Siti Nor Azreen Ahmad Termizi
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Preferred name
Siti Nor Azreen Ahmad Termizi
Official Name
Siti Nor Azreen, Ahmad Termizi
Alternative Name
Ahmad Termizi, S. N.A.
Termizi, S. N.A.Ahmad
Termizi, Siti Nor Azreen Ahmad
Main Affiliation
Scopus Author ID
57000566700
Researcher ID
GXA-2631-2022

Research Output

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Effect of heat sink design on the thermal characteristic in computational fluid dynamics analysis

2020-12-18 , Khor Chu Yee , Mohd Al-Hafiz Mohd Nawi , Ishak M.I. , Kee W.C. , Rosli M.U. , Mohd Riduan Jamalludin , Siti Nor Azreen Ahmad Termizi

The thermal management in the electronic device or system using the heat sink is important to ensure the device or system operating under the allowable temperature. The present study aims to investigate the thermal characteristic (i.e., temperature distribution) of the various heat sink designs via computational fluid dynamics (CFD) analysis. The electronic cooling process of the heat sink is carried out via CFD software. The temperature distribution of the various heat sink designs (i.e., plate fin, circular pin fin and rectangular fin) was analyzed and compared. The CFD analysis revealed the plate fin heat sink has lowest temperature distribution on the fin region. High temperature distribution was observed on the pin fin heat sink. The non-uniform temperature distribution was attributed by the direction of inlet airflow, whereas the low temperature was found in the region that close to the inlet airflow. Thus, the research findings indicated the design of heat sink significantly affects the temperature distribution during the electronic cooling process.

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Conceptual Design Selection of Motorcycle Handle Brake Lever Component by TRIZ and Simulation

2021-01-01 , Rosli M.U. , Siti Nor Azreen Ahmad Termizi , Khor Chu Yee , Mohd Al-Hafiz Mohd Nawi , Chong C.S. , Ishak M.I.

The fuel consumption of vehicles can be affected by the weight of the vehicle. Trending on replacing the metal part or product with lighter composite material has emerged. By using polymer composite instead of metal material in producing an automotive component, the total weight of the vehicle will be reduced. This research aims to develop the conceptual designs of new lighter weight motorcycle handle brake lever by integrating Theory of Inventive Problem Solving (TRIZ) and FEA simulation. This research generates the best concept design based on user needs and product design specifications. TRIZ contradiction matrix and 40 inventive principles solution were applied in the early solution generation stage. The principle solution parameters for the specific design features were later refined using Morphological Chart to systematically develop numbers of concept design. After numbers of significant FEA simulation, decision-making processes are performed in selecting the most appropriate concept design. A design was selected as the best conceptual design as it has scored the highest in the concept rating. This research proves the significant contribution of integrating TRIZ and FEA simulation that will benefit the industry in conceptual design phase of producing a new product.

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Mechanical Design and Analysis of Safety Medical Syringe for Needlestick Injury Prevention

2021-01-01 , Ishak M.I. , Rosli M.U. , Siti Nor Azreen Ahmad Termizi , Khor Chu Yee , Mohd N.A. , Mohd Al-Hafiz Mohd Nawi

The occurrence of needlestick injury especially among healthcare workers and patients is really significant since long time ago. Apart from improper syringe usage management, the reuse syringe components and unsafe sharp wastes management also contribute to the incidence of unexpected injuries. It was reported that one of every 250 accidental needlesticks may result in the infection of human immunodeficiency viruses (HIV), Hepatitis B (HBV), or Hepatitis C (HCV). Based on the user needs identification, promising safety mechanism and handling as well as single use of the syringe are of major interests. Thus, the aim of the study was to design and develop a new syringe that completed with safety and ergonomic features to avoid the related injuries. Primary and secondary data had been collected through interview, observation and journal articles with a series of design concept development, three-dimensional (3-D) modelling, and computational technical evaluation stages were then undertaken. A number of mock-ups and prototype of the product was produced via rapid prototyping process which is 3-D printing approach using acrylonitrile butadiene styrene (ABS) as the material. The results showed that the proposed design of safety syringe is satisfactory in terms of its structural strength and working principle. Further enhancement may be necessary to strengthen the role of the material and needle cap in compensating the function of the syringe.

