Now showing 1 - 10 of 44
  • Publication
    Thermal, Microstructure, and Hardness Properties of Molybdenum Nanoparticles Added Tin -Bismuth Solder Alloy for Low-Temperature Soldering Application
    ( 2023-01-01)
    Singh A.
    ;
    Durairaj R.
    ;
    Natarajan E.
    ;
    ;
    Janasekaran S.
    The melting, microstructure, and hardness properties of the tin (Sn)-bismuth (Bi) solder alloy added with molybdenum (Mo) nanoparticles were investigated. The results showed that the Sn-Bi solder alloy with Mo nanoparticles fully melts at 148.00 °C, and the melting temperature was not drastically disordered by the Mo nanoparticles additions. The Mo has a high-melting point of 2623 °C, hence could not interfere with the solidification process of the molten Sn-Bi solder alloy. The microstructural morphology of the Sn-Bi added with Mo nanoparticles had much finer and compact lamellar structure compared to that of the unreinforced Sn-Bi solder alloy. Together with the dispersed Mo nanoparticles, there were Bi phases breaking out in the microstructure of the Mo-reinforced Sn-Bi solder alloy. Results from the hardness test showed a leap in the hardness value of 0.4 Hv, for the Mo containing Sn-Bi solder alloy. Presence of Mo nanoparticles and finer microstructure are believed to be the factors behind the increase. Reinforcing small quantity of Mo nanoparticles to the Sn-Bi solder alloy shows improvement to the microstructure and hardness as well as keeping the melting temperature below 150 °C.
  • Publication
    Prototype Design for Rubik’s Cube Solver
    Rubik’s cube is a modern day plastic material puzzle, where the one need to twist and turn to solve the multicolour squares. At the end, the puzzle need to be solved to make all the same colour cubes on the same surfaces. High intelligence is needed to solve it at a shorter time. Therefore, this research is to create a robot solver to solve the Rubik’s cube in short time smartly. Initially, the algorithm will scan the six surfaces of unsolved cube through a webcam and register the colours in the memory. Once it is completed, the solving algorithm will analyse and instruct the servo motors to twist and turn based on the computed solution. It is then pass it to the solving algorithm to identify the solving process and send the moving instruction to the motors by Raspberry Pi. The robot body was constructed using laser cutter. It is to make sure that the measurements are accurate and correct. To solve the cube, four servo motors with high efficiency were used to twist the cube in certain legit with the rules of the game. Another four servo motors are connected to the rack and pinion gears by clamping to hold the Rubik’s cube from falling when it is twisted. An improvised “Kociemba Algorithm”, also called as “The Two-Phase-Algorithm” is used. It reduced the required moves to solve the cube into a maximum of 25 moves and a minimum of 19. Conclusively, the final prototype discussed in this paper is tested with the solving algorithm. The results are presented.
  • Publication
    Mathematical Modelling Development of Sound Transmission Loss for Laminated Glass Using Response Surface Methodology
    The purpose of this study is to identify parameters that affect the rate of sound transmission loss. Mathematical model of sound transmission loss (STL) is developed for laminated glass and maximize the STL of laminated glass by using response surface methodology (RSM). The main objective of this study is to determine the type of material and number of interlayers for laminated glass on the STL performance. The two-load transfer function method (TFM) coupled with LMS Test Lab Acoustic software to determine the STL. The analysis was made by observing the performance of STL with respect to different materials used, such as glass and Perspex. Besides that, number of interlayers for laminated glass also had been studied for the performance of STL. Next, the RSM will be applied to develop mathematical modelling of STL for laminated glass. Optimization on the variable of laminated glass also has been conducted to obtain optimum variable of laminated glass in order to deliver optimum STL performance.
  • Publication
    In-situ Noise Measurement and Analysis for the Motorcycle Muffler
    ( 2020-01-01) ;
    Chuah H.G.
