Nitsche Type Mortaring for some Elliptic Problem with Corner Singularities

The paper deals with Nitsche type mortaring as a finite element method (FEM) for treating non-matching meshes of triangles at the interface of some domain decomposition. The approach is applied to the Poisson equation with Dirichlet boundary conditions (as a model problem) under the aspect that the interface passes re-entrant corners of the domain. For such problems and non-matching meshes with and without local refinement near the re-entrant corner, some properties of the finite element scheme and error estimates are proved. They show that appropriate mesh grading yields convergence rates as known for the classical FEM in presence of regular solutions. Finally, a numerical example illustrates the approach and the theoretical results. Received July 5, 2001; revised February 5, 2002 Published online April 25, 2002     

Numerical simulation of partial discharge propagation in cable joints using the finite difference time domain method

In this second of a series of three papers, the authors investigate partial discharge (PD) detection and propagation in cable joints. The complex nature of cable joints leads to errors when PD analysis is carried out using conventional equivalent circuits. The authors use the finite difference time domain method to determine the transient electromagnetic fields caused by simulated PD in model cable joints.     

Cellulose dyeing parameters of 18 isomeric phenylazo-H-acid dyes containing two different reactive groups

Eighteen isomeric dyes, each based on phenylazo-H-acid and containing two reactive groups, namely a monochlorotriazine group and a sulphuric acid ester of ß-hydroxyethylsulphone, were applied to cotton fabric by an exhaustion process at 60d?C. The following properties were studied: spectra, uptake curves of the dyes before and after adding sodium carbonate, affinity, diffusion rate, and rates of hydrolysis and of reaction with cellulose, as evidenced by fixation and colour yield. Some significant correlations were found, but some missing or poor correlations indicated that there are further parameters or relationships between parameters that remain to be elucidated.     

A framework for application systems engineering

Interactive Application Systems (IAS) attend to the information needs of application experts, i.e. problem-solving end-users within particular application environments. As such, IAS must be customized functionally and behaviourally toward both user and environment. Such customizing must be feasible in an economical fashion. The study claims that this objective is met by appropriate IAS development tools and by a basic IAS architecture that consists of the following main building blocks: a general-purpose dialogue processor that is controlled by a particular user interface specification, called information net; a library of software modules and packages for providing system functions on the basis of reusable software; and a data management system that may, just like the library elements, be procured from outside, perhaps even including an already existing information base. The paper discusses the approach in detail with particular emphasis on information nets and on the integration of reusable software into a total system. The paper argues that the approach is flexible enough to accommodate (rapid) prototyping, i.e. procuring of first versions of an IAS, that may be used during requirements analysis to refine the user wishes, or operationally during an interim period until the final system becomes available.     

Korrosionsverhalten eines seewasserbeständigen,nichtmagnetisierbaren Chrom-Nickel-Molybdän-Stahles hoher Festigkeit

Ausgehend von den Stählen X 5 CrNiMo 17 13 und X 4 CrNiMoN 19 16, Entwicklung höher stickstofflegierter Chrom-Nickel-Molybdän-Stähle zur Steigerung der Festigkeit ohne Beeinträchtigung der Beständigkeit gegen Korrosion. Beschreibung der mechanischen Eigenschaften und der Korrosionsbeständigkeit (Lochfraß, interkristalline Korrosion, Spannungsrißkorrosion) von niob/tantalstabilisierten Stählen mit rd. 0,03% C, 19 bis 23% Cr, 15,5 bis 17,5% Ni, 3% Mo und 0,3 bis 0,4% N.     

Variation of the Microwave Brightness Temperature of Sea Surfaces Covered with Mineral And Monomolecular Oil Films

Airborne microwave radiometer measurements over mineral and monomolecular oil films and adjacent clean sea surfaces are reported. An artificial crude-oil spill experiment in the New York Bight area showed a brightness temperature increase of the sea surface at 1.43 GHz as expected from a multilayered system with different dielectric constants. However, a monomolecular surface-film experiment with oleyl alcohol conducted in the North Sea during MARSEN in 1979 showed a strong brightness temperature depression at 1.43 GHz and no change in brightness temperature at 2.65 GHz. It is postulated that the monomolecular layer, because of its physical and chemical properties, polarized the underlying water molecules so strongly that the emissivity decreased from 0.31 to 0.016. It is estimated that the effective dielectric constant changed from 90 to 5.2 × 104. Because these phenomena occurred at 1.43 GHz it may be concluded that this frequency is very close to the center of a new anomalous dispersion region resulting from a restructuring of the water layer below the surface film.