Modern Physics Letters B

An ${\mathrm{\text{As}}}_2{\mathrm{\text{Se}}}_3$-based chalcogenide highly nonlinear photonic crystal fiber (PCF) with concentric rings consisting of air-holes is proposed to achieve extraordinary flat and small chromatic dispersion in mid-infrared region. This is obtained by design and optimization of the PCF cross-sectional structure. The dispersion variation between ±5 ps/(nm$\cdot$km) is obtained over 800 nm bandwidth. Both the effective mode area and nonlinear coefficient of the proposed PCF within the whole wavelength range from $3\mu \mathrm{\text{m}}$ to $5\mu \mathrm{\text{m}}$ are investigated. Furthermore, the output supercontinuum (SC) optical spectra for different pump wavelengths located at the normal and abnormal dispersion region are investigated, respectively. The results show that the broadest SC with −20 dB spectral width of 1034 nm covering from $3.887\mu \mathrm{\text{m}}$ to $4.921\mu \mathrm{\text{m}}$ is obtained for the pump wavelength of $4.357\mu \mathrm{\text{m}}$ with 100 fs secant hyperbolic pulse of the peak power of 10 kW. Our PCF design offers a low-cost SC source, which can find potential application in mid-infrared photonics.

We proposed a general method for the systematic calculation of unstable cycles in the Zhou system. The variational approach is employed for the cycle search, and we establish interesting symbolic dynamics successfully based on the orbits circuiting property with respect to different fixed points. Upon the defined symbolic rule, cycles with topological length up to five are sought and ordered. Further, upon parameter changes, the homotopy evolution of certain selected cycles are investigated. The topological classification methodology could be widely utilized in other low-dimensional dissipative systems.

Content-based image retrieval (CBIR) system generally retrieves images based on the matching of the query image from all the images of the database. This exhaustive matching and searching slow down the image retrieval process. In this paper, a fast and effective CBIR system is proposed which uses supervised learning-based image management and retrieval techniques. It utilizes machine learning approaches as a prior step for speeding up image retrieval in the large database. For the implementation of this, first, we extract statistical moments and the orthogonal-combination of local binary patterns (OC-LBP)-based computationally light weighted color and texture features. Further, using some ground truth annotation of images, we have trained the multi-class support vector machine (SVM) classifier. This classifier works as a manager and categorizes the remaining images into different libraries. However, at the query time, the same features are extracted and fed to the SVM classifier. SVM detects the class of query and searching is narrowed down to the corresponding library. This supervised model with weighted Euclidean Distance (ED) filters out maximum irrelevant images and speeds up the searching time. This work is evaluated and compared with the conventional model of the CBIR system on two benchmark databases, and it is found that the proposed work is significantly encouraging in terms of retrieval accuracy and response time for the same set of used features.

Designing an efficient filtering technique is an ill-posed problem especially for image affected from high density of noise. The majority of existing techniques suffer from edge degradation and texture distortion issues. Therefore, in this paper, an efficient weighted nuclear norm minimization (NNM)-based filtering technique to preserve the edges and texture information of filtered images is proposed. The proposed technique significantly improves the quantitative improvements on the low rank approximation of nonlocal self-similarity matrices to deal with the overshrink problem. Extensive experiments reveal that the proposed technique preserves edges and texture details of filtered image with lesser number of visual artifacts on visual quality. The proposed technique outperforms the existing techniques over the competitive filtering techniques in terms of structural similarity index metric (SSIM), peak signal-to-noise ratio (PSNR) and edge preservation index (EPI).

Thermoelectric properties of organic materials have attracted much attention for the potential application in clean energy sources. In this work, we use the master equation method to calculate transport properties of the organic material when there is a temperature gradient in the material. The themoelectric property is analyzed with our model under different temperatures and different disorder strengths. It will be helpful to understand the thermoelectric property of organic materials and make good use of the heat energy.

