Particle Theory Research Articles

ROTHSTEIN CODE TRANSFORMATIONS AS A DIGITAL OPTICAL SCALING METHOD

The Rothstein code data transformation method is a largely forgotten and underutilized method originally theorized from optics and retinal recruitment. The code is a binary representation of the slope of a line or scaling factor and can transform data and images similar to matrix multiplications except with built-in interpolations. The theoretical validation of the method presented in the original publications is complex. The purpose of this paper is to borrow from quantum theory and dual nature of light, particle and wave, to simplify the theoretical understanding. With this understanding, the method becomes more intuitive in the example applications that follow. These application examples include digital resampling of data for signal processing applications, examples for matrix scaling such as for the management of discordant data sets, and for image processing.

Study of deep eutectic solvents (DESs) performance on aromatics (benzene and thiophene) extraction: thermophysical study

Thermophysical properties of some binary mixtures of novel choline chloride-based deep eutectic solvents and two aromatics (benzene and thiophene) were measured to evaluate the nature of solute–solvent interactions at T = (283.15–303.15) K and atmospheric pressure. Choline chloride was selected as hydrogen bond donor and (mono-, di- and tri-) ethylene glycols or (mono-, di- and tri-) ethanolamines were used as hydrogen bond donors. The density (d), speed of sound (u), viscosity (η) and refractive index (nD) data were measured for binary mixtures of benzene or thiophene with the selected DESs at T = (283.15–303.15) K. The apparent molar volume (Vφ), standard partial molar volume (Vφ0 ), partial molar isentropic compression (κφ0 ), excess molar volume (VE), viscosity B-coefficient and molar refraction (RD) values, were obtained for the binary mixtures at dilute region of aromatics. These quantities are used for interpreting of the studied DESs and benzene or thiophene molecular interactions. Also, the scaled particle theory (SPT) was used for calculation of interaction volume (Vint), and cavity volume (Vcav). The obtained results indicate that DESs with amine functional groups interact more effectively with benzene or thiophene rather than ethylene glycolic-based DESs.

Interpretation of Action Potential Generation Mechanism in Cardiomyocytes by Potassium Channel “Origami Windmill” Model

The study of the action potential of cardiomyocytes is as important as the study of nerve fiber cells. The theoretical basis of the action potential of cardiomyocytes is the ionic theory formed by nerve fiber cells. Its core point of view: the decline phase of the action potential of cells is dominated by K+ outflow. Applying the principle of the K+ channel “origami windmill” model, the mechanism of action potential generation of nerve fiber cells has been reasonably explained, and a point contrary to the ion theory has been drawn: the phase of the action potential decline is dominated by K+ influx. Similarly, applying the principle of the K+ channel “origami windmill” model can also give a reasonable explanation for the mechanism of action potential generation of cardiomyocytes. The difference between cardiomyocyte action potential and nerve fiber cell: In addition to K+, Cl-, Na+, the process of generating cardiomyocyte action potential also involves the participation of Ca2+. Ca2+ inflow in the rising phase will shorten the depolarization time; Ca2+ inflow in the falling phase will prolong the repolarization time. K+, Ca2+ space substitution proportion: rotate into 2 K+, squeeze out 3 Ca2+, and 4 extra negative charges in the cell, the proportion is 2: 3: 4; Conversely, squeeze out 2 K+, rotate into 3 Ca2+, 4 extra positive charges the cells, the proportion is 3: 2: 4. Na+, Ca2+ space substitution proportion: rotate into 1 Na+, squeeze out 1 Ca2+, and 1 extra negative charges in the cell, the proportion is 1: 1:1; Conversely, rotate into 1 Ca2+, squeeze out 1 Na+, there is 1 more positive charge in the cell, and the proportion is 1: 1: 1. Application of “origami windmill” model principle, can reasonably explain the cardiomyocytes action potential generation mechanism, further proveding “origami windmill” the model theory, “the theory of dove-like particles”“the theory of braincell activation” of science, also proved that the viewpoint of “action potential descending phase, dominated by K+ internal current” is correct. The scientific and rational interpretation of the action potential of cardiomyocytes has far-reaching impact and great significance to the basic theoretical research and clinical practice of the heart from now on.

