The Ultra-Violet Imaging Telescope (UVIT) is one of the payloads in ASTROSAT, the first Indian Space Observatory. The UVIT instrument has two 375 mm telescopes: one for the far-ultraviolet (FUV) ...channel (1300-1800 ), and the other for the near-ultraviolet (NUV) channel (2000-3000 ) and the visible (VIS) channel (3200-5500 ). UVIT is primarily designed for simultaneous imaging in the two ultraviolet channels with spatial resolution better than 1 8, along with provisions for slit-less spectroscopy in the NUV and FUV channels. The results of in-orbit calibrations of UVIT are presented in this paper.
Plants associate with communities of microbes (bacteria and fungi) that play critical roles in plant development, nutrient acquisition and oxidative stress tolerance. The major share of plant ...microbiota is endophytes which inhabit plant tissues and help them in various capacities. In this article, we have reviewed what is presently known with regard to how endophytic microbes interact with plants to modulate root development, branching, root hair formation and their implications in overall plant development. Endophytic microbes link the interactions of plants, rhizospheric microbes and soil to promote nutrient solubilization and further vectoring these nutrients to the plant roots making the soil‐plant‐microbe continuum. Further, plant roots internalize microbes and oxidatively extract nutrients from microbes in the rhizophagy cycle. The oxidative interactions between endophytes and plants result in the acquisition of nutrients by plants and are also instrumental in oxidative stress tolerance of plants. It is evident that plants actively cultivate microbes internally, on surfaces and in soils to acquire nutrients, modulate development and improve health. Understanding this continuum could be of greater significance in connecting endophytes with the hidden half of the plant that can also be harnessed in applied terms to enhance nutrient acquisition through the development of favourable root system architecture for sustainable production under stress conditions.
This paper presents the design and performance analysis of Proportional Integral Derivate (PID) controller for an Automatic Voltage Regulator (AVR) system using recently proposed simplified Particle ...Swarm Optimization (PSO) also called Many Optimizing Liaisons (MOL) algorithm. MOL simplifies the original PSO by randomly choosing the particle to update, instead of iterating over the entire swarm thus eliminating the particles best known position and making it easier to tune the behavioral parameters. The design problem of the proposed PID controller is formulated as an optimization problem and MOL algorithm is employed to search for the optimal controller parameters. For the performance analysis, different analysis methods such as transient response analysis, root locus analysis and bode analysis are performed. The superiority of the proposed approach is shown by comparing the results with some recently published modern heuristic optimization algorithms such as Artificial Bee Colony (ABC) algorithm, Particle Swarm Optimization (PSO) algorithm and Differential Evolution (DE) algorithm. Further, robustness analysis of the AVR system tuned by MOL algorithm is performed by varying the time constants of amplifier, exciter, generator and sensor in the range of −50% to +50% in steps of 25%. The analysis results reveal that the proposed MOL based PID controller for the AVR system performs better than the other similar recently reported population based optimization algorithms.
•CH4 emission was increased by 26% in rice-fish than rice alone.•N2O emission was decreased by 9% in rice-fish with common carp than rice alone.•The GWP and CEE increased by 29.5% in rice-fish with ...common carp than rice alone.•Rice+common carp in rainfed shallow lowland is economic, higher C credit compliance.•Indian major carps (mrigal rohu and catla) emit less GHGs than common carp.
Four fish species namely, Cirrhinus mrigala H. (mrigal), Labeo rohita H. (rohu), Cyprinus carpio L. (common carp) and Catla catla H. (catla) were introduced along with rice (Oryza sativa L.) cv. Varshadhan, in a rainfed shallow (0–25cm water depth) Inceptisol to evaluate the effect of fish species on methane (CH4) and nitrous oxide (N2O) emission in a rice-fish farming system. On seasonal basis, the emission of CH4 was significantly higher by 26% under rice-fish co-culture compared to rice alone. The maximum emission of CH4 (36% higher) was found under rice+common carp farming. On contrary, the emission of N2O was significantly lower by 9% under rice-fish compared to rice alone. Although the global warming potential (GWP) was highest (29.5% more) in rice+common carp, the CH4 and N2O emission from this treatment per unit of total yield (rice+fish) were at par and significantly lower, respectively, compared to rice alone. Further, it provided significantly higher yield (rice+fish) and economic benefit over rice and other rice+fish species combinations. The integration of common carp with rice in rainfed shallow lowland ecology is thus, one of the viable options for livelihood of the small and marginal farmers besides, higher carbon (C) credit compliance. However, Indian major carps, mrigal rohu and catla in order, are potentially less harmful in terms of GHGs emission in shallow rice fields besides, higher profitability and carbon credit compliance compared to rice farming alone.
Similarity solutions are obtained for one-dimensional cylindrical shock wave in a self-gravitating, rotational axisymmetric non-ideal gas with azimuthal or axial magnetic field in the presence of ...conductive and radiative heat fluxes. The total energy of the wave is non-constant. It is obtained that the increase in the Cowling number, in the parameters of radiative as well as conductive heat transfer and the parameter of the non-idealness of the gas have a decaying effect on the shock wave however increase in the value of gravitational parameter has reverse effect on the shock strength. It is manifested that the presence of azimuthal magnetic field removes the singularities which arise in some cases of the presence of axial magnetic field. Also, it is observed that the effect of the parameter of non-idealness of the gas is diminished by increasing the value of the gravitational parameter.
