bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Hydroxyl Terminated Epoxidized Natural Rubber as a Binder for Solid Rocket Propellant
Authors: binti Abdul Razak Nor Erma Shuhadah , bin Mohd Nor Hussin , bin Wan Ali Wan Khairuddin
Published: November 2014

Hydroxyl terminated epoxidized natural rubber (HTENR) was prepared by oxidative degradation of epoxidized natural rubber (ENR) with cobalt (II) acetylacetonate (co (II) aa) as a chemical agent in toluene as a solvent. Different of cobalt amount and reaction time used to study the effect on molecular weight. It was found that the number average molecular weight (Mn) and weight average molecular weight (Mw) depended on the reaction time and cobalt amount. Burning rate of solid propellant based on HTENR binder is 2.93mm/s which is approximately same with HTPB binder with 3.0mm/s. As a conclusion, HTENR binder is suitable to be used as a binder for solid rocket propellant.
Tensile Properties of Hybrid Sugar Palm/Kenaf Fibre Reinforced Polypropylene Composites
Authors: Bachtiar Dandi , Siregar Januar Parlaungan , bin Sulaiman Ahmad Syahrizan , bin Mat Rejab Mohd Ruzaimi
Published: November 2014

Study on hybridization of two types of natural fibres reinforced thermoplastic composites was an alternative option in research on natural composites. This paper presents the investigation on tensile properties of combining sugar palm and kenaf fibres reinforced polypropylene composites. The hybrid composites were prepared with different amounts of fibres (i.e. 10%, 20% and 30% by weight percent) while the ratios between sugar palm and kenaf fibre are 30:70, 50:50 and 70:30. The composites have been fabricated using melt mixer technique and followed by compression molding process. The specimens were cut according ASTM Standard D638 for conducting the tensile testing. The results shown that tensile strength of composites tend to decreased when the content of loading fibres increased. Among the composites with different ratios, the hybrid composites that contain more kenaf fibres exhibit the higher value in tensile strength than the composites that contain more sugar palm fibres.
Surface Characteristics of Porous Coconut Shell Carbon Impregnated with Bimetallic Catalysts
Authors: Ibrahim Yakub , Khairul Anwar Mohd Said , Sutan Norsuzailina Mohamed , Taufiq-Yap Yun Hin , Surahim Mahmud
Published: November 2014

Selective Catalytic Reduction catalyst (Cu-Mn/CSC) was derived from coconut shell carbon (CSC). The bimetallic catalysts, Copper and Manganese (Cu-Mn), were deposited onto CSC using wet impregnation technique while the calcination stage was performed under low temperature ambient air. The samples were then characterized using nitrogen adsorption-and-desorption, carbon dioxide temperature-programmed desorption, ammonia temperature-programmed desorption, hydrogen temperature-programmed reduction as well as scanning electron microscopy. The results showed that the synthesis process increased the external surface area and regulated the distribution of slit-shape pores on Cu-Mn/CSC. Besides, Cu-Mn was found to be reduced and the surface has more acidic groups compared to basic. These findings indicated the potential of using CSC as a precursor for NOx-Selective Catalytic Reduction catalyst.
Investigations on Composite Flexural Behaviour with Inclusion of CNT Enhanced Silica Aerogel in Epoxy Nanocomposites
Authors: Mazlan Norkhairunnisa , Termazi Norasiah , Abdul Rashid Suraya , Rahmanian Saeed
Published: November 2014

Growing of carbon nanotubes (CNT) on the surface of highly porous silica aerogel offers a means to tailor the mechanical properties between fiber and matrix interface of a composite. The growth of CNT on the silica aerogel surface was done using chemical vapour deposition (CVD) technique. In this study, the morphology of the produced CNT was investigated by Scanning Electron Microscope (SEM) for confirmation of CNT existence. The composite were then prepared by shear mixing technique. Flexural strength of the CNT-SilAe/Epoxy nanocomposite were assessed as a function of CNT-SilAe concentration and dispersion in epoxy matrix. The flexural modulus and strength of epoxy composite increased significantly with inclusion of CNT-SilAe. The optimum loading of CNT-SilAe in epoxy composites was attained at 2 wt%, where the improvement in flexural strength and modulus were 8% and 11%, respectively.
Fabrication of Poly Caprolactone (PCL) Based Microspheres for Drug Delivery and Tissue Engineering Application
Authors: Nyoke Goon Chia , Sultana Naznin
Published: November 2014

This paper reports the fabrication of poly (caprolactone) (PCL) based biodegradable microspheres using freeze-drying technique for drug delivery and tissue engineering application. Microspheres play an important role in tissue engineering and drug delivery applications. The properties can determine the success or failure of the development of the materials. Biodegradable and biocompatible synthetic polymer, PCL was used to fabricate biodegradable microspheres in this study. Through a double emulsion and freeze-drying technique, the microspheres were produced. Different concentrations of polymers were used to fabricate the microspheres. The microspheres were characterized using different techniques.
Thermal Properties Determination of Polypropylene/Rice Straw Biocomposite Foam via DSC
Authors: Tugiman Nazuha , Mohamad Zurina , Wan Abdul Rahman Wan Aizan
Published: November 2014

