124 research outputs found
The impact of polymer grafting from a graphene oxide surface on its compatibility with a PDMS matrix and the light-induced actuation of the composites
Poly(dimethyl siloxane) (PDMS)-based materials with improved photoactuation properties were prepared by the incorporation of polymer-grafted graphene oxide particles. The modification of the graphene oxide (GO) surface was achieved via a surface initiated atom transfer radical polymerization (SI ATRP) of methyl methacrylate and butyl methacrylate. The modification was confirmed by thermogravimetric analysis, infrared spectroscopy and electron microscopy. The GO surface reduction during the SI ATRP was investigated using Raman spectroscopy and conductivity measurements. Contact angle measurements, dielectric spectroscopy and dynamic mechanical analyses were used to investigate the compatibility of the GO filler with the PDMS matrix and the influence of the GO surface modification on its physical properties and the interactions with the matrix. Finally, the thermal conductivity and photoactuation properties of the PDMS matrix and composites were compared. The incorporation of GO with grafted polymer chains, especially poly(n-butyl methacrylate), into the PDMS matrix improved the compatibility of the GO filler with the matrix, increased the energy dissipation due to the improved flexibility of the PDMS chains, enhanced the damping behavior and increased the thermal conductivity. All the changes in the properties positively affected the photoactuation behavior of the PDMS composites containing polymer-grafted GO. © 2017 by the authors.LO1504, MOE, Ministry of EducationGrant Agency of the Czech Republic [16-20361Y]; Ministry of Education, Youth and Sports of the Czech Republic-program NPU I [LO1504]; SRDA [APVV-15-0545]; VEGA [VEGA 2/0161/17]; Slovak Academy of Sciences [SAS-MOST JRP 2014-9
Velkomoravská rotunda z Pohanska u Břeclavi
Studie seznamuje s archeologickým objevem, který byl učiněn roku 2006 na severovýchodním předhradí Pohanska. Během následujících pěti let zde proběhl interdisciplinárně pojatý výzkum, který odkryl pozůstatky dosud neznámé raně středověké církevní architektury – rotundy obklopené rozsáhlým pohřebištěm (152 jedinců). K dnešnímu dni tak evidujeme na Pohansku již druhý velkomoravský kostel. Odkryv první křesťanské svatyně stál v roce 1958 na počátku systematických archeologických výzkumů, které na lokalitě a v jejím okolí probíhají kontinuálně dodnes. Za nejdůležitější výsledek nových výzkumů považujeme zjištění, že základní nosná konstrukce rotundy ze severovýchodního předhradí byla vybudována ze dřeva, i když kostel se z vnějšího pohledu jevil jako celokamenný. Pozoruhodná je i přítomnost pěti hrobů v interiéru chrámu. Dva muži a tři děti ve věku od 18 měsíců do 12 let zde byli uloženi pod podlahu již stojící stavby. Na základě nálezů z hrobů v kostele i mimo něj datujeme existenci stavby do vrcholného velkomoravského období (druhá pol. 9. stol.) s pravděpodobným přesahem do prvních decennií 10. stol.The study presents the archaeological discovery made in 2006 in the northeast suburb of Pohansko. The interdisciplinary excavation conducted at the site over the following five years revealed the remains of previously unknown early medieval church architecture – a rotunda surrounded by a large cemetery in which one-hundred and fifty-two individuals were buried. The rotunda represents the second Great Moravian church discovered at Pohansko. The first Christian shrine was discovered in 1958 at the beginning of systematic archaeological excavations that continue at the site and the surrounding area to this day. The most significant finding from the latest excavation is that the basic load-bearing structure of the rotunda in the northeast suburb was made of wood, despite the fact that the church appeared from the outside to be made entirely of stone. The presence of five graves inside the church is likewise noteworthy. Two men, and three children aged between eighteen months and twelve years were buried beneath the floor of the church at a time when the building was already standing. Based on finds from the graves in and outside of the church, the existence of the rotunda can be dated to the high Great Moravian period in the second half of the ninth century, with a probable duration into the first decades of the tenth century
Influence of heat treatment and nickel content on the properties of GX4CrNi13-4 steel
For the EN GX4CrNi13-4 martensitic stainless steel, research was conducted to investigate the impact of the quenching intensity and the content of nickel on the mechanical properties and amount of retained austenite. It was found that the amount of retained austenite significantly increases with growing nickel concentration. On the other hand, the cooling rate at quenching makes a difference only if the cooling is intensive, then amount of retained austenite decrease. A higher nickel content improves the mechanical properties. With more intensive cooling, the tensile strength decreases while the yield strength increases. The ductility is not significantly affected by the cooling intensity
Meloxicam Elevates Serum Concentration of Erythropoietin and Numbers of Bone Marrow Erythroid Progenitor Cells in Sublethally Gamma-Irradiated Mice
Meloxicam, a non-steroidal anti-inflammatory drug selectively inhibiting cyclooxygenase-2, has been found to enhance the regeneration of erythroid progenitor cells (BFU-E) in the femoral bone marrow of mice when administered after sublethal irradiation (4 Gy gamma-rays). In mice treated with meloxicam once daily on days 3, 4, 5, and 6 after irradiation, the values of BFU-E per femur in meloxicam-treated mice were on days 7 and 14 after irradiation at the levels of 156 % and 191 %, respectively, related to those in irradiated saline-treated controls (P P P < 0.05). These findings may have practical implications in the treatment of myelosuppression
Megaphylogeny resolves global patterns of mushroom evolution
