Characteristic Physical Parameters Research Articles

Solar cycle variation in the properties of photospheric magnetic concentrations

It is widely accepted that eruptive phenomena on the Sun are related to the solar magnetic field, which is closely tied to the observed magnetic concentrations (MCs). Therefore, studying MCs is critical in order to understand the origin and evolution of all forms of solar activity. In this paper, we investigate the statistics of characteristic physical parameters of MCs during a whole solar cycle by analyzing magnetograms from 2010 to 2021 observed by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO). We discover that there are differences between large- and small-scale MCs in diffenent phases of the solar cycle. By analyzing the distributions of the magnetic flux, area, and magnetic energy of MCs, we find that the small-scale MCs obey a power-law distribution, and that the power indices vary very little with the phases of the solar cycle. However, for the large-scale MCs, although they also obey the power-law distribution, the power indices are clearly modulated by the different phases of the solar cycle. We also investigate the relation between the maximum magnetic field strength (Bmax) and the area of MCs (S) and find the same property. The relation for the large-scale MCs is modulated by the phases of the solar cycle, while it is still independent of the phases of the solar cycle for the small-scale MCs. Our results suggest that small- and large-scale MCs could be generated by different physical mechanisms.

A new method for determining the intrinsic resistance energy of H‐atom transfer reaction and structure–activity relationship of H‐donating ability

AbstractThe intrinsic resistance energy ΔG≠XH/X of H‐donor XH in hydrogen atom transfer (HAT) reaction is usually used to evaluate the kinetic H‐donating ability. In this article, a new method for determining ΔG≠XH/X of H‐donor in HAT reaction was proposed by the definition of thermo‐kinetic parameter ΔG≠o (XH) = 1/2[ΔG≠XH/X + ΔGo (XH)]. ΔG≠o (XH) is the characteristic physical parameter of XH to describe the H‐donating ability in a chemical reaction during a certain reaction time, ΔGo (XH) is the bond dissociation free energy. The kinetic studies of HATs between 20 alcohols, ethers, alkanes and amines (XH) with cumyloxyl radical [PhC (CH3)2O•, CumO•] were researched, and ΔGo (XH), ΔG≠XH/X, and ΔG≠o (XH) were used to investigate the H‐donating abilities of the studied substrates in thermodynamics, kinetics, and HAT reaction. The effect of structures of XH on these three parameters, the structure–activity relationship, such as the influence of electronic, steric, polar and stereoelectronic effects of substituents, heteroatoms insertion in cycloalkanes, and cis–trans configurational isomerism on the H‐donating abilities were discussed in detail. This study not only provides a new method for determining ΔG≠XH/X but also systematically studies the factors affecting the H‐donating ability, laying a foundation for the selection, design, and synthesis of more efficient antioxidants.

Quantitative evaluation of H-donating abilities of C(sp3)-H bonds of nitrogen-containing heterocycles in hydrogen atom transfer reaction.

Nitrogen-containing heterocycles are an important class of antioxidants, and their reactivity and selectivity in hydrogen atom reactions have attracted significant interest from chemists. In this work, the kinetics of hydrogen atom transfer reactions from C(sp3)-H bonds of 28 nitrogen-containing heterocycles, oxygen-containing heterocycles, alicyclic amines and cycloalkanes, which were denoted as XH, to the CumO˙ radical, were investigated. The characteristic physical parameter of the substrate, i.e., the thermo-kinetic parameter ΔG≠o(XH), was determined using the kinetic equation [ΔG≠XH/Y = ΔG≠o(XH) + ΔG≠o(Y)] to quantitatively evaluate the H-donating ability of XH. The effects of the substrate structure, substituent attached to the nitrogen atom, and ring size on the H-donating ability were discussed carefully. By comparing the H-donating abilities of cycloalkanes, alicyclic amines and nitrogen/oxygen-containing heterocycles, the influence of the introduction of N, O, or carbonyl groups in the carbon ring on the H-donating ability of C(sp3)-H bond was determined. The electronic, steric and stereo-electronic effects of the groups were also discussed. Herein, we not only quantitatively determined the H-donating ability of the substrate, but also provided ideas for the synthesis of new antioxidants.

Three-dimensional inversion analysis of transient electromagnetic response signals of water-bearing abnormal bodies in tunnels based on numerical characteristic parameters.

