Volume 37 (01) January 2025

Electrical Discharge Machining (EDM) is an advanced non-traditional method for precision material removal using repeated electrical discharges. Itutilizes a programmable tool electrode to intricately shape designs. Existing research has highlighted that current EDM control systems are often intricate, sluggish, and costly. In addressing these limitations, there is a notable opportunity to enhance the design of an advanced EDM control system, that is both sophisticated and cost-effective. Therefore, the authors proposed an integration of a pulse generator, control system, timer, and flushing system using a Programmable System-on-Chip (PSoC) microcontroller to regulate the gap between an electrode a workpiece, flushing system, and the overall EDM machining process. The pulse generator algorithm was developed to effi ciently manage T_on and T_off, while the Proportional Integral Derivative (PID) algorithm was employed to uphold the gap between the electrode and the workpiece. Additionally, the timer algorithm was closely associated with the machining process timing. Activation of the second servo pump at 80% of machining was implemented to enhance the flushing pressure rate. The EDM-PSoC system was utilized with the experiment conduction at three different current settings (2A, 4A, and 6A) over five periods, and results were compared with the EDM-Existing system. The experimental outcomes revealed a notable increase in Material Removal Rate (MRR),averaging 0.1348 mm³/min at 6A. Furthermore, the EDM-PSoC system demonstrated high consistency in each repetition experiment conducted at lower currents, achieving MRRs of 0.0142 mm³/min at 2A and 0.0560 mm³/min at 4A. Comparatively, the EDM-PSoC system improved the average MRR by 49% compared to the traditional EDM-Existing system. The depth of the machined workpiece produced by the EDM-PSoC system was deeper than the EDM-Existing system at equivalent time settings. Consequently, the findings indicate that the EDM-PSoC system achieved a
higher MRR relative to the conventional EDM procedure, thus improving significantly the system efficiency.

Keywords: Electrical Discharge Machining (EDM); Material Removal Rate (MRR); PSoC Microcontroller

Additive manufacturing has a good application prospect in aerospace, medical implantation and other fields, but the molding surface quality is poor, without post processing can not meet the requirements of high service, polishing processing is a key link in the high-performance metal additive manufacturing technology chain. This paper summarizes the characteristics of the ladder effect, the high roughness of the forming surface. In recent years, additive manufacturing technology, also known as 3D printing, has been highly valued by aviation enterprises for its unique advantage in rapid prototyping, particularly for complex metal parts. However, due to the layer-by-layer growing process of 3D printing, the built parts often have poor surface roughness and are not suitable for practical use without post-treatment. Based on this foundation, the primary focus of research in the field of additive manufacturing for metal parts polishing includes electrochemical, laser, and abrasive flow polishing technologies. The progress in these areas is examined with consideration given to various manufacturing processes, different types of metal powder materials, and diverse structures (such as porous structure and high aspect flow channels) found in additive manufacturing samples. This review summarizes the research findings related to surface roughness, material removal, surface residual stress, profile accuracy retention, and other technical indicators associated with the polishing process for additive manufacturing metal parts. Finally, the paper discusses potential future developments in polishing technology for 3D printed metal parts.

Keywords: Additive manufacturing; molding surface; electrochemical polishing; laser polishing; abrasive flow machining

The escalating scarcity of potable water in remote and arid regions necessitates increased reliance on sustainable solutions, notably solar stills. The imperative need to achieve high productivity and peak hour efficiency in these devices is critical to effectively addressing water shortages. This study explored modified solar still designs aimed at improving the productivity and peak-hour efficiency of the water desalination process. The experimental investigations involved various parameters, including water depth (10, 20, and 30 mm), mass flow rate (10, 15, and 20 kg/h), and glass thickness (4, 5, and 6 mm) for both traditional and stepped solar stills. The experimental layout followed an L18 orthogonal array. It was structured with 2¹×3³ = 18 combinations, ensuring comprehensive coverage of the factors and levels involved, and the outputs were systematically examined using the Taguchi approach to identify the optimal parameter values. Stepped solar stills have emerged as superior, demonstrating higher peak-hour efficiency and productivity than traditional solar stills. The most influential parameters, ranked by eff ectiveness,were the type of solar still, water depth, glass thickness, and mass fl ow rate. The optimal conditions for achieving maximum productivity (3881 ml) and peak hour effi ciency (22.03%) were identifi ed, including a stepped solar still, 10 mm water depth, 15 kg/h mass fl ow rate, and 4 mm glass thickness. The experimentally measured values were closely aligned with the predicted values, verifying the accuracy of the Taguchi model with minimal error (0.81% in productivity and 0.49% in peak hour effi ciency).

Keywords: Desalination; water distillation; solar energy; traditional solar still; stepped solar still; saline water

Date palm leaf fibers are suitable for engineering applications due to their availability, inexpensiveness, and ecofriendliness. However, there is a risk of biodegradation in the long term. This paper explores date palm leaf fiiber (DPL) properties and the protection of the fibers from biodegradation to enhance their lifespan. To this end, two coating materials (bitumen and polyurethane) were used separately. Physical and mechanical tests were conducted to determine the most effective material to coat the DPL fibers. To comprehensively assess the performance of the coated fibers, their morphology was examined via microstructure analysis using scanning electron microscopy (SEM) and energy dispersive X-ray analyses (EDX) tests. This analysis encompasses their material properties, chemical composition, water absorption, and degradation, providing a thorough understanding of the protective coatings’ impact on the DPL fibers. The tensile strength test results revealed that the maximum tensile strength of the bitumen coated date palm fiber (DPLB) is 7.4 MPa. The tensile strength is two times greater than the polyurethane coated date palm leaf fiber (DPLP) and untreated date palm leaf fiber (UDPL). The results of the degradation test revealed that the weight loss percentage is equal to 45.5 and 25 in the case of the UDPL and DPLP fibers, and no loss in weight in the case of the DPLB fiber. Out of all the test results, bitumen is considered the best due to its ability to resist the attack of chlorides and sulfate ionspresent in groundwater on top of being cheap, simple, and efficient.

Keywords: Bitumen; degradation; geo-natural materials; SEM/EDX; tensile strength

This study analyzes challenges and success factors in the use of solar energy in Malaysia’s manufacturing sector. A hierarchical tree based on the Analytical Hierarchy Process (AHP) method was modeled to identify the sub-criteria of challenge aspects and success factors. A questionnaire study based on the sub-criteria was conducted on 30 respondents among supervisors and above from various companies involved in the electrical, electronic, and mechanical manufacturing industries that employ machines intensively in the Klang Valley area, Malaysia. Data for the study were collected from survey respondents’ evaluations. The collected data was analyzed using the AHP method. Findings show that there is a significant positive relationship between the challenges and success factors of implementing solar energy in the manufacturing industry in Malaysia. As a result of the study, government initiatives are the key challenges and success factors for the industry involved in utilizing solar energy. The development of a framework for solving the challenge of using solar energy in the industry has been proposed. As a result, the framework can provide added value to government and funding agencies involved in improving Malaysia’s solar energy policy. This contribution will assist them with drafting, developing, and improving existing policies and plans, thereby, leading to more solar energy usage in Malaysia’s manufacturing industry.

