This paper provides a comprehensive study on the heat transfer and entropy generation rates in a channel partially filled with a porous medium and under constant wall heat flux. The porous inserts are attached to the walls of the channel and the system features internal heat sources due to exothermic or endothermic physical or physicochemical processes. Darcy-Brinkman model is used for modellin...

Warning indicators of the dam body's temperature are required for the real-time monitoring of the service conditions of concrete dams to ensure safety and normal operations. Warnings theories are traditionally targeted at a single point which have limitations, and the scientific warning theories on global behavior of the temperature field are non-existent. In this paper, first, in 3D space, the...

The changes in excess thermodynamic quantities upon the contact of two solutes immersed in a solvent are analyzed using the radial-symmetric and three-dimensional versions of the integral equation theory. A simple model mimicking a solute in water is employed. The solute-solute interaction energy is not included in the calculations. Under the isochoric condition, the solute contact always leads...

Using the five-site transferable intermolecular potential (TIP5P) we perform molecular dynamics simulations to investigate the relationship between the excess entropy and anomalies of water. We find that the two-body excess entropy is an ideal quantity to predict the regions of structural, dynamic, and thermodynamic anomalies of water in its pressure-temperature and density-temperature phase di...

In the modeling of solids the free energy, the energy, and the entropy play a central role. We show that the free entropy, which is defined as the negative of the free energy divided by the temperature, is similarly important. The derivatives of the free energy are suitable thermodynamical driving forces for reversible (i.e. Hamiltonian) parts of the dynamics, while for the dissipative parts th...

We present a model for evaluating the specific heat of lattice spin systems. It is based on the knowledge of high-temperature series expansions, the total entropy of the system and the low-temperature expected behavior of the specific heat as well as the ground-state energy. By the choice of an appropriate variable (entropy as a function of energy), a stable interpolation scheme between low and...

It is shown that in a stressed granular packing, the effect of the applied pressure and structural randomness on the contact force distribution can be described accurately by a variational principle of minimizing energy subject to the constraint of keeping entropy at a fixed value. The constraint on entropy may be regarded as a measure of the degree of retained disorderness in the system. This ...

We propose a system for measuring entropy 1 variations, S, in thermal systems using pyroelectric sensors. 2 These sensors convert time-dependent temperature variations 3 into electrical current. Consequently, heat and temperature 4 variations are obtained, and sensor entropy is inferred. Various 5 polyvinylidene fluoride and lead zirconate titanate sensors have 6 been tested. Two types of measu...

It is shown that the well-known LANDAu-damping entropy paradox can be resolved by considering a macroscopic entropy as defined by CLAUSIUS instead of the microscopic entropy defined by BOLTZMANN. Although both entropy definitions are identical for equilibrium configurations, the same in general is not true for non-equilibrium configurations. To extend the entropy definition of CLAUSIUS to non-e...

Our XMM-Newton observations of Abell 85 confirm the extended 4 Mpc filament first detected with ROSAT, which has an X-ray temperature of about ∼ 2 keV and is probably made of groups falling on to the cluster. A comparison of the temperature map with numerical simulations show that Abell 85 had intense merging activity in the past and is not fully relaxed, even in the central region. Finally, a ...