Volume 36 (03) May 2024

Biodegradable and environmentally friendly composite materials such as wood plastic composites (WPCs) have gained attention in industrial applications due to environmental concerns and global sustainability goals. However, owing to their unique structures and properties, cutting on WPCs can be challenging. Continuous wave (CW) mode laser may result in heat build-up and easily warp the WPCs during laser cutting. Therefore, minimizing these defects and determining the cutting parameters that influence the heat-affected zone (HAZ) by pulsed mode laser is essential. In this present work, 1 mm thickness of WPC 30 wt.% of wood fiber (WF) filled with recycled high-density polyethylene (rHDPE) has been experimentally cut by single-mode pulsed fiber laser to evaluate the minimum laser energy required to cut the WPC and the influence of cutting parameters on the HAZ. The HAZ was measured using a digital microscope, and the statistical significance of the cutting parameters to HAZ was determined by analysis of variance (ANOVA). The results confirmed that a minimum linear energy of more than 9 J/mm is required to cut the WPC. It has been found that the cutting speed is the major influence on the HAZ, followed by pulse width. Adequate interaction time by cutting speed and duration of the single-laser pulse also significantly affects the cutting process. The higher gas pressure could minimize the HAZ at the surrounding cutting region of the WPCs. Understanding the influence of these parameters could minimize the thermal effect of HAZ and improve the laser cut quality.

Keywords : laser cutting; natural composite; linear energy; ANOVA; material processing

This technical paper explains the fabrication and chacterization method of a three-dimensional bone scaffold composed of porous bioceramics and natural polymers for bone tissue engineering applications. In brief, hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) were mixed in a 7:3 ratio and fabricated as the porous bioceramic framework, while gelatin or collagen was used as an additional polymer on the bioceramic framework. Various techniques have been explored for creating pores within the bone scaffold. Micro-computed tomography scan results demonstrate that sacrificial template and binder techniques successfully produce uniform porous bone scaffolds. The average porosity for the scaffolds (n=6) is 52.36% ± 3.2, with 51.27% ± 3.3 being interconnected. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirm that there is no characteristic chemical structure transformation in the bioceramic. The PO₄³⁻ and HPO₄³⁻ groups are retained in the HA/β-TCP bioceramic after sintering at a high temperature of 1300°C. Polymers are successfully incorporated into the porous bioceramic framework through negative pressure followed by positive pressure. Mechanical testing results show that the maximum compressive strength of the collagen-free bioceramic framework is 1.750 ± 0.212 MPa, while the collagen-containing bioceramic framework is higher at 1.905 ± 0.007 MPa. The corresponding maximum compressive strain for the collagen-free bioceramic framework is 1.565 ± 0.757%, whereas the collagen-containing bioceramic framework is approximately three times higher, at 5.540 ± 1.032%. In conclusion, the porous HA/β-TCP bioceramic scaffold is compatible with tissue engineering applications and can enhance the mechanical strength of the bioceramic scaffold to resemble cancellous bone mechanical strength.

Keywords: Hydroxyapatite, Beta-tricalcium phosphate, bioceramic

Cage fish farming in Malaysia’s coastal areas is a significant industry that provides food and income for local communities. Since the country’s catch-fishing resources have been fully exploited, there is a huge market for developing the aquaculture industry to increase fish output and supply. However, disease outbreaks, pollution, and environmental degradation must be addressed to ensure sustainable and environmentally responsible practices. This can result in increased stress levels and susceptibility to diseases, ultimately impacting the overall well-being of fish populations within the aquatic ecosystem. Water quality plays a crucial role in fish farming as it significantly impacts the health and productivity of fish. However, the specific critical water analysis parameters that are most relevant to cage aquaculture in Malaysian coastal regions have not been comprehensively identified and defined, leading to uncertainties in monitoring and managing water quality. In the past, water quality detection needed manual sampling and laboratory analysis, which were time-consuming and resource intensive. This traditional approach cannot deliver real-time data. This literature examines the important water analysis parameters and contemporary technology that has the potential to be adopted by fish farmers in Malaysia and addresses the financial implications of such an adoption. The review protocol started by selecting the relevant literature and several important things were considered during the selection process. The identification and definition of critical water analysis parameters emerge as fundamental to effective water quality monitoring and management in cage aquaculture. By delineating these parameters, we can tailor monitoring strategies using recent technologies to the unique environmental conditions of Malaysian coastal regions, thus enabling more precise interventions when deviations occur.

Keywords: Water quality, Fish Farming, Coastal area, Water Analysis, Aquaculture Technology

Scientists and engineers are continually attempting to enhance the performance of asphalt pavements by altering the asphalt. Because of their natural compatibility with asphalt cement as well as their exceptional properties, polymers may offer an excellent opportunity for asphalt modification to extend service life and reduce early distress by enhancing the properties of hot-mix asphalt. This study aims to explain how the various polymers influence the properties of hot mix asphalt with a wet procedure using asphalt produced locally at the Al-Durah refinery and various polymers. Styrene-butadiene-styrene (SBS), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), and (PVC+SBS) are examples of these polymers. Three and five per cent of the polymer are utilized for SBS, PTFE, and PVC, respectively. The asphalt cement ratio for (SBS+PVC) was 2.5% by weight at various blending times. The polymer asphalt mixtures are evaluated using Wheel Track tests and then compared to the conventional mixture. The modification of bitumen with polymers enhanced its conventional properties, such as viscosity. In addition, it was determined that the mechanical properties of HMA prepared with PMB samples, as measured by wheel track experiments, improved with increasing polymer contents.

Keywords: Asphalt, polymer, viscosity, wheel truck, SBS, PVC, PTEF

The robot arm is a device consisting of a moving chain of links connected by joints. Electrical motors are frequently used to move each robot arm joint. An end-effector that can move freely in space is usually attached to one end of the robot platform, which is fixed. Robot arms can do repetitive operations at rates and precision far exceeding human operators. Nowadays, robot arm systems are widely used worldwide to increase the quality and efficiency of the manufacturing process in the industry. Typical applications of the robot arm system are assembly, painting, welding, pick and place operation, and others. Besides, many industries employ robot arms for various jobs such as selecting and putting, painting, and material handling. However, one of the most challenging issues in completing these jobs is determining the target location of the robot arm’s end-effector. There are two different methods for analyzing the robot arm’s movement: forward and inverse kinematic analysis. Based on the visual servo algorithm, this study uses inverse kinematics to execute the pick and place operation. First, an object recognition algorithm is implemented to identify the object to be grasped. Then, an algorithm to avoid any obstacles is done. The study’s findings show that good system performance has been obtained in all three algorithms: first, object recognition algorithm, second, obstacle avoidance algorithm, and lastly, visual servobased pick and place operation. Thus, it can be concluded that the robot arm’s visual servo algorithm is suitable for pick-and-place applications.

