Development of Efficient Frequency and Sensitivity of Transducer on Flaw Measurement by Using Ultrasonic Testing Method on Thin Carbon Steel Plate

Throughout several decades, welded pipes are some of the critical areas that required scheduled inspection. The Ultrasonic Testing Flaw Detector (UTFD) method of Non-Destructive Testing (NDT) is one of the reliable technologies for early detection of any internal flaw that would present an impressive danger. The objective of the research is to determine the selection of transducer in detecting defect at Carbon Steel sample with single Vee butt joint. The experimental work in this study is using two different frequencies of transducer, which are 2MHz and 4Mhz. Each of the transducer represent by three different angles, which are 45°, 60° and 70°. The sample with thickness, t = 12mm is inspected with several types of scanning movement including depth, swivel, orbital and lateral scanning. Other parameter involves is different sensitivity of the transducer by controlling the gain of the machine. From the observation of the results, the sensitivity is directly proportional with the angle of the transducer, where for 4MHz, the readings for gain at 45°, 60° and 70° angles are 43.30 dB, 47.50 dB and 48.30 dB, respectively. At the end, it can be concluded that 4MHz transducer of 60° angle provide the most accurate measurement of flaw detector compared with other angles. Furthermore, this research also shows that when the frequency is increase, it produces shorter wavelength and better resolution with shorter beam spread compared to low frequency transducer

Seismic Evaluation of High-Rise Building Performance During Earthquakes by Employing Shear Wall Framing Systems

It is vital to consider earthquakes in high-rise building design due to the potential seismic hazards that can pose substantial dangers to the structural integrity and safety of these structures. These buildings are more prone to lateral forces and vibrations during an earthquake, given their height and mass. Incorporating seismic design measures, such as the use of shear walls, helps mitigate the effect of earthquakes on tall buildings, ensuring their resilience and the protection of human life and buildings. Designing structures exclusively for seismic protection may be economically impractical, given the rare occurrence of earthquakes during a structure\u27s lifespan. Despite the infrequency of earthquakes in Malaysia, concerns among Malaysians have arisen due to seismic activities in neighbouring countries, prompting a need for considerations in constructing structures that address both economic feasibility and potential seismic threats. This research focuses on evaluating the seismic performance of a 50-story tall building during earthquakes, utilizing shear wall framing systems. Response spectrum analysis is applied to assess various parameters such as displacement, drift, and stiffness at different levels. The results of these parameters in a building with shear walls positioned at both the centre and corners are compared to those of a structure lacking shear walls. The study reveals that the placement of shear walls and the symmetry of the frame impact the building\u27s performance during earthquakes. According to the findings, structures with shear walls demonstrate better resistance to deformation caused by seismic loads compared to buildings without shear walls. Therefore, integrating shear walls into tall buildings proves to be an advantageous strategy for mitigating seismic damage in high-rise structures. Therefore, incorporating shear walls into tall buildings proves to be a beneficial approach to mitigate seismic damage in high-rise structures.

Evaluation of Micro Hardness of Magnesium Alloy Coated with ZnO and Al2O3

Magnesium and its alloys have wide range of application in automobile and aircraft industries because of its excellent mechanical properties i.e. high strength to weight ratio, availability and good castability etc. However, some challenges occur in using magnesium and its alloys in automobiles where the material has to withstand high wear and it has to be hard.  In this work a study has been done on eleven samples of magnesium alloy AZ91 coated with different percentage mixture of ZnO and Al2O3 particles by plasma spray method. Effect of presence of ceramic particles on the surface of substrate was studied. Micro Vickers hardness test was conducted on the samples, and it was found that the hardness of the samples decreases with decreasing percentage of Al2O3 particles. Firstly, the hardness decreases slightly with decreasing percentage of Al2O3 particles and beyond 50% Al2O3 particles composition mixture the hardness decreases rapidly. Result shows that the contribution of Al2O3 particles plays important role in increasing the hardness of coated surfac

The Proximate and Ultimate Composition of Pulverised Coconut Shell

Biomass is gaining traction as a renewable energy source as they play a major role in global green transition. Authors believe that coconut shell has a huge potential comparable to wood and sawdust in burning appliances. However, the use of coconut shell in combustion industry still limited and unconventional due to limited of studied and uncommonly practiced. Hence, the analysis of coconut shell on its properties is a must as well as to highlight the good side of coconut shell as a fuel. The coconut shell residues were collected, dried, purified,  crushed and grinded to obtain in pulverised form. Then, the sample of pulverised coconut shell was undergo the proximate and ultimate analysis based on standard needs (ASTM E871, E872 and D1102). The results obtained were compared to other types of fuel. From the comparison findings, coconut shell has a huge potential to be utilize as fuel due to its low moisture content, low ash content, higher heating value and has sustainably sourced in Malaysia.

Non-Linear Modelling and Control of Permanent Magnet Synchronous Machine for Actuator Applications

Permanent magnet synchronous motors grabbed the attention due to their intrinsic characteristics. Aerospace applications necessitate great dependability and while reducing weight, complication, fuel intake, working expenses, and environmental effects. All these demands can be fulfilled to some extent with the PMSM motors because of their characteristics. The mathematical modelling of an Interior permanent magnet synchronous motor (IPMSM) including nonlinearities is proposed in this paper. The conventional models neglect nonlinearities such as hysteresis and eddy current losses, parameters variation with respect to rotor angle, magnetic saturation, cross-coupling effect, armature reaction, etc. The present model considers core loss and inductance varying concerning rotor position. Usually, the core loss is taken as a constant loss, but it varies with the speed. Ignoring the above parameters may deteriorate the performance of the motor in real-time compared to linear model. To validate the efficacy of the proposed model, two models are simulated in MATLAB and the results are compared

