Response of oceanic cyclogenesis metrics for NARGIS cyclone:a case study

In this study, variability of two oceanic cyclogenesis metrics, tropical cyclone heat potential (TCHP) and effective oceanic layer for cyclogenesis (EOLC) in the Bay of Bengal (BoB) during NARGIS cyclone is investigated. EOLC represents the geopotential thickness of near surface stratified layer forms because of the spread of low salinity waters due to fresh water influx from rivers and precipitation. Climatological fields of TCHP and EOLC reveal that NARGIS translated towards the region of higher EOLC as seen in the observations. A maximum daily sea surface cooling of 2 °C is observed along the right and rear side of NARGIS track

Finite element modelling of natural vibration problems

Finite element models of Modified Rayleigh-Ritz, Galerkin, Least Square, Hybrid (Pian's) and Collocation methods are presented for natural vibration problems. A comparative assessment is made of these methods with Rayleigh-Ritz finite element models. This study brings out that the Galerkin model is relatively superior. A method of improving the accuracy in the estimation of eigenvalues is also included

Unravelling the Components of a Multi-Thermal Coronal Loop Using Magnetohydrodynamic Seismology

Coronal loops, constituting the basic building blocks of the active Sun, serve as primary targets to help understand the mechanisms responsible for maintaining multi-million Kelvin temperatures in the solar and stellar coronae. Despite significant advances in observations and theory, our knowledge on the fundamental properties of these structures is limited. Here, we present unprecedented observations of accelerating slow magnetoacoustic waves along a coronal loop that show differential propagation speeds in two distinct temperature channels, revealing the multi-stranded and multi-thermal nature of the loop. Utilizing the observed speeds and employing nonlinear force-free magnetic field extrapolations, we derive the actual temperature variation along the loop in both channels, and thus are able to resolve two individual components of the multi-thermal loop for the first time. The obtained positive temperature gradients indicate uniform heating along the loop, rather than isolated footpoint heating.Comment: accepted for publication in Ap

Lime-Stabilized Black Cotton Soil and Brick Powder Mixture as Subbase Material

Various researchers, for the past few decades, had tried to stabilize black cotton soil using lime for improving its shrinkage and swelling characteristics. But these days, the cost of lime has increased resulting in increase in need for alternative and cost effective waste materials such as fly ash and rice husk ash. Brick powder, one among the alternative materials, is a fine powdered waste that contains higher proportions of silica and is found near brick kilns in rural areas. The objective of the study is to investigate the use of lime-stabilized black cotton soil and brick powder mixture as subbase material in flexible pavements. Black cotton soil procured from the local area, tested for suitability as subbase material, turned out to be unsuitable as it resulted in very less CBR value. Even lime stabilization of black cotton soil under study has not showed up the required CBR value specified for the subbase material of flexible pavement by MORTH. Hence the lime-stabilized black cotton soil is proportioned with brick powder to obtain optimum mixture that yields a better CBR value. The mixture of 20% brick powder and 80% lime-stabilized black cotton soil under study resulted in increase in the CBR value by about 135% in comparison with lime-stabilized black cotton soil. Thus it is promising to use the mixture of brick powder and lime-stabilized black cotton soil as subbase material in flexible pavements

Simulation of Droplet Formation, Ejection, Spread, and Preliminary Designof Nozzle for Direct Ceramic Inkjet Printing

Recent advances in drop-on-demand (DOD)-type inkjet printing techniques have increasedresearch activities in the area of direct ceramic inkjet printing. In an attempt to develop a ceramicinkjet printer for the manufacture of ceramic components with their sizes in micro scale, theformation of ceramic ink droplet (ethyl alcohol loaded with different volume fractions of aluminaparticles) and its spread from a reservoir using piezoelectric actuation are simulated. The propertiesof the ceramic ink are taken from the data reported in literature. The simulations were performedwith computational fluid dynamics software (CFD-ACE+), CFDRC. This study gives details ofthe interaction among different physical phenomena that contribute to the droplet formation andejection process. The results from this study are being used for a preliminary design of nozzleand for the preparation of ceramic inks to achieve the desired droplet characteristics

Multithermal apparent damping of slow waves due to strands with a Gaussian temperature distribution

Funding: T.V.D. was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 724326), the C1 grant TRACEspace of Internal Funds KU Leuven, and a Senior Research Project (G088021N) of the FWO Vlaanderen. V.P. is supported by SERB start-up research grant (File no. SRG/2022/001687). A.W.H. acknowledges the financial support of the Science and Technology Facilities Council (STFC) through Consolidated Grants ST/S000402/1 and ST/W001195/1 to the University of St Andrews and support from the European Research Council (ERC) Synergy grant “The Whole Sun” (810218).Context Slow waves in solar coronal loops are strongly damped, but the current theory of damping by thermal conduction cannot explain some observational features. Aims We investigated the propagation of slow waves in a coronal loop built up from strands of different temperatures. Methods We considered the loop to have a multithermal, Gaussian temperature distribution. The different propagation speeds in different strands led to a multithermal apparent damping of the wave, similar to observational phase mixing. We used an analytical model to predict the damping length and propagation speed for the slow waves, including in imaging with filter telescopes. Results   We compared the damping length due to this multithermal apparent damping with damping due to thermal conduction and found that the multithermal apparent damping is more important for shorter period slow waves. We quantified the influence of instrument filters on the wave’s propagation speed and damping. This allowed us to compare our analytical theory to forward models of numerical simulations. Conclusions We find that our analytical model matches the numerical simulations very well. Moreover, we offer an outlook for using the slow wave properties to infer the loop’s thermal properties.Peer reviewe

Medicated Candies - A new perspective of classical concept

Kasa /cough is one of the most common respiratory condition that afflict every human being at some point in their life. Ayurveda classics have described five types of Kasa. The mode of administration of Oushadha in this Vyadhi is told as Muhurmuhu i.e. frequent administration of medicine. Certain Oushadha Yogas when administered in this Kala may hamper the Agni and Ahara Kala. So, a Yoga which when administered once, act as a sustained release medicament, without hampering the Agni and Ahara Kala would fit the requirement for this way of administration. Such a dosage form that we could find in our classics was Lehya in the form of Candy. In this study, one such Yoga mentioned for Pittaja Kasa Chikitsa in Ashtanga Hridaya, containing Draksha, Pippali, Sharkara was modified into the form of candy. Prepared candies served the purpose of providing sustained release of medicine, repeated administration without altering the Agni and Ahara Kala and finally relief from Kasa. It can be concluded that modified dosage forms that do not adulterate the classical concepts, but are suitable for the current times is the need of hour. Ayurveda practitioners need to look into this aspect of Chikitsa and come up with such novel methods