2,227 research outputs found
Electron-photon Interaction and Thermal Disequilibrium Irreversibility
Atoms continuously interact with the photons of the electromagnetic fields in their environment. This electromagnetic interaction is the consequence of the thermal nonequilibrium. It introduces an element of randomness to atomic and molecular motion, which brings to the decreasing of path probability required for microscopic reversibility of evolution. In any atomic electron-photon interaction an energy footprint is given to the atom, and the emitted photon looses energy. The emission of radiation isn’t time reversible and this causes the irreversibility in macroscopic systems
Radiative feedback and cosmic molecular gas: the role of different radiative sources
We present results from multifrequency radiative hydrodynamical chemistry
simulations addressing primordial star formation and related stellar feedback
from various populations of stars, stellar energy distributions (SEDs) and
initial mass functions. Spectra for massive stars, intermediate-mass stars and
regular solar-like stars are adopted over a grid of 150 frequency bins and
consistently coupled with hydrodynamics, heavy-element pollution and
non-equilibrium species calculations. Powerful massive population III stars are
found to be able to largely ionize H and, subsequently, He and He, causing
an inversion of the equation of state and a boost of the Jeans masses in the
early intergalactic medium. Radiative effects on star formation rates are
between a factor of a few and 1 dex, depending on the SED. Radiative processes
are responsible for gas heating and photoevaporation, although emission from
soft SEDs has minor impacts. These findings have implications for cosmic gas
preheating, primordial direct-collapse black holes, the build-up of "cosmic
fossils" such as low-mass dwarf galaxies, the role of AGNi during reionization,
the early formation of extended disks and angular-momentum catastrophe.Comment: 19 pages on MNRA
Thermoeconomics: a holistic approach to technical development
The present days represent a crossroad in the history of humanity, and of the whole Earth. Complex dynamics both of growing the poverty distribution, and of increasing of ecological environmental and socio-economic degradation, are generating a difficult socio-economic system of despair from which it is very difficult to escape. Engineering and technological improvements can represent new possibilities for the renewal of the world, but a new indicator for the decision makers is required. The result, THDI, improves the usual HDI, by taking into account also the technical and ecological level by using the CO2 emissions and the sg quantities, related to the irreversibility of a process
Nonequilibrium Temperature: An Approach from Irreversibility
Nonequilibrium temperature is a topic of research with continuously growing interest because of recent improvements in and applications of nonequilibrium thermodynamics, with particular regard to information theory, kinetic theory, nonequilibrium molecular dynamics, superfluids, radiative systems, etc. All studies on nonequilibrium temperature have pointed out that the definition of nonequilibrium temperature must be related to different aspects of the system, to the energy of the system, and to the energy fluxes between the system and its environment. In this paper, we introduce a definition of nonequilibrium temperature based on the Gouy–Stodola and Carnot theorems in order to satisfy all these theoretical requirements. The result obtained links nonequilibrium temperature to the electromagnetic outflow, generated by irreversibility during microscopic interaction in the system; to the environmental temperature; to the mean energy; and to the geometrical and physical characteristics of the system
The Gouy-Stodola Theorem—From Irreversibility to Sustainability — The Thermodynamic Human Development Index
Today, very complex economic relationships exist between finance, technology, social needs, and so forth, which represent the requirement of sustainability. Sustainable consumption of resources, production and energy policies are the keys for a sustainable development. Moreover, a growing request in bio-based industrial raw materials requires a reorganization of the chains of the energy and industrial sectors. This is based on new technological choices, with the need of sustainable measurements of their impacts on the environment, society and economy. In this way, social and economic requirements must be taken into account by the decision-makers. So, sustainable policies require new indicators. These indicators must link economics, technologies and social well-being, together. In this paper, an irreversible thermodynamic approach is developed in order to improve the Human Development Index, HDI, with the Thermodynamic Human Development Index, THDI, an indicator based on the thermodynamic optimisation approach, and linked to socio-economic and ecological evaluations. To do so, the entropy production rate is introduced into the HDI, in relation to the CO2 emission flows due to the anthropic activities. In this way, the HDI modified, named
Thermodynamic Human Development Index THDI, results as an indicator that considers both the socio-economic needs, equity and the environmental conditions. Examples of the use of the indicator are presented. In particular, it is possible to highlight that, if environmental actions are introduced in order to reduce the CO2 emission, HDI remains constant, while THDI changes its value, pointing out its usefulness for decision makers to evaluate a priori the effectiveness of their decisions
