Existence Of Radiation Research Articles

Computational assessment of flow and heat transfer characteristics through Cu + Al2O3 + TiO2 ternary hybrid nanomaterial host-water with shape effect

ABSTRACT Solar energy stands out as a vital source of thermal power derived from the sun. Its capacity finds applications across various technological domains, including photovoltaic panels, solar vehicles, solar lighting infrastructure, and solar water pumps. The contemporary landscape emphasizes the integration of solar energy in industries, notably exemplified by the prevalence of solar-powered charging stations. This article proposes a new perspective on heat transport analysis, incorporating the shape effect on the ternary hybrid nanofluid model along with considerations of thermal radiation, Cattaneo–Christov heat flux factor, heat source, and sink. For the evaluation, three differently shaped ternary hybrid nanoparticles are taken into account including platelet-shaped Cu , cylindrical-shaped A l 2 O 3 , and disc-shaped Ti O 2 . Through boundary layer approximations, the contributions of radiation, heat source, and sink variables are implemented into the regulating equations. The redesigned ordinary differential equations are numerically solved employing the NDSolve method after treating similarity variables. In the case of physical quantities, multiple linear regression is introduced to discover solutions for the flow elements. Augmentation in the momentum of dissimilarly shaped Cu , A l 2 O 3 and Ti O 2 nanoparticles enhance the velocity of ternary hybrid nanofluid flow more than that of spherical-shaped nanoparticles. The significant heat transfer is observed in mono, hybrid and ternary nanofluids with the existence of radiation and heat source phenomena. The multiple linear regression precisely forecasted the physical quantities with the error 10 − 3 . An application of a ternary hybrid nanofluid in a solar powered charging station can efficiently perform and successfully address an energy crisis by exhibiting an acceptable amount of power. This capability contributes to the reliable charging of electronic devices. Also, the machine learning technique can reliably and accurately perform the heat transfer analysis.

A numerical study on MHD Maxwell fluid with nanoparticles over a stretching surface: Impacts of thermal radiation, convective boundary condition and induced magnetic field

The current study investigates the influence of induced magnetic field and convective boundary condition on the behavior of a magnetohydrodynamic (MHD) Maxwell fluid including nanoparticles flowing through a stretching sheet. Furthermore, the analysis considers the existence of radiation. Numerical solutions to the basic governing equations are achieved using the Runge–Kutta–Fehlberg technique. The impact of various physical parameters on concentration, velocity, and temperature profiles is deployed through graphs. The primary conclusions of this study are that increasing the Magnetic parameter decreases the Induced Magnetic field while increasing the Deborah parameter improves the velocity profile. Temperature distribution is growing due to increased estimates of the Radiation, Biot number, and Deborah number values. When the Lewis number values are raised, the concentration profiles get smaller but there is an opposite scenario deployed as the Thermophoresis parameter upsurges. The findings of this study are consistent with those that have been previously reported. The phenomenon of flow induced by a stretched surface finds several applications in various industrial and technological domains, including copper wire production, polymer extrusion, article manufacturing, and fiber synthesis. Induced magnetic fields are extremely prominent in many areas of science and technology, including electromagnetism, magnetic materials, and magnetic resonance imaging (MRI).

Velocity and Thermal Slips Impact on the Williamson Fluid Flow above a Stretching Sheet in the Existence of Radiation and Inclined Magnetic Field

Research has been conducted on the study of the velocity and thermal slips' impact on the Williamson fluid flow above a stretching sheet in the existence of an inclined magnetic field and Radiation. By applying the proper similarity conversions, the governing equations (PDEs) are reduced to a set of non-linear ODEs, and a numerical solution is produced by using MATLAB in-built solver bvp4c package. The impacts of the dimensionless characteristics on the flow patterns are analyzed visually, and the values of the friction, Nusselt, and mass transfer quantities are tabulated to exemplify how the various physical factors have an influence. We noted that the velocity profile enhances the rising estimations of velocity slip and the temperature profile increases with Q increase.