Keywords: Challenges; success factors; solar energy usage; renewable energy; manufacturing

Using saccharose (sugar) as fuel to synthesise hydrotalcite via the combustion method to produce biodiesel could potentially have social and economic benefits in the field of renewable energy. However, it could spark a debate on food vs fuel since a higher demand for saccharose in the energy sector while ensuring adequate supply for the food sector could increase the price of saccharose. Therefore, this study proposes utilising a new alternative material from agricultural waste, coconut shell, to synthesise the hydrotalcite catalyst and use it to produce biodiesel from waste cooking oil. This study found that the hydrotalcite synthesised using coconut shell as fuel and calcined at 650 ℃ (HT-CS 650) yielded 93.25% biodiesel compared to the 74.14% biodiesel yield when synthesising hydrotalcite using saccharose. The XRD showed that the synthesised hydrotalcite retained its layered double hydroxide structure up to 650 °C calcination temperature. The BET analysis showed that the HT-CS 650 has the highest surface area of 115.558 m²/g compared to the 28.326 m²/g surface area of the reference hydrotalcite (HT-SS 650). The HT-CS 650 can be reused for up to three cycles with a minimum biodiesel yield reduction of 9.09%. This study has demonstrated that agricultural waste is a more suitable fuel for synthesising hydrotalcite in the combustion method and using it to improve the transesterification reaction for biodiesel production.

Keywords: Hydrotalcite; biodiesel; transesterifi cation; coconut shell; combustion method

The aim of this paper is to characterise the strain-based fatigue reliability of a lower arm suspension system using strain signals captured from different types of road load conditions. Given the challenges of acquiring comprehensive loading history data and the inherent difficulties in capturing accurate load–time history data through laboratory or fiield-testing, a stochastic modelling approach was developed. Strain loads obtained from strain gauges were stochastically induced to generate random loads, which were then used to assess fatigue reliability based on the experimental data. The fatigue life, ranging from 3.43 x 10⁵ – 9.02 x 10⁵ cycles per block for highway, rural, and campus roads, was evaluated using the rainfl ow cycle counting technique through the strain life models, i.e. CoffinManson, Morrow, and Smith-Watson-Topper. Furthermore, the reliability of the induced fatigue life data was modelled using a Weibull distribution, resulting in a mean cycle to failure for the lower arm falling within the range of 1.92 x 10⁶ to 2.53 x 10⁶ cycles per block. Among the various road conditions analyzed, the highway exhibited the highest fatigue life, indicating that it is less prone to failure compared to other road conditions, which can be attributed to the smoother road profile. Hence, the use of stochastically induced random loads is proposed as an effective method for assessing strain-based fatigue reliability in aiding for the prediction of the durability and structural integrity of the lower arm suspension system.

Keywords: Fatigue reliability; strain life; durability; limited data; lower arm

Concrete is the primary material for such shielding due to its mechanical and structural properties, suitable for neutron and gamma radiation protection. This review provides a comprehensive examination of the impact of nuclear irradiation on the structural integrity of concrete used in biological shielding within nuclear power plants (NPPs). This review highlights the critical role of the hydrogen content of concrete in attenuating neutron flux and its versatility in shape, density, and cost-effectiveness. The review was systematically collected and reviewed previous research papers on the topic, focusing on studies that address the degradation of mechanical properties in concrete exposed to gamma and neutron radiation. Our methodology involved an extensive literature search, critical analysis, and synthesis of findings from peer-reviewed journals, conference proceedings, and technical reports that specifically address the degradation of mechanical properties in concrete structures exposed to gamma and neutron radiation. Gamma radiation induces radiolysis in hydrated cement paste, while neutron radiation causes alterations in the crystalline structure of aggregates, leading to volumetric expansion and reduced mechanical strength. Additionally, this review highlights the combined effects of chemical attacks, moisture, and elevated temperatures on concrete degradation during reactor operation. The key findings underscore the need for further research into the degradation mechanisms of concrete biological shielding, emphasizing the influence of various types of nuclear radiation. This understanding is crucial for ensuring concrete’s long-term durability and effectiveness in NPPs, thereby contributing to the safe and sustainable operation of nuclear energy facilities.

Keywords: Biological shielding concrete; nuclear power plants; Aggregate; Degradation neutron; Gamma rays; neutron radiation

Despite extensive research on the association between life satisfaction and city-level economic, socio-demographic, and management variables, few studies have explored the spatial and socio-economic aspects of neighbourhood environments, particularly in developing countries. This study aims to fill this gap by investigating the determinants of life satisfaction, with a focus on the impact of various neighbourhood environment aspects on residential satisfaction and overall subjective well-being in Jeddah, Saudi Arabia. A comprehensive residential satisfaction survey was conducted in 2020, involving 405 randomly selected households from 14 neighbourhoods. Using an ordinal logistic regression model, the study analyzed the perceived significance of physical and socio-demographic attributes in residential areas. The findings reveal 24 key determinants of both overall life satisfaction and residential satisfaction, classified into four primary dimensions: demographic attributes, housing characteristics, the physical environment of the neighbourhood, and the social environment. Additionally, the study established a significant association and mutual relationship between life satisfaction and residential satisfaction. This research contributes to the theoretical debate and empirical research on life satisfaction by highlighting the crucial role of the residential environment in predicting overall subjective well-being. It underscores the importance of integrating life satisfaction into policies aimed at enhancing the residential environment. The implications of this study suggest that urban planners and policymakers need to prioritize improving neighbourhood conditions to enhance the quality of life for residents, particularly in developing urban contexts. By addressing these determinants, cities can foster environments that promote higher life satisfaction and well-being among their inhabitants.

Keywords: Life satisfaction; subjective wellbeing; residential satisfaction; Jeddah; Saudi Arabia

The integration of Lean Manufacturing (LM) and Industry 4.0 (I4.0), also known as Lean Manufacturing 4.0 or Smart Factory, is increasingly adopted by manufacturers for their effectiveness in reducing losses and improving efficiency. Despite their established benefits, there is a notable gap in comprehensive analyses regarding the integration of I4.0’s Manufacturing Execution System (MES) and Total Productive Maintenance’s Overall Equipment Effectiveness (OEE) within lean practices. Therefore, the purpose of this paper is to provide a comprehensive literature review offering thorough insights into the trends, applications, and impacts of Lean Manufacturing 4.0. Utilizing a systematic literature review, this research initially assesses 250 papers for bibliometric trends, narrowing down to 44 papers for content analysis. The bibliometric analysis reveals trends in Lean Manufacturing 4.0 publications, including historical series, publications across countries, highly cited articles and types of papers. Noteworthy findings from the content analysis are the frequent connection between LM’s Process Mapping and I4.0’s MES, as well as the frequent association of I4.0’s Internet of Things with LM’s OEE. The OEE-I4.0 integration is predominantly characterized by enhanced OEE and real-time data utilization, while MES-Lean integration showcases documented impacts on production efficiency, resource management, and continuous and operational system improvement. This study highlights the importance of adopting relevant Lean Manufacturing 4.0 practices for manufacturers and scholars. The importance of Lean Manufacturing 4.0 practices and the understanding of connections between OEE and I4.0, as well as MES and LM, are addressed in this study, emphasizing the imperative for businesses to adopt Lean Manufacturing 4.0.