Why does thermomagnetic resonance affect cancer growth? A non-equilibrium thermophysical approach
Recently, the low frequency thermomagnetic effects on cancer cells have been analysed, both theoretically and experimentally. They have been explained by introducing an equilibrium thermodynamic approach. But, in this context, two related open problems have been highlighted: (1) Does there exist a magnetic interaction or do there exist any other processes? (2) Do there exist also thermal effects? Here, we introduce a non-equilibrium thermodynamic approach in order to address an answer to these questions. The results obtained point out that: (a) the effect produced by the electromagnetic wave is just a consequence of the interaction of the magnetic component of the electromagnetic wave with the biological matter; (b) the interaction of the electromagnetic wave causes also thermal effects, but related to heat transfer, even if there have been applied low frequency electromagnetic waves; (c) the presence of the magnetic field generates a symmetry breaking in the Onsager’s coefficients, with a related perturbation of the cancer stationary state
Non-Equilibrium Thermodynamic Approach to Ca2+-Fluxes in Cancer
Living systems waste heat in their environment. This is the measurable effect of the irreversibility of the biophysical and biochemical processes fundamental to their life. Non-equilibrium thermodynamics allows us to analyse the ion fluxes through the cell membrane, and to relate them to the membrane electric potential, in order to link this to the biochemical and biophysical behaviour of the living cells. This is particularly interesting in relation to cancer, because it could represent a new viewpoint, in order to develop new possible anticancer therapies, based on the thermoelectric behaviour of cancer itself. Here, we use a new approach, recently introduced in thermodynamics, in order to develop the analysis of the ion fluxes, and to point out consequences related to the membrane electric potential, from a thermodynamic viewpoint. We show how any increase in the cell temperature could generate a decrease in the membrane electric potential, with a direct relation between cancer and inflammation. Moreover, a thermal threshold, for the cell membrane electric potential gradient, has been obtained, and related to the mitotic activity. Finally,we obtained the external surface growth of the cancer results related (i) to the Ca2+-fluxes,(ii) to the temperature difference between the the system and its environment, and (iii) to the chemical potential of the ion species
Biofuels from Micro-Organisms: Thermodynamic Considerations on the Role of Electrochemical Potential on Micro-Organisms Growth
Biofuels from micro-organisms represents a possible response to the carbon dioxide mitigation. One open problem is to improve their productivity, in terms of biofuels production. To do so, an improvement of the present model of growth and production is required. However, this implies an understanding of the growth spontaneous conditions of the bacteria. In this paper, a thermodynamic approach is developed in order to highlight the fundamental role of the electrochemical potential in bacteria proliferation. Temperature effect on the biosystem behaviour has been pointed out. The results link together the electrochemical potential, the membrane electric potential, the pH gradient through the membrane, and the temperature, with the result of improving the thermodynamic approaches, usually introduced in this topic of research
A first thermodynamic interpretation of the technology transfer activities
In the last years new interdisciplinary approaches to economics and social
science have been developed. A Thermodynamic approach to socio-economics has
brought to a new interdisciplinary scientific field called econophysics. Why
thermodynamic? Thermodynamic is a statistical theory for large atomic system
under constraints of energy[1] and the economy can be considered a large system
governed by complex rules. The present job proposes a new application, starting
from econophysic, passing throughout the thermodynamic laws to interpret and to
described the Technology Transfer (TT) activities. Using the definition of
economy (i.e. economy[dictionary def.] = the process or system by which goods
and services are produced, sold, and bought in a country or region) the TT can
be considered an important sub-domain of the economy and a transversal new area
of the scientific research. The TT is the process of transferring knowledge,
that uses the results from the research to produce innovation and to ensure
that scientific and technological developments could become accessible to a
wider range of users. Starting from important Universities (MIT, Stanford,
Oxford, etc) nowadays the TT is assuming a central role. It is called the third
mission, together with education and research. The importance to provide new
theories and tools to describe the TT activities and their behavior, has been
retained fundamental to support the social rapid evolution that is involving
the TT offices. The presented work uses the thermodynamic theories applying
them to Technology Transfer and starting from the concept of entropy, exergy
and anergy. The output analysis should become an help to make decision to
improve the TT activities and a better resources employment
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