bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the Relationship between Tool Wear and Surface Finish in Turning with Carbide Tool
Authors: Amorim Heraldo J. , Neto Augusto O. Kunrath
Published: February 2014

The aim of this work is to analyze the tool wear effects on surface finish of machined components. Long-term machinability tests were performed for ASTM 1040 and 1045 carbon steels with carbide tools, in which tool wear and surface roughness were periodically evaluated. Surface finish was analyzed as a function of processed material and cutting speed with new machining tool, and a significant influence was found for cutting speed at a confidence interval of 10%. When evaluated as a function of time and tool wear, surface roughness showed an exponential relationship with both variables. However, a high dispersion occurs close to the end of tool life, especially for AISI 1040 steel. Weak influence of cutting speed (for the range of speeds tested) was observed on the relationship between tool wear and surface finish, indicating that a single equation can describe its behavior for all studied conditions. The relationship between the surface roughness and the cutting time was found to be stronger for the ABNT 1040 steel.
Photoluminescene and Fourier Transform Infrared Measurement of Undoped Diamond-Like Carbon Thin Films by Direct Current – Plasma Enhanced Chemical Vapour Deposition
Authors: Yik Jackie Chen Keng , bin Deraman Karim , Kit Ong Wai , Wan Shamsuri Wan Nurulhuda , Hussin Rosli
Published: February 2014

Undoped diamond like thin films have been prepared by using Direct Current - Plasma Enhanced Chemical Vapour Deposition system. A potentially diamond thin films was fabricated in the presence of gas mixture which accordance to the ratio CH4(1%) + H2(39%) + Ar (60%). The substrate temperature was controlled and adjusted from 300 °C to 500 °C in a vacuum chamber with the optimum pressure of 4 X 10-1Torr. The films were characterized by X ray diffraction microscopy (XRD), Photoluminescene spectroscopy (PL) and Fourier Transform Infrared (FTIR) spectroscopy. It shows that, XRD pattern shown that the film was formed in the amorphous phase with a high fraction of sp3hybridization. Luminescene band shows the peak position at (3.16 eV and 2.94 eV), (3.16 eV and 2.95 eV), (3.17 eV and 2.93 eV) and (3.26 eV) for the films deposited at 300, 350, 400 and 500 °C, respectively. The structural configuration of film obtained which corresponding to the sp3hybridization of C H bonding gives a most significant result at approximately 760 cm-1region was presented.
Effect of TiC Particulates on the Microstructure and Mechanical Properties of Aluminium-Based Metal Matrix Composite
Authors: Suraya Sulaiman , Sulaiman Shamsuddin , Munira Ali , Fazilah Abdul Aziz
Published: February 2014

In this research, metal-matrix composites (MMCs) of aluminium-11.8% silicon alloy matrix reinforced with titanium carbides particulates were fabricated by the casting technique. Aluminium-11.8% silicon alloy is selected as the matrix material and titanium carbide as particulates are mixed in different weight percentages, 5%, 10%, 15% and 20%wt. The cylinder composite castings are made by pouring the composite mixture in copper permanent-molds. The microstructure and mechanical properties of these composite materials were investigated. The effects of reinforced materials on weight percentages addition of particulate on the particulate distribution in aluminium-11.8% silicon alloy composites and SEM observation of the fracture surfaces of tensile tested specimens were deliberate. Moreover, cylinder castings without particulate addition are made and compared with the result based on the properties and microstructural features. It is found that the microstructure and mechanical properties of composites significantly improved by the use of particle reinforced into aluminium alloy.
Review of Aluminum Chip Machining Using Direct Recycling Process
Authors: Shahrom Mohamad Syahmi , Yusoff Ahmad Razlan
Published: February 2014

This paper reviews the chain of aluminum Direct Recycling process. Direct Recycling is one of intelligent process to recycle the aluminum waste. The current method for recycle waste aluminum, was affect on the environmental issues. This paper focus on the aluminum waste from machining process, also called chips produced from turning and milling process. From chip collected, next compaction process are compressed to the certain amount pressure for consolidating the materials. Lastly to produce a new material, the process is extrusion process. The most important issue to get a quality of a product is, how to control the pressure during both of process. During this process also available in hot and cold condition. From review, it was that cold compaction process more popular implemented compared to hot compaction. Then almost researchers applied hot extrusion it is because to cover sintering process.
Cutter Path Strategies for Shoulder Milling of Thin Deflecting Walls
Authors: Izamshah RAJA , Zulhairy Mohd , Kasim Mohd Shahir , Hadzley Mohd , Amran Mohd , Amri Mohd , Sivaraos
Published: February 2014

The main problem associate with the machining of thin-wall component is the wall deflection which resulting in dimensional surface error that leads to part rejection. The magnitude of wall deflection is induced by the cutting force generated during the material removal process which is governed mainly from the selection of cutter path strategies. Therefore, it is necessary to judge the machining performance of a different cutter path prior to actual machining. In this paper, the machining accuracy of three cutter path strategies namely waterline-step, overlapping-step and tree wise-steps for machining thin-wall component were investigated. It was found that there is a variation in wall accuracy for different cutter path strategies. Based on the experimental results waterline cutter path produced the least surface error followed by overlapping and tree-wise steps.
Thin Walled Part Warping Overcoming by Honeycomb Ribs Design
Authors: Manaf Ahmad Rosli Abdul , Zawawi Mohd Zairulnizam , Adly Nik Zuraida Imran
Published: February 2014

