Minimization of entropy generation due to MHD double diffusive mixed convection in a lid driven trapezoidal cavity with various aspect ratios

Entropy generation minimization has significant importance in fluid flow, heat and mass transfer in an enclosure to get the maximum efficiency of a system and to reduce the loss of energy. In the present study, the analysis of mixed convection fluid flow, heat and mass transfer with heat line and mass line concept and entropy generation due to the effects of fluid flow, heat flow, mass flow and magnetic field in a trapezoidal enclosure with linearly heated and diffusive left wall, uniformly heated and diffusive lower wall, cold and nondiffusive right wall, adiabatic and zero diffusion gradient top wall have been reported. Parametric studies for the wide range of Prandtl number (Pr = 0.7 for air cooling system and Pr = 1000 for the engines filled with olive or engine oils), Rayleigh number (Ra = 103–105), aspect ratio (A = 0.5–1.5) and inclination angle of the cavity (ϕ = 45°–90°) have been performed, which help to construct the perfect shape of cavity in many engineering and physical applications so that the entropy is minimum to get the maximum efficiency of any system. The finite-difference approximation has been used to find out the numerical solutions. Biconjugate Gradient Stabilized (BiCGStab) method is used to solve the discretized nonhomogeneous system of linear equations

Stability of a functional equation in complex banach spaces

Using fixed point technique, in the present paper , we wish to examine generalization of the Hyers-Ulam-Rassias stability theorem for the functional equations f ( 2 x + i y ) + f ( x + 2 i y ) = 4 f ( x + i y ) + f ( x ) + f ( y ) (0.1) and f ( 2 x + i y ) − f (i x − 2 y ) = − 4 f (i x − y ) + f ( x ) − f ( − y ) (0.2) in complex Banach spaces .Publisher's Versio

Influence of thermal radiation on non-Darcian natural convection in a square cavity filled with fluid saturated porous medium of uniform porosity

Influence of thermal radiation on natural-convection flow in a square cavity filled with a porous medium of uniform porosity having isothermal vertical walls and adiabatic horizontal walls, has been studied numerically by using finite-difference method with staggered grid distribution. The simulation is performed by considering both Darcian and non-Darcian models. Governing momentum and energy equations are solved numerically to obtain velocity and temperature fields for various values of different physical parameters. It is seen that increasing the thermal radiation parameter enhances the local Nusselt number on the left vertical wall whereas the reverse effects are observed due to increase in the heat generating parameter when Ra = 109. The temperature at the mid-horizontal plane decreases with increase in the value of Rayleigh number up to a certain distance from the left vertical wall and beyond that distance the opposite trend is observed. The temperature at the mid-horizontal plane increases with increase in the value of heat generating parameter

Magnetic fields and young stellar objects in cometary cloud LDN 1616

LDN 1615/1616 and CB 28 (hereafter, L1616) together form a cometary globule located at an angular distance of about 8 degrees west of the Orion OB1 association, aligned roughly along the east-west direction, and showing a distinct head-tail structure. The presence of massive stars in the Orion belt has been considered to be responsible for the radiation driven implosion mode of star formation in L1616. Based on the latest Gaia EDR3 measurements of the previously known young stellar objects (YSOs) associated with L1616, we find the distance to this cloud of 384$\pm$5 pc. We present optical polarimetry towards L1616 that maps the plane-of-sky component of the ambient magnetic field (B$_{POS}$) geometry. Based on the proper motion of the YSOs associated with L1616, we investigate their plane-of-sky motion relative to the exciting star $\epsilon$ Ori. Using the Gaia EDR3 measurements of the distances and proper motions of the YSOs, we find two additional sources comoving with the known YSOs. One comoving source is HD33056, a B9 star and the other might be a young pre-main sequence star not reported in previous studies. The mean direction of B$_{POS}$ is found to follow the cloud structure. This could be the effect of dragging of the magnetic field lines by the impact of the ionizing radiation from $\epsilon$ Ori. Based on the pressure exerted on L1616, and the ages of the associated YSOs, we show that it could possibly be the main source of ionization in L1616, and thus the star formation in it

EXERCISE ON PRESCRIPTION AUDIT : A TOOL FOR PHARMACOLOGY PRACTICAL LESSON

To improve the understanding and perception about rational prescribing among the Undergraduate (UG) students, a record based study 'exercise on prescription audit' was undertaken as self-directed learning strategy. Study was conducted on Objectively Structured Evaluation of pharmacotherapy taking one year record of prescriptions in Bed Head Tickets (BHTs) of discharged Ophthalmic in-patients. Standard format for prescription writing, WHO guide to Good prescribing and Essential Medicines were followed to assess the in-patient prescriptions. Students improved markedly (p< 0.001) in audit of real prescriptions. Results revealed that 37 types of drugs were prescribed over 948 BHTs. Completeness of the prescription showed 100% perfection in maximum indicators with exception in judicious investigations (99.89%), medication information (89.32%) and relevant advices for patient (97.12%). Subsidiary or symptomatic drugs (56.76%) were prescribed more than the core drugs (43.24% of total drugs prescribed). Generic prescription was 54.05%. Study in turn improved the understanding and perception about rational prescribing among the students. The students gained knowledge about the utilization of different types of dosage forms of drugs. Prescription audit as self-directed learning must be a tool for practical lesson of Pharmacology for UG-course as well as for PG-curriculum

Effects of ultraviolet radiation on pigmentation and malondialdehyde content of three aquatic macrophytes

A study has been done in order to evaluate the ill effects of UV-A,UV-B and UV-C on pigmentation and malondialdehyde content of floating macrophytes (Lemna sp., Pistia sp. and Eichhornia sp.) in one, three, and five days interval. Study results revealed that all types of ultraviolet light (UV-A, UV-B, and UV-C) did not produce same extent of ill effects on the studied macrophytes. Pistia sp. and Eichhornia sp. showed similar reduction pattern of chl a/chl b ratio with respect to control. Results also suggest that among the three types of radiation only UV-B showed higher level of changes in both the pigment and malondialdehyde content. Moreover, among the three tested macrophytes only Lemna sp. showed some protective role against UV radiation compared to other to macrophytes

Merging Filaments and Hub Formation in the G083.097++03.270 Molecular Complex

We uncover a hub-filament system associated with massive star formation in the G083.097$+$03.270. Diagnosed with simultaneous $^{12}$CO, $^{13}$CO, and C$^{18}$O line observations, the region is found to host two distinct and elongated filaments having separate velocity components, interacting spatially and kinematically, that appear to have seeded the formation of a dense hub at the intersection. A large velocity spread at the hub in addition to clear bridging feature connecting the filaments in velocity are indicating merging of filaments. Along the filaments axis, the velocity gradient reveals a global gas motion with an increasing velocity dispersion inward to the hub signifying turbulence. Altogether, the clustering of Class I sources, a high excitation temperature, a high column density, and presence of a massive outflow at the central hub suggest enhanced star formation. We propose that merging of large-scale filaments and velocity gradients along filaments are the driving factors in the mass accumulation process at the hub that have sequentially led to the massive star formation. With two giant filaments merging to coincide with a hub therein with ongoing star formation, this site serves as a benchmark for the `filaments to clusters' star-forming paradigm.Comment: 12 pages, 7 figures, 1 table, accepted for publication in Ap