bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Characterization of Gold Nanoparticles Grafted on Nanoporous Anodic Aluminum Oxide (AAO) Membrane
Authors: Yazid Hanani , Nekhia Nek Zamzila , Adnan Rohana , Md Jani Abdul Mutalib
Published: April 2015

Gold nanoparticles (Au NPs) supported on nanoporous anodic aluminium oxide (AAO) membrane has been successfully prepared by direct anionic exchange for further application in catalysis. The nanoporous AAO membrane is immersed in HAuCl4 solution at different pH to achieve gold nanoparticles grafted on AAO (Au-AAO). It was found that the pH of the HAuCl4 solution played an important role for controlling the size of Au NPs as well as the amount of Au depositing on the surface of AAO membrane. The prepared Au-AAO membranes were characterized by diffuse reflectance UV-Vis spectroscopy, high-resolution scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectroscopy.
The Effects of Water Saturation on Dynamic Mechanical Properties in Red and Buff Sandstones Having Different Porosities Studied with Split Hopkinson Pressure Bar (SHPB)
Authors: Kim Eun Hye , de Oliveira Davi Bastos Martins
Published: April 2015

Dynamic mechanical behavior of geomaterials has been widely observed in tunneling, oil and gas extraction, and blasting in civil and mining applications. It is important to understand how much energy is necessary to break or fail geomaterials to optimize the design of blasting patterns, oil and gas extractions, demolition, military defense, etc. However, there is little understanding for quantifying the required energy to break geomaterials under dynamic loading. More importantly, as typical geomaterials tend to hydrate, it is necessary to understand how much energy will be needed to break the structures under water saturation. Thus, in this study, we analyzed the consumed energy used to deform geomaterials using a split Hopkinson pressure bar (SHPB), enabling to measure stress and strain responses of geomaterials under dynamic loading condition of high strain rate (102–104/sec). Two different saturation levels (dry vs. fully saturation) in two sandstone samples having different pore sizes were tested under dynamic loading conditions. Our results demonstrate that dynamic mechanical strength (maximum stress) is greater in the dry geomaterials when compared with the saturated samples, and Young’s modulus (or maximum strain) can be a useful parameter to examine porosity effects between dry and saturated geomaterials on dynamic mechanical properties.
The Effects of Reservoir Area Extent on the Performance of a Vertical Well in a Reservoir Subject to Bottom Water Drive
Authors: Eiroboyi I. , Obeta P.O.
Published: April 2015

Reservoir performance can be understood from system type curves. The type curve gives vivid information about maximum pressure drops, magnitude of near wellbore effects, reservoir fluid and wellbore properties needed to ascertain the strength of available drive mechanism, maximum withdrawal rates and remaining fluid in real time. This paper investigates the effects of reservoir area extent on the performance of a reservoir, subject to active bottom water, when it is completed with a vertical well. Type curves of dimensionless pressures and dimensionless pressure derivatives were produced for various dimensionless values of area extent of the reservoir. These type curves were developed from solutions to flow equations using relevant source and Green’s functions. From the results, it can be observed that the larger the reservoir area extent, the larger the dimensionless pressure drop, the longer the time it takes to attain steady state. This is validated from the pressure derivative curve, which shows that reservoirs with large area extent are characterized by longer period of radial flow and subsequently delay in the attainment of steady state, thus prolonging the arrival of bottom water.
Analysis of the Airborne Sound Insulation Performance of Floor Structures Based on the Intensity Method
Authors: Yeon Jun Oh , Kim Kyoung Woo , Yang Kwan Seop , Kim Myung Jun
Published: April 2015

Apartment buildings are constructed using box frame structures that integrate slabs and wall frames, and vibrations can easily travel through these integrated box frame structures. On the other hand, such a framed structure generates fewer gaps between structural elements, assuring a superior insulation performance of airborne sound compared to wooden houses. Vertically installed equipment running through different floor levels can serve as a transmission route for airborne sound of specific frequency bands. In this study, we sought to develop technical methods to improve the inter-floor airborne sound insulation performance. To this end, we measured the sound insulation performance of floor structures and intensity levels in noise penetration areas. The sound insulation performance of the living room floor structure was measured to exceed 51 dB, which was superior to that of the restroom floor by 2–7 dB. Intensity measurements identified the central and corner areas of the living room as high-level noise areas.
Preparation and Characterization of Temperature-Sensitive 2-Hydroxy-3-Allyloxy Propyl Starch Ether
Authors: Ju Ben Zhi , Ma Wei , Yuan Hong Liang , Zhang Shu Fen
Published: April 2015

A temperature-sensitive 2-hydroxy-3-allyloxy-propyl starch ehter (HAPS) was prepared by regulating the hydrophilic-lipophilic balance of etherified starch. Allyl glycidyl ether (AGE) was used as the hydrophobic reagent. 1H-NMR was used to characterize the structure of products and determine the degree of substitution of etherified starch. UV-Vis and fluorescence spectroscopy methods were adopted to investigate the properties of HAPS aqueous solution. The results showed that the LCST of HAPS was reduced as the DS. When the cmc of HAPS decreases and DS increases, formation of micelles in an aqueous solution by self-assembly is possible.
Study on the Cooling System of the Electronic Equipment in the Cabin of the Stratospheric Airship
Authors: Shi Hong , Jiang Yan Long , Cai Yu Fei
Published: April 2015

