313 articles found
Using a Toy Model to Improve the Quantization of Gravity and Field Theories
John Klauder
Subject: Physical Sciences, General & Theoretical Physics Keywords: Affine quantization; Ashtekar-like variables; gravity and field theories
A half-harmonic oscillator, which gets its name because the coordinate is strictly positive, has been quantized and determined that it was a physically correct quantization. This positive result was found using affine quantization (AQ). The main purpose of this paper is to compare results of this new quantization procedure with those of canonical quantization (CQ). Using Ashtekar-like classical variables and CQ, we quantize the same toy model. While these two quantizations lead to different results, they both would reduce to the same classical Hamiltonian if $\hbar\rightarrow0$. Since these two quantizations have differing results, only one of the quantizations can be physically correct. Two brief sections illustrate how AQ can correctly help quantum gravity and the quantization of most field theory problems.
Non-Equilibrium Quantum Brain Dynamics: Super-radiance and Equilibration in 2+1 Dimensions
Akihiro Nishiyama, Shigenori Tanaka, Jack A. Tuszynski
Subject: Physical Sciences, Other Keywords: non-equilibrium quantum field theory; quantum brain dynamics; kadanoff–baym equation; entropy; super-radiance
We derive time evolution equations, namely the Schrodinger-like equations and the Klein-Gordon equations for coherent fi elds and the Kadanoff-Baym (KB) equations for quantum fluctuations, in Quantum Electrodynamics (QED) with electric dipoles in 2 + 1 dimensions. Next we introduce a kinetic entropy current based on the KB equations in the 1st order of the gradient expansion. We show the H-theorem for the Leading-Order self-energy in the coupling expansion (the Hartree-Fock approximation). We show a conserved energy in the spatially homogeneous systems in the time evolution. We derive aspects of the super-radiance and the equilibration in our single Lagrangian. Our analysis can be applied to Quantum Brain Dynamics, that is QED with water electric dipoles. The total energy consumption to maintain super-radiant states in microtubules seems to be within the energy consumption to maintain the ordered systems in a brain.
Reconciling the Cosmological Constant with the Energy Density of Quantum Field Theories of the Zeropoint
Remi Cornwall
Subject: Physical Sciences, General & Theoretical Physics Keywords: Zeropoint Energy; Cosmological Constant; Stress Energy Tensor; Einstein Field Equations; Standard Model; Dark Energy; Quantum Gravity
Online: 31 March 2022 (14:01:14 CEST)
This paper results from our investigation into novel means of electromagnetic propulsion. It requires the basis of our claims to be put on a sound theoretical footing regarding the purported momentum exchange with the electromagnetic field. One of these concerns is the huge discrepancy between the energy density of the Zeropoint and its purported manifestation as the Cosmological Constant. Here we state that it is manifestly wrong to introduce the zeropoint at zero order into the stress-energy tensor, because it is something which describes zero particle count. As a fluctuation, it belongs in a higher order Taylor expansion in frequency of the stress-energy tensor. Furthermore in the 3rd order in the Einstein constant our procedure is some 9 orders of magnitude too small. We make up this difference by suggesting that vacuum energy is much higher still and that more degrees of freedom exist in physics beyond the Standard Model or that there is interaction energy between the modes.
A New Understanding of Macroscopic Electromagnetic Phenomena at the Micro Level
Jack Van
Subject: Physical Sciences, General & Theoretical Physics Keywords: charge; current; electric field; magnetic field
Online: 21 June 2019 (08:39:42 CEST)
As we all know, contemporary electromagnetic theory is based on the macroscopic electromagnetic theory established by the 19th century. Because of the lack of microscopic cognition in that era, various electromagnetic phenomena could only be explained and described at the macro level, and their origins could not be explained at the micro level. And because of the microscopic understanding of atomic physics in the 20th century, new progress has been made. Considering that it is now the 21st century, this paper attempts to establish a new theory of microscopic interpretation of classical electromagnetic theory based on the new cognition of atomic physics in the 20th century. Starting from the general assumption, the current will be interpreted as the momentum flow produced by the directed collision between electrons; the charge will be interpreted as a form of expression of electron motion; the voltage is interpreted as the potential difference (energy level difference) of the electron orbit. In the end, this paper successfully developed a new microscopic electromagnetic theory by introducing microscopic atomic physics and rigid body mechanics models to Maxwell's macroscopic electromagnetic theory.
Working Paper REVIEW
Framed Experiments and Games in Agriculture: A Systematic Review of the 21st Century in Economics and Social Science
J. Nicolas Hernandez-Aguilera, Max Mauerman, Alexandra Herrera, Kathryn Vasilaky, Walter Baethgen, Ana Maria Loboguerrero, Rahel Diro, Yohana Tesfamariam Tekeste, Daniel Osgood
Subject: Social Sciences, Other Keywords: review; games; field experiments; agriculture
Online: 12 August 2020 (14:47:11 CEST)
Framed experiments and games are a useful medium to understand how context affects individual and group decision-making. They are particularly relevant for field research in agriculture, where alternative experimental designs can be costly and unfeasible. After a systematic review of the literature, we found that the volume of published studies employing coordination and cooperation games increased during the 2000-2020 period. In recent years, there has been greater attention given to natural resource management, conservation, and ecology areas, especially in strategic regions for agriculture sustainability. Other games, such as trust and risk games, have come to be regarded as standards of framed field experiments in agriculture. Regardless of sectoral focus, most games' results are subject to internal and external validity criticism. In particular, a significant portion of the games showed potential recruitment biases against women and no opportunities for a continued impact assessment. However, games' validity should be judged on a case-by-case basis. Specific cultural aspects of games might reflect the real context, and generalizing games' conclusions to different settings is often constrained by cost and utility. Overall, games in agriculture could benefit from more significant, frequent, and inclusive experiments and data – all possibilities offered by digital technology. Present-day physical distance restrictions may accelerate this shift. New technologies and engaging ways to approach farmers might represent a turning point for games in agriculture in the 21st century.
Special Properties of Plane Solenoidal Fields
Vladimir I. Semenov
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: solenoidal field; potential field; Helmholmtz-Weyl decomposition
There are given algebraic and integral identities for a pair or a triple of plane solenoidal fields. As applications, we obtain sufficient potentiality conditions for a plane vector field. The integral identities are also important for exact a priori estimates.
Bending of Electric Field Lines and Photon Trajectories in a Static Gravitational Field
Ashok Singal
Subject: Physical Sciences, General & Theoretical Physics Keywords: Special relativity; General relativity; Electromagnetism; Bending of electric field lines in a gravitational field; Electric field lines of a freely falling charge; Bending of photon trajectories in a gravitational field
It is well known that the photon trajectories follow a curved path in a gravitational field. We explore here the gravitational bending of electric field lines. It seems that the electric field lines of a charge, supported in a gravitational field, follow exactly the trajectories of photons emitted isotropically from a source situated at the charge location. From a detailed examination of the electrostatic field of a charge accelerated uniformly in the instantaneous rest frame, exploiting the strong principle of equivalence, one can determine the bending of the electric field lines of a charge in a gravitational field. The fraction of electric field lines crossing a surface, stationary above or below the charge in the gravitational field, is shown to be exactly similar to the fraction of photon trajectories, emitted from a source placed at the charge location, intersecting that surface. On the other hand, for a freely falling charge in the gravitational field there is no such bending of electric field lines. The field lines continue to extend in radial straight lines from the instantaneous 'present' position of the charge, as do the trajectories of photons streaming away from the instantaneous position of a freely falling source in the gravitational field. The electric field configuration of a freely falling charge in the gravitational field is shown to be exactly the same as that of a charge moving uniformly in an inertial frame with velocity equal to the instantaneous ``present'' velocity of the freely falling charge.
Absence of Electric Field outside a Static Charged Black Hole - Something Awry in Reissner-Nordström Metric
Subject: Physical Sciences, General & Theoretical Physics Keywords: Black Hole has no hair; Electromagnetic field of a charged black hole, Electromagnetic field of a supported charge in gravitational field; electric fields follow photo trajectories in gravitational field
Using the principle of equivalence, it has recently been shown that the electrostatic field lines of a charge, stationary in the gravitational field, bend exactly like the trajectories of photons emitted isotropically from a source at the charge location and that the fraction of electric flux crossing a surface `below' or `above' the charge is exactly similar to the fraction of photon trajectories intersecting these surfaces, with more flux in the downward direction than upward. As one goes much deeper in the gravitational field, all electric field lines increasingly point in the vertically downward direction as is also the case for a stream of photons. Since photon trajectories as well as electric field lines, at any location in the gravitational field, are affected by the local space-time curvature an inference can be drawn that this parallel between the photon trajectories and the electric field lines is a general result. We could then apply these results in the external gravitational field of a black hole, where the trajectories of photons in the gravitational field are already well-known and the behaviour of electric field lines of a stationary charge could be inferred therefrom. Accordingly, we show that the electric field through an external spherical surface surrounding the black hole steadily reduces as the charge location approaches the event horizon (Schwarzschild radius), and like photons from a source inside the Schwarzschild radius cannot escape outside, the electric field lines of a charge within the black hole too remain trapped inside the event horizon. From this one arrives at a conclusion that, contrary to the conventional wisdom, the electric charge contained inside a static black hole cannot be detected or inferred by an external observer. A black hole, said to have no hair with the only external identifying characteristics being mass, electric charge, and angular momentum, is therefore all the more `hairless', as even its charge cannot be ascertained. The derivation of the Reissner-Nordström metric, supposedly describing the gravitational field of a static charged black hole, presumes an external stress-energy tensor of the electrostatic field, as per Gauss law, even for the charges contained within the black hole. However, the absence of electric flux external to a static charged black hole implies that such a charged black hole is not described correctly by the Reissner-Nordström metric and the consequential peculiarities of the space-time geometry, leading in specific cases to the idea of a naked intrinsic singularity and a need for the ``cosmic censorship'' hypothesis, also do not arise here.
Phase-Field Model for the Simulation of Brittle-Anisotropic and Ductile Crack Propagation in Composite Materials
Christoph Herrmann, Daniel Schneider, Ephraim Schoof, Felix Schwab, Britta Nestler
Subject: Engineering, Automotive Engineering Keywords: phase-field; multiphase-field; grey cast iron; brittle fracture; ductile fracture; anisotropic fracture
Online: 28 July 2021 (12:16:13 CEST)
In this work, a small-strain phase-field model is presented, which is able to predict crack propagation in systems with anisotropic brittle and ductile constituents. To model the anisotropic brittle crack propagation, an anisotropic critical energy release rate is used. The brittle constituents behave linear-elastically, in a transversely isotropic manner. Ductile crack growth is realised by a special crack degradation function, depending on the accumulated plastic strain, which is calculated by following the J2-plasticity theory. The mechanical jump conditions are applied in solid-solid phase transition regions. The influence of the relevant model parameters on a crack, propagating through a planar brittle-ductile interface, and furthermore a crack developing in a domain with a single anisotropic brittle ellipsoid, embedded in a ductile matrix, is investigated. We demonstrate that important properties, concerning the mechanical behaviour of grey cast iron, such as the favoured growth of cracks along the graphite lamellae and the tension-compression load asymmetry of the stress-strain response, are covered by the model. The behaviour is analysed on basis of a simulation domain consisting of three differently oriented elliptical inclusions, embedded in a ductile matrix, which is subjected to tensile and compressive load. The used material parameters correspond to graphite lamellae and pearlite.
Relevance of Team Cohesion in Training of Track and Field Athletes: A Review
Hamish D'souza, Ravindra Walmiki, Manohar Mane
Subject: Behavioral Sciences, Social Psychology Keywords: team, cohesion, track and field
Team spirit is often considered a peculiar characteristic of sportspersons. While the importance of unity among athletes is evident in team games, its relevance in the training of sportspersons of individual sports, especially track and field athletics, is often not recognized. The purpose of this study is to review how team cohesion impacts athletes of various sports and understand how it could contribute to the overall performance of track and field athletes, who mainly compete individually.
Conformal Symmetry and Supersymmetry in Rindler Space
J.W. Van Holten
Subject: Physical Sciences, General & Theoretical Physics Keywords: Conformal field theory; supersymmetry; Rindler space
This paper addresses the fate of extended space-time symmetries, in particular conformal symmetry and supersymmetry, in two-dimensional Rindler space-time appropriate to a uniformly accelerated non-inertial frame in flat 1+1-dimensional space-time. Generically, in addition to a conformal co-ordinate transformation, the transformation of fields from Minkowski to Rindler space is accompanied by local conformal and Lorentz transformations of the components, which also affect the Bogoliubov transformations between the associated Fock spaces. I construct these transformations for massless scalars and spinors, as well as for the ghost and super-ghost fields necessary in theories with local conformal and supersymmetries, as arising from coupling to 2-D gravity or supergravity. Cancellation of the anomalies in Minkowski and in Rindler space requires theories with the well-known critical spectrum of particles arising in string theory in the limit of infinite strings, and is relevant for the equivalence of Minkowski and Rindler frame theories.
Inhomogeneous Phases in the Chirally Imbalanced 2+1-Dimensional Gross-Neveu Model and Their Absence in the Continuum Limit
Laurin Pannullo, Marc Wagner, Marc Winstel
Subject: Physical Sciences, Nuclear & High Energy Physics Keywords: inhomogeneous phases; chiral imbalance; isospin imbalance; 2+1 dimensional field theories; Gross-Neveu model; mean-field
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We study the μ-μ45-T phase diagram of the 2+1-dimensional Gross-Neveu model, where μ denotes the ordinary chemical potential, μ45 the chiral chemical potential and T the temperature. We use the mean-field approximation and two different lattice regularizations with naive chiral fermions. An inhomogeneous phase at finite lattice spacing is found for one of the two regularizations. Our results suggest that there is no inhomogeneous phase in the continuum limit. We show that a chiral chemical potential is equivalent to an isospin chemical potential. Thus, all results presented in this work can also be interpreted in the context of isospin imbalance.
Application of Numerical Tools to Investigate a Leaky Aquitard beneath Urban Well Fields
Farhad Jazaei, Brian Waldron, Scott Schoefernacker, Daniel Larsen
Subject: Engineering, Civil Engineering Keywords: groundwater model; well field; pre-field investigation; aquitard breach
Memphis aquifer is the primary drinking water source in Shelby County (Tennessee, USA) and supplies industrial, commercial, and residential water. Memphis aquifer is separated from the Shallow aquifer by a clayey layer known as Upper Claiborne Confining Unit (UCCU). All of the production wells in the Memphis area are screened in the Memphis aquifer or even deeper in the Fort Pillow aquifer. Traditionally, it was assumed that the UCCU could fully protect the Memphis aquifer from the contaminated Shallow aquifer groundwater. However, recent studies show that at some locations the UCCU is thin or absent which possibly leads to the contribution of Shallow aquifer to the Memphis aquifer. Accurately locating the breaches demands expensive and difficult geological or geochemical investigations, especially within an urban area. Hence, a pre-field investigation to identify the locations where the presence of breaches is likely can significantly reduce the cost of field investigations and improve the their results. In this study, to identify the locations where the presence of breaches in the UCCU is likely we use three different analyses: (1) pilot point calibration (PPC), (2) velocity and flow budget (VFB), and (3) particle tracking (PT) to post-process the developed groundwater results. These pre-field numerical investigations provide relevant and defensible explanations for groundwater flow anomalies in an aquifer system for informed decision-making and future field investigations. In this study, we identify five specific zones within the broad study area which are reasonable candidates for the future field investigations. Finally, we test the results of each analysis against other evidence for breaches to demonstrate that the results of the numerical analyses are reliable and supported by previous studies.