Group Theoretical Derivation of Consistent Free Particle Theories

The difficulties of relativistic particle theories formulated by means of canonical quantization, such as those of Klein–Gordon and Dirac, ultimately led theoretical physicists to turn to quantum field theory to model elementary particle physics. In order to overcome these difficulties, the theories of the present approach are developed deductively from the physical principles that specify the system, without making use of canonical quantization. For a free particle these starting assumptions are invariance of the theory and covariance of position with respect to Poincaré transformations. In pursuing the approach, the effectiveness of group theoretical methods is exploited. The coherent development of our program has shown that robust classes of representations of the Poincaré group, discarded by the known particle theories, can in fact be taken as bases for perfectly consistent theories. For massive spin zero particles, six inequivalent theories have been determined, two of which do not correspond to any of the current ones; all of these theories overcome the difficulties of Klein–Gordon one. The present lack of the explicit transformation properties of position with respect to boosts prevents the complete determination of non zero spin particle theories. In the past a particular form of these transformation properties was adopted by Jordan and Mukunda. We check its consistency within the present approach and find that for spin frac{1}{2} particles there is only one consistent theory, which is unitarily related to Dirac’s; yet, once again, it requires classes of irreducible representations previously discarded.

Understanding of Solid-Fluid Kinetics and Mass Transfer: From Ideal to Non-ideal Models, From Perfect Spheres to Moon Landscape

Throughout the decades, the solid-fluid processes have been modelled with the hypothesis of ideal, non-porous particles. Numerous relevant industrial reactions with reactive solids do not involve ideal slabs, spheres or cylinders, but instead the particles have rough surfaces comparable of the Moon with cracks and craters. The theory of non-ideal solid particles is briefly reviewed and the effect of the non-ideality is illustrated for batch processes. In general, surface roughness results in the increase of the apparent reaction with respect to the solid reactant.

Charge Asymmetry in Top Quark Pair Production

The top quark is the heaviest elementary particle known. It has been proposed many times that new physics beyond the current theory of elementary particles may reveal itself in top quark interactions. The charge asymmetry in the pair production of a fermion and its antiparticle has been known for many decades. Early measurements of such asymmetry in top quark pair production showed a disagreement with the prediction by more than 3 standard deviations. Many years of an effort on both experimental and theoretical side have allowed to understand the top quark pair charge asymmetry better and to bring back the agreement between the measurements and the theory. In this article, these efforts are reviewed together with the discussion about a potential future of such measurements.

Trajectory-based conservation laws for massive spin-zero relativistic quantum particles in 1 + 1 spacetime

We present novel aspects of a trajectory-based theory of massive spin-zero relativistic quantum particles. In this approach, the quantum trajectory ensemble is the fundamental entity. It satisfies its own action principle, leading to a dynamical partial differential equation (via the Euler-Lagrange procedure), as well as to conservation laws (via Noether’s theorem). In this paper, we focus on the derivation of the latter. In addition to the usual expected energy and momentum conservation laws, there is also a third law that emerges, associated with the conditions needed to maintain global simultaneity. We also show that the nonrelativistic limits of these conservation laws match those of the earlier, nonrelativistic quantum trajectory theory [J. Chem. Phys. 136, 031102 (2012)].

Effect of deep eutectic solvents based on choline chloride on the thermodynamic and transport properties of D-fructose in aqueous solution

In this work, the effect of some deep eutectic solvents (DESs) based on choline chloride on the thermodynamic and transport properties of D-fructose in aqueous solutions was investigated. Using the vapor-liquid equilibrium (VLE) data, water activity (aw), osmotic coefficient and vapor pressure data were obtained. The performance of different local composition models such as Wilson, e-NRTL, and UNIQUAC for correlating of these data have been examined. The calculated negative values of Gibbs free energies of transfer (ΔGtri) indicate favorable interaction of DESs with D-fructose. Further, the standard partial molar volumes Vφ0, partial molar isentropic compressibility Kφ0, viscosity B-coefficient and molar refractions RD for the solutions have been calculated from the measured density and speed of sound, viscosity and refractive index data at T = (288.15 to 318.15) K. Interaction volume Vint and cavity volume Vcav have been computed from scaled particle theory (SPT) to probe solute-solvent interactions. The viscosity B-coefficients was used to discuss structure-making tendency of the solutions studied.

