Thermal Bath Research Articles

Relying on the French territorial offer of thermal spa therapies to build a care pathway for long COVID-19 patients.

Work on long COVID-19 has mainly focused on clinical care in hospitals. Thermal spa therapies represent a therapeutic offer outside of health care institutions that are nationally or even internationally attractive. Unlike local care (hospital care, general medicine, para-medical care), their integration in the care pathways of long COVID-19 patients seems little studied. The aim of this article is to determine what place french thermal spa therapies can take in the care pathway of long COVID-19 patients. Based on the case of France, we carry out a geographic mapping analysis of the potential care pathways for long COVID-19 patients by cross-referencing, over the period 2020-2022, the available official data on COVID-19 contamination, hospitalisations in intensive care units and the national offer of spa treatments. This first analysis allows us, by using the method for evaluating the attractiveness of an area defined by David Huff, to evaluate the accessibility of each French department to thermal spas. Using dynamic geographical mapping, this study describes two essential criteria for the integration of the thermal spa therapies offer in the care pathways of long COVID-19 patients (attractiveness of spa areas and accessibility to thermal spas) and three fundamental elements for the success of these pathways (continuity of the care pathways; clinical collaborations; adaptation of the financing modalities to each patient). Using a spatial attractiveness method, we make this type of geographical analysis more dynamic by showing the extent to which a thermal spa is accessible to long COVID-19 patients. Based on the example of the French spa offer, this study makes it possible to place the care pathways of long COVID-19 patients in a wider area (at least national), rather than limiting them to clinical and local management in a hospital setting. The identification and operationalization of two geographical criteria for integrating a type of treatment such as a spa cure into a care pathway contributes to a finer conceptualization of the construction of healthcare pathways.

On the coupling of three-level quantum refrigerators in the weak coupling limit

We propose a model of two identical autonomous quantum refrigerators that interact through their qubits coupled to cold thermal baths. We consider the same specific disposition for each refrigerator related to a three-level system coupled to different thermal baths and, in turn, to a qubit as the object to be cooled. By coupling the two systems, we show that under certain conditions on the model parameters, the devices can operate in the regime of an independent autonomous quantum refrigerator or be subject to an adjustment of the thermodynamic performances. We further investigate the correlations induced by the interaction between the two refrigerators, and illustrate their behavior with respect to their thermodynamic performances. We have found that adjusting the different interaction constants of the model can lead to an evolution of the quantum correlations of the two machines that is inversely related to the behavior of the thermodynamic quantities of both refrigerators. However, this is not necessarily the case when the temperatures of the model are considered as the reference parameters.

SWOT analysis of a liquid-dominated active geothermal system for non-electrical uses of geothermal energy: A case study, Seferihisar-İzmir

There are numerous natural outflows, 3 thermal baths, 9 disused geothermal wells, and 3 private companies operating in the Seferihisar geothermal system, including a power plant generating electricity. The potential of these resources is suitable for non-electrical use of geothermal energy, such as greenhouse heating and thermal tourism. SWOT analysis method has been used to assess the pros and cons of the geothermal resource in Seferihisar, aiding the identification of suitable applications and investments for both present and future projects. The region is rich in terms of geothermal resources and has convenient access to both public and ware transport, which are described as strengths of the resource. However, poor management and an excess of licensed geothermal fields weaken the effective consumption of the system. A huge number of projects have led to opposition from environmentalist groups. The proven technology of geothermal energy has resulted in an increase in incentives and investment consolidations with governmental support. In the light of SWOT analysis, considering SO, ST, WO, and WT strategies, the untapped geothermal resources present in the Seferihisar geothermal system, combined with the natural attractions and cultural richness of the county, will contribute significantly to non-electrical/direct uses of the geothermal energy in the near future

Quantum Carnot thermal machines reexamined: Definition of efficiency and the effects of strong coupling.