Poly(ethylene oxide), PEO, based solid polymer electrolyte with different loadings of a lithium salt, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), has been investigated to study the role ...of PEO–Li cross-linking on segmental dynamics and free volume structure of PEO which consequently determine thermal, mechanical, and ion conduction properties of the electrolyte. In order to investigate the interrelation between segmental dynamics, free volume structure, and ion conduction mechanism, broadband dielectric spectroscopy and positron annihilation spectroscopy have been employed. The ion conduction process in the polymer electrolyte has been explained according to Almond–West formalism considering two different universalities dominating at different temperature or frequency regimes. Ionic conductivity was observed to increase in a nonlinear trend with salt loading, confirming the additional role of the ion diffusion process. The present study has shown that segmental dynamics and free volume structure of PEO-electrolyte which primarily govern the ion diffusion process are interrelated. These have been invoked to explain the observed variations in ionic conductivity, crystallinity, ductility, and thermal stability of PEO–LiTFSI electrolytes.
The area lies between Hugli river in the northwest and Bidyadhari river in the east and includes the East Kolkata Wetlands. The East Kolkata Wetlands is included in the List of Wetlands of ...International Importance (“Ramsar List”), as per the Convention on Wetlands signed in Ramsar, Iran, in 1971. This wetland has been declared as a Ramsar site on the 19th August 2002 (Ramsar site no. 1208) and therefore has acquired an international status. The area is a part of the lower deltaic plain of the Bhagirathi-Ganga river system and is generally flat in nature. The sub-surface geology of the area is completely blanketed by the Quaternary fluviatile sediments comprising a succession of clay, silty clay, sand and sand mixed with occasional gravel. The Quaternary aquifer is sandwiched between two clay sequences. The confined aquifer is made up of moderately well sorted sand and reflects fluviatile environment of deposition. The regional groundwater flow direction is from east to west. Detailed geochemical investigations of 40 groundwater samples along with statistical analysis (for example, correlation and principal component analysis) on these chemical data reveal: (i) four types of groundwater quality, for example, good, poor, very poor and water unsuitable for drinking purpose, (ii) four hydrochemical facies which may be assigned to three broad types such as “fresh”, “blended”, and “brackish” waters, (iii) the evolution of the “blended” water is possibly due to hydraulic mixing of “fresh” and “brackish” waters within the aquifer matrix and/or in well mixing, and (iv) absence of Na-Cl facies indicates continuous flushing of the aquifer.
One-dimensional self-similar unsteady flows behind a spherical or cylindrical shock wave driven out by a piston moving with time according to a power law in a dusty gas is investigated. The medium is ...assumed to be the mixture of small solid particles of micro-size and a non-ideal gas. The solid particles are uniformly distributed in the mixture, and the shock wave is assumed to be driven by the inner surface (piston). It is assumed that the equilibrium flow-conditions are maintained and the moving piston continuously supplies the variable energy input. Similarity solutions exist only when the surrounding medium is of constant density. Solutions are obtained, in both cases, when the flow between the shock and the piston is isothermal or adiabatic. The shock waves in non-ideal dusty gas can be important for the description of shocks in supernova explosions, in the study of a flare produced shock in the solar wind, the central part of starburst galaxies, nuclear explosion, rupture of the pressurized vessel, in the analysis of data from exploding wire experiments, and cylindrically symmetric hypersonic flow problems associated with meteors or re-entry vehicles, etc. The findings of the present work provided a clear picture of whether and how the non-idealness of the gas and the presence of the magnetic field affect the propagation of shock and the flow behind it. It is interesting to note that in the presence of azimuthal magnetic field, the pressure and density vanish at the piston and hence a vacuum is formed at the center of symmetry for both the isothermal and adiabatic flows, which is in excellent agreement with the laboratory condition to produce the shock wave.
We demonstrated platinum nanomaterials with different morphologies to act as a potential nanocatalyst for polymer electrolyte fuel cell through one-step electrodeposition.
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In the ...present work, the three-dimensional ultra-fine platinum nanoflowers are directly deposited on carbon-coated gas diffusion layer electrode (C-GDL) by a single-step electrodeposition method towards the application of polymer electrolyte fuel cells. The surface morphology, particle size distribution, crystallinity, and chemical oxidation state of platinum nanoflowers are examined using various techniques. The morphological features of the Pt nanostructures are highly influenced by the difference in current density. Notabely, the Pt nanospheres converts into three-dimensional nanoflower with an increase in current density from −1.6 to –32 mA cm−2. Electrodeposited Pt catalyst on C-GDL as the cathode catalyst was fabricated and steady-state polarization studies were carried out. Mainly, the fuel cell performance is analysed considering the electrodeposited Pt morphology. Among the prepared electrocatalysts, the nanoflower shaped Pt catalyst exhibit a high peak power density of 660 mW cm−2 at 0.6 V in PEFC.
While the similarity methods through shock waves are spaciously explored in a dust-filled gas, the implications of magnetism and gravity in a dust-filled non-ideal gas, considering thermal conduction ...as well as radiation flux, were not addressed before. This document is about the self-similar flow solutions originated via a travelling piston in a dust-filled non-ideal gas considering increasing energy, gravity field, variable magnetic (axial or azimuthal) field, thermal conduction, and radiation flux. It has been established that the magnetic field existence has an emaciating impact on the strength of the shock. The compression of the media is lessened by a growth of the gravitational factor at every location in the flow zone behind the shock. The non-ideal nature of gas allows shock intensity to decrease and enlarges the extent between the piston and the shock. It is worthwhile noting that the pressure and density, in the piston, dissipate in the existence of an azimuthal magnetic field; and thus the vacuum forms at the centre of symmetry that is in perfect accordance under the environment of laboratories to generate the shock wave.
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