Keywords: Robot Arm; Visual Servo; Inverse Kinematic; Pick and Place

The large amount of rice straw production in Southeast Asia presents both challenges and opportunities for sustainable environmental management. Improper rice straw management poses significant environmental challenges, prompting interest in utilizing it for bioenergy production as a sustainable solution. However, a comprehensive understanding of the environmental implications throughout the entire lifecycle of rice straw utilization is poorly understood. A comprehensive approach of life cycle assessment (LCA) could provide valuable information concerning the environmental impact of rice straw utilisation for bioenergy. Therefore, this study attempts to provide a brief overview of the LCA of rice straw utilisation as a source of bioenergy in Southeast Asia. Several search engines and databases, including Springer, Web of Science, and Scopus, were used to select the articles for this review. These searching strategies involve three main processes: identification, screening, and eligibility. Following those process, a total of 13 articles were included in this review. The findings indicated that biochemical conversion pathways for producing bioethanol and biogas yield the greatest environmental benefits notably through greenhouse gas emissions reduction. This highlights the potential of rice straw bioenergy as a promising avenue for mitigating the impacts of climate change by curbing GHG emissions. In summary, this research underscores the significance of comprehending the holistic environmental implications of rice straw utilization for bioenergy, emphasizing the potential of specific conversion pathways to contribute to sustainable rice straw management and climate change mitigation in Southeast Asia, encouraging further research in this field for practice refinement and widespread adoption.

Keywords: rice cultivation; rice straw management; bioenergy; life-cycle assessment; sustainability

Earth retaining structures, ERSs, are used in many engineering fields. Special considerations and technical knowledge in geotechnical engineering should be adopted in the modeling, analysis, and design of ERSs. Some of these considerations are related to the soil models, and (quality, settlement, and inclination) of the backfill and foundation soils of the retaining wall, RW, as presented in this critical review. This review shows that the analysis and design of ERSs are highly affected by model adopted for soil behavior, and the quality and characteristics of backfill materials. The backfill materials affect the selection of material type and performance of the ERSs, furthermore, they impact the soil interaction with RW. In selecting an appropriate model, it is important to consider the effect of soil history and stress changes that may the soil experience in the future. The design of some types of ERSs, backfilled with a material predominantly finer than the coarse sand grain size, should be conducted with precautions due to the possibility of lateral earth pressure (LEP) changing from active state to at-rest state after construction. It is worthwhile to consider both short-term and long-term settlements in the analysis and design of ERSs as there are specific types of ERSs that can tolerate large short-term settlements but cannot tolerate large long-term settlements. Finally, under both static and dynamic loadings, the angle of inclination of the backfill soil greatly affects the distribution of LEP and the value of the resultant force behind the RW.

Keywords: Retaining walls design; Soil modeling; Plastic equilibrium; Rigid-plastic; Settlement toleration

Biogas-fed proton exchange membrane fuel cell (PEMFC) plants offer a sustainable energy solution, but their operation can pose significant hazards and risks. Ensuring the safety of these plants is paramount, especially given the potential for fires, explosions, and chemical exposures. This study evaluated hazards and risks in biogasfed proton exchange membrane fuel cell (PEMFC) plants using six analytical methods: Dow’s fire and explosion index (FEI), Dow’s chemical expo-sure index (CEI), Hazard and Operability Study (HAZOP), Risk Matrix Analysis (RMA), Bayesian Network (BN) and ALOHA® software hazard modelling. The FEI analysis revealed that the anaerobic digester and bio-gas storage tank exhibited severe hazards (FEI =170), thereby signifying the highest risks within the plant. CEI analysis revealed the spread of the highest hydrogen sulfide (H2S) concentration up to 129 meters from the anaerobic digester and storage tank location. Further assessment was conducted, calculating risk values using the RMA and performing additional HAZOP analysis specifically for these units. The results confirmed similar risk levels (4-20) between the units, except for a higher explosion risk in the storage tank. The novelty of this research lies in the application of Bayesian Network (BN) analysis. In addition to assessing the hazards associated with PEMFC, our BN analysis reveals that the risk of fire attributed to PEMFC ranges between 10% and 18%, while the risk of explosion falls within the range of 3% to 17%. Based on the hierarchy control concept, several effective mitigation controls were proposed to enhance the safety of biogas-fed PEMFC plants. In future research, a deeper exploration of human error and equipment malfunctions within hazard modelling is crucial for a more precise hazard assessment.

Keywords : Hazard Identification; Risk Assessment; Biogas; PEM Fuel Cell; Sewage Treatment Plant

The uncontrollable of sago bagasse waste from sago industry production become an environmental issue as it just dumping directly into nearby rivers which can affect a river pollution if not treated well. As it still has about 70% starch content, it has a potential to be converted to the others value-added product such as animal feed. However, before it can be converted to others product, it should go through a drying process to reduce its higher moisture content (90 wt.%), as well to prevent any micro bacteria growth and for long lasting packaging. Thus, this study focused on the evaluation of drying process at T=70 and 80 °C on reducing of its final moisture content by using three drying approaches: fluidized bed dryer (FBD), micro-oven and direct sunlight drying. Then, these samples of dried sago were analysed to determine its properties of starch, fibre, and ash, as well to study its functional organic chemical group by using Fourier infrared transform (FTIR) method. The results show the reduction of sago water content by FBD shown a significant result as compared to others drying methods as the FBD method produces a good solid mixed between particles. Besides, the drying rate using the FBD was achieved in a shorter time within 30 min as compared to oven which within 2 hours and sunlight drying within 6 days to achieve similar final desired moisture content at 11 wt.%. The analysis on the starch properties using the FBD was also almost 75% more higher than oven, which is about 70% starch content. Moreover, the presence of starch was successful proven by the presence of acrylic acid at a wavelength of 1539.72 cm-1 for FBD sample by using FTIR. In addition, using the FBD, the sago waste can maintain its quality as an animal feed by reached a brightness level, W1 as compared to the slurry sago waste where the dried sago using FBD is 58.78%, meanwhile the fresh slurry sago waste is 93.31%. In conclusion, the sago drying in the FBD at T=80 °C was selected as the optimum drying condition as it had achieved a short drying rate for desired final 11 wt.% moisture content and resulted in better on the chemical and physical analysis.

Keywords: Sago bagasse; Fluidized bed dryer (FBD); Oven drying; Sun light drying; Starch

Ferrofluids are known as magnetic liquids that are colloidal suspensions of ultrafine, single domain magnetic particles in either aqueous or non-aqueous liquids. For such fluids, the problem arises in calculating thermal conductivity, viscosity, and thermodynamic properties on nanoparticles and ferrofluids. Thus, the main objective is to determine thermal conductivity and viscosity for ferro-nanoparticles and ferrofluids. For this study, the ZnO and Fe3O4 are checked for mechanical properties such as SEM, TEM and XRD. Then, being suspended into the diesel engine oil SAE-50 as base fluid and surfactant, Triton-100, in preparation of two-step method. Ferrofluids are prepared for 0.1%, 0.4% & 0.7% w/v and stability of nanofluids are being observed for 5 days. From the results obtained experimentally, the nanoparticles were found to be in good stability as no coagulate occur. This is because the EDLRF acts as the opposite to Van der Waals attractive force which separates the particles from each other. Finally, the thermal conductivity and viscosity for ferro-nanoparticles and ferrofluids were successfully obtained and demonstrated. Statistical mechanics are then discussed to calculate the properties of ferrofluids. The analytical results from statistical mechanics are potentially be used to compare with the experiment data.