Whether the strong coupling to thermal baths can improve the performance of quantum thermal machines remains an open issue under active debate. Here we revisit quantum thermal machines operating with the quasistatic Carnot cycle and aim to unveil the role of strong coupling in maximum efficiency. Our analysis builds upon definitions of excess work and heat derived from an exact formulation of the first law of thermodynamics for the working substance, which captures the non-Gibbsian thermal equilibrium state that emerges at strong couplings during quasistatic isothermal processes. These excess definitions differ from conventional ones by an energetic cost for maintaining the non-Gibbsian characteristics. With this distinction, we point out that one can introduce two different yet thermodynamically allowed definitions for efficiency of both the heat engine and refrigerator modes. We dub them excess and hybrid definitions, which differ in the way of defining the gain for the thermal machines at strong couplings by either just analyzing the energetics of the working substance or instead evaluating the performance from an external system upon which the thermal machine acts, respectively. We analytically demonstrate that the excess definition predicts that the Carnot limit remains the upper bound for both operation modes at strong couplings, whereas the hybrid one reveals that strong coupling can suppress the maximum efficiency rendering the Carnot limit unattainable. These seemingly incompatible predictions thus indicate that it is imperative to first gauge the definition for efficiency before elucidating the exact role of strong coupling, thereby shedding light on the ongoing investigation on strong-coupling quantum thermal machines.

Thermodynamic uncertainty relations in the presence of non-linear friction and memory

A new thermodynamic uncertainty relation (TUR) is derived for systems described by linearly coupled Langevin equations in the presence of non-linear frictional forces. In our scheme, the main variable represents the velocity of a particle, while the other coupled variables describe memory effects which may arise from strongly correlated degrees of freedom with several time-scales and, in general, are associated with thermal baths at different temperatures. The new TUR gives a lower bound for the mean-squared displacement of the position of the particle, including its asymptotic diffusion coefficient. This bound, in several examples worked out here, appears to be a good analytical estimate of the real diffusion coefficient. The new TUR can be also applied in the absence of any external force (with or without thermal equilibrium between the baths), a case which usually goes beyond the scope of original TURs. We show applications to non-linear frictional models with memory, such as the Coulomb and the Prandtl-Tomlinson models, usually representative of friction at the nano-scale and within atomic-force microscopy experiments.

Light squeezing enhancement by coupling nonlinear optical cavities

In this paper, we explore the squeezing effect generated by two coupled optical cavities. Each cavity contains a second-order nonlinear material and coherently pumped by a laser. Our results show that light intensity is strongly improved due to the presence of the nonlinearities and mainly depends on the detunings between external laser frequencies and cavity modes. More interestingly, the proposed scheme could enhance light squeezing for moderate coupling between cavities : the squeezing generated by one cavity is enhanced by the other one. For resonant interaction, highest squeezing effect is obtained near resonance. When fields are non resonant, squeezing increases near resonance of the considered cavity, but decreases for large detunings relative to the second cavity. Further, when the dissipation rate of the second cavity is smaller than the first, the squeezing could be improved, attaining nearly the perfect squeezing. While the temperature elevation has a negative impact overall on the nonclassical light, squeezing shows an appreciable resistance against thermal baths for appropriate parameter sets.

Derivation of the Langevin Equation from the Microcanonical Ensemble.

When writing down a Langevin equation for the time evolution of a "system" in contact with a thermal bath, one typically makes the implicit (and often tacit) assumption that the thermal environment is in equilibrium at all times. Here, we take this assumption as a starting point to formulate the problem of a system evolving in contact with a thermal bath from the perspective of the bath, which, since it is in equilibrium, can be described by the microcanonical ensemble. We show that the microcanonical ensemble of the bath, together with the Hamiltonian equations of motion for all the constituents of the bath and system together, give rise to a Langevin equation for the system evolution alone. The friction coefficient turns out to be given in terms of auto-correlation functions of the interaction forces between the bath particles and the system, and the Einstein relation is recovered. Moreover, the connection to the Fokker-Planck equation is established.

Thermodynamic precision in the nonequilibrium exchange scenario.

