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In this paper, a single-species stochastic population model is considered in the presence of density-dependent proportional harvesting. The stochastic model is considered to include the effects of fluctuation in the predation rate and environmental variability. Coloured cross-correlated Gaussian coloured noises are used to generate stochastic fluctuations. Steady-state probability distribution function and stationary potential are determined using the approximate Fokker–Planck equation. Phenomenological bifurcation analysis and mean first passage time have been computed. The average population density in the outbreak state is calculated using normalised probability distribution of the outbreak state. The species outbreak control strategy has been proposed. The key observations of this study are the negative cross-correlation strength-induced noise enhanced stability (NES) phenomenon and the environmental stochasticity-induced resonant activation (RA) phenomenon. Bistable to monostable phase regime shift is observed to depend on the environmental stochasticity whereas monostable to bistatble phase regime shift is observed to depend on correlation time of the environmental stochasticity.

Many decomposition methods have been developed and applied to find bearing fault in recent years, but it is quite difficult to effectively extract the bearing fault characteristics, especially under strong noise and variable speed conditions. Among them, empirical mode decomposition (EMD) is the most widely used. To improve the extraction effect of rolling bearing fault features, this paper proposes a bearing fault extraction algorithm based on fractional Fourier transform (FRFT). The collected vibration signal is first analysed by envelope demodulation and mean normalisation. Secondly, the EMD method is used to remove many noise interferences and retain the bearing fault characteristics. Finally, an effective FRFT filtering algorithm is applied to find fault characteristic signal and remove the residual noise. Both simulated and experimental analyses are conducted to illustrate the performance of the proposed method. The results indicate that this method can accurately and completely extract the unknown bearing fault features from raw signal, which contains noise and irrelevant vibration signals. The proposed algorithm may provide reference for the fault diagnosis of other machine elements, such as gears.

L-Histidine (C₆H₉N₃O₂), one of the most prominent positively charged amino acids, has shown a lot of potential as a future molecular device. A subcomponent of proteins, L-Histidine has been acknowledged for its applications in designing future switching devices and logic gates. Interpreting its transport parameters while aligning it as a central molecule with a series of metallic electrodes using a self-consistent function and implementing the density functional theory and non-equilibrium Green’s function (NEGF-DFT) approach for our computational analysis, we observe that the proposed devices exhibit dissimilar rectification ratios (RR), besides demonstrating negative differential resistance (NDR) regimes. The RRs of DFT-D3 corrected and the uncorrected molecular device is also compared to verify the impact of van der Waals (vdW)-type interaction on current–voltage characteristics. The molecular device with copper electrodes yields the maximum rectification ratio of 8.1, while the device with palladium electrodes yields the highest peak-to-valley current ratio of 1.28. Such a study proffers the idea of choosing proper electrodes for exploring the rectification ratio of biomolecules. Moreover, using these L-Histidine-based molecular devices, we have proposed AND Logic gate and OR Logic gate, which can pave the way to an alternate research area of using peptides as future molecular devices.

The present investigation elucidated the influence of nanoparticle volume fraction and temperature on the thermal conductivity and viscosity of water-based CuO, TiO₂ and ZnO nanofluids. All the nanoparticles used in the present study were synthesised using the chemical co-precipitation method and their structural and morphological features were explored by XRD and FESEM techniques, respectively. The investigated fluids were prepared using the two-step method by dispersing 0.1–0.5 wt% nanoparticles in distilled water. The thermal conductivities of all the nanofluids were determined in the temperature range of 30–70°C and viscosity in the range of 300–360 K. The experimental study demonstrated that the thermal conductivity and viscosity of the nanofluids depend on volume fraction and temperature. The dynamic viscosity and the thermal conductivity of all the nanofluids increased with the increase in the volume concentration of solid particles. The viscosity decreased and thermal conductivity increased with an increase in temperatures. When the three nanofluids are compared at the specified temperature range, CuO nanofluids showed higher thermal conductivity of 0.5856–0.6332 W({/})mK for 0.1 wt% and 0.6476–0.7465 W({/})mK for 0.5 wt% volume concentration and better viscosity than TiO₂ and ZnO nanofluids. The obtained experimental data were compared with some existing thermal conductivity and viscosity models. While comparing the thermal conductivity models, the P Bhattacharya model showed good agreement, whereas no viscosity model agrees with the experimental results. Thus, the obtained results of the prepared nanofluids are useful for conducting further studies in nanofluids.