The purpose of this research is to determine the surface morphologies, microstructural and thermal properties of tungsten-based composites that consist of 93 wt.% tungsten (W), 6 wt.% vanadium carbide (VC) and 1 wt.% graphite (C) powders. W-6 wt.% VC-1 wt.% C powders were mechanically alloyed (MA’d) for 6 hrs using a ${\mathrm{\text{Spex}}}^{\mathrm{\text{TM}}}$ with a rate rpm using tungsten carbide vial and balls and sintered at $1750^{\circ }\mathrm{\text{C}}$ for under ${\mathrm{\text{N}}}_2$, ${\mathrm{\text{H}}}_2$ gas flow conditions. The phase composition and microstructural characterization of the tungsten composites were carried out using X-ray diffractometer (XRD), Scanning Electron Microscopy (SEM) and Raman Spectroscopy. SEM images showed the distribution of the tungsten (W), vanadium carbide (VC) and graphite (C) powders and porosity in the tungsten matrix. The Raman spectra exhibited two major peaks, which are recorded at 1331 (vs) ${\mathrm{\text{cm}}}^{-1}$ and 1583 (vs) ${\mathrm{\text{cm}}}^{-1}$ in the Raman spectra. These bands represented carbon phases such as disordered graphite (D) and graphite (G). Thermogravimetric analysis (TGA) measurements were performed to obtain the weight loss and thermal stability of samples in the temperature range $30$–$1100^{\circ }\mathrm{\text{C}}$ under argon gas atmosphere. The TG curve revealed a total loss of 3.3% of weight at this temperature range. It is considered that the cause of mass loss is due to the oxidation and gas desorption of materials.

Current study involves laser-induced gold nanoparticles (GNPs) for breast cancer therapy. GNPs as a therapeutic agent using nanophotolysis approach are discussed. Coulomb explosion of GNPs is studied numerically using MATLAB. Our findings show that $8.40\times 10^{20}$ ions are generated for short pulse laser interaction of 8 ns and laser irradiation of 2 J/cm² penetrates in the tumor depth of 3.30 cm. Cluster size of 98 nm produced $13.08\times 10^{22}$ nanobullets that target the breast tumor. Short pulse laser of 2.27 ns generates maximum shock front velocity of $9.98\times 10^6$ cm/s. Shock front of 20–146 $\mu$m is produced for effectively damaging the breast cancer tissues. A total of 825 cells are damaged by $12.6\times 10^6$ ions. Current results are matched with the literature and are in good correlation. Hence, we conclude that laser-irradiated GNPs using nanophotolysis approach are useful for targeted therapy of breast tumor.

We study the scaling properties of two-dimensional turbulence using dimensional analysis. In particular, we consider the energy spectrum both at large and small scales and in the “inertial ranges” for the cases of freely decaying and forced turbulence. We also investigate the properties of an “energy condensate” at large scales in spatially finite systems. Finally, an analysis of a possible inverse cascade in freely decaying turbulence is presented.

In this work, Sr-substituted samples of single-phase spinel monoferrites with chemical formula ${\mathrm{\text{Ba}}}_{1-x}{\mathrm{\text{Sr}}}_x{\mathrm{\text{Fe}}}_2{\mathrm{\text{O}}}_4$ (x = 0.00, 0.33, 0.67, 1.00) were synthesized using sol–gel auto-combustion method. In order to confirm the single-phase formation of these samples, a sample (x = 0.00) was chosen for heat treatment at different temperatures (100, 300, 400, 600 and $700^{\circ }\mathrm{\text{C}}$) for 4 h. The heat treated sample was then investigated by X-ray diffraction (XRD) analysis and results showed that a single-phase sample can be successfully synthesized at a temperature of $600^{\circ }\mathrm{\text{C}}$, which is much lower than that reported in earlier literature for synthesis of same structured samples. All the synthesized samples were then sintered at $700^{\circ }\mathrm{\text{C}}$ for 4 h to achieve better crystallinity. From XRD patterns, lattice parameters, cell volume and XRD density as a function of Sr-substitution were calculated. Scanning electron microscopy (SEM) results showed that the grain size increased as the temperature was increased. Fourier transform infrared spectroscopy (FTIR) results confirmed the single-phase spinel monoferrites at $700^{\circ }\mathrm{\text{C}}$. From M–H loops (x = 0.0, 0.33, 0.67 and 1.00), different magnetic parameters such as saturation magnetization $(M_s)$, remanance $(M_r)$, coercivity $(H_c)$ and magnetic moment $(n_B)$ were calculated. Magnetocrystalline anisotropy constant and Y–K angles of Sr-doped Ba monoferrites were also calculated. In addition, the variation of different dielectric parameters (real permittivity, imaginary permittivity, real permeability, imaginary permeability, ac conductivity and loss tangent) as a function of frequency (1–6 GHz) has been discussed in this work. The results suggest that the synthesized materials have many advantages over previously reported single-phase spinel monoferrites.

