bluuebunny/crossref_metadata_2025 huggingface dataset:
La symbolisation du dire chez l’enfant et ses parents. Enjeux psychiques des fonctions testimoniale et narrative
Authors: Pouillaude Elie
Published: December 2024

Cet article propose de mettre en lumière les notions de fonctions testimoniale et narrative dans la clinique de l’échec des processus de symbolisation du dire chez l’enfant et le parent confronté aux troubles de l’enfant. La pratique de la narrativité renvoie fondamentalement à une activité des processus de liaison. Il existe une fonction symboligène essentielle de ces processus mis en œuvre par la fonction narrative dans l’adresse de l’enfant ou de son parent à un thérapeute en position de témoin. Cette fonction narrative s’appuie sur l’intériorisation de la fonction testimoniale et son adresse à l’environnement. Ensemble elles œuvrent à la symbolisation du dire face aux risques de l’acte ou de la panne de rêverie comme destins de l’éprouvé.
Revisiter la question de l’adolescence
Authors: Quentel Jean-Claude
Published: December 2024

La clinique de l’adolescent oblige à s’interroger sur les processus qui se mettent en place à la sortie de l’enfance. Elle conduit notamment à creuser la fameuse « subjectivation » qui se ferait véritablement jour à cette époque. La théorie de la médiation de Jean Gagnepain, en dissociant la problématique du désir de celle de l’être, autrement dit le registre du pulsionnel et celui de l’identitaire, vient sur ce point conforter de diverses manières les élaborations théoriques des psychanalystes qui ont fait le choix de travailler avec des adolescents. Elle les enrichit par ailleurs d’une conception dialectique du fonctionnement de l’être.
La battaille du lait ! L’image idéal de la Sainte Mère
Authors: Kalchevska-Zarkova Irina
Published: December 2024

À travers les mouvements des femmes durant les derniers 70 ans à l’Ouest et à l’Est de L’Europe, l’observation des mères venues en consultation et l’exigence contemporaine de l’allaitement on développera l’idée qu’aujourd’hui encore et même plus les femmes courent après une image idéale de la maternité. Dans une époque où tout est possible et tout est rempli l’image de la mère et de la maternité parfaites s’impose. Le sujet ne peut pas s’échapper et les symptômes ne tardent pas, surtout chez les enfants.
Le secretum des objets combinés
Authors: Vincendeau Jean Louis
Published: December 2024

L’objet vient combler la distance entre le site et le sol. Des objets abandonnés, invisibles pour tout un chacun, sont recueillis, rassurés, éclairés, adoptés dans un nouveau monde. Pour mettre en relation deux objets hétéroclites il ne suffit pas de les poser au hasard, il resterait à défricher une dimension dont on ne parle guère et tracer des connivences restées jusqu’alors inédites. Dire le silence des objets déposés.
Economic evaluation of potential improvement in two-stage network data envelopment analysis: A case study in the banking sector
Authors: Li Xun , Kazemi Matin Reza , Hossein Yadollahi Amir , Khalafi Fariba
Published: December 2024

This paper investigates the concept of potential improvement within two-stage network data envelopment analysis (DEA) models, with a focus on its application in the banking sector. Network DEA, which evaluates the internal structure of decision-making units (DMUs), is instrumental in assessing operational efficiency within complex networks. Our study provides a detailed review of these methodologies and explores the concept of normalized potential improvement (NPI), specifically extending it to two-stage network production processes. We conduct a comparative analysis of both radial Farrell and non-radial NPI approaches to offer a comprehensive evaluation. To illustrate the practical application of these concepts, we assess the performance of 35 bank branches operating within two-stage structures. The objective is to provide insights aimed at optimizing efficiency in the banking sector from an economic standpoint.
Endovascular Treatment of Type II Endoleaks: Update and Overview
Authors: Dalzell Christina G. , Sheeran Daniel P. , Angle John F. , Wilkins Luke R.
Published: December 2024

Endoleaks are a common complication following endovascular aneurysm repair, despite EVAR being the preferred method for the repair of abdominal aortic aneurysms. Endoleaks are continued blood flow into the aneurysmal sac, or more broadly elevated pressure outside of the endograft, and are classified into five types based on the source of blood flow or elevated pressure. Type II endoleaks are the most common and are a result of retrograde flow to the sac most commonly from the inferior mesenteric artery or lumbar artery. Endovascular treatment options for type II endoleaks include transarterial, transcaval, translumbar, and transabdominal approaches. This review discusses the indication for endovascular treatment of type II endoleaks, the selection of approach, and technical considerations.
New effects in superconducting vortex bridges
Authors: Lykov A. N. , Prishchepa S. L.
Published: December 2024

Superconducting films made of V3Si were used to study the properties of vortex microbridges. New characteristics of the behavior of bridges with vortex motion were observed. At low temperatures voltage jumps, whose positions depend on the magnetic field, were observed on the current–voltage characteristics (IVC) of autonomous contacts. The oscillatory nature of the behavior of current steps, induced on the IVC by external electromagnetic radiation, with a change in the magnetic field was observed. The nature of this stepped structure is, in some cases, temperature dependent. The results obtained agree with the vortex model of processes occurring in bridges.
Mechanisms of nonlinear attenuation of ultrasound in superconductors
Authors: Glushchuk N. I. , Shumeiko V. S.
Published: December 2024

