Sample records for bednak imon dominik

  1. Color variations during activity states of the binary V Sge

    NASA Astrophysics Data System (ADS)

    Šimon, V.; Shugarov, S.


    Color variations in V Sge during various states of its activity in the course of 1995-1997 show that B-V gets bluer while U-B does not change significantly. Comparison of our data with the outburst observed by Herbig et al. (1965) shows that although the character of the activity in V Sge changed during the last decades (Šimon and Mattei 1999) the colors and their variations remained similar. .

  2. Synthesis and structures of new uranyl malonate complexes with carbamide derivatives

    SciTech Connect

    Serezhkina, L. B.; Grigor’ev, M. S.; Medvedkov, Ya. A.; Serezhkin, V. N.


    Crystals of new malonate-containing uranyl complexes [UO{sub 2}(C{sub 3}H{sub 2}O{sub 4})(Imon)(H{sub 2}O)] (I) and [UO{sub 2}(C{sub 3}H{sub 2}O4)(Meur){sub 3}] (II), where Imon is imidazolidin-2-one (ethylenecarbamide) and Meur is methyl-carbamide, have been synthesized and studied by X-ray diffraction. Both compounds crystallize in the monoclinic system with the following unit-cell parameters (at 100 K): a = 11.1147(10) Å, b = 6.9900(6) Å, c = 14.4934(12) Å, β = 92.042(2)°, V = 1125.30(17) Å{sup 3}, sp. gr. P2{sub 1}/n, Z = 4, R{sub 1} = 0.0398 (I); a = 16.6613(5) Å, b = 9.5635(3) Å, c = 22.9773(6) Å, β = 103.669(2)°, V = 3557.51(18) Å{sup 3}, sp. gr. C2/c, Z = 8, R{sub 1} = 0.0207 (II). The crystals are composed of electroneutral chains [UO{sub 2}(C{sub 3}H{sub 2}O{sub 4})(Imon)(H{sub 2}O)] and mononuclear groups [UO{sub 2}(C{sub 3}H{sub 2}O{sub 4})(Meur){sub 3}] as the structural units belonging to the crystal-chemical groups AT{sup 11}M{sub 2}{sup 1} and AB{sup 01}M{sub 3}{sup 1} (A =UO{sub 2}{sup 2+}, T{sup 11} and B{sup 01} = C{sub 3}H{sub 2}, M{sup 1} = Imon, H{sub 2}O, or Meur), respectively, of uranyl complexes. The packing modes of the uranyl-containing complexes were analyzed by the method of molecular Voronoi—Dirichlet polyhedra.

  3. Biographical sketch: Franz König, MD 1832-1910.


    Brand, Richard A


    This biographical sketch on Franz König corresponds to the historic text, The Classic: Ueber freie Körper in den Gelenken [On loose bodies in the joint] (1887), available at DOI 10.1007/s11999-013-2824-y (Translated by Drs. Richard A. Brand and Christian-Dominik Peterlein).

  4. Biography Today: Sports Series. Profiles of People of Interest to Young Readers. Volume 3, 1999.

    ERIC Educational Resources Information Center

    Harris, Laurie Lanzen, Ed.; Abbey, Cherie D., Ed.

    This third volume is part of a series of biographies that profile individuals of interest to young people over the age of 9 years. The entries in this volume include Joe Dumars, basketball; Jim Harbaugh, football; Dominik Hasek, hockey; Michelle Kwan, figure skating; Rebecca Lobo, basketball; Greg Maddux, baseball; Fatuma Roba, marathon running;…

  5. Cosmic Radiation Fields: Sources in the early Universe

    NASA Astrophysics Data System (ADS)

    Raue, Martin; Kneiske, Tanja; Horns, Dieter; Elsaesser, Dominik; Hauschildt, Peter

    The workshop "Cosmic Radiation Fields - Sources in the Early Universe" (CRF 2010) focuses on the connection between the extragalactic infrared background and sources in the early universe, in particular stars powered by dark matter burning (Dark Stars; DS). The workshop covers the following topics: the cosmic infrared background, formation of early stars, dark stars, effect of dark matter in the early universe, dark matter halos, primordial star formation rate, and reionization. Further information can be found on the conference webpage: Organizing committee: Tanja Kneiske, Martin Raue, Dominik Elsaesser, Alexander Gewering-Peine, Peter Hausschildt, Dieter Horns, and Andreas Maurer.

  6. Long-term color variations of the peculiar X-ray binary V Sagittae

    NASA Astrophysics Data System (ADS)

    Šimon, V.; Shugarov, S.; Marsakova, V. I.