Keywords: Overall Equipment Eff ectiveness (OEE); Manufacturing Execution System (MES); Internet of Things (IoT), Lean Manufacturing 4.0; Smart Factory.

This study explores a hybrid approach aimed at enhancing the shear performance of reinforced concrete (RC) beams. The methodology involves the incorporation of industrial steel chips having length 75mm to 100mm in combination with varying widths of wire mesh reinforcement. Comprehensive shear tests were conducted on precisely prepared beam specimens measuring 150mm×150mm×900mm to assess shear strength, crack patterns, and failure modes. The study induces steel chips into the concrete mix at a rate of 0.9% by weight and comprises eight sets of specimens,including a control sample without any mesh reinforcement, along-with specimens reinforced with wire mesh strips ranging from 12.5mm to 87.5mm in width. Notably, the inclusion of steel chips and wire mesh enhances the shear behavior of concrete beams across all samples. As the steel chips and wire mesh acts like small-diameter bars, contributing to the enhancement of shear by improving the interlocking of concrete constituents and eff ectively distributing stresses throughout the beam’s cross-section, leading to distinctive diagonal crack patterns on the beam surfaces. The study unveils that with the increasing width of the wire mesh, there is an increase in the number of cracks while the crack widths decreases. The test outcome reveals that percentages increase of 13.66, 22.89, 31.37, 46.50, 55.00, 66.80 and 78.60 respectively, demonstrating the effective enhancement of shear strength through the utilization of wire mesh and steel chips.

Keywords: Wire mesh; crack pattern; reinforcing material; steel chips; shear strength

To overcome odor problem, sweat degradation by bacteria is inhibited. In this research, modified complex coacervation technique involves formation of Nano capsules, which stores antimicrobial and fragrant compounds. Modified Complex Coacervation technique requires high-speed mixing of the solution to produce Nano capsules. In this research Sodium Alginate, Gelatin and Gum Arabic were used as wall materials. Aloe vera and peppermint essential oil were used in a core at equal weight with wall materials. Prepared coated samples by synthesized Nano capsules were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Formaldehyde Release Test and AATCC 100 test for antimicrobial activity for validation of formation of Nano capsules, which possessed antimicrobial and fragrant properties.

Keywords: Odorless fabric; fragrance fabric; sodium alginate; gum Arabic; gelatin; SEM; FTIR

The primary method used by conventional fire detection systems is sensor-based detection, which has limitations in terms of accuracy and detection time. Traditional approaches and techniques could be improved by the latest advancements in computer vision-based technologies for fire prediction and detection. Consequently, this paper aims to provide a comprehensive literature analysis of earlier research on fire detection and prediction using the computer vision techniques. The Preferred Reporting Items for Systemic Reviews and Meta-Analyses, or PRISMA 2020, are applied in this systematic review. Three databases such as the Web of Science, Scopus, and IEEE were searched for pertinent publications to include in this review for this study. The systematic review reveals that existing studies predominantly focused on fire flame rather than smoke detection. Moreover, the majority of research has centered on forest fires in the particular context of occurrence, neglecting indoor or interior environments. Video surveillance systems emerge as the primary source of hardware and datasets utilized in these investigations. Notably, convolutional neural networks (CNNs) stand out as the most frequently employed deep learning approach for classification purposes. The systematic review clarifies the state of fire detection research using computer vision techniques by combining data from several academic sources. Through a systematic approach, this study contributes a deeper understanding of the opportunity and challenges in leveraging visionbased technologies for fire detection and prediction.

Keywords: Systematic literature review; vision-based; fire detection; fire prediction; machine learning

E-wallet is a fintech digital tool that allows to make cashless, quick, and easy transactions, and to review and analyze payment histories. Meanwhile, the expansion of digital wallet usage has contributed to a surge in overspending where users do not benefit from generated expenditure data to improve personal financial management. The objective of this study is to compare existing delivery technologies operational features to ensure the best suited delivery technology is adapted into the proposed adaptive money management embedded e-wallet design. A review was conducted to find relevant articles published between 2017 to 2021. The main inclusion criteria were English articles that discuss the applications of NFC, QR code, Digital (online)-only, and/or SMS. The search resulted in 159 articles but only 12 met all the inclusion criteria. The review highlights the advantages and disadvantages of using the three technologies in financial applications. This review suggests that QR payment is most popular, secure, fast, and cost-effective compared to NFC and SMS, as delivery technology best suited for the adaptive management embedded e-wallet that incorporated the four blocks of Fintech technologies namely, blockchain, AI, IoT and RPA. Overall, a QR code enabled e-wallet can expedite and automate the process of analyzing transactions, thus providing a solution to secure transactions and better money management.

Keywords: Digital payment; Digital wallet; NFC; QR; SMS

Resin based dental composites is one of the promising dental materials that serves as an alternative to metal and amalgam restorations, as they resemble natural tooth and widely used in restorative dental treatments such as tooth decay and oral lesions. Despite several ongoing researches and innovations, the primary challenges associated with composite restorations are their limited durability, sensitivity, shrinkage and leakage. This research aimed to address these challenges and develop an innovative dental composite resulting in a minimal discomfort to the patient and improve long term therapeutic eficacy. To overcome these challenges silica Nano- particles, with antibacterial agent was incorporated. Nano- particles of silica acted as filler, which was extracted from a bio-waste (rice husk). The addition of anti-microbial agents helped to minimize leakage due to shrinkage as these materials have small particle size, offering a wide range of biological, chemical and mechanical properties. This was followed by characterization techniques which includes; SEM, XRD, FTIR and particle characterization that were evaluated and compared. The peaks of Silicon dioxide in XRD was recorded at 21.67, 38.38 and 44.68. Extracted silica particle size 47. 66 μm was further reduced to Nano size with an average size of 200 nm. FTIR spectrum showed the relative transmittance at 1000- 1090 cm^-1. The results met the standard measures and was much cheaper than currently used in dental industry. In future, comparative analysis testing including compressive or tensile strength and anti-bacterial testing can be performed that may further prove its potential and can be followed by clinical trials also.