A method is developed whereby it is possible to take simultaneous account of the total contribution of the processes of ordinary and Andreev localization of resonance excitations to the nonlinear attenuation of longitudinal short-wave length sound in superconductors. It is shown that each type of nonlinearity is characterized by its own nonlinear parameter and can occur in pure form in the domain of the external parameters where its threshold is a minimum and at sound amplitudes near that threshold.
Superconductivity of metals with a charge density wave
Authors: Kasatkin A. L. , Pashitskii É. A.
Published: December 2024

It is shown that in anisotropic metals with a Peierls-like structural transition there arises a dielectric gap at nested (flat) portions of the Fermi surface. Then, the interaction of electrons with charge-density wave collective oscillations (phasons) can cause an increase in the critical temperature for the transition into the superconducting state.
Change in the mechanisms of diffusion of positive charges in solid helium-4 in low fields
Authors: Mekhov-Deglin L. P. , Efimov V. B. , Golov A. I.
Published: December 2024

It is shown with the help of direct measurements of the velocity of charges in samples of helium-4, grown under pressures of 30−32 atm, that the previously observed1 inflection in the J(T) curves describing the temperature dependence of the current through a diode in solid helium-4 in low fields, are due to the changes in the velocity of charges, i.e., to a change in the dominant mechanism of diffusion with a decrease in temperature.
Hydrodynamics of superfluid crystals
Authors: Vardanyan G. A. , Papoyan K. V. , Sedrakyan D. M.
Published: December 2024

It is shown that three-velocity hydrodynamics equations describing the properties of a two-condensate crystal determine the low-frequency spectrum with allowance for superfluid drag. The drag on one superfluid component of density ρ12(s) from another component of density ρ22(s), gives rise to two branches of vibrations of frequencies ω1 and ω2, unlike the case of a one-condensate crystal. The absorption coefficient for transverse sound in a one-condensate crystal is expressed in terms of the quantum-mechanical characteristic quantity that describes the tunneling of atoms.
Energy of interaction of a helium film with a metal surface
Authors: Gerasimenko V. I.
Published: December 2024

The energy of interaction of a macroscopic film of helium of arbitrary thickness with a metallic substrate as a function of the electron density of the metal is calculated. The total interaction energy of the film with the surface is represented as a sum of the van der Waals attraction energy and the repulsion energy, which is identified with the increase in the energy of the electrons in the metal accompanying the deposition of the film. It is shown that the coupling of the film to the surface is weaker than the coupling of isolated helium atoms.
X-ray studies of the structure and thermal expansion of methane isotopes
Authors: Prokhvatilov A. I. , Isakina A. P.
Published: December 2024

X-ray studies of the structure, lattice parameters and thermal expansion coefficients of solid CH3D, CH2D2, and CHD3 have been carried out in the temperature range from 2 K to Ttr. It was established that the crystallographic symmetry of the orientationally ordered phases of the methane isotopes is similar to that observed in the low-temperature phases of methane and deuteromethane. The quantitative features of the isotope effect in molar volume, thermal expansion coefficient, and volume jumps at the phase transitions were determined. Some conclusions are drawn, on the basis of the results obtained, about the structural properties of phase III and about the second phase transition in pure methane.
Effect of random localized thermal disturbances on the stability of superconductors
Authors: Levchenko E. V. , Chechetkin V. R.
Published: December 2024

The formation time of the minimum propagating zone in a superconductor is calculated for weak, random, localized thermal disturbances. For “dense” noise the problem reduces to solving the functional Fokker–Planck equation.
Effect of magnetic dilution on the phase transition in the NixZn1–xSiF6 · 6H2O system
Authors: D’yakonov V. P. , Levchenko G. G. , Fita I. M. , Tsintsadze G. A.
Published: December 2024

The dependence of the magnetic ordering temperature on the concentration of Ni2+ ions has been measured in the system NixZn1−x ⋅ 6H2O. The results obtained have been analyzed within the framework of the molecular field model.
Interference of macroscopic states in the presence of quantum tunneling
Authors: Dmitrenko I. M. , Tsoĭ G. M. , Shnyrkov V. I.
Published: December 2024

In studying the decomposition of the metastable states of superconducting quantum interferrometers, anomalous peaks were observed in the probability density, whose appearance is associated with resonance tunneling between macroscopic states.
Sound in He II at high and low pressures
Authors: Adamenko I. N. , Tsyganok V. I.
Published: December 2024

An expression derived earlier by the authors for the mass operator is used to calculate the high-pressure sound absorption coefficient and the roton-induced renormalization of the first-sound velocity. It is shown that the kinetic theory of sound propagation in He II changes considerably with an increase in the pressure. The results of the calculations are compared with the existing experimental data.
New resistive state of wide superconducting films
Authors: Volotskaya V. G. , Dmitrenko I. M. , Sivakov A. G.
Published: December 2024

