Investigation of tribological properties of CuO/palm oil nanolubricant using pin-on-disc tribotester

It has been proposed that nanoparticles have the ability to enhance the tribological properties of lubricants. In the present research, the tribological properties of a palm-oil-based nanolubricant with copper (II) oxide (CuO) nanoparticles have been investigated experimentally using a pin-on-disc tribotester. The experiments were conducted at a sliding speed of 0·2m/s and an applied load of 9·8 N, which corresponds to a contact pressure of 0·93GPa for 60min duration. Commercial mineral oil (SAE40) was used for comparison purposes. The results show that the tribological properties of the palm-oilbased lubricant were improved with the presence of copper (II) oxide nanoparticles, showing huge reductions in coefficient of friction and wear scar diameter of about 56 and 48%, respectively. The findings revealed that the presence of copper (II) oxide in palm kernel oil (PKO) reduced the roughness of the pin surface by 43·7%. The results also show that the tribological properties of the copper (II) oxide/palm-oil-based nanolubricant were comparable to those of SAE40

The influence of Zinc-Dialkyl-Dithiophosphate (ZDDP) additives on the tribological performance of RBD palm kernel / Nurul Farhanah Azman...[et al.]

Vegetable oil based lubricant has received much attention in recent years due to its biodegradable properties, low toxicity and environmental friendly. This study used refined, bleached and deodorized (RBD) palm kernel blended with zinc-dialkyl-dithiophosphate (ZDDP) to evaluate the tribological performance as a potential alternative lubricant. The ZDDP additives were added with concentration of 0wt%, 1wt%, 3wt% and 5wt%. Commercial mineral oil SAE 40 was used for comparison purposes. The tests were performed at 1.5 m/s and 3.5 m/s of sliding speed under 9.81 applied load for 1 hour at room temperature. The results indicate that the presence of ZDDP in RBD palm kernel have improved both friction reducing and anti-wear performance. The formulation of RBD palm kernel have the potential to be used as a substitution for mineral based lubricant in near future. The authors would like to express their thanks to the Research Management Centre (RMC) of Universiti Teknologi Malaysia for the Research University Grant, GUP (12H98, 09H64), Fundamental Research Grant Scheme, FRGS (4F610), and Ministry of Education of Malaysia and Ministry of Higher Education for their support; they also thank the Faculty of Mechanical Engineering, Universiti Teknologi Malaysia for the laboratory facilities

Experimental investigation of the effectiveness of jet impingement cooling system on the pressure side of the turbine blade

The effectiveness of the jet impingement system on the turbine blade pressure side has been experimentally investigated. The effects of height-to-diameter ratio and air velocity on the effectiveness of jet impingement were studied. Experiments was performed under varying height-to-diameter ratios (H/D = 5, 10, 15, 20) where the distance from the nozzle to the pressure side surface ranged from 20, 40, 60 and 80 mm with a constant nozzle diameter of 4 mm. The Nusselt number is calculated to determine the cooling effect of the pressure side model surface. Experiments were also performed at varying air velocity at 6.4 m/s and 12.6 m/s. The findings revealed that there was no direct relationship between Nusselt number and H/D ratio where the optimum cooling impact at a velocity of 6.4 m/s was found to be at H/D=15, whereas at a velocity of 12.6 m/s it was found to be at H/D=5. The findings also reveal that the amount of Nusselts rises as the air velocity increases

Fire resistance rating for gypsum and kapok fiber composite materials

Fire rated door is one of the passive fire protection systems that can prevent fire and smoke from spreading when a fire occurs. The purpose of this study was to analyze fire rated doors made of Gypsum and Kapok fiber composites. This fire rated door has been manufactured in accordance with Malaysian Standard MS1073: Part 2: 1996. This fire rated door has been modified with various composite compositions and thicknesses. The results showed that the fire rated door made of Gypsum and Kapok fiber can last from 30 to 60 minutes. This study clearly shows that door thickness is very important in the manufacture of fire rated door

Tropical and subtropical Asia's valued tree species under threat

Tree diversity in Asia's tropical and subtropical forests is central to nature-based solutions. Species vulnerability to multiple threats, which affects the provision of ecosystem services, is poorly understood. We conducted a region-wide, spatially explicit vulnerability assessment (including overexploitation, fire, overgrazing, habitat conversion, and climate change) of 63 socio-economically important tree species selected from national priority lists and validated by an expert network representing 20 countries. Overall, 74% of the most important areas for conservation of these trees fall outside of protected areas, with species severely threatened across 47% of their native ranges. The most imminent threats are overexploitation and habitat conversion, with populations being severely threatened in an average of 24% and 16% of their distribution areas. Optimistically, our results predict relatively limited overall climate change impacts, however, some of the study species are likely to lose more than 15% of their habitat by 2050 because of climate change. We pinpoint specific natural forest areas in Malaysia and Indonesia (Borneo) as hotspots for on-site conservation of forest genetic resources, more than 82% of which do not currently fall within designated protected areas. We also identify degraded lands in Indonesia (Sumatra) as priorities for restoration where planting or assisted natural regeneration will help maintain these species into the future, while croplands in Southern India are highlighted as potentially important agroforestry options. Our study highlights the need for regionally coordinated action for effective conservation and restoration

