Charge Parameters Research Articles

ГЕОДЕЗИЧЕСКИЕ ОРБИТЫ И ЭКСПОНЕНТЫ ЛЯПУНОВА ЧЕРНОЙ ДЫРЫ ФРОЛОВА

Binary black holes maintain unstable orbits at very close distances. In the simplest case of geodesics around a Schwarzschild black hole, the orbits, although unstable, are regular and depend only on the mass. In more complex cases, geodesics may depend on charge, rotation, and other parameters. When perturbed, unstable orbits can become a source of chaos. All unstable orbits, whether regular or chaotic, can be quantified by their Lyapunov exponents. Exponents are important for observations because the phase of gravitational waves can decohere in Lyapunov time. If the time scale of dissipation due to gravitational waves is shorter than the Lyapunov time, the chaos will be damped and practically unobservable. These two time scales can be compared. Lyapunov exponents should be used with caution for several reasons: they are relative and dependent on the coordinate system used, they vary from orbit to orbit, and finally, they can be deceptively diluted by transitional behavior for orbits that pass in and out of unstable regions. The stability of circular geodesic orbits of Frolov's black hole space-time is studied in this work. The influence of the black hole charge and the scale parameter on the stability of geodesic orbits and the Lyapunov exponent is analyzed. It is shown that the region of stable circular orbits increases with the black hole charge Q and the scale parameter ℓ . The largest region of stable circular orbits of Frolov's black hole is reached at Q = M and ℓ = 0.75M.

Charged boson stars revisited

We consider again stationary solutions to the spherically symmetric Einstein–Maxwell–Klein–Gordon system, commonly known as “charged boson stars”, originally studied by Jetzer and Van Der Bij (Phys Lett B 227:341, 1989). We construct families of charged boson stars in the ground state, for different values of the charge parameter q, and different values of the central scalar field. Following Jetzer and Van Der Bij, one can define a critical value for the charge q=q_c that corresponds to the value for which the Coulomb repulsion of the bosonic particles exactly cancels their newtonian gravitational attraction. We confirm the claim made by Pugliese et al. (Phys Rev D, 2013. https://doi.org/10.1103/physrevd.88.024053) that super-critical solutions exist for a limited range of charges above the critical value q>q_c (though we find an even smaller range of q for which this is possible). Our analysis indicates, however, that all such super-critical solutions are gravitationally unbound, and are therefore expected to be unstable. One of the main results of our analysis is the fact that, even though we do find a family of slightly super-critical solutions in the sense that q>q_c, there are no super-critical solutions in the sense that the total charge Q is larger than the total mass M of the system.

Study on Motion Law of Flyer Driven by Micro-Detonator

In order to provide design parameters for the micro-initiation train of the built-in MEMS Safety and Arming Device, and solve the reliable transmission problem of the micro-initiation train due to the small charge amount. Based on the structure of micro initiating explosive sequence, the test device is designed in the paper. The photon Doppler Velocimeter (PDV) was used to test the velocity of flyer driven by the micro-detonator, and the influence of the parameters of the flyer, acceleration chamber and charge on the flyer velocity was obtained. That is, when the flyer thickness is the same, the charge density is high and the flyer velocity is high; and the specific charge parameters need to match the specific flyer thickness, so as to obtain the flyer with high consistency and stable flight, and then achieve the ideal impact initiation effect. For the effect of the flyer velocity, the charge density is greater than the charge height, and the charge height is greater than the diameter of the charge.

