Highway traffic noise prediction using method fully compliant with ISO 9613: comparison with measurements

In this study, we introduce outdoor sound simulation that is fully compliant with ISO 9613 yet with some complementary methods that enhance its applicability; for example, calculation of sound attenuation due to undulating terrain in octave bands, geometric divergence in the near-field of the source, and short-term wind effects. Using the method, we have carried out highway traffic noise prediction and measurement for 12 sites with representative road shapes and structures. In the prediction, the sound power level for a road segment was estimated by the method suggested in ASJ Model-1998 with experimental corrections to the overall noise level and spectrum. Comparing results between predicted and measured noise levels show good correspondence at direct, diffracted and reflected sound fields within 30m from the center of the near side lane.     

Thermodynamics of a Bose-Einstein condensate with free magnetization

We study thermodynamic properties of a gas of spin 3(52)Cr atoms across Bose-Einstein condensation. Magnetization is free, due to dipole-dipole interactions. We show that the critical temperature for condensation is lowered at extremely low magnetic fields, when the spin degree of freedom is thermally activated. The depolarized gas condenses in only one spin component, unless the magnetic field is set below a critical value, below which a nonferromagnetic phase is favored. Finally, we present a spin thermometry efficient even below the degeneracy temperature.     

Thermodynamics of a quasi-two-dimensional heisenberg ferromagnet with single-ion anisotropy

A quasi-two-dimensional ferromagnet (S = 1) with easy axis type anisotropy and interplanar exchange J and intraplanar exchange K is examined within the framework of the spin-wave approximation. An expression for the Curie temperature that is dependent on both the anisotropy parameter D (D/J 1) and on the exchange parameter ratio =K/J is obtained from the self-consistent equations. The important role of the single-ion anisotropy in the formation of the long-range magnetic order in two-dimensional systems is shown.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 94–101, March, 1988.The authors are grateful to S. S. Aplesnin for performing all the numerical computations and to I. S. Sandalov and A. F. Sadreev for useful discussions.     

Thermodynamics of the HMF model with a magnetic field

We study the thermodynamics of the Hamiltonian mean field (HMF) model with an external potential playing the role of a “magnetic field”. If we consider only fully stable states, the caloric curve does not present any phase transition. However, if we take into account metastable states (for a restricted class of perturbations), we find a very rich phenomenology. In particular, the caloric curve displays a region of negative specific heat in the microcanonical ensemble in which the temperature decreases as the energy increases. This leads to ensembles inequivalence and to zeroth order phase transitions similar to the “gravothermal catastrophe” and to the “isothermal collapse” of self-gravitating systems. In the present case, they correspond to the reorganization of the system from an “anti-aligned” phase (magnetization pointing in the direction opposite to the magnetic field) to an “aligned” phase (magnetization pointing in the same direction as the magnetic field). We also find that the magnetic susceptibility can be negative in the microcanonical ensemble so that the magnetization decreases as the magnetic field increases. The magnetic curves can take various shapes depending on the values of energy or temperature. We describe first order phase transitions and hysteretic cycles involving positive or negative susceptibilities. We also show that this model exhibits gaps in the magnetization at fixed energy, resulting in ergodicity breaking.     

Thermodynamics of a dense self-avoiding walk with contact interactions

A lattice model is used to study the properties of an infinite self-avoiding linear polymer chain that occupies a fraction, 01, of sites on ad-dimensional hypercubic lattice. The model introduces an (attractive or repulsive) interaction energy between nonbonded monomers that are nearest neighbors on the lattice. The lattice cluster theory enables us to derive a double series expansion in and d^–1 for the chain free energy per segment while retaining the full dependence. Thermodynamic quantities, such as the entropy, energy, and mean number of contacts per segment, are evaluated, and their dependences on, , andd are discussed. The results are in good accordance with known limiting cases.     