MHD STAGNATION POINT FLOW WITH THERMAL RADIATION AND SLIP EFFECT OVER A LINEAR STRETCHING SHEET

This research investigates the flow of stagnation point magnetohydrodynamic (MHD) and heat transfer along the stretched sheet in the existence of radiation and slip effects. With the help of similarity variables, the governing partial differential equations (PDEs) are transformed into ordinary differential equations (ODEs). The BVP4C technique in Matlab function has been used to simplify the governing ODEs. The numerical outcomes for temperature and velocity profiles, coefficient of skin friction and Nusselt Number have been achieved and matched with the findings in literature. The findings are compared to previously reported results. In addition, the impacts of numerous related parameters on the profiles of velocity and temperature are shown, and the results of every related parameter are presented using graphs. The velocity profile decreases as the magnetic force, suction, and permeability parameters rise.

Numerical Solution of Radiative and Dissipative Flow on Non-Newtonian Casson Fluid Model via Infinite Vertical Plate with Thermo-Diffusion and Diffusion-Thermo Effects

This research presents mathematically developed model to examine non-Newtonian Casson fluid flow in the existence of radiation, Ohmic dissipation, thermo-diffusion and diffusion-thermo over infinite vertical plate domain. Using similarity transformations, the governing partial derivative related to fluid model is transmuted to ordinary derivative equations and then solved computationally by adopting Runge-Kutta method via shooting quadrature in mathematical software MAPLE. The impacts of various considered effects were assed and solutions for momentum velocity profiles, heat transfer energy and mass transfer concentration profiles are investigated via graphical presentation. The outcomes show that radiation and magnetic field increased heat distribution and improvement in yield stress through an enhancement in Casson term reduces the flow speed. Presence of Cross diffusion terms has remarkable impact on thermal and solutal profiles. Further, numerical significances of engineering quantities such as skin friction, Nusselt number and Sherwood number are provided in tabular form. Finally, to justify the outcomes of this study, a resemblance is taken with earlier published works and found there is good correlation.

Modeling and computation of nanofluid for thermo-dynamical analysis between vertical plates

It is well fact that the computational complexity of unsteady and viscoelastic nanofluid can be measured by mathematical modeling that allows the suitable performance for variations from specific to particular rheological parameters. This manuscript addresses the fractionalized mathematical modeling of an unsteady incompressible Maxwell transient free convection flow of nanofluids in the existence of radiation as well as damped thermal flux by using the Caputo time-fractional derivative. The integral transform technique is invoked on the fractionalized governing equations to find the exact solution. The numerical solution to the problem is also attained by utilizing Stehfest and Tzou algorithms. Finally, for the sake of graphical illustration, the comparative analysis for validating both algorithms on velocity and temperature profiles is performed numerically. The temperature and velocity curves are reduced by growing α for small time, and behavior is contrary for large time. By growing values of [Formula: see text] declines the velocity profiles. Velocity is linearly proportional to relaxation time λ, and the boundary layer difference is decreased by increasing the time. Our achieved solutions via two different numerical methods, that is, Stehfest and Tzou are equal.

New Features of the Pulsar B0950+08 Radiation at the Frequency of 111 MHz

Results of long time observations of the pulsar B0950+08 are given. These observations were carried out at the LPA radio telescope at the frequency of 111 MHz from January of 2016 to May of 2019 (450 days). A strong variability in emission of this pulsar has been detected with changes in signal to noise ratios hundreds of times. Part of the long-time flux density variability can be explained by refractive scintillations in the interstellar medium. The existence of radiation between the interpulse (IP) and main pulse (MP) was confirmed. It was more powerful than at high frequencies. We detected the unusual IP and precursor (Pr) radiation on 2017 August 1. On the basis of 65 strong IPs we found the correlations between energies of IP and Pr and between the phase of IP and the distance Pr–IP. It is shown that the observed peculiarities of this pulsar can be explained in the frame of the aligned rotator model. We estimated distances of radiation levels from the center of the neutron star. The calculated value of the initial period of 0.2 s means that not all pulsars are born with millisecond periods. The large age of the pulsar (6.8 million years) and the small angle between its magnetic moment and the rotation axis (less than 20°) confirm the suggestion related to pulsar evolution with respect to alignment.