Quench dynamics in the one-dimensional mass-imbalanced ionic Hubbard model

Using the time-dependent Lanczos method, we study the nonequilibrium dynamics of the one-dimensional ionic-mass imbalanced Hubbard chain driven by a quantum quench of the on-site Coulomb interaction, where the system is prepared in the ground state of the Hamiltonian with a different Hubbard interaction. The exact diagonalization method (Lanczos algorithm) is adopted to study the zero temperature phase diagram in equilibrium, which is shown to be in good agreement with previous studies using density matrix renormalization group (DMRG). We then study the nonequilibrium quench dynamics of the spin and charge order parameters by fixing the initial and final Coulomb interactions while changing the quenching time protocols. Our study shows that the time evolution of the charge and spin order parameters strongly depend on the quenching time protocols. In particular, the effective temperature of the system will decrease monotonically as the quenching time is increased. By taking the final Coulomb interaction strength to be in the strong coupling regime, we find that the oscillation frequency of the charge order parameter increases monotonically with the Coulomb interaction. By contrast, the frequency of the spin order parameter decreases monotonically with increasing Coulomb interaction. We explain this result using an effective spin model and a two-site Hubbard model in the strong coupling limit. Finally, we take the final Coulomb interaction strength to be in the weak coupling regime and find that the oscillation frequency of both the charge and spin order parameters increases monotonically with decreasing Coulomb interaction. Our study suggests strategies to engineer the relaxation behavior of interacting quantum many-particle systems.

Bidirectional converter based on G2V and V2G operation with time of usage-based tariff analysis and monitoring of charging parameters using IoT

In recent days the high penetration of EVs have an impact on the load demand and it will be increased further. This results in stress on the grid and proper energy management in the charging stations. Recent development also enables smart communication between EV user and charging station. A bidirectional converter-based charging station works on V2G and G2V modes for charging the EV battery and supports the grid or isolated power station when it is needed. In this paper, a brief discussion on the previous development of bidirectional conversion is presented. A bidirectional converter is modeled and simulated in Simulink. In G2V mode, the time of energy-based tariff is used for the cost calculation, and for V2G mode, the system monitoring of the EV charging parameters is presented where the pricing varies from 11.09 Rs. To 16.27 Rs. For an hour of power consumption using a 2.54 kW charger on a probabilistic model. For V2G operation, the inverter voltage and grid voltage in synchronization is presented. An IoT-based system is initiated in Simulink using thing speak. This put the data in the cloud and further the data is monitored and fetched from the cloud using a web application.

An adaptive low-temperature mutual pulse heating method based on multiplexing converters for power-redistributable lithium-ion battery pack

Efficient and low-cost battery heating is particularly significant for recovering the available capacity and power of batteries at low temperatures. This paper proposes an adaptive mutual pulse heating (MPH) method to achieve the on-board heating of batteries, reusing the drive circuitry of batteries as heaters without any extra devices. To this end, a dual cubature Kalman filter-based co-estimator is developed based on an electrothermal model to capture battery state of charge (SOC), core temperature, and equivalent electrical parameters under rapid temperature-rise. The MPH current is updated online by the predicted maximum permissible charge/discharge current and the regulated heating duty ratio, which are formulated by considering multiple constraints and fuzzy feedback mechanisms. Experimental results show that with the MPH current profiles, batteries can be heated from −20 °C to 0 °C within 199.8 s, only consuming 5.99 % of cell capacity. Through capacity tests, increment capacity, and differential voltage analysis, there is no obvious battery degradation after 580 repeated heating cycles. Moreover, the preset heating period of less than 2 s has little impact on the heating duration, while when it is larger than 2 s, the heating duration increases with the heating period due to the inefficient heating.

Physiologically Based Pharmacokinetic Modeling to Characterize the Effect of Molecular Charge on Whole-Body Disposition of Monoclonal Antibodies.