Polymer foam biocomposites based on polypropylene/rice straw (PP/RS) were successfully prepared by using an extrusion foaming process. The compounding of PP and RS was performed in a twin-screw extruder which was blended with crosslinker; dicumyl peroxide (DCP) and blowing agent; azodicarbonamide (AZ). The foam biocomposite was extruded at temperatures of 180, 190, 190 and 200 °C respectively, which set from the feeder until the die zone. The thermal properties were investigated by using differential scanning calorimetry (DSC).
Pyrolysis of Empty Fruit Bunch (EFB) in a Vertical Fixed Bed Reactor
Authors: Azduwin K. , Ridzuan Mohd Jamir Mohd , Mohamed A.R. , Hafis S.M.
Published: November 2014

Uncontrolled uses of fossil fuels lead to serious energy problems and since Malaysia is one of the largest producers of palm oil in the world, it has caused a lot of waste such as empty fruit bunches (EFB) which can actually be converted into renewable energy via pyrolysis. In this work, firstly the characterizations of the EFB were analyzed such as elemental, proximate and component analysis. The pyrolysis experiment of empty fruit bunch using vertical fixed-bed reactor was conducted at different pyrolysis temperature range from 300 - 600 °C and the particle size of EFB was also varied from 125-250 μm with constant nitrogen flow rate of 100 cm3/min, heating rate of 30 °C/min, and 30 minutes hold time. For the effect of temperature, the optimum pyrolysis temperature was 500 °C to produce maximum yield of bio-oil which is 39.2 wt. % while 46.13 wt. % is the highest bio-oil yield produced at size of 500-710 μm for the effect of particle size. The analysis on bio-oil was conducted by using Fourier Transform Infrared (FTIR) with the results shows for the presents of phenol/alcohol group, ketones and C-O bond. The bio-oil obtained is in the acidic condition with pH 3.5.
Green Synthesis and Characterization of Hydroxyapatite from Fish Scale Biowaste
Authors: Sukaimi Jamali , Hamzah Sofiah , Ghazali Mohd Sabri Mohd
Published: November 2014

The present study was undertaken to study the effect of calcinate temperature on characteristics of hydroxyapatite synthesized from the fish scale (FHAp). The FHAp calcined at different temperatures starting from 100 up to 300 °C. The structures of FHAP were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The analytical results show that the FHAp quality increased as the calcin temperature increased. The FHAp displayed excellent characteristics in term of particle size, morphology and properties and crystalinity after calcined at 300 °C, FHAp 300. From this study, it founded that 300 °C is the lowest calcin temperature could be applied to synthesize high quality of HAp from fish scale biowaste.
Pyrolysis of Palm Pressed Fibre (PPF) towards Maximizing Bio-Oil Yield in a Fixed-Bed Reactor
Authors: Azduwin K. , Ridzuan Mohd Jamir Mohd , Mohamed A.R. , Hafis S.M.
Published: November 2014

Increasing demand of fossils fuel for many purposes has cause for the limited sources which lead to the finding for new alternative energy based on biomass because of its sustainable properties. Palm-pressed fibre (PPF) is the biomass waste from palm oil processing which has use minimally for boiler to generate heat. The pyrolysis of PPF in a fixed-bed reactor has the potential as an alternative for its conversion into bio-oil, bio-char and gas. The characterization of PPF where involves elemental analysis, proximate analysis, calorific analysis and component analysis. The pyrolysis of the PPF was performed in the fixed-bed reactor at temperature between 300 - 700 °C and heating rate in the range of 10-70 °C/min with constant flow of nitrogen at 100 cm3/min and 30 minutes hold time.The highest bio-oil yield produced was 44.98% at optimum temperature 500°C and heating rate 30°C/min. By analysis the bio-oil using Fourier transform infrared spectroscopy (FTIR), it was found to contains alkenes, ketones, polymeric hydroxyl compound, carboxylic acid, aldehyde and water.
Impacts of Implementation of IBS Score Regulations of CIDB on the Concrete Volumes Required for Building Projects in Malaysia
Authors: Ahmed Sami Mustafa M.E. , Zawawi Noor Amila Wan Abdullah , Ghazali Zulkipli B.
Published: November 2014

Improvement of construction industry will contribute to the economy of Malaysia because it is one of the five sectors used to calculate the national GDP. This fact is encouraging the Construction Industry Development Board (CIDB) of Malaysia to prepare many development plans like Roadmap 2003-2010, CIMP 2006-2015, and Roadmap 2011-2015. Adoption of the Industrialized Building System (IBS) is the step stone for all these plans. CIDB has created an indicator to assess the degree on industrialization for applied building system; IBS score. Furthermore, CIDB has specified the minimum values of this score for the building projects of government and private sector. This paper discusses the effects of adjusting these values on the structural design of an office building. The CIDB method of calculating the IBS score, the moment distribution method of structural analysis and BS8110 code of design will be used to analyze the selected case study.
Investigation of Plastic Injecting Moulding Process Optimization in Complex Shape Product
Authors: Abd Aziz Ahmad Aizuddin Bin , Sulaiman Sreenivasan , Moe Aung Lwin , bin Abu Aminudin
Published: November 2014

