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Presents a direct solution method for the determination of the capacitance, conductance or inductance of static linear problems with the dual finite element method. The direct solution method provides an entirely energy‐based method for the calculation of these global parameters and differs from the conventional solution techniques in that no recourse is required to the intermediate determination of the potential distribution. The direct solution method can be seen as the reduction of a dual circuit parameter network for the finite element representation. Compares the dual‐circuit parameter description with another, well‐known variational method called “Tubes and Slices”. Shows that by aligning the finite element mesh with the approximate positions of the equipotentials and flux lines in the system, the dual finite element model can be simplified to the equivalent of Tubes and Slices model and that both methods can produce exactly the same results.

Quality of the weld joint produced by high-frequency induction (HFI) welding of steel tubes is attributed to a number of process parameters. There are several important process parameters such as the speed of the welding line, the angle of the approaching strip edges, the physical configuration of the induction coil, impeder, formed steel strip and weld rolls with respect to each other, the pressure of the weld rolls and frequency of the high-frequency current in the induction coil. The purpose of this paper is to develop a 3D model of tube welding process that incorporates realistic material properties and movement of the strip.

3D numerical simulation by the finite element method (FEM) can be used to understand the influence of these process parameters. In this study, the authors have developed a quasi-steady model along with the coupling of electromagnetic and thermal model and incorporation of non-linear electromagnetic and thermal material properties.

In this study, 3D FEM model has been established which gives results in accordance with previously published work on induction tube welding. The effect of the Vee-angle and frequency on the temperature profile created in the strip edge during the electromagnetic heating is studied.

The authors are now able to simulate the induction tube welding process at a more reasonable computational cost enabling an analysis of the process.

A 3D model has been developed for induction tube welding. A non-linearly coupled system of Maxwell’s electromagnetic equation and the heat equation is implemented using the fixed point iteration method. The model also takes into account non-linear magnetic and thermal material properties. Adaptive remeshing is implemented to optimise mesh size for the electrical skin depth of induced current in the strip. The model also accounts for the high welding-line speeds which influence the mode of heat transfer in the strip.

The paper explores the geometrical structure of electrodynamics using the algebra of differential forms. Stokes' theorem links the local to the global geometrical features of electromagnetic systems. The gauge invariance of the potentials is shown to be linked to the geometry of a circle in the complex plane, which exhibits the inner geometry of electrodynamics. The total geometry of a system is a combination of this inner geometry with the usual space‐time geometry. The application of these geometrical features to computation is explained.

The purpose of this paper is to examine the current situation in numerical field computation, paying special attention to the role of education in developing new ideas to meet the ever growing demands of industry.

The purpose of this paper is to emphasise the analogies between variational and network formulations using geometrical forms, with the purpose of developing alternative but otherwise equivalent derivations of the finite element (FE) method.

FE equations for electromagnetic fields are examined, in particular nodal elements using scalar potential formulation and edge elements for vector potential formulation.

It is shown how the equations usually obtained via variational approach may be more conveniently derived using integral methods, employing a geometrical description of the interpolating functions of edge and facet elements. Moreover, the resultant equations describe the equivalent multi‐branch circuit models.

The approach proposed in the paper explores the analogy of the FE formulation to loop or nodal magnetic or electric networks and has been shown to be very beneficial in teaching, especially to students well familiar with circuit methods. The presented methods are also helpful when formulating classical network models. Finally, for the first time, the geometrical forms of edge and facet element functions have been demonstrated.

The aim of the paper is to find the effective algorithms of electromagnetic torque calculation.

The proposed algorithms are related to the analysis of electrical machines using the methods of equivalent magnetic networks. The presented permeance and reluctance networks are formulated using FE methods. Attention is paid to the algorithms of electromagnetic torque calculation for 3D models. The virtual work principle is applied. The principle is adapted to the discrete network models. The network representations of Maxwell's stress formula are given.

The proposed method of electromagnetic torque calculation can be successfully applied in the 3D calculations of rotating electrical machines. It can be used for scalar and vector potential formulations. The obtained results and their comparison with the measurements show that the method is sufficiently accurate.

The presented formulas of electromagnetic torque calculation are universal and can be successfully applied in the FE analysis of electrical machines using nodal and edge elements.

The paper seeks to present a methodology using the numerical Schwarz‐Christoffel (SC) transformation in order to extract a subdomain from a simply‐connected source‐free two‐dimensional field domain. The aims to present an application to the design of an electrostatic micromotor.

The methodology can be usefully applied to reduce the size of complicated field regions with irregularly shaped boundaries. In the subdomain, finite‐element (FEM) analyses can then be performed with limited computational effort.

The synthesis of the conditions along the sub‐domain boundary, which is piecewise approximated by potential and flux lines, is carried out by performing repeated field analyses. Several comparisons among FEM and SC results are presented, to validate the proposed approach.

Refined techniques of conformal mapping are used in order to extract a suitable subdomain from a large field domain of an electrostatic micromotor. This allows one to focus the analysis directly on the region where the field distribution is to be investigated.

Presents a review on implementing finite element methods on supercomputers, workstations and PCs and gives main trends in hardware and software developments. An appendix included at the end of the paper presents a bibliography on the subjects retrospectively to 1985 and approximately 1,100 references are listed.

The paper presents a historical review, the state of the art and recent advances in the field of computational electromagnetics at leading universities and research institutes in Poland. Contributions made by Polish scientists to the development of fundamental electromagnetism, as well as to computational methods, are emphasized, and some conclusions are drawn regarding expected future developments.

The purpose of this paper is to evaluate the effect of different drying methods on quality attributes of beetroot slices.

Three drying methods (sun, oven and freeze-drying) were applied to dry fresh slices of beetroot cultivar (Beta vulgaris). The chemical composition, minerals, nitrate, betalains, total phenolic, total flavonoid and color were measured for fresh and dried slices.

The chemical composition, minerals, nitrate, bioactive compounds and color were measured for fresh and dried slices. Regardless of the drying method, the results showed that the chemical composition, total energy, minerals and nitrate of the dried slices were significantly (p=0.05) increased compared to that of fresh slices. Sun and oven drying of the slices significantly (p=0.05) reduced total betalain and betacynin. However, betaxanthin was significantly (p=0.05) increased. Total phenolics content of fresh beetroot was significantly (p=0.05) increased after sun and oven drying but total flavonoids were decreased. The 2,2,-diphenyl-2-picryl-hydrazyl (DPPH) of fresh beetroot was increased significantly (p=0.05) after sun and oven drying. The measurement of the color of the powder showed that there is a decrease in lightness (L) depending on the drying method applied. A maximum reduction in lightness was observed in powder of sun-dried slices. The color of the powder obtained from freeze-dried slices was stable compared to other drying methods.

Beetroot is a rich source of nutrients but with short shelf life. Dried beetroot has more keeping quality than the fresh one.

The study uses beetroot as a rich source of nutrients as well as natural antioxidant source. Betalain compounds are preserved in beetroot and a high source of phenolics and flavonoids. Flavonoids are a group of phenolic products of plant metabolism with high antioxidant properties to protect against diseases without side effects.