This paper discusses in detail precision end-milling approach in order to study the chips morphology of AISI 316L stainless steel which affects the machinability to a greater extent. The cutting speed ranges of 80 to 140 m/min while the feed rate ranges from 0.025 mm/tooth to 0.04 mm/tooth were investigated. Scanning electron microscope (SEM) was used for the 3D-view analysis in order to study the top surface, length of chip, width, thickness of chips and shear bands of the chips. Experimental results conclude that the chip length increases with an increase in cutting speed (VC). Furthermore, the chip width decreases with an increase in feed rate (f). The chips become thicker as the cutting speed is increased. A relationship was built between the surface roughness and surface integrity with the chip morphology.

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The research was mainly focused towards developing a device that was economical and affordable to patients recovering from foot and ankle injuries with a better chance of rehabilitation in comparison to the existing devices. The Mechanical properties of Shape Memory Alloy (SMA) wires which are used as actuators in the Stewart platform rehabilitation device are experimentally investigated to estimate displacement and force developed. In order to investigate the relationship between force and deflection of the upper platform, a accelerometer (ADXL335 with 3 axis) has been mounted on the moving platform to measure the deflection angle. Six force sensors have been fabricated and mounted with a three pairs of strain gauges to measure the force developed by the respective actuators. Calibration of the Sensor has been accomplished with known weights and for the tilt sensor with the indexing table of a CNC (Computerized Numerical Control) machine. SMA wires actuated Stewart platform rehabilitation device had been designed, fabricated and tested experimentally with the transducers mentioned above. The prototype is demonstrated to the orthopedic departments of the hospital and the trails were conducted with the experts for their opinion and feedback. They were enthusiastic and very much in favors for this device.

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The effect of total length and presence of bearings towards torsional stiffness of Low Stiffness Resilience Shaft (LSRS) in Semi Active Steering (SAS) is discussed in this paper. LSRS, an integral component of the SAS is a flexible shaft that can replace the conventional rigid shaft of the steering system and allows active control to be performed. Static structural torsional test simulations using ANSYSTM were performed on arrangements of 4 wire rope strands with different lengths in order to select the best one for the optimum performance of the LSRS. With the total length of the wire ropes equal to their lay lengths being the defining factor, three different LSRS namely LSRS A, LSRS B and LSRS C were modeled and then analyzed. LSRS A was found out to be the stiffest with an average torsional stiffness of 12.30 N.m/rad and LSRS C the most torsionally flexible, having the least average stiffness of 4.93 N.m/rad. Furthermore, LSRS I, II and III were modelled based on the number of bearings along the total length of the LSRS. The total length was kept constant at 300mm. LSRS I with 2 bearings in between was found out to be the stiffest compared to LSRS II with 1 and LSRS III with no bearings in between. It can be concluded that the increase in the length of the wire rope shows a decrease in the torsional stiffness of the LSRS and the presence of bearings along the length of the LSRS increases its torsional stiffness.

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Water sprinkler system is considered one of the main water-based fire suppression systems. Due to the turbulent nature of fire, prediction of water sprinklers activation time required performing numerous experiments and tests to understand the nature of the parameters involved in changing the activation time. It was noticed that the angle where the sprinkler arms are oriented towards the hot gas jet resulting from a fire had a great impact on the activation time of the sprinkler. In this research the orientation of the sprinkler’s arm was changed by using Computational Fluid Dynamics (CFD) simulation. It was found that changing the sprinkler arm angle from perpendicular to the flow (90°) to 60°, 30° and parallel to the flow (0°) has resulted in increasing the sprinkler activation time by about 8%, 84%, and 163% respectively. The effect of sprinkler activation time variation was investigated on stacked wood pallets heat release rate. It was found that with a parallel orientation the fire is allowed to grow 2.5 times more in terms of Heat Release Rate (HRR) than with perpendicular orientation.

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The stringent emission regulations and the need to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative solution to these issues. However, the combustion control is the main obstacle to its development. Fuel combinations with substantial different in reactivity such as diesel/compressed natural gas (CNG) shows desirable combustion output and demonstrate great possibility in controlling the combustion. This paper will discuss the control method of diesel/CNG (DCNG) mixture combustion with a variation of wall temperature. The experiment was done in a constant volume combustion chamber with both fuels were directly injected into the chamber. The wall temperature was varied from 45?C to 75 ?C with an increment of 15?C. The increment of wall temperature reduces the combustion performance of DCNG. It is caused by slower combustion rate of DCNG that indicated by its long combustion duration. Regardless the combustion performance reduction, it was found that the combustion delay of DCNG was not affected by the wall temperature.

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Nowadays, carbon and low alloy steels are widely exercised in pipeline construction. By having high pressure of CO2 which is used for the flooding reservoir, the oil fields lifetime could be increase. Basically, CO2 are able to dissolve in the existence of the brine water and forming carbonic acid. Carbonic acid could be expressed as a corrosive media. Inhibitor injection method can be used to prevent CO2 corrosion in the pipeline. Imidazoline is one of the most common corrosion inhibitor which is used to prevent CO2 corrosion. This inhibitor has high effectiveness towards corrosion mitigation. The corrosion rate is related to various factors such as; temperature, inhibitor concentration, and pH of environment. In this study, corrosion rate measurements were done based on weight loss test and linear polarization resistance (LPR) test, the results proved that the corrosion rate will become lower at greater inhibitor concentration. Furthermore, the corrosion rate will greatly increase due to decreasing in pH of the surrounding. Moreover, the corrosion rate will slightly increase as the temperature of the surrounding increase. As an overall conclusion, this research would benefit one to estimate the corrosion rate in different surrounding condition by inserting the values of factor A, B, and C in this provided governing equation harvested by Box Behnken design.

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This study investigates the effect of using different roof run-off coefficient values in an office building in Malaysia on the water savings provided by rainwater harvesting system which is used to supply water for toilet flushing and irrigation purposes. In this paper rainwater harvesting system model is developed which reads the hourly rain fall data and calculates water consumption and savings. The harvesting tank sizes and roof run-off coefficient values were varied. It is found that as the values of roof run-off coefficient decreased, the amount of water saved remains almost unchanged for all investigated tanks sizes. A correlation is developed which relates roof run-off coefficient, volume of water saved and the tank sizes which can be used as useful design and sizing tool by buildings’ designers to predict the amount of water saved for a specific rain water harvesting size.

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A theoretical model for the estimation of turbulent heat transfer has been developed employing the eddy diffusivity equation of Van Driest. Experiments have been undertaken for turbulent flow with Al2O3 nanofluid in base liquid Ethylene Glycol-water (EG-W) mixture of ratio 40:60 for a maximum concentration of 1.5% at a bulk temperature of 50 and 70oC. The numerical results for heat transfer are observed to be in good agreement with the experimental data with the nanofluid property equations developed. The maximum concentrations for which heat transfer enhancement can be attained are estimated to be 1.4% and 2.05% at 50 and 70oC respectively under turbulent flow.

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The objective of this study was to investigate the performance of dual fuel combustion in a compression ignition engine powered by blend diesel/palm oil biodiesel (50%:50%) and simulated gasification gas. The in-cylinder pressure data was collected for each crank angle in order to investigate the combustion characteristics at constant half load over a range of pilot fuel substitution rate. Substantial differences in the in-cylinder peak pressure occurred and three phases of the dual fuel combustion process were clearly seen in the heat release rate curves when the engine load was maintained at half load. Maximum cylinder pressure was obtained with syngas dual fuelling at lower substitution rates. Lower engine efficiency of 33.84% was observed with syngas dual fuelling at the highest substitution rate of pilot fuel (28%).

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The technique of artificial roughness is used by researcher to augment the heat transfer coefficient in force convection between the absorber and air in solar air heater. In the present paper, a new artificial roughness (pin shape protrusion) on the absorber plate was used to achieve the enhancement in heat transfer coefficient of free convection between absorber plate and air. A specially designed test rig was fabricated for experimental measurements, comprising of four sections of 0.48 x 0.07 x 2.0 m, to acquire data of four different cases. The conical pins were used with three different relative height roughness, e/Dh, = 0.01636, 0.0245 and 0.0327 and one standard smooth un-protrusion flat plate absorber was used as a basis for comparison. The data for from the four test rigs were recorded simultaneously. The measurements were carried out at five inclination angles 10°, 30°, 50°, 70°, and 90° to get the optimum angle of operation for free convection solar air heater. The results show that the conical pin artificial roughness has enhanced the heat transfer rate of the solar air heater by up to 41% as compared to the un-protrusion absorber plate heat transfer rate in free convection solar air heater. The heat transfer rate and Nusselt number are highest for relative height roughness e/Dh = 0.0327. The optimum inclination angle was found to be 50 degrees, at which the solar air heater performed most efficiently.

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Growth in energy demand has become a major concern in the earth today. The shortage of main fuel derived from conventional fossil fuel has led to an increasing demand on new source of energy, the renewal energy. Renewal energy is the proven alternative to overcome these problems. For the case of palm oil mills, the palm fibre and shell are the main source of renewal energy and cogeneration are adopted in exploiting these renewal energy sources. For this case study, the potential of these renewal energy sources were being investigated using thermodynamic analysis. Sie-Manggaris Palm Oil Mill Cogeneration Plant has been selected as a case-study model. From the analysis, it was found that the available fuel, which was accounted only palm fiber and shell, was able to generate steam up to 45,000 kg h-1. This would give the potential energy production of 157 GJ h-1 and easily able to fulfill the need of the utility requirement for the entire plant. Although, the current configuration of the existing cogeneration system would impose the deficit power of 4 kWh ton FFB-1 and has to be supported using diesel generator set at the diesel consumption rate of 0.8 L ton FFB-1. The current boiler capable to convert 1 kg of fuel to 3.35 kg of steam with the turbine steam rate at 30 kg kWh-1. Retrofit design of the existing plant is necessary in order to overcome the low energy efficiency. Substantial amount of power production could be generated if utilizing the high-energy efficient equipment.

