Effect Of Strong Magnetic Field Research Articles

Analysis of Calophyllum Inophyllum Biodiesel Combustion with Variations of Magnetic Field Strength

The problems facing the world today are limited fossil fuels and increasing global warming due to fuel emissions. Therefore, there is a need to transition from fossil energy to alternative energy that is environmentally friendly and renewable. Biodiesel is an alternative material that can be used as a substitute for diesel fuel. This research aims to improve the combustion quality of calophyllum inophyllum biodiesel using the magnetic field influence method. The combustion test method uses a Bunsen burner and variations in magnetic strength of 4000 gauss, 8000 gauss and 12000 gauss are given. The equivalent ratios used in combustion analysis are 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1:1.1, and 1:1.2. The fuel and air flowing in the Bunsen pipe are heated to a constant temperature of 250°C for the fuel evaporation process. Then the resulting flame was analyzed for its combustion characteristics with RGB color variables, laminar burning velocity, and flame height. The research results show that the stronger the magnetic field effect, the more optimal the combustion quality will be. This is indicated by the increasingly strong magnetic field effect exerted on the flame, causing the red color intensity to decrease, the laminar burning velocity to increase, and the flame height to decrease. This is because the magnetic field can influence the movement of O2 molecules and cause a change in the orientation of the hydrocarbon from para to ortho. As a result, diffusion combustion becomes minimal and the combustion reaction becomes faster.

Diamagnetic corrections to low-excited electronic states of light molecular systems

Compact astrophysical objects like white dwarfs and neutron stars generate very strong magnetic fields. In their atmosphere, accretion disks, and the interstellar medium surrounding them, the predominant matter consists of hydrogen, helium and few-particle atoms and molecules. In this work, we have studied the effects of strong magnetic fields on light atomic and molecular systems like hydrogen molecular ions and antiprotonic helium. The full energy of the investigated systems is calculated in the Born-Oppenheimer approximation for a few low-lying electronic states. We investigate the case where the leading effect comes from the quadratic magnetic field term in the interaction Hamiltonian. The electronic energies and wavefunctions are computed in spheroidal coordinates by a finite difference method on a nonequidistant grid. The diamagnetic contributions to the total energy for an arbitrary value of the magnetic field strength are also calculated in perturbation theory. Then they are compared with the exact results, and where possible - with previous calculations. The electronic energy terms could be used for precise computations of the spectral lines of the hydrogen molecular ion and antiprotonic helium. This will allow searching for objects, like neutron stars and white dwarfs with strong magnetic fields, containing such molecular systems in their atmospheres or accretion discs. When the effects from the approximations are taken into account, the tabulated results presented in this work could also find an application in studies for much weaker magnetic field strengths existing in laboratory environments.

Equation of state and anisotropy of pressure of magnetars

AbstractMagnetars are the neutron stars with the highest magnetic fields up to 1015–1016 G. It has been proposed that they are also responsible for a variety of extra‐galactic phenomena, ranging from giant flares in nearby galaxies to fast radio bursts. Utilizing a relativistic mean field model and a variable magnetic field configuration, we investigate the effects of strong magnetic fields on the equation of state and anisotropy of pressure of magnetars. It is found that the mass and radius of low‐mass magnetars are weakly enhanced under the action of the strong magnetic field, and the anisotropy of pressure can be ignored. Unlike other previous investigations, the magnetic field is unable to violate the mass limit of the neutron stars.

Symmetry and reactivity of π-systems in electric and magnetic fields: a perspective from conceptual DFT.