Nowadays, the strategic value of the stratospheric airship attracts more and more attention of the countries. Based on the analysis of the working performance of the stratospheric airship, a cooling system of the electronic equipment is designed and its performance throughout the flight altitude is investigated. The results show that the single cooling system based on cold plate cannot fulfill the cooling task in the extreme hot day and a parallel cooling system as a bench should be designed .meanwhile, the temperature of the cold plate is gradually decreased and then gradually rose with the altitude. The lowest temperature in the process is-35.95°C which would has effect on the performance of the cold plate. Therefore , electrical heating system and frequency regulating speed ventilator are proposed in the above cooling system which is responsible for the electronic equipment at the optimum temperature .
Cooling Rate Analysis of Thin Wall Ductile Iron Using Microstructure Examination and Computer Simulation
Authors: Sulamet-Ariobimo Rianti Dewi , Soedarsono Johny Wahyuadi , Suharno Bambang
Published: April 2015

Cooling rate plays an important role in thin wall ductile iron solidification, due to their thickness. Casting simulation is use as a tool to estimate the cooling rate. In the other hand, every microstructure has its own cooling rate. This paper explores the similarity of solidification mechanism between simulation and graphite characteristics. Three types of casting design simulated and produced. Solidification mechanism is analyzed based on cooling rate sequence and trend line matching. Temperature gradient and thermocouple function represent simulation while graphite characteristic represent experiment. The result shows that similarity in solidification mechanism is not found between simulation with experiment due to lack of parameters in both sides.
Chemical Changes of Cement Caused by Aggressive Environment
Authors: Pernicová Radka , Dobiáš Daniel
Published: April 2015

The chemical changes of cement structures exposed to aggressive environments are explored in this paper. In the predetermined time intervals the influence of the aggressive liquid, namely 5% wt. non-flowing sulphate solution, on mineralogical composition was tested. The chemical changes caused by corrosive sulphate environment on the testing specimens were determined in dependence on the different type of cement. From the results obtained follows that different kind of cement has impact on the sulphate resistance.
Heuristics for an m-Machine Re-Entrant Permutation Flowshop with the Objective of Total Tardiness
Authors: Choi Seong Woo
Published: April 2015

We focus on an m-machine re-entrant flowshop scheduling problem with the objective of minimizing total tardiness. In the re-entrant flowshop considered here, routes of all jobs are identical as in ordinary flowshops, but the jobs must be processed multiple times on the machines. We present heuristic algorithms, which are modified from well-known existing algorithms for the general m-machine flowshop problem or newly developed in this paper. For evaluation of the performance of the algorithms, computational experiments are performed on randomly generated test problems and results are reported.
Effect of Oil Flow Velocity on Hydraulic Shock
Authors: Bureček Adam , Hružík Lumír , Vašina Martin
Published: April 2015

The article is focused on experimental investigation of oil dynamics in long pipe at non-stationary flow. The non-stationary flow is realized by sudden closing of seat valve at the end of the long pipe. For this reason the oil pressure is suddenly increased and hydraulic shock is created. There is described the influence of oil flow velocity on hydraulic shock in this article. The pressure is measured near the seat valve. Furthermore this process is mathematically simulated using Matlab SimHydraulics software and is compared with the experiment.
Dynamic Characteristics Research of Magneto-Rheological Fluid Engine Mount
Authors: Pan Gong Yu , Wang Qian Qian , Yang Xin
Published: April 2015

In order to improve the vibration isolation performance of engine mount, a new type of magneto-rheological semi-active mount with multiple inertia tracks is designed based on the existing magneto-rheological semi-active mount . The mechanical model is established according to the mount. The expression of the dynamic stiffness and damping lag angle is deduced, then the dynamic characteristics is simulated in the simulation software. At the same time, verify this model correct by the experiments.
Improving the Efficiency of Power Generation Plants Based on Internal Combustion Engines
Authors: Budko Artem Yur’evich , Medvedev M.Yu. , Matsiborko Vladimir Vladimirovich
Published: April 2015

This paper describes a method developed by the authors for the detection and estimation of knock intensity in the cylinders of internal combustion engines. The method is based on the spectral analysis of the ion current signal, which is detected within the combustion chamber of the engine. The method allows estimation of the total wave packet energy for different waves speed and frequency. The estimation results of wave’s energy arising in the normal and knock combustion to engine VAZ 2110 are also presented in the paper work.
Kinematic Optimization of Parallel Manipulators with a Desired Workspace
Authors: Yang Ze Guo , Shao Ming Lei , Shin Dong Ik
Published: April 2015

A kinematic optimization method of parallel manipulators is presented in this paper. A desired workspace for a parallel manipulator is usually an essential requirement in a practical application. Additionally, a good kinematic performance and/or a relatively small physical size would be of great significance. A dexterity index is utilized to measure the kinematic performance of parallel manipulators. A method to define the physical size of a parallel manipulator is introduced. The cost function is then formulated as a linear combination of a dexterity index and a physical size measurement. The Optimization Tool Box of MATLAB is applied to solve the optimization problem. Finally, a general Stewart-Gough platform is taken as an example to specify the design methodology.
Synthesis of Ettringite
Authors: Gemrich Jan , Jiroušková Kateřina , Kulísek Karel , Magrla Radek
Published: April 2015

The exposure of cement to high concentration of sulphate anions for a prolonged time period can lead to the formation of secondary ettringite and thaumasite. The preparation of synthetic ettringite is described in this paper.
Screening for Ibuprofen-Sachharin Co-Crystal Formation in Wet Milling
Authors: Abd Hashib Syafiza , Anuar Nornizar , Jamburi Norasikin , Ahmad Nur Fazizi , Abd Rahim Syarifah
Published: April 2015

