Volume 35 (05) September 2023

Timber gridshells have the potential to be a sustainable and cost-effective solution for long-span applications and free-form architecture. Despite this, their overall use has been limited, and there is a lack of research focusing on their construction materials. This literature review aims to investigate timber gridshells and their construction materials to identify the criteria used in selecting suitable materials for gridshell applications. A review of peerreviewed scientific articles, books, and theses was conducted to gather information on timber gridshells, construction materials used in gridshells, timber used in active bending structures, and building standards. The research findings identified six main factors that are important when selecting a suitable material for timber gridshell application: structural strength and strength grading, bending strength and behaviour, bending strength/bending elasticity ratio, durability, commercial availability, and cost. These findings are also discussed to identify the characteristics that make a material suitable for timber gridshell applications, depending on the gridshell’s context, whether in a tropical or international context. This review serves as a necessary reference for architects and engineers when selecting materials for their timber gridshell projects, providing insight into the selection criteria for construction materials and sharing information on the material properties of suitable timber gridshell materials.

Keywords : Timber gridshell; construction material; material selection; selection criteria.

Wind energy is one of the renewable energy resources that is gaining attention from industry players and researchers. In the last few years, there is an increasing interest in small-scale wind turbines as a power generator in built environments as the urgency to reduce carbon footprint in urban areas increases as well as reducing adverse effects of fossil fuels on human health and the environment. Generally, wind turbines can be categorized into two categories which are horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs). VAWTs have good potentials to be developed considering their suitability to be used in complex wind conditions associated with built environments. However, the number of research, publications, as well as basic understanding of flow phenomena associated to the performance of VAWTs such as dynamic stall, flow separation, flow curvature effect and blade-wake interaction are scarce. These flow phenomena are attributed by operational and geometrical parameters that significantly affect the overall performance of VAWTs that includes turbine power generation and aerodynamic characteristics. This paper provides a review and discussion of the effects of various design parameters such as blade profile, blade pitch angle and turbine solidity on the performance of VAWTs and serves as a basic guideline to the designer in designing an ideal VAWT

Keywords: Optimization; design parameter; vertical axis wind turbine; wind energy; renewable energy

Due to the growing of the city population, progressively more vehicles are moving through the urban area in demand for parking lots, often causal to the worldwide difficulty of traffic jams. The existing parking system does not have a decent method to know whether the slots are empty or not. So, the user/driver has to rummage around to find an empty slot. As a result, there is a lot of traffic jam on the road, which destroys the normal life of the people. This paper focuses on how to improve the existing parking lot’s occupancy detection system in a scientific way and proposed the smart parking occupancy detection system named rPark. rPark is offered as an innovative technique for detecting parking occupancy. For the initial stage, Ultra High Frequency static RFID chips are installed on the asphalt and cross-examined by RFID interrogator antennas over the parking spots to notice the usage status. A maximum of the difficulties of the existing state-of-the-art parking usage recognition methods are not existing in this scheme. rPark was examined and employed to illustrate an experimental analysis in a physical domain out-of-doors parking spot and has been verified to have a system’s parking detection accuracy is about 100%.

Keywords: rPark, Smart Parking, Parking Lot, RFID, Cloud Database

The process of machining involves the removal of metal from the work material using one or more cutting tool and depending on the type of machine and machining process such as turning, milling, or grinding processes. These are the major machining processes in the manufacturing industry. In this study, a turning process of S45C carbon steel work material was conducted using a carbide cutting tool. Due to its desirable characteristics in term of qualities and affordable for mass production, S45C material is frequently used in the industry to produce automotive components. The focus of this study was to develop a database for monitoring the condition of the cutting edge during the machining operation by referring to the cutting force and the average of flank wear land (VB) at the cutting edge. The machining process was conducted in a dry condition without lubricants or coolants. The machining parameters used were cutting speed, V = 200 m/min, feed rate, f = 0.2 mm/rev, and depth of cut, d = 0.25 mm. The machining condition chosen in this study is similar with the machining condition used in the industry for machining S45C. The machining results found that the tool life was 119 minutes at flank wear, Vb = 0.3 mm. The relationship between cutting force and flank wear has been developed to establish a database based on the 2D I-Kaz coefficient. The 2D I-Kaz coefficient is then used for the purpose of monitoring and predicting the status of the cutting tool condition in the next machining process. The online monitoring of the cutting tool condition is expected to be able to control the quality of the components produced as well as to ensure that only worn-out cutting tool is replaced

Keywords: Material S45C; Cutting force; Online monitoring of the cutting tools; Turning process; 2D I-Kaz coefficient.