Keywords: Ferrofluid, ZnO nanofluid, Fe3O4 nanofluid, stability of nanofluid.

The acquisition of essay writing skills holds compulsory significance for all Malaysian Vocational Certificate (SVM) students at Vocational Colleges (KV), as these skills are embedded within the SVM Malay language course curriculum. Generally, students at KV exhibit a range of weak to moderate mastery levels in essay writing, particularly in terms of structuring and organizing essays in a systematic manner. Evidently, lackluster student performance was accentuated when a subset of students failed to respond adequately to essay prompts during the End of Semester Assessment, emerging as a substantial contributor to the failure rates within the Malay language subject. A survey unveiled a deficiency in systematic essay writing proficiency, resulting in student hesitancy and disinterest in addressing essay-related queries. In response, the researcher introduced a formulaic approach to essay writing with the aim of elevating student performance. A sample of 24 students from the Electronics Technology Program was selected randomly to participate in this study. Consequently, a study was conducted employing pre-test and post-test assessments to evaluate the effectiveness of the introduced formulaic approach within the study sample. The gathered data revealed a notable shift in student achievement levels, evidenced byimprovements in grades post-intervention and alignment with the prescribed scoring criteria. Initially absent in pre-test outcomes, the attainment of an ‘A’ grade by the study sample became evident following the post-test, wherein the formulaic approach was integrated into the teaching and learning process. This study establishes that students are capable of proficiently and systematically honing their Malay essay writing skills. Through the implementation of a structured methodology, it becomes apparent that learners can effectively bridge identified gaps, thereby enhancing their overall mastery of the subject matter. Consequently, this research holds implications for pedagogical practices geared towards fostering heightened competency in essay writing among SVM students.

Keywords: Essay Writing; Formula Method; Malay Language; KV Learning; Mastery of Writing

In recent years, watershed resilience has garnered a substantial interest driven by the need to sustainably manage vital ecosystems in the face of increasing pressures such as climate change and land-use alterations, leading to assortment of definitions and assessment approaches. This overabundance has occasionally manifested in ambiguity and, at times, contributed improper implementations. This review evaluates the capacities, and frameworks employed in quantifying watershed resilience across various geographical contexts. It synthesizes the current state of knowledge to identify trends, limitations, and areas requiring further investigation. Due to the limited number of prior researches synthesizing watershed resilience quantification methods, the primary contribution of this study lies in its consolidation and synthesis of diverse research efforts, shedding light on the evolving landscape of watershed resilience quantification. By critically examining the strengths and weaknesses of existing definitions and adopted frameworks, we aim to provide a roadmap for future research in this field. Additionally, this review emphasizes the importance of developing standardized indicators and frameworks to facilitate more robust and comparative assessments of watershed resilience. A critical research gap is the lack of a universally accepted assessment framework for watershed resilience, hindering comparability and decisionmaking. We advocate for interdisciplinary collaboration to establish a common framework integrating ecological, hydrological, and social aspects of resilience. In conclusion, this review underscores the urgent need to advance watershed resilience quantification and offers a clear research agenda. Addressing research gaps and fostering interdisciplinary collaboration can significantly contribute to the evolving field of watershed resilience assessment and management.

Keywords: Watershed; Resilience; Hydrologic Resilience; Resilience Quantification, Resilience Frameworks

Sustainable manufacturing has become a critical concern across various industries, including aerospace, automotive, and services. It involves the creation of manufactured products through economically sound processes that minimize negative environmental impacts while conserving energy and natural resources. Additionally, sustainable manufacturing aims to enhance employee, community, and product safety.This paper focuses on the machining process as a key component of sustainable manufacturing. Machining is widely used in manufacturing industries to fabricate components, but it also significantly contributes to environmental pollution. Sustainable machining has been a topic of discussion for over a decade. In sustainable machining processes, every factor acts differently like, the tool life, productivity, and effective utilization of resources must be increased. In contrast, the machining cost, machine cutting power, and adverse effect of cooling and lubrication fluids will be decreased. Important aspects of sustainable machining include dry and near-dry machining, cryogenic machining, and minimum quantity lubricant (MQL) were presented in this article. The effectiveness of these processes is assessed based on cutting tool life and the quality of machined components. In addition, the advancements consideration such as novel process variations, process hybridization, the use of sustainable tools and green transfer mediums, and the optimization of process parameters. Recommendations include increasing efficiency and reducing waste by incorporating recyclable tools in the machine industry implementing either stand alone or hybrid sustainable lubrication machining techniques.

Keywords: Sustainable Manufacturing; Dry Machining; MQL; Cryogenic Machining

Rolling of metals has found applications in automotive, construction, agriculture, railroads, housing, metal furniture making, home appliances, electronic cabinetry, pipes and tubing etc. These have as well contributed to human and environmental sustainability. Nevertheless, the applications of metal rolling processes and machines have not been adequately harnessed in our locality due to unavailability of the rolling machine in small scale industries, laboratories and workshops in institutions of learning in the region. Annealing heat treatment was carried out on a mild steel round bar of 50 mm diameter and length of 200 samples. The samples were charged into an SXL muffle furnace with an annealing temperature of 950oC. The mechanical properties and the microstructure of the rolled mild carbon steel were evaluated. The results of the performance evaluation of the machine through assessment of the metallurgical characteristics of the rolled products from the machine and assessment of mechanical properties such as tensile strength and hardness of the rolled products from the machine showed an increase in the tensile strength from 250.85 MPa to 258.85 MPa, an increase in the ultimate tensile strength from 535.88 MPa to 540.05 MPa, an increase in the hardness from 140 HV to 145 HV, and a decrease in the percentage ductility of the mild carbon steel from 56% to 51%. Also, the optical micrograph of the rolled samples shows a coarse microstructure of grain refinement from slipping and pilling of dislocations.