Nowadays, plastic injection molding is widely used in the production of very complex parts and it enables to produce numerous parts within one cycle. Molding conditions or process parameters are crucial for productivity and quality of desired products. This research aims to investigate the state-of-the-art approach to find optimal parameters characteristics in plastic injection molding process. Fill time, average velocity, pressure, clamp force, cooling time and volumetric shrinkages are selected as process parameters in this research. Nokia 6680 model is used for revealing process optimization. Two case studies based on two plates and three plate moulding layout are conducted to suggest the plastic injection mold optimization process. The process parameters of two proposed layouts are compared based on Mold flow Plastics Insight (MPI) analysis results. Result show that three plate moulding satisfy not only the process quality but also the product quality characteristics in this injection moulding process.
Removal of Reactive Black 5 Dye Using a New Polyacrylamide Grafted Cellulose Flocculant Derived from Pandan Leaves: Optimization Study
Authors: Yahya Noor Yahida , Ngadi Norzita , Muhamad Ida Idayu , Jusoh M.
Published: November 2014

In this study, performance of polyacrylamide grafted cellulose flocculant derived from Pandan leaves to treat reactive black 5 (RB5) dye from aqueous solution were investigated. Response surface methodology (RSM) and Box-Behnken design (BBD) of experiment were employed to identify the optimum condition for chemical oxygen demand (COD) reduction in RB5 dye. The optimization was based on three operating variables; initial dye concentration, flocculant dosage and pH. The optimum condition for COD reduction was achieved at initial dye concentration of 0.03 g/l with flocculant dosage of 0.06 g, at pH 11.72. Under this condition, the reduction of COD was achieved up to 54.24%. Linear and quadratic effects of flocculant dosage and pH are the most significant in affecting the degree of flocculation efficiency. The coefficient of determination (R2) of 81.77% for percentage reduction of COD level confirms that the models used in predicting the degree of flocculation efficiency has a very good agreement with the experimental results.
Thermal Properties Determination of Polypropylene/Rice Straw Biocomposite Foam via TGA
Authors: Tugiman Nazuha , Mohamad Zurina , Wan Abdul Rahman Wan Aizan
Published: November 2014

Polymer foam biocomposites based on polypropylene/rice straw (PP/RS) were successfully prepared by using an extrusion foaming process. The compounding of PP and RS was performed in a twin-screw extruder which was blended with crosslinker; dicumyl peroxide (DCP) and blowing agent; azodicarbonamide (AZ). The foam biocomposite was extruded at temperatures of 180, 190, 190 and 200 °C respectively, which set from the feeder until the die zone. The thermal properties were investigated by using thermal gravimetric analysis (TGA).
Study of Thermal Energy Storage Using Oleic Acid
Authors: Firman Firman , Wardana I.N.G. , Soeparman Sudjito , Hamidi Nurkholis
Published: November 2014

Currently, implementation of storage energy technologies is much growing. Various types of fatty acids have been used as energy storage materials. However, the use of oleic acid is required advance study. Identification of Oleic acid is conducted using FTIR test standard of ASTM E 1252-07 and the chemical composition materials are determined by GC-MS. The analysis of melting temperature and crystallize temperature are done using DSC test standard of ASTM D 3419-08. From FTIR test, it is obtained that the spectra results show the identification of oleic acid (C18H34O2) and the GC-MS test shows that the material composition has a purity concentration of 87.317%. Meanwhile, DSC test show that oleic acid could store heat energy at 6.58°C and crystallization is performed at-4.33°C.
The Thermal Instability Analysis of Functionally Graded Carbon Nanotube Composite Plates Using Finite Element Method
Authors: Rasid Z.A. , Yahaya Hafizal
Published: November 2014

In recent years carbon nanotube (CNT) has been combined with polymers to take advantage of the extremely high strength and stiffness of the CNT. This paper reports a study on the thermal instability of carbon nanotube reinforced composites (CNTRC) plate subjected to uniform temperature rise. Finite element method (FEM) formulation was developed based on the first order shear deformation theory. The extended rule of mixture was used to determine the effective properties of the CNTRC plate. The CNTRC plate was functionally graded in its thickness direction. The results of the thermal instability were validated using past results and several parametric studies were then conducted using the developed formulation. The parametric studies showed that the critical temperature of the CNTRC was increased with the increase of the CNT volume fraction and the FG-4 configuration gave the highest critical temperature.
Optimization of Biodiesel Production from Transesterification of Waste Cooking Oils Using Alkaline Catalysts
Authors: Zamberi M.M. , Ani Farid Nasir , Hassan S.N.H.
Published: November 2014

The transesterification of waste vegetable oil (WVO) with methanol in the presence of potassium hydroxide (KOH) is studied in order to produce biodiesel. All the results were evaluated using central composite design by applying a double 5 level 3 factor full factorial designs. Twenty experiments were replicated under the typical range of parameter conditions coded as x1 for oil molar ratio, x2 as catalyst concentration and x3 for reaction time. The experimental fatty acid methyl ester (FAME) are compared with the predicted FAME using RSM. The optimal predicted FAME production was obtained at 92.60%. It is specified under conditions of molar ratio 4:1 mol/mol, 0.5033 wt% catalyst concentration and reaction time of 60 minutes.
Brief Review: Electrochemical Performance of LSCF Composite Cathodes - Influence of Ceria-Electrolyte and Metals Element
Authors: Ahmad Sufizar , Bakar M.S.A. , Rahman Hamimah Abdul , Muchtar A.
Published: November 2014

