Effect Of Magnetic Field Research Articles

Effect of magnetic field on growth and protein concentration in aboveground herbage of field pea (Pisum sativum L.) cultivars

Research of the exposure of young pea (Pisum sativum L.) plants of two cultivars (Gold and Uran) to magnetic field (MF) of different flux densities (250 and 350 mT) was conducted in controlled conditions during 20 days. Pea plants were continuously exposed to magnetic field of neodymium magnets. Upon the statistical analysis there were revealed significant effects of MF treatments (P 0.01) on root freshweight, aboveground herbage freshweight and total plant freshweight. Cultivars differed in root (P 0.05), stem (P 0.01) and total plant length (P 0.05). There was also revealed significant Treatment × Cultivar interaction for all the tested traits.

Effects of general magnetic field therapy in comprehensive medical rehabilitation on the quality of life of patients with breast cancer

BACKGROUND: The Short Form-36 (SF-36) is one of the most widely used tools to assess quality of life in breast cancer patients. According to MEDLINE, the SF-36 is used in 95.0% of research studies to assess the quality of life in various diseases. Advantages of SF-36 include wide availability, ease of use, and high validity. AIM: The aim of the study was to evaluate the effect of general magnetic field therapy in comprehensive medical rehabilitation on the quality of life parameters using a SF-36 questionnaire in breast cancer patients at 2–4 days and 1.0–1.5 months after surgery. MATERIALS AND METHODS: A randomized, placebo-controlled study was conducted in patients (n=107) after surgery for breast cancer. All patients were divided into three groups balanced by age and clinical and functional parameters, and received a course of medical rehabilitation which included individual postoperative sessions of exercise therapy (posture treatment; movement therapy with breathing, general stimulating, special, and relaxation exercises; sensorimotor training using a biofeedback simulator; individual sessions with a medical psychologist; one session of instrumental physiotherapy). Comprehensive medical rehabilitation included fluctuating current therapy in group 1 (n=35), local magnetic field therapy in group 2 (n=35), and general magnetic field therapy in group 3 (n=37). RESULTS: Analysis of quality of life parameters in the early postoperative period demonstrated effectiveness of the comprehensive physical rehabilitation program using exercise therapy, balance boards, and sessions with a psychologist in combination with one of the physical treatment options. Positive results increase patients’ confidence in the success of their rehabilitation. After providing the general magnetic field therapy in comprehensive medical rehabilitation, most of the SF-36 quality of life parameters improved, which indicates the beneficial effects of the general magnetic field on situational and personal anxiety, asthenic and vegetative manifestations, and sleep, as well as prolongation of these effects. Patients who received fluctuating current therapy as part of medical rehabilitation improved their pain index and physical function, probably due to analgesic and anti-inflammatory effects of this treatment option. CONCLUSION: Comprehensive physical rehabilitation combined with physical therapy increases the patient’s independence in daily living, self-care, and mobility.

The theoretical approach for description of magnetic properties and magnetocaloric effect in all-d-metal Heusler alloys Ni2−xCoxMn1.25Ti0.75

This paper investigates the influence of Co addition and atomic ordering on the magnetic and magnetocaloric properties of all-d-metal Heusler alloys Ni2−xCoxMn1.25Ti0.75, which exhibit a second-order magnetic phase transition. The modeling approach employed is based on the density functional theory and Monte Carlo method. The atomic ordering is considered with reference to the fully ordered structure, L21, and the partially ordered structure, B2. It is demonstrated that in both structures, the predominant magnetic state within the cubic austenitic phase is characterized by ferromagnetic ordering. An increase in the Co content results in the strengthening of the ferromagnetic exchange interactions between Mn, Ni, and Co, as well as an increase in the Curie temperature. For the ground state L21 structure, the largest Curie temperature values are observed, exceeding those of the B2 structure by almost 100 K. The temperature dependencies of the magnetization and magnetocaloric effect (ΔSmag) in magnetic fields up to 2 T are calculated using the Heisenberg Hamiltonian by the Monte Carlo method. The largest effect (ΔSmag≈1.4 J/kg K) is observed for the compound with x = 0.375 and B2 structure at temperature ≈150 K, whereas for L21-Ni1.5Co0.5Mn1.25Ti0.75 and B2-Ni1.25Co0.75Mn1.25Ti0.75, ΔSmag of 1.05 J/kgK appears in the vicinity of room temperature.