Keywords: Rolling Mill; Heat Treatment; Mild Carbon Steel; Hardness; Tensile Strength

Germanium selenide (GeSe) is a potential absorber material for thin film solar cells. However, many physical, electronic parameters and practical defect configurations that result in different effects on the performance of GeSe solar cells are not fully understood. In this study, a baseline of a GeSe thin film solar cell was designed and simulated using SCAPS-1D simulator. The physical and electronic parameters of the absorber layer is varied to investigate their effect on the performance of the solar cell. The simulation uses absorption files extracted from Xue et al. 2016 and the SCAPS-1D absorption model. Practical defect configurations are also introduced in GeSe thin film solar cells to optimize solar cell performance. Simulation results show that baseline GeSe solar cells had obtained Voc 0.62 V, Jsc 39.52 mA/cm², FF 79.34 and ƞ 19.48%. Simulation using the SCAPS-1D absorption model achieved a more accurate JSC contour graph compared to simulation using absorption files extracted from Xue et al. 2016. The highest efficiency of 26.13% was achieved at 1.40 eV bandgap, 4.27 eV electron affinity, 10 cm2/Vs hole mobility, 1E+18 1/cm³ hole concentration and 2000 nm GeSe layer thickness. For bulk defect, an increase in defect concentrations or capture cross section hole and electron (σ) reduce efficiency. For interfacial defect GeSe/CdS, total density of 1E+12 1/cm² with σ of 1E-13 cm², total density of 1E+18 1/cm2 with σ of 1E-19 cm², total density of 1E+16 1/cm² and 1E+18 1/cm² with σ of 1E-16 cm² have critical impact to solar cell.

Keywords: GeSe Thin Film Solar Cell; Bandgap; Electron Affinity; Hole Mobility; Hole Concentration; Thickness; Defect

Worldwide, SARS-CoV-2 has been responsible for millions of fatalities and extensive disability. Hence, to stop the spread of novel viruses like SARS-CoV-2, Omicron, and other worrying types, rapid and accurate diagnostic techniques are needed to identify symptomatic and asymptomatic carriers as soon as feasible. Early recognition and diagnosis are essential to effective epidemic management. However, different viral strains’ shapes and spatial characteristics are similar, complicating image classification, especially in medical virology. This study uses a super-pixels segmentation technique based on transmission electron microscopy (TEM) images to differentiate SARS-CoV-2 from SARS-CoV. This paper aims to develop a method that enables virologists to detect and diagnose viral infections more accurately. In results, SARS-CoV-2 had a median area of 25,145.54 pixels and SARS-CoV of 38,591.35 pixels. The model can help to better understand how viruses develop, spread, diagnose and contain outbreaks. Furthermore, an exceptionally low root mean square error (RMSE) of 0.0275 between the segmentation of the viral area between humans and machines is obtained. Indeed, this low error rate indicates the accuracy of this automated measurement technique. Finally, the developed superpixel segmentation technique provides quick and reliable identification of coronaviruses, promising to significantly contribute to medical virology and help manage epidemics by simplifying prompt viral diagnosis.

Keywords: SARS-CoV-2, SARS-COV, Artificial intelligence, superpixel segmentation, Transmission Electron Microscopy

Limonene production represents a compelling opportunity in the global market, given its competitive landscape dominated by a few key players who control nearly half of the industrial-grade limonene market. Due to the high polyisoprene content in vehicle tyres, along with the rising number of waste rubber tyres, the production of limonene by pyrolysis of tyres may represent a future trend to turn waste into wealth. Hence, a conceptual plant design was carried out to determine the feasibility of limonene production from waste rubber tyres in Malaysia. This feasibility study involved Aspen Plus simulation and illustrated the main processes using Process Flow Diagram (PFD), Piping and Instrumentation Diagram (P&ID), and comprehensive stream table integrating material and energy balances. The desired product, which is limonene, was produced by the gas-solid pyrolysis within a conical spouted bed reactor (CSBR) in an inert atmosphere of non-oxidizing, achieving limonene of 98% purity. Besides, process optimization via pinch analysis has been performed to recover 223.84 kWh of energy using heat integration, resulting in 62.06% of energy saving. From the economic analysis conducted, the total capital investment is RM12.9 million and the annual revenue is RM124.7 million with an annual limonene production of 543.1 tons. The financial analysis demonstrated a robust return on investment (ROI) of 303%, a simple payback period of 0.33 years and ta Net Present Value (NPV) of RM 432.2 million.

Keywords: Waste rubber tyre; Limonene; Conceptual plant design; Process optimization; Economic analysis

The purpose of this paper is to explore the role of Machine Learning (ML) in fortifying the security of cloudbased Internet of Things (IoT) systems, using a comprehensive security management approach. The methodological approach involved comparing different ML techniques such as Decision Trees, Random Forest, Support Vector Machines, and Convolutional Neural Networks. Their effectiveness was evaluated based on the accuracy of threat detection in cloud-based IoT systems. The findings revealed that Convolutional Neural Networks demonstrated the highest accuracy rate (98%) in threat detection, thereby significantly enhancing the security of IoT systems. It also identified improvements in threat detection, prevention, response, and system recovery across all ML techniques. Research limitations were primarily the rapidly evolving nature of both ML and IoT technologies, necessitating continual reassessments. The scope was also limited to cloud-based IoT systems, leaving room for further research on other types of IoT systems. The practical implications included improved system security, which could lead to increased trust and wider adoption of IoT technology in various sectors, from healthcare to home security. The social implications entail a safer digital environment, contributing to data privacy and reducing the risk of cyber threats for individuals and communities. The originality of this paper lies in its comprehensive approach to IoT security management using ML, providing valuable insights into the effectiveness of different ML techniques in enhancing threat detection accuracy.

Keywords: Machine Learning, Cloud-based IoT, Security Management, Threat Detection, System Performance

After serving their intended purpose, traditional asphalt pavements are destroyed and dumped across the neighboring fields in Pakistan, affecting the natural environment. Only 15% of the old asphalt material has been recycled on the Motorway (M-2) near Shekhupura. Thus, the current study was intended to increase the amount of recycled asphalt, utilizing waste engine oil (WEO), waste cooking oil (WCO), and waste brown grease (WBG) as rejuvenators. Therefore, the asphalt mixture containing 50% recycled materials, rejuvenated with 5%, 10%, 15%, 20%, and 25% WEO, WCO, and WBG, respectively, were investigated. The asphalt samples for Marshall Stability, indirect tensile strength, and rut resistance were prepared and tested as per ASTM D1559, ASTM D979, and ASTMD8360, respectively. The results showed that WEO, WCO, and WBG of 15% and 20%, respectively, are best for equating the properties of recycled binder to those of neat binder, except for ductility characteristics. The results also demonstrated that, in comparison to the traditional asphalt mixture, asphalt mixes with 50% recycled materials performed significantly better in terms of Marshall stability at 15% utilization of WEO, WCO, and WBG, respectively. Additionally, it is established that recycled asphalt mixture, at WEO of 15%, displayed equivalent rut resistance to virgin asphalt mixture. The results of this study will help recycle old asphalt materials for practical engineering purposes, lowering the dependence on natural resources and benefiting the environment.