The transient electromagnetic inversion of detection signals mainly depends on fast inversion in the half-space state. However, the interpretation results have a certain degree of uncertainty and blindness, so the accuracy and applicability of the three-dimensional full-space inversion need to be investigated. Two different three-dimensional full-space inversions were carried out. First, the numerical characteristic parameters of the response signals were extracted. Then, the correlations between the numerical characteristic parameters and physical parameters of the water-bearing abnormal bodies were judged, and the judgment criterion of the iterative direction was proposed. Finally, the inversion methods of the iterative algorithm and the BP neural network were utilized based on the virtual example samples. The results illustrate that the proposed numerical characteristic parameters can accurately reflect the response curve of the full-space surrounding rock. The difference in the numerical characteristic parameters was used to determine the update direction and correction value. Both inversion methods have their advantages and disadvantages. A single inversion method cannot realize the three-dimensional inversion of the physical parameters of water-bearing abnormal bodies quickly, effectively and intelligently. Therefore, the benefits of different inversion methods need to be considered to comprehensively select a reasonable inversion method. The results can provide essential ideas for the subsequent interpretation of the three-dimensional spatial response signals of water-bearing abnormal bodies.

Comparative case study of two methods to assess the eruptive potential of selected active regions

Solar eruptive events, like flares and coronal mass ejections, are characterized by the rapid release of energy that can give rise to emission of radiation across the entire electromagnetic spectrum and to an abrupt significant increase in the kinetic energy of particles. These energetic phenomena can have important effects on the space weather conditions and therefore it is necessary to understand their origin, in particular, what is the eruptive potential of an active region (AR). In these case studies, we compare two distinct methods that were used in previous works to investigate the variations of some characteristic physical parameters during the pre-flare states of flaring ARs. These methods consider: i) the magnetic flux evolution and magnetic helicity accumulation, and ii) the fractal and multi-fractal properties of flux concentrations in ARs. Our comparative analysisis based on time series of photospheric data obtained bythe Solar Dynamics Observatory between March 2011 and June 2013. We selected two distinct samples of ARs: one is distinguished by the occurrence of more energetic M- and X-class flare events, that may have a rapid effect on not just the near-Earth space, but also on the terrestrial environment; the second is characterized by no-flares or having just a few C- and B-class flares. We foundthat the two tested methods complement each other in their ability to assess the eruptive potentials of ARs and could be employed to identify ARs prone to flaring activity. Based on the presented case study, we suggest that using a combination of different methods may aid to identify more reliably the eruptive potentials of ARs and help to better understand the pre-flare states.

Preparation, spectroscopic, characterizations and biological studies of new charge transfer complexes formed between fluconazole drug with various acceptors

Charge transfer complexes developed during the interaction of Fluconazole drug (FLU) as an electron donor with different types of electron acceptors, including σ-type as iodine (I2), and π-types as 2,3-dinitrosalsylic acid (HDNS), Tetracyanoethylene (TCNE) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The formed complexes were characterized using various techniques as UV–Vis spectra, Thermal analyses, spectrophotometric measurements, 1H NMR and FTIR Spectroscopy. It was found that the stoichiometry of all developed complexes was a 1:1 M ratio between fluconazole and acceptors (I2, HDNS, TCNE and DDQ). The characteristic physical parameters data such as ionization potential (ID), The oscillator strength (ƒ), formation constant (KCT), transition dipole moment (μ), free energy (ΔG), and energy of interaction (ECT) of the formed CT-complexes have also been reported. Eventually, the synthesized complexes were screened for their microbial and antioxidant activities.

The Efficiency of Aqueous Vermiculite Dispersion Fire Extinguishing Agent on Suppressing Three Typical Power Batteries

Abstract Fire extinguishing technology has become an important component for addressing battery safety issues. To accelerate the research of fire extinguishing technology for typical power batteries used in electric vehicles and electric aircraft, in this paper, an aqueous vermiculite dispersion (AVD) fire extinguishing agent is used to suppress the thermal runaway (TR) of batteries in various material systems. Two characteristic physical parameters, namely, temperature and flue gas composition, are analyzed and compared in two scenarios (with and without the fire extinguishing agent). Two typical clean fire extinguishing agents (Novec 1230 and 2-BTP) are also applied in the fire extinguishing experiment. The cooling effect of these two extinguishing agents is compared, demonstrating the advantages of the AVD extinguishing agent in terms of extinguishing and cooling.