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In Metal matrix composites (MMC) the microstructural aspects such as reinforcement size, shape and distribution plays important role in the deformation behavior of composites. To study the thermal and structural deformation behavior of real microstructure, an analytical approach was proposed by developing a two dimensional (2D) model from a microstructure image of magnesium hybrid composites and magnesium CNT composites. Samples of both magnesium hybrid (1%CNT, 2% silicon carbide) and magnesium mono composite (1%CNT) were fabricated using stir casting method. The microstructure images of samples were converted into equivalent CAD format using canny edge detection method. In the present work the deformation behavior such as the thermal stress and strain and structural analysis were studied by using finite element analysis. Experimental tensile testing of magnesium hybrid composites was also conducted.

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The tendency of the external coating of underground pipeline to disbonded is highly due to the service environment. The inadequate coating also becomes one of the contributing factors in the disbonded of an underground pipeline. The function and desired characteristics of an external coating are very important issues. In this work, the performance of Polyaniline (PANI) in epoxy coatings has been investigated by performing the cathodic disbonding test. Varies concentration of PANI was used to find the lowest disbonded radius. The test was carried out at two differents conditions for the comparisons purpose. The results were compared with previously stated effects of the potential, time, pH of NS4 soil solution. It was found that the cathodic disbonding radius decreased with increase the PANI content in the epoxy coating system.

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Major irreversibility's in the absorption chillers are due to heat transfer between the absorption cycles and the environment. This effect also occurs for LiBr/H2O steam absorption chillers. This study investigated the effect of external heat transfer processes on LiBr/H2O steam absorption chillers installed at two district cooling plants in Malaysia. The study was done by evaluation of operating data. The heat transfer processes occurring at the desorbers, evaporators, condensers and absorbers for the absorption chillers at these two plants were investigated using reversible and zero order models. It is noted that the trends shown by the reversible and zero order models indicate the irreversibility occurred for the absorption chillers at both plants. The COPs figures for reversible and zero order models for the absorption chillers at one of the plant indicate lower values. One possible cause of this occurrence was due to lower temperatures of returned chilled water. Hence in order to improve COP, the temperatures of returned chilled water should be increased.

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Friction stir welding (FSW) is a solid state welding technique that has been used in various industries for joining different materials which are difficult or impossible to be welded by conventional welding methods. Complexity of the geometry and a three dimensional character has made the FSW process complicated in comparison with other techniques. Therefore, theoretical study of FSW is challengeable and the governing equation prediction is challengeable. Finite element analyses of FSW can predict various parameters of the welding processes such as temperature profile, deformations, stresses, residual stress and forces. It can also help to investigate the material behavior, which can be time-consuming by using experiments. The process complexity requires the choice of the best finite element software appropriate to the results to be predicted. This paper has compared different finite element analyses which have been done for the numerical simulation of FSW. The results showed that, ABAQUS®, ANSYS® and FLUENT® software have been the most common software in those papers which have focused on FSW modeling. In the terms of mechanical properties such as thermo mechanical behavior, strain, stress and friction simulation, models created using ABAQUS and ANSYS have achieved greater accuracy. Figures show that, FLUENT software for simulating material flow and fluid dynamic behavior modeling has been the pioneer software.

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The hydrodynamic journal bearings are widely used in different industries for high speed and high loads. Meanwhile, its performance and reliability is a big concern. Surface texturing is a suitable and an accepted way to improve its performance. In this paper, the altered Reynolds equation is done to calculate the load carrying capacity for convergent long journal bearings with slip and no-slip pattern. Furthermore, to investigate the load carrying capacity performance some defined parameters has changed to study their changes towards the performance of journal bearing, e.g. number of slip regions, depth of grooved, etc. From the results, it can be seen that increasing the slip and no-slip region length gives a promising impact towards the load carrying capacity for convergent long journal bearing.

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This study investigated the impact of fumigating different percentages of anhydrous ethanol (E) and cetane number enhancer (CNE) on the combustion, performance as well as exhaust pollutants of DI diesel engine. The addition of this mixture (ECNE) exhibited higher premixed combustion peaks, faster combustion process, and higher coefficient of variation of indicated mean effective pressure (IMEP) and reduced maximum in-cylinder temperature, in comparison with neat diesel (D). The total combustion duration as well as the ignition delay prolonged when ECNE fumigated compared to that of diesel fuel only. The combustion characteristics of ECNE ratios at high load could be recovered to diesel fuel by introducing CN enhancer, but a large difference occurs at lower load. Neither Ethanol only nor ECNE presented better thermal efficiency (BTE) and brake specific fuel consumption (BSFC) than the baseline diesel fuel. Engine performance with ECNE fumigation is highly susceptible to operating conditions; therefore, it is necessary to optimize the specific thermal conditions for implementing a fumigation approach. ECNE increased total hydrocarbons (THC) and carbon monoxide (CO), reduced particulate matter (PM) and nitrogen oxides (NOx) in comparison with pure diesel fuel. However, the amount of this reduction was markedly affected by engine operating mode. The DECNE (85% diesel+10% ethanol+ 5%Cetane enhancer) showed the best trade-off between the engine performance, combustion and emissions characteristics (PM vs NOx + THC) among the ECNE ratios.

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The offshore facilities are growing in number, size and complexity and so are the fire risks. Liquefied natural gas (LNG) is one of the most common hydrocarbon fuel produced in an offshore oil and gas platforms. LNG can cause different types of fires such as jet fire, pool fire, flash fire and fire ball. Among the various offshore accidents, pool fire is the most repeated phenomenon. It has the potential to cause significant injury to personnel, discontinuity of operations and damage to structure and equipment. Wind speed significantly affect the incident heat due to fuel radiation in case of pool fires in upwind and downwind direction. It is, therefore, requisite to quantify the hazards posed by pool fires in upwind and downwind direction at different wind speeds. The study is focused on modeling of pool fire using Computational Fluids Dynamics (CFD) with varying wind speed. For CFD modeling, Fire Dynamic Simulator (FDS) and Pyrosim are used. Effect of wind speed on smoke movement in downwind direction is investigated. The incident heat flux due to pool fire heat radiation is determined in upwind and downwind direction. Furthermore, radiative heat flux is utilized to calculate the impact on human for 1st degree of burn, 2nd degree of burn and death in upwind and downwind direction. The results exhibited that incident heat flux and probability of injury varies significantly in downwind direction by increasing wind speed and minor variation have been found in upwind direction.

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An underwater glider is a class of autonomous underwater vehicles. While these gliders typically move in a saw-tooth pattern, a spiral motion, which may more effective for specific applications, is considered here. The spiral motion of glider may extend its possible applications such as delivery or recovery equipment for subsea installation. In this paper, a spiral glide path for the glider is considered, and the corresponding dynamic model based on Lagrangian principle and analytical expressions determined. The steady-state spiraling equations were derived and solved recursively using the solve algorithm. The results compare well with simulation results based on Newton’s method. The spiraling motion is highly maneuverable, with less than 1 m turning radius.

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Mg2-xCxNi (x= 0, 0.1, 0.2, 0.5) type alloys were prepared by mechanical alloying and their electrochemical hydrogen storage characteristics were investigated in 6 M KOH solution. Characterization of the crystal structure of the milled products using X-ray diffractometry exhibited the formation of Mg2Ni-based nano-crystallites after ~5h for the initial mixture with stoichiometric composition of Mg2Ni and Mg1.9C0.1Ni. However, Mg2Ni-based nano-crystallites were synthesized after 15 and 20h of milling in the case of Mg1.8C0.2Ni and Mg1.5C0.5Ni, respectively. The results show that increasing the carbon content of initial powder mixture decreases the formation kinetics of Mg2Ni-based nano-crystallites. In addition, increasing milling time resulted in decreasing and increasing the mean crystallite size and lattice strain of Mg2Ni structure in all milled products. Furthermore, the negative electrode made from Mg1.9C0.1Ni ternary milled product after 30 hour of milling exhibited the highest initial discharge capacity and longest discharge life at all the ball milling durations. This observation was attributed to the formation of the porous unstable Mg(OH)2 layer due to the intercalation of Mg, which have the high rate of solubility in strongly basic solutions, and thus the exposition of the underlying electro catalytically active Ni sites for the sample without carbon addition.

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Base liquid properties are critical in heat transfer due to their flexible capabilities to suit a wide range of applications. The addition of two pure miscible liquids alters thermo-physical properties, which could in turn influence the desired heating or cooling performance. A binary mixture of engineered base liquid with nanoparticle dispersions results in enhanced properties as compared to base fluid mixture. In this paper, thermophysical properties viz. viscosity, density and thermal conductivity are evaluated for silica nanofluid in glycerol/ethylene glycol mixture in 60:40 ratio for particle concentration in the range of 1.0 to 4.0% vol. and temperatures of 20oC–80oC. The experimental results showed that the properties of density and viscosity decreased whilst specific heat capacity and thermal conductivity of the nanofluid both increased with temperature. The property enhancement ratio for flow under turbulent conditions indicates heat transfer enhancements at low concentrations and high temperature for the SiO2 nanofluid.