Thin walled plastic parts are subjected to warpage after injection. Warpage can be overcome by the ribs features. This experimental project is to design a honeycomb ribs replacing the normal ribs to overcome part warping. The parameters included ribs height, the ribs thickness and the honeycomb size. Finite Element Analysis (FEA) simulations for each honeycomb ribs design are analyzed with Autodesk Moldflow Insight software and the part which result the worst warping value, part with medium warping value and part with less warping value were chosen to validate them by fabricating the core and cavity inserts to produce the actual product. The part warping is measured and then compared with the data from the simulation. Thus, the best design parameter of honeycomb ribs is identified.
Velocity Measurements Using High-Speed Imaging System for Impact Test
Authors: Jaafar Abdul Aziz , Majeed Anwar P.P. Abdul , Sapuan S.M. , Basri Shahnor
Published: February 2014

This paper presents the velocity measurements for an impact test on a laminated fibre-glass composite plate. The free flight kinematic properties of a blunt-nosed cylindrical projectile on the upstream and downstream of a test coupon were measured using a high-speed camera imaging system. A visual geometric detection technique is discussed and it is shown that the uncertainties of velocity measurements are associated with an imposed constraint on the camera viewing area and shutter speed.
Analysis of Two-Layered Film Journal Bearing with Partial Slip Surface
Authors: Rao T.V.V.L.N. , Rani A.M.A. , Nagarajan T. , Hashim F.M.
Published: February 2014

Based on the approach of two-layered film consisting of different Newtonian viscosities, the present study examines the effects of partial slip bearing configuration on load capacity and friction coefficient for journal bearing. Navier slip boundary conditions are used to analyze partial slip configuration. A modified Reynolds equation for a journal bearing with two-layered film on a partial slip surface is presented. The modified Reynolds equation is derived taking into consideration of magnitude of lubricant layers film thickness, viscosities and the extent of partial slip on the bearing surface. The Reynolds boundary conditions are used in the analysis to predict nondimensional load capacity and coefficient of friction. Partial slip of bearing surfaces has a potential to improve load carrying capacity and reduce coefficient of friction for two-layered film journal bearing.
Smart Fan Controller Add-On (SMAFAC) for Home Ceiling Fan for Home Power Optimization
Authors: Md Sani Zamani , Syahid Shaharrudin Hj , Noordin Aminurrashid , Jaya Awangku Khairul Ridzwan Awangku , Izzuddin Tarmizi Ahmad , Jaafar Hazriq Izzuan , Ahmad Arfah
Published: February 2014

The rising electricaltariff for domestic usage is a well-known issue due to the increase ofpopulation and the scarce of the natural resources to generate the powersupplies. One of the common appliances which can be found in medium householdis the AC fan (table and ceiling) which is manually in operation to control thespeed. It contributes up to 10% of domestic household power consumption.Malaysia, a tropical country with temperature constantly drops from midnight tomorning from 32 °C to 27 °C. This paper presents an innovation of a SmartController Fan (SMAFAC) as a universal external controller as add-on toautomatically controlling the existing ceiling fan speed. It is designed basedon a microcontroller based system which using the temperature sensor as aninput and automatically trigger and control the capacitor fan regulator circuitto control the speed of the fan. The circuit is designed to interface with thecapacitor fan regulator, thus could reduce the power consumption approximatelyat 27% from 12am to 7am for 30 days.
Issue on Calibration of Direct Feed Biconical Antenna in a Semi-Anechoic Chamber Using Standard Antenna Method
Authors: Sapuan Syarfa' Zahirah , Mohd Jenu Mohd Zarar , Kazemipour Alireza
Published: February 2014

Antenna calibration is crucial to ensure the accuracy of Electromagnetic Compatibility (EMC) measurement results. Standard Antenna Method (SAM) is one of the methods widely used in antenna calibration which requires reference antenna with known Antenna Factor (AF) in a free space environment. The work presented in this paper is on the calibration of the AF of a direct-feed biconical antenna in a semi-anechoic chamber (SAC) with considerations given to the effects of ground plane, antenna height, reference antenna type and effects of phase center. The frequency range for the analysis is from 200 MHz to 2 GHz. It is found that antenna located 1.5 m from ground provides the best result compared to modeling. In addition, the phase centers of the reference and test antenna must be at the same positions during the measurements.
Automatic Classification of Wood Texture Using Local Binary Pattern & Fuzzy K-Nearest Neighbor
Authors: Khairuddin Ismail Mohd , Abuassal Ali , Abdelrahim Ali , Abidin Amar Faiz Zainal , Mohamad Syahrul Hisham , Alsawi Mutaz , Nordin Nur Anis , Jaafar Hazriq Izzuan
Published: February 2014

The price of the wood according to the type of wood. Classification of the woods can be done by studying its texture. This paper introduces Fuzzy k Nearest Neighbor to classify 25 types of wood. The woods images have been taken from the Wood Database of the Centre for Artificial Intelligence & Robotics, Universiti Teknologi Malaysia. The features of wood images are extracted using Local Binary Pattern. The results of this paper shows improvement in wood classification compare to the previous literature.
Forecasting Demand: Development of a Fuzzy Growth Adjusted Holt-Winters Approach
Authors: Abdesselam M. , Karim A.N. Mustafizul , Emrul Kays H.M. , Sarker R.A.
Published: February 2014

