Phenomenological Description Research Articles

Rheological Behavior of Cement Paste: A Phenomenological State of the Art

With the interest aroused by the development of modern concretes such as printable or self-compacting concretes, a better understanding of the rheological behavior, directly linked to fresh state properties, seems essential. This paper aims to provide a phenomenological description of the rheological behavior of cement paste. The first part is devoted to the most common testing procedures that can be performed to characterize the rheological properties of cement suspensions. The second one deals with the complexities of the rheological behavior of cement paste including the non-linearity of flow behavior, the viscoelasticity and yielding, and the structural build-up over time.

A Unifying Perspective of Common Motifs That Occur across Disparate Classes of Materials Harboring Displacive Phase Transitions

AbstractSeveral classes of materials manifest displacive phase transitions, including shape memory alloys, many electronically correlated materials, superconductors, and ferroelectrics. Each of these classes of materials displays a wide range of fascinating properties and functionalities that are studied in disparate communities. However, these materials’ classes share similar electronic and phononic instabilities in conjunction with microstructural features. Specifically, the common motifs include twinned microstructures, anomalies in the transport behavior, softening of specific phonons, and frequently also (giant) Kohn anomalies, soft phonons, and/or nesting of the Fermi surface. These effects, phenomena, and their applications have until now been discussed in separate communities, which is a missed opportunity. In this perspective a unified framework is presented to understand these materials, by identifying similarities, defining a unified phenomenological description of displacive phase transitions and the associated order parameters, and introducing the main symmetry‐breaking mechanisms. This unified framework aims to bring together experimental and theoretical know‐how and methodologies across disciplines to enable unraveling hitherto missing important mechanistic understanding about the phase transitions in (magnetic) shape memory alloys, superconductors and correlated materials, and ferroelectrics. Connecting structural and electronic phenomena and microstructure to functional properties may offer so‐far unknown pathways to innovate applications based on these materials.

The experience of pain and its ontological modelling from a philosophical point of view: Phenomenological description and ontological revision of theMcGill Pain Questionnaire.

The aim of the article is to identify, on the basis of the phenomenological and ontological analysis of the experience of pain and the ways in which this experience is expressed in natural language, an ontological modelling of the language of pain and, at the same time, a revision of the traditional version of the McGill questionnaire. The purpose is to provide a different characterisation and an adequate evaluation of the phenomenon of pain, and, consequently, an effective measure of the actual experience of the suffering subject.

Transverse momentum broadening of medium-induced cascades in expanding media

In this work, we explore the features of gluonic cascades in static and Bjorken expanding media by numerically solving the full BDIM evolution equations in longitudinal momentum fraction x and transverse momentum {{varvec{k}}} using the Monte Carlo event generator MINCAS. Confirming the scaling of the energy spectra at low-x, discovered in earlier works, we use this insight to compare the amount of broadening in static and expanding media. We compare angular distributions for the in-cone radiation for different medium profiles with the effective scaling laws and conclude that the out-of-cone energy loss proceeds via the radiative break-up of hard fragments, followed by an angular broadening of soft fragments. While the dilution of the medium due to expansion significantly affects the broadening of the leading fragments, we provide evidence that in the low-x regime, which is responsible for most of the gluon multiplicity in the cascade, the angular distributions are very similar when comparing different medium profiles at an equivalent, effective in-medium path length. This is mainly due to the fact that in this regime, the broadening is dominated by multiple splittings. Finally, we discuss the impact of our results on the phenomenological description of the out-of-cone radiation and jet quenching.

Irreversible Geometrothermodynamics of Open Systems in Modified Gravity.