Keywords: Recycled Asphalt Materials Marshall Mix Design, Rejuvenators, Moisture susceptibility, Rutting Resistance

Vertical axis wind turbines (VAWTs) are expected to have good market potential in the near future. However, it suffers from relatively lower performance in contrast with the market-leading horizontal axis wind turbine (HAWT). To overcome the disadvantages of VAWTs and improve their performance, this study aims to experimentally investigate the effect of flat plate guiding walls on the performance of VAWTS. The experimental study was carried out in an open-jet wind tunnel with an airflow speed range between 8 – 12 m/s and a different tip speed ratio (TSR). The rotor is of NACA0021 with three blades, 50 mm length, 300 mm diameter and 300 mm height. The guiding wall row is composed of six flat plates. The results show that a straight-bladed vertical axis wind turbine surrounded by guiding walls could be self-starting at the wind velocity of 4 m/s which is lower than the wind speed required for the turbine without guiding plates is about 5 m/s. The rotational speed increases for all test conditions with the increase in wind velocity. The power coefficient (Cp) increases with TSR (λ) until reaching its peak at experimental results for all tests. The power coefficient of the turbine reaches its highest value Cp = 0.25 at λ = 1.79 at 12 m/s with the guiding walls. The optimal Cp using the fixed guiding walls shows about 23% improvement at 8 m/s in contrast with the optimal Cp of the reference turbine without the guiding walls.

Keywords: Wind energy; VAWT; Guiding walls; Darrieus wind turbine; TSR.

Although photovoltaic thermal (PVT) offers ascertain of benefits, it also has its own limitations. The efficiency of PVT is diminished due to heat gain experienced by its photovoltaic module when subjected to solar radiation. Jet impingement has been recognised as a highly successful technique for the purpose of cooling solar modules, particularly in the context of bifacial module applications. An energy analysis of a reversed circular flow jet impingement on a bifacial PVT collector was perform through an indoor experiment utilizing a solar simulator. The jet plate outlet was varied into four different configurations: one hole (1h), three holes (3h), four holes (4h) and five holes (5h) to identify the jet plate outlet configuration that contributes to the best energy efficiency. The experiment was carried out using a constant solar irradiance of 900 W/m2 and mass flow rate between 0.01 kg/s to 0.14 kg/s. The study’s findings indicate that configuration 1h exhibited the best photovoltaic efficiency of 11.09%. Additionally, the highest thermal efficiency recorded was 63.2%. In summary, it can be concluded that configuration 1h exhibits an overall photovoltaic thermal efficiency of 74.28% when subjected to a mass flow rate of 0.14 kg/s. This configuration outperforms other jet plate outlet configuration in terms of energy performance.

Keywords: Jet impingement, Photovoltaic Thermal, Bifacial module, Solar collector, Heat transfer

It has always been a challenge for blind and visually impaired (BVI) people to comprehend the information on tactile graphics materials. Despite the advancements in tactile graphic design, a comprehensive understanding of how they explore and interpret raised-line tactile graphics is still lacking. To bridge this gap, this paper introduces a fingertip tracking system employing color marker detection algorithm to investigate the cognitive process of four totally blind participants associated with the Malaysian Association for The Blind (MAB). Each participant was provided with five distinct kinds of raised-line tactile graphics for reading, and their reading activities were afterwards recorded. All participants exhibited diverse interpretations, exploration times, and difficulty perceptions, showcasing the subjective nature of cognitive processing. It is identified that the complex diagram took longer time of exploration with an average time of 141 seconds compared the simple diagram with an average time of 27.5 seconds. It shows that the complexity of the diagrams did impact participants’ cognitive process. Based on the distribution and concentration of fingertip locations, every tactile graphic has salient regions that have been focused on by every participant for recognition and interpretation of the information. It was also identified that the frequently performed exploratory procedures among participants were contour following and lateral motions. However, their reading strategies were too random and lacked systematic patterns. The system aims to be an instrument for visualising the cognitive process underpinning the exploration and interpretation of tactile graphics by people with visual impairment and blindness.

Keywords: Tactile graphics; Visually impairment; Computer vision system; Exploratory procedure

The shortage of human labor is increasing; thus, more agricultural machinery and equipment are expected to enter the agricultural sector. One of the agricultural machinery widely studied nowadays involves robot arms. Therefore, developing robot arms is a hot issue in this field. The ideal structure of the robot arm with optimal length is currently gaining popularity and being used in many sectors, such as manufacturing and agriculture. This is closely related to the dynamic structure of agricultural areas. Therefore, this study uses the forward kinematic modeling method to design an optimal robot arm to achieve a specific coordinate in a dynamic environment. The robot in this study arm mimics the boom and arm installed on a tractor. The forward kinematic problem in this study is defined using the Denavit-Hartenberg (DH) convention method. The DH convention is commonly used to solve kinematic analysis problems of a robot arm. Simulation of kinematic modeling is performed using MATLAB software. This study studies various optimization algorithms to compare the performance of algorithms that can achieve the optimal length with minimum errors. The comparison between artificial bee colony (ABC) and particle swarm optimization (PSO) is studied. At the end of the study, the best algorithm was selected for the robot arm design with a four-degree-of-freedom (4-DOF). The best algorithm, i.e., the PSO algorithm, is evaluated by calculating mean square error (MSE of 0.00108527), root mean square error (RMSE of 0.01678), mean absolute error (MAE of 0.004286081), and end-effector position error (error of 0.080557045), where the best algorithm has the lowest value of error.

Keywords: Agricultural; Structural optimization; Robot manipulator; Artificial bee colony, Particle swarm optimization; Forward kinematic

Inconel 718 is a nickel-based alloy that has been developed with superior mechanical strength, creep resistance, and corrosion, as well as erosion resistance at temperatures above 649 ˚C. It is suitable to be used for aircraft engine components such as turbine discs. However, it also has low heat conductivity and the presence of hard carbide particles in its alloy worsens the machining conditions with high cutting temperature, and high shear force and promotes work hardening. Thus, this study aims to evaluate the surface integrity of Inconel 718 in terms of surface roughness, plastic deformation, and micro-hardness alterations after the turning process. Cryogenic CO2 cooling was supplied along the cutting process to reduce cutting temperatures and the machining performances were compared with dry machining. The experimental works show that the dry machining resulted in lower surface roughness by up to 42.15% as compared to cryogenic. However, the depth of plastic deformation under dry machining was much more severe than in cryogenic machining driven by higher cutting temperatures and pressure from the worn tool. The depth of plastic deformation became more distinct as the cutting speed increased. While the microhardness alteration of the machined surface was higher under cryogenic machining due to extensive cooling capacity by the CO2 flow. Thus, this study reveals that cryogenic cooling during metal cutting can produce products that have better wear resistance as well as higher surface hardness.

