In this paper, we analyze the advanced Feynman’s mechanism from the well-known Feynman’s Lectures on Physics, under the maximum power output, maximum efficient power, and maximum power density criterion. Considering this mechanism like a thermal engine, and using a simplified model, the physical existence regions for these objective functions are shown. We also show their comparison for given values of a defined dimensionless parameter. The behavior for each case of both the general and the normalized forms of the objective functions is compared graphically and the existence of certain intervals of values for the variable parameter used, in which the relation of these objective functions change, is determined. Additionally, it is shown that as the numerical value of the mentioned variable parameter used approaches zero, the area of the region of physical existence of the objective functions is greater. The results of the mentioned comparison are discussed, and appropriate conclusions are included.

In this paper, we show an analysis of the global stability of a Curzon–Ahlborn engine considering that the working substance of the engine satisfies the Van der Waals equation of state, which is more general than the ideal gas case. We use the Lyapunov stability theory for the case where the engine operates at a maximum power output. We analyze the steady state of the intermediate temperatures as well as the asymptotic behavior of the performance of the engine. Additionally, we study the relationship between the inherent time delay by analyzing the dynamic properties of the system and the stability of the steady state. We present illustrative graphs of the obtained results. Finally, we include a brief discussion of the obtained results and appropriate conclusions.

This paper presents so-called thermoelectric generators (TEGs), which are considered thermal engines that transform heat into electricity using the Seebeck effect for this purpose. By using linear irreversible thermodynamics (LIT), it is possible to study the thermodynamic properties of TEGs for three different operating regimes: maximum power output (MPO), maximum ecological function (MEF) and maximum power efficiency (MPE). Then, by considering thermoelectricty, using the correspondence between the heat capacity of a solid and the metabolic rate, and taking the generation of energy by means of the metabolism of an organism as a process out of equilibrium, it is plausible to use linear irreversible thermodynamics (LIT) to obtain some interesting results in order to understand how metabolism is generated by a particle’s released energy, which explains the empirically studied allometric laws.

In a world increasingly dependent on digital computers, understanding the relationship between information theory and thermodynamics is essential. A recent attempt to address this issue was made by A. De Vos who, using a reversible model within the framework of finite-time thermodynamics, derived Carnot’s law, Landauer’s principle, Ohm’s law, and even Moore’s law. Following De Vos et al., this paper first recovers the efficiency of Curzon and Ahlborn, and then establishes the so-called endoreversible Landauer principle for a traditional computer gate, assuming the gate operates in the Maximum Power regime. However, two other regimes are particularly important: the Omega function and the Efficient Power function. By considering these, we obtain the corresponding thermodynamic efficiencies and compare them against that of the Maximum Power regime.

In this paper it is shown the experimental measurements made of the generated radiation by mobile phones, and the corresponding conclusions when comparing them with the values provided by the manufacturers. The so-called specific absorption rate (SAR) is calculated from the amount of electromagnetic energy emitted by mobile phones and absorbed by the human body. It was found that the measurements obtained are within the allowed values, which suggests that the radio frequency emitted by these mobile phones does not have negative effects on human health. These devices have a SAR value provided by the manufacturers, but such values are not completely reliable However, the possibility that its use may cause other harm to human health is not ruled out. The measurements and experimental results were part of the development of a project at a Public University in Mexico City. Â

In the present paper, an algorithm was developed to represent the behavior of the current SARS-CoV-2 virus epidemic in Mexico, known as COVID-19, to obtain a likely scenario for the coming months and provoke a healthy discussion about the problem. The data reported by government entities is considered first by analyzing a simple model, via the construction of a polynomial, and then building an exponential type function, from the so-called logistic function. A numerical comparison is made with the officially provided data, and the graphs obtained from the solutions found are shown, including a brief explanation on how to interpret them appropriately. Finally, the possible scenario for the following months of the development of the epidemic in Mexico is discussed. Â