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Various demulsification methods have been proposed and reported in literatures to solve water-in-oil (W/O) emulsion. Nevertheless, there is a case where demulsification process cannot break the emulsion 100%. The process left behind some amount of rag layer (stubborn emulsion) with greater stability than the original emulsion. Common combined demulsification method (heating, demulsifier injection, and gravity settling) is found ineffective to give expected residence time. Therefore, the work aims to propose aeration into the combined demulsification method for better separation efficiency and as a cheap alternative to solve the stubborn emulsion. The effects of the combination methods are investigated through a designed experiment. The best operating conditions are identified through an optimization using Design Expert software. The optimization goals are to maximize oil recovery and water separation, to minimize the rag layer and to reduce the demulsification cost. Based on the results, the best operating condition is at ˜42oC with injection of 200 ppm chemical demulsifier and ˜73 cc/min. of aeration rate. The solution was able to provide 58.23% of oil separation fraction with only 12.42% rag layer within 30 min. The demulsification cost is as low as US$0.13/barrel.

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This paper describes motion control strategy of an underwater glider in the presence of external disturbances based on state feedback and full order observer feedback. In this paper, we will be concerned only with the phugoid motion in the vertical plane. A control strategy for the glider was implemented with fast and stable convergence. Simulation results show that the open loop system is controllable and observable. The results suggest the use of a well-known guidance for fast tracking and stability control.

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A study on working principle of an overrunning clutch was conducted and a set of simplified mathematical equation was derived for different working conditions of the mechanism. This paper presents a method of simplified modelling to predict the output speed by applying the derived mathematical equations using user-written subroutine in ADAMS/Solver. The model was assumed to have negligible slipping torque and static friction. The subroutine written and compiled in C++ language using Microsoft Visual Studio is programmed for the modelling of the simplified model in ADAMS/View to simulate the mechanism. A model of an overrunning clutch using actual dimensions including rollers was modelled and simulated using ADAMS/View for comparison purposes. The average magnitude of output speeds was found to be identical but the trends were slightly different due to slipping torques.

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Life-cycle cost (LCC) is the most frequently used economic model for decision making that considers all costs in the life of a system or equipment. The LCC of repairable equipment highly depends on the reliability and availability of the equipment. Optimum equipment reliability reduces failure which in turn reduces disruption of product that have a direct link to maintenance and production cost. This paper presents a mathematical model to estimate the life cycle cost (LCC) of repairable equipment. Operation and Maintenance cost are calculated using activity based costing. Pump system containing two pumps in a parallel configuration is taken as a case and their LCC is analyzed using the developed model. The developed model is used to assess alternative replacement option of the existing pump system. The alternative options are either to continue with the existing system or to replace one of the pumps that have highest downtime or to replace both pumps.

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Grain refinement during semi-solid processing is believed to augment the mechanical properties of metals. The introduction of nucleation in the die pool, generated as a result of localize solidification of molten metal, over a sloping plate can serve as an economical and efficient way for grain refinement. In this research, flow from the sloping plate was used for enhancement of material properties through grain refinement in gravity die casting using Aluminum alloy LM25. The castings were prepared with different slope angles of 800mm long, naturally cooled Stainless Steel plate, with varying angles of 150 increments with the horizontal. The specimens obtained were then tested for microstructure characterization, tensile strength and percentage elongation. Conclusions were drawn on the grain size and precipitate morphology as a function of angle of sloping plate. Microstructure examination, elongation measurements and tensile tests show that best properties were achieved with the sloping angle of 60°.

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Friction stir welding (FSW) process is a solid state joining process in which a non-consumable tool is used to generate frictional heat in the abutting surfaces. The welding parameter such as welding speed, tool rotational speed, and tool profile plays a major role in deciding the weld joint strength. In this investigation, effect of welding parameters and tool pin profile on Mechanical properties in AA6061 aluminum alloy was studied. Friction stir welding of aluminum alloy plates with a thickness of 6 mm are used to perform Friction Stir Weld joints. Tapered cylindrical, and square pin profiles have been used to fabricate the joints at three different rotational speeds i.e. 1500, 2000 and 2500 rpm with two traverse speeds of 20 and 40 mm/min. The mechanical properties (tensile strength, hardness) of the joints have been evaluated and analyzed. It has been observed that the design of tool pin profile has considerable effect on tensile properties. Square pin profile tool produces the best tensile properties compared to tapered cylindrical tool pin profiles.

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The normal practices in transporting gas from sources to consumers are using gas pipeline. One option to optimize the transportation cost is to model the distribution pipeline using mathematical programming. The aim of this paper is to present the transportation programming model for minimizing the cost of gas transportation. The model has included three units, gas production sites, refinery stations and consumers or cities. The model solved by two parts. The first part is gas transportation from production sites to refinery stations and the second part is gas transportation from refinery stations to consumers. The Vogel method is used to solve the model. The Iranian natural gas network is used as case study. The data of the network was collected from Iranian Natural Gas Company directly. The results of the comparison between two parts of the model and case study reveal that the Iranian natural gas network could save approximately 7 percent of the current cost by using the results of the model.

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This paper presents a stepwise approach for designing a Parabolic Trough Solar Collector system, which is the fastest growing technology amongst concentrated solar power technologies. This technology is mainly being used for electricity generation by steam power cycles, but there is huge potential for this technology to be used in industrial heating applications. Though this technology is already developed and successfully been used in many developed countries, but there is barely any development in Malaysia. The performance of parabolic trough collector system is highly dependent on geographic location and meteorological conditions. A parabolic trough solar heating system has been designed and simulated using meteorological data of Ipoh, Malaysia. Thermal performance of the designed system was evaluated for fixed load and without thermal energy storage. A unique set of conditions is required for designing the PTC system but the solar radiation and incident angle changes throughout the year. So, setting appropriate design point conditions is crucial in designing of PTC system. The effect of field size on capacity factor and dumped energy is also explained, using the concept of solar multiple. It was noted that increase in field size have very little impact on capacity factor for solar multiple values higher than 2. This study was conducted for solar-only system without thermal energy storage which resulted low annual capacity factor. So, it is not worth depending solely on solar energy, combination of solar with conventional fuel system can significantly contribute in reduction of fuel usage also the addition of thermal energy storage can add to its value even more.

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Decision making and risk assessment are becoming a challenging task in oil and gas due to the risk related to the uncertainty and imprecision. This paper proposed a model for the risk assessment based on multi-criteria decision making (MCDM) method by integrating Fuzzy-set theory. In this model, decision makers (experts) provide their preference of risk assessment information in four categories; people, environment, asset, and reputation. A fuzzy set theory is used to evaluate likelihood, consequence and total risk level associated with each category. A case study is presented to demonstrate the proposed model. The results indicate that the proposed Fuzzy MCDM method has the potential to be used by decision makers in evaluating the risk based on multiple inputs and criteria.

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Finding a location in a campus is a problem, especially during the beginning of the semester for both new students and lecturers. Studies on building location need to be conducted to solve problems by employing Geographic Information System (GIS). The purpose of the study was to design an interective map by using a web application. In accordance with MS1795 code, the data are divided into various types of building available in the university campus. An interective map application is designed with information to the fact that classrooms and laboratories are location that is often searched by users. With the ArcGIS 10.2 application, a location query system is developed. The interective map is designed specifically to the needs of the users which includes students and lecturers. Studies result have shown that GIS is an important device to determine the location on a map. The interective map is also very useful for location-determining purposes in the university campus and is beneficial to all parties.

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In Round-Robin Scheduling, the time quantum is fixed and processes are scheduled such that no process uses CPU time more than one time quantum in one go. If time quantum is too large, the response time of the processes will not be tolerated in an interactive environment. If the time quantum is too small, unnecessary frequent context switch may occur. Consequently, overheads result in fewer throughputs. In this study, we propose a priority Round-Robin algorithm with dynamic quantum time (PDQT). The algorithm used the old fixed quantum time to generate new one for each process depending on its priority. The simple Round-Robin algorithm has been improved by about 20%. By controlling quantum time, we experience fewer context switches and shorter waiting and turnaround times, thereby obtaining higher throughput.

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This paper describes key phrase extraction algorithm in Presentation Mining called MiKe2. The algorithm extracts key phrases and keywords from a collection of presentation slides to be generated into a visual knowledge display looks like a mind map. MiKe2 takes a statistical approach by combining the n-grams frequency count and weight from the C-Value approach. The algorithm is hoped to improve performance in Presentation Mining by automatically generating a high quality mind map that could improve teaching and learning in general.

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Android applications continue to dominate the mobile market as time passes. However, software quality of the application remains a challenge. Analysis of the android application has been done by different researchers in the area of security, power consumption and performance of the android application. Source code refactoring has been used in android application to improve power consumption and execution time. In the area of testing that certify the quality of the product to continue keeping the app in the market place, analysis of the application is yet to be explored and research is yet to cover refactoring to improve android application testing. This paper proposes an analysis tool that improves the testing process of the android application. Our analysis tool extends the ApkAnalyzer and refactors the bytecodes generated to reduce the test path thus test cases generated are limited and have efficient coverage.

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Cryptographic hash functions are used to protect the integrity of information. Hash functions are implemented in applications such as; Message Authentication Codes, pseudo random number generators and key derivation functions. Thus, this arguably suggests the need for continuous development of hash functions. Traditionally, hash functions are designed based on existing block ciphers due to challenges and difficulties faced in constructing new hash functions from the scratch. However, the key generation for each encryption process results to huge computational cost. In order to reduce computational cost, only a limited instantiations of the block cipher such as the permutations and boolean operators are used as the underlying compression functions. Few works have been proposed in developing a less computational cost but secure and efficient compression function. This paper proposes a different approach (PQ and 3PQ) in constructing compression function based on permutations and non-associative quasi group. Analysis of experimentation results have demonstrated that the proposed compression functions are suitable for operation in constraints environments (both memory and processing power) with very minimal computational cost. Similarly, the obtained results also shows the proposed compression functions have an effective one-way function, strong avalanche property and easy to implement.