Quantum counterpart of measure synchronization: A study on a pair of Harper systems

Measure synchronization is a well-known phenomenon in coupled classical Hamiltonian systems over last two decades. Here, synchronization in a pair of coupled Harper systems is investigated both in classical and quantum contexts. It seems that the concept of measure synchronization is restricted in the classical limit as it involves with the phase space. We show the quantum counterpart of the synchronization in a pair of coupled quantum kicked Harper chains. In the quantum context, the coupling occurs between two spins chains via a time and site dependent potential. We use the average interaction energy between the participating systems as an order parameter in both the contexts to establish a connection between the classical and the quantum scenarios. Besides, we also study the entanglement between the chains and difference between the average bare energies in the quantum context. Interestingly, all such indicators suggest a connection between the MS transition in classical maps and a phase transition in quantum spin chains.     

Letter: Gravitational Thermodynamics of a Vaidya Black Hole

The path integral approach is applied to the statistical thermodynamics of a radiating Vaidya black hole. The entropy still satisfies the Bekenstein-Hawking formula, except for a negligible term. The entropy production, as a measurement of the irreversibility, is also obtained.     

Fluctuating Diffusivity of RNA-Protein Particles: Analogy with Thermodynamics

A formal analogy of fluctuating diffusivity to thermodynamics is discussed for messenger RNA molecules fluorescently fused to a protein in living cells. Regarding the average value of the fluctuating diffusivity of such RNA-protein particles as the analog of the internal energy, the analogs of the quantity of heat and work are identified. The Clausius-like inequality is shown to hold for the entropy associated with diffusivity fluctuations, which plays a role analogous to the thermodynamic entropy, and the analog of the quantity of heat. The change of the statistical fluctuation distribution is also examined from a geometric perspective. The present discussions may contribute to a deeper understanding of the fluctuating diffusivity in view of the laws of thermodynamics.     

Thermodynamics of a biaxial antiferromagnet

The thermodynamic potential, magnetization, and spin contribution to the heat capacity of a biaxial antiferromagnet have been calculated over a wide range of temperatures and external magnetic fields for various limiting cases. The features of the thermodynamic quantities peculiar to a biaxial antiferromagnet have been studied.     

Thermodynamics of a dense plasma

Journal of Applied Spectroscopy -     

Thermodynamics of a pion gas

The thermodynamics is presented for a gas of uncharged pions coupled to a static nucleon background through a classical Yukawa interaction. By using invariant phase space in the grand canonical ensemble it is possible to write a general analytical form for the thermodynamical functions.     

Thermodynamics of Molecular Chains with a Local Asymmetric Double-Well Potential

The thermodynamics of one dimensional chains with asymmetric double-well on-site potential is investigated. Pseudo-Schrödinger equation resulting from the transfer integral method is solved numerically and in terms of semiclassical approximation. This allows exact calculation and qualitative interpretation of the partition function, free energy and the specific heat function. The specific heat exhibits a characteristic hump similar to the one observed in the structures with a symmetric double-well potential. In some systems, another extremely narrow and extremely high, peak might be developed indicating an entropy driven phase transformation. Comparison between this highly simplified model and more practical approaches to the phenomena of photoinduced phase transformations is discussed underlying the possibility of manifestation of quantum effects in some (spin-crossover) systems.     

Thermodynamics of superconductors with a disorder induced increased coulomb repulsion

We show that thermodynamic properties can be used to determine whether, the degradation in T_c with increasing disorder observed in some A-15 compounds, is due to a reduction in electronic density of states and/or electron-phonon interaction or is due instead to an increase in Coulomb repulsion $\text{μ}{}^1$ coming from increased localization as suggested by Anderson et al.     

Thermodynamics of a one-dimensional interacting Fermi system with magnetic impurities

The thermodynamics of a model of a one-dimensional metal with an attractive electron-electron and an antiferromagnetic electron-impurity interaction is fotmulated. The impurity contribution to the specific heat and magnetic susceptibility is calculated numerically.