    We present an analysis of the color variations of the X-ray binary V Sge during high, medium and low state of its activity over the years 1995-1997, using UBV data. We resolved the track of V Sge in the color diagrams (B-V and U-B versus mag(V)) during transitions between the states and show that the color variations on the orbital time scale are significantly smaller than the changes caused by the long-term activity. The mean B-V decreases by 0.15 mag during the upper part of the transition (brightness higher than 11.5 mag(V)) from the low to the high state but stays almost constant below this level. On the contrary, U-B does not change significantly during the whole transition. Comparison of our data with those of Herbig et al. (\\cite{Herbig}) shows that although the character of the long-term activity in V Sge changed significantly during the last decades (Šimon & Mattei \\cite{Simon}) the colors and their variations with the brightness level remained similar. Table~2 is only available in electronic form at the CDS via anonymous ftp to ( or via

  7. Lagrangian Modeling of the Atmosphere

    NASA Astrophysics Data System (ADS)

    Schultz, Colin


    Like watching a balloon borne by the breeze, a Lagrangian model tracks a parcel of air as it flows through the atmosphere. Whether running forward or backward in time, Lagrangian models offer a powerful tool for tracking and understanding the fates, or origins, of atmospheric flows. In the AGU monograph Lagrangian Modeling of the Atmosphere, editors John Lin, Dominik Brunner, Christoph Gerbig, Andreas Stohl, Ashok Luhar, and Peter Webley explore the nuances of the modeling technique. In this interview Eos talks to Lin about the growing importance of Lagrangian modeling as the world settles on climate change mitigation strategies, the societal value of operational modeling, and how recent advances are making it possible to run these complex calculations at home.

  8. Offshore Wind Farms in the North Sea: Is there an effect on the zooplankton community?

    NASA Astrophysics Data System (ADS)

    Auch, Dominik; Dudeck, Tim; Callies, Ulrich; Riethmüller, Rolf; Hufnagl, Marc; Eckhardt, André; Ove Möller, Klas; Haas, Bianca; Spreitzenbarth, Stefan; van Beusekom, Justus; Walter, Bettina; Temming, Axel; Möllmann, Christian; Floeter, Jens


    The climate conference in Paris 2015 has resulted in ambitious goals to mitigate the extent of global climate warming within this century. In Germany, the expansion of renewable energy sources is without any alternative to match the own aims of greenhouse gas reductions. Therefore, in the German EEZ of the North Sea around 10 offshore wind farms (OWFs) are already working and more are currently planned or already under construction. At this already substantial level of offshore wind energy production little is known about the effects of OWFs on the pelagic ecosystem. Earlier investigations have shown an increase of benthic organisms settling on hard substrates provided by the power plant foundations. However, the effects of offshore power plants on lower trophic level organisms within the water column are poorly understood. Thus, we investigated the abundance and distribution of zooplankton within and around OWFs. The analysis was based on optical data derived from a Video Plankton Recorder (VPR). The VPR was mounted on a TRIAXUS system including a suite of different sensors, hence allowing to combine zooplankton information with ambient hydrographic parameters. The combination of the VPR and the TRIAXUS system enabled us to analyse continuous zooplankton and hydrographic data with a high spatial resolution. In this study, we present results of transects through the OWFs Global Tech I, BARD Offshore 1, and Alpha Ventus. The analysis exhibits distinct pattern in the spatial distribution both of physical state variables and of plankton organisms within the vicinity of OWFs, especially of meroplankton, the larval phase of benthic organisms. Keywords: Offshore Wind Farms, Zooplankton, TRIAXUS, Video Plankton Recorder, Meroplankton Corresponding author: Dominik Auch, Institute for Hydrobiology and Fisheries Science, University of Hamburg, Olbersweg 24, 22767 Hamburg, Germany;

  9. Distribution of 7Be, 210Pb and 137Cs in watersheds of different scales in the Seine River basin: inventories and residence times.