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Thorough understanding of the rainfall-runoff processes that influence watershed hydrological response is important and can be incorporated into the planning and management of watershed resources. Soft computing techniques and inferential statistics were used to assess 2 rainfall-runoff models and their runoff predictive accuracy in this article. The 1954 simplified SCS runoff model was found to be statistically in-significant under two Null hypotheses rejection and paved way for the model calibration study to produce regional specific runoff model through calibration according to regional hydrological conditions in Peninsula Malaysia. The new runoff model out-performed non-calibrated SCS runoff model and reduced its RSS by 27%. A 3D runoff difference model was created as a collective visual representation between the (SCS) non-calibrated and calibrated new model, it also showed that both under and over design risks were less significant at high CN (urban) area and more profound under higher rainfall depths. On average, rural and forest catchments of Peninsula Malaysia faced 7% (lower CN area as much as 22%) CN down scaling adjustment due to regional hydrological calibration in order to achieve better runoff predictions.

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Language researchers introduce parse tree sentence visualisations to help users understand sentence structures. However, language research in parse tree sentence visualisation for Bahasa Melayu (Malay language) still has not attracted enough researchers to produce a model and a prototype which enable the visualisation of Bahasa Melayu (BM) sentences. Trends for BM language researches are mostly geared towards developing parsers (sentence checkers) for BM sentences. The learning of BM words has been achieved manually up to now. Sentence formation has to be learned at the school level. Thus, BMTutor has been introduced to help students in learning Malay sentences and word classes through a computerized visualisation method. Researchers have identified the difficulties faced by students in understanding word class and sentence structures. This will certainly benefit students especially those who have difficulties in understanding sentence structure. The BM Tutor helps to understand the BM sentence structure by combining four components, which are 1) sentence checker; 2) sentence corrector, 3) parse tree sentence visualization, and 4) word attribute components. During the development phase, the result of the tested prototype showed 87.5% of the BM sentences were successfully parsed with only one parse tree visualisation output for each sentence used.

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Time series analysis is an important technique for future forecasting of time dependent variables. Keeping future visualization in mind, time series analysis is applicable to a wide variety of applications. In this work, neural network autoregressive (NNAR) model, a non-linear model is applied for forecasting of per capita disposable income. The average available money per person after the deduction of income taxes is called as the per capita disposable income. It is an indicator of the economic condition of a nation. Forecasting of per capita disposable income is essential in helping the government assessing its economic state with respect to the economy of other developing countries of the world. Financial critical situation like inflation can also be assessed by forecasting of per capita disposable income. Future policies and plans can also be formulated by the planning commission of a country upon observations of the results obtained from this work.

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In many research and development fields, the stakeholders faced dilemma to acquire the accurate multi-criterion decision making (MCDM) outcomes. Observations showed that the inaccuracy of MCDM outcomes might be due to the missing of the right context for decision making process. This research is motivated to propose a contextualization approach for better critical issues’ decision making support. The proposed triad-based contextualisation approach comprises three (3) processes namely the context characterisation, context representation, and context interpretation. At the end of a contextualisation process cycle, a set of consistent triad relationships would be derived to represent the current context of a critical issue. The context could be served as the right objective for guiding any critical issue’s MCDM process. Experiment showed that the consistency of the Analytic Hierarchy Process (AHP) outcome has been improved when the stakeholder used the proposed contextualization approach to depict the the right context as the objective for decision making deliberations. It is believed that once the proposed approach is conducted in many contextualisation process cycles with the help of machine learning systems and advance analytics tools in the future, it could produce a useful set of contexts or objectives for better critical issues’ decision making insights.

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In email spam detection, not only different parts and content of emails are important, but also the structural and special features of these emails have effective rule in dimensionality reduction and classification accuracy. Because spammers constantly change patterns of spamming messages using different advertising images and words to form new pattern features or attributes, feature subset selection and ensemble classification are necessary to address these issues. Recently, various techniques based on different algorithms have been developed. However, the classification accuracy and computational cost are often not satisfied. This study proposes a new ensemble feature selection techniques for spam detection, based on three feature selection algorithms: Novel Binary Bat Algorithm (NBBA), Binary Quantum Particle Swarm Optimization (BQPSO) Algorithm, and Binary Quantum Gravitational Search Algorithm (BQGSA) along with the Multi-layer Perceptron (MLP) classifier. The achieved results showed accuracy very near to 100% in email spam detection.

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This paper compares the performance of text similarity algorithms that use pure cosine function and two others that use Dice function and considers word relatedness. Relatedness of two words is determined in a case by looking at lexical relationship, and in another case by looking at the co-occurrences of two words in a corpus. Text similarity score is used in classification of Indonesian short texts using k-nearest neighbour. The study employed more than 150 short texts, of which 112 were used in learning and 43 were used for testing. The short texts were sentences or phrases from a SWOT (strength, weakness, opportunity and threat) analysis of an organization. Manual classification of the SWOT issues was conducted by the organization and the result was treated as classification target. Our research shows that the factor of word relatedness in semantic vectors increase the level of sentence similarity score and it enhances the performance of text classification. Without word relatedness, the F-Measure of k-nearest neighbour classification algorithm is 0.39. Inclusion of word relatedness using lexical relationship in a classification algorithm improve F-Measure as high as 0.595, while word relatedness based on co-occurrences increases F-Measure to a level of 0.4.

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Cloud computing is a combination of various established technologies like virtualization, dynamic elasticity, broad band Internet, etc. to provide configurable computer resources as a service to the users. Resources are shared among many distrusting clients by abstracting the underlying infrastructure using virtualization. While cloud computing has many practical benefits, resource sharing in cloud computing raises a threat of Cache-Based Side Channel Attack (CSCA). In this paper a solution is proposed to detect and prevent guest Virtual Machines (VM) from CSCA. Cache miss patterns were analyzed in this solution to detect side channel attack. Notification channel between client and cloud service provider (CSP) is introduced to notify CSP about the consent of client for running the prevention mechanism. Cache decay mechanism with random decay interval is used as a prevention mechanism in the proposed solution. The performance of the proposed solution is compared with previous solutions and the result indicates that this solution posses least performance overhead with a constant detection rate and compatible with existing cloud computing model.

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In a cervical cancer screening procedure, a patient’s Pap smear slide is presented to determine presence of abnormalities. Conventionally, features of individual cells are measured and analysed in the initial screening step. Based on the analysis results at the cellular level, the Pap smear slide is classified as positive (abnormal) or negative (normal). However, each slide presents data on thousands of cells. Consequently, classifying the slide based on cell-by-cell analysis is very time consuming and prone to ‘false negative’ problems. In this paper, we propose group-based classification (GBC) approach to classify a slide by measuring the slide data as a whole instead of scrutinizing the cells individually. This means measuring the slide’s features once from a group of cells to obtain a diagnosis. We apply two group-based nearest neighbour techniques; voting and pooling schemes to label each slide. The performances of the group-based nearest neighbour techniques are evaluated against existing k-nearest neighbour classifier in terms of accuracy and area under the receiver operating characteristic curve (AUC). The group-based nearest neighbour classifiers show favorable accuracy compared to the existing k-nearest neighbour classifier.

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Missing data is a common problem faced by researchers in many studies. The occurrence of missing data can produce biased results at the end of the study and affect the accuracy of the findings. There are various techniques to overcome this problem and multiple imputation technique is the best solution. Multiple imputation can provide a valid variance estimation and easy to implement. This technique can produce unbiased result and known as a very flexible, sophisticated approach and powerful technique for handling missing data problems. One of the advantages of Multiple Imputation is it can use any statistical model to impute missing data. Hence the selection of the imputation model must be done properly to ensure the quality of imputation values. However the selection of imputed model is actually the critical step in Multiple Imputation. This research study a linear regression model (LR) as the selected imputation model, and proposed the new algorithm named Linear Regression with Half Values of Random Error (LReHalf). The proposed algorithm is used to improve the performance of linear regression in the application of Multiple Imputation. Furthermore this research makes comparison between LR and LReHalf. The performance of LReHalf is measured by the accuracy of imputed data produced during the experiments. Future research is highly suggested to increase the performance of LReHalf model. LReHalf was recommended to enhance the quality of MI in handling missing data problems, and hopefully this model will benefits all researchers from time to time.

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Agrotech plays an important role in the production of out-of-season fruits, flowers and vegetable as well as high value and sensitive plants. The greenhouse concept has been widely used in precision agriculture to acquire the best quality for the production of fruits or vegetables. However a fully automated system, taking into considerations the different phases of plant growth and the optimal requirement by the plants during these growth periods and cycle is not fully designed and available. The optimal plant growth depends on several parameters such as irrigation, soil moisture, humidity, temperature, radiation of light, pH level, and CO². Thus, this project develops an automated scheduler system by considerating with all optimal plant growth requirements for every each phase of the plant to ensure that all subjects (mango) will grow perfectly. Main hardware component within project is Memsic, Zigbee and smart phone for display while MP Lab and LabView are used for software elements. It is anticipated, by using this system labor and maintenance cost will be cheaper and the process of monitoring and collecting data or information is more easy and efficient.

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Feature selection has become the vital step in many data mining application for instances classification. Feature selection eliminates irrelevant attribute to obtain high quality features that may contribute in enhancing classification process and producing better classification results. This study is conducted with the intention to find out the most appropriate features that may lead to the best accuracy for various datasets of same domain, which is medical domain. During the experiments, comparisons were made between six benchmark feature selection methods based on eight medical datasets. Then, the performance were analyzed based on two machine learning algorithms; Naïve Bayes and KNN with and without feature selection in term of F-Measure and ROC on those medical datasets. From the experiment the optimum feature subsets are found. Moreover, the findings effectively support the fact that feature selection helps in increasing the classifier performance with existence of minimum number of features. However, no single feature selection methods that best satisfy all datasets and learning algorithms and this will simplify by assumption that features are independent for a given class variable. Hence, it still enables to obtain the optimal dimensionality of the feature subsets within the respective medical datasets.

