of reinforced concrete. The influences of anode profiles for RC corrosion simulation have been analyzed. Further works are needed to reduce the computational effort of corrosion simulation.
The Influence of Inertia Weight on Particle Swarm Optimization in Boundary Element Inverse Analysis for Rebar Corrosion Detection
Authors: Fonna Syarizal , Ridha M. , Huzni Syifaul , Ariffin Ahmad Kamal
Published: April 2013

Particle Swarm Optimization (PSO) has been applied as optimization tool in various engineering problems. Inverse analysis is one of the potential application fields for PSO. In this research, the behavior of PSO, related to its inertia weight, in boundary element inverse analysis for detecting corrosion of rebar in concrete is studied. Boundary element inverse analysis was developed by combining BEM and PSO. The inverse analysis is carried out by means of minimizing a cost function. The cost function is a residual between the calculated and measured potentials on the concrete surface. The calculated potentials are obtained by solving the Laplace’s equation using BEM. PSO is used to minimize the cost function. Thus, the corrosion profile of concrete steel, such as location and size, can be detected. Variation in its inertia weight was applied to analyze the behavior of PSO for inverse analysis. The numerical simulation results show that PSO can be used for the inverse analysis for detecting rebar corrosion by combining with BEM. Also, it shows different behavior in minimizing cost function depending on inertia weight.
Effect of Compaction Load and Heat Treatment in Manufacturing of HSS Cutting Inserts under Nitrogen-Based Atmosphere
Authors: Talib R.J. , Mahaidin Ahmad Aswad , Manaf Samsiah Abdul , Fazira Mohamed Fadzil , Selamat Mohd Asri
Published: April 2013

High speed steels (HSS) is used in manufacturing of cutting tools and wear components because of its superior mechanical properties and wear resistance. In this study, the optimization manufacturing parameters such as compacting pressure and heat treatment temperatures will be studied. The powder of HSS and iron phosphorous were dryly mixed for 30 minutes. The mixed powders were compacted at the pressure in the range of 300- 632 MPa, sintered in the temperature range of 1100 - 1225 °C, annealed in the temperature range of 1100 - 1175 °C and tempered in the temperature range of 500 - 600 °C. The mechanical properties of the samples are analyzed using Vicker’s microhardness tester, universal tensile machine and the microstructures of the sintered sample were observed using field emission scanning electron microscope. Test results revealed that the optimum manufacturing parameters are as follows; (i) compacting pressure of 632 MPa, (ii) sintering temperature of 1200°C, (iii) annealing temperature of 1175 °C, (iv) tempering temperature of 500 °C.
Prediction of Welding Parameters and Weld Bead Geometry for GMAW Process in Overhead T-Fillet Welding Position (4F)
Authors: Yaakub Mohamad Yazman , Tham Ghalib , Wan Abd Rahim Wan Muhamad Amirun , Mohd Radzi Muhammad Amir Rusydi , Mahmud Azhar
Published: April 2013

The prediction of welding parameters and weld bead geometry for GMAW process in Overhead T-fillet welding position (4F) is presented in this paper. This welding position is applied in construction of steel structures and ship building. The task to discover the range of welding parameter that can deposit quality fillet weld in overhead position is difficult, and the cost of developing them by trial and error is high. Robotic GMAW welder is employed to weld in 4F position with CO2 shielding. The current, voltage and speed as parameters, wire extension at 13mm constant. Only weld coupons are analyzed by macro-etching and the fillet geometry is plotted graphically to display the correlation with the respective welding parameter, particularly the heat input. Trend-lines with mathematical formulas are selected to develop the fillet geometry predictor. The predicted fillet geometry is validated by comparing with the values from actual welded coupons. The mean absolute deviation (MAD) of the predicting calculator is less than 1.0mm, it is therefore accurate and valid for industrial application.
Preparation and Properties of a New Polymer-Modified Cement Mortar Containing Iron Tailings Sand
Authors: Xiao Li Guang , Liu Gang , Feng Shuo , Zhang Shi Ting
Published: April 2013

Iron tailing is a kind of mineral waste from industrial processing and magnetic separation of iron ore, which severely pollute the air, soil property and the source of water. For large scale tailing ponds (dam height >100 m), the accident could cause a substantial damage. Therefore, it is significant to appropriately utilize the tailings. The present paper systematically studies the possibility of complete replacement of quartz sand with the iron tailings in polymer modified cement mortar used in external wall insulation plaster. The effects of redispersible polymer powers, cellulose ether, water reducing agent, lignin and polypropylene fiber on the performance of polymer modified cement mortar have been discussed. The results show that the performance of polymer-modified cement mortar composed of iron tailings has reached the national standard of external wall insulation system in China.
Synergies between Polymers and Cement Concrete Providing Opportunities for Sustainable Construction
Authors: Van Gemert Dionys
Published: April 2013