Irrespective of the type of items manufactured by an industry, environment is now becoming progressively more and more competitive than the past few decades. To sustain in this severe competition, companies have no choice but to manage their operations optimally and in this respect the importance of more accurate demand prediction cannot be exaggerated. This research presents a forecasting approach tailoring the multiplicative Holt-Winters method with growth adjustment through incorporation of fuzzy logic. The growth parameter of the time series values is adjusted with the conventional Holt-Winters method and tested for predicting the real-life demand of transformer tank experienced by a local company. The result obtained by applying the new approach shows a significant improvement in the accuracy of the forecasted demand and sheds light on further enhancement of the proposed method by optimizing other time series parameters through fuzzy logic application for possible application in prediction of demand having trend, seasonal and cyclical changes.
Antecedents of Knowledge Quality-A Conceptual Study among Malaysian SMEs
Authors: Jayashree Sreenivasan , Malarvizhi Chinnasamy Agamudainambhi , Dorasamy Magiswary , Rad Mehrnaz Fahimi
Published: February 2014

It has been an issue for all companies to obtain high quality products and services as it increases their efficiency as well as the effectiveness. By emergence of information systems (IS) the concept of quality were expanded to data and information and by virtue of this, knowledge quality as an obscure concept emerged. This research proposes to examine the essential antecedents (requirements) of knowledge quality which are functional diversity, absorptive capacity, and knowledge networks apart from investigating whether there is any relationship between knowledge quality and innovation in Malaysian Small and Medium Sized Enterprises. This study is expected to benefit the Malaysian industries economically by establishing the fact that innovation leads to success.
Feasibility Study of Additive Manufacturing Technology Implementation in Malaysian Automotive Industry Using Analytic Hierarchy Process
Authors: Rahim Siti Lydia , Maidin Shajahan
Published: February 2014

Additive Manufacturing (AM) is the direct production of finished goods using additive fabrication techniques. AM done in parallel batch production can provide a large advantage in speed and cost. Currently, the efforts to utilize AM concept and technology have several problems particularly in Malaysian automotive industry. Such existing problems have discouraged the enhancement of process and product development of automotive industry. In providing the solution, by implementing AM technology, there is potential to speed up the development of automotive parts and move towards mass customization. Several issues have been discovered by discussion with PROTON. This paper presents the critical decision factors in implementing AM in Malaysian automotive industry. Analytic hierarchy process (AHP) is used to develop the framework of decision making in order to assess the factor affecting the AM implementation. The study shows that the main factors affects the implementations of AM are financial, technological, organization and design practice. The most important aspect to be considered is the investment cost. Finally, the information presented in this paper can also assist a potential user in choosing to implement or not to implement AM technology. Keywords:Additive Manufacturing, Analytic Hierarchy Process,Automotive Industry
Experimental Investigation on Friction Coefficient of Engineering Polymers Sliding against Different Counterface Materials
Authors: Rahaman Mohammad Lutfar , Chowdhury Mohammad Asaduzzaman , Nuruzzaman Dewan Muhammad
Published: February 2014

In this research, friction coefficients of engineering polymers such as nylon and polytetrafluoroethylene (PTFE) are investigated under normal load and sliding velocity. Experiments are conducted when nylon and PTFE slide against different counterface pin materials such as mild steel and stainless steel 202 (SS 202). Experiments are carried out at different normal loads 2, 4 and 6 N, and sliding velocities 0.2, 0.4 and 0.6 m/s. Results show that in general, friction coefficient of nylon decreases with the increase in normal load and sliding velocity. On the other hand, during friction process, PTFE shows different trend i.e. friction coefficient of PTFE increases with the increase in normal load and sliding velocity. Moreover, it is observed that at identical operating conditions, the values of friction coefficient of nylon and PTFE are different depending on normal load, sliding velocity and counterface material.
Effect of Waste Edible Animal Oil on Physical Properties of Aged Asphalt
Authors: Sang Yang , Chen Mei Zhu , Wen Jin , Leng Bin Bin , Wu Shao Peng
Published: February 2014

In order to explore the feasibility of waste edible animal oil used as the asphalt rejuvenator, this study investigated the effect of waste edible animal oil on softening point, penetration, ductility and viscosity of aged asphalt binders. The aged asphalt binders were obtained from the indoor simulating aging processes by using Thin Film Oven Test (TFOT) and Pressure Aging Vessel (PAV). The results show that the dosage of waste animal oil has different effect on physical properties of aged asphalt. Both 70# asphalt and SBS modified asphalt have the optimal content of waste edible animal oil to achieve the best physical properties. The optimal contents of waste edible animal oil for 70# asphalt and SBS modified asphalt are 6% and 4%, respectively.
Effect of Waste Edible Vegetable Oil on High Temperature Properties of Different Aged Asphalts
Authors: Leng Bin Bin , Chen Mei Zhu , Wu Shao Peng
Published: February 2014