A geometric, or theoretical, stress-concentration factor is the ratio of the actual maximum stress at the discontinuity to the nominal stress. Stress concentrations occur when there are irregularities in the geometry or material of a structural component that cause an interruption to the flow of stress. This arises from such details as holes, grooves, notches, and fillets. A detailed understanding of the stress concentration around the hole is essential for optimal design and resilience to mechanical failure. Therefore, in the design of structures, it is essential to study the effects of polygonal discontinuities in structures to achieve convenient and efficient designs. The current paper investigated the stress concentration factor around the polygonal holes in the finite structural steel plate, assuming a plane stress state and uniaxial compression loading. The present study provides a complete finite element analysis of stress concentrations in structural steel plates with polygonal cutouts (triangular, square, pentagonal, and hexagonal), in contrast to the side ratio of a polygonal hole, and the length, and height ratio of a square hole. The increasing order of stresses and SCF are square, triangular, pentagonal, and hexagonal. Due to the more edges of polygonal shapes parallel to the loading direction and minimum corners positioned in the direction of loading, a square-shaped hole produces 40% less SCF than a hexagonal-shaped hole.

Keywords: Stress concentration factor, finite plate, finite element method, polygonal cutout, structural discontinuity

Welding practical work is a compulsory learning process for all mechanical engineering students in Malaysian polytechnics, students will spend 2 to 4 hours a week doing practical work. Because of that, this situation can cause problems for students when performing tasks, including body posture and manual handling during practical work which can result in musculoskeletal disorders (MSD), in addition non-standard instructions for performing tasks also happen. This study aims to identify the risk of postural problems during welding practical work and suggest an appropriate ergonomic posture assessment to reduce the risk of MSD. In order to assess the position of body posture during welding practical work at technical education institutions, the Rapid Upper Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA) tools were used to observe body posture during practical work and specifically to see the bending level of body parts during work welding practice. Analysis and evaluation were carried out using REBA and RULA and found that the final score for RULA was at a value of 7 and the score for REBA was 9 in the same welding practical. Based on these two scores it was found that welders are at high risk to getting cumulative trauma disorder (CTD) which can also result in MSD. In conclusion, both REBA and RULA body posture assessment tools can be used to assess body posture when carrying out practical work, however, REBA is more suitable because there is an assessment of the leg part which usually involves the leg part while welding, either standing, sitting or squatting (CTD).

Keywords: Ergonomics, musculoskeletal disorders, ergonomic posture assessment, RULA, REBA, welding practical work

The Malaysia-Thailand Joint Development Area (MTJDA) Authority was legally formed in 1979 by a Memorandum of Understanding (MOU) and a 1990 Agreement on the Constitution and Other Matters of MTJDA between the Malaysian and Thai governments. The MOU’s main goal is to explore and exploit oil and gas resources in a contested maritime area. According to the agreement, the Joint Development Area (JDA) is located in the North Malay Basin, off the coast of Thailand. This was a bilateral agreement permitted by the UNCLOS. Since production began in 2005, the area has significantly aided Malaysia and Thailand’s economic and energy security. The goal of this research is to look into the issues and challenges in political and economic aspects that could affect the bilateral agreement once it expires in 2028. The perspectives of decision-makers, industry participants, and government officials were gathered through qualitative methods, which included secondary data and interviews. The results show that the Malaysia-Thailand Joint Development Area has been a close partnership for the past 40 years, and both countries should keep the agreement because the JDA is defined as joint efforts by Malaysia and Thailand to explore and exploit natural gas resources through enhanced bilateral diplomatic relations, as well as contribute to global economic growth. Under the current JDA, the emphasis is on strengthening bilateral diplomatic relations through cooperative cooperation. Because the current arrangements benefit both countries in terms of strengthening their partnership, Malaysia and Thailand should keep the agreement in place.