Synergetic actions between cement and polymer provide performance improvement and a wide range of new and innovative properties and applications. Polymers can reduce the impact of construction industry on environment, by decreasing the carbon footprint of cement production. In such a way construction industry will be able to meet increasing demands of a growing world population. Renovation and restoration, largely figuring in the concept of sustainable construction development, thank their growing share in construction activity to the input of polymers in repair materials and rehabilitation procedures.
Durability of Polyester Resin Concrete in Different Chemical Solutions
Authors: Jamshidi Masoud , Alizadeh Mohammadreza , Salar Milad , Hashemi Abdolreza
Published: April 2013

Polymer concretes (PC) were introduced to building and construction industry more than 50 years ago. Gradually, they became a suitable substitute for concrete structures; however, their application was shortly diminished due to the higher costs. In this research a homemade cost-quality effective resin (unsaturated polyester) is used as binder in the polymer concrete production. Laboratory specimens made and evaluated for compressive stregth tests. A comparative study was performed on effect of different chemicals (organic and inorganic acids, alkalis, sodium sulfate, gasoline and water) on durability of the polymer concrete specimens after six months of exposure.
Damping Properties of EVA Modified Cement Pastes
Authors: Zhang Zhen Lei , Wang Pei Ming , Wu Jian Guo
Published: April 2013

Earthquakes, wind buffeting, ocean waves， noise vibration and explosion are all harmful to people’s life. For controlling the vibrations, one way is by improving the material damping capacity. Effects of improving the damping properties of cement based material by adding polymer, fiber and interfacial modification have been admitted. Whereas the relationship of the influence of the dosage of polymer to the damping functions and the changes of damping behaviors at different frequency, temperature environment have received much less attention. Furthermore, ethylene-vinyl acetate (EVA) which used as one of the mainly modified has been widely applied in various aspects such as improving ductility, impermeability and mechanical properties. However, the ability of EVA modification in cement on improving the damping capacity has received less attention. The main objective of this paper is to research the damping behavior of EVA modified cement pastes at different frequencies, temperatures and polymer contents by dynamic mechanical analyzer. Experimental results showed that damping property of EVA modification in cement was dramatically increased. For a certain EVA modified cement paste, tanδ slightly increases with the frequency increases and a sharp peak was found at the glass transition temperature. The SEM images indicated that there was a morphological difference in the plain cement paste and EVA modified cement paste.
Effect of Cyclic Exposure of Chemicals on Compressive Strength of Polyester Resin Based Polymer Concrete
Authors: Jamshidi Masoud , Ghasemi Mohammad Javad , Hashemi Abdolreza
Published: April 2013

Polymer concretes (PC) were introduced to building and construction industry more than 50 years ago. Gradually, they became a suitable substitute for concrete structures. Their superior properties againt aggresives introduced them as a good overlay for concrete structures; however, their application was shortly diminished due to the higher costs. In this research a homemade cost-quality effective resin (unsaturated polyester) is used as binder in the polymer concrete production. Polymer concrete specimens were evaluated for compressive strength and its fluctuation due to cyclic exposure to different aggresive solutions (sulfuric acid, nitric acid, citric acid, chloridric acid, sodum sulfate, water, demineralized water, sodium hydroxid, potasium hydroxid and gas oil). It was found that PC specimens degraded more in alkali conditioned in comparison to acid solutions.
Strength of Porous Polymer Concrete and Growth Properties of Plant within Planting Polymer Block Using Unsaturated Polyester Resin
Authors: Sung Chan Yong , Kim Young Ik
Published: April 2013

This research was performed to provide strength property of porous polymer concrete using unsaturated polyester resin depending on the amount of binder and planting properties on coverage ratio and growth of plants in planting polymer block through planting of cool-season grass and herbaceous plant in porous polymer block. The compressive strength of porous polymer concrete depending on the binder contents and aggregate sizes were in the range of 17.1 to 23.2MPa. In the planting polymer block with Tall fescue, Perennial ryegrass and Alfalfa, the coverage ratio (in 12 weeks after seeing) were more than 7 point regardless of the kinds of plants, respectively. The roots length of plants in planting polymer block completely passed through not only the block with height of 5 cm but also the block with height of 10 cm in 20 weeks after seeding. Planting polymer block with Tall fescue, Perennial ryegrass and Alfalfa indicates that it will be advantageous to environment-friendly greening works such as greening of slopes and revetments
Influence of Adding Encapsulated Phase Change Materials in Aerial Lime Based Mortars
Authors: Cunha Sandra , Aguiar José Barroso , Ferreira Victor , Tadeu António
Published: April 2013

Increasingly in a society with a high growth rate and standards of comfort, the need to minimize the currently high energy consumption by taking advantage of renewable energy sources arises. The mortars with incorporation of phase change materials (PCM) have the ability to regulate the temperature inside buildings, contributing for an increase in the level of thermal comfort and reduction of the use of heating, ventilation and air conditioning (HVAC) equipment, using only the energy supplied by the sun. However, the incorporation of PCM in mortars modifies some of its characteristics. Therefore, the main objective of this study was the characterization of mortars doped with two different phase change materials. Specific properties of different PCM, such as particle size, shape and enthalpy were studied, as well as the properties of the fresh and hardened state of these mortars. Nine different compositions were developed which were initially doped with microcapsules of PCM A and subsequently doped with microcapsules of PCM B. It was possible to observe that the incorporation of phase change materials in mortars causes differences in properties such as compressive strength, flexural strength and shrinkage. After the study of the behaviour of these mortars with the incorporation of two different phase change materials, it was possible to select the composition with a better compromise between its aesthetic appearance, physical and mechanical characteristics.
Recent Trends in Research and Development Activities of Polymer-Modified Paste, Mortar and Concrete in Japan
Authors: Ohama Yoshihiko , Masahiro Ota
Published: April 2013