Based on the asphalt rejuvenation theory and some related studies, waste cooking oil can be used for asphalt regeneration. The objective of this study is to investigate the high temperature properties of aged asphalt binder with waste edible vegetable oil. The materials used for this study included three sources of virgin asphalt (60-80 grad, 40-60 grad, SBS modified asphalt), three sources of aged asphalt (virgin asphalt aged by RTFOT and PAV), and waste edible vegetable oil with five percentages (3.0, 4.0, 5.0, 6.0, and 7.0% of rejuvenating asphalt). The high temperature characteristics of these rejuvenated asphalts were tested including viscosity and rutting resistance factor (phase angle and complex modulus). The results indicated that three aged asphalt with an appropriate amount of waste edible vegetable oil can respectively achieve the demand of virgin asphalt in rutting resistance factor, phase angle and complex modulus. It means that waste edible vegetable oil could recover high temperature performance of aged asphalt to the level of original asphalt at a certain amount. Moreover, waste edible vegetable oil can slightly reduce the viscosity value of the aged asphalt and thus decrease the mixing and compaction temperature of the mixture.
Comparison of Life Cycle Environmental Impacts between Natural Gypsum Board and FGD Gypsum Board
Authors: Peng Zhen Guo , Ma Li Li , Gong Xian Zheng
Published: February 2014

This paper gets two inventories of environmental load of two kinds of gypsum plasterboards by studying the production processes of the natural gypsum board and flue gas desulfurization (FGD) gypsum through life cycle assessment. The results show that the total life cycle environment load of the natural gypsum board is 6% higher than the FGD gypsum board. Human toxicity effect increases by 72% and the consumption of non-renewable resources is 76% higher than the total life cycle environment load of natural gypsum board.
Investigation of Rheological Characteristics of Carbon Fiber Modified Asphalt Binder
Authors: Pang Ling , Wang Peng , Li Bo , Pan Pan , Wu Shao Peng
Published: February 2014

The performance of asphalt concrete is strongly dependent on the rheological properties of asphalt binders. In this paper, PAN carbon fiber was employed to improve the conductivity of asphalt mixture. To better understand the performance of conductive asphalt mixture, the present study investigated the rheological characteristics of asphalt binders containing PAN carbon fiber. Additionally, scanning electron microscopy (SEM) was used to elucidate the microstructure and interface reaction between the asphalt and the PAN carbon fiber. Experimental results showed that carbon fibers in the asphalt can overlap each other and form a three-dimensional space structure, which could transfer and buffer the stress. Moreover, the addition of PAN carbon fiber increases the complex shear modulus of modified asphalt binders, which means higher resistance to the permanent deformation. Furthermore, the reduction of phase angle implied the increment of elastic portion in the visco-elastic of carbon modified asphalt binder.
Effect of Aggregate Morphological Characteristics on the High-Temperature Performance of Steel Slag Based HMA
Authors: Qiu Liu Jing Zi , Chen Zong Wu , Wang Meng , Zeng Wen Bo
Published: February 2014

Steel slag, taking up about 20% of crude steel output in China, has caused many serious problems to environment, such as soil damage, water pollution. Research on the way of effective application of steel slag is always a hot topic. The utilization of steel slag in road construction as coarse aggregate is a promising way. Many researches on the mechanical characteristics of steel slag based HMA have been conducted in laboratory, and the quality indexes of steel slag such as angularity coefficient, dust content can be controlled by artificial way due to small demand for research destination. The lack of effective way to control the quality indexes of steel slag aggregate during processing is one of the main factors that limits its wide use in entity projects. In order to express the significance of quality control in steel slag aggregate production, this paper estimates the effect of different morphology on high-temperature performance of steel slag based HMA. High-temperature performances were carried out by wheel tracking test and permanent deformation test, results were discussed in this research.
Prediction of Fatigue Life of Steel-Slag Asphalt Concrete Based on Four Point Bending Test
Authors: Zhang Xin Yan , Tu Liang Liang , Gao Yang , Li Shan
Published: February 2014

Steel slag reserves of our country has reached 200 million tons and each year it will increase 100 million tons. Slag accumulation occupied a large number of enterprises space and made pollution to the environment. Since steel slag based asphalt pavements have been utilized for a certain history, their fatigue life necessitates comprehensive investigation imperatively. In this paper, the fatigue life of steel-slag asphalt mixture was tested through the four-point bending test. The results showed that steel slag prepared mixture was superior to limestone mixture after several freeze-thaws, with respect to moisture sensitivity, and was suitable for asphalt treated base (ATB). The fatigue life of slag asphalt mixture with low content limestone was longer.
Properties and Mechanism Analyse of High-Elasticity Modified Asphalt
Authors: Hao Zeng Heng , Gao Bo
Published: February 2014

Aiming at the fatigue cracking problem of the asphalt mixture on steel deck pavement surface, high-elasticity modified asphalt was developed. high-temperature properties, low-temperature properties and fatigue properties of modified asphalt and modified asphalt mixture were tested. The fatigue life of high-elasticity modified asphalt has been greatly improved, which was at least 25 times as long as that of common asphalt. The mechanism was explained clearly that the fatigue life of asphalt mixture could be improved by reducing the failure energy after each hysteresis loop of asphalt mixture, according to the dissipated energy theory for asphalt mixture. Projects proved that high-elasticity modified asphalt extremely improved the fatigue life of asphalt mixture on the steel bridge deck.
Rheological Properties of High Grade Asphalt and its Mixture
Authors: Ye Qun Shan , Ye Chang Jian , Sun Zhi Lin
Published: February 2014