    ;
    ; ;
    Lok, Chip Hao
    Noise from the vehicles is one of the noise pollutions to the environment. The noises emitted by the vehicles have to obey the requirement of regulation of maximum sound pressure level permitted for respective vehicles. In this study, the aim is to reduce the noise emitted from the motorcycle muffler. The noise emitted from the motorcycle muffler is analyzed and measured using a sound level meter. The average sound pressure level of the motorcycle muffler is determined in certain conditions. The sound pressure levels for original installed muffler are recorded as 76.4dB, 79.5dB and 82.3dB under the constant speed of 10km/hr, 20km/hr and 30km/hr respectively by engaging 2nd gear. For the acceleration with the scope of 0 km/hr to 30 km/hr, the difference of sound pressure level between 2nd and 4th gear engaged is 5.4dB. The study is continued by using a modified muffler which contains sound absorptive materials. The absorptive materials chosen are glass wool, cotton and Styrofoam and they are taking turn to be placed into the modified muffler to reduce the sound pressure level. Then the experiment is repeated. By applying 100g absorptive materials in the modified muffler, the reduction of sound pressure level are recorded as 12.6% (glass wool), 7.5% (cotton) and 4.4% (Styrofoam) compared with original installed muffler while 2nd gear engaged. Styrofoam is observed does not perform significantly in absorbing sound or noise in this study. Glass wool demonstrates relatively better sound energy absorption compared with cotton. In general, soft and porous materials are considered good performance in sound absorption. Denser materials are better at soundproofing or sound blocking. Therefore, glass wool with relatively higher density among the investigated absorptive materials in this study has the greatest sound absorption performance.
  • Publication
    Performance of concrete gravity dam with various height of dam based on static pushover analysis
    The study was related to the performance of the concrete gravity dam with a various height of dam based on static pushover analysis. Based on the concepts of nonlinear static pushover analysis, a lateral incremental load is applied to the dam body after exerting gravitational and hydrostatic loads. In a concrete gravity dam, inertia loads and hydrodynamic loads are the types of lateral loads generated in earthquakes. The four concrete dams of various height had been analyzed by using ABAQUS. For each model, there were 10 trials analysis of increasing lateral load until the dam reached its limit state. The four finite elements of the concrete gravity dam with various height will be designed. The various height of concrete gravity dam has been specified to 50m, 75m, 100m and 125m. The analysis had been run and the limit state of concrete gravity dam such as cracking will be determined. The magnitude of lateral pushover load will be increased consequently until the dam reached its limit state.
  • Publication
    Acoustical Analysis and Optimization for Micro-Perforated Panel Sound Absorber
    The main objective of this study is to maximize the rate of sound absorption by applying the parameters of micro-perforated plate (MPP) such as the holes diameter, holes spacing, thickness of MPP, and air cavity depth of MPP. In this study, an optimization algorithm – Firefly algorithm is adopted to determine an optimum set of four parameters for MPP. There are four pieces of MPP with different holes of diameter and spacing was used as specimens. The two-microphone impedance tube method was used to measure sound absorption coefficient (SAC) of MPP sound absorber according to ASTM E1050-12 standard. From the experiments, MPP C (hole diameter = 0.5 mm, hole spacing = 7 mm) for both air cavity depth (30 & 60 mm) score the highest SAC which is 1.00 while MPP B (hole diameter = 0.9 mm, hole spacing = 5 mm) obtain the lowest SAC for air cavity of 30 and 60 mm, which are 0.62 and 0.54 respectively. Then, the firefly algorithm is applied to obtain the optimal solution the set of parameters for MPP sound absorber to reduce the noise level. Hence, it is concluded that by increasing the air cavity depth, holes spacing, and decreasing holes diameter size can increase the rate of sound absorption for MPP. The optimal set of parameters obtained from this study for MPP sound absorber for air cavity, hole diameter and holes spacing are 30, 0.71 mm and 0.5 respectively.
  • Publication
    Quantifying geometrically necessary dislocation with surface roughness effect in copper (111) under indentation
    ( 2023-01-01)
    Kok W.M.