In this work, we explore the formalism of the irreversible thermodynamics of open systems and the possibility of gravitationally generated particle production in modified gravity. More specifically, we consider the scalar-tensor representation of f(R,T) gravity, in which the matter energy-momentum tensor is not conserved due to a nonminimal curvature-matter coupling. In the context of the irreversible thermodynamics of open systems, this non-conservation of the energy-momentum tensor can be interpreted as an irreversible flow of energy from the gravitational sector to the matter sector, which, in general, could result in particle creation. We obtain and discuss the expressions for the particle creation rate, the creation pressure, and the entropy and temperature evolutions. Applied together with the modified field equations of scalar-tensor f(R,T) gravity, the thermodynamics of open systems lead to a generalization of the ΛCDM cosmological paradigm, in which the particle creation rate and pressure are considered effectively as components of the cosmological fluid energy-momentum tensor. Thus, generally, modified theories of gravity in which these two quantities do not vanish provide a macroscopic phenomenological description of particle production in the cosmological fluid filling the Universe and also lead to the possibility of cosmological models that start from empty conditions and gradually build up matter and entropy.

Numerical modeling of cyclic softening/hardening behavior of carbon steels from low- to high-cycle fatigue regime

The aim of this study is to characterize the stress–strain behavior of three construction steels (SM490, SM570, and F18B) through both experimental and numerical investigations. The material performance was evaluated by conducting tests on round bar specimens subjected to monotonic, fatigue, and incremental step fully reversed loading conditions. The experimental campaign was conducted to provide valuable information on the mechanical performances of the steels and data for calibrating the material constants required for numerical analyses. The numerical simulations aimed to demonstrate the effectiveness of the proposed unconventional plasticity model, the Fatigue SS model (FSS), in describing the non-linear behavior of the materials under a broad range of loading conditions, including stress states below and beyond the macroscopic yield condition. This aspect is a significant advantage of the FSS model, as conventional elastoplastic theories fail to provide a phenomenological description of inelastic material deformation under stress states within the yield condition. The good agreement between the experimental and numerical results confirms the validity of the calibration of the material constants and the reliability of the computational approach.

A phenomenological model for the magnetodielectric effect in magnetoelectric composites

This paper proposes a phenomenological description for the nonlinear dielectric permittivity dependence on magnetic field, also called Magnetodielectric (MD) Effect, in strain mediated magnetoelectric composites. The description is derived by incorporating the dielectric dependence on electric polarization, thermodynamic constitutive equations, and magneto-mechanical effects. Moreover, the proposed expression successfully reproduces the experimental behavior reported in existing literature and can provide an explanation for the observed anisotropic effect. Simulations performed using the derived expression demonstrate an inherent correlation between the coupling of piezoelectric and magnetostrictive coefficients and the observed MD coefficient curves as measured in experiments. The validity of the model was verified by application to KNN/CFO and KNN/NFO multiferroic particulate composite samples.

The double empathy problem and the problem of empathy: neurodiversifying phenomenology

The notion that autistic individuals suffer from empathy deficiencies continues to be a widespread assumption, including in many areas of philosophy and cognitive science. In response to this, Damian Milton has proposed an interactional approach to empathy, namely the theory of the double empathy problem. According to this theory, empathy is fundamentally dependent on mutual reciprocity or salience rather than individual, cognitive faculties like theory of mind. However, the theory leaves open the question of what makes any salient interaction empathic in the first place. The aim of this paper is to integrate core tenets of the theory of the double empathy problem specifically with classical, phenomenological descriptions of empathy. Such an integration provides further conceptual refinement to the theory of the double empathy problem while recognizing its core tenets, but it also introduces important considerations of neurodiversity to classic, phenomenological descriptions of empathy.

