Electro-osmotic driven flow of Eyring Powell nanofluid in an asymmetric channel

This article aims to investigate the numerical study of electroosmotic flow of the Eyring Powell fluid under the peristaltic mechanism with the influence of the porous medium in the micro-channel. The modified system is applied externally to an electrical field in the horizontal direction and to a magnetic field in the transverse direction. The flow of nanofluids is considered in the computation. The governing equations in the nano-fluid flow are modulated. Influence of lubrication theory approximation longequations are shortened. Reduced coupled nonlinear partial differential equations like velocity and energy equations are numerically solved using the powerful and well-known mathematical software MATHEMATICA by built in NDSolve command. The influence of various important parameters on the velocity and temperature profile is summarised by graphs.

Modeling of 980 nm and 1470 nm Laser Radiation Absorbance Efficiency in the Blood Vessel Depending on the Structure of Titanium–Containing Optothermal Fiber Converter

Using quartz fiber with titanium-containing optothermal fiber converter (TOTFC) is promising in endovenous laser coagulation (EVLA) for the treatment of varicose veins. This study aims to research the variation in the optical properties of TOTFC as its microstructure changes under the condition that TiO2 spheres inside converter are arranged in such a way that the Mie theory approximation can be applied. The absorbance efficiency of laser energy with 980 nm and 1470 nm wavelengths for TOTFC has been calculated. Optical multidimensional simulation for the EVLA process was developed and calculated. The optimal ranges of microstructure’s parameters for TOTFC in the EVLA process were discussed.

Connecting quantum calculus and harmonic starlike functions

Quantum calculus or q-calculus plays an important role in hypergeometric series, quantum physics, operator theory, approximation theory, sobolev spaces, geometric functions theory and others. But role of q-calculus in the theory of harmonic univalent functions is quite new. In this paper, we make an attempt to connect quantum calculus and harmonic univalent starlike functions. In particular, we introduce and investigate the properties of q-harmonic functions and q-harmonic starlike functions of order ?.

Localized Conical Edge Modes in Optics of Spiral Media (First Diffraction Order)

In cholesteric liquid crystals (CLC) problems related to the localized optical modes for a non-collinear geometry are studied here in the two wave dynamic diffraction theory approximation. This approximation, which insures the results accuracy order of δ (where δ is the CLC dielectric anisotropy), is applied because for a non-collinear geometry there is no exact analytic solution of the Maxwell equations and a theoretical description of the experimental data becomes more complicated. The dispersion equation for non-collinear localized edge modes (called conical modes (CEM)) is found and analytically solved for the case of thick layers and for this case the lasing threshold and the conditions of the anomalously strong absorption effect are found. It is shown that qualitatively CEMs are very similar to the localized edge modes (EM) in CLCs related to a collinear geometry, i.e., for the case of light propagation along the spiral axis however the CEMs differ by their polarization properties (the CEM eigen polarizations are elliptical ones depending on the degree of CEM deviation from the collinear geometry in contrast to the circular eigen polarizations in the EM case). What is concerned of the CEM quantitative values of the parameters they are “worth” (the photonic effects are not so pronounced) than for the corresponding ones for EM. The CEM lasing threshold is higher than the one for EM, etc. Performed theoretical studies of possible conversion of EMs into CEMs showed that it can be due to the EM reflection at dielectric boundaries at the conditions of a high pumping wave focusing. Known experimental results on the CEM are discussed and optimal conditions for CEM observations are formulated.

First Principles Study of the Vibrational and Thermal Properties of Sn-Based Type II Clathrates, CsxSn136 (0 ≤ x ≤ 24) and Rb24Ga24Sn112

After performing first-principles calculations of structural and vibrational properties of the semiconducting clathrates Rb24Ga24Sn112 along with binary CsxSn136 (0 ≤ x ≤ 24), we obtained equilibrium geometries and harmonic phonon modes. For the filled clathrate Rb24Ga24Sn112, the phonon dispersion relation predicts an upshift of the low-lying rattling modes (~25 cm−1) for the Rb (“rattler”) compared to Cs vibration in CsxSn136. It is also found that the large isotropic atomic displacement parameter (Uiso) exists when Rb occupies the “over-sized” cage (28 atom cage) rather than the 20 atom counterpart. These guest modes are expected to contribute significantly to minimizing the lattice’s thermal conductivity (κL). Our calculation of the vibrational contribution to the specific heat and our evaluation on κL are quantitatively presented and discussed. Specifically, the heat capacity diagram regarding CV/T3 vs. T exhibits the Einstein-peak-like hump that is mainly attributable to the guest oscillator in a 28 atom cage, with a characteristic temperature 36.82 K for Rb24Ga24Sn112. Our calculated rattling modes are around 25 cm−1 for the Rb trapped in a 28 atom cage, and 65.4 cm−1 for the Rb encapsulated in a 20 atom cage. These results are utilized to predict the lattice’s thermal conductivity (approximately 0.62 W/m/K) in Rb24Ga24Sn112 within the kinetic theory approximation.

Nonlinear Dynamics of Rotating Structures and Helicopter Blades

This work explores the effects of geometrical nonlinearities in the vibration analysis of rotating structures and helicopter blades. Structures are modelled via higher-order beam theories with variable kinematics. These theories fall in the domain of the Carrera Unified Formulation (CUF), according to which the nonlinear equations of motion of rotating blades can be written in terms of fundamental nuclei, whose formalism is an invariant of the theory approximation. The inherent three-dimensional nature of CUF enables one to include all Green-Lagrange strain components as well as all coupling effects due to the geometrical features and the three-dimensional constitutive law. Numerical solutions are considered and opportunely discussed. Also, linearized and full nonlinear solutions for vibrating rotating blades are compared both in case of small amplitudes and in the large deflections/rotations regime.