Experimental evaluation of physicochemical properties and tapping torque of hexagonal boron nitride in modified jatropha oils-based as sustainable metalworking fluids

In consideration of the important role of environmentally begin metalworking fluid (MWF) in the machining industry, jatropha oil has been acknowledged as a suitable type of lubrication based oil. Despite its advantages, crude jatropha oil (CJO) had its main drawback in terms of poor thermaloxidative stability due to the presence of unsaturated molecules that leads to oxidation reaction. The objective of this study was to evaluate the physicochemical properties and tapping torque of newly developed modified jatropha oils (MJOs). Initially, CJO was chemically modified through the transesterification process at various molar ratios of jatropha methyl ester (JME) to trimethylolpropane (TMP) to produce a series of MJOs denoted as MJO1, MJO3, and MJO5. Hexagonal boron nitride particles at concentrations of 0.05, 0.1 and 0.5 wt% were mixed with the MJOs. MJOs with and without hBN particles were analysed based on the physicochemical testing (i.e., acid value, viscosity, viscosity index (VI) and flash point) and tapping torque test (i.e., tapping torque, thrust force and tapping torque efficiency). Experimental results showed an improvement of physicochemical properties of these newly developed MWFs with the increase in JME:TMP molar ratio and concentration of hBN particles. MJO5 displayed the best physicochemical properties with the highest VI of 196, compared with MJO3 and MJO1. The addition of 0.5 wt% of hBN particles in MJO5 (MJO5c) caused the highest VI achieved at 228, compared with the other samples. The average tapping torque and thrust force were reduced approximately by 15% and 45%, respectively using MJO5a (0.05 wt% of hBN particles with MJO5), compared with SE. MJO5a also demonstrated an improvement of 118% tapping torque efficiency that indicated an excellent machining performance. In conclusion, MJOs containing hBN particles showed better performances on the lubricating property. Among the samples, MJO5a could be proposed to substitute synthetic ester as a sustainable MWF for machining processe

Performance of modified jatropha oil in combination with hexagonal boron nitride particles as a bio-based lubricant for green machining

This study evaluates the machining performance of newly developed modified jatropha oils (MJO1, MJO3 and MJO5), both with and without hexagonal boron nitride (hBN) particles (ranging between 0.05 and 0.5 wt%) during turning of AISI 1045 using minimum quantity lubrication (MQL). The experimental results indicated that, viscosity improved with the increase in MJOs molar ratio and hBN concentration. Excellent tribological behaviours is found to correlated with a better machining performance were achieved by MJO5a with 0.05 wt%. The MJO5a sample showed the lowest values of cutting force, cutting temperature and surface roughness, with a prolonged tool life and less tool wear, qualifying itself to be a potential alternative to the synthetic ester, with regard to the environmental concern

The performance of modified jatropha-based nanofluid during turning process

The industry's extensive use of petroleum-based metalworking fluid (MWF) harms the environment and humans. The production of bio-based MWF, especially from crude jatropha oil (CJO), has therefore taken numerous initiatives. This aimed to formulate newly modified jatropha oil (MJO) with the addition of 0.05wt.% hBN and 0.05wt.% MoS2 as the nanofluid for MWF. The performance of the nanofluids was determined through the turning process in terms of cutting temperature, workpiece surface roughness, tool life and tool wear of the tool lubricated by the nanofluids. The performance of the nanofluid samples was compared with the synthetic ester (SE). From the results, after conducted 100mm axial cutting length MJO+hBN+MoS2 recorded the lowest in cutting temperature and surface roughness compared to all samples. The result shows that MJO+hBN+MoS2 has longer tool life (6500mm) compared to SE (6000mm). Abrasion and adhesion were observed as the dominant tool wear mechanism. In conclusion, MJO+hBN+MoS2 shows better machining performance and has the potential to be an environmentally friendly metalworking fluid

Developmental research of sustainable technologies to minimise problematic road embankment settlements

Challenging, problematic and non-uniform ground conditions are a night mare to geotechnical engineers tasked with the design and construction of buildings and transport infrastructure. These often suffer undesirable structural settlements. Designing within the current understanding of geotechnics; settlement in peat and organic soils need to be recognised to include the known “primary and secondary consolidation characteristics” and the lesser known “tertiary consolidation phase”. These eventually contribute cumulatively to the consequential uneven and hazardous “bumpy road” surfaces. Undulating flexible road pavements result primarily from the transference of the heavy self-weight of the embankment fill to yielding and non-uniform subgrade. The adoption of conventional design/repair methods such as pile, vertical drain, soil replacement and soil stabilisation are expensive and inappropriate in very soft ground conditions. These then lead to unjustifiably high and repetitive maintenance costs. There being no one quick fix solution for all; pragmatic research must necessarily identify the best/progressively improved practical and sustainable solution. A viable solution is to develop criteria and explore the concept of a “masonry arch bridge structure/lintel-column structure” and adopting sustainable materials through pragmatic searching for appropriate recyclable waste materials. This will lead to the basis for a sustainable, innovative, strong, stiff, permeable composite mat structure that can be used on soft and/or yielding ground conditions. Conceptual lightweight fill technology including the popularly used expanded polystyrene (EPS) and the innovative composite mats recently being developed by the research team are outlined

Optical and electrical characteristics of (LiCl)x(P2O5)1-x glass.