    Le Cloarec, Marie-Françoise; Bonté, Philippe; Lefèvre, Irène; Mouchel, Jean-Marie; Colbert, Steven


    The activity of environmental radionuclides ((7)Be, (210)Pb and (137)Cs) was monitored in nested catchments, inside the Seine River basin. Suspended matter data was collected at 8 different watersheds, ranging from order 1 to order 7, and ranging in size over 4 orders of magnitude. Suspended matter was analyzed for (210)Pb, (137)Cs and (7)Be, and used to calculate the flux of sediments out of each watershed. Monthly atmospheric flux data of (210)Pb and (7)Be was analyzed to assess the input flux of each into the watersheds, taking into account the rainfall during sampling periods. Taking advantage of the different half-lives of (7)Be (53 days) and (210)Pb (22 years), a two-box model was built for each of the catchments following a methodology previously developed by Dominik et al. [Dominik J, Burrus D, Vernet JP. Transport of the environmental radionuclides in alpine watershed. Earth Planet Sci Letters 1987; 84: 165-180.]. The model divides the watershed into a soil box and a rapid reservoir and provides insight into the removal rate of suspended matter from the surrounding watershed. The model enables the assessment of the surface area and the residence time of slow and rapid reservoirs to describe the fate of contaminants of atmospheric origin inside the river basin. The model was improved by considering the dissolved fraction in the total flux and adding the (137)Cs inventory as an additional constraint. The effects of these changes are discussed. Residence times in the soil box, characterized by low transport velocity, range between 4800 years at Melarchez (order 1) to about 30000 years at Andresy and Poses (order 7). They remain constant in each watershed over a large range of variation of atmospheric fluxes of (7)Be and (210)Pb during the whole study, but are sensitive to SM variations. The residence time in the rapid box, which includes the surface of the river and immediate surroundings, is less than one year, while its surface area is in the range 0.6% to


    SciTech Connect

    Schraepler, Rainer; Blum, Juergen


    Observed protoplanetary disks consist of a large amount of micrometer-sized particles. Dullemond and Dominik pointed out for the first time the difficulty in explaining the strong mid-infrared excess of classical T Tauri stars without any dust-retention mechanisms. Because high relative velocities in between micrometer-sized and macroscopic particles exist in protoplanetary disks, we present experimental results on the erosion of macroscopic agglomerates consisting of micrometer-sized spherical particles via the impact of micrometer-sized particles. We find that after an initial phase, in which an impacting particle erodes up to 10 particles of an agglomerate, the impacting particles compress the agglomerate's surface, which partly passivates the agglomerates against erosion. Due to this effect, the erosion halts for impact velocities up to {approx}30 m s{sup -1} within our error bars. For higher velocities, the erosion is reduced by an order of magnitude. This outcome is explained and confirmed by a numerical model. In a next step, we build an analytical disk model and implement the experimentally found erosive effect. The model shows that erosion is a strong source of micrometer-sized particles in a protoplanetary disk. Finally, we use the stationary solution of this model to explain the amount of micrometer-sized particles in the observational infrared data of Furlan et al.

  11. Planet Formation

    NASA Astrophysics Data System (ADS)

    Klahr, Hubert; Brandner, Wolfgang


    1. Historical notes on planet formation Bodenheimer; 2. The formation and evolution of planetary systems Bouwman et al.; 3. Destruction of protoplanetary disks by photoevaporation Richling, Hollenbach and Yorke; 4. Turbulence in protoplanetary accretion disks Klahr, Rozyczka, Dziourkevitch, Wunsch and Johansen; 5. The origin of solids in the early solar system Trieloff and Palme; 6. Experiments on planetesimal formation Wurm and Blum; 7. Dust coagulation in protoplanetary disks Henning, Dullemond, Wolf and Dominik; 8. The accretion of giant planet cores Thommes and Duncan; 9. Planetary transits: direct vision of extrasolar planets Lecavelier des Etangs and Vidal-Madjar; 10. The core accretion - gas capture model Hubickyj; 11. Properties of exoplanets Marcy, Fischer, Butler and Vogt; 12. Giant planet formation: theories meet observations Boss; 13. From hot Jupiters to hot Neptures … and below Lovis, Mayor and Udry; 14. Disk-planet interaction and migration Masset and Kley; 15. The Brown Dwarf - planet relation Bate; 16. From astronomy to astrobiology Brandner; 17. Overview and prospective Lin.

  12. Herbig stars' near-infrared excess: An origin in the protostellar disk's magnetically supported atmosphere

    SciTech Connect

    Turner, N. J.; Benisty, M.; Dullemond, C. P.; Hirose, S.


