Development And Characterization Of The Ionic Polymer Metal Composite Actuated Contractile Water Jet Thruster

Ionic Polymer Metal Composite (IPMC) is a type of smart material that can be utilized as the actuator for contractile water jet thruster (CWJT) which is an alternative thruster for autonomous underwater vehicle (AUV). The advantages of IPMC actuator are light, flexible, able to be utilized underwater and consuming low voltage. However, IPMC low actuation force has limited the thrust generation. Hence, this research had been conducted to investigate the character of the fluid flow generated by the IPMC actuation on the CWJT. This investigation includes the observation on the relation of few factors that influence the thrust generation such as the nozzle aperture size, supply voltage for IPMC actuation and actuation frequency. This research consists of designing the conceptual prototype thruster, fabricating and characterizing the IPMC actuator, simulating the fluid flow of the prototype design and few experiments for data validation. The results and validation from the experiments showed that nozzle aperture size and actuation frequency of the IPMC actuator were influential factors in the development of IPMC actuated CWJT. The feasible actuation frequency was 0.1 Hz. Any higher frequency than 0.1 Hz would decline the CWJT contraction performance. The maximum thrust achieved in this research was 4.52 mN at 6 V supply. It is not feasible for heavy and more than 1 m long AUV. However, it suits for small or micro AUV that works in low current waters

Development And Characterization Of The Ionic Polymer Metal Composite Actuated Contractile Water Jet Thruster

Ionic Polymer Metal Composite (IPMC) is a type of smart material that can be utilized as the actuator for contractile water jet thruster (CWJT) which is an alternative thruster for autonomous underwater vehicle (AUV). The advantages of IPMC actuator are light, flexible, able to be utilized underwater and consuming low voltage. However, IPMC low actuation force has limited the thrust generation. Hence, this research had been conducted to investigate the character of the fluid flow generated by the IPMC actuation on the CWJT. This investigation includes the observation on the relation of few factors that influence the thrust generation such as the nozzle aperture size, supply voltage for IPMC actuation and actuation frequency. This research consists of designing the conceptual prototype thruster, fabricating and characterizing the IPMC actuator, simulating the fluid flow of the prototype design and few experiments for data validation. The results and validation from the experiments showed that nozzle aperture size and actuation frequency of the IPMC actuator were influential factors in the development of IPMC actuated CWJT. The feasible actuation frequency was 0.1 Hz. Any higher frequency than 0.1 Hz would decline the CWJT contraction performance. The maximum thrust achieved in this research was 4.52 mN at 6 V supply. It is not feasible for heavy and more than 1 m long AUV. However, it suits for small or micro AUV that works in low current waters

Structural analysis of long arm excavator boom for optimization performance under maximum breakout condition

Long Arm Excavators are widely used in the construction site for excavating deep holes or trenches. However, due to the often-severe work conditions, such as large lifting loads, poor ground conditions to sustain the machine’s self-weight, Long Arm Excavator parts are subjected to constant wear and tear, incurring downtime losses and safety issues. The boom is considered the most critically affected part of the machine in these work conditions, where the high forces and unpredictable elements at the worksite could severely affect the machine’s overall performance. A potential solution is the reinforcement of the boom to improve its robustness. As an industrial collaborative project, the present study examines the performance of an existing machine with simulated improvement of the boom with such an approach, i.e. incorporation of stiffener reinforcement. Simulation works were carried out with Ansys Workbench 19.2 to assess the boom’s performance in terms of resulting stress, strain and deformation under a series of improved conditions, which include varying the dimensions and positions of the stiffeners on the boom. The improved conditions were Improvement I: stiffeners thickness reduction to 10mm, Improvement II: a combination of different stiffeners thickness reduction which 10mm and 8mm at critical and non-critical part of the boom, Improvement III: removal of half intermediate stiffeners thickness 12mm and Improvement IV: removal of half intermediate stiffeners thickness 8mm. Structural analysis was conducted based on the maximum breakout condition in which the excavator generates maximum digging force. From the analysis, it was found that the maximum equivalent stress of the boom decreased with the number of stiffeners. The combination of different stiffeners thickness could also increase the boom’s strength while decreasing the maximum equivalent stress. The lowest maximum equivalent stress of the boom was achieved via Improvement II with a reduction of 26.1% maximum equivalent stress. Removal of non-critical part stiffeners also kept stress values under the designated stress limits against fatigue failure, i.e. 44.49 MPa and 42.47 MPa (Improvement III and IV). In summary, the optimal design could be obtained with improvement II. This would effectively save on the manufacturing costs while maximizing the machine’s performance on-site, simultaneously reducing downtime and hence operating costs and time