Specific Ion Effects on the Colloidal Stability of Layered Double Hydroxide Single-layer Nanosheets

The surface charge properties and aggregation behavior of positively charged Mg-Al-NO3 layered double hydroxide (LDH) single-layer nanosheetsdispersed in water were investigated in the presence of K+salts with different mono-, di-, and trivalent anions, using electrophoresis and dynamic light scattering techniques. An increase in the salt concentration can significantly decrease the effective surface charge density (σeff) of LDHs, leading to the aggregation of nanosheets. The critical coagulation concentration (CCC) or ionic strength (CCIS) of salts for nanosheets significantly decreases with an increase in the valence of anions. Specific ion effects, with a partially reverse Hofmeister series, are observed. Based on the Stern model and the DLVO theory, the relationship of CCC with σeff and the ionic valences of salts (zi) is theoretically analyzed, which can accurately describe the dependence of CCC on the σeff and zi, but cannot explain the origin of specific ion effects. To explore the origin of specific ion effects, a correlation between CCIS and the specific adsorption energy (Esc) of anions within the Stern layer is developed. Especially, an empirical relationship of Esc with the characteristic physical parameters of anions is proposed. Our model can accurately predict the CCISs of at least monovalent anions and divalent anions (CO32- and SO42-), demonstrating that the specific ion effects observed can be attributed to the differences in ionic size, polarizability, and hydration free energy (or the formation capacity of anion-cation pairs) of different anions. This work not only deepens the understanding of specific ion effects on the colloidal stability, but also provides useful information for the potential applications of LDH single-layer nanosheets.

The Storm Time Development of Source Electrons and Chorus Wave Activity During CME‐ and CIR‐Driven Storms

AbstractWhistler mode chorus waves influence the dynamics of the Earth's radiation belts and the inner magnetosphere through gyroresonant wave particle interactions. Chorus waves are generated by anisotropic hot electrons from a few to tens of keV, called source electrons, which have increased access from the nightside plasma sheet to the inner magnetosphere during geomagnetic storms. The primary drivers of geomagnetic storms are coronal mass ejections (CMEs) and corotating interaction regions (CIRs). Through differences in their characteristic physical parameters, they can each impact the nightside plasma sheet differently. Using Van Allen Probes observations, we have conducted a superposed epoch analysis of chorus wave activity and source electron development across all local times between L = 2–6 during 25 CME‐ and 35 CIR‐driven storms. The superposed epoch analysis shows that chorus wave power follows the storm phase‐dependent access of the source electron population. Chorus waves and source electrons are observed on the dawnside during the main phase, when open drift path access via eastward convective drift from the plasma sheet is enhanced. During the recovery phase, chorus waves and source electrons are observed at all magnetic local times with low intensities, exemplifying the formation of a weak symmetric, trapped electron population. A linear theory approximation for wave growth from source electron observations shows that increased wave growth follows the enhanced source electrons during each storm phase. CME and CIR storms display similar behavior and levels of average wave power; however, chorus wave activity reaches lower L‐shells during CME storms on average.

Phase Transition in Cylindrical Ising Nanowires and Nanotubes: Approximation of the Molecular Field Theory

Within the approximation of the molecular field theory, the critical behavior of cylindrical Ising nanowires and nanotubes is studied. The model considered in this work consists of ferromagnetic spins Sc situated in the core of the system and ferromagnetic spins Ss situated on the surface wall; they are interconnected by the exchange coupling J1. The transition temperature Tc for such systems has been calculated as a function of exchange interaction parameters. The influence of the surface exchange interaction and surface coupling on the magnetodynamic behavior of the system have been studied. Some characteristic properties obtained on the phase diagram are related to the ratio of characteristic physical parameters on the surface and core of the abovementioned nanostructures.

Фазовый переход в цилиндрических изинговых нанопроволоках и нанотрубках: приближение теории молекулярного поля

AbstractWithin the approximation of the molecular field theory, the critical behavior of cylindrical Ising nanowires and nanotubes is studied. The model considered in this work consists of ferromagnetic spins S _c situated in the core of the system and ferromagnetic spins S _s situated on the surface wall; they are interconnected by the exchange coupling J _1. The transition temperature T _c for such systems has been calculated as a function of exchange interaction parameters. The influence of the surface exchange interaction and surface coupling on the magnetodynamic behavior of the system have been studied. Some characteristic properties obtained on the phase diagram are related to the ratio of characteristic physical parameters on the surface and core of the abovementioned nanostructures.

Acceleration of the Flow and Increase in the Enthalpy in an Ionized Gas Source by an Electric Field in the Constant Mach Number Regime

The possibility of passing from some characteristic physical parameters (stagnation enthalpy, temperature, pressure, density, etc.) to other preset parameters is investigated within the problem of control over a radial source (vortex) in the regime of the Mach number maintained constant by energy input and an external force (radial electric field in the given case). The variations of the total enthalpy upon the variation of the energy- and force-similarity parameters are demonstrated in the case when the force per unit mass and per unit volume is specified for identical convection current and conduction current, as well as for a conducting current prevailing over the convection current, and vice versa. In the limit of a negligibly small convection current or a conduction current, a transition to analytic solutions is demonstrated for the case of a purely energy action and a purely force action. Analytic dependences of the velocity increment (kinetic energy), temperature, and total enthalpy on the intensities of the external force and energy input, on the Mach number, and on the length of the zone of action are obtained.