Co-crystallization process has been used in pharmaceutical industry in producing new class of API solids due to its advantages such as physical stability and solubility.The objective of this study is to characterize the co-crystal formation of ibuprofen with saccharin as a co-crystal former through wet milling by using XRD, FTIR and DSC. A study of co-crystal formation from ibuprofen and saccharin has been conducted by using wet milling with the presence of solvent. The PXRD results showed a new phase which is believed a new crystalline has been successfully formed. The DSC analysis showed a new melting point for the new phase. However, the functional group assessment showed the presence of an unknown functional group in the system.
Kinetic Mechanism on Synthesis of Copper Nanoparticle from Reduction Reaction - Effect of Temperature
Authors: binti Mohd Yusof Noorsuhana , Jai Junaidah , Hafizie Zaini Ahmad , Alias Nur Hashimah , Ghazali Nurul Aimi , binti Idris Sitinoor Adeib
Published: April 2015

Copper nanoparticles, due to their interesting properties, low cost preparation and many potential applications in catalysis, cooling fluid or conductive inks, have attracted a lot of interest in recent years. In this study, copper nanoparticles were synthesized through the palm leaves extract that act as reducing agent. In this synthesis route, the hydroxyl groups of the polyphenols in palm extract are capable to act as reducing agent for reduction reaction. The effect of temperature given starting with control parameters at room temperature proceeds to 40, 50, 60, 70 and 80°C with the time length of 2 hours and 10 milimol copper nitrate aqueous solution. Characterization had been conducted using the instrument of UV-vis spectrophotometer, FTIR and ESEM. The average size of all powder nanoparticles was found to 109, 86, 196, 133, 241, and 230nm accordingly from room temperature till 80°C. The correspondence analysis of the results yielded that the optimum temperature was at 40°C which is 86nm of average copper nanoparticle size.
Synthesis of Zeolites from Treated Oil Palm Ash
Authors: Pa Faizul Che , Abdullah Chik , Fazlul Bari
Published: April 2015

In this study, the ability of treated oil palm ash aided with kaolin powder to produce zeolites is studied. The use of treated oil palm ash in the zeolites conversion seems to be an option for waste materials management. Characterization of treated oil palm ash from Malaysia’s palm oil plantation has been acquitted. The treated oil palm ash and kaolin powder are used as the starting material for the synthesis of zeolites materials. The method chose for the zeolites conversion is alkaline hydrothermal treatment. The chemical composition, crystalline phases and elemental composition of treated oil palm ash and as-synthesized samples were characterized and studied. From the analysis, the treated oil palm ash was a fertile source of silica and exists as quartz phase. The outcomes have significant motivation for the production of zeolites by using low cost material such as treated oil palm ash.
Antimicrobial Protein Produced by Lactobacillus plantarum ATCC8014 in the Presence of Cymbopogon  Sp. Essential Oils
Authors: Mohd Noor Hanina , Muhamad Hairul Shahril , Ismail Ismatul Nurul Asyikin , Shukri A’firah Mohd Sakri , Mat Radzi Salina , Rehan Maryam Mohamed , Kader Abdul Jalil Abdul
Published: April 2015

Protein production by bacteria might be increased in stressful conditions such as in the presence of antimicrobial agents. Many studies proved that antibiotics or antimicrobial agents at low concentration are able to activate or repress gene transcription process in bacteria. However, there are still few studies on potential of natural antimicrobial compounds such as Cymbopogon essential oils acting as specific chemical signal that can trigger biological functions of bacteria. Therefore, this study aims to explore the potential of natural antimicrobial compound (Cymbopogon flexuosus and Cymbopogon nardus) at low concentration in regulating proteins production by Lactobacillus plantarum ATCC8014. The bacteria cells of L. plantarum ATCC8014 are exposed to Cymbopogon essential oils at low concentration in fermentation process for 48 hours at 37°C. SDS-PAGE analysis showed that a new intracellular protein with approximate size of 40 kDa was produced by L. plantarum ATCC8014 after being enhanced with C. nardus essential oil. Besides, the intracellular proteins, each with approximate size of 85 kDa, 45 kDa and 28 kDa synthesized by L. plantarum ATCC8014 prior to inducing with C. nardus or C. flexuosus were expressed differently. Some of the intracellular proteins were highly expressed and some of the proteins were repressed based on the intensity of protein bands appeared. Hence, L. plantarum ATCC8014 in the presence of Cymbopogon essential oils at low concentration could regulate the intracellular proteins production. The isolated protein also showed antimicrobial activity against selected Gram-positive and Gram-negative bacteria.
Isolation of Potential Alkaliphilic Cellulase-Producer Strains from Limestone Area of Perlis
Authors: Zainuddin Nor Izzah , Abd Rahman Khadijah Hanim , Shaari Abdul Razak , Mohd Yusof Siti Jamilah Hanim
Published: April 2015

Alkaliphilic cellulases-producer fungi were isolated from soil of limestone areas in Perlis. The potential strain was isolated by soil dilution plate method on enriched selective medium using CMC as substrate at different pH levels. Eleven isolates of different morphological colonies were screened using the hydrolysis capacity test by Gram’s iodine. Out of eleven colonies, five showed positive results as the hydrolysis zone formed. BK1 showed the highest hydrolysis capacity among all sample strains for every pH levels. Eventually, four strains were selected to be further explored as cellulolytic fungi for the production of alkaline cellulase in the future.
An Investigation on Rigidity of Ball-Socket Hip Joint Replacement
Authors: Normahira M. , Ahmad Firdaus A.Z. , Molijol G.N.
Published: April 2015

