Narrow Results

Recently, various ways are investigated to augment heat transfer in different applications such as porous ceramic domain. Adding nanoparticles to fluid is the best operational way to increase the conduction of fluids. In this paper, migration of nanofluid inside a porous duct under the impact of magnetic force is scrutinized. LBM is applied to present comprehensive parametric analysis for various concentrations of nanofluid, Hartmann, Reynolds, and Darcy numbers. Outputs illustrate that Nu augments with improve of Lorentz forces. Augmenting Da significantly enhances the convective flow in our model.

Materials with novel properties and compounds of intelligent material combinations are a key to innovation in various successful sectors of the global industry as well as for its export. Magnetorheological elastomer materials have interesting physical properties; most of these properties are modified and adapted under the influence of external parameters such as the magnetic field. In this work, an experimental characterization of the magnetorheological elastomers (MRE) loaded with 20% of the iron particles was made. The results showed that the properties of these materials can be modified very selectively and reversibly under the influence of magnetic field, where the stiffness of the material varies depending on the magnetic field intensity that influences the attractive force between iron particles.

This research paper investigates areas of identifying the community structures which can help us to uncover organizational principles in complex networks. So far, a large number of algorithms have been introduced to discover the community structures, but the majority of these algorithms are suitable just for the unweighted networks. We present a new hierarchical method that identifies communities in weighted and unweighted networks based on the magnetic field. In our approach, the nodes are considered as a set of stationary/mobile magnetic nodes where these magnets can attract and repulse under the influence of an acting force. Based on the magnetic force between magnetic poles, we propose the law of node gravitation LNG and node repulsion LNR. Our method identifies a set of stationary magnetic nodes (SMNs). Each SMN attracts a group of mobile nodes and at the same time, they do not influence one another by any acting force. Then, we construct the stationary magnetic communities (SMCs) based on the law of community gravitation and repulsion. Our method finishes when all the magnets in the network become stationary. The experimental results are presented to prove the performance of our method in several real networks including weighted and unweighted networks.

For increasing the cooling performance within the system with one circular hot wall, combinations of nanotechnology and Kelvin force have been utilized. Iron oxide with fraction of 0.04 has been added to water and properties were estimated according to homogenous model. Appearance of wire near the middle of circular wall generates space-dependent Kelvin force which acts like gravity force and boosts the migration of ferrofluid. To gain the solution, CVFEM was applied to measure the values of scalars. Before employment of numerical approach, the equations become simplified with defining the vorticity formulation. Utilizing FHD makes the fluid move faster inside the domain and more effective collision with walls happens. Nu elevates about 108.05% by applying FHD when $\mathrm{\text{Ra}}=\mathrm{\text{1e3}}$. When ${\mathrm{\text{Mn}}}_F=0$ and 4e3, imposing greater buoyancy forces offers augmentation of Nu about 11.54% and 0.01%. Utilizing ferrofluid instead of H₂O makes Nu to rise around 14.15%.

In this study, we investigate the special type of magnetic trajectories associated with a magnetic field ${ℬ}$ defined on a 3D Riemannian manifold. First, we consider a moving charged particle under the action of a frictional force, $f$, in the magnetic field ${ℬ}$. Then, we assume that trajectories of the particle associated with the magnetic field ${ℬ}$ correspond to frictional magnetic curves ($f$-magnetic curves$)$ of magnetic vector field ${ℬ}$ on the 3D Riemannian manifold. Thus, we are able to investigate some geometrical properties and physical consequences of the particle under the action of frictional force in the magnetic field ${ℬ}$ on the 3D Riemannian manifold.

In this paper, we study a special type of magnetic trajectories associated with a magnetic field ${ℬ}$ defined on a 3D Riemannian manifold. First, we assume that we have a moving charged particle which is supposed to be under the action of a gravitational force $G$ in the magnetic field ${ℬ}$ on the 3D Riemannian manifold. Then, we determine trajectories of the charged particle associated with the magnetic field ${ℬ}$ and we define gravitational magnetic curves ($G$-magnetic curves) of the magnetic vector field ${ℬ}$ on the 3D Riemannian manifold. Finally, we investigate some geometrical and physical features of the moving charged particle corresponding to the $G$-magnetic curve. Namely, we compute the energy, magnetic force, and uniformity of the $G$-magnetic curve.

In this study, we firstly characterize modified magnetic particles and associated magnetic fields by considering the evolution of the charged particle together with its modified frame construction in 3D space. Then, we compute the energy flows of each modified magnetic particles in terms of its curvature and torsion in the space. Finally, we obtain energy flux density, the intensity of the light, power of modified magnetic particles in the space.

Transmission loss of acoustic metamaterials (AM) made of double thin plates with magnetic (negative) stiffness was analyzed using theory, finite element analysis and experimental techniques. The theoretical formulation was done using a rectangular duct below the first cut off frequency, the model is then validated against finite element method and experiment. Two cubic magnets were used, their interaction force and the resulted magnetic stiffness were calculated. The sound transmission loss (STL) of the structure is calculated for plane wave condition, the addition of magnetic mass shifts STL peaks to the lower frequency compared to a structure without mass. The slight increase in STL for small negative stiffness in experiment is not enough to cancel the effect of air compressibility. However, a significant enhancement could be expected if negative stiffness can be made large enough in the double thin plates. The developed AM can be employed as a prospective sound engineering control at low frequency.

Single protein crystals are indispensable in the determination of the three-dimensional structure of proteins and other biological macromolecules by X-ray crystallography. The quality of the crystals governs the resolution limit or accuracy of the atomic positions calculated. The purpose of this chapter is to describe the idea of using magnetic fields to grow better quality protein crystals. The possibilities as well as limitations will be discussed.