280 research outputs found

    Persistent organic pollutants (PCBs and OCP) in air and soil from Ulaanbaatar and the Lake Hovsgol region, Mongolia

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    The investigations of POPs in soil and air in three urban and rural sites of the Mongolia are presented. The POPs distribution in air repeats the POPs distribution in soil on the area investigated. The POPs levels in soil and air are lower than maximum permissible concentrations (MPC) and preliminary permissible concentrations (PPC) of PCBs and OCP accepted in Russia. POPs levels in Mongolian soil obtained in the investigation are comparable with those from background areas of the world. POPs levels in Mongolian air are in the frame of concentrations found in the world. The PCB homological pattern in soil near electric power station in Ulaanbaatar is close to homological pattern in PCB technical mixture (Sovol or Arochlor 1254). The homological patterns in soil from other sites changed due to the redistribution of PCB congeners in the environment. The ratio of DDT and its metabolites indicates fresh entrance of DDT in the environment of Mongolia due to the atmospheric transboundary transport from countries using DDT (China, India) or from local agricultural sources. Hazard indexes in result from human exposure with POPs in soil and air are lower by 2-4 orders than 1 that denotes the possible default of disturbances in target organ and system. CR under the same scenario corresponds to the first diapason that is taken by population as negligible risk, not differ from usual everyday risks. Such risks donā€™t require additional measures for the reducing of risks and their levels are a subject of periodical control. The necessity of additional investigation of POPs distribution and the fate in Mongolian environment is indicated.DOI: http://dx.doi.org/10.5564/mjc.v12i0.176 Mongolian Journal of Chemistry Vol.12 2011: 69-7

    The Hydration Structure at Yttria-Stabilized Cubic Zirconia (110)-Water Interface with Sub-Angstrom Resolution

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    The interfacial hydration structure of yttria-stabilized cubic zirconia (110) surface in contact with water was determined with ~0.5 Å resolution by high-resolution X-ray reflectivity measurement. The terminal layer shows a reduced electron density compared to the following substrate lattice layers, which indicates there are additional defects generated by metal depletion as well as intrinsic oxygen vacancies, both of which are apparently filled by water species. Above this top surface layer, two additional adsorbed layers are observed forming a characteristic interfacial hydration structure. The first adsorbed layer shows abnormally high density as pure water and likely includes metal species, whereas the second layer consists of pure water. The observed interfacial hydration structure seems responsible for local equilibration of the defective surface in water and eventually regulating the long-term degradation processes. The multitude of water interactions with the zirconia surface results in the complex but highly ordered interfacial structure constituting the reaction front.ope

    Comparative characterisation of forest litter on sod-podzolic soils of Forest Experimental Dacha in RSAUā€“MAA named after K.A. Timiryazev

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    Forest litter under linden and pine forests was studied at the Forest Experimental Dacha of the RSAUā€“MAA named after K.A. Timiryazev. Despite significant differences in physical and chemical parameters between the litter formed under the conditions of different forest communities, the properties of sod-podzolic soils formed under both vegetation types are quite similar. The litter under linden forest has higher ash content, it is less acidic and contains almost 2 times more exchangeable bases, the content of hydrogen and nitrogen is higher by 0.82 wt% and 0.66 wt%, respectively. The litter of linden and pine forests, according to the atomic ratios HĀ :Ā C, CĀ :Ā N and the degree of oxidation, are equal to 1.82, 30.3, -0.92 and 1.64, 45.7, -0.71, respectively; the litter of linden forests differs from litter of pine forests in the higher content of aliphatic, nitrogen-rich, reduced organic compounds. In the litter of linden forests concentration coefficients of phosphorus and magnesium 1.2 times higher; of carbon, potassium and aluminium ā€“ 1.3 times higher; of calcium ā€“ 1.4 times higher; of nitrogen ā€“ 1.8 times higher, and of silicon ā€“ 3 times higher, than in the litter of pine trees. However, the concentration factor of manganese in the pine forest litter is 1.9 times higher compared to the litter of linden. According to the results of UV spectroscopy, water-soluble organic matter of pine forest litter, unlike water-soluble organic matter of linden forest litter, is more enriched by components of aromatic origin. This is evidenced by higher values of SUVA254 and lower values of coefficients E2/E3 and E4/E6

