bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational Investigation of Heat Transfer of Nanofluids in Domestic Water Heat Exchanger
Authors: Che Sidik Nor Azwadi , Keen Lee Yoke , Fazeli Alireza
Published: November 2014

Recent development of nanotechnology led to the concept of using suspended nanoparticles in the heat transfer fluids to improve the heat transfer properties of the base fluids. The heat transfer enhancement by nanofluids is the significant concerns in the efficiency of domestic water heat exchanger system. A computational investigation of the heat transfer in a domestic water heat exchanger is conducted on the water and water-based nanofluids. Copper (Cu) nanoparticle and Alumina (Al2O3) nanoparticle are selected in the water-based nanofluids. Volume fraction of nanoparticle in the nanofluids is set at 0.5 %, 1.0 %, 1.5 %, 2.0 %, 2.5 %, and 3.0 %. Heat exchanger has been invented for the heat transfer from one medium to another medium in many heat transfer systems. Domestic water heat exchanger can be used in a heat pump domestic water heating system. The density, the thermal conductivity, and the dynamic viscosity of the water base fluid are increased while the specific heat capacity of the water base fluid is reduced with the addition of copper as well as alumina nanoparticle. Addition of copper nanoparticle into the water-based heat transfer fluid significantly increases the domestic hot water temperature. The efficiency of domestic water heat exchanger system is optimum when 1.5 % copper or alumina nanoparticle is added into the water-based heat transfer fluid.
Progressive Freeze Concentration of Coconut Water: Effect of Coolant Temperature on Process Efficiency and Heat Transfer
Authors: Nor Zanariah Safiei , Noor Naimah Mohamed Nor , Ngadi Norzita , Zakaria Zaki Yamani , Mazura Jusoh
Published: November 2014

In this research, coconut water was concentrated by applying progressive freeze concentration (PFC) using coil crystallizer. Overall heat transfer coefficient (U) was analyzed from the process by varying different coolant temperature values since both of them are closely related. In this case, heat transfer efficiency depends strongly on ice crystal formed on the inner cooled surface and is explained theoretically from that angle. At optimum flowrate, operation time and initial concentration best results were observed at-10oC of coolant temperature where the concentration efficiency and effective partition constant (K) obtained were 48% and 0.2 respectively. Meanwhile, U obtained at the first and second stages were 183.0046 W/m2oC but dropped at lower value at later stage at 154.9625 W/m2oC due to ice fouling.
Behaviour of Ice Crystal Growth in a Vertical Finned Cylindrical Freeze Concentrator
Authors: Nurul Aini Amran , Shafirah Samsuri , Ngadi Norzita , Zakaria Zaki Yamani , Mazura Jusoh
Published: November 2014

Behaviours of ice crystal growth at two different operating parameters namely coolant temperature and circulation time were investigated for progressive freeze concentration (PFC) of glucose solution through a vertical finned crystallizer (VFC). Two determinant parameters which are ice production rate (mu), and water recovery (WR) were used to illustrate the behaviours of ice crystal growth in this study. From the result, higher ice production rate (mu) and water recovery (WR) were achieved at lower coolant temperature. On the other hand, longer circulation time resulted in lower ice production rate (mu), but at the same time increased the water recovery (WR). The maximum ice production rate (mu) and water recovery (WR) attained through this study were 1.522 gm-2s-1 and 51.131 %, respectively.
Effect of Circulation Flowrate on the Performance of a Spiral Finned Freeze Concentrator
Authors: Shafirah Samsuri , Nurul Aini Amran , Ngadi Norzita , Zakaria Zaki Yamani , Mazura Jusoh
Published: November 2014

Progressive freeze concentration (PFC) has emerged as a viable technology for concentration of liquid solution. In this study, a newly designed spiral finned crystallizer to improve productivity of PFC process was proposed. The spiral fin is presented based on the advantage of additional surface area to the spiral finned crystallizer. The performance of spiral finned crystallizer was analysed by the system efficiency and the effect of circulation flowrate. It was found that the efficiency of the system has significantly improved in terms of a lower effective partition constant and a higher recovered solute. An effective partition constant of 0.35 and a recovered solute of approximately 0.96 g of glucose per 1 g of initial glucose were obtained. Thus, spiral finned crystallizer for PFC system is evidently an effective system to concentrate solution and to produce pure ice crystal.
Numerical Analysis on the Effects of Mixed Convection of Particles Removal Flow over Heated Cavity Using Multi-Relaxation Time Thermal Lattice Boltzmann Method
Authors: Che Sidik Nor Azwadi , Ali Khan Aman
Published: November 2014

This paper provides numerical study of the effects of mixed convection on particles removal from a cavity using multi-relaxation time thermal lattice Boltzmann method (LBM) for compute the flow and isotherm characteristics in the bottom heated cavity located on a floor of horizontal channel. A point force scheme was applied for particles-fluid interactionand double-distribution function (DFF) was coupled with MRT thermal LBM to study the effects of various grashof number (Gr) and Aspect Ratio (AR) on the efficiency of particles removal. The results show that change in Grashof number and Aspect ratio causes a dramatic different in the flow pattern and particles removal efficiency.
Strong Shielding Interaction Analysis Using J-Integral
Authors: Daud Ruslizam , Majid M.S. Abdul , Afendi Mohd , Amin N.A.M. , Ariffin Ahmad Kamal , Abdullah Shahrum
Published: November 2014