The current–voltage characteristics and the distribution of the pair and quasiparticle potentials along the current in wide superconducting films in a dynamic mixed state and under nearly isothermal conditions were investigated experimentally. It is shown that as in the case of a narrow superconducting channel, wide films under certain critical conditions, due to the nonlinear properties of moving vortices, are unstable to the formation of phase-slip lines whose structure is analogous to the phase-slip centers in narrow channels. It is noted that the theory of phase-slip centers must be generalized to the case of films with arbitrary thickness in a magnetic field taking into account the specific features of the motion of vortices in the region of unbalance of the branches of the quasiparticle spectrum.
Contribution to the theory of configurational relaxation of doped quantum crystals
Authors: Strzhemechnyi M. A. , Tokar’ O. I.
Published: December 2024

Using the example of dilute solid solutions of helium isotopes, we construct a theory of the configurational relaxation of quantum crystals that takes account of the finite rate of quantum diffusion. The probabilities of elementary processes leading to the formation and dissociation of impurity nearest-neighbor pairs are considered in detail. The configurational relaxation problem is solved within the framework of a model in which the kinetics of a chosen pair of impurities at sufficiently large interimpurity distances is described by the diffusion equation with appropriate boundary conditions.
Quasi-two-dimensional weakly coupled superconducting junctions on the surface of a semiconductor with a strongly doped surface channel
Authors: Alfeev V. N. , Gritsenko N. I.
Published: December 2024

Josephson junctions with superconducting film electrodes on the surface of a semiconductor, whose surface region is doped with an impurity to a fixed depth up to degeneracy of free charge carriers, are investigated using a two-dimensional physical model based on a microscopic approach.
Electron energy spectrum and the de Haas–van Alphen effect in the ordered compound Cd3Mg
Authors: Khotkevich V. V. , Pluzhnikov V. B. , Svechkarev I. V. , Grechnev G. E. , Anderson J. R. , Pickett W. E.
Published: December 2024

De Haas–van Alphen oscillations have been observed in the ordered intermetallic compound Cd3Mg at 1.5 to 4.2 K in fields up to 70 kG. The angular dependence of the oscillation frequencies in the range of 2.1 to 6.0 MG was studied. Effective masses of carriers and Dingle temperatures were measured for some characteristic orientations of the magnetic field with respect to the crystal axes. The band structure of Cd3Mg is calculated on the basis of the Animalu-Heine model pseudopotentials. A model of the Fermi surface of Cd3Mg was constructed and an interpretation of the oscillations observed experimentally is proposed.
The influence of deformation effects on the stability of a charged helium surface in a capacitor
Authors: Tatarskiĩ V. V.
Published: December 2024

The influence of deformation effects on the stability of a helium surface in a capacitor is considered. It is shown that the critical density is reduced when deformation is taken into account.
Equilibrium phase diagram of nitrogen–krypton solid solutions
Authors: Prokhvatilov A. I. , Yantsevich L. D.
Published: December 2024

The equilibrium phase diagram of nitrogen–krypton solid solutions has been studied by the x-ray method. The mutual solubility limits of the components were determined in the temperature range from 5 K to the melting temperature of the mixtures. The temperature and concentration dependences of molar volumes of the phases observed have been studied. The coexistence of two phases of the same symmetry was observed at T > 49 K, namely hexagonal crystals of krypton and nitrogen. The possibility of supercooling the hexagonal phase of krypton to extremely low temperatures was demonstrated. Based on the temperature dependences obtained for the ratio of lattice parameters c/a for the hcp phase of krypton, the suggestion is made of an appreciable increase in the correlation intermolecular interaction of nitrogen molecules in these crystals at T < 30K.
Features of the exciton–phonon interaction in nitrogen cryocrystals
Authors: Fugol’ I. Ya. , Stepanenko V. M. , Shamfarova O. Ya.
Published: December 2024

The exciton absorption at the transitions a1Πg←X1Σg+ and w1Δ0←X1Σg+ is studied in α-N2 and N2−Ar in order to determine the features of the exciton-phonon interaction in α-nitrogen. The first spectral moments of the vibronic transition bands are calculated for pure and impure crystals, and evidence is found that both free and self-localized excitons are manifested in the absorption spectrum of α-nitrogen. The parameters of the exciton–phonon interaction are estimated. It is established that in solid nitrogen the a- and w-excitations correspond to excitons with effective masses of opposite sign. Analysis of the temperature dependence of the first moments of the absorption band w(0)←X(0)3 shows that for α-nitrogen there is a linear exciton–phonon interaction in the temperature range 6−30 K.
Statistical-mechanical theory of vacancy interactions in heavy-rare-gas crystals
Authors: Brook-Levinson É. T. , Chernetsov O. D.
Published: December 2024

Within the framework of the classical statistical-mechanical theory of crystals we have derived expressions for the effective vacancy–vacancy and vacancy–atom interaction potentials and analyzed their dependence on the temperature and pressure. The activation energies have been calculated for vacancy and divacancy migration in a fcc lattice. We analyze the dependence of the structure of vacancy microclusters on the thermodynamic conditions.
Band structure and stability of the compound Cd3Mg
Authors: Grechnev G. E. , Svechkarev I. V. , Khotkevich V. V.
Published: December 2024

