71 research outputs found
Contributions of the Geophysical Institute of the Slovak Academy of Sciences. Series of meteorology
Available from Slovak Centre of Scientific and Technical Information, under signature: A559682 / Slovenska Technicka Univerzita v BratislaveSIGLESKSlovak Republi
Nanocomposite SAC solders: morphology, electrical and mechanical properties of Sn–3.8Ag–0.7Cu solders by adding Co nanoparticles
The effect of nanosized Co admixtures on the microstructure and physical properties of Sn–3.8Ag–0.7Cu solder and corresponding solder joints was investigated. The composite Sn–3.8Ag–0.7Cu ribbons with minor additions of Co nanoparticles (up to 1.0 wt%) were fabricated using the conventional planar flow casting method. The structure of nanostructured alloys was studied by X-ray diffraction and transmission electron microscopy. The electrical resistivity of Sn–3.8Ag–0.7Cu ribbons doped with nanoCo was measured by the standard four-point method. The microstructure and mechanical properties of corresponding solder joints (with Cu as substrate) were studied. It was shown that nanoCo additions led to minor changes in the electrical resistivity of Sn–3.8Ag–0.7Cu solder ribbons, while the nanoCo doped Sn–3.8Ag–0.7Cu solder joints (up to 0.5 wt% Co) revealed the reinforced microstructure accompanied by enhanced mechanical properties.© The Author(s) 201
Soil moisture and runoff generation in small mountain basin
This publication is the national report 1997 of the International Hydrological Programme UNESCO project 1.1 FRIENDAvailable from Slovak Centre of Scientific and Technical Information, under signature: A560687 / Slovenska Technicka Univerzita v BratislaveSIGLESKSlovak Republi
Experimental Study of Phase Composition of B-Fe-Mn-V Alloys and Thermodynamic Calculations of Phase Equilibria in the B-Mn-V and B-Fe-Mn-V Systems
Phase compositions of B-Fe-Mn-V alloys were studied by several experimental methods (DTA measurement, X-ray diffractions, and scanning electron microscopy). Besides the experimental study of the quaternary system, thermodynamic modelling of the ternary B-Mn-V system by the Calphad method and thermodynamic calculations for the quaternary B-Fe-Mn-V system were performed. Calculations for the quaternary system are based on the ternary subsystems (B-Mn-V, B-Fe-V, B-Fe-Mn, and Fe-Mn-V). Boron is modelled as an interstitial element in all solid solutions of vanadium, manganese, and iron. Very good agreement between experimental results and thermodynamic calculations was achieved. The created thermodynamic database is suitable for thermodynamic calculations of phase diagrams for all the ternary subsystems and also for the B-Fe-Mn-V quaternary system.© 2018 Viera Homolová et a
Strukturne suvislosti vyvoja transformujucej sa ekonomiky SR Pracovne materialy
This paper analyses the main tendencies in the Slovak economy development during the process of transformation of centrally planned economy into market one. Analysis is based on two input-output tables for the years 1987 and 1993 and compares economic structures and relations in two different periods: before velvet revolution and in the first year of existence of independent Slovak republic. This analysis is focused on the main structural changes in development of basic indicators used in system of national accounts such as gross output, intermediate consumption and final uses as well as imports and exportsAvailable from Slovak Centre of Scientific and Technical Information, under signature: A559965 / Slovenska Technicka Univerzita v BratislaveSIGLESKSlovak Republi
Viola elatior, V. pumila and V. stagnina in Austria, Czechia and Slovakia: a story of decline
Specimens of Viola elatior (VE), V. pumila (VP), and V. stagnina (VS) in 38 Austrian, Czech, and Slovak public herbaria were revised, and almost 1700 specimens were found from the three countries. Apart from VE, the quality of original identifications was rather poor, especially of VS specimens (VS is frequently confused laso with V. canina). This, together with nomenclatural confusion lasting over the whole 19th century, makes the use of old literature records rather problematic. Hybrids are usually difficult-to-identify, and they are rarer than generally believed. VS and VP have similar distribution patterns: they occur mainly in floodplains of large lowland rivers and adjacent hill countries of the N part of Bohemia, in S and Central Moravia, E Austria, and S Slovakia; they may be classified as river corridor plants. VS differs from VE and VP mainly by its presence in S Bohemia and its absence from large parts of S Slovakia, as well as by its rarity in Austria and Slovakia. All three species grow predominantly in regions with relatively warm and dry climate: most localities are situated in regions with mean annual temperature 7–11 °C and mean annual precipitation 401–700 mm. A temporal analysis of records has shown that all three species have been declining in all three countries: generally, this decline has been the weakest in Austria, with 46–61% of grid cells with occurrences confirmed after 1980 (compared with the number of grid cells with records from 1801–2008), and the strongest in Slovakia, with 18–32% of grid cells with occurrences confirmed after 1980. The causes of decline include mainly river canalization and subsequent changes in land use, as well as urbanization, and recently also afforestations. VE may also be endangered by modern forestry practices. The inclusion of all three species in national Red Lists and subsequent conservation measures are justified and necessary, though national Red List status may be different
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