Transport and Field Emission Properties of MoS2 Bilayers
Francesca Urban, Maurizio Passacantando, Filippo Giubileo, Laura Iemmo, Antonio Di Bartolomeo
Subject: Physical Sciences, Condensed Matter Physics Keywords: transition metal dichalcogenides; MoS2; field effect transistor; field emission
We report the electrical characterization and the field emission properties of CVD-grown MoS2 bilayers deposited on SiO2/Si substrate. Current-voltage characteristics are measured in the back-gate transistor configuration, with Ti contacts patterned by electron beam lithography. We confirm the n-type character of as-grown MoS2 and we report normally-on field effect transistors. Local characterization of field emission is performed inside a scanning electron microscope chamber with piezo-controlled tungsten tips working as the anode and the cathode. We demonstrate that an electric field of ~200 V/μm is able to extract current from the flat part of MoS2 bilayers, which therefore can be conveniently exploited for field emission applications even in low field-enhancement configurations. We show that a Fowler-Nordheim model, modified to account for electron confinement in 2D materials, fully describes the emission process.
Quantum Information Hidden in Quantum Fields
Paola Zizzi
Subject: Physical Sciences, Particle & Field Physics Keywords: quantum field theory; quantum information; quantum geometry
We investigate a possible reduction mechanism from (bosonic) Quantum Field Theory (QFT) to Quantum Mechanics (QM), in a way that could explain the apparent loss of degrees of freedom of the original theory in terms of quantum information in the reduced one. This reduction mechanism consists mainly in performing an ansatz on the boson field operator, which takes into account quantum foam and non-commutative geometry. Through the reduction mechanism, QFT reveals its hidden internal structure, which is a quantum network of maximally entangled multipartite states. In the end, a new approach to the quantum simulation of QFT is proposed through the use of QFT's internal quantum network
Retro-Fitting Earth-Field Compensation Coils to the Vertical Cryostat GERSEMI in FREIA
Volker Ziemann, Rolf Wedberg, Tord Peterson, Anders Wiren
Subject: Physical Sciences, Applied Physics Keywords: magnetic field compensation; vertical cryostat; FREIA
We describe the design and construction of coils to compensate the earth's magnetic field in the vertical cryostat GERSEMI in the FREIA laboratory at Uppsala University.
ARBTools: A Tricubic Spline Interpolator for Three-Dimensional Scalar or Vector Fields
Paul Walker, Ulrich Krohn, Carty David
Subject: Mathematics & Computer Science, Other Keywords: ARBTools, Python, three-dimensional interpolation, spline, vector field, scalar field, smoothing
ARBTools is a Python library containing a Lekien-Marsden type tricubic spline method for interpolating three-dimensional scalar or vector fields presented as a set of discrete data points on a regular cuboid grid. ARBTools was developed for simulations of magnetic molecular traps, in which the magnitude, gradient and vector components of a magnetic field are required. Numerical integrators for solving particle trajectories are included, but the core interpolator can be used for any scalar or vector field. The only additional system requirements are NumPy.
Determining a Quantum Theory of the Infinite-Component Majorana Field
Luca Nanni
Subject: Physical Sciences, Particle & Field Physics Keywords: infinite-component spinor; superluminal Lorentz transformations; Dirac field; tachyon field
In this paper, the quantum theory of the infinite-component Majorana field for the fermionic tower is formulated. This study proves that the energy states with increasing spin are simply composite systems made by a bradyon and antitachyons with half-integer spin. The quantum field describing these exotic states is obtained by the infinite sum of four-spinor operators, which each operator depends on the spin and the rest mass of the bradyon in its fundamental state. The interaction between bradyon-tachyon, tachyon-tachyon and tachyon-luxon has also been considered and included in the total Lagrangian. The obtained theory is consistent with the CPT invariance and the spin-statistics theorem and could explain the existence of new forms of matter not predictable within the standard model.
Formal Binary Logic, Tidal Forces and the Equivalence Principle
Holger Döring
Subject: Physical Sciences, Acoustics Keywords: equivalence-principle; Einstein-Lift; EP; formal binary logic; inhomogenious gravity- field; acceleration- field; radial-field; tidal-forces
Mass plays a strange multiple role in classical physics. This results in a difference between gravity and all other forces - a difference that stood at the beginning of Einstein's development of his general theory of relativity. The equivalence principle (EP) deals with homogenious gravitational fields, which, in fact, don't exist in nature. There is only an approximation for this field in Einstein-Lift possible for local situations. Nevertheless this EP can be true, because in classical formal binary logic there can be formulated a true conclusion from a wrong premise or assumption.
Ablation patterns in externally applied electric and magnetic fields
Jovan Maksimovic, Soon Hock Ng, Tomas Katkus, Nguyen Hoai An Le, James W. M. Chon, Bruce C C Cowie, Tao Yang, Yves Bellouard, Saulius Juodkazis
Subject: Materials Science, Nanotechnology Keywords: ablation; electric field; magnetic field; debris; femtosecond laser fabrication; Silicon; near edge X-ray absorption fine structure (NEXAFS)
To harness light-matter interaction at nano-/micro-scale better control tools have to be developed. Here, it is shown that by applying external electric and/or magnetic field, ablation of Si and glass under ultra-short (sub-1~ps) laser pulse irradiation can be controlled via the Lorentz force $\mathbf{F} = e\mathbf{E} + e[\mathbf{v}\times\mathbf{B}]$, where $\mathbf{v}$ is velocity of charge $e$, $\mathbf{E}$ is the applied electrical bias and $\mathbf{B}$ is the magnetic flux density. The external electric E-field was applied during laser ablation using suspended micro-electrodes above glass substrate with an air gap for the incident laser beam. The counter-facing Al-electrodes on Si surface were used to study debris formation patterns on Si. Debris was deposited preferentially towards the negative electrode in the case of glass and Si ablation. Also, an external magnetic field was applied during laser ablation of Si in different geometries and is shown to affect ripple formation. The vectorial nature of the Lorentz force widens application potential of surface modifications and debris formation in external E-/B-fields with potential applications in mass and charge spectroscopes.
A Further Study of a Scalar-Tensor Theory in Minkowski Spacetime
Jian-Bo Deng, Miao-Yi Deng, Peng-Zhang He
Subject: Physical Sciences, Acoustics Keywords: scalar-tensor theory; Minkowski spacetime; scalar field
In this work, we discuss a newly proposed scalar-tensor theory in Minkowski spacetime. The basic frame in Minkowski spacetime is obtained. Consider a charged particle in the electromagnetic field, we make an attempt to connect this theory with conventional quantum theory. Two specific models are chosen to calculate values of the time delay.
Magnetic Field Alignment, a Perspective in the Engineering of Collagen-Silica Composite Biomaterials
Nicolas Debons, Kenta Matsumoto, Noriyuki Hirota, Thibaud Coradin, Toshiyuki Ikoma, Carole Aimé
Subject: Materials Science, Biomaterials Keywords: bionanocomposites; collagen; high magnetic field; silica particles
Major progress in the field of regenerative medicine are expected from the design of artificial scaffolds that mimic both the structural and functional properties of the ECM. The bionanocomposites approach is particularly well fitted to meet this challenge as it can combine ECM-based matrices and colloidal carriers of biological cues that regulate cell behavior. Here we have prepared bionanocomposites under high magnetic field from Tilapia fish scale collagen and multifunctional silica nanoparticles (SiNPs). We show that scaffolding cues (collagen), multiple display of signaling peptides (SiNPs) and control over the global structuration (magnetic field) can be combined into a unique bionanocomposite for the engineering of biomaterials with improved cell performances.
Kaleidoscope States as a Statistical Mixture in the Jaynes-Cummings Model: Entropy and Purification
Jorge Anaya-Contreras, Arturo Zúñiga-Segundo, Hector Moya
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: Atom-field interactions; Entropy; Jaynes-Cummings model
We investigate some of the fundamental features of the interaction of mixed kaleidoscope states, namely, particular statistical mixtures of coherent states, with two-level atoms in the Jaynes-Cummings model framework. We begin our analysis by calculating the von Neumann entropy of the field which is determined with help of the virtual atom method. Oscillations appear in this entropy that indicate a state of purity greater than the initial state, {it i.e.}, a purification of the initial state is achieved. In this oscillatory region, we obtain the field Wigner function that resembles Schrodinger's cats.
Geomagnetic Induced Current Data Generation and Analysis in Power System Installations
Chijioke Ejimofor, James Eke
Subject: Engineering, Automotive Engineering Keywords: Geomagnetic induced current (GIC); Magnetic field component (dB/dt); Geomagnetic data (GMD); Corona mass ejections (CMEs); Electric field (E)
Geomagnetic induced current (GIC) is a ground end manifestation associated with the space weather perturbations that should be greatly taken into account by the society. Although the GICs implication to the power system is not regular, it can cause large scale of system failure. In equatorial, the power system is considered safe since the most intense of geomagnetic storm happened in high latitude. However, the internal damage due to GICs which finally led to the South African power system failure has totally changed the normal perception. Therefore, a preliminary investigation on the GICs activity in equatorial region is performed to understand the space weather impact to the power system. Time derivative of the horizontal magnetic field component (dB/dt) is done to indicate the GICs activity value based on Faraday's law. All the reported power failures are compiled to produce the threshold value of dB/dt, which possibly cause the harmful effect to the system. Then, dB/dt analysis is extended to show the pattern of GICs activity in function of magnetic latitude and local time. The results reveal that power network in equatorial region has possibly suffered by GIC. Plus, high number of intense GIC activity in this region occurred during dayside.
Gompertz Kinetics in Developmental Fields: An Information Theory Approach
Steven Baranowitz
Subject: Biology, Anatomy & Morphology Keywords: Developmental Field; Gompertz Equation; Information Theory; Developmental Biology
A model for cell proliferation in developmental fields is derived from information theory using a few biological postulates. The model provides an explanation for the success of the Gompertz equation in describing the growth of embryonic, neoplastic, and regenerative systems. Although this equation has been applied to many growth phenomena, its use has been entirely empirical. A theoretical justification for the use of the Gompertz equation in characterizing developmental processes is presented. The model also accounts for a reported relationship among the parameters of the Gompertz equation. A method for quantification and comparison of the determination of developmental fields at different levels of organization is suggested.
Dynamics of Periodic Waves in a Neural Field Model
Nikolai Bessonov, Anne Beuter, Sergei Trofimchuk, Vitaly Volpert
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: neural field models; integrodifferential equations; wave; brain stimulation
Online: 8 March 2020 (06:55:15 CET)
Periodic travelling waves are observed in various brain activities including visual, motor, language, sleep, and so on. There are several neural field models describing periodic waves assuming nonlocal interaction and, possibly, inhibition, time delay, or some other properties. In this work we study the influence of asymmetric connectivity functions and of time delay on the emergence of periodic waves and on their properties. Nonlinear wave dynamics is studied, including modulated and aperiodic waves. Multiplicity of waves for the same values of parameters is observed. External stimulation in order to restore wave propagation in a damaged tissue is discussed.
Mode Profile Shaping in Wire Media: Towards an Experimental Verification
Taylor Boyd, Jonathan Gratus, Paul Kinsler, Rosa Letizia, Rebecca Seviour
Subject: Physical Sciences, Optics Keywords: spatial dispersion; field profile; metamaterials; photonics; RF engineering
We show that an experimentally plausible system consisting of a modulated wire medium hosted in a metal cavity can preserve the longitudinal field profile shaping predicted by Boyd et al. (2018) on the basis of a perfectly periodic wire-only structure. These new frequency domain numerical results are a significant step towards justifying the construction of an experimental apparatus to test the field profile shaping in practise.
Spectral Function of a Boson Ladder in an Artificial Gauge Field
Roberta Citro, Anna Minguzzi, Edmond Orignac, Stefania De Palo, Nicolas Victorin
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: bosonization; Bogoliubov approximation; artificial gauge field; spectral functions
Online: 3 February 2020 (05:04:49 CET)
We calculate the spectral function of a boson ladder in an artificial magnetic field by means of analytic approaches based on bosonization and Bogoliubov theory. We discuss the evolution of the spectral function at increasing effective magnetic flux, from the Meissner to the Vortex phase, focussing on the effects of incommensurations in momentum space. At low flux, in the Meissner phase, the spectral function displays both a gapless branch and a gapped one, while at higher flux, in the Vortex phase, the spectral function displays two gapless branches and the spectral weight is shifted at a wavevector associated to the underlying vortex spatial structure which can indicate a 8 supersolid-like behavior. While the Bogoliubov theory, valid at weak interactions, predicts sharp delta-like features in the spectral function, at stronger interactions we find power-law broadening of 10 the spectral functions due to quantum fluctuations as well as additional spectral weight at higher 11 momenta due to backscattering and incommensuration effects. These features could be accessed in 12 ultracold atom experiments using radio-frequency spectroscopy techniques.
A Unified Field Theory Derived from a Magnetic Confinement Method that Stimulates Curvature Upon Charged Particles Relative to a Solitary Location that Produces Energy from Particle Deviation
Samuel Moss
Subject: Physical Sciences, General & Theoretical Physics Keywords: fusion, magnetic reconnection, quantum gravity, general relativity, unified field theory, field reversal
This interdisciplinary work presents a novel patent pending method of inertial electrostatic confinement (IEC) fusion called the Nuclear Electromagnetic Shaping Accelerator Reactor (NESAR) that addresses all of the major failure problems with currently known methods of IEC fusion. A brief background of previous IEC methods that generate a negative potential well to accelerate ions for fusion will be reviewed and compared to the NESAR method of magnetic confinement. In addition, a direct comparison will be presented between the NESAR and the tokamak method of fusion. The NESAR method of fusion obtains the plasma oscillation and compression capabilities of a tokamak without producing the catastrophic magnetic reconnection disruptions that currently plague tokamaks. Since the NESAR can oscillate charged particles comparable to the tokamak, this work will briefly review the history of the tokamak, how sawtooth magnetic reconnection occurs, and how the NESAR precludes the occurrence of magnetic reconnection. This work will also review the beginnings of a novel unified field theory that has obtained interest from the Defense Advanced Research Projects Agency (DARPA). This unified field theory is based upon the trajectory of charged particle movements within the NESAR, which is the only concept of magnetic confinement in the world that may allow charge particles to collectively interact relatively to a solitary location. Due to this possible capability, the confined charged particles have the potential to experience curved trajectories; allowing for the effects of curvature deviation to be placed upon the charged particle within the magnetic confines of the NESAR. If charged particles can experience curvature deviation then deviated acceleration is generated; allowing the electromagnet field to be propelled to a higher spatial dimension that could influence spacetime. Finally, this work will review another theory that explains how magnetic pole reversals are observed by the National Aeronautics and Space Administration's (NASA) coiled magnetic field detectors. This theory requires little to no postulations to be framed and it is purely based upon the trajectory of charged particles within the NESAR, Michael Faraday's law of induction, and experimental observations of rotating plasmas.