A 3-dimensional hip joint implant model was constructed which separates into three individual parts namely femoral stem with neck, femoral head and acetabular cup. Each part were assigned with the specific materials and a total of 3000 N loads was applied to mimic the body weight of an adult in static position or in double leg standing position. The results of the stress distribution were obtained from the finite element analysis for the difference diameter for each component of ball-socket and neck as well as the difference materials. The results showed that an optimum diameter of femoral ball-socket with 36 mm and titanium alloy have design rigidity which provided better performance and longer life span based on 13.922 Mpa equivalent stress .
Synthesis and Characterization of Novel Hybrid MWCNT-Muscovite Composite Filler
Authors: Abdul Kudus Muhammad Helmi , Md Akil Hazizan , Zakaria Muhammad Razlan , Md Saleh Siti Shuhadah
Published: April 2015

A novel hybrid carbon nanotube-muscovite (CNT-muscovite) compound was synthesized via chemical vapour deposition (CVD) by directly grown CNT on muscovite particles. The synthesis of CNT using nickel catalyst and muscovite as a substrate material is rarely found. Morphological analysis using scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) showed that the CNT was successfully grown on muscovite flaky particles. The CNT-muscovite compound can be potentially used as a new class of filler in polymer composites technology.
Chemical Composition, Antioxidant Activity and Functional Properties of Mango (Mangifera indica L. var Perlis Sunshine) Peel Flour (MPF)
Authors: Noor Shazliana Aizee Abidin , Siti Nadherah Mohamad , Mahmad Nor Jaafar
Published: April 2015

This study was to investigate the proximate composition, total antioxidant activity and functional properties of mango (Mangifera indica L. var Perlis Sunshine) peel flour. The proximate analysis (g/100g) was determined as carbohydrate (84.6%), fat (4.0%), total protein (1.6%), total dietary fiber (54.2%), soluble dietary fiber, (SDF) (20.0%), insoluble dietary fiber, (IDF) (34.2%) and calories (381 kcal/100g). The studies also indicated that mango peel flour from Perlis Sunshine varieties can neutralized DPPH radicals by neutralized 80.00% of free radicals, thus contained about 22.4 mg/g of total flavonoids contents (TFC) values and 21.7 mg/g of total phenolic contents (TPC) values. Functional properties of between wheat flour and mango peel flour concentration were analyzed in terms of water and oil holding capacity, foaming capacity and stability, swelling capacity, emulsion activity and stability, and bulk density, respectively. The present data may provide guideline for food formulation based on Perlis Sunshine mango peel flour.
Evaluation of Potential Alternative Ingredients for Formulation of Fish Feed
Authors: Naqtahnain Hamid Siti Nurhafa Imra , Mohd Yusof Siti Jamilah Hanim , Zakaria Zarina , Abdullah Rozaini
Published: April 2015

Freshwater aquaculture has high production rate, but the inconsistency supply of feeds can lead to low quality of fish. This initiates a high demand of fish feeds with complete diet to assist in growth and performance of the reared fish. The conventional fish meal has high protein content but it is expensive and can lead to high manufacturing cost of fish feeds. Therefore, present study is conducted to demonstrate nutritional value in several potential ingredients for formulation of new and economically favorable fish feed formulation for catfish. Proximate analysis of earthworm powder, fish meal, leucaena leucocephala leaves, soybean waste and rice bran was performed to analyze their moisture, ash, protein and crude fiber content. While amino acid analysis was carried out to obtain amino acid profiles. Based on the results, the selected ingredients demonstrated remarkable nutritional content which are required in the catfish diet, thus indicate their high potential as substitute ingredients in fish feed formulation.
An Efficient Scheduling Technique for Biological Sequence Alignment
Authors: Md Isa Mohd Nazrin , Zainol Murad Sohiful Anuar , Ahmad Mohamad Imran , Ramli Muhammad M. , Che Ismail Rizalafande
Published: April 2015

Computing alignment matrix score to search for regions of homology between biological sequences is time consuming task. This is due to the recursive nature of the dynamic programming-based algorithms such as the Smith-Waterman and the Needleman-Wunsch algorithmns. Typical FPGA-based protein sequencer comprises of two main logic blocks. One for computing alignment scores i.e. the processing element (PE), while another logic block for configuring the PE with coefficients. During alignment matrix computation, the logic block for configuring the PE are left unused until the time consuming alignment matrix computation finished. Therefore, a new technique, known as overlap computation and configuration (OCC) is proposed to minimize the time overhead for performing biological sequence alignment. The OCC technique simultaneously updating substitution matrix in a processing element (PE) systolic array, while computing alignment matrix scores. Results showed that, the sequencer achieves more than two order of magnitude speed-up higher compared to the state of the art, at negligible area overhead, if any.
The Effects on Tensile and Morphology of Ethylene Propylene Diene Monomer Blended with Recycled Nitrile Gloves (EPDM/NBRr)
Authors: Norhafizah Z. , Noriman N.Z. , Sam S.T. , Hanafi Ismail , Omar M.F.
Published: April 2015

Blending of two or more polymer together can reduce the cost and better processing advantages of product. Waste rubber powders blending with polymeric materials provide an improvement to the rubber quality. In this work, the effects on tensile and morphology of ethylene propylene diene monomer blended with recycled nitrile gloves (EPDM/NBRr) were studied. Four different compositions of ethylene diene monomer (EPDM) and recycled acrylonitrile butadiene rubber (NBRr) with two different size of NBRr (S1: 250-500μm and S2: 3-10cm) were used. The compositions of EPDM/NBRr prepared were at 95/5, 15/85, 25/75 and 35/65 respectively. The properties of tensile and resilience of EPDM/NBRr blends were determined. Results indicated that the tensile strength and elongation at break (Eb) of EPDM/NBRr blends decrease as increase in NBRr for both S1 and S2. However, the tensile modulus (M100) shows an increment with increase NBRr. Results of resilience decreases and scanning electron microscopy study indicates that when more than 35 phr of NBRr content were used, NBRr exhibited a weak EPDM/NBRr matrix interaction, thus decreasing the mechanical properties of EPDM/NBRr blends. For overall results, 15 phr ratio of NBRr in EPDM/NBRr (S1) blend showed an optimum result respectively.
Effect of Copper Concentration on Characterization of Cu2Zn0.8Cd0.2SnS4 Pentrary Alloy Nanostructures
Authors: Ibraheam A.S. , Al-Douri Y. , Hashim Uda
Published: April 2015

