Proceedings of the National Academy of Sciences, India Section A: Physical Sciences最新文献

“Nadi Pariksha,” i.e., measurement of the pulse, has been documented to be used by Ayurveda for assessing diseases and various other psychological conditions. Ayurveda and another ancient medicine system like traditional Chinese medicine (TCM) and traditional Korean medicine have thousand years of experience in wrist pulse analysis to diagnose the subject's health condition and the root cause of a disease. According to ancient literature, a human’s health status is dependent on three essential constitutions Vata, Pitta, and Kapha (Cun, Guan, and Chi in TCM). The term “tri-dosha” is used to characterize them. An imbalance of these doshas causes disease. Therefore, in modern health practices, it is necessary to understand these pulses imbalance with modern signal processing techniques. In this review, an attempt has been made to discuss the classical hypotheses of pulse measurement based on different Ayurvedic parameters and modern wrist pulse parameters like pulse wave analysis using pulse wave velocity and pulse rate variability. The various modern parameters and other feature extraction methods used to detect multiple diseases are also discussed.

In the present paper, the propagation of space-charge waves through elliptical plasma waveguide in an axial magnetic field is investigated. First we consider a metallic coaxial waveguide with an elliptical cross section including an annular vacuum-plasma-vacuum and then an elliptical plasma waveguide is considered. In the electrostatic approximation, by using the Poisson, continuity and momentum equations and so applying boundary conditions, dispersion relations of the waves are derived. The potentials, the components of the electric fields, the electron density, and electron velocity components in terms of Mathieu functions are introduced. The results of the numerical study and the discussion are presented as well.

Heavy mineral study of sediment samples collected from Gulf of Khambhat, off Alang, Gujarat, shows a predominance of opaque minerals represented by titanomagnetite, magnetite and ilmenite over non-opaque minerals like pyroxene and amphiboles and traces of sillimanite, zircon, garnet and monazite. The bulk sediments contain up to 28.5% of heavy minerals with an average of 12.5%. Within the heavy minerals, more than 50% are opaque in nature represented by titanomagnetite, magnetite and ilmenite. SEM–EDX studies on handpicked opaque grains indicated a higher concentration of vanadium up to 1.1%. The result of EDX studies was confirmed by AAS analysis of magnetic heavy mineral fraction that showed a concentration of vanadium up to 0.36%. Subsequently, XRD analysis of the heavy minerals of randomly selected samples revealed the presence of vanadium-bearing titanomagnetite as well as the vanadium mineral phase, melanovanadate. EPMA studies carried out in titanomagnetite grains that revealed V₂O₃ content of 0.36–1.7% with an average of 1.3%. Based on the analytical studies, it is inferred that the vanadiferous titanomagnetites in the Gulf of Khambhat are possibly drained from Deccan basalt mainly through the Rivers of Narmada and Tapti.

In the present article, we proposed the fractional-order Kober and generalized Weyl q-integrals involving a basic (or q-) analogue of multivariable Aleph-function. Similar assertions for the Riemann–Liouville and Weyl fractional q-integral transforms are also presented. Several corollaries are also established to strengthen the results. By specializing the various parameters and variables in the basic analogue of multivariable Aleph-function, we can obtain a large number of results involving a remarkably wide variety of useful basic functions.

In this study, we have derived entropy measures for Gompertz distribution and truncated Gompertz distribution. We consider nine entropy measures to compute the relative loss of entropy when the underlying probability distribution is truncated Gompertz distribution instead of the Gompertz distribution. The numerical comparisons of relative loss in entropy are made to establish which entropy measure has advantages over the other.