    Young stars with masses 2-8 times solar, the Herbig Ae and Be stars, often show a near-infrared excess too large to explain with a hydrostatically supported circumstellar disk of gas and dust. At the same time, the accretion flow carrying the circumstellar gas to the star is thought to be driven by magnetorotational turbulence, which, according to numerical MHD modeling, yields an extended low-density atmosphere supported by the magnetic fields. We demonstrate that the base of the atmosphere can be optically thick to the starlight and that the parts lying near 1 AU are tall enough to double the fraction of the stellar luminosity reprocessed into the near-infrared. We generate synthetic spectral energy distributions (SEDs) using Monte Carlo radiative transfer calculations with opacities for submicron silicate and carbonaceous grains. The synthetic SEDs closely follow the median Herbig SED constructed recently by Mulders and Dominik and, in particular, match the large near-infrared flux, provided the grains have a mass fraction close to interstellar near the disk's inner rim.

  13. The Formation Of The First Solids In The Solar System: An Investigation Of CAI Diversity

    NASA Astrophysics Data System (ADS)

    Taillifet, Esther; Baillié, K.; Charnoz, S.; Aléon, J.


    Chondritic meteorites are primitive bodies and therefore an important source of information on the first moments of planets formation. Chondrites contain several materials especially calcium and aluminum rich inclusions (CAIs), known to be the oldest objects of the solar system (4.567 Gyr - Amelin et al., 2002; Connelly et al., 2008) and thus the first solids to be formed. CAIs appear in various textures, sizes and compositions in chondrites. Though, all of them should have formed at high temperature (1300-1800 K) in the same region of the solar nebula by condensation from the gas (e.g. Grossman, 1972; Yoneda & Grossman, 1995; Petaev & Wood, 1998; Ebel & Grossman 2000). To answer this problem we study the CAI formation within the solar nebula using numerical simulations. For this work we developed a self consistent thermodynamical model of the solar nebula (see associated talk from Baillié et. al ) based on previous works (Calvet et. al, 1991; Hueso & Guillot, 2005; Dullemond, Dominik and Natta, 2001). Using this model, we simulate the young system with Lagrangian Implicit Disk Transport code (LIDT - Charnoz et. al, 2010). We will focus on the very first instants of the CAIs within the few years following their condensation. We will report our first results in terms of thermal history and investigate if turbulence-driven transport may explain the CAI diversity.

  14. Development of plasma bolometers using fiber-optic temperature sensors

    NASA Astrophysics Data System (ADS)

    Reinke, M. L.; Han, M.; Liu, G.; van Eden, G. G.; Evenblij, R.; Haverdings, M.; Stratton, B. C.


    Measurements of radiated power in magnetically confined plasmas are important for exhaust studies in present experiments and expected to be a critical diagnostic for future fusion reactors. Resistive bolometer sensors have long been utilized in tokamaks and helical devices but suffer from electromagnetic interference (EMI). Results are shown from initial testing of a new bolometer concept based on fiber-optic temperature sensor technology. A small, 80 μm diameter, 200 μm long silicon pillar attached to the end of a single mode fiber-optic cable acts as a Fabry-Pérot cavity when broadband light, λo ˜ 1550 nm, is transmitted along the fiber. Changes in temperature alter the optical path length of the cavity primarily through the thermo-optic effect, resulting in a shift of fringes reflected from the pillar detected using an I-MON 512 OEM spectrometer. While initially designed for use in liquids, this sensor has ideal properties for use as a plasma bolometer: a time constant, in air, of ˜150 ms, strong absorption in the spectral range of plasma emission, immunity to local EMI, and the ability to measure changes in temperature remotely. Its compact design offers unique opportunities for integration into the vacuum environment in places unsuitable for a resistive bolometer. Using a variable focus 5 mW, 405 nm, modulating laser, the signal to noise ratio versus power density of various bolometer technologies are directly compared, estimating the noise equivalent power density (NEPD). Present tests show the fiber-optic bolometer to have NEPD of 5-10 W/m2 when compared to those of the resistive bolometer which can achieve <0.5 W/m2 in the laboratory, but this can degrade to 1-2 W/m2 or worse when installed on a tokamak. Concepts are discussed to improve the signal to noise ratio of this new fiber-optic bolometer by reducing the pillar height and adding thin metallic coatings, along with improving the spectral resolution of the interrogator.