A Warped Five-Dimensional Spacetime Conformally Revisited
Reinoud Jan Slagter
Subject: Physical Sciences, General & Theoretical Physics Keywords: conformal invariance; brane world models; U(1) scalar-gauge field; dilaton field
We show that the Einstein field equations for a five-dimensional warped spacetime, where only gravity can propagate into the bulk, determine the dynamical evolution of the warp factor of the four-dimensional brane spacetime. This can be explained as a holographic manifestation. The warped 5D model can be reformulated by considering the warp factor as a dilaton field ($\omega$) conformally coupled to gravity and embedded in a smooth $M_4 \otimes R$ manifold. On the brane, where the U(1) scalar-gauge fields live, the dilaton field manifests itself classically as a warp factor and enters the evolution equations for the metric components and matter fields. We write the Lagrangian for the Einstein-scalar-gauge fields in a conformal invariant setting. However, as expected, the conformal invariance is broken (trace-anomaly) by the appearance of a mass term and a quadratic term in the energy-momentum tensor of the scalar-gauge field, arising from the extrinsic curvature terms of the projected Einstein tensor. These terms can be interpreted as a constraint in order to maintain conformal invariance. By considering the dilaton field and Higgs field on equal footing on small scales, there will be no singular behavior, when $\omega\rightarrow 0$ and one can deduce constraints to maintain regularity of the action. Our conjecture is that $\omega$, alias warp factor, has a dual meaning. At very early times, when $\omega \rightarrow 0$, it describes the small-distance limit, while at later times it is a warp (or scale) factor that determines the dynamical evolution of the universe. We also present a numerical solution of the model and calculate the (time-dependent) trace-anomaly. The solution depends on the mass ratio of the scalar and gauge fields, the parameters of the model and the vortex charge $n$.
Non-Standard Hierarchies of the Runnings of the Spectral Index in Inflation
Chris Longden
Subject: Physical Sciences, General & Theoretical Physics Keywords: early universe cosmology; testing inflation; multi-field inflation
Recent analyses of cosmic microwave background surveys have revealed hints that there may be a non-trivial running of the running of the spectral index. If future experiments were to confirm these hints, it would prove a powerful discriminator of inflationary models, ruling out simple single field models. We discuss how isocurvature perturbations in multi-field models can be invoked to generate large runnings in a non-standard hierarchy, and find that a minimal model capable of practically realising this would be a two-field model with a non-canonical kinetic structure. We also consider alternative scenarios such as variable speed of light models and canonical quantum gravity effects and their implications for runnings of the spectral index.
Prevalence of Sub-clinical Mastitis and Associated Risk Factors at Cow Level in Dairy Farms in Southwestern Part of Bangladesh
Md. Abu Sayeed, Md. Ashikur Rahman, Md. Saiful Bari, Ariful Islam, Md. Mizanur Rahman, Md. Ahasanul Hoque
Subject: Biology, Animal Sciences & Zoology Keywords: Sub Clinical Mastitis; prevalence; Surf Field Mastitis Test; Jhenaidah
A cross-sectional study was carried out to determine the prevalence of subclinical mastitis (SCM) among medium to large scale household dairy farms in southwestern district, Jhenaidah, Bangladesh during July to December 2019. A total of 78 (n=100) lactating cows from household dairy farms (N=32) having three or more dairy cows were selected randomly as sampled populations. Milk samples were screened for SCM by using Surf Field Mastitis Test (SFMT). The prevalence of SCM varied among farm level [71.9% (95% CI: 53.3-86.3)], individual animal level [67.9% (95% CI: 56.4-86.3)] and quarter level [29.5% (95% CI: 24.5-34.9)]. Descriptive statistics represented the farmers and farm demography, characteristics of the sampled population, and overall management feature. Random Effect Logistic Regression identified, Body Condition Score (BCS) [OR=3.8 and 2.9, at cows level and quarter level respectively (BCS-2 vs. BCS-≥3)], and breed [OR=5.1 and 2.9, at cows level and quarter level respectively (HF× Sahiwal vs. HF × Local)] as potential risk factors. This study shows that SCM is highly prevalent in the study area, which is a major threat to the dairy industry's production performance. Regular screening by SFMT, proper hygiene, improve the management system, and farmer's awareness is required to control the disease.
Preprint COMMUNICATION | doi:10.20944/preprints202111.0373.v1
Geoscience Fieldwork in the Age of Covid-19 and Beyond: Commentary on the Development of a Virtual Geological Field Trip to Whitefish Falls, Ontario, Canada
Alexander L. Peace, Jeremy J. Gabriel, Carolyn Eyles
Subject: Earth Sciences, Geology Keywords: geological fieldwork; virtual field trips; geoscience education
In response to the COVID-19 pandemic, and resultant cancellation of geoscience fieldwork, as well as outstanding accessibility issues inherent in conducting fieldwork, we developed a virtual geological fieldtrip (VFT) to the Huronian age deposits in the Whitefish Falls area, Ontario, Canada. This region is a geologically significant site in which many Ontario universities conduct undergraduate teaching due to the high-quality exposures. In this contribution we describe and comment on the development of this openly available resource, the motivations in doing so, the challenges faced, its pedagogical impact and relevance, as well as provide suggestions to others in the development of such resources. Our multimedia VFT combines 360° imagery, georeferenced data on integrated maps, and multi-scale imagery (aerial/drone, outcrop, and thin section images). The VFT was built using the Esri Storymaps platform, and thus offers us the opportunity to review the effectiveness of building such resources using this medium, as well as our approach to doing so. We conclude that the Esri Storymaps platform provides a sound medium for the dissemination of multimedia VFTs, but that some aspects of in-person fieldwork remain hard to replicate. Most notably, 'hands on experience' and specific activities such as geological mapping. In addition, while VFTs alleviate some accessibility barriers to geoscience fieldwork, substantial barriers remain that should remain the focus of both pedagogical and geoscience work.
Electrode Cooling Effect on Out-of-Phase Electrothermal Streaming in Rotating Electric Fields
Weiyu Liu, Yukun Ren, Ye Tao, Xiaoming Chen, Qisheng Wu
Subject: Physical Sciences, Fluids & Plasmas Keywords: electrothermal flow; rotating electric field; out-of-phase smeared structural polarization; electrode cooling; external natural convection; co-field flow rotation
In this work, we focus on investigating electrothermal flow in a rotating electric field (ROT-ETF), with primary attention paid to the horizontal traveling-wave electrothermal (TWET) vortex induced at the center of the electric field. The frequency-dependent flow profiles in the microdevice are analyzed using different heat transfer models. Accordingly, we address in particular the importance of electrode cooling in ROT-ETF as metal electrodes of high thermal conductivity while substrate material of low heat dissipation capability are employed to develop such microfluidic chips. Under this circumstance, cooling of electrode array due to external natural convection on millimeter-scale electrode pads for external wire connection occurs and makes the internal temperature maxima shift from the electrode plane to a bit of distance right above the cross-shaped interelectrode gaps, giving rise to reversal of flow rotation from a typical repulsion-type to attraction-type induction vortex, which is in good accordance with our experimental observations of co-field TWET streaming at frequencies on the order of reciprocal charge relaxation time of the bulk fluid. These results point out a way to make a correct interpretation of out-of-phase electrothermal streaming behavior, which holds great potential for handing high-conductivity analytes in modern microfluidic systems.
Re-Emergence of Dengue Serotype 3 in the Context of a Large Religious Gathering Event in 2018 in Touba City, Senegal
Idrissa Dieng, Cheikh Fall, Aboubacry Gaye, Mamadou Aliou Barry, Oumar Faye, Marie Henriette Ndione, Mamadou Diop, Ousmane Faye, Cheikh Loucoubar, Amadou Sall
Subject: Biology, Other Keywords: Dengue; Touba; Mass gathering; Field Investigation; Mobile laboratory; Phylogeny; Phylogeography
Dengue virus (DENV) was detected in Senegal in 1979 for the first time. Since 2017, unprecedented frequent occurrence of DENV outbreaks was noticed yearly. In this context, epidemiological and molecular evolution data are paramount to decipher virus diffusion route. In the current study, a dengue outbreak occurred in Senegal in 2018 in the context of the largest religious gathering with 263 confirmed DENV cases out of 832 collected samples, including 25 life-threatening cases and 2 deaths. It was characterized by a co-circulation of dengue serotypes 1 and 3. Phylogenetic analysis based on the E gene revealed that the main detected serotype in Touba city was DENV-3 and belonged to Genotype III. Bayesian phylogeographic analysis was performed and suggested one viral introduction around 2017.07 (95 % HPD = 2016.61 – 2017.57) followed by cryptic circulation before identification of the first case on 01 October 2018. DENV-3 strains are phylogenetically related, with strong phylogenetic links between strains retrieved from Burkina Faso and West African countries. These phylogenetic data substantiate epidemiological data of the DENV-3 origin and spread between African countries and subsequent diffusion after religious mass events. The study also highlighted the usefulness of the Mobile Laboratory during outbreak response allowing rapid diagnosis resulting in improved patient management.
Large-Scale Multiscale Modeling of Phase Transformation in Nanocrystalline Materials: Atomistic and Phase-Field Methods
Mehrdad Yousefi
Subject: Materials Science, Nanotechnology Keywords: molecular dynamics; phase-field; polycrystalline materials; phase transformation
In this research, atomistic molecular dynamics simulations are combined with mesoscopic phase-field computational methods in order to investigate phase-transformation in polycrystalline Aluminum microstructure. In fact, microstructural computational modeling of engineering materials could help to optimize their mechanical properties for industrial applications (e.g. directional solidification for turbine blades). As a result, a multiscale modeling approach is developed to find a relation between manufacturing variables (e.g. temperature) and microstructural properties of crystalline materials (e.g. grain size), which could be used to develop an advanced manufacturing process for sensitive applications. The results show that atomistic modeling of grain growth could be used as a first-principle approach in order to study phase transformation's kinetics, which could capture morphology of polycrystalline materials more accurately. On the other hand, phase-field mesoscopic approach needs less computational efforts, but still it relies on semi-empirical data to capture accurate phase transformation regimes, which makes this approach suitable for rapid examining of new manufacturing conditions as well as its effects on microstructural properties of polycrystalline materials.
Investigation on Deformation Behavior in the Surface of Metal foil with Ultrasonic Vibration-Assisted Micro-Forging
ZiDong Yin, Ming Yang
Subject: Materials Science, Nanotechnology Keywords: microfoming; energy field assisted micro/nanoforming; ultrasonic vibration
Excitation of the acoustic field leading to the Blaha effect affects the plasticity of the material significantly in ultrasonic vibration-assisted forming. In a micro-forming field, the effects are more significant in the deformation in surface of materials [1]-[3], in which reduction of the surface roughness based on the increasing of plastic deformation of surface asperity was effective [4]. On the other hand, the effect on deformation behavior of the bulk region indicted reduction in the yield stress of materials, and not only acoustic effect [5], but also impact effect is found to generate a large amount of dislocation and produce plastic deformation [6][7]. However, the effect on the bulk is more significant as that on the surface. Differences in the effect on the surface and the bulk are not clarified. In this study, the mechanism of the deformation in the surface of the material with ultrasonic vibration assistance is investigated and compared with that in the bulk. Forging tests using a newly developed ultrasonic vibrator were carried out on pure Cu foils with various process conditions. The longitudinal vibration frequency of the ultrasonic transducer is 60∓2kHz, and the vibration amplitude is in an adjustable range of 0~10μm. Forging test was carried out at different initial stress, specimen size and amplitude. The difference in acoustic softening and impact effects on the surface and the bulk was discussed.
The Electromagnetic Wave Without a Magnetic Component: A Thought Experiment
Sherif Tawfik
Subject: Physical Sciences, General & Theoretical Physics Keywords: foundations of physics; electrodynamics; electromagnetic wave; magnetic field; electric field; Ampere; Biot-Savart
The well-known coupling between the magnetic and electric fields in electromagnetic radiation is revisited in light of the recent introduction of a microscopic theory for the Ørsted magnetic field induction. I argue that, if the Ørsted magnetic field induction does indeed have a microscopic origin rather than the continuum solution offered by the Maxwell-Ampere equation, the "electromagnetic wave"' propagating in vacuum will not have a magnetic component.
Preprint TECHNICAL NOTE | doi:10.20944/preprints202211.0477.v1
Inertial Sensors-Based Estimation of Temporal Events in Skating Sub-Techniques While In-Field Roller Skiing
Frédéric Meyer, Magne Lund-Hansen, Jan Kocbach, Trine M. Seeberg, Øyvind Sandbakk, Andreas Austeng
Subject: Life Sciences, Biophysics Keywords: cross-country skiing; temporal event detection; wearable sensors; field analysis
The aim of this study was to adapt a treadmill-developed method for determination of inner-cycle parameters in cross-country roller ski skating for a field application. The method is based on detecting initial and final ground-contact of poles and skis during cyclic movements. Eleven athletes skied four laps of 2.5 km at low and high endurance-intensity, using two types of skis with different rolling coefficients. Participants were equipped with inertial measurement units (IMUs) attached to their wrists and skis, while insoles with pressure sensors and poles with force measurements were used as reference systems. The method based on IMUs was able to detect more than 97% of the temporal events compared to the reference system. The inner-cycle temporal parameters had a precision ranging from 49 to 59 ms, corresponding to 3.9% to 13.7% of the corresponding inner-cycle duration. Overall, this study showed good reliability of using IMUs on athlete's wrists and skis to determine temporal events, inner-cycle parameters and the performed sub-techniques in cross-country roller ski skating in field-conditions.
Convergence in Quantum Field Theory without Use of Renormalization
Biswaranjan Dikshit
Subject: Physical Sciences, Particle & Field Physics Keywords: Renormalization, Quantum Field Theory, Electron self energy, Vacuum polarization
In quantum field theory (QFT), it is well known that when Feynman diagrams containing loops are evaluated to account for self interactions, probability amplitude comes out to be infinite which is physically not admissible. So, to make the QFT convergent, various renormalization methods are conventionally followed in which an additional (infinite) counter term is postulated which neutralizes the original infinity generated by diagram. The resulting finite values of amplitudes have agreed with experiments with surprising accuracy. However, proponents of renormalization methods acknowledged that this ad-hoc procedure of subtraction of infinity from infinity to reach at a finite value is not at all satisfactory and there is no physical basis for bringing in the counter term. So, it is desirable to establish a method in QFT which does not generate any infinite term (thus not requiring renormalization), but which predicts same results as conventional methods do. In this paper, we describe such a technique taking self interaction quantum electrodynamics diagram representing electron or photon self energy. In our method, no problem of infinity arises and hence renormalization is not necessary. Still, the dependence of calculated probability amplitude on physical variables in our technique comes out to be same as conventional methods. Using similar procedure, we hope, the problem of non-renormalizability of quantum gravity may be solved in future.