We discuss exchange scenario thermodynamic uncertainty relations for the work done on a two-qubit entangled nonequilibrium steady state obtained by coupling the two qubits and putting each of them in weak contact with a thermal bath. In this way we investigate the use of entangled nonequilibrium steady states as end points of thermodynamic cycles. In this framework we prove analytically that for a paradigmatic unitary it is possible to construct an exchange scenario thermodynamic uncertainty relation. However, despite holding in many cases, we also show that such a relation ceases to be valid when considering other suitable unitary quenches. Furthermore, this paradigmatic example allows us to shed light on the role of the entanglement between the two qubits for precise work absorption. By considering the projection of the entangled steady state onto the set of separable states, we provide examples where such projection implies an increase of the relative uncertainty, showing the usefulness of entanglement.

Thermodynamic properties of the noncommutative quantum Hall effect with anomalous magnetic moment

In this paper, we study the thermodynamic properties of the noncommutative quantum Hall effect (NCQHE) with anomalous magnetic moment (AMM) for both relativistic and nonrelativistic cases at high temperatures, where the thermodynamic properties are: the Helmholtz free energy, the entropy, the mean energy, and the heat capacity. We also work with the Euler-MacLaurin formula to construct the partition function. Next, we plotted the graphs of properties as a function of temperature for different values of the magnetic field and of the NC parameters. We note that the Helmholtz free energy decreases with the temperature, increases with the NC parameters, and can decrease or increase with the magnetic field, while the entropy increases with the temperature, decreases with the NC parameters, and can decrease or increase with the magnetic field. Besides, the mean energy increases linearly with the temperature and the heat capacity satisfies the Dulong-Petit law, which also verified that the AMM does not influence the thermodynamic properties.

Tracer dynamics in polymer networks: Generalized Langevin description.

Tracer diffusion in polymer networks and hydrogels is relevant in biology and technology, while it also constitutes an interesting model process for the dynamics of molecules in fluctuating, heterogeneous soft matter. Here, we systematically study the time-dependent dynamics and (non-Markovian) memory effects of tracers in polymer networks based on (Markovian) implicit-solvent Langevin simulations. In particular, we consider spherical tracer solutes at high dilution in regular, tetrafunctional bead-spring polymer networks and control the tracer-network Lennard-Jones (LJ) interactions and the polymer density. Based on the analysis of the memory (friction) kernels, we recover the expected long-time transport coefficients and demonstrate how the short-time tracer dynamics, polymer fluctuations, and the viscoelastic response are interlinked. Furthermore, we fit the characteristic memory modes of the tracers with damped harmonic oscillations and identify LJ contributions, bond vibrations, and slow network relaxations. Tuned by the LJ interaction parameter, these modes enter the kernel with an approximately linear to quadratic scaling, which we incorporate into a reduced functional form for convenient tracer memory interpolation and extrapolation. This eventually leads to highly efficient simulations utilizing the generalized Langevin equation, in which the polymer network acts as an additional thermal bath with a tunable intensity.

Thermal noise energy regulation in a double-cavity magnomechanical system

We investigate the thermal transport characteristics in a double-cavity magnomechanical system with a yttrium iron garnet sphere. We explore mainly the performance parameter of the thermo-phonon flux flowing from the thermal bath of a mechanical motion into the magnomechanical system and study its dependence on the cavity field detuning and decay, the magnon-photon and magnon-phonon coupling strengths, and the Kerr nonlinear coefficient of magnon. We find that the direction and magnitude of the steady-state thermophonon flux in the magnomechanical system can be controlled flexibly by modulating these system parameters. In particular, the interference effect of quantum transitions in the multi-mode magnomechanical system results a multiple dip structure in the heat flow pattern. The results obtained her e help demonstrate the thermal noise energy harvesting and rectification by the cavity magnomechanical setup.