Mathematical modeling of steady MHD Casson fluid flow with stretching porous walls in existence of radiation, chemical reaction, and thermal diffusion effect

This expression presents the steady (independent of time) MagnetoHydroDynamics (MHD) Casson fluid (non‐Newtonian shear‐thinning) flow with thermal radiative impression between two equivalent plates within stretched porous walls. The mass and heat transfer experimentation founded in the company of buoyancy force, viscous dissipative impact, and thermo diffusion impact on squeezing flow are explained along with thermal radiative impression also with heat source/sink outcomes. The governing PDEs (partial differential equations) modified into ODEs (ordinary differential equations) via appropriate similarity modification. The ODEs are extricated by Runge–Kutta's fourth‐order scheme and shooting performance. The outcomes of several parameters (nondimensional numbers) on velocity, temperature, and concentration are evaluated with the service of diagrams and tables. The result displays that the fluid velocity growths with increment of Grashof number. The effect of Reynolds number, Hartman number (magnetic number), non‐Newtonian Casson fluid parameter, and so forth are also interpreted for velocity profile, mass transfer, and heat transfer. In the last, the skin friction coefficient, Sherwood number (mass transfer coefficient), and Nusselt numbers (heat transfer coefficient) are also reputed. Also, validation of the current paper is given in Table 2.

A numerical study on gasification of a single char particle in supercritical water for hydrogen production

Supercritical water gasification technology provides a promising way for the efficient and clean utilization of coal. Char conversion in supercritical water is a complex coupled process of flow, heat transfer and reaction, and particle-scale study can provide important details for its in-depth understanding. A numerical work was conducted in this paper to investigate the influence of multiple factors on the gasification behavior of a single char particle in supercritical water. The results showed that the increase of temperature significantly benefited the char conversion and hydrogen production. Convection promoted the char gasification mainly by enhancing the heat transfer, and its improvement on effective mass transfer was quite limited. The existence of radiation is conducive to the char conversion, and cannot be ignored in some cases. The results derived from surface Damköhler number indicated that the gasification lied in kinetically controlled regime and tended to move towards diffusion controlled regime with larger inflow temperature, lower Reynolds number and larger particle size.

Спосіб визначення геометричних параметрів колових підкранових колій

Висвітлено проблеми визначення геометричних параметрів колових підкранових колій. Розглянуто відомі методики контролю геометрії криволінійної підкранової колії. Із появою нових сучасних електронних тахеометрів постало завдання розроблення нового способу вимірювання підкранової колії полярного крана реакторного відділення. Запропоновано нову методику визначення геометричних параметрів колових підкранових колій за допомогою електронного тахеометра, який полягає у визначенні координат точок, замаркованих на колії. На віддалях 20 мм від краю колії з інтервалом у 2,81 м розмічують керном і насвердлюють 48 точок діаметром 3 мм. Виміри виконують з трьох станцій, на яких попередньо закріплюють встановлюють три штатива з підставками, на яких послідовно встановлюють електронні тахеометри або відбивачі. Вимірювання виконують почергово в секторах 25÷7, 7÷37, 12÷42, 25÷42 і використовують міні-призму. За результатами вимірів аналітично розраховують геометричні параметри колії і дані для оптимального рихтування. Використання способу визначення геометричних параметрів колових підкранових колій згідно з пропонованим винаходом підвищує оперативність проведення виконання геодезичної зйомки, ефективність знаходження геометричних даних та зумовлює зниження витрат часу для одержання результату. За допомогою універсального апроксимуючого алгоритму знайдено радіуси та розраховано дані для рихтування колії колового крана, що допомагає знизити затрати на виконання ремонтних робіт.