Keywords: Malaysia-Thailand Joint Development Area; bilateral arrangement; oil and gas resources; issues and challenges; political and economic factors

Presently, there has been a significant growth in the solar PV technology due to various factors such as clean technology, zero carbon emission and low maintenance. However, it becomes significant to extract the power in abundance from solar PV system due to its intermittent nature. To extract the significant power, a suitable maximum power point tracking (MPPT) technique has been presented. The MPPT technique is developed based on the hybrid fuzzy logic (FL) and improved incremental and conductance (IInC) method. The aim of developing hybrid FL-IInC technique for MPPT is to regulate duty cycle so that maximum power point (MPP) is achieved with stable and accurate outcomes during dynamic and steady state conditions. The IInC method was developed by regulating the duty cycle and step-size. of It was observed that proposed hybrid FL-IInC delivers accurate and stable results as compared with IInC method. During the model testing at the irradiance with 1000w/m2, the achieved MPPT efficiency was 99.96% as compared with the IInC with an outcome of 98.47% for the improved technique. Additionally, the settling time for the proposed hybrid FL-IInC was less compared with the IInC method. All the simulations were conducted with the MATLAB Simulink Platform. In future, the hybrid FL-IInC method can be employed with other conditions such as partial shading for better applicability

Keywords : Maximum power point; fuzzy logic; Incremental and conductance; Photovoltaic module array; Renewable energy; Matlab/simulink

The Fused Deposition modelling technique is widely accepted by industries as it is the one of the most convenient modern technology. The fused deposition modelling (FDM) is one of the additive manufacturing techniques which are largely used for printing of metal/thermoplastic materials with ease of design flexibilities the proposed research had been carried out for the investigation and optimization of process parameters for product or application development through FDM. The FDM- (Fused deposition Modelling) is widely used for product development and do contain various control variables. Here the process relates to nozzle temperature, base plate temperature, filament feed, filament material and deposition speed. The research presented here had been conducted considering nozzle temperature, layer thickness, and internal profile as variables for specimen manufacturing. In Aerospace application, optimization process is highly required for the Properties of material, weight and other effects. Hence the tensile specimen had been prepared to represent an aerospace application of ducts for airflow. The full factorial design of experiments had been considered for experimental investigation. The design of experiment had been conducted with three factors; three no. of parameters at three different levels Hence, A total no. of 27 representation samples had been prepared for tensile test and surface roughness for the Optimum result. The results had given considerable parametric effect as an outcome. The optimized results had been manufactured on an Ultimaker3D printer machine and tested which confirmed the results. The outcomes will assure optimal manufacturing process parameters of FDM for improved mechanical properties.

Keywords: Additive Manufacturing, FDM Process, Acrylonitrile butadiene styrene (ABS) Material, Surface Roughness, Full Factorial Method, Tensile Strength

Modern day world gives huge importance to sustainable construction and demolition (C&D). Governments and companies all over the world, are striving to develop methods, which reduce waste. A good step is to reduce, reuse and recycle (3R principle) construction and demolition waste. Essential for these activities is to have proper estimates of waste, that would be generated on construction and demolition of structures. Current practice in construction industry compromises on accurate estimation and audit of waste produced and recycled in construction and demolition. Considering this anomaly, this research is conducted to develop a BIM based system, for better waste estimation. The system is aimed towards estimating total waste produced, along with classifying waste that could be recycled or that must be disposed after building demolition. Initially, available waste estimation systems and their limitations are analysed. Consequently, a waste estimation is performed on a residential building model designed in Revit structures software. Successively, the data from Revit is input to a software programmed in C++ language to get estimates of waste. The research results into formation of a framework that estimates waste for any building required to be demolished. The framework has capability of estimating amount of total waste generated along with the amount of recyclable and disposable waste. Along with that, the framework gives an estimate of the cost of total amount of waste produced, specifying amount saved on recycling/reusing.