Viscosity test, dynamic shear test, dynamic modulus test and creep test were conducted to investigate the rheological properties of high modulus asphalt and its mixture. Test results indicated that the viscosity of hard grade asphalt could be increased when compared with the ordinary asphalt, especially at high temperatures. The complex shear modulus and dynamic modulus of hard-grade asphalt binder and its mixture were increased, which implied that the stiffness of them was enhanced. Furthermore, the elastically portions for viscoelastic property of asphalt binders were increased, which resulted in the reduction of phase angle for hard grade asphalt binders and mixtures. The rutting parameter for hard-grade asphalt mixture was increased remarkably, which revealed that the resistance to permanent deformation could be significantly improved for hard grade asphalt mixture.
Study on Materials Composition Design of Asphalt Mixture in Upper Layer of Xisang Highway
Authors: Zhang Guo Fei , Zeng Wen Bo , Ding Ping Ping , Zhang Qing Hu
Published: February 2014

In this paper, Marshall Design method and Bailey method were utilized to design the material composition of upper layer in Xisang highway, China. And its road performance was estimated by Marshall Test, freeze and split test, wheel tracking test and fatigue test. Under the designed graduation, the residual stability ratio, split strength ratio and dynamic stability are 89.3%, 88.0% and 7752 (times/mm) respectively and the results can meet the requirement of upper layer standard in China. It confirms that the designing process of materials composition is reasonable.
Study on Noise Reduction Mechanism and Surface Performance of Crumb Rubber Micro-Surfacing Material
Authors: Zhao Mei Ling , Zhao Zhi Jie
Published: February 2014

Recently, micro-surfacing is more widely used to protect the asphalt pavement for its superiority in China. This paper investigated the effects of the waste rubber on the micro-surfing material. First, the noise reduction mechanism was analysis. Then, the surface performance of the micro-surfacing mixture was characterized in the laboratory. Sound absorption and vibration damping theory was put forward in this paper. The addition of crumb can slightly improve the surface performance of the pavement.
UV Aging Performance of Asphalt Containing LDHs
Authors: Liu Pan Fei , Zheng Jun , Wu Shao Peng
Published: February 2014

In this paper the effect of Layered double hydroxides (LDHs) on aging properties of asphalts was studied. The thin film oven test TFOT tests and ultraviolet (UV) aging process were used to simulate short-term and long-term aging of asphalts, respectively. After aging, the physical properties and dynamic shear rheological behaviors of LDHs modified asphalts were investigated. The viscosity of LDHs modified asphalts was measured by Brookfield viscometer before and after UV aging. After UV aging, with an increase of LDHs, softening point and viscosity value of modified asphalts decreased, while both of ductility and penetration increased, compared to base asphalts. Temperature sweep tests showed that the complex modulus of LDHs modified asphalts was lower than that of base asphalt, while phase angle was higher. The results showed that LDHs improved the UV aging resistance of the asphalt, and it could prevent asphalt from UV aging.
Application of Fiber Reinforced Waterproof Technology in Xisang Highway Bridge Deck Waterproof Layer
Authors: Wang Hong Bin , Jiang Cheng Jian , Delehei  , Feng Xue Da
Published: February 2014

By Using polymer modified asphalt bridge deck waterproof coating synchronous shearing spraying technology, the fiber reinforced bridge deck waterproofing adhesive layer had succeed carried out in Xisang highway bridge. Shear test was conducted in the waterproof layer structure. When completed bridge deck pavement, core was drilled and samples were carried out pull-out test. The results indicate that fiber reinforced bridge deck waterproof layer can improve waterproof coating gave resistance, crack resistance and tensile ability. The introduction of asphalt bridge deck waterproof can improve the bonding strength between the layers and the overall shear strength of the waterproof layer, enhance the overall waterproof effect and enhance the service life of asphalt layer effectively.
Application of Slurry Seal Technology in the Reconstruction Project of G303
Authors: Ma Ming , Liu Tao , Zhang Guo Fei , Li Kai Xuan
Published: February 2014

This paper introduces the slurry seal technology, the development and application of slurry seal technology, as well as the features and functions. Combined with the application of slurry seal technology in the reconstruction project of national road 303 of China, the technical indicators, the technical points and economic benefit are investigated.
Influence of Fly Ash Fineness on Autoclaved Energy Conservation Block's Performance and Hydration Products
Authors: Ma Bao Guo , Cai Li Xiong , Jian Shou Wei , Su Lei
Published: February 2014

This article discussed the influence of FA fineness on the production performance and usability through the autoclaved aerated concrete slurry gas foaming curve and basic physical properties of blocks; meanwhile, studied the influence of different fineness FA on the composition and morphology of hydration products through X-ray diffraction analysis and scanning electron microscopic analysis, The results show that in the cement-fly ash-lime system autoclaved aerated concrete, the higher fineness of FA, the more water it need, and more sensitive the slurry presents; when the FA residue decrease from 17.8% to 8% through a 0.045mm square hole sieve screen, its specific surface area enlarge from 325m2/Kg to 388m2/Kg, the autoclaved aerated concrete specific strength increase by 53.24% and 40.96% in the case of the same ratio of water and resemble extended degree, respectively. Keep on increasing FA fineness does harm to its specific strength. The crystallinity of tobermorite, which is the main hydration products of autoclaved aerated concrete decreases with the increasing of FA fineness, however, crystallite size become larger.
Investigation on High Volume Steel Slag - Rice Husk Ash Composite Binder Properties
Authors: Wang Yan Hua , Cai Jun , Ding Pin Pin , Wang Ya Jun
Published: February 2014