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Effect of twist blade distributor on velocity distribution in a swirling fluidized bed

2020-12-18 , Mohd Al-Hafiz Mohd Nawi , Ishak M.I. , Rosli M.U. , Suhaida Rasman S.N. , Mohd Riduan Jamalludin , Siti Nor Azreen Ahmad Termizi , Khor Chu Yee

Swirling Fluidized Bed (SFB) is one of the liquid-solid interaction in fluidization improved from conventional systems. This system is usually viewable in the power generation, chemical industry, material production and drying processes. Inside the SFB, there is annular blade distributor which will cause the air to pass through and create a swirl motion on the bed. The energy consumption of a fluidized bed system depends on the distributor's design. The current study has purpose a new design that applies to existing designs of blade inclination angle. The simulation study was conducted using Computational Fluid Dynamics (CFD) to obtain the result of velocity distribution and pressure drops on various blade distributor designs. This study uses two (2) twist angle (80 and 100 ) via number of blade distributor (40, 50 and 60). In this study, tangential velocity is the main velocity component by reason of the velocity represents the rotating air velocity in fluidization system. Overall, the design of the 100 twist angle and 40 blades distributor are the best distributors of blades compared to others.

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Multi Response Optimization of Injection Molding Parameters for Artificial Phalanx Bone Using Response Surface Methodology

2021-01-01 , Khor Chu Yee , Mohd Al-Hafiz Mohd Nawi , Ishak M.I. , Zainal S. , Rosli M.U. , Siti Nor Azreen Ahmad Termizi

Unintended features of the injected part may affect the quality of the product. The present study aims to optimize the injection molding parameters and minimize the shrinkage and sink marks for artificial phalanx bone of the index finger via response surface methodology (RSM). The injection molding process was numerically simulated by the software. The combination of the process parameters was designed by Central Composite Design (CCD) in RSM. Three important process parameters were considered, which are melting temperature, cooling time and injection pressure. Meanwhile, two responses (i.e., volumetric shrinkage and sink marks) were considered in the multi-objective optimization. Regression model, ANOVA analysis and perturbation plot analysis were also highlighted in this study. The simulation results revealed two most significant factors towards the responses and the optimum setting of process parameters were recommended to minimize the shrinkage and sink marks of the injected artificial phalanx bone. The optimum injection molding process parameters are 240 °C of melting temperature, 40 s of cooling time and 12 MPa of injection pressure. The optimized results are expected to be used as the reference in the fabrication of the artificial phalanx bone via injection molding.

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The effect of multi-staged swirling fluidized bed on air flow distribution

2020-07-09 , Mohd Al-Hafiz Mohd Nawi , Ishak M.I. , Rosli M.U. , Musa N.M. , Siti Nor Azreen Ahmad Termizi , Khor Chu Yee , Faris M.A.

Fluidization is characterized as an activity that transforms fine solids into a liquidstate via contact with either a gas or a liquid. Currently, Swirling Fluidized Bed (SFB) is one of the new system that contribute on flow mixing to the beds due to the gas source which impart on the solid particles. Further the fluidized beds system are used mostly in the chemical process industry, mineral processing, processes energy and etc. Based on the current fluidized bed system there are still lacking in reducing high pressure drop and keep the energy consumption at high efficient condition. Due to this tips, the conceptual design of a multi-stages SFB was proposed to improve fluidization quality and minimize elutriation at the same time without requiring any extra facilities. By using the simulation method (Ansys Fluent) the behavior of velocity component via selected configuration of fix blades number (30) and through to variant of blade horizontal inclination angle (10°, 12° & 15°) the multi-stage SFB will be investigate. Aims of this study is to identify the air flow behavior at first and second stage blade distributor. Therefore, effect with less blades number in producing on high uniformity velocity would be acquired. The present study has found that by using blade inclination angle of 10° the high velocity magnitude (more than 60 m/s) at two different level of stage distributor can be reached. Moreover, it clearly be seen at blade inclination angle, 15° the velocity uniformity was sustain at certain width and less superficial velocity value occurred compared to other configurations.

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Computation Fluid Dynamics Simulation of Airflow Ventilation System in 3D Indoor Mushroom Cultivation House Model

2021-01-01 , Siti Nor Azreen Ahmad Termizi , Zakaria Z. , Khor Chu Yee , Mohd Al-Hafiz Mohd Nawi , Thing C.P. , Ishak M.I. , Rosli M.U.