Solid oxide fuel cells (SOFC) are an efficient and clean power generation devices. Low-temperature SOFC (LTSOFC) has been developed since high-temperature SOFC (HTSOFC) are not feasible to be commercialized because high in cost. Lowering the operation temperature has caused substantial performance decline resulting from cathode polarization resistance and overpotential of cathode. The development of composite cathodes regarding mixed ionic-electronic conductor (MIEC) and ceria based materials for LTSOFC significantly minimize the problems and leading to the increasing in electrocatalytic activity for the oxygen reduction reaction (ORR) to occur. Lanthanum-based materials such as lanthanum strontium cobalt ferrite (La0.6Sr0.4Co0.2Fe0.8O3-δ) recently have been discovered to offer great compatibility with ceria-based electrolytes to be applied as composite cathode materials for LTSOFC. Cell performance at lower operating temperature can be maintained and further improved by enhancing the ORR. This paper reviews recent development of various ceria-based composite cathodes especially related to the ceria-carbonate composite electrolytes for LTSOFC. The influence of the addition of metallic elements such as silver (Ag), platinum (Pt) and palladium (Pd) towards the electrochemical properties and performance of LSCF composite cathodes are briefly discussed.
Effect of Rubber Seed Oil and Palm Oil Biodiesel Diesel Blends on Diesel Engine Emission and Combustion Characteristics
Authors: Khalil Ibrahim , Aziz A. Rashid A. , Yusuf Suzana
Published: November 2014

Diesel engine emission has been considered as major air pollution sources. Feedstocks blending method is motivated by cost reduction and property enhancement. In this paper crude rubber seed oil and palm oil are mixed in 50:50 vol. % and converted to biodiesel. Thermophysical property of the biodiesel was studied. Blends with varying contents of diesel and biodiesel 5-20 vol. % were prepared. Engine emissions and combustion characteristics were measured and analysed. The CO emission was reduced but the exhaust gas temperature and NOx emission increased proportional to the blends ratio. Premixed combustion phase in all tested blends start earlier the neat diesel .Short ignition delay and lower heat release rate were noticed.
Effects of Alkaline Treatments on the Tensile Strength of Napier Grass Fibres
Authors: M. Haameem J.A. , Abdul Majid M.S. , Haslan M. , Afendi Mohd , Helmi E.A. , Idris Fahmi
Published: November 2014

This paper presents the experiment test of the Napier grass fibres to determine the tensile strength of the Napier grass fibre. . Napier grass fibre is a natural source of fibre which is extracted from the internodes of Napier grass stems. Napier grass fibres were extracted trough conventional water retting process. However, the main disadvantages of natural fibres in composites are the poor compatibility between fibre and matrix and the relative high moisture absorption. These Napier grass fibre then undergoes alkaline chemical treatment using sodium hydroxide (NaOH) to improve the surface roughness and to minimize the water absorption into the cellulose. The treatment is conducted with different concentration of NaOH at 5%, 10%, 15% and 20% respectively. The single fibre tensile test was conducted using Instron micro tester. Based on the tests conducted, the results show that the fibre treated 10% concentrations yield the strongest tensile test compared to untreated Napier grass fibre.
Characterization of In Situ Cu-NbC-VC Nanocomposite by Mechanical Alloying and Microwave Sintering
Authors: Wan Omar Wan Mohd Hilmi Hussein , Bashirom Nurulhuda , Hussain Zuhailawati , Almanar Indra Putra , Wan Ibrahim Wan Abdul Rahman Assyahid
Published: November 2014

This paper presents a study on the characterization of physical and electrical properties of Niobium Carbide (NbC) and Vanadium Carbide (VC) in Copper (Cu) matrix by mechanical alloying (MA) technique. The elemental powders of Cu, Niobium (Nb), Vanadium (V) and synthetic graphite powder were mechanically alloyed for 30 hours at 400 rpm in a planetary ball mill according to the stoichiometric ratio of Cu-(10-x) vol%NbC-(0+x) vol%VC (x=0,1,3,5,7,9) under Argon atmosphere. The as-milled powder were compacted at 400 MPa and sintered using microwave sintering furnace at 900°C with 1 hour soaking time. The phase identification was made by using the X-ray Diffraction (XRD) analysis. The microhardness, relative density and apparent porosity of sintered pellets were measured using Vickers microhardness and Archimedes principle, respectively. Electrical conductivity was measured using 2 point probe technique. Density of composite increase with increasing NbC content, while electrical conductivity also increase when NbC was added. Microhardness showed that single phase carbide has higher hardness value then multicarbide.
Effect of Cooling and Isothermal Aging on Microstructure Using Electroless Nickel (Boron) Plating
Authors: Wirda Kahar Hardinna , Akhtar A.M. Zetty , Idris Siti Rabiatull Aisha , Ishak Mahadzir
Published: November 2014

This paper presents a study on relationship of cooling rates towards the intermetallic compound (IMC) morphology. Cooling rate is an important parameter as it has significant effect towards the IMC microstructure formation that indirectly affects solders joint reliability. However, there is still insufficient study regarding the effect of cooling rate on the IMC thickness and microstructure behavior by using Nickel Boron as surface finish material in the electronic packaging industry. In this study, Sn-3Ag-0.5Cu solder was used on Nickel Boron as coating layer. Cooling rates were obtained by cooling specimens in different media which is water and air. The elemental composition was confirmed using Energy-dispersive X-ray spectroscopy and the microstructure of each IMC then analyzed using optical microscope, image analyzer and ImageJ. In this study, faster cooling rate (water) found to provide thicker IMC (6μm) compared to the other medium used. The morphology shape of each IMC also differs between different medium of cooling. IMC that undergoes faster cooling showed continues like layer while the one using air cooling formed scallop like IMC.
Study on Fibre Length and Composition of Kenaf-Polypropylene (K-PP) Composite for Automobile Interior Parts
Authors: Loh X.H. , M. Daud M. Ahadlin , Selamat Mohd Zulkefli
Published: November 2014

