Due to renaturalization of trained watercourses, the capacity of the channel is often reduced. This paper deals with influence of non-symetrical obstacles placed into channels of small trained streams upon flow characteristics. In the framework of hydraulic research on aerodynamical model, four types of obstacles of various shape were used. An evaluation of their influence on total channel resistance in dependence on depth of flow and a spacing of the obstacles is presented. and Vlivem revitalizačních zásahů do upravených vodních toků zpravidla dochází ke zmenšení kapacity koryta. Předkládaný článek se zabývá vlivem nesymetrických revitalizačních prvků, vkládaných do upravených koryt malých vodních toků, na charakter proudění. V rámci fyzikálního výzkumu na aerodynamickém modelu byly použity 4 typy prvků, které různým způsobem zasahovali do průtočného profilu. V tomto článku je zhodnocen jejich vliv na celkové odpory koryta v závislosti na hloubce proudění a vzdálenosti prvků.
This paper describes the airliner wing flutter sensitivity analysis. The sensitivity coefficients define the influence of the structural parameter changes to tthe structure eigenvalue and flutter stability characteristics. Evaluated structural parameters represent the possible changes of the structure due to the installation of the smart high-lift devices at the leading and trailing edge region. In general, we can suppose the increasing of the mass and mass moment of inertia around the elastic axis and decreasing of the stiffness. Described effects are ordinarily considered destabilizing regarding the flutter. The main aim of the presented work is to evaluate the impact of components to the stability and to define the most critical regions or parameters. and Obsahuje seznam literatury
Assessment of ultimate aeroelastic response of slender facades equipped with thin plexiglass sheets. The wave approach is used for modeling of aeroelastic wind forcing. The analysis of structural response is based on the transient dynamics. Some theoretical approaches are specified with experimental verification in the wind canal. The comparison of numerical and experimental approaches is made in order to demonstrate the efficiency of the procedures suggested. and Obsahuje seznam literatury
The paper studies applications of C*-algebras in geometric topology. Namely, a covariant functor from the category of mapping tori to a category of AF-algebras is constructed; the functor takes continuous maps between such manifolds to stable homomorphisms between the corresponding AF-algebras. We use this functor to develop an obstruction theory for the torus bundles of dimension 2, 3 and 4. In conclusion, we consider two numerical examples illustrating our main results., Igor Nikolaev., and Obsahuje seznam literatury
In this paper it is proved that an abelian lattice ordered group which can be expressed as a nontrivial lexicographic product is never affine complete.
Let $\Delta $ and $H$ be a nonzero abelian linearly ordered group or a nonzero abelian lattice ordered group, respectively. In this paper we prove that the wreath product of $\Delta $ and $H$ fails to be affine complete.
Identities for the curvature tensor of the Levi-Cività connection on an almost para-cosymplectic manifold are proved. Elements of harmonic theory for almost product structures are given and a Bochner-type formula for the leaves of the canonical foliation is established.
Based on the study of type material, two new genera of cestodes (Cyclophyllidea: Anoplocephalidae) are proposed for Paranoplocephala Lühe, 1910 sensu lato species from African rodents. Afrojoyeuxia gen. n., proposed for A. gundii (Joyeux, 1923) comb. n. from Ctenodactylus gundi (Rothmann) (Hystricomorpha: Ctenodactylidae), is characterized by a high length/width ratio of mature proglottids, longitudinally extensive testicular field positioned anterior to the female glands, an ovoid or subspherical cirrus-sac and a thick, conical cirrus. Hunkeleriella gen. n., proposed for H. dasymidis (Hunkeler, 1972) comb. n. from Dasymys incomtus (Sundevall) (Myomorpha: Muridae), differs from related genera mainly by its short (10-20 mm) and wide strobila and neck, unilateral genital pores (exceptionally with a few changes per strobila), the position of the genital pores (slightly anterior to the middle of proglottid margin) and initially tube-like early uterus (later reticulated). Parandrya Gulyaev et Chechulin, 1996, earlier suggested to be a junior synonym of Paranoplocephala, is considered to be a valid, independent genus. Evidence of non-monophyly and need for a taxonomic revision of Paranoplocephala sensu lato, as well as the phylogenetic position of A. gundii and H. dasymidis are discussed.