The paper presents results from three large scale experiments on seven reinforced concrete panels obtained during an extensive experiemental program. This was aimed at possible application of cement reduced (fly ash replaced)) concretee in the production of precast segmental linings for tunnels created by a tunnel boring machine (TBM). In particular, this paper is focused on the comparison of fire resistance of enhanced mixtures loaded by the Rijkswaterstaat (RWS) fire curve, which assumes 50 m3 fuel tanker fire lasting for 120 minutes. The presented results include spalling, overall damage of the surface and temperature distribution of the tested panels The paper also presents description of the proposed method for the evaluation of the extent of spalling during the experiments since, due to the extreme temperatures, the direct observation of the exposed surface is not possible. and Obsahuje seznam literatury
Thermal silica-based geopolymer composites reinforced by approximately 45 vol.% of unidirectional carbon HTS 5631 1600tex 24K fibers were synthesized and fabricated at optimal range of curing conditions, the effects of thermal exposure in a forced air furnace at high temperatures up to 1000 °C for 1 hour on the thermal-mechanical properties of the geocomposites were studied. The flexural properties of the resulting composites were determined on a universal testing machine under three-point bending mode in accordance with ASTM C 1341-06 and the results show that the mechanical properties of geocomposite retained nearly 50 to 60%, after thermal exposure up to 1000 °C, in comparison with these of the geocomposite tested at 20 °C. The microstructure of the geocomposites was analyzed by means of Scanning Electron Microscope (SEM) after calcination, at temperature higher than 800 °C the microstructure of geocomposite looks like foamed composites and the adhesion between the fiber and matrix still show very well. Energy Dispersive X-ray Analysis (EDX) was used to determine the initial reaction layer on the fiber will be presented as well. and Termické geopolymerní kompozity na bázi křemene zesílené asi ze 45 objemových procent jednosměrovými uhlíkovými vlákny HTS 5631 1600tex 24K byly syntetizovány a vyrobeny za optimálního rozsahu vytvrzovacích podmínek. Byl studován vliv teplotní expozice sálací pece až 1000 °C po dobu jedné hodiny na tepelně mechanické vlastnosti geokompozitů. Ohybové vlastnosti získaných kompozitů byly zjištěny pomocí univerzálního zkušebního stroje ve tříbodovém ohybovém modu v souladu s ASTM C 1341-06. Výsledky ukazují, že mechanické vlastnosti geokompozitů se po teplotní zátěži až 1000 °C zachovávají z 50 - 60 % ve srovnání se zkoušenými kompozity při 20 °C. Mikrostruktura geokompozitů po kalcinaci byla analyzována pomocí elektronového skenovacího mikroskopu (SEM) při teplotě nad 800 °C. Mikrostruktura geokompozitů připomíná pěnové kompozity, adheze mezi vlákny a matricí je stále velmi dobrá. Rovněž bylo ukázáno, jak byla užita energetická disperzní rentgenová analýza (EDX) pro určení výchozí reakční vrstvy.
The type species of the genus Glossocercus Chandler, 1935, G. cyprinodontis Chandler, 1935, was described as metacestode (larval stage) from the mesentery of the sheepshead minnow fish (Cyprinodon variegatus Lacépède) from Galveston Bay, Texas. The description was based on the morphology of the rostellar hooks; however, the features of the internal morphology of the proglottides could no be provided. In the present study we describe for the first time the features of the adult G. cyprinodontis from the intestine of Pelecanus occidentalis Linnaeus, Nycticorax nycticorax Linnaeus and Egretta rufescens Gmelin in Mexico. Glossocercus cyprinodontis possesses similar strobilar morphology with the two other congeneric species, both distributed in the Neartic and Neotropical regions, i.e. Glossocercus caribaensis (Rysavy et Macko, 1971) and Glossocercus auritus (Rudolphi, 1819). However, G. cyprinodontis differs mainly in the shape of the rostellar hooks (those of G. cyprinodontis possess the handle and the guard strongly sclerified compared to those of G. auritus and G. caribaensis) and their size (total length of 175-203 mm in G. cyprinodontis compared to 189-211 mm in G. caribaensis and 220-285 mm in G. auritus). Generic diagnosis of Glossocercus is emended: rostellar hooks in two rows with ten hooks of different shape and length in each, scolex large and globular, proglottides craspedote, wider than long, genital pores irregularly alternating, vagina transverse, surrounded by epithelial cells, ventral to cirrus-sac, uterus bar-shaped in mature proglottides, occupies all space between osmoregulatory ducts with eggs in gravid proglottides, ovary lobed in middle of proglottis, cirrus-sac elongate, between osmoregulatory canals, cirrus armed with spinitriches and apical tuft of slender spinitriches.
The male of the gonad-infecting nematode Philometra filiformis (Stossich, 1896) (Philometridae) is for the first time described, based on specimens from the ovary of the marine fish Pagellus erythrinus (Linnaeus) from the Tyrrhenian Sea off Sicily, Italy. It is mainly characterized by the testis extending anteriorly nearly to the anterior end of body, the oesophagus without a usual anterior inflation, the absence of a dorsal barb or distinct transverse lamellae on the tip of the gubernaculum, the measurements of the spicules and the gubernaculum, and a fairly long body.