A thermo-magnetic bag model for the quark-gluon plasma

In this work we study the pressure of the quark-gluon plasma (QGP) in the presence of a weak magnetic field, using a minimally enhanced model of a weakly interacting gas of quasi-particles in a thermal bath. We include the magnetic field effects through the quark mass that has been modified using a recently proposed thermo-magnetic coupling. This thermo-magnetic coupling emerges form the quark-gluon vertex in the HTL approximation [1]. We use Lattice QCD [2] data, to constrain the thermo-magnetic bag function of the quasi-particle model and provide an estimate of the thermo-magnetic vacuum energy density. We then compute the transverse pressure of the system and compare with similar results from the literature. We find that the inverse magnetic catalysis already built within this thermo-magnetic coupling allows a robust description of this Lattice QCD data for the pressure of the QGP in the presence of a weak magnetic field. The extension to the thermal quasi-particle model we have introduced here, makes it easier to pursue further phenomenological studies that require simulations with an EoS that has integrable quasi-particle thermodynamic variables which have the general features of lattice data in the weak magnetic field regime.

Characterization of percutaneous absorption of calcium, magnesium, and potentially toxic elements in two tailored sulfurous therapeutic peloids: a comprehensive in vitro pilot study

Pelotherapy treatments in thermal spas, which utilize peloids composed of clay minerals mixed with saltwater or mineral-medicinal water, can have various effects on spa users, ranging from therapeutic to potential adverse reactions. Despite the widespread use of peloids, comprehensive information on the penetration and permeation of essential and potentially toxic elements into deeper layers of the skin during pelotherapy is limited. Understanding the concentrations of these elements is crucial for evaluating therapeutic benefits and ensuring safety. This study investigates the in vitro availability and absorption of calcium, magnesium, and potentially toxic elements in two peloids, considering their formulation matrix. To replicate the pelotherapy methodology, an in vitro permeation experiment was conducted using a vertical diffusion chamber (Franz cells) and a biological system with human skin membranes from five Caucasian women, age range between 25 and 51 years. The experiment involved heating the peloids to 45℃. The results emphasize the possible transport properties of chemical elements in peloids, providing valuable information related to potential therapeutic efficacy and safety considerations. Despite no apparent differences between peloids’ chemical composition, the method identified permeation variations among chemical elements. The methodology employed in this study adheres to the guidelines outlined by OECD for analyzing skin absorption through an in vitro approach. Furthermore, it aligns with the associated OECD guidance document for conducting skin absorption studies. The replicability of this methodology not only facilitates the analysis of peloids pre-formulation but also provides a robust means to evaluate the effectiveness of therapeutic elements during topical administration, particularly those with potential toxicity concerns.

Dark radiation from the primordial thermal bath in momentum space

Motivated by the stunning projections for future CMB surveys, we evaluate the amount of dark radiation produced in the early Universe by two-body decays or binary scatterings with thermal bath particles via a rigorous analysis in momentum space. We track the evolution of the dark radiation phase space distribution, and we use the asymptotic solution to evaluate the amount of additional relativistic energy density parameterized in terms of an effective number of additional neutrino species ΔN eff. Our approach allows for studying light particles that never reach equilibrium across cosmic history, and to scrutinize the physics of the decoupling when they thermalize instead. We incorporate quantum statistical effects for all the particles involved in the production processes, and we account for the energy exchanged between the visible and invisible sectors. Non-instantaneous decoupling is responsible for spectral distortions in the final distributions, and we quantify how they translate into the corresponding value for ΔN eff. Finally, we undertake a comprehensive comparison between our exact results and approximated methods commonly employed in the existing literature. Remarkably, we find that the difference can be larger than the experimental sensitivity of future observations, justifying the need for a rigorous analysis in momentum space.