Analysis of the Wind Environment around the High-Rise Building in the Coastal Region, South Korea during Typhoon 'Hinnamnor' Invasion
Jongyeong Kim, Yongju Kwon, Byeonggug Kang, Joowon Choi, Soonchul Kwon
Subject: Earth Sciences, Environmental Sciences Keywords: Field measurement; Typhoon; High-rise building; Strong wind
The overcrowding of high-rise buildings in the city adversely affects the wind environment by changing the air currents in the surrounding areas. In particular, extreme climate phenomena caused by climate change are stronger and more frequent, causing social damages in cities. To comprehensively better understand the wind properties around high-rise buildings, actual filed measurement is necessary to determine the environment assessment of wind effect. We performed the on-site measurement on LCT residential complex regions (411.6m tall) with highly concentrated high-rise buildings in coastal city Busan, South Korea under extreme weather conditions such as typhoon invasions to determine wind fluid characteristics. In the field monitoring, five anemometers were installed to analyze the wind environment around high-rise buildings when typhoon 'Hinnamnor' invaded. Compared to the nearby weather station operated by KMA(Korea Meteorological Administration), the gust was 3.7 times stronger and the max 1 min-mean wind speed was 3.1 times stronger, and the characteristics of the downward wind and the canyon wind were shown depending on the location characteristics of the point. Turbulence intensity decreased as the wind speed increased and converged to a certain value. Likewise, the gust factor also decreased as the wind speed increased and converged to 2.0, which is considered to be the parameter that best represents the intensity of the instantaneous gust caused by the skyscraper wind effect.
From Mechanisms to Functions: The Role of Synchronization in the Intrahippocampal Circuits
Ivan Mysin, Liubov Shubina
Subject: Medicine & Pharmacology, Allergology Keywords: theta rhythm; gamma rhythm; coherence; local field potential; hippocampus
The brain rhythms are essential for information processing in neuronal networks. Oscillations recorded in different brain regions can be synchronized and have a constant phase difference, i.e. be coherent. Coherence between local field potential (LFP) signals from different regions in the brain may be correlated with the performance of cognitive tasks, from which it is concluded that these regions of the brain are involved in the task performance together. In this review, we discuss why coherence occurs and how it is coupled to the information transfer between different regions of the hippocampal formation. Coherence in theta and gamma frequency ranges is described since these rhythms are most pronounced during the hippocampus-dependent attention and memory. We review in vivo studies of interactions between different regions of the hippocampal formation in theta and gamma frequency bands. The kay provisions of the review: 1) coherence emerges from synchronous postsynaptic currents in principal neurons, occurring as a result of synchronization of neuronal spike activity; 2) synchronization of neuronal spike patterns in two regions of the hippocampal formation can be realised through induction or resonance; 3) coherence at a specific time point reflects the transfer of information between regions of the hippocampal formation, in particular, gamma coherence reflects the coupling of active neuronal ensembles. Overall, coherence is not an epiphenomenon, but an important physiological process that has certain generation mechanisms and performs important functions in information processing and transmission across the brain regions.
Heat Source Modeling in Selective Laser Melting
Elham Mirkoohi, Daniel E. Seivers, Hamid Garmestani, Steven Y. Liang
Subject: Engineering, Mechanical Engineering Keywords: temperature field; additive manufacturing; selective laser melting; heat source modeling
Selective laser melting is an emerging Additive Manufacturing (AM) technology for metals. Intricate three-dimensional parts can be generated from the powder bed by selectively melting the desired location of the powders. The process is repeated for each layer until the part is built. The necessary heat is provided by a laser. Temperature magnitude and history during SLM directly determine the molten pool dimensions, thermal stress, residual stress, balling effect, and dimensional accuracy. Laser-matter interaction is a crucial physical phenomenon in the SLM process. In this paper, five different heat source models are introduced to predict the three-dimensional temperature field analytically. These models are known as steady state moving point heat source, transient moving point heat source, semi-elliptical moving heat source, double elliptical moving heat source, and uniform moving heat source. The analytical temperature model for all of the heat source models are solved using three-dimensional differential equation of heat conduction with different approaches. The Steady state and transient moving heat source are solved using separation of variables approach. However, the rest of models are solved by employing the Green's functions. Due to the high magnitude of the temperature in the presence of the laser, the temperature gradient is usually high which has a substantial impact on thermal material properties. Consequently, the temperature field is predicted by considering the temperature sensitivity thermal material properties. Moreover, due to the repeated heating and cooling, the part usually undergoes several melting and solidification cycles, this physical phenomenon is considered by modifying the heat capacity using latent heat of melting. Furthermore, the multi-layer aspect of metal AM process is considered by incorporating the temperature history from the previous layer since the interaction of the layers have an impact on heat transfer mechanisms. The proposed temperature field models based on different heat source approaches are validated using experimental measurement of melt pool geometry from independent experimentations. The detailed explanation of the comparison of models is also provided. Moreover, the effect of process parameters on the balling effect is also discussed.
Line Shapes in a Magnetic Field: Trajectory Modifications II: Full Collision-Time Statistics
Spiros Alexiou
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: Stark broadening; magnetic field; spiralling trajectories; collision-time statistics
In a previous paper\cite{simplified}, a variation of the Collision-time Statistics method was applied to identify the relevant perturbers for line broadening under the action of a constant magnetic field. As discussed, that version was simplified and inadequate for low magnetic field and/or large perturber mass (ions). The purpose of the present work is to augment the previous work, so that such cases, corresponding to the Larmor radius exceeding the maximum impact parameter, can be handed efficiently. The results may also be used to construct analytic, i.e. impact/unified models under the usual assumptions in these models.
Impact of Cholesterol on the Stability of Monomeric and Dimeric Forms of the Translocator Protein TSPO: a Molecular Simulation Study
Zeineb Si Chaib, Alessandro Marchetto, Klevia Dishnica, Paolo Carloni, Alejandro Giorgetti, Giulia Rossetti
Subject: Life Sciences, Biophysics Keywords: TSPO; Martini Force-Field; cholesterol
The translocator protein (TSPO) is a transmembrane protein present in the three domains of life. Its functional quaternary structure consists of one or more subunits. In mouse, the dimer-to-monomer equilibrium is shifted in vitro towards the monomer by adding cholesterol, a natural component of mammalian membranes. Here, we present a coarse-grained molecular dynamics study on the mouse protein in the presence of a physiological content and of an excess of cholesterol. The latter turns out to weaken the interfaces of the dimer by clusterizing mostly at the inter-monomeric space and pushing the contact residues apart. It also increases the compactness and the rigidity of the monomer. These two factors might play a role for the experimentally observed incremented stability of the monomeric form with increased content of cholesterol. Comparison with simulations on bacterial proteins suggests that the effect of cholesterol is much less pronounced for the latter than for the mouse protein.
A Novel Multirobot System for Distributed Phenotyping
Tianshuang Gao, Homagni Saha, Hamid Emadi, Jiaoping Zhang, Alec Lofquist, Arti Singh, Baskar Ganapathysubramanian, Soumik Sarkar, Asheesh Singh, Sourabh Bhattacharya
Subject: Engineering, Other Keywords: Field Robotics; Multi-robot System
Phenotypic studies require large datasets for accurate inference and prediction. Collecting plant data in a farm can be very labor intensive and costly. This paper presents the design, architecture (hardware and software) and deployment of a distributed modular agricultural multi-robot system for row crop field data collection. The proposed system has been deployed in a soybean research farm at Iowa State University.
A Molecular Basis of Olfaction: Odorant-Specific Electric-Field Emission
Frank LaBella, Filipe Fernandes
Subject: Keywords: olfaction, olfactory, odorants, pheromones, smell, electric field, electromagnetic radiation, electric field sensor, insect antennae
Online: 4 September 2018 (14:31:22 CEST)
The olfactory system is capable of distinguishing individual odorants from among a virtually unlimited number. Fish, for example, detect changes in the electric field environment induced by prey and other sources. Floral electric fields exhibit variations in pattern and structure, which can be discriminated by bumblebees. We have constructed an electric field sensor, which, in the course of focussing on achieving maximum sensitivity and consistency, ultimately resembles features of the insect sensorium. A "fingerprint" 3D plot ( time, frequency range, voltage amplitude), representing the emitted electric field profile, is presented for each of a variety of odorants and other chemicals. The substance-specific electric-field emission and identification is not impeded by containers or barriers or distance.
Mathematical Optimisation of Magnetic Nanoparticles Diffusion in the Brain White Matter
Tian Yuan, Yi Yang, Wenbo Zhan, Daniele Dini
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: Brain Diseases; Blood-Brain Barrier; Magnetic Field; Nanoparticle; Drug Delivery
Magnetic Nanoparticles (MNPs) is a promising technique to cure brain diseases. On the one hand, by serving as drug carriers, they can bypass the blood-brain barrier and deliver drug molecules to the brain parenchyma; on the other hand, their transport trajectory can be manipulated by applying an external magnetic field. However, due to the complex microstructure of brain tissues, e.g. the anisotropy of white matter (WM), how to achieve desired drug distribution patterns, e.g. uniform distribution, by tuning the drug delivery system is largely unknown. Here, in this study, by adopting a mathematical model capable of capturing the diffusion trajectories of MNPs in the microstructures, we systematically investigated the effects of key parameters in the MNPs delivery system on the equivalent diffusion coefficient of MNPs in the microenvironment of brain WM. The results show that uniform distribution of MNPs in anisotropic tissues can be achieved by adjusting the particle size and magnetic field. We have not only obtained a deeper understanding on how to optimise the MNPs delivery system, it can also be anticipated that an improved mathematical model could even help to achieve complex drug distribution patterns in the complicated brain environment by designing an appropriate combination of the key parameters.
Streamline-Based Simulation of Nanoparticle Transport in Field-Scale Heterogeneous Subsurface Systems
Bin Wang, Yin Feng, John Blears, Karsten Thompson, Richard Hughes
Subject: Engineering, Energy & Fuel Technology Keywords: Streamline-based simulation; Nanoparticle transport; Reservoir simulation; Field-scale simulation
Nanoparticle (NP) transport is increasingly relevant to subsurface engineering applications such as aquifer characterization, fracture electromagnetic imaging and environmental remediation. An efficient field-scale simulation framework is critical for predicting NP performance and designing subsurface applications. In this work, for the first time, a streamline-based model is presented to simulate NP transport in field-scale subsurface systems. It considers a series of behaviors exhibited by engineered nanoparticles (NPs), including time-triggered encapsulation, retention, formation damage effects and variable nanofluid viscosity. The key methods employed by the algorithm are streamline-based simulation (SLS) and an operator-splitting (OS) technique for modeling NP transport. SLS has proven to be efficient for solving transport in large and heterogeneous systems, where the pressure and velocity fields are firstly solved on underlying grids using finite-difference (FD) methods. After tracing streamlines, one-dimensional (1D) NP transport is solved independently along each streamline. The adoption of OS enhances flexibility for the entire solution procedure by allowing different numerical schemes to solve different governing equations efficiently and accurately. For the NP transport model, an explicit FD scheme is used to solve the advection term, an implicit FD scheme is used for the diffusion term and an adaptive numerical integration is used to solve the retention terms. The model is implemented in an in-house streamline-based code, which is verified against analytical solutions, a commercial FD reservoir simulator (ECLIPSE) and an academic FD colloid transport code (MNMs). For a 1D homogeneous case, the effluent breakthrough curves (BTC) produced by the in-house simulator are in good agreement with the analytical solution and MNMs, respectively. For a two-dimensional (2D) heterogeneous case, the BTC and concentration pattern of the in-house simulator all match well with the solution produced by commercial simulator. Simulations on a synthetic three-dimensional (3D) nanocapsule application engineering design case, are performed to investigate the effect of fluid and NP properties on the displacement pattern of an existing subsurface fluid.
A Promising Physical Pest-Control System Demonstrated in a Greenhouse Equipped with Simple Electrostatic Devices that Excluded all Insect Pests
Yoshihiro Takikawa, Koji Kakutani, Yoshinori Matsuda, Teruo Nonomura, Shin-ichi Kusakari, Hideyoshi Toyoda
Subject: Biology, Agricultural Sciences & Agronomy Keywords: electric field screen; pest management; photo-selective nets; whiteflies
Applied electrostatic engineering can be used to construct greenhouses that prevent entry of insect pests. Two types of electric field screen were used to exclude pests from the greenhouse: single- and double-charged dipolar electric field screens (S- and D-screen, respectively). The S-screen consisted of iron insulated conductor wires (ICWs) arrayed in parallel (ICW-layer), a grounded metal net on either side of the ICW-layer, and a direct current voltage generator. S-screens were attached to the side windows of the greenhouse to repel whiteflies (Bemisia tabaci) that approached the nets. The D-screen was installed in a small anteroom at the greenhouse entrance to capture whiteflies entering through it. The ICW-layers of the D-screen were oppositely charged with equal voltages and arrayed alternately, and an insulator board or grounded metal net was placed on one side of the ICW-layer. The ICW-layers captured whiteflies entering the electric field of the double-charged dipolar electric field. Three screens equipped with yellow or gray boards or a grounded metal net were installed in the anteroom based on the airflow inside the room, as most whiteflies were brought in by air when the door was opened. Two D-screens with boards were useful for directing the airflow toward the wall with the netted D-screen. This screen eliminated the insects and the pest-free air was circulated inside the greenhouse. The D-screen with the yellow board attracted the whiteflies and was effective for trapping them when there was no wind. Our method kept the greenhouse pest-free throughout the entire period of tomato (Solanum lycopersicum) cultivation.
