bluuebunny/crossref_metadata_2025 huggingface dataset:
Porous Concrete Paving Blocks Using Coarse Aggregate
Authors: Nur Hidayah A.H. , Hasanan Md. Nor , Ramadhansyah P.J.
Published: June 2014

The objective of the study is to investigate the potential of using Porous Concrete Paving Blocks (PCPB) as a part of paving surface. Laboratory tests were conducted to compare and examine the effect of particle sizes of coarse aggregate. Two coarse aggregate sizes were selected; passing 8 mm retains 5 mm and passing 10 mm retains 8 mm. The fine aggregate was eliminated from mixes. The water to cement ratio used was 0.35. Compressive strength and skid resistance tests were performed to evaluate the properties of PCPB. The test results indicated that there was a reduction in the strength when coarse aggregate at different size was used. Scanning electron microscopy showed that voids, poor bonding and lack of adhesion at the boundaries of the aggregate with cement paste contributing to the low PCPB strength. However, both PCPB specimens provide 30 % to 40 % increase in skid resistance compared to Concrete Paving Blocks (CPB).
Effects of Stone Powder on Water Absorption and Biodegradability of Low Density Polyethylene/Palm Pressed Fibre Composite Film
Authors: Aris Noor Fatheyah , Majid Rohah A. , Hassan Wan Hasamudin Wan , Abd Rahman Mohd Faizal , Ng Yik Mun
Published: June 2014

This study was aimed to develop semi-biodegradable low density polyethylene (LDPE)/oil palm pressed fibre (PPF) composite film for agriculture applications such as nursery bag and plastic mulch. Biodegradability and water absorbency are among the properties need to be considered. Biocomposite plastic that rich with cellulose normally takes faster time to biodegrade as the fibres become the food source of microbes in soil. It also absorbs water easily due to hydrogen bonding formation between the cellulose and the water molecules. To have a balance between these properties is important to determine the service life of the film. Inorganic filler, stone powder with particle size of 37 micron was incorporated at 5, 10 and 15 phr into a mixture of LDPE/PPF, in order to improve both properties. The stone has undergone a catalytic transmuted process to produce fine powder using technology patented by Blapol Sdn Bhd. The mixture was compounded using twin screw extruder and palletized prior to blown into a sheet of film. The effects of stone powder onto water absorption and biodegradability were studied. The percentage of water absorption was decreased about 13 % with addition of 15 phr stone powder, which is thought due to the ability of stone powder to interfere the formation of hydrogen bonding between hydroxyl groups of cellulose and water molecules. Meanwhile, the weight loss in biodegradability test has been slow down, probably due to inorganic nature of stone powder that takes longer time to be digested by microbes in soil.
Effect of Salicylic Acid / Ethanol Treatment on Tensile Properties and Morphology Analysis of Recycled High Density Polyethylene / Wood Fiber Composites
Authors: Hanif M.P.M. , Supri A.G. , Firuz Z.
Published: June 2014

The effect of salicylic acid as a coupling agent on the tensile properties, and morphology analysis of recycled high density polyethylene/wood fiber (rHDPE/WF) composites were studied. Both composites rHDPE/WF and rHDPE/WFM (treatment with salicylic acid) were prepared using Brabender Plasticorder at temperature of 160°C and rotor speed of 50 rpm. The result indicated that rHDPE/WFM composites with salicylic acid exhibit higher tensile strength and modulus of elasticity but lower elongation at break than rHDPE/WF composites. The SEM micrographs showed that the wood fiber was more widely dispersed in the rHDPE matrix with addition of ethyl salicylate than rHDPE/WFM.
Tensile Strength of Untreated Napier Grass Fibre Reinforced Unsaturated Polyester Composites
Authors: M. Haameem J.A. , Majid M.S. Abdul , Ubaidillah E.A.H. Engku , Afendi Mohd , Daud R. , Amin N.A.M.
Published: June 2014

This paper describes the experimental investigation of the tensile strength of untreated Napier grass fibre reinforced polyester composites. Napier grass fibres were extracted trough conventional water retting process and used as reinforcing materials in the polyester composite laminates. Tensile tests were then conducted for the composite specimens from the laminates at 25% fibre loading using the electronic extensometer setup to obtain the tensile properties. The results show significant differences in tensile strength between random short fibres laminates and random long fibre laminates with the long fibres yield almost 45 % higher in the strength. The laminates also show higher maximum strength compared to other commonly available natural fibre composites with over 70 % increase in the maximum strength compared to the short kenaf fibre reinforced composites.
Comparison on the Characteristics of Bio-Based Porous Carbons by Physical and Novel Chemical Activation
Authors: Mohammed Jibril , Nasri Noor Shawal , Zaini Muhammad Abbas Ahmad , Dadum Usman Hamza , Ahmed Murtala Musa
Published: June 2014

