Generalized Electromagnetic fields in Chiral Medium

The time dependent Dirac-Maxwell's Equations in presence of electric and magnetic sources are written in chiral media and the solutions for the classical problem are obtained in unique simple and consistent manner. The quaternion reformulation of generalized electromagnetic fields in chiral media has also been developed in compact, simple and consistent manner

Electro-acoustic Scattering from a Pulsating Sphere

In this paper, we show the RCS enhancement due to the acoustic disturbances around a pulsating sphere. The acoustic variation is modeled with the dielectric inhomogeneities around the sphere caused by the pressure fluctuations due to the acoustic source. RCS is computed for the modeled dielectric pulsating sphere, a cube, and a cone on a cylinder across a frequency band using Finite Difference Time Domain (FDTD) method. The RCS of the pulsating sphere and other objects considered are dominated by the background scattering from the pulsating object. In this work, we show that the dielectric variation due to the acoustic source can be detected even if there is no scattering from the object. The scattering from the dielectric variation leads to the detection of Bragg scattering along with a significant increase in RCS.Comment: 8 Page

Bayesian framework for characterizing cryptocurrency market dynamics, structural dependency, and volatility using potential field

Identifying the structural dependence between the cryptocurrencies and predicting market trend are fundamental for effective portfolio management in cryptocurrency trading. In this paper, we present a unified Bayesian framework based on potential field theory and Gaussian Process to characterize the structural dependency of various cryptocurrencies, using historic price information. The following are our significant contributions: (i) Proposed a novel model for cryptocurrency price movements as a trajectory of a dynamical system governed by a time-varying non-linear potential field. (ii) Validated the existence of the non-linear potential function in cryptocurrency market through Lyapunov stability analysis. (iii) Developed a Bayesian framework for inferring the non-linear potential function from observed cryptocurrency prices. (iv) Proposed that attractors and repellers inferred from the potential field are reliable cryptocurrency market indicators, surpassing existing attributes, such as, mean, open price or close price of an observation window, in the literature. (v) Analysis of cryptocurrency market during various Bitcoin crash durations from April 2017 to November 2021, shows that attractors captured the market trend, volatility, and correlation. In addition, attractors aids explainability and visualization. (vi) The structural dependence inferred by the proposed approach was found to be consistent with results obtained using the popular wavelet coherence approach. (vii) The proposed market indicators (attractors and repellers) can be used to improve the prediction performance of state-of-art deep learning price prediction models. As, an example, we show improvement in Litecoin price prediction up to a horizon of 12 days

Defence Electronics Applications Laboratoty, Dehradun

A system has been built and tested for automated change detection between multi-temporal panchromatic images. This paper discusses the implementation issues, associated tools, and finally summarises initial tests on IRS IC/ID and other high-resolution images. Key characteristics of this system are integration of technologies having high degree of registration, normalisation of the effects of radiometry; selectivity to specific type of changes, refinement of changes by thresholding, and assignment of presence and absence of object and tools for updation/deletion of change mask. A semi-automatic technique for selection of control points in an image having affine distortion has been implemented. Linear regression is used for normalisation of the images. Two change detection techniques, namely image subtraction and image ratioing have been used to find the global change mask. Selective threshold is used to generate target mask. Target mask is shown in two colours to depict presence and absence of the object. Method based on ratioing has been found to be more sensitive to spectral variations and provides better detection of changes

PHYTOCHEMICAL SCREENING AND ANTI-TRICHOSPORON ACTIVITY OF PLUMBAGO ZEYLANICA LINN

Objective: To evaluate the anti-Trichosporon activity of a medicinal plant, Plumbago zeylanica Linn and to find out the phytochemicals responsible for this activity with the use of four solvent extracts; methanol, ethanol, acetone and chloroform. Methods: To evaluate the antifungal activity, two methods were used. Agar well diffusion assay to determine the diameter of zone of inhibition (in mm) and MIC (in mg/ml) was determined through Tube dilution broth assay. Phytochemical screening for preliminary analysis of secondary metabolites was done through chemical methods. Results: Trichosporon asahii was found to be most sensitive to methanol extract of P. zeylanica with inhibition zone of 35 mm and T. inkin with 30 mm zone of inhibition. MIC results also showed that the methanol extract was most effective in lowest concentration against T. asahii with MIC at 6.2 mg/ml and inhibited T. inkin at 25 mg/ml. Phytochemical screening of plant extracts revealed the presence of certain phyto-constituents like alkaloids, steroids, flavonoids, phenols, glycosides, tannins etc. Conclusion: The present study proved the sensitivity of the yeast Trichosporon spp. to different extracts of P. zeylanica. T. asahii was found to be more sensitive towards the extracts. Methanol extract proved to be most effective compared to ethanol, acetone and chloroform as it gave the maximum zones and lowest MIC result. Phytochemical analysis proved the presence of certain phytochemicals which was responsible for their antifungal activity

Evaluation of Snow Parameters using Passive Microwave Remote Sensing

The study of snow characteristics using conventional techniques for vast, rugged andremote snow covered areas of Himalayas is very difficult. In the present study, the satellite dataof SSM/I sensor has been used. Changes in snow accumulation result in related variations inpassive microwave brightness temperature. This study attempts to develop new algorithms usingbrightness temperature for snow water equivalent (SWE) and snow depth that will suit theIndian Himalayan conditions. The snow and meteorological data recorded in the field is usedto determine the empirical coefficients, which have been further used in the algorithmdevelopment. The parameters evaluated can be used as the input for the avalanche risk analysis,as one can estimate average snow depth and SWE of the area which are main input for avalancheforecasting. Algorithms are further used for the prediction of snow depth and SWE for subsequentwinters using the brightness temperature. A good correlation was found between the predictedand the observed values from the ground observatory data

Quaternion Analysis for Generalized Electromagnetic Fields of Dyons in Isotropic Medium

Quaternion analysis of time dependent Maxwell's equations in presence of electric and magnetic charges has been developed and the solutions for the classical problem of moving charges (electric and magnetic) are obtained in unique, simple and consistent manner

Nucleotide analysis of pome fruit virus isolates detected in apple and pear samples from Italy and India

In the framework of a joint research project between Italy and India field surveys were done in different pear and apple growing areas of North of India and Central and Southern Italy. Samples were collected from plants belonging to common and local varieties and molecularly analyzed for the detection of the main pome fruit viruses (Apple stem pitting virus, Apple stem groving virus, Apple chlorotic leaf spot virus, Apple mosaic virus) by using harmonized diagnostic protocols.The sequence homology was evaluated and a phylogenetic tree was built, on the basis of which, the Indian isolate of ASGV showed maximum sequence identity at a nucleotide level to Italian isolates when analyzed by BLAST (http://blast.ncbi.nlm.nih.gov/Blast.cgi). Similarly, a maximum identity, ranging from 90-93%, was found for the Italian isolates of ASPV and pear and apple isolates from Poland, while a sequence homology ranging from 83 to86% was observed within the Indian isolates of ASPV. Multiple alignment of the Indian pome ACLSV-isolates indicate maximum variability in the middle portion while the first 140 nucleotides are maximally conserved and shared a percent identity at nucleotide level of 86-100% with the Italian isolates.The ApMV Indian isolates showed maximum (92-99%) sequence homology to the Korean isolate (AY125977) from apple. However, a comparison with other isolates from different host plant species revealed a clustering of Indian isolates with a Czech isolate from pear and a sequence homology of 84 to 98%. Phylogenetic analysis showed that sequence variability was independent to the geographical origin or the host for all the investigated viruses.Keywords: ACLSV, ASPV, ASGV, ApMV, sequences analysis, Italy, India