Universal equilibration dynamics of the Sachdev-Ye-Kitaev model

Equilibrium quantum many-body systems in the vicinity of phase transitions generically manifest universality. In contrast, limited knowledge has been gained on possible universal characteristics in the non-equilibrium evolution of systems in quantum critical phases. In this context, universality is generically attributed to the insensitivity of observables to the microscopic system parameters and initial conditions. Here, we present such a universal feature in the equilibration dynamics of the Sachdev-Ye-Kitaev (SYK) Hamiltonian – a paradigmatic system of disordered, all-to-all interacting fermions that has been designed as a phenomenological description of quantum critical regions. We drive the system far away from equilibrium by performing a global quench, and track how its ensemble average relaxes to a steady state. Employing state-of-the-art numerical simulations for the exact evolution, we reveal that the disorder-averaged evolution of few-body observables, including the quantum Fisher information and low-order moments of local operators, exhibit within numerical resolution a universal equilibration process. Under a straightforward rescaling, data that correspond to different initial states collapse onto a universal curve, which can be well approximated by a Gaussian throughout large parts of the evolution. To reveal the physics behind this process, we formulate a general theoretical framework based on the Novikov–Furutsu theorem. This framework extracts the disorder-averaged dynamics of a many-body system as an effective dissipative evolution, and can have applications beyond this work. The exact non-Markovian evolution of the SYK ensemble is very well captured by Bourret–Markov approximations, which contrary to common lore become justified thanks to the extreme chaoticity of the system, and universality is revealed in a spectral analysis of the corresponding Liouvillian.

Outskirts of dark matter haloes

Halo models of large scale structure provide powerful and indispensable tools for phenomenological understanding of the clustering of matter in the Universe. While the halo model builds structures out of the superposition of haloes, defining halo profiles in their outskirts---beyond their virial radii---becomes increasingly ambiguous, as one cannot assign matter to individual haloes in a clear way. In this paper, we address this issue by finding a systematic definition of mean halo profile that can be extended to large distances---beyond the virial radius of the halo---and matched to simulation results. These halo profiles are compensated and are the key ingredients for the computation of cosmological correlation functions in an amended halo model. The latter, introduced in our earlier work [A. Y. Chen and N. Afshordi, Phys. Rev. D 101, 103522 (2020)], provides a more physically accurate phenomenological description of nonlinear structure formation, which respects conservation laws on large scales. Here, we show that this model can be extended from the matter auto-power spectrum to the halo-matter cross-power spectra by using data from $N$-body simulations. Furthermore, we find that this (dimensionless) definition of the compensated halo profile, ${r}^{3}\ifmmode\times\else\texttimes\fi{}\ensuremath{\rho}(r)/{M}_{200c}$, has a near-universal maximum in the small range of 0.03--0.04 around the virial radius, $r\ensuremath{\simeq}{r}_{200\mathrm{c}}$, nearly independent of the halo mass. The profiles cross zero into negative values in the halo outskirts---beyond $2--3\ifmmode\times\else\texttimes\fi{}{r}_{200\mathrm{c}}$---consistent with our previous results. We provide a preliminary fitting function for the compensated halo profiles (extensions of Navarro-Frenk-White profiles), which can be used to compute more physical observables in large scale structure.

Nonlocal Kondo effect and two-fluid picture revealed in an exactly solvable model.

Understanding the nature of local-itinerant transition of strongly correlated electrons is one of the central problems in condensed matter physics. Heavy fermion systems describe the f-electron delocalization through Kondo interactions with conduction electrons. Tremendous efforts have been devoted to the so-called Kondo-destruction scenario, which predicts a dramatic local-to-itinerant quantum phase transition of f-electrons at zero temperature. On the other hand, two-fluid behaviors have been observed in many materials, suggesting coexistence of local and itinerant f-electrons over a broad temperature range but lacking a microscopic theoretical description. To elucidate this fundamental issue, here we propose an exactly solvable Kondo-Heisenberg model in which the spins are defined in the momentum space and the -space Kondo interaction corresponds to a highly nonlocal spin scattering in the coordinate space. Its solution reveals a continuous evolution of the Fermi surfaces with Kondo interaction and two-fluid behaviors similar to those observed in real materials. The electron density violates the usual Luttinger's theorem, but follows a generalized one allowing for partially enlarged Fermi surfaces due to partial Kondo screening in the momentum space. Our results highlight the consequence of nonlocal Kondo interaction relevant for strong quantum fluctuation regions and provide important insight into the microscopic description of two-fluid phenomenology in heavy fermion systems.