Keywords: Construction Industry, BIM, Waste Management, Sustainable Development, Sustainable Construction.

The most complex problem for any civil engineering work is when the structure which is laying on the soil is weak. Jamshoro shale is an example of such problematic soil, which gets expanded as soon as it is exposed to moisture and shrinks back once it dries. Such phenomenon is very critical for the structures and road networks built on shale forming settlements and cracks. Such kinds of soil must be stabilized by chemical or mechanical techniques to make them strong enough to carry the loads and resist settlements and cracking. The stabilization of the ground by utilizing or adding any chemical agent is a sustainable approach; it strengthens the soil properties without replacing or wasting the soil present. In this research, the treatment of lime with shale is been performed to observe the modification of the geotechnical characteristics of the soil. The different proportions of Hydrated Lime 0%, 7%, 8%, and 9% were mixed by the dry weight of soil to investigate the effect of lime on the compaction and plasticity characteristics of the shale. Various tests such as the modified proctor test, liquid limit test, and plastic limit test performed in the laboratory. From the results, it was observed that the properties of Jamshoro shale such as plasticity index, optimum moisture content, and maximum dry density were improved. The plasticity index of shale dropped to 2% from 24%. That suggests lime can be used as an economical and eco-friendly stabilizing agent.

Keywords: Soil Stabilization, Lime, Compaction, Expansive soil, Plasticity.

Due to population growth and increasing urbanization trends, there is a shortage of water around the world. Irrigation systems are critical for increasing crop output and ensuring food security. Desertification caused by humans and water shortages have further exacerbated the world’s regular water scarcity, putting a significant impact on food production. Water scarcity and rising food demands necessitate greater efficiency in water use, both in rain-fed and irrigated agriculture. Hence, it is the most demanding requirement for the farming community to use some type of irrigation planning to conserve the limited water resources. The purpose of this study is to calculate crop water requirements and irrigation scheduling for some major crops in Sindh using the CROPWAT model developed by FAO of United Nations. In this regard, selection from among the major crops cultivated in the Sindh province of Pakistan was made in such a way at least one crop from each category be included in this research. Accordingly, Wheat as Rabi, Rice as Kharif, Sugarcane as Perineal and Chili and Rape-seed Mustard as Cash Crops were selected. CROPWAT model calculates crop water requirements and irrigation scheduling from existing or new climatic- and crop-information. The Input crop data for CROPWAT software was obtained from various online resources and published information, whereas, climatic data incorporated in the CLIMWAT tool attached with CROPWAT was utilized. In addition, the software used average rainfall data of the particular years for each crop observed at DRIP Tandojam metrological station. The results of water requirements for the crops were obtained through CROPWAT model are: Wheat (352.1 mm); Rice (1662.5 mm); Sugarcane (2184.5 mm); Chili (714.4 mm); and Rape-seed Mustard (475.6 mm), while those by lysimeter were: Wheat (415 mm); Rice (1633 mm); Sugarcane 2150 mm); Chili (808.9 mm); and Rape-seed mustard (424.87 mm). These results delineate that there is decrease in crop water requirement of Wheat, Rice, Sugarcane and Chili to the tune of 15%, 1.5%, 11.6% and 1.7%, respectively, whereas an increase of 12% for Rape-seed mustard.

Keywords: Crop Water Requirement, Irrigation Requirement, Irrigation Scheduling, CROPWAT Model

Increasing construction activity around the globe has raised the demand for cement to 4.4 giga-tonnes/year, making it costlier, and its consumption second to water. Meanwhile, a tonne of clinker produces a tonne of CO2 on a large consumption of natural resources of raw materials and energy of 10–11 EJ/year, which is why an affordable and environmentally sustainable substitute for cement is needed today. Pakistan possesses more than 30 million buffalos. Each can produce up to 15 kg of dung per day, resulting in 450 million kg of dung produced in Pakistan alone. This research aims to investigate the pozzolanic activity of Buffalo dung ash and determine the optimum conditions for developing the ash, along with the optimum dosage as cement replacing material in Normal concrete. For this purpose, five buffalo dung ash samples were prepared by calcining the dung in a muffle furnace for a 1-hour duration at 400°C, 500°C, 600°C, 700°C, and 800°C, and after cooling, sieving through a No. 100 sieve. The Strength Activity Index was determined as per ASTM C311. The results showed that developed ash at 600oC has a maximum Strength Activity Index of 94.2%, meeting the ASTM C618 standards for pozzolanic material, which was further confirmed by X-ray Fluorescence analysis. Furthermore, when 5%, 10%, 15%, and 20% of this ash were used as cement substitutes in concrete, the compressive strength increased by 11.2% on 10% substitution compared to the control mix. Based on the parameters investigated, it was found optimal to replace 10% of the cement in the concrete with buffalo dung calcined at 600°C for 1 hour.

