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Heuristic Estimation of the Vacuum Energy Density of the Universe: Part II-Analysis Based on Frequency Domain Electromagnetic Radiation

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Journal of Electromagnetic Analysis and Applications 2024年第1期16卷 1-9页

作者： Vernon Cooray Gerald Cooray Marcos Rubinstein farhad rachidi Department of Electrical Engineering Uppsala University Uppsala Sweden Karolinska Institute Stockholm Sweden HEIG-VD University of Applied Sciences and Arts Western Switzerland Yverdon-les-Bains Switzerland Electromagnetic Compatibility Laboratory Swiss Federal Institute of Technology (EPFL) Lausanne Switzerland

In Part I of this paper, an inequality satisfied by the vacuum energy density of the universe was derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to a constant and relativistic speed at a distance L from a perfectly conducting plane. The charge of the electron was represented by a spherical charge distribution located within the Compton wavelength of the electron. Subsequently, the electron is incident on the perfect conductor giving rise to transition radiation. The energy associated with the transition radiation depends on the parameter L. It was shown that an inequality satisfied by the vacuum energy density will emerge when the length L is pushed to cosmological dimensions and the product of the radiated energy, and the time duration of emission is constrained by Heisenberg’s uncertainty principle. In this paper, a similar analysis is conducted with a chain of electrons oscillating sinusoidally and located above a conducting plane. In the thought experiment presented in this paper, the behavior of the energy radiated by the chain of oscillating electrons is studied in the frequency domain as a function of the length L of the chain. It is shown that when the length L is pushed to cosmological dimensions and the energy radiated within a single burst of duration of half a period of oscillation is constrained by the fact that electromagnetic energy consists of photons, an inequality satisfied by the vacuum energy density emerges as a result. The derived inequality is given by where is the vacuum energy density. This result is consistent with the measured value of the vacuum energy density, which is 5.38 × 10-10 J/m. The result obtained here is in better agreement with experimental data than the one obtained in Part I of this paper with time domain radiation.

关键词： Classical Electrodynamics Electromagnetic Radiation Action Radiated Energy Photon Heisenberg’s Uncertainty Principle Dark Energy Vacuum Energy Cosmological Constant Hubble Radius

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Hints of the Photonic Nature of the Electromagnetic Fields in Classical Electrodynamics

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Journal of Electromagnetic Analysis and Applications 2023年第3期15卷 25-42页

Several recent publications show that the electromagnetic radiation generated by transmitting antennas satisfy the following universal conditions: The time domain radiation fields satisfy the condition A ≥ h/4π ⇒q ≥ e where A is the action of the radiation field, which is defined as the product of the radiated energy and the duration of the radiation, h is the Planck constant, e is the electronic charge and q is the charge associated with the radiating system. The frequency domain radiation fields satisfy the condition U ≥ hv ⇒q ≥ e where U is the energy radiated in a single burst of radiation of duration T/2 and v is the frequency of oscillation. The goal of this paper is to show that these conditions, which indeed are expressions of the photonic nature of the electromagnetic fields, are satisfied not only by the radiation fields generated by physical antennas but also by the radiation fields generated by accelerating or decelerating electric charges. The results presented here together with the results obtained in previous studies show that hints of the photonic nature of the electromagnetic radiation remain hidden in the field equations of classical electrodynamics, and they become apparent when the dimension of the radiating system is pushed to the extreme limits as allowed by nature.

关键词： Classical Electrodynamics Electromagnetic Radiation Action Radiated Energy Photon Heisenberg’s Uncertainty Principle Dark Energy Vacuum Energy Hubble Radius

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Heuristic Estimation of the Vacuum Energy Density of the Universe: Part I—Analysis Based on Time Domain Electromagnetic Radiation

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Journal of Electromagnetic Analysis and Applications 2023年第6期15卷 73-81页

In this paper, an inequality satisfied by the vacuum energy density of the universe is derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to a constant and relativistic speed at a distance L from a perfectly conducting plane. The charge of the electron is represented by a spherical charge distribution located within the Compton wavelength of the electron. Subsequently, the electron is incident on the perfect conductor giving rise to transition radiation. The energy associated with the transition radiation depends on the parameter L. It is shown that an inequality satisfied by the vacuum energy density will emerge when the length L is pushed to cosmological dimensions and the product of the radiated energy and the time duration of emission are constrained by Heisenberg’s uncertainty principle. The inequality derived is given by ρΛ ≤ 9.9×10-9J/m3 where ρΛ is the vacuum energy density. This result is consistent with the measured value of the vacuum energy density, which is 0.538 × 10-9J/m. Since there is a direct relationship between the vacuum energy density and the Einstein’s cosmological constant, the inequality can be converted directly to that of the cosmological constant.

