The present investigation deals with the utilization of Watermelon rind (WR) as a prolific adsorbent for the removal and recovery of Ce (III) and Pr (III) ions from aqueous solution. The processed WR was used in the batch adsorption studies for optimizing the variables such as pH, contact time, dose and initial metal ion concentration. The maximum loading capacity of the WR was calculated to be 56.8 and 55.3 mg g(-1) for Ce (III) and Pr (III) ions respectively. The equilibrium tends to fit well with Langmuir and Freundlich isotherms and pseudo second order kinetic model and further the system is spontaneous and exothermic in nature. The WR has capability of repeated usage which was evidenced from desorption studies. In conclusion, the WR is a potential adsorbent for the sequestration of Ce (III) and Pr (III) ions from aqueous solution. (C) 2021 Elsevier Ltd. All rights reserved.

This study reports the use of hydrophobic ionic liquid (IL) based on D-galactose for the recovery of Ce (III) and Pr (III) ions from solutions. The equilibrium data were obtained by optimization of batch parameters, and various isotherms and kinetic models were utilised to predict the mechanistic process of sequestration of ions. The Arrhenius activation energies are found to be between 5–40 kJ, suggesting the physisorption process of ions onto IL. The present process is understood to be rapid and exothermic in nature according to thermodynamic experiments. The loading capacity was found to be 179.3 g L−1 and 141.5 g L−1, respectively, for Ce (III) and Pr (III) ions at pH 5 with a contact time of 30 min and dose being 0.1 g L−1. The higher uptake capacity is attributed to the presence of a highly electronegative fluorine atom in the IL. These results highlight the potential application of IL in the sequestration of Ce (III) and Pr (III) ions from any water sources.

Cyclohexanol (C6H13–OH) is an advanced biofuel derived from ligno-cellulosic biomass that is suitable for compression ignition engine with several properties closer to fossil diesel. This study analyzes the emissions of a direct-injection (DI) diesel engine fueled with cyclohexanol/diesel blends containing 10% (CHX10), 20% (CHX 20), and 30% (CHX30) by volume and an investigate carried out naturally aspirated, exhaust gas recirculation (EGR) 0, 10 and 20% and varying the injection timings 19°, 21° and 23° CA bTDC. According to the experimental results, the CO emissions decreased in CHX20 blend at 21° CA bTDC compared to pure diesel, the HC emissions decreased in CHX30 blend at 21° CA bTDC compared to pure diesel, the NOx emissions lower in 21° CA bTDC at all test blends, and the smoke opacity lower in 23o CA bTDC at all test blends. This investigation concluded that the variation of injection timing and EGR had an extensive effect for reducing emissions characteristics of the diesel engine.

The agricultural waste and industrial waste are available in abundance globally and causes risk to health as well asthe environment.Thus, theireffective and eco-friendly utilization has always been a challenge for scientific applications. The need for high performance materials has caused a shift in research from monolithic to composite materials. This paper presents a study on the mechanical and tribological properties of stir cast aluminium matrix Hybrid composites (MMHC) containing reinforcements using both agricultural waste (coconut shell ash) and industrial waste (fly ash) of particle size 45-50μm at four different compositions. This study mainly focuses on automobile components which frequently fails due to poor wear resistance. Test samples were casted in four different composition by varying the volume fraction of metal matrix composite and coconut shell ash. Hardness test, tensile strength test, percentage elongation were carried out to find their mechanical properties. The results shows that significant Improvement in hardness and percentage of elongation as the weight % of coconut Ash increases in MMHC.It has been observed that tensile properties decreases, as the weight % of coconut ash increases in MMHC. The optical and scanning electron micrographs of the samples indicated uniform distribution of the reinforcement particles in the matrix without any voids.

In this work, the effect of sub-zero treatment on the mechanical properties of an Al–Si–Mg–Mn alloy welded by GTAW (gas tungsten arc welding) leads to significant softening in the welded region. The latter is due to melting and resolidification in the welded region, which have resulted in decomposition of the strengthening precipitates. The experiments were performed on GTAW welded plates of 6 mm thickness by varying the heat inputs, namely, of 370, 317.1, 277.5, 246.4, and 222 J/mm, and sub-zero treatment time periods. The Sub-Zero treatment was performed at–45°C using dry ice; hardness and microstructure investigations were performed in the welded region of the Al‒Si–Mg–Mn alloy that was studied in two different conditions, namely, as-welded and in that formed after post weld sub-zero treatment with artificial aging. It was found that the post weld Sub-Zero treatment followed by artificial aging had led to realization of significantly higher hardness values in the welded region due to the recurrence of the precipitation sequence.

The consequence of sub-zero treatment on the mechanical properties of welded AA6082-T6 by Gas Tungsten Arc Welding (GTAW) which in turn softens the heat concentrated welded region owing to dissolution of the strengthening precipitates. The sub-zero i.e. Shallow Cryogenic Treatment (SCT) is carried out on GTAW welded plate having a thickness of 6 mm at -77°C by varying the electrode travel speed and sub-zero treatment periods. Welded region of AA6082 were tested for hardness and microstructure by adapting three different conditions such as welded, post weld artificial aging with and without sub-zero treatment. Result revealed that the amount of softening in the welded region is indirectly proportional to electrode travel speed during welding process. It is also observed that the post weld SCT with artificial aging has increased the micro hardness values on the welded region as a consequence of the reactivation in the sequence of precipitation.

In this study, the outcome of adding n-butyl alcohol to jatropha methyl ester on the emissions characteristics of compression ignition engines is investigated. Single cylinder diesel engine was fuelled with n-butyl alcohol / jatropha methyl ester blends. The doping volume of n-butyl alcohol to jatropha methyl ester blends was in the range of 10, 20 and 30%. Emission parameters such as Hydro carbon (HC), Carbon monoxide (CO), Nitrogen oxides (NOX) and Smoke emissions were examined at different load conditions. The engine speed was maintained constant throughout the trail. This work resulted in a significant reduction in reduction in all the emissions. Addition of n-butyl alcohol as additive improves the rate of combustion, mixing and vaporization of the blends with air and reduces the emissions associated with it. Further, it can be used in the existing engine with any modification. This also results that the addition of n-butyl alcohol to jatropha methyl ester reduces the emissions associated with it. Further, no damage to engine components was observed during the trail.