1,013 research outputs found
First description of myxozoans from Syria: novel records of hexactinomyxon, triactinomyxon and endocapsa actinospore types
Oligochaete worms collected in late March and early April 2005 from 3
freshwater biotopes in Syria were surveyed over an 11 wk period for
myxosporean parasites (Myxozoa). Three types of novel actinospore
stages were identified from 1 host species, Psammoryctides albicola. A
hexactinomyxon was found in 6 P. albicola (7.5%) collected from a
branch of the River Orontes, north of the city of Hama. A
triactinomyxon and an endocapsa were found in single P. albicola
specimens from the Al-Thaurah region of the Euphrates River (Lake
Assad). No oligochaetes collected from Al-Ghab fish farm (Orontes
region) released actinospores during the observation period. The
present study is the first description of myxosporeans, including
actinospore stages, from Syria. The 3 types described herein differ
morphologically and molecularly (18S rDNA) from published records
Infection of cultured and freshwater fishes with monogeneans in Syria
During a survey made in 2004 and 2005 in Syrian fish farms of the Orontes valley and on natural water fishes harvested in the Orontes River and in Lake Assad (a water reservoir of the Euphrates River), 145 specimens of fish belonging to 15 fish species were examined for monogenean infections. Eleven monogenean species (8 Dactylogyrus spp., 1 Silurodiscoides sp. and 2 Cychlidogyrus spp.) were found in the gills. Monogeneans infecting farm-cultured fishes were the same as those commonly occurring in cyprinids (Dactylogyrus anchoratus, D. extensus, D. lamellatus) and filapia (Cychlidogyrus tilapiae, C. arthracan thus) cultured in Europe and in tropical countries. Among monogeneans found in fishes of natural waters, typical representatives of the Tigris-Euphrates Basin (Dactylogyrus carassobarbi, D. holciki) and species common in the Holoarctic zoogeographical zone (D. alatus, D. carpathicus, D. distinguendus and Silurodiscoides vistulensis) were equally found
Живучесть и разрушение многоэлементных конструкций
Статья посвящена комплексному исследованию повреждающих воздействий на технические системы и процессу их разрушения. Особое внимание уделяется живучести многоэлементных конструкций с уже накопленными повреждениями и проявлению масштабного эффекта, который связан с увеличением их высоты и размеров. Рассмотрена перспектива совместного использования современных программных комплексов и нейросетевых технологий для описания и моделирования многопараметрических систем с учетом внешних негативных факторов
UWB channel characterization in 28 ghz millimeter waveband for 5G cellular networks
The demands of high data rate transmission for future wireless communication technologies are increasing rapidly. The current bands for cellular network will not be able to satisfy these requirements. The millimeter wave (mm-wave) bands are the candidate bands for the future cellular networks. The 28 GHz band is the strongest candidate for 5G cellular networks. The large bandwidth at this band is one of the main parameters that make the mm-wave bands promising candidate for the future cellular networks. To know the wideband channel behavior in mm-wave bands, the wideband channel characterizations are required. In this paper, the 3D WINNER model is used to model the wideband channel at 28 GHz band. Based on this model, the time dispersion parameters at 28 GHz mm-wave band are investigated. The root mean square delay spread and the mean excess delay are the main parameters that can be used to characterize the wideband channel. Morever, the cumulative distribution function (CDF) is used to model the RMS delay spreads. The results show that the RMS delay spread varies between 4.1 ns and 443.7 ns
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