This study was to investigate the relationship between fibre length and composition of fibre inside the composite. In this study, three different fibre lengths were used namely 1cm, 1.5cm and 2cm; filling in various kenaf fibre/polypropylene (K/PP) ratio composite with fibre composition range from 10% until 50%. Maleic anhydride (MA) was added as additive to improve bonding between filler and matrix which is 0.3g. Properties of composite were measured using hardness and density test. Dino lite was used to observe the bonding inside composite. After testing, author founds out that polypropylene will give impact on hardness when mix with maleic anhydrice. Kenaf fibre will affect density of composite when it is submerge in water during testing. Kenaf fibre will tends to absorbs water if it is not fully cover by polypropylene. Maleic anhydride was proved can improve strength of composite after added inside composite.
Numerical Simulation of Forced Heat Convection Turbulent Magnetic Nanofluid Flow in a Square Channel
Authors: Che Sidik Nor Azwadi , Jafni Husnan
Published: November 2014

This paper presents numerical study of turbulent nanofluid (Fe3O4 - water) flow in a square straight channel. An ANSYS FLUENT commercial software was employed to investigate the flow and thermal characteristic of the flow in the range of Reynolds number 10,000 to 50,000 and nanoparticle volume concentration from 0% to 2%. The results show that by increasing the Reynolds number, the Nusselt number increased for both pure water and nanofluid cases. The thermal conductivity and viscosity of the nanofluid were increased with an increase in the particle volume concentration and yields enhancement of heat transfer.
Analyzes of Film Cooling from Cylindrical and Row Trenched Holes with Alignment Angle of 90 Degrees at Low Blowing Ratio
Authors: Ehsan Kianpour , Che Sidik Nor Azwadi
Published: November 2014

The current study was conducted to analyze the effects of cylindrical and row trenched cooling holes with alignment angle of 90 degrees at blowing ratio, BR = 1.25 on the film cooling effectiveness near the end wall surface of a combustor simulator. In the current research a three dimensional representation of Pratt and Whitney gas turbine engine was simulated and analyzed with a commercial finite volume package FLUENT 6.2.26. This 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 arrangement, 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 end wall surface, film cooling effectiveness is increased three times compared to the cooling performance of baseline case.
Effect of Combination Factors of Operating Pressure, Nozzle Diameter and Riser Height on Sprinkler Irrigation Uniformity
Authors: Osman Manal , Hassan Suhaimi B. , Yusof Khamaruzaman B. Wan
Published: November 2014

The irrigation uniformity of sprinkler irrigation system depends on many design factors such as nozzle type, nozzle diameter, operating pressure and riser height. An experimental study was performed to investigate the effect of combination factors of operating pressure, nozzle diameter and riser height on sprinkler irrigation uniformity. Different operating pressures, nozzle diameters and riser heights have been used. The irrigation uniformity coefficients such as coefficient of uniformity (CU) and distribution uniformity of low quarter (DUlq) have been studied. This study concluded that, the irrigation uniformity of sprinkler irrigation system was more affected by the combination of operating pressure, nozzle diameter and riser height.
Analyzes of Film Cooling Effectiveness from Cylindrical and Staggered Compound Cooling Holes with Alignment Angle of 30 Degree at the End of Combustor
Authors: Salimi Shahin , Che Sidik Nor Azwadi , Jahanshaloo Leila , Ehsan Kianpour
Published: November 2014

A numerical simulation has been performed for the investigation of flow and heat transfer characteristics of a film cooling injected through a hole with cylindrical and compound angle orientation. This paper presents the effects of coolant injector configuration of cylindrical and compound cooling holes with alignment angle of 30 degree at blowing ratio, BR = 3.18 on the film cooling effectiveness near the end wall surface of a combustor simulator. In the current research a three dimensional representation of Pratt and Whitney gas turbine engine was simulated and analyzed with a commercial finite volume package ANSYS FLUENT 14.0. This study has been performed with Reynolds-averaged Navier-Stokes turbulence model (RANS) on internal cooling passages The results indicate that using compound angle cooling holes injection, give much better protection than that obtained when simple angle cooling holes were used.
Numerical Simulation of Nanofluids for Improved Cooling Efficiency in Microchannel Heat Sink
Authors: Mohamad Noh Nur Hazwani , Che Sidik Nor Azwadi
Published: November 2014

Numerical simulation on 3-dimensional rectangular cross section of microchannel heat sink is conducted to investigate the effect of various type coolant consist of water and different type of nanofluids on the cooling performance of microchannel heat sink. FLUENT, a Computational Fluid Dynamic (CFD) is used as the solver of simulation. A rectangular microchannel with hydraulic diameter of 86um and length of 10mm under the boundary condition of constant heat flux and laminar flow with uniform inlet velocity with five sets of working fluid with different nanofluids. The defined model is validated with previous studies of numerical analysis. Results of present work show that using Diamond-H2O as cooling lead to higher efficiency of heat transfer in microchannel heat sink in comparison to others nanofluid and base fluid. Numerical results show that increasing the thermal conductivity of working fluid can enhanced heat transfer. Nusselt number follows the incremental in Reynolds number.
Computational Analysis of Nanofluids in Heat Exchanger
Authors: Che Sidik Nor Azwadi , Wei Chan Shi , Fazeli Alireza
Published: November 2014