  15. Characteristics of dune-paleosol-sequences in Fuerteventura. - What should be questioned?

    NASA Astrophysics Data System (ADS)

    Faust, Dominik; Willkommen, Tobias; Yanes, Yurena; Richter, David; Zöller, Ludwig


    Characteristics of dune-paleosol-sequences in Fuerteventura. - What should be questioned? Dominik Faust, TU Dresden, Germany Tobias Willkommen, TU Dresden, Germany Yurena Yanes, CSIC Granada/Cincinatti, Spain/USA David Richter, TU Dresden, Germany Ludwig Zöller, Uni Bayreuth, Germany The northern part of Fuerteventura is characterized by large dune fields. We investigated dune-paleosol-sequences in four pits to establish a robust stratigraphy and to propose a standard section. An interaction of processes like dune formation, soil formation and redeposition of soils and sand are most important to understand the principles of landscape development in the study area. To our mind a process cycle seem to be important: First climbing-dunes are formed by sand of shelf origin. Then soil formation could have taken place. Soil and/or sand were then eroded and deposited at toe slope position. This material in turn is the source of new sand supply and dune formation. The described cycle may be repeated several times and this ping-pong-process holds on. The results are sections composed of dune layers, paleosols and colluvial material interbedded. Fundamental questions still remain unanswered: Is climate change responsable for changes in process combination (e.g. from dune formation to soil formation)? Or are these features due to divergence phenomenon, where different effects/results (dune and soils) may be linked to similar causes (here: climate)? Assuming that different features (soils and dunes) were formed under one climate, increasing soil forming intensity could be mainly a function of decreasing sand supply. This in turn could be caused by reduced sand production (s. ZECH et al. accepted). However geochemical data and mollusc assemblages point to changing environments in space and even climate modifications in time.

  16. Midplane Ices in the Embedded Phase

    NASA Astrophysics Data System (ADS)

    Drozdovskaya, Maria; Walsh, Catherine; van Dishoeck, Ewine


    Icy grains in the midplanes of the youngest protoplanetary disks are the building blocks of protoplanets and protocometary bodies. Our Solar System shows significant chemical diversity. The chemical content is thought to be either inherited from the initial prestellar cloud, out of which our Solar System formed, or formed in-situ during the subsequent evolution of the protoplanetary disk. In this poster, the chemical analysis of midplanes in the context of globally evolving and collapsing star-forming systems will be presented. Previous studies compared various solid species relative to water ice in comets and towards young protostars [e.g., 1, 2, 3]. It remains unclear whether the overlap in abundances is just a coincidence or whether the origins of cometary ices are that of a prestellar cloud. For this work, an axisymmentric 2D semi-analytic collapse model [4], wavelength-dependent radiative transfer calculations with RADMC3D [5] and a comprehensive gas-grain chemical network [6] are used to pin down ice abundances in a midplane. The methanol content of protoplanetary disks will be presented [7], but also that of other main ice components, such as water, carbon monoxide and carbon dioxide [8]. Our models can be used to probe the validity of theories on the origin of chemical complexity and also to access the degree of processing upon inheritance into the forming disk.[1] Öberg K. I., Boogert A. C. A., Pontoppidan K. M., van den Broek S., van Dishoeck E. F., Bottinelli S., Blake G. A., Evans, II N. J., 2011, ApJ, 740, 109[2] Mumma M. J., Charnley S. B., 2011, ARA&A, 49, 471[3] Bockelée-Morvan D. et al., 2000, A&A, 353, 1101[4] Visser R., van Dishoeck E. F., Doty S. D., Dullemond C. P., 2009, A&A, 495, 881[5] Dullemond C. P., Dominik C., 2004, A&A, 417, 159[6] Walsh C., Millar T. J., Nomura H., Herbst E., Widicus Weaver S., Aikawa Y., Laas J. C., Vasyunin A. I., 2014, A&A, 563, A33[7] Drozdovskaya M. N., Walsh C., Visser R., Harsono D., van Dishoeck E. F., 2014

  17. PEGASUS - An Austrian Nanosatellite for QB50

    NASA Astrophysics Data System (ADS)

    Scharlemann, Carsten; Seifert, Bernhard; Kohl, Dominik; Birschitzky, David; Gury, Lionel; Kerschbaum, Franz; Obertscheider, Christof; Ottensamer, Roland; Reissner, Alexander; Riel, Thomas; Sypniewski, Richard; Taraba, Michael; Trausmuth, Robert; Turetschek, Thomas