Numerical accuracy in assessing the strong shielding interaction that promotes cracking process based on continuum mechanics is presented in this paper. Crack interaction limit (CIL) and crack unification limit (CUL) are investigated based on strain energy release rate approach. The case of two interacting edge crack in finite body is simulated using finite element analysis and J-integral. As a result, the trend of CIL and CUL is presented to prove the limit and unification of energy release can be numerically shown at higher and lower crack-to-width ratio at two crack interval ratio b = 1 and b = 0. It can be concluded that the CIL and CUL is geometrically dependent.
The Natural Frequency of the Shape Memory Alloy Anti-Symmetric Angle-Ply Composite Plates Using Finite Element Method
Authors: Rasid Z.A.
Published: November 2014

Shape memory alloy (SMA) wires were embedded within laminated composite plates to take advantage of the shape memory effect (SME) property of the SMA. Active modal modification of SMAC plates was studied using the finite element method (FEM). A linear FEM formulation was developed based on the first order shear deformation theory. The effect of SMA was captured by adding the geometric stiffness matrix to the stiffness matrices of composite plates. Two methods of frequency improvements are considered here: The active property tuning (APT) and the active strain energy tuning (ASET) methods. The values of recovery stress for the ASET analysis were determined from Brinson’s model. The effects of several parameters on the natural frequencies of the SMAC plates were studied. It was found that the effect of SMA is similar for couples of frequency modes where frequencies of mode I and IV seems to have affected the most by SMA.
Finite Element Analysis on Brake Disc of an Educational All-Terrain-Vehicle
Authors: Hassan Muhammad Zahir , Fudhail Abdul Munir , Salim Mohd Azli
Published: November 2014

All-terrain vehicle is famously used for various purposes such as in civilian and military. The use of finite element analysis in a preliminary design stage has been demonstrated to be cost and time effective. In this paper, the finite element analysis of a brake disc for All-Terrain-Vehicle (ATV) is demonstrated. Eulerian-Lagrangian method was employed in this work where simple annular ring was used as the disc model. This study is limited to thermal and contact analysis between the disc and brake pad. The results in term of temperature and stresses distribution is obtained and presented. Moreover, the lateral displacement of the disc due to the friction contact is also shown. These results are then used to as a technical guideline in designing brake system for a fully customized ATV
New Phrase Chunking Algorithm for Myanmar Natural Language Processing
Authors: Aung Myintzu Phyo , Moe Aung Lwin
Published: November 2014

Chunking is the subdivision of sentences into non recursive regular syntactical groups: verbal chunks, nominal chunks, adjective chunks, adverbial chunks and propositional chunks etc. The chunker can operate as a preprocessor for Natural Language Processing systems. This study aims to proposed new phrase chunking algorithm for Myanmar natural language processing. The developed new algorithm accepts Myanmar tagged sentence as input and generates chunks as output. Input Myanmar sentence is split into chunks by using chunk markers such as postpositions, particles and conjunction and define the type of chunks as noun chunk, verb chunk, adjective chunk, adverb chunk and conjunction chunk. The algorithm was evaluated with POS tagged Myanmar sentences based on three measures parameters. According to the results, good accuracy of Precision, Recall and F-measure were obtained with new developed algorithm.
Effect of Surface Roughness Parameters and Surface Texture for Reduced Friction
Authors: Syahrullail Samion , Nuraliza Noorawzi
Published: November 2014

The aim of the present research was to investigate the possibility of contact surfaces with reduced friction using surface roughness analysis. For this purpose, various aluminum pin samples with different lubricant using different sliding speed values were prepared. To evaluate influence of roughness parameters on friction and wear, lubricated pin-on-disk tests were carried out under different speed contact conditions. Test results show that surfaces with high values surface roughness results in reduced friction. To investigate the effect of surface topography on surface roughness parameters and consequently on friction, real roughness profiles were virtually altered to achieve virtually textured surfaces.
Enhancing Rollover Prevention and Vehicle Stability of Heavy Vehicle under Disturbance Effect
Authors: Yakub Fitri , Mori Yasuchika
Published: November 2014

This study enhances the model predictive control for coordination of active rear steering and direct yaw moment control maneuvers for rollover prevention, lane change maneuver, and vehicle stability in heavy vehicle system under the influence of front steering angle as a disturbance to the system. A single-track mode of lateral-yaw motions based on a linearized vehicle model with linear tire characteristics is used for controller design, while the vehicle model used includes roll dynamic motion for the double-track model with a nonlinear tire model. We tested the vehicle at middle forward speed and we propose braking control algorithm based on left and right of rear wheels instead of front and rear wheels. The simulation results show the proposed coordinated control yielded better performance for rollover prevention, and also useful to maintain and enhance vehicle stability along the desired path, and has the ability to eliminate the effect of disturbance.
Design Studies and Analysis of Single Phase 8S-12P Field Excitation Flux Switching Motor
Authors: Husin Zhafir Aizat , Sulaiman Erwan , Khan Faisal , Mazlan Mohamed Mubin Aizat , Omar Mohd Fairoz
Published: November 2014

This paper presents a new structure of field excitation flux switching motor (FEFSM) as an alternative candidate of non-permanent magnet (PM) machine. The rotor is consisted of only stack of iron and hence, it is reliable and appropriate for high speed operation. Initially, the coil arrangement tests are examined to validate the operating principle of the motor and to identify the zero rotor position. Furthermore, the profile of flux linkage, induced voltage, cogging torque, torque and power characteristics are observed based on 2D finite element analysis (FEA). Initial performances show that 8S-12P FEFSM produce torque and power of 8.79Nm and 1.5kW, respectively with low cogging torque and sinusoidal flux waveform. Further design refinement and optimization will be conducted to improve the performances of the motor.
Application of Flexural Timber Reinforcement in Light Concrete Beam Structure
Authors: bin Zubir Mohammad Amirulkhairi , Mohamad Nurul Jannah
Published: November 2014