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Delay Tolerant Networks (DTNs) enable communication in challenged environments where end to end connectivity may not exist at some intervals. DTNs use store, carry and forward paradigm for delivering the message from one node to other node. Routing in DTNs is considered a challenging task because of the frequent disconnections and short contact durations. In present paper we evaluate the performance of some popular routing protocols used in DTNs based on characteristics like delivery probability, delivery latency and overhead ratio. Evaluating the performance of routing protocol requires suitable simulation tool so that the parameters used in simulation may be varied widely and the evaluated performance gives the result closer to the real world scenario. We used ONE (Opportunistic Network Environment) simulator for our simulation for providing a comparative analysis of performance of routing protocols.

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Digital image correlation technique is a non destructive testing (NDT) tool for measuring deformation and failure of material have been used in this study over conventional methods such as strain gauges and extensometer. ASTM and other institutions have developed specific standards for composites. In the aim to inform the developed models of finite element/numerical and analytical, tensile tests were conducted on composite adherend and polymer adhesive specimens to obtain the stiffness and strengths of all constituents. Materials used for the testing campaigns are Glass Fiber Reinforced Polymer (GFRP) and Carbon Fiber Reinforced Polymer (CFRP) as well as adhesive materials for bulk testing Araldite 2015 and Sikalfex 292. The digital image correlation (DIC) technique is utilized for the characterisation of the constitutive and failure behavior of the constituent materials, with focus on the composite and polymer adhesive material system.

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Phase induced intensity noise (PIIN) is one of the noises involved in incoherent OCDMA systems. In this paper, we analyze the influence of PIIN on the system performance of new proposed 2-D Hybrid FCC- MDW code. The numerical result indicates PIIN is a major factor of the performance depreciation as compared to the shot noise and thermal noise. The comparison results with thermal noise and shot noise reveals that the system performance is seriously affected by PIIN and other two noises can be neglected. Moreover, the numerical analysis demonstrates the PIIN value of the proposed code is lower than the 2-D Perfect Difference (PD) code and 2-D Modified Double Weight (MDW) code. Consequently, the performance of the 2-D Hybrid FCC- MDW OCDMA system is better than other two codes. The results presented here may facilitate improvements in the understanding to develop a new incoherent OCDMA code.

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We propose a model that illustrates how digital Wayang Kulit (DWK) helps students learn mathematics in primary school. Wayang Kulit (WK) is unlikely to last long due to lack of safeguarding. Hence, there is an urgent need to preserve this cultural heritage from extinction. Drawing from the facts that there is deficient in performance of primary school children in mathematics. Henceforward, we proposed a conceptual model that illustrates how digital WK helps students learn mathematics. We use the model to develop a DWK using RAD method. The DWK, given a persona name e-WayCool, demonstrates how WK can be transformed into mathematics’ learning object. In order to support the engagement and entertainment in DWK, the needs for effective interaction design with three dimensions of Interaction Design (IxD) theory are added. The 15-questions USE was distributed to measure the performance of DWK. The students perceived e-WayCool as useful (79%) and satisfying (83.4%). The result showed that the students perceived high satisfaction towards the proposed digital WK. It indicates DWK is effective for mathematics learning at primary level, and as such, the model proposed can be generalized to a wider domain.

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Gas turbines are used in oil platforms, floating liquid natural gas (FLNG) plants, and land based distributed power plants to generate power. In Malaysia, as much as 40% of the total electricity (e.g. an estimated 783 MW in Peninsular Malaysia, 289 MW in Sarawak, and 42 MW in Sabah) comes from gas turbine driven power plants. Some of the challenges in gas turbine operations are stringent safety and emission control requirements, urgent need to reduce life cycle cost, and the need to sustain high efficiency regardless of operating conditions, changing fuel cost, electricity tariff and electricity demand. The idea that got attention and intended to address these issues is the concept of integrated approach to remaining useful life prediction and operation scheduling. The purpose of the present paper is to review the literatures specific to gas turbine prognostics. The reviewed methods include regression methods, physics based models, computational intelligence (artificial neural network and fuzzy systems, evolutionary-based method), and hybrid approaches. As it turned out, (i) there is no readily available method that can be used to integrate reliability information into a prognostics model, (ii) the benchmark data from NASA is the only available information that can be used to test new algorithms, (iii) commercial software's like Gate Cycle, PROSIS, and GSP have been used to generate data for diagnostics and prognostics studies, (iv) thermo economic or exergetic approach seems to be less applied to prognostics.

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Harvesting the wind energy has existed since ancient civilization such as sailing ships. Nowadays, wind energy is harvested to generate an electrical energy using a wind generator. In order to ensure safety and durability of the wind generator, the performance and the characteristic of the generator needs to be investigated. Unfortunately, the purchased wind generator does not come with a detail drawing and electrical properties that are required for modeling purposes in the Finite Element Analysis (FEA) software. An image processing techniques is proposed to acquire the dimension of the generator internal parts. In order to generate a quality mesh, an adaptive meshing technique is used in the magnetostatic solver before it is imported into the transient solver in Ansys Maxwell. The proposed method to acquire the dimension produces error approximately 5 percent. Furthermore, using adaptive meshing technique proposed in this study, simulation results are in good agreement with experimental results with approximately 3 percent of error.

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Long Term Evolution (LTE) is broadly available to the world. The upcoming trend in LTE-Advanced (LTE-A) emphasizes the enhancement in spectrum efficiency, capacity and cell-edge user throughput and thus highlights the small cell technologies. With the advantage of small size, Femtocell is able to be deployed at "Died zone" and thus satisfying the service expectation particularly to cell-edge users. Femtocell is also an inexpensive compact base station to increase mobile operators’ capacity and coverage at the same time increases users' data throughput. With the increase of small cells in the network, the proposed Fractional Frequency Reuse (FFR) which intelligently reuse the spectrum helps to mitigate Inter-Cell Interference (ICI), at the same time, improve spectrum efficiency. A hybrid topology which incorporated Femtocell and FFR is analyzed in this paper. The available spectrum is divided into four ranges and reused intelligently. The hexagonal cells are further divided into inner and outer regions. Inner region radius and resource is intelligently controlled to achieve maximum performance and user fairness. The performance of the system is observed over a short period of time by considering users' mobility. The system is improved and User Satisfaction (US) is maintained at high level over a period of time.

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This paper proposed the use of population estimation in a new meta-heuristic called Cuckoo search (CS) algorithm to minimize the training error, achieve fast convergence rate and to avoid local minimum problem. The CS algorithm which imitates the cuckoo bird’s search behavior for finding the best nest has been applied independently to solve several engineering design optimization problems based on cuckoo bird’s behavior. The algorithm is tested on five benchmark functions such as Ackley function, Griewank function, Rastrigin function, Rosenbrock function and Schwefel function. The performance of the proposed algorithm was compared with Particle Swarm Optimization (PSO), Wolf Search Algorithm (WSA) and Artificial Bee Colony (ABC). The simulation results show that the CS with Levy flight out performs PSO, WSA and ABC, when the cuckoo population is varied.

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In this work, we investigate the impact of different ground plane (GP) structures of the ultra-thin body and buried oxide SOI MOSFETs (UTBB SOI MOSETs) on the digital and analog figures-of-merits (FoM) with gate length of Lg= 25 nm and 10 nm. Different GP structures are found to have significant impact on the drain-induced barrier lowering (DIBL) while the impact on subthreshold-slope (SS) is negligible. Incorporation of localized ground plane of p-type in the substrate underneath the channel (referred herein as GP-B structure) provides excellent results of DIBL as of the incorporation of n+/p+/n+ structure underneath the buried-oxide (referred herein as GP–C structure). The effective suppression of the substrate depletion effect is observed with showing no increase in the potential under the channel for both GP–B and GP-C structures between low (Vd=20 mV) and high (Vd=1 V) drain bias. However, as the simulations were extended to analog FoM, it is found that only GP-B structure managed to maintain excellent result in terms of voltage gain, Av while GP-C showed deteriorations due to an early increase in output conductance, gdat low frequency.

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Nanocrystalline zinc oxide has wide range of applications such as high power transparent thin film transistors, optical waveguides, conductive gas sensors and transparent electrodes for photo-electrochemical applications. In this paper, we demonstrated the fabrication of zinc oxide (ZnO) nanorods (NRs) with ZnO seed layers using a chemical bath deposition (CBD) method on glass substrates. This paper reports the influence of ZnO seed layer conditions which are annealed ZnO seed layer and as-prepared ZnO seed layer on the morphological, structural and optical properties of ZnO NRs. We found that annealing the seed layer at 500ºC changes the ZnO NRs morphological and optical properties but remaining the structural property.

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Swarm intelligence metaheuristic search algorithms are quite popular methods to solve many complex optimization problems in the real life. Bat algorithm is a recent addition to the family of metaheuristics. Bat uses echo-location behavior of the bats to search optima convergence point in the search trajectory. Although, it has proven its mettle in finding optimal solutions, there are certain parameters that have not been investigated to improve convergence in Bat. Therefore, this paper explores the variations in parameters such as pulse rate, loudness and echo-location in Bat algorithm. The parameter enhancement is simulated on a set of benchmark functions and compared with other state of the art algorithms such as; particle swarm optimization, wolf search, and artificial bee colony. The simulation results show that Bat algorithm performance high correlates with the parameter adjustment.