Mobility and diffusion of intruders in granular suspensions: Einstein relation

The Enskog kinetic equation is considered to determine the diffusion D and mobility λ transport coefficients of intruders immersed in a granular gas of inelastic hard spheres (grains). Intruders and grains are in contact with a thermal bath, which plays the role of a background gas. As usual, the influence of the latter on the dynamics of intruders and grains is accounted for via a viscous drag force plus a stochastic Langevin-like term proportional to the background temperature T b. In this case, the starting kinetic equations are the Enskog and Enskog–Lorentz equations for grains and intruders, respectively, with the addition of Fokker–Planck terms to each one of the above equations. The transport coefficients λ and D are determined by solving the Enskog–Lorentz kinetic equation by means of the Chapman–Enskog method adapted to inelastic collisions. As for elastic collisions, both transport coefficients are given in terms of the solutions of two integral equations, which are approximately solved up to the second order in a Sonine polynomial expansion. Theoretical results are compared against numerical solutions of the inelastic Enskog equation by means of the direct simulation Monte Carlo method. In general, good agreement between theory and simulations is found, especially in the case of the second Sonine approximation. Knowledge of the coefficients λ and D allows us to assess the departure of the (conventional) Einstein relation ϵ=D/(Tbλ) from 1. As expected from previous results for driven granular gases, it is shown that when the bath temperature T b is replaced by the intruder temperature T 0 in the Einstein relation, the origin of the deviation of ε from 1 is only due to the non-Maxwellian behavior of the reference state of intruders (measured by the cumulant c 0). Since the magnitude of c 0 is in general very small, deviations of the (modified) Einstein relation ϵ0=D/(T0λ) from 1 cannot be detected in computer simulations of dilute granular gases. This conclusion agrees well with previous computer simulation results.

Effects of a thermal bath and the accelerated motion on collective transitions of two atoms in an entangled state

Transition rates of a uniformly accelerated atom coupled to a vacuum scalar field are identical with those of one being static in a thermal bath at a temperature proportional to the proper acceleration a, i.e., TU=a2π\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T_U=\\frac{a}{2\\pi }$$\\end{document}. We discuss in this paper whether there exists such an equivalence in the electromagnetic field case if more atoms are involved. To be specific, we explore the similarities and distinctions between effects of a thermal bath and those of the uniformly accelerated motion by comparing the transition rates of a two-atom system initially in the symmetric or antisymmetric entangled state [|ψ±⟩\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$|\\psi _{\\pm }\\rangle $$\\end{document}] in two cases, i.e., two static atoms in a thermal bath [the thermal case] and two atoms uniformly accelerated in vacuum [the acceleration case]. We discover that, for some particular orientations of atomic dipole moments, coherent radiation which happens in the acceleration case never occurs in the thermal case. The rates in the acceleration case with a low acceleration which means a low TU\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T_U$$\\end{document} can be smaller or larger and even equal to their counterparts in the thermal case; while the rates in the acceleration case with a high acceleration which means a high TU\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T_U$$\\end{document} are always much larger than their counterparts in the thermal case. Our results suggest that effects of a thermal bath and those of the uniformly accelerated motion on transition properties of a two-atom system in |ψ±⟩\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$|\\psi _{\\pm }\\rangle $$\\end{document} are not necessarily distinctive, but can be equivalent if the acceleration is relatively low, depending on the value of the interatomic separation.

Business Opportunities and Drivers for Health and Spa Tourism: A Qualitative Research on Baile Felix Spa Resort, Romania

The tourism sector has witnessed continuous development over the last few decades, overcoming various challenges and crises. This resilience underscores the remarkable diversity of managerial and entrepreneurial initiatives capable of meeting the ever-growing and unpredictable global demand. Our objective is to explore the perceptions of factors and opportunities that encourage the launch and management of businesses in health and spa tourism utilizing a qualitative methodology. Our conclusions are based on the analysis of 32 hotel managers’ and small business owners’ interviews in a relevant tourist resort in Romania. This study reveals that all four types of identified opportunities and drivers influencing business creation and management in health and spa tourism (i.e., improving work quality and independence, professional and personal development, responses to opportunities, and upgrading existing services) are substantially influenced by gender, relevant work experience, and education. The novelty of our research lies in highlighting the influence of these drivers according to a specific context given by the size, management type, and ownership structure of tourism ventures, as well as the difference between large hotel managers and small business owners in terms of their perception and goals. We acknowledge that the limited number of interviewees and the spatially bound context of the research may have an effect on the relevance of the results. This study’s findings underscore the necessity for compromise and collaboration among diverse stakeholders in the tourism industry, particularly when developing long-term strategies for health and wellness destinations. This collaborative approach plays a critical role in promoting the well-being and prosperity of individuals, businesses, and the entire local community.

