Urea Formaldehyde Composites Reinforced with Sago Fibres Analysis by FTIR, TGA, and DSC

Agricultural material or biomaterial plays an important role in the field of fibre-reinforced polymeric materials with their new range of applications and achieves the ecological objective. Composition and structure of the nature fibre and matrix must be taken into consideration for the end use. In this project, Sago fibre particleboard bonds with Urea Formaldehyde to form composite. Fourier Transform Infrared (FTIR) spectra are used to characterize the Sago/Urea Formaldehyde composite in terms of their functional group and bonding. Sago/UF composite with smaller particle and higher loading of fibre with 15 wt% of UF matrix has the higher curing properties. The composite will have a denser structure by adopting bigger particle and higher loading of UF matrix. The Sago/UF composite only endures a single stage of decomposition. Thermal stability results indicate that particle size, particle/matrix interface adhesion, and particle loading have great influence on the thermal properties of the composites

A Numerical Approach to the Efficient Analysis of2D RF-MEMS Capacitor with Accelerated Motion

The advancement in new numerical technique is the key to success of newer generation RF MEMS devices. In this paper, a novel time-domain modeling technique that has the capability to accurately simulate the transient effect of RF MEMS variable capacitors with accelerated motion controlled by the coupling of the electrostatic and mechanical forces is presented. The relation between the sinusoidal modulations of the frequency with the acceleration is shown. Its validity has been demonstrated in comparison between the computational results of the displacement with the theoretical results. Both results are in very good agreement. The next work will be considered to include the damping coefficient. Due to its numerical efficiency, the proposed technique can be a useful technique, which makes it suitable for the numerical analysis of the moving boundary problem in the near futur

Fatigue life cycle prediction equation based on grain angles and stress levels for Acacia Mangium

This study aims to investigate and understand the nature of Acacia mangium axial fatigue strengths under repeated stress. Acacia mangium trees, which were cut to produce oven-dried dog bone shaped specimens, were tested in repeated axial-tensile loading with sinusoidal waveform. Findings of this study had shown that Acacia mangium has a significant difference in the strengths parallel and perpendicular to the grain line. Extreme reduction in tensile strength for 0° and 90° grain angles saw a shift from 143.87 MPa to 6.32 MPa (a 95.6% reduction of the Ultimate Tensile Strength). It was observed that the Acacia mangium N-S (Wöhler) plots showed an exponential correlation, in which the N – intercept of the vertical axis was at five (5) million cycles, while the intercept of the horizontal S – axis, was at 143.87 MPa. It was also observed that Acacia mangium has a fatigue endurance limit at 10% of the ultimate tensile strength. From static testing, the Osgood’s coefficient of species for Acacia mangium, (a), was identified algebraically to be 0.49. The finding showed that life cycles predicted by the Fatigue Life Prediction Equation as having almost similar magnitudes with the results defined by the verification test for each stress level. The comparison between the verification test results and the predictions by the equation indicated an impressive fit between them at 30° grain angle

Effects of density of sago/urea formaldehyde particleboard towards its thermal stability, mechanical and physical properties

This study examined the effect of density on the thermal stability, physical and mechanical properties of sago particleboard. Sago particles and Urea Formaldehyde (UF) were used as raw materials in the fabrication process. The fabrication and testing method were based on JIS A 5908 standard. The samples were prepared based on different desired density and went through a series of thermal stability, mechanical and physical tests. Mechanical properties of the composites were characterized by tensile, flexural, impact strength, screw test and internal bonding which had great influence on the particleboard performance. All the panels were tested for physical properties (water absorption and thickness swelling) to identify their use for indoor application. Thermal properties like thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) for the Sago/UF composites were analysed. The results showed particleboard with 800 kg/m3exhibited the optimum strength on Internal Bonding, Screw test, Bending and Flexure test. Particleboard with 700 kg/m3has better performance on Impact test. 500 kg/m3 showed better curing properties with DSC. TGA showed that all the Sago/UF particleboard decompose with single-stage and were decomposed into three main steps like water absorption, volatile and char

Effect of pressing pressure on physical and mechanical properties of ELAEIS GUINEENSIS fronds composite board

