•Journal• ISSN: 2289-4659
Journal of Mechanical Engineering and Sciences
Universiti Malaysia Pahang
About: Journal of Mechanical Engineering and Sciences is an academic journal published by Universiti Malaysia Pahang. The journal publishes majorly in the area(s): Computer science & Ultimate tensile strength. It has an ISSN identifier of 2289-4659. It is also open access. Over the lifetime, 660 publications have been published receiving 5069 citations. The journal is also known as: JMES.
Topics: Computer science, Ultimate tensile strength, Surface roughness, Finite element method, Engineering
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Papers
TL;DR: In this paper, the efficiency of an evacuated tube solar collector using water-based Titanium Oxide (TiO2) nanofluid at the Pekan Campus (3 32' N, 103 25' E), Faculty of Mechanical Engineering, University Malaysia Pahang, for the conversion of solar thermal energy was evaluated.
Abstract: Experiments are undertaken to determine the efficiency of an evacuated tube solar collector using water-based Titanium Oxide (TiO2) nanofluid at the Pekan Campus (3 32’ N, 103 25’ E), Faculty of Mechanical Engineering, University Malaysia Pahang, for the conversion of solar thermal energy. Malaysia lies in the equatorial zone with an average daily solar insolation of more than 900 W/m2, which can reach a maximum of 1200 W/m2 for most of the year. Traditionally water is pumped through the collector at an optimum flow rate, for the extraction of solar thermal energy. If the outlet temperature of the water is high, further circulation of the water through the collector is useless. This is due to the low thermal conductivity of water of 0.6 W/m.K compared to metals which is many orders higher. Hence it is necessary to reduce the surface temperature either by pumping water at a higher flow rate or by enhancing the fluid’s properties by the dispersion of nanoparticles. Pumping water at higher flow rates is not advantageous as the overall efficiency of the system is lowered. Liquids in which nanosized particles of metal or their oxides are dispersed in a base liquid such as water are known as 'Nanofluids'. This results in higher values of thermal conductivity compared to the base liquid. The thermal conductivity increases with the concentration and temperature of the nanofluid. The increase in thermal conductivity with temperature is advantageous for application in collectors as the solar insolation varies throughout the day, with a minimum in the morning reaching a maximum at 2.00p.m and reducing thereafter. The efficiency of the collector estimated using a TiO2 nanofluid of 0.3% concentration is about 0.73, compared to water which is about 0.58. The efficiency is enhanced by 16.7% maximum with 30–50nm sized TiO2 nanoparticles dispersed in the water, compared to the system working solely with water. The flow rate is fixed at 2.7 liters per minute for both liquids.
122 citations
TL;DR: In this article, the effect of different contents of filler on the properties of OPA-filled unsaturated polyester (UP/OPA) composites has been investigated, together with thermal gravimetric analysis and differential scanning calorimetric (DSC).
Abstract: Oil palm ash (OPA) is available in abundance, is renewable, can be obtained at no cost and shows good performance at high thermal conditions. Combinations of the unsaturated polyester with natural fillers have been reported to improve the mechanical and thermal properties of composites. Utilisation of oil palm ash as a filler in the manufacture of polymer composites can significantly reduce the requirement for other binders or matrixes of composite materials. This research uses oil palm ash as a filler to form composites through the investigation of the effect of different contents of filler on the properties of OPA-filled unsaturated polyester (UP/OPA) composites. The effect of different volume fractions, i.e., 0, 10, 20 and 30 vol.% of oil palm ash introduced into 100, 90, 80 and 70 vol.% of an unsaturated polyester matrix on the composite mechanical properties, i.e., tensile and flexural, has been studied, together with thermal gravimetric analysis (TGA) and differential scanning calorimetric (DSC). Specimens were prepared using compression moulding techniques based on the ASTM D790 and D5083 standards for flexural and tensile tests, respectively. The tensile and flexural mechanical properties of UP/OPA composites were improved in modulus by increasing the filler content. Thermal stability of the composites increased as the OPA filler content was increased, which was a logical consequence because of the high thermal stability of the silica compound of the OPA filler compared with that of the UP matrix. The results from the surface electron microscope (SEM) analysis were the extension of mechanical and thermal tests.