Intersubjectivity and the Project of a Phenomenology of the Social World

Abstract In this paper, I discuss the guidelines of a phenomenology of the social world in the wake of Alfred Schutz and José Ortega y Gasset. While the latter was not, for a long time, acknowledge as a phenomenologist, the former is a well-known critique of Husserl’s theory of intersubjectivity and of the possibility of grounding a community of transcendental Egos. Both, however, remained faithful to some basic phenomenological tenets, namely, that individual subjectivity has a relational character, the circumstances in which men live are a part of their life, and life is characterized by its openness to the world. On this basis, they both carried out a phenomenological description of social existence, stressing its two main assumptions: 1) there are things that must be taken for granted; 2) habitualities, typical constructions, and systems of relevance are the primary ways of dealing with social events and other fellow citizens. In different ways, they both showed that the traditional objections opposed to phenomenology regarding its capacity to address mundane human existence stemmed from a misunderstanding of its basic tenets and intentions.

Analysis of the Change of Preservice Teachers' Self-Efficacy on Science Teaching and Learning in Online Overseas Education Volunteer Activities and Phenomenological Description on Their Experience

Analysis of the Change of Preservice Teachers' Self-Efficacy on Science Teaching and Learning in Online Overseas Education Volunteer Activities and Phenomenological Description on Their Experience

Empty satisfaction—a social phenomenology of late modern enjoyment

Phenomenological analyses of enjoyment are relatively rare; also, the few known attempts (e.g. Levinas) are elaborated in a transcendental fashion, without reflecting on the socio-historical constituents. The article aims at filling this gap by elaborating a social phenomenology of late modern enjoyment. Firstly, the experience is analysed with the help of general phenomenological descriptions: the visceral, existential and ethical constituents are mapped. The second section explores the structural transformations affecting these constituents, based on various critical theories of modernization: the impact of the reified control over the visceral; social disintegration; persistent inequalities; over-burdening of intimacy is analysed. In the concluding section, a diagnosis of times is elaborated: the cost of controlling enjoyment on the visceral level is the giving up of its existential and ethical constituents. To break this paradoxical cycle, the “actor-networks” (Latour) of visceral stimulation need to be “hacked” by including existential and ethical dimensions as well.

Tensor Representation Method Applied to Magnesium Alloys

The tensor representation method (TRM) offers tensorial tools suitable for streamlining the development of constitutive models. The TRM reduces the empiricism of phenomenological descriptions and provides physics-based justifications for the tensorial construction of material models. The method is presented in a stepwise manner, thus giving the reader an opportunity to appreciate the details of the concept. The selected material is magnesium alloy AZ31B (wt% composition: Mg 95.8, Al 3.0, Zn 1.0, and Mn 0.2), and the choice is not coincidental. The hexagonal close-packed (hcp) structure of rolled sheets exhibits highly directional plastic flow, while the crystallographic reorientations add to the complexity of the material’s behavior. A generic structure of the deformation mechanisms is determined first. In the next step, the TRM tools enable the coupling of the mechanisms with proper stimuli. Lastly, the thermo-mechanical flow rules for plasticity and twinning complete the constitutive description. The model predictions for Mg AZ31B have been compared with experimental data, demonstrating a desirable level of predictability.

Epitaxial La0.5Sr0.5MnO3‐δ Bipolar Memristive Devices with Tunable and Stable Multilevel States

AbstractValence change memories are novel data storage devices in which the resistance is determined by a reversible redox reaction triggered by voltage. The oxygen content and mobility within the active materials of these devices play a crucial role in their performance. Therefore, materials which present fast oxygen migration properties and can accommodate variable oxygen stoichiometry are promising candidates. In this work, the perovskite La0.5Sr0.5MnO3‐δ (LSM50) as memristive material is studied, which presents a more facile oxygen vacancy formation and faster oxygen migration compared to other strontium‐substituted manganites. For the first time reproducible resistive switching is reported in epitaxial LSM50‐based devices with active Ti electrodes, which show large operating window and stable multilevel states. Based on the structural, chemical, and electrical results, a simple phenomenological description of the resistive switching phenomena taking place in these novel LSM50‐based memristive devices is proposed.