Influence of Different Tillage Depth on Soil and Maize Yields in Three Growing Seasons in the North China Plain
Li-Shu Wang, Hai-Gang Guo, Li-Xuan Wang, Dong-Juan Cheng
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Soil bulk density; Water consumption; Rotary tillage; Photosynthetic rate; Field capacity
Rotary tillage is a main management tillage practices and widely applied in the North China Plain. However, the long term rotary tillage (depth of 20 cm) results in soil compaction and plow pan formation, which reduces water use efficiency and nutrient uptake, and then impedes the yield increase. In this study, a 3-year field experiment was conducted to investigate the influence of different depths of tillage on soil bulk density, field capacity, water use, photosynthetic rate, nutrients and maize yields in the North China Plain. Three depths of tillage (D20, depth of 20 cm; D25, depth of 25 cm; D30, depth of 30 cm) were assessed. D25 and D30 significantly reduced soil bulk density and improved field capacity in 10-20 and 20-30 cm soil layer, compared to D20. Soil water consumption for D25 was significantly higher 10.12% and 6.61% than that for D20 and D30, respectively. Photosynthetic rate for D25 significantly improved than that for D20 and D30. Total nitrogen in 0-20cm soil layer decreased with the depths of tillage. The maize yields for D25 significantly increased by 20.92% and 21.56% compared to that for D20 and D30, respectively. Structural equation models showed that the total effects of tillage, total nitrogen, photosynthesis and soil water consumption on yields were 0.019, -0.628, 0.121, and 0.895 (path coefficients λ), respectively. The results demonstrated that D25 could improve maize yields, water use efficiency, photosynthetic rate by improving soil water consumption. Depth of 25 cm is optimal tillage practice for the maize production in the North China Plain.
Some Results for a Time Interval Approach to Field Theory and Gravitation
Harmen Henricus Hollestelle
Subject: Physical Sciences, General & Theoretical Physics Keywords: Time interval; equilibrium; field theory; complementarity; field operator; gravitation; wave propagation surface; emission source; cosmology
This paper consists of two parts. In part I some new relations for a field theory with time intervals are derived. One concept of field theory evaluated is complementarity, another is field operators both defined within a time interval description. Part II includes specific results and commentary. Discussed are time interval dependent wave propagation surfaces for star source emission waves and derived is a metric propagation surface area requirement. The results allow to consider one same field that like gravitation within General Relativity applies to both non zero and zero mass. The associated field energy is space time dependent for non zero mass, and is related to a space time dependent metric tensor for zero mass wave particles. Defined is internal energy transfer where wave particle numbers increase linearly and mass and momentum diminish, decrease inversely with the distance from the wave emission source. The commentary are applications related to cosmological overall volume and temperature dependence.
Wheat Varietal Differences in Below Ground Biomass Revealed by a Semi-Quantitative Estimation of Wheat Root DNA in Soil Samples
Huw Jones, Steven Bentley, Lydia Smith, Alison Karley, Tracy Valentine, Charlotte White, Rhys Ashton, Lesley Boyd
Subject: Biology, Agricultural Sciences & Agronomy Keywords: root biomass; wheat; field crops; black-grass; high-throughput; variety trials
Root research on field grown crops is hindered by the difficulty of estimating root biomass in soil. Root washing, the current standard method is laborious and expensive. Biochemical methods to quantify root biomass in soil, targeting species-specific DNA, have potential as a more efficient assay. We combined an efficient DNA extraction method, designed specifically to extract DNA from soil, with well-established quantitative PCR methods to estimate the root biomass of twenty-two wheat varieties grown in field trials over two seasons. We also developed an assay for estimating root biomass for black-grass, a common weed of wheat cultivation. Two robust qPCR assays were developed to estimate the quantity of plant root DNA in soil samples, one specific to wheat and barley, and a second specific to black-grass. The DNA qPCR method was comparable, with high correlations, with the results of root washing from soil cores taken from winter wheat field trials. The DNA qPCR assay showed both variety and depth as significant factors in the distribution of root biomass in replicated field trials. The results suggest that these DNA qPCR assays are a useful, high throughput tool for investigating the genetic basis of wheat root biomass distribution in field grown crops, and the impact of black-grass root systems on crop production.
Effect Of Adding Different Quantity And Sizes Of Volcanic Ash On Improving Some Hydro-Physical Properties Of Vertisol in Houran Plain (Syria)
Iman Ahmad, Suleiman Salim, Abd Al Karim Ahmad Jaafar
Subject: Engineering, Other Keywords: Vertisols; Volcanic Ash; Field Capacity; Air Porosity; Volumetric Swelling
The research aims to improve some of the physical and hydro-physical properties of some Vertisols in the southern region (part of the eastern Houran Plateau) in Sweda Governorate at the south of Syria. Using different quantities of volcanic ash, soil samples were collected from the Al-Thahallah village from a depth of (0-30) cm, The experiment was designed according to the complete random design with one factor that represents the ash quantity (1.25, 2.5, 5) %, with three replicates for each treatment in addition to the control treatment a0. The experiment was carried out within the plastic pots during agricultural season 2018/2019, in which the wheat of the Sham variety 3 were cultivated as a cover plant. The results showed that the addition of volcanic ash at the quantity of 5% led to a significant increase in the infiltration rate by (328.60) %,%, where the filtration rate increased from 0.42 cm/hr -1 to 1.80 cm.h-1, as well as for each of the air porosity by (89) % and the volume of infiltrate water by (40) %, compared with the control. The above-mentioned addition also resulted in a decrease in both dry bulk density, total soil porosity and volumetric swelling coefficient by (18.60, 5.80, 314) % Respectively, compared to the control. The addition also contributed to the reduce in the weighted moisture content when saturation and the field capacity, at the level of significance of 5%. The research recommends adding volcanic ash to the soil at a quantity of 5%, and adding enhancements with volcanic ash at various levels such as organic waste.
Celestial and Quantum Propagation, Spinning, and Interaction as 4D Relativistic Cloud-Worlds Embedded in a 4D Conformal Bulk: From String to Cloud Theory
Mohammed B. Al-Fadhli
Subject: Physical Sciences, General & Theoretical Physics Keywords: Conformal Spacetime; Brane-World Modified Gravity; Quantum Field Theory
Considerable efforts have been devoted to modifying gravity, which aim to elucidate the possible existence or nature of dark matter and energy, describe observational data more effectively, and formulate quantum gravity. In addition, despite the immense success of the quantum field theory, the framework requires renormalization techniques and breaks down at high energies. Recently, the Planck legacy 2018 release has confirmed the existence of an enhanced lensing amplitude in the cosmic microwave background power spectra, which prefers a positively curved early Universe with a confidence level higher than 99%. This study considers the implied curvature of the early Universe as the curvature of "the background or 4D conformal bulk as a manifestation of vacuum energy" and distinguishes it from the localized curvature that is induced in the bulk by the presence of celestial objects that are regarded as "4D relativistic cloud-worlds." Analogously, because gravity appears to emerge owing to spacetime curvature and does not exhibit critical characteristics shared by other fields, it has been incorporated as the local curvature of the bulk affecting the embedded quantum fields that are regarded as propagating "4D relativistic quantum clouds." To consider the effects of the bulk on embedded clouds, this paper presents interaction field equations in terms of brane-world modified gravity and the perspective of geometrization of the quantum mechanics wherein gravity is manifested by the curvature of 4D conformal bulk as an indicator of the field strength of vacuum energy on the embedded 4D relativistic clouds in addition to the boundary interactions, which could remove the singularities and satisfy a conformal invariance theory. A visualization of the evolution of the 4D relativistic cloud-worlds over the conformal spacetime of the 4D bulk is presented, whereas the standard said theories can be recovered from the interaction field equations.
Surround Modulation Properties of Tectal Neurons in Pigeon Characterized by Moving and Flashed Stimuli
Xiaoke Niu, Shuman Huang, Minjie Zhu, Zhizhong Wang, Li Shi
Subject: Life Sciences, Other Keywords: surround suppression; extra-classical receptive field; optic tectum; size tuning
Surround modulation is a phenomenon whereby costimulation of the extra-classical receptive field and classical receptive field would modulate the visual responses induced individually by classical receptive field. However, there lacks systematic study about surround modulation properties existing in avian optic tectum. In this study, neuronal activities are recorded from pigeon optic tectum, and the responses to moving and flashed squares and bars of different sizes are compared. The statistical results showed that most tectal neurons presented surround suppression as stimuli size grew larger both in moving and flashed paradigms, and the suppression degree induced by larger flashed square was comparable with that by moving one when it crossed near the cell's RF center, which corresponds to fully surrounding condition. The suppression degree grew weaker when the stimuli move across the RF border, which corresponds to partially surrounding condition. Meanwhile, the fully surround suppression induced by flashed square was also more intense than partially surrounded by flashed bars. The results provide new insight for understanding the spatial arrangement of lateral inhibitions from feedback or feedforward streams, which would help to make clear the generation mechanism of surround modulation found in avian optic tectum.
The Hydromechanical Interplay in the Three-dimensional Limit Equilibrium Analyses of Unsaturated Slope Stability
Panagiotis Sitarenios, Francesca Casini
Subject: Engineering, Automotive Engineering Keywords: unsaturated slope; Ruedlingen field experiment; lateral resistance; limit equilibrium solution
Online: 5 January 2021 (13:20:58 CET)
The paper presents a three-dimensional slope stability limit equilibrium solution for translational, planar failure modes. The proposed solution uses Bishop's average skeleton stress combined with the Mohr – Coulomb failure criterion to describe soil strength evolution under unsaturated conditions while its formulation ensures a natural and smooth transition from the unsaturated to the saturated regime and vice versa. The proposed analytical solution is evaluated by comparing its predictions with the results of the Ruedlingen slope failure experiment [1]. The comparison suggests that despite its relative simplicity the analytical solution can capture well the experimentally observed behaviour and highlights the importance of lateral resistance consideration together with a realistic interplay between mechanical parameters (cohesion) and hydraulic (pore water pressure) conditions.
Entropy, Information and Symmetry, Ordered is Symmetrical, II: System of Spins in the Magnetic Field
Edward Bormashenko
Subject: Physical Sciences, General & Theoretical Physics Keywords: entropy; symmetry; ordering; elementary magnets; magnetic field; j-fold symmetry
Abstract: The second part of the paper develops the approach, suggested in the Entropy 2020, 22(1), 11; https://doi.org/10.3390/e22010011 , which relates ordering in physical systems to their symmetrizing. Entropy is frequently interpreted as a quantitative measure of "chaos" or "disorder". However, the notions of "chaos" and "disorder" are vague and subjective to a much extent. This leads to numerous misinterpretations of entropy. We propose to see the disorder as an absence of symmetry and to identify "ordering" with symmetrizing of a physical system; in other words, introducing the elements of symmetry into an initially disordered physical system. We explore the initially disordered system of elementary magnets exerted to the external magnetic field H ⃗. Imposing symmetry restrictions diminishes the entropy of the system and decreases its temperature. The general case of the system of elementary magnets demonstrating the j-fold symmetry is treated. The interrelation T_j=T/j takes place, where T and T_j are the temperatures of non-symmetrized and j-fold-symmetrized systems of the magnets correspondingly.
Volatiles Play an Important Role in the Attractiveness of Food for Trapping the Stored Grain Pests Oryzaephilus surinamensis L. (Coleoptera: Silvanidae)
Maidinai Sabier, Jirui Wang, Xia Wang, Jiande Jin, Zhunjing Wang, Zhihong Liao, Bo Shen, Jin Lu, Jianyu Deng, Xingquan Liu, Guoxin Zhou
Subject: Biology, Anatomy & Morphology Keywords: Oryzaephilus surinamensis; food mixtures; field trapping; volatiles; antennal response
Online: 7 April 2021 (17:20:53 CEST)
The Oryzaephilus surinamensis L. (Coleoptera: Silvanidae), is widely distributed all over the world, this beetle causes serious damage to stored products. Much attention has been paid to use food attraction or food volatile as a non-pollution method to achieve pest management. However, in this study, six most attractive food to O. surinamensis were selected among thirty eight food. Furthermore, the food mixture M17 with the best attractiveness were selected among the eighteen food mixtures combined by these six foods at different ratio. Subsequently food mixture M17 were tested in actual barn and compared with commercial attractant. We collected the volatile from food mixture, the volatile compounds attractive to this beetle also. We identified six electrophysio-logically active compounds responsible for the attraction of O. surinamensis, among the six chemically identified compounds, nonanal, dodecane, tridecaneand β-caryophyllene significantly attracted O. surinamensis when tested individually in behavioral assays. Blend of six chemicals according to food volatile concentration was most attractive to the beetles. The findings of this study reveal that food mixture M17 and food volatile can be potentially used for development of effective attractants for management of O. surinamensis.
The Influence of Electron Solid-State Plasma on Attenuation of Longitudinal Sound Waves in a Conductor
Alexander Yushkanov
Subject: Keywords: longitudinal sound wave; electric field; electrons; kinetic equation; sound attenuation
In the present work the problem of the attenuation of longitudinal sound oscillations in a conducting medium are considered. The proposed approach is based on the dynamic interaction of electron gas with the lattice vibrations. This interaction is manifested in the modification of kinetic equation for electrons. The process is accompanied by generation of an electric field.
Exponentials and Logarithms Properties in an Extended Complex Number Field
Daniel Tischhauser
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: Complex number field; Complex exponentiation; Complex logarithm; Exponential and logarithm identities
It is well established the complex exponential and logarithm are multivalued functions, both failing to maintain most identities originally valid over the positive integers domain. Moreover the general case of complex logarithm, with a complex base, is hardly mentionned in mathematic litterature. We study the exponentiation and logarithm as binary operations where all operands are complex. In a redefined complex number system using an extension of the C field, hereafter named E, we prove both operations always produce single value results and maintain the validity of identities such as logu (w v) = logu (w) + logu (v) where u, v, w in E. There is a cost as some algebraic properties of the addition and subtraction will be diminished, though remaining valid to a certain extent. In order to handle formulas in a C and E dual number system, we introduce the notion of set precision and set truncation. We show complex numbers as defined in C are insufficiently precise to grasp all subtleties of some complex operations, as a result multivaluation, identity failures and, in specific cases, wrong results are obtained when computing exclusively in C. A geometric representation of the new complex number system is proposed, in which the complex plane appears as an orthogonal projection, and where the complex logarithm and exponentiation can be simply represented. Finally we attempt an algebraic formalization of E.
Task-fMRI Group and Functional Connectivity Analysis of the Brain During Faradarmani Consciousness Field Connection
Mohammad Ali Taheri, Sara Torabi, Noushin Nabavi, Fatemeh Modarresi-Asem, Majid Abbasi Sisara, Ali Rezaei, Parisa Maftoun, Farid Semsarha
Subject: Keywords: Consciousness Field; functional connectivity; task fMRI
Task fMRI has played a critical role in recognizing the specific functions of the different regions of human brain during various cognitive activities. This study aimed to investigate group analysis and functional connectivity in the Faradarmangars brain during the Faradarmani CF (FCF) connection. Using task functional MRI (task-fMRI), we attempted the identification of different activated and deactivated brain regions during the Consciousness Filed connection. Clusters that showed significant differences in peak intensity between task and rest group were selected as seeds for seed-voxel analysis. Connectivity of group differences in functional connectivity analysis was determined following each activation and deactivation network. In this study, we report the fMRI-based representation of the FCF connection at the human brain level. The group analysis of FCF connection task revealed activation of frontal lobe (BA6/BA10/BA11). Moreover, seed based functional connectivity analysis showed decreased connectivity within activated clusters and posterior Cingulate Gyrus (BA31). Moreover, we observed an increased connectivity within deactivated clusters and frontal lobe (BA11/BA47) during the FCF connection. Activation clusters as well as the increased and decreased connectivity between different regions of the brain during the FCF connection, firstly, validates the significant effect of the FCF and secondly, indicates a distinctive pattern of connection with this non-material and non-energetic field, in the brain.
