Constant Magnetic Field Strength Research Articles

Assessing the efficacy of magnetic water treatment: A concise review and experimental investigation

The utilization of magnetic water treatment has gained significant attention as a promising method for addressing scaling and water quality issues. This strategy has attracted interest due to its ability to potentially alter the behavior of dissolved particles in water. This investigation aimed to examine the impact of magnetic water treatment utilizing two different pipe materials, "iron pipe" and "PVC pipe", with a specific emphasis on the levels of total dissolved salts (TDS). Unexpectedly, the research findings indicate a positive correlation between the number of coil turns and the levels of TDS, which contradicts the popular belief that magnetic treatment would lead to a decrease in TDS. For instance, at a flow rate of 1 mL/s, TDS levels increase from an average of 265 ppm to roughly 277 ppm utilizing 500 and 2000 coil turns around an iron pipe, respectively. Similarly, when using a PVC pipe, TDS levels increase from around 263 ppm to 271 ppm as the magnetic field intensity increases. Furthermore, experiments carried out at an increased flow rate under a constant magnetic field strength show an inverse relationship with TDS. The TDS levels fall from 265 ppm to 261 ppm and from 263 ppm to 260 ppm as the flow rate rises from 1 mL/s to 6 mL/s for iron and PVC pipes, respectively. This intriguing phenomenon presents a challenge to long-held theories and highlights the complex relationship between magnetic fields, pipe materials, and water chemistry. Despite the unexpected results, the increase in the total dissolved salts indicates a possible improvement in reducing scaling, a common problem in fluid systems. In this discourse, this study analyzes the ramifications of these discoveries and underscores the necessity for additional investigation in order to elucidate the intricate mechanisms that underlie these interactions and enhance the efficacy of magnetic water treatment approaches. This research enhances the comprehension of water treatment strategies and emphasizes the significance of customizing procedures to suit individual scenarios in order to achieve efficient water quality control.

Investigation on the microscale memory dependence effect of thermo-viscoelastic rod based on fractional strain theory

Based on fractional strain theory and considering microscale memory dependent effect, the transient response of a one-dimensional micro-nano-structured viscoelastic rotating rod under the action of a moving heat source is investigated in the paper. The rod is placed in a magnetic field of constant strength and its outer surface is unconstrained. The effects of the kernel function, time lag factor, fractional order strain parameter, rotational parameter, visco-thermoelastic relaxation time, and nonlocal parameter on the distribution of the physical field in the rod are obtained by solving the governing equations through the Laplace integral transform and its numerical inverse transform. The results show that the fractional strain parameters and rotational angular velocity have little effect on the dimensionless temperature, but have significant effects on the dimensionless displacement, stress, and strain. The kernel function, time delay factor, viscoelastic relaxation time, and nonlocal parameter have different degrees effects on temperature, displacement, stress, and strain.

Effect of Spherical Polarization on the Magnetic Spectrum of the Solar Wind

Magnetic fluctuations in the solar wind are often observed to maintain constant magnitude of the magnetic field in a manner consistent with spherically polarized large-amplitude Alfvén waves. We investigate the effect of spherical polarization on the magnetic spectral index through a statistical survey of magnetic fluctuations observed by Parker Solar Probe between 20 R ⊙ and 200 R ⊙. We find that deviations from spherical polarization, i.e., changes in ∣ B ∣ (compressive fluctuations) and one-dimensional discontinuities, have a dramatic effect on the scaling behavior of the turbulent fluctuations. We show that shallow k −3/2 spectra are only observed for three-dimensional structures of constant magnetic field strength, which we identify as large-amplitude Alfvén waves. The presence of compressive fluctuations coincides with a steepening of the spectrum up to k −5/3. Steeper power-law scalings approaching k −2 are observed when the fluctuations are dominated by discontinuities. Near-Sun fluctuations are found to be the most spherically polarized, suggesting that this spherical state is fundamental to the generation of the solar wind. With increasing distance from the Sun, fluctuations are found to become less three-dimensional and more compressive, which may indicate the breakdown of the Alfvénic equilibrium state.