    ;
    Chuah H.G.
    ;
    How H.G.
    ;
    Teoh Y.H.
    ;
    Yee H.M.
    ;
    The present study investigated the geometrically necessary dislocation (GND) with the influence of the surface roughness by establishing the relation of roughness in GND for indentation. The single crystal copper with (111) oriented surface plane was chosen and polished to various roughness levels ranging from 32.7 to 224 nm and subjected to indentation. The increase in surface roughness revealed to increase in the GND and statistically stored dislocation density. As the indentation force decrease from 9.8 to 0.245 N, the plastic strain gradient related to GND increase from 0.0001 up to 0.0017 µm−1 for each 1 nm increment of surface roughness.
  • Publication
    MICROWAVE ABSORPTION ANALYSIS ON HEATED EDIBLE SPIRULINA WITH VARIOUS TEMPERATURES
    This paper discusses the microwave absorption analysis of edible Spirulina by using WR62 and WR90 rectangular waveguides in conjunction with Agilent P-series Vector Network Analyzer (PNA). Heat might lead to the degradation of spirulina. This phenomenon involves the chemical and physical reaction that is associated with the variation of dielectric properties. These properties determine the propagation mechanism of microwaves within the sample or material. Hence, an assessment method to detect a nutrient change in spirulina due to heat is necessary. In this context, a microwave absorption measurement system was developed to study the reflection coefficient, transmission coefficient, and absorption coefficient of Spirulina tablets over temperature. The transmission/Reflection line method is well-known because it is non-destructive and rapid in analyzing chemical and physical properties. In this work, Spirulina tablet is used since it is a popular food supplement that is believed to be able to treat diseases is and good for health. The reflection, transmission, and absorption measurements were conducted on Spirulina from 12.4GHz to 18GHz.
  • Publication
    Analysis of Vibration for Grass Trimmer
    Grass trimmer is identified as a type of machine which contributes high vibration level and can cause hand-arm vibration. Hand-arm vibration syndrome (HAVS) can cause musculoskeletal disorder, neurology and complex vascular. The risk of developing HAVS is depending on the magnitude of vibration transmitted to the tool handle, the duration of vibration exposure and the user sensitivity to HAVS. In this study, a prototype handle is designed to reduce the vibration level. Three rubber mounts were used as isolator in the experiment. There are three isolators was selected to measure the different acceleration between the specimen. In addition, the transmissibility of engine was selected to compare between the original and three different isolators but on transmissibility of handle was compared between three rubber mounts. Every isolator has different value of stiffness and damping. When stiffness and damping are decrease in value; the vibration level was decreases. However, decrement of stiffness and damping, the value of transmissibility were decreases. In addition, the dynamic behavior as natural frequency and mode shapes of free analysis was determined between the original handle and the prototype handle. According to the analysis, the local and global vibration were found in the vibration mode of the grass trimmer.
  • Publication
    Smart SMS- based appointment management system for hospitals in rural area
    Nowadays, many hospitals are seeking for smart managing their operations. Based on the discussion with a local private hospital in Penang, Malaysia, there are problems in managing the appointments of dialysis patients. The dialysis center staffs currently having manual management system, where the staffs will call the patients one by one to find out whether they are available to fill the empty slots for the dialysis for the day. It is indeed troublesome for the staffs and the patients. Patients at times are not ready for filling the slots even though they wanted the dialysis, may be due to last minute arrangement for timing and transports. Thus, there is a need to have a system which can manage the appointments for dialysis patients. The purpose of the research is to automate the existing manual appointment system by the help of computerized devices, and to develop a dialysis appointment management system which is user-friendly, simple, fast and cost - effective. The main function of the system is to make an appointment and to store patient details, which will be an easier retrieval for the attendants. The system will identify the empty slots available, and will contact the patients to check the availability. Based on the input from the patients through Short Messaging System (SMS), the appointment will be sorted. The administrators can login to the Smart Appointment Management System using an authorized username and password for viewing and making changes manually.