A Novel Rectangular Slot Loaded Microstrip Patch Antenna

In this communication the inclined slot loaded rectangular microstrip patch antenna fed by microstripline is presented for modern communication system. The antenna is housed in a volume of 5X3X0.16cm3. The low loss tangent and commercially available modified glass epoxy substrate material is used for the fabrication of the antenna. The design concept is presented. The proposed antenna gives a maximum bandwidth of 20.78% and overall bandwidth of 44.49% with operating range of 8.28 GHz to 12 GHz. The antenna shows broadside and linear radiation characteristics with a peak gain of 7.08 dB. The experimental and simulated results are compared. This antenna may find its applications in X-band range communication systems.

Spintronics phenomena induced by THz radiation in narrow-gap HgCdTe thin films in an external constant electric field

The responses of uncooled (T = 300 K) and cooled to T = 78 K antenna-coupled Hg1–xCdxTe-based narrow-gap thin-film photoconductors having large spin-orbit coupling and irradiated by the terahertz (THz) radiation (linearly or circularly polarized) have been investigated. Powerful THz radiation excitation causes photocurrents, which signs and magnitudes are controlled by orientation of antenna axes, an external constant electric field direction and orientation of the polarized (circular or linear) radiation electric field falling onto photoconductors. The observed effects seem to be caused by the spin currents observed in devices where spintronic effects are revealed. spintronic phenomena, photoconductors, THz radiation, HgCdTe.

Entropy generation of peristaltic Eyring–Powell nanofluid flow in a vertical divergent channel for biomedical applications

Exploring the movement of blood in a blood vessel has been fascinated by clinicians and biomedical researchers because it is predominant in cell tissue engineering, drug targeting and various treatments like hypothermia, hyperthermia, and cancer. It is noticed that numerous non-Newtonian rheological fluids like Carreau fluid, tangent hyperbolic fluid, Eyring–Powell fluid and viscoelastic fluid manifest the characteristics of blood flow. Further, the investigation of entropy generation can be used to raise the performance of medical equipments. Consequently, the present mathematical model scrutinizes the transport characteristics and entropy generation of the peristaltic Eyring–Powell nanofluid in a permeable vertical divergent channel in the presence of dissipation and linear radiation. The non-similar variables are employed to convert the dimensional partial differential equations into dimensionless form which are tackled by the Homotopy perturbation method. The impacts of emerging parameters like Eyring–Powell parameters, left and right wall amplitudes, thermophoresis, mean flow rate, radiation, permeability parameter, Brownian motion, Eckert number, Hartman number on Eyring–Powell nanofluid axial velocity, temperature, and concentration are manifested. Present results disclose that the thermal Grashof number highly inflates the pressure rise. Eyring–Powell nanofluid temperature reduces for uplifting the linear radiation parameter. Growing values of the non-uniform parameter lead to move the trapping bolus towards the left and right wall. The total entropy generation diminishes for magnifying the temperature difference parameter.

Entropy Generation Incorporating γ-Nanofluids under the Influence of Nonlinear Radiation with Mixed Convection

Nanofluids offer the potential to improve heat transport performance. In light of this, the current exploration gives a numerical simulation of mixed convection flow (MCF) using an effective Prandtl model and comprising water- and ethylene-based γγ−Al2O3 particles over a stretched vertical sheet. The impacts of entropy along with non-linear radiation and viscous dissipation are analyzed. Experimentally based expressions of thermal conductivity as well as viscosity are utilized for γγ−Al2O3 nanoparticles. The governing boundary-layer equations are stimulated numerically utilizing bvp4c (boundary-value problem of fourth order). The outcomes involving flow parameter found for the temperature, velocity, heat transfer and drag force are conferred via graphs. It is determined from the obtained results that the temperature and velocity increase the function of the nanoparticle volume fraction for H2O\C2H6O2 based γγ−Al2O3 nanofluids. In addition, it is noted that the larger unsteady parameter results in a significant advancement in the heat transport and friction factor. Heat transfer performance in the fluid flow is also augmented with an upsurge in radiation.

Composite structure manufacturing at wheel steel strengthening with linear radiation profile of ytterbium fiber laser

There are presented theoretical and experimental investigations of wheel steel laser thermal treatment with the use of ytterbium fiber laser. Thermal treatment modes are obtained on the basis of the mathematical modeling preliminarily carried out of the heat propagation processes by a finite element method.

Physical Aspects on MHD Micropolar Fluid Flow Past an Exponentially Stretching Curved Surface

The present analysis is composed of heat transfer characteristics on MHD free convective stagnated flow of micropolar liquid due to stretching of an exponential curved sheet. The flow is supposed to be time-independent and not turbulent. The impact of non-linear radiation, unequal heat source/sink, Joule heating and variable thermal conductivity are supposed. Appropriate alterations are mused to change the original PDEs as ordinary ones and then solved by shooting and fourth order Runge-Kutta-Fehlberg integration schemes. Graphs are outlined to inspect the impacts of sundry non-dimensional variables on the distributions of velocity, micro rotation and temperature. We discern that there is an augmentation in the fields of heat with Eckert number, nonlinear radiation and irregular hear parameters. Also it is motivating to comment that material parameter is a decreasing function of velocity. We establish the consequences in this analysis evidence to be extremely agreeable with the obtainable consequences.