1,366 research outputs found

    Correction of artificial jumps in the historical geomagnetic measurements of Coimbra Observatory, Portugal

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    The Coimbra Magnetic Observatory (International Association of Geomagnetism and Aeronomy code COI) in Portugal has a long history of observation of the geomagnetic field, spanning almost 150 yr since the first geomagnetic measurements in 1866. These long instrumental geomagnetic records provide very important information about variability of geomagnetic elements and indices, their trends and cycles, and can be used to improve our knowledge on the sources that drive variations of the geomagnetic field: liquid core dynamics (internal) and solar forcing (external). <br><br> However, during the long life of the Coimbra Observatory, some inevitable changes in station location, instrument's park and electromagnetic environment have taken place. These changes affected the quality of the data collected at COI causing breaks and jumps in the series of geomagnetic field components and local K index. Clearly, these inhomogeneities, typically shift-like (step-like) or trend-like, have to be corrected or, at least, minimized in order for the data to be used in scientific studies or to be submitted to international databases. <br><br> In this study, the series of local K index and declination of the geomagnetic field are analysed: the former because it allows direct application of standard homogenization methods and the latter because it is the longest continuous series produced at COI. For the homogenization, visual and statistical tests (e.g. standard normal homogeneity test) have been applied directly to the local geomagnetic K index series (from 1951 to 2012). The homogenization of the monthly averages of declination (from 1867 to 2012) has been done using visual analysis and statistical tests applied to the time series of the first differences of declination values, as an approximation to the first time derivative. This allowed not only estimating the level of inhomogeneity of the studied series but also detecting the highly probable homogeneity break points. These points have been cross-checked with the metadata, and the COI series have been compared with reference series from the nearest geomagnetic stations and, in the case of declination series, from the recent geomagnetic field model COV-OBS to set up the required correction factors. As a result, the homogenized series measured in COI are considered to be essentially free of artificial shifts starting from the second half of the 20th century, and ready to be used by the scientific community

    Влияние Скандинавского ледника на климатические условия Восточно-Европейской равнины по данным численного моделирования проекта

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    In this paper results of climate simulation in East-European Plain (EEP) by coupled climate models (which take part in project PMIP II (Paleoclimate Modeling Intercomparison Project)) are tested for different climatic periods (pre-industrial, Last Glacial Maximum (LGM)). The main parameters for comparison were: temperature, precipitations, evaporation and the Volga runoff. As a result, the model CNRM (Centre National de Recherches Meteorologie, France) was chosen as the best for this territory for pre-industrial climate. Its results were used to calculate runoff of the Volga river during the LGM and modern climate. «Climatic» component of the Volga runoff was calculated as the difference between precipitation and evaporation in the watershed. The «climatic» part of the Volga runoff 21 kyr decreased by 30% compared with the modern (according to model CNRM). The main reason for the low values of «climatic» runoff was a reduction of precipitation on the territory of Volga watershed. The decrease of evaporation could not compensate for the deficit of precipitation. However, according to paleoreconstructions and the results of PMIP II simulation, a significant change to the hydrological regime of the Volga River (21 kyr BP) could be due to the contribution of melt water (about 384 km³/year). This means that to «climatic» component of runoff (about 78 km³/year), one has to add volume of the melt water of the Scandinavian ice sheet, which within the territory of Volga watershed. The results were used to assess the level of the Caspian Sea during this period (changes in the Caspian sea level compared with modern was about 48 meters. Рассматриваются результаты работы глобальных климатических моделей, участвующих в проекте PMIP 2 (Paleoclimate Modelling Intercomparison Project), по воспроизведению современного климата и климата последнего ледникового максимума (LGM) для территории Восточно-Европейской равнины. Приводится набор возможных критериев для оценки качества воспроизведения современного климата в этом регионе, выполнено сравнение моделей. Для климата LGM проанализированы поля температуры, осадков, рассчитан сток р. Волга без и с учётом возможного вклада талых вод Скандинавского ледника. Полученные результаты использованы для оценки уровня Каспийского моря в этот период

    Effect of carbamylated darbepoetin administration at different doses on the thymus and spleen structure of rats

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    In this article, the morphological features of the structure of the thymus and spleen under the influence of carbamylated darbepoetin in different doses were studied. The material for the study was 40 white male rats of the Wistar bree

    The Comparative Analysis of the Identification of Parasitic Fungi Races Affecting the Soil and Cultivated Vegetable and Cucurbits Crops in the Astrakhan Region

