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The effectiveness of power generation of the piezoelectric energy harvester (PEH) depends on the coupling between its resonant frequency and the oscillation frequency of the vibration source. The resonant frequency of a PEH is determined by its structural design, and therefore, to improve piezoelectric energy harvester performance, the piezoelectric energy harvester must be optimally designed to achieve the resonant frequency that matches the excitation frequency of the vibration source. This paper presents the design and detailed calculation of the piezoelectric energy harvester in the form of a bimorph piezoelectric circular diaphragm (PCD) structure by finite element analysis (FEA) using the software package ANSYS. Based on analyses and calculations, the optimal structure of the piezoelectric circular diaphragm energy harvester is proposed to meet the specified resonant frequency response matching the vibration source frequency. Detailed calculations of the PEH were performed with an excitation frequency of 100 Hz. With an optimal load resistor of 10.1 kΩ, an output power of 0.287 W was generated at 100 Hz (equal to the resonant frequency of the PEH) under an amplitude of harmonic excitation of 0.1mm. In addition, the research results can be used to fabricate piezoelectric circular diaphragm energy harvester operating at a resonant frequency suitable for the available vibrations.

This paper describes the results of a field investigation with the objective of evaluating the possibility to produce drone-derived 3D digital point clouds sufficiently dense and accurate to determine the rock mass rating (RMR) in the underground mine in Bukit Kachi. Agisoft Photoscan software was used for producing the three-dimensional points cloud from the two-dimensional images' sequences. The rock mass rating was evaluated by using Discontinuity Set Extractor (DSE) and Dips 7.0 in Rockscience software. Results from this research show that 3D digital point clouds, derived from the processing of drone-flight images, were successfully used for reliable representation of discontinuity of the tunnel. According to the results of the analysis, both Tunnel A and Tunnel B are classified as "fair rock." Meanwhile, Tunnel A is failing due to geological conditions of feldspar decomposition that are classified as class I, which is "very poor rock." According to Dips 7.0 analysis, the major direction of discontinuity set of Tunnel A for Window right is N300 – N310, while for Window left is N350 – N360. The most dominant discontinuity direction for Tunnel B Window right is N340 – N350, and the orientation for Window left is N10 – N20. When manual mapping and DSE analysis are compared, both orientations of the discontinuity do not give the same direction due to less data reading in the field and high accuracy from the software.

In the current unstable economy, every fabricating sector has continuously made attempts to ensure its survival by adopting new and effective procedures to improve productivity. The industry's production issues were brought on by poor equipment handling, a lack of inventory classification, and an unorganized storage area. So, the objective is to reduce the waste, risk of labour, production cost, and time, and increase the workspace and production, thus gradually influencing the industry's overall profit. It can be achieved by implementing the most relevant lean techniques. Lean, an emerging technology, is used in manufacturing sectors to find and eliminate waste and increase efficiency. It is a completely customer-based strategy that concentrates on the value chain and its improvement. In this paper, lean analysis suggests using a 5S for restructuring the storage area, Kanban, and Kaizen for properly handling waste. It is observed that there is a significant improvement after this implementation.

Currently, the manufacturing industries play an important part in the global economy. I t is critical for the industries to maintain the high standards of goods and products. Various machines / systems have been developed for determining dimensional stability or the lack of filling in a casting product, thereby rejecting the defective products. The existence of the casting product is detected using an infrared or ultrasonic sensor. When a product arrives along the conveyer, the sensor can detect its measurements. If the product has the necessary proportions and dimensions, it is moved to the accepted bin; otherwise, it is denied by a pneumatic actuator and placed in the rejecter bin. Eventually, a profound learning model that categorizes into two different categories has been studied to automate the manual inspection procedure in the casting failure system. This automated casting fault separation machine is accurate, reliable and low cost which makes it suitable for small scale industries with easy segregation of high quality products. The objective of this paper is to review the various automatic systems developed for separating casting fault.

