Hofmeister (Czechia)

Thin hard layers deposited on cutting tools known as ‘coatings’ serve as a protective barrier against abrasion and adhesion wear, while also protecting against thermal and chemical processes that deteriorate the cutting performance of the tool. Coating properties including non-zero thickness, surface roughness, and chemical composition affect the cutting process significantly when compared to uncoated tools. The mechanical properties of coatings can be compared using specific, standardized measurement methods that provide indirect information about the behavior of the coating in a given application of the machining. In practice, it is necessary to evaluate the cutting ability by experimental testing of a given combination of cutting tool, workpiece, cutting conditions and cutting environment. This article discusses various experimental procedures that help to recognize the suitability of a coating for a particular application. These procedures can be applied alone, or in combination, as required by the cutting process. Each of these procedures have associated advantages and disadvantages, as described in this paper.

Abstract The implicit dynamic solution of multibody and finite element simulations with kinematic constraints requires the assembly of KKT‐like matrices, which are constant in structure, but unsymmetric in the most general case. Basically, the numerical solution is computed by means of a Newton‐Raphson iterative scheme and applying a direct sparse solver in this context demands a reordering step prior to the actual iterative solution procedure. This means that the sparsity pattern of the KKT structure has to be known in advance for all possible configurations and loading situations that are going to be employed along each stand along simulation step.In this contribution, we present a scheme, in which the sparsity pattern is extracted dynamically from the assembly code of KKT‐like matrices. The underlying sparse scheme is transparent to the element and constraint iteration matrix assembly. This is enabled by exploiting the structure and order of events during the element matrix assembly. The proposed strategy is implemented with an object‐oriented programming style in a modern Fortran 2008 environment.

Click to increase image sizeClick to decrease image sizeSummaryThe regulation of the differentiation of protonema in Funaria hygrometrica was investigated. On the one hand it is dependent on substances which are passed on from the protonema to the substrate and from here influence protonema growth and bud-formation.On the other hand the formation and maintenance of a certain state of differentiation is determined by the supply of photosynthesis products, especially NADPH2 from the whole protonema being guaranteed. Transportation from one cell to another in isolated filaments could be clearly proved for nucleotides, sugars and cytokinines.ZusammenfassungDie Regulation der Differenzierung im Protonema von Funaria hygrometrica wurde untersucht. Sie ist einerseits von Substanzen abhängig, die vom Protonema an das Substrat abgegeben werden und von dort aus Protonemawachstum und Knospenbildung beeinflussen.Andererseits ist die Entstehung und Aufrechterhaltung eines bestimmen Differenzierungszustandes dadurch bestimmt, daβ ein Nachschub von Photosyntheseprodukten, insbesondere NADPH2 aus dem Gesamtprotonema gewährleistet ist. Ein Transport von Zelle zu Zelle in isolierten Caulonemafäden konnte für Nucleotide, Zucker und Cytokinine eindeutig nachgewiesen werden.