Cu2Zn0.8Cd0.2SnS4 pentrary alloy nanostructure were prepared and deposited on glass substrates with different copper concentrations ( 0.3, 0.5, 0.7 and 0.9 mol/L ) using Sol gel – spin coating method.morphological and analytical studies were investigated by Field Emission-Scanning Electron Microscope (FE-SEM), atomic force microscopy (AFM). It is found that the average grain size of Cu2Zn0.8Cd0.2SnS4 pentrary alloy nanostructure is 51.92 to 76.43 nm for the thin films prepared at 0.3, 0.5, 0.7 and 0.9 mol/L respectively .
Synthesis of Nanoporous Zinc Oxide by Anodizing of Zinc in Distilled Water
Authors: Voon Chun Hong , Derman Mohd Nazree B. , Hashim Uda , Lim B.Y. , Ting Sam Sung , Foo Kai Loong , Ten Seng Teik
Published: April 2015

In this work, ZnO nanoporous thin films were formed by anodizing of Zn plates in 500 ml distilled water of 25°C at voltage ranged from 10 V to 30 V. As anodized zinc plates were characterized by using SEM and XRD. Characterization of as anodized Zn plates using SEM showed that the morphology of the as anodized Zn plates were significantly influenced by the anodizing voltages. Nanoporous ZnO thin films were formed when 25 V and 30 V were used while ZnO thin films without nanoporous structures were formed when 10 V, 15 V and 20 V were used. XRD analysis indicated the ZnO thin films formed at 10 V to 30 V were of hexagonal wurtzite structures.
Langmuir-Blodgett Film of Multi-Walled Carbon Nanotubes for Hydrogen Sensor on Paper
Authors: Ramli Muhammad Mahyiddin , Mat Isa Siti Salwa , Md Isa Mohd Nazrin , Kasjoo Shahrir Rizal , Henley Simon J.
Published: April 2015

Langmuir-Blodgett technique was applied to build optically homogeneous film of functionalized multi-walled carbon nanotubes (MWCNTs) on paper substrate. The palladium (Pd) nanoparticles were drop-casted onto MWCNTs network films before being exposed in hydrogen (H2) gas molecules environment under vacuum and atmospheric pressure at room temperature. The results demonstrate that the functionalized MWCNTs dispersed with Pd nanoparticles show good H2 sensing response on paper substrate where the sensitivity of around 10 % was recorded at only 2 minutes exposure time.
Characteristics of Carbonized Bamboo at Various Temperatures
Authors: Munirah N.R. , Noriman N.Z. , Zakaria Muhammad Salihin , Fatin M.H. , Sam S.T.
Published: April 2015

The effect of carbonization temperature and heating rate on the characteristics of carbonized bamboo were investigated. Bamboo was carbonized at different temperature (250, 450 and 650°C) and heating rate (5 and 15°C/min). The results obtained shows that the char yield decreased with increasing temperature as well as heating rate. The carbon content is higher at higher temperature and heating rate. It also was observed from X-Ray Fluorescence (XRF) analysis that potassium and silica were the most predominant elements in carbonized bamboo. From Fourier Transform Infrared Spectroscopy (FTIR) spectra, it can be seen that most of the functional groups were diminished as the raw bamboo was carbonized and the intensity decreased with increasing carbonization temperature. Carbonization at 650°C with heating rate of 15°C/min was the best parameter for producing carbonized bamboo which content higher carbon.
Dye-Sensitized Solar Cell Using Syzygium Cumini Fruit as Natural Dye Utilizing Titanium Dioxide
Authors: Hambali Nor Azura Malini Ahmad , Yusof N. Roshidah , Norhafiz Hashim M. , Mat Isa Siti Salwa
Published: April 2015

In this paper we present fabrication and experimental results to the field of dye-sensitized solar cells, more particularly relates to Syzygium cumini fruit dyes as sensitizers. A dyes molecule from Syzygium cumini fruit adsorbs to each particle of the titanium dioxide. A dyes molecules act as absorbance of the visible light. Simultaneously, titanium dioxide plays a role as griping and absorbs place for natural dye molecules. Thus, an important component for overall performance in term of efficiency for dye-sensitized solar cells is the photogeneration from the absorbed dye in titanium dioxide. The dye-sensitized solar cells fabricated with the extract of Syzygium cumini fruit dye produced fill factor of 0.317 and conversion efficiency of 2.0 %.
Annealing Effect on Titanium Dioxide Layer in Paired Hybrid Carbon Nanotubes - Graphene as Dye Sensitized Solar Cell Working Electrode
Authors: Mat Isa Siti Salwa , Muda M.R. , Ramli Muhammad Mahyiddin , Hambali N.A.M.
Published: April 2015