Aerodynamic Layout Design and Internet of Things Control Simulation of Micro-Sized Coaxial Twin-Rotor Flight System

A small collapsible common-axis dual-rotor drone has been designed independently by performance indicators. The model was computed through three-dimensional modeling and meshing. Using Fluent software, the wind tunnel test simulation of the blades was obtained, and the results of the blade model test were compared with the results of the blade model. The lift data of CFD at different speeds were consistent with the results of the paddle model test, with a maximum error of only 12.46%. Using the mesh Boltzmann method (LBM) based on smooth particle theory, the non-normal aerodynamic strain of the most severe conditions in the flat flight is selected for modeling analysis. The aerodynamic layout design of a type of coaxial twin-rotor aircraft and its nonlinear six-degree-of-freedom flight simulation modeling and control system were verified. The results show that the design of the common-axis twin-rotor aircraft can meet the higher aerodynamic index requirements. The control performance and wind disturbance resistance of the designed aircraft are tested and verified by the flight simulation of Matlab/Simulink, and the simulation results show that the system can achieve the desired control goal by adding the closed-loop altitude controller and speed controller. It also provide a basis for further study of its aerodynamic properties.

Dynamics of active nematic defects on the surface of a sphere.

A nematic liquid crystal confined to the surface of a sphere exhibits topological defects of total charge +2 due to the topological constraint. In equilibrium, the nematic field forms four +1/2 defects, located at the corners of a regular tetrahedron inscribed within the sphere, since this minimizes the Frank elastic energy. If additionally the individual nematogens exhibit self-driven directional motion, the resulting active system creates large-scale flow that drives it out of equilibrium. In particular, the defects now follow complex dynamic trajectories which, depending on the strength of the active forcing, can be periodic (for weak forcing) or chaotic (for strong forcing). In this paper we derive an effective particle theory for this system, in which the topological defects are the degrees of freedom, whose exact equations of motion we subsequently determine. Numerical solutions of these equations confirm previously observed characteristics of their dynamics and clarify the role played by the time dependence of their global rotation. We also show that Onsager's variational principle offers an exceptionally transparent way to derive these dynamical equations, and we explain the defect mobility at the hydrodynamics level.

Demixing and tetratic ordering in some binary mixtures of hard superellipses.

We examine the fluid phase behavior of binary mixtures of hard superellipses using the scaled particle theory. The superellipse is a general two-dimensional convex object that can be tuned between the elliptical and rectangular shapes continuously at a given aspect ratio. We find that the shape of the particle affects strongly the stability of isotropic, nematic, and tetratic phases in the mixture even if the side lengths of both species are fixed. While the isotropic-isotropic demixing transition can be ruled out using the scaled particle theory, the first order isotropic-nematic and the nematic-nematic demixing transition can be stabilized with strong fractionation between the components. It is observed that the demixing tendency is strongest in small rectangle-large ellipse mixtures. Interestingly, it is possible to stabilize the tetratic order at lower densities in the mixture of hard squares and rectangles where the long rectangles form a nematic phase, while the squares stay in the tetratic order.

The sweetness response and thermophysical properties of glucose and fructose in the aqueous solution of some deep eutectic solvents at T= (288.15–318.15) K

Thermophysical properties elucidate the sweetness response, taste quality and hydration characteristics of saccharides in the aqueous solutions and offer significant information for pharmaceutical and food industries. In this current work, the effect of some neoteric green solvents as named deep eutectic solvents (DESs) on the sweetness response, taste quality and hydration behavior of the glucose and fructose solutions have been investigated from apparent specific volumes ASV, apparent specific isentropic compressibility ASIC parameters. The standard partial molar volumes Vφ0, transfer apparent molar volumes ΔtrVφ0, partial molar isentropic compressibilities Kφ0, viscosity B-coefficients and molar refractions RD the aqueous solutions of saccharides in choline chloride (ChCl)-urea, ChCl-ethylene glycol (EG), dimethyl ammonium chloride (DMAC)-ethylene glycol as DESs have been calculated from measured density, speed of sound, viscosity and refractive index data at T= (288.15–318.15) K. The results indicated that glucose in the aqueous solutions of ChCl-urea has the strongest interactions and get stronger with increasing the concentration of DES and temperature. Interaction volume Vint and cavity volume Vcav have been computed from scaled particle theory (SPT).

