On the theoretical understanding of nanocrystalline soft magnetic materials

Nanocrystalline structures offer a new opportunity for tailoring soft magnetic materials. The most prominent examples are devitrified glassy FeCuNbSiB alloys, which exhibit a homogeneous ultrafine grain structure of bcc FeSi, with grain sizes of typically 10 to 15 nm and random texture. Due to the small grain size, the local magnetocrystalline anisotropy is randomly averaged out by exchange interactions so that there is only a small anisotropy net effect on the magnetization process. Moreover, the structural phases present lead to low or vanishing saturation magnetostriction. Both the suppressed magnetocrystalline anisotropy and the low magnetostriction provide the basis for the superior soft magnetic properties comparable to those of Permalloys or near-zero magnetostrictive Co-base amorphous alloys, but at a higher saturation induction.     

Developments in Plasma Processes for Extractive Metallurgy

With the recent availability of commercial plasma-generating devices capable of reliable performance at powers as high as 30 MW, the applications of plasma technology in high-temperature extractive metallurgy are rapidly increasing. Some of the more promising process developments are reviewed in this paper, as are newer reactor designs.     

Current and future materials in advanced gas turbine engines

Future gas turbine engines will have better fuel efficiencies and lower operating costs. This will require new and advanced materials with higher temperature capabilities. This paper discusses some of the presently applied materials in the turbine section of gas turbines, and reviews the material developments that are occurring and will be necessary for the near and long term futures. Reprinted from “Sermatech Review, Number 51, Spring 1995≓, Sermatech International Incorporated, 155 S. Limerick Road, Limerick, PA 19464-1699. Tel: (610) 948-5100, Fax: (610) 948-0811. The acknowledgment section indicates where this paper originally appeared.     

Intermetallic phase formation in directionally solidified Al−Si−Fe alloy

The present study has been undertaken to better understand the solidification behavior of Al−Si−Fe alloys containing 7wt.% Si and 0.9wt.% Fe, with particular regard to the formation of phase during controlled solidification and influence of growth rates on intermetallic phase selection. The alloys studied were Al-7Si-0.9Fe alloys, which were produced by a modified Bridgman solidification arrangement. These alloys were solidified unidirectionally with different growth rates (1–30mm/min). The solidified microstructure of these alloys consists of the growth of primary aluminum and multiple second phase reactions.     

Modeling Close Packing of 3D Objects

The paper represents the concept of Φ-functions and quasi Φ-functions as an efficient tool for mathematical modeling of three-dimensional packing problems for convex geometrical objects with continuous translations and rotations. A mathematical model of close packing of convex geometrical objects is formulated and its basic properties are considered. A solution method is proposed, which includes the following stages: constructing initial points, computing local extrema, and passing from one local minimum to another. The solution approach is efficient to solve optimization packing problems. Numerical examples are given.     

Generalized differentiability and integrability for fuzzy set-valued functions on time scales

This paper deals with the fuzzy set-valued functions of real variables on time scale whose values are normal, convex, upper semicontinuous and compactly supported fuzzy sets in \(\mathbb {R}^{n}\). We introduce and study the fundamental properties of new class of derivative called generalized delta derivative (\(\Delta _{g}\)-derivative) and generalized delta integral (\(\Delta _{g}\)-integral) for such fuzzy functions.     

Mathematical modeling of the dynamics of anomalous migration fields within the framework of the model of distributed order

The authors perform mathematical modeling of the dynamics of a locally nonequilibrium (in time) geomigration process in a geoporous medium saturated with a salt solution, on the basis of a sub-diffusion model described by a distributed-order system of equations.