A hybrid lubricant with improved thermal and tribological properties was developed by blending multiwalled carbon nanotubes (MWCNTs) with alumina-based nanoparticles into cutting fluid at fixed ...volumetric proportions (10:90). The hybrid cutting fluid was prepared in different volumetric concentrations (0.25, 0.75, and 1.25 vol%), and the tribological properties and contact angles were measured using pin-on-disc tribometry and goniometry, respectively. The study showed a reduction in wear and friction coefficient with increasing nanoparticle concentration. The cutting fluid performance was investigated using minimum quantity lubrication (MQL) in the turning of AISI 304 stainless steel. Regression models were developed for measuring the temperature and tool flank wear in terms of cutting speed, feed, depth of the cut, and nanoparticle concentration using response surface methodology. The developed hybrid nanolubricants significantly reduced the tool flank wear and nodal temperature by 11% and 27.36%, respectively, as compared to alumina-based lubricants.
In the manufacturing industry, during machining, the conventional cutting fluid plays a vital role; however, extravagant use of cutting fluids due to its disposal affects the environment badly. ...Nowadays, due to these advantages of conventional cutting fluids, alternative methods of conventional cutting fluids or alternative methods are preferred. One of the most preferred methods may be the minimum quantity lubrication technique with conventional or nanoparticle-enriched cutting fluids. The present paper has a compilation of the investigations based on MQL application in different machining processes such as turning, milling, grinding, and drilling. The machining also involves hard-to-machine alloys. The paper discusses cryogenic MQL in brief and opens the domain for work in future. The purpose of this paper is to provide a quick reference for researchers working on the practical use of MQL lubricants with nanopowders dissolved and their application in machining for different materials.
Ablative composites serve as sacrificial materials, protecting underlying materials from high-temperature environments by endothermic reactions. These materials undergo various phenomena, including ...thermal degradation, pyrolysis, gas generation, char formation, erosion, gas flow, and different modes of heat transfer (such as conduction, convection, and radiation), all stemming from these endothermic reactions. These phenomena synergize to form a protective layer over the underlying materials. Carbon, with its superb mechanical properties and various available forms, is highlighted, alongside phenolics known for good adhesion and fabric ability and elastomers valued for flexibility and resilience. This study focuses on recent advancements in carbon-and-phenolic and carbon-and-elastomeric composites, considering factors such as erosion speed; high-temperature resistance; tensile, bending, and compressive strength; fiber–matrix interaction; and char formation. Various authors’ calculations regarding the percentage reduction in linear ablation rate (LAR) and mass ablation rate (MAR) are discussed. These analyses inform potential advancements in the field of carbon/phenolic and carbon/elastomeric ablative composites.
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•CR4 cold rolled steel sheet has been air bent.•XRD peak broadening analysis has been conducted for different samples.•CR4 steel sheet has compressive lattice strain, in all the three ...orientation.•Lattice strain increases after air bending across thickness.•Results about lattice strain are highly useful for industries.
In this study, the effect of orientation and bending has been investigated on CR4 steel for lattice constant, crystallite size and lattice strain. The one mm thick sheet of CR4 steel was bent through air-bending. The samples were prepared by using wire electric discharge machining (WEDM) followed by polishing for X-ray diffraction study. The peaks were analysed using QualX 2.1 software and lattice constant was analysed using Bragg’s law and lattice strain using Williamson-Hall’s method. Result shows, lattice constant is smallest on rolled face and after bending it increases along thickness. Whereas, the lattice strain is compressive in nature for all three orientations. However, for 0°orientation lattice strain (0.5%) is more across the thickness as compared to 90°orientation lattice strain (0.34%). Crystallite size was analysed by Scherrer’s method and Williamson-Hall’s method. Williamson-Hall’s crystallite size is observed to be smaller than Scherrer’s crystallite size. Further, crystallite size is observed to be the smallest on the rolled face. Moreover, after bending force application, enhancement in the lattice strain is observed while the size of the crystallite is reduced noticeably.