Effect of magnetic nanofluid on cooling of hot obstacles in a minichannel: Optimization of obstacle size and spacing

This study conducts a numerical simulation of laminar flow of water/alumina nanofluids (NFs) in a channel with 5 hot obstacles. Obstacles and the wall beneath them have a high temperature, and the top wall is insulated. Also, the beginning and end parts of the bottom wall are insulated. The low-temperature homogenous NFs flow increases in temperature after hitting the obstacles and leaves the channel of length 20. Under the obstacles and the hot wall, a downward magnetic field of constant strength is applied. By altering the height of obstacles (HOB) between 0.1 and 0.7, the width between 0.1 and 1, and spacing between 0.1 and 1, the streamlines, temperature, local Nu, and average Nusselt number (Nu) are examined in the channel. In addition, the response surface methodology is used to conduct an optimization to obtain the maximum Nu and maximum outlet NFs temperature (T-NFs) in the channel by changing the mentioned parameters in associated ranges. The control volume method and Simple algorithm are used for simulations. Results of this study indicated that increasing the obstacle spacing and height causes the local Nu on the bottom wall to increase, the T-NFs in the middle of channel to increase, and the Nu in the channel to decrease. The maximum Nu occurs for the minimum obstacle size and smallest obstacle spacing; in this case, the Nu is higher by 611% than that of the case with maximum obstacle size and largest obstacle spacing.

Thermal activity of hot bodies trapped inside a moving chamber with a complex fluid under the influence of MHD and buoyancy forces

Strengthening the thermal transfer of hot bodies is one of the topics that the old and new researches aim at due to its wide use in the fields of applied engineering. This research includes a study of thermal activity of five hot objects placed inside a cold chamber and rotating at constant speed. An equilateral triangular shape is the cross-sectional shape of the bodies. A rheologically complex fluid is poured into the chamber completely. A magnetic field of constant strength is applied to the x-direction of the chamber. The items studied here are: the rheological nature of the fluid by changing the value of power-law index (n = 0.8, 1 and 1.2), the rotational speed of the chamber is in terms of the Reynolds number (Re = 5 to 40), the magnetic field strength expressed in terms of the Hartmann number (Ha = 0 to 100) and finally buoyancy force (Ri = 0 to 50). The investigation was carried out using a numerical method adopted by a digital simulator with very high characteristics. The results showed that the thermal activity varies from one body to another. The effect of magnetic field on Nusselt number of the bodies decreases as the value of power-law increases.

Required toroidal confinement for fusion and omnigeneity

Deuterium–tritium (DT) burning requires a long energy confinement times compared to collision times, so the particle distribution functions must approximate local Maxwellians. Non-equilibrium thermodynamics is applicable, which gives relations among transport, entropy production, the collision frequency, and the deviation from a Maxwellian. The distribution functions are given by the Fokker–Planck equation, which is an advection–diffusion equation. A large hyperbolic operator, the Vlasov operator with the particle trajectories as its characteristics, equals a small diffusive operator, the collision operator. The collisionless particle trajectories would be chaotic in stellarators without careful optimization. This would lead to rapid entropy production and transport—far beyond what is consistent with a self-sustaining DT burn. Omnigeneity is the weakest general condition that is consistent with a sufficiently small entropy production associated with the thermal particle trajectories. Omnigeneity requires that the contours of constant magnetic field strength be unbounded in at least one of the two angular coordinates in magnetic surfaces and that there be a symmetry in the field-strength wells along the field lines. Even in omnigenous plasmas, fluctuations due to microturbulence can produce chaotic particle trajectories and the gyro-Bohm transport is seen in many stellarator and tokamak experiments. The higher the plasma temperature above 10 keV, the smaller the transport must be compared to gyro-Bohm for a self-sustaining DT burn. The hot alphas of DT fusion heat the electrons. When the ion–electron equilibration time is long compared to the ion energy confinement time, a self-sustaining DT burn is not possible, which sets a limit on the electron temperature.