Using nonlocal semi-empirical pseudopotentials, we calculate the electron energy spectrum of the compound Cd3Mg at T = 0. The detailed dependences of the density of electron states indicate significant differences between the band structures of Cd3Mg and pure cadmium. We trace the evolution of the total energy of the crystal during the transition from cadmium to the disordered phase and then the ordered phase of Cd3Mg. The energy of the band structure is shown to be a minimum in the ordered phase.
Relaxational shift of the EPR line in a superconductor
Authors: Khaliullin G. G. , Khusainov M. G.
Published: December 2024

The pronounced energy dependence of the electron density of states in a superconductor is shown to cause an appreciable temperature-dependent g-factor shift of the localized spin. The shift has a positive sign and can significantly compensate the rapid decrease with decreasing temperature of the usual polarization Knight shift of the EPR line.
Stationary Josephson effect in a system with ordered localized magnetic impurities in the barrier
Authors: Kuplevakhskiĭ S. V. , Fal’ko I. I.
Published: December 2024

The effect of ordering of localized magnetic impurities (LMI) in an insulating intercalation on the stationary Josephson effect is investigated using a microscopic Hamiltonian. A formula is obtained for the Josephson current in the region VS2θ2≪VN21−0vFVN−1; the condition VS2θ2cr=VN2+vF2 for the Josephson current to vanish due to scattering of Cooper pairs by LMI in the region of the barrier is established. The behavior of the Josephson current at the barrier j(0) as a function of VS2θ2 is predicted, it is shown that it is related to the competition between two physical effects in the region 0≤VS2θ2≤VN2+vF2: “transillumination” of the potential barrier and suppression of the order parameter in the region of the barrier due to scattering by LMI.
Nonequilibrium states in superconductors with a charge density wave under tunneling injection
Authors: Molotkov S. N.
Published: December 2024

The nonequilibrium states arising under tunneling injection in superconductors with a structural transition are investigated. The case of symmetrical SD–I–SD tunnel junction is examined [SD is the superconductor in which the structural rearrangement of the lattice and a charge density wave (CDW) appear due to the characteristics of the single-particle electronic spectrum of the symmetrical metallic phase; I is the insulator]. It is shown that when a voltage close to the threshold for creation of Cooper quasiparticles is applied to the tunnel junction, a threshold instability, leading to an S-shaped current–voltage characteristic, arises. As a result of this, layered Umklapp waves are possible (in the case when the external voltage is fixed) between states with different values of the superconducting order parameter and of the amplitude of the CDW. With a fixed current such inhomogeneous distributions are stationary. The general restrictions on the magnitude of the nonequilibrium quasiparticle distribution function n(ε), when the quasiparticles are created by the source in an energy range greatly exceeding the dielectric and superconducting gaps, are also discussed. In the general case, the restriction n(ε) <1/2, which holds in the usual superconductors, is absent in superconductors with CDW. This fact can in principle lead to a diffusion instability and to paramagnetism in nonequilibrium superconductors with CDW.
Theory of helimagnetic ordering in weak itinerant magnets
Authors: Povzner A. A. , Strashnikov O. G. , Volkov A. G.
Published: December 2024

The low-temperature characteristics of helimagnetic ordering of weak itinerant magnets are investigated. Based on the theory of fluctuations of the local spin density, taking into account the exchange and relativistic antisymmetric spin–spin interaction in a system of collectivized electrons, expressions are found for the wave vector of the magnetic structure, the Néel temperature, and the dependence of the magnetization on the external magnetic field. These expressions agree with the experimental data on weak itinerant helimagnets.
Manifestation of the dynamic Jahn–Teller effect in the EPR spectrum of Cu2+ in ZnSiF6 · 6H2O
Authors: Vasyukov V. N. , Lukin S. N. , Tsintsadze G. A.
Published: December 2024

We report a study of the EPR spectrum of the Jahn–Teller centers Cu2+ in ZnSiF6 · 6H2O using a frequency of 74 GHz. The spectrum observed may be described within a model of three geometrically inequivalent centers with a rhombic g-tensor: gz = 2.467 ±0.005; gy =2.11 ±0.01; gx = 2.10±0.01; and gy−gx = 0.0097 ±0.0005. The observed rhombicity of the g -tensor cannot be explained quantitatively by the static Jahn-Teller effect and the trigonal component of the crystal field of the crystal matrix, and requires extension of the theory to vibronic states in the case of strong Jahn–Teller coupling.
Internal friction in the superconductor Pb–In containing dislocations surrounded by an atmosphere of impurity atoms in a magnetic field H <H
c10
Authors: Beloshapka V. Ya. , Platkov V. Ya.
Published: December 2024

The penetration of a magnetic field H into the superconducting single-crystal Pb–ln, containing dislocations surrounded by an atmosphere of impurity atoms was investigated by the method of amplitude-dependent internal friction. It was found that the magnetic field penetrates into a single crystal containing such defects if H <Hc10. The dependence of the dislocation internal friction δ on H has the form of a curve with a peak situated near Hc10. The influence of the temperature and the amplitude of deformation on the function δ(H) was studied. The results indicate that the critical superconducting parameters change in the region of the crystal where the content of the components of the alloy changes locally.
Enhancement of the superconducting state in the 2H-NbSe2–hydrogen system
Authors: Obolenskii M. A. , Beletskii V. I. , Chashka Kh. B. , Basteev A. V.
Published: December 2024