Three new species of dicyemid mesozoans are described for the first time from Australian octopus and cuttlefish species. Dicyemennea floscephalum sp. n. is described from Octopus berrima Stranks et Norman (southern keeled octopus) collected from Spencer Gulf and Gulf St. Vincent, South Australia, Australia and represents the first description of a species of Dicyemennea Whitman, 1883 from Australian waters. Dicyema papuceum sp. n. and D. furuyi sp. n. are described from Sepia papuensis Hoyle (Papuan cuttlefish) collected from Shark Bay, Western Australia, Australia. Dicyemennea floscephalum sp. n. is a medium to large species that reaches approximately 4.9 mm in length. The vermiform stages are characterised by having 23-28 peripheral cells, and a disc-shaped, flower-like calotte in larger individuals. An anterior abortive axial cell is absent in vermiform embryos and verruciform cells were not observed in nematogens and rhombogens. Infusoriform embryos comprise 37 cells; one nucleus is present in each urn cell. Dicyema papuceum sp. n. is a small species that reaches approximately 1.1 mm in length. The vermiform stages are characterised by having 30-33 peripheral cells and a relatively small, cap-shaped calotte. An anterior abortive axial cell is absent in vermiform embryos and verruciform cells were occasionally observed in nematogens. Infusoriform embryos comprise 37 cells; two nuclei are present in each urn cell. Dicyema furuyi sp. n. is a large species that reaches approximately 5.3 mm in length. The vermiform stages are characterised by having 22-24 peripheral cells and an elongate calotte. An anterior abortive axial cell is absent in vermiform embryos and verruciform cells were not observed in nematogens and rhombogens. Infusoriform embryos comprise 37 cells; one nucleus is present in each urn cell. Three secondary nematogens were also observed in the right renal appendages of two host individuals, confirming the occurrence of this form.
Two species of mayfly nymphs, Habroleptoides modesta (Hagen) and Habrophlebia lauta (Eaton) (Ephemeroptera: Leptophlebiidae), were found as suitable experimental intermediate hosts of the fish nematode Rhabdochona denudata (Dujardin, 1845) (Rhabdochonidae), an intestinal parasite of Palaearctic cyprinids. The parasite's eggs were obtained from nematode gravid females parasitizing the European chub, Leuciscus cephalus (L.), of the Rokytná River, Czech Republic. At the water temperature of 9°C, the eggs of R. denudata were ingested by the intermediate host and the hatched, toothed (with a minute cephalic boring tooth) first-stage larvae about 200 µm long penetrated into the body cavity of the mayfly. There the larvae grew and moulted twice (on 16-18 and 30-35 days p.i.) before attaining the third stage, which is already infective for the fish definitive host. Infective larvae of this stage were about 1.5 mm long and their morphology resembled that of adults except for the vestibule structure; they became encapsulated as in those of other congeneric species.
Metacestodes of Mesocestoides sp. were recorded from Sturnus vulgaris (Passeriformes: Sturnidae) in the Czech Republic in April 2002. They were found in a cutaneous cyst and in the thoracic region of the body cavity of the bird. This is the first record of metacestodes of Mesocestoides sp. in this host species in Europe as well as the first finding of the formation of a cutaneous cyst provoked by this parasite. Additional specimens from Apodemus agrarius (Mammalia: Rodentia) from Bulgaria and Lacerta agilis (Reptilia: Squamata) from the Czech Republic were compared with that from S. vulgaris. Sequence data from the V4 variable region (18S rDNA) were used to compare genetic variability among these and previously characterized isolates of Mesocestoides spp. A number of distinct clades were recognized, with metacestodes from L. agilis showing the highest degree of relative divergence.
Potorolepis gulyaevi sp. n. (Cestoda: Hymenolepididae) is described from the Chinese horseshoe bat, Rhinolophus sinicus Andersen (Chiroptera: Rhinolophidae), from southern China. The new species differs from known species of the genus by the shape, number and size of rostellar hooks, the relative position and length of the cirrus-sac and the morphology of gravid uterus. This is the first report of a member of the genus from non-marsupial mammals and the first record of a Potorolepis Spassky, 1994 from eastern Asia. The generic diagnosis of Potorolepis is amended.
Although the hindgut of some insects represents a rich source of intestinal trichomonads, their diversity is only poorly understood. The aim of the present study was to investigate the presence and abundance of intestinal trichomonads in true bugs (Heteroptera). We microscopically examined intestinal contents of more than 780 specimens belonging to 28 families of true bugs from localities in China, Ghana and Papua New Guinea for the presence of intestinal endosymbionts. More than 120 samples were examined also by means of PCR using trichomonad-specific primers. We determined sequences of SSU rDNA and ITS region of two isolates of the genus Simplicimonas Cepicka, Hampl et Kulda, 2010 and one isolate of Monocercomonas colubrorum (Hammerschmidt, 1844). Although our results showed that trichomonads are very rare inhabitants of the intestine of true bugs, two of three isolated flagellates belong to species specific for reptiles. The possibility of transmission of trichomonads between reptiles and true bugs is discussed.