Applied Mechanics and Materials Vol. 819

Abstract: The demand and usage of vegetable oil utilization in lubricants for many applications increased prompting by continued growing environmental concerns. Today, vegetable oil attracts attention as biodegradable alternates for synthetic esters because they are cheaper and can be obtained from sources that are renewable. The main objectives of this experiment were to measure the friction force at various speeds and to observe the surface roughness before and after experiment. In this experiment, RBD palm olein as represented vegetable oil has been tested by compare the result with fully synthetic oil and mineral-based oil by using modified pin-on-disc machine. Pure RBD palm olein, recorded only 7.4% of increment of maximum friction force compared to results for mineral-based oil. Observation based on surface roughness show that RBD palm olein works as effective as fully synthetic and mineral-based oil since only 14.6% increment of overall surface roughness for the whole shaft. Therefore, the performance of vegetable oil which in this experiment is RBD palm olein, can be improve by adding additive so increase it properties such as can withstand at high load, high flash point parameter, small wear scar diameter, less oxidation rate, and coefficient of friction.

Abstract: The extended uses of mineral oil based lubricant have continuously troubling the global environment issues. The remaining mineral oil resources also being the most debated issues in renewable energy conferences. Vegetable oils are still offering the highest possibility in replacing the mineral oil resources. This research is concerning on how to eliminate one of the disabilities found in palm oil based lubricant which is oxidation. Palm oil possessed unsaturated double bond in which susceptible to oxidation process. The simplest approach is to blend the palm oil based with anti – oxidant agent homogenously. This research was conducted using double fractionated palm oil (SPL) as lubricant and Tertiary-Butyl-Hydroquinone (TBHQ) as anti – oxidant agent to determine the tribology behavior including the coefficient of friction, wear scar diameter and the surface roughness profile. The experiment was also conducted using four-ball tribotester by following ASTM D4172B standard. Superior Mineral Engine Oil (EO) was used as comparison. The results found that SPL+TBHQ was able to reduce the coefficient of friction and provided lower surface roughness value. However it was unable to minimize the mean wear scar diameter compared to EO. The physical appearances of wear worn are also being observed in this research.

Abstract: The purpose of this feasibility study is to elucidate the effect of surface modification on the curvature cup made of Acrylonitrile Butadiene Styrene (ABS) against metal ball bearing was investigated. In the tribology soft on hard (SoH), the pits embedded on the curvature cup have shown potential for reducing friction in curvature structure. A modified four ball machine as a hard-on-soft screening machine has been used to evaluate the friction on the curvature cup sample with an inner diameter of 12.8 mm. This study revealed that the treated curvature cup with pit in lubricated of palm oil optimizes the rate of frictional and allows for a stable of soft on hard sliding contact.

Abstract: A study has been created on the wear rate and friction constant for various material under the impact of load and material where the equipment pin on disk has been used to investigate the specification on the wear and constant of friction (COF) theory. The issues occur because of the metal-to-metal contact once interaction between two surfaces creates friction, wear and heat. It’ll cause every element life shortened, economically wasted, surface damage and cracks. This paper evaluates via pin on disc tribometer using SKD II and aluminum alloy, A 5083 as work pieces material. The test was tested using different type of lubricant (palm olein and mineral based oil) with different load. The result shows palm olein is more than mineral-based oil for constant friction as sliding speed increased and wear scar diameter lubricated with palm olein lower at low and high speed compared to the oil. As a conclusion, palm olein has better performance properties in terms of friction reduction (coefficient of friction) and wear resistance (anti-wear properties) at low and high speed. Pin that lubricated with palm olein showed small wear scar diameter compared to the mineral based oil. Therefore, palm olein has risk to use as a lubricant of mating components.

Abstract: Vegetable oils are bio-fluids that could replace petroleum-based products due to its environment friendly characteristics and becoming an important source of bio-lubricants. The great advantage of vegetable oils is that they are widely available, renewable source of bio-lubricants. Moreover, vegetable oil based lubricant have shown the potential to reduce carbon dioxide and hydrocarbon emissions when operated in engines. There are two ways to use vegetable oil as a bio-lubricant, either use directly the neat vegetable oil without any additives or use with certain blending ratio of the vegetable oil with mineral lubricant. In this paper, the influences of the normal load on the tribological characteristics for the blending of two types of vegetable oils were investigated and compared with commercial lubricant oil by the use of the four ball tribotester. The vegetable blends are RBD palm olein and Jatropha oil ratio of RBD40/J60. All experimental works were conforming to ASTM D4172. The results exhibited that the both blending of RBD palm olein and Jatropha oil has lower the wear scar of ball bearings and coefficient of friction compared to commercial lubricant oil. As a conclusion, the blending of RBD palm olein and Jatropha oil has better performance compared to commercial lubricant oil or neat RBD palm olein.