关键词： Classical Electrodynamics Electromagnetic Radiation Action Radiated Energy Photon Heisenberg’s Uncertainty Principle Dark Energy Vacuum Energy Cosmological Constant Hubble Radius

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Characteristics of different charge transfer modes in upward flashes inferred from simultaneously measured currents and fields

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High Voltage 2020年第1期5卷 30-37页

作者： Lixia He Mohammad Azadifar Quanxin Li Marcos Rubinstein Vladimir A.Rakov Arturo Mediano Davide Pavanello farhad rachidi Electromagnetic Compatibility Laboratory Swiss Federal Institute of Technology(EPFL)1015 LausanneSwitzerland Department of Atmospheric Physics Nanjing University of Information Science and TechnologyNanjingPeople's Republic of China University of Applied Sciences of Western Switzerland(HES-SO) 1400 Yverdon-les-BainsSwitzerland Department of Electrical Engineering Wuhan UniversityWuhanPeople's Republic of China Department of Electrical and Computer Engineering University of FloridaFloridaUSA Institute of Electronics and Mathematics National Research University Higher School of EconomicsMoscowRussia Department Electronics and Communication Engineering University of ZaragozaZaragozaSpain Institute of Sustainable Energy University of Applied Sciences of Western Switzerland(HES-SO)1950 SionSwitzerland

The authors present an analysis of different charge transfer modes during upward negative *** analysis includes a total number of 94 pulses that occurred during two upward negative flashes recorded at the Säntis *** pulses included 59 mixed-mode(MM)initial continuous current(ICC)pulses,17 M-component-type ICC(M-ICC)pulses,8 returnstroke pulses,and 10 classical M-component(MC)*** is found that the initial stage of the flash is responsible for the largest share of the total charge transferred to the *** results for the electric fields associated with the considered charge transfer modes are presented and *** stroke(RS)and MM pulses were simulated adopting the MTLE model,while MCs and M-ICC pulses were simulated using the guided wave model of Rakov et *** simulated results are shown to be in good agreement with simultaneous records of electric fields measured at a distance of 15 km from the Säntis *** inferred velocities for MCs and M-ICC pulses range from 2.0×10^(7) to 9.0×10^(7) m/s,and the corresponding junction point heights range from 1.0 to 2.0 *** inferred pulse velocities for RSs and MM pulses range from 1.3×10^(8) to 1.65×10^(8) m/*** inferred current attenuation constants of the MTLE model obtained in this study range from 0.3 to 0.8 km,lower than the value of 2 km previously suggested for RSs in downward *** obtained results support the assumption that the mode of charge transfer to the ground giving rise to MM pulses is similar to that of *** results are also in support of the generally assumed similarity between M-ICC pulses and classical MCs.

关键词： flash charge transfer

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Applying the Protective Mn-Co-La_(2)O_(3)Coating on Crofer 22 APU Ferritic Stainless Steel Used as Solid Oxide Fuel Cell Interconnects

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 872-888页

作者： farhad Mohsenifar Hadi Ebrahimifar Ahmad Irannejad Department of Materials Engineering and Metallurgy Faculty of EngineeringShahid Bahonar University of KermanKermanIran Mechanical Engineering Department Faculty of EngineeringHigher Education Complex of Bam76615-314BamIran Department of Materials Engineering Faculty of Mechanical and Materials EngineeringGraduate University of Advanced TechnologyKerman ***Iran