The extension of conceptual density-functional theory (conceptual DFT) to include external electromagnetic fields in chemical systems is utilised to investigate the effects of strong magnetic fields on the electronic charge distribution and its consequences on the reactivity of π-systems. Formaldehyde, H2CO, is considered as a prototypical example and current-density-functional theory (current-DFT) calculations are used to evaluate the electric dipole moment together with two principal local conceptual DFT descriptors, the electron density and the Fukui functions, which provide insight into how H2CO behaves chemically in a magnetic field. In particular, the symmetry properties of these quantities are analysed on the basis of group, representation, and corepresentation theories using a recently developed automatic program for symbolic symmetry analysis, QSYM2. This allows us to leverage the simple symmetry constraints on the macroscopic electric dipole moment components to make profound predictions on the more nuanced symmetry transformation properties of the microscopic frontier molecular orbitals (MOs), electron densities, and Fukui functions. This is especially useful for complex-valued MOs in magnetic fields whose detailed symmetry analyses lead us to define the new concepts of modular and phasal symmetry breaking. Through these concepts, the deep connection between the vanishing constraints on the electric dipole moment components and the symmetry of electron densities and Fukui functions can be formalised, and the inability of the magnetic field in all three principal orientations considered to induce asymmetry with respect to the molecular plane of H2CO can be understood from a molecular perspective. Furthermore, the detailed forms of the Fukui functions reveal a remarkable reversal in the direction of the dipole moment along the CO bond in the presence of a parallel or perpendicular magnetic field, the origin of which can be attributed to the mixing between the frontier MOs due to their subduced symmetries in magnetic fields. The findings in this work are also discussed in the wider context of a long-standing debate on the possibility to create enantioselectivity by external fields.

Temperature and strong magnetic field effects in dense matter

Temperature and strong magnetic field effects in dense matter

Linear global stability of a flow past a sphere under a streamwise magnetic field

The global linear stability analysis for the magnetohydrodynamic liquid metal flow past an insulated sphere subjected to a constant streamwise magnetic field is investigated in the range of the Reynolds number $Re\leq 400$ and the interaction number $N\leq 40$ coupled with direct numerical simulations, where $N$ stands for strength of the electromagnetic force. The stability of the steady axisymmetric base flow to independent time-azimuthal modes is discussed. Five critical curves associated with various wake transitions are obtained in the $\{Re, N\}$ phase diagram. These critical curves reveal the stabilising effect of a weak magnetic field, the destabilising effect of a strong magnetic field and re-stabilising effect of a much stronger magnetic field. To explore the impact of the magnetic field on flow instability, a sensitivity analysis utilizing an adjoint method is performed for the first regular bifurcation. Sensitivity functions of growth rate to base-flow modifications and Lorentz force are defined to identify the region that has the most significant influence on flow instability, such as the recirculation region responsible for the stabilising effect at a weak magnetic field and the shear layer region responsible for the destabilising effect at a strong magnetic field. Furthermore, a competition between the stabilising and shear destabilising effects of the magnetic field is discussed. This analysis provides valuable insights into the non-monotonic effect of the magnetic field on flow instability.

Magnetoconvection in a horizontal duct flow — A parametric study

Mixed convection flows in a horizontal duct with a heated bottom wall and a magnetic field imposed in the horizontal transverse direction are analyzed numerically using the two-dimensional approximation valid in the limit of strong magnetic field effect. A parametric study is carried out to understand the effect of the Reynolds, Hartmann, and Grashof numbers on the flow. The focus is on the convection instability of the quasi-two-dimensional states that occur under strong magnetic fields. The range of existence of such states is established. Linear stability analysis and simulations of nonlinear regimes demonstrate that high-amplitude low-frequency magnetoconvective fluctuations are generated by the instability in a broad range of parameters and that their strength is not diminished as the magnetic field becomes stronger. Good agreement with experimental data is found.

Impact ionization of highly charged ion-atom collisions considering strong magnetic field and plasma screening effect

The impact ionization process of target is a crucial issue in the study of Heavy Ion Beam (HIB)-driven Magnetized Inertial Fusion (MIF). The collision systems between heavy projectile ions (Xeq+, Biq+, Uq+) and light target atoms/ions (H, D, T, 3He, 3He+, 11B) are promising candidate reactions for fusion power. In this study, the impact ionization process in medium-energy (ranges 1–100 MeV/u) is studied numerically based on the extended Classical-trajectory Monte Carlo (CTMC) method, where the effects of projectile charge state, external magnetic field and plasma screening on the single ionization process are considered. The results show that the existed external magnetic field results in a decrease of the yield of ionized high-energy electrons, whereas the yield of backward emitted electrons is increased. The effect of plasma screening on the ionization process is shown to be determined by the competition between the screening charge of projectile ion and the target nucleus. Thus, a significant decrease of ionization cross section is found in the low energy region since the screening charge of projectile ion is dominant. However, the screening effect of target nucleus charge is dominant in high energy region, where a significant increase of ionization cross sections is found.