Synthesis of ferrofluid using magnetite (Fe3O4), citric acid and deionized water and its characterizations for the application of a non-uniform magnetic thermosyphon

The performance improvement of a thermosyphon for disseminating heat is significant for the thermal management of a system. Furthermore, the water as the working liquid in a thermosyphon has an operating limit. Therefore, adding particles in the nanofluids as a working liquid could improve the thermal properties of thermosyphon and boiling temperature. Additionally, the effects of a non-uniform magnetic field on the ferrofluid thermosyphon at three locations: evaporator, adiabatic, and condenser were analysed. In this investigation, a two-step method was utilized, the ferrofluid was synthesized using magnetite (Fe3O4), citric acid, and deionized water. First, the Fe3O4 nanoparticles and associated ferrofluid were fully characterized from X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), magnetic properties analysis, zeta potential, and thermal properties, respectively. Then, the performance of thermosyphon heat pipes filled using high filling ratios of 70, 80, 90, and 100% of stable synthesized ferrofluid at 0.5wt% were examined. The results were compared to water using similar filling ratios that have been experimentally evaluated. The thermosyphon heat pipe (copper container) has a diameter of 12.7mm and a length of 200mm. The thermal performance test of the thermosyphon filled using the ferrofluid suggested a thermal resistance decrease from 1.95 to 1.20 °C/W with filling ratios of 70 to 90% of evaporator volume. The effective thermal conductivity of the thermosyphon is improved from 685 to 1160W/m°C at similar filling ratios. On the other hand, higher thermal resistance and lower effective thermal conductivity of thermosyphon filled using water were obtained at similar filling ratios of 70 to 90%. The values are 2.2 to 1.3 °C/W and 600 to 1000W/m°C, respectively. Moreover, the thermosyphon filled using the ferrofluid with a filling ratio of 90% and a non-uniform magnetic field (two sides) on the evaporator section has a thermal resistance and an effective thermal conductivity of 1.9 °C/W and 690W/m°C. The result has a lower thermal conductivity value compared to the thermosyphon filled with ferrofluid without a non-uniform magnetic field at a similar filling ratio of 90% of 1160W/m°C. This occurs due to less particle deposition on the inner surface of the thermosyphon as an effect of the magnetic field. A non-uniform magnetic field effect to the several sections of the thermosyphon (e.g., evaporator, adiabatic, and condenser) as the novelty of the research required to be modified to optimize the results.

Risk evolution and prevention and control strategies in emergency responses for Arctic maritime transportation

The intertwined and complex risks involved in the various stages of the Arctic maritime transportation emergency response severely hinder the response's effectiveness. The present study aims to develop a risk coupling network involved in the Arctic maritime transportation emergency response. First, an Arctic maritime transportation emergency response scenario is defined by reviewing SAR manuals and agreements, emergency guidelines of ships, and emergency drill videos. Second, the control structure of the emergency response process is systematically analyzed through Systems-theoretic process analysis, and a risk coupling network with task-layer, unsafe control actions-layer, and risk-layer is developed. Third, the robustness of the risk coupling network is stimulated by random and deliberate attacks, where deliberate attacks are based on the measured results of node degree, betweenness centrality, and integrated values. Finally, critical risk factors are determined based on the results of the network robustness analysis, and targeted prevention and control strategies of critical risk factors for the Arctic maritime transportation emergency response are proposed. The research findings suggest that equipment/system failures, personnel experience and expression capabilities, the effects of high-latitude magnetic fields, response times to assistance requests, and the preparedness of emergency resources should be focused on during Arctic maritime transportation emergency response.