Motivated by a series of work demonstrating the effect of molecular charge on antibody pharmacokinetics (PK), physiological-based pharmacokinetic (PBPK) models are emerging that relate in silico calculated charge or in vitro measures of polyspecificity to antibody PK parameters. However, only plasma data has been used for model development in these studies, leading to unvalidated assumptions. Here, we present an extended platform PBPK model for antibodies that incorporate charge-dependent endothelial cell pinocytosis rate and nonspecific off-target binding in the interstitial space and on circulating blood cells, to simultaneously characterize whole-body disposition of three antibody charge variants. Predictive potential of various charge metrics was also explored, and the difference between positive charge patches and negative charge patches (i.e., PPC-PNC) was used as the charge parameter to establish quantitative relationships with nonspecific binding affinities and endothelial cell uptake rate. Whole-body disposition of these charge variants was captured well by the model, with less than 2-fold predictive error in area under the curve of most plasma and tissue PK data. The model also predicted that with greater positive charge, nonspecific binding was more substantial, and pinocytosis rate increased especially in brain, heart, kidney, liver, lung, and spleen, but remained unchanged in adipose, bone, muscle, and skin. The presented PBPK model contributes to our understanding of the mechanisms governing the disposition of charged antibodies and can be used as a platform to guide charge engineering based on desired plasma and tissue exposures.

Express-diagnostics of the properties of ЫРЫ materials using chrono-topographic analysis of thermal vision data

Subject of research: the article is devoted to the development of a methodology for express diagnostics of material properties based on the measurement of macrokinetic parameters of the SHS process.
 Purpose of research: plotting the dependence of the microhardness of SHS products on the propagation velocity of the SHS wave and its temperature.
 Methods and objects of research: the research objects were the SHS process in the Ni-Al system and the reaction products; To measure the propagation velocity of a high-temperature synthesis wave, an original method of chrono-topographic analysis of thermal imaging data was used; temperature control was carried out by an original method of spectral-brightness pyrometry. The study of the microhardness of experimental samples was carried out using an FM-800 microhardness tester.
 Main results of research: in the course of experimental studies, it was shown that the error in determining the propagation velocity of the SHS wave by the method of chrono-topographic analysis of thermal imaging data is 0.1 %, and the error in temperature measurement by the method of spectral-brightness pyrometry is estimated at 0.5 %. It is concluded that the main factor influencing the total error in the SHS wave propagation velocity in the experiment is the inaccuracy of setting the charge parameters for a set of samples. The absolute value of the total error was 3.2 %. A diagnostic trajectory has been constructed that makes it possible, based on the SHS propagation rate and reaction temperature, to evaluate the microhardness of the product and draw a conclusion about the quality of charge preparation for the production of a material with desired properties.

Characteristic Substituent Effect Model for the Infrared Intensities of the X2CY (X = H, F, Cl, Br; Y = O, S) Molecules.

Many years ago, the gas-phase infrared fundamental intensities of Cl2CS were determined within experimental error from the experimental intensities and frequencies of F2CO, Cl2CO, and F2CS. An additive characteristic substituent shift relationship between atomic polar tensors of these molecules formed the basis for these calculations. Here, QCISD/cc-pVTZ-level Quantum Theory of Atoms In Molecules (QTAIM) individual charge, charge transfer, and polarization contributions to these atomic polar tensor elements are shown to obey the same basic relationship for the extended X2CY (Y = O, S; X = H, F, Cl, Br) family of molecules. QTAIM charge and polarization contributions, as well as the total equilibrium dipole moments of the X2CY molecules, also follow this characteristic substituent shift model. The root-mean-sqaure error for the 231 estimates of these parameters is 0.14 e or only about 1% of the total 10 e range of the Atomic Polar Tensor (APT) contributions determined from the wave functions. The substituent effect APT contribution estimates were used to calculate the infrared intensities of the X2CY molecules. Although one serious discrepancy was observed for one of the CH stretching vibrations of H2CS, accurate values were within 45 km·mol-1 or about 7% of the 656 km·mol-1 intensity range predicted by the QCISD/cc-pVTZ wave functions. Hirshfeld charge, charge transfer, and polarization contributions are also found to follow this model, although their charge parameters do not follow electronegativity expectations.