Modeling Bainite Dual-Phase Steels: A High-Resolution Crystal Plasticity Simulation Study

A bainite dual-phase (FB) steel containing polygonal ferrite and granular bainite is thermo-mechanically rolled, followed by an accelerated cooling. Two different cooling rates are applied to obtain two different materials. The aim of the study is to explore the reasons for the differences in the mechanical response experimentally observed for these two materials which are modeled by means of high-resolution crystal plasticity simulations with a phenomenological constitutive description. First, the CP parameters of the individual constituents are determined. Second, different three-dimensional (3D) representative volume elements (RVEs)—one of which includes the substructure of bainite—are used to study the mechanical properties of both FB microstructures. It is shown that, in contrast to the macroscopic response, the microscopic response differs among the RVEs. Third, a comparison of both materials is performed by analyzing their stress–strain response. The onset of plasticity in granular bainite is found to be different for both materials in addition to the strain partitioning, although they both obeyed the iso-work assumption. Finally, a parameter study is carried out in order to investigate the correlation between different microstructures and damage initiation that can be seen experimentally in this steel. It is shown that the difference in ultimate elongation may depend on whether the first voids appear within polygonal ferrite or at the phase boundary.

Anomaly-free scale symmetry and gravity

In this Letter, we address the question of whether the conformal invariance can be considered as a global symmetry of a theory of fundamental interactions. To describe Nature, this theory must contain a mechanism of spontaneous breaking of the scale symmetry. Besides that, the fundamental theory must include gravity, whereas all known extensions of the conformal invariance to the curved space-time suffer from the Weyl anomaly. We show that conformal symmetry can be made free from quantum anomaly only in flat space. The presence of gravity would reduce the global symmetry group of the fundamental theory to the scale invariance only. We discuss how the effective Lagrangian respecting the scale symmetry can be used for the description of particle phenomenology and cosmology.

Applicability of Hubbert model to global mining industry: Interpretations and insights

The Hubert’s model has been introduced in 1956 as a phenomenological description of the time evolution of US and world oil fields production. It has since then acquired a vast notoriety as a conceptual approach to resource depletion. It is often invoked nowadays in the context of the energy transition to question the limitations induced by the finitude of mineral stocks. Yet, its validity is often controversial despite its popularity. This paper offers a pedagogical introduction to the model, assesses its ability to describe the current evolution of 20 mining elements, and discusses the nature and robustness of conclusions drawn from Hubbert’s model considered either as a forecast or as a foresight tool. We also propose a novel way to represent graphically these conclusions as a “Hubbert’s map” which offers direct visualization of their main features.

Neuronal avalanches: Sandpiles of self-organized criticality or critical dynamics of brain waves?

Analytical expressions for scaling of brain wave spectra derived from the general nonlinear wave Hamiltonian form show excellent agreement with experimental "neuronal avalanche" data. The theory of the weakly evanescent nonlinear brain wave dynamics [Phys. Rev. Research 2, 023061 (2020); J. Cognitive Neurosci. 32, 2178 (2020)] reveals the underlying collective processes hidden behind the phenomenological statistical description of the neuronal avalanches and connects together the whole range of brain activity states, from oscillatory wave-like modes, to neuronal avalanches, to incoherent spiking, showing that the neuronal avalanches are just the manifestation of the different nonlinear side of wave processes abundant in cortical tissue. In a more broad way these results show that a system of wave modes interacting through all possible combinations of the third order nonlinear terms described by a general wave Hamiltonian necessarily produces anharmonic wave modes with temporal and spatial scaling properties that follow scale free power laws. To the best of our knowledge this has never been reported in the physical literature and may be applicable to many physical systems that involve wave processes and not just to neuronal avalanches.