This paper discussed the possibilities of the processed steel slag and rice husk ash in building mortar replace cement. Experimental results show that after suitable mix designs cube compressive strength of composite binders using can meet the building mortar standard. The novel composite cementitious materials need larger water absorption, but their frost resistance, drying shrinkage, sulfate resistance relate to the pure cement varying degrees upgrade.
Life Cycle Assessment of PVC-U Plastic Window Production
Authors: Wang Shu Ping , Chen Wen Juan , Wang Zhi Hong , Gong Xian Zheng , Zhao Chun Zhi , Ma Li Ping
Published: February 2014

Based on life cycle assessment (LCA), a quantitative analysis and evaluation of resources consumption, energy consumption and pollutant emissions caused by windows production were carried out. The result shows that AP, POCP and GWP are the main contributors of the total environment burden of windows production process, and the proportion is almost 97%. At the stage of windows parts production, the main environmental pressures of windows production process are from windows profiles and glass production process. The result shows that the key of the windows production energy-saving are the windows profiles and glass production process.
Influence of LDHs on Chloride Ion Binding in Cementitious Materials
Authors: Duan Ping , Shui Zhong He , Chen Guo Wei
Published: February 2014

Layered double hydroxides (LDHs) materials could be used in cement and concrete for their ions capturing capacity and to enhance durability of concrete. In this work, properties and chloride binding capacity of different types of LDHs were compared, micro-mechanism of chloride binding of LDHs were analyzed and chloride binding of cement paste incorporating LDHs were investigated. The experimental results show that Mg-Al-NO3 LDHs presents higher chloride ion binding capacity at initial time compared to LDOs calcinated at 500 °C while ion binding capacity of LDHs calms down and LDOs increases with increasing mixing time. Cement paste incorporating LDHs presents higher chloride binding capacity compared with reference sample. All types of LDHs performed beneficial effect on the chloride penetration resistance especially with addition of 1% Mg-Al-NO3 LDOs.
Influence of Concrete with Lithium-Slag and Steel Slag by early Curing Conditions
Authors: Wu Fu Fei , Shi Ke Bin , Dong Shuang Kuai
Published: February 2014

Using industrial waste (lithium-slag and steel-slag) for the preparation of high-performance concrete, and the same mix proportion’s concrete are cured using six kinds method, which is cured to the required age later and tests its chloride ion diffusion coefficient by RCM method. The results show that: the chloride ion diffusion coefficient of 28d and 84d decreases with the lower water-binder ratio. It can achieve RCM-Ⅴ grade when the water to binder ratio is 0.27. The admixtures total of 275-350kg/m3 is appropriate when the water to binder ratio is constant.The diffusion of water conservation,water solution with 5% Nacl after 7d water conservation,water solution with 5% Nacl after 14d water conservation,water solution with 5% Nacl after 7d in water conservation and water solution with 5% Nacl after 14d in water conservation is 1.5, 3.1, 2.5, 2.8 and 2.3 times than standard conservation , so the effect of early different curing ways to HPC can not be ignored.
Influences of Admixtures on Properties of Foam Concrete with Iron Tailings
Authors: Xiao Li Guang , Liu Chang , Zhang Shi Ting , Wang Wen Bin
Published: February 2014

Iron tailings are mineral wastes obtained from industrial processing and magnetic separation of iron ore. A type of superplasticizer with high water reducing rate and early strength gaining property is characterized in this study. The influence of admixtures, i.e. superplasticizer, early strength agent and accelerating agent, on the mechanical strength, setting and hardening time of foam concrete containing iron tailings has been investigated. Further, the microstructure of foam concrete is observed. This study demonstrates high-strength foam concrete with excellent thermal insulation property can be prepared using iron tailings, cement, fly ash, silica fume, polypropylene fiber, superplasticizer, early strength agent, accelerating agent and foaming agent, which develops a new route for the comprehensive utilization of iron tailings.
Study on Different Diameter Porous Steel Slag to Early Cracking Resistance of Concrete by Internal Curing
Authors: Liu Pan , Shi Ke Bin , Zhang Lin Lin
Published: February 2014

In order to solve the serious question of early cracking of concrete in drying environment in the western of china. Using the same volume steel slag substituting fine aggregate (coarse aggregate) to mixing concrete with its porous characteristics, which are carried out by the knife-edge method. The result shows that: the compressive strength of steel slag concrete is better than the blank group at 7d and 28d ages;The Water holding capacity, the time of early cracking of concrete is delayed, the width and area of crack is significantly reduced with the increase of steel slag in same water-cement ratio. Simultaneously, the water retention and the crack resistance of concrete using steel slag stone is better than concrete using steel slag sand in same dosage. The porous steel slag can improve the internal relative humidity of concrete, restrain the early shrinkage of steel slag concrete, and help to improve early cracking resistance of concrete from the view of internal curing.
Study on Preparation of Low-Thermal Expansion Coefficient Concrete with Fly Ash
Authors: Ding Sha , Shui Zhong He , Pan Teng , Chen Wei
Published: February 2014

The low-thermal expansion coefficient (CTE) of cement paste and concrete are designed and prepared with fly ash in this study. The thermal expansion property and pore structure of cement/concrete are tested by Thermal Dilatometer, MIP, and SEM. The test results show that the addition of fly ash lowers the thermal expansion rate and coefficient of hardened paste. The increase of addition level is accompanied by the decrease of the thermal expansion coefficient. The introduction of fly ash could improve the pore structure of concrete, thus improve the thermal expansion property of cement concrete.
Rapidly Maturing SiC Junction Transistors Featuring Current Gain (β) > 130, Blocking Voltages up to 2700 V and Stable Long-Term Operation
Authors: Sundaresan Siddarth G. , Jeliazkov Stoyan , Grummel Brian , Singh Ranbir
Published: February 2014