A Probe of Micro Space-Time by the Study of Scalar Fields
JIan-Bo Deng, Miao-Yi Deng, Qi-Qi Fan, Peng-Zhang He
Subject: Physical Sciences, Acoustics Keywords: general relativity; scalar field; variational principle
In this work, we try to find a way to describe the physical law of micro-world under the frame of a space-time theory. By introducing the scalar fields $\mathcal{D}\left( x\right)$ and $\zeta\left( x\right) $, we rewrite the action of conventional field theory and the Lagrangian describing the motion of the particle, where a modified space-time relation is obtained. To test the correctness of this attempt, we demonstrate the Klein-Gordon equation by the Hamilton-Jacobi method in four dimensional form and present a time delay for the ground state of hydrogen atom.
External Field-Controlled Ablation: Magnetic Fields
Jovan Maksimovic, Soon Hock Ng, Tomas Katkus, Bruce C. C. Cowie, Saulius Juodkazis
Subject: Physical Sciences, Optics Keywords: ablation; magnetic field; femtosecond laser fabrication
Laser ablation of silicon under an external applied magnetic field with different orientations was investigated in respect to the scanning direction and polarisation of the laser beam, by observation of the ablation patterns and debris deposition. Ultra-short ∼230 fs laser pulses of 1030 nm wavelengths were used in the single and multi-pulse irradiation modes. Ablation with an externally applied magnetic B-field (B ≈ 0.1 T) is shown to strongly affect debris formation. The mechanism of surface plasmon polariton (SPP) wave can explain the ablated periodic patterns observed with alignment along the magnetic field lines.
Force Prevalence Analysis
Alex Schaller
Subject: Keywords: Field, gravitation, electricity, unification, force, theory.
The electric field is enormously more powerful than the gravitational field. However, in our normal experience there is no electric field, the electric force is missing. How is it that when you get to larger and larger scales the gravitational field is extremely important whereas the electric field becomes less and less important [1]? This paper proposes a model to explain why gravitation dominates at a larger scale.
Gravitation in Unified Scalar Field Theory
Alexander Chernitskii
Subject: Physical Sciences, General & Theoretical Physics Keywords: Unified field; space-time film; soliton-particle; gravitation; dark matter; gravitational screening
The scalar field of space-time film is considered as unified fundamental field. The field model under consideration is the space-time generalization of the model for a two-dimensional thin film. The force and metrical interactions between solitons are considered. These interactions correspond to the electromagnetic and gravitational interactions respectively. The metrical interaction and its correspondence to the gravitational one are considered in detail. The practical applications of this approach are discussed.
Embodying Cognition in Cognitive Behavioral Therapy
Tania Pietrzak, Christina Lohr, Beverly Jahn, Gernot Hauke
Subject: Behavioral Sciences, Applied Psychology Keywords: embodiment; CBT; interpersonal synchrony; therapeutic alliance; emotional regulation; emotional field; emotional mastery
The Embodied Cognitive Behavior Therapy (ECBT) approach for the treatment of emotional disorders in clinical settings is presented. The model integrates cognitive behavioral theory, neuroscience and embodied cognition. ECBT draws from evidence of bidirectional effects between modes of bottom up (sensori-motor simulations giving rise to important basis of knowledge) and top down (abstract mental representations of knowledge) processes in psychotherapy. The paper first describes the dominance of the traditional mentalistic view of cognition and its limitations. Evidence for the embodied model of cognition and emotion is reviewed whilst highlighting its advantages as a complimentary process model to deepen and broaden talking therapies. An overview is given of the switch (e.g., the technique of balancing) between top-down and bottom-up orientation in the ECBT model as well as a clear description of the method for emotional regulation, acceptance of unwanted emotions and emotional mastery. ECBT builds on and extends the unconscious processes of the 'Interpersonal Synchrony' (IS) model identified by Koole and Tschacher [1], to enhance the therapeutic alliance for emotional co-regulation. A new idea is proposed that both embraces and extends the IS model: embodiment techniques of imitation and movement synchronization in the Emotional Field of our method be used in a conscious way to speed up the calming effects of co-regulation and the client's self-regulatory capacity. The paper ends with an outline of the criteria needed to become an embodied therapist. A case study is given highlighting these aspects.
Numerical Analysis of the Main Wave Propagation Characteristics in a Steel-CFRP Laminate Including Model Order Reduction
Andrey Mikhaylenko, Natalie Rauter, Nanda Kishore Bellam Muralidhar, Tilmann Barth, Dirk A. Lorenz, Rolf Lammering
Subject: Engineering, Mechanical Engineering Keywords: guided ultrasonic waves; fiber metal laminate; dispersion diagram; displacement field
Online: 2 June 2022 (04:41:42 CEST)
Guided ultrasonic waves are suitable for use in the context of structural health monitoring of thin-walled, plate-like structures. Hence, observing the wave propagation in the plates can provide an indication of whether damage has occurred in the structure. In this work, the wave propagation in fiber metal laminate consisting of thin steel foils and layers of carbon fiber-reinforced polymer is studied, focusing on the main propagation characteristics like dispersion diagrams and displacement fields. For this purpose, the dispersion diagrams derived from the analytical framework and numerical simulations are first determined and compared to each other. Next, the displacement fields are computed using the global matrix method for two excitation frequencies. The results derived from the analytical framework is used to validate numerically determined displacement fields based on a 2D and a 3D modeling approach. For both investigations the results of the analytical treatment and the numerical simulation show good agreement. Furthermore, the displacement field reveals the typical and well-known characteristics of the propagation of guided waves in thin-walled structures. Since the use of full 3D models involves a very high computational cost, this work also successfully investigates the possibility for model order reduction to decrease the computational time and costs of the simulation without the loss of accuracy.
Some String Cosmological Models in Bianchi Type III Space-Time with Magnetic Field and Vacuum Energy Density
Raj Bali, Subhash Bola
Subject: Physical Sciences, Astronomy & Astrophysics Keywords: String, Cosmological, Bianchi Type III, Magnetic Field, Vacuum Energy Density.
Bianchi type III string cosmological models (massive and geometric) in presence of magnetic field with vacuum energy density following the techniques used by Letelier (1979) and Stachel (1980) are obtained. We find that the energy conditions (dominant as well as weak) given by Hawking and Ellis (1974) are satisfied for the models. Also the solutions obtained satisfy conservation equation for massive string with magnetic field and vacuum energy density. The models in general, represent anisotropic phase of space-time due to the presence of string. However, the models isotropize at late time and in special case. It has also been shown that the magnetic field is directly linked with the matter. For string dust model, the state finder parameters {r,s} are in excellent agreement with Planck results (Sahni et al. (2003)). The physical and geometrical aspects of the models with special cases are also discussed.
Edge-based Color Image Segmentation using Particle Motion on Vector Fields Derived from Local Color Distance Images
Wutthichai Phornphatcharaphong, Nawapak Eua-Anant
Subject: Mathematics & Computer Science, General & Theoretical Computer Science Keywords: Color images segmentation; Particle Motion; Local Color Distance Images; Normal compressive vector field; Edge vector field
This paper presents an Edge-based color image segmentation derived from the method of Particle Motion in a Vector Image Fields (PMVIF) that could previously be applied only to monochrome images. Instead of using an edge vector field derived from a gradient vector field and a normal compressive vector field derived from a Laplacian-gradient vector field, two novel orthogonal vector fields, directly computed from a color image, one parallel and another orthogonal to the edges, were used in the model to force a particle to move along the object edges. The normal compressive vector field is derived from the center-to-centroid vectors of local color distance images. Next, the edge vector field is derived by taking the normal compressive vector field, multiplied by differences of auxiliary image pixels to obtain a vector field analogous to a Hamiltonian gradient vector field. Using the PASCAL Visual Object Classes Challenge 2012 (VOC2012) and the Berkeley Segmentation Data Set and Benchmarks 500 (BSDS500), the benchmark score of the proposed method is provided in comparison with those of the traditional PMVIF, Watershed, SLIC, K-means, Mean shift, and JSEG. The proposed method yields better RI, GCE, NVI, BDE, Dice coefficients, faster computation time, and noise resistance.
Liquid Metal Flow under Traveling Magnetic Field: Solidification Simulation and Pulsating Flow Analysis
Evgeniy Shvydkiy, Egbert Baake, Diana Köppen
Subject: Materials Science, Metallurgy Keywords: electromagnetic stirring; forced convection; traveling magnetic field; liquid metal; solidification; numerical analysis; pulsed magnetic field; gallium
Non steady applied magnetic field impact on a liquid metals has good prospects for industry. For a better understanding of heat and mass transfer processes under these circumstances, numerical simulations are needed. A combination of finite elements and volumes methods was used to calculate the flow and solidification of liquid metal under electromagnetic influence. Validation of numerical results was carried out by means of measuring with ultrasound Doppler velocimetry technique, as well as with neutron radiography snapshots of the position and shape of the solid/liquid interface. As a result of the first part of the work, a numerical model of electromagnetic stirring and solidification was developed and validated. This model could be an effective tool for analyzing the electromagnetic stirring during the solidification process. In the second part, the dependences of the velocity pulsation amplitude and the melt velocity maximum value on the magnetic field pulsation frequency are obtained. It was found numerically the ability of the pulsating force action to develop higher values of the liquid metal velocity at a frequency close to the MHD resonance. Obtained characteristics give a more detailed description of the electrically conductive liquid behaviour under action of pulsating traveling magnetic field.
Using FTA Cards as a Rapid and Field Tool for Detection and Serotyping of Foot-and-mouth Disease Virus in Libya
Fadila Abosrer, Elfurgani Kraim, Emiliana Brocchi, Giulia Pezzoni, Santina Grazioli, Abdunaser Dayhum, Ibrahim Eldaghayes
Subject: Life Sciences, Virology Keywords: FTA cards; foot-and-mouth disease; RT-PCR; field; sequence
Foot and Mouth Disease (FMD) is a viral disease, widespread and highly contagious affecting mainly cloven-hoofed domestic and wild animals. FMD can lead to high economic losses due to reduction in animals' production such as drop of milk production, loss of body weight and high mortality rate in young ruminants. Sixteen nasal swabs and epithelial tissues were collected from animals showing typical clinical signs of FMD during the last FMD outbreak in Libya in 2018-2019. Blood samples, swabs and epithelial tissues impressions on Flinders Technology Associates (FTA) cards were shipped to the FMD Reference laboratory in Brescia, Italy, and tested for the detection of FMD viruses. Nucleic acids were extracted from the FTA cards and molecular testing of the examined FTA cards confirmed that the FMD virus circulating in Libya was serotype O. Sequencing analysis of the FMD virus VP1 gene confirmed that FMD virus strain was serotype O/East Africa 3 (O/EA-3) topotype. The phylogenetic of the VP-1 gene of the FMD virus showed very high nucleotide identity (99.8%) between the virus circulating in Libya and the Algerian FMD virus strains isolated in Algeria on 2018 and 2019.
Evaluation of the CDOM Absorption Coefficient in the Arctic Seas by Sentinel-3 OLCI Data
Dmitry Glukhovets, Oleg Kopelevich, Anna Yushmanova, Svetlana Vazyulya, Sergey Sheberstov, Polina Karalli, Inna Sahling
Subject: Earth Sciences, Oceanography Keywords: OLCI Sentinel-3; Barents; Kara seas; absorption coefficient; uncertainties; field data
The main goal of our work is the revealing of problematic issues related to estimates of the absorption coefficient of colored organic matter in the northern seas from data of the Ocean and Land Color Instrument (OLCI) on the Sentinel-3 satellites. In particular, a comparison of the OLCI standard error estimates ADG443_NN_err., relating to the measurement and retrieval of the geophysical products, with the uncertainties in the real situation of the northern seas, where the natural conditions are extremely unfavorable (first of all, frequent cloudiness, low Sun heights). We conducted a comprehensive multi-sensor study of the uncertainties using various approaches, first at all, directly comparing the data from satellite (OLCI Sentinel-3 and four other ocean color sensors) and field measurements in five sea expeditions 2016-2019, by using the different processing algorithms. Our analysis has shown that the real uncertainties of the final product are significantly higher than the calculated errors of the ADG443_NN_err., which is 100% and ~10%. The main reason for that is the unsatisfactory atmospheric correction. We present the results of the analysis of the different effecting factors (satellite sensors, processing algorithms, use of the other parameters), and formulate the tasks of future work.
Investigating Non-Linear Dynamic Behavior of Dual Steel Frames under the Effect of Near and Far Fields to Fault
Hamid Reza Ashrafi, Soroush Dadgar, Peyman Beiranvand
Subject: Engineering, Civil Engineering Keywords: dual steel frame; far field from fault; near field to fault; time history non-linear dynamic analysis
This study sought to investigate steel frames' performance with dual lateral loader system (Frame bending + bracings of divergent and convergent) in near and far filed to fault. In order to this, four categories of steel frame with dual system with 8, 10 and 12 story are designed with average formation based on existing seismic regulation in 2800 standard of Iran and tenth chapter of national regulations of construction (planning and performing steel construction). Time history non-linear dynamic analysis under the effect of near and far field earthquakes has been done on plan's models. Then the maximum of floors' dislocation, floors' drift, roof dislocation, base shear and energy curves of frames are shown and compared with each other. All non-linear time history analyses have been accomplished using PERFORM 3D software.
Behavior of Floquet Topological Quantum States in Optically Driven Semiconductors
Andreas Lubatsch, Regine Frank
Subject: Physical Sciences, Condensed Matter Physics Keywords: topological insulators; Floquet states; Dynamical Mean Field Theory; semiconductors; strongly correlated electronics
Spatially uniform optical excitations can induce Floquet topological band structures within insulators which can develop similar or equal characteristics as are known from three-dimensional topological insulators. We derive in this article theoretically the development of Floquet topological quantum states for electromagnetically driven semiconductor bulk matter and we present results for the lifetime of these states and their occupation in the non-equilibrium. The direct physical impact of the mathematical precision of the Floquet-Keldysh theory is evident when we solve the driven system of a generalized Hubbard model with our framework of dynamical mean field theory (DMFT) in the non-equilibrium for a case of ZnO. The physical consequences of the topological non-equilibrium effects in our results for correlated systems are explained with their impact on optoelectronic applications.