Performance of composite boards usually depends on the raw materials selection and fabrication parameters. This paper presents the effect of different level of applied pressure towards the performance of the end product of Elaeis guineensis composite board. The OPF was collected from a private plantation in Sarawak and refined into smaller particles by using a crusher machine. Sieved OPF particles that retained on the 0.60mm sieve mesh were used to fabricate composite boards with a targeted density of 0.7g/cm3. The 20 cm × 20 cm × 0.50 cm composite boards were fabricated under same hot press temperature of 160℃ for three different applied pressures of 5MPa, 6MPa, and 7MPa respectively. The physical and mechanical properties test were conducted according to the Japanese Industrial Standard (JIS A5908:2003). It is indicated from the results that the performance of Elaeis guineensis composite board improved with increasing applied pressure. The composite boards satisfied the provision set for the internal bond (IB) strength and modulus of rupture (MOR) in JIS A5908:2003. Unfortunately, the thickness swelling percentage exceeded the maximum set value. Overall performance investigated that Elaeis guineensis composite board is suitable to be used in indoor applications such as based materials, decorative boards, and teaching aids

Macro-surface Modification through Exploitation of Rivets and Dimples –Numerical and Experimental

Research related to rivets and dimples has been conducted as early as the 1930s. The irregularities of surfaces have believed to be a factor to fuel consumption increase of airplanes. NASA reported that it is vital to eliminate the surface irregularities or other protuberances from the surface that is exposed to the airflow [1]. This is believed to due to the extreme increase of the drag coefficient

VARIATION OF CHEMICAL PROPERTIES, CRYSTALLINE STRUCTURE AND CALORIFIC VALUES OF NATIVE MALAYSIAN BAMBOO SPECIES

The chemical properties of four common Malaysian bamboo species locally known as Beting (Gigantochloa levis), Semantan (Gigantochloa scortechinii), Lemang (Schizostachyum brachyladum) and Akar (Bambusa vulgaris) were studied. Chemical analysis shows that the alkaline extractive content for Malaysian bamboo species studied was within 24.4% to 25.6%, ethanol-toluene extractive content for Malaysian bamboo species was within 4.0% to 7.2% and water extractive content was within 10.4% to 12.8%. The average value of holocellulose content for Malaysian bamboo was between 64.5% to 70.67%, Klason lignin within 25.3% to 28.4%, cellulose content was between 28.5% to 33.8% and α-cellulose content for all bamboo species was within the range of 40.7% to 47.9%. The crystallinity of bamboo samples was between 42.0 to 44.4%, indicating their semi-crystalline structure.  Heating value of bamboo ranged between 17.0 MJ/kg to 18.1 MJ/kg with G. scortechinii having the highest heating value.. The Inductive Couple Plasma Atomic Emission Spectroscopy (ICP-ES) analysis showed that Potassium (K) and Calcium (C) were the major elements in the ash of all bamboo samples. This study demonstrates the potential of native bamboo species as an alternative sustainable raw material to wood for a wide range of applications

Engineering Mathematics I: A Case Study of First Year Students at Faculty of Engineering, UNIMAS

The subject of mathematics is important as a prerequisite and requirement as most topics in engineering courses widely employ these fundamentals. The paper will describe an analysis based on Engineering Mathematics I course results for first year student of Semester I 2009/2010 academic year at the Faculty of Engineering, University of Malaysia Sarawak (UNIMAS). The aim is to identify the topics within Engineering Mathematics I, which may cause some difficulties for new students to understand. The performance that directly related to the students’ weaknesses is obtained from the continuous assessments of the course, end of semester report analysis based on course outcomes and item analysis. The results will be used as the basis for improving the teaching and learning process for this course

Effect of annealing temperature on electrical properties of hybrid ZnO/PTAA based heterojunction diode

A hybrid type heterojunction diode based on Zinc Oxide (ZnO) and Poly(triarylamine)(PTAA) thin films is fabricated using radio frequency and spin coating method. These are conducted in ambient condition. This research is done to investigate the effects of temperature on Schottky properties of ZnO/PTAA diode. PTAA is chemically dissolved in chloroform solution and deposited onto ZnO thin film at different spin rate of 1000 RPM and 2000 RPM. The fabricated diode is then annealed for 20 mins at a temperature ranging from 100 °C to 150 °C and surface morphological of fabricated diodes is observed using advance material microscope (HIROX). Investigation of current-voltage (I-V) is carried out in various bias voltage from -4.0 V to 4.0 V using Keithley 4-point prob. Investigation revealed that, diode show rectifying behaviour towards the increasing in annealing temperature. The highest ideality factor obtain is 1.62 at 120°C for 1000 RPM with barrier height of 0.745 eV and series resistance of 2.645 KΩ. The barrier height of diodes increases gradually with increasing in temperature while ideality factor decreases. Meanwhile, series resistance decreases significantly over increasing temperature from 4.28 KΩ to 0.412 KΩ for 1000 RPM and 4.166 KΩ to 0.063 KΩ for 2000 RPM. It clearly reveals that the temperature is highly correlated with the ideality factor of the device thus effecting the barrier height and series resistance in the devic