Timber is a capable alternative for reinforcement in concrete beam because it possesses high strength ratio compare to its weight although its strength is incompatible to steel. This study was conducted to highlight the flexural behaviour of beam reinforced with two types of timber; Balau and Meranti. Comparisons of behaviour have been made between samples applying the Reinforced Concrete Design to EC2. The result of flexural test shows that steel reinforcement beam (SRB) carried the utmost loads compared to timber sample beam which reinforced with Balau (BRB) and Meranti (MRB). Compared to the flexural strength of SRB, BRB reached about 69 % of the value while MRB reached to 66 % respectively. It was found that the failure mode of the timber beam was closely related to the load-deflection behaviour same as conventional steel beam. The larger the load-deflection value, the wider the range of cracking occurred.
Mechanical Properties of Epoxidized Palm Oil/Epoxy Resin Blend
Authors: Alsagayar Zyad Salem , Rahmat Abdul Razak , Arsad Agus , Fakhari Alireza , binti Wan Tajulruddin Wan Nurhayati
Published: November 2014

In this paper, a blend of epoxy resin and epoxidized palm oil (EPO) was prepared to investigate its mechanical properties. Epoxy and EPO were mixed for 20 minutes at room temperature before mixed with hardener and followed by curing for 2 hours at 100 °C. Tensile, flexural and impact tests were conducted to characterize the blend. In general, the tensile and flexural properties of epoxy resin/EPO decreased when the amount of EPO increased. However, strain at break, toughness and impact strength was slightly increased when the amount of EPO was increased up to 20%.The mechanical properties were reduced due to the reduction of the cross linking density and effect of plasticizer.
Numerical Validation for Wind Flow Field in a Street Canyon under Unstable Atmospheric Condition
Authors: Yazid Afiq Witri Muhammad , Che Sidik Nor Azwadi , Salim Salim Mohamed , Mansor Shuhaimi
Published: November 2014

This paper reports on the validation study of a commercial computational fluid dynamics program, ANSYS FLUENT v14. The purpose of the study was to determine the best turbulent model that can reproduce appropriately the wind flow field of turbulent flow in street canyon under different thermal atmospheric condition. Standard k-ε (SKE) and Large Eddy Simulation (LES) techniques were chosen as the turbulent model for the validation study. It was found that LES could well calculate a complex simulation involving isothermal flow and thermal flow with different thermal intensity and different heat location in street canyon.
Recent Development on Fracture Analysis of Solder Joints
Authors: Ooi E.P. , Daud R. , Amin N.A.M. , Hong T.W.
Published: November 2014

Solder joints failure due to thermal loads and mechanical loads is a significant reliability concern in electronic devices. From literatures, little attention is paid to the development of methods on predicting fracture behavior of solder joint under mixed-mode loading. In reality, the solder joints are exposed to drop impact, vibration loading, bending, and twisting of PCBs. Study on this matter will lead to prediction of fracture load, prevalent fracture mode, exact joint interconnect size and life of joints under brittle and fatigue failure. This paper presents a review of recent fracture analysis on solder joints.
Review on Pipelines in Offshore Platform Processing System
Authors: Ervina Efzan Mohd Noor , Kesahvanveraragu S.
Published: November 2014

Pipelines are essential for transporting energy utilities such as oil, natural gas and coal for the nation. Similarly, pipelines are the only medium installed at offshore region to convey oil, gas, chemicals and water. Currently, corrosion is being a major problem for offshore pipeline occurrences around the world. Hence, this paper discussed on the pipelines in offshore platform and the corrosion of corresponding pipeline materials.
Ageing Effects on Burst Pressure Test of Impacted Glass Fibre Reinforcement Epoxy (GRE) Pipes
Authors: Hawa A. , Abdul Majid Mohd Shukry , Afendi Mohd , Haslan M. , Pranesh Krishnan , Amin N.A.M.
Published: November 2014

The main objective of this experimental study is to investigate the effects of hydrothermal ageing on the pressure bearing capacity of the E-glass/epoxy composite pipes subjected to impact loadings. The pipes were produced by the conventional filament winding technique comprises of six antisymmetric layers with (±55°)3 winding angles. The pipes were immersed in tab water for period of 500, 1000, and 1500 hours. The specimens were impacted at three different energy levels; 5 J, 7.5 J, and 10 J using an instrumented drop weight impact testing machine (IMATEK IM10). The samples were then subjected to pressure test until distinct leakage failure is observed. The results indicates that peak force and contact time increase with increasing impact energy. The tests results show that the burst pressure decreases with increase in energy levels during impact loading. During the burst tests, several damage types named leakage and eruption were observed.
Plasticity Behaviour of Sand Matrix Soils
Authors: Tan Choy Soon , Marto Aminaton , Makhtar Ahmad Mahir , Pakir Faizal
Published: November 2014

Natural sand does always contain significant amounts of fine particles, but previous study always assumes that the typical engineering characteristic of clean sand was remarkably representing as to all types of sand matrix soils. Studies reported that additional of plastic fines could either impose additional or reduce the liquefaction resistance of sand matrix soils. Therefore, the aim of this paper is to examine the plasticity behaviour of sand matrix soils through experimental study. The Atterberg Limit test was carried out on plastic fines mixtures and sand matrix soils. Results show that the plasticity behaviour is depending on the type of presenting plastic fines. The absorption of clay mineral is the key element to in manipulating the plasticity behaviour of plastic fines. It can be concluded that the absorption of montmorillonite is better compare to kaolinite.
Parameter Sensitivity Study for Optimization of 12Slot-8Pole Three-Phase Wound Field Switched-Flux Machine
Authors: Khan Faisal , Sulaiman Erwan , Ahmad Md Zarafi , Aizat Zhafir
Published: November 2014

