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Further evidence on the effect of magnetism on lattice vibrations: The case study of sigma-phase Fe0.525Cr0.455Ni0.020alloy

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arXiv 2022年

作者： Dubiel, Stanislaw M. Zukrowski, Jan Faculty Of Physics And Applied Computer Science AGH University Of Science And Technology KrakówPL-30-059 Poland Academic Center For Materials And Nanotechnology AGH University Of Science And Technology KrakówPL-30-059 Poland

Sigma-phase Fe0.525Cr0.455Ni0.020alloy was studied by means of Mössbauer spectrometry in the temperature range of 5-293 K. The average center shift, , determined from the recorded Mössbauer spectra was shown to significantly deviate from the Debye model in the temperature range below ∼50 K i.e. in the magnetic state of the sample. The deviation is obviously due to the effect of magnetism on the lattice dynamics of the studied sample. Analysis of the -data in the paramagnetic phase in terms of the Debye model yielded the value of 437(7) K for the Debye temperature. © 2022, CC BY-NC-ND.

关键词： Lattice vibrations

Electric field-based quantization of the gauge invariant Proca theory

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arXiv 2023年

作者： Damski, Bogdan Jagiellonian University Faculty of Physics Astronomy and Applied Computer Science Lojasiewicza 11 Kraków30-348 Poland

We consider the gauge invariant version of the Proca theory, where besides the real vector field there is also the real scalar field. We quantize the theory such that the commutator of the scalar field operator and the electric field operator is given by a predefined three-dimensional vector field, say E up to a global prefactor. This happens when the field operators of the gauge invariant Proca theory satisfy the proper gauge constraint. In particular, we show that E given by the classical Coulomb field leads to the Coulomb gauge constraint making the vector field operator divergenceless. We also show that physically unreadable gauge constraints can have a strikingly simple E-representation in our formalism. This leads to the discussion of Debye, Yukawa, etc. gauges. In general terms, we explore the mapping between classical vector fields and gauge constraints imposed on the operators of the studied theory. Copyright © 2023, The Authors. All rights reserved.

关键词： Vectors

Quantum correction to a new Wilson line-based action for Gluodynamics

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arXiv 2023年

作者： Kakkad, Hiren Kotko, Piotr Stasto, Anna Faculty of Physics and Applied Computer Science AGH University of Krakow al. A. Mickiewicza 30 Krakow30-059 Poland Physics Department The Pennsylvania State University 104 Davey Lab University ParkPA16802 United States

We discuss a new classical action that enables efficient computation of the gluonic tree amplitudes but does not contain any triple point vertices. This new formulation is obtained via a canonical transformation of the light-cone Yang-Mills action, with the field transformations based on Wilson line functionals. In addition to MHV vertices, the action contains also NkMHV vertices, where 1 ≤ k ≤ n − 4, and n is the number of external legs. We computed tree-level amplitudes up to 8 gluons and found agreement with standard results. The classical action is however not sufficient to obtain rational parts of amplitudes, in particular the finite amplitudes with all same helicity gluons. In order to systematically develop quantum corrections to this new action, we derive the one-loop effective action, in such a way there are no quantum contributions missing at one loop. Copyright © 2023, The Authors. All rights reserved.

关键词： Trees (mathematics)

Quality and Efficiency of Manual Annotation: Pre-annotation Bias

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arXiv 2023年

作者： Mikulová, Marie Straka, Milan Štěpánek, Jan Štěpánková, Barbora Hajič, Jan Institute of Formal and Applied Linguistics Computer Science School Faculty of Mathematics and Physics Charles University Prague Czech Republic

This paper presents an analysis of annotation using an automatic pre-annotation for a mid-level annotation complexity task - dependency syntax annotation. It compares the annotation efforts made by annotators using a pre-annotated version (with a high-accuracy parser) and those made by fully manual annotation. The aim of the experiment is to judge the final annotation quality when pre-annotation is used. In addition, it evaluates the effect of automatic linguistically-based (rule-formulated) checks and another annotation on the same data available to the annotators, and their influence on annotation quality and efficiency. The experiment confirmed that the pre-annotation is an efficient tool for faster manual syntactic annotation which increases the consistency of the resulting annotation without reducing its quality. Copyright © 2023, The Authors. All rights reserved.