Keywords: Silica nanoparticles; anti-bacterial agent; shrinkage; biocompatibility

Petroleum hydrocarbons and waste streams have polluted the environment, harmed human health, affected socioeconomic conditions, and impacted communities in oil-producing countries. The aim of the study is to identify hotspots of contaminated water, create spatial risk maps of pollution from the petroleum industry and develop a novel index to estimate ecosystem pollution named physico-chemical risk index (PRI). Ten sites in the Al-Gharraf oil field were analyzed for their water quality. The highest results of the six-month sample analysis were PH (8.7), DO (11.5mg/L), turbidity (70.3 NTU), temperature (34 C), BOD₅ (37.8 mg/L), COD (101 mg/L) and TSS (109 mg/L). To achieve the above objectives, different methods and techniques were used; one of them is inverse distance weighting(IDW) with GIS to create geographical maps of the measured parameters. The IDW method was used to accurately map the distribution of ecosystem parameters of the oil field. The PRI was performed to compare the threshold values for pollutant elements with the contamination of the site. The threshold value for contaminated water in Garraf oil field is 24.328 and is determined by the PRI index. The analysis is carried out at regular intervals and compared with the threshold values. This work has created an important database for the oil industry that should be used to monitor ecosystems.

Keywords: geographic information system (GIS); inverse distance weighting (IDW); physico-chemical risk index (PRI); water contamination; oil field.

This research is significant to investigate the eff ect of synthesis parameters (weight loading ratio CNCs: Fe₂O₃, sonication temperature, sonication time) on cellulose nanocrystals (CNCs) modified with iron oxide (Fe₂O₃) nanoparticles. The CNCs/Fe₂O₃ adsorbent was synthesized via the ultrasonic-assisted chemical co-precipitation method. All synthesized samples were analysed using linear alkyl-benzene sulfonate (LAS) removal from laundry wastewater using a batch adsorption study. The CNCs/Fe₂O₃ adsorbent was characterised using FTIR, TGA, N₂ sorption-desorption, and SEM-EDX analyses to understand its chemical and physical properties. The highest removal of LAS was found at a 1:1.5 ratio of CNCs: Fe₂O₃, 80°C of sonication temperature, and 90 min of sonication time, with ±90% removal of LAS. The FTIR analysis revealed several functional groups in the CNCs and CNCs/Fe₂O₃ adsorbent. The CNCs showed a hydroxyl group and aromatic ring in lignin around the spectrum of 3000 – 3400 cm^{-1 and 1640 cm-1, respectively. The broad shoulder for the hydroxyl group in the CNCs was reduced to a small peak due to the formation of iron oxide. Thermal analysis from the TGA analysis showed a significant weight loss of around 50 – 200°C due to the destruction of the cellulose structure. As for the N₂ sorption-desorption analysis, the CNCs/Fe₂O₃ adsorbent exhibits a larger surface area compared to the CNCs, in which the porous structure can be observed in the CNCs/Fe₂O₃ adsorbent from the SEM morphology. Overall, the addition of Fe₂O₃ via ultrasound-assisted coprecipitation method contributes to the development of the CNCs structure while changing the properties of the CNCs/Fe₂O₃ as a potential adsorbent for LAS in the laundry wastewater application, thereby offering a practical solution for wastewater treatment.}

Keywords: Adsorption; cotton-cloth waste; cellulose-nanocrystals; Fe2O3 impregnation; laundry wastewater; linear alkyl-benzene sulfonate (LAS); ultrasound-assisted

Magnesium-air fuel cell (MAFC) is a hybrid system that combines the design of a fuel cell and a battery, requiring a constant replacement of anode and electrolyte to operate. MAFC application is limited for short-term high-power applications like emergency and portable power supplies because of severe corrosion problems impairing the performance of MAFC. Hence, this study focuses on performance by investigating the effect of electrolyte volume, electrodes position, and electrolyte concentration on performance of Mg–air fuel cell. Three sets of experiments were conducted starting with variation in volume of electrolyte. Then, it is applied in the cell configuration to test the MAFC performance with different electrode position. Lastly, the best electrode position is applied to the new modified MAFC together with the chosen electrolyte to investigate the effect of electrolyte concentration on MAFC performance. Finding shows that electrolyte volume not really significant to the performance while higher NaCl concentration can increase the performance of MAFC significantly. 10 wt% of NaCl produce the highest power density of 38.95 mW.cm^-2 and operating voltage of 1.67 V. Unfortunately, higher corrosion rate was observed in higher NaCl concentration. Finally, adding sodium phosphate act as corrosion inhibitor manage to suppress the corrosion reaction and lowers the corrosion rate.

Keywords: Cell confi guration; corrosion; magnesium; magnesium-air fuel cell; metal-fuel cell

Based on the fi ndings of short-term research, biofuels are determined to be an acceptable replacement for petroleum diesel fuel. Extended research using these kinds of oils as fuel identified issues with engine wear and upkeep. A 200-hour test was conducted on a single-cylinder compression ignition engine to examine the eff ects of fueling on engine longevity. This research work was carried out to investigate the long-term endurance test of DF100 (diesel fuel) as the base fuel, and blended fuels: DF95WCO5 (5% waste cooking oil and 95% DF), and DF65WCO20Pe15 (20% waste cooking oil, 65% DF, and 15% n-pentanol) through single-cylinder compression ignition (CI) engine. Further, the effects of DF100, DF95WCO5% and DF65WCO20Pe15 on exhaust valve surface deposits were also investigated. The SEM and EDS analysis showed that DF95WCO5 has a higher concentration of carbon deposits around the exhaust valve surface as compared to DF100 and DF65WCO20Pe15. Further, ternary blend fuel had minimal carbon deposits on the exhaust valve as compared to as compared to remaining both. This evidenced that the addition of pentanol significantly reduced the carbon deposition on the exhaust valve surface. About DF, DF95WCO5, and DF65WCO20Pe15, the percentage of carbon layer on exhaust valve surfaces is 44.67%, 45.42%, and 16.01%, respectively. For the fuel DF65WCO20Pe15, there was very little exhaust valve deposit formation during experimental examination. The ternary blend fuel also observed less concentration of Iron, Copper, Nickel and wear debris concentration as compared to DF100 and DF95WCO5.

Keywords: Waste cooking oil; exhaust valve deposition; viscosity; density; wear analysis

In the present paper, the Taguchi method is implemented to figure out which set of process parameters is optimal for forming dissimilar aluminum alloy blank joints together using friction stir welding. In single-point incremental forming (SPIF), four process parameters were taken into consideration: rotational speed, feed rate, step size, and wall angle. Measurements were made on both sides, inner and outer of each surface of the formed part due to dissimilar material of tailor welded blanks (TWBs) to see the pattern and relationship. The results show that step size is the most important parameter, then the wall angle. The rotating speed and feed rate had the least impact on surface roughness. The optimal parameters are a 0.2 mm step size, a 55-degree wall angle, a 1500 rpm rotational speed, and a 1000 mm/min feed rate for the inner and outer surfaces of AA5052. While the AA6061 gives the optimum values of 0.2 mm step size, a 55-degree wall angle, and a 1000 mm/min feed rate on the inner and outer of the measured surface, the slightly different optimum values on the rotational speed are 1250 rpm and 1750 rpm for the inner and outer surfaces, respectively. On Analysis of Variance (ANOVA) showed the step size has a greater percentage contribution effect on the surface roughness of formed TWBs than any other parameter. Furthermore, confirmation test results using optimal conditions showed good agreement wit experimental findings.

