Thermodynamics and Energy

1503 Submissions

[5] viXra:1503.0260 [pdf] submitted on 2015-03-30 12:49:34

The Concept of System and the Physical Significance of the Quantities Work and Heat

Authors: Rodrigo de Abreu
Comments: 4 Pages. Técnica 1, 50-53 (1987).

In this paper the concept of system is related to the concepts of entropy, work and heat. Through the analysis of three models it is shown that the arbitrariness in the choice of the system is related to the existence of parts of the Universe whose energy is only a function of the deformation variables. For this reason those parts may or may not be included in the system or in the work term. With this in mind we propose a new interpretation of the quantity heat and a non orthodox enunciation of the Second Principle of Thermodynamics.
Category: Thermodynamics and Energy

[4] viXra:1503.0258 [pdf] submitted on 2015-03-30 14:06:33

Critical Remarks on Landauer’s Principle of Erasure–dissipation. Including Notes on Maxwell Demons and Szilard Engines.

Authors: Laszlo B. Kish, Claes-Goran Granqvist, Sunil P. Khatri, Janusz M. Smulko
Comments: 4 Pages. Accepted paper at the International Conference on Noise and Fluctuations (ICNF 2015); to be published in its IEEE proceedings.

We briefly address Landauer’s Principle and some related issues in thermal demons. We show that an error-free Turing computer works in the zero-entropy limit, which proves Landauer’s derivation incorrect. To have a physical logic gate, memory or information-engine, a few essential components necessary for the operation of these devices are often neglected, such as various aspects of control, damping and the fluctuation–dissipation theorem. We also point out that bit erasure is typically not needed or used for the functioning of computers or engines (except for secure erasure).
Category: Thermodynamics and Energy

[3] viXra:1503.0225 [pdf] submitted on 2015-03-28 12:23:31

A New Perspective in Thermodynamics: The Energy-Entropy Principle

Authors: Rodrigo de Abreu
Comments: 8 Pages. Técnica 2, 33-40 (1991)

In this paper, through the criticism of the paradigmatic view of thermodynamics, we aim at showing a new perspective attained in this matter. The generalization of heat as internal energy (generalization of the kinetic energy concept of heat) permits the generalization of the Kelvin postulate: "It is impossible, without another effect, to convert internal energy into work" (no reference to heat or to a heat reservoir).
Category: Thermodynamics and Energy

[2] viXra:1503.0145 [pdf] submitted on 2015-03-18 08:26:52

A One-Dimensional Model of Irreversibility

Authors: M. de Abreu Faro, Rodrigo de Abreu
Comments: 27 Pages. EPS 10 TRENDS IN PHYSICS 10th General Conference of the European Physica Society, Abstracts p. 314 (1996)

The main purpose of this paper is to show that it is possible to understand the origin of irreversibility with a simple one-dimensional model of a collisionless gas. We begin by studying a one-particle "gas" and then we generalise the results to an N-particle gas. The gas particles are enclosed in a cylinder and their movement is perpendicular to a frictionless piston. Only elastic collisions of the particles with the cylinder bottom and the piston are consider. In order to understand the origin of irreversibility we compare the solution obtained for the differential equation f=dp/dt, where the force f on the piston is due to the gravitational field and to the particle collisions on the piston, with the solution obtained for the momentum conservation law. When the number of particles increases and are not in phase, both solutions must agree most of the time in agreement with a statistical formulation. Therefore irreversibility exists in a model without friction between the piston and the cylinder wall and without heat flux between the gas and the exterior. And, although this is commonly suggested, it is not due to mathematical hypothesis like the use of a mean value for the force due to the particle collisions. In fact irreversibility has its origin in the interaction between the particles through the piston and then the statistical formulation agree with am exact and deterministic solution, most of the time and for most of the initial conditions, but not for all time and all the initial conditions.
Category: Thermodynamics and Energy

[1] viXra:1503.0141 [pdf] submitted on 2015-03-17 07:29:53

Mechanics and Thermodynamics: a Semantic Problem of Classification Contribution to the Solution of a Controversial Issue

Authors: Rodrigo de Abreu
Comments: 6 Pages. Técnica 3, 39 (1991)

ABSTRACT An ill-formulated problem gives rise to paradoxes.However, once concepts are conveniently defined, such false paradoxes are easily eliminated. In mechanics,one of the concepts generally held as fundamental is the reversibility of its equations. Hence, the well-known statement that mechanics is irreconcilable with thermodynamics. We propose to show that only apparently are the two branches independent and that wrong assumptions are at the basis of this misinterpretation.
Category: Thermodynamics and Energy