Conformal theory of gravitation and cosmology

The postulate of universal local Weyl scaling (conformal) symmetry modifies both general relativity and the Higgs scalar field model. Conformal gravity (CG) has recently been fitted to rotation data for 138 galaxies. The conformal Higgs model (CHM) acquires a gravitational effect that fits observed Hubble expansion for redshifts (7.33 Gyr) accurately with only one free constant parameter. Conformal theory explains dark energy and does not require dark matter, providing a viable alternative to the ΛCDM standard paradigm. Vanishing of centripetal acceleration outside a galactic halo boundary is a unique implication of the theory. The fit to observed astrophysical data by conformal models CG and CHM is shown here to account for both parameters w2 and λ of postulated Higgs potential , responsible for symmetry-breaking finite in particle theory. Recent criticism of CG is resolved here by showing that CG and CHM are interdependent but compatible. Nonclassical CG radial acceleration parameter γ is determined by the CHM. A recently established empirical relationship between classical and nonclassical galactic radial acceleration requires parameter γ to be independent of galactic mass. Conformal theory is shown here to be consistent with this and with the v4 baryonic Tully-Fisher relation for galactic rotation velocities.

Classical analogies for the force acting on an impurity in a Bose–Einstein condensate

We study the hydrodynamic forces acting on a small impurity moving in a two-dimensional Bose–Einstein condensate at non-zero temperature. The condensate is modelled by the damped-Gross Pitaevskii (dGPE) equation and the impurity by a Gaussian repulsive potential coupled to the condensate. For weak coupling, we obtain analytical expressions for the forces acting on the impurity, and compare them with those computed through direct numerical simulations of the dGPE and with the corresponding expressions for classical forces. For non-steady flows, there is a time-dependent force dominated by inertial effects and which has a correspondence in the Maxey–Riley theory for particles in classical fluids. In the steady-state regime, the force is dominated by a self-induced drag. Unlike at zero temperature, where the drag force vanishes below a critical velocity, at low temperatures the impurity experiences a net drag even at small velocities, as a consequence of the energy dissipation through interactions of the condensate with the thermal cloud. This dissipative force due to thermal drag is similar to the classical Stokes’ drag. There is still a critical velocity above which steady-state drag is dominated by acoustic excitations and behaves non-monotonically with impurity’s speed.

Surface Free Energy of a Hard-Disk Fluid at Curved Hard Walls: Theory and Simulation.

In this work, we examine the surface thermodynamics of a hard-disk fluid at curved hard walls using Monte Carlo (MC) simulation and a generalized scaled particle theory (gSPT). The curved walls are modeled as hard disks of varying radii, R. The surface free energy, γ, and excess surface volume, vex, for this system are calculated as functions of both the fluid packing fraction and the wall radius. The simulation results are used to test, for this system, the assumptions of morphometric thermodynamics (MT), which predicts that both γ and vex are linear functions of the surface curvature, 1/R, for a two-dimensional system. In addition, we compare the simulation results to the gSPT developed in this work, as well as with virial expansions derived from the known virial coefficients of the binary hard-sphere fluid. At low to intermediate packing fractions, the non-MT terms (terms of higher order than 1/R in a expansion of γ and vex) of γ are zero within the simulation error; however, at the highest densities, deviations from MT become significant, similar to what was seen in our earlier simulation work on the three-dimensional hard-sphere/hard-wall system. In addition, the new gSPT gives improved results for both γ and vex over standard scaled particle theory (SPT) but underestimates the deviations from MT at high density.

Integrated evanescent field detector for ultrafine particles-theory and concept.