This paper presents parameter sensitivity study and performance analysis of 12Slot-8Pole three-phase wound field switched-flux machine (WFSFM). The proposed machine consists of 6 armature slots, 6 field-excitation coil (FEC) slots and 8 rotor poles. All active parts such as armature coil and FEC are located on the stator, while the rotor part consists of only single piece iron. This makes the machine becoming more robust and more suitable to be apply for high speed motor drive system applications. The deterministic design optimization approach is used to treat several design parameters defined in rotor, armature and FEC slot area to achieve better results than initial design. 2-D finite element analysis (FEA) is used to study various characteristics of machine. Since the initial design fail to attain the maximum torque and power, therefore the performance of machine is enhanced by refinement of several design parameters. After design refinement, WFSFM has achieved the maximum torque of 22.34 Nm and power of 5.27 kW at maximum field current density, Je of 30 A/mm2 and armature current density, Ja of 30Arms/mm2 which is approximately 3 times the torque and 2 times the power of initial design.
Magnetic Flux Analysis of E-Core Hybrid Excited FSM with Various Rotor-Pole Topologies
Authors: Zakaria Siti Nur Umira , Sulaiman Erwan
Published: November 2014

This paper presents magnetic flux analysis of E-Core Hybrid Excited FSM with various rotor pole topologies. The stator consists of three active fluxes sources namely armature coil, field excitation coil and permanent magnet, while the rotor consists of only stack of iron which is greatly reliable for high speed operation. Initially, coil arrangement tests are examined to validate the operating principle of the motor and to identify the zero rotor position. Then, performances of 6S-4P, 6S-5P, 6S-7P and 6S-8P E-Core HEFSMs such as flux path, flux linkage, cogging torque and flux distribution are observed. As conclusion, 6S-5P and 6S-7P designs have purely sinusoidal flux waveform and less cogging torque suitable for high torque and power motor.
Solar Pumping System for Rural Areas Water Supply in Nigeria
Authors: Muhammadu Masin Muhammadu
Published: November 2014

Nigeria is endowed with abundant energy resources, both conventional and renewable, which can potentially provide the country with a sufficient capacity to meet the ambitions of both urban and rural Nigerians of a full, nationwide electrification level. Yet, Nigeria has one of the lowest consumption rates of electricity per capita in Africa. With the demand superseding the generation, there is inequitable access of rural communities to the electricity service in the country. There are inherent obstacles militating against the effective implementation of an orderly energy policy in Nigeria. The inefficiencies over shadowing the allocation of energy resources coupled with the near depletion of fossil fuels, make it imperative for the country to exploit its huge natural renewable resources to avoid a worsening energy supply scenario and provide feasible solar water pump to rural dwellers. This paper presents the applications of solar water pumping which are already quite significant and are growing at steady rate. Solar energy is suitable for small-scale water pumping in remote areas where the demand is regular, such as for drinking water, but it may also be used for irrigation. Most areas in Nigeria have climates suitable for solar pumping. A review is given of the use of solar energy for water pumping to improve the living conditions of the population in rural areas and to develop techniques for utilization of solar energy in a tropical environment condition. Results, suggests that, solar powered water pumping must be encouraged, promoted, invested, implemented, and demonstrated by full scale in Nigeria.
Stabilization of Marine Clay by Biomass Silica (Non-Traditional) Stabilizers
Authors: Marto Aminaton , Mohd Yunus Nor Zurairahetty , Pakir Faizal , Latifi Nima , Mat Nor Ahmad Hakimi , Tan Choy Soon
Published: November 2014

The presence of marine clay in Iskandar Malaysia Region, Nusajaya had caused expensive solutions in the construction of structures and roads. Alternatively, soil treatment is suggested to increase the strength of the unsuitable material to meet the constructions requirement for foundation and also to achieve the specifications for development work. In this study, a series of laboratory test has been conducted to determine the potential of Biomass Silica (BS), one of the commercial brands namely “SH-85” to stabilize marine clay to form the basis of a strong, reliable land for construction of roads and building. Testing program involves obtaining specimens of marine clays from various locations at Iskandar Malaysia Region, followed by laboratory tests to determine the Atterberg limits and Unconfined Compressive Strength (UCS) for treated and untreated of marine clay soils. The proportions of BS added were 3, 6, 9, 12 and 15% and tested at 0, 3, 7 and 28 days curing periods. The results shows that the Plasticity Index (PI) was reduce with increment of BS content. While, an addition of BS content increase in strength treated soils 60 times more than untreated soils, which is gain in early 7 curing days period. This finding indicates the BS is a suitable stabilizer for the marine clay to become strong foundation for construction of road and building.
Magnetotransport Investigations of Two-Dimensional Electron Gas for AlGaN/GaN Heterostructure
Authors: Lv Meng , Yu Guo Lin , Xu Yong Gang , Lin Tie , Dai Ning , Chu Jun Hao
Published: November 2014

Magnetotransport properties are investigated in two-dimensional electron gas (2DEG) of AlGaN/GaN heterostructure, including the Drude conductance, the Shubnikov-de Haas (SdH) oscillations and the change with temperature, the electron-electron interaction (EEI) and the change with temperature, the weak antilocalization (WAL) and the change with temperature etc.
Effect of Controlling Concentration on the Properties of SnO2 Nanocystalline for Dye Sensitized Solar Cells
Authors: Song Jie Guang , Hua Lin , Shen Qiang , Wang Fang , Zhang Lian Meng
Published: November 2014

