This work focuses on analysis of longfiber unidirectional carbon-epoxy composite using finite element method on a unit cell. A micromechanical model of he unit cell is created in computational system MSC Marc using orthotropic elastic fibers and isotropic elastoplastic matrix. The plasticity of the matrix is prescribed in the model by a hardening function. Material parameters of the
micromodel are identified using gradient optimization method in OptiSLang system. In the optimization, stress-strain relations obtained from the micromodel are compared with the stress-strain relations from a nonlinear macromodel. The macromodel of the composite material was created in author‘s previous work. Parameters of the macromodel were identified from experimental tensile tests also using optimization with MSC Marc and OptiSLang. and Obsahuje seznam literatury
Toxoplasma gondii Nicolle et Manceaux, 1908 is an obligate intracellular parasite with the ability to infect mammals and birds. The only definitive hosts for T. gondii are felids, as the parasites form immature oocysts that are shed in the faeces. Here we introduce cat cells as a model for the study of experimental toxoplasmosis. We selected epithelial cells derived from cat kidneys (CRFK) as a target to determine the intracellular fate of bradyzoites of the T. gondii ME49 strain. In parallel, we compared this infection using epithelial cells from the rat intestine (IEC-6), considering the enteroepithelial development that occurs in the cat. Different ratios of parasites to host cells were assayed over the course of a 14-day-infection. The intracellular development of T. gondii was dependent on the source of the epithelial cells and also on the parasite/host cell ratio. Cystogenesis was well established in the CRFK cell line at a ratio of 1 : 10 after 10-14 days of infection. This cellular model system opens a new field of investigation into the molecular aspects of the interactions between T. gondii and feline epithelial cells. The CRFK cell line appears to be a potential cellular model for large scale cyst production in vitro, which would allow a reduction in the number of animals used and/or replacement of animals by in vitro cultures.
An application of Mittag-Leffler lemma in the category of quotients of Fréchet spaces. We use Mittag-Leffler Lemma to prove that for a nonempty interval ]a, b[⊂ R, the restriction mapping H∞(]a, b[+iR) → C∞ (]a, b[) is surjective and we give a corollary.