Enhancement of the upper critical field Hc2 and the superconducting transition temperature Tc has been observed experimentally in the system HxNbSe2 (x ≤0.01) subjected to cycling of an external magnetic field at temperatures below Tc. This effect is assumed to be due to hydrogen ordering in the field of the vortex lattice in a dynamic mixed state.
Propagation of longitudinal ultrasonic waves in metals
Authors: Gokhfel’d V. M. , Kaganov M. I.
Published: December 2024

The propagation of a longitudinal sound wave in a metallic half-space is studied. The existence of a nonexponentially damped, anomalous sound wave, that moves with the Fermi velocity, is predicted in the collisionless limit. The influence of the electronic spectrum on the damping of such a wave is discussed.
Peculiarities of vortex pinning on grain boundaries
Authors: Prokhorov V. G. , Tret’yachenko K. G. , Kaminskiĭ G. G.
Published: December 2024

Using a model of pinning, associated with scattering of electrons by grain boundaries, the dependences of the elementary pinning force per unit length of the vortex line on the degree of purity of the metal and on the grain size are calculated.
Point-contact spectra of PrNi5 in the thermal electron-transit regime. Comparison with theory
Authors: Akimenko A. I. , Yanson I. K.
Published: December 2024

The point-contact spectra of PrNi5, measured in the thermal electron-transit regime, are compared with theoretical results. The thermal electron-transit regime in PrNi5 appears when the conduction electrons interact with magnetic excitons, i.e., a nonphonon mechanism of creation of the thermal regime is realized. The agreement between the experimental curves and the theoretical results indicates that information on the electron–quasiparticle interaction function in metals can be obtained from point-contact spectra by means of calculation.
Low-temperature anomalies of sound absorption by interacting paraelectric centers in crystals
Authors: Akhmadullin I. Sh. , Saburova R. V.
Published: December 2024

The linear response of a system of paraelectric centers to an external acoustic disturbance is investigated. It is shown that impurity paraelectric centers interact with each other and with lattice vibrations. The linear response consists of a resonance part and a relaxation part. The collectivization of one-particle states of the paraelectric centers induces temperature anomalies of the dissipative part of the acoustic susceptibility.
Dispersion of acoustic phonons in dilute solutions of 3He in 4He
Authors: Rudavskii É. Ya. , Chagovets V. K.
Published: December 2024

A new relaxation process in the phonon-impurity system is identified by means of precision relative measurements of the sound velocity in dilute solutions of 3He in 4He. The characteristic relaxation time to equilibrium in a phonon gas with anomalous dispersion in the presence of impurities is determined. It is shown that the measured temperature variations of the sound velocity in dilute solutions of 3He in 4He at various frequencies are in good agreement with the predictions of the new kinetic theory of solutions.
Decrease in the effective activation energy for thermal-conductivity restoration processes in 4He crystals upon doping with 3He
Authors: Levchenko A. A. , Mezhov-Deglin L. P.
Published: December 2024

The paper shows that in deformed 4He crystals containing no more than 0.5% 3He impurities the effective activation energies for processes of restoration of the thermal conductivity to the initial value coincide with the activation energies for the diffusion of point defects. An increase in the impurity concentration to 5% led to a decrease in the effective activation energy for the restoration processes by a factor of 2–3.
Nonlinear spin wave theory for ferromagnetic chains with uniaxial anisotropy of the easy plane type
Authors: Chubukov A. V.
Published: December 2024

We consider the determination of the ground state energy and the lowest lying excitations for ferromagnetic Heisenberg spin chains with uniaxial anisotropy of the “easy plane” type in an external magnetic field directly along the anisotropy axis. The ratio of the anisotropy and exchange constants (α) is assumed small, but the size of the site spin S is arbitrary. To first order in α the exact results are shown to differ from the quasiclassical results only by the substitution α→α˜=α[1−(1/2)S]. The asymptotic behavior of the transverse spin correlation function is discussed, and a comparison is made between the theoretical results and recent experiment data.
Influence of the interaction of distant atoms on the structural states of a one-dimensional atomic chain
Authors: Beloshapkin V. V. , Zaslavskii G. M. , Tret’yakov A. G.
Published: December 2024

Equations for the equilibrium positions of a one-dimensional chain with interactions between distant atoms are compared with an equivalent dynamic system. An analysis is made of the solutions of the dynamic system and the corresponding types of structures. A parameter K¯ that characterizes the degree of overlapping of resonances in the equivalent system is introduced. A modulated state of the chain is shown to exist for K¯≪1. Metastable stochastic structures of the chain are formed when K¯≳1.
Possibility of a phase transition in hydrogen–deuterium solid solutions
Authors: Bereznyak N. G. , Sheĭnina A. A.
Published: December 2024

Features associated with a phase transition in solid solutions are observed on the P−T dependences of the isochores of hydrogen–deuterium solutions in the two-phase liquid–crystal region. The projection of the lines of three-phase equilibrium of the liquid and two solid solutions on the P−T plane is determined.
On the bound states of quasiparticles
Authors: Bar’yakhtar V. G.
Published: December 2024