Keywords: Surface roughness; single point incremental forming; tailor welded blanks; Taguchi method

Anthropogenic activities have resulted in considerable water quality degradation in water sources due to a common problem of the excessive nutrient content (phosphorus) in receiving water, resulting in eutrophication. Even though various wastewater treatment methods have been applied, focusing on phosphorus removal through biological, physical, and chemical treatment, there is still a need to identify the eco-friendly method using the adsorption process and verify the theoretical and experimental data via kinetic and isotherm models. Hence, this study investigates phosphorus removal efficiency from water onto raw marsh clam shells and verifies the experimental and theoretical data with kinetic and isotherm studies. The variable of this study used different masses (2, 4, 6, 8, 10 g) of adsorbents with particle sizes from 1.18 mm to 2.36 mm to remove phosphorus from an aqueous solution (5 mg/L). The physicalchemical properties of adsorbents were examined using X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-ray Fluorescence (EDXRF), and Fourier Transform Infrared Spectroscopy (FTIR) to support the experimental data and identify the possibility of phosphorus adsorption. The batch experiment data obtained were verified using the kinetic (pseudo-first-order and pseudo-second-order) and isotherm (Langmuir and Freundlich) models. The experiments showed that the best contact time for all masses was 1440 min and the best adsorbent dose was 10 g with 78.0%removal. By comparing the two adsorption isotherm models, the study finds that the adsorption isotherm fits the Langmuir isotherm model with a correlation coefficient, R² of 0.9006. The novel use of adsorbent marsh clam shell as a potential adsorbent in the application of future water treatment technologies.

Keywords: Adsorption; phosphorus; kinetic; isotherm; marsh clam shell

The increasing adoption of transformative technologies, such as the Internet of Things (IoT), has brought convenience and optimization to various domains. However, it has also introduced new challenges, including the vulnerability to Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks. DDoS attacks have shown an alarming rise in frequency and potency, making it crucial to devise efficient mechanisms to prevent such attacks and safeguard communication networks. IoT networks, with their numerous interconnected devices and limited resources, are particularly susceptible to DDoS attacks. Traditional rule-based approaches have proven insufficient to cope with the dynamic nature of modern attacks, leading to the emergence of deep learning-based detection and mitigation techniques. Deep learning models, supported by real-world datasets, off er promising results with detection rates exceeding 98%. This study explores various deep learning architectures, focusing on their success in DDoS attack detection, particularly in IoT networks. It also addresses the challenges associated with such networks and highlights potential areas for future research.

Keywords: Convolutional Neural Networks (CNNs); deep learning; Distributed Denial of Service (DDoS); Internet of Things (IoT); Long Short Term Memory (LSTM); transfer learning

The utilization of the jet impingement technique is a prevalent approach in enhancing the efficiency of photovoltaic thermal (PVT) collector through the augmentation of heat transfer rate. The present work introduces a novel approach known as the reverse circular flow jet impingement (RCFJI) on a PVT collector. The performance analysis of the PVT collector was assessed through the utilization of CFD simulation. The RCFJI was installed to a jet plate which incorporates 36 holes. The holes were positioned at a spacing of 113.4 mm (x-axis) and 126 mm (y-axis). The air outlet channel of the jet plate has been configured into four different configurations: one hole (1h), three holes (3h), four holes (4h) and five holes (5h) to analyze the best outlet configuration leading to the highest energy performance. The simulation evaluation encompassed a range of solar irradiance spanning from 600 W/m² to 900 W/m², while the mass flow rates varied from 0.01 kg/s to 0.14 kg/f for each geometrical design. Based on the research, the configuration that records the highest efficiency was 1h. The maximum photovoltaic efficiency recorded was 11.38% at 600 W/m² and mass fl ow rate of 0.14 kg/s. While the maximum thermal efficiency was 63.2% at solar irradiance 900 W/m² and mass flow rate of 0.14 kg/s.

Keywords: Jet impingement; photovoltaic thermal; heat transfer; solar collector; CFD Simulation

The solar-assisted heat pump drying (SAHPD) system uniquely incorporates solar-heating refrigerant through hot water from solar evacuated tubes, offering distinct advantages. This study analyzed three experimental setups: a heat pump dryer (HPD) without solar assistance, SAHPD configuration 1 (C1-SAHPD) with solar-heated refrigerant at the discharge line, and SAHPD configuration 2 (C2-SAHPD) with solar-heated refrigerant between condensers, both for performance and economic viability. The experiments maintained consistent parameters, including 5.5 kg of Pandan leaf (Pandanus amaryllifolius), an airflow rate of 0.135 kg/s, and a refrigerant operating pressure of 9.65 bar. The SAHPDs operated when the hot water temperature in the storage tank reached between 70°C and 90°C, with a daily average radiation intensity ranging from 0.670 to 1.102 kW/m² for heating the water. The study revealed average coefficients of performance (COP_avg) of 5.34, 5.43, and 6.53 for HPD, C1-SAHPD, and C2-SAHPD, respectively. The specific moisture extraction rate (SMER) for HPD was 2.64, while C1-SAHPD and C2-SAHPD had SMERs of 1.88 and 2.71 at solar fractions of 0.34 and 0.45, respectively. Notably, C2-SAHPD reduced electricity consumption by 46%. The payback period for drying 11 kg of Pandan leaves per day was 4.56 months for HPD, 4.32 months for C1-SAHPD, and 3.84 months for C2-SAHPD. The study concluded that C2-SAHPD was the most efficient dryer system for Pandan leaves based on its higher efficiency, SMER, and cost recovery. Additionally, the performance optimization presented in this study contributed to developing a novel technique for classifying dryer technologies.

Keywords: Solar assisted heat pump dryer; solar-heating refrigerant; R32; COP; dual condenser; evacuated tube

In many practical applications, AISI 1045 carbon steel is subjected to various external factors, one of which is vibration. This vibration can induce resonance in the material, ultimately leading to fatigue due to cyclic stress. The aim of this study is to investigate the mechanical behavior of AISI 1045 carbon steel when subjected to both static and cyclic loading conditions, and to assess how its fatigue properties change across different test frequencies, and to validate a mathematical model that predicts fatigue life through statistical analysis. To ensure accurate and standardized testing, the specimen geometry follows the ASTM E466 standard for tensile and stress-life tests, and the ASTM E290 standard for three-point bending tests. The study involves conducting a series of mechanical tests, including tensile tests, stress-life tests, and three-point bending tests, which provide critical data on the material’s fatigue life under various conditions. By analyzing the results, the researchers aim to establish a clear relationship between the applied load frequency and the material’s fatigue life. Additionally, based on this relationship, they propose a mathematical model to predict the fatigue life of AISI 1045 carbon steel across different frequencies. This model could be useful in estimating the durability and performance of components made from this steel when subjected to dynamic and fluctuating loads, helping engineers design more reliable system and predicting material performance under varying operational conditions.