There is significantly abundant portion of waste agricultural materials in the world serving as environmental challenge, however, they could be converted into useful value added products like activated carbon. Coconut shell based carbons were synthesized using physical activation by CO2 and chemical activation with potassium hydroxide and potassium acetate. The BET surface areas and pore volumes are 361m2/g and 0.19cm3/g for physical activation, 1353m2/g and 0.61cm3/g for activation with KOH and 622m2/g and 0.31cm3/g for potassium acetate activated carbon. From the Fourier Transform Infrared Spectroscopy analysis, hydroxyls, alkenes and carbonyl functional groups were identified with more prominence on the chemically activated porous carbons. Thermogravimetric analysis (TGA) results showed occurrence of moisture pyrolysis at 105°C, the pyrolysis of hemicellulose and cellulose occurred at 160–390°C and lignin at (390-650°C). Carbonization at 700°C and 2hrs had highest yield of 32%. Physical activation yielded lower surface area with approximately 88% micropores. On the other hand, chemically activation yielded higher surface area with elevated mesopores. The porous carbons can be applied to salvage pollution challenges.
Computational Investigation of Film Cooling from Cylindrical and Row Trenched Cooling Holes near the Combustor End Wall
Authors: Che Sidik Nor Azwadi , Ehsan Kianpour
Published: June 2014

This study was accomplished in order to investigate the effects of cylindrical and row trenched cooling holes with alignment angle of 0 degree and 90 degree at blowing ratio, BR = 3.18 on the film cooling performance adjacent to the endwall surface of a combustor simulator. In this research a three dimensional representation of Pratt and Whitney gas turbine engine was simulated and analyzed with a commercial finite volume package FLUENT 6.2. The current study has been performed with Reynolds-averaged Navier-Stokes turbulence model (RANS) on internal cooling passages. This combustor simulator combined the interaction of two rows of dilution jets, which were staggered in the stream wise direction and aligned in the span wise direction, with that of film cooling along the combustor liner walls. The findings of the study declared that with using the row trenched holes near the endwall surface, film cooling effectiveness is doubled compared to the cooling performance of baseline case.
Effect of Nano-Clay and their Dispersion Techniques on Compressive Properties of Unsaturated Polyester Resin
Authors: Fartini M.S. , Majid M.S. Abdul , Afendi Mohd , Daud R. , Mohamad Azizul
Published: June 2014

This paper aims to understand the relationship between processing parameters and compressive properties of nanoclay filled polyester resin (dispersion method and wt% of nanoclay particles). Unsaturated polyester resin with 0-5 wt% nanoclay content was prepared by hand mixing and through shears mixing of water bath shaker. Static uniaxial compression tests were conducted to investigate how the unsaturated polyester resins with nanoclay contents and processing will effect on the compressive stress-strain behaviour and compression properties. The experimental results show that the compressive strength and elastic modulus of nanomodified resin are significantly affected by type of mixing methods to prepare the specimens and the ratio of nanoparticles content during mixing. It was found out that the compressive strength and compressive modulus increase with the nanoclay content. The findings also indicate the dispersion of nanoclay by hand-mixed method yield higher compressive strength compared to that dispersed by water shaker bath.
The Oxidation Effect of Palm Oil Based Lubricant Using Four – Ball Tribotester
Authors: Syahrullail Samion , Zulhanafi Paiman
Published: June 2014

Lubrications industry is widely expand throughout the years. Well established mineral oil based promised the highest demand all over the world. But as the environmental concern is debated at most of world conferences, people are thinking to find the alternative for mineral oil replacement due to its non-biodegradable behaviour. The best suited source that having quite a par characteristic with mineral oil is vegetable oil. Vegetable oil is well known with its super bio-degradable characteristic. The source is renewable and does not require huge cost as compared to mineral and synthetic oil in term of exploration, development, production and transportation. Palm oil based is best suited among the vegetable oil series because of its stability and sources around the world. The major issue of palm oil based lubricant is low oxidative stability as the lubricant is commonly used at very high temperature and long shelf life application. Therefore some modification of molecule structure is needed by adding selected anti-oxidant at certain ratios. Tertier-butyl-hydroquinone (TBHQ) is used as anti-oxidantin this study. The results showing that a sufficient concentration of anti-oxidantprovides better solution for the low oxidative stability issues raised in palm oil based lubricants. The TBHQ also showed good characteristic in protecting two mating surfaces in wear scar analysis.
Transient Removal of Contaminants in Cavity of Mixed Convection in a Channel by Constrained Interpolated Profile Method
Authors: Che Sidik Nor Azwadi , Ahmad Sofianuddin A.S. , Ahmat Rajab K.Y.
Published: June 2014

Research in contaminated fluid flow becomes an interest in fluid dynamic research recently. In pipeline involving mix solution, residues can accumulate and deposit usually trapped inside the pipeline. This problem was studied by model it as a cavity channel flow with small particles inside the cavity enhanced by mixed convection. Constrained interpolated profile (CIP) was used to solve advection part of momentum equation while non-advection was solved by using finite difference for fluid part. Passive particles were located inside a square cavity in a channel represent contaminant in the cavity. Bottom wall of the cavity was heated to create mixed convection effect in the removal process and represent by various Grashof number. Validation study was done with experimental study at isothermal condition and show good comparison to present study. Higher removal process was observed at higher Grashof number. In the beginning of removal process, the contaminants were removed faster but after some period, the removal rate began to slow down and steady stated was achieved. At steady state, there will be no more removal of particle and it will remain circulate in the cavity.
Simulation Film Cooling in the Leading Edge Region of a Turbine Blade (Trench Effect on Film Effectiveness from Cylinder in Crossflow)
Authors: Bin Pairan Mohamad Rasidi , Binti Asmuin Norzelawati , bin Salleh Hamidon
Published: June 2014