In this paper is study the performance of heat exchangers by using computational analysis method. In past decade’s years, many researchers had discovered that nanofluids have a brilliant efficient in the heat transfer process. They believes that applied the nanofluids in the heat transfer equipment would bring a better enhancement compare with the conventional cooling fluids. In the literature journals, the authors have specified focused on the thermal conductivity, specific heat, density, and viscosity of nanofluids. They believes these are the most significant factors of the working fluids that would influence the efficiency of heat exchanger. In this study, an imitated real-life marine transport used of shell and tube heat exchanger to be analyzed. The shell and tube sides of heat exchanger will be filled with Water or nanofluids and Water or seaWater in respectively. The nanofluids will be assumed as single-phase nanofluids with variant of volume fraction of copper and alumina. The computational result of Water at the shell and tube sides will be used as validation of data compared with the technical performance specification given by the supplier. Further, the efficiency of different volume fraction of nanofluids and the optimum of volume fraction of nanofluids in this system would be discussed in the simulation results.
Removal of Contaminant Effectiveness in Cavity Channel Flow with Different Heated Wall Position
Authors: Che Sidik Nor Azwadi , Ahmat Rajab K.Y. , Ahmad Sofianuddin A.S.
Published: November 2014

Numerical simulation on removal of contaminated cavity in channel was done for various Richardson number and at three different heated wall inside square cavity. Constrained interpolated profile method (CIP) was used to solve advection part of Navier-Stokes equation while non-advection part was solved by using finite central difference. The contaminant has same properties as the fluid and very small so that the particle can be treated without affected the fluid flow. Simulations shows that heated right wall produced the highest removal process and heated left wall will removed the fewest of contaminant from cavity.
Synthesis and Characterization of Biochars from Textile Sludge Precursors
Authors: Sohaimi Khairunissa Syairah Ahmad , Ngadi Norzita , Najlaa Yac’cob Nurul Atiqah
Published: November 2014

Oil pollution is considered as one of the major problem to the sea and also public watercourse. Oil pollution give bad effects to many aspects like to marine life, water treatment system and overall aquatic ecosystem. Thus, this study is focusing on the oil pollution treatment by using adsorption process. For that purpose, this study investigated the potential of textile sludge (TS) which considered as abundant sludge as a source of biochars. Biochars (BC) from textile sludge was prepared by carbonization at different temperatures; 105 °C, 200 °C, 400 °C, and 700 °C. The synthesized biochars; BC105, BC200, BC400, BC700 was characterized using FTIR spectroscopy and BET surface area. The results obtained from characterization showed that BC700 showed the highest BET surface area, 161.9945m2/g while, the highest percentage yield of biochar was obtained at temperature 105 °C with 98.20%. From FTIR results, BC700 showed less peaks which indicated less presence of functional groups compared to BC105, BC200 and BC400 due to decomposition of raw textile sludge wastes at high elevated temperature. The characterization results also showed that BCs produced from textile sludge wastes have potential for oil pollution treatment.
Effect of Coolant Temperature on Desalination Process via Progressive Freeze Concentration
Authors: Farah Hanim Ab. Hamid , Norfatiha A.Rahim , Ngadi Norzita , Zakaria Zaki Yamani , Mazura Jusoh
Published: November 2014

The world is still suffering from a shortage of clean water supply and the problem is expected to become more serious in the future. Consequently, researchers have been trying to find the best solution to address this problem by introducing new desalination technologies that are able to accommodate the demand for clean water which is increasing from time to time. One of the new technologies introduced is the desalination of seawater through freeze concentration. In this study, progressive freeze concentration (PFC) is implemented to produce pure water in the form of ice crystal block and leave behind a higher concentration solution. The effect of coolant temperature was investigated and the efficiency of the system was reviewed based on the value of effective partition constant, K which is defined by the ratio of solute in ice and liquid phase. The low value of K leads to the best efficiency for the system. Apart from that, the efficiency, E% and salinity reduction were also calculated in order to determine the system performance.
Use of CFD to Study the Resistance of Sprint Master Canoe
Authors: Yaakob Omar , Ahmed Yasser M. , Othman M. Rizal
Published: November 2014

The resistance and the hydrodynamic characteristics of the Sprint Master canoe that is used in Universiti Teknologi Malaysia (UTM) have been studied at different speeds using Computational Fluid Dynamics (CFD) method. The resistance of the canoe at different speeds has been measured in UTM marine technology center (MTC). The finite volume code Ansys CFX has been used for carrying out the numerical simulations for the hull form of the canoe at the same experimental speeds. The Volume of Fluid method (VOF) has been used with Ansys CFX for capturing the free surface flow around the canoe hull at the same experimental speeds. The Shear Stress Transport (SST) turbulence model has been used in the RANSE code. The grid generator ICEM CFD has been used for building the grids for the RANSE code solver. The numerical results compare very well with the experimental results at the different speeds.
Investigation of Auto-Ignition of Heptane-CNG Mixture in HCCI Engine
Authors: Firmansyah Firmansyah , Aziz A. Rashid A.
Published: November 2014

