Dynamical behavior of a boundary layer separation is studied using both theoretical analysis and experimental approach. The dynamical nature of the phenomenon is demonstrated on a simple case of a boundary layer in adverse pressure gradient studied experimentally. The Time-Resolved PIV technique was used to study instantaneous structure of the separation region and its time development. Distinctive coherent structures and their dynamical behavior were identified using the BOD method. and Obsahuje seznam literatury
Článek se zabývá analýzou jazykových prostředků v dialogickém diskurzu literárního díla. Studuje propojení tří paralelně strukturovaných vrstev dialogu v úryvku z románu Penelopy Lively Heat Wave, a to explicitního dialogu mezi postavami románu, vnitřního vzájemného dialogu mezi hrdinkou a postavami románu, a vnitřního dialogu hrdinky románu. Autorka se zároveň snaží popsat a zhodnotit jazykové prostředky, kterými tvůrce literárního díla dosahuje v dialogu autentičnosti, a konfrontuje je s prostředky ozvláštnění významu.
Článek si klade za cíl konfrontovat vyjádření vidovosti ve francouzštině a v češtině a komentuje některé problémy překladu s tím spojené. Zatímco v češtině je slovesný vid gramatikalizován, francouzština musí pro vyjádření vidovosti volit jiné, pro ni specifické prostředky. Autorka se věnuje především oblasti morfologie francouzského slovesa, a to slovesným minulým časům a polemizuje s některými zjednodušujícími vidovými charakteristikami těchto časů. Dochází к závěru, že lze těžko hodnotit situaci v jednom jazyce pomocí kategorií, které fungují v jazyce typologický odlišném a že řešení problému je nutno hledat na úrovni textu.
In this paper we introduce a class of maps possessing a multivalued homotopy lifting property with respect to every topological space. We call these maps multifibrations and they represent a formally stronger concept than that of shape fibration. Multifibrations have the interesting property of being characterized in a completely intrinsic way by a path lifting property involving only the total and the base space of the fibration. We also show that multifibrations (and also, with some restrictions, shape fibrations) have a lifting property for homotopies of fine multivalued maps. This implies, when the spaces considered are metric compacta, that the possibility of lifting a fine multivalued map is a property of the corresponding strong shape morphism and not of the particular map considered.
This paper aims to examine whether self-reported home valuations can be a substitute for objective market data in studies on the level of housing wealth inequality. In order to achieve this aim, information on subjective values of flats and their features in Warsaw (Poland) and Prague (Czechia) was used. Next, hedonic models were estimated to calculate the objective values of these residential properties. The results indicated that, on average, homeowners overestimated their real estate by 2.10% in Warsaw and underestimated by 5.49% in Prague. Finally, using tests for the equality of variances, it was examined whether the level of housing wealth inequality differed significantly when calculated using subjective and objective home values. The findings showed that self-reported home values cannot serve as a perfect proxy for market values when assessing the level of housing wealth inequality in both cities.
Let T be an operator acting on a Banach space X, let σ(T) and σBW (T) be respectively the spectrum and the B-Weyl spectrum of T. We say that T satisfies the generalized Weyl’s theorem if σBW (T) = σ(T) \ E(T), where E(T) is the set of all isolated eigenvalues of T. The first goal of this paper is to show that if T is an operator of topological uniform descent and 0 is an accumulation point of the point spectrum of T, then T does not have the single valued extension property at 0, extending an earlier result of J. K.Finch and a recent result of Aiena and Monsalve. Our second goal is to give necessary and sufficient conditions under which an operator having the single valued extension property satisfies the generalized Weyl’s theorem.
We define Knopp-Kojima maximum modulus and the Knopp-Kojima maximum term of Dirichlet series on the right half plane by the method of Knopp-Kojima, and discuss the relation between them. Then we discuss the relation between the Knopp-Kojima coefficients of Dirichlet series and its Knopp-Kojima order defined by Knopp-Kojima maximum modulus. Finally, using the above results, we obtain a relation between the coefficients of the Dirichlet series and its Ritt order. This improves one of Yu Jia-Rong's results, published in Acta Mathematica Sinica 21 (1978), 97–118. We also give two examples to show that the condition under which the main result holds can not be weakened.
Extrasporogonic stages of Sphaerospora sp. from the kidneys of Atlantic salmon (Salmo salar L.) were successfully transmitted via intra-peritoneal injection to naive Atlantic salmon and brown trout (Salmo trutta L.). Rainbow trout (Oncorhynchus mykiss Walbaum) could not be infected in this way. Transmitted extrasporogonic stages continued their development to form sporogonie stages and mature spores in the kidney tubules. Extrasporogonic stages, sporogonie stages and mature spores of the parasite in both experimentally infected hosts were morphologically identical to the equivalent stage in naturally infected Atlantic salmon, although minor differences were seen in spore dimensions. A farm-based exposure experiment confirmed the susceptibility of brown trout to the salmon Sphaerospora, These results are consistent with the view that the salmon Sphaerospora is Sphaerospora truttae Fischer-Scherl, El-Matbouli et Hoffmann, 1986. The parasite is redescribed according to the guidelines of Lom and Arthur (1989) since details of extrasporogonie stages, the ultrastructure of extrasporogonic and sporogonie stage development, and of the parasite’s epidemiology are known from Atlantic salmon but not from other reports.
The ultrastructure of the scolex tegument, bothridial pits (“ciliated pits) and rhyncheal system of Otobothrium mugilis Hiscock, 1954 is described from plerocerci collected from the teleosts Arius graeffei Kncr ct Steindachner and Mugil cephalus Linnaeus. Scanning electron microscopy revealed that filamentous microtriches with shortened caps are abundant across the entire surface of the tegument. Palmate microtriches are dominant on the bothridia and their margins. The surfaces of bothridial pits were covered with large bifid microtrichcs. The bothridial pits arc strongly muscularised invaginations of the tegument. Nervous tissues were not observed within the pits and it is probable that these structures function as accessory attachment structures. The wall of each tentacle sheath consists of one to three bands of fibrils, lined internally by a thin cytoplasmic layer. The tentacular walls are cellular, containing myofilaments. The fibrils of the tentacular walls are arranged into discrete blocks of parallel fibrils and appear to be intracellular. Tentacular walls are lined externally by a modified membrane with an external glycocalyx. Tentacular hooks arc solid, bound externally by a membrane. The body of the hook contains numerous longitudinal canaliculi and an elcctron-opaquc medulla lies at the centre of the hook.