Film cooling is one of the cooling techniques applied to the turbine blade. Gas turbine used film cooling technique to protect turbine blade from directly expose to the hot gas to avoid the blade from defect. The focus of this investigation is to investigate the effect of embedded three difference depth of trench at coolant holes geometry. Comparisons are made at four difference blowing ratios which are 1.0, 1.25 and 1.5. Three configuration leading edge with depth Case A (0.0125D), Case B (0.0350D) and Case C (0.713D) were compared to leading edge without trench. Result shows that as blowing ratio increased from 1.0 to 1.25, the film cooling effectiveness is increase for leading edge without trench and also for all cases. However when the blowing ratio is increase to 1.5, film cooling effectiveness is decrease for all cases. Overall the Case B with blowing ratio 1.25 has the best film cooling effectiveness with significant improvement compared to leading edge without trench and with trench Case A and Case C.
3D Finite Element Stress Analysis of Butt Adhesively Bonded Dissimilar Joint: Effect of Bond Thickness on Strength
Authors: Izzawati Basirom , Afendi Mohd , Afif M. , Nurhashima S. , Daud R. , Amin N.A.M. , Majid M.S. Abdul
Published: June 2014

The butt joint is the most studied type of adhesive joints in the literature. However, the joint strength prediction of joints is still a controversial issue as it involves a lot of factors that are difficult to quantify such as the yielding of the adherend, the plasticity of the adhesive and the bondline thickness. The present work is concerned with the three dimensional (3D) finite element stress analysis of butt adhesively bonded dissimilar joint. The objective of the present study was to analyse the effect of bond thickness on mechanical strength of butt adhesively bonded dissimilar joint. Aluminum alloy and steel were selected and five thicknesses were studied for each adherend: 0.2, 0.4, 0.6, 0.8, and 1.0 mm respectively. In order to quantify the influence of bondline thickness, adherend and durability of the butt joint, the 3D finite element models of ANSYS used to obtain the stress distributions. Mechanical properties of adhesive were determined by tensile test and ANSYS analysis. A statistical analysis of simulation results shows that the butt joint strength becomes stronger while the bondline gets thinner and adhesive gets tougher.
Friction and Wear Performance of Double Fraction Palm Olein Lubricant Using Pin-on-Disk Tribometer
Authors: Syahrullail Samion , Nuraliza Noorawzi
Published: June 2014

In the present of analysis, the wear rate and friction coefficient of various material is investigated and it were compared below the result of sliding speed wherever the equipment pin on disk machine has been used. Experiments were carried out with 2 totally different pins fabricated from aluminum alloy (AA5083) and pure aluminum (A1100). Experiments were conducted at normal load in step with according to testing, 10 N with totally different sliding speed 1, 3, 5 m/s ,continuous flow lubricating substance, double fraction palm olein (DFPO). The result shows that the material from pure aluminum higher material compared to the aluminum alloy in sliding condition. The morphology of the worn surface was ascertained using high optical research. The magnitude of the friction constant and wear rate are totally different in material depending on the speeds and additionally material.
Wear Characterization of Aluminum Lubricated with Palm Olein at Different Normal Load
Authors: Syahrullail Samion , Azmi Ahmad Mohd , Sapawe Norzahir , Khalid Amir
Published: June 2014

The pin-on-disk tester is a method used for investigating wear. The sliding mechanism between the pin and the disc experimentally creates wear. In this paper, the wear characteristics of an aluminium pin sliding on an SKD11 disc lubricated with double fraction palm olein were investigated. The pin was made from pure aluminum A1100. The results were compared with those of tests in which the disc was lubricated with commercial hydraulic oil. In both sets of experimental conditions, the normal load varied from 4 to 10 kg. Rotational speed was set to 1200 rpm. From this study, it was found that different types of lubricant affect the wear progression and friction coefficient during a sliding movement. The wear progression and friction coefficient depend also on the load applied, surface roughness, pressure applied and contact surface area.
Natural-Synthetic Polymer Blend Composite Scaffold for Bone Tissue Engineering: Study of In Vitro Degradation and Protein Adsorption
Authors: Sultana Naznin
Published: June 2014

In the current study, poly (hydroxy butyrate-co-hydroxy-valerate) (PHBV) was blended with a synthetic polymer poly (L-lactic acid) (PLLA), to control the degradation rate and process of composite scaffolds, as PLLA has a much higher degradation rate than PHBV. PHBV/PLLA blends were used as polymer matrices for composite scaffolds. Emulsion freezing / freeze-drying technique was used to fabricate composite scaffolds based on these blends and containing nanosized hydroxyapatite (nHA).In vitrodegradation tests of composite scaffolds were conducted by immersing samples in phosphate buffered saline (PBS) for various periods of time. It was found that the composition of polymer blends affected water uptake of scaffolds. Composite scaffolds exhibited enhanced adsorption of bovine serum albumin (BSA), a model protein.
Energy Analysis and Compressor Performance of Refrigerator System Using Programmable Logic Control (PLC)
Authors: Henry Nasution , Munan W.G. , Azhar Abdul Aziz , Sumeru Kasni , Zulkarnain Abdul Latiff
Published: June 2014

