International Journal of Integrated Engineering
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Exoskeletons for Elderly Activity of Daily Living Assistance: A Review of Upper Limb Exoskeletons and Assessments
Get PDFPopulation ageing is a major global issue faced by almost all countries and regions. As of 2022, the elderly population aged 65 and above made up approximately 10% of the world\u27s population, with projections suggesting this will rise to 16%, or 1.5 billion individuals, by 2050. The ageing process causes a significant reduction in muscle strength, flexibility, agility, and endurance in the elderly. The application of assistive wearable technology, specifically exoskeletons, is anticipated to enhance elderly performance in activities of daily living. However, exoskeletons are complex integrated systems that exhibit a tight connection with the user and must fulfil various user-specific design requirements in terms of functional performance and user experience. Previous studies have reported several design requirements and evaluations of exoskeletons used to assist the elderly in performing activities of daily living. This review article aims to present an overview of upper-limb exoskeletons designed for elderly assistance, with a focus on exoskeleton types and assessments specifically focused on elderly participation during the assessment, the task performed, and assessment parameters. Seventeen upper limb exoskeletons were identified from the literature and categorised based on supported body segment and structure. Most of the exoskeletons are either in the embodiment design or prototyping stages, and their evaluations were performed in the laboratory or in a simulated environment. Elderly participation in exoskeleton assessment is rare, and there is currently a lack of standardised assessment for exoskeleton assessment.
 
Nanostructuring of Additively Manufactured 316L Stainless Steel via High-Pressure Torsion for Enhanced Strength and Corrosion Performance
Get PDFBulk nanostructured materials (BNM) are defined as metallic materials with grain sizes <100 nm, and are known to possess superior mechanical and functional properties compared to those with grain sizes in the micron and millimeter ranges. In this study, high-pressure torsion (HPT), a nanostructuring approach that imposes compressive stress and extreme torsional strain on bulk materials is applied to an additively manufactured (AM) 316L stainless steel (316L SS) for 10 revolutions. The grain sizes, hardness, and corrosion performance before and after HPT are evaluated by using extensive microscopy techniques, Vickers hardness (HV) measurements, and electrochemical tests conducted in 3.5 wt.% NaCl solution, respectively. The results show that after 10 HPT revolutions, nano-sized grains (average: ~42 nm) are obtained, whereas a three-fold increase in HV values from ~220 HV to ~600 HV are observed. Furthermore, the corrosion performance is also significantly enhanced as indicated by the reduction in corrosion rate from 2.53 µm/year initially, to 0.48 µm/year after HPT processing. These results highlight the benefits of HPT in producing bulk nanostructured materials with remarkably high hardness and excellent corrosion performance, potentially useful for a myriad of applications
TSDT vs CPT and FSDT for Free Vibration Analysis of Functionally Graded Incompressible Plates
Get PDFThis article studies vibrational behavior of incompressible functionally graded plates through using classical, first-order shear, and third-order shear deformation plate theories. The plate material properties are assumed to vary continuously in the direction of thickness according to a power law function. The equations of motion are derived together with the continuity equations and are then solved analytically for rectangular plates with simple supports. The natural frequencies for the homogeneous state of the plate are compared with the results of other theories presented in the previous works. This comparison shows that in transverse vibration analysis, classical and first-order shear theories for incompressible plates are not as accurate as for compressible ones. It is shown that this issue is due to the fact that according to the classical and the shear theory of the first order, unlike the higher order theories, the hydrostatic pressure that appears in the incompressible materials cannot carry bending (transverse) loads. Therefore, the equivalent bending stiffness of the plate and as a result its bending frequencies decrease. Consequently, to analyze the vibration behavior of plates made of functionally graded incompressible materials, whether the plate is either thin or thick, higher order theories should be used. Finally, third-order shear deformation theory has been taken into consideration to study the vibration behavior of rectangular plates made of functionally graded incompressible materials, and detailed parametric studies have been carried out based on it