Homogeneous (LiCl) x (P2O5)1 − x glasses were synthesised using a melt-quenching method for x = 0.1–0.6 in the interval of 0.05. The amorphous structure of the samples was evident by the X-ray diffraction spectrum. The short range structures of the binary phosphate samples were examined by Fourier transform infrared spectroscopy, whilst the density of the samples was measured as supportive data for the investigations. The results of refractive indices as measured using an ellipsometer reveal the homogeneity of samples and was found to depend on the glass composition. The electrical properties of the glasses were investigated by ac impedance spectroscopy from 10 mHz to 1 MHz for temperatures ranging from room temperature to 573 K. An estimation of the bulk resistivity was obtained by taking the intercepts on the real axis at low frequencies of the complex impedance plot. The dc conductivities derived from the reciprocal of resistivity values were found to obey the Arrhenius relationship, and its activation energy shows a decreasing trend with the increase in LiCl content in the glass. Lastly, an equivalent circuits consisting of real and complex capacitors is proposed to describe the dielectric response of the glass

Turning Natural Fiber Reinforced Cement Composite as Innovative Alternative Sustainable Construction Material: A Review Paper

In recent years, a great deal of interest in concrete leads to the most frequently used sustainable construction material. Using of natural fiber as fiber reinforcement effectively improved strength, ductility and durability requirements of high performance cement composites. Regretly, natural fibers are dumped as agricultural waste (e.g. coconut, bamboo, wood or chips, bast fiber, leaf fiber, seed and fruit fibers, etc), so can be easily available low cost. The applications of natural fiber for sustainable construction material design can be done as filler or masonry composites, reinforcement, thermal conductivity, cementations/binder, etc. Previous and current researchers focusing the natural fiber to improve the properties of lightweight composites still required a lot of investigations to make it improved. However, the present work consists of the availability of natural fiber waste substance, sustainable construction materials are evaluated for their physico-mechanical properties of sustainable construction materials, method of production and environmental impact of several materials. No doubt, the application of natural fiber provides a solution to conservation of natural resource and energy

Mechanistic approach for reducing the thickness of asphalt layer incorporating steel slag aggregate

This study aimed to evaluate the possibility of reducing the thickness of asphalt layer as a novel solution for the high density of asphalt layer incorporated with steel slag aggregate, which increase the cost of transportation. MechanisticEmpirical Pavement Design (MEPDG) approach was employed to evaluate the benefits of introducing polyvinyl alcohol fiber in terms of reducing the thickness of asphalt layer as well as the extension service life of asphalt layer. On the other hand, the correlation between creep strain slope (CSS) and secant creep stiffness modulus (SCSM) were assessed to provide a better evaluation and understanding concerning of the outputs of the dynamic creep test. The findings of this study showed that introducing polyvinyl alcohol fiber into the mixtures at the optimum content (0.5 kg/ton) have reduced the thickness of asphalt layer by approximately 10%. Additionally, polyvinyl alcohol fiber has increased the performance of the asphalt mixtures concerning of resilient modulus and dynamic creep. Furthermore, the correlation between CSS and SCSM was strong, which indicates that evaluation of permanent deformation using CSS and SCSM parameters provides better actual assessment than accumulation strain

The Distribution and Zonation of Barnacles Around Intertidal Shores of Penang Island

The intertidal shores around Penang Island were surveyed for the distribution of barnacles from 14th November 2011 to 31st January 2012. The sampling was done by using 20 cm x 20 cm transect to count the barnacles. Three replicates were taken for each zonation available of the intertidal areas; i.e. upper, middle, and lower zonations, at every sampling site. From the result, three species were identified, including Euraphia withersi and Chthamalus malayensis from Family Chthamalidae, and Balanus amphitrite amphitrite from Family Balanidae. Chthamalus malayensis was found to be most abundant among the three species with 44.24% of total population; and Tg. Tokong recorded the highest abundance of this species (28.22%). This was followed by Euraphia withersi with 38.77%; which was found to be densely populated at Gelugor (21.92%). Balanus amphitrite amphitritewas least abundant with only 16.99% and mostly found at Gurney Drive (26.24%).The distribution of the three species of barnacles also varied among the sampling locations. Gertak Sanggul recorded the highest relative abundance of all three species of barnacles at 18.01%; while the location with the least relative abundance of barnacles is Queensbay with 0.33%.Based on ‘Non-Supervised Artificial Neural Network' (ANN), distinct zonation was observed where Chthamalus malayensis was more dominant on the upper zonation; Euraphia withersi on the middle zonation; and Balanus amphitrite amphitrite on the lower zonation. The interaction betweenbarnacles with other barnacles leads to competitive exclusion and niche partitioning which created zonations among the species. Interspecies interaction that brought by predation also played a part in the distribution of barnacles. Apart from that, the distribution was affected by the sampling sites and humanactivities; such as embankment, land reclamation, and residential development

Changes of physical properties during microwave processing of sagon

This study was designed to investigate the best and efficient method of processing sagon, a traditional snack food, using a microwave oven. Microwave cooking was conducted at three output powers of 90, 170 and 340 W. The effects of salt and different formulations on physical (moisture, water activity, color, surface morphology) as well as sensory properties of sagon were also investigated. Microwave heating reduced the time of cooking and/or drying compared with that of conventional way. The color of sagon was solely dependent on microwave output power and sugar content; the higher the output power the lesser is lightness and the greater is redness and yellowness, but texture and surface roughness showed better at medium microwave heating (170 W) confirmed by the micrographs. Microwave processing of sagon having high sugar content (60%) in the formulation at rather higher output power (340 W) resulted in most preferred sagon compared with that of conventional one available in the local market. Addition of salt bought about slightly higher reading of water activity and moisture content