Keywords: Cryogenic machining; Dry machining; Inconel 718; Surface integrity

The material M303 is commonly used in the fabrication of machinery, automotive components, locomotive axle housings, and injection moulds. It is a stainless martensitic chromium steel known for its high strength, wear resistance, and corrosion resistance. The primary purpose of this study is to investigate the machinability of M303 under cryogenic conditions, specifically focusing on high cutting speeds. By exploring the effects of cryogenic machining on M303, the study aims to provide insights into the performance and characteristics of this material under extreme cutting conditions. This study investigates the influence of cutting parameters on the machinability of M303 in a cryogenic environment using liquid nitrogen (LN2) and coated carbide cutting tools in a high-speed turning process. The study focuses on high cutting speeds and examines essential machinability factors, including cutting forces, surface finish, and tool life. The experimental design utilises a Taguchi L4 orthogonal array to systematically study feed rates (0.1-0.2 mm/rev), depth of cut (0.2-0.6 mm), and high cutting speeds (260-340 m/min). Notably, at a low cutting speed of 260 m/min, coupled with low feed rates and depth of cut, the study reveals the longest tool life of 48.57 mintues was achieved. This condition is characterized by a good surface finish and low cutting forces with Ra of 0.9 µm and cutting force of 100 N respectively. The predominant wear occurs on the flank face, primarily due to fracturing and chipping, especially under high combinations of cutting parameters. Conversely, gradual wear is observed under low combinations of cutting parameters, resulting in an extended tool life. In conclusion, the application of LN2 proves effective under conditions of low cutting parameters. The study suggests that the risk of fracturing the cutting tool increases at higher feed rates and depths of cut, especially when combined with elevated cutting speeds. This research provides valuable insights into optimizing the machining of M303 for enhanced efficiency and tool longevity.

Keywords: M303, machinability, cryogenic, LN2, Taguchi Method

Fused Deposition Modelling (FDM) employs Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), and other materials to manufacture items from Computer Aided Design (CAD) files in recent era. Process parameter optimization could aid in producing durable products. This article presents multi-objective parametric optimization for the FDM process. The infill density, orientation angle, and layer height characteristics are studied in proposed work. In this task, PLA material is used to create FDM parts. Using Taguchi grey relational analysis, the printing time, surface roughness, dimensional accuracy, and tensile strength are optimised. Analyses of Variance (ANOVA) assesses the importance of process factors relative to response parameters. The recommended method aids decision analysts in comprehending the whole evaluation process and expedites the production of components with exceptional surface finish, dimensional accuracy, and tensile strength with optimum time. The layer height, orientation angle, and infill density have the most effects on surface roughness, according to the data. Finally, the results shows that the orientation angle, layer height, and infill density have the greatest effects on dimensional variance. Grey Relational Grade (GRG) was able to ascertain the ideal values of the parameters layer height (0.3 mm), orientation angle (90°), and infill density (40%) using the Grey Taguchi Method.

Keywords: Fused deposition modelling (FDM); Polylactic Acid (PLA); Taguchi grey relational analysis (TGRA); Analysis of variance (ANOVA).

Taking into consideration the historical, cultural, social, and economic worth, historic structures are an essential component of the built environment. It is crucial to preserve historic structures in a sustainable manner, and to restore them so they continue to function effectively in the long run. The focus to attain standards such as BREEAM, LEED, etcetera, have been developed to fulfil more comprehensive strategic objectives when constructing new buildings, however, these requirements are insufficient when they are utilised for adjustments to older buildings. Few people are aware of the qualities of historic houses, and there are not many historic buildings that have aspects that increase their sustainability and dispel the notion that they are of lesser quality. Nonetheless, due to the unique characteristics of historic structures, it is necessary to modify and analyse the current traditional buildings and add new parameters that are not addressed by any of the grading systems under consideration. The current research aims to analyse the academic articles on design solutions for adaptability in buildings, and adaptation of an architectonic traditional building worldwide. Accordingly, this study has extracted from 24 articles that are based on a myriad of articles which have been analysed and collected from “Scopus, Web of Science, Google Scholar, IEEE, and Science Directs” under systematic literature review (PRISMA).

Keywords: Traditional building, Sustainability, Smart sustainable, Adaptations, Architectonic, PRISMA

Friction stir spot welding (FSSW) is a solid-state single-point welding technique that uses a rotating tool consisting of a shoulder and a pin for joining nonferrous metals and alloys. FSSW produces a keyhole at the welding point, which decreases the mechanical strength of the joints. This study investigates the influences of tool rotational speed (1000, 1250, and 1500 rpm) and dwell time (5, 10, and 15 s) on the shear fracture load of the FSSW joints. Two different grades of aluminium alloy plates, i.e., AA6061 and AA7075 were used to produce similar (7075-7075 and 6061-6061) and dissimilar (6061-7075) alloy joints. The plates with a thickness of 3 mm were folded above each other before a rotating tool pin was plunged through the thickness of the top plate to obtain an FSSW lap joint. It was found that tool rotational speed and dwell time induced a considerable impact on the microstructure, and shear strength. The results indicated that the grain size of microstructure in similar and dissimilar joints was affected by the rotational speed and dwell time. The grain size of the microstructure increased as rotational speed and dwell time increased. The results also showed that a tool rotational speed of 1250 rpm and dwell time of 10 s gave the highest shear fracture load for 7075-7075 similar and 6061-7075 dissimilar joints. However, for 6061-6061 similar joints, the highest mechanical strength was obtained at 1250 rpm and 10 s.

Keywords: Friction stir spot welding; Rotational speed; Dwell time; Fracture load; Aluminium alloys

The grain refinement by high-pressure torsion (HPT) process and high-temperature stability have been studied in a commercial non-heat-treated aluminium alloy, 5052. The HPT process was conducted on 10 mm disks of the alloys at room temperature with an applied pressure of 6 GPa for 5 and 10 turns with a rotation speed of 1 rpm. The HPT processing leads to microstructural refinement with an average grain size of ~188 nm and ~156 nm for 5 turns and 10 turns with an increased value of dislocation density. The Vickers microhardness test was performed at 100 gf for a duration of 15 s. It was found that the hardness increased from the onset of straining and saturated at approximately 165 Hv after processing at both 5 and 10 turns. The samples were then annealed at high temperatures. The study demonstrated that annealing at 200 °C for 1 h reduced the hardness by 30% in both samples and enlarged the gain sizes to 226 nm. The results indicated that the rate of hardness decrease is faster in 10 turns compared with 5 turns thus explaining the higher kinetic annihilation phenomenon observed in higher straining in 10 turns due to the higher stored energy in the grains.

Keywords: AA5052; Non-heat-treated aluminium alloy; Severe plastic deformation; Ultrafine-grained material

Additive manufacturing (AM) or better known as 3D printing is a manufacturing method based on powder metallurgy technology that is able to produce a 3D component. Selective laser melting (SLM) is one of the AM methods capable of producing metal 3D components, however, residual stresses are often produced in such component due to repeated melting and solidification of metal during the printing process. The residual stresses can deteriorate the performance of the 3D components’ mechanical properties if not removed or reduced. Heat treatment processes are often used to remove the residual stresses. The basic parameters of heat treatment are heating temperature, heating rate, cooling rate and holding time. Based on the basic parameters, the effect of holding time in heat treatment is still less reported for 3D components printed via SLM. Therefore, in this study, the effect of holding time on the mechanical properties and microstructure of 3D titanium alloy (Ti6Al4V) components was intestigated. A total of 9 sets of cubic samples were printed on different processing parameters such as laser power (225W, 275W, 325W), scanning speed (800mm/s, 1100mm/s, 1400 mm/s), layer height (0.3mm) and hatching distance (0.10mm, 0.12mm, 0.14mm ). It was found that hardness of 383 – 448 HV was obtained where samples P3, P9 and P5 gave the highest, medium and lowest hardness values. Based on the microstructure observation, α + β phase and martensite structures are produced due to the vanadium content of 4% and heat treated at 935°C. A critical review was also studied to compare previous studies that used different holding times on SLM-printed Ti6Al4V 3D components. It was found that different holding times did not have a significant effect on the mechanical properties of Ti6Al4V 3D components where the outcome of previous studies alligns with that of from this study. In addition, past works have also reported that heat treatment is able to lower the residual stresses in SLM-printed Ti6Al4V 3D components. Finally, the effectiveness of heat treatment in reducing the residual stresses in SLM-printed Ti6Al4V 3D components at different printing parameters should also be studied to understand the mechanism of microstructural changes during and after heat treatment.