关键词： Efficiency

Non-equilibrium dynamics of dipole-charged fields in the Proca theory

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arXiv 2023年

作者： Damski, Bogdan Jagiellonian University Faculty of Physics Astronomy and Applied Computer Science Lojasiewicza 11 Kraków30-348 Poland

We discuss the dynamics of field configurations encoded in the certain class of electric (magnetic) dipole-charged states in the Proca theory of the real massive vector field. We construct such states so as to ensure that the long distance structure of the mean electromagnetic field in them is initially set by the formula describing the electromagnetic field of the electric (magnetic) dipole. We analyze then how such a mean electromagnetic field evolves in time. We find that far away from the center of the initial field configuration, the long range component of the mean electromagnetic field harmonically oscillates, which leads to the phenomenon of the periodic oscillations of the electric (magnetic) dipole moment. We also find that near the center of the initial field configuration, the mean electromagnetic field escapes from its initial arrangement and a spherical shock wave propagating with the speed of light appears in the studied system. A curious configuration of the axisymmetric mean electric field is found to accompany the mean magnetic field in magnetic dipole-charged states. Copyright © 2023, The Authors. All rights reserved.

关键词： Electromagnetic fields

Transport properties and doping evolution of the Fermi surface in cuprates

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arXiv 2023年

作者： Klebel-Knobloch, Benjamin Tabis, Wojciech Gala, Mateusz A. Barišić, Osor S. Sunko, Denis K. Barišić, Neven Institute of Solid State Physics TU Wien Vienna1040 Austria AGH University of Krakow Faculty of Physics and Applied Computer Science Krakow30-059 Poland Institute of Physics Bijenička cesta 46 ZagrebHR-10000 Croatia Department of Physics Faculty of Science University of Zagreb Bijenička cesta 32 ZagrebHR-10000 Croatia

Measured transport properties of three representative cuprates are reproduced within the paradigm of two electron subsystems, itinerant and localized. The localized subsystem evolves continuously from the Cu 3d9 hole at half-filling and corresponds to the (pseudo)gapped parts of the Fermi surface. The itinerant subsystem is observed as a pure Fermi liquid (FL) with material-independent universal mobility across the doping/temperature phase diagram. The localized subsystem affects the itinerant one in our transport calculations solely by truncating the textbook FL integrals to the observed (doping- and temperature-dependent) Fermi arcs. With this extremely simple picture, we obtain the measured evolution of the resistivity and Hall coefficients in all three cases considered, including LSCO which undergoes a Lifshitz transition in the relevant doping range, a complication which turns out to be superficial. Our results imply that prior to evoking polaronic, quantum critical point, quantum dissipation, or even more exotic scenarios for the evolution of transport properties in cuprates, Fermi-surface properties must be addressed in realistic detail. © 2023, CC BY.

关键词： Transport properties

New simplified energy flow management algorithms for a DC bus-coupled photovoltaic-grid hybrid system

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Energy Systems 2025年 1-13页

作者： Mbende, Ernest Titi Pesdjock, Mathieu Jean Pierre Muluh, Fombu Andrew Kenne, Godpromesse Department of Electrical and Power engineering Research Unit of Automation and Applied Computer Science IUT-FV Bandjoun University of Dschang P.O. Box 134 west Bandjoun Cameroon Department of Physics Research Unit of Condensed matter electronics and signal processing Faculty of Science University of Dschang P.O. Box 67 west Dschang Cameroon Department of Electrical and Electronic Engineering National Higher Polytechnic Institute University of Bamenda P.O. Box 39 North West Bambili Bamenda Cameroon