Numerical scrutinization of micropolar and Walters-B non-Newtonian fluids motion under the influence of thermal radiation and chemical reaction

Purpose The purpose of this study is to explore numerical scrutinization of micropolar and Walters-B non-Newtonian fluids motion under the influence of thermal radiation and chemical reaction. Design/methodology/approach The two fluids micropolar and Walters-B liquid are considered to start flowing from the slot to the stretching sheet. A magnetic field of constant strength is imposed on their flow transversely. The problems on heat and mass transport are set up with thermal, chemical reaction, heat generation, etc. to form partial differential equations. These equations were simplified into a dimensionless form and solved using spectral homotopy analysis method (SHAM). SHAM uses the basic concept of both Chebyshev pseudospectral method and homotopy analysis method to obtain numerical computations of the problem. Findings The outcomes for encountered flow parameters for temperature, velocity and concentration are presented with the aid of figures. It is observed that both the velocity and angular velocity of micropolar and Walters-B and thermal boundary layers increase with increase in the thermal radiation parameter. The decrease in velocity and decrease in angular velocity occurred are a result of increase in chemical reaction. It is hoped that the present study will enhance the understanding of boundary layer flow of micropolar and Walters-B non-Newtonian fluid under the influences of thermal radiation, thermal conductivity and chemical reaction as applied in various engineering processes. Originality/value All results are presented graphically and all physical quantities are computed and tabulated.

Study of spatial organisation of magnetic field directed gold-pickering-ferrofluid-nanoemulsion in spin coated film

The magnetic field directed self-assembly of the nanoparticles is cheap, fast and easy method to prepare the patterned thin film useful for various applications. However, the dipole-dipole interaction between nanoparticles at the interface generates the rough-edged patterns even at microscale causing the excess optical scattering making it unsuitable for the optical applications. In this work, the magnetic field was applied during the spin coating of the Polyethylene glycol 40S (PEG) capped Gold-Pickering ferrofluid nanoemulsion (PEG-C-GM-FF) dispersed in aqueous Polyvinyl alcohol (PVA) solution with different viscosities. Optimised combination of spinning speed and magnetic field strength was achieved to prepare the film with the straight chains of PEG-C-GM-FF required for the optical applications. It is a quick, cost-effective, non-intrusive and simple method for achieving a thin layered array of chains with tuneable gaps between them. The image analysis revealed that the Full Width Half Maximum (FWHM) representing the PEG-C-GM-FF chain spatial density across the substrate for each aqueous phase viscosity decreases with the increase in the spin speeds at constant magnetic field strength. The FTIR (Fourier Transformed Infrared Spectroscopy) of the patterned thin film showed that the intensity of the 2927 ​cm−1 vibrational band corresponding to CH bond in PVA was seen to be linearly increasing with the spatial density of the PEG-C-GM-FF chains. In comparison to the gold strip patterns printed with the nanolithography technique; the magnetically aligned array of PEG-C-GM-FF showed a potential for preparing photonic antenna suitable for enhancing the optical absorption and detect low concentration analyte.

Maser polarization simulation in the circumstellar envelope of an evolving star

An important phenomenon in a pulsing AGB (Asymptotic Giant Branch) star is the variability of its circumstellar envelope. The study of stimulated radiation called SiO maser (microwave amplification by stimulated emission of radiation) in the inner edge of the envelope shows fluctuations in polarization during the stellar pulsation period which is caused by the unstable magnetic field around the AGB star and needs to be investigated in order to understand it. We simulate the maser signal and polarization by using a computer code to describe the circumstellar envelope of the AGB star for comparison with the observations. The methods, i) Generate the energy transition of the stimulation matrix ii) Simulate the first stimulation from an electric field background iii) Convert the radiation to the frequency domain by using Fourier transform iv) Simulate the observation by amplifying radiation along a line of sight within the medium toward an observation position. At this stage, we set the tubular maser cloud with a constant magnetic field strength toward the observer. The program can simulate the maser signal and polarization, brighter when stimulating with a longer medium; the simulated polarization agrees well with expectations for this magnetic field orientation. Further works need to be carried out by testing this program with many cases to explain the obtained data from actual observations.

