15 research outputs found
The Hamburg/SAO survey for low metallicity blue compact/HII-galaxies (HSS-LM). I. The first list of 46 strong-lined galaxies
We present the description and the first results of a new project devoted to
the search for extremely metal-deficient blue compact/HII-galaxies (BCGs) and
to the creation of a well selected large BCG sample with strong emission lines.
Such galaxies should be suitable for reliable determination of their oxygen
abundance through the measurement of the faint [OIII]4363A line. The goals of
the project are two-fold: a) to discover a significant number of new extremely
metal-poor galaxies (Z <= 1/20 Zo), and b) to study the metallicity
distribution of local BCGs. Selection of candidates for follow-up slit
spectroscopy is performed on the database of objective prism spectra of the
Hamburg Quasar Survey. The sky region is limited by delta >= 0 deg. and b^ii <=
-30 deg. In this paper we present the results of the follow-up spectroscopy
conducted with the Russian 6m telescope. The list of observed candidates
contained 52 objects, of which 46 were confirmed as strong-lined BCGs
(EW([OIII]5007) >= 100 A). The remaining five lower excitation ELGs include
three BCGs, and two galaxies classified as SBN (Starburst Nucleus) and DANS
(Dwarf Amorphous Nucleus Starburst). One object is identified as a quasar with
a strong Ly_alpha emission line near 5000 A (z~3). We provide a list with
coordinates, measured radial velocities, B-magnitudes, equivalent widths
EW([OIII]5007) and EW(H_beta) and for the 46 strong-lined BCGs the derived
oxygen abundances 12+log(O/H). The abundances range between 7.42 and 8.4
(corresponding to metallicities between 1/30 and 1/3 Zo). The sample contains
four galaxies with Z < 1/20 Zo, of which three are new discoveries.Comment: 19 pages, 13 figures, accepted for publication in A&A, corrected
typos, reference
The Holocene history of the NE Black Sea and surrounding areas: An integrated record of marine and terrestrial palaeoenvironmental change
Here we present an almost complete and integrated Holocene record of marine and terrestrial palaeoenvironmental change from the NE shelf of the Black Sea. A dinoflagellate cyst record used to reconstruct Holocene sea-surface conditions highlights that the NE shelf was a brackish water environment, with a minimum salinity of 7 psu in the early-Holocene before changing at a gradual rate to a more saline environment with maximum salinities of ~18 psu being reached around 3 cal. ka. A warming phase was detected from 6 cal. ka BP, with warmest conditions between 3 and 2.5 cal. ka BP. A pollen record is used to examine the major climate and land-use changes in the eastern Black Sea region. Biome reconstructions show that the temperate deciduous forest dominates throughout the record, although with an overall decline. From early-Holocene to the first hiatus around ~9 cal. ka BP, Pinus pollen dominates, while taxa representing a mixed oak-hornbeam-beech forest are less abundant, indicating relatively cool and dry conditions. Between ~7.9 and ~6.1 cal. ka BP, a thermophilous deciduous forest established, suggesting an overall warming trend and humid conditions. From 4 cal. ka BP, Pinus dominates the pollen record, accompanied by an increase of herbs, implying an opening of the landscape, which would coincide with the beginning of the Meghalayan Age. The integrated record of the marine and terrestrial climate indicators supports the notion that this change in landscape may have been triggered by a combination of warmer and drier conditions and human activities in this region
New approach for wine authenticity screening by a cumulative
New methodological approach for rapid control of wine authenticity without sample preparation, based on the quantitative NMR spectroscopy (qNMR) of the protium 1H and deuterium 2H nucleus is suggested. The content of dominant (e.g. water, ethanol) and some minor (e.g. glycerol, organic acids) components of wine are determined from qNMR 1H spectra for authentication of molecular composition. The sum of all exchanging hydrogen atoms of wine's components provide the 1H signal with a chemical shift of 4.8 ppm. Accounting for their content from 1H spectrum allows us calculate the 2H isotopic content in wine water from integral intensity of corresponding signal in the 2H qNMR spectrum using an internal or external standard with a known content of the 2H isotope. The possible addition of water can be found from comparison of this value with values of surface and/or ground waters from corresponding viticulture areas. This approach was used for white and red wines from the Black Sea region (Krasnodar area & Crimea peninsula). The 2H contents in investigated wines range from 157 to 165 ppm. The maximum 2H isotope content in surface waters does not exceed 148 ppm. A qNMR measurement of wine according to the proposed approach takes some minutes, that significantly exceeds the laboriousness of methods based on IRMS/SIRA (e.g. δ13C, δ18O). The error of qNMR measurements is less than 2.0%. The qNMR screening of deuterium (2H) in ethanol can be used for detection of possible wine chaptalization. This approach is similar to the known SNIF-NMR method. The positive difference with this method is the use of minimal quantity of enriched 2H standard and measurement of integral intensities of all signals instead of heights. It allows to reduce measurements' time as well as to measure the 2H content of all fragments of ethanol molecules – CH3−, CH2−, OH-groups. The publication has been prepared with the support of the “RUDN University Program 5–100”
Appropriate levels of physical capacities development in adolescents with different state of health
Мета: обґрунтувати відповідність рівня розвитку фізичних можливостей дівчаток 12-13 років з різним рівнем фізичного здоров'я.