Numerical simulation of CuCr alloys vacuum arc under conditions of arc contraction, deflection, and anode vapor

In practical arc ignition processes of high-current vacuum arcs, despite the calibration effect of the axial magnetic field, the strong magnetic constriction force still causes the arc to contract. Additionally, during the actual electrode opening process, due to the random nature of the arcing position, the center of the arc column is often not located at the center of the electrode. At this point, the behavior of the vacuum arc can be understood as an asymmetric three-dimensional (3D) process under the influence of the spatial magnetic field, affecting the generation of anode vapor and the characteristics of arc species. Therefore, it is useful to conduct simulation studies on multi-species vacuum arc behavior considering arc contraction and arc deflection. In this paper, the spatial magnetic field distribution under different electrode effective areas and different arc center deflection distances have been simulated, and the influence of actual magnetic field-induced by arc contraction and deflection on 3D spatial distribution characteristics of arc plasma has been studied based on a 3D multi-species (CuCr alloys) vacuum arc model with anode vapor. The simulation results show that with the contraction of the arc column, the area occupied by neutral atomic vapor decreases correspondingly, but the ionization and recombination process between the arc column regions becomes more intense. The axial current density and electron temperature distribution around the neutral atomic vapor area become more non-uniform. When the arc column deviates from electrode center, the neutral atomic vapor area shows an asymmetrical distribution on both sides of the arc column center axis, and the axial current density and electron temperature gather and enhance in the opposite direction of the arc deflection, thereby significantly affecting the distribution of arc species.

Propagation of cylindrical converging shock wave in rotating ideal gas containing dust particles

In this article, the propagation of strong converging cylindrically symmetric shock waves in ideal dusty gas is studied using the Lie group technique while considering the effect of an axial magnetic field in a rotating gas atmosphere. The constant density in an undisturbed medium is assumed, whereas the magnetic field, the azimuthal, and axial components of fluid velocity are considered to be varying. The arbitrary constants appearing in the expressions for infinitesimals of the Local Lie group of transformations bring about three different cases of solutions, i.e., with power-law shock path, exponential-law shock path, and a particular case of power-law shock path. Numerical solutions are obtained in the cases of the power-law shock path. The self-similar solutions to the problem are obtained, and the effect of the Shock Cowling number, the mass concentration of solid dust particles, the relative specific heat, the ratio of the density of solid particles, and the ambient azimuthal velocity exponent on the shock evolution are depicted through graphs.

Boundary layer flow and heat-mass transfer of shear-thinning nanofluid past a thin needle: electroperiodic magnetic field and thermo-diffusion effects

Heat and mass transfer in a boundary layer flow (BLF) of shear-thinning nanofluid (NF) around a thin needle has various practical applications including industrial processes, like medical devices, complicated cooling systems, high-efficiency thermal control in microelectronic devices, and chemical reactors designs. With a focus on its practical applications, this work investigates the heat and mass transfer effectiveness in a BLF of shear-thinning fluid containing alumina-copper nanoparticles around a thin needle subject to electroperiodic magnetic field in a nonlinear radiative environment. A comparative analysis is done for heat-mass transfer performance of alumina-copper-water-tangent hyperbolic fluid and water-tangent hyperbolic in order to optimize thermal and mass transmission efficiency by highlighting the importance of latent heat, nanomaterial load and thermo-diffusion processes. This work is novel because such comparative investigation on heat-mass transfer for alumina-copper-water-tangent hyperbolic fluid and water-tangent hyperbolic is not taken yet. The governing model for a BLF around a thin needle are solved using Runge Kutta fourth order (RK-4) method. The findings shows that the action of electroperiodic magnetic field greatly improves mass transfer and heat transfer performance. Latent heat effect and needle thickness enlargement improve the rate of heat-mass. Elevating the Weissenberg number modifies the flow dynamics. Adding more alumina-copper nanoparticles to the mixture increases its thermal conductivity and as a result increases the heat transfer rate. The Dufour number had a positive effect on temperature distribution. The activation energy, and Soret numbers all worked together to significantly alter the concentration profile. The mixture () show better heat-mass transfer efficiency as compared to () fluid.