Keywords: Carbon steel; vibration fatigue; frequency; fatigue life; cyclic loading

Terrestrial laser scanning (TLS) is a powerful tool for generating detailed 3D models of elevated structures such as bridges, towers, and buildings. However, the quality of the resulting models heavily depends on the setup configuration of the TLS system. This research evaluates the precision of 3D point cloud data of elevated structures acquired through TLS at different distances. The data processing was performed using Cyclone Register360 software. The study aimed to evaluate the accuracy of point cloud data obtained from various TLS setup locations and compare it with the measurements obtained from a Total Station. Four different distances were used to set the TLS to scan the three elevated structure piers. The acquired data was then processed using Cyclone Register360 software to eliminate noise, visually align, and precisely register the point clouds. The results indicated that shorter distances between TLS setups resulted in more accurate point cloud data, with reduced error rates, highlighting the need to locate the scanner effectively. The study also highlighted the capabilities of Cyclone Register360 in improving the precision of point cloud data through effective data processing techniques. The findings demonstrate the significance of precise scanning distance evaluation in TLS applications to ensure high-quality data capture. It is vital for comprehensive 3D modeling and analysis of elevated structures. These valuable insights apply to specialists in surveying, engineering, and architecture. It offers guidance on the best practices for TLS setups, which can improve the accuracy and reliability of measurements. Further studies should examine the influence of other factors, such as scanning angles and environmental conditions, on the precision of TLS data.

Keywords: TLS; point cloud; accuracy; elevated; structure

Earthquakes are one of the natural occurrences that can lead to massive disasters, either on structures or infrastructure. The seismic response and performance of underground infrastructure such as tunnels against earthquake vibrations is predictably severe due to the complex interaction between tunnels and the surrounding soil, especially one embedded in poor soil material properties. In view of this, previous experiences of tunnel damages
subjected to earthquake loads have been reported in the literature. Thus, rigorous analysis is necessary to provide indepth knowledge and understanding of the seismic response of tunnels which beneficial to engineering practitioners in especially in early design stage in order to avoid the future risk of tunnel damage and failure during an unpredictable earthquake event. The aim of this study is to investigate the effect of overburden depth on seismic response of tunnels using the simplified pseudo-static analysis, while simultaneously to emphasize the shortcoming of conventional closed-form solution. This study presents a two-dimensional (2D) simplified pseudo-static analysis of soil-tunnel model embeded at 10m and 20m overburden depth subjected to increasing levels of seismic intensity at the transverse direction of tunnel axis. The numerical investigation was performed using the finite element program PLAXIS 2D. The circular shaped tunnel lining are assumed to be elastic, while the soil is considered as homogeneous, and isotropic in plane strain condition. Considering the complex soil-tunnel interaction, the tunnel lining and soil interface is assumed as no-slip condition. The numerical result of pseudo-static analyses were compared with the conventional closed-form Wang‘s analytical solution to verify the reliability of the obtained results. The results denoted that the tunnel embedded at 10m overburden depth experienced considerable seismic-induced deformation and structural forces than tunnel buried at 20m depth. The deformation and seismic induced structural forces of tunnel increased with increment on the magnitude of earthquake loadings. Thus, it can be concluded that the shallow tunnel suffered more damages compared to the tunnel embedded at deeper depth. Overburden depth of tunnel plays a significant role in modifying the seismic response of tunnel apart of the imposed magnitude of earthquake loadings. The conventional closed-form analytical method tends to overestimate the seismic response of tunnel compared to numerical pseudo-static analysis.

Keywords: Seismic response; tunnels; soft soil; rock; pseudo-static analysis

Kuala Lumpur City (KLC) is susceptible to disasters because of its large population, crucial infrastructure, and vital economy. In this study, we used the disaster risk maps generated for flash floods and landslide hazards in KLC to identify key areas for humanitarian assistance and disaster relief (HADR) activities. We employed analysis and simulations to determine the most effective evacuation routes from key areas to crucial HADR centres, including medical facilities, police stations, fire stations, and temporary evacuation centres, during a disaster. We conducted the investigation by considering factors like evacuation time, route accessibility, and overall efficiency. We proposed multiple routes during the disaster scenario, including the use of alternative roads with reduced capacity if the major roads became inaccessible. This case study highlights the significance of ongoing evaluation and improvement of evacuation preparations. The measures, including the use of cutting-edge traffic management systems, frequent practice sessions and instruction for emergency responders, and heightened public awareness and preparedness initiatives, could potentially improve evacuation time. By implementing these strategies, KLC may enhance its ability to withstand and respond to disaster scenarios, thereby safeguarding lives and mitigating the potential consequences of disasters. The results of this study could provide useful insights for Kuala Lumpur City Hall to plan evacuation routes during a disaster.

Keywords: Urban disaster; landslides; fl ash fl ood; riskmap; evacuation routes

Kuala Lumpur, the capital city of Malaysia, is vulnerable to various natural and man-made disasters. Kuala Lumpur City (KLC) encounters distinctive difficulties in managing urban disasters, mainly because of its dense population, critical infrastructure, and economic importance. Mapping the hazards and risks of disasters in KLC is crucial for enhancing its resilience against disasters and ensuring the effectiveness of emergency response, humanitarian aid, and disaster relief efforts. The objective of this study is to develop a comprehensive master plan for the management of disasters in KLC. The plan will serve as the initial phase in the civil-military coordinating response architecture for humanitarian aid and disaster relief (HADR). The approach entails creating a hazard map delineating regions susceptible to flash fl oods and landslides, frequently occurring in KLC. In addition, a vulnerability map was generated to evaluate the region’s proneness to disasters and identify safe areas within KLC. Additionally, road vulnerability assessments were performed to determine the most direct route for HADR activities. Furthermore, a customised disaster risk map was created exclusively for the KLC. This work contributes to the growing body of literature on urban disaster management, offering valuable insights for other metropolitan areas facing similar challenges.

Keywords: Urban disaster; landslides; fl ash fl ood; hazard map; vulnerability map; risk map

General automation in household chores uses technology and devices to carry out conveniently or aid in completing ordinary domestic duties, enhancing daily living. However, the traditional method of ironing clothes is one of the everyday tasks around the house that has been waiting for a revolution for a long time. The ironing task is still done by hand and is not automated. The problem is that ironing excessive clothes, especially school uniforms, for a week’s usage can be laborious and time-consuming. Anyone would experience boredom, tiredness and fatigue due to this circumstance when ironing continually. Therefore, to solve the issue, this project was developed to eliminate the tedious ironing process. This project aims to develop an automatic cloth ironing machine using a few low-cost electronic and mechanical components and compare the timing of cloth ironing using an automatic machine and by hand. As a result, a prototype presented a revolutionary initiative that combines modern technology and automation to revolutionise traditional clothing ironing methods. It can respond to specifi c fabric types and sizes, ensuring consistency in the ironing process. In conclusion, a prototype was successfully designed and developed with various low-cost electronic components and mechanical devices, e.g. an Ultrasonic Sensor HC-SR04, Arduino UNO, a belting system and a steam generator. Then, using the machine is slightly slower by 40 seconds compared to ironing manually. This achievement reassures the potential of the machine. Future development plans include using two steam plates to iron the back and front of the clothes and using a steam generator with a higher power that produces much steam.