Optoelectronic features of Zn_1-xGd_xO (x = 0.01, 0.03 and 0.05) nanorods were explored through a series of optical characterizations. The presence of different functional groups and vibrational modes in the samples were observed through Fourier-transform infrared (FTIR) and Raman characterizations, respectively. The characteristic stretching vibrational modes of Zn–O and Gd-Zn–O were probed through FTIR. The peaks appeared in the Raman spectra are associated with the characteristics of ZnO samples. The bandgap of the ZnO sample decreased from 3.19 to 3.16 eV with increasing Gd doping concentration as evident from UV–Visible spectroscopy. Photoluminescence measurement showed the signature of intrinsic defects and the colour emission of the samples shifted more towards the green emission region with Gd doping concentration. Our study demonstrates the possible usefulness of the materials in commercial UV lighting applications.

In this paper, we use four-dimensional quaternionic algebra to describe space-time geodesics in curvature form. The transformation relations of a quaternionic variables are established with the help of basis-transformations of quaternion algebra. We deduce the quaternionic covariant derivative that explains how the quaternion components vary with scalar and vector fields. The quaternionic metric tensor and the geodesic equation are also discussed to describe the quaternionic line element in curved space-time. We examine a quaternionic metric tensor equation for the Riemannian Christoffel curvature tensor. We present the quaternionic Einstein’s field-like equation, which indicates that quaternionic matter and geometry are equivalent. Relevance of the work:In recent decades, hypercomplex algebra, viz., quaternion and octonions, has been widely used to explain various branches of physics. In this way, we have investigated quaternionic transformations and field equations in curved space-time. The present novel work will help to explain the characteristics of the curved space-time universe in terms of quaternion algebra. It can also be used to describe quaternionic gravitational waves, the black hole formulation, and so on.

In this study, fuzzy subalgebras and ideals with t-conorms on Sheffer stroke Hilbert algebras are discussed. We state and prove relationships between the level-set of a fuzzy subalgebra with a t-conorm T (briefly, T-fuzzy subalgebra) and a subalgebra of a Sheffer stroke Hilbert algebra. Then the composition of T-fuzzy subalgebras and homomorphisms of Sheffer stroke Hilbert algebras are analyzed. By defining fuzzy subalgebras of Sheffer stroke Hilbert algebras, the relationships between fuzzy subalgebras and T-fuzzy subalgebras of this algebraic structure are investigated. Also, it is shown that every fuzzy ideal with t-conorm T (in short, T-fuzzy ideal) is a T-fuzzy subalgebra but the converse does not generally hold. As in T-fuzzy subalgebras of Sheffer stroke Hilbert algebras, some properties of the T-fuzzy ideals are proved.

Magh mela, a smaller form of Kumbh mela, organize every year in Prayagraj. With the emergence of novel corona virus, there is worldwide discussion to find out the effective way to organize or cancel the mass gathering events. The present study assesses the challenges in organization of mass gathering events like Magh mela held at Prayagraj, India in 2021. The correlation between increased cases of COVID-19 and Magh mela-2021 has been highlighted through statistical analysis and growth curves using the available data. The study finds that there is a correlation between the Magh mela-2021 mass gathering event and increased rate of COVID-19 infections. After the Magh mela 2021, the average daily increase in the COVID-19 cases started to increase. It was found 4.25%, 6.28% and 2.73% in India, Uttar Pradesh and Prayagraj, respectively.

An indoor visible light positioning system using the received signal strength intensity method and the trilateration technique with user mobility support is proposed for applications, e.g. healthcare. Accurate position information of medical staffs and patients is required for data transmission, tracking, navigation, etc. Seamless data transmission while user is on the move has been conceptualized considering the optical network formed by photosensor (light emitting diode)-based transmitters. Efficiency of these services depends on the position accuracy. To investigate factors contributing to higher position errors in a practical environment, the proposed system is evaluated. Evaluation is done through simulation and experiment for different channel conditions, and the receiver rotation due to user mobility. Simulation results show an average two-dimensional position error of 0.32 m in a channel with a strong background light illumination level of − 60 dBm. Experimental results show that the mean position error is 0.7 m in a normal daytime indoor light condition.