It is shown that if the quasiparticle energy depends in a power-law fashion on the momentum and if the exponent n exceeds the dimensionality of the space d, then a quite weak attraction leads to the formation of a bound state of two quasiparticles in the region of their low momenta. The bound state of two Goldstone bosons is formed for n > d + 2m (2m is the total sum of the power indices of the momentum dependence of the amplitude of the pair interaction).
Energy dissipation during vortex motion in thin hard superconductors
Authors: Kiryushin A. A. , Nechiporenko I. N.
Published: December 2024

An investigation was performed on the energy dissipation in thin hard type-II semiconductors due to displacement of the cores of the normal phase under the action of an alternating current and an alternating external magnetic field.
An Investigation on the Component Efficiencies of Supersonic Ejector
Authors: Samant Arpit , Shukla Rahul
Published: December 2024

This report aims to investigate different component efficiencies present in CRKEC based ejector model. This study calculates the efficiencies of component on-design and off-design condition. This study shows the effect of the inlet, secondary, and exit pressure on the efficiencies of the nozzle, mixing, diffuser and entrainment efficiency of supersonic ejector. The literature’s definitions of ejector component efficiencies are listed below. There is a discussion of how ejector shapes, operating circumstances, and working fluid properties affect ejector efficiency. Future studies on ejector efficiency, ideal design, and control of ejectors and ejector systems will benefit from this research. The literature’s definitions of ejector component efficiencies are listed below.
A new tool to solve data related problem with source coding theorem
Authors: Dwivedi Aakanksha , Naresh Saraswat Ram
Published: December 2024

The most significant aspect of the new generalization of entropy

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ℜ
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that we provide in this study is its ability to derive the most significant entropies that are well recognized and have an impact on applied mathematics and information theory. In this article, some important characteristics of

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have been investigated. In this piece, we also present a new generalized mean code word length

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1

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(

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)

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and find the source coding theorem relationship between

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A LTNE approach on the study of transverse hydromagnetic on mixed convection in a channel.
Authors: Kumar Ashok , Saini Akshay , Kumar Ashok , Singh Negi Anup
Published: December 2024

This article reports the investigation of magneto-hydro-dynamic (MHD) fluid flow in a channel occupied within a porous medium. When the temperature of the porous surface and fluid surface are not equal, this is known as LTNE. In this paper, mixed convection in a vertical porous channel along with a transverse hydromagnetic effect is reported. The fluid in the channel is assumed electrically conducting and flow is due to the external pressure gradient and the buoyancy force. To describe the flow in a porous medium non-Darcy-Brinkman-Forchheimer extended (NDBF) model is considered here. The local thermal non-equilibrium (LTNE) model is used and the governing equations are solved numerically using the Chebyshev spectral collocation method (CSCM) and a significant agreement is found with the analytical solution in the special case. Extensive focus is given to the impact of heat transfer coefficient, Hartman number, and Darcy number on the fluid flow mechanism at fixed values of other parameters. The numerical results show that The fluid flow, as well as heat transfer, are reduced on decreasing media permeability via changing Darcy number. Both Nusselt numbers for solid and fluid reduce on reducing Darcy parameter. The velocity is reduced in the middle region of the channel on increasing Hartman number, while it is increasing near the walls. The effect of heat transfer coefficient and Hartman number on temperature is meager.
Triplet Order Adaptive Seventh-Order WENO Scheme for Compressible Flows
Authors: Arun Govind Neelan A , Rathan Samala
Published: December 2024

Accurately determining shock structures is crucial for assessing the loads on supersonic flights. Achieving precision in aero-thermal load estimation for high Mach number flows demands the use of higher-order high-resolution algorithms. This study introduces a specific higher-order high-resolution scheme renowned for its exceptional shock-resolving capabilities. While many seventh-order schemes typically achieve only fourth or seventh-order accuracy, the presented scheme can attain accuracy levels of fourth-, sixth-, or seventh-order. Notably, it precisely satisfies the Taylor series with zero residues, unlike many existing schemes that yield small non-zero residues. This accomplishment is attributed to a novel weighting function that breaks the direct connection between the smoothness indicator and the weighting function. The scheme’s effectiveness is validated using gas dynamics Euler equations, particularly in scenarios involving step-like discontinuities such as shock tube problems and double Mach reflection test cases. Across various test cases, the proposed scheme consistently demonstrates minimal errors and exhibits outstanding shock-resolving properties.
Investigation of the robustness of a novel input preshaping vibration control technique
Authors: Riboli M. , Dall’Olio F. , Manconi E. , Ghazizadeh Ahsaei A. , Silvestri M.
Published: December 2024

This work presents a study on the robustness of a novel preshaping command input method for vibration control of moving flexible structures. The methodology is based on a time-parameterised B-spline approach, with control points determined by solving a linearly constrained quadratic optimisation. The objective function minimises the vibrational energy, while the constraints set the kinematic limits of the motion control. Two case studies are considered to investigate the robustness and performance of the proposed method with respect to modelling errors: a triple pendulum on a cart and a rotating Euler-Bernoulli beam. The models are implemented in a Modelica language to simulate the virtual system response under varying operating conditions.
Dispersion Characteristics of Flexural Waves in Vacuo and Submerged Fluid-filled Pipes
Authors: Roslan Mohd , Nalisa Adila , Muggleton  , Jennifer M , Ferguson  , Neil
Published: December 2024