Vibration analysis of nanobeams subjected to gradient-type heating due to a static magnetic field under the theory of nonlocal elasticity

Nanoelectromechanical systems (NEMS) have received great interest from researchers around the world since the advent of nanotechnology and nanoengineering. This can be attributed due to the unique characteristics of NEMS devices and their wide range of applications. Among these applications, nanobeams and nanotubes now have an important role in the design of a variety of NEMS engineering devices. In the current research, the thermoelastic vibration analysis of Euler–Bernoulli nanobeams has been investigated using the theory of non-local elasticity proposed by Eringen. Also to study the effect of temperature change, the generalized thermoelastic model with dual phase-lag (DPL) is applied. The studied nanobeam is subjected to an axial thermal excitation load and surrounded by a magnetic field of constant strength. The Laplace transform technique has been used to solve the system differential equations and to find an approximate analytical solution for the different physical fields of the nanobeam. The numerical results obtained for the studied variables have been graphically clarified and discussed analytically. The effects of various influencing factors such as magnetic field strength, temperature change, non-local parameter as well as ramp type parameter have been examined and studied in detail.

Evolution of Large-amplitude Alfvén Waves and Generation of Switchbacks in the Expanding Solar Wind

Abstract Motivated by recent Parker Solar Probe (PSP) observations of “switchbacks” (abrupt, large-amplitude reversals in the radial magnetic field, which exhibit Alfvénic correlations), we examine the dynamics of large-amplitude Alfvén waves in the expanding solar wind. We develop an analytic model that makes several predictions: switchbacks should preferentially occur in regions where the solar wind plasma has undergone a greater expansion, the switchback fraction at radii comparable to PSP should be an increasing function of radius, and switchbacks should have their gradients preferentially perpendicular to the mean magnetic field direction. The expansion of the plasma generates small compressive components as part of the wave’s nonlinear evolution: these are maximized when the normalized fluctuation amplitude is comparable to sin θ , where θ is the angle between the propagation direction and the mean magnetic field. These compressive components steepen the primary Alfvénic waveform, keeping the solution in a state of nearly constant magnetic field strength as its normalized amplitude δB/B grows due to expansion. The small fluctuations in the magnetic field strength are minimized at a particular θ-dependent value of β, usually of order unity, and the density and magnetic-field-strength fluctuations can be correlated or anticorrelated depending on β and θ. Example solutions of our dynamical equation are presented; some do indeed form magnetic-field reversals. Our predictions appear to match some previously unexplained phenomena in observations and numerical simulations, providing evidence that the observed switchbacks result from the nonlinear evolution of the initially small-amplitude Alfvén waves already known to be present at the coronal base.

Модель біоенергетичного резонансу

The research is devoted to the study of the behavior of the generalizing magnetization vector in the seeds of agricultural crops under the action of longitudinal constant and transverse alternating magnetic fields by the method of nuclear magnetic resonance. Based on the theoretical studies, the value of the average magnetic susceptibility per unit volume of seed χ and the value of the magnetization vector were determined. For the system of microparticles of cells of plant origin, the average magnetic susceptibility per unit volume of seed is χ = 2.1 · 10-5, and the magnetization vector M=13.125 mA/m at a longitudinal constant magnetic field strength H = 625 A/m. When a weak transverse alternating magnetic field is superimposed on the frequency, the oscillation frequencies of the magnetization vectors M coincide with the field frequency, which is a condition for the occurrence of magnetic resonance. The longitudinal magnetization vector during the transition from the ground state to the excited state (resonant) describes a trajectory in the form of a spiral on the surface of the sphere. A mathematical model for a biological system taking into account the Earth's magnetic field is built. It is established that for the technology of pre-sowing treatment of seeds of agricultural crops, the inductor, which creates a constant magnetic field, must be located so that the vector of the constant magnetic field of the inductor coincides with the vector of the Earth's magnetic field. Keywords: bioenergetic resonance, pre-sowing treatment of crop seeds, direct magnetic field, alternating magnetic field, longitudinal and transverse relaxation