Матеріали і методи. У дослідженні взяли участь 101 учениця старших класів 12-13 років. Вибір старшокласниць цього віку зумовлений найбільшою варіативністю їх морфофункціонального стану. Оцінку фізичного здоров’я дівчат проводили за методикою Г. Л. Апанасенко. Фізичну підготовленість оцінювали за допомогою 13 рухових тестів, які визначають різні аспекти фізичних можливостей дівчат.
Результати: Визначено відповідні нормативи фізичної підготовленості дівчаток 12-13 років з різним рівнем здоров'я та раціональні параметри рухової активності.
Висновки. Виявлено, що основним принципом реалізації занять розвивально-оздоровчого спрямування з фізичного виховання підлітків є диференційоване використання навантажень та оцінка їхньої фізичної підготовленості. Розраховані за допомогою коефіцієнтів кореляції та рівнянь регресії відповідні значення показників фізичного розвитку у дівчаток 12-13 років з різним рівнем фізичного здоров’я дають змогу за допомогою відповідних вправ усунути відхилення в показниках їх здоров’я.The aim: To justify the appropriate levels of physical capabilities development in 12-13-years-old girls with different levels of physical health.
Materials and methods: The research involved 101 12-13-years-old female high-school students. The choice of female high-school students of this age is due to the greatest variability of their morpho-functional state. The physical health of the girls was assessed according to the method of H. L. Apanasenko. Physical fitness was assessed with the help of 13 motor tests that determine different aspects of girls’ physical capabilities.
Results: Appropriate normative standards of physical fitness for 12-13-years-old girls with different levels of health and rational parameters of physical activity were determined. It was established that a rational option for planning physical training for 12-13-years-old girls is: 26 % of time should be spent on strength development; speed and strength qualities and agility - by 22 %; endurance - 18 % and speed qualities - 12 %.
Conclusions: It was found that the main principle of the implementation of developmental and health-oriented training sessions for the physical education of adolescents is the differentiated use of loads and assessment of their physical fitness. Calculated with the help of correlation coefficients and regression equations, the appropriate values of physical development in 12-13-years-old girls with different levels of physical health make it possible, using appropriate exercises, to eliminate deviations in their health indicators
New approach for wine authenticity screening by a cumulative 1H and 2H qNMR
New methodological approach for rapid control of wine authenticity without sample preparation, based on the quantitative NMR spectroscopy (qNMR) of the protium 1H and deuterium 2H nucleus is suggested. The content of dominant (e.g. water, ethanol) and some minor (e.g. glycerol, organic acids) components of wine are determined from qNMR 1H spectra for authentication of molecular composition. The sum of all exchanging hydrogen atoms of wine's components provide the 1H signal with a chemical shift of 4.8 ppm. Accounting for their content from 1H spectrum allows us calculate the 2H isotopic content in wine water from integral intensity of corresponding signal in the 2H qNMR spectrum using an internal or external standard with a known content of the 2H isotope. The possible addition of water can be found from comparison of this value with values of surface and/or ground waters from corresponding viticulture areas. This approach was used for white and red wines from the Black Sea region (Krasnodar area & Crimea peninsula). The 2H contents in investigated wines range from 157 to 165 ppm. The maximum 2H isotope content in surface waters does not exceed 148 ppm. A qNMR measurement of wine according to the proposed approach takes some minutes, that significantly exceeds the laboriousness of methods based on IRMS/SIRA (e.g. δ13C, δ18O). The error of qNMR measurements is less than 2.0%. The qNMR screening of deuterium (2H) in ethanol can be used for detection of possible wine chaptalization. This approach is similar to the known SNIF-NMR method. The positive difference with this method is the use of minimal quantity of enriched 2H standard and measurement of integral intensities of all signals instead of heights. It allows to reduce measurements' time as well as to measure the 2H content of all fragments of ethanol molecules – CH3−, CH2−, OH-groups. The publication has been prepared with the support of the “RUDN University Program 5–100”
Mass-spectrometric study on
