Guides “bimorphes” d''ondes ultrasoniques “bimorph” ultrasonic wave guides”

An analysis of the dispersion of elastic waves is presented for two types of long ultrasonics wave-guides that we qualify of “bimorph”: (i) a “three-layer” guide made of two different materials and (ii) a “clad core” guide built up of a rectangular core surrounded by a cladding, the materials of the rod and cladding having different properties. An analytical model is proposed to describe the extensional, flexural and torsional motions in “bimorph” wave guides having two geometrical and material symmetry axes. The asymptotic behaviour of the model allows one to select the material properties which lead to modes guided essentially either in the central layer or in the core of the bimorph guide. Moreover, the dispersive properties of a “bimorph” can be controlled through the choice of geometrical and material parameters.     

„Ideale“ Lötverbindung und „optimale“ Lötverbindung

If due to the market analysis a company makes the decision for the production of a new product by application of soldering and special the soldering with temporarily liquid solder, this one is then made specifically after that the company specific construction and production preparation. Either the decision for soldering is technically and/or economically well‐founded or she is even unavoidable by so‐called mixed material connections in the assemblies. This hybrid design finds application increasing today. In the contribution on hand the analysis and assessment of the soldering theory and practice is carried out under the point of view of the possible production of “ideal soldered connections” and “optimal soldered connections”.     

“Low-Tech” Innovations

This paper is about an industrial sector which, according to the usual socio-scientific indicators, is referred to as “low-tech”, respectively as non-research intensive and which mostly comprises “traditional” industries. The interest in this sector is motivated by the contradictory situation that, on the one hand, the debate about the perspectives of modern societies focuses on the rapidly growing importance of technological innovations, knowledge and research-intensive economic sectors while, on the other hand, traditional industries make up a considerable fraction of employment and production, especially also in developed economies. On the basis of the results of extensive empirical research, this contribution tries to find answers to the basic question, whether one can speak of an innovation mode typical of the low-tech sector. The institutional based innovation systems approach forms the categorical basis of the analysis. In order to elucidate the specific features of low-tech innovations, they are, in conclusion, compared to the general characteristics of high-tech-based innovation processes.     

Differentiation between the terms ”confined masonry“ and ”infill masonry“

This publication concerns the differentiation between the terms ”confined masonry“ and ”infill masonry“ using the example of the national technical approval Z‐17.1‐1145 – POROTON S9 MW –vertically perforated clay units with integrated thermal insulation using thin layer mortar [1].     

“Style” and technology

A rational approach to dealing with the problems created by developing technologies requires a new account of what is involved in proper management. A tripartite distinction is introduced between being reasonable, being rational, and having style. These notions are based on the commonsense principle of rationality (CPR), to be rational one must learn from experience. The proper management of technology requires more than learning from experience (being rational) and having the proper goals (being reasonable); it requires style, which entails being reasonable and acting in accordance with a given standard systematically over time.