The study of dye-sensitized solar cells (DSCs) based on nanocrystalline films of high band gap semiconductors is a progressive field of research that is being carried out by scientists in a wide range of laboratories. To improve the conversion efficiency of the DSCs, the SnO2 nanorots photocurrent, the effect of controlling concentration on the properties of SnO2 nanocrystalline were investigated via the hydrothermal method, and characterized by XRD, HRTEM, BET and Absorption spectrum. Though analysis the results, the conclusion is shown the pure SnO2 is preparation, the prepared SnO2 nanocrystalline under 0.05mol/L shows the particle-shape crystalline, the surface area of SnO2 nanocrystalline is 102.1683m2/g. The prepared SnO2 nanocrystalline under 1mol/L the fiber-shape crystalline, the surface area of SnO2 nanocrystalline is 79.7591m2/g. The absorbance of SnO2 nanocrystalline shows the strong absorption in the ultraviolet ray range, the absorbance of synthesized SnO2 nanocrystalline under the concentration of SnCl4 solution for 1mol/L shows the higher value.
Study on Preparation and Property of Carbon Fiber/HA Composites by Centrifugal Slip Casting Method
Authors: Li Qiang , Yu Jing Yuan , Meng Xiu Juan
Published: November 2014

In this paper, centrifugal slip casting method was use to prepare carbon fiber/HA composites using the nanoHA particles and carbon fibers as initial materials. The morphology of the carbon fiber after modification of p-aminobenzoic acid was observed. The rheological characteristic of the carbon fibers/HA slurries was studied. The effects of the centrifugal acceleration on green density uniformity of carbon fiber/HA composites were analyzed. The bending strength and fracture toughness of carbon fiber/HA composites were measured. The results show the roughness of carbon fibers treated by p-aminobenzoic acid increases. At the pH of 10 and 5 wt% dispersant, the HA slurries with 3 vol% carbon fibers have good fluidity. After centrifuged at 2860 G for 30 min, the green compacts of HA composites have high and uniform the green density. After sintered at 1100°C for 1h, compared with carbon fiber/HA composites prepared by dry pressing, the modified carbon fiber/HA composites prepared by centrifugal slip casting have higher bending strength and fracture toughness of 89.4 MPa and 1.92MPa1/2, respectively.
The Preparation, Structure and Electrical Conductivity of Ag-Doped La1-x-ySrxCuyMnO3-δ (0.05≤x≤0.4, y=0.1) Ceramics
Authors: Cao Yi , Lin Bao Ping , Yang Hong , Sun Ying
Published: November 2014

In this paper, we have presented a comprehensive study about the preparation, structure and electrical conductivity of Ag-doped La1-x-ySrxCuyMnO3-δ(0.05≤x≤0.4, y=0.1) ceramics. We first doped Ag into La1-x-ySrxCuyMnO3-δcompounds using a sol-gel method and then the gels were sintered at 1000°C by Muffle furnace. The structure variation was systematically characterized by the X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that that silver merged well into the lattice of La1-x-ySrxCuyMnO3-δand z at.% Ag-doped La1-x-ySrxCuyMnO3-δcompounds precipitated only in one phase. As indicated by the conventional four-probe method and UV-Vis diffuse reflectance spectroscopic (DRS), the addition of Ag was dramatically effective in enhancing the electrical conductivity, whereas a slight effect of the addition of Ag on UV-Vis diffuse reflection was observed. Furthermore, the electrical conductivity increased with the enhanced sintering temperature within the temperature of 1000 °C, which proved that the dominant mechanism of the conductivity of Ag-doped ceramics was hole hopping transfer.
Effect of Doping Ions on Structure and Electrical Properties of Lead-Free KNN Ceramics
Authors: Yin Na , Jalalian Abolfazl , Gai Zhi Gang , Zhao Lan Ling , Wang Xiao Lin
Published: November 2014

Doping effect on the lattice parameters, vibration modes, dielectric and piezoelectric properties of LiSbO3, LiTaO3 and LiNbO3 substituted lead-free K0.5Na0.5NbO3 (KNN) ceramics are investigated. All compositions are crystallized in morphotropic phase boundary region. Enhanced piezoelectric and electromechanical response d33 ~176–197 pC/N, kp ~45%–48%, and kt~34%–47% obtained in the doped ceramics are due to the presence of the polymorphic phase transition between orthorhombic and tetragonal phase at room temperature.
Preparation and Electrical Property of Mg2Si Thin Film by Pulsed Laser Deposition
Authors: Yang Mei Jun
Published: November 2014

Mg2Si thin film on Si(100) substrate was obtained by pulsed laser deposition. Effects of the annealing procedure on the growth of Mg2Si film were discussed. X-ray, atomic force microscopy (AFM) and field-emission scanning electron microscopy (FESEM) were applied for the phase and microstructure of the obtained Mg2Si film. The results revealed that the annealing procedure was very important for the crystallization of Mg2Si thin film. The Ar partial pressure of 10Pa, temperature of 500°C and time of 30min for annealing were the optimal annealing parameters for Mg2Si thin film formation. Furthermore, electrical properties of the obtained Mg2Si thin film were detected. The results showed that the maximal resistivity of Mg2Si thin film was 7Ω·cm within the temperature range of 110~230°C. And the resistivity gradually decreased with the increase of temperature, which was the characteristic behaviour of a semiconductor. Carrier concentration of the film was negative in the temperature range of testing, showing Mg2Si thin film as n-type semiconductor.
Study of Natural Dye Sensitized Solar Cells with TiO2/ZnO Composite Thin Film as Photoanode
Authors: Zhao Su Qin , Li Hai Qin , Ma Yuan Liang , Ma Yan , Li Xiao Lei , Ji Hui Ming
Published: November 2014