Titanium Dioxide (TiO2) layer was deposited on conductive transparent glass substrate (ITO glass) at room temperature using doctor blade method. The TiO2 layer was annealed at 450 °C, 550 °C and 650 °C in a vacuum chamber for 1 hour. The morphology and porosity of TiO2 after annealed at different temperatures were characterized using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Spectrum Parameter Analyzer (SPA). Photocatalytic activity at different annealing temperatures was measured for dye sensitized solar cell that was fabricated using the new in-house carbon nanotubes-graphene hybrid as the dye material. The results showed that, the optimum annealing temperature was 450 °C. At that temperature, the active photocatalytic activity, which was initiated by the anatase TiO2 formation in paired with hybrid system as the working electrode, has contributed to the highest conversion efficiency of 0.0016% of the device performance.
Thermal Properties of Linear Low Density Polyethylene/Thermoplastic Starch/Banana Fiber Composites
Authors: Enaid Abduati Salem Abrahem , Ab Wahab Mohamad Kahar
Published: April 2015

The effect of thermoplastic starch (TPS) and banana fiber contents on thermal characteristics of linear low-density polyethylene (LLDPE) matrix were investigated. The measurements from differential scanning calorimetric (DSC) and thermogravimetric analysis (TGA), proved the effectiveness of TPS and banana fiber in improving the blend degradation. On the other hand the LLDPE/TPS/banana fiber composites showed better thermal stability than the LLDPE/TPS blend, which is reflected to the LLDPE chains movement restriction. The incorporation of banana fiber into the LLDPE/TPS blends was found to interfere with the chains movement and resulting in more thermally stable and improving the blends stiffness.
The Effects of Partial Replacement of Virgin Polyethylene (vPE) with Recycled Polyethylene (rPE) in vPE/rPE/Ethylene Propylene Diene Terpolymer (EPDM) Blends: Thermal Properties and Swelling Behaviour
Authors: Hanafi Ismail , Woon H.W. , Noriman N.Z. , Ting Sam Sung , Nik Yahya N.Z.
Published: April 2015

Studies on the thermoplastic elastomers (TPEs) had been extensively done. The incorporation of recycled materials into the TPEs formulation had been analysed, particularly involving recycled plastic due to its properties. The effects of partial replacement of virgin polyethylene (vPE) with recycled polyethylene (rPE) on the thermal properties and swelling behaviour of vPE/rPE/EPDM blends were studied. The discarded polyethylene used in the study was obtained from local wire insulation industry. The thermal properties and swelling behaviour of the blends were analyzed. Results show that increasing of sulfur loading had improved the thermal stability of the blends. The swelling percentage and swelling index of vPE/rPE/EPDM blends also decreased, inversely proportional to the increasing of sulfur loading. Thus, the increased incorporation of sulfur loading had improved the chemical and oil resistance of the blends.
Fabrication and Microstructure of Clay-Based Geopolymer Ceramic Using Powder Metallurgy Method
Authors: Jaya Nur Ain , Al Bakri Abdullah Mohd Mustafa , Ghazali Che Mohd Ruzaidi , Binhussain Mohammed , Kamarudin Hussin , Ahmad Romisuhani , Tran Mien Van
Published: April 2015

Geopolymers can be transforms into ceramics upon sintering. This paper reports the effect of temperature on the mechanical properties and microstructure of Na based kaolin geopolymer ceramic. The Na2O.Al2O3.4SiO2 was fabricated through powder metallurgy method. The geopolymers samples were exposed to temperature from 900 °C up to 1200 °C. The relative density, total porosity and flexural strength of sintered sample ranged approximately 84%-95%, 5.04%-15.73% and 20-70 MPa respectively. SEM analysis on as-sintered sample showed glassy phase while polished sample showed the pore structure and distribution. XRD results showed that nepheline appeared in all heated samples. Samples heated to 1200 °C achieved highest flexural strength and toughness of 70MPa due to the optimum density.
Effect of Aluminium Addition on Microstructure and Microhardness of Sn-0.7Cu-xAl Lead-Free Solder Alloy
Authors: Abdul Razak Nurul Razliana , Adli Nisrin , Saud Norainiza , Musa Sayyidah Amnah
Published: April 2015

The effect of Al particles addition on the microstructure and microhardness of Sn-0.7Cu-xAl lead-free solder was systematically investigated. The Sn-0.7Cu-xAl solder alloy was successfully fabricated via powder metallurgy (PM) method which consists of mixing, compaction and sintering. Results show that the crystallization of Sn occurs in two different modifications; α-Sn and β-Sn, where the formation of β-Sn able to reinforce the solder matrix. The Al particles also distributed homogeneously along the grain boundaries. The microhardness was improved by 19% as the weight percentage of the Al particles increased up to 1.0 wt.%.
Properties of Waste Eggshell as Calcium Oxide Catalyst
Authors: Ahmad Razi , Rohim Rohazriny , Ibrahim Naimah
Published: April 2015

The widespread usage of commercial calcium oxide (CaO) may lead to the depletion due to its non-renewable resources. CaO from eggshell waste has been studied to replace commercial CaO as it is cheaper and reduce cost of production. The objective of this study was to characterize CaO from waste eggshell. Raw eggshell was analyzed by thermal gravimetric analyzer (TGA) to obtain calcination temperature. The raw eggshell and calcined eggshell were characterized by x-ray fluorescence (XRF) and Fourier transform infrared (FTIR) spectroscopy to obtain elemental composition and functional group distribution. The morphologies of eggshell structures were determined by scanning electron microscope (SEM). TGA showed that the suitable temperature for calcination was 900oC. XRF and FTIR results showed that calcium carbonate (CaCO3) in the raw eggshell had been transformed to CaO. The irregular shape of raw eggshell also had been changed to regular shape for calcined eggshell.
Effect of Phthalic Anhydride Content on Properties of Soy Protein Isolate/Kapok Husk Biofilm
Authors: Pani Sellivam Ramyah Kalai Chelvie , Husseinsyah Salmah , Teh Pei Leng , Zakaria Marliza Mosthapa , Ismail Hanafi
Published: April 2015