This project present an experimental test results on energy consumption of a refrigerator compressor triggered by using thermostat and programmable logic control (PLC). The PLC modulates the speeds of the compressor according to refrigeration load using inverter based on control law written in the PLC memory. The temperature setting for both thermostat and PLC were varied at-8 °C and-10 °C respectively. At-8°C the results indicate PLC consumed 4.45 to 6.79% less energy compared to thermostat setting. While at-10°C, the saving made through PLC is in the range of 6.43 to 12.88%. The fluctuation of freezer compartment is better when PLC controlled. As the energy input to compressor is lower due to the slower speed, this enhanced the coefficient of performance (COP).
Design and Development of Light Weight Engine Mounting for UTeM Formula Varsity Race Car
Authors: Rahmat Mohd Sabirin , Fauzi Ahmad , Mansor Muhd Ridzuan , Yamin Ahmad Kamal Mat , Tamaldin Noreffendy
Published: June 2014

This manuscript provides the design of the engine mounting for Formula Varsity Race Car. Several concept designs were generated for the engine mounting and the final design was selected through in 3D modeling software namely CATIA V5 CAD software during the design phase in this project. The Aluminum Alloy 6061 T6 was selected as the lightweight engine mounting material due to high strength, light weight and versatility with many manufacturing processes. The light weight engine mounting was analyzed using finite element analysis in bending and yield strength cases. The result of the engine mounting analysis showed that the engine mounting is able to perform safely as per design requirement.
Modelling and Validation of Vehicle Ride Comfort Model
Authors: Abu Bakar Saiful Anuar , Samin Pakharuddin Mohd , Azhar Abdul Aziz
Published: June 2014

This paper presents the development of a validated seven degrees of freedom (7DOF) of vehicle ride comfort model for a Malaysian made passenger vehicle. The mathematical equations of the ride model, which consists seven degrees of freedom, are represented. Ride test known as pitch mode test was conducted to validate the reliability of the developed simulation model. The test was conducted using a fully instrumented test vehicle where the sensors installed were used to gather information on vehicle’s vertical and pitch motions. The data collected are used to tune certain parameters value in the simulation model, to ensure the developed simulation model can be used to represent the ride dynamics behaviour of the test vehicle. The result shows that the developed simulation model is capable in representing the ride dynamics behaviour of the test vehicle.
Effects of Biodiesel Derived by Waste Cooking Oil on Fuel Consumption and Performance of Diesel Engine
Authors: Khalid Amir , Mudin Azim , Jaat M. , Mustaffa Norrizal , Manshoor Bukhari , Fawzi Mas , Razali Mohd Azahari , Ngali Mohd Zamani
Published: June 2014

Biodiesel is the alternate fuel which is derived from renewable sources either is vegetable oils or animal fats. For that reason, the vehicle run by Bio-diesel Fuel (BDF) has been a potential option and the alternative sources of fuel are receiving a lot attention in the automotive industry. The use waste cooking oil (WCO) biodiesel as an alternative fuel in engines has advantages from both economic and the emissions of carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas. Purpose of this study is to investigate the effects of waste cooking oil blended fuel, engine speed and test load conditions on the fuel properties, combustion characteristics and engine performance. The engine speed was varied from 1500 to 3000 rpm, load test condition varied by dynapack chassis dynamometer in 0, 50 and 100% and blends of 5(WCO5), 10(WCO10) and 15vol%(WCO15) waste cooking oil with the diesel fuel. The results showed that the use of WCO as biodiesel results in a higher fuel consumption rate, especially at low engine speed and full load condition.
Arm Effect on Performance of Vertical Axis Current Turbine Using RANS Simulation
Authors: Behrouzi Fatemeh , Malik Adi Maimun Abdul , Nakisa Mehdi , Ahmed Yasser Mohamed
Published: June 2014

Climate changing, electrical demands, rising diesel fuel prices, as well as fossil fuel-based energy is limited and in fact is depleting ,are subjects to use of renewable technologies. Among the different renewable energy technologies, hydro power generation (large and small scale) is the prime choice in terms of contribution to the world's electricity generation by using water current turbines.CFD simulation using two equations turbulence model was carried out to compare performance of conventional savonius turnine and new consept of vertical axis turbine. This study was coducted to reach suitable desigh of vertical axis turbines for capturing more kineticenergy of current via of others esspecially,low current speed.
Implementation of Wireless Thermal Camera Remote Control System
Authors: Wooi Chin Leong , Abdul-Malek Zulkurnain , Mashak Saeed Vahabi
Published: June 2014

Thermographic inspection is a very safe and non-invasive monitoring technique, widely used in electrical substations and other power plants. A thermal image can be obtained to help in identifying abnormal heating regions in power equipment. Under high voltage circumstances, it is a hazard for personals to capture the image at a close distance from the power equipment. This paper described the development of a remote control monitoring system for a thermal camera. XBEE is a new and popular protocol for wireless communication because of its low power assumption, large network capability and the ability to organize a network automatically. 10 samples data are collected within the 30m and the successful transfer rate reached 98.89%. Remote control of thermal camera helps human keep distance from the high electric field and at the same time convenient for a user to conduct online condition monitoring in order to prevent any accident in power station.
Effect of Ambient Temperature Zinc Oxide Surge Arrester Condition Monitoring
Authors: Abdul-Maleka Zulkurnain , Khavari Amir Hesam , Hadi Nabipour Afrouzi , Vahabi-Mashak Saeed
Published: June 2014

