Volume 80, Issue 8

Combining artificial intelligence (AI) and photonic biosensors is a new method of high-accuracy bacterial detection. In the present work, a decision tree classifier is used, aimed at the classification of bacterial species by taking readings from the wavelength measurements extracted from photonic sensor simulations performed using Rsoft. The data set is processed through univariate analysis, Kernel density estimation (KDE) and box plot evaluation, and optimized feature selection as well as outlier removal. The classifier is trained with a 70.27 % classification accuracy. Performance evaluation using a confusion matrix highlighted the classification efficiency. The obtained findings show the promise of AI based photonic bio sensing for the bacterial infectious diseases.

We revisit the Dicke superradiance problem, where an ensemble of N identical two-level systems undergoes collective spontaneous decay. While an exact analytical solution has been known since 1977, its algebraic complexity has hindered practical use. Here we present a compact, closed-form solution that expresses the dynamics as a finite sum over residues or, equivalently, a complex contour integral. The method yields explicit populations of all Dicke states at arbitrary times and system sizes, and generalizes naturally to arbitrary initial conditions. Our formulation is computationally efficient and offers structural insights into the role of spectral degeneracies and Lindbladian eigenmodes in collective decay.

Let G be a connected graph. The resistance distance among two vertices is defined as the effective resistance between the corresponding nodes in the electrical network constructed from G by replacing each edge with a unit resistor. The Kirchhoff index is an important distance-based topological index corresponding to graphs, which is the sum of all the resistance distances pairs of G . Let B n be a linear polyomino chain with n squares. The linear triangular chain is a graph with 2 n triangles, characterized by randomly adding an edge to each square of B n so as to make it into two triangular faces. In this paper, by standard techniques of electrical networks and the recursion formula for resistance distances, we characterize the linear triangular chains with extreme Kirchhoff index.

This study examines the heat and mass transfer enhancement in MHD nanofluid flow coupled with elastic interface dynamics. The research numerically simulates the combined effects of nonuniform magnetic fields, chemical reactions, stretching velocity ratio, thermal radiation, and heat sink on nanofluid behavior over an elastic surface with convective boundary conditions. Key findings include (i) increased magnetic field strength reduces velocity and concentration while raising temperature near the wall; (ii) radiation, thermophoresis, chemical reaction, heat sink, and convection parameters enhance temperature; (iii) the impact of radiation and heat sink on concentration is significant and influenced by thermophoresis, with opposite trends near and far from the wall; (iv) convective heat transfer is enhanced by stretching velocity ratio, radiation, and convection but weakened by chemical reaction and heat sink; (v) convective mass transfer is augmented by stretching velocity ratio, radiation, heat sink, and chemical reaction but weakened by thermophoresis; and (vi) stretching velocity ratio, magnetic field, and variable viscosity parameters increase skin-friction coefficient.

We have studied the formation of arbitrary amplitude ion-acoustic solitary structures using the Sagdeev pseudo-potential approach in an unmagnetized dusty plasma system in the absence of collision whose constituents are Combined Kappa–Cairns distributed electrons, negative-charged stationary dust particulates, and adiabatic warm ions. This system supports both positive and negative potential conventional solitons along with the coexistence of these two solitons, double layers, and supersolitons of negative polarity. Different types of solitary structures along with the impacts of the plasma parameters, viz., Mach number, superthermal parameter, and nonthermal parameter, of this system on the amplitudes of these structures have been investigated by plotting the pseudo-potential with respect to the electrostatic potential. The formation of supersoliton after the formation of soliton has been illustrated using the mechanical analogy of phase portraits. The transitions of soliton to supersoliton and soliton to double layer have been illustrated.

A multi-component unmagnetized dusty plasma, comprising negatively charged heavy ions at two different temperatures, q-nonextensive distributed electrons, Cairn’s distributed nonthermal ions, and arbitrarily charged mobile dust, is considered to study the head-on collision (HOC) phenomena of dust-acoustic (DA) waves (DAWs), and dust-acoustic shock waves (DASHWs) and the formation of DA Korteweg de Vries (KdV) and KdV Burger (KdVB) solitons, solitonic and periodic soliton structures, higher-order DA solitons’ (DASs) structure, as well as Sagdeev potential structure. The extended Poincaré-Lighthill-Kuo (ePLK) method is used to derive the KdV and KdVB equations describing the dynamics of solitons and shocks in plasmas. It is found that the relevant plasma parameters are vital in forming the soliton structures, phase shifts, and the collision processes of KdV and KdVB solitons. The compressive solitonic potential structures are produced due to the effects of the temperature ratio of low-temperature ion to high-temperature ion ( σ 1 ) and the strength of electron nonextensivity ( q ). On the other hand, due to the effect of σ 1 , both compressive and rarefactive periodic potentials are produced. The superposition principle is followed by the solitons, but not by the shocks in the colliding regions. For the higher-order correction, both the compressive and rarefactive DASs are produced, whereas, in the zeroth-order case, only the compressive DASs are produced. Both the depth and width of the Sagdeev potential of DAWs increase due to the influence of the density ratio of the lower ion to dust ( μ 1 ) and q but decrease with increasing nonthermality parameter ( β ).

This paper works on the study of intense Laguerre–Gaussian (LG) laser beam in plasma channel using the ignitor–heater technique. The first beam, i.e., the ignitor beam is responsible for the creation of plasma through the ionization of air, while the second beam, i.e., heater beam creates the plasma channel with parabolic density profile by heating the plasma electrons. In this preformed plasma channel, the third principle beam, i.e., LG laser beam is guided. Being highly intense, LG laser beam changes the rest mass of the plasma electrons and relativistic nonlinearity comes into play, which combinedly effects the guiding of laser beam with preformed channel. Starting from the plasma and channel formation, the differential equation for the beam width parameter for the LG beam is derived using the method of moments. The effect of different modes of LG beam on the beam width parameter in a plasma channel created by the two pulse technique is visualized. It is observed from the present study that the higher modes of LG beam are more significant for optical guiding of the beam.

TiCrN films were deposited on stainless steel 316L using a 13.56 MHz RF magnetron sputtering system with a titanium–chromium target and Ar-N 2 gas mixture. The objective of this study was to investigate the influence of substrate bias, ranging from 0 V to −100 V, on the resulting film properties. The films were analysed using grazing incidence X-ray diffraction (GIXRD), nanoindentation, Raman spectroscopy, and potentiodynamic polarization tests to assess their properties. XRD results show that all structures of the films are crystalline and changed with varying bias voltage. The hardness significantly increased from 17.4 to 19.6 GPa when the bias voltage was increased from 0 to −25 V, followed by a slight decrease to 17.4 GPa at −75 V and as further decrease to 13 GPa at −100 V. The best corrosion current density of the film deposited at 0 V was 2.32 nA/cm 2 , which is about 27 times less than that of the uncoated steel 63.015 nA/cm 2 .

We present a generalized Debye scattering formula for amorphous materials under small mechanical strain, incorporating anisotropy via an anisotropic pair distribution function (PDF) g ( r , θ , ϕ , ϵ ) and spherical harmonics to derive the scattered intensity I ( Q , ϵ ). The strain-response coefficients h kl ( r , θ , ϕ ) introduced here could be computed from material parameters, enabling diffraction experiments to measure these properties. We derive explicit formulas for triaxial, planar, and uniaxial deformation cases, assuming a linearized strain ‖ ϵ ‖ ≪ 1, ignoring O ( ϵ 2 ) $\mathcal{O}\left({{\epsilon}}^{2}\right)$ terms.