Comparative Analysis of Modular Pin-Fin Heat Sink Performance: Influence of Geometric Variation on Heat Transfer Characteristics

The advancement of digital technology in the age of Industrial Revolution 4.0 has driven other engineering sectors to keep up with the progressive demand for high-performance computing and electronics. Thermal management is one of the fields that play a crucial role in maintaining the performance of electronic devices by keeping the system temperature at an optimum level and preventing overheating. A heat dissipation device widely employed in computing and other electronic systems’ heat management is a fin-type heat sink, owing to its robust and simple design. In this work, the authors evaluated heat sinks of different pin-fin cross-sectional geometry, arranged in a staggered configuration, in terms of heat transfer characteristics under forced convection. Three basic geometries were chosen on the grounds of manufacturing easiness and market availability: circular, square, and hexagonal. All the tested geometries had approximately the same hydraulic diameter. Therefore, the results could be compared to each other. The investigation revealed that the square cross-section induced an excellent convection coefficient, hence higher heat dissipation, compared to the counterparts. The tradeoff between heat transfer performance and size-related parameters, such as surface area and material volume, is also discussed in this paper

The Effects of Fin Cant Angle and Fin Height on the Performance of a Low Altitude Rocket

It is known that aerodynamics play an important role in the stability of a rocket. Stability has been defined as a system\u27s tendency to recover or revert to its initial state following a perturbation. The location of the centre of gravity and the centre of pressure fundamentally determines the stability of the rocket. One of the main issues with a small rocket is that the viscous effect becomes more prominent, which may significantly alter the pressure distribution around its body.  Hence, when the scale is reduced, the study of aerodynamics effect on the rocket’s centre of pressure (thus stability) becomes more crucial. In this present study, we investigate the stability of a low-altitude rocket by determining the effect of spin stabilisation on rocket stability. The locations of centre gravity and centre pressure are determined in this study using the Barrowman equations. It was found that a fin height of 4 cm produces the ideal static margin of approximately 1.5. Furthermore, largest fin cant of 10° yields highest apogee. In general, the rocket\u27s static stability improves when the fin height is increased, while the fin cant angle affects the dynamic stability

Sustainability of Energy Conservation in HVAC System Using Fuzzy Logic

Nowadays, air-conditioning systems are installed in buildings to provide a healthy and comfortable environment for the occupants. However, it will consume a large amount of energy resulting in an expensive cooling cost in the building. This paper presents an approach to minimize the energy consumption of the heating, ventilation and air conditioning (HVAC) system. The main objective is to provide a solution to reduce the energy consumption of a house air system using fuzzy logic by controlling the expansion valve of the air conditioner. The membership functions of fuzzy logic consisting of two inputs and one output were used as a method to control the output temperature of the system. The output shows a reduction in the cooling cost of the HVAC system in a building

Numerical Optimization of Plasmonic CuO-Based Semi-Transparent Thin Film Solar Cell Device via L9 Taguchi Orthogonal Array Method and ANOVA

The future of smart cities and energy-efficient infrastructures are very much dependent on photovoltaic materials that are sustainable, functional and affordable. In this context, copper oxide (CuO)-based solar cells provide the advantages of energy harvesting coupled with semi-transparent light transmission. In this work, a p-CuO thin film layer was used together with n-doped zinc oxide (ZnO), Al-doped zinc oxide (AZO) and indium tin oxide (ITO) to form a semi-transparent thin film solar cell (STFSC) model developed using SCAPS-1D and optimized using Taguchi L9 orthogonal array and analysis of variance (ANOVA). Optimized parameters for the CuO absorber and ZnO window/buffer layers were obtained for the best values for doping variation level and layer thickness. With the optimized design parameters, the performance of the STFSC device was improved in terms of the open circuit voltage (Voc), short circuit current (Jsc), fill factor (FF) and efficiency (ƞ). Furthermore, the power conversion efficiency (PCE) of the STFSC device with and without CuO plasmonic nanoparticles correspond to 10.27 % and 15.57 % respectively. The increased light absorption was due to the effect of the larger surface area of the CuO plasmonic nanoparticles in the p-CuO absorber layer which increased light absorption and subsequently increasing the photocurrent

Demonstration of Efficacy of Exploiting ChatGPT Data to the Transformers-Based Models by Performing Bangla Intent Analysis

With the expanding mode of online opinion sharing, an automatic approach to intent analysis is necessary and useful in the practical scenario. Intent analysis inspects persons\u27 and entities’ viewpoints from online user-created texts. Conventional sentiment analysis deals with two classes: positive and negative. In this study, to extend the conventional sentiment analysis task, intent analysis deals with more important classes to obtain deeper insights. Accordingly, this study deals with five classes: pessimism, optimism, suggestion, sarcastic, and miscellaneous. Intent analysis with machine learning essentially needs a massive amount of data to generate a robust model. However, manually accumulating the training data is expensive, particularly in less dominant languages like Bangla. Hence, to obtain sufficient training data, this study generates, collects, and pre-processs Bangla restaurant data for the task by OpenAI ChatGPT API through prompt and data augmentation. These data are called “source data”. As no user-generated Bangla data is available in the literature, this study prepares and validates a new Bangla intent analysis dataset by collecting user-generated real data. These data are referred to as “target data”. Source data is utilized to assist the target task (i.e., main task) performed on the target data. By utilizing both source and target data, three approaches are proposed: combined data approach, semi-supervised learning, and stepwise learning. Experimental results demonstrated that the proposed semi-supervised learning with transformers-based models is effective in improving the performance of the target data by exploiting ChatGPT-generated source data. The best F1 score of the proposed semi-supervised learning is 0.74, while that of the baseline is 0.72. Additionally, we proposed some feature concatenation methods. In this case, the highest F1 score is 0.7