Constraints on star formation in Orion A from Gaia

ABSTRACT We develop statistical methods within a Bayesian framework to infer the star formation history from photometric surveys of pre-main-sequence populations. Our procedures include correcting for biases due to extinction in magnitude-limited surveys, and using distributions from subsets of stars with individual extinction measurements. We also make modest corrections for unresolved binaries. We apply our methods to samples of populations with Gaia photometry in the Orion A molecular cloud. Using two well-established sets of evolutionary tracks, we find that, although our sample is incomplete at youngest ages due to extinction, star formation has proceeded in Orion A at a relatively constant rate between ages of about 0.3 and 5 Myr, in contrast to other studies suggesting multiple epochs of star formation. Similar results are obtained for a set of tracks that attempt to take the effects of strong magnetic fields into account. We also find no evidence for a well-constrained ‘birthline’ that would result from low-mass stars appearing first along the deuterium-burning main sequence, especially using the magnetic evolutionary tracks. While our methods have been developed to deal with Gaia data, they may be useful for analysing other photometric surveys of star-forming regions.

Comparison of Effect of Strong Magnetic Field on Microstructure and Photo Absorption Performance of CaTiO3 and TiO2

The study found that after strong magnetic field treatment of CaTiO3 along with the increase of interplanar distance and lattice constant, the band gap was reduced and the photo absorption performance was improved. The higher the applied magnetic field strength, the smaller the rutile TiO2 lattice is, and the change of magnetic field on the lattice constant is nonlinear. The change before and after 6T is significant, while after the 9T treatment, the light absorption capacity in the violet region can be improved and the effect of strong magnetic field rutile lattice can be largely eliminated by simple heat treatment.

ON α- MARTENSITE NUCLEATION IN STEELS AND IRON ALLOYS

Purpose. To investigate the possibility of martensite nucleation on magnetic (concentration) inhomogeneities of chrome-nickel steels austenite.
 Research methods. Generalization of experimental and theoretical studies of the strong magnetic field effect on the martensitic transformation in steels and iron alloys, taking into account the magnetic state of austenite
 Results. The analysis of the magnetic state of austenite and the abnormally large strong magnetic field effect on the martensite point displacement in 40X2H20 steel indicates that the transformation of austenite into martensite in it is a “magnetic first order phase transition”.
 Scientific novelty. Some features of the martensitic transformation in steels and iron alloys are explained. It is assumed that martensite during the “magnetic γ→α- transition” originates on magnetic inhomogeneities with a disoriented magnetic structure of the spin glass type. Forced magnetostriction during paraprocess and spontaneous magnetostriction below the Curie point lead to the emergence of collinear ferromagnetism with a change in the coordination number from 12 to 8. High all-round pressure leads to the occurrence of collinear antiferromagnetism and the γ-phase stabilization. In paramagnetic austenite the nucleation of α-martensite occurs on dislocation nuclei, the sizes of which have the same order of magnitude (by volume) as the magnetic inhomogeneities in the Fe-Ni system.
 Practical value. The results obtained in the work expand the concept of martensitic transformation in steels and provide grounds for explaining some kinetic features in them.

Particle simulation of the strong magnetic field effect on dust particle charging process

A particle-in-cell simulation is modeled and run on a dusty plasma to determine the effect of the magnetic field on the process of dust-particle charging through electron–ion plasma. The electric field is solved through the Poisson equation, and the electron-neutral elastic scattering, excitation, and ionization processes are modeled through Monte Carlo collision method. The effects observed from the initial density of the plasma, the initial temperature of the electrons, and the changing magnetic field are included in this simulation model. In the dust particle charging process, saturation time and saturation charge are compared. An increase in the magnetic field does not reduce time to reach the saturation state. Determining the magnetic field boundaries which depend on the physical properties of the plasma, can be contributive in some areas of dusty(complex) plasma. The applications of the results obtained here for fusion plasma conditions and space and laboratory plasmas are discussed. The results here can be applied in future simulation models with a focus on the dust particle movement and their effect on plasma, leading to the modeling of different astrophysical plasmas thorough laboratory experiments.