Analysis of influencing factors of projectile velocity in low-speed sub-caliber launch

In the ballistic performance testing field of human body protection and armor protection, aiming at the demand of sub-caliber launch of assembled ammunition with the mass range of 4 ~ 16 g and velocity range of 280 ~ 500 m/s, establish the mathematical model of interior ballistic with MATLAB, calculate the interior ballistic state, and analyze the influence law of the change of charge parameters and projectile mass with the launch velocity. The results show that the propellant does not burn completely as the small-mass projectile leaves the barrel; under the same chamber volume, the projectile velocity increases with the charge mass, and this trend gradually decrease with the increasing chamber volume; under the same charge mass, the projectile velocity decreases with the increase of chamber volume, and this trend gradually increases with the increasing charge mass; under the same projectile mass, the projectile velocity decreases with the increase of charge mass, and this trend remains basically unchanged as the projectile mass increases. The analysis and calculation results are verified by the firing test. The results show that although there are differences between the actual charge quality and the calculation results, the obtained velocity changing trend is basically consistent with the trend revealed by the calculation results. The analysis and verification results can provide guidance for understanding the influencing factors affecting the launch of sub-caliber low-speed projectile, and have positive significance for improving the ballistic performance testing ability and promoting the development of the protection industry.

Crosslinked Chitosan Nanoparticles with Muco-Adhesive Potential for Intranasal Delivery Applications.

Intranasal drug delivery is convenient and provides a high bioavailability but requires the use of mucoadhesive nanocarriers. Chitosan is a well-established polymer for mucoadhesive applications but can suffer from poor cytocompatibility and stability upon administration. In this work, we present a method to obtain stable and cytocompatible crosslinked chitosan nanoparticles. We used 2,6-pyridinedicarboxylic acid as a biocompatible crosslinker and compared the obtained particles with those prepared by ionotropic gelation using sodium tripolyphosphate. Nanoparticles were tested to evaluate the size and the surface charge, as well as their stability in storage conditions (4 °C), at the nasal cavity temperature (32 °C), and at the body temperature (37 °C). The crosslinked chitosan nanoparticles showed a size around 150 nm and a surface charge of 10.3 mV ± 0.9 mV, both compatible with the intranasal drug administration. Size and surface charge parameters did not significantly vary over time, indicating the good stability of these nanoparticles. We finally tested their cytocompatibility in vitro using SHSY5Y human neuroblastoma and RPMI 2650 human nasal epithelial cells, with positive results. In conclusion, the proposed synthetic system shows an interesting potential as a drug carrier for intranasal delivery.

Gravitational Lensing of Acoustic Charged Black Holes

We study the gravitational lensing of acoustic charged black holes in strong and weak field limit approximations. For this purpose, we first numerically obtain the deflection limit coefficients and deflection angle in the strong field limit. We observe that the strong deflection angle α D increases with increasing magnitude of the charged parameter Q and that the strong deflection angle α D of an acoustic charged black hole with tuning parameter ξ = 4 is greater than that of a standard Reissner–Nordström black hole (ξ = 0). We also study the astrophysical consequences via strong gravitational lensing by taking the example of various supermassive black holes in the center of several galaxies and observe that the acoustic charged black hole could be quantitatively distinguished from standard Reissner–Nordström (ξ = 0) and standard Schwarzschild (ξ = 0, Q = 0) black holes. Furthermore, by using the Gauss–Bonnet theorem, we derive the weak deflection angle in the background of an acoustic charged black hole in the curved spacetime. We find that, for fixed values of the charged parameter Q and the tuning parameter (ξ = 0 or 4), the weak deflection angle σ D decreases with the impact parameter b. We also observe that the weak deflection angle σ D decreases with increasing magnitude of the charged parameter Q for a fixed value of the tuning parameter (ξ = 0 or 4). Our results suggest that the observational test for an acoustic charged black hole is indeed feasible, and it is generalized to the cases of acoustic Schwarzschild (Q = 0), standard Reissner–Nordström (ξ = 0), and standard Schwarzschild (ξ = 0, Q = 0) black holes.