This paper presents a new simplified linear self-adjusting algorithm and an improved artificial ant colony self adjusting algorithm, for optimal energy flow management of a photovoltaic-grid hybrid energy system coupled through a DC link. The two proposed algorithms rely on the voltage error in the stabilization of the AC link to self determine a compensation current and hence power deficit, which is automatically extracted from the back-up storage to maintain an uninterrupted service and ensure the balance between power production and consumption. Numerical simulation results in Matlab/simulink under different scenarios show the effectiveness of the algorithms in mitigating the challenges posed by the intermittent nature of the photovoltaic source and also in facilitating the rapid and flexible integration of the renewable energy source. The algorithms also contribute effectively in regulating the AC bus voltage and in maintaining the frequency and total harmonic distortion within acceptable standards. The specificity of the two proposed algorithms is the fast response speed of the system in balancing power output and consumption. A comparative study of the proposed algorithms with a proportional integral (PI) controller under different operating modes clearly show the superiority of the new linear self-adjusting algorithm in terms of system stability, response time, error reduction and total harmonic distortion mitigation. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.

关键词： Power management (telecommunication)

A Simple Method for Determining Center Shift and Spectral Area of a Mössbauer Spectrum

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arXiv 2022年

作者： Dubiel, Stanislaw M. Żukrowski, Jan Faculty of Physics and Applied Computer Science AGH University of Science and Technology KrakówPL-30-059 Poland Academic Center for Materials and Nanotechnology AGH University of Science and Technology KrakówPL-30-059 Poland

A very simple method for determining the center (isomer) shift, CS, and the spectral area, A, of a Mössbauer spectrum is outlined. Its applicability is demonstrated in two examples viz. pyrite and a ternary sigma-phase Fe-Cr-Ni compound. Sets of the spectra recorded in the temperature interval of 78-295 K for the former, and 78-295 K for the latter were analyzed with the simple and a standard method. CS(T)- and A(T)data obtained with both ways of the spectra analysis were analyzed in terms of the Debye model. The determined values of the Debye temperatures agree well within the error limit with each other proving that this very simple method is suitable for a quick determining of CS and A spectral parameters. © 2022, CC BY-NC-ND.

关键词： Pyrites

Through-Wall Human Sensing Using mmWave FMCW Radar 4

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Through-Wall Human Sensing Using mmWave FMCW Radar

4th Research, Invention, and Innovation Congress: Innovative Electricals and Electronics, RI2C 2023

作者： Phaisiri, Kritthee Boonpoonja, Akkarat Kittiyanpunya, Chainarong Kaemarungsi, Kamol Chudpooti, Nonchanutt Department of Electrical and Computer Engineering Faculty of Engineering King Mongkut’s University of Technology North Bangkok Bangkok Thailand Department of Mechatronics Engineering Faculty of Engineering Rajamangala University of Technology Rattanakosin Nakhon Pathom Thailand National Electronics and Computer Technology Center National Science and Technology Development Agency Pathumthani Thailand Department of Industrail Physics and Medical Instrumentation Faculty of Applied Science King Mongkut’s University of Technology North Bangkok Bangkok Thailand

ISBN: (纸本)9798350330618

This paper experimentally demonstrates the through wall sensing to detect human movement using a mmwave FMCW radar operating in the 60 GHz to 64 GHz band. The mmWave radar data processing framework focuses on the generation of point cloud data. Each human movement is illustrated with point cloud data, whose represents the position and orientation of pose, usually in 3D-cartesian coordinate system. In experiments, point cloud data from sensing through two different walls were collected for three activities into a 3 m by 3 m room. The data was analyzed through a comparison between the position of point cloud data and the position of the actual posture movement. The results prove that a mmWave radar placed behind the wall of the room is suitable for human detection and tracking in indoor environments, in terms of consistency with the actual posture. . ©2023 IEEE.

关键词： Frequency modulation