Feasibility Study on IPMC Actuated Contractile Water Jet Thruster Body Contraction

This research was conducted to investigate the feasibility of Ionic Polymer Metal Composite (IPMC) as the actuator for Contractile Water Jet Thruster (CWJT). The thrust that generated from the accelerated volume of ejected fluid depends on the IPMC actuator contraction performance. During this investigation, the variation of contraction frequency and nozzle aperture influence on the body deformation was carried out. The results of the experiments exhibit that the body contraction decreased tremendously from 0.05 Hz to 0.15 Hz. The body contraction has no apparent decrement for more than 0.15 Hz of contraction frequency. Besides, larger nozzle aperture has relatively more body contraction than smaller nozzle aperture. These results show that the fixed actuation force and the contraction frequency have a significant influence on the CWJT body contraction

Ergonomic posture assessment of butchers: a small enterprise study in Malaysia food industry

The development of small and medium-sized enterprises (SMEs) is crucial for improving the economy of a rural area. However, this can cause working posture problems, such as musculoskeletal disorders (MSDs) and cumulative trauma disorders (CTDs). This is especially true for butchers, who work in SMEs that still depend on manual handling processes without standard operating procedures. Posture analysis evaluations using the Rapid Upper Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA) tools have been used to analyse the working postures of butchers working in SMEs. The aim of this study was to identify butchers’ risks of working posture problems, and to propose an ergonomic workstation designed to reduce MSDs and CTDs. This study was focused on smoked meat preparation. The butchers there spend 5–8 hours a day cutting and trimming meat. The assessment was conducted using RULA and REBA worksheets. The RULA score for the meat trimming process was 7, with a score of 6 for the meat cutting process. As for REBA, the score was 5 for both the meat trimming and meat cutting processes. Based on these scores, the butchers were at higher risks for MSDs and CTDs. Therefore, a new ergonomic workstation design was proposed based on the principles of motion economy

Numerical simulation analysis on water jet pressure distribution at various nozzle aperture

The low velocity water jet is required by small scale Unmanned Underwater Vehicle (UUV) to control its position, either to remain statics in its position or to perform a slow and steady locomotion. However, the water jet performance is influenced by the size of nozzle aperture. By studying the pressure distribution around the nozzle area, the water jet velocity could be determined and characterized. In this studies, the ejection pressure was fixed at 23.37 Pa according to the constant actuation. Studies were conducted using ANSYS Fluent software. The results show that the water jet velocity and dynamic pressure are higher for larger nozzle aperture size at constant pressure. The total pressure and dynamic pressure had the lowest pressure drop at certain nozzle aperture size but became constant when the nozzle size was wider. This finding is useful in designing the UUV that powered by contractile water jet thruster

Design of a low cost coin acceptor for vending machine

Coin acceptor is a device that receive and identifies the validity of the coin. It works by analyzing the coin it received based on its mass, size, diameter, thickness, metal composition, and then sends an appropriate signal through the output connection. However, the cost of purchasing the device is rather high compare to self-fabricate where the current surveys on online shows that the device will cost around RM150-300. This cost is consider high for SME who just planning to start their vending machine business. Therefore, the alternative to come out with a design for a low cost coin acceptor for the vending machine had been done. To make sure the cost will not be high the scope of the project has been determine where the device is designed to only accept the second series version of RM0.50 which is 27 mm in diameter. In this project, the design is produced by using Solidworks software and the coin identification mechanism was designed by integrating the like of sensors, actuators and microcontroller which is the basic component of a coin acceptor. To further reduce the cost a new mechanism of a rejection hole were introduced to replace and eliminate number of sensor used. The expected cost to fabricate the design was expected to be around RM138 and further cost reduction can be done with further research on reducing the product component