Numerical simulation of MHD hybrid nanofluid flow by a stretchable surface

• Flow of hybrid nanofluid, C u , A l 2 O 3 with two base fluids H 2 O a n d C 2 H 6 O 2 is examined • Flow considered through stretching surface • Finite difference scheme is used to solve the system of PDE's • The effect of magnetic field and thermal radiation are examined. Viscous fluid; Finite difference scheme; Magnetic field; Joule heatingThis article investigates the flow of hybrid nanofluid containing nano particles, Copper ( C u ) -Alumina Oxide ( A l 2 O 3 ) with two base fluids Water ( H 2 O ) and Ethylene glycol ( C 2 H 6 O 2 ) over a stretching surface. Magnetic field of constant strength is applied. Effects of Joule heating and viscous dissipation are contributed into energy equation. System of partial differential equation (PDE's) governs the continuity, momentum, and energy equations. Using suitable dimensionless parameters, the system of PDE's is transformed into dimensionless form. Numerical computations made employing finite difference method (FDM). This method converts the nonlinear PDE's to simple algebraic equations and by using variational technique the approximate solution is obtained technique. Impacts of important flow variables on velocity, skin friction and Nusselt number are shown graphically. The velocity decreases for higher Hartmann number and opposite behavior holds for Reynolds number. Temperature decays for Hartmann number while it enhances for Prandtl ( P r ) , Eckert ( E c ) and Reynold numbers. Comparison of both hybrid nanofluids are displayed graphically. It is concluded that C u − A l 2 O 3 / C 2 H 6 O 2 have more thermal conductivity than C u − A l 2 O 3 / H 2 O .

Influence of Magnetic Field upon The Wear of Steel/Steel and Brass/Steel Combinations under Dry and Lubricated Conditions.(Dept.M)

An experimental investigation was carried out to elucidate the role of magnetic field on the wear behavior and surface roughness variations of steel/steel and brass/steel combinations under dry and oil lubricated sliding conditions. A reciprocating pin-on- plate wear testing machine was used with normal loads of either 5 N or 10 N and with maximum sliding speed of 0.03 m/s. A constant magnetic field strength of 796 A/in was applied to the rubbing surfaces during tests conducted in the presence of magnetic field. The results of the experiments show that the presence of magnetic field has a significant effect upon reducing wear rates of both tested combinations of materials under dry and lubricated sliding conditions. Furthermore. an improvement in counterface surface roughness was observed and measured due to the presence of magnetic field between sliding surfaces.

Static Magnetic Field (2–4 T) Improves Bone Microstructure and Mechanical Properties by Coordinating Osteoblast/Osteoclast Differentiation in Mice

Static magnetic field (SMF), with constant magnetic field strength and direction, has a long history of basic and clinical research in bone biology. Numerous studies demonstrate that exposure to moderate SMF (1 mT-1 T) can increase bone mass and bone density. However, few studies pay attention to the effects of high SMF (>1 T) on the skeletal system. To investigate the physiological effects of high SMF on bone, mice were exposed to 2-4 T SMF for 28 days. Bone microstructure and mechanical properties were examined. The activity of osteoblasts and osteoclasts involved in bone remodeling was evaluated in vivo and in vitro. Compared with the unexposed group, 2-4 T significantly improved the femoral microstructure and tibial mechanical properties. For bone remodeling in vivo, the number of osteoblasts and bone formation was increased, and the osteoclastic number was decreased by 2-4 T. Moreover, the expression of marker proteins in the femur and concentrations of biochemical indicators in serum involved in bone formation were elevated and bone resorption was reduced under 2-4 T SMF. In vitro, osteoblast differentiation was promoted, and the osteoclastic formation and bone resorption ability were inhibited by 2 T SMF. Overall, these results demonstrate that 2-4 T SMF improved bone microarchitecture and strength by stimulating bone formation and restraining bone resorption, and imply that high SMF might become a potential biophysical treatment modality for bone diseases with abnormal bone remodeling. Bioelectromagnetics. © 2021 Bioelectromagnetics Society.