Keywords: Ironing; ultrasonic sensor; arduino; belting system; steam generator

Epoxy resin demonstrates remarkable adhesion, mechanical properties, and heat resistance, however, its inherent brittleness warrants attention. Therefore, hybrid composite was prepared using epoxy resin as the polymer matrix, with carboxyl- terminated butadiene nitrile liquid rubber (CTBN), and nanosilica as the reinforcement materials to increase the mechanical properties. The loading for CTBN and nanosilica are set to (5 wt.%, 10 wt.%, 15 wt.% and 20 wt.%); and (1 wt.%, 2 wt.%, 3 wt.% and 4 wt %.); respectively. The epoxy composites are toughened by adding various loadings of CTBN. Then, fracture toughness and viscoelastic viscosity properties of the composites are measured. At 15 wt.% of CTBN loading, nanosilica are added at different loadings to examine the improvement of composites. Then, fracture toughness (K_IC), the glass transition temperature (Tg), loss modulus (E”) and storagemodulus (E’) were all measured. Incorporating CTBN into epoxy matrix improves fracture toughness up to 79.4%, with optimum loading of 15 wt.%. Nanosilica content also significantly impacts fracture toughness, with a maximum enhancement of 107.7% at 3 wt.% loading. The glass transition temperature increases with CTBN content, reaching 17.01% improvement at 15 wt.% loading and 18.32% improvement at 20 wt.% loading. Nanosilica is also found to increase glass transition temperature, reaching 74.49°C, at 3 wt.% loading and 83.33°C, at 4 wt.%. The loss modulus increases as CTBN and nanosilica loading increases. At a loading of 20 wt.% CTBN, it reaches a maximum value of up to 164.7%. Adding further 4 wt.% nanosilica to 20 wt.% CTBN, resulted in an increase in loss modulus up to 1600%. The storage modulus also increases as CTBN and nanosilica loading increases to 20 wt.% and 4wt.%, respectively and it reached 1662% from neat epoxy. In conclusion, a combination of 15 wt.% CTBN and nanosilica have increased the fracture toughness and viscoelastic viscosity properties of epoxy composites.

Keywords: Fracture toughness; glass transition temperature; CTBN; nanosilica; hybrid

This study demonstrates the utilization of a Scandium Oxide (Sc₂O₃) film as a passive saturable absorber (SA) for pulse generation within the C-band region in an Erbium-Doped Fiber Laser (EDFL) cavity for possible applications in metrology, sensing, and medical diagnostics. The SA was fabricated using Sc₂O₃ powder, with polyvinyl alcohol (PVA) employed to form the film. The experimental setup utilized an all-fiber ring cavity configuration. Q-switching was achieved over a range of pump powers from 48.8 mW to 84.8 mW. It is observed that as the pump power increased, the repetition rate rose from 42.3kHz to 82.8 kHz, accompanied by a reduction in pulse width from 5.04 μs to 2.82 μs. At a pump power of 84.8 mW, the system achieved a maximum output power of 6.75 mW and a maximum pulse energy of 81.6 nJ. The EDFL also has a high signal-to-noise ratio (SNR) at the fundamental frequency which is 55.4 dB, highlighting the stability of the Q-switched pulses.

Keywords: Fiber laser; Q-switching; saturable absorber; scandium oxide

This paper investigates the correlation between rubber elasticity and strain measurement, aiming to advance the understanding and utilization of natural rubber in Structural Health Monitoring (SHM). Natural rubber, derived from latex found in rubber-producing plants, possesses exceptional elasticity and resilience, allowing strain measurement applications. This study employs strain gauge sensors and a Wheatstone bridge configuration to accurately assess the strain experienced by various rubber samples which are Rubber 1, Rubber 2, and Rubber 3 under different loading conditions. The differences between all three rubber samples are in the content of carbon black of size in the rubber. Rubber 1 contains carbon black of size N330 (60%), Rubber 2 contains carbon black of size N550 (60%), and Rubber 3 does not contain any carbon black. Through experimental analysis, it is demonstrated that as the applied load increases, the measured strain detected by the strain gauge rises, leading to an increase in the bridge output voltage. The proposed method, Rubber 2 is increased 11.94% in elasticity compared to Rubber 1 and Rubber 3 increased 15.82% in elasticity compared to Rubber 1. Among the tested rubber samples, Rubber 3 with higher elasticity exhibits a more signifi cant increase in output voltage, indicating a stronger response to applied stress. The proposed strain measurement system effectively captures rubber elasticity, providing valuable insights into the mechanical properties of rubber components. Furthermore, this research aligns with Sustainable Development Goals (SDG), particularly SDG 12: Responsible Consumption and Production, by leveraging Malaysia’s abundant natural rubber resources for innovative applications in structural health monitoring. Overall, this study contributes to the advancement of SHM techniques and the sustainable utilization of natural resources, with potential implications for various industries, including civil engineering and material science.

Keywords: Elasticity; strain measurement; natural rubber; structural health monitoring; strain gauge sensors; sustainable development

Mechanical sifting and manual grading have conventionally been utilised to assess the grade of aggregates. Nonetheless, such evaluations require a range of mechanical, chemical, and physical examinations, typically conducted manually, resulting in a process that is tedious, subjective, and labour-intensive. This research aims to provide an image-based classification system for the categorisation of aggregates. An artifi cial neural network (ANN) has been used to analyse the acquired images and categorise their shapes. The composite images are obtained and utilised as the input parameter for prediction prior to the thresholding step. The Log-sigmoid (Logsig) activation function, utilised in a Multilayer Perceptron (MLP) network, exhibits a lower mean square error (MSE) and superior regression performance relative to the Pureline activation functions. The Logsig-based network has a MSE of 1.7473 and a regression capability of 0.9521.

Keywords: Aggregate; MLP network; Training algorithm; MSE; Regression

As electricity demand increases day by day due to economic growth, the process of transmitting efficient electrical power is vital. Thus, a power simulation study is required to determine the mechanism of the transmission line, and possible faults that occurred in the transmission line system. On a daily basis, single line to ground fault (L-G), double line to ground fault (2L-G), and triple line to ground fault (3L-G) are the faults that normally occur in the long transmission line system. In this project, a model of a 300km/500 kV EHV transmission line consisting of a three-phase source, distribution line, and load is simulated using MATLAB software. When the L – G fault is applied, the voltage is diminished to zero and upon fault clearance, the R – G line produced overvoltage and overcurrent by 518.9 kV and 1889 A, which increased about 46.83% and 15.67% compared to normal lines of Y – G and B – G at 353. kV and 1633 A. Then, for the 2L – G fault, again the voltage is reduced to zero and when fault clearance occurred, the R – G and Y – G lines experienced overvoltage and overcurrent at 570.4 kV and 708.5kV, which showed more than 60% transient compared to normal line B-G at 353.4 kV. In Contrast, the 3L – G fault causes all transmission lines to experience overvoltage and overcurrent at different times and can damage the whole transmission system. Thus, to reduce the severe impact of fault, the Inverse Definite Minimum Time Over Current (IDMT O/C) relay protection is installed in the line model.