Functional Optimization of Smart Street Lamp via Hybrid Kano-DEMATEL Model: A Case Study on Hebi Area, China
Get PDFWorld\u27s major cities are rapidly advancing towards the development of smart cities. Smart street lamps, due to their integration and systematization, have become the most promising physical infrastructure for realizing smart city construction. However, current smart street lamps face obstacles such as functional redundancy, arbitrary design, and neglect of urban residents\u27 emotional needs, with the function setting of smart street lamps being a prominent challenge. Research how to optimize function settings to enhance cost-effectiveness and practicality is crucial. However, existing research in this area is limited, lacks systematic and quantitative analysis methods, and does not explore the complexity and interrelationships between functional integration adequately. Consequently, it fails to address the issues of avoiding redundant and mismatched functional settings of smart street lamps. This paper proposes a novel approach that leverages the strengths of the Kano model and the DEMATEL method, culminating in the establishment of a hybrid Kano-DEMATEL Model for comprehensively ranking smart street lamp functions. The model comprises four layers: the target layer, the Kano criterion layer, the DEMATEL criterion layer, and the requirements sorting table layer. The ordering strategy involves using the Kano model as the primary criterion and complementing it with the DEMATEL method as the secondary criterion. This model brings clarity to the importance of optimizing various indicators, provides a clearer understanding of the strengths and weaknesses of product functions, and considers correlations and complementarities between different functions, ultimately enhancing the cost-effectiveness and practicality of smart street lamps. By applying this model, this paper obtained a thorough ranking of the 21 must-be, expected, and attractive functions of smart street lamps. Furthermore, aligning these findings with specific regional research requirement, the functions of new smart street lamps were successfully optimized in the Hebi area, leading to substantial improvements and successful construction outcomes
Visual Inspection and Non-Destructive Test (NDT) on ASTM A36 Welded Joints Produced by GMAW
Get PDFLow-carbon steel is often used for welding joints, whether in the form of structural steel or other materials; the application of this material is used in shipbuilding, bridge construction, and other fields. Welding inspection is needed to determine the quality of the weld. Visual inspection and non-destructive testing (NDT) are techniques in welding inspection. This study aims to determine the results of visual inspection and non-destructive testing (NDT) on welding joints of low-carbon steel produced by GMAW. The welding joints used are V-butt joints with a bevel angle of 300, 10 mm thick plate, 2.6 mm root gap, variations in welding layers: 3 layers (root pass, filler pass, and capping), and 4 layers (root pass, 2 filler passes, and capping), filler metal ER 70S-6 0.8 mm, and CO2. Volts, current, travel distance, and shielding gas flow rate are welding parameters. The tests carried out were visual inspection referring to limits for imperfections in ISO 6520-1, non-destructive tests (NDT) that were carried out, namely penetrant tests and radiography tests. The visual inspection and non-destructive testing (NDT) on specimen 1 reveal an internal defect, specifically a lack of fusion; the specimen should be rejected. Specimen 2 shows an imperfection in the surface area, namely in the form of spatter (2 spots), and there are internal imperfections in the form of porosities with an area of less than 3%. The specimen should be accepted.