    PEGASUS - An Austrian Nanosatellite for QB50 C. Scharlemann* David Birschitzky* Lionel Gury*, Franz Kerschbaum~, Dominik Kohl#, Christof Obertscheider*, Roland Ottensamer~, Alexander Reissner+, Thomas Riel#, B. Seifert+, Richard Sypniewski*, Michael Taraba?, Robert Trausmuth*, Thomas Turetschek?, …. (*)University of Applied Sciences Wiener Neustadt, Austria (+)FOTEC GmbH, Wiener Neustadt, Austria (+) Spaceteam, TU Wien, Austria (~) University Wien, Wien, Austria The QB50 project is an international project with the goal to send up to 50 Nanosatellites, a.k.a. CubeSat, into the Thermosphere. The scientific goal of this mission is to monitor over a period of up to nine months the prevailing conditions in this rather unknown part of Earth's atmosphere. Each of the 50 nanosatellites will be equipped with one of three possible scientific instruments: (i) a set of Langmuir probes, (ii) atomic oxygen measurement device, (iii) ion/neutral mass spectrometer. All satellites will be launched together and released in a string-of-pearls type fashion. It is predicted that the satellites will drift apart rather rapidly following the release. Therefore, the QB50 missions offers the possibility of a measurement grid in the thermosphere of unprecedented scope and accuracy. One of the satellites, named PEGASUS, is designed and build by a team of Austrian researches and students. PEGASUS will be equipped with the aforementioned Langmuir probes and will provide information about essential properties of the plasma in the thermosphere such as the electrontemperature and -density. In order to ensure the capability to collect and downlink the data over several months, PEGASUS requires about the same types of subsystems as one would find on large-scale satellites. This includes an attitude control system, an on-board computer, telecommunication devices, an electrical power systems allowing to harvest the solar power and either distribute or store it for later use, a thermal control system

  18. A Complex Organic Slushy Bathing Low-Mass Protostars

    NASA Astrophysics Data System (ADS)

    Drozdovskaya, Maria; Walsh, Catherine; Visser, Ruud; Harsono, Daniel; van Dishoeck, Ewine


    Complex organic molecules are ubiquitous companions of young forming stars. They were first observed in hot cores surrounding high-mass protostars [e.g., 1], but have since also been detected in the environs of several low-mass counterparts [e.g., 2]. Recent studies have shown that colder envelopes and positions with impinging outflows may also glow with emission from complex organic species [e.g., 3, 4]. For this meeting, I would like to present physicochemical modeling results on the synthesis of complex organics in an envelope-cavity system that is subject to non-thermal processing. This includes wavelength-dependent radiative transfer calculations with RADMC [5] and a comprehensive gas-grain chemical network [6]. The results show that the morphology of such a system delineates three distinct regions: the cavity wall layer with time-dependent and species-variant enhancements; a torus rich in complex organic ices, but not reflected in gas-phase abundances; and the remaining outer envelope abundant in simpler solid and gaseous molecules. Within the adopted paradigm, complex organic molecules are demonstrated to have unique lifetimes and be grouped into early and late species [7]. Key chemical processes for forming and destroying complex organic molecules will be discussed. In addition, the results of adding newly experimentally verified routes [8] into the existing chemical networks will be shown.[1] Blake G. A., Sutton E. C., Masson C. R., Phillips T. G., 1987, ApJ, 315, 621[2] Jørgensen J. K., Favre C., Bisschop S. E., Bourke T. L., van Dishoeck E. F., Schmalzl M., 2012, ApJ, 757, L4[3] Arce H. G., Santiago-García J., Jørgensen J. K., Tafalla M., Bachiller R., 2008, ApJ, 681, L21[4] Öberg K. I., Bottinelli S., Jørgensen J. K., van Dishoeck E. F., 2010, ApJ, 716, 825[5] Dullemond C. P., Dominik C., 2004, A&A, 417, 159[6] Walsh C., Millar T. J., Nomura H., Herbst E., Widicus Weaver S., Aikawa Y., Laas J. C., Vasyunin A. I., 2014, A&A, 563, A33[7] Drozdovskaya

  19. Residence time of suspended particles in the Garonne River (SW France): indications derived from Th-234, Be-7 and Pb-210

    NASA Astrophysics Data System (ADS)

    Schmidt, Sabine; Saari, Hanna-Kaïsa


    -temporal variations. Temporal changes in Th-234/Pb-210 and 7Be/210Pb activity ratios (ARs) are complex, depending on river discharge and suspended matter load. To derive sediment ages from the present dataset, two distinct models have been used: 1/ based on radionuclide budget (Dominik et al, 1987, Earth Planet. Sci. Lett. 84 165-180), and 2/ using Be-7/Pb-210 ARs (Matisoff et al, 2005, Earth Surf. Process. Landforms 30 1191-1201). These age estimates will be detailed in order to discuss particulate transport processes in the Garonne river during contrasted hydrological periods (flood and low waters).

