1,174 research outputs found

    State policy in the sphere of waste management

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    The article is devoted to the political aspects of waste management. The present situation with production and consumption wastes is presented in existing economic, legal and moral-psychological mechanisms for implementing environmental policy are shown. State interest to the problem of waste became evident only towards the end of the 19th century when schemes of collection, removal, and burial of waste in landfills began to appear in cities. This system actually remained unchanged until the present day, and only now its modernization begins. The specifics of state policy in the sphere of management of municipal waste are considered. The quantity of waste has increased sharply; it was necessary to allocate huge territories for their burial. In addition, the composition of waste has changed significantly. When minerals are mined, mineral substances that are not typical for a given area are taken out to the surface, and municipal waste began to contain a noticeable percentage of artificially created substances, especially plastics. Thus, waste became the most important polluter of the environment, its influence on public health significantly increased. Ecological prerequisites for the emergence, social discontent and even conflicts, which are beginning to acquire political character, are shown. The activity of the authorities on the implementation of environmental policy is disclosed; its priorities and hierarchy of tasks to be solved in this area are also described. Bottlenecks in the eco-political line of the state are indicated. It is noted, that those who make economic decisions often ignore the political aspect of the problem. The activity of the executive authorities on the implementation of the main requirements of state environmental policy is demonstrated

    INFLUENCE OF HYDROCORTISONE AND BETA-ADRENERGIC RECEPTOR BLOCKADE IN EFFECTOR PHASE OF THE IMMUNE RESPONSE ON PHAGOCYTIC ACTIVITY OF REGIONAL LYMPH NODE CELLS, BLOOD MONOCYTES AND PERITONEAL MACROPHAGES

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    It was established that hydrocortisone reduces the phagocytic activity of regional lymph node cells and peritoneal mononuclear phagocytes, but does not affect the relative parameters of the phagocytic activity of peripheral blood monocytes in the effector phase of immune response in rats. Effects of hydrocortisone were significantly modified by the administration of beta-adrenoceptor antagonist propranolol hydrochloride

    Ferromagnetic resonance in systems with competing uniaxial and cubic anisotropies

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    We develop a model for ferromagnetic resonance in systems with competing uniaxial and cubic anisotropies. This model applies to (i) magnetic materials with both uniaxial and cubic anisotropies, and (ii) magnetic nanoparticles with effective core and surface anisotropies; We numerically compute the resonance frequency as a function of the field and the resonance field as a function of the direction of the applied field for an arbitrary ratio of cubic-to-uniaxial anisotropy. We also provide some approximate analytical expressions in the case of weak cubic anisotropy. We propose a method that uses these expressions for estimating the uniaxial and cubic anisotropy constants, and for determining the relative orientation of the cubic anisotropy axes with respect to the crystal principle axes. This method is applicable to the analysis of experimental data of resonance type measurements for which we give a worked example of an iron thin film with mixed anisotropy.Comment: 7 pages, 3 figure

    The role of alkane coordination in C–H bond cleavage at a Pt(II) center

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    The rates of CFormula H bond activation for various alkanes by [(N–N)Pt(Me)(TFEd3)]+ (N Formula N = ArFormula NFormula C(Me)Formula C(Me)Formula NFormula Ar; Ar = 3,5-di-tert-butylphenyl; TFE-d3 = CF3CD2OD) were studied. Both linear and cyclic alkanes give the corresponding alkene-hydride cation [(N–N)Pt(H)(alkene)]+ via (i) rate determining alkane coordination to form a CFormula H {sigma} complex, (ii) oxidative cleavage of the coordinated CFormula H bond to give a platinum(IV) alkyl-methyl-hydride intermediate, (iii) reductive coupling to generate a methane {sigma} complex, (iv) dissociation of methane, and (v) beta-H elimination to form the observed product. Second-order rate constants for cycloalkane activation (CnH2n), are proportional to the size of the ring (k ~ n). For cyclohexane, the deuterium kinetic isotope effect (kH/kD) of 1.28 (5) is consistent with the proposed rate determining alkane coordination to form a CFormula H {sigma} complex. Statistical scrambling of the five hydrogens of the Pt-methyl and the coordinated methylene unit, via rapid, reversible steps ii and iii, and interchange of geminal CFormula H bonds of the methane and cyclohexane CFormula H {sigma} adducts, is observed before loss of methane