TiO2/ZnO composite thin film was prepared by sequentially spread TiO2and ZnO thin film on the ground layer by layer with sol-gel method respectively. Two different natural dyes (Hehuang safflower yellow pigment and Lycium ruthenicum Murr pigment) were used as sensitizer respectively to sensitize TiO2/ZnO thin film photoanodes and be assembled into solar cells. Dipping time of photoanodes stayed in sensitizer was investigated systematically and the results show that higher photovoltaic conversion efficiency can be obtained with extension of immersing time. The phase structure, crystallinity, morphology and optical property of photoanode were characterized based on XRD, SEM and UV-vis measurements.
Cavitation Erosion Resistance of Ti-Ni Intermetallic Coatings Prepared by Low Pressure Plasma Spray Process
Authors: Lin Qiu Sheng , Zhou Ke Song , Deng Chun Ming , Deng Chang Guang , Kuang Zi Qi , Zeng Wei
Published: November 2014

In the current work, low pressure plasma spray process (LPPS) was applied to deposit Ti-Ni intermetallic coatings with Ni-clad Ti powder as feedstock. The microstructure and phase transition of LPPS sprayed Ti-Ni coating were investigated. Cavitation erosion resistance was examined using a standard ultrasonic cavitation test. The coating mainly consisted of TiNi phase with a certain amount of Ti2Ni, Ni3Ti phase and a few Ti phase. A few pores concentrated on the boundaries of the sprayed splats. The TiNi coating exhibited excellent cavitation erosion resistance.
Synthesis and Electrochemical Properties of Cathode Material LiNi0.8Co0.1Mn0.1O2 via Li, Mg, Al Dopping
Authors: Yuan Sha , Liu Liang Bin , Tang Yan Ping , Wang Jian Hua , Guo Yu Zhong
Published: November 2014

Coprecipitation method is adopted to prepare LiNi0.8Co0.1Mn0.1O2, to discuss the factors of affecting electrochemical properties and structure at lithium ion battery cathode material LiNi0.8Co0.1Mn0.1O2. In order to improve the electrochemical properties of materials, LiNi0.8Co0.1Mn0.1O2 materials were modified by doping the cation of Li or Mg or Al. Through the charge-discharge tests in the range of 2.5~4.3V, the result show that doped Mg samples with a discharge capacity and high efficiency as well as the lowest capacity loss, the initial discharge capacity is 205.9mA.h/g, after 20 cycles the discharge capacity reached 142.4mA.h/g.
XPS Study and First-Principles Calculations of the Structural and Electronic Properties of Type-VIII Clathrates Ba8Ga16-xCuxSn30
Authors: Li De Cong , Quan Yan Hong , Ren De Hua , Deng Shu Kang
Published: November 2014

In the present work we report on the Single-crystal samples synthesis of type-VIII clathrates Ba8Ga16−xCuxSn30(x = 0, 0.75, 1, 1.5, 2) by the Sn-flux method and the effects of Cu doping Ba8Ga16Sn30have been investigated using x-ray photoemission spectroscopy (XPS). The structural and electronic properties have been studied by first-principles method based on the density-functional theory. We found that the Cu doping induced rearrangement of host-cage configuration, and consequently change of the electron transport properties. It was found that the binding energies for the Ba8Ga16−xCuxSn30series decrease with increasing Cu substitution, resulting in a decrease of stability. Calculations indicate that these alloys are all indirect gap semiconductors and the band gap increases with increasing Cu content. Theoretical results indicate that Cu doping Ba8Ga16−xCuxSn30should bep-type semiconductors, which does not agree with the previous experimental results.
Recycling of Construction and Demolition Waste Material for Energy Savings in India
Authors: Brar Tejwant S. , Kamal M. Arif , Emerson Pinto
Published: November 2014

Buildings are an integral part for development in any sector of economic growth and they consume resources not only during their construction but also for operation throughout their life. The design, construction, operation, maintenance, and ultimately the removal of buildings consume large amounts of energy, water, and building materials, and generate large quantities of waste, and pollute the air and water. The amount of resources consumed, waste generated can be judged from the fact that in any development project, the component of construction is quite large.The Indian construction industry has accounted for approximately 50% of the country's capital outlay in successive Five Year Plans, and projected investment continues to show a growing trend. Out of 48 million tonnes of solid waste generated in India, C&D (construction and demolition) waste makes up 25% annually. Despite this the use of recycled material in construction is not much, which can largely be attributed to various factors like lack of awareness on the part of designers/engineers, lack of awareness campaigns and appreciation of using recycled materials, unorganized market of recycled construction material, absence of a proper solid waste management system in urban areas, lack of tax incentives and poor implementation of legislation on the use of recycled materials. It is high time that the above said issues about the use of recycled material in construction in our country be addressed so as to achieve economy in construction coupled with easing burden on natural resources thereby resulting in cleaner environment.
Soil Based Building Materials for Energy Efficiency
Authors: Liuzzi Stefania , Stefanizzi P.
Published: November 2014