Pipelines are widely recognised as the most efficient and sustainable infrastructure for water transportation in the water management and distribution industries, but their efficiency is often compromised by leaks. In this paper, the low-frequency flexural behaviour is investigated to estimate the dispersion characteristic of free flexural wave propagation in MDPE water pipes. It is investigated under two conditions: an empty and fluid-filled pipe either surrounded by air or by water. An Euler Bernoulli prediction model was developed for these pipe scenarios, and validation experiments were conducted on a 1.8-metre-long pipe. Results showed that the flexural wavenumber is lower in an empty pipe compared to a water filled pipe. This is because the water adds mass, which reduces the wave speed. The behaviour of the flexural waves is also affected by the fluid outside the pipe, where the external fluid adds mass to the pipe wall, causing the wavespeed to decrease. Experimental results are in good agreement with an analytical model at low frequencies but not at higher frequencies, since higher-order bending waves are present in the experiment results.
Prediction of ground vibrations from rail tunnels –finite-element, boundary-element and wavenumber calculations
Authors: Auersch L
Published: December 2024

The prediction of ground and building vibrations has been established for surface lines and has now been extended to tunnel lines. The wave propagation in homogeneous or layered soils (the transmission) is calculated by an integration in wavenumber domain. The wave amplitudes at different distances and for different frequencies will be analysed for the following situations. 1. The horizontal propagation from a surface point to a surface point constitutes the basic rules. 2. The horizontal propagation from a source point at depth to a receiver point at depth which is related to a building with a deep basement or on a pile foundation. 3. The propagation from depth to the surface, which is the normal case for free-field measurements, has some different characteristics, for example a weaker attenuation with the horizontal distance from the source, which can be approximated by the full-space solution and the reflection rules for incident waves. The emission from a tunnel structure has been calculated by a finite-element model of the tunnel combined with a boundary-element model of the soil giving the reduction compared to a point-load excitation. The immission has been analysed by finite-element models of tunnel-soil-building systems for examples of research and consultancy work. Measurement results from a high-speed and a metro line confirm some of the established rules.
Uncertainty quantification for damage detection in 3D printed auxetic structures based on ultrasonic guided-wave using Flipout probabilistic convolutional neural network
Authors: Lu Houyu , Farrokhabadi Amin , Rauf Ali , Talemi Reza , Gryllias Konstantinos , Chronopoulos Dimitrios
Published: December 2024

The auxetic structure is widely used in aviation, bio-engineering, automation, and other industries due to its outstanding properties, such as being lightweight, high strength-to-weight ratio, and absorbing energy. Neural network methods have been popularly used for auxetic structures’ structural health monitoring. However, the performance of neural network methods in unknown areas is limited. To increase the reliability of the network model, more comprehensive uncertainty quantification is needed for damage detection in unknown areas. This paper introduces a comprehensive framework for health diagnosis and uncertainty quantification in 3D-printed auxetic structures made of polylactic acid. The framework involves quasi-static uniaxial compression and ultrasonic tests conducted simultaneously to capture ultrasonic signals at different deformation states. Critical damage deformation is identified based on observed deformation patterns and variations in signal energy. Using the Hilbert transform, two damage-sensitive features—envelope and phase—are extracted. These features serve as input data for the Flipout probabilistic convolutional neural network (FPCNN) model, which integrates pseudo-independent weight perturbations and a Gaussian probabilistic layer within the visual geometry group 13 architecture to predict structural deformations and associated uncertainties. The uncertainty quantification framework, based on variational inference and the conditional covariance law, effectively separates and quantifies the predictive variance of the network model into aleatoric and epistemic uncertainty. This framework’s feasibility is demonstrated through compression and ultrasonic tests, utilizing the FPCNN. This showcases the uncertainty quantification capabilities of the FPCNN model.
Response probability density of a single-degree-of-freedom linear system under non-Gaussian random excitation with dominant frequency
Authors: Tsuchida Takahiro
Published: December 2024

The response probability density function (PDF) of a single-degree-of-freedom linear system under non-Gaussian random excitation with a non-zero dominant frequency is investigated. The non-Gaussian excitation is a zero-mean stationary stochastic process prescribed by a first-order PDF and a power spectral density (PSD) with bandwidth and dominant frequency parameters. Uniform and Laplace distributions are considered for the excitation PDF. Monte Carlo simulations are performed to obtain the stationary displacement and velocity PDFs of the system. The simulation results indicate that the effects of excitation non-Gaussianity on the response PDFs vary greatly, depending on the bandwidth and dominant frequency of the excitation PSD. Particularly, the excitation non-Gaussianity appears strongly in the response PDFs when the excitation has a narrow bandwidth and the excitation dominant frequency matches the natural frequency of the system. Next, it is shown that when the excitation and response waveforms are similar, the response PDFs take a shape similar to the excitation PDF; on the other hand, when the waveforms are different, the response PDFs are nearly Gaussian, irrespective of the shape of the excitation PDF. Furthermore, as a quantitative index of waveform similarity, the maximum absolute value of the normalized cross-correlation function of excitation and response is introduced. The correspondence between the index value and the non-Gaussianity of the response PDF is revealed.
Design of Sonic Cage to attenuate noise in Mines using Sonic Crystal and Melamine Foam
Authors: Swain Manish Kumar , Naik H.K. , Jena D.P.
Published: December 2024