94 citations
TL;DR: In this paper, rice husks filler polyester composites were used as filler and unsaturated polyester resin as the matrix, and the surface fracture of the tensile test specimens were analyzed by using Scanning Electron Microscopy.
Abstract: In this study, rice husks filler polyester composites were produced with rice husks as filler and unsaturated polyester resin as the matrix. Several weight percentages of filler loadings were used; 10 wt%, 15 wt%, 20 wt% and 25 wt% in order to gain insights into the effect of filler content on the mechanical properties and water intake of the composites. The surface fractured of the tensile test specimens were analysed by using Scanning Electron Microscopy. From the findings, the tensile strength of the rice husks filled unsaturated polyester resin composites was found to be decrease as the filler loading increased. However, as it increased to 25 wt%, the strength was slightly increased. As for the young modulus, it showed remarkable increased for 15 wt% of rice husks. Nevertheless, it was decreasing as the rice husks were continually increased up to 25 wt%. Water absorption test was also conducted and the results showed that the composites absorb more water as the weight percentage of rice husks increased, which attributed to the ability of rice husks fillers to absorb water.
93 citations
TL;DR: In this article, the performance of an 80 W floating photovoltaic (PV) panel in a pond simulator was discussed, whereby in a two hour experiment it showed up to 15.5% increment of energy gain compared to a normal PV panel.
Abstract: Photovoltaicpanels are used to generate electric power. The surface temperature of the photovoltaic (PV) panels will affect theirefficiency,where the increment of temperature will decreasetheir efficiency and total power gain. In this study, we will discuss the performance of an 80 W floating photovoltaic (PV) panel in a pond simulator, whereby in a two hour experiment it shows up to 15.5% increment of energy gain compared to a normal photovoltaic (PV) panel. The floating photovoltaic (FPV) panel was designed by replacing the photovoltaic panel frame with a material that has the ability to float on a water surface and is capable of transferring heat at the back of the photovoltaic surface. A heat sink is used to transfer heat at the bottom of the photovoltaic panel, which will decrease the surface temperature when placed on the water surface. The best performance of the photovoltaic panel is 1000 W/m 2 fora surface temperature of 25°C; however,the efficiency will drop by 0.485% per1°C temperature increment.The system can be used on lakes, ponds or dams.
78 citations
TL;DR: In this article, a review of various types of heterogeneous solid catalysts used in the production of biodiesel via the transesterification of WCO is presented, and the advantages and drawbacks of these heterogeneous catalysts are presented.
Abstract: The need for fossil fuels and the emissions generated from these fuels are increasing daily. Researchers are concerned with global warming as well as climate change; and energy sustainability and material usages are important issues today. Waste cooking oil (WCO) can be processed into biodiesel as an alternative fuel to replace diesel. Production of biodiesel using WCO as the feedstock has been of growing interest for the last two decades. A number of research papers related to the improvements in production, raw materials and catalyst selection have been published. This paper reviews the various types of heterogeneous solid catalyst in the production of biodiesel via the transesterification of WCO. The catalysts used can be classified according to their state presence in the transesterification reaction as homogeneous or heterogeneous catalysts. Homogeneous catalysts act in the same liquid phase as the reaction mixture, whereas heterogeneous catalysts act in a solid phase with the reaction mixture. Heterogeneous catalysts are non-corrosive, a green process and environmentally friendly. They can be recycled and used several times, thus offering a more economic pathway for biodiesel production. The advantages and drawbacks of these heterogeneous catalysts are presented. Future work focuses on the application of economically and environmentally friendly solid catalysts in the production of biodiesel using WCO as the raw material.
76 citations
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 42 |
| 2024 | 41 |
| 2023 | 43 |
| 2022 | 52 |
| 2021 | 19 |
| 2020 | 100 |