Soy protein isolate (SPI)/kapok husk (KH) based biofilms were prepared by casting method. The effect of phthalic anhydride (PA) content on tensile properties and morphology were studied. The PA was use as a crosslink agent. It was found that the increasing PA content have increased the tensile strength and modulus of elasticity of biofilms, whereas the elongation at break decreased. At 1.5 % of PA showed the highest tensile strength and modulus of elasticity of crosslink biofilms. The morphology study indicates the crosslinking with PA improved the interfacial interaction between KH and SPI matrix.
Effect of Particle Size of W-Brass Composite on Gamma-Ray Absorption Coefficient
Authors: Mohammed Kahtan S. , Azeez Ali Basheer , Al Bakri Abdullah Mohd Mustafa , Kamarudin Hussin , Rahmat Azmi B.
Published: April 2015

In this study, the dependence of gamma-ray absorption coefficient on amount and particle size of tungsten (W) in W-brass sintered compacts was investigated. To attain this goal, two sets of different W wt. % were prepared (W 65wt. %, W75wt. % and W85 wt. %). One set has compacts of as received powder and the other set has compacts of ball milled powder. The results showed that gamma-ray attenuation coefficient is inversely proportional to the particle size of the tested sintered compacts and directly proportional to the W content. Vickers microhardness, attenuation properties and microstructural characterization were carried out on the sintered samples. The attenuation test was conducted using gamma spectrometer with Genie 200 software. The samples of ball milled powder and of the highest volume fraction of W showed the highest hardness and attenuation values.
Tensile Properties of Recycled Polypropylene (rPP)/Chloroprene Rubber (CR) Blends: Effect of CR Content
Authors: Husseinsyah Salmah , Yeng Chan Ming , Wei Ken Part
Published: April 2015

Polymer blending is one of the methods used to improve some insufficient properties of conventional polymers. The objective of this work was to study the effectiveness of CR content on the tensile properties and morphology study of recycled polypropylene (rPP)/ chloroprene rubber (CR) blends. The results indicated that the tensile strength and modulus of elasticity of rPP/CR blends decreased, however elongation at break increased as increasing CR content. The morphology study of rPP/CR blends showed the incompatibility between rPP and CR with the detachment of CR particles and CR particles pulled out from rPP surface.
Effects of Oven Ageing on Linear Low Density Polyethylene (LLDPE)/ Recycled Acrylonitrile Butadiene Rubber (NBRr)/ Rice Husk Powder (RHP) Composites
Authors: Ariffin Nurliayana , Ragunathan Santiagoo , Ting Sam Sung , Ismail Hanafi
Published: April 2015

The thermal degradation of linear low density polyethylene (LLDPE)/ recycled acrylonitrile butadiene rubber (NBRr)/ rice husk powder (RHP) composites with and without epoxidized nature rubber (ENR-50) were studied. The thermal degradation of this composite was evaluated for 30 days using oven ageing. The NBRr content was manipulated in this work and the particle size for the rice husk powder was 150-300 μm. The composites were prepared by using two-roll mills at 180 °C and then were compressed at 180 °C to produce a 1 mm thin sheets. The dumbbell samples then were analysed by using universal testing machine and field emission screening electron microscopy for tensile and morphological properties. The results obtained showed that tensile strength was decreased with the increasing of NBRr content for both oven ageing and control composites. However the oven ageing composites recorded much lower tensile properties. This may possibly due to the chain session of LDPPE matrix at longer heat exposure duration. This finding is supported by the morphological micrograph with less ductile features of the respective specimens.
Tensile Properties of Linear Low Density Polyethylene (LLDPE)/ Recycled Acrylonitrile Butadiene Rubber (NBRr)/ Rice Husk Powder (RHP) Composites
Authors: Santiagoo Ragunathan , Ting Sam Sung , Hanafi Ismail , Jaafar Mastura
Published: April 2015

The compatibilizer effect of ENR-50 on the tensile properties and morphology of linear low density polyethylene (LLDPE)/ recycled acrylonitrile butadiene rubber (NBRr)/ rice husk powder (RHP) composites has been studied. The RHP size utilize in this work is 150 – 300 μm. LLDPE/NBRr/RHP composites were prepared by melt mixing technique at 180 °C for 9 minutes at 50 rpm rotor speed using heated two roll mill. The series of composites investigated were 100/0/5, 80/20/5, 70/30/5, 60/40/5, 50/50/5, and 40/60/5. The composites were analysed by using tensile test and morphology examination. The result showed that the tensile strength of composite was decreased with the increasing of recycled acrylonitrile butadiene rubber (NBRr) content while elongation at break (Eb) were increased. However, the tensile strength and elongation at break result for composites with ENR-50 as compatibilizer showed higher values. The morphological finding supports the tensile properties which indicate better interaction between the RHP filler and LLDPE/NBRr matrix in the presence of ENR-50 compatibilizer.
Characterization of Epoxy-Layered Silicates Filled with Fly Ash-Based Geopolymer
Authors: Mat Daud Yusrina , Kamarudin Hussin , Ruzaidi Che Mohd , Osman Azlin Fazlin , Al Bakri Abdullah Mohd Mustafa , Binhussain Mohammed
Published: April 2015