Recent studies on ultrafine particles (UFP), which are smaller than 100 nm, emphasized their hazardous potential to the human organism. They are comparable in size to typical nano-organisms such as viruses and can penetrate physiological barriers in a similar way. Currently, there are no low-cost and miniaturized detectors for UFP available. In our first experiments with an integrated evanescent field particle detector, we could already successfully detect single 200 nm polystyrene latex (PSL) spheres, although the implemented waveguide geometry was only rudimentary optimized with costly 3D simulations. We developed a fast and structured optimization model for waveguide geometry and operation wavelength of an integrated evanescent field particle detector in order to exploit its full potential for the detection of discrete analytes in the UFP size range. The optimization model is based on a modified formulation of Mie theory and its computational effort is reduced by a factor of 100 compared to 3D simulations. The optimization potential of the sensor response signal is demonstrated for several waveguide geometries that can be produced with established semiconductor fabrication technology at high production volumes and low costs. An optimized silicon nitride waveguide features sensor response signals that are about one order of magnitude higher compared to previous experiments, which pushes the limit of detection even further down to particle sizes below 100 nm. A small integrated evanescent field particle detector based on this optimized waveguide will be used for the first low-cost and miniaturized devices that can monitor the personal exposure to UFP.

From particles to firms: on the kinetic theory of climbing up evolutionary landscapes

This paper constitutes the first attempt to bridge the evolutionary theory in economics and the theory of active particles in mathematics. It seeks to present a kinetic model for an evolutionary formalization of economic dynamics. The new derived mathematical representation intends to formalize the processes of learning and selection as the two fundamental drivers of evolutionary environments [G. Dosi, M.-C. Pereira and M.-E. Virgillito, The footprint of evolutionary processes of learning and selection upon the statistical properties of industrial dynamics, Ind. Corp. Change, 26 (2017) 187–210]. To coherently represent the aforementioned properties, the kinetic theory of active particles [N. Bellomo, A. Bellouquid, L. Gibelli and N. Outada, A Quest Towards a Mathematical Theory of Living Systems (Birkhäuser-Springer, 2017)] is here further developed, including the complex interaction of two hierarchical functional subsystems. Modeling and simulations enlighten the predictive ability of the approach. Finally, we outline the potential avenues for future research.

Extended filtration model for diesel particulate filter based on diesel particulate matter morphology characteristics

This study proposes an extended filtration model for diesel particulate filter based on diesel particulate matter morphology characteristics. This model introduces the parameter of variable effective density to modify the filtration model and develops the global filtration correction coefficient ϑp to consider the changes of PM morphological parameters. The specific calculation formulas of these two parameters are given in the paper. The filtration model proposed in this paper is based on the theory of spherical particles packed bed. Results show that the prediction error of the extended model can be as low as 0.66%, the average prediction error is 1.17%, and the prediction accuracy is improved by 34.08% compared with the former model. Filtration efficiency growth coefficient Egro exhibits a bimodal distribution, and the PM in the two particle size ranges of 110–140 nm and greater than 500 nm is more sensitive to the micro-changes in parameters caused by PM deposition in the porous substrate. In addition, the filtration time interval has the greatest influence on the growth rate, especially for the small and medium particle sizes ranging between 166.5 and 294.3 nm.

The Bisognano\u2013Wichmann Property for Asymptotically Complete Massless QFT

We prove the Bisognano–Wichmann property for asymptotically complete Haag–Kastler theories of massless particles. These particles should either be scalar or appear as a direct sum of two opposite integer helicities, thus, e.g., photons are covered. The argument relies on a modularity condition formulated recently by one of us (VM) and on the Buchholz’ scattering theory of massless particles.

Parameter Estimation and Measurement of Social Inequality in a Kinetic Model for Wealth Distribution

This paper deals with the modeling of wealth distribution considering a society with non-constant population and non-conservative wealth trades. The modeling approach is based on the kinetic theory of active particles, where individuals are distinguished by a scalar variable (the activity) which expresses their social state. A qualitative analysis of the model focusing on asymptotic behaviors and measurement of inequality through the Gini coefficient is presented. Finally, some specific case-studies are proposed in order to carry out numerical experiments to validate our model, characterize societies and investigate emerging behaviors.