    The Image of a Hero in Western and Russian Social Advertising

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    The article is devoted to a comparative study of the image of a hero / superhero in Russian and Western social advertising. The relevance of the study is determined by the contrast of globalization processes, on the one hand, and the desire to preserve nationally oriented values, on the other. The novelty of the study lies in comparing the ideological and linguocultural representations of the image of the hero / superhero, reflected in the socio-advertising text. The results of the study are based on a contextual analysis of the geroy and hero tokens, supergeroy and superhero , as well as non-verbal symbols associated with these concepts presented in the structure of creolized advertising text. In the structure of the image of the hero / superhero, both semantic components (for example, a military metaphor) and specific representations that are determined by the cultural code and ideological identifications, are revealed that are common for Russian and Western social advertising. It is proved that those components of the heroā€™s image that are connected with the axiology of culture (ā€œpeaceful heroismā€ interpreted as socially approved behavior in general) are more likely to have positive connotations than those that are due to ideological ideas. It is concluded that the image of a superhero in Russian linguistic culture, on the one hand, is understandable and even already familiar, on the other hand, it is rejected as a representative of an alien culture and ideology

    The design features of the body of the portable electrocardiograph "ECG-EXPRESS"

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    The sequence of the industrial product shaping is specified, the main modeling characteristics of the configuration and some of its parts are designated subject to the electrocardiograph design and the technologies used for the production of its body

    Effects of water on the stochastic motions of propane confined in MCM-41-S pores

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    Hydrocarbons confined in porous media find applications in a wide variety of industries and therefore their diffusive behavior is widely studied. Most of the porous media found in natural environments are laden with water, which might affect the confined hydrocarbons. To quantify the effect of hydration, we report here a combined quasielastic neutron scattering (QENS) and molecular dynamics (MD) simulation study on the dynamics of propane confined in the 1.5 nm-wide micropores of MCM-41-S in the presence of water at 230 and 250 K. To eliminate the strong incoherent signal from water and emphasize the propane signal we have used heavy water (D2O). QENS data show two dynamically different populations of propane in MCM-41-S and suggest that the presence of water hinders the diffusion of propane. Weak elastic contributions to the QENS spectra suggest that only long-range translational motion of propane molecules contributes to the quasielastic broadening. MD simulations carried out using a model cylindrical silica pore of 1.6 nm diameter filled with water and propane agree with the experimental finding of water hindering the diffusion of propane. Further, the simulation results suggest that the slowing down of propane motions is a function of the water content within the pore and is stronger at higher water contents. At high water content, the structure and the dynamics, both translational and rotational, of propane are severely impacted. Simulation data suggest that the rotational motion of the propane molecule occurs on time scales much faster than those accessible with the QENS instrument used, and thus explain the weak elastic contribution to the QENS spectra measured in the experiments. This study shows the effects of hydration on the structure and dynamics of volatiles in porous media, which are of interest for fundamental understanding and applied studies of confined fluids

    IMMEDIATE RESULTS OF HEPATECTOMY FOR METASTATIC COLORECTAL CANCER

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    Incorporation of bevacizumab to preoperative regional chemotherapy (CT) failed to increase the volume of intraoperative blood loss and the frequency of postoperative complications. Addition of the drug in the regional CT group significantly enhanced the rate of its effect up to 64 % and that of grade III medical pathomorphism up to 55 %. Regardless of the pattern of surgeries, the rate of complications after extended hepatectomy did not differ significantly in the treatment groups. Irrespective of treatment, the rate of acute liver failure rose when the volume of surgery was increased from conventional hemihepatectomy to extended hemihepatectomy. Acute liver failure was prominent (21%) among the complications in the treatment group. The highest incidence of acute liver failure in the comparable groups was observed in the preoperative regional CT group
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