This research studies the effect of Mn-Co-La_(2)O_(3) coating synthesized by the electrodeposition method on the oxidation resistance and electrical conductivity of the Crofer 22 APU stainless steel interconnect plates in solid oxide fuel *** test samples were characterized by a field emission scanning electron microscope(FESEM)equipped with energy dispersive spectroscopy(EDS),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).The oxidation kinetics of the coated and uncoated samples were studied by tracking their weight changes over time at 800°C,showing that the oxidation mechanism for all samples follows the parabolic *** oxidation rate constant(k_(p))values of the coated sample compared with that of the uncoated one indicated a reduction in the oxidation rate of the steel substrate in the presence of the Mn-Co-La_(2)O_(3) *** examination of the cross-section of different samples after the isothermal oxidation for 500 h at 800°C exhibited that applying the composite coating leads to a decrease in the thickness of the chromia layer formed on the steel ***,under these conditions,the area-specific resistance(ASR)of the coated sample(13.11 mΩcm^(2))is significantly lower than that of the uncoated one(41.45 mΩcm^(2)).

关键词： Area specific resistance Oxidation Fuel cell Composite coating

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Emergence of Friedmann Equation of Cosmology of a Flat Universe from the Time-Energy Uncertainty Principle

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Journal of Modern Physics 2017年第12期8卷 1979-1987页

作者： Vernon Cooray Gerald Cooray farhad rachidi Department of Engineering Sciences Uppsala University Uppsala Sweden Karolinska Institute Stockholm Sweden école polytechnique fédérale de Lausanne Lausanne Switzerland

Friedmann equation of cosmology is based on the field equations of general relativity. Its derivation is straight-forward once the Einstein’s field equations are given and the derivation is independent of quantum mechanics. In this paper, it is shown that the Friedmann equation pertinent to a homogeneous, isotropic and flat universe can also be obtained as a consequence of the energy balance in the expanding universe between the positive energy associated with vacuum and matter, and the negative gravitational energy. The results obtained here is a clear consequence of the fact that the surface area of the Hubble sphere is proportional to the total amount of information contained within it.

关键词： Friedmann Equation Expansion of the Universe Vacuum Energy Dark Energy Time-Energy Uncertainty Principle Holographic Principle Hubble Sphere

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Analysis of cohesive particles mixing behavior in a twin-paddle blender:DEM and machine learning applications

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Particuology 2024年第7期90卷 350-363页

作者： Behrooz Jadidi Mohammadreza Ebrahimi farhad Ein-Mozaffari Ali Lohi Department of Chemical Engineering Toronto Metropolitan University350 Victoria StreetToronto M5B 2K3Canada

This research paper presents a comprehensive discrete element method(DEM)examination of the mixing behaviors exhibited by cohesive particles within a twin-paddle blender.A comparative analysis between the simulation and experimental results revealed a relative error of 3.47%,demonstrating a strong agreement between the results from the experimental tests and the DEM *** main focus centers on systematically exploring how operational parameters,such as impeller rotational speed,blender's fill level,and particle mass ratio,influence the *** investigation also illustrates the significant influence of the mixing time on the mixing *** gain a deeper understanding of the DEM simulation findings,an analytical tool called multivariate polynomial regression in machine learning is *** method uncovers significant connections between the DEM results and the operational parameters,providing a more comprehensive insight into their *** multivariate polynomial regression model exhibited robust predictive performance,with a mean absolute percentage error of less than 3%for both the training and validation sets,indicating a slight deviation from actual *** model's precision was confirmed by low mean absolute error values of 0.0144(80%of the dataset in the training set)and 0.0183(20%of the dataset in the validation set).The study offers valuable insights into granular mixing behaviors,with implications for enhancing the efficiency and predictability of the mixing processes in various industrial applications.

关键词： Machine learning Granular mixing Discrete element method Mixing kinetics and mechanism Cohesive particles

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Advances in Manta Ray Foraging Optimization:A Comprehensive Survey

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Journal of Bionic Engineering 2024年第2期21卷 953-990页

作者： farhad Soleimanian Gharehchopogh Shafi Ghafouri Mohammad Namazi Bahman Arasteh Department of Computer Engineering Urmia BranchIslamic Azad UniversityUrmiaIran Department of Computer Engineering Tabriz BranchIslamic Azad UniversityTabrizIran Department of Computer Engineering Maybod BranchIslamic Azad UniversityMaybodIran Department of Software Engineering Faculty of Engineering and Natural ScienceIstinye UniversityIstanbulTurkey

