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Doping in pristine 2D materials brings about the advantage of modulating wide range of mechanical properties simultaneously. However, intrinsic defects (such as Stone-Wales and nanopore) in such hybrid materials are inevitable due to complex manufacturing and synthesis processes. Besides that, defects and irregularities can be intentionally induced in a pristine nanostructure for multi-synchronous modulation of various multi-functional properties. Whatever the case may be, in order to realistically analyse a doped graphene sheet, it is of utmost importance to investigate the compound effect of doping and defects in such 2D monolayers. Here we present a molecular dynamics based investigation for probing mechanical properties (such as Young’s modulus, post-elastic behaviour, failure strength and strain) of doped graphene (C14 and Si) coupling the effect of inevitable defects. Spatial sensitivity of defect and doping are systematically analyzed considering different rational instances. The study reveals the effects of individual defects and doping along with their possible compounded influences on the failure stress, failure strain, Young’s modulus and constitutive relations beyond the elastic regime. Such detailed mechanical characterization under the practically relevant compound effects would allow us to access the viability of adopting doped graphene in various multifunctional nanoelectromechanical devices and systems in a realistic situation.

Despite the tremendous capabilities of Molecular dynamics (MD) simulations, they suffer from the limitation of computationally intensive and time-consuming nature. This hinders the seamless discovery of nanomaterials with adequate computational insights. Over the last decade, graphene has received widespread attention from the scientific community due to its extra-ordinary multi-physical properties, primarily focusing on the fundamental physics and chemistry along with the notion of scalable synthesis. However, the recent advances in machine learning have opened new frontiers in the research of such exceptional two-dimensional materials where the boundaries of different multi-physical properties could be pushed further efficiently with the assistance of deep computational intelligence. Here we propose a coupled machine learning (ML) based approach to investigate the critical mechanical responses of graphene by capturing the underlying physics of the system through an (D-)optimally minimum number of MD simulations. We have investigated five different internal and external controlling input features like temperature, strain rate, nanostructural defects, doping, and chirality, which influence the critical mechanical properties of graphene such as the constitutive behavior including fracture strength, failure strain and Young's modulus. Even though the aspect of computational intensiveness in molecular dynamics simulations is addressed through the coupled ML based approach, in a data-driven comprehensive analysis, it is often difficult to get complete information about the concerning input parameters including their statistical distributions and occurrence bounds. Thus, it becomes difficult to carry out computational investigations based on powerful techniques like Monte Carlo simulation. To mitigate this lacuna, here we have exploited the ML-assisted approach for developing a level-based fuzzy framework at nano-scale under sparse input descriptions. In this article, we first demonstrate the computational efficiency achieved through the proposed ML based framework without compromising quality of the analysis, followed by data-intensive correlation analysis, sensitivity and uncertainty quantification considering various levels of the influencing system parameters, revealing detailed computational insights on mechanical properties of graphene including the coupled interactive influence of intrinsic defects and doping.

The utility of carbon nanotubes as the reinforcement agents in polymer and metal matrix composites has opened up a new avenue in the development of novel composite materials with exceptional strength and stiffness to weight ratios. Such exploitation of superior mechanical properties of carbon nanotubes depends on their inherent irregularities and structural integration. The nanotubular structures of carbon are prone to topological defects and heteroatom dopants due to the inevitable complexities in nano-synthesis. The objective of this article is to quantify the compound influence of such inherent structural irregularities (such as single vacancy defects and nanopores) and foreign atom inclusions (such as nitrogen and boron atoms) on the mechanical characteristics (like constitutive relation, fracture strength, failure strain and Young’s moduli) of single-walled carbon nanotubes (SWCNT) under various multi-physical influences (such as temperature, strain rate, diameter and chirality) based on molecular dynamics (MD) simulations. The current investigation also includes a detailed analysis on the variation in mechanical characteristics of CNTs under different spatial distributions of defects and doping.

The cause for the failure of an air compressor has been investigated. It was found that a pre-existing fatigue crack was present at the root of the impeller blade. Transients and unsteady operation of the equipment prior to the accident are thought to have grown the fatigue crack to its critical size, thereby causing an imbalance in the impeller rotation and leading to failure.

N,N-dialkyl aliphatic amides with varying alkyl groups have been compared with organophosphorous extractants, tri-n-butyl phosphate (TBP) for third phase formation behavior during the extraction of Th(IV) and U(VI) from nitric acid medium. Dihexyl decanamide (DHDA) appears to be better in comparison to TBP with respect to third phase formation during thorium extraction. The effects of aqueous phase acidity and the nature of diluents on the third phase formation are studied. The limiting organic phase concentration (LOC) values for U(VI) and Th(IV) with branched chain, di(2-ethylhexyl) isobutyramide (D2EHIBA) increased with ligand concentration, while the critical aqueous concentration (CAC) values of metal ions decreased.

The failure of a high mast lamp post was analysed. The mast failed by bending at a position just opposite to the maintenance pocket. It appears that the failure was due to wind load, which the structure could not bear. The elemental analysis and mechanical properties determination of the failed mast materials was as per the recommended values. However, the mechanical properties were slightly higher compare to recommended values and this is because of the presence of very fine pearlite in the microstructure. The probable causes might be due to faulty installation and/or damage during installation, severe weather condition or events such as high-speed storm, etc. or fatigue caused by the unpredictable phenomenon of harmonic vibration.