Several epoxy nanocomposites incorporating layered silicates and fly ash based geopolymer were analysed by utilising the wide angle X-Ray diffraction (XRD) to characterise the nanoscale dispersion of the layered silicates. The morphological study of the nanocomposites using X-ray diffraction was an operative method to identify exfoliated and intercalated structures in the nanocomposite. It was discovered that the exfoliated structure was observed in the nanocomposites filled with montmorillonite (MMT) and fly ash-based geopolymers; while the intercalated structure was found in the nanocomposites with 3wt% of MMT. The results suggest that that the addition of fly ash-based geopolymers into epoxy/MMT mixture may contribute to superior compressive properties, in comparison to those nanocomposites without geopolymer filler addition.
Color and Antioxidant Changes in Various Natural Rubber Processes
Authors: Siriwong Suwimon , Rungvichaniwat Adisai , Klinpituksa Pairote , Musa Khalid Hamid , Abdullah Aminah
Published: April 2015

Fresh field natural rubber was coagulated by acetic acid, soaked in water at room temperature (WRT) or 70°C (W70) for 1 hr, and then dried in an oven at 40°C. Non-soaked natural rubber samples (NoW) served as a control. Two grades of natural rubber, namely air-dry sheet (ADS) and ribbed smoked sheet No.3 (RSS3) derived from the same latex, were also investigated. All dry rubber samples were characterized with Lovibond colorimeter according to ASTM D3157, as well as with a HunterLab spectrophotometer. Furthermore, all the dry rubber samples were dissolved in a chloroform:methanol mixture (4:1 v:v). The rubber was then precipitated out of the solution with methanol, and the remaining solution was quantitatively analyzed for total phenolic content (TPC). The plasticity retention index (PRI) was determined for all the dried rubber samples according to ASTM D3194. It was found that WRT, W70 and ADS were similar in lightness L*, while RSS3 had the lowest L*. W70 had the lowest redness a*, which increased in the order WRT, NoW, RSS3 and ADS. W70 also had the lowest yellowness b*, which increased in the order RSS3, NoW and WRT and ADS. Moreover, TPC was the lowest for the W70 sample, increasing in the order ADS, WRT, NoW and RSS3. The PRI was highest for W70, and decreased in the order WRT, RSS3, NoW and ADS. All of the PRI values observed were comparatively high relative to blocked standard Thai rubber 20 (STR20).
Influence of Montmorillonite Treated with Cetyl Trimethyl Ammonium Bromide Addition in Epoxy-Kenaf Composites
Authors: Zuliahani A. , Rozman H.D. , Rozyanty Abdul Rahman
Published: April 2015

The use of natural fiber as reinforcement in polymer composites has gained importance recently due to environmental concern and its abundance availability from agricultural crops and wood industry [1]. Many advantages offered by natural fibers over synthetic fibers include low density, greater deformability, low cost per unit volume, recyclability and biodegradability [2-3]. In addition, the mechanical properties of natural fibers such as flax, hemp, jute, sisal and kenaf are comparable with glass fiber in respect of strength and modulus [4]. Hence, many studies have been carried out to replace the synthetic fiber for composite preparation.
The Effect of Microwave Sintering Time to PM Aluminum Alloys
Authors: Derman Mohd Nazree B. , Mohd Suhaimi Syaza Nabilla , Che Daud Zuraidawani
Published: April 2015

Microwave sintering is new sintering technology method to produce Al alloys. The advantages of this method because of very short sintering time and less production cost compare to conventional sintering. However, the main problems in microwave sintering are required to be controlled sintering time due to rapid sintering mechanism. Therefore the effect of microwave sintering time to PM Aluminium will be studied. The compacted and sintered aluminium powder is placed in a microwave oven at a different period of 5 minutes, 10 minutes, 15 minutes and 20 minutes. Compression of 150 MPa is applied on aluminium powder to form pellets. Palette is shaped to 1cm in diameter and weighs 1g. SiC is placed together with aluminium samples in the microwave for the purpose of absorbing electromagnetic energy and is converted to heat. Results of different period sintering of aluminium pallet production altered physical properties of each sample. For a rapid sintering time, aluminium pallet does not show any binding reaction between powder particles. Whereas, for long microwave sintering period, solid particles phase change into solid-liquid phase caused by the movement and the formation of bonds between particles. Hence, this will be affecting the mechanical properties of the sample material.
The Influence of NaOH Concentration on Molar Ratios of Palm Oil Boiler Ash Based Geopolymer
Authors: Zarina Yahya , Kamarudin Hussin , Al Bakri Abdullah Mohd Mustafa , Ismail Khairul Nizar , Abd Razak Rafiza , Sandhu Andrei Victor
Published: April 2015

Palm oil boiler ash (BA) has been synthesis with alkaline activator to produce boiler ash based geopolymer. The ratio of BA/alkaline activator and Na2SiO3/NaOH was fixed for the entire experiment, where six different of NaOH concentration (6 M, 8 M, 10 M, 12 M, 14 M, 16 M) was used to produce geopolymer paste. The compressive strength of geopolymer paste with NaOH concentration 14 M showed the maximum strength which is 13.9 MPa. The strength reduce when geopolymer paste used NaOH concentration more than 14 M. In term of molar oxides SiO2/Al2O3 , Na2O/SiO2 and H2O/Na2O with the increasing of NaOH concentration Na2O/SiO2 ratio also increased but H2O/Na2O ratio decreased. Meanwhile SiO2/Al2O3 ratio remain constant because the BA/alkaline activator and Na2SiO3/NaOH ratio were constant in this study. The XRD analysis illustrated that the value of 2θ for all geopolymer samples were approximately the same which is 27° with major components of quartz and minor component of cristobalite.