Equality Drowned in Thermal Water – Environmental Racism and Antisemitism in the Context of Tourism-Centred Modernisation in Interwar North-East Hungary

This paper discusses the interrelationship between discourse about the natural environment and nationalist ideologies in interwar Hungary through a case study on the politicisation of bath culture. As a result of the peace treaty that ended World War One, in the 1930s and 1940s, a previously neglected thermal bath town in North-east Hungary became a target for national scale real estate development as well as virulent antisemitism. In order to legitimate antisemitic policy barring Jews from public baths, Hungarian Christian nationalists evoked myths about Jewish bodies being unclean and infectious and used the term ‘Galician Jew’ in reference to Galicia in Eastern Europe, a region historically associated with dirtiness and backwardness. The present study explores the discourse developing around access to thermal resources and argues that the discriminatory bath decrees pushed by the far right were the first step towards the disenfranchisement and eventual extermination of the Hungarian Jewish community.

Architectural Heritage and Archetypal Landscape Approaches Facing Environmental Hazards

The research question in this paper concerns elements of nature, such as earth, water, fire, and air, as they have a dual meaning, indicating both hazard and heritage. The relationship of cities with blue–green infrastructure is an example of this. Cities might be surrounded by either water or forest, though the latter has been less investigated as a nature-based solution for climate change adaptation. The connection between water and architecture can also be seen in the seafront type of architectural design, in the architecture of harbours, port facilities, aquariums or thermal baths. This paper aims to present a comprehensive analysis of all of these various architecture programs that were carried out during the first half of the twentieth century. Although the styles of Art Nouveau and Interwar were widely spread, otherness in regional geographical locations drew lessons from the vernacular architecture. Inspiration was drawn mainly from southern Europe in the Cycladic islands for the interwar/international style and towards the east and centre of the continent in Romania and Hungary and up to the north in the Baltic states for the national romantic art nouveau style. A local seismic culture is prevalent in areas that are affected by earthquakes. In the context of the geological conditions related to water and earthquake hazard, the anthropic reshaping of rivers and canals (and alluvial soil deposits) generates liquefaction vulnerability. Significant also is the way in which the urban wildland interface shapes the relationship between wild green space and cities. Urban protected nature parks and urban forests contribute to wellbeing but are also vulnerable to wildfire. This research attempts to find equivalents to the local seismic culture in cases of climate change-induced hazards, such as floods and wildfires, in Romania, Italy and Portugal. As part of the project presented for the case study featured in this paper, significant documentation was achieved through literature reviews and field trips. For the latter, walkscape methodology was used, which was also useful for the first round of results and the mapping required to indicate earthquake hazards near water locations in Bucharest, Romania.

An Exact Expression for Multidimensional Spectroscopy of a Spin‐Boson Hamiltonian

AbstractMultidimensional coherent spectroscopy is a powerful tool to characterize nonlinear optical response functions. Typically, multidimensional spectra are interpreted via a perturbative framework that straightforwardly provides intuition into the density matrix dynamics that give rise to specific spectral features. When the goal is to characterize system coupling to a thermal bath however, the perturbative formalism becomes unwieldy and yields less intuition. Here, an approach developed by Vagov et al. is extended to provide an exact expression for multidimensional spectra of a spin‐boson Hamiltonian up to arbitrary order of electric field interaction. The utility of this expression is demonstrated by modeling polaron formation and coherent exciton‐phonon coupling in quantum dots, which strongly agree with experiment.