Mushroom-forming fungi (Agaricomycetes) have the greatest morphological diversity and complexity of any group of fungi. They have radiated into most niches and fulfil diverse roles in the ecosystem, including wood decomposers, pathogens or mycorrhizal mutualists. Despite the importance of mushroom-forming fungi, large-scale patterns of their evolutionary history are poorly known, in part due to the lack of a comprehensive and dated molecular phylogeny. Here, using multigene and genome-based data, we assemble a 5,284-species phylogenetic tree and infer ages and broad patterns of speciation/extinction and morphological innovation in mushroom-forming fungi. Agaricomycetes started a rapid class-wide radiation in the Jurassic, coinciding with the spread of (sub)tropical coniferous forests and a warming climate. A possible mass extinction, several clade-specific adaptive radiations and morphological diversification of fruiting bodies followed during the Cretaceous and the Paleogene, convergently giving rise to the classic toadstool morphology, with a cap, stalk and gills (pileate-stipitate morphology). This morphology is associated with increased rates of lineage diversification, suggesting it represents a key innovation in the evolution of mushroom-forming fungi. The increase in mushroom diversity started during the Mesozoic-Cenozoic radiation event, an era of humid climate when terrestrial communities dominated by gymnosperms and reptiles were also expanding.Fil: Varga, Torda. Hungarian Academy Of Sciences; HungríaFil: Krizsán, Krisztina. Hungarian Academy Of Sciences; HungríaFil: Földi, Csenge. Hungarian Academy Of Sciences; HungríaFil: Dima, Bálint. Eötvös Loránd University; HungríaFil: Sánchez-García, Marisol. Clark University; Estados UnidosFil: Lechner, Bernardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Sánchez-Ramírez, Santiago. University of Toronto; CanadáFil: Szöllosi, Gergely J.. Eötvös Loránd University; HungríaFil: Szarkándi, János G.. University Of Szeged; HungríaFil: Papp, Viktor. Szent István University; HungríaFil: Albert, László. Hungarian Mycological Society; HungríaFil: Andreopoulos, William. United States Department Of Energy. Joint Genome Institute; Estados UnidosFil: Angelini, Claudio. Jardin Botanico Nacional Ma. Moscoso; República DominicanaFil: Antonín, Vladimír. Moravian Museum; República ChecaFil: Barry, Kerrie W.. United States Department Of Energy. Joint Genome Institute; Estados UnidosFil: Bougher, Neale L.. Western Australian Herbarium; AustraliaFil: Buchanan, Peter. Manaaki Whenua-landcare Research; Nueva ZelandaFil: Buyck, Bart. Muséum National d'Histoire Naturelle; FranciaFil: Bense, Viktória. Hungarian Academy Of Sciences; HungríaFil: Catcheside, Pam. State Herbarium Of South Australia; AustraliaFil: Chovatia, Mansi. United States Department Of Energy. Joint Genome Institute; Estados UnidosFil: Cooper, Jerry. Manaaki Whenua-landcare Research; Nueva ZelandaFil: Dämon, Wolfgang. Oberfeldstrasse 9; AustriaFil: Desjardin, Dennis. San Francisco State University; Estados UnidosFil: Finy, Péter. Zsombolyai U. 56.; HungríaFil: Geml, József. Naturalis Biodiversity Center; Países BajosFil: Haridas, Sajeet. United States Department Of Energy. Joint Genome Institute; Estados UnidosFil: Hughes, Karen. University of Tennessee; Estados UnidosFil: Justo, Alfredo. Clark University; Estados UnidosFil: Karasinski, Dariusz. Polish Academy of Sciences; Poloni
Proceedings of the 12th International Conference on Kinanthropology
Proceedings of the 12th Conference of Sport and Quality of Life 2019 gatheres submissions of participants of the conference. Every submission is the result of positive evaluation by reviewers from the corresponding field. Conference is divided into sections – Analysis of human movement; Sport training, nutrition and regeneration; Sport and social sciences; Active ageing and sarcopenia; Strength and conditioning training; section for PhD students
REFLECT – Research flight of EURADOS and CRREAT: Intercomparison of various radiation dosimeters onboard aircraft
Aircraft crew are one of the groups of radiation workers which receive the highest annual exposure to ionizing
radiation. Validation of computer codes used routinely for calculation of the exposure due to cosmic radiation
and the observation of nonpredictable changes in the level of the exposure due to solar energetic particles, requires continuous measurements onboard aircraft. Appropriate calibration of suitable instruments is crucial,
however, for the very complex atmospheric radiation field there is no single reference field covering all particles
and energies involved. Further intercomparisons of measurements of different instruments under real flight
conditions are therefore indispensable.
In November 2017, the REFLECT (REsearch FLight of EURADOS and CRREAT) was carried out. With a
payload comprising more than 20 different instruments, REFLECT represents the largest campaign of this type
ever performed. The instruments flown included those already proven for routine dosimetry onboard aircraft
such as the Liulin Si-diode spectrometer and tissue equivalent proportional counters, as well as newly developed
detectors and instruments with the potential to be used for onboard aircraft measurements in the future. This
flight enabled acquisition of dosimetric data under well-defined conditions onboard aircraft and comparison of
new instruments with those routinely used.
As expected, dosimeters routinely used for onboard aircraft dosimetry and for verification of calculated doses
such as a tissue equivalent proportional counter or a silicon detector device like Liulin agreed reasonable with each other as well as with model calculations. Conventional neutron rem counters underestimated neutron
ambient dose equivalent, while extended-range neutron rem counters provided results comparable to routinely
used instruments. Although the responses of some instruments, not primarily intended for the use in a very
complex mixed radiation field such as onboard aircraft, were as somehow expected to be different, the verification of their suitability was one of the objectives of the REFLECT. This campaign comprised a single short
flight. For further testing of instruments, additional flights as well as comparison at appropriate reference fields
are envisaged. The REFLECT provided valuable experience and feedback for validation of calculated aviation
doses
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