Homogeneous Charge Compression Ignition (HCCI) operating principals have been widely investigated yet the uncontrollable combustion of HCCI is the major obstacle in its development. This paper is trying to increase the understanding on the auto-ignition and combustion process of several fuels to be applied in HCCI combustion system. This paper investigates variation of fuel composition between heptane and compressed natural gas (CNG) with the composition ranges from 10-100% heptane/CNG. The investigation was done in a constant volume chamber with elevated temperature (800°C). Three lambdas were tested for each fuel, namely 0.8, 1, 1.2 and 2. From the results, it is found that the mixture composition highly affects the output of the combustion of dual fuel where CNG is able to suppress heptane combustion at CNG percentage more than 40%. Furthermore, homogeneity level highly determines the types of combustion produced by the mixture, distributed or propagation flame.
Sauter Mean Diameter Profiles of Droplets in a Continuous Spray Stream
Authors: Naz Muhammad Yasin , Sulaiman Shaharin Anwar , Ari-Wahjoedi Bambang
Published: November 2014

In this study, a modified starch solution was heated upto 80°C and continuously sprayed into ambient air with an axi-symmetric full cone nozzle operated at two different load pressures 3 and 5 bar. The generated sprays were characterized for axial Sauter Mean Diameter (SMD) by using a non-intrusive Phase Doppler Anemometry (PDA) technique. A monotonic decrease in SMD downstream to the nozzle exit was noticed at 5 bar load pressure. At 3 bar load pressure, initially, SMD decreased between 10-20 mm downstream, then increased between 20-40 mm and finally reached to its lowest values at 100 mm downstream. Overall, the SMD measured at 3 and 5 bar load pressures was decreased from 99 to 66 μm and 85 to 57 μm respectively after moving 100 mm downstream.
Parametric Study on a Thermal Energy Storage Containing Single PCM Sphere
Authors: Amin N.A.M. , Mohamad Azizul , Majid M.S. Abdul , Daud R. , Afendi Mohd , Said Mohd Azizi , Bruno Frank , Belusko Martin
Published: November 2014

Mathematical representation of the thermal energy storage (TES) containing an encapsulated phase change material (PCM) in Medium Density Polyethylene sphere is investigated. The model applied the Effectiveness - Number of Transfer Unit (ɛ-NTU) method. The performance of a TES is presented in terms of the phase change effectiveness. The mathematical formulation of the model discussed will be used in future research with the suggestion to maximize the heat transfer between the heat transfer fluid and the PCM.
The Effects of Fibre Contents on the Tensile Strength and Surface Morphology of High Density Polyethylene/Palm Pressed Fibre Biocomposite Film
Authors: Noor Fatheyah Aris , Majid Rohah A. , Mohana Hasniza Mohamad Darus , Wan Hasamuddin Wan Hassan
Published: November 2014

Palm pressed fibre (PPF) with particle size of 200 micron was utilized as a filler to produce environment friendly biocomposite film. PPF contains 5-6% oil residue after the oil extraction process and the oil can be used as a lubricant to assist the distribution of PPF throughout the matrix of plastic resin during processing. In this study, high density polyethylene (HDPE) plastic resin was incorporated with untreated PPF at four different weight percentages namely, 5, 10, 15 and 20 wt%. Each mixture was compounded via twin screw extruder prior to compression moulding into film sheets with thickness of 0.15mm. Maleic anhydride (MAH) and glycerol were used as compatibilizer and plasticizing agents. The effect of PPF loading on the tensile strength and the surface morphology were the main interest. It was found that by increasing the PPF contents had increased the stiffness of the films but reduced the tensile strength and elongation at break due to weak interfacial adhesion between HDPE matrix and PPF. This was probably due to insufficient amount of MAH to compatabilize the increasing amount of PPF, thus resulting non-uniform PPF distribution across the HDPE matrix. The findings were supported by SEM micrographs which showed rough surface and the disruption of the continuous phase of HDPE matrix, thus weakening the strength and flexibility of the samples. HDPE/PPF biocomposite has a potential to be used in agriculture sectors such as mulching film.
Jet Impingement Cooling System on the Pressure Side of Turbine Blade
Authors: Musa Mohamad Nor , Khalid Mohamed Izhar Mohamed
Published: November 2014

This study is to investigate the effectiveness of jet impingement cooling system on the turbine blade pressure side. The objective of this study is to determine the mass blowing rate referred to Reynolds number and the nozzle exit to surface distance which will produce the highest cooling effectiveness which will be shown as Nusselt number. A model of CF6-50 blade is made from mild steel and an experiment to study the jet impingement cooling effectiveness on the pressure side of turbine blade is conducted. The parameters that are included in the experiment are the Reynolds number, Re = 646, 1322, 1970 and 2637; and nozzle exit to surface distance, s/d = 4.0 cm, 8.0 cm and 12.0 cm. The results obtained are calculated and graphs for each experiment are made. The result shows that the jet impingement cooling effectiveness are the highest at where the nozzle is pointed and the cooling effectiveness decreases as it travels further away on the blade. The theory of jet impingement cooling is presented and the several factors that affect jet impingement cooling are also discussed.
Stochastic Homogenized Properties for Honeycomb Microstructure Based on First Order Perturbation
Authors: Basaruddin Khairul Salleh
Published: November 2014