Andrographis paniculata (Burm.f.) Nees (Acanthaceae), commonly known as Kalmegh is used both in Ayurvedic and Unani system of medicines for a number of ailments related to digestion, hepatoprotection, hypoglycemic, and as anti-bacterial, analgesic, anti-inflammatory, vermicidal and antiacene. Ten accessions of A. paniculata from different sources were screened to assess the yield and its components besides andrographolides on three harvesting dates viz. 70, 100, 130 days after plantation corresponding to calendar months of September, October and November. The results revealed its successful growth in the subtropical region of Jammu, with last week of October ideal for obtaining maximum dry herbage (931.3 kg/ha) and total andrographolide yield (61.83 kg/ha), respectively. On the basis of leaf/stem ratio the relative estimates of total andrographolide is higher in October (46%) than September (15%) or November (39%). Accession Acc.1 and Acc.9 have been identified as the best sources for obtaining higher drug yield.

The complex permittivity at 8.93 GHz static permittivity and high frequency limiting permittivity have been determined for pyridine and piperidine in dilute solution of benzene at 303, 313, 323 and 333K. The relaxation time values and the dipole moment values have been calculated from the dielectric data. Various thermodynamical parameters have also been calculated for dielectric relaxation as well as for the viscous flow processes. All these physical parameters are interpreted in terms of the effect of structural change between pyridine and piperidine. The study reveals the existence of both the intramolecular and overall orientations in piperidine while only a single relaxation process in pyridine. The comparative study of enthalpies of activation for the dipolar relaxation and the viscous flow suggests the absence of any solid rotator phase in the piperidine molecule but it is expected to exist in pyridine.

In order to study the dielectric behaviour of isolated molecules, measurements of dielectric parameters: static permittivity (ϵ0) at frequency 100 KHz., high frequency limiting permittivity (ϵ∞) at frequency of the D-lines of sodium, permittivity (ϵ′) and loss factor (ϵ″) at frequency 8.93 GHz., have been made on the two rapeseed-mustard oil varieties i.e. Hyola-401 and PCR-7 in dilute solutions of benzene at 30, 40, 50 and 60°C. The relaxation times have also been determined from the measured data. The present study suggests the existence of both the intramolecular and overall orientation in the triglyceride molecules of both the samples under investigation. The results indicate that relaxation times τ(1) and τ(2) are larger for PCR-7 oil molecules as compared to that of Hyola-401 oil. These are explained on the basis of chain length of the fatty acid present as a major constituent in the respective oil samples. The effect of temperature variation on these relaxation times is also discussed in terms of the effect on chain length and intermolecular cooperative relaxation.

A spectrophotometric method has been developed for the determination of uranium(VI) using ascorbic acid. Uranium in the hexavalent state forms a reddish-brown coloured complex with ascorbic acid. The colour intensity of the complex is maximum at pH 4.2–4.5 and is stable for 24 hr. The absorbances of uranium(VI)—ascorbic acid complex at 360 and 450 nm are used for its quantification. Uranium in the range 8–200 μg/ml has been determined with good precision. The method allows the determination of uranium in the presence of many metal ions present as impurities. The described method is simple, accurate and applicable to uranium concentration relevant to the PUREX process and thus can be used for analytical control purposes.

The theoretical status of hadrons as quark composites is examined from the point of view of a simultaneous understanding of their on-shell (mass spectra) and off-shell (form factors, transition amplitudes) properties. To that end we first offer a perspective view of the emerging scenario in quark physics since the seventies, preceded by a quick overview of some important ideas and models in the pre-QCD phase that were to determine the shape of the subsequent (post-QCD) developments. The primary emphasis is on theoretical approaches to effective confinement (pending a formal resolution of the confinement problem within a QCD-Lagrangian framework, Lattice or otherwise), in providing a fuller perspective from high to low energy physics or vice-versa. To that end greater stress is laid on light quark systems which are more sensitive to the confinement regime, and more prone to relativistic effects than on heavy quarkonia (on which many reviews exist). Two broad theoretical approaches obeying Lorentz and gauge invariance are identified: (i) QCD sum rules as a means of extrapolation from high to low energies; and (ii) dynamical equations for providing a microcausal link in the opposite direction (from low to high energies). The latter represents the major focus of attention in this article, with the Bethe-Salpeter Equation (BSE) providing a formal plank for a comparative assessment of several models. The Null-plane ansatz which facilitates the reduction of the 4-D BSE to a covariant 3-D form also provides the language for its comparison with other covariant 3-D equations. In particular, attention is drawn to the interesting possibility of reconstructing the 4-D BS wave function from its 3-D form (in a two-tier fashion) as a practical tool for generating higher Fock-space components ( q q effects ) in the BS wave function, and (more interestingly) for a clean separation between soft and hard QCD effects. To illustrate one such practical tool for an integrated view of different hadronic sectors within a single framework, the results of a two-tier BS model are presented in respect of q q , qqq, gg, ggg, gq q states and compared with experiment as well as with the results of other contemporary models. The N.R Resonating Group Method, which becomes necessary for bigger (six-quark) systems is briefly discussed from the point of view of its compatibility with a relativistic form of quark dynamics motivated from the BSE.

Chromatographic separation of the petrol extract of Andrographis paniculata roots resulted in the isolation and characterization of two new flavonoids, 5-hydroxy-7,8-dimethoxyflavanone and 5-hydroxy-3,7,8,2′-tetramethoxyflavone, as well as the known flavonoid 5-hydroxy-7,8-dimethoxyflavone.