ELECTRIC VEHICLE ONBOARD CHARGING VIA HARRIS HAWKS OPTIMIZATION-BASED FRACTIONAL-ORDER SLIDING MODE CONTROLLER

Electric vehicles (EVs) have become more popular due to their excellent efficiency and pollution-free benefits. The technology requirements for onboard chargers are increasing as the number of electric vehicles increases. This research proposes a fractional-order sliding mode controller (FOSMC) for power converters to improve the efficiency of the onboard battery charger. The Harris Hawks optimization (HHO) algorithm chooses the FOSMC parameters. Independent controllers are used in a two-stage charging scheme. The grid-side ac–dc converter helps to smooth the current and voltage in the dc bus while reducing the harmonic frequency in the grid. A dc-dc converter with a constant current–constant voltage curve regulates the charging parameters of the battery on the battery side. Experiments show that HHO-based FOSMC improves the overall dynamic response of the onboard battery charger. Moreover, the proposed method performs with a current total harmonic distortion (THD) of less than 2 %. The proposed method improves 98% efficiency than existing methods such as SSA-PID and SSA- FOAFPIDF controllers.

Quasinormal modes of extended gravity black holes through higher order WKB method

Black hole’s quasinormal frequencies are basically the complex numbers which provide information about the relaxation of perturbations and depend on the characteristics of the spacetime and types of perturbations. In this paper, we evaluate the spectrum of the quasinormal modes of Hayward black hole in Einstein–Gauss–Bonnet gravity, Hayward black hole in anti-de Sitter space (AdS) spacetime, and 4-dimensional black hole in Einstein–Lovelock gravity. By utilizing the 6th-order WKB resonance technique, we examine the quasinormal modes frequencies [Formula: see text] by shifting the charge parameter [Formula: see text] (it is also identified with the cosmological constant), circular harmonic index [Formula: see text], and mass of scalar field [Formula: see text]. We observe that 6th-order WKB method gives quite high accuracy when the multipole number [Formula: see text] is larger than the overtone [Formula: see text]. We observe that real and imaginary components of the quasinormal modes are not linear functions similar to Reisnner–Nordström-AdS. For large values of charge, quasinormal ringing becomes slower to settle down to thermal equilibrium and hence the frequency of the oscillation becomes smaller.

A viable relativistic charged model of super-dense star LMC X-4

In this work, we present an exact interior solution to a physically acceptable Einstein–Maxwell equation system, assuming a static and spherically symmetric spacetime with a distribution of matter from a perfect charged fluid to represent a generalization of a model for a perfect chargeless fluid. The charge parameter modifies the mass function, its compactness rate and the comportment of the speed of sound. The behavior analysis of the functions of density, pressure and charge shows that the solution is applicable for the description of relativistic compact stars. In particular, we analyze the behavior of these functions for the values of observed mass [Formula: see text] and the theoretical radius interval estimated previously [Formula: see text][Formula: see text]km from the star LMC X-4. Thus, the biggest charge value of maximum charge [Formula: see text]C occurs for the maximum compactness [Formula: see text].

Shadow of the 5D Reissner–Nordström AdS black hole

In this paper, we discuss the shadow cast by the charged Reissner–Nordström (RN) anti-de Sitter (AdS) black hole. With the help of the Killing equation and Hamilton–Jacobi equation, we calculate the geodesic equations for null particles. With the help of geodesics of null particle, we then determine the celestial coordinates ([Formula: see text], [Formula: see text]) and the shadow radius of the RN AdS black hole. We present a graphical analysis of the black hole shadow and find that shadow is a perfectly dark circle. The impacts of charge and cosmological constant of the RN AdS black hole on the radius of shadow are also presented. In this connection, the radius of the shadow is a decreasing function of the charge. Furthermore, we study the effects of plasma medium on the RN AdS black hole shadow. Here, we find that radius of circular shadow increases with increasing plasma parameter. We study the shadow radius for the constrained values of charge and cosmological constant from the [Formula: see text] and [Formula: see text] black holes. In addition, we also discuss the energy emission the rate of RN black hole. The effects of parameters like charge, cosmological constant and plasma parameter on energy emission rate are analyzed graphically.