    Temperature dependence of self-trapped exciton luminescence in nanostructured hafnia powder

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    The intrinsic optical properties and peculiarities of the energy structure of hafnium dioxide largely determine the prospects for applying the latter in new generation devices of optoelectronics and nanoelectronics. In this work, we have studied the diffuse reflectance spectra at room temperature for a nominally pure nanostructured HfO2HfO_2 powder with a monoclinic crystal structure and, as well its photoluminescence in the temperature range of 40 - 300 K. We have also estimated the bandgap EgE_g under the assumption made for indirect (5.31 eV) and direct (5.61 eV) allowed transitions. We have detected emission with a 4.2 eV maximum at T < 200 K and conducted an analysis of the experimental dependencies to evaluate the activation energies of thermal quenching (140 meV) and enhancement (3 meV) processes. Accounting for both the temperature behavior of the spectral characteristics and the estimation of the Huang-Rhys factor S >> 1 has shown that radiative decay of self-trapped excitons forms the mechanism of the indicated emission. In this case, the localization is mainly due to the interaction of holes with active vibrational modes of oxygen atoms in non-equivalent (O3fO_{3f} and O4fO_{4f}) crystal positions. Thorough study of the discussed excitonic effects can advance development of hafnia-based structures with a controlled optical response.Comment: 21 pages, 7 figures, 2 tables, 56 references. Keywords: hafnium dioxide, self-trapped exciton, F-center, thermal quenching of luminescence, luminescence enhacement, Huang-Rhys factor, effective phonon energy, bandgap widt

    Soft normed rings

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    Nitric Oxide Has a Concentration-Dependent Effect on the Cell Cycle Acting via EIN2 in Arabidopsis thaliana Cultured Cells

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    Ethylene is known to influence the cell cycle (CC) via poorly characterized roles whilst nitric oxide (NO) has well-established roles in the animal CC but analogous role(s) have not been reported for plants. As NO and ethylene signaling events often interact we examined their role in CC in cultured cells derived from Arabidopsis thaliana wild-type (Col-0) plants and from ethylene-insensitive mutant ein2-1 plants. Both NO and ethylene were produced mainly during the first 5 days of the sub-cultivation period corresponding to the period of active cell division. However, in ein2-1 cells, ethylene generation was significantly reduced while NO levels were increased. With application of a range of concentrations of the NO donor, sodium nitroprusside (SNP) (between 20 and 500 μM) ethylene production was significantly diminished in Col-0 but unchanged in ein2-1 cells. Flow cytometry assays showed that in Col-0 cells treatments with 5 and 10 μM SNP concentrations led to an increase in S-phase cell number indicating the stimulation of G1/S transition. However, at ≥20 μM SNP CC progression was restrained at G1/S transition. In the mutant ein2-1 strain, the index of S-phase cells was not altered at 5–10 μM SNP but decreased dramatically at higher SNP concentrations. Concomitantly, 5 μM SNP induced transcription of genes encoding CDKA;1 and CYCD3;1 in Col-0 cells whereas transcription of CDKs and CYCs were not significantly altered in ein2-1 cells at any SNP concentrations examined. Hence, it is appears that EIN2 is required for full responses at each SNP concentration. In ein2-1 cells, greater amounts of NO, reactive oxygen species, and the tyrosine-nitrating peroxynitrite radical were detected, possibly indicating NO-dependent post-translational protein modifications which could stop CC. Thus, we suggest that in Arabidopsis cultured cells NO affects CC progression as a concentration-dependent modulator with a dependency on EIN2 for both ethylene production and a NO/ethylene regulatory function
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