212 research outputs found

    Challenges and opportunities for energy recovery from municipal solid waste in the Russian Federation

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    Energy recovery from municipal solid waste (MSW) is currently a key factor in waste management in Russia, as can be seen from the corresponding changes in the state regulatory framework. The paper presents a comparative assessment of different waste flow characteristics; it focuses on pre-treatment options and the method of subsequent thermal treatment. It reflects the basic method of untreated MSW incineration and other advanced technologies which have different levels of waste preparation. Step-by-step research has been carried out in a large Russian city in order to determine different technological approaches to recovering energy from MSW. The study included: 1) field studies of the composition and characterization of MSW; 2) laboratory studies of MSW thermal properties, i.e. moisture, ash content and calorific value; 3) several options for waste treatment schemes with equipment of different technical specifications; 4) analysis of material flow, energy flow and key substance flow according to these considered schemes. The research revealed that for all seasons a significant proportion of MSW (almost 40%) is represented by fines (below 50 mm). On average, the energy potential of MSW (the total content of waste paper, polymers, textiles, wood, multilayer packaging, leather, rubber, footwear) amounts to about 40%. It was found that MSW calorific value depends on fraction size, since screening (over 50 mm) is characterized by high moisture and low content of valuable components, compared to MSW greater than 50 mm in size. Pre-processing and treatment of MSW allows solid recovered fuel (SRF) to be obtained with a calorific value similar to brown coal. The energy balance of the process allows the conclusion that 33.8% of initial MSW energy potential is concentrated in residues from the sorting process, since it has a relatively low calorific value of 4.8 MJ/kg, but a high mass fraction of 47.9%. In the process of MSW treatment and solid fuel production, most of the chlorine and mercury (80% and 55% respectively) is removed by the rest of the sorting process. The data obtained in the study can be used in selecting the optimal option for energy recovery from MSW. © 2019 WIT PressACKNOWLEDGEMENT The work was supported by Act 211 Government of the Russian Federation, contract № 02.A 03.21.0006

    Kinetics of epitaxial formation of nanostructures by Frank-van der Merwe, Volmer-Weber and Stranski-Krastanow growth modes

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    Nowadays, two-dimensional crystals (2D materials) and structures with quantum dots (0D materials) are considere

    Highly diastereoselective 1,3-dipolar cycloaddition of nonstabilized azomethine ylides to 3-nitro-2-trihalomethyl-2H-chromenes: Synthesis of 1-benzopyrano[3,4-c]pyrrolidines

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    Reactions of 3-nitro-2-trifluoro(trichloro)methyl-2H-chromenes, including 2-unsubstituted derivatives, with N-alkyl-α-amino acids (sarcosine, proline) and paraformaldehyde proceed diastereoselectively to give 1-benzopyrano[3,4-c]pyrrolidines in good yields as a result of a 1,3-dipolar cycloaddition of the intermediate nonstabilized azomethine ylide at the Δ3-bond of the chromene system. © 2013 Elsevier Ltd. All rights reserved

    Black Sea coastal forecasting system

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    The Black Sea coastal nowcasting and forecasting system was built within the framework of EU FP6 ECOOP (European COastalshelf sea OPerational observing and forecasting system) project for five regions: the south-western basin along the coasts of Bulgaria and Turkey, the north-western shelf along the Romanian and Ukrainian coasts, coastal zone around of the Crimea peninsula, the north-eastern Russian coastal zone and the coastal zone of Georgia. The system operates in the real-time mode during the ECOOP project and afterwards. The forecasts include temperature, salinity and current velocity fields. Ecosystem model operates in the off-line mode near the Crimea coast

    Effect of a boron implantation on the electrical properties of epitaxial HgCdTe with different material composition

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    In this work the experimental results of investigations of the dynamics of accumulation and spatial distribution of electrically active radiation defects when irradiating epitaxial films of Hg1-xCdxTe (MCT) with different material composition (x). The films, grown by molecular beam epitaxy (MBE) were irradiated by B ions at room temperature in the radiation dose range 1012 -1015 ions/cm2 and with ion energy 100 keV. The results give the differences in implantation profiles, damage accumulation and electrical properties as a function of the material composition of the film

    Properties of arsenic-implanted Hg1-xCdxTe MBE films

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    Defect structure of arsenic-implanted Hg1-xCdxTe films (x=0.23–0.30) grown with molecular-beam epitaxy on Si substrates was investigated with the use of optical methods and by studying the electrical properties of the films. The structural perfection of the films remained higher after implantation with more energetic arsenic ions (350 keV vs 190 keV). 100%-activation of implanted ions as a result of post-implantation annealing was achieved, as well as the effective removal of radiation-induced donor defects. In some samples, however, activation of acceptor-like defects not related to mercury vacancies as a result of annealing was observed, possibly related to the effect of the substrate

    Accumulation and annealing of radiation donor defects in arsenic-implanted Hg0.7Cd0.3Te films

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    Processes of accumulation and annealing of radiation-induced donor defects in arsenic-implanted Hg0.7Cd0.3Te films were studied with the use of the Hall-effect measurements with processing the data with mobility spectrum analysis. A substantial difference in the effects of arsenic implantation and post-implantation activation annealing on the properties of implanted layers and photodiode ‘base’ layers in Hg0.7Cd0.3Te and Hg0.8Cd0.2Te films was established and tentatively explained

    Second-order nonlinear optical properties of composite material of an azo-chromophore with a tricyanodiphenyl acceptor in a poly(styrene-co-methyl methacrylate) matrix

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    © 2017 Elsevier B.V.The composite material of new synthesized 4-((4-(N,N-n-dibutylamino) phenyl)diazenyl)-biphenyl-2,3,4-tricarbonitrile (GAS dye) in commercial poly(styrene-co-methyl methacrylate) (PSMMA) was prepared, poled and its nonlinear optical properties compared with DR1 dye were studied. High thermal stability of the composite material was revealed, and the maximal concentration of the chromophore was found to reach ∼20 wt%. The dipole moment, polarizability tensor, and first hyperpolarizability tensor of the investigated dyes were calculated by within the framework of the coupled perturbed density functional theory. A nanosecond second-harmonic generation Maker fringes technique was used which is capable of providing the magnitude of the second-order nonlinearity of optical materials at a wavelength of 1064 nm. For the tested GAS–PSMMA composite material, maximal coefficient d33 was found to be 50 pm/V. The nonlinear optical response, which was achieved here, shows possible usefulness of the GAS dye as a component for molecular design of nonlinear-optical materials with advanced characteristics
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