151 research outputs found

    Hydro Power Plants

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    Case study of ozone anomalies over northern Russia in the 2015/2016 winter: measurements and numerical modelling

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    Episodes of extremely low ozone columns were observed over the territory of Russia in the Arctic winter of 2015/2016 and the beginning of spring 2016. We compare total ozone columns (TOCs) from different remote sensing techniques (satellite and ground-based observations) with results of numerical modelling over the territory of the Urals and Siberia for this period. We demonstrate that the provided monitoring systems (including the new Russian Infrared Fourier Spectrometer IKFS-2) and modern three-dimensional atmospheric models can capture the observed TOC anomalies. However, the results of observations and modelling show differences of up to 20&thinsp;%–30&thinsp;% in TOC measurements. Analysis of the role of chemical and dynamical processes demonstrates that the observed short-term TOC variability is not a result of local photochemical loss initiated by heterogeneous halogen activation on particles of polar stratospheric clouds that formed under low temperatures in the mid-winter.</p

    Materials of the final reports on the joint Soviet-American experiment on the Kosmos-936 biosatellite

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    Biological experiments onboard the Kosmos-936 investigated the effect of weightlessness on the basic components of cells, the genetic structure and energy apparatus. Genetic studies were made on the Drosophila melanogaster. Experiments were made on higher vegetation and fungi as well. The results indicate that weightlessness cannot be the principal barrier for normal development. An experiment with ectopic osteogenesis in weightlessness was carried out. Measurements were made of cosmic radiation inside and outside the biosatellite

    КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ ЛЕЧЕНИЯ БОЛЬНОГО РАКОМ ВОСХОДЯЩЕГО ОТДЕЛА ОБОДОЧНОЙ КИШКИ, ВОЗНИКШЕГО НА ФОНЕ ДЛИТЕЛЬНОГО ПРИЕМА ИММУНОДЕПРЕССАНТОВ ПОСЛЕ АЛЛОТРАНСПЛАНТАЦИИ ТРУПНОЙ ПОЧКИ ПО ПОВОДУ ДЕКОМПЕНСИРОВАННОЙ ПОЧЕЧНОЙ НЕДОСТАТОЧНОСТИ

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    A case report of a patient with advanced colorectal cancer complicated by 18-year immunosuppressive drug therapy after kidney transplantation is presented. Long-term use of immunosuppressive drugs may complicate postoperative period, but must not be a contradiction to extensive abdominal and pelvic surgery.В статье представлено клиническое наблюдение пациента, страдающего раком ободочной кишки с осложненным течением на фоне длительного (в течение 18 лет) приема иммуносупрессоров после операции пересадки почки. Показано, что длительный прием иммунодепрессантов, хотя и значительно замедляет процессы тканевой регенерации, все же не является абсолютным противопоказанием для выполнения обширных полостных операций на органах желудочно-кишечного тракта

    Quality assessment of integrated water vapour measurements at the St. Petersburg site, Russia: FTIR vs. MW and GPS techniques

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    The cross-comparison of different techniques for atmospheric integrated water vapour (IWV) measurements is the essential part of their quality assessment protocol. We inter-compare the synchronised data sets of IWV values measured by the Bruker 125 HR Fourier-transform infrared spectrometer (FTIR), RPG-HATPRO microwave radiometer (MW), and Novatel ProPak-V3 global navigation satellite system receiver (GPS) at the St. Petersburg site between August 2014 and October 2016. As the result of accurate spatial and temporal matching of different IWV measurements, all three techniques agree well with each other except for small IWV values. We show that GPS and MW data quality depends on the atmospheric conditions; in dry atmosphere (IWV smaller than 6mm), these techniques are less reliable at the St. Petersburg site than the FTIR method. We evaluate the upper bound of statistical measurement errors for clear-sky conditions as 0.29±0.02mm (1.6±0.3%), 0.55±0.02mm (4.7±0.4%), and 0.76±0.04mm (6.3±0.8%) for FTIR, GPS, and MW methods, respectively. We propose the use of FTIR as a reference method under clear-sky conditions since it is reliable on all scales of IWV variability

    Salinity modulates thermotolerance, energy metabolism and stress response in amphipods Gammarus lacustris

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    Temperature and salinity are important abiotic factors for aquatic invertebrates. We investigated the influence of different salinity regimes on thermotolerance, energy metabolism and cellular stress defense mechanisms in amphipods Gammarus lacustris Sars from two populations. We exposed amphipods to different thermal scenarios and determined their survival as well as activity of major antioxidant enzymes (peroxidase, catalase, glutathione S-transferase) and parameters of energy metabolism (content of glucose, glycogen, ATP, ADP, AMP and lactate). Amphipods from a freshwater population were more sensitive to the thermal challenge, showing higher mortality during acute and gradual temperature change compared to their counterparts from a saline lake. A more thermotolerant population from a saline lake had high activity of antioxidant enzymes. The energy limitations of the freshwater population (indicated by low baseline glucose levels, downward shift of the critical temperature of aerobic metabolism and inability to maintain steady-state ATP levels during warming) was observed, possibly reflecting a trade-off between the energy demands for osmoregulation under the hypo-osmotic condition of a freshwater environment and protection against temperature stress