Keywords: Laser selective melting (SLM); Titanium alloy (Ti6Al4V), Heat treatment; Microstructure; Hardness

Selective laser melting (SLM) 3D product is capable of producing varied surfaces such as top, core and bottom surface depending on the product dimensions and building orientation. Each surface may have differences in physical and mechanical properties such as surface roughness, microhardness, and microstructure. Therefore, this study examined the effects of SLM processing parameters as well as volumetric energy density (VED) on surface roughness, microhardness and microstructure on different 3D product surfaces. In this study, a sample of titanium alloy cube (Ti6Al4V) with different surfaces of up skin 1 (US1), up skin 2 (US2), core skin (CS) and down skin (DS) are printed on a 30° building orientation printed through the SLM process. There are nine sets of parameters printed based on the Taguchi 𝐿9 experimental design method. All printed cube samples were heat treated to remove the residual stresses generated during the printing process. The effect of processing parameters on micro hardness as well as microstructure on each surface has been studied. This study found that SLM printed Ti6Al4V produced almost identical surface quality for different surfaces of the cubic samples. Surface roughness of US2 ranging between 15.38 µm and 26.22 µm, while DS is slightly rougher with surface roughness in the range of 16.05 µm and 27.64 µm. Microhardness in the nine processing sets however was found to have a bigger difference in values of 387 ± 10 HV (US2) and 362 ± 10 HV (DS). In general, US2 surfaces were found to have high microhardness compared to the DS surfaces due to the formation of long, straight needle-like martensitic microstructure.

Keywords: Selective Laser Melting, Processing parameter, Surface roughness, Microhardness

The gamification approach is popular method in education as it has been widely utilized in many fields. The project focuses on designing a game for interactive learning of lean manufacturing activities to create an alternative learning method that would gain interest and efficiency in learning. Integration of gamification approach and interactive learning method was used to illustrate a virtual lean manufacturing education and training by means of users’ interaction towards provided interactive learning materials and participation in playing the designed game. Input of the project which is learning materials was developed by analysing numerous articles regarding common lean manufacturing tools and practices. Interactive elements such as animation, sound effects, lecture voice, and videos were applied in each learning material to deliver an adequate understanding of each topic. Construction of the game platform is being developed using ActivePresenter software which includes simulation videos of the production line using FlexSim software to visualize a real production floor which provides a clearer picture of the production system for users. The game should include a basic assessment of lean manufacturing practices by considering its complexity and difficulty level for users with inadequate or does not have experience in the field. The outcome of the project is expected to successfully design a basic game platform for lean manufacturing education by means of interactive learning. Users will be able to learn lean manufacturing systems using the designed interactive learning materials included in the games and self-assess themselves as the game publishes the correct and best answer option in case they answer wrongly.

Keywords: Gamification; Interactive learning; Lean Manufacturing; Education; Asynchronous learning

Altair INSPIRE Form is a computer simulation developed for designing and modelling sheet metal forming processes. Within the modules, the design and formability prediction can be simulated and optimized. Thus, this study focuses on analysing the formability of sheet metal Aluminium alloy AA6061 by simulating numerically a multistage forming of an end-wall process where the material properties and process parameters gained from the literature were used as input. The geometrical model was validated by comparing its formability with the literature that was simulated by Altair HyperForm. Then, to statistically analyse the influence of forming parameters on formability, Analysis of Variance (ANOVA) was applied with the design of experiment approach using the Response Surface Methodology (RSM). The simulation results observed similar strain rate distributions between Inspire Form and HyperForm under a safe forming process. For the formability of Aluminium alloy AA6061, loose metal zones with wrinkles, excessive thinning up to 23.13%, and the maximum equivalent stress at 414.6 MPa were expected to be generated. These findings clearly explained that forming parameters such as blank holder force and punch velocity have to be carefully controlled for this ductile material. The ANOVA shows a significant influence of coefficient friction and punch velocity on thinning percentages. The likelihood of tearing to form at a higher thinning percentage and its appearance was observed in the Forming Limit Diagram which evaluates its formability. The validation of optimized parameters by simulation work is concluded to be successful as no fracture appeared in this simulation with a small percentage error at 2.19% between the simulation and the predicted value.

Keywords: MAltair Inspire Form; Sheet Metal Forming; Response Surface Methodology (RSM); ANOVA

In previous years, the world witnessed great urban development which increased interest in this aspect. To keep pace with this development, several things and new materials have been created to raise the standard of road construction. One of these things is the use of nanomaterials. Currently, the use of nanomaterials has become common to improve the asphalt mixtures which are used in the construction of flexible pavement because of the rise in traffic volumes and vehicles loads. This study deals with review of past related studies that improving the properties of asphalt mixtures through the use of nanometakaoline in the hot asphalt mixture in different proportions. Different proportions of nanometakaoline were used for the Hot Mixture Asphalt properties revised in these studies which were shown that the adding of nano-metakaoline led to improve the properties of Hot Mixture Asphalt to resist the traffic load and environmental effects. They used Marshall Test, indirect test, wheel track tests and others tests to exam the properties of improved Hot Mixture Asphalt and compared with the standard mixture (control).

Keywords: Metakaolin, Nano-materials, hot mixture asphalt, Marshall Test, indirect test, improvement

Forest restoration is an effort to restore the growth and balance degraded forest ecosystems, through various approaches such as reforestation, land restoration, endangered species conservation, and forest fire prevention. Conventional field data collection challenges, such as limited spatial coverage, tall tree measurement difficulties, and human observation errors, hinder canopy-scale functional traits monitoring and extraction across forest treatments. The study addresses the importance of forest restoration and the challenges associated with conventional field measurements in extracting canopy scale functional traits by utilizing Airborne light detection and ranging (LiDAR) technology for more accurate information involving the old growth, natural regeneration, and active restored forests in Danum Valley Conservation Area and INFAPRO Sabah. The study utilized diverse processing algorithms, allometric equations, and correlative modeling methods. At the grid level, various LiDAR functional traits were calculated, leaf area index, gap fraction, and canopy density, alongside assessment of multiple correlative modeling strategies. Linear regression and analysis of variance analyzed relationships between LiDAR-derived and field-derived canopy scale functional traits between different forest treatments. The results showed high R-squared values ranging from 0.73 to 0.91, Anova F-statistics and probability values (p) showed that there is a strong relationship between the field data and predicted LiDAR values for three-canopy scale functional traits in different forest treatment types. These results indicate that LiDAR technology is effective in predicting canopy scale functional traits and has the potential to provide accurate and detailed information on forest restoration areas for future conservation and management efforts.