  20. The Cost-Optimal Distribution of Wind and Solar Generation Facilities in a Simplified Highly Renewable European Power System

    NASA Astrophysics Data System (ADS)

    Kies, Alexander; von Bremen, Lüder; Schyska, Bruno; Chattopadhyay, Kabitri; Lorenz, Elke; Heinemann, Detlev


    . "Investigation of balancing effects in long term renewable energy feed-in with respect to the transmission grid." Advances in Science and Research 12.1 (2015): 91-95, doi:10.5194/asr-12-91-2015 [2] Heide, Dominik, et al. "Reduced storage and balancing needs in a fully renewable European power system with excess wind and solar power generation." Renewable Energy 36.9 (2011): 2515-2523 [3] Rodriguez, R.A.: Weather-driven power transmission in a highly renewable European electricity network, PhD Thesis, Aarhus University, November 2014 [4] Pfluger, B. et al.: Tangible ways towards climate protection in the European Union (EU long-term scenarios 2050), Fraunhofer ISI, Karlsruhe, September 2011

  1. Impact of river regulation on potential sediment mobilization and transport in an Alpine catchment

    NASA Astrophysics Data System (ADS)

    Costa, Anna; Molnar, Peter; Lane, Stuart N.; Bakker, Maarten


    The upper Rhône basin (upstream of Lake Geneva) has been heavily affected by human activities during the last century. The most evident impacts are related to river regulation, specifically flow impoundement, flow abstraction and channelization. In the last century and mainly since 1960, several large dams have been built along the main tributaries of the Rhône River, resulting in the water storage of a volume equal to 20% of the total annual river flow. The dams are part of hydropower systems which abstract water from streams and transfer it through complex networks (intakes, tunnels and pumping stations) to the reservoirs. Hydropower production leads to regulated flow in the Rhône: mostly an increase of winter flows, a reduction of summer flows, and a decrease of flood peaks. The sediment supply into Lake Geneva has decreased following dam construction (Loizeau & Dominik, 2000) due to the storage of sediment in upstream reservoirs, in rivers with reduced sediment transport capacity due to flow abstraction, and due to the development of sediment mining. Our hypothesis is that streamflow regulation itself has dramatically impacted the sediment transport dynamics of the system. We investigate the impacts of flow regulation on the sediment transport regime, by analysing the effects on potential sediment transport capacity (bedload). By the use of different bedload transport formulae (Meyer-Peter Müller, Wilcock and Crowe), the potential sediment transport capacity is computed at different cross sections within the basin. Potential sediment mobility occurs when the applied bed shear stress exceeds a critical value, τ>τc. The applied bed shear stress is computed as τ=ρghS, with water depth (h) measured from rating curves. We obtain an estimate of the energy slope (S) from the analysis of the river cross section, assuming uniform flow. The critical value of bed shear stress τc is computed using empirical formulae as a function of the grain diameter (ds). To

  2. Spitzer spectroscopy of newly discovered clusters of star formation in Serpens

    NASA Astrophysics Data System (ADS)

    Merín, B.; Pontoppidan, K. M.; Geers, V. C.; Dullemond, C. P.; Harvey, P.; van Dishoeck, E. F.; Augereau, J. C.; Kessler, J.; Boogert, A. C. A.; C2d Team

    We have discovered a uniquely rich star-forming region covering 0.5 sq. degrees near the Serpens Core from IRAC/MIPS maps obtained with the Spitzer Space Telescope within the Cores to Disks (c2d) Legacy program. The region contains three clusters apparently at different evolutionary stages, suggesting that sequential star formation has taken place. A number of the sources in this sample has been observed with the IRS spectrometer and will be presented and analysed here in relation to the general evolutionary picture for the region. In particular, the spectra contain signatures of silicates allowing the detailed comparison of grain composition, crystallinity, size distribution as well as physical structure of the disks between illustrative objects in the region at different evolutionary stages. 1. Introduction Mounting evidence points to the period between 1 and 10 Myrs as the most probable time-scale for the evolution of the circumstellar disks around young stars and the possible formation of planets. For example, the inner hot dust as traced by near-infrared photometry has been found to disperse within 3-6 Myrs (Haish et al. 2001). The dust has also been observed to crystallize due to thermal annealing in the innermost parts followed by strong radial mixing (van Boekel et al. 2004). Mid-infrared spectra coupled with disk models indicate that disks evolve from a flared geometry to a flat self-shadowed geometry (Meeus et al. 2001), as grains grow and settle to the mid-plane (Dullemond & Dominik 2004). Most of these previous studies are based on spectra of a handful of objects spread across the sky. A better statistical picture of disk evolution can be obtained by comparing disk populations in different co-eval clusters. 2. New star forming clusters in Serpens As part of the Cores to Disks (c2d) Legacy mapping campaign of molecular clouds (Evans et al. 2003), we discovered a region of ~0.5 square degrees in the Serpens molecular cloud (d ~ 250 pc) that is very rich