Finite element analysis of mixed convection flow in a trapezoidal cavity with non-uniform temperature

A two dimensional flow analysis in a cavity shaped isosceles trapezium is carried out. Non-parallel sides of a trapezium are adiabatic. A varying sinusoidal temperature is applied to the lower wall while the upper wall is at constant temperature. Upper wall of the cavity moves with a velocity η0 in the positive x-direction. Also, B0 is constant magnetic field of strength aligned in the same x-direction and Newtonian fluid is considered. The values of magnetic field parameter used are Ha=0,50, the Richardson number is Ri=0.1,1,10, Re=100 is Reynolds number used for the analysis, the amplitude of sinusoidal temperature is m=0.25,0.5,1. The impacts of different leading parameters are analyzed by plotting streamlines for flow fields and isotherm contours for temperature of the flow dynamics. The graphs that signify the variation of average Nusselt number and local Nusselt number are sketched for both lower and upper walls of the cavity. Result indicated that with constant temperature the top wall of the boundary layer thickness decreases as Richardson number Ri increases and for bottom wall with variable temperature. The Nusselt number gets higher with an increment in the amplitude of the oscillation of temperature function. Furthermore, the study revealed that the average Nusselt number gets reduced as the intensity of magnetic field is enhanced. The variation in transit of heat at the bottom wall is similar but the maximum value of heat transfer at the bottom wall shows a variation from 3.8 to 20 when Ha=0 and from 3 to 18 when Ha=50. The accuracy of the present numerical algorithms is also established.

Asymptotic Growth of the Local Ground-State Entropy of the Ideal Fermi Gas in a Constant Magnetic Field

We consider the ideal Fermi gas of indistinguishable particles without spin but with electric charge, confined to a Euclidean plane {{mathbb {R}}}^2 perpendicular to an external constant magnetic field of strength B>0. We assume this (infinite) quantum gas to be in thermal equilibrium at zero temperature, that is, in its ground state with chemical potential mu ge B (in suitable physical units). For this (pure) state we define its local entropy S(Lambda ) associated with a bounded (sub)region Lambda subset {{mathbb {R}}}^2 as the von Neumann entropy of the (mixed) local substate obtained by reducing the infinite-area ground state to this region Lambda of finite area |Lambda |. In this setting we prove that the leading asymptotic growth of S(LLambda ), as the dimensionless scaling parameter L>0 tends to infinity, has the form Lsqrt{B}|partial Lambda | up to a precisely given (positive multiplicative) coefficient which is independent of Lambda and dependent on B and mu only through the integer part of (mu /B-1)/2. Here we have assumed the boundary curve partial Lambda of Lambda to be sufficiently smooth which, in particular, ensures that its arc length |partial Lambda | is well-defined. This result is in agreement with a so-called area-law scaling (for two spatial dimensions). It contrasts the zero-field case B=0, where an additional logarithmic factor ln (L) is known to be present. We also have a similar result, with a slightly more explicit coefficient, for the simpler situation where the underlying single-particle Hamiltonian, known as the Landau Hamiltonian, is restricted from its natural Hilbert space text{ L}^2({{mathbb {R}}}^2) to the eigenspace of a single but arbitrary Landau level. Both results extend to the whole one-parameter family of quantum Rényi entropies. As opposed to the case B=0, the corresponding asymptotic coefficients depend on the Rényi index in a non-trivial way.