Keywords: Buffalo Dung ash, Pozzolanic activity, XRF, Cement Replacement Material

Construction industry of Pakistan has a great contribution in uprising the GDP of the country. When compared with the construction industries of some developed countries of the world it still lacks in utilizing the modern methods of construction. Most of the organizations are relying on traditional ways of construction and are not ready to equip themselves with the advanced techniques of construction that may help them do their projects more effectively and efficiently. Prefabrication is the future of modern and sustainable construction which can maximize the capability of constructing the structures without compromising not only the time, cost and quality of project but also the environment. Prefabrication is rapidly increasing in construction, and previous researchers have identified various positive impacts of prefabrication on projects. However, prefabricated construction is less preferred over traditional methods of construction in Pakistan. Therefore, a comparison is required between conventional RCC building and a prefabricated (precast RCC) building to unearth the potential benefits of adopting prefabrication on overall cost of project. To achieve this, a BIM based multi-dimensional model of conventional and prefabricated building is developed using Autodesk Revit. A detailed comparison between both the methods of construction with respect to material, labor, transportation and time made the benefits of prefabricated construction clear over conventional construction. Prefabrication method is 84% faster and costs about 13.46% less than conventional method of construction. This comprehensive contrast will help to better understand and encourage the construction industry to move towards the prefabricated construction.

Keywords: RCC Structures, Prefabrication, Concrete Structures, Economical Suitability, Building Information Modelling (BIM).

Carbon dioxide (CO2) is a corrosive and inflammable gas found in natural gas. The most widely technique used for CO2 separation in the natural gas industry is via amine absorption method. However, due to the corrosive nature of amines, researchers actively looking for an alternative method to separate CO2. Therefore, the emulsion liquid membrane (ELM) was developed to address this issue. In spite of that, it still remains as challenge to find suitable formulation to produce stable emulsion with good CO2 removal performance. In this study, the amine blend emulsion containing Methyldiethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) with Tween80 (Polysorbate-80) were prepared. An aqueous phase was formed by blending of MDEA and AMP in sodium hydroxide (NaOH) solution. The organic phase composed of kerosene and Tween-80 used as surfactant. The effect of varying concentrations of Tween-80 on the emulsion stability and CO2 absorption capacity of ELM were investigated in this study. The emulsion was prepared by mixing the aqueous and organic phases for 5 minutes at a speed of 10,000 rpm until it become homogenous. The CO2 absorption capacity was conducted in a rotating disc contactor column with a 2-bar pressure of CO2 gas supply. This study demonstrated that, by blending of 8% v/v MDEA and 4% v/v AMP with 10% v/v Tween-80, 56.89% of CO2 removal could be achieved while maintaining an emulsion stability of 95%.

Keywords: Carbon dioxide, Emulsion liquid membrane, Amine absorption, Emulsion stability, Tween-80

