arXiv subjects

Tetsuo Yabuki

Publications and source records attributed to Tetsuo Yabuki.

4 recordsLinked to original sources

arXiv2025

Generalized formulation for ideal light-powered systems through energy and entropy flow analysis Part 2: Beyond the first-order evaluation under realistic conditions

This study formulates the ideal efficiency of light-powered systems in the most general form, based on the first principle of energy-entropy flow analysis under the condition of zero entropy generation within the system. A unified formula for the ideal efficiency of light-powered systems is presented in this study. The formula incorporates the absorption ratio |$\varepsilon$| as an indicator beyond the first-order evaluation based on photon number, for light with a dilution indicator d, and it is extended to cases where entropy is simultaneously discarded from the system via radiation and heat. Selecting the appropriate Y-factors and p-parameters from this study for given conditions allows us to accurately and systematically derive the ideal efficiencies of light-powered systems and correctly classify the multiple ideal efficiencies that were previously confused, such as the Jeter, Spanner, and Landsberg-Petela efficiencies which form the basis of practical efficiency. This study also classified existing light-powered systems into two models: the piston-cylinder radiation model and the flowing radiation model, and demonstrated that the latter model is suitable for micro light-powered systems. Finally, this study clarified two issues with the ideal efficiency proposed by Landsberg and Tonge (often referred to as the Landsberg limit) based on the classical flowing radiation model, and derived a new ideal efficiency using a simple mathematical model based on Einstein's theory of radiation and absorption in a two-level system, which assumes quantum transitions, to resolve those problems. The newly obtained ideal efficiency was found to behave very similarly to the Carnot efficiency.

physics.gen-ph↗

arXiv2023

Generalized formulation for ideal light-powered systems through energy and entropy flow analysis Part1. Based on the first-order evaluation

In this study, the theoretical maximum efficiency $\eta_{max}$ and the Boltzmann-type factor giving the concentration ratio of excited-to-ground state pigment-molecules for photosynthetic systems under irradiation with arbitrary photon flux density $n_\gamma(\lambda)$, solid angle $\Omega$, and degree of polarization P, are formulated in the most fundamental and general way through energy and entropy flow analysis, using reversibility and the first-order evaluable condition by the photon number change, which is a quasi-equilibrium condition between the radiation and the system, as essential conditions. The radiation temperature for the diluted monochromatic light as non-equilibrium, obtained by the fundamental formulation of this study is found to agree with the conventional radiation temperature, often called the effective temperature, for a given photon flux density (light intensity), provided that $\Omega$ and P of the radiation are 4$\pi$ and 0, respectively. The reason for this agreement is discussed in the final section. The formulation in this study allows quantitative analyses that are not possible with conventional radiation temperature. As examples, the formulation of $\eta_{max}$ taking into account entropy changes due to photochemical reactions such as glucose production by photosynthesis, and various quantities under irradiation at arbitrary $\Omega$ and P are presented. In Appendix C, a specific and rigorous proof, using elementary geometry, of the fact that the entropy of radiation diluted on its way from the Sun to the Earth remains unchanged from its original value, until it is scattered by the Earth's atmosphere, which is guaranteed only in general terms by Liouville's theorem, is given.

cond-mat.stat-mech↗

arXiv2017

Finite-Size Corrections to the Excitation Energy Transfer in a Massless Scalar Interaction Model

We study the excitation energy transfer (EET) for a simple model in which a massless scalar particle is exchanged between two molecules. We show that a finite-size effect appears in EET by the interaction energy due to overlapping of the quantum waves in a short time interval. The effect generates finite-size corrections to Fermi's golden rule and modifies EET probability from the standard formula in the Forster mechanism. The correction terms come from transition modes outside the resonance energy region and enhance EET probability substantially.

physics.chem-ph↗

arXiv2009

Evaluation of pedodiversity and land use diversity in terms of the Shannon Entropy

Recently, the Shannon entropy, which was introduced originally as a measure of information amount, has been widely used as a useful index of various diversities such as biodiversity and geodiversity. In this work we have evaluated the diversity of soil and land use, in both composition distributions and spatial distributions, in terms of the Shanonn entropy. Moreover we have also proposed how to estimate the connection between the diversity of soil and land use in the spatial distribution using mutual entropy, and carried out the estimation of its connection.

physics.data-an↗