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The Wireless Sensor Networks (WSN) has a limited power supply because each node was equipped with a battery. In most situations, they are deployed in a hostile environment where it is exceptionally hard to change or charge their batteries. Because of this, it becomes challenging in WSN to prolong the system lifetime and at the same time achieve a better throughput. The number of nodes in the network is regarded as the most significant factor in the WSN performance. Therefore, the current paper aimed to study the effect of the number of nodes on the performance of WSN. Quality of service (QoS) performance metrics in the study were network lifetime, energy dissipation and throughput in a different number of nodes. In addition, during the study, we proposed and implemented the graphical user interface (GUI) tools to generate the Network Simulator 2 (NS-2) script code for topology scenario file, and the graph tools (GT) to plot the NS-2 simulation results. The visual basic language was used to design the GUI for generating the NS-2 script code while MATLAB was used to design the GT. Simulation experiments were conducted using NS-2.34 with Massachusetts Institute of Technology (MIT) extension LEACH protocol for a different number of nodes. We conclude that the increasing number of nodes can cause decreasing the throughout and consuming high energy, hence, resulting in the reduction of network lifetime.

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This paper presents a design of compact Multiple Input Multiple Output (MIMO) of Planar Inverted F-Antenna (PIFA) involving parameters which may affect the characteristics of PIFA. The proposed antenna consists of two ports with one patches operates at GSM frequencies which is 0.9 GHz and 1.8 GHz. The single antenna is fabricated on an inexpensive FR4 a dielectric constant of ? = 4.3, with thickness of substrate that is 1.54 mm and the thickness of patch is 0.035 mm. The simulated result represents that the proposed antenna obtained the reflection coefficient as needed which is at least = -6 dB for single antenna design and also for MIMO configuration of antenna. Simulation by using CST Microwave Studio program and measurement on the final prototype antenna were carried out and compared. A MIMO system characteristic of a two port MIMO antenna is performed. A two port antenna for mobile applications is designed, the antenna shows good in frequency drop, radiation pattern and reflection coefficient.

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Many Web 2.0 interactive online sites have grown at an alarming rate and they have changed the communication and collaboration behavior of knowledge workers in knowledge driven organizations. Social networking sites are online platforms that allow people to collaborate and communicate through a variety of services. These social networking sites drive new forms of social interaction, allowing users to intermingle and cooperate with each other by exchanging ideas by posting updates and comments. It is crucial to comprehend how social relationships affect the content shared among knowledge workers in virtual worlds. Lately many social network features were introduced based on some feedbacks found by researchers in the area of affective computing. Since affect is a thorny and cryptic area of research in psychology field, it is unidentified whether the knowledge sharing activity and the affect are closely related in the Information Systems research. Hence this research investigates the relationships of positive and negative affect and knowledge sharing attitude among knowledge workers in organization. Furthermore, the influence of social communication and social collaboration behavior on knowledge sharing behavior will also be analyzed in the proposed Affect TPB Model.

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Today’s world is full of modern technologies and automotive industry is one of the industry that is evolving to modern technology. Hybrid and electric car is under improvement for a better efficiency. This paper emphasizes the development and analysis of retrofit electromagnetic energy regenerative suspension system test rig. The test rig will be used for the testing of the system in the laboratory. The system functions as the harvesting system that generates power for vehicle usage. Complete design of the test rig is clearly discussed in the paper including the drafting, analysis and fabrication. It is get that the designed test rig can be used for the testing which has been assembled with the main component of the real vehicle suspension system with the regenerative system. The test rig can be useful for validating the real vehicle test with the laboratory test.

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The main problem is the inevitable grain growth when metallic material operated in high temperature. Therefore, the main objective is to improve the thermal stability of Fe80Cr20 alloy for interconnect. The most promising technology to improve the properties by ultrasonic technique (UT). The materials was treated using ultrasonic with frequency of 35 kHz at various holding time of 3.5 h, 4.5 h and 5 h. Characterization and analysis were carried out by using Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and Thermo Gravimetric Analysis (TGA). Ultrasonic technique can reduce the crystallite size from 138.656 nm to 37.477 nm, improve the finer surface morphology and more homogenous powder size as compared to untreated sample (raw material). Thermal stability was improved appropriate 9% when treated using ultrasonic technique at 4.5 h as compared to raw material. Therefore, that technique is required for improving the fine and homogenous powder size as well as thermal stability of Fe80Cr20 alloy as metallic material.

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Arenga Pinnata, a sustainable and eco-friendly material obtained from nature is eligible as alternative for synthetic fibre in sound absorber which is hazardous to human health. This paper discusses the sound absorption properties of this natural fibre. During the processing stage, Arenga Pinnata fibres are treated with alkaline treatment individually and mix with various mixing ratio of natural rubber (latex). The thickness of each sample is kept constant at 50mm. Method used to measure sound absorption coefficient (a) is the Impedance Tube Method (ASTM E1050-09) which is a standard test method for impedance and absorption of acoustical materials using a tube, two-way microphones and a digital frequency analysis system. The results showed that sound absorption coefficients of Arenga pinnata samples mix with natural rubber were better than the sample without natural rubber as binder. The better sound absorption performance obtained from 80:20, Arenga Pinnata and natural rubber mixed sample which gives the value of 0.8 to 0.9 at 1000 Hz and 4000 Hz compare to other mixing ratio samples. Moreover, empirical model proposed by Delany-Bazley are used to support the normal incidence sound absorption result as a preliminary prediction. The physical properties of the Arenga Pinnata fibres such as density, porosity, tortuosity and flow resistivity were also been tested. The physical properties results agree that, they significantly influence the acoustical performance. All the outcomes demonstrate that, this selected natural fibre is a promising light and environment-friendly sound absorption material.

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Silicon carbide has gain much attention in recent years as the best material for the application in harsh environment condition. This is due to their excellent properties such as good wear resistance with high hardness and strength at elevated temperature. In this study, the sintered specimen of silicon carbide with sintering additives of four different compositions were fabricated using powder metallurgy method. Physical properties were measured by means of bulk density and apparent porosity whereas the mechanical property was measured in term of hardness. From this study, it can be observed that the silicon carbide was sintered to about 0.93 of its relative density by using alumina and yttria as sintering additives. This finding was as a result of a eutectic liquid formed between alumina and yttria at sintering temperature of 1930?C. The specimen with 25 wt. % of sintering additives gave the maximum value of hardness of 2601 HV.

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Friction stir welding (FSW) is a new promising solid state joining process which utilizes frictional heat to soften and joint (stirred) both metals together. This process is mainly invented to cater for a difficult-to-weld material such as aluminium but nowadays can be used to joint magnesium, copper, titanium, and steel. The only limitation is the tool materials rather than the material itself. The objective of this present study is to analyse the relationship between the temperature distributions on advancing and retreating side against the fracture location of the friction stir welded AA6063-T6 pipe butt joint. Several K-type thermocouples will be located at certain locations along the weld line of the pipe in order to take the real time measurement. The tensile test will be conducted to determine the maximum loading and fracture location for each friction stir welded (FSWed) sample. It was found that the advancing side gave higher temperature than retreating but fracture occurred either on advancing or retreating side of the specimens.

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In friction stir welding, pin profile of the tool has a strong influence on weld quality due to its key-role in material flow. Its influence has been investigated on nylon-6 plates using three different pin profiles; threaded, square and tapered. Marker material insert technique was utilized for visual analysis of material flow of post-weld specimens. Results have shown uniform vertical stirring with symmetrical pattern for all pins either marker material is on advancing side or retreating side. Unlike metals, major role of pin profile was found in horizontal displacement in which square pin showed largest backward displacement of marker material. Moreover, no forward flow on any side (advancing or retreating side) of all pin profile was found.

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PV/Diesel Power Generation Scheme was adopted to replace the stand-alone diesel power generation system in rural villages and schools in Malaysia. As the diesel fuel costs fluctuates over the year and the PV module showing inefficiency and incapability to totally replace diesel generators, hydro power is identified as an essential add-on power sources to the current PV/Diesel system. Hence, this paper studies the preliminary elements and analyse the potential for PV/Diesel/Pico Hydro hybrid system to be applied in SK Sungai Tiang in Royal Belum, Perak. The comparison between PV/Diesel hybrid and PV/Diesel/Pico Hydro hybrid with emphasis placed on the amount of fuel savings and total cost needed to implement the PV/Diesel/Pico Hydro hybrid based on capital cost and operational & maintenance cost (O&M).

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The present study deals with the numerical investigations of aluminium pressure vessel behavior when impacted by spherical and blunt steel projectiles. One of the main causes of vessel rupture is the reduction of the vessel strength caused by external impact or material defect. The safety of the pressure vessel is vital because of its high working pressure which is more than 20 MPa and any untoward incidents must be avoided. Therefore, the main goal of this study is to predict the deformation and vessel strength behaviors for varying projectile shape, target thickness and impact velocity under low velocity impact conditions. In the modelling process, Johnson-Cook plasticity model was selected for the vessel material (Al 6061-T6) and direct impacts were subjected on the mid and dome vessel zones with varying parameters. The dynamic explicit analysis of the problem was carried out using ABAQUS finite element code. It has been concluded that, the target vessel exhibited lower impact resistance for blunt projectile compared to spherical projectile under the same impact loading conditions. Also, the damage which occurred in the dome vessel zone was greater than on the cylindrical area of the vessel, which leads to a specific design requirement in the dome zone. Finite element simulation results were compared with the numerical results in the literature and a good agreement was found.

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One of the most common external corrosion failures in petroleum and power industry is due to corrosion under insulation (CUI). Despite being external, ironically the challenges are in the prevention and detection. The difficulty in corrosion monitoring has contributed to the scarcity of corrosion rate data to be used in Risk-Based Inspection (RBI) analysis for degradation mechanism due to CUI. Limited data for CUI presented in American Petroleum Institute standard, (API 581) reflected some uncertainty for both stainless steels and carbon steels which limits the use of the data for quantitative RBI analysis. The objective of this paper is to present a fuzzy-based model to estimate CUI corrosion rate of carbon steel based on the API data. The fuzzy model has five inputs, which are operating temperature, type of environment, type of insulation, pipe complexity and insulation condition while the output in terms of CUI corrosion rate. The membership functions for both inputs and output will be discussed in details. A number of rules were used to perform defuzzification. After development of this fuzzy logic model, its root mean square error value (RMSE) and mean absolute deviation value (MAD) against API 581 data has also been checked, which revealed quite satisfactory results. The results from this model would provide corrosion engineers enough information about CUI corrosion rates concern to their plant so that they will be able to do necessary inferences in a more quantitative approach.