Various methods have been developed to monitor surge arrester condition and predict the probable interruption which can be caused by the failure of surge arresters. This paper aims to carry out experimental and simulation work to find the relationship between the aging level, arrester surface temperature and ambient temperature. COMSOL simulation software was used for the modeling of 120kV rated gapless ZnO surge arresters. It is observed from both the simulation analysis and experimental data that the leakage current and temperature increase as a consequence of an increase in the applied voltage across the arrester. The thermal profile of the ZnO surge arrester changes depending on the aging level and the ambient temperature. The surface temperature simulation results compare well with the experimental results, for the case of varying aging levels.
Chemical Analysis on the Effect of Pulsed Electric Fields in Pineapple Juices Preservation
Authors: Dastgheib Ali Mohammad , Buntat Zolkafle , Sidik Muhammad Abu Bakar
Published: June 2014

The application of high voltage electric field for preservation of fruit juices has a promising scope in the food industry. The pulsed electric field (PEF) is an innovative non- thermal technique and free from bio-toxic effects. The technique has a viable solution of the problem yet faced in the food industry to prolong life and preserve and maintain quality with natural properties of the liquid food and beverages. In this study, we have treated the pineapples juice samples by different strengths of pulsed electric field such as 10, 20 and 30kV/cm for 5 minutes in each test. This study used new design of helix treatment chamber with three different lengths of 20, 30and 50cm. In these experiments, all samples were kept in same and normal condition with a temperature around 25-26 andthe humidity was between 55 and 65%. Then the observation based on chemical tests such as pH, conductivity, salinity and total dissolved solids (TDS) was recorded for all samples before and after the test. Based on results obtained by chemical parameters suggest that the injection on pulsed electric field of 30 kV/cm by the 50 cm treatment chamber has the best effect on pineapple juices characteristic as compared to the other value. The result of this experiment is encouraging and supportive of the better way for pasteurization the pineapple juices and increasing longevity of pineapple juices.
The Effect of Magnitude and Shape of Applied Voltage on the Partial Discharge Behavior in Cylindrical Cavity within a Dielectric Material
Authors: Hadi Nabipour Afrouzi , Hadi Nabipour-Afrouzi , Abdul-Malek Zulkurnain , Vahabi-Mashak Saeed , Khavari Amir Hesam
Published: June 2014

One of the important phenomena which is important in equipment when they are under high voltage stress is Partial discharge (PD). Partial discharge measurement is commonly used to evaluate the performance of the insulation in high voltage system. Modeling of the discharge in insulation can give a better understanding of this important phenomenon. A cavity within a dielectric material is a highly stressed area and the ideal place for starting partial discharge and breakdown. The applied voltage is one of the important factors that PD activity is influenced by that. Previous studies have considered the behavior of PD activity in a spherical cavity at 50Hz of sinusoidal applied voltage. However, still not so much work on the simulation of the PD activity in the cavity under different condition. Also, there is little data are available on the effect of parameters on the PD activity. This paper describes the behavior of PD activity as a function of applied voltage in a cylindrical cavity within a homogeneous dielectric. COMSOL and MATLAB software were used to carry out the simulation based on the finite element method (FEM). The number of PDs per cycle changed with different applied voltage so the highest number of PD at 20kV and the lowest value at 8kV. The maximum PD magnitude is raised from 1200pC at 8kV to 2400pC at 20kV applied voltage. The number of PD is most prevalent for sinusoidal followed by triangular waveform and then sawtooth. Comparison of the simulation results and experimental results are in good agreement. The result can help the researcher to understand more about the characteristics and behavior of partial discharge. Which may help the insulation diagnostic testing or condition monitoring.
Surge Arrester Leakage Current Analysis by Using Particle Swarm Optimization Technique
Authors: Saeed Vahabi Mashak , Abdul-Malek Zulkurnain , Hadi Nabipour Afrouzi , Wooi Chin Leong , Khavari Amir Hesam
Published: June 2014

Surge arresters, as protective equipment, are used to limit any overvoltage in a power system resulting from various sources. The surge arrester affects from degradation due to the continuous operating voltage system as well as due to repeated lightning current discharge. Therefore, condition monitoring and health diagnostics of surge arresters are a necessary issue. Hence, as a feasible solution, a condition monitoring based on leakage current measurement techniques was selected to tackle the problem of age diagnostics of surge arresters. The Particle Swarm Search Algorithm was introduced as a method for extracting the third harmonic resistive component, Ir3rd, from the total leakage current. To employ this method for extracting Ir3rd, codes were developed in Matlab. The setting of Particle Swarm Search Algorithm was configured for extracting Ir3rd and accuracy of 94% was obtained.
Power Generator of Electrical Discharge Machining (EDM) System
Authors: Erawan Minhat Ade , Yahya Azli , Nor Hisham Khamis , Syahrullail Samion , Zurkarmawan Abu Bakar , Trias Andromeda
Published: June 2014

Electrical Discharge Machining (EDM) is a non-conventional manufacturing process of removing materials. The uniqueness of EDM process is the removal of the unwanted materials without direct contact between the electrode and workpiece. EDM power generator provides power source of EDM system. It supplies voltage and current to produce spark erosion. Power supply and pulse generator are two important parts in EDM power generator. By choosing the proper power supply and pulse generator to the application, a great result for Material Removal Rate (MRR) can be achieved. Efficiency of EDM power generator depends on the configurations of power supply used. This study reviews and summarizes some previous development of EDM power generator and their effectiveness.
Numerical Simulation of Wind Flow Structures and Pollutant Dispersion within Street Canyon under Thermally Unstable Atmospheric Conditions
Authors: Witri Afiq Muhammad Yazid , Che Sidik Nor Azwadi , Mohamed Salim Salim
Published: June 2014