Effective Material and Static Magnetic Field for the 2-D/1-D-Problem of Laminated Electrical Machines

Effective Material and Static Magnetic Field for the 2-D/1-D-Problem of Laminated Electrical Machines

Enantioseparation of antihistamines using magneto-thin-layer chromatography: The effects of various orientations and intensities of magnetic fields

The effect of magnetic fields produced by magnet and solenoid was investigated for the first time in the enantioseparation of antihistamines using thin-layer chromatography. The racemic mixtures of cetirizine and hydroxyzine were selected as the model drugs for studying the magnetic field effect on enantioseparation. The magnets were fixed to a U-shape blade that rotated around the separation chamber by a motor to apply a magnetic field perpendicular to the direction of mobile phase movement. Also, the separation chamber was positioned within a solenoid, and an electric current was utilized to apply the magnetic field in a parallel direction to the mobile phase movement. L-arginine was added to the mobile phase as a chiral selector to perform the enantioseparation of drugs. When magnets generate the magnetic field, both in attraction and repulsion, the spots become broader and the peak height decreases as the magnetic field intensity and rotation speed of the magnets increase. An increase in peak height was observed in the presence of the magnetic field generated by + 3.25A current in the solenoid. Regardless of the type of applied magnetic field, the retention factor values exhibited slight reductions. It was observed that separated enantiomers were similarly affected by various magnetic fields. The distribution coefficient, mass transfer, equilibrium, and lipophilicity were all potentially influenced by the magnetic field, which could explain the alterations.

Investigation of heat transfer properties of CuZnFe2O4-water and NiZnFe4O4-water nanofluids under magnetic field effect

Investigation of heat transfer properties of CuZnFe2O4-water and NiZnFe4O4-water nanofluids under magnetic field effect

Electro-Osmotic Mechanism of Ellis Fluid With Joule Heating, Viscous Dissipation, and Magnetic Field Effects in a Pumping Microtube.

The dynamics of electro-osmotically generated flow of biological viscoelastic fluid in a cylindrical geometry are investigated in this paper. This flux is the result of walls contracting and relaxing sinusoidally in a magnetic environment. The blood's viscoelasticity and shear-thinning viscosity are the primary causes of its non-Newtonian characteristics. Hence, the rheology of the fluid (blood) is accurately captured with the Ellis fluid model. Both Joule heating and viscous dissipation are accounted for during thermal analysis. The electric potential induced in the electric double layer (EDL) is obtained by applying the Debye-Huckel linearization to the nonlinear Poisson-Boltzmann equation. Mathematical modelling is incorporated in cylindrical coordinates in wave frame of reference. Assuming a long wavelength and creeping flow characterized by a low Reynolds number, the Ellis fluid model's governing equations are simplified. The resulting differential equations are evaluated numerically via the built-in tool NDSolve of the Mathematica. Graphical representations are utilized to visually and comprehensively assess the thermal characteristics, flow features, heat transfer coefficient, and skin friction coefficient. Various factors are taken into consideration, including the impact of Ellis fluid parameters, electric double layer, magnetic field, Brinkman number, and Ohmic dissipation. Ellis fluid's axial velocity boosts with a rise of the electro-osmotic parameter and power-law index while decreasing with an increase in the Hartmann number and material fluid parameter. The fluid temperature is directly proportional to EDL parameter and parameters of Ohmic and viscous dissipation. The presence of both electric and magnetic fields may aid in the management and control of Ellis fluid (blood) mobility at different temperatures, which is helpful in controlling bleeding during surgeries. The current model may be used in clinical scenarios involving the gastrointestinal system and capillaries, electrohydrodynamic therapy, delivery of drugs in pharmacological, and biomedical devices. This research creates a theoretical model that can predict the effects of different parameters on the characteristics of fluid flows that are like blood.