This paper deals with the dynamics of optical solitons in nonlinear Schrödinger equation (NLSE) with cubic-quintic law nonlinearity in the presence of self-frequency shift and self-steepening. This type of equation describes the ultralarge capacity transmission and traveling of laser light pulses in optical fibers. Two robust analytical approaches are employed to determine contemporary solutions. Some new explicit rational, periodic and combo periodic soliton solutions are extracted using the extended trial equation method. The Riccati–Bernoulli sub-ODE method provided us with singular and dark soliton solutions. The constraints found are necessary for the existence of solitons.

We have attempted to study how viscous flux flow affects the crack–inclusion interaction in a long rectangular slab of superconductor during the decreasing field stage under zero-field cooling (ZFC) magnetization process systematically. After some manipulation, the effect of viscous flux flow on the crack–inclusion problem within the superconductor is discussed base on J-integral theory. The simulated results indicate that with the increase of viscous flux flow, the stress intensity factor will increase correspondingly, but the trend of the curve with the elastic modulus, crack length and inclusion radius does not change, associated with the distance between the left crack tip and the inclusion. Compared with viscous flux flow, the effect of the crack length on crack propagation may be more significant under a lower viscous flux flow rate. However, at the higher viscous flux flow, the opposite is true.

A design of digital application specific integrated circuit (ASIC) of quartz-gyro is proposed in this paper. The digital drive circuit with fast-start oscillation and digital detection circuit with low noise are adopted to implement the digital output of the main circuit node and high precision angular velocity detection. The interface circuit is fabricated in a standard 0.35 $\mu$m CMOS technology and test result shows the angular random walk and zero stability are $0.022^{\circ }$/$\sqrt{\mathrm{\text{h}}}$ and $2.9^{\circ }$/h ($1\sigma$), respectively. The bias-instability is $1^{\circ }$/h (Allen). The nonlinearity is limited to 0.035% and the zero temperature drift is $16^{\circ }$/h from $-45^{\circ }\mathrm{\text{C}}$ to $85^{\circ }\mathrm{\text{C}}$. The chip exhibits great superiority on the aspects of high precision angular velocity digital detection and temperature characteristics of overall system.

In this paper, a new two-lane lattice hydrodynamic model is presented by accounting for the “backward looking” effect and the relative flow information. Linear analysis is applied to deduce the linear stability condition. With this method, we can demonstrate that “backward looking” and relative flow information have great positive significance in improving traffic flow stability. Nonlinear analysis is performed to derive the mKdV equation, which can represent transmission characteristic of density waves. The results achieved by the numerical simulation are consistent with theoretical analytical results. Numerical results indicate that both “backward looking” effect and relative flow information are helpful to heighten the traffic flow stability efficiently in two-lane traffic model.

In this study, two integration techniques are employed to reach optical solitons to the $(n+1)$-dimensional nonlinear Schrödinger’s equation $((n+1)$-NLSE$)$ with Kerr and power laws nonlinearities. These are the undetermined coefficient and Bernoulli sub-ODE methods. We acquired bright, dark, and periodic singular soliton solutions. The necessary conditions for the existence of these solitons are presented.