Mikrosvět elementárních částic, atomů a procesů odehrávajících se mezi nimi je plný podivností. Částice může projít naráz dvěma různými štěrbinami, fotony mohou být navzájem provázané na obrovské vzdálenosti, kočka (alespoň ona pověstná Schrödingerova) může být zároveň živá i mrtvá... Může pozoruhodný kvantový svqt dovolit i stav, kdy by nějaká látka bya sočasně pevná a supratekutá? A mohou kvantové supratekuté systémy pomoci osvětlit jeden z posledních nevyřešených problémů klasické fyziky - turoblenci? Vědci, včetně českých, intenzivné hledají odpovědi. and Jana Olivová.
In this paper we investigate the relations between torsion classes of Specker lattice ordered groups and torsion classes of generalized Boolean algebras.
The contribution is a continuation of [2] which deals with analytic solution of torsion of a bar with simply connected profile, i.e. profile without holes. In this paper the case of multiply connected profile, i.e. profile with holes, is studied. The stress-strain analysis leads to the Airy stress function Φ. On boundary of each hole the function Φ has prescribed an unknown constant value completed with an integral condition. The mathematical model is also derived from the variational principle.
The second part of the paper contains solutions for the ring profile and for comparison also for incomplete ring profiles including the ‘broken‘ ring profile. The results are compared in tables and pictures. and Obsahuje seznam literatury
The contribution deals with strain-stress analysis of torsion of a non-circular bar. Mathematical model is exactly derived and solutions are introduced and visualised for cases of triangular, rectangular and some other profiles. and Obsahuje seznam literatury
We investigate the Zassenhaus conjecture regarding rational conjugacy of torsion units in integral group rings for certain automorphism groups of simple groups. Recently, many new restrictions on partial augmentations for torsion units of integral group rings have improved the effectiveness of the Luther-Passi method for verifying the Zassenhaus conjecture for certain groups. We prove that the Zassenhaus conjecture is true for the automorphism group of the simple group PSL(2, 11). Additionally we prove that the Prime graph question is true for the automorphism group of the simple group PSL(2, 13)., Joe Gildea., and Obsahuje seznam literatury
By a torsion of a general connection $\Gamma $ on a fibered manifold $Y\rightarrow M$ we understand the Frölicher-Nijenhuis bracket of $\Gamma $ and some canonical tangent valued one-form (affinor) on $Y$. Using all natural affinors on higher order cotangent bundles, we determine all torsions of general connections on such bundles. We present the geometrical interpretation and study some properties of the torsions.
One of the most important problems in communication network design is the stability of network after any disruption of stations or links. Since a network can be modeled by a graph, this concept is examined under the view of vulnerability of graphs. There are many vulnerability measures that were defined in this sense. In recent years, measures have been defined over some vertices or edges having specific properties. These measures can be considered to be a second type of measures. Here we define a new measure of the second type called the total accessibility. This measure is based on accessible sets of a graph. In our study we give the total accessibility number of well known graph models such as Pn, Cn, Km,n, W1,n, K1,n. We also examine this new measure under operations on graphs. A simple algorithm, which calculates the total accessibility number of graphs, is given. We observe that when any two graphs of the same size are compared in stability, it is inferred that the graph of higher total accessibility number is more stable than the other one. All the graphs considered in this paper are undirected, loopless and connected.
Total carotenoids assessed spectrophotometrically in crude extracts may be considerably overestimated when high contents of phenolic compounds are co-extracted. In this case, the absorbance tails of phenolics extend well into the blue part of the spectrum, interfering with carotenoid estimation. Extracts of phenolic-rich organs, with a low ratio of photosynthetic to heterotrophic and/or supportive cells (for example, stems or twigs) are vulnerable to such pitfalls and may need chromatographic separation of carotenoids. and E. Levizou, Y. Petropoulou, Y. Manetas.