Smart and Intelligent Prayer System for Elderly Muslim with IoT
Get PDFAn assistive and monitoring prayer system has been designed to help elderly Muslims in performing their daily prayers. However, the system has several limitations in the aspect of efficiency, cost, size, complexity, security and usability. In this paper, several enhancements have been proposed to improve the existing smart prayer system including a better approach to retrieve exact prayer times, efficient way to retrieve current date/time, two different sensors used to detect the physical movements, smaller microcontroller with a built-in Wi-Fi module and the fabrication of PCB board. On the monitoring system, this project offers a more user’s friendly mobile application with several enhanced features. Reminder and authentication features are added to the mobile application for increased security and usability. The mobile application only allowed authorized or registered users to use the mobile application to view prayer performance of the elderly and send a prayer reminder to the elderly. The proposed system implements Internet of Things (IoT) technology, with a microcontroller communicating with the database through Wi-Fi, and data is modified before being displayed via the mobile application. Experimental testing shows a high level of support for the system\u27s commercialization due to its ability to assist and monitor the elderly with their daily prayers. This new smart prayer system offers a more reliable assistive and monitoring system for elderly Muslim
Mutual Coupling Reduction of Super Wide Band MIMO Antenna Using Metamaterial Periodic Defected Ground Structures for THz Applications
Get PDFIn this article, a double negative (DNG) material inspired periodic defected ground structure is presented to reduce mutual coupling and gain enhancement of super wide band multiple input and multiple output antenna (SWBMA) for terahertz (THz) applications. For THz applications, a dual port super wide band MIMO antenna with size of 0.35 λ0 ×0.17 λ0 ×0.02 λ0 (57 ×27.6 ×3.36 µm3) has been designed on quartz substrate. The simulated results of proposed antenna exhibit fractional bandwidth (FWB) of 164% at 9.9THz resonant frequency (1.75 to 18THz) with peak gain 9.2dBi, and average radiation efficiency 89% throughout the super wide band spectrum. By inserting DNG meta-material based periodic defected ground structures in between inverse L stubs on ground plane, an isolation S12/S21 between radiating elements of Si,j ≤ -25dB has been attained. MIMO parameters of designed antenna are also investigated and it is observed that ECC<0.0025, DG>9.98 dB, TARC<-15dB, MEG<-3dB, and CCL<0.225bps/Hz throughout spectrum of antenna.By evaluating the characteristics of proposed antenna, it can be concluded that the proposed MIMO antenna can be a good candidate for high-speed THz applications like future 6G, high-speed Radar, and radiometric applications
Fabrication and Implementation of PVA Thin Film-based Relative Humidity Sensor
Get PDFThis paper presents the fabrication of polyvinyl alcohol (PVA)-based relative humidity sensors using copper interdigitated electrodes (IDEs). These sensors were fabricated by patterning copper IDEs onto FR4 fiberglass substrates and coating them with a thin film of PVA. By varying the number of IDE electrode pairs and the concentration of PVA, the sensors exhibited different resistance values, demonstrating an inverse relationship with the number of IDE electrodes and PVA concentration. Additionally, the thickness of the sensing layer, controlled by spin coating speed, affected the resistance of the sensors. The fabricated sensors achieved a humidity measurement range from 50% to 99% RH based on resistance changes. Furthermore, an interface circuit was designed to integrate the fabricated sensors with an ESP8266 microcontroller, achieving accurate measurements above 74% RH
A Study of Automatic Pineapple Leaf Fibre Extraction Machine Using Bidirectional Rolling Mechanism
Get PDFPineapple leaf fibres are well known around the world due to the good material properties when woven together and environment friendly. Nevertheless, it takes a lot of effort and time to extract the fibres from the pineapple leaves. Consequently, various machines have been constructed around the world to automate this process, which has helped save time and increased the output productivity remarkably. This paper proposed a novel design of the automatic pineapple leaf fibre extraction machine using bidirectional rolling mechanism. The proposed mechanism will improve the efficiency of the pineapple leaf fibre extraction process that simultaneously enhances the quality of the output fibres.
The Influence of Eugenol in Lubrication Properties of Crude Jatropha Curcas Lin
Get PDFIn machining processes, vegetable oil based lubricant has very promising future to substitute petroleum based lubricant. Due to sustainability issue, lubricants from natural resources is sought after as complement or even substitute for non renewable lubricants. Jatropha curcas Lin oil (JCO) is one of such natural oil. When tested as lubricant, JCO demonstrates good performance and decomposition properties. The research on JCO usually study the performance the oil by characterizing of friction reduced parameters and rarely to analyze deeper in terms of the role of molecular interaction between components of vegetable oil and metal surfaces. To analyses the moleculer interaction, a commercially available software for molecular interaction simulation is employed. In order to simulate the interactions, the procedure of simulation are firstly construct molecular model of JCO components. The model then is employed as basis for the software to calculate interactive forces of each atom or molecule with the neighboring one thru their positions. From the simulation results, it was concluded that value of Dipole Moment, Polarisability, and Bond Energy of Jatropha oil compound decreased when the concentration of Eugenol is increasing. The conclusion is hold true up to 20% of eugenol addito