A stochastic analysis of multi-scale problem in honeycomb microstructure was introduced in this paper to determine the variation of macroscopic homogenized properties considering uncertainty of micro-property. By assuming the fluctuation of micro-property, specifically the Young's modulus, is in Gaussian normal distribution, the macroscopic (homogenized) properties was formulated in stochastic manner based on first order perturbation approach. Next, the macroscopic property of honeycomb microstructure considering the geometrical defect that might be occurred in manufacturing process was also predicted. The numerical results showed that even with minor geometrical defect could affect the macroscopic properties. It proved the essential of stochastic homogenization method in predicting the reliable macroscopic property for microstructure design.
Mathematical Models for Productivity Rate of Automated Lines with Reliability Attributes of Mechanisms
Authors: Usubamatov Ryspek , Sin Tan Chan
Published: November 2014

Automated lines with complex structures consist of stations and mechanisms with different levels of reliability. Most publications that present the mathematical models for productivity of automated lines are based on simplifications to derive the approximate equations of productivity. Simplification is based on the premise that all stations of the automated lines have one level of reliability, and balancing of technological process on stations is conducted evenly, etc. However, manufacturers need correct and clear mathematical models to enable the calculation of the productivity of the automated lines with high accuracy. This paper presents the analytical approach to the productivity rate of the automated lines with stations and mechanisms, with different failure rates, and processing times. The proposed mathematical models allow for the output of automated lines to be modelled with results that are close to actual productivity.
Analysis of Soil Nailing under Earthquake Loading in Malaysia Using Finite Element Method
Authors: Mohammad Zaki Mohd Faiz , Wan Ahmad Wan Amiza Amneera , Ayob Afizah , Ying Teoh Khai
Published: November 2014

Soil nailing has become a widely accepted method and offers a practical solution towards construction of permanent retaining wall, slope stabilization and protection of existing cuts from failure. In Malaysia, soil nailing is typically performed on cut slope and installed with grouting as preventatives method due to erosion problem. However, although the effectiveness of soil nailing system may be well understood by practitioners, the slope failure and collapses of deep excavation are continuously occurs, especially for the construction in the earthquake zone. Malaysia has numerous experiences of earthquake even this country has been categorized as low seismicity group. Hence, it is become important in the scope of geotechnical engineering to analyze and study the effect of earthquake to soil nailing systems in Malaysia. Aims of this paper are to focus and study this technical issue using the application of finite element program. This research study selects PGA of 0.08g based on the location of major population in Malaysia. Safety factor was calculated in this finite element program using phi-c reduction. Soil nailing relatively give satisfactory response under seismic, so pseudo-static method is applied for seismic loading study. Based on the static analysis results, the FOS for the deep excavation stabilized with soil nailing is 1.54. However, by considering the earthquake or seismic loading, the FOS reduces to 1.16 and the percentage of reduction is about 25%. Total displacement was observed slightly difference in soil nailing analysis during an earthquake and static analysis
The Deformation of Human Eyeball when Undergoing Scleral Buckling
Authors: Ismail Zuhaila , Fitt Alistair , Please Colin
Published: November 2014

Scleral buckling is a surgical technique to treat rhegmatogenous retinal detachment (RRD). Vision may be affected by the scleral buckle. Since the buckle is pushed into the sclera towards the detached retina, it may change the shape and the focal length of the eyeball. A paradigm mathematical model of human eyeball is set up to examine how the focal length of the eye is affected under the action of the external force. In particular, this model has been developed using the membrane equations of equilibrium for axisymmetric spherical shells. Using numerical analysis the resulting displacements of the eyeball will be examined. The results of the scleral buckle may prove useful to predict changes in focal length.
Mathematical Modeling on Thermal Energy Storage Systems
Authors: Amin N.A.M. , Said Mohd Azizi , Mohamad Azizul , Abdul Majid Mohd Shukry , Afendi Mohd , Daud R. , Bruno Frank , Belusko Martin
Published: November 2014

Mathematical representations of the encapsulated phase change material (PCM) within thermal energy storage (TES) models are investigated. Applying the Effectiveness - Number of Transfer Unit (ɛ-NTU) method, the performances of these TES are presented in terms of the effectiveness considering the impact of different variable parameters. The mathematical formulations summarized can be used for future research work with the suggestion to maximize the heat transfer within the storage. Thus the optimisation on the configuration of the encapsulation can be done through a parametric analysis.
Model Sensitivity Test of Large Eddy Simulation for Wind Flow and Pollutant Dispersion in a Street Canyon
Authors: Yazid Afiq Witri Muhammad , Che Sidik Nor Azwadi , Salim Salim Mohamed , Mansor Shuhaimi
Published: November 2014

This paper reports on the model sensitivity analysis of a commercial computational fluid dynamics program, ANSYS FLUENT v14. The purpose of the analysis was to determine the appropriate modeling settings for numerical model of the case study. A full scale of a simplified urban street canyon was modelled and the turbulent flow was calculated using Large Eddy Simulation (LES) techniques. The model sensitivity tests involved are mesh sensitivity, statistically steady state and sampling. Adequate numbers of cells, period time to achieve statistically steady state (SST) and sampling time to simulate wind flow and pollutant dispersion in street canyon were determined through systematic tests.