Dynamic study of Weyl tensor corrected f(R) gravity

We investigate the cosmological and thermodynamic aspects of Weyl tensor corrected [Formula: see text] gravity. For this purpose, we assume some well-known cosmological bouncing scenarios such as symmetric bounce cosmology, oscillatory cosmology, matter bounce cosmology, little rip cosmology, superbounce cosmology and develop some cosmological parameters. For instance, the equation of state parameter [Formula: see text] describes the quintessence phase for symmetric bounce cosmology, vacuum phase for oscillatory, little rip and matter bounce cosmology while it gives both quintessence and vacuum phases for matter bounce cosmology. It is also observed that the squared speed of sound [Formula: see text] gives positive behavior for all models resulting in that the models assumed are stable. We evaluate generalized second law of thermodynamics which remains valid for all cosmological models except symmetric bounce cosmology. Moreover, we also investigate the thermal equilibrium condition [Formula: see text] and found its validity for all models except symmetric bounce cosmological model.

Cosmological implications in f(P) gravity

In the framework of [Formula: see text] gravity, we examine the nature of cosmological parameters by choosing different models of [Formula: see text] gravity at past, present as well as future epoch for Hubble parameter from parameterized deceleration parameters. It is found that equation of state parameter leads to quintessence behavior and its ranges lie within Planck data for different constraints. We also study the squared sound speed and the thermodynamics for specific choice of constants. The squared sound speed corresponds to the viable results. Similarly, the validity of GSLT is also investigated for both linear and nonlinear models of [Formula: see text] theory. However, the thermal equilibrium condition holds for both [Formula: see text] models for specific choice of constants.

Simulation of chemo-thermo-mechanical problems in cement-based materials with Peridynamics

A chemo-thermo-mechanical problem is solved using a peridynamic approach to investigate crack propagation in non-reinforced concrete at early-age. In the present study, the temperature evolution and the variation of the hydration degree in conjunction with the mechanical behaviour of cement-based materials are examined. Firstly, a new peridynamic model is introduced to solve fully coupled chemo-thermal problems by satisfying thermal equilibrium condition and hydration law simultaneously and then the effects of the chemo-thermal analysis are imposed in the mechanical framework to investigate all the interactions. The proposed approach is used to solve 2D chemo-thermo-elastic problems and then it is applied to investigate the fracture of concrete structures. Additionally, we examine the accuracy of the method by comparing the crack paths, temperature and hydration degree with those achieved by applying other numerical methods and the experimental data available in the literature. A good agreement is obtained between all sets of results.

Opto-Electro-Thermal Modelling of Thin-Film Hydrogenated Amorphous Silicon (a-Si:H) Photovoltaic Cell

A one-dimensional opto-electro-thermal simulator for an a-Si:H based thin-film solar cell is developed. The simulator includes optical, electrical, and thermal modelling for a complete modelling of energy conversion in a-Si:H based solar cells. Particularly, the thermal impact on the performance of the cell has been studied. Cell performance is worse when thermal simulation is included compared to simulations where temperature is kept constant. This implication suggests that cell performance is typically overestimated in simulations where the thermal effect is ignored. A simplified optical model was used, reducing the computational resources required in the study. The electrical model proposed in this study extends the classical drift-diffusion model to include the effects of temperature. The proposed thermal model considers the energy conservation in a non-thermal equilibrium condition between electron, optical phonons, and acoustic phonons. While simplifications have been used to reduce the complexity of the simulations, the program captures the essential behaviour of the cell with reasonable accuracy. Hence, the developed program is useful for a-Si:H based thin-film solar cell design and optimization.

Analysis of cubic gravity through cosmic aspects

In the context of cubic gravity for flat FRW metric we discuss the behavior of cosmological parameters (equation of state (EoS) parameter and square speed of sound) at Hubble horizon with the four different models of Hubble parameter. We observe the validity of generalized second law of thermodynamics (GSLT) and thermal equilibrium condition. It is found that cosmological parameters lie within the observational constraints. Also, GSLT and thermal equilibrium condition holds in almost all cases of Hubble parameter.

Cosmological and thermodynamics consequences of viscous modified theories of gravity

The illustration of cosmic acceleration is being presented in the framework of DGP braneworld and dynamical Chern–Simons modified gravity in the presence of casual Israel–Stewart formalism. In this way, we discuss the evolution parameter which leads to the accelerated expansion of the universe in the phantom as well as quintessence region for both gravities. The squared speed of sound [Formula: see text] leads to the stable behavior of the current physical system in both gravities in the later epoch. Also, the entropy variation, as well as thermal equilibrium condition, remains valid in both frameworks at the present and later epoch.

Particle Creation and Thermal Aspects of Viscous Generalized Cosmic Chaplygin Gas

We investigate the particle creation, as well as the thermodynamics phenomenon of viscous generalized cosmic Chaplygin gas as a cosmic fluid by assuming the flat FRW universe. For this purpose, we extract various parameters such as the energy density ( ρ ) , Hubble parameter ( H ) , declaration parameter ( q ) , temperature ( T f ) , and particle number density ( n ) in the presence of three different models of the particle creation rate ( Γ ). We discuss the validity of the generalized second law of thermodynamics and thermal equilibrium condition under three models of Γ and discuss the graphical behavior of above-mentioned terms.

Thermodynamics of Various Entropies in Specific Modified Gravity with Particle Creation

We consider the particle creation scenario in the dynamical Chern-Simons modified gravity in the presence of perfect fluid equation of state p=(γ-1)ρ. By assuming various modified entropies (Bekenstein entropy logarithmic entropy, power law correction, and Renyi entropy), we investigate the first law of thermodynamics and generalized second law of thermodynamics on the apparent horizon. In the presence of particle creation rate, we discuss the generalized second law of thermodynamics and thermal equilibrium condition. It is found that thermodynamics laws and equilibrium condition remain valid under certain conditions of parameters.

Mechanism and its Mathematical Expressions of Stress-Induced Light Emission of ZnS:Mn/Polyester Composite

Mechanism of mechanoluminescence of the composite of Mn-doped ZnS particles and polyester resin is developed based on the principle of Fermi-level shift, associated by piezoelectric effect. As the electron-hole recombination is responsible for light emission, it is possible to determine the number of emitted photons from the difference in number of conducting electrons between the stressed state and the thermal equilibrium condition. For the given emission color, characteristics of photomultiplier tube and deformation conditions, the emitted photons can be approximated. The model is expressed as A[exp (Bσ2) - 1] where σ is the applied stress, a pre-exponential A illustrates the efficiency of luminescent centers and the influences of dielectric and piezoelectric constants of ZnS host and temperature are displayed as the exponent factor B.