The present study continues the 2015–2016 research project on biological characteristics of stable isotopes fractionation in grapes taking into account the agro-climatic growth conditions of this representative of the C3-pathway of photosynthesis group of plants in different geographical Black Sea regions. The first parts of the project were presented at the 39th and 40th Congresses of OIV in Bento Gonçalves (Brazil) and Sofia (Bulgaria). The scientific data on compositions of 13C/12C carbon and 18O/16O oxygen stable isotopes in carbohydrates, organic acids, and intracellular water were obtained for grapes of 2015–2016 growing seasons in the four areas of the Crimean peninsula as well as in several areas of the Don Basin and the Western Caspian region. This report presents the results of the 2017 season study of 13C/12C carbon and 18O/16O oxygen stable isotopes in carbohydrates and intracellular water of 12 red and white grape varieties (Aligote, Rkatsiteli, Sauvignon Zeleny, Chardonnay, Cabernet Sauvignon, Sauvignon Blanc, Merlot, Risling, Pinot Noir, Cabernet Franc, Sira, Krasnostop) as well as in ethanol of wines made from corresponding grapes from the Crimean Peninsula and South-West Coast of the Greater Caucasus. To measure the ratio of carbon isotopes 13C/12C in grape (must) carbohydrates and wine ethanol the Flash-Combustion technique (FC-IRMS/SIRA) has been used, while the method of isotopic equilibration (EQ-IRMS/SIRA) has been used for the measurement of 18O/16O oxygen isotopes ratio in the intracellular water of grapes (must) and in the water fraction of wine. The GC-Combustion technique (GC-IRMS/SIRA) has been used for the first time to measure the carbon isotopes 13C/12C distribution in ethanol of studied wines. It has been found that the δ13CVPDB values for carbohydrates of red and white grape varieties as a result of biological fractionation of carbon isotopes in the agro-climatic conditions of plant growth (2017 season) for the studied geographical areas formed the following quantitative ranges: from − 26.72 to − 23.35‰ (the Crimean Peninsula) and from − 25.92 to − 23.87‰ (South-West Coast of the Greater Caucasus). The δ13CVPDB values for wine ethanol are in the following ranges: from − 28.15 to − 24.47‰ (the Crimean Peninsula) and from − 27.29 to − 25.78‰ (South-West Coast of the Greater Caucasus). The δ18OVSMOW values in intracellular water of grapes of the 2017 season range from − 1.24 to 2.17‰ (the Crimean Peninsula) and from 1.08 to 4.09‰ (South-West Coast of the Greater Caucasus). The results of this study show, in comparison with the results of studies of the 2015 and 2016 seasons, a decrease in the δ13CVPDB values for carbohydrates of grapes and ethanol of wine, which is explained by the changed climatic conditions of grapes growing in the vegetation period of 2017
Mass-spectrometric study on13C/12C carbon and18O/16O oxygenstable isotopes distributions in grapes and wines from the BlackSea regions
The present study continues the 2015–2016 research project on biological characteristics of stableisotopes fractionation in grapes taking into account the agro-climatic growth conditions of this representativeof the C3-pathway of photosynthesis group of plants in different geographical Black Sea regions. The firstparts of the project were presented at the 39th and 40th Congresses of OIV in Bento Gonc ̧alves (Brazil) andSofia (Bulgaria). The scientific data on compositions of13C/12C carbon and18O/16O oxygen stable isotopes incarbohydrates, organic acids, and intracellular water were obtained for grapes of 2015–2016 growing seasonsin the four areas of the Crimean peninsula as well as in several areas of the Don Basin and the Western Caspianregion. This report presents the results of the 2017 season study of13C/12C carbon and18O/16O oxygen stableisotopes in carbohydrates and intracellular water of 12 red and white grape varieties (Aligote, Rkatsiteli,Sauvignon Zeleny, Chardonnay, Cabernet Sauvignon, Sauvignon Blanc, Merlot, Risling, Pinot Noir, CabernetFranc, Sira, Krasnostop) as well as in ethanol of wines made from corresponding grapes from the CrimeanPeninsula and South-West Coast of the Greater Caucasus. To measure the ratio of carbon isotopes13C/12Cin grape (must) carbohydrates and wine ethanol the Flash-Combustion technique (FC-IRMS/SIRA) has beenused, while the method of isotopic equilibration (EQ-IRMS/SIRA) has been used for the measurement of18O/16O oxygen isotopes ratio in the intracellular water of grapes (must) and in the water fraction of wine. TheGC-Combustion technique (GC-IRMS/SIRA) has been used for the first time to measure the carbon isotopes13C/12C distribution in ethanol of studied wines. It has been found that theδ13CVPDBvalues for carbohydratesof red and white grape varieties as a result of biological fractionation of carbon isotopes in the agro-climaticconditions of plant growth (2017 season) for the studied geographical areas formed the following quantitativeranges: from−26.72 to−23.35‰ (the Crimean Peninsula) and from−25.92 to−23.87‰ (South-West Coastof the Greater Caucasus). Theδ13CVPDBvalues for wine ethanol are in the following ranges: from−28.15to−24.47‰ (the Crimean Peninsula) and from−27.29 to−25.78‰ (South-West Coast of the GreaterCaucasus). Theδ18OVSMOWvalues in intracellular water of grapes of the 2017 season range from−1.24to 2.17‰ (the Crimean Peninsula) and from 1.08 to 4.09‰ (South-West Coast of the Greater Caucasus). Theresults of this study show, in comparison with the results of studies of the 2015 and 2016 seasons, a decreasein theδ13CVPDBvalues for carbohydrates of grapes and ethanol of wine, which is explained by the changedclimatic conditions of grapes growing in the vegetation period of 201