Abstract: In this paper a review on recent development in Low Energy Nuclear Reaction (LENR) is presented along with scope and challenges. As the name suggests Low Energy Nuclear Reaction (LENR) is a phenomenon of nuclear reaction occurring in metal hydrides at ambient temperature. The products are generally Helium & significant amount of useful heat energy. During the process Transmutation of metal (host) occurs; occasionally producing some charged particles and neutrons. The LENR are successfully carried out with various elements namely; nickel, gold, palladium, platinum, titanium, certain superconducting ceramics, etc. LENR poses itself as a source of pollution free and inexhaustible energy source. It produces tremendous amount of heat energy during the reaction which surpasses all the available energy sources by a factor of hundredths to millions. Besides this it is also useful in transmutation of nuclear wastes. To initiate LENR there are various views floating around in scientific community. The purpose is to bring together two nuclei at low energy to fuse together as a single nucleus. A large amount of force is required which is generally obtained through plasma arc or accelerated high energy ions. But in case of LENR all the nuclear reaction occur at low energy thus saving excessive amount of energy required for activation. One of the most studied LENR involves palladium. The palladium is used at a loading between 0.9 and 0.94 to produce optimum results. It is a source of Energy which is more eco-friendly and productive than all the available energy sources known to us. Statistically 1% of the total Ni production can power the World that too at one-fourth the cost of burning fossils. Models are being developed with Carbon replacing Ni, thus it will convert carbon to nitrogen. LENR is also being developed for using nuclear wastes as fuel, transmuting them into non-radioactive elements. This will tag LENR as much greener and cleaner source. LENR is being also developed to be used as an alternative and richer energy source to radioactive fuels (like Pu-238), currently being used to power space probes. Thus it helps reduce the generation of hazardous nuclear wastes.

Abstract: This paper is a review about process, progress and operation principle of renewable technology using water current as a clean, green and renewable energy to generate electricity for areas especially remote site that access to water but they are poor in electricity.

Abstract: This paper presents an optimized energy system model for a small locality in Kutubdia Island, Bangladesh at latitude of 21.82 °N, longitude of 91.86 °E. This isolated island is located at the southern coast of Bangladesh, separated from the main land by the Kutubdia channel. At present, grid connection from the mainland is not present and is not planned in the near future. The proposed energy system comprises Solar PV, Wind turbines, Biogas generators for power generation whereas a diesel generator has been used as backup power supply and batteries have been considered to facilitate energy storage. Hybrid Optimization Model for Electric Renewable (HOMER) has been used to obtain an optimized system comprising all the renewable energy resources present. The designed energy system consists of 28 kW Solar PV panels, 30 kW Wind Turbines, 8 kW Biogas Generator, 9 kW Diesel Generator. The system generates electricity with a renewable fraction of 97%. The cost of electricity has been estimated as US$ 0.42/kWh considering 10% Rate of Return with an initial capital cost of US$ 199,541.

Abstract: This study presents four analysis at unit 4 Kamojang geothermal power plant are exergy analysis at current condition, exergy efficiency optimization, economic optimization, and exergoeconomic optimization with wellhead valve pressure as a variable. Calculations are conducted by using the MATLAB. Thermodynamics characteristic of geothermal fluid assumed as water characteristic which get from REFPROP. Wellhead pressure operational condition 10 bar has exergy efficiency 31.91%. Exergy efficiency optimization has wellhead valve pressure 5.06 bar, exergy efficiency 47.3%, and system cost US$ 3,957,100. Economic optimization has well pressure 11 bar, exergy efficiency 22.13%, and system cost US$ 2,242,200. Exergoeconomic optimization has 15 optimum condition. Exergoeconomic optimization aims to analyze the optimum wellhead valve pressure for maximum exergy efficiency and minimum cost of power plant system.

Abstract: In this paper an improved method for fuel cost apportionment of a combined power cum a desalination plant is presented. The conventional analysis for cogeneration systems has been, hitherto, the energetic (enthalpy) method which is useful for efficiency evaluation purposes, but it may not be fully accurate for capturing the “quality of fuel energy” consumed by processes in producing two or more useful effects, e.g., electricity and water. An exergy destruction procedure is proposed for the cost apportionment of fuel energy consumed where the available work potential of expanding stream can be fully accounted for cost distribution of the designed processes. For example, the turbines, that is used for power generation, exploits mainly the sensible-energy changes of high enthalpy steam undergoing expansion at high pressures and temperatures, whilst the thermally-activated desalination processes, such as the multi-effect distillation (MED), needed only the high latent-heat of bled-steam but at low pressures that has negligible work potential if the steam were to be used in the turbines. From this analysis, the incurred exergy destruction by the desalination processes is only 2%-7% of the total destruction available to the plant with bled-steam up to 50% of the total flow. We examined the ratio of exergy destruction consumed by the water to power production and, such a ratio is used as a basis for the fuel-cost determination in the cogeneration plant. It captures not only the realistic exergetic value of bled-steam of MED desalination, but it exposes the major shortcomings of the conventional enthalpy changes where a disproportion share of the input fuel cost, up to 32% of the total fuel input, may have been erroneously apportioned and giving an unfair valuation of the operational water cost.