Storage is an important aspect of any business. All businesses must store goods and materials safely, especially warehouses, factories, shops, food, agricultural, and construction businesses. Leaving materials exposed reduces their overall quality; hence, certain structures are used to safely retain the materials for further use. These are called storage structures. A silo is a commonly used storage structure for the storage of bulk materials such as grain and cement. This paper deals with the design of a steel silo for the storage of pozzolana cement. A storage silo is essentially made up of a cylinder-shaped wall and a hopper bottom. Steel Silos are gaining more popularity in terms of cement storage usage. A 150-ton capacity steel silo has been designed for a seismic zone-2 [1] location in Madurai, Tamil Nadu, India (therefore omitting the inclusion of seismic loads). The preliminary design of the silo structure is carried out with the help of Indian Standard code books. Indian Standard code books such as IS 9178-Parts 1,2 & 3 (1979) were used for the basic design. Other necessary code books were used for load calculations. The plan and elevation of the Silo have been drafted by using AutoCAD. The designed Silo is analysed using STAAD Pro. The pile foundation of the Steel Silo has also been designed and analysed using STAAD Foundation.

Thermoelectric technology is one of the fast-developing technologies in the present days due to its excellent heat transfer and heat conversion capabalities. This uses the electromotive force produced by the temperature difference at each end of the device to produce electricity and vice versa. There are various applications developed based on this thermoelectric technology which includes thermoelectric coolers, thermoelectric generators, and thermoelectric air conditioners. This paper provides a comprehensive analysis of thermoelectric (TE) technologies, starting with a complete summary of their working principles explaining the effects like Seebeck, Peltier, and Thomson effects, as well as optimization techniques, applications, semi-conductor materials used, and potential future developments.

Cenospheres are valuable material contained inside the fly ash. Its low weight, low density, and high strength made it very versatile and can be used in various fields. The way of separating the cenosphere from the fly ash consists of two categories, wet and dry separation. For wet separation, it involves submerging the fly ash inside a mixture made either by pure acetone, pure water, or a mixture of water and acetone with different mixing ratios before stirring the mixture. The cenospheres, floating on top of the mix due to low density, can be collected and dried. The dry separation technique involves putting the fly ash into a cyclone separator at a constant velocity. The fly ash will then move into the bottom of the cyclone. Particles can also be separated by diameter sizes by sieving. By manipulating various parameters, cenosphere yield may differ. This paper is written to help gain more understanding on cenosphere properties and its separation method.

The tremendous exhaustion of resources, a surprising price increase of petroleum fuel and worldwide ecological issues implement to find renewable fuel for compression ignition engine. Non-edible vegetable oils have proven consensus to opt as a replacement for diesel fuel due to comparable properties and less-pollutant characteristics. Using Unmixed Untreated Non-edible Vegetable Oil (UUNVO) in the CI engine matches the needs of a sustainable future and restricts the intensifying cost involved in biodiesel production. This paper aims to review the influence of various UUNVO (Karanja, Jatropha, Neem, Linseed, Mahua and Rubber Seed etc.) on the important performance parameters and emission level of diesel engine. UUNVO can be fuelled to the unmodified CI engine. However, the viscosity of UUNVO is reasonably higher compare to diesel fuel at room temperature, which deteriorates the engine performance and exhaust emission. Minor changes in the injection line for preheating the UUNVO and operating parameters are the way to improve it. It can clearly understand here that preheated UUNVOs typically increase NOx emissions and decrease PM, HC, and CO emissions level compared to standard diesel. UUNVO can substitute diesel fuel completely for short-duration operation. With the long-duration operation, UUNVO produces problems like poor engine performance, injector chocking, and erosion of piston crown, rings, cylinder liner, and other internal parts, and degradation of the lubricant. Problems raised due to durability can be minimized by controlling operational parameters.