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This paper provides a review of the electrode position process that is used to produce nickel-cobalt / alumina (Ni-Co/Al2O3) composite coatings. The electrode position techniques, consisting of direct current, pulse current and pulse reverse current, sediment electrode position, and CO2 bath, are described. The effects of electrode position variables, including applied current density, deposition time, particle concentration and use of surfactants, are also explained. The paper then discusses the limitations of previous studies, such as lack of focus on the effectiveness of this coating in corrosive and erosive environments, and the effects of alumina particles on coating microstructures. It also suggests longer exposure to corrosive media for more significant corrosion study. Further research needs to be conducted in order to improve the corrosion and erosion resistance of Ni-Co/Al2O3 in harsh environments, such as marine conditions.

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Having the current constraints of serious water shortage which might cause more concern rather the depleting fuel resources and also the worrying global warming phenomenon, the power plants performance has to be evaluated based on not only energy efficiency but also water efficiency and environmental emission point of view. Therefore, power plants water consumption and emission production should be optimized simultaneous with the optimization of energetic performance. In other words, a high performance power plant would be considered as a high efficient, low water consumer and low emitting plant. In this paper the main indicators for the evaluation of energetic performance, water consumption and emission level of different pollutants are studied and then the global trend of these indicators for IRAN power plants investigated over a ten-year period, ending to 2012. The results show that the energetic performance of gas power plants seems to be higher than that of for steam and combined cycle power plants. Obtaining a 28 percent growth in overall energy efficiency of gas plants compared to the first year and achieving an average 85 percent peak load provision during ten years proved this fact. The water consumption criterion for wet-cooling steam plants decreased significantly to 0.6 m3/MWh at the end of tenth year. Finally, using the low quality fuel, whether oil or gas, has led to an 8.5 g/kWh SOx emission level from steam power plants. The most increase in CO2 emission is related to the steam power plants which has been equal to overall CO2 emission from the gas power plants, 850 g/kWh, at the end of ten-year period.

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The heat flux density and distribution are the main dominant design parameters for the solar tower plant output power and receiver formation. Beside the plant geometries of the tower height, heliostat dimensions, field layout, and the optical properties, the quality of these two values depends on the heliostat field efficiency, which outlined in the mirror tilt angle cosine effect, reflected rays’ spillage loss, heliostat distribution blocking and shadowing and tracking control error. To investigate the annual heat flux collecting quantity and distribution for an experimental field, distributed and located in Universiti Teknologi Petronas, a detailed dual axis tracking model is elaborated herein.

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A good maintenance strategy requires a good reliability, availability and maintainability (RAM) analysis in order to cater the real problem to specific equipment or a system. Resolving the real problem will improve the equipment/system reliability to ensure higher availability of the system to operate. In this paper, two crude oil transfer pumps were selected for RAM analysis. The analysis was done based on individual dominant failure mode that contributed to failures of the pumps. Firstly, reliability and maintainability analysis were carried out to obtain the required parameters. Then, reliability block diagram (RBD) was constructed and simulated to obtain the availability of the crude oil transfer pump system. This analysis can help to identify critical failure modes that affect the system reliability which directly affect the operational availability of the pump system.

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The objective of this research was to examine the effects of low-stiffness-resilient-shaft (LSRS) maximum deflection angle on the response of a vehicle equipped with Semi Active Steering System (SAS) during the failure of Steer-by-wire (SBW). Modelling of LSRS stiffness that considers deflection angle was proposed and incorporated to the 3-DOF bicycle model of the vehicle dynamic. Simulations were performed on MATLAB/SIMULINK for several vehicle longitudinal speeds and the LSRS maximum deflection angles by applying a standard step steer input. Simulation results showed that vehicle responses were considered safe from roll over problem during the specified cornering maneuver since the lateral acceleration and yaw velocity values of the SAS system were always lower than the ones of the conventional systems. The turning radius was found to increase as the maximum deflection angle increased. However, the turning radius became constant after a certain maximum deflection angle was used. The maximum deflection angle of LSRS to be as low as possible, between 10o to 30 o was suggested for keeping a consistent vehicle’s drivability.

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Hydro cyclone are widely used in oil and gas industry particularly in this study similar to de-oiling process or improve purification of discharged water. As offshore oil production started to decline over time with high water cut in the production stream, this usually cause unprofitable production for huge expenditures in water handling. The periodically collapse in oil price further heightened the awareness on production technology to reduce unit costs. This paper offers a comprehensive suite of numerical simulation to predict the performance of oil-water hydro cyclone in an effort to reduce amount of water production at surface. Separation performance impact from single, dual and quad inlets configuration is simulated based on a tested turbulence and multiphase model. This investigation was carried out using Computational Fluid Dynamics in ANSYS-FLUENT 14 environment. The hydro cyclone swirling flow was simulated using RNG swirl dominated k-?? Turbulence model while the interface between crude oil and water was achieved using the Discrete Phase model. Based on the simulation results, it is concluded that hydro cyclone separation efficiency is affected by inlet velocities at tangential inlet and number of tangential inlets.

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Gas turbine performance is very responsive to ambient and operational conditions. If the engine is not operating at its optimum conditions, there will be high energy consumption and environmental pollution. Hence, a precise simulation model of a gas turbine is needed for performance evaluation and fault detection and diagnostics. This paper presents a twin shaft industrial gas turbine modeling and validation. To develop the simulation model component maps are important, however they are property of the manufacturers and classified documents. In this case, known the compressor pressure ratio, speed, and flow rate, the missing design parameters, namely turbines inlet temperatures and pressure ratios were predicted using GasTurb simulation software. Once the design parameters are developed, the nearest compressor and turbine maps were selected from GasTurb map collection. Beta lines were introduced on each map so that the exact corresponding value can be picked for a given two parameters of a given map. After the completion of components model, a simulation model was developed in Matlab environment. The equations governing the operation of individual component were solved using iteration method. The simulation model has modular nature; it can be modified easily when a change is required. The parameters that the model can predict include terminal temperature and pressure, flow rate, specific fuel consumption, thermal efficiency and heat ratio. To demonstrate the validity of the developed model, the performance of GE LM2500 twin shaft gas turbine operating in a gas oil industry at Resak PETRONAS platform in Malaysia was predicted and compared with operational data. The results showed that an average of 5, 3.8 and 3.7 % discrepancies for compressor discharge temperature and pressure, and fuel flow rate, respectively. This comparison of results showed good agreement between the measured and predicted parameters. Thus, the developed model can be helpful in performance evaluation of twin shaft gas turbines and generation of data for training and validation of a fault detection and diagnostic model.

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To remain profitable, it is important for oil and gas companies to reduce plant shutdown due to system or equipment failure. Effective root cause failure analysis is crucial to ensure that real causes of failure are identified, corrected and prevented from recurring. The effectiveness of RCFA depends on various factors such as expertise and organizational system which vary from one plant to another. This paper aimed to investigate current RCFA practices in oil and gas industry and propose areas for improvement. In this study, a comprehensive survey was conducted among RCFA investigators from various plants on important aspects of RCFA namely; investigation team, data collection, process knowledge, tool competency, report, recommendation and RCFA system in organization. From the survey, some good practices were highlighted especially in team formation and tool competency. Nevertheless, some areas need improvement such as RCFA database and sharing information.

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This paper presents the validation done on the simulation procedure for a vertical oil/water flow. A 3-D steady state simulation was carried out to predict the behavior of the oil/water flow in the well bore with presence of a hydro cyclone separator. The procedure is then validated against a previous experimental work of oil/water flow in a vertical pipe. The volume fraction distribution profile for the simulation is compared against the profile obtained from the experimental work for three cases of mean volume fraction: 0.068, 0.135 and 0.205. The simulation results for oil volume fraction distribution agrees with the results with error of difference falling below 12%. This agreement shown in the results concludes that the procedure applied is acceptable.

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Vibrations can be initiated in a number of ways, and if resonances are involved, can result in very significant effects. Vibration can cause reliability problems on equipment and fatigue failures. A dynamic vibration absorber, or vibration neutralizer, is a tuned spring-mass system which reduces or eliminates the vibration of a harmonically excited system. When dynamic vibration absorber is tuned to the frequency of forced vibration of a structure, the device can completely eliminate the vibration by creating an anti-resonance at the frequency of vibration. However, any change in the frequency of vibration from the tuned frequency renders the device largely ineffective. The major drawback of the passive dynamic vibration absorber is that it is suitable only for a narrow band width of operation and therefore, it is useful in eliminating single frequency resonant vibrations. An active vibration absorber comprising a spring–mass system attached to a rigid base and an actuator utilizing the feedback taken from the absorber mass is proposed. The actuator is controlled by the feedback taken from the absorber mass itself. Optimization design of an active vibration absorber for the minimization of the resonant vibration amplitude of a single degree-of-freedom vibrating structure is derived. The effects of optimum tuning parameters on the vibration reduction of the primary structure are revealed based on the analytical model. Design parameters an active vibration absorber are optimized for the minimization of the resonant vibration amplitude of the vibrating structure.

