Designing & Analysis of Supercapacitor Hybrid Battery System with Regenerative Braking

This work implements the help of a super capacitor hybridized with a battery pack to power a motor to work an electric bike. The supercapacitor of specification is built in combination with the battery pack to work in pair at instances where more load in needed. For example in situations like accelerating, decelerating, and climbing a slope. The supercapacitor is recharged while in motion using two different technologies: 1. Regenerative Braking and 2. Generator incorporated into wheel hub. Regenerative braking is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In this mechanism, the electric traction motor uses the vehicle's momentum to recover energy that would otherwise be lost to the brake discs as heat. This contrasts with conventional braking systems, where the excess kinetic energy is converted to unwanted and wasted heat due to friction in the brakes, or with dynamic brakes, where the energy is recovered by using electric motors as generators but is immediately dissipated as heat in resistors. In addition to improving the overall efficiency of the vehicle, regeneration can significantly extend the life of the braking system as the mechanical parts will not wear out very quickly. The system uses Faradays Law of Electromagnetic Induction to induce an EMF and generate voltage by passing a current carrying conductor through a rotating magnetic field. Using this implementation, it has been noted that the battery life has been increased significantly and the total range of the bike has also increased considerably. Keywords: Batteries, Battery pack, Supercapacitor, Hybrid power system, Dynamo mechanism

Magnetic fields in the solar convection zone

It has been a prevailing picture that active regions on the solar surface originate from a strong toroidal magnetic field stored in the overshoot region at the base of the solar convection zone, generated by a deep seated solar dynamo mechanism. This article reviews the studies in regard to how the toroidal magnetic field can destabilize and rise through the convection zone to form the observed solar active regions at the surface. Furthermore, new results from the global simulations of the convective dynamos, and from the near-surface layer simulations of active region formation, together with helioseismic investigations of the pre-emergence active regions, are calling into question the picture of active regions as buoyantly rising flux tubes originating from the bottom of the convection zone. This article also gives a review on these new developments.

Thermal evolution of the Earth's core during its formation taking into account heat release from the short-lived radioisotopes 26Al and 60Fe

Research subject. Based on the two-stage mechanism of the Earth's heterogeneous accumulation, previously proposed by V.N. Anfilogov and Yu.V. Khachay, the thermal evolution of the core during its formation was studied. Account is taken of both the heat release from 26Al, the content of which was established with a fairly reliable accuracy, and that from 60Fe.Materials and methods. The methods of mathematical modelling were used. Calculations were carried out for three estimates of the fractional content of the radioisotope 60Fe to stable 56Fe at the time of CAI formation (Ca-Al-In- clusions, calcium- and aluminium-rich inclusions found in carbonaceous chondrites) based on the results of various authors.Results. As a result of numerical experiments, variants of the temperature and melting temperature distributions at different stages of the core formation for different 60Fe/56Fe ratios were obtained.Conclusions. The results show that the central region of the forming core can remain melted even by the end of its accumulation. As a consequence, in this region for this time, the conditions for free thermal convection and, accordingly, for the implementation of the MHD dynamo mechanism remain.

Biermann battery as a source of astrophysical magnetic fields

A large number of galaxies have large-scale magnetic fields which are usually measured by the Faraday rotation of radio waves. Their origin is usually connected with the dynamo mechanism which is based on differential rotation of the interstellar medium and alpha-effect characterizing the helicity of the small-scale motions. However, it is necessary to have initial magnetic field which cannot be generated by the dynamo. One of the possible mechanisms is connected with the Biermann battery which acts because of different masses of protons and electrons passing from the central object. They produce circular currents which induce the vertical magnetic field. As for this field we can obtain the integral equation which can be solved by simulated annealing method which is widely used in different branches of mathematics