A Wellness Mobile Application for Smart Health: Pilot Study Design and Results.

Wellness is one of the main factors crucial in the avoidance of illness or disease. Experience has shown that healthy lifestyle programs are an important strategy to prevent the major shared risk factors for many diseases including cardiovascular diseases, strokes, diabetes, obesity, and hypertension. Within the ambit of the Smart Health 2.0 project, a Wellness App has been developed which has the aim of providing people with something similar to a personal trainer. This Wellness App is able to gather information about the subject, to classify her/him by evaluating some of her/his specific characteristics (physical parameters and lifestyle) and to make personal recommendations to enhance her/his well-being. The application can also give feedback on the effectiveness of the specified characteristics by monitoring their evolution over time, and can provide a positive incentive to stimulate the subject to achieve her/his wellness goals. In this paper, we present a pilot study conducted in Calabria, a region of Italy, aimed at an evaluation of the validity, usability, and navigability of the app, and of people’s level of satisfaction with it. The preliminary results show an average score of 77.16 for usability and of 76.87 for navigability, with an improvement of the Wellness Index with a significance average of 95% and of the Mediterranean Adequacy Index with a significance average of as high as 99%.

Pressure-induced phase-transition and improvement of the microdielectric properties in yttrium-doped SrZrO3

In this study, the effect of pressure on undoped and 5% yttrium-doped SrZrO3 (SZY0 and SZY5) were conducted from the ambient condition to with a diamond anvil cell. The comparison of the high-pressure Raman spectra of SZY0 and SZY5 indicate that SZY0 displays a rigid structure without any structural modification, whereas for SZY5 a structural transition at is revealed. Some characteristic physical parameters such as bulk conductivities, grain boundary conductivities, Warburg diffusion coefficient, transference number and bulk relaxation frequency were determined by the high-pressure impedance spectroscopy data. An obvious discontinuous inflexion point (at ) for SZY5 sample is observable which was also verified the phase-transition of the Raman spectroscopy results. A mixed conduction mechanism for both SZY0 and SZY5 are coexisting for both SZY0 and SZY5 in a wide pressure range. The pressure-induced phase-transition of SZY5 would result in an inversion of conduction mechanism that is characterized by the dominant charge carriers transformation from electron to ion. The Maxwell-Wagner relaxation arising at the interfaces of grain and grain boundary indicates that Y-doping and pressure could make the ions diffusion much easier through the boundaries and finally enhance the dielectric performance of the sample. It is suggested that pressure could be a useful tool to manipulate the microstructure and dielectric performance of polycrystal through altering the grain boundary distribution.

Investigation of Guided-Particle Transport for Noninvasive Healing of Damaged Piping Systems by Use of Electro-Magneto-Mechanical Methods

Summary Virtually all engineering applications involve the use of piping, conduits, and channels. In the petroleum industry, piping systems are extensively used in upstream and downstream processes. These piping systems often carry fluids that are corrosive, which leads to wear, cavitation, and cracking. The replacement of damaged piping systems can be quite expensive, both in terms of capital costs and in operational downtime. This motivates the present research on noninvasive healing of cracked piping systems. In this investigation, we propose to develop computational models for characterizing noninvasive repair strategies involving electromagnetically guided particles. The objective is to heal industrial-piping systems noninvasively, from the exterior of the system, during operation, resulting in no downtime and minimal relative cost. The particle accumulation at a target location is controlled by external electromagnetic/mechanical means. There are two primary effects that play a role for guiding the particles to the solid-fluid-interface/wall: mechanical shear caused by the fluid flow, and an electrical or magnetic force. In this work we develop and study a relationship that characterizes contributions of both, and ascertain how this relationship scales with characteristic physical parameters. Characteristic nondimensional parameters that describe system behavior are derived, and their role in design is illustrated. A detailed, fully 3D discrete-element-simulation framework is presented, and illustrated by use of a model problem of magnetically guided particles. The detailed particle behavior is considered to be regulated by three effects: the field strength, the mass-flow rate, and the wall interactions.