Improving the methods of polar crane runway rail parameters during a geodesic control

The purpose of this work is to show that using electronic flexible rulers, digital gradienters, electronic motometers and other special-purpose tools effectively solves the problem of automating the measuring process of polar crane runway rails geodesic parameters. It is recommended to use the special modifications for eliminating appreciable and systematic errors. The existence of radiation in the Atomic Power Station premises offers insights into the process of geodesic works. People can access the reactor building only when the reactor is not working. That's why the developed methods of geodesic measurements should provide the highest quality and reliability of obtained results, as well a partial or full measurements automation. The results of geodesic measurements are influenced by the air vibration, oscillation, and temperature drops between the floor and runwail rails levels [1–3]. During this, the contractor has to take the necessary measurements as fast as possible, which can decrease the quality and cause raw miscounts. There are a lot of methods for determining the planned-high-altitude positions of runway rail. The most famous among them are Ruskov [4, 5] and Burak methods.[6, 7]. According to the Burak method, the rail axis is marked as the middle of the surveying rod and the distances between the rail axis points are measured. According to the measurements, the radius of rail axis and the deviation of rail axis points from the radius are determined. However, this famous method is too time-consuming. It requires using 50m tape measures for measuring the distances between the rail points. It doesn't provide efficiency of measurements and further control of rail lining. Except this, you have to lift or drop the crane mechanisms to take the measurements. Deformations of runway rails may lead to the outage of works. The geometric runway rail parameters are checked in the first days of PPR, before starting the technological repair operations [7, 8]. The periodicity of defining the runway rail parameters depends on the conditions of its operation and reliability of under the crain constructions. In average, it is one cycle a year during the PPR according to the requirements in regulatory documents. That's why increasing the efficiency of geodesic checking of runway rails reliability by incorporating new methods and technologies is a significant task.

Dark energy and collapsing axial system

This paper investigates the effects of dark source term on the dissipative axially symmetric collapse by taking self-interacting Brans–Dicke (SBD) gravity as a dark energy (DE) candidate. We discuss physically feasible energy source of the model and formulate all the dynamical variables as well as structure scalars. It is found that the dark source term is one of the source of anisotropy and dissipation in the system. Further, we obtain structure scalars in this background. In order to discuss factors describing dissipative collapse, we develop equations related to the evolution of dynamical variables, heat transport equation as well as super-Poynting vector. We conclude that the thermodynamics of the collapse, evolution of kinematical terms (like expansion scalar, shear and vorticity) and inhomogeneity are affected by dark source term. Finally, we study the existence of radiation having repulsive gravitational nature in this collapse scenario.

Series solution for heat transfer of continuous stretching sheet immersed in a micropolar fluid in the existence of radiation

PurposeThe purpose of this paper is to study a two‐dimensional steady convective flow of a micropolar fluid over a stretching sheet in the presence of radiation with constant temperature.Design/methodology/approachThe corresponding momentum, microrotation and energy equations are analytically solved using homotopy analysis method (HAM).FindingsTo validate the method, investigate the accuracy and convergence of the results, a comparison with existing numerical and experimental results is done for several cases. Finally, by using the obtained analytical solution, for the skin‐friction coefficient and the local Nusselt number as well as the temperature, velocity and angular velocity, profiles are obtained for different values of the constant parameters, such as Prandtl number, material, boundary and radiation parameter.Originality/valueIn this paper, a series solution is presented for the first time.

Electrodynamics of Radiating Charges

The theory of electrodynamics of radiating charges is reviewed with special emphasis on the role of the Schott energy for the conservation of energy for a charge and its electromagnetic field. It is made clear that the existence of radiation from a charge is not invariant against a transformation between two reference frames that has an accelerated motion relative to each other. The questions whether the existence of radiation from a uniformly accelerated charge with vanishing radiation reaction force is in conflict with the principle of equivalence and whether a freely falling charge radiates are reviewed. It is shown that the resolution of an electromagnetic “perpetuum mobile paradox” associated with a charge moving geodetically along a circular path in the Schwarzschild spacetime requires the so-called tail terms in the equation of motion of a charged particle.