Additive manufacturing (AM) is an effective technology for repairing and restoring automotive components. However, the effectiveness of additive manufacturing technology in repair and restoration is highly influenced by several factors related to components and process. The objective of this paper is to improve the decision-making in repair and restoration of a turbocharger with AM. In this article, a Fuzzy-Genetic approach was presented as a decision-making tool for repairing a remanufacturable component. Fuzzy logic (FL) is deployed as the method to model the design parameters of a turbocharger, such as design complexity, failure mode, damage size, disassembleability, preprocessing, temperature, durability, pressure ratio and mass flow rate to model the relationship between the inputs and outputs using Mamdani model with their membership functions. Genetic algorithm optimization method was used to optimize the cost of the repairing process once the decision on whether the turbocharger was repairable was determined by the Fuzzy system. The FL approach applied rules affecting the process, the robustness and accuracy of the model increases with a higher number of rules. The work focuses on the dataset related to design information, which represents as a knowledge base for decision parameters on design optimization to automate repair process during remanufacturing. The results showed the effects of the design parameters on repairing and replacement decisions, and how the fuzzy model related the inputs to the outputs based on the generated rules. In conclusion, FGA method can be used to improve the repair and restoration process of a turbocharger through AM technology.

Keywords: Fuzzy-GA; turbocharger; additive manufacturing; hybrid method

A modern power system with a generation mix of conventional and renewable energy sources (RES) creates stability issues. This requires a detailed analysis of the system with an exact share of active power through the generating sources according to nature, location, and control. The interconnected network with a large number of rotating machines at the generation side works coherently with each other. As the share of RES increases, it leads to reduce rotational inertia in the power system. The most important factor affected by inertia is the rate of change of frequency (RoCoF). The higher RoCoF leads the system more vulnerable to small disturbances in the power system. In a large power system network with numerous generating sources and transmission lines, it is difficult to determine the availability of inertia in the system. This paper incorporates the concept of graph theory in the IEEE 30 bus system to analyze the impact of heterogenous inertia distribution on frequency stability. The graph theory network gives the idea about the distance between the nodes and it is helpful to find the share of power from the generating sources. In this paper, we calculate the shortest path between the nodes or substations by using Dijkstra’s algorithm. The betweenness centrality of the node detects the vulnerable nodes in the system from the frequency response point of view.

Keywords: Renewable Energy Sources, Inertia Constant, Rate of change of frequency, Graph theory, Dijkstra’s Algorithm.

Hematopoiesis is a process in which hematopoietic stem cells produce other mature blood cells in the bone marrow through cell proliferation and differentiation. The hematopoietic cells are cultured on a petri dish to form a different colony-forming unit (CFU). The idea is to identify the type of CFU produced by the stem cell. Several software has been developed to classify the CFU automatically. However, an automated identification or classification of CFU types has become the main challenge. Most of the current software has common drawbacks, such as the expensive operating cost and complex machines. The purpose of this study is to investigate several selected convolutional neural network (CNN) pre-trained models to overcome these constraints for automated CFU classification. Prior to CFU classification, the images are acquired from mouse stem cells and categorized into three types which are CFU-erythroid (E), CFU-granulocyte/macrophage (GM) and CFU-PreB. These images are then pre-processed before being fed into CNN pre-trained models. The models adopt a deep learning neural network approach to extract informative features from the CFU images Classification performance shows that the models integrated with the pre-processing module can classify the CFUs with high accuracies and shorter computational time with 96.33% on 61 minutes and 37 seconds, respectively. Hence, this work finding could be used as the baseline reference for further research.

Keywords: Automated stem cell classification; Colony-forming unit (CFU); Deep learning; Convolutional neural network (CNN)

Alternative fuel is considered to be suitable oils in diesel engines, which are well known for their ability to diminish lubricant oil debris and noise emissions. A minute research has been done to examine the long-term effects of using blend fuel. In this study, two blend fuels: diesel and waste cooking oil (DF95WCO5), and diesel, waste cooking oil and n-pentanol (DF65WCO20Pe15) were chosen and compared with diesel fuel (DF) to investigate the impact of these blends on noise emission in diesel engine. In order to evaluate the kinematic viscosity and density and determine the effect on sound pressure levels, lubrication oil samples were taken throughout the test at intervals of 20 hours. A literature review was done for the current work’s analysis of the literature on the noise emissions from diesel-waste cooking and n-pentanol fuel blends. When the engine was fueled with DF65WCO20Pe15 blend, the engine lubricating oil analysis revealed an extreme wear issue, decreased viscosity, and increased density values. The conclusion is that single cylinder diesel engines can use binary blend DF95WCO5 and ternary blend DF65WCO20Pe15 without any adjustments. DF65WCO20Pe15, in contrast to the reference fuel, achieved some superior outcomes.