Physical properties of natural dyes based on lawsonia inermis, azadiractha indica and curcuma longa coated with superhydrphobic coating for textile applications

Natural dyes based on Lawsonia Inermis, Azadiractha Indica and Curcuma Longa were used in this study to produce eco-friendly and non-toxic fabric to the people. The extraction process of natural dyes is aqueous technique and hot bath dyeing. The aim is to find the optimum concentration of natural dyes and superhydrophobic coating oncotton fabric for green technology dyeing. The data obtained is subjected to quantitativeanalysis. It is found that coated fabrics have higher physical strength than uncoatedfabrics. The coated scale for crocking test, weather resistance of fabric and washingtest are 5 (excellent) compared to the uncoated dyed cotton fabric. The optimumconcentration obtained from Lawsonia Inermis, Azadiractha Indica and CurcumaLonga is F (1.50 g/ml). The results can help to reduce the usage of synthetic dye intextile application

The open air electrical-field activated sintering and forming of micro components.

As the demand for the miniature products has increased significantly, so also has the need for these products to be produced in a rapid, flexible and cost-efficient manner. The application of electroplasticity shows significant potential to produce the components by using powder materials. Nevertheless, previous research has shown that there are still significant challenges to be met in order to achieve increased relative densification of product samples and simplification of the process. The process concept in this study comprises the combination of electrical-field activated sintering and forming processes. Therefore, the aims of the research were to establish the process concept for the manufacture of micro-components by using the machine that will be fabricated which could be used more practically in the small factories, whereas the Gleeble 3800 machine is more suitable for extended experimental work and further analysis in the laboratory. The cost to purchase the Gleeble 3800 machine was more expensive compared to the proposed fabricating machine. In addition to that, to design the iterations of die sets along with other tooling for machine setup to enable the series of experiment to produce of micro-components from powder materials. A comprehensive literature review on micromanufacturing, size effects, powder metallurgy and the electroplasticity process will be conducted. This efficient process has the potential to produce components with a high relative density around 90% or higher which was a difficult task to complete with the traditional method due to the influences from the size-effect issues in the micro-forming process and will contribute to the clean environment and decrease a pollution due to no usage of green compacts and argon gas. Changes in the particles concerning deformation and breaking are crucial in the course of achieving the densification in the proposed process which differs from a conventional sintering process

Preparation and Performance Test of PEFB Reinforced Box Waste Coated Superhydrophobic Coating for Shoe Sole Application

The study presents preparation and performance test of Palm Empty Fruit Bunches (PEFB) reinforced box waste coated superhydrophobic coating for shoe sole application. The main purpose of this analysis is to determine the optimal composition of PEFB reinforced with box waste for use in shoe soles. In this study, the use of PEFB and box waste is to replace the synthetic materials in the application of the shoe sole. Additionally, environmental problems can be reduced by using waste PEFB as a value-added product rather than biomass waste. Sample preparation involved grinding of PEFB fibers and box waste, blending processes of different PEFB percentages at 20%, 40%, 60% and 80% mixed with 50% box waste. Followed by the process of mixing with epoxy and hardener, and finally coated with superhydrophobic coating using a spray gun method. Epoxy resin and hardener are used as binders for the bonding between the PEFB fiber matrix and the box waste to be applied to the shoe sole. The study was carried out in both mechanical and physical studies. The test for tensile strength showed 40% PEFB reinforced with 50% box waste with 181.36N maximum load and 16.70% of strain. The 40% PEFB composition showed the optimum bursting pressure to 13.62kgf and the abrasion resistance had a lower weight loss of 0.28 g. The 80% higher proportion of PEFB indicates a lower density of 1.06g/cm3 and a higher porosity of up to 0.44%. It is also revealed that 40% of box waste provided the best composition for the application of the shoe soles