The Characteristic Dissolution and Physical Chemistry Parameter of Synthetic Pyromorphite

The Dissolution of Synthetic Pyromorphite was Studied at 25°C in a Series of Batch Experiments. in Addition, the Aqueous Concentrations from the Batch Dissolution were Used to Calculate the Solubility Product and Free Energy of Formation of Pyromorphite. the Results of the Fourier Transform Infrared Spectroscopy Analyses Indicated that the Synthetic, Microcrystalline Pyromorphite with Apatite Structure Used in the Experiments has Not Changed after Dissolution. the Mean KspValue was Calculated for Pb5(PO4)3Cl of 10-78.31 at 25°C; the Free Energy of Formation ΔGf0[Pb5(PO4)3Cl] was-3756.82kJ/mol.

Studying the physical parameters of a solid state nuclear track detector

Solid state nuclear track detectors (SSNTDs) are widely used to measure various types of ionizing radiation. Thus, studying the physical parameters of SSNTDs, such as the bulk etch rate, the track etching efficiency and detector sensitivity which could affect the registration efficiency, is important. This paper presents a simple technique used to study the dependence of those characteristic physical parameters of SSNTDs on the alpha-particle energy. The detector sensitivity and the alpha track diameter were found to decrease exponentially with increasing alpha-particle energy’s, which implies that the SSNTDs can be used as alpha-particle spectrometers. The bulk etch rates of the LR-115 and the CR-39 detectors were found to be 3.75 ± 0.21 µm h−1 and 1.72 ± 0.14 µm h−1, respectively. Moreover, the calibration coefficients of the LR-115 and the CR-39 detectors, placed in a diffusion cup with a fiberglass filter exposed to radon source inside a 50 L calibration chamber (supplied by Genitron, Germany), were found to be 0.036 ± 0.004 and 0.17 ± 0.03 [α-tracks cm−2 per (Bq m−3 day)], respectively.

Metallicity in the merger Seyfert galaxy NGC 6240

We have calculated the physical conditions throughout the NLR of the merger Seyfert galaxy NGC 6240 by modelling the observed optical and infrared line ratios. We have found that the optical spectra are emitted by clouds photoionised by the power-law radiation flux from the AGN (or AGNs), and heated mainly by the shock accompanying the propagation of the clouds outwards. The infrared line ratios are emitted from clouds ejected from a starburst which photoionises the gas by the black-body radiation flux corresponding to a stellar colour temperature of about 50,000 K. Both the flux from the AGN and the ionization parameters are low. The most characteristic physical parameters are the relatively high shock velocities (>400 km/s) and low preshock densities (about 40-60 cm-3) of the gas. The C/H, N/H, O/H relative abundances are higher than solar by a factor lower or about 1.5. We suggest that those high relative abundances indicate trapping of H into H2 molecules rather than high metallicities. Adopting an initial grain radius of 1 micron, the dust temperatures calculated in the clouds reached by the power-law radiation flux and by the black-body radiation flux are 81 K and 68 K, respectively.

Information processing mechanisms in microtubules at physiological temperature: Model predictions for experimental tests

Both direct and indirect experimental evidence has shown signaling, communication and conductivity in microtubules (MTs). Theoretical models have predicted that MTs can be potentially used for both classical and quantum information processing although controversies arose in regard to physiological temperature effects on these capabilities. In this paper, MTs have been studied using well-established principles of classical statistical physics as applied to information processing, information storage and signal propagation. To investigate the existence of information processing in MTs we used cellular automata (CA) models with neighbor rules based on the electrostatic properties of the molecular structure of tubulin, and both synchronous and asynchronous updating methods. We obtained a phase diagram of possible dynamic behaviors in MTs that depend on the values of characteristic physical parameters that can be experimentally verified.

Relationships between the main parameters of the stationary two-dimensional vortical flows in the planetary atmosphere

In a two-dimensional (2D) model of the planetary atmosphere, the convective flow of vorticity represents a strong non-linearity able to drive the fluid toward a quasi-coherent vortical pattern. This is similar to the highly organized motion generated at relaxation in ideal Euler fluids. The problem of the atmosphere is, however, fundamentally different since now there is an intrinsic length, the Rossby radius. Restricting to a purely hydrodynamic model we have derived a differential equation governing the stationary, 2D, highly organized vortical flows in the planetary atmosphere. After briefly recalling the derivation, we present results of a numerical study of this differential equation. The most characteristic solution shows a strong similarity with the morphology of a tropical cyclone. Quantitative comparisons with observational data are favorable and several relationships were derived connecting the characteristic physical parameters of the tropical cyclone: the radius of the eye-wall, the maximum azimuthal velocity, and the radial extension of the vortex.