Sonic crystals (SCs) are structures made of sound scatterers periodically arranged in a square or triangular lattice. Recent research on sonic crystals has demonstrated that they are efficient materials for controlling the propagation of sound. They attenuate sound in certain frequency bands due to Bragg scattering across the periodic scatterers. This range of frequencies is known as the bandgap, and it is found that sound propagation is significantly reduced in this bandgap region. Belt conveyors linked sequentially to create extensive pathways across surface mines contribute significantly to noise pollution. Typically, noise emission regulations are surpassed in areas where these conveyors operate, especially at night. The operation of belt conveyors predominantly contributes to the overall noise produced by the technological infrastructure. Hence, it is crucial to aim at decreasing their noise emissions. So, with an aim to attain elevated noise reduction, various intuitive sonic cage designs made of sonic crystals such as rigid scatterers, resonant scatterers, and multi resonant scatterers were suggested and followed by the calculation of free-field insertion loss (IL). Insertion Loss (IL) refers to the decrease in noise level at a specific location resulting from the installation of a noise control device along the sound path between the sound source and that particular location. The novelty of this work is that a class of periodic structures, called the radial sonic crystals are presented, in polar coordinates. The initial investigation shows the insertion loss of the proposed sonic cage followed by calculation of insertion loss of hybrid sonic cage design using melamine foam.
Recent Advances and Prospect of Coating-based Microwave Absorber
Authors: Hussin R , Mahmud M N , Ain M F , Ariff Z M , Yahaya N Z
Published: December 2024

The development of microwave absorbers (MAs) involves using electromagnetic (EM) absorbing materials primarily composed of matrix and filler materials designed as composites that enhance EM absorption. Key requirements for MAs include thinness, light weight, broad bandwidth, high absorption, stable thermal response, and strong mechanical properties. However, conventional composite-based MAs tend to be thick, heavy, narrow-band, less absorbent, less stable thermally and weak mechanically. This review highlights the potential of coating-based MAs in solving these problems using coating techniques, including thermal spray coating, liquid processing coating, and vapor deposition coating. The goal is to meet the key requirements while addressing limitations such as slow processing, material waste, and high-temperature resistance.
Nutrient leaching analysis in cover crop management to enhance the nutrient cycling process in coconut plantations
Authors: Tenjaya M C , Suwardi  , Oktariani P , Sumawinata B , Fawzi N I , Randrikasari O
Published: December 2024

This study investigates the dynamics of nutrient cycling within closed-system peatland ecosystems, focusing on the role of nutrient leaching in enhancing biomass productivity. Conducted in a coconut plantation in Pulau Burung District, Indragiri Hilir Regency, Riau Province, the research quantitatively assesses the leaching of essential nutrients into a 10 cm layer of peat soil resulting from cover crop decomposition. These cover crops, integral to the plantation’s organic coconut production strategy, are managed through periodic cutting (every four months) and natural decomposition on the field. To closely replicate field conditions, the study employed a lysimeter method to measure the nutrients leached into the leachate. Over an observation period of eight weeks, nutrient leaching was systematically measured to determine the availability of nutrients to plants. Key findings include significant leaching rates of potassium (K) at 90.9 kg/ha/year, calcium (Ca) at 9.4 kg/ha/year, and iron (Fe) at 1109.9 g/ha/year through the peat layer. In contrast, the leaching of magnesium (Mg), copper (Cu), zinc (Zn), and manganese (Mn) was negligible, suggesting low concentrations in the cover crops and potential chelation, which impedes their mobility. This research highlights the critical role of cover crop management in promoting nutrient cycling, which is essential for sustaining the productivity and environmental health of peatland agricultural systems. The findings advocate for the integration of such practices into peatland management strategies to improve overall ecosystem sustainability.
Pellets From Three Types of Wood As Alternative Energy
Authors: Nuwa  , Damanik Maya Monika
Published: December 2024

The study’s primary goal is to assess the biopellet quality derived from waste Ulin (Eusideroxylon zwageri), Meranti Putih (Shorea bracteolata Deyr), and Rengas (Gluta spp.) using SNI 8021: 2014. The second is to compare the three varieties of Ulin wood—Meranti Putih, Rengas, and Ulin wood—in terms of quality. This study’s analysis employed a completely randomized design (CRD), with Ulin, Meranti Putih, and Rengas as the three wood species treatments, and three replications of each treatment. With the exception of density value, the quality of Ulin, Meranti Putih, and Rengas wood pellets was found to meet SNI 8021-2014 criteria. Ulin wood pellets’ density value only satisfies SNI 8021-2014 requirements. The treatment of several wood species utilized as raw materials for wood pellet production did not result in appreciable differences in the values of bound carbon content, moisture content, ash content, volatile matter content, or compressive strength. However, the calorific value that results from the density value is very important. When used to make wood pellets, Ulin sawdust is of higher quality than Meranti Putih and Rengas.