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High purity, high surface area silica nanoparticles could be produced from rice husk through chemical pre-treatment and combustion process. Acid leaching as efficient method of removing metallic impurities was employed during the chemical pre-treatment of rice husk prior to the burning process. In this paper, nano silica was generated from rice husk through citric and hydrochloric acids leaching by reflux boiling at 373K for 7200s so as to eliminate inorganic impurities and induce the hydrolysis of organic substances followed by burning at 973K of the residual solid husks from the leached husk. The generated silica nanoparticles were characterized to be of high purity (greater than 99%) by X-ray Fluorescence (XRF) analysis in all the two acids treated husks. X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive Spectroscopy (EDS) confirmed this percentage purity as detection of negligible impurities. Brunauer Emmett Teller (BET) surface area of 234.6m2/g and 215.8m2/g with a pore diameter of 5.3nm and 5.5nm were obtained for hydrochloric and citric acids treated husks respectively, which proved the generated silica nanoparticles to be of high surface area. Danger is less with citric acid as compared to hydrochloric acid and with proven efficiency in removal of metallic impurities in rice husk and production of high purity silica, citric acid may be the best alternative.

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Modern techniques to model torsional drill string vibration have positive impact to the efficiency of oil and gas drilling. The need for torsional model is evident from their detrimental effect to the bottom hole assembly (BHA) fitness. The model can cater planning for more efficient parameter selections for BHA and controlling surface parameter to reduce such vibration. In this paper, the models for torsional vibrations are classified based on their functional concept. The validation techniques are also reported with each classification of the model for torsional vibrations.

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The Fractional Frequency Reuse (FFR) scheme combines the benefits of universal Frequency Reuse and Frequency Reuse Factor (FRF)3. Universal Frequency Reuse scheme has high spectral efficiency while FRF=3 scheme is normally used to mitigate Intercell Interference (ICI) in a cellular system. Nevertheless, the advancement of the wireless technology does not stop here. The trend of Long Term Evolution-Advanced (LTE-A) is still looking forward to further penetration in better coverage, higher capacity and higher spectrum efficiency. Femtocell is a promising option in terms of cost-effectiveness, coverage and capacity improvement in hybrid network. Furthermore, the physical size of Femtocell allows it to be deployed at "Died zone" and improve the cell-edge user performance. This paper evaluates the performance of hybrid network with three different networks, universal FRF, FFR scheme and FFR with Femtocell power control scheme. The performance is evaluated base on SINR experienced by Macrocell users and Femtocell users. The ultimate goal of the research is to analyze the performance of hybrid network and further reduce the impact of the interference generated by Femtocells. The result shows that both FFR and power control schemes improve the SINR of cell edge Macrocell user.

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Gas turbines have become the dominant technology for power generation. They can be quickly assembled and put to service. They are convenient for engine exchange during system overhaul. The emission of NOx, SOx, CO, and particulates are also significantly law as compared to coal fired power plants. However, their maintenance cost is relatively high. The perceived best approach to reduce the cost is by using a proactive maintenance strategy in which a real-time diagnostics system plays a key role. The purpose of this paper is to review application of Orthonormal Basis Filters (OBFs) to fault detection and diagnostic systems design. The types of OBFs studied include Laguerre filters, Meixner filters, Kaurtz filters, Generalized OBF, and Markov-OBF. The combination of OBFs and computational intelligence methods (artificial neural network, fuzzy systems, and evolutionary optimization) are also highlighted. The review shows that, even though OBFs have been around for more than a decade, their application is limited to model identification only. As such, the only diagnostic problem revealed so far is that concentrating on stirred tank reactor. Therefore, to extend the use of OBFs to power plants, there needs to be further study in the context of power plants or specifically gas turbines.

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Stainless steel has been known for its high performance in manufacturing industries, oil and gas industries for minimum susceptibility to defect such as corrosion. Welding is a relevant joining process with heat application capable of altering the microstructure of corrosion resistance alloy CRA. Intergranular corrosion or weld decay is a welding defect in stainless steel due to sensitization known as the formation of chromium carbide on heat affected zone. Analysis of quenched sample in water , normalized sample after welding and heat treatment sample after welding were studied using SEM, hardness test and energy dispersive spectroscopy. The result obtained from SEM showed that there was more carbide precipitation on welded sample without quenching and heat treatment. EDS suggested that less composition of chromium at heat affected region of quench and heat treated sample.

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Nowadays, polycrystalline diamond compact (PDC) cutters performance dropped and affects the performance of drilling efficiency. The objective of this project is to investigate the effect of PDC cutters geometry and optimize their geometry features. An intensive study in PDC cutters geometry would help complete the section with high penetration and low wear rate. Relatively deepened analysis was carried out and come out with four important geometries features that can help in improving the penetration and reduce wear rate. They are chamfer angle, back rake angle, side rake angle and diameter. An appropriate optimization method that effectively controls all influential geometries factors during PDC cutters manufacturing is therefore critical. By adopting L9 Taguchi OA, the simulation experiment is conducted by using explicit dynamics finite element analysis (FEA). A1B1C3D1 are identified as the optimal geometry. The set of optimum geometries is identified as the following: chamfer angle of 15°, back rake angle of 0°, side rake angle of 30°, and diameter of 8 mm. The optimized PDC bit is expected to drill with high ROP that can reduce the rig time which in its turn, may reduce the total drilling cost.

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For lathe machining, pre-processing of the CAD data in Computer Aided Process Planning (CAPP) is essential since it is the link between CAD and CAM. Thus, cylindrical part model orientation is important to be determined in order to ensure the cutting parameter is correctly setup. Without proper orientation during the pre-processing of the cylindrical part model, further calculation and setup will be erroneous. Therefore, this paper will focus on initial part orientation and its processing in order to generate the delta volume of material to be removed for the lathe machining. By using feature based method, axis from normal vector of the recognized face from the cylindrical part model will be analyzed and configured to the required orientation. The algorithm will later generate the Sub Delta Volume for Finishing (SDVF) and Sub Delta Volume for Roughing (SDVR) of the part model. Consequently, volumes of the SDVF and SDVR will be estimated and compared.

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The growing interest and increasing installation capacity of photovoltaic (PV) power plants have raised the awareness of the necessity and importance of better managing the PV power plant system in order to harvest the optimal energy yield from PV power plant. To accomplish the above objectives, sufficient supervision and monitoring the health and performance of the PV system are necessary. This paper presented a remote PV plant in UTP to be monitored remotely. The performance ratio of the PV power plant is evaluated based on the data collected through Sunny Portal. The result obtained shows that the low performance ratio of the PV power plant not only as a result of less power demand from the load but also due to the state of charge of the battery bank. The PR of the PV power plant varies between 12.90% and 29.74%.

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The mechanism and efficiency of inhibition of the ethanol extract from galangal rhizome on the carbon steel API 5L X65 corrosion in an environment appropriateness to the conditions of a petroleum well had been studied using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (Tafel plot). The results showed that the ethanol extract from galangal rhizome is good inhibitor. The inhibition efficiency increased as the galangal extract concentration was increased and the inhibition reached its optimum at 200 ppm by 87%. Potentiodynamic polarization studies clearly reveal that galangal rhizome acts essentially as cathodic-type inhibitor. The experimental impedance data were analyzed according to a proposed equivalent circuit model for the electrode/electrolyte interface, its show that the corrosion inhibition mechanism took place through the adsorption process which formed an uneven protective film on the carbon steel surface. The adsorption took place physically following Langmuir's adsorption isotherm with the adsorption energy of -14.96 kJ.mol-1.

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The critical micelle concentration (CMC) of an imidazoline-based corrosion inhibitor in CO2-saturated 3% NaCl solution was determined via electrochemical measurements, namely electrochemical impedance spectroscopy and linear polarization resistance. The electrochemical parameters, polarization resistance (Rp) and charge transfer resistance (Rct), were plotted against the inhibitor concentrations. CMC of the studied inhibitor was determined from the plots, where the slope changed their values. Analysis of the impedance data revealed that the adsorbed inhibitor films had different structures, which were influenced by the concentration of the inhibitor.

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Road transport is a key source of ambient pollution especially in urban regions. While the moderation of engine-out emissions from road transport is seen as key in the improvement of global air quality, the overall sales of automobiles which contribute to air pollution keep rising. This trend has impelled global alertness due to the grave consequences of human exposure to air pollutants. In this light, a study was conducted to review the steps that are being taken by stakeholders in the automotive industry in contending the menace, in terms of research and development; the economy cum the suitability of the methods and devices that are being used in extenuating engine-out emissions. The study revealed that modern hardware based solutions such as high-pressure fuel injection equipment (FIE), sophisticated piezo-injectors, diesel particulate filters (DPF) and associated control systems are prevalent among the existing methods in use by engine designers and manufacturers. However, these technologies are prone to salient setbacks such as limited durability, high cost and difficulty in installing on extant engines, among others. Hence, much as the modern hardware based solutions had to offer, yet there were no one-size-fits-all solutions in place. Most of the existing solutions enjoy, at best, relative advantages over one another. Conversely, the significant revelation of this study were the plethora of prospects that the fuel based solutions and combustion based solutions could offer various stakeholders in the drive towards finding an enduring panacea to engine-out emissions. Therefore, there are room for progress in research and development toward finding sustainable solutions to the threats that engine-out emissions pose to humans and the environments.

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This study presents an investigation for the development of tool life models during heat assisted machining and conventional dry end milling of AISI 316L stainless steel. The models have been developed and compared in order to evaluate the influence of external heat in machinability improvement of AISI 316L stainless steel using uncoated WC-Co insert. Three (3) level factorial design was utilized in establishing the tool life models in terms of cutting speed and feed as independent cutting parameters. All of the machining tests have been conducted within particular range of parameters using 100% cutter immersion. Tool life and response contours of metal removal have been investigated. Analysis of variance (ANOVA) was used to determine the most significant factors affecting the tool life. The results show that cutting speed is the main influencing factor on the tool life of uncoated WC-Co insert during cutting at both elevated temperature condition or while conventional machining at room temperature of AISI 316L stainless steel. This is followed by the feed and the machining temperature in the same order.

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