Numerical studies were conducted to envisage the wind flow structures in street canyon for differential heated wall and Richardson numbers. Two-equation turbulence models, namely the Standard k-ε, Renormalization Group (RNG) k-ε and Realizable k-ε were applied to investigate the effect of flow structure on pollutant dispersion in a square street canyon. The obtained results demonstrate that the differentially heated wall/floor gives significant effects on the wind flow field compared with those under isothermal conditions. At low Richardson number, vortex intensification was observed for the case of ground or leeward heated wall. Meanwhile, for the case of windward heated wall, the ventilation was much reduced due to the buoyancy force that produces upward motion near the wall to form the secondary vortex. At higher Froude number (convective flows) case, the buoyancy flow has no discernible effects on the flow structures.
Keywords— Street canyon; thermal flow; wind flow structures; pollutant dispersion; turbulence models
Validate of Local Exhaust Ventilation (LEV) Performance through Analytical, Experimental and Computational Fluid Dynamic (CFD): A Case Study Model
Authors: Hasan Nor Halim , bin Said Md Radzai , Leman Abdul Mutalib , Binti Asmuin Norzelawati
Published: June 2014

Local Exhaust Ventilation (LEV) system are a tools in engineering control stated in Occupational safety and health management system where to protect a workers from inhale the contaminant that will effected to their breathing system. To design, construct and applications of LEV are followed an international guidance such as American Conference of Governmental Industrial Hygienist (ACGIH).A sample two inlet and outlet of LEV system are design based on ACGIH including hood, ducting branch, main ducting, elbow, y-tee, fan and stack. The design is based on ACGIH standard with assuming the contaminant are fumes with 2 inlet of 6 inches round duct and outlet is 8 inches round type. The result from calculation according to the size of branch duct size, main duct size, fan capacity and stack size. Other data contribute are velocity and pressure drop along the duct.LEV system are design by using Solid Work Software and export file to Ansys 14.0, where the simulation are used to compare the result of velocity and differentials of pressure before proceeds to construct the system as additional in design process as follow in ACGIH Standard. Finally result of this study indicated that no significant different of the result of velocity along the ducting between design, experimental and compare with the simulation results.Where the analysis shows different compare with analytical almost below 30% and further study on comparative different of static pressure should carry out.
Prediction of Wind Flow around High-Rise Buildings Using RANS Models
Authors: Behrouzi Fatemeh , Sidik Nor Azwadi Che , Malik Adi Maimun Abdul , Nakisa Mehdi
Published: June 2014

Recently, CFD (Computational Fluid Dynamics) is being increasingly used to investigation of the flow around high-rise buildings. In this study, prediction of wind flow around two cases high-rise buildings model placed within the surface boundary layer were carried out using various turbulence models. The accuracy of two-equation turbulence models were compared with experimental data of Architectural Institute of Japan (AIJ).as a result, all two-equation models are shown overestimation the reattachment length behind the buildings.
The Role of the Syk/Shp-1 Kinase-Phosphatase Equilibrium in B Cell Development and Signaling
Authors: Alsadeq Ameera , Hobeika Elias , Medgyesi David , Kläsener Kathrin , Reth Michael
Published: June 2014

Signal transduction from the BCR is regulated by the equilibrium between kinases (e.g., spleen tyrosine kinase [Syk]) and phosphatases (e.g., Shp-1). Previous studies showed that Syk-deficient B cells have a developmental block at the pro/pre–B cell stage, whereas a B cell–specific Shp-1 deficiency promoted B-1a cell development and led to autoimmunity. We generated B cell–specific Shp-1 and Syk double-knockout (DKO) mice and compared them to the single-knockout mice deficient for either Syk or Shp-1. Unlike Syk-deficient mice, the DKO mice can generate mature B cells, albeit at >20-fold reduced B cell numbers. The DKO B-2 cells are all Syk-negative, whereas the peritoneal B1 cells of the DKO mice still express Syk, indicating that they require this kinase for their proper development. The DKO B-2 cells cannot be stimulated via the BCR, whereas they are efficiently activated via TLR or CD40. We also found that in DKO pre-B cells, the kinase Zap70 is associated with the pre-BCR, suggesting that Zap70 is important to promote B cell maturation in the absence of Syk and SHP-1. Together, our data show that a properly balanced kinase/phosphatase equilibrium is crucial for normal B cell development and function.
T Cell–Intrinsic Function of the Noncanonical NF-κB Pathway in the Regulation of GM-CSF Expression and Experimental Autoimmune Encephalomyelitis Pathogenesis
Authors: Yu Jiayi , Zhou Xiaofei , Nakaya Mako , Jin Wei , Cheng Xuhong , Sun Shao-Cong
Published: June 2014