A descriptive analysis and some definitions of clays are provided at the beginning of the chapter; after that the most common earthen materials are introduced. A list of the most common worldwide building techniques and physical parameters is provided. The main building regulations are reported in a brief summary.At the end of the chapter, according to the main important studies, hygrothermal and physical performances of earthen building materials are discussed.
Energy Efficient Skylight Design in Tropical Houses
Authors: Al-Obaidi Karam M. , Ismail Mazran , Abdul Rahman Abdul Malek
Published: November 2014

Skylight roofing construction isa practical complement to electric lighting even in various climatic conditions. However, a purely energy efficient building that ignores what the environment can contribute, particularly in tropical regions, will consume more energy. This problem can be found in landed houses specifically in Malaysia due to high impact of solar radiation and the length of the daylight period all year round. The lack of understanding the potential of skylight design is one of the main challenges. This paper aims to examine several passive glazing materials in the form of glass and plastic as well as dimensions and orientations under the Malaysian environmental conditions to determine the efficiency of this skylight construction design. The study was carried out by computer simulation to specify the thermal and daylighting loads in a specific room size. The resultsshow the significance of polycarbonate glazing as an efficient skylight material in the tropical houses. This materialdelivers well distributed natural light with less heat impact. This study provides useful quantitative and qualitative information for building professionals and architects in the tropics.
Thermodynamic Analysis of Chemical Vapor Deposition Progress for SiC Coatings
Authors: Chen Ming Wei , Qiu Hai Peng , Jiao Jian , Li Xiu Qian , Wang Yu , Xie Wei Jie
Published: November 2014

Equilibrium compositions of chemical vapor deposition progress for silicon carbide (CVD-SiC) coatings with MTS/H2 mixture system were calculated by means of HSC Chemistry5.0 code, and influences of the reaction temperature (T), the system pressure (P) and the composition of raw materials (molar ratio of H2 to SiCH3Cl3, β) were investigated. Thermodynamic analysis showed that the value of nC /nSiC in reaction product decreased to a minimum and then increased with the increase of the reaction temperature between 700-1600°C, which meant an optimal reaction temperature existed theoretically for CVD-SiC coatings with highest purity. Furthermore, CVD-SiC coatings with high purity were obtained by experiments under the reaction pressure of 10kPa, H2/SiCH3Cl3 value of 10 and reacton temperature of 1100°C, which was in accordance with the theoretical prediction.
The Effects of Sulfate Anion Exchange on Structural Feature and Thermal Behavior of Y2(OH)5NO3•nH2O Layered Hydroxide Nanosheets
Authors: Liu Wei Gang , Wu Xiao Li , Zhu Qi , Li Ji Guang , Sun Xu Dong
Published: November 2014

Layered rare-earth hydroxide nanosheets (3-8 nm thick) of Y2(OH)5NO3·nH2O (NO3--LYH) were successfully synthesized in one step via chemical precipitation at ~4 °C and pH ~8, using yttrium nitrate and ammonium hydroxide as reagents. The interlayer NO3- was found to be free ions and can be completely replaced with SO42- to yield Y2(OH)5(SO4)0.5·nH2O (SO42--LYH). Thermal decomposition behavior of the SO42--LYH was studied in detail, and the phase and morphology evolutions upon calcination in the temperature range 500-1100 °C were also investigated. Characterizations via XRD, FE-SEM, TEM, and FT-IR found that anion exchange did not bring about any appreciable change to the 2-dimensional crystallite morphology but the basal spacing of the crystal structure shrank from ~0.884 to 0.840 nm owing to the indirect coordination of SO42- to the Y3+ ions. DTA/TG and XRD analysis found that the NO3--LYH converts to Y2O3 at ~600 °C, but the SO42--LYH decomposes to oxide at a higher temperature of ~1000 °C via monoclinic Y2O2SO4 in the range of 800-900 °C. The resultant Y2O3 particles have an average size of ~60 nm.
Influences of Working Power on Properties for Boron Films Deposited by R. F. Magnetron Sputtering
Authors: Yang Yi Ming , Ren Bing , Huang Jian , Tang Ke , Wang Jun Nan , Yu Hong Ze , Wang Lin Jun
Published: November 2014

Boron and boron-rich boride has attracted considerable attention in the past few years for their wide varieties of structures and property associated with their unusual three-center electron-deficient bonds. Boron film also exhibits many unique and fascinating properties, such as high melting point (~ 2500K) with low density, high harness close to diamond, and excellent thermoelectric property. In this paper, boron (10B) films were prepared on (100) silicon substrate by radio frequency (r. f.) magnetron sputtering method under the different working pressure and power with a target of boron and boron oxide (B:B2O3 40wt%). After 3 hours sputtering deposition, the substrate was covered with boron films tightly. The morphology of deposited films under different temperature was characterized by high resolution scanning electron microscopy (HRSEM), FTIR spectrum (FTIR), Raman spectrum (Raman). The results show that the film contains boron and little oxygen. At last, the growth mechanism of B film was analyzed.
Effect of MgAl2O4 Micrpowder on Physical Properties of Corundum Castables
Authors: Hu Yao Sheng , Chen Ping An , Zhu Bo Quan , Ma Zheng , Li Xiang Cheng
Published: November 2014

Corundum-based castables were prepared by using tabular corundum, micropowder of MgAl2O4spinel and calcium aluminate cement as raw materials, as well as the addition of dispersion agent and retarder. The effect of spinel contents on physical properties of the castables has been investigated. The results showed that as the samples were heat treated at 1100 °C and 1600 °C, the linear shrinkage rate decreased and the strength of rupture and crushing at room temperature increased with spinel content increasing, while apparent porosity and bulk density remained the same. The hot modulus of rupture increased from 12 MPa to 20MPa with 67% growth rate, and crushing strength after thermal shock increased from 80MPa to 105MPa with 32% growth rate. The increasing of high-temperature properties was attributed to the staggered distribution between MgAl2O4spinel and CA6.
Ferroelectric Properties of Bi3.25Ho0.75Ti2.97V0.03O12
Authors: Chen Min , Mei X.A. , Huang C.Q.
Published: November 2014