SiC npn Junction Transistors (SJTs) with current gains as high as 132, low on-resistance of 4 mΩ-cm2, and minimal emitter-size effect are demonstrated with blocking voltages > 600 V. 2400 V-class SJTs feature blocking voltages as high as 2700 V combined with on-resistance as low as 5.5 mΩ-cm2. A significant improvement in the current gain stability under long-term high current stress is achieved for the SJTs fabricated by the high gain process.
Static and Dynamic Performance Evaluation of >13 kV SiC-ETO and its Application as a Solid-State Circuit Breaker
Authors: Rezaei Mohammad Ali , Wang Gang Yao , Huang Alex Q. , Cheng Lin , Palmour John W. , Scozzie Charles
Published: February 2014

This study addresses the transient and steady-state performance of a >13 kV SiC ETO as a Solid-State Circuit Breaker (SSCB). The developed SiC-ETO is based on a 1 cm2, 15 kV SiC p-GTO with an extremely low differential resistance. Static performance of the device, including the on-state voltage drop at different temperatures and different currents has been carried out in this paper. Furthermore, transient performance of the device, including the turn off energy of the device has been studied. Also, the superior performance of the p-type SiC-ETO has been exploited to design and implement a solid-state circuit breaker. The studies verify the superiority of the SiC p-ETO compared to other solid state devices for this application.
Nuclear Radiation Detectors Based on 4H-SiC p+-n Junction
Authors: Issa Fatima , Vervisch Vanessa , Ottaviani Laurent , Szalkai Dora , Vermeeren Ludo , Lioussy Abdallah , Kuznetsov Andrej , Lazar Mihai , Klix Axel , Palais Olivier , Hallén Anders
Published: February 2014

Silicon carbide (SiC) radiation detectors were realized by 10B implantation into the metal contact in order to avoid implantation-related defects within the sensitive area of the 4H-SiC pn junction. No post implantation annealing was performed. Such detectors respond to thermal neutrons showing consistent counting rates as function of external reverse bias voltages and radiation intensity.
High Speed Rail Awaits the next Breakthrough of Power Semiconductors
Authors: Uzuka Tetsuo , Masada Eisuke
Published: February 2014

High Speed Rail (HSR) is expanding rapidly in the whole world in this decade. Almost all the high-speed trains are fed by high-voltage AC and are equipped with several large motors. In addition, High-speed trains have a strict restriction for both mass and size. Thus, HSR needs power semiconductors that can handle high-voltage and giant current. In addition, EMC problems become larger in these days, thus higher speed of switching is expected. From simple silicon diodes in 1960s, thyristors, GTO thyristors, IGBTs and until new wide gap devices such like SiC, the progress of power semiconductor and cooling system directly pulls the performance of high-speed rolling stock. In some cases, fixed installations for HSR are equipped with flexible AC transmission systems (FACTS) such as static VAR compensators (SVC), also.
High-Efficiency Power Conversion Using Silicon Carbide Power Electronics
Authors: Nee Hans Peter , Rabkowski J. , Peftitsis D. , Tolstoy G. , Colmenares J. , Sadik Diane Perle , Bakowski M. , Lim Jang Kwon , Antonopoulos A. , Ängquist L. , Zdanowski M.
Published: February 2014

The message of this paper is that the silicon carbide power transistors of today are good enough to design converters with efficiencies and switching speeds beyond comparison with corresponding technology in silicon. This is the time to act. Only in the highest power range the devices are missing. Another important step towards high powers is to find new solutions for multi-chip circuit designs that are adapted to the high possible switching speeds of unipolar silicon carbide power transistors.
Inverter-Rectifier Using SiC Power Devices for Bidirectional Wireless Power Transfer System of Electric Vehicles
Authors: Hachisuka Michihiro , Fukuhara Takuya , Kaneko Yasuyoshi , Abe Shigeru
Published: February 2014

The bidirectional wireless power transfer system will have many advantages to charge the batteries of the electric vehicles. In their power supply circuit, the efficiency of the inverter and rectifier is important for total system efficiency. The inverter-rectifier, which is a type of power supply circuit in this system, performs inverter operation and rectifier operation. To reduce the loss of operation modes of both, we decided to use SiC power devices that are able to reduce switching loss. However, there is a problem of high conduction loss caused by the use of SiC power devices in rectifier operation. We propose the method of parallelizing SiC-MOSFET and diode of low forward voltage, and achieved a higher efficiency.
High Temperature Resistant Packaging for SiC Power Devices Using Interconnections Formed by Ni Micro-Electroplating
Authors: Kato Noriyuki , Shigenaga Akiyoshi , Tatsumi Kohei
Published: February 2014