Numerical simulation of YSO jet collimated by toroidal magnetic fields and radiative cooling effect

Abstract The mechanism of generation and collimation of YSO jets remains an unsolved problem and is a research hotspot in contemporary astrophysics. Here, we conducted a two-dimensional (2D) cylindrical coordinates simulation experiment using radiative magnetic-hydro-dynamic FLASH code and systematically analyzed the effects of toroidal magnetic fields generated by Biermann Battery term and radiative cooling effect on jet evolution. In the simulation, strong toroidal magnetic fields are generated at the boundary of the plasma flow. A comparison of jets generated in different cases indicates that the magnetic fields play a significant role in hydrocarbon (CH) plasma jet collimation, surpassing the impact of radiative cooling effects. Additionally, it is observed that the magnetic fields can alter knots velocities. This platform provides a way to investigate the role of toroidal magnetic fields in jet evolution without external devices and provides a better understanding of the evolution of protostellar jets.

The IMF Clock Angle Effect on the Tail Cross Section of the Martian Magnetic Pileup Boundary and Bow Shock

Using a three-dimensional global magnetohydrodynamic (MHD) simulation model, we investigate the effects of different interplanetary magnetic field (IMF) clock angles on the tail configuration of the Martian magnetic pileup boundary (MPB) and bow shock (BS). The study reveals the following: (1) The cross sections of the tail MPB and BS are approximately elliptical. The MPB tail cross section generally elongates in the direction of the IMF clock angle, whereas the BS tail cross section is roughly elongated perpendicular to the IMF clock angle direction. (2) An IMF with a northward component can cause the tail cross section of the MPB to shift slightly to the south when the intense crustal magnetic fields are located on the dayside. (3) As the tail distance from Mars increases, the eccentricity of the cross section ellipses of both the MPB and BS tail increases, as well as the major and minor axes. Additionally, the major and minor axes of the tail MPB’s cross section ellipses begin to decrease at the far magnetotail, suggesting that the Martian MPB tail might be a closed structure on the nightside.

Effects of horizontal magnetic fields on flow morphologies and global transports in liquid metal thermal convection

We report an experimental study of Rayleigh–Bénard convection of liquid metal GaInSn in a cuboid cell with an aspect ratio of 0.5 under the effect of a horizontal magnetic field. The Rayleigh number spans a range of $3.8\times 10^5 \leqslant Ra \leqslant 1.1\times 10^7$ , while the magnetic field strength reaches up to 0.5 T, corresponding to a maximum Hartmann number to 2041. By combining temperature and velocity measurements, we identify several flow morphologies, including a novel cellular pattern characterized by four stacked vortices that periodically squeeze and induce velocity reversals. Based on the identified flow morphologies, we partition the entire ( $Ra, Ha$ ) parameter space into five distinct flow regimes and systematically investigate the flow characteristics within each regime. The temperature gradient and oscillation frequency exhibit scaling relationships with the combined parameters $Ra$ and $Ha$ . Notably, we observe a coupling between flow regime and global transport efficiencies, particularly in a regime dominated by the double-roll structure, which experiences a maximum 36 % decrease in heat transfer efficiency compared with the single-roll structure. The dependencies of heat and momentum transport on $Ra$ and $Ha$ follow scaling laws as $Nu \sim (Ha^{-2/3}RaPr^{-1})^{3/5}$ and $Re \sim (Ha^{-1}RaPr^{-1})^{4/3}$ , respectively.

Analytical Study of Magnetohydrodynamic Casson Fluid Flow over an Inclined Non-Linear Stretching Surface with Chemical Reaction in a Forchheimer Porous Medium

This study investigates the steady, two-dimensional boundary layer flow of a Casson fluid over an inclined nonlinear stretching surface embedded within a Forchheimer porous medium. The governing partial differential equations are transformed into a set of ordinary differential equations through similarity transformations. The analysis incorporates the effects of an external uniform magnetic field, gravitational forces, thermal radiation modeled by the Rosseland approximation, and first-order homogeneous chemical reactions. We consider several dimensionless parameters, including the Casson fluid parameter, magnetic parameter, Darcy and Forchheimer numbers, Prandtl and Schmidt numbers, and the Eckert number to characterize the flow, heat, and mass transfer phenomena. Analytical solutions for the velocity, temperature, and concentration profiles are derived under simplifying assumptions, and expressions for critical physical quantities such as the skin friction coefficient, Nusselt number, and Sherwood number are obtained.