Bi3.25Ho0.75Ti2.97V0.03O12(BHTV) ceramics was prepared by solid state reaction. This sample had polycrystalline Bi-layered perovskite structure without preferred orientation, and consisted of well developed plate-like grains with random orientation. BHTV caused a large shift of the Curie temperature ( TC) of Bi4Ti3O12(BIT) from 675 °C to 398 °C. The remanent polarization and the coercive field of the BHTV ceramics were 28μC/cm2and 56kV/cm at an electric field of 90kV/cm, respectively. Furthermore, the dielectric permittivity and dissipation factor were 298 and 2.8×10-3at 1MHz, respectively. These ferroelectric properties of BHTV ceramics are superior to V-doped Bi4Ti3O12(~20μC/cm2and 80kV/cm) and (Sr, Ta)-doped Bi4Ti3O12(~12μC/cm2and 71kV/cm) ceramics. In addition, the dense ceramics of BHTV could be obtained by sintering at temperatures 100─200 °C lower than those of the SrBi2Ta2O9system.
Ferroelectric Properties of Bismuth Titanate Ceramics by Tm2O3/V2O5 Substitution
Authors: Li Bei , Liu X.B. , Chen M. , Mei X.A.
Published: November 2014

The ferroelectricity of Bi3.25Tm0.75Ti2.97V0.03O12 (BTTV) ceramic prepared at 1200°C by a conventional ceramic technique was investigated. The ceramic possess random-oriented polycrystalline structure. The remanent polarization (Pr) and coercive field (Ec) of the BTTV ceramics are 25 μC/cm2 and 70kV/cm, respectively. The Pr value of the BTTV ceramics up to 25 μC/cm2 is larger than that of the BTT ceramics. Therefore, co-sustitution of Tm and V in Bi4Ti3O12 (BIT) ceramics is effective for the improvement of the ferroelectricity of Bi4Ti3O12 ceramics.
The Influence of Pulse Width on Microstructure and Mechanical Properties of CrNx Coatings Deposited by HPPMS
Authors: Xu Xiang Min , Zhang Hao , Jin Yi Bin , Zhao Hao Chen , Duo Shu Wang
Published: November 2014

CrNx coatings were deposited by high power pulse magnetron sputtering in a closed field unbalanced system. The influence of pulse width on microstructure and mechanical properties of CrNx coatings was examined. Morphologies different from those fabricated by traditional magnetron sputtering were obtained, phase structures were also changed in the process. The coatings hardness were always improved in the increasing pulse length, while the best adhension of CrNx coatings about 25N was get when pulse length was 60us.
Influence of HF-SCG Immersion Treatment on Corrosion Resistance of the Ultrasonic Micro-Arc Oxidation Bio-Coating on Pure Magnesium
Authors: Li Mu Qin , Liu Jiang , Li Jun Gang , Cai Ding Sen , Zhao Yong Hui
Published: November 2014

Ceramic coatings were fabricated on pure magnesium in silicate electrolyte system by ultrasonic micro-arc oxidation (UMAO) process, and then silica sol (CSG) and HF-CSG treatment were carried out on micro-arc oxidation coatings. The corrosion potential (Ecorr) and corrosion current density (Icorr) of the compound coatings were analyzed by electrochemical corrosion workstation. The corrosive morphology of the coatings was observed by scanning electron microscopy (SEM). Results showed that the Ecorr of the coating with CSG and HF-CSG treatment increased by 55 mV and 69 mV respectively in comparison with that of single UMAO coating, and its Icorr reduced an order of magnitude, which had enhanced the corrosion resistance.
The Method to Test the Homogeneity of Concrete
Authors: Liu Li , Yang Wen
Published: November 2014

As the ultra high way and long distance pumping concrete became increasingly common, the engineers not only required the concrete have large liquidity but also increasingly concerned about the homogeneity of concrete. However, without effective and convincing method, currently the engineers had to assess and judge the homogeneity just by their sight, feel and experience. In order to test the homogeneity rapidly, exactly and quantitatively, a new device and method was developed relaying on the theory that the barycentre of the concrete which was filled in regular-shape container would deflect away from the shape-centre of the container more or less if the components with different density in concrete separated to stratifications. C30 and C40 concrete whose slump≥180mm and slump flow≥480mm were tested by this method and their homogeneity modulus (Cv) were figured out by the supporting formula. The result showed that the homogeneity of concrete was accredited if 0.90<Cv<1.10, and Cv was closer to 1.00, the homogeneity was better.
Analysis of Advanced Research Methods of Cement-Based Materials
Authors: Zheng Yan , Cui Su Ping , Wang Ya Li , Wang Zi Ming , Mao Qian Jin
Published: November 2014

The hydration of cement is known to be a complex phenomenon. Although the broad pattern of reactions and microstructural development are known, a number of important questions remain unanswered. How to select the proper techniques is what the research people think of for now. This paper reviewed the domestic and international research progress and presented the advantages and disadvantages of these methods and the application prospects. Nuclear magnetic resonance spectroscopy (NMR), nanoindentation and electron microscopy techniques of cements were expounded in detail. Furthermore, through analyzing the results obtained by different research methods, the paper predicted the development prospect of advanced testing method of cement-based materials.