This paper comprehensively analyzes the Manta Ray Foraging Optimization(MRFO)algorithm and its integration into diverse academic *** in 2020,the MRFO stands as a novel metaheuristic algorithm,drawing inspiration from manta rays’unique foraging behaviors—specifically cyclone,chain,and somersault *** biologically inspired strategies allow for effective solutions to intricate physical *** its potent exploitation and exploration capabilities,MRFO has emerged as a promising solution for complex optimization *** utility and benefits have found traction in numerous academic *** its inception in 2020,a plethora of MRFO-based research has been featured in esteemed international journals such as IEEE,Wiley,Elsevier,Springer,MDPI,Hindawi,and Taylor&Francis,as well as at international conference *** paper consolidates the available literature on MRFO applications,covering various adaptations like hybridized,improved,and other MRFO variants,alongside optimization *** trends indicate that 12%,31%,8%,and 49%of MRFO studies are distributed across these four categories respectively.

关键词： Manta ray foraging optimization Metaheuristic algorithms Hybridization Improved Optimization

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Lorentz Force from a Current-Carrying Wire on a Charge in Motion under the Assumption of Neutrality in the Symmetrical Frame of Reference

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Journal of Modern Physics 2018年第14期9卷 2473-2481页

作者： Antonio Sunjerga Franjo Sokolic Marcos Rubinstein farhad rachidi Electromagnetic Compatibility Laboratory EPFLSwitzerland Department of Physics Faculty of ScienceSplitCroatia University of Applied Sciences Western Switzerland Yverdon-les-BainsSwitzerland

It is commonly assumed that a wire conducting an electric current is neutral in the laboratory frame of reference (the rest frame of the lattice of positive ions). Some authors consider that the wire is neutral only in a symmetrical frame of reference, in which the velocities of electrons and protons have equal norm and opposite direction. In this paper, we discuss the Lorentz transformation between different frames of reference in the context of the special theory of relativity for a current-carrying conducting wire and a probe charge in motion with respect to the wire. A simple derivation of the Lorentz force in the laboratory frame of reference for the assumed neutrality in a symmetrical frame of reference is presented. We show that the Lorentz force calculated assuming neutrality in the symmetrical frame of reference and the one assuming neutrality in the laboratory frame of reference differ by a term corresponding to a change in the test charge speed of one half the drift velocity of the electrons.

关键词： Special Theory of Relativity Current-Carrying Wire Neutral Frame Symmetrical Frame Lorentz Force Drift Velocity

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An efficient tool for Parkinson's disease detection and severity grading based on time-frequency and fuzzy features of cumulative gait signals through improved LSTM networks

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Medicine in Novel Technology and Devices 2024年第2期22卷 38-50页

作者： farhad Abedinzadeh Torghabeh Yeganeh Modaresnia Seyyed Abed Hosseini Department of Biomedical Engineering Mashhad BranchIslamic Azad UniversityMashhadIran Department of Electrical Engineering Mashhad BranchIslamic Azad UniversityMashhadIran

Parkinson's disease(PD)is a widespread neurodegenerative condition that affects many individuals *** identification and monitoring of disease progression are crucial to effectively managing symptoms and preventing motor *** research proposes an automated PD diagnosis and severity-grading model based on time-frequency and fuzzy features using improved uni-directional and bi-directional long short-term memory networks with sensitive hyperparameters *** utilize vertical ground reaction force signals collected from Physionet's publicly available dataset recorded during regular and dual-task clinical trials of walking *** the cumulative signal of both feet was then utilized and segmented into 30-s windows without further ***,we extracted only four key time-frequency and fuzzy features from each segment,effectively capturing the signal's inherent *** optimization is employed in both detection and grading approaches to fine-tune the two critical hyperparameters:the initial learning rate and the number of hidden units in the *** detection phase yields an exceptional accuracy of 99.19%,surpassing state-of-the-art studies with the same *** the grading phase,classification based on the unified PD rating scale values achieves an accuracy of 92.28%.The proposed study delves into the potential of cumulative gait signals as a powerful diagnostic tool for PD,aiming to extract precise and intricate information by implementing straightforward and minimal processing *** method demonstrates significant effi-ciency in terms of complexity,cost,and energy consumption by utilizing a single-dimensional signal,eliminating the need for pre-processing steps,and limiting the features used for training.

关键词： Parkinson's disease grading Cumulative gait signal Vertical ground reaction force fuzzy feature Bayesian optimization Long short-term memory

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