This paper investigates the reason behind the low magnetic field computation in cylindrical coordinates using finite difference method, when boundary conditions of the third or fourth kind are used. The same field computation has also been performed using the finite element method but this problem did not occur. It thus, presents a technique to overcome the problem of low magnetic field calculation using finite difference method. The results obtained by the new technique are in close agreement with the finite element method as well as the analytical solution. Finally, an analysis of the possible source of error in modeling MAGNETOSTATIC boundary conditions in finite difference formulation of vector Poisson or Laplace equation in cylindrical coordinates is performed.

In this paper, the self-focusing property of an intense circularly polarized laser pulse in hot magnetized plasma is investigated theoretically. First, an envelope equation governing the spot-size of the laser beam for both left-and right-hand polarizations has been derived in the presence of a planar wiggler. Furthermore, non-linear dispersion relation of laser pulse is obtained by using Maxwell’ s equations and relativistic fluid momentum equation. The numerical results show that with increasing the wiggler field, strength self-focusing of the right-hand polarization laser pulse is enhanced, while for the left-hand polarization, laser de-focusing is enhanced. In addition, it is shown that with increasing the wiggler frequency, the normalized laser power has an enhancing behavior. Besides, it is found that effect of the wiggler field on the density profile in the right-hand polarization is more prominent.

The effect of length variation on the magnetic properties of NiFe alloy nanowires electrodeposited into the alumina template was investigated. The diameter (45±2.5 nm) and length (~1.9, 7.12, 8.3, 9.5 and 13.3mm) of the nanowires were estimated from scanning electron microscopy images. Energy dispersive spectroscopy results showed Ni3Fe7 composition of the alloy nanowires. The magnetic properties of the samples were investigated by vibrating sample magnetometer. It showed that with increasing the length of the nanowires from 1.9±0.1mm to 13.3±0.66mm, coercivity reduced from 1050 Oe to 705 Oe and squareness reduced from 0.64 to 0.46. The results proved increasing the MAGNETOSTATIC INTERACTION between the nanowires with length. Progress toward the multi-domain behavior was predicted caused to drastically reduce in the coercivity.

To assesse the iron and silicon effects on the yield and physiological characteristics of green pea, Wando cultivar by ASGrow Corporation was used in three levels of iron chelate (0.05, 0.1 and 0.3 gr per l-1) and silicon (0, 14 and 28 mg per l-1), as a factorial experimental in completely randomized design with three replications. In this experiment, characterisics such as fresh and dry weight of grain, the number of grain per pod, concentration of Fe, Cu, Mn, Zn and Si in leaf and grain were measured. Results showed that the INTERACTION of Fe and Si was significant at p<0.01 on grain fresh and dry wigeht, concentratin of leaf and grain Fe, leaf Mn, leaf and grain Zn and leaf Si and the application of Fe and Si was significant separately, on other traits such as number of grain per pod, concentration of leaf and grain Cu, Mn and Si in grain.  The Mean squares showed that the application of Fe and Si significantly increased fresh and dry grain weight and Si laef concetration and decreased the concentratin of leaf and grain Fe and Mn as well as grain Mn.  The enhancement of Fe and Si application separately decreased the concentration of Mn, Cu and zinc leaf and grains, but the Si concentration of leaf and grain were increased by Si application. The concentration of Fe, Mn, Cu and Zn were decreased in leaf and grain because of antagonistic effects. It can be concluded that Si reduces the harmfull effects of high levels of iron toxicity and the application of 0.1 g/l and 25 mg/l can be recommended as the best treatments.

Fe49Co33Ni18 nanowire arrays (175 nm in diameter and lengths ranging from 5 to 32mm) were fabricated into nanopores of hard-anodized aluminum oxide templates using pulsed ac electrodeposition technique. Hysteresis loop measurements indicated that increasing the length decreases coercivity and squareness values (from 274 Oe and 0.58 to200 Oe and 0.105, respectively), indicating the increase in MAGNETOSTATIC INTERACTIONs between the nanowires (NWs).On the other hand, first-order reversal curve measurements showed a linear correlation between the MAGNETOSTATIC INTERACTIONs and length of NWs. It was also found that with increasing length, the domain structure of NWs changed from single-domain to pseudo single-domain state. A multidomain-like behavior is also seen for the longest NWs length. Increasing the length of NWs resulted in an increase inthe INTERACTION and decrease in the array coercive field (Hc Array) as beingsmaller than that of individual NWs (Hc FORC).The observed CFD component in the FORC diagrams of FeCoNi NWs with shorter lengths was a consequence of non-uniform length distributions.

The computation of magnetic field distribution around conducting structures due to current-carrying conductors is used in a wide range of industrial applications, including eddy-current and magnetic-shielding problems. This paper presents an analytical modeling technique for evaluating the electromagnetic field distribution in magneto static regime due to an arbitrary wire loop in the vicinity of a conducting half space. The technique uses the two-dimensional Fourier transform to solve the governing equation formulated in terms of a magnetic scalar potential. The main feature of the model is its ability to analyze two and three-dimensional excitation geometry, with similar degree of computation burden. This feature stems from the fact that in this model, knowledge of the field distribution at the place of the conductor surface in free space suffices to compute the filed in the presence of the conductor. To demonstrate the accuracy of the model, we consider two special cases of rhombic and elliptic wire inducers. The comparison of our results with those obtained using the conventional algorithm in the literature validates the accuracy of the model introduced in this paper. To show the generality of the model, we also present results associated with a wire - loop inducer with a three - dimensional geometry for which no analytical solution is available in the literature.

This paper poses two MAGNETOSTATIC problems in cylindrical with different ‎permeabilities for each region. In the first problem the boundary condition of the ‎second kind is used while in the second one, the boundary condition of the third kind ‎is utilized. These problems are solved using the finite element and finite difference ‎methods. In second problem, the results of the finite difference method show low ‎magnetic vector potential as well as the magnetic field density when compared t the ‎finite element results and in the linear case, to the analytical solution. This paper ‎investigates the reason behind the low MAGNETOSTATIC field computation in cylindrical ‎coordinates using the finite difference method when boundary condition of the third ‎kind is used. It then, presents a technique to overcome the problem of low magnetic ‎field calculation using the finite difference method. The results obtained by the new ‎technique are in close agreement with the finite element method as well as the ‎analytical solution. Finally, it analyzes the possible source of error in modeling ‎MAGNETOSTATIC boundary conditions in finite difference formulation of vector Poisson ‎or Laplace"s equation in cylindrical coordinates‎‏.‏