High temperature SiC devices require the materials for packaging also capable of working at higher temperature than those for Si devices. SiC devices are expected to help hybrid vehicle power control units (PCUs) produce higher power in a more compact size as SiC can withstand higher voltages and temperatures (above 300°C) than silicon with less power loss. The improvement of interconnection technologies is increasingly becoming a top priority, particularly for the operation of SiC devices at relatively high temperatures. We propose a new interconnection method using nickel electroplating to replace Al wire bonding or die-bonding using solder materials. During the evaluation of the reliability of interconnections annealed at up to 500°C, we observed no significant changes in mechanical or electrical properties. We found that micro-plating connections can be used successfully for high-temperature-resistant packaging for SiC devices.
SiC Power Devices Operation from Cryogenic to High Temperature: Investigation of Various 1.2kV SiC Power Devices
Authors: Chailloux Thibaut , Calvez Cyril , Thierry-Jebali Nicolas , Planson Dominique , Tournier Dominique
Published: February 2014

The aim of this study consists in comparing the effects of temperature on various SiC power devices. Electrical characteristics have been measured for temperatures from 100K to 525K. All devices are suitable for high temperature. However, SiC MOSFETs are not a good choice for cryogenic temperature, while SiC BJTs are less affected by temperature than other components, especially for cryogenic temperature.
Controlling the Carrier Concentration of Epitaxial Graphene by Ultraviolet Illumination
Authors: Eless Viktoria , Yakimova Rositza , Pearce Ruth
Published: February 2014

Silicon carbide (SiC) is a well-known material for UV detection however the effect of UV illumination on the electron donation between the substrate, interfacial (or buffer layer) and graphene is not well understood. The effect of ultraviolet (UV) illumination on the carrier concentration of an epitaxial graphene hall bar device is investigated by scanning Kelvin probe microscopy (SKPM) and transport measurements in ambient and vacuum conditions. Modulation of the carrier concentration is demonstrated and shown to be due to both substrate and environmental effects.
Electrical Nanocharacterization of Epitaxial Graphene/Silicon Carbide Schottky Contacts
Authors: Giannazzo Filippo , Hertel Stefan , Albert Andreas , La Magna Antonino , Roccaforte Fabrizio , Krieger M. , Weber Heiko B.
Published: February 2014

Epitaxial graphene fabricated by thermal decomposition of the Si-face of silicon carbide (SiC) forms a defined interface to the SiC substrate. As-grown monolayer graphene with buffer layer establishes an ohmic interface even to low-doped (e. g. [N] ≈ 1015 cm-3) SiC, and a specific contact resistance as low as ρC = 5.9×10-6 Ωcm2 can be achieved on highly n-doped SiC layers. After hydrogen intercalation of monolayer graphene, the so-called quasi-freestanding graphene forms a Schottky contact to n-type SiC with a Schottky barrier height of 1.5 eV as determined from C-V analysis and core level photoelectron spectroscopy (XPS). This value, however, strongly deviates from the respective value of less than 1 eV determined from I-V measurements. It was found from conductive atomic force microscopy (C-AFM) that the Schottky barrier is locally lowered on other crystal facets located at substrate step edges. For very small Schottky contacts, the barrier height extracted from I-V curves approaches the value of 1.5 eV from C-V and XPS.
Solid Phase Growth of Graphene on Silicon Carbide by Nickel Silicidation: Graphene Formation Mechanisms
Authors: Escobedo-Cousin Enrique , Vassilevski Konstantin , Hopf Toby , Wright Nicholas , O'Neill Anthony G. , Horsfall Alton B. , Goss Jonathan P.
Published: February 2014

This work presents experimental evidence of the formation mechanisms of few-layer graphene (FLG) films on SiC by nickel silicidation. FLG is formed by annealing of a 40 nm thick Ni layer on 6H-SiC at 1035ºC for 60 s, resulting in a Ni2Si layer which may be capped by any Ni that did not react during annealing. It has been proposed that FLG forms on top of the Ni during the high temperature stage. In contrast, during cooling, carbon atoms which were released during the silicidation reaction may diffuse back towards the Ni2Si/SiC interface to form a second FLG film. After annealing, layer-by-layer de-processing was carried out in order to unequivocally identify the FLG at each location using Atomic force microscopy (AFM) and Raman spectroscopy.
Ion-Beam Irradiation Effect in the Growth Process of Graphene on Silicon Carbide-on-Insulator Substrates
Authors: Okano Motochika , Edamoto Daiki , Uchida Kentaro , Omura Ichiro , Ikari Tomonori , Nakao Motoi , Naitoh Masamichi
Published: February 2014

We investigated the effect of ion-beam irradiation of the 3C-SiC(111) surface on the growth of graphene by the SiC surface-decomposition method. When a 3C-SiC(111) surface was irradiated by 1 keV Ar+ ions at a dose of 4.5 × 1015 cm2 in an ultra-high-vacuum chamber and then annealed at 1200 °C for 1 min, the formation of graphene layers was promoted in comparison with that in the absence of ion-beam irradiation. X-ray photoelectron spectroscopy studies showed that Ar ion bombardment of the 3C-SiC(111) caused breakage of surface bonds and helped Si atoms to desorb from the surface.
Magnetoresistance of AlGaN/GaN High Electron Mobility Transistors on Silicon
Authors: Roensch Sebastian , Sizov Victor , Yagi Takuma , Murad Saad , Groh Lars , Lutgen Stephan , Sickmoeller Markus , Krieger M. , Weber Heiko B.
Published: February 2014

We present temperature dependent magnetoresistance measurements on the 2-dimensional electron gas of epitaxially grown AlGaN/GaN heterojunctions on silicon (Si). We report on the quantum correction to the classical conductance. In particular we found weak localization, electron-electron-interaction, and Shubnikov-de Haas oscillations. The results verify the high material quality of the investigated GaN on silicon.