Water treatment sludge (WTS) is a by-product produced in the process of water treatment plants (WTP). It is estimated that an ordinary WTP produces over 10,000 tonnes of WTS per day, which has become a major concern in the management of WTS. Numerous previous studies have been accomplished to determine a safe disposal method and the potential reuse of WTS. In most investigations, material characterisation was the adopted method. It is known that each WTP produces different chemical composition of WTS according to raw water intake and the treatment process. The aim of this paper is to examine the chemical composition of WTS in the WTP at Melaka. The WTS sample is collected from WTP after the pressing process, where large amounts of water have been removed. The sample is tested using the Scanning Electron Microscopy with energy dispersive X-ray (SEM-EDX) and X-ray Diffraction (XRD). The SEM-EDX results revealed that by weight percentage (%), WTS contains zirconium (Zr) (28 to 46%), oxygen (28 to 40%) and carbon (7 to 26%). Aluminium and silicon have weight percentages ranging from 7 to 8%. The outcomes are then confirmed by XRD, which showed the high intensity of Zr and α-Zr at approximately 35.3 and 36.1. of 2θ. Based on these findings, the suitable and potential reuse of WTS would be the extraction of Zr. However, further research is required to verify the consistency of Zr in WTS.

Robot grasping detection methods are categorized into two-dimension (2D) and three-dimension (3D) approaches. In 2D grasp detection, gripper pose prediction occurs directly on RedGreenBlue (RGB) images, limiting grasp direction. Conversely, 3D grasp detection predicts gripper pose using 3D point clouds, allowing greater grasp flexibility. However, the data volume of 3D point clouds hampers real-time detection. To address this, this paper proposes a novel grasping detection algorithm that combines 2D images and 3D point clouds. Initially, a Single Shot MultiBox Detector (SSD) network generates 2D prediction boxes on RGB images. Through enhancements to the prior box scaling, the accuracy of bounding the target object is improved. Subsequently, 2D boxes are transformed into 3D frustums, and extraneous data points are removed. By utilizing Random Sampling Consistent Segmentation (RANSAC) and Euclidean Clustering Segmentation Algorithm (ECSA), the target point clouds are isolated, and subsequently, the spatial pose of the target is represented using an Oriented Bounding Box (OBB). Processed point clouds enter an enhanced PointNet Grasp Pose Detection (PointNetGPD) algorithm, In contrast to the original approach involving extensive random sampling of grasp candidates, the enhanced PointNetGPD method enables the selective sampling of grasp candidates by incorporating pose constraints between the target and gripper. Following this, the generated grasp candidates are subjected to evaluation through a scoring process conducted by an assessment network. Ultimately, the robotic arm is guided to perform the grasp associated with the highest score. In the experimental phase, the proposed algorithm demonstrated a high success rate in capturing multiple targets, along with a reduced grasping time. These results underscore the algorithm's superior grasping quality and enhanced real-time performance when compared to similar algorithms.

Sustainability is one of the most challenging concepts in the global mining industry. The purpose of this is to limit the harmful effects of mineral extraction on the environment and at the same time to meet the present and future needs of civilization. Therefore, we should blaze the path leading to sustainability and supply security, as well as identify the factors affecting these concepts. Thus, in this paper, the main factors are listed and defined. They are divided into two main categories: the positives and the negatives. The positives are the longevity of the minerals' mining, the index of the annual met need, the environmental-social condition of the resources, and the condition of the resources in friend countries. Also, the negative ones are the harmful chemicals released, the energy required per ton of minerals, annual CO2 emitted per ton, and recyclability. Accordingly, the factors can be used to make a strategic plan for the future of the minerals supply of a country. So, the framework developed leads the authorities to find the solutions to the sustainability of minerals' supply and increase the security of mining productions.

Infectious disease such as COVID-19 is one of the major concerns in Malaysia as it becomes the second killing disease and causes huge number of death and spread to other regions of the world if left unchecked. In developed countries, infectious diseases are often preventable, but lack of medical devices in detecting it makes the death cases increase. The growth of different COVID-19 mutation has given so much challenges in detecting, preventing and curing. This gives motivation to researchers in order to solve this global problem by creating and advancing the detection tools and methods. Time, equipment availability, and the biological nature of COVID-19 influence the selection of appropriate detection techniques. This paper summarizes the comprehensive review on the type of diagnostic tests and biosensors available in detecting COVID-19 disease.