Keywords: Diesel Engine; Sound Pressure Level; Leg; Ternary blend fuel; Kinematic Viscosity; Desnsity

Aluminium (Al) is thoroughly used as a sacrificial metal for the protection of steel in seawater. Aluminium is rarely used as a sacrificial anode without being alloyed due to its built-in properties to get passivates and form a passive layer and the continuity of its layer depends on the chemical composition and microstructure. In this paper, Aluminium-Magnesium(5xxx) system is considered because magnesium remarkably affects the chemical properties by changing the microstructure of Aluminium from a homogeneous solid solution to a complex structure with multiple intermetallic phases. In this research work developing Aluminium-Magnesium alloys containing 2.5 and 4.5 weight percent magnesium. The microstructures of pure aluminium and developed alloys were studied and the effect of the distribution of magnesium whether as a second phase particle, intermetallic compound or precipitates on the performance of aluminium sacrificial anode was discussed. Standard weight loss method and potentiodynamic tests are used to evaluate the performance of alloy sacrificial anode. The result shows that as the magnesium content increases corrosion rate of developed alloy increases and corrosion potential shifts in more negative directions. Corrosion potential is increased by 250 mV at 4.5% magnesium because of the formation of an intermetallic compound of aluminium& Magnesium (β phase – Al3Mg2) at the grain boundary. Magnesium improves the corrosion rate of developed alloy,it acts as a depassivators for the passive film of Aluminium by forming intermetallic compound and this compound has different electrochemical properties that leads to corrosion of aluminium and improves the performance of aluminium sacrificial anode.

Keywords: cathodic protection, Aluminiumand its alloy, AluminiumSacrificial anode,Passivation and corrosion of Aluminium.

Octagonal castellated beam is fabricated by adding spacer plates between the web joints of the hexagonal castellated beam to further increase the beam depth. The resulted deep beam is advantageous to enhance the shear carrying capacity and moment resistance. However, large web openings are prone to Vierendeel mechanism in the deformation that lowers the overall beam performance due to formation of plastic hinges. The present paper is concerned with non-linear analysis to predict the ultimate load behaviour of octagonal castellated beams. Finite element models were developed by using a commercial programme LUSAS. The numerical models were first validated against the experimental results reported by other researchers. This study aims to propose the ideal configuration of web opening stiffeners and evaluate the effectiveness of the additional stiffening material for different beam span lengths. Provision of ring stiffeners is effective in short span beams in respect of resistance to Vierendeel failure. The stiffeners have increased the ultimate load to the extent of 73% in which the strength restoration is considerably near to the capacity of its parent universal beam. In long span beams, however, the stiffeners can only improve the performance up to 26.61% with larger additional steel materialthan that of shorter span. In all cases, the stiffener thickness is found to be the governing factor to restoring the loss of shear strength due to large web openings. The number of stiffeners contributes no appreciable variation of ultimate load particularly in long span beams where bending is prominent

Keywords: Octagonal castellated beam; Stiffened web opening; Finite element analysis; Ultimate performance; Vierendeel deformation

The potential of smart cities to alleviate the challenges of urban development in relation to population, resources, and environment is widely recognized, making it a key urban development trend for the future. Smart street lamps (SSLs) are a crucial component of smart city infrastructure. However, their current unreasonable function settings and appearance design do not meet the emotional needs of residents and come at a high construction cost, resulting in decreased user satisfaction. Based on WOS and CNKI databases, 39 literatures on the aspects of theory, steps and technologies of KE, 32 literatures on the development, basic functions, construction, existing problems, and key technologies of SSLs, and 6 papers on street lamps functions or appearance design research based on KE be reviewed in this paper. Therefore, the application of KE method in SSL design be extensively reviewed, with emphasis on the future development direction of KE, the design principles of SSLs, and the implementation of KE in SSL design. This review aims to summarize the research gaps, future research directions, and future development trends of KE and SSL. Ultimately, the review concludes that the integration of KE in SSL design research is crucial to improve SSL products’ rationality, openness, and amicability, guided by scientific SSL design principles.