Modelling of coronary artery stenosis and study of hemodynamic under the influence of magnetic fields

Investigating magnetic blood flow characteristics through arteries and micron-size channels for clinical therapies in biomedicine is becoming increasingly important with the rise of point-of-care diagnostics devices. A computational fluid dynamics (CFD) investigation is conducted to explore blood flow within a coronary artery affected by an elliptical stenosis near the artery wall under the influence of a magnetic field. The novelty of our study is the integration of Navier-Stokes and Maxwell's equations to calculate body forces on fluid flow, coupled with the application of magnetic fields both longitudinally and vertically, and the use of the Carreau-Yasuda model to analyse non-Newtonian blood rheology. Blood flow is modelled by solving the incompressible continuity and momentum equations, considering laminar and non-Newtonian properties, with the finite element-based solver COMSOL Multiphysics. The CFD model is validated using previously published analytical and computational data. This study investigates the effects of magnetic fields on blood flow through stenotic arteries with 25 %, 35 %, and 50 % stenosis, examining how the magnetic field and its orientation impact variations in velocity profiles, pressure drop, and wall shear stress (WSS). Our results show that magnetic fields can effectively manipulate blood flow, causing acceleration or deceleration depending on field direction. Significant changes in hemodynamics are observed, particularly at 50 % arterial stenosis, highlighting the profound impact of stenosis on flow characteristics. Compared to healthy arteries, the velocity change in stenosed arteries increased by 16.5 %, 29.4 %, and 62.1 % for 25 %, 35 %, and 50 % stenosis, respectively. The findings advance experimental models of blood flow in magnetic fields, highlighting the critical importance of regulating blood velocity and pressure. These insights are particularly valuable for developing drug delivery systems and magnetic-driven blood pumps.

External Field‐Assisted Metal–Air Batteries: Mechanisms, Progress, and Prospects

ABSTRACTMetal–air batteries are an appealing option for energy storage, boasting a high energy density and environmental sustainability. Researchers focus on the catalyst design to solve the problem of sluggish cathode reaction kinetic. However, in some cases, where thermodynamic regulation is required, the role of catalysts is limited. Based on catalysts changing reaction kinetics, external fields can change the thermodynamic parameters of the reaction, further reduce overpotential, and accelerate the reaction rate. By selecting appropriate external fields and adjusting controllable variables, greater flexibility and potential are provided for reaction control. This paper reviews the basic principles by which several external fields influence metal–air batteries. Additionally, some design strategies of photoelectrode materials, the similarities and differences of different magnetic field effects, and some research progress of the ultrasonic field, stress field, and microwave field are systematically summarized. Multifield coupling can also interact and produce additive effects. Furthermore, introducing external fields will also bring about the problem of aggravated side reactions. This paper proposes some research methods to explore the specific reaction mechanism of external field assistance in more depth. The primary objective is to furnish theoretical direction for enhancing the performance of external field‐supported metal–air batteries, thereby advancing their development.

Computation of stretching disks fluid flow of hybrid nanofluid under the effect of variable magnetic field

Computation of stretching disks fluid flow of hybrid nanofluid under the effect of variable magnetic field

Photoacoustic and plasmaelastic waves propagation in semiconductor medium heated by pulsed excitation with magnetic field effect

Semiconductor materials play a crucial role in the fields of science, engineering, and technology due to their high importance. In this work, photoelastic (PE) deformations due to the photonically excited processes are studied according to the photogenerated carriers (plasma waves) during the recombination processes. A photoacoustic theoretical model for the optically excited Silicon (Si) polymer material under the effect of magnetic field is introduced. The coupled between the acoustic and plasm-thermomechanical waves is considered. The governing equation according to the photo-thermoelasticity theory with acoustic pressure is derived. The optoelectronic and thermoelastic properties of semiconductor material are taken into account. The analytical expression of the main physical fields (temperature, mechanical stress, displacement, carrier density, and acoustic pressure) is obtained mathematically using the harmonic wave technique. The theoretical results are represented graphically due to the strength of the magnetic field in two and three dimensions (2D and 3D) and some comparisons are investigated.