The noncanonical NF-κB pathway induces processing of the NF-κB2 precursor protein p100, and thereby mediates activation of p52-containing NF-κB complexes. This pathway is crucial for B cell maturation and humoral immunity, but its role in regulating T cell function is less clear. Using mutant mice that express a nonprocessible p100, NF-κB2lym1, we show that the noncanonical NF-κB pathway has a T cell–intrinsic role in regulating the pathogenesis of a T cell–mediated autoimmunity, experimental autoimmune encephalomyelitis (EAE). Although the lym1 mutation does not interfere with naive T cell activation, it renders the Th17 cells defective in the production of inflammatory effector molecules, particularly the cytokine GM-CSF. We provide evidence that p52 binds to the promoter of the GM-CSF–encoding gene (Csf2) and cooperates with c-Rel in the transactivation of this target gene. Introduction of exogenous p52 or GM-CSF to the NF-κB2lym1 mutant T cells partially restores their ability to induce EAE. These results suggest that the noncanonical NF-κB pathway mediates induction of EAE by regulating the effector function of inflammatory T cells.
Chronic widespread pain in spondyloarthritis
Authors: Atzeni F. , Boccassini L. , Di Franco M. , Alciati A. , Marsico A. , Cazzola M. , Cassisi G. , Sarzi-Puttini P.
Published: June 2014

The pain associated with spondyloarthritis (SpA) can be intense, persistent and disabling. It frequently has a multifactorial, simultaneously central and peripheral origin, and may be due to currently active inflammation, or joint damage and tissue destruction arising from a previous inflammatory condition. Inflammatory pain symptoms can be reduced by non-steroidal anti-inflammatory drugs, but many patients continue to experience moderate pain due to alterations in the mechanisms that regulate central pain, as in the case of the chronic widespread pain (CWP) that characterises fibromyalgia (FM). The importance of distinguishing SpA and FM is underlined by the fact that SpA is currently treated with costly drugs such as tumour necrosis factor (TNF) inhibitors, and direct costs are higher in patients with concomitant CWP or FM than in those with FM or SpA alone. Optimal treatment needs to take into account symptoms such as fatigue, mood, sleep, and the overall quality of life, and is based on the use of tricyclic antidepressants or selective serotonin reuptake inhibitors such as fluoxetine, rather than adjustments in the dose of anti-TNF agents or disease-modifying drugs.
Simultaneous dual pathology in lymph node
Authors: Mandal Prakas Kumar , Sarkar Supriyo , Ghosh Malay Kumar , Bhattacharyya Maitreyee
Published: June 2014

[Abstract]Tubercuous lymphadenitis and Non Hodgkins’ Lymphoma are common in India. As both diseases can occur in elderly persons there is a definite chance of co-existence of both diseases; but that coexistence has not been reported. Here we present a unique case in an elderly woman who had synchronous double pathology of tuberculosis (TB) and Diffuse Large B cell Lymphoma (DLBCL) of the lymph nodes.  Key words:- lymph nodes, tuberculosis (TB), Diffuse Large B cell Lymphoma (DLBCL).
IMMUNOLOGICAL DEREGULATION IN HODGKIN’S DISEASE
Authors: Di Raimondo Francesco , La Nasa Giorgio
Published: June 2014

Hodgkin’s Disease (HD) has a unique histology since only a few neoplastic cells are surrounded by inflammatory accessory cells that in the last years have emerged as crucial players in sustaining the course of disease. In addition, recent studies suggest that the abnormal activity of these inflammatory cells (such as deregulation in Tregsignaling, expansion of myeloid derived suppressor cells, HLA-G signaling and NK dysfunction) may have prognostic significance. This review is focused on summarizing recent advanced in immunological defects in HD with translational implications.
African Primary Care Research: Qualitative interviewing in primary care
Authors: Reid Steve , Mash Bob
Published: June 2014

This article is part of a series on African Primary Care Research and focuses on the topic of qualitative interviewing in primary care. In particular it looks at issues of study design, sample size, sampling and interviewing in relation to individual and focus group interviews.There is a particular focus on helping postgraduate students at a Masters level to write their research proposals.
A three musketeering approach to pastoral care: Reflections on collaboration between pastoral care, narrative therapy and positive psychology
Authors: Brunsdon Alfred R.
Published: June 2014

In the current times of change, deconstruction and ever-growing relativisation, pastoral praxis finds itself in methodological limbo. Pastoral practitioners currently face the challenge of effectively reaching postmodern people through the pastoral process. This challenge is intensified by the innate tension between revelation and experience in pastoral theology as well as the philosophical migration from modernism to postmodernism, which necessitates an on-going rethinking of pastoral praxis. This research investigates a collaborative approach between pastoral care, narrative therapy and positive psychology as a possible method for dispensing pastoral care. A broad outline of these approaches as well as their underlying philosophical frameworks is contemplated in order to evaluate their suitability for a pastoral collaboration. Markers for a collaborative model are suggested where the narrative and positive psychology are employed as strategies in a so-called three- musketeering approach to pastoral care.
Thoracic Epidural Teratoma: Case Report and Review of the Literature
Authors: Quon Jennifer L. , Grant Ryan A. , Huttner Anita J. , Duncan Charles C.
Published: June 2014

Purpose

Spinal teratomas comprise a rare subset of spinal cord tumors, and here, we describe an even rarer childhood thoracic extradural-intracanalicular teratoma. The clinical presentation, management, and pathophysiology of these tumors are reviewed to promote recognition and guide treatment of these lesions.