Keywords: Appearance design; Functions; Kansei Engineering; Smart Street Lamps

Traffic noise during school hours can disrupt students’ learning focus especially in the classroom and can affect communication between teachers and students. This study was conducted to asses traffic noise levels for four selected schools along few main roads in Bandar Baru Bangi and analyse the data using the guideline recommended by the Malaysia Department of Environment (DOE). Data was collected using 01dB SOLO sound level meters using the decibel A-weighted (dBA) for L_Aeq, L₁₀, L₅₀, L₉₀, L_Aeqmax dan L_Aeqmin. The measurement was collected during the respective peak hour on school days which are 7.00am -9.00am for morning session, 12.00pm-2.00pm for noon and 5.00pm -7.00pm for evening session. The measured noise then analysed and compared with the recommended standards set by the DOE. From the measurement, it was found that traffic near the Greenview Islamic International School recorded up to 76.3dB(A) for L_Aeq, 110.3 dB(A) for L_Amax, L₁₀ = 78.4 dB(A) and L₉₀ = 67.6 dB(A) during the period of 12.00pm to 1.00pm. All the measured traffic noise at the respective school also logged a high noise level for their L_Aeq measurement. In conclusion, the study showed that the traffic noise level pollution experience by the schools along the main roads in Bandar Baru Bangi district were alarming which are exceeding the recommendation from DOE. This finding can help policymakers and stakeholders used as reference in sense of noise pollution management for better acoustics comfort at school area.

Keywords: Traffic noise; Sound level meter; School; Noise Pollution

Reflectarray antennas have emerged as one of the most suitable choice for 5G network base station antennas due to their ability to combine the advantages of parabolic reflectors and phased array antennas. These antennas offer a lightweight structure, high gain, and low impedance mismatch losses. High gain and low loss are crucial factors in ensuring the antenna delivers low latency and high-quality 5G radio signals. The application of 5G technology becomes more practical and efficient with the capability to adjust the functionality of a single 5G antenna or enable reconfiguration. This reconfigurable technique simplifies the multi-antenna systems and significantly reduces costs, making it more practical and systematic. Furthermore, this reconfigurability is particularly beneficial for satellite applications, as it allows for the reconfiguration of the signal in the event of satellite movement on the space. This paper aims to discuss the historical development of reconfigurable reflectarray antennas, focusing on the innovations in each configurable mechanism. The paper further explores the classification of configurations employed by this antenna, encompassing frequency configuration, radiation pattern, polarization, and hybrid configurations that integrate multiple existing configuration classifications. Finally, the research paper provides a discussion of the most recent research and innovations in the configurable mechanisms of reflectarray antennas.

Keywords: Reflectarray antenna, reconfigurable, 5G network; phase range

Bandar Baharu District in southern of Kedah, Malaysia is extremely rich in laterite soil. The district is distinguished by the widespread presence of laterite soil, making it critical to thoroughly explore its physical, chemical, and morphological properties. Understanding these properties is essential for determining the acceptability and behaviour of laterite soil in a variety of engineering and building applications. Thus, the objective of this study is to analyze and evaluate the physical, chemical, and morphological properties of the selected laterite soil. Three sources of laterite soils have been identified in Sungai Kechil, Bandar Baharu, and Relau. The samples are labeled as SS-A, SS-B, and SS-C. The soils are categorized as SM, SC and MH respectively according to classification by Unified Soil Classification System (USCS). Since the pH values were less than 6, all of the soils were acidic. The X-ray fluorescence (XRF) characterization shows that the three soil samples have three main chemical components, namely silicon dioxide (SiO₂), aluminium oxide (Al₂O₃) and iron oxide (Fe₂O₃). According to the X-Ray diffraction analysis (XRD) results, the minerals discovered in the laterite soils were gibbsite, quartz, kaolinite, and magnetite. Based on the scanning electron microscope (SEM) image, the sample with the highest fine particle content, which is 55.7% for the SS-C sample, shows the smallest pore size.

Keywords: Physical properties, Chemical properties, Morphological properties, Laterite soil, Bandar Baharu District