555 research outputs found
Examination of mechanical and medical application properties of coronary stents
The medical application properties of coronary stents describe their behaviour in the human vascular system from planting to functioning. However these properties have great importance to surgeons, not all of them have standardized examination methods. In our study we demonstrate three procedures, which can be used to examine stents, considering the referred properties, like flaring, trackability and MSA (metallic surface area). In the course of our research four stents were investigated, three made of tube and one made of wire, and the results were promising about the application of these methods described in the followings
Corrected synonymies: the identities of Strymon bicolor (Philippi, 1859) and Strymon heodes (Druce, 1909) (Lepidoptera: Lycaenidae)
The South American hairstreak species Strymon bicolor (Philippi, 1859) and S. heodes (Druce, 1909) are diagnosed and their synonymies are revised. The distribution of S. bicolor is restricted to the Andean-Patagonian region south of the Atacama Desert and represented now in Argentina and Chile by seven available species group names, considered as subjective synonyms. However, some of these names can most probably be considered as valid taxa. A key to identification is given for distinguishing the superficially most similar Strymon species patterned by orange scaling in the dorsal wing surfaces. It is noted that the Austral S. bicolor group and the Central Peruvian S. heodes appear to belong to a mimicry ring inhabiting the dry areas of the Andes
Does Institutional Trust in East Central Europe differ from Western Europe?
A tanulmány az intézmények iránti állampolgári bizalom mintázatait vizsgálja Nyugat-, illetve Kelet-Közép-Európában az ESS adatait használva
Analysis of 355 nm Nd:YAG laser interaction with patterned flexible circuit substrates
This paper describes a new approach in modeling the interaction and ablation mechanisms of 355 nm Nd:YAG laser and polyimide material.
Generating micro-structures by laser micromachining of inhomogeneous patterned flexible substrates is limited because only a rough estimation on etch rate is possible with a specific set of process parameters. In order to exploit the potential of laser micro-machining, i.e. to generate structures in the resolution range of the focal spot diameter (~10-20 &mu m), the effect of laser beam needs to be calculated pulse-by-pulse.
The novelty of the model is that it incorporates the main beam properties of a solid-state laser, the structure of the substrate and the accumulated heat caused by successive pulses, while it eliminates the details of molecular processes which are still considered but only by means of
experimental constants.
The model also introduces a new conception of ablation threshold as it is defined as a temperature value instead of pulse energy. This allows the calculation of the amount of ablated material by determining the temperature distribution of the processed material after each laser pulse. This way the model can also take the patterned inhomogeneous structure of the substrate into account, thus allowing material processing by lasers at high resolution.
Experimental and simulation results are compared and evaluated to obtain the model constants (like ablation threshold temperature, transformation efficiency of pulse energy into heat etc.) for 355 nm Nd:YAG lasers and polyimide materials and also for the verification of the model
Does Institutional Trust in East Central Europe differ from Western Europe?
A tanulmány az intézmények iránti állampolgári bizalom mintázatait vizsgálja Nyugat-, illetve Kelet-Közép-Európában az ESS adatait használva
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