34 research outputs found

    Study of correlation of production and decay planes in π3π\pi\to3\pi diffractive dissociation process on nuclei

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    A large correlation of production and decay planes of (\pi^-\pi^+\pi^-)-system in dissociation of π\pi^--beam 40 GeV/c on nuclear targets was observed. The dependence of the correlation on atomic number, Feynmann variable and transversal momentum as well as on invariant mass of the pion triple and neutral pion pair were investigated. It was shown that the phenomenon has a clear dynamic origin and resembles the single spin asymmetry behavior.Comment: 8 pages, latex epsfig.sty, 5 eps figures. Submitted to Yad. Fiz

    Solution combustion synthesis of α-Al2O3 using urea

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    The processes involved in the solution combustion synthesis of α-Al2O3 using urea as an organic fuel were investigated. The data describing the influence of the relative urea content on the characteristic features of the combustion process, the crystalline structure and the morphology of the aluminium oxide are presented herein. Our data demonstrate that the combustion of stable aluminium nitrate and urea complexes leads to the formation of α-alumina at temperatures of approximately 600-800 °C. Our results, obtained using differential thermal analysis and IR spectroscopy methods, reveal that the low-temperature formation of α-alumina is associated with the thermal decomposition of an α-AlO(OH) intermediate, which was crystallised in the crystal structure of the diaspore. © 2012 Elsevier Ltd and Techna Group S.r.l

    Четверта міжнародна наукова-практична конференція «Комп’ютерне моделювання в хімії і технологіях та системах сталого розвитку»

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    Основу сучасних метеорологічних моделей складають нелінійні тривимірні рівняння конвективної дифузії. Задача реалізації цих рівнянь є обчислювально складною. В даній роботі пропонується застосування розпаралелювання на відеографічних процесорах при реалізації метеорологічних моделей. Представлено результати розв'язання тестової задачі за допомогою технології CUDA та графічного прискорювача. Проведено аналіз отриманих результатів.The basis of modern meteorological models are nonlinear three-dimensional convection diffusion equations. The problem of realization of these equations is computationally complex. In this paper the application of parallelization with graphics processors for meteorological models implementation is proposed. The results of solving the test problem using CUDA technology with graphics processing unit are presented. An analysis of the obtained results provided.Основу современных метеорологических моделей составляют нелинейные трехмерные уравнения конвективной диффузии, реализация которых является вычислительно сложной задачей. В работе предлагается применение распараллеливания на видеографических процессорах при реализации метеорологических моделей. Представлены результаты решения тестовой задачи с помощью технологии CUDA с их анализом

    Evidence for Exotic J^{PC}=1^{-+} Meson Production in the Reaction pi- p --> eta pi- p at 18 GeV/c

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    Details of the analysis of the eta pi- system studied in the reaction pi^{-} p --> eta pi^{-} p at 18 GeV/c are given. Separate analyses for the 2 gamma and pi+ pi- pi0 decay modes of the eta are presented. An amplitude analysis of the data indicates the presence of interference between the a(2)(1320)- and a J^{PC}=1^{-+} wave between 1.2 and 1.6 GeV/c^2. The phase difference between these waves shows phase motion not attributable solely to the a(2)(1320)-. The data can be fitted by interference between the a(2)(1320)- and an exotic 1^{-+} resonance with M = 1370 +-16 +50 -30} MeV/c^2 and Gamma = 385 +- 40 +65 -105 MeV/c^2. Our results are compared with those of other experiments.Comment: 50 pages of text and 34 figure

    Elevational Patterns of Species Richness, Range and Body Size for Spiny Frogs

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    Quantifying spatial patterns of species richness is a core problem in biodiversity theory. Spiny frogs of the subfamily Painae (Anura: Dicroglossidae) are widespread, but endemic to Asia. Using spiny frog distribution and body size data, and a digital elevation model data set we explored altitudinal patterns of spiny frog richness and quantified the effect of area on the richness pattern over a large altitudinal gradient from 0–5000 m a.s.l. We also tested two hypotheses: (i) the Rapoport's altitudinal effect is valid for the Painae, and (ii) Bergmann's clines are present in spiny frogs. The species richness of Painae across four different altitudinal band widths (100 m, 200 m, 300 m and 400 m) all showed hump-shaped patterns along altitudinal gradient. The altitudinal changes in species richness of the Paini and Quasipaini tribes further confirmed this finding, while the peak of Quasipaini species richness occurred at lower elevations than the maxima of Paini. The area did not explain a significant amount of variation in total, nor Paini species richness, but it did explain variation in Quasipaini. Five distinct groups across altitudinal gradient were found. Species altitudinal ranges did not expand with an increase in the midpoints of altitudinal ranges. A significant negative correlation between body size and elevation was exhibited. Our findings demonstrate that Rapoport's altitudinal rule is not a compulsory attribute of spiny frogs and also suggest that Bergmann's rule is not generally applicable to amphibians. The study highlights a need to explore the underlying mechanisms of species richness patterns, particularly for amphibians in macroecology

    An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 2: impacts on organisms and ecosystems

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    New information on the lethal and sublethal effects of neonicotinoids and fipronil on organisms is presented in this review, complementing the previous WIA in 2015. The high toxicity of these systemic insecticides to invertebrates has been confirmed and expanded to include more species and compounds. Most of the recent research has focused on bees and the sublethal and ecological impacts these insecticides have on pollinators. Toxic effects on other invertebrate taxa also covered predatory and parasitoid natural enemies and aquatic arthropods. Little, while not much new information has been gathered on soil organisms. The impact on marine coastal ecosystems is still largely uncharted. The chronic lethality of neonicotinoids to insects and crustaceans, and the strengthened evidence that these chemicals also impair the immune system and reproduction, highlights the dangers of this particular insecticidal classneonicotinoids and fipronil. , withContinued large scale – mostly prophylactic – use of these persistent organochlorine pesticides has the potential to greatly decreasecompletely eliminate populations of arthropods in both terrestrial and aquatic environments. Sublethal effects on fish, reptiles, frogs, birds and mammals are also reported, showing a better understanding of the mechanisms of toxicity of these insecticides in vertebrates, and their deleterious impacts on growth, reproduction and neurobehaviour of most of the species tested. This review concludes with a summary of impacts on the ecosystem services and functioning, particularly on pollination, soil biota and aquatic invertebrate communities, thus reinforcing the previous WIA conclusions (van der Sluijs et al. 2015)

    Deterministic Periodical and Quasiperiodical Surfaces of III-V Compounds: Preparation, Investigations and Applications

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    Autocorrelation functions for rough (random, quasiperiodical and deterministicperiodical) surfaces are deduced from the surface profiles determined by using the line-by-line analysis of atomic force microscopy images. It is shown that the initial parts of autocorrelation functions have a Gaussian form. An attempt to use the concept of fractal as a bridge between deterministic periodic and random (spontaneous) surfaces including quasiperiodic ones have been made

    RBE of "Prometeus" Facility Protons for Irradiation of Tumor Cells in Vitro with One and Three Fields

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    The study was aimed to the biological effectiveness of the proton scanning beam of the first Russian medical facility. The clonogenic assay of B-16 tumor cells was used as a test system. Cell irradiation was carried out in a suspension condition in a water phantom. Single and three-field exposures were studied. The dose interval was 2-8 Gy. The energy range from 47.5 to 92.0 MeV was used for the Bragg peak formation. The relative biological effectiveness of protons comparing to gamma-rays was 1.2 for single-field and 1.5 for three-field irradiation. The results obtained agree with literature data related to the used cell culture (B-16) and linear energy transfer range (3÷8 keV/µm)
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