Resonance Dipole-Dipole Interaction Between Two Accelerated Atoms in the Presence of a Reflecting Plane Boundary
Wenting Zhou, Roberto Passante, Lucia Rizzuto
Subject: Physical Sciences, Particle & Field Physics Keywords: dipole-dipole interaction; unruh effect; quantum field theory in curved space
We study the resonant dipole-dipole interaction energy between two uniformly accelerated identical atoms, one excited and the other in the ground state, prepared in a correlated Bell-type state, and interacting with the scalar field or the electromagnetic field nearby a perfectly reflecting plate. We suppose the two atoms moving with the same uniform acceleration, parallel to the plane boundary, and that their separation is constant during the motion. We separate the contributions of vacuum fluctuations and radiation reaction field to the resonance energy shift of the two-atom system, and show that Unruh thermal fluctuations do not affect the resonance interaction, which is exclusively related to the radiation reaction field. However, nonthermal effects of acceleration in the radiation-reaction contribution, beyond the Unruh acceleration-temperature equivalence, affect the resonance interaction energy. By considering specific geometric configurations of the two-atom system relative to the plate, we show that the presence of the mirror significantly modifies the resonance interaction energy between the two accelerated atoms. In particular, we find that new and different features appear with respect to the case of atoms in the free space, related to the presence of the boundary and to the peculiar structure of the quantum electromagnetic field vacuum in the locally inertial frame. Our results suggest the possibility to exploit the resonance interaction between accelerated atoms, as a probe for detecting the elusive effects of atomic acceleration on radiative processes.
COR/LEA Proteins as Indicators of Frost Tolerance in Triticeae: A Comparison of Controlled Versus Field Conditions
Klára Kosová, Miroslav Klíma, Ilja Tom Prášil, Pavel Vítámvás
Subject: Biology, Anatomy & Morphology Keywords: cold acclimation; vernalization; frost tolerance; dehydrins; COR14b; growth chambers; field trials
Low temperatures in the autumn induce enhanced expression/relative accumulation of several cold-inducible transcripts/proteins with protective functions from Late-embryogenesis-abundant (LEA) superfamily including dehydrins. Several studies dealing with plants grown under controlled conditions revealed a correlation (significant quantitative relationship) between dehydrin transcript/protein relative accumulation and plant frost tolerance. However, to apply these results in breeding, field experiments are necessary. The aim of the review is to provide a summary of the studies dealing with the relationships between plant acquired frost tolerance and COR/LEA transcripts/proteins relative accumulation in cereals grown in controlled and in the field conditions. The impacts of cold acclimation and vernalization processes on the ability of winter-type Triticeae to accumulate COR/LEA proteins are discussed. The factors determining dehydrin relative accumulation under controlled cold acclimation treatments versus field trials during winter seasons are discussed. In conclusion, it can be stated that dehydrins could be used as suitable indicators of winter surival in field-grown winter cereals but only in plant prior to the fullfilment of vernalization requirement.
Relating Catalytic Activity of Cr/HZSM-5 in Oxidative Dehydrogenation of Liquefied Petroleum Gas under External DC Electric Field to the Fermi Level Position and Electrical Properties
Amin Alamdari, Ramin Karimzadeh
Subject: Chemistry, Chemical Engineering Keywords: electric field; oxidative dehydrogenation; LPG, Cr-/HZSM-5; electrical properties
CrHZSM-5 was placed in an electric field with appropriate strength in a quartz packed bed reactor with CO2 as oxidant to analyze its catalytic activity. Olefin yield increases with decrease in band gap since lattice oxygen mobility increases by reducing band gap. Fermi level change at the catalyst surface affects the catalytic activity. One way to change Fermi level is use electric field. In high voltage electric field, energy band was curved, bending of the energy band promoted the activity and Fermi level position is increasing. The CCD experiments were carried out with Design-Expert 7.3 software to determine the interaction between four operating variables, namely: temperature, electrical current, gap distance and metal loading. The levels of the independent variables were: temperature (550-700 °C), electrical current (0-12 mA), gap distance (6-14 mm), metal loading (0.5-7.5 %wt.). The conversion of LPG (Liquefied petroleum gas) was greatly increased by weak and effective application of an electric field to the catalyst bed. The obtained results indicated that the maximum yield value (46.94%) can be achieved under 673.66 °C, input electrical current of 11.01 mA, gap distance of 6.55 mm and metal loading of 3.98 wt.%.
Metrics with Zero and Almost-zero Einstein Action in Quantum Gravity
Giovanni Modanese
Subject: Physical Sciences, General & Theoretical Physics Keywords: general relativity; euclidean quantum gravity; path integral; lattice field theory; metropolis algorithm
We generate numerically on a lattice an ensemble of stationary metrics, with spherical symmetry, which have Einstein action SE « ħ. This is obtained through a Metropolis algorithm with weight exp(-β2SE2) and β » ħ-1. The squared action in the exponential allows to circumvene the problem of the non-positivity of SE. The discretized metrics obtained exhibit a spontaneous polarization in regions of positive and negative scalar curvature. We compare this ensemble with a class of continuous metrics previously found, which satisfy the condition SE=0 exactly, or in certain cases even the stronger condition R(x)=0 for any x. All these gravitational field configurations are of considerable interest in quantum gravity, because they represent possible vacuum fluctuations and are markedly different from Wheeler's ''spacetime foam''.
Investigation of Clay Balls in Asphalt Pavement
Weiguang Zhang, Jusang Lee, Hyung Jun Ahn
Subject: Engineering, Civil Engineering Keywords: clay ball; asphalt pavement; pattern and density; infrared image collection system; field core
Clay ball is a pavement surface defect which refers to a clump in which clay or dirt is mixed with hot asphalt mixture. Clay ball is typically caused by a combination of aggregate contamination of clay or soil, high aggregate moisture, and low production temperature at the asphalt plant. It usually appears a few weeks or months after paving under traffic load, after being liquefied and knocked from the pavement surface. Clay balls can be the source of potholing, raveling, and other issues such as moisture infiltration and reduced ride quality. This paper presents an investigation of the clay balls on US-31 one winter after construction in Hamilton County, Indiana. In order to understand the pavement condition, their severity was measured using both visual observation and infrared image collection system. In addition, a clay ball distribution pattern, its density, and cores condition were evaluated. A precipitation effect on clay ball formation was investigated for finding a cause of the clay balls. The investigation found that infrared image collection system was appropriate in detecting the clay balls. The clay balls were elliptic in shape with 1 inch to 4 inches in diameter, and the maximum clay ball depth is almost penetrating the entire surface course. It was also found that the asphalt paving on the raining days or right after raining could increase the potential of clay balls. Monitoring of aggregate moisture during construction on or after raining days should be able to reduce the risk of clay balls.
Wave Effects on the Initial Dilution of Untreated Wastewater Discharge for Santa Marta´s Submarine Outfall (Colombia)
Francisco-Fernando García-Rentería, Gustavo Ariel Chang Nieto, Gustavo Hernández Cortés
Subject: Engineering, Civil Engineering Keywords: Near field; dilution; submarine outfall, waves effects
The initial dilution generated by the final disposal of untreated wastewater through a submarine outfall in Santa Marta was examined with a near-field dilution model. Northward and eastward seawater velocity, salinity, and temperature profiles from a 3D hydrodynamic model were used to provide the oceanic conditions to calculate the dilution. At the wastewater discharge site, the upwelling phenomenon occurs two times a year, the major from December to March and the minor in July, eliminating the stratification condition of seawater. The results of the dilution model showed that in these periods the plume reaches the water surface achieving dilutions greater than 100. In addition, the external wave effect on the initial dilution of submarine outfall discharge in Santa Marta was determined. Surface waves increase dilution during the dry period of the year when trade winds increase the surge and start the upwelling phenomenon. The Dilution with/without waves factor is up to 1.90 for the center of the plume on the water column.
Preprint SHORT NOTE | doi:10.20944/preprints202203.0190.v1
Are Tensorial Affinities Possible?
Golden Gadzirayi Nyambuya
Subject: Physical Sciences, General & Theoretical Physics Keywords: Weyl Geometry; Tensorial affine; unified field theory
This short reading is an extraction from our previous work (Nyambuya 2020), the purpose of which is to make clear that it is very much possible to use Weyl (1918)'s idea of a conformal metric to achieve tensorial affinities. We are of the strong view that this is very important as it is predominantly assumed that this not possible. We want to dispel this myth once and for al-time.
Resolution of the Measurement Problem from a Quantum Gravity Perspective
Stuart Marongwe
Subject: Keywords: Measurement Problem; Quantum Gravity; Quantum Field Theory
Recent advances in the theory of quantum gravity show that the Ricci flow serves as the time evolution operator for the vacuum energy density and that in the presence of baryonic matter, the Ricci flow is analogous to the heat equation in the presence of a heat sink. Here we show using the equations of quantum gravity, that quantum information can be modelled as a thermal fluid consisting of a superposition of weakly excited eigenstates of a quantum field and that each eigenstate vector has an associated eigenstate potential well. The depth of the potential well depends on the amplitude of the eigenstate vector. Measurement is then considered as a selection by tuning process which only allows an eigenstate resonating with the detector to be detected. During the detection process, the resonating eigenstate vector increases in amplitude, deepening its potential well such that the other weakly excited states rapidly drain their small excitation energies into it via the principle of minimum action. This draining process is the act of collapsing the wave function to a specific state. Also, the presence of the eigenstate potential wells is what cancels out the infinities from high energy interactions.
Preprint ARTICLE | doi:10.3390/sci1020045
Influence of Gravitational Shielding on Time Dilation
Stanley Raj, Sohan Jheeta, Daniel, Arun Krishna, Joseph Pious, Hudson Oliver
Subject: Keywords: gravitational shielding; Casimir effect; electromagnetic field; gravity
This research work investigates the possibility of shielding gravity. The ultimate purpose of this work is to understand the reality behind the concept of Gravitational Shielding (GS) and time dilation. Since the 19th century, scientists have tried to arrive at an understanding of GS via the use of various experiments. Unfortunately, some experiments failed to prove the existence of gravitational shielding, whereas some results proclaimed the possibility of attaining GS. The original phenomenon exhibited by nature cannot easily be understood, but some experiments have demonstrated that the answer may lie behind the mysterious GS. If GS is proved, then in the future, it would be possible to travel across black holes by defying gravity or through any bigger mass having high gravitational field. To unravel the mystery of GS, this work investigates the history of GS and considers the future vision of technologically advanced spacecraft or other warp drive mechanisms with appropriate gravitational shielding. Though the problem is very complex, this research work tries to come to a deeper understanding and explanation of the complexity involved in achieving gravitational shielding.
Landauer Principle: Re-Formulation of the Second Thermodynamics Law or a Step to Great Unification?
Subject: Physical Sciences, General & Theoretical Physics Keywords: Landauer principle; entropy; information; relativity; particle; field
The Landauer principle supplies the estimation of the minimal mass of a particle which is capable to record/erase information within a thermal bath at the temperature of T. Particles lighter than m ˜ 0 = k B Tln2 c 2 will not transform the information to the surrounding bodies and are well expected to be undetectable. The relation of the Landauer principle to the problem of "dark matter" is discussed. The maximal informational content of a particle at rest, estimated as I max = m 0 c 2 k B Tkn2 is introduced. The Landauer principle also allows the estimation of minimal energy of the field which is capable to record/erase 1 bit of information in the surrounding at the temperature of T. The relativistic aspects of the Landauer principle and its relation to the relativistic transformation of temperature are addressed.
Weak and Strong Warm Logamediate Anisotropic Inflationary Universe Model
Wajiha Javed, Iqra Nawazish, Mohsin Raza Khan, Ali Övgün
Subject: Physical Sciences, General & Theoretical Physics Keywords: warm inflation; slow roll approximation; scalar field
This paper is given to the investigation of warm inflation using Modified Chaplygin gas in the background of locally rotationally symmetric Bianchi Identity type I. We find out the field equations and perturbations parameters such as; scalar power spectrum, scalar spectral index, scalar potential and tensor to scalar ratio under slow roll approximation. We find out these parameters in directional of Hubble parameter during the Logamediate inflationary regime in weak and strong case. These comological parameters shows that the anisotropic model is also compatible WMAP$7$ with recent observational data Planck $2018$.
Unification of Electromagnetism and Gravitation
Raymond Beach
Subject: Physical Sciences, General & Theoretical Physics Keywords: unified field theory; electromagnetism; Maxwell's equations; gravitation; general relativity; general relativity; Einstein's field equations; gravitational radiation; hidden variable; dark matter; cosmological constant
Using four field equations, a recently proposed theory that covers the phenomenology of classical physics at the level of the Maxwell and Einstein Field Equations (M&EFEs) but then goes further by unifying electromagnetic and gravitational phenomena in a fundamentally new way is reviewed. Predictions of the field equations are shown to be consistent with those of the M&EFEs through specific solutions; a particle-like solution representing a point charge, and two radiative solutions representing electromagnetic and gravitational waves. A unique feature of the full set of field equations is that charge and mass are treated as dynamic fields instead of being introduced as external parameters as is done with the classical M&EFEs, a feature that enables a procedure for quantizing the mass, charge and angular momentum of particle-like solutions. Finally, antimatter is naturally accommodated by the theory and definite predictions regarding the interactions of matter and antimatter with gravitational fields are made.
A Unified Theory of All the Fields in Elementary Particle Physics Derived Solely from the Zero-Point Energy in Quantized Spacetime
Shinichi Ishiguri
Subject: Physical Sciences, Particle & Field Physics Keywords: zero-point energy; quantized time-space static electromagnetic field; gravity field; weak interaction; strong interaction; masses of W and Z; mass of a neutrino; β collapse; quantized Einstein gravity equation
We propose a new theory beyond the standard model of elementary-particle physics. Employing the concept of a quantized spacetime, our theory demonstrates that the zero-point energy of the vacuum alone is sufficient to create all the fields, including gravity, the static electromagnetic field, and the weak and strong interactions. No serious undetermined parameters are assumed. Furthermore, the relations between the forces at the quantum-mechanics level is made clear. Using these relations, we quantize Einstein's gravitational equation and explain the Dark Energy in our universe. Beginning with the zero-point energy of the vacuum, and after quantizing Newtonian gravity, we combine the energies of a static electromagnetic field and gravity in a quantum spacetime. Applying these results to the Einstein gravity equation, we substitute the energy density derived from the zero-point energy in addition to redefining differentials in a quantized spacetime. We thus derive the quantized Einstein gravitational equation without assuming the existence of macroscopic masses. This also explains the existence of the Dark Energy in the universe. For the weak interaction, by considering plane-wave electron and the zero-point energy, we obtain a wavefunction that represents a β collapse. In this process, from a different point of view than Weinberg-Salam theory, we derive the masses of the W and Z bosons and the neutrino, and we calculate the radius of the neutron. For the strong interaction, we previously reported an analytical theory for calculating the mass of a proton by considering a specific linear attractive potential obtained from the zero-point energy, which agrees well with the measurements. In the present study, we calculate the strong interaction between two nucleons, i.e., the mass of the pi-meson. The resulting calculated quantities agree with the measurements, which verifies our proposed theory.