A novel multi-party quantum key agreement protocol, where the channels are independent of parameters is proposed in this paper. The proposed multi-party quantum key agreement (MQKA) protocol utilises the non-maximally entangled Bell states with unknown parameters as quantum resources and performs the unitary operation to encode key information. In the parameters-independent channels, each party does not need to know the parameters of the channels being operated on. Compared with the previous MQKA protocols that are designed based on maximally entangled states, our protocol can work without knowing the parameters of the non-maximally entangled states which is convenient for experiments. Furthermore, security analysis shows that the proposed protocol can resist outsider and participant attacks.

The projected shell model (PSM) was employed to study the signature inversion of ({}^{160}hbox {Tm}) and ({}^{161}hbox {Tm}) isotopes. The Hamiltonian of these isotopes were constructed and solved to obtain the energy levels and the (gamma )-ray transition energies. The rotational bands of the odd–odd ({}^{160}hbox {Tm}) and odd–even ({}^{161}hbox {Tm}) isotopes of thulium nucleus were constructed based on the (pi hfrac{11}{2} otimes upsilon ifrac{13}{2}) Nilsson configuration to calculate the kinetic and dynamic moments of inertia, (gamma )-ray transition energy ((Delta {I}=1)) and the staggering parameter (S(I)). Yrast band with two signatures for both isotopes have been extracted and compared with the experimental data. The anomalous splitting and signature inversion occurred due to the quadruple deformation in both isotopes. Analysis of level staggering and signature inversion show that signature inversion for the ({}^{160}hbox {Tm}) isotope occurs at low spin region, while for the ({}^{161}hbox {Tm}) isotope, it occured in the intermediate spin region. As expected, zig-zag behaviour and phase transition, as well as signature of energy splitting are clearly indicated in figures showing variation of S(I) and (Delta E) with spin. This behaviour is more visible for the odd–even ({}^{161}hbox {Tm}) isotope than for the odd–odd ({}^{160}hbox {Tm}) isotope. Good agreement between the calculated results and experimental data confirms the success of the PSM model.

The aim of the present analysis is to study the influence of Thompson and Troian slip on forced convective nanofluid flow over a permeable plate in Darcy porous medium in the presence of zero nanoparticle flux at the boundary. By the appropriate make-over, the foremost partial differential equations (PDEs) are abridged to ordinary differential equations (ODEs) and numerical solutions for the nonlinear equations are subsequently attained by shooting technique. Due to enhanced permeability parameter, speed and concentration of the liquid increase but the width of the momentum boundary layer and temperature reduce. The current analysis discloses that by reducing the width of the boundary level, the rising (velocity) slip parameter forces the fluid speed and concentration to increase while dimensionless temperature reduces for increasing (velocity) slip. Compared to blowing, liquid speed and concentration are superior for suction. With the rise in Brownian motion parameter, concentration diminishes whereas with the rise in thermophoresis parameter, temperature is found to rise. The results achieved in this examination expose various motivating characteristics which demand additional investigation of the problem.

A quantum version of the linear cryptanalysis technique is presented in this paper. So far, only a certain part of some classical cryptanalysis techniques was converted for quantum processing to gain speed-up while analysing a symmetric primitive. However, none of the quantum version of these attacks, including linear cryptanalysis, completely uses quantum computing for all the steps. We developed a quantum version for all the steps of the linear cryptanalysis. The proposed quantum linear cryptanalysis is applied on the quantum version of a toy cipher. Performance analysis shows that the quantum version of the linear cryptanalysis offers quadratic speed-up in different steps of the attack. It can be used to attack any cipher that is vulnerable against linear cryptanalysis.

In this article, the heat transfer of Al(_2 textrm{O}_3)–Cu/H(_2)O in the magnetohydrodynamic (MHD) stagnation point flow in the direction of an exponentially stretching/shrinking sheet with the effect of heat source, thermal radiation and viscous dissipation is examined. The inclusion of dissipative heat, thermal radiation and additional heat source enriches the study as well. Using suitable similarity transformations, the governing partial differential equations are transformed into ordinary differential equations (ODEs). The ODEs are solved numerically by the built-in function bvp4c in MATLAB. By the addition of nanoparticle, effects of various parameters were studied, and the outcomes revealed that the skin friction coefficient decreases and the local Nusselt number increases. In comparison, viscous dissipation causes an improvement in the fluid thermal state and, as a result, triggers the thermal boundary layer to rise.

In this work, the sound velocity and some of the mechanical, optical and optical phonon frequencies of the semiconductor β-GaN have been studied. The proposed temperature dependency of the pseudopotential form factors was used together with the empirical pseudopotential technique (EPM). The precise form factors for each temperature are computed using the suggested model. Calculations have been done to determine the temperature-dependent values of the energy gaps, sound velocity, refractive index, elastic constants, mechanical moduli, phonon frequencies and dielectric constants. The findings and the published and experimental data in the literature are in good agreement. These findings can be used as a guide for physical parameter values that are difficult to quantify experimentally.