    Results from the Soviet-American gallium experiment

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    A radiochemical 71Ga-71Ge experiment to determine the primary flux of neutrinos from the Sun began measurements of the solar neutrino flux at the Baksan Neutrino Observatory in 1990. The number of 71Ge atoms extracted from 30 tons of gallium in 1990 and 57 tons in 1991 was measured in twelve runs during the period of January 1990 to December 1991. For the 1990 data, we observed the capture rate to be 20 + 15 -20 (stat) ± 32 (syst) SNU, resulting in a limit of less than 79 SNU (90% CL). This is to be compared with 132 SNU predicted by the Standard Solar Model. The 1991 data, taken with 57 tons of gallium, shows a non zero 71Ge signal. A final result from the 1990 and 1991 data is still pending completion of studies of possible systematic effects. © 1993

    Emission Monitoring Mobile Experiment (EMME): An overview and first results of the St. Petersburg megacity campaign 2019

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    Global climate change is one of the most important scientific, societal and economic contemporary challenges. Fundamental understanding of the major processes driving climate change is the key problem which is to be solved not only on a global but also on a regional scale. The accuracy of regional climate modelling depends on a number of factors. One of these factors is the adequate and comprehensive information on the anthropogenic impact which is highest in industrial regions and areas with dense population – modern megacities. Megacities are not only “heat islands”, but also significant sources of emissions of various substances into the atmosphere, including greenhouse and reactive gases. In 2019, the mobile experiment EMME (Emission Monitoring Mobile Experiment) was conducted within the St. Petersburg agglomeration (Russia) aiming to estimate the emission intensity of greenhouse (CO2_{2}, CH4_{4}) nd reactive (CO, NOx_{x}) gases for St. Petersburg, which is the largest northern megacity. St. Petersburg State University (Russia), Karlsruhe Institute of Technology (Germany) and the University of Bremen (Germany) jointly ran this experiment. The core instruments of the campaign were two portable Bruker EM27/SUN Fourier transform infrared (FTIR) spectrometers which were used for ground-based remote sensing measurements of the total column amount of CO2_{2}, CH4_{4} and CO at upwind and downwind locations on opposite sides of the city. The NO2_{2} tropospheric column amount was observed along a circular highway around the city by continuous mobile measurements of scattered solar visible radiation with an OceanOptics HR4000 spectrometer using the differential optical absorption spectroscopy (DOAS) technique. Simultaneously, air samples were collected in air bags for subsequent laboratory analysis. The air samples were taken at the locations of FTIR observations at the ground level and also at altitudes of about 100 m when air bags were lifted by a kite (in case of suitable landscape and favourable wind conditions). The entire campaign consisted of 11 mostly cloudless days of measurements in March–April 2019. Planning of measurements for each day included the determination of optimal location for FTIR spectrometers based on weather forecasts, combined with the numerical modelling of the pollution transport in the megacity area. The real-time corrections of the FTIR operation sites were performed depending on the actual evolution of the megacity NOx_{x} plume as detected by the mobile DOAS observations. The estimates of the St. Petersburg emission intensities for the considered greenhouse and reactive gases were obtained by coupling a box model and the results of the EMME observational campaign using the mass balance approach. The CO2_{2} emission flux for St. Petersburg as an area source was estimated to be 89 ± 28 ktkm2^{-2} yr 2^{-2} , which is 2 times higher than the corresponding value in the EDGAR database. The experiment revealed the CH4_{4} emission flux of 135 ± 68 tkm 2^{-2} yr 1^{-1}, which is about 1 order of magnitude greater than the value reported by the official inventories of St. Petersburg emissions (∼ 25 tkm2^{-2} yr 1^{-1} or 2017). At the same time, for the urban territory of St. Petersburg, both the EMME experiment and the official inventories for 2017 give similar results for the CO anthropogenic flux (251 ± 104 tkm 2^{-2} yr 1^{-1} s. 410 tkm 2^{-2} yr 1^{-1}) nd for the NOx_{x} anthropogenic flux (66 ± 28 tkm2^{-2} yr 1^{-1} vs. 69 tkm 2^{-2} yr 1^{-1})

    A blueprint for a simultaneous test of quantum mechanics and general relativity in a space-based quantum optics experiment

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    In this paper we propose an experiment designed to observe a general-relativistic effect on single photon interference. The experiment consists of a folded Mach-Zehnder interferometer, with the arms distributed between a single Earth orbiter and a ground station. By compensating for other degrees of freedom and the motion of the orbiter, this setup aims to detect the influence of general relativistic time dilation on a spatially superposed single photon. The proposal details a payload to measure the required effect, along with an extensive feasibility analysis given current technological capabilities
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