Magnetic-field Induced Deformation in Hybrid Stars

The effects of strong magnetic fields on the deconfinement phase transition expected to take place in the interior of massive neutron stars are studied in detail for the first time. For hadronic matter, the very general density-dependent relativistic mean field model is employed, while the simple, but effective vector-enhanced bag model is used to study quark matter. Magnetic-field effects are incorporated into the matter equation of state and in the general-relativity solutions, which also satisfy Maxwell’s equations. We find that for large values of magnetic dipole moment, the maximum mass, canonical mass radius, and dimensionless tidal deformability obtained for stars using spherically symmetric Tolman–Oppenheimer–Volkoff (TOV) equations and axisymmetric solutions attained through the LORENE library differ considerably. The deviations depend on the stiffness of the equation of state and on the star mass being analyzed. This points to the fact that, unlike what was assumed previously in the literature, magnetic field thresholds for the approximation of isotropic stars and the acceptable use of TOV equations depend on the matter composition and interactions.

Strong Magnetic Field Annealing for Improved Phthalocyanine Organic Thin-Film Transistors.

Thin-film microstructure, morphology, and polymorphism can be controlled and optimized to improve the performance of carbon-based electronics. Thermal or solvent vapor annealing are common post-deposition processing techniques; however, it can be difficult to control or destructive to the active layer or substrates. Here, the use of a static, strong magnetic field (SMF) as a non-destructive process for the improvement of phthalocyanine (Pc) thin-film microstructure, increasing organic thin-film transistor (OTFTs) mobility by twofold, is demonstrated. Grazing incident wide-angle X-ray scattering (GIWAXS), X-ray diffraction (XRD), and atomic force microscopy (AFM) elucidate the effect of SMF on both para- and diamagnetic Pc thin-films when subjected to a magnetic field. ASMF is found to increase the concentration of oxygen-induced radical species within the Pc thin-film, lending a paramagnetic character to ordinarily diamagnetic metal-free Pc and resulting in magnetic field induced changes to its thin-film microstructures. In a nitrogen environment, without competing degradation effects of molecular oxygen, SMF processing is found to favorably improve charge transport characteristics and increase OTFT mobility. Thus, post-deposition thin-film annealing with a magnetic field is presented as an alternative and promising technique for future thin-film engineering applications.

Expanding fireball in magnetar bursts and fast radio bursts

ABSTRACT A fireball of radiation plasma created near the surface of a neutron star (NS) expands under its own pressure along magnetic field lines, and produces photon emission and relativistic matter outflow. We comprehensively classify the expanding fireball evolution into five cases, and obtain the photospheric luminosity and the kinetic energy of the outflow, taking into account key processes; lateral diffusion of photons escaping from a magnetic flux tube, effects of strong magnetic field, baryon loading from the NS surface, and radiative acceleration via cyclotron resonant scattering, some of which have not been considered in the context of gamma-ray bursts. Applying our model to magnetar bursts with fast radio bursts (FRBs), in particular the X-ray short bursts from SGR 1935+2154 associated with the Galactic FRB 20200428A, we show that the burst radiation can accelerate the outflow to high-Lorentz factor with sufficient energy to power FRBs.

Evolution of Urca Pairs in the Crusts of Highly Magnetized Neutron Stars

We report on the effects of strong magnetic fields on neutrino emission in the modified Urca process. We show that the effect of Landau levels on the various Urca pairs affects the neutrino emission spectrum and leads to an angular asymmetry in the neutrino emission. For low magnetic fields, the Landau levels have almost no effect on the cooling. However, as the field strength increases, the electron chemical potential increases resulting in a lower density at which Urca pairs can exist. For intermediate field strength, there is an interesting interference between the Landau level distribution and the Fermi distribution. For high enough field strength, the entire electron energy spectrum is eventually confined to a single Landau level producing dramatic spikes in the emission spectrum.