A Miniature Permanent Magnet Assembly with Localized and Uniform Field with an Application to Optical Pumping of Helium
Garnet Cameron, Jonathan Cuevas, Jeffrey Pound Jr., David Shiner
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: optical pumping; annular permanent magnet; miniature magnet; laser orbital angular mo-mentum; collimated magnetic field; fringe magnetic field
Atomic state preparation can benefit from a compact and uniform magnetic field source. Simulations and experimental measurements have been used to design, build, and test such a source as shown by optical pumping of atomic Helium. This source is a 9.5 mm (3/8") OD x 6.7 mm (1/4") ID x 9.5 mm (3/8") long, NdFeB-N42 assembly of 1.6 mm (1/16") thick customized annular magnets. It has octopole decay with a residual dipole far field from imperfect dipole cancelations. It has greater than 50% clear aperture with uniform and collimated magnetic field consistent with the prediction of several models. Octopole roll-off localizes the field minimizing the need for shielding in applications. The device is applied to a high precision 3,4He laser spectroscopy experiment using σ+ or σ- optical pumping currently resulting in a measured 99.3% preparation efficiency and in accordance with a rate-equation model.
Optimization of Line-Tunneling Type L-Shaped Tunnel Field-Effect-Transistor for Steep Subthreshold Slope
Faraz Najam, Yun Seop Yu
Subject: Engineering, Electrical & Electronic Engineering Keywords: band-to-band tunneling; L-shaped tunnel field-effect-transistor; double-gate tunnel field-effect-transistor; corner-effect
Recently L-shaped tunneling field-effect-transistor (LTFET) has been introduced to overcome the thermal subthreshold limit of conventional metal-oxide-semiconductor field-effect-transistors (MOSFET). In this work, shortcoming of LTFET was investigated. It was found that corner effect present in LTFET effectively degrades its subthreshold slope. To get rid of corner effect a new type of device with dual material gates is presented. The new device termed as DG-LTFET gets rid of the corner effect and results in a significantly improved subthreshold slope of less than 10 mV/dec, and an improved ON/OFF current ratio over LTFET. In this work DG-LTFET was evaluated for different device parameters, and bench-marked against LTFET. This work presents an optimum configuration of DG-LTFET in terms of device dimensions and doping levels, to get the best subthreshold, ON current and ambipolar performance from the DG-LTFET.
Vector Potential, Magnetic Field, Mutual Inductance, Magnetic Force, Torque and Stiffness Calculation between Current-Carrying Arc Segments with Inclined Axes in Air
Slobodan Babic
Subject: Physical Sciences, Applied Physics Keywords: Magnetic vector potential; magnetic field; mutual inductance; magnetic force; torque; stiffness
In this paper we give the improved and new analytical and semi-analytical expression for calcu-lating the magnetic vector potential, magnetic field, magnetic force, mutual inductance, torque, and stiffness between two inclined current-carrying arc segments in air. The expressions are ob-tained either in the analytical form over the incomplete elliptic integrals of the first and the sec-ond time or by the single numerical integration of some elliptical integrals of the first and the second kind. The validity of the presented formulas is proved from the special cases when the inclined circular loops are treated. We mention that all formulas are obtain by the integral ap-proach except the stiffness which is found by the derivative of the magnetic force.
Classifying Superconductivity in ThH-ThD Superhydrides
Evgueni Talantsev
Subject: Physical Sciences, Condensed Matter Physics Keywords: hydrogen-rich superconductor; classifying superconductors; thorium-hydrogen and thorium-deuterium superconductors; upper critical field
Satterthwaite and Toepke (1970 Phys. Rev. Lett. 25 741) discovered that Th4H15-Th4D15 superhydrides exhibit superconductivity and have no isotope effect. The latter is fundamental contradiction with the concept of electron-phonon mediated superconductivity of Bardeen-Cooper-Schrieffer (BCS) theory. Soon after this work, Stritzker and Buckel (1972 Zeitschrift für Physik A Hadrons and nuclei 257 1-8) reported that superconductors in PdHx-PdDx system exhibit reverse isotope effect. Yussouff et al (1995 Solid State Communications 94 549) extended this finding on PdHx-PdDx-PdTx system. Recent interest to hydrogen- and deuterium-rich superconductors is based on the discovery of near-room-temperature superconductivity in highly-compressed H3S (Drozdov et al. 2015 Nature 525 73) and LaH10 (Somayazulu et al 2019 Phys. Rev. Lett. 122 027001). To date, there is no clarity about isotope effect in H3S-D3S system, because thorough examination of available experimental data reported by Drozdov et al (2015 Nature 525 73) shows that H3S-D3S system perhaps has reverse isotope effect. In attempt to reaffirm/disprove our primary idea that the mechanism for near-room-temperature superconductivity in hydrogen-rich superconductors is not BCS electron-phonon interaction, we analyse the upper critical field data, Bc2(T), in Th4H15-Th4D15 phases (Satterthwaite and Toepke 1970 Phys. Rev. Lett. 25 741) and two recently discovered high-pressure hydrogen-rich phases of ThH9 and ThH10 (Semenok et al 2019 arXiv:1902.10206). As the result, it is found that all known to date thorium super-hydrides/deuterides are unconventional superconductors which have Tc/TF ratios within a range of 0.008 < Tc/TF < 0.120, where Tc is the superconducting transition temperature and TF is the Fermi temperature.
Mean-field Theory of the Meissner Effect in Bulk Revisited
Ladislaus Banyai
Subject: Physical Sciences, Acoustics Keywords: BCS superconductivity; mean field; current-current interaction; internal/external fields; stability; Meissner effect
We show that the implementation of the 1/c² transverse current-current interaction between electrons into the standard self-consistent electron BCS model in bulk under thermal equilibrium ensures in the stable superconductive phase the full compensation of a constant external magnetic field by the internal magnetic field created by the electrons i.e. one has an ideal diamagnet. However, no proof of the phenomenological London equation emerges within the bulk approach.
Relativistic Mass of Gravitational Field
yin zhu
Subject: Physical Sciences, General & Theoretical Physics Keywords: Relativistic mass of gravitational field; Total mass of a galaxy; Constitution of the mass of a star with field
It is discovered that the gravitational field on the surface of a neutron star is with a relativistic mass density of 2.65*1016~5.87*1018kgm-3 which can be larger than the mass density of the neutron star (~1017kgm-3). And, the total relativistic mass of the gravitational field of the Sun is ~107 times the mass of the Sun. For different stars, the relativistic mass of the gravitational field is larger as the mass density of the star is larger. In the Milky Way, the total relativistic mass of the gravitational fields is much larger than the total mass of the stars, planets and gas. And, the relativistic mass density of the observed strongest magnetic field is 2.17*108kgm-3. This discovery should be a new frame to understand the fundamental problem of physics.
The Correlation between Rotational Gravity and Magnetic Field of Celestial Body
Ying-Qiu Gu
Subject: Physical Sciences, Astronomy & Astrophysics Keywords: Earth magnetic field; celestial magnetic field; magnetic dipole; Clifford algebra; Dirac equation; spin-gravity coupling potential; curved space-time
The magnetic field of the earth plays an important role in the ecosystem, and the magnetic field of celestial bodies is also important in the formation of cosmic large-scale structures, but the origin and evolution of the celestial magnetic field is still an unresolved mystery. Many hypotheses to explain the origin have been proposed, but there are some insurmountable difficulties for each one. At present, the theory widely accepted in scientific society is the dynamo model, it says that, the movement of magnetofluid inside celestial bodies, which can overcome the Ohmic dissipative effect and generate persistent weak electric current and macroscopic magnetic field. However, this model needs an initial seed magnetic field, and the true values of many physical parameters inside the celestial body are difficult to obtain, and there is no stable solution to the large range of fluid motion. These are all difficulties for the dynamo model. Furthermore, it is difficult for the dynamo to explain the correlation between the dipole magnetic field and angular momentum of a celestial body. In this paper, by calculating the interaction between spin of particles and gravity of celestial body according to Clifford algebra, we find that a rotational celestial body provides a field $\Omega^\alpha$ for spins, which is similar to the magnetic field of a dipole, and the spins of charged particles within the celestial body are arranged along the flux line of $\Omega^\alpha$, then a macroscopic magnetic field is induced. The calculation shows that the strength of $\Omega^\alpha$ is proportional to the angular momentum of the celestial body, which explains the correlation between the magnetic intensity and angular momentum. The results of this paper suggest that further study of the effects of internal variables such as density, velocity, pressure and temperature of a celestial body on $\Omega^\alpha$ may provide some new insights into the origin and evolution of celestial magnetic field.
Geometric Unification of Electromagnetism and Gravitation
Subject: Physical Sciences, General & Theoretical Physics Keywords: unified field theory; electromagnetism; Maxwell's equations; gravitation; General Relativity; Einstein's field equation; gravitational radiation; dark matter; dark energy; antigravity
Online: 4 November 2019 (04:04:58 CET)
A recently proposed classical field theory comprised of four field equations that geometrically couple electromagnetism and gravitation in a fundamentally new way is reviewed. The cornerstone of the theory equates the derivatives of the Maxwell tensor to a vector field contracted with the Riemann-Christoffel curvature tensor. The new theory's field equations show little resemblance to the field equations of classical physics, but both Maxwell's equations of electromagnetism and Einstein's equation of General Relativity augmented by a term that can mimic the properties of dark matter and dark energy are shown to be a consequence. Emphasized is the unification brought to electromagnetic and gravitational phenomena as well as the consistency of solutions of the new theory with those of the classical Maxwell and Einstein field equations. Unique to the four field equations reviewed here and based on specific solutions to them are: the emergence of antimatter and its behavior in gravitational fields, the emergence of dark matter and dark energy mimicking terms in the context of General Relativity, an underlying relationship between electromagnetic and gravitational radiation, the impossibility of negative mass solutions that would generate repulsive gravitational fields or antigravity, and a method for quantizing the charge and mass of particle-like solutions.
Light Dispersion in Gravitational Field
Subject: Physical Sciences, General & Theoretical Physics Keywords: dispersion of light; gravitational field; fundamental physics constant; vacuum; speed of light; spectroscopic binary system; double gravitational lens
In any region of a space, the gravitational field cannot be eliminated. The speed of light in a vacuum has never been observed and cannot be observed with current technology. Till now, only the speed of light in a gravitational field has been observed. Here, it is presented that light could be dispersion in a gravitational field analogous to the dispersion of light in the Newtonian prism experiment. The relativistic mass density on the surface of a neutron star is on the level of 1017kgm-3 while on the surface of the Earth is only 6.63*10-7kgm-3, the speed of light acted by the gravitational field of a neutron star is much larger than that by the Earth. Therefore, light dispersion in strong gravitational field could be generally observed from the picture of a star and it should have been observed through the spectroscopic binary system.
Low Order Harmonics Control in Stair Case Waveform by a Novel Estimation based Technique
Salman Ahmad, Atif Iqbal, Imtiaz Ashraf, Sanjeevikumar Padmanaban, Mohammed Meraj
Subject: Engineering, Electrical & Electronic Engineering Keywords: staircase waveform; harmonics control; field programming gate array (FPGA); estimation; iterative technique; VHDL
Few switching transitions in high power and medium voltage application of Power converters are desirable. The selective harmonics elimination (SHE) pulse width modulation offers a better quality waveform with lower switching transitions and hence lower switching losses. The SHE is a pre-programmed modulation technique where certain amounts of lower order harmonics are removed and fundamental voltage is controlled. After Fourier analysis of output waveform, a set of nonlinear transcendental equations is obtained which exhibits, multiple, unique or no solution in different range of modulation index (MI). In this paper, an iterative method based on the Jacobian estimate is proposed to solve a highly non-linear set of SHE equations. The proposed technique is easy in implementation and can solve a large number of such equations as computation of the Jacobian matrix in the subsequent iteration is estimated from the previous values. Moreover, the proposed method also removes the singularity problem, especially for large SHE equations. High accuracy in the initial guess is also not essential for this method and can converge to the solution with any random initial guess. The computational and simulation results are given to validate the concept. The hardware result is provided to confirm the computational and simulation results.
Magnetic Entropic Forces Emerging in the System of Elementary Magnets Exposed to the Magnetic Field
Subject: Physical Sciences, Condensed Matter Physics Keywords: entropic force; magnetic field; linear system of elementary magnets; ordering; temperature; repulsion force.
Temperature dependent entropic force acting between the straight direct current I and the linear system (string with length of L) of N elementary non-interacting magnets/spins μ is reported. The system of elementary magnets is supposed to be in the thermal equilibrium with the infinite thermal bath T. The entropic force at large distance from the current is given by Fmagnen=Nμ02μ2I24π2kBTr3 , where r is the distance between the edge of the string and the current I, and kB is the Boltzmann constant; (r≫L is adopted). The entropic magnetic force is the repulsion force. The entropic magnetic force scales as Fmagnen~1T , which is unusual for entropic forces. The effect of "entropic pressure" is predicted for the situation when the source of the magnetic field is embedded into the continuous media, comprising elementary magnets/spins.
Urban Canyon in the CBD of Rio de Janeiro (Brazil): Thermal Profile of Avenida Rio Branco during Summer
Lidiane de Oliveira Lemos, Antonio Carlos Oscar-Júnior, Francisco Mendonça
Subject: Earth Sciences, Atmospheric Science Keywords: Urban climate; thermal field; three-dimensional structure; surface temperatures; heat islands; thermal inversion
This study aims to evaluate the land surface temperature (LST) and the thermal characteristics of the Urban Canopy Layer (UCL) of the urban canyon in Avenida Rio Branco in the Central Business District (CBD) of Rio de Janeiro during summer. In order to conduct this evaluation, two methods were employed: 1) TIRS Landsat-8 sensor for data selection and processing (latest generation, 2011-2020); ; 2) field survey using nine sampling points — seven along two mobile transects, one fixed point, and one vertical measurement point, which required the use of a RPA (Remotely Piloted Aircraft). Three categories of analysis were established for the field survey based on the prevailing synoptic situations: stability, instability, and post-instability. The CBD is characterized by extensive areas with surface heat islands, in which temperatures were higher than 38.9°C; the areas with milder LSTs were Campo do Santana, Avenida Rio Branco, and one of the Mixed-Use Zones (Praça Mauá). With respect to Rio Branco Avenue, the LST niches of lowest elevation were derived through building shadowing; however, the orbital data diverged from the observation data of the ten field-study days. In situ data revealed that the characteristics urban morphology of Avenida Rio Branco is susceptible to the formation of heat islands, presenting heat islands of very strong magnitude (over 6.1°C) in atmospheric stability, strong magnitude (4.1-6.0°C) in atmospheric instability, and moderate magnitude (2.1°C-4.0°C) in post-atmospheric instability. Despite the synoptic situation, thermal cores were concentrated at 1 pm. The intersection between Avenida Rio Branco, Rua do Ouvidor, and Praça Mauá stored most of the solar energy received during the day due to the greater sky obstruction caused by the verticalization. Finally, vertical analysis demonstrated the formation of a thermal inversion on the night of the highest mean air temperature (29.5°C), probably, due to the roughness and number of buildings in the urban canyon.