Evolution of gravitational radiation from black hole under the influence of Einstein–Gauss–Bonnet gravity

In our work, we compute the 4-dimensional Einstein–Gauss–Bonnet gravity black hole solution by applying the Newman–Janis approach and also examine the Hawking temperature. The generalized uncertainty principle (GUP) is applied to compute the Lagrangian field equation and by using the semi-classical phenomenon, we analyze the modified Hawking temperature. By taking into account the graphical analysis, we check the stable conditions of the black hole with the influence of rotation parameter, charged parameter and quantum gravity parameter. Furthermore, we compute the logarithmic entropy corrections in the background of corrected temperature and standard entropy for corresponding black hole. We study the behavior of different thermodynamics quantities like Helmholtz free energy, internal energy, Gibbs free energy and heat capacity under these fluctuations. In our analysis, we note that these corrections enhance the stability of this system, so, under the effects of these corrections, the considered geometry becomes more stable.

Investigation of the radiative decay $b \to s \gamma$ in the 3-4-1-1 model

We investigate the branching ratio of the radiative decay $b\to s \gamma$ in the 3-4-1-1 model with arbitrary charge parameters $p,q$. We show that the new Higgs bosons, $\mathcal{H}_1^\pm$, and the new gauge bosons $W_{13,14 }^{\pm p,q}, Z_{2,3}$ contribute to this decay. Of these sources, the main contribution comes from the interaction of the singly-charged Higgs boson. If the spontaneous breaking of the enlarged gauge group symmetry down to the electroweak group is around a few TeVs, the predictions for the branching ratio Br($b\to s \gamma$) and meson mixing are both consistent with experimental constraints.

Radii of spherical photon orbits around Kerr-Newman black holes

The spherical photon orbits around a black hole with constant radii are particular important in astrophysical observations of the black hole. In this paper, the equatorial and non-equatorial spherical photon orbits around Kerr-Newman black holes are studied. The radii of these orbits satisfy a sextic polynomial equation with three parameters, the rotation parameter $u$, charge parameter $w$ and effective inclination angle $v$. It is found that there are two polar orbits and one is inside and the other is outside the event horizon. For orbits in the equatorial plane around an extremal Kerr-Newman black hole , we find three positive solutions to the equation and provide analytical formulas for the radii of the three orbits. It is also found that a critical value of rotation parameter $u=\frac{1}{4}$ exists, above which only one retrograde orbit exists outside the event horizon and below which two orbits (one prograde and one retrograde) exist outside the event horizon. For orbits in the equatorial plane of a nonextremal Kerr-Newman black hole, there are four or two positive solutions. A critical curve in $(u,w)$-plane which separates the regions is also found. On this critical curve, the explicit formulas of three solutions are found. There always exist two equatorial photon orbits outside the event horizon in this case. For orbits between the above two special planes, there are four or two solutions to the general sextic equation. When the black hole is extremal, it is found that there is a critical inclination angle $v_{cr}$, below which only one orbit exists and above which two orbits exist outside the event horizon for a rapidly rotating black hole $u>\frac{1}{4}$. At this critical inclination angle, exact formula for the radii is also derived. Finally, a critical surface in parameter space of ($u,w,v$) is shown that separates regions with four or two solutions.

A general phase-modulating solution for generating optical array with arbitrary dimensions via mapping space

It is of great significance to control the energy, location, topological charge, and other parameters of each beam in three-dimensional space. Thus, optical array is proposed and widely used in processing, communication, microscopy, storage, and other fields. However, the current methods to generate optical array are only effective in specific scenarios. In this work, we present an efficient and general method, which separates iterative calculation and parameter selection by introducing a special mapping space, allowing the generation of optical arrays with arbitrary dimensions, optional parameters, and any energy ratios. This method is compared with traditional methods from both simulation and experiment and is superior in diffraction efficiency, focus amount, and calculation speed. Additionally, a five-dimensional optical array with specially designed parameters is produced to show the versatility for different parameters. It shows advantages in beam shaping and parallelization and will be instrumental for applications in information storage, industrial processing, and three-dimensional imaging.