Keywords: Forest Restoration; LiDAR; Canopy Scale Functional Traits.

Equatorial plasma bubbles (EPBs), which are depletions in the ionosphere disrupting radio waves, exhibit complex dynamics influenced by neutral winds. The present study aims to investigate the relationship between the onset of EPBs and the velocities of neutral winds. The onset of EPBs was determined from the rate of the Total Electron Content Index (ROTI) keogram obtained using Global Positioning System (GPS) data over the Southeast Asia sector. Meanwhile, thermospheric neutral winds were measured using a Fabry-Perot interferometer (FPI), and the height of the F layer was acquired from an ionosonde, both instruments positioned in Kototabang (KTB), Indonesia. The observations are classified into two cases based on the strength of winds: strong and weak winds on different nights. This study successfully reported the onset time and location of EPBs occurred at 1320 UT (2120 LT) and 100° (500 km) longitude, attributed to pre-reversal enhancement (PRE). We conclude that thermospheric neutral wind makes a significant contribution to the observed onsets of EPBs driven in the zonal direction. Therefore, this finding reinforces past studies that have shown an increase in the height of the F layer could play an important role in determining the onset of EPBs.

Keywords: Equatorial plasma bubbles onset; Neutral winds velocities; Southeast Asia

As modern electronic devices become smaller, manufacturers are increasingly producing compact devices for space technology. Transparent antennas are seen as the solution to this problem. With the presence of a transparent antenna, it can save antenna installation space as its transparency properties allow it to be integrated with solar technology. However, the use of transparent material on the antenna causes the antenna gain to be low due to the low conductivity of the material. When a low conductivity material is used it also causes the antenna efficiency to decrease. Therefore, modifications to the antenna design are needed to overcome such problems. This study aims to design a transparent antenna that can operate on Ku-band. The aim of this study is to identify the effect of transparent materials on conductivity, design a transparent antenna with an efficiency as low as 85% and design a grid array antenna to increase gain. The material verification test is carried out by making a comparison of the material in the antenna design simulation that works on Ku-band. The transparent antenna material selected is Indium Tin Oxide (ITO). Then, the design of the grid array antenna is carried out to increase the antenna gain hence for high efficiency. In this research, 8 loops grid array antennas increase the gain by 52% compared to reference antennas. The antenna meets performance requirements and can be integrated with solar panels to efficiently harness sunlight for electricity generation, while effectively transmitting and receiving wireless signals.

Keywords: ITO; Grid Array Antenna; Transparent; Ku-Band; High Gain

The impact of geomagnetic substorms on space weather and various technology on the Earth urges the need to detect the phenomenon. However, the brief period of substorm occurrences makes it more difficult to directly detect them, therefore, their detection by proxy in the form of precursors need to be done. Pi2 pulsations, which is a damped irregular signal in the horizontal component of the geomagnetic field ( as a reliable precursor to substorms. The cessation of Hz), is seen index that previously was the main detection indicator of Pi2 pulsations motivates this study to introduce a new detection method by implementing machine learning. In this study, several features were extracted from geomagnetic field data based on several statistical parameters, impulsive and signal metrics to be used in the development of classification model. The development was performed based on the automated machine learning (AutoML) approach that determines the best algorithm and optimizes the hyperparameters automatically. AutoML tries various algorithms like ensemble, neural network, Naïve Bayes, support vector machine, k-nearest neighbour and binary decision tree that are optimized by Asynchronous Successive Halving Algorithm. An ensemble classification model was determined to be the best performing model with an accuracy of 99.15%. It was then used in the development of near-real tine detection system. The system streams the geomagnetic field data continuously and reports the Pi2 detections on an open cloud repository, The detection system is envisioned to be one of the reference sources to inquire the occurrences of Pi2 pulsations globally.

Keywords: Pi2 Pulsations; Geomagnetic Field; Automated Machine Learning; Near-Real Time Detection System

The faint young sun (FYS) was introduced as a paradox by prominent astronomer Carl Sagan dan George Mullen. This paradox posits that the luminosity of the sun 4.6 billion years ago (when it came into existence) was less than 30% of its current luminosity. The variation in solar radiance might have facilitated the Origin of Life (OOL) on Earth by influencing prebiotic chemistry, especially in the formation of prebiotic polyester. Polyester, synthesized from alpha hydroxy acids(ɑHAs), serves as a model studied as a framework that facilitates OOL. Studies indicate that polyester gels can form from dehydration reactions of ɑHAs in wet-dry cycles, potentially initiating prebiotic life. Moreover, various investigations have demonstrated that ultraviolet UV light has been known to initiate prebiotic chemical reactions, as well as produce polyester. However, experiments have been done, but none has truly explored broadband light from the FYS. Furthermore, prebiotic polymerization induced by FYS has not been shown. In this paper, we will discuss about FYS, some research conducted regarding prebiotic reactions induced by UV light, and the prospects of how FYS’ broadband light might be beneficial for prebiotic polymerization involving polyester.

Keywords: Faint Young Sun, Broadband of light, origins of life, gels, polyesters

Energy has a significant role in the socio-economic growth for any country. The energy originates from fossil fuels, which are non-renewable and enact an undesirable impact on the environment. Waste cooking oil can be utilized in diesel engine directly. Preheating and trans-esterification process are expensive to convert waste cooking oil into biodiesel. This research aims to replace diesel with waste cooking oil as binary blend and compared with diesel fuel. Engine testing at the constant speed of 1300 rpm at constant load. This study revealed that, addition of waste cooking oil reduced exhaust gas temperature as compared to base line fuel. In case of noise emission, sound level for emulsion fuel DF95WCO5 was reduced compared to DF. In this study, a single-cylinder CI engine was run for 200 hours on two fuel samples: DF (diesel fuel) as the baseline fuel and DF95WCO5 (5% waste cooking oil and 95% DF). During the endurance test, the effects of DF95WCO5 on engine head deposits were studied. According to the investigation’s findings, visual inspection of both fuel samples revealed some deposit buildup on injectors. SEM (scanning electron microscopy) and EDX (energy dispersive X-ray spectroscopy) analysis revealed that the engine running with DF95WCO5 formed more carbon deposits on and around the head. It can be concluded that binary emulsion can be used in compression ignition engine without any engine alterations. Consequently, WCO can be proficiently used to reduce detrimental effects and reduce fossil fuel dependency.

Keywords: Diesel engine, Waste cooking oil, Exhaust gas temperature, Noise emission. Head deposit formation