Tribological behaviour of zinc dialkyl-dithiophosphate (zddp) as a lubricant additive in rbd palm stearin

The effects of ZDDP additive concentrations in refined, bleached and deodorized (RBD) palm stearin on the tribological behaviour were tested. Pure RBD palm stearin and additive added with concentration of 0%, 1%, 3% and 5% (in weightage) were used in pin-on-disk triboteter (ASTM G99). Tests were performed under 3.5 m/s sliding speed and 9.81 N force applied on the pin. Each test was run in an hour at room temperature. Friction and wear performance of pure RBD palm stearin and ZDDP-added were compared. The results show that the presence of ZDDP additive in RBD palm stearin improved both friction and wear performance. ZDDP additive also can effectively act as antioxidant agent in RBD palm steari

Improvement of the lubrication performance of RBD palm stearin as an alternative lubricant under different sliding speeds

Vegetable oils have gained global att-ention to be used as an alternative lubricant to reduce the dependency on natural resources of petroleum-based lubricants due to concern over environmental problems. In this study, a refined, bleached and deodorized (RBD) palm stearin was chosen as the base lubricant, and its lubrication performance was investigated using a pin-on-disk tribotester. A zinc dialkyl-dithiophosphate (ZDDP) additive in concentrations of 1 wt%, 3 wt% and 5 wt% was blended with RBD palm stearin to improve the lubrication performance of the base lubricant. Commercial semi-synthetic oil (SAE15W50) was used for comparison purposes. The experiments were conducted under various sliding speeds (1.5 ms(-1), 2.5 ms(-1) and 3.5 ms(-1)) under normal force of 9.81 N for an hour. The lubrication performance of the tested lubricants was presented by the coefficient of friction, wear scar diameter, wear rate, surface roughness and wear worn surface of the pin specimen. The results show that an increase in ZDDP concentrations has improved the lubrication performance of the RBD palm stearin. RBD palm stearin with 5 wt% ZDDP additive shows a smaller coefficient of friction than that of SAE15W50, but creates a slightly larger wear scar diameter and wear rate

Tribological performance of raw and chemically modified RBD palm kernel

The objective of MITC2015 is for the scientists, scholars, engineers and students from universities, research institutions and industries all around the world to present findings of ongoing research activities, and hence foster research collaborations between the universities and the industries. The other objective is to introduce young tribologists in the scientific field of tribology through keynote lectures and presentations, to offer mentoring through senior scientists, and to foster the building of networks through the informal style of the event

Air flow analysis and effect of angle on rotation vane blade through 90-degree by computational fluid dynamic

The effects of different angles of rotation vane blades on the flow characteristics in a pipe bend were numerically examined in this work using computational fluid analysis (CFD). The model’s geometry included a straight inlet pipe of 1 m length, a 90° pipe bend with a 0.1 m cross-section diameter, a straight outlet pipe of 1 m length, and the installation of rotating vane blades at 10° and 33° angles. The simulation’s input parameters include fluid viscosity (0.000017894 kg/m.s), fluid density (1.225 kg/m3), and inlet fluid velocity (10, 14, 20, 24, 26, and 30 m/s). The simulations’ output parameters include velocity and pressure measured at two points: section A-A (before the pipe bend) and section B-B (after pipe bend). The findings demonstrate that the velocity and pressure distribution is somewhat uneven at section B-B owing to the presence of the rotating vane. The most efficient rotation vane blade angle is 10° since it has the lowest velocity, static pressure, and pressure drop

Physicochemical homogeneity of stingless bee honey (Heterotrigona itama) produced in the west coast, east coast and inland area of Peninsular Malaysia

BACKGROUND: The nutritional composition of stingless bee honey (SBH) can be affected by different climates and soil composition across different geographical areas. However, the range of attributes set for a honey quality standard should be inclusive. This study analysed the sugar profile's physiochemical properties, including quantifying the rare sugar trehalulose, organic acid and mineral composition of SBH collected from inland, and west and east coasts of Peninsular Malaysia. Forty-three SBH (Heterotrigona itama) samples were collected and labelled as <20 and <40 West Coast (<20WC, <40WC), <20 and <40 East Coast (<20EC, <40EC) and Inland, according to their distance from the coasts. RESULTS: The moisture, pH and sugar composition of all SBH samples adhered to the Malaysian Kelulut Honey Standard (MS2683:2017) but not to the International Codex Standard (CODEX) for honey. Trehalulose presence in all samples, regardless of geographical area, was predominant alongside fructose and glucose. Only hydroxymethylfurfural (HMF) content and electrical conductivity (EC) results complied with both standards. The principal component analysis biplot showed that the discrimination of SBH according to the five different areas was not feasible, indicating sample homogeneity. CONCLUSION: The physicochemical evaluation of SBH from Peninsular Malaysia shows mainly homogeneous attributes of samples across geographical locations. These findings demonstrated that the current MS2683:2017 is relevant and accommodates all SBH of H. itama species produced in Peninsular Malaysia. Furthermore, the trehalulose range calculated in this study can be implemented as a new benchmark for the indicator of SBH honey quality standard by national and international food standard committees