Modeling and optimization of flank wear and surface roughness of Monel-400 during hot turning using artificial intelligence techniques

This work aims to model and investigate the effect of cutting speed, feed rate, depth of cut and the workpiece temperature on surface roughness and flank wear (responses) of Monel-400 during turning operation. It also aims to optimize the machining parameters of the above operation. A power-law model is developed for this purpose and is corroborated by comparing the results with the artificial neural network (ANN) model. Based on the coefficient of determination (R2), mean square error (MSE), and mean absolute percentage error (MAPE) the results of the power-law model are found to be in close agreement with that of ANN. Also, the proposed power law and ANN models for surface roughness and flank wear are in close agreement with the experiment results. For the power-law model R2, MSE, and MAPE were found to be 99.83%, 9.9×10-4, and 3.32×10-2, and that of ANN were found to be 99.91%, 5.4×10-4, and 5.96×10-2, respectively for surface roughness and flank wear. An error of 0.0642% (minimum) and 8.7346% (maximum) for surface roughness and 0.0261% (minimum) and 4.6073% (maximum) for flank wear were recorded between the observed and experimental results, respectively. In order to optimize the objective functions obtained from power-law models of the surface roughness and flank wear, GA (genetic algorithm) was used to determine the optimal values of the operating parameters and objective functions thereof. The optimal value of 2.1973 µm and 0.256 mm were found for surface roughness and flank wear, respectively

Tribological Characterisation of Graphene Oxide as Lubricant Additive on Hypereutectic Al-25Si/Steel Tribopair

The performance of a lubricant greatly depends on the additives it involves. However, recently used additives produce severe pollution when they are burned and exhausted. Therefore, it is necessary to develop a new generation of green additives. Graphene oxide (GO) is considered to be environmentally friendly. The scope of this study is to explore the fundamental tribological behavior of graphene, the first existing 2D material, and evaluate its performance as a lubricant additive. The friction and wear behavior of 0.5 wt% concentrations of GO particles in ethanol and SAE20W50 engine oil on a hypereutectic Al-25Si alloy disc against steel ball was studied at 5 N load. GO as an additive reduced the wear coefficient by 60–80% with 30 Hz frequency for 120 m sliding distance. The minimum value of the coefficient of friction (0.057) was found with SAE20W50 + 0.5 wt% GO. A possible explanation for these results is that the graphene layers act as a 2D nanomaterial and form a conformal protective film on the sliding contact interfaces and easily shear off due to weak Van der Waal's forces and drastically reduce the wear. Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and Raman spectroscopy were used for characterization of GO and wear scars

The desert hamsterPhodopus roborovskii (Satunin, 1903) (Rodentia, Cricetidae) from north-western Tibetan plateau, Ladakh, India: an addition to the mammalian fauna of the Indian subcontinent

During a systematic survey of the small mam-mals in the relatively unexplored north-western regions of the Tibetan plateau in India, we captured and identified the desert hamster Phodopus roborovskii using molecular phylogenetic methods. We also provide revised distribu-tional estimates for this species using niche modelling (Maxent and 19 bioclimatic variables), taking into account sampling bias. We evaluated suitable habitats for the spe-cies, identifying regions in the Trans-Himalayas that may harbour this species. This study improves the knowledge of the desert hamster’s range and is a new record and an addition to the Indian sub-continental mammalian fauna, ~750 km southward extension from its known range

To Evaluate Antimicrobial Efficacy of Calcium Hydroxide Against Enterococcus Faecalis Either with or Without Natural Medicaments

Aim: Antimicrobial effectiveness of calcium hydroxide against E. faecalis is the primary goal of this research, which aims to compare the effects of calcium hydroxide with and without the addition of turmeric and ocimum tenuiflorum extract. Ingredients and Procedure: Using calcium hydroxide and herbal extracts, the samples were divided into six groups. Normal saline, turmeric extract, and tulsi extract are in groups A1, B1, and C1 respectively. Calcium hydroxide and saline are in Group A; calcium hydroxide and turmeric extract are in Group B; and basil extract is in Group C. Enterococcus faecalis may be grown in brain heart infusion broth (BHI). Three equal-sized sets of media are placed in each of three wells with a diameter of 4 mm on each media plate. A sliding calliper is used to identify inhibitory zones after 1-2 days of incubation at 37°Celsius. Results: This study's statistical findings were generated entirely with SPSS version 18. P values of less than 0.04 were deemed significant. ANOVA and post hoc Games Howell tests were used to compare the mean inhibition zone