Mushrooms represent different species of fungi that can be found anywhere with suitable environmental condition for them to survive in soil. Oyster mushroom (Pleurotus ostreatus) is the second most cultivated mushroom worldwide due to simple cultivation, low cost production technology and high biological efficiency. Ventilation system of an indoor mushroom cultivation house is significant to ensure the removal of metabolic gas such as carbon dioxide, CO2 which produced by the mushrooms. High concentration of carbon dioxide grows oyster mushroom with long stems and small undeveloped caps. Therefore, the ventilation system with good airflow was investigated to ensure good quality of mushroom yielded. In this study, a computational fluid dynamics (CFD) simulation was used to simulate the airflow ventilation system in a 3D indoor mushroom cultivation house model geometry. The speed of fans was examined to determine the effective ventilation system in the geometry. The results indicated that the velocity of fan with speed 3 gave the efficient ventilation system in the model. This is due to the least CO2 concentration accumulated in the model by circulating the most CO2 out of the model. The physical mechanisms of these phenomena were analyzed which can be a basis for predicting the airflow in the real-world operation.

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A Novel Green Technology Kaffir Lime Extract as Lizard Repellent

2020-03-18 , Mohd Al-Hafiz Mohd Nawi , Ishak M.I. , Rosli M.U. , Ayub M.A.R.M. , Khor Chu Yee , Siti Nor Azreen Ahmad Termizi , Ishak N.

The ubiquity of lizard in homes and has caused huge problem to human. They are one of the very important agents to transmit Salmonella that cause food poisoning towards human being. Through this research the potential of Kaffir lime peel toward lizard was reported. The process to produce Kaffir lime extract is hydrodistillation extraction method. The repellency test of essential oil will be assess at different concentration (0%, 25%, 50%, 75% and 100%). The duration of observation will be test from 3 to 6 hour duration. The results has shown that the concentration up to 50% and above of essential oil from Kaffir lime peel extraction may reflect the lizards in a state of discomfort.

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Influence of Twisted Blades Distributor Towards Low Pressure Drop in Fluidization Systems

2021-01-01 , Zulkifli R.M. , Mohd Al-Hafiz Mohd Nawi , Ishak M.I. , Rosli M.U. , Siti Nor Azreen Ahmad Termizi , Khor Chu Yee , Faris M.A.

Swirling Fluidized Bed (SFB) is one of the systems that proposed vortexing to solid mixing due to a given gas source which impart on the solid mixing. This system is usually be used in the power generation, chemical industry, material production and drying processes. However, the used of blade distributor in SFB is still produced high-pressure drop even though it has been claimed the successful variant in fluidization systems. By using an annular blade distributor in a twist, the condition will cause in low-pressure drop and keep the energy consumption of a fluidized bed system in high efficient. The simulation study using Computational Fluid Dynamics (CFD) has been selected to investigate to the behaviour of velocity component and to determine the effects of the plenum chamber (axial entry) on airflow behaviour via twist blade distributor configurations. This study uses two (2) twist angle (80 and 100°) via several blade number 40, 50 and 60. Therefore low-pressure drop and high uniform velocity has be the main goal in this observation. The result of this study found that design on 100° twist angle via 40 number of blades distributor shows low a pressure drop besides being able to maintain the high airflow uniformity compared to other configurations.

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The modified phase inversion and sintering technique for fabrication of ceramic membrane: Influence of kaolin composition and drying temperature

2021-05-03 , Mohd Riduan Jamalludin , Siti Nor Azreen Ahmad Termizi , Khor Chu Yee , Hubadillah S.K. , Mohd Al-Hafiz Mohd Nawi , Ishak M.I. , Rosli M.U.

The practical use of ceramic membrane has been limited by their fabrication technique and brittleness. Nowadays, phase inversion and sintering technique for ceramic membrane fabrication has been received widely attention. However, the unavoidable unstable structure for fabrication of flat-sheet ceramic membrane using this technique is still becoming an issue. To overcome this problem, in this paper, flat-sheet ceramic membrane have been developed via modified phase inversion and sintering technique using kaolin as main ceramic material, polyethersulfone (PESf) as the polymeric binder and N-methylpyyrolidone (NMP) as the solvent, respectively. The modified phase inversion has been done by adding drying process before the immersion into solvent. The influence of kaolin composition (60-80g) and drying temperature (room temperature and 3oC) have been investigated extensively to optimize the preparation. The results showed that the ceramic membrane prepared at 80g kaolin composition with drying temperature of 3oC displayed the highest bending strength of 53.1g with excellent BSA and humic acid rejection. Therefore, this study proved that the problem of unstable fabrication technique for flat-sheet ceramic membrane can be solved via modified phase inversion through the influence of high composition and low drying temperature.

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