The present paper reviews the recent trends in research and development activities of polymer-modified paste, mortar and concrete in the Japanese construction industry. In Japan, the active research and development of the polymer-modified paste, mortar and concrete have been carried out for the past about 50 years, and they are nowadays used as dominant construction materials in various applications because of their high performance, multifunctionality and sustainability compared to conventional cement paste, mortar and concrete. The recent research and development activities of the polymer-modified paste, mortar and concrete are concerned with repair, strengthening or retrofitting systems for deteriorated reinforced concrete structures, liquid-applied membrane waterproofing systems, high-grade redispersible polymer powders, intelligent repair materials, and reaction to fire as repair materials in building construction. Standardization work for the polymer-modified paste, mortar and concrete has been in progress in recent years, and useful national and institutional standards have been published till now.
Evolution in Modeling Cement Hydration and Polymer Hardening in Polymer-Cement Concrete
Authors: Van Gemert Dionys , Beeldens Anne
Published: April 2013

Several researchers have attempted to explain the synergies between cement and polymer in PCC by modeling the formation of the complex microstructure of polymer-cement mortar and concrete. The starting three-step model was proposed by Y. Ohama already in 1987, but numerous refinements and modifications to this model have been proposed since then. The paper deals with the physical mechanisms, described by the models, and shows the improvements added in the successive models, leading to a better understanding of the synergies realized by the interaction and collaboration of polymers and hydraulic cement.
Effect of Ca2+ Ions on the Film Formation of an Anionic Styrene/n-Butylacrylate Latexpolymer in Cement Pore Solution
Authors: Pavlitschek Thomas , Gretz Markus , Plank Johann
Published: April 2013

Several methods were employed to study the time dependent film formation of a self synthesized anionic latex dispersion in water and cement pore solution. First, a model carboxylated styrene/n-butyl acrylate latex dispersion possessing a minimum film forming temperature (MFFT) of 18 °C and a glass transition temperature (Tg) of 30 °C was synthesized via emulsion polymerization. Next, its film forming behaviour was studied at 40 °C, using an ESEM instrument. The analysis revealed that upon removal of water, film formation occurs as a result of particle packing, particle deformation and finally particle coalescence. Film formation is significantly hindered in synthetic cement pore solution. This effect can be ascribed to adsorption of Ca2+ ions onto the surface of the anionic latex particles and to interfacial secondary phases. This layer of adsorbed Ca2+ ions hinders interdiffusion of the macromolecules and subsequent film formation of the latex polymer.
Influence of SBR Latex on the Formation of C-S-H in C3S Paste
Authors: Yue Xu Bo , Wang Ru
Published: April 2013

Tricalcium silicate (C3S) was synthesized at 1500oC using calcium carbonate and silicon oxide. The formation of the hydrates of C3S in the presence of 10% styrene-butadiene rubber (SBR) latex was evaluated. The morphology of the calcium silicate hydrate (C-S-H) was studied using SEM, and the calcium to silica ratio of the C-S-H was studied using EDS. The results show that the SBR latex forms film on the surface of the C3S particles and the C-S-H and delays the hydration of C3S. The C-S-H in the paste modified by SBR latex is shorter and thicker than that in the control at the same hydration time. After 1 day, the calcium to silica ratio of the modified paste is higher than that of the control.
Development of a New Polymercement Waterproofing Screed with Secondary Materials
Authors: Taranza Luboš , Drochytka Rostislav
Published: April 2013

Throughout the world the issue of waste raw materials is still a very important topic. This paper is focused on the possibility of the use of waste raw material originated at high-temperatures by the combustion of black coal as a partial substitution of filler component during the development of new waterproof levelling material designated for concrete constructions. The use of the fly-ash as partial substitution of the filler component has important ecological and economic contribution.
Determination of Molecular Weight and Distribution of Polycarboxylate Superplasticizer by Triple Detection GPC
Authors: Lu Zi Chen , Wang Zi Ming , Lu Fang , Li Hui Qun
Published: April 2013

The molecular weight and molecular weight distribution (MWD) of polycarboxylate superplasticizer (PCE) was measured by gel permeation chromatograph (GPC) which combined three different detectors, namely refractive index detector (RI), laser light scattering detector (LS) and viscosity detector (VIS). By conducting numerous experiments, what the different peak stand for in the chromatogram was verified and the best sample concentration range in the GPC experiment was also determined. Besides, based on the analysis to the RI chromatogram, the theory on using peak area ratio to denote concentration ratio was put forward. What’s more, the calculation of macromonomer reaction ratio using the peak area in the RI chromatogram was introduced.