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    The habitat of plant pathogens does not remain constant and undergoes significant changes. Therefore, the reasons have to be revealed: the emergence of fungal infectious matter in the soil; the infection source and rate, which may have epiphytotic character under environmental factors of the disease development and consequently lead to the reduction in the yield of vegetable and cucurbits crops. As a result, it is necessary to conduct monitoring and objective diagnosis of the phytosanitary condition of the planting of vegetables and melons. In this case, the identification of parasitic fungi races of the Astrakhan region remains relevant and timely

    Volume of the quantum mechanical state space

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    The volume of the quantum mechanical state space over nn-dimensional real, complex and quaternionic Hilbert-spaces with respect to the canonical Euclidean measure is computed, and explicit formulas are presented for the expected value of the determinant in the general setting too. The case when the state space is endowed with a monotone metric or a pull-back metric is considered too, we give formulas to compute the volume of the state space with respect to the given Riemannian metric. We present the volume of the space of qubits with respect to various monotone metrics. It turns out that the volume of the space of qubits can be infinite too. We characterize those monotone metrics which generates infinite volume.Comment: 17 page

    Results of hydrological studies and channel analysis of the Ganges (Padma) River at the construction site of the “Rooppur” NPP

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    This work presents the results of research on channel processes in the Padma River (Republic of Bangladesh) at the construction site of the “Ruppur” Nuclear Power Plant (NPP). The fluvial characteristics of the Padma River were presented, including: the water outflow regime, characteristics of anthropogenic impact on the river outflow and assessment of the present state of the channel and floodplain. The research was conducted based on field expeditions, during which data on morphology, dynamics, hydrological and hydraulic conditions for the formation of the floodplain-channel complex were collected. Moreover, the water discharges and suspended sediments, as well as the longitudinal profiles of the water level and the channel morphology were measured. The presented research has shown that comprehensive and planned regulation of selected sections of rivers could lead to the channel stabilization and support the rational use of water resources for different purposes, e.g. power plants, municipal purposes, etc. Moreover, detailed research on channel deformation in selected areas indicated the major role of natural factors (geological structure, the type of sediments delivered to the river, vegetation cover, etc.) in the past and present fluvial processes

    The ways to improve the biological and morphological parameters of young fattening pigs

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    Studies were carried out to find the new ways to improve the efficiency of iodine use for the young pigs. During the scientific and economic experiment it was found that bringing iodine to the physiological norm, in combination with introduction of 3% bentonite clay into the diets of young fattening pigs, provided a positive effect on the morphological composition of carcasses, slaughter parameters and meat quality of the pigs. So fattening the yelts with the diets with a physiological norm of iodine in combination with 3% bentonite clay allowed young pigs of the 3rd experimental group to reach a slaughter weight of 78.95 kg at the age of 8 months, which is 10.1% more than in the control group, and 4.2% and 2.5% more in comparison with the 1st and 2nd experimental groups. The slaughter yield in yelts of the 3rd experimental group increased by 2.43% (P&lt;0.05) compared to the control group. The largest (30.17 cm2) area of the “rib eye” was recorded in the 3rd experimental group, which is 5.60% more than the control one, while the carcasses of pigs of the 3rd experimental group contained muscle tissue by 4.74% (P&lt;0.05) more than the same in the control group. Analysis of the Musculus longissimus showed a significant increase in protein content in the 3rd experimental group by 1.22% compared to the control group (P&lt;0.05). The protein-quality parameter was significantly higher in the muscle tissue of young pigs of the 3rd experimental group and amounted to 10.90 (P&lt;0.05), which is 1.12% higher than in the muscle tissue of the control group yelts. The maximum content of oleic acid was found in the lard of animals of the 3rd experimental group — 49.59, which is 1.28% (P&lt;0.05) higher than in the control group.

    Quantum correlations and distinguishability of quantum states

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    A survey of various concepts in quantum information is given, with a main emphasis on the distinguishability of quantum states and quantum correlations. Covered topics include generalized and least square measurements, state discrimination, quantum relative entropies, the Bures distance on the set of quantum states, the quantum Fisher information, the quantum Chernoff bound, bipartite entanglement, the quantum discord, and geometrical measures of quantum correlations. The article is intended both for physicists interested not only by collections of results but also by the mathematical methods justifying them, and for mathematicians looking for an up-to-date introductory course on these subjects, which are mainly developed in the physics literature.Comment: Review article, 103 pages, to appear in J. Math. Phys. 55 (special issue: non-equilibrium statistical mechanics, 2014
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