Remarkable progress has been established in the field of nanoenergetic materials (mixture of nanoscale fuel and oxidizer) since the advent of nanotechnology. Combustion of nanoenergetic materials ...depends on many key factors like synthesis route, equivalence ratio, morphology of constituents, and arrangements and handling of materials. For tailoring and tuning of the combustion properties of nanoenergetics, sound knowledge of the reaction mechanism is needed; in this review article a schematic study on the reaction mechanism is presented. By employing various routes and strategies in synthesizing and nanoengineering of the fuel or/and oxidizer to realize a significant evolution from normal physical mixing of nanopowders to the formulation of core/shell nanostructures, the nanoenergetic materials achieved the best ever combustion properties in terms of combustion reactivity, ignition sensitivity, energy density, etc. Overall, in this article, a critical state-of-the-art review of the existing literatures has been conducted to feature the main developments in the molecular combustion modeling of melting, oxidation, and core-shell reaction/diffusion of nanoaluminum and the molecular modeling of combustion reactivity and ignition sensitivity of nanoenergetic materials.
In this study, epoxy resin blended with graphite/talc micro fillers are used to fabricate the composite bearing balls of uniform diameter of 12.7 mm. These bearing balls were tested in four ball test ...rig for investigation of friction and wear. The fabricated composite bearing ball of composition graphite (10 wt%) /talc (10 wt%)/epoxy demonstrated a significant reduction by ∼63% in coefficient of friction and a moderate increment by ∼34% in wear resistance as compared to pure epoxy bearing ball under dry condition. Further, the compressive strength and hardness test were carried out on the composite bearing balls which revealed a reduction in compressive strength after adding the fillers but approximately similar compressive strength and a marginal improvement in hardness by ∼5% was exhibited by graphite (10 wt%)/talc (10 wt%) /epoxy composite bearing ball with respect to pure epoxy bearing ball. Hence, the fabricated polymer composite bearing balls can be implemented for low to moderate load bearing application with enough capability to eliminate the bulk lubrication requirements as in case of conventional metallic bearing balls.
Urdbean or blackgram is one of the important multi‐season pulse crops grown in India. Improved seed quality and resistance to Mungbean yellow mosaic India virus (MYMIV) are the important objectives ...of the urdbean breeding program. For this, knowledge of inheritance for seed quality traits and MYMIV resistance is essentially required. Therefore, an attempt has been made to understand the inheritance of seed traits like seed luster, seed coat color, mosaic on seed surface, and MYMIV reaction using intra‐ and inter‐specific bi‐parental populations. The inheritance results revealed that in DPU88‐31 × LBG‐685 population, the shining seed registered dominance over the dull trait, while the green seed coat color exhibited dominance over the brown seed coat color. However, the inter‐specific F2 population derived from IPU11‐02 × Pant M 6 deviated significantly from Mendelian ratios and supported severe segregation distortion for seed traits, while the mosaic on seed coat or mottling character studied in interspecific population demonstrated a dominant digenic inheritance pattern. In five inter‐ and intra‐specific F2 populations, MYMIV resistance demonstrated monogenic dominant inheritance, which was also validated in F3 generations. Furthermore, linkage analysis exhibited an association between seed luster and seed coat color, while no association was noticed between seed traits and MYMIV resistance. The normality tests revealed that seed width and 100 seeds weight were controlled by a few major genes, while other quantitative traits were governed by many genes with small additive effects. The skewness suggested that complementary gene interactions were present among genes controlling 100 seed weight in the intra‐specific cross, while duplicate gene interactions were involved in the inter‐specific cross. The identified monogenic traits and linked morphological marker after further enrichment of the linkage group could be used as an important tool in the regular breeding program.
A series of tetrahydro-β-carbolines and 1,3,5-triazine hybrids have been synthesized and evaluated for their cytotoxicity against a panel of eight human cancer cell lines and normal human fibroblasts ...(NIH3T3). It led us to discovery of racemic compounds
69,
71 and
75, which are selectively cytotoxic towards KB (oral cancer) cell line with IC
50 values of 105.8, 664.7 and 122.2 nM, respectively; while their enantiopure forms are less active and not selective. Enantiopure compound
42 showed 2.5 times more selectivity towards MCF7 cells over normal fibroblast NIH3T3 cells with an IC
50 value of 740 nM, also arrests cell cycle in G
1 phase and induces apoptosis in MCF7 and MDA MB231cell lines.
A series of tetrahydro-β-carbolines and 1,3,5-triazine hybrids have been synthesized and evaluated for their cytotoxicity against a panel of eight human cancer cell lines and normal human fibroblasts (NIH3T3).
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