Entropy Generation in a Dissipative Nanofluid Flow under the Influence of Magnetic Dissipation and Transpiration

The present study explores the entropy generation, flow, and heat transfer characteristics of a dissipative nanofluid in the presence of transpiration effects at the boundary. The non-isothermal boundary conditions are taken into consideration to guarantee self-similar solutions. The electrically conducting nanofluid flow is influenced by a magnetic field of constant strength. The ultrafine particles (nanoparticles of Fe3O4/CuO) are dispersed in the technological fluid water (H2O). Both the base fluid and the nanofluid have the same bulk velocity and are assumed to be in thermal equilibrium. Tiwari and Dass’s idea is used for the mathematical modeling of the problem. Furthermore, the ultrafine particles are supposed to be spherical, and Maxwell Garnett’s model is used for the effective thermal conductivity of the nanofluid. Closed-form solutions are derived for boundary layer momentum and energy equations. These solutions are then utilized to access the entropy generation and the irreversibility parameter. The relative importance of different sources of entropy generation in the boundary layer is discussed through various graphs. The effects of space free physical parameters such as mass suction parameter (S), viscous dissipation parameter (Ec), magnetic heating parameter (M), and solid volume fraction (ϕ) of the ultrafine particles on the velocity, Bejan number, temperature, and entropy generation are elaborated through various graphs. It is found that the parabolic wall temperature facilitates similarity transformations so that self-similar equations can be achieved in the presence of viscous dissipation. It is observed that the entropy generation number is an increasing function of the Eckert number and solid volume fraction. The entropy production rate in the Fe3O4−H2O nanofluid is higher than that in the CuO−H2O nanofluid under the same circumstances.

Analysis of Nonlinear Vibrations of Slightly Curved Tripled-Walled Carbon Nanotubes Resting on Elastic Foundations in a Magneto-Thermal Environment

In this work, nonlocal elasticity theory is applied to analyze nonlinear free vibrations of slightly curved multi-walled carbon nanotubes resting on nonlinear Winkler and Pasternak foundations in a thermal and magnetic environment. With the aid of Galerkin decomposition method, the systems of nonlinear partial differential equations are transformed into systems of nonlinear ordinary differential equations which are solved using homotopy perturbation method. The influences of elastic foundations, magnetic field, temperature rise, interlayer forces, small scale parameter and boundary conditions on the frequency ratio are investigated. It is observed form the results that the frequency ratio for all boundary conditions decreases as the number of walls increases. Also, it is established that the frequency ratio is highest for clamped-simple supported and lowest for clamped-clamped supported. Further investigations on the controlling parameters of the phenomena reveal that the frequency ratio decreases with increase in the value of spring constant (k1) temperature and magnetic field strength. It is hoped that this work will enhance the applications of carbon nanotubes in structural, electrical, mechanical and biological applications especially in a thermal and magnetic environment.

Magnetically Actuated Artificial Microswimmers as Mobile Microparticle Manipulators

AbstractMicroscale swimming robots have been envisaged for many biomedical applications such as targeted drug delivery, where the microrobot will be expected to navigate in a fluid environment while carrying a payload. We show that such a payload does not have to be physically bound to the swimmer, but may be instead manipulated by the microrobot through hydrodynamic interaction. We consider a magnetically actuated artificial microswimmer, whose locomotion induces a disturbance velocity field in the fluid, which moves a cargo particle in its vicinity. The problem investigated in this paper is therefore one of coupled locomotion-manipulation of two bodies in a fluid. The swimmer is actuated by a uniform, rotating magnetic field of constant strength leading to net motion in the direction perpendicular to the plane of rotation if the frequency associated with the periodic magnetic field is above a critical frequency. Below this critical frequency, the swimmer tumbles in place without net locomotion. Controlled motion of the particle and swimmer is achieved by switching the planes of rotation of the magnetic field and the frequency of the magnetic field above and below the critical frequency. The results of this paper show that microswimmers can be utilized as mobile manipulators of microparticles in a fluid.