Molecular charge distributions in strong magnetic fields: a conceptual and current DFT study

The effect of strong magnetic fields on the charge distribution of the hydrogen halides, HO and NH is studied in the context of recent extensions of conceptual density functional theory to include additional variables such as external magnetic fields. From conceptual DFT studies on atoms in strong magnetic fields, changes in electronegativity and hardness suggest a reversal in polarity for all three diatomic molecules under these conditions. This is confirmed by current DFT calculations on these molecules in the presence of strong magnetic fields parallel and perpendicular to the internuclear axis; in the former case the electric dipole moment only undergoes small changes whereas in the latter case it changes significantly and also reverses in direction, doing so at lower field strength if the geometry is relaxed. The absence of a dipole moment induced perpendicular to the bond when a magnetic field is applied in this direction is understood by consideration of time reversal symmetry. Similar results are obtained for HO and NH; this may be an important point to consider in future studies focused on the unresolved question on the behaviour of hydrogen bonding in applied magnetic fields.

The Effect of Strong Magnetic Field and Engine Rotation on Fuel Consumption and Exhaust Gas Emissions for Gasoline Engines

An Iincreasing number of means of transportation in various cities causes air pollution. There have been many studies to reduce air pollution due to motorized vehicles. One of them relates to the fuel line. The purpose of this study was to determine the relationship between the strength of the magnetic field in the fuel line on fuel consumption and exhaust emissions. The research method uses a pure experimental method. The independent variables are magnetic field strength (51, 102, 152, 202, and 249 gauss) in the fuel line and engine speed (1500 rpm, 2500 rpm, 3500 rpm and 4500 rpm). The dependent variable is fuel consumption (ltr/hour) and exhaust emissions. Test was carried Fourier transform infrared out to determine the chemical compound group of the fuel. The results showed that the highest concentration of transmittance at a wavelength of 2850 cm־¹ - 2970 cm־¹ was 77.75% with a magnetic field strength of 249 gauss, when compared to standard conditions it was 33.05%. At a strong magnetic field of 249 gauss with a rotation of 2500 rpm, it can save fuel consumption of 0.2 liters/hour. In addition, it can also reduce the level of exhaust gas O₂ by 4.16% (3500 rpm), CO gas by 1.29% (2500 rpm), CO₂ gas by 5.2% (1500 rpm) and HC gas by 215.66%. (4500 rpm).

Antikaon condensation in magnetized neutron stars

This study investigates the possibility of antikaon condensation in strongly magnetized neutron stars (NSs) with [Formula: see text]-equilibrium condition using chiral [Formula: see text] model and chiral perturbation theory (ChPT). We explore the effect of finite strong magnetic field on particle fraction, effective masses of kaon/antikaon, and equation of state (EoS). The longitudinal EoS gets softened; whereas in transverse EoS, stiffness is observed as the magnetic field strength increases. The presence of antikaon condensation causes softness in both the longitudinal and transverse EoS. Finally, we investigate the structure of NSs through the mass–radius relation, tidal deformability, and Love number and present possible comparison with recent work in the field. The presence of antikaon condensed phase decreases the mass of NSs corresponding to both EoS (longitudinal and transverse). For longitudinal pressure, the mass–radius shows decrement with increase in magnetic field strength; whereas transverse pressure causes an increment.

Melting of Quarkonia in strong magnetic field

In this paper, spectra of the quarkonium states has been studied using the conditions temperature, chemical potential and the magnetic field. Here our main focus is to study the effect of strong magnetic field on the quarkonium properties. The binding energies and the dissociation temperature for the ground and the first excited states of the charmonium and bottomonium in the presence of strong magnetic field at chemical potential μ = 500 MeV has been studied. Here we use quasiparticle(QP) Debye mass depending upon temperature, magnetic field and chemical potential obtained from the quasiparticle approach. The Debye mass strongly increases at different values of temperature and magnetic field. The binding energy decreases with increase in the temperature at different magnetic field eB=0.3, 0.5, and 0.7 GeV2 and also decreases with magnetic field at different at T=200,300 and 400 MeV for the J/ψ, Ψ’, ϒ, and ϒ’ states of the quarkonia. The dissociation temperature of the quarkonium states falls with the increasing values of the magnetic field at critical temperature Tc =197 MeV.