Methods

We report the case of a 21-month-old boy who presented with marked spasticity, as well as failure to ambulate and meet motor milestones. Additionally, we provide a literature review of spinal teratomas, including their clinical presentation, work-up, pathophysiology, and underlying genetics.

Results

An MRI of the spine revealed a large dorsal epidural tumor extending from T3 to T10 with heterogeneous contrast enhancement and severe spinal cord compression. The tumor was resected revealing a cystic mass with tissue resembling hair, muscle, as well as cartilage; pathology confirmed the diagnosis of teratoma. Gross total resection was achieved, and the child eventually gained ambulatory function.

Conclusions

Given that spinal teratomas are rare entities that can present with significant neurologic compromise, they must remain on clinicians’ differentials. Unfortunately, the exact origin of these tumors remains inconclusive and requires further investigation.
Electrocardiographic and cardiovascular diagnostic characteristics of patients receiving long-term opioid therapy for pain
Authors: Mason, MD Jay W. , Schwertschlag, MD, PhD Ullrich S. , Klutzaritz, BS Vicki , Canafax, PharmD Daniel M.
Published: June 2014

Objective: To examine cardiovascular and electrocardiogram (ECG) abnormalities seen in patients with chronic pain receiving long-term opioid therapy and to compare them with findings in normal subjects.Setting: Clinical pharmaceutical drug trial in a phase I pharmacology unit (normal subjects) and multiple phase 2b study sites (pain patients).Patients: Four hundred sixty-one pain patients with constipation due to longterm opioid therapy who were screened for a clinical trial of an investigational treatment for opioid-induced constipation.Interventions: None; all data used in this study were obtained prior to drug treatment.Main outcome measures: This is a retrospective analysis of ECG abnormalities and clinical cardiovascular abnormalities in study participants compared with those in a normal reference group of 36,999 subjects.Results: Numerical ECG values were modestly but not clinically significantly different in the pain patients requiring opioids (mean heart rate +1.5 BPM, PR +5.2 milliseconds, QRS - 4.7 milliseconds, and QT corrected for heart rate using the Fridericia formula +7.2 milliseconds). The largest difference in ECG diagnoses between the two groups was a fivefold greater incidence of previous myocardial infarction in the pain patient group (4.1 percent vs 0.8 percent). In addition, 50 percent of the pain patient group had a clinical cardiovascular diagnosis.Conclusions: Patients with significant chronic pain requiring opioids have underlying clinical disorders that may be associated with abnormal cardiovascular physiology and ECGs. Clinicians who manage patients with chronic pain should be aware of the higher incidence of cardiovascular disease in this group.
Comparison of mixed layer heights from airborne high spectral resolution lidar, ground-based measurements, and the WRF-Chem model during CalNex and CARES
Authors: Scarino A. J. , Obland M. D. , Fast J. D. , Burton S. P. , Ferrare R. A. , Hostetler C. A. , Berg L. K. , Lefer B. , Haman C. , Hair J. W. , Rogers R. R. , Butler C. , Cook A. L. , Harper D. B.
Published: June 2014

Abstract. The California Research at the Nexus of Air Quality and Climate Change (CalNex) and Carbonaceous Aerosol and Radiative Effects Study (CARES) field campaigns during May and June 2010 provided a data set appropriate for studying the structure of the atmospheric boundary layer (BL). The NASA Langley Research Center (LaRC) airborne high spectral resolution lidar (HSRL) was deployed to California onboard the NASA LaRC B-200 aircraft to aid in characterizing aerosol properties during these two field campaigns. Measurements of aerosol extinction (532 nm), backscatter (532 and 1064 nm), and depolarization (532 and 1064 nm) profiles during 31 flights, many in coordination with other research aircraft and ground sites, constitute a diverse data set for use in characterizing the spatial and temporal distribution of aerosols, as well as the depth and variability of the daytime mixed layer (ML) height. The paper describes the modified Haar wavelet covariance transform method used to derive the ML heights from HSRL backscatter profiles. HSRL ML heights are validated using ML heights derived from two radiosonde profile sites during CARES. Comparisons between ML heights from HSRL and a Vaisala ceilometer operated during CalNex were used to evaluate the representativeness of a fixed measurement over a larger region. In the Los Angeles basin, comparisons of ML heights derived from HSRL measurements and ML heights derived from the ceilometer result in a very good agreement (mean bias difference of 10 m and correlation coefficient of 0.89) up to 30 km away from the ceilometer site, but are essentially uncorrelated for larger distances, indicating that the spatial variability of the ML height is significant over these distances and not necessarily well captured by limited ground stations. The HSRL ML heights are also used to evaluate the performance in simulating the temporal and spatial variability of ML heights from the Weather Research and Forecasting Chemistry (WRF-Chem) community model. When compared to aerosol ML heights from HSRL, thermodynamic ML heights from WRF-Chem were underpredicted in the CalNex and CARES regions, shown by a bias difference value of −157 m and −29 m, respectively. Better agreement over the Central Valley than in mountainous regions suggests that some variability in the ML height is not well captured at the 4 km grid resolution of the model. A small but significant number of cases have poor agreement when WRF-Chem consistently overestimates the ML height in the late afternoon. Additional comparisons with WRF-Chem aerosol mixed layer heights show no significant improvement over thermodynamic ML heights, confirming that any differences between measurement and model are not due to the methodology of ML height determination.