Radiation in the process of the formation of voids

This paper aims to investigate the influence of inhomogeneous radiation in void formation. Since the process of void formation is non-linear, a fully relativistic model, which simulates the evolution of voids from the moment of the last scattering until the present instant, is presented. It is found that in order to obtain a model of a void which evolves from δ0=−10−5 at the last scattering moment to the present day δ=−0.94, the existence of radiation must be taken into account. The ratio of radiation energy density to matter energy density in cold dark matter (CDM) models at the moment of last scattering is 1/5. This paper proves that such a value of radiation energy density cannot be neglected and influences the first stages of void evolution. Namely, it is important to the process of structure formation and hence significantly influences the dynamics of the Universe in the first millions of years after the last scattering. From the fact that the evolution of voids proceeds differently in various cosmological background models, we use the process of void formation to put some limits on values of cosmological parameters. We find that the model with Ωmat∼ 0.3 fits the observational data best.

Properties of optical transition radiation and Vavilov–Cherenkov radiation for charged particle inclined flight through a plate of metal

In this work a detailed derivation of all elements of optical transition radiation emitted by charged particle inclined flight through parallel absorbing plate is presented. The contribution of the main fractions of optical transition radiation in copper is analyzed and the existence of radiation, which is equivalent to Vavilov–Cherenkov radiation is shown.

X-ray and energetic neutral particle emission from Saturn's magnetosphere

A description is presented of observations of the Voyager 1 spacecraft obtained a few days before encounter of the Saturn magnetosphere in November 1980. As Voyager 1 has no special experiment onboard for X-ray and neutral particle detection, the sensitivity and directional measurements of the low energy charged particle (LECP) analyzer is used to identify the neutral radiation above the charged particle background. The LECP telescope uses a silicon detector of 96.6 micrometers thickness and 0.08 sq cm area to accumulate counts in eight separate sectors near the ecliptic plane. The existence of radiation above the detector background emanating from the vicinity of Saturn, upstream from the bow shock is shown. The excess counts are most plausibly attributed to neutral radiation, that is, X rays and/or neutral energetic particles. However, in connection with quantitative considerations the observed excess counts are probably not due to X-rays. It is concluded that charge exchange of energetic ions with satellite tori is an important loss mechanism at Saturn as well as at Jupiter.

Cavity self-induced step for a Dayem bridge

The existence of radiation from a Dayem bridge is demonstrated by the observation of a self-induced cavity step. The form of the step is explained in terms of a dc-current-biased resistively shunted ideal Josephson device coupled to a resonance circuit. The behavior when a capacitor is included is also discussed.

Cherenkov Radiation due to Passage of an Oscillating Dipole

Simple expressions of radiation caused by an oscillating dipole moving with a uniform velocity have been deduced. Region of radiation is much wider than that of usual Cherenkov radiation. Some interesting features as two cones of radiation, existence of radiation in the non-Cherenkov region and the interference like phenomenon in the intensity of radiation are found which are not present in the usually traced Cherenkov radiation.

On the energy conservation for the motion of a radiating electron with particular reference to the hyperbolic motion

The energy conservation in the motion of a radiating electron is studied by means of the finite differences equation proposed by Caldirola. The acceleration energy or the Schott’s energy, that occurs in the classical theory of Dirac-Eliezer, does no longer appear in the conservation equation. The rate of radiated energy reduces to an obvious relativistic generalization of the classical Larmor’s law, when terms inτ0n withn⩾3 (whereτ0=4/3(e2/m0c3)) are neglected. Exact calculations are performed in the case of the hyperbolic motion and the existence of radiation is confirmed.