Keywords: Faults in transmission line; Extra High Voltage (EHV); Simulink/MATLAB; IDMT O/C.

A few years back the power requirement of electronic devices was very high. But with the technological developments in the field of internet-based systems, the design of low-powered microelectronic devices, WSN and IoT devices became necessary. In these systems the size and the power requirement are low and in most situations the replacement of batteries is challenging. For these microelectronic and IoT devices the abundant energy harvester is very useful. Among different abundant energy resources, vibrational energy harvesting with piezoelectric cantilever beam energy harvesters is of interest. This research work presents the design and analysis of an energy harvester (EH) which contains a single piezoelectric cantilever beam that captures the vibrational energy of the suspension bridge. This approach ties the two things together by framing piezoelectric energy harvesting as a solution to the power challenges faced by low-powered devices, making the transition feel more natural and connected. The main challenge in the design was matching the resonance frequency of the bridge with a piezo EH which is around 2.5Hz to extract maximum power. To overcome this problem Eigen frequency analysis in COMSOL Multiphysics is done. The 3D geometry of single beam piezo EH is designed and analyzed in COMSOL Multiphysics solid works. In this research work a relationship is established between the geometrical parameters of the single beam piezo EH and Eigen frequency based on the first six Eigen frequency analyses in COMSOL Multiphysics. For fi nite element analysis(FEA) a piezo single beam harvester is vibrated by application of force which is equal to the vibrational force (0.98m/s²) in the suspension bridge. The force of (0.98 m/s²) is chosen because it avoids resonating with critical system components. The output from the harvester is achieved at a resonance frequency of 2.5Hz. The output from the piezo is very low 800 milli volts at 2.5Hz. The output results of piezo EH are also compared with a cantilever beam with a single-branch structure.

Keywords: Energy harvesting; vibration; IoT; WSN; micro-devices

Titanium carbo-nitride (TiCN) inserts are vital for cutting operations, particularly in high-temperature conditions. Conventional machining methods lead to rapid wear of tools, frequent need for tool changes, high costs associated with tool replacement, and extensive usage of synthetic cutting fl uids that are environmentally damaging. This study aims to minimise tool wear and promote circular economy. This study examines the process of machining T6061 aluminium alloy using TiCN inserts treated with hybrid microwave (HMW) energy at 220℃ for 20 minutes, with silicon dioxide (SiO2) as the susceptor. Recycled cooking oil is utilised for Minimum Quantity Lubrication (MQL). Analysed were the density, hardness, and microstructural images. Tool wear of TiCN was assessed during dry and wet machining using three different cutting speeds (166, 210, 263 m/min) while maintaining a constant feed rate of 0.6mm/rev and depth-of-cut of 0.4 mm. The findings show the density and hardness of TiCN (HMW) increased by 4% and 7% respectively compared to the TiCN (untreated) insert. The tool wear of TiCN (HMW) has reduced by 5% (MQL) and 24% (dry) compared to the TiCN (untreated) insert. MQL with recycled cooking oil decreased tool wear by 40% compared to dry machining. The microstructural images of the TiCN (HMW) and TiCN (untreated) structures reveal no noticeable variations. TiCN (HMW) has improved wear resistance, and it is particularly beneficial when utilising recycled cooking oil in MQL machining.

Keywords: T6061 Aluminium alloy; TiCN insert; hybrid microwave treatment; MQL machining; recycled cooking oil

The Covid-19 outbreak has profoundly affected teaching and learning, necessitating a careful transition back to conventional methods in the post-pandemic era. This study examines the Continuous Quality Improvement (CQI) of Course X in Civil Engineering during and after Covid-19, focusing on specific challenges faced and measures implemented during this transition. The evaluation includes an assessment of academic performance through diagnostic tests, course outcomes, program outcomes, and student feedback as components for planning effective CQI initiatives. Overall CO-PO performance metrics indicate that in semester 20214, CO1-PO1 was attained at 86%, while CO2-PO2 achieved 71%. However, during face-to-face assessments in semesters 20224 and 20234, a significant decline was observed: CO1-PO1 dropped to 54% and 53%, respectively, while CO2-PO2 decreased to 61% in semester 20224 and slightly increased to 62% in semester 20234. These findings underscore that while students adapted well to online learning, they faced significant barriers when transitioning back to hands-on activities. This research provides targeted insights into enhancing educational delivery methods post-pandemic, highlighting the necessity of integrating traditional and innovative teaching strategies to foster student engagement and improve learning outcomes. The implications are particularly relevant for educators and policymakers as they refine curricula and teaching methodologies to address the evolving needs of students in response to global disruptions.

Keywords: Continuous quality improvement; Covid-19; civil engineering education; program outcomes;academic performance

Program outcomes (POs) are essential components in outcome-based education (OBE), reflecting a graduate’s attribute and ability to demonstrate competencies at appropriate levels. Typically, POs are derived from the graduate attributes (GA) specified by accrediting bodies such as the Engineering Accreditation Council (EAC). The attainment of POs is assessed through various methods, including direct and indirect assessment tools. This study evaluates the reliability and effectiveness of POs attainment analysis and measurement using cumulative model and culminating model approaches. The analysis was conducted on a cohort of 226 students who graduated in September 2017, consisting of two entry channels: 115 diploma students and 111 matriculation students. Comparative analysis results indicate that both models reliably measure POs attainment, however the culminating model shows better performance of POs attainment compared to the cumulative model. The average percentage difference between the two models for diploma students is 4.64% and no difference for PO9 and PO10. For the matriculation intake group the average percentage difference between the two models is 3.82% and no difference for PO6 and PO11. In conclusion, both models facilitate systematic POs attainment analysis for all students and provide insights into the strengths and limitations of each model, contributing to the ongoing improvement of OBE practices and ensuring that graduates meet the required competencies and standards.

Keywords: Program outcome; outcome-based education; graduate attribute; accreditation & continuous quality improvement

This paper presents the investigation of student online feedback (SUFO) for Course X of the Civil Engineering degree programme over five years in relation to before, during and after Covid-19. Several approaches to student feedback were conducted focusing on the students of semesters 20192, 20194, 20202, 20204, 20212, 20214, 20222, 20224, 20232 and 20234. The study only refers to the specific Course X. The parameters for student feedback were the students’ overall impression of course X, the professionalism of the lecturers, the teaching and learning activities and the infrastructure. The study shows that the transition from physical to online courses has led to a decline in all parameters assessed, especially in the 2019 semester 4, indicating a significant negative impact of the switch to online learning on students’ perception of Course X in the Civil Engineering programme.

Keywords: Student online feedback; Covid-19; civil engineering degree programme; online class; physical class