Magnetic fields from cosmological bulk flows

ABSTRACT We explore the possibility that matter bulk flows could generate the required vorticity in the electron–proton–photon plasma to source cosmic magnetic fields through the Harrison mechanism. We analyse the coupled set of perturbed Maxwell and Boltzmann equations for a plasma in which the matter and radiation components exhibit relative bulk motions at the background level. These background bulk motions induce a relative velocity between the matter and cosmic microwave background rest frames at the present time, i.e. a bulk flow, with an amplitude β. We find that, to first order in cosmological perturbations, bulk flows with velocities compatible with current Planck limits (β < 8.5 × 10−4 at $95{{\ \rm per\ cent}}$ CL) could generate magnetic fields with an amplitude 10−21 G on 10 kpc comoving scales at the time of completed galaxy formation that could be sufficient to seed a galactic dynamo mechanism.

Cosmic rays from the nearby starburst galaxy NGC 253: the effect of a low-luminosity active galactic nucleus

ABSTRACT NGC 253 is a nearby starburst galaxy in the Sculptor group located at a distance of ∼3.5 Mpc that has been suggested by some authors as a potential site for cosmic ray acceleration up to ultrahigh energies. Its nuclear region is heavily obscured by gas and dust, which prevents establishing whether or not the galaxy harbours a supermassive black hole coexisting with the starburst. Some sources have been proposed in the literature as candidates for an active nucleus. In this work, we aim at determining the implications that the presence of a supermassive black hole at the nucleus of NGC 253 might have on cosmic ray acceleration. With this aim, we model the accretion flow on to the putative active nucleus, and we evaluate the feasibility of particle acceleration by the black hole dynamo mechanism. As a by-product, we explore the potential contribution from non-thermal particles in the accretion flow to the high-energy emission of the galaxy. We found that in the three most plausible nucleus candidates, the emission of the accretion flow would inhibit the black hole dynamo mechanism. To rule out completely the influence that a putative nucleus in NGC 253 might have in cosmic ray acceleration, a better clarification concerning the true nature of the nucleus is needed.

Self-gravity in magnetized accretion discs as a result of a dynamo mechanism with outflows

ABSTRACT We investigate the stationary model of a geometrically thin, magnetized accretion disc, which has a dipole-symmetry magnetic field that is produced by an α−ω dynamo and can emanate winds from the disc’s surfaces. Although self-gravity has an important role in the evolution of astrophysical systems, it has been disregarded in many cases, because the equations become more complicated when the mass distribution of the disc is included in the total gravitational potential. In this paper, we consider the effects of self-gravity on the above-mentioned model. It is shown that in the presence of vertical self-gravity, while the magnetic diffusivity decreases, the magnetic field bends and the inflow speed increases. Also, in the inner parts of the disc, mass flux resulting from the wind has a positive value compared with the non-self-gravitating solution, in which all accreted materials are lost. These results can be used for the discs of active galactic nuclei, in which self-gravity is only important in the vertical direction. However, for other types, such as the discs surrounding young stellar objects, self-gravity can be considered in both vertical and radial directions. Here, our analysis of fully self-gravitating discs has revealed that, in this case, the inflow speed depends on the radius. In the model we study, it is also found that the outflows have no effective contribution to the removal of angular momentum for certain radii r ≥ 6R, as is > 60°. However, the system cannot be stabilized by viscous dissipation.

Hot Magnetic Stars in Exotic Multiple Systems

A strong and stable magnetic field covering the whole surface is a landmark of chemically peculiar or CP stars. To explain the origin of mag- netic stars, several hypotheses were proposed, which depending on the mech- anism and time of formation can be grouped into three main. The magnetic field may originate in the protostellar medium (“fossil field”), turbulent layers of a star (“dynamo” mechanism) or in the other environment. In either scenario, binary stars appear as a merit of its reliability. Recent advances in observational astrophysics uncovered a bunch of new binary magnetic stars that were considered as rare before. We outline the results of studies of exotic binary and multiple systems with magnetic CP components: HD 6757, HD 34736, and HD 40759.