  3. PREFACE: Nano- and microfluidics Nano- and microfluidics

    NASA Astrophysics Data System (ADS)

    Jacobs, Karin


    compressible fluids Kerstin Falk and Klaus Mecke Wetting, roughness and flow boundary conditions Olga I Vinogradova and Aleksey V Belyaev Molecular transport and flow past hard and soft surfaces: computer simulation of model systems F Léonforte, J Servantie, C Pastorino, and M Müller Simulations of slip flow on nanobubble-laden surfaces J Hyväluoma, C Kunert and J Harting Electrophoretic transport of biomolecules across liquid-liquid interfaces Thomas Hahn, Götz Münchow and Steffen Hardt Wetting morphologies and their transitions in grooved substrates Ralf Seemann, Martin Brinkmann, Stephan Herminghaus, Krishnacharya Khare, Bruce M Law, Sean McBride, Konstantina Kostourou, Evgeny Gurevich, Stefan Bommer, Carsten Herrmann and Dominik Michler Imbibition in mesoporous silica: rheological concepts and experiments on water and a liquid crystal Simon Gruener, and Patrick Huber Theory and simulations of water flow through carbon nanotubes: prospects and pitfalls Douwe Jan Bonthuis, Klaus F Rinne, Kerstin Falk, C Nadir Kaplan, Dominik Horinek, A Nihat Berker, Lydéric Bocquet, and Roland R Netz Structure and flow of droplets on solid surfaces P Müller-Buschbaum, D Magerl, R Hengstler, J-F Moulin, V Körstgens, A Diethert, J Perlich, S V Roth, M Burghammer, C Riekel, M Gross, F Varnik, P Uhlmann, M Stamm, J M Feldkamp and C G Schroer Stability and dynamics of droplets on patterned substrates: insights from experiments and lattice Boltzmann simulations F Varnik, M Gross, N Moradi, G Zikos, P Uhlmann, P Müller-Buschbaum, D Magerl, D Raabe, I Steinbach and M Stamm Micro-capsules in shear flow R Finken, S Kessler and U Seifert Micro-rheology on (polymer-grafted) colloids using optical tweezers C Gutsche, M M Elmahdy, K Kegler, I Semenov, T Stangner, O Otto, O Ueberschär, U F Keyser, M Krueger, M Rauscher, R Weeber, J Harting, Y W Kim, V Lobaskin, R R Netz, and F Kremer Dynamics of colloids in confined geometries L Almenar and M Rauscher Dynamics of red blood cells and vesicles in

  4. Cosmic Lens Reveals Distant Galactic Violence

    NASA Astrophysics Data System (ADS)


    By cleverly unraveling the workings of a natural cosmic lens, astronomers have gained a rare glimpse of the violent assembly of a young galaxy in the early Universe. Their new picture suggests that the galaxy has collided with another, feeding a supermassive black hole and triggering a tremendous burst of star formation. Gravitational Lens Diagram Imaging a Distant Galaxy Using a Gravitational Lens CREDIT: Bill Saxton, NRAO/AUI/NSF Click on image for details and more graphics. The astronomers used the National Science Foundation's Very Large Array (VLA) radio telescope to look at a galaxy more than 12 billion light-years from Earth, seen as it was when the Universe was only about 15 percent of its current age. Between this galaxy and Earth lies another distant galaxy, so perfectly aligned along the line of sight that its gravity bends the light and radio waves from the farther object into a circle, or "Einstein Ring." This gravitational lens made it possible for the scientists to learn details of the young, distant galaxy that would have been unobtainable otherwise. "Nature provided us with a magnifying glass to peer into the workings of a nascent galaxy, providing an exciting look at the violent, messy process of building galaxies in the early history of the Universe," said Dominik Riechers, who led this project at the Max Planck Institute for Astronomy in Germany and now is a Hubble Fellow at the California Institute of Technology (Caltech). The new picture of the distant galaxy, dubbed PSS J2322+1944, shows a massive reservoir of gas, 16,000 light-years in diameter, that contains the raw material for building new stars. A supermassive black hole is voraciously eating material, and new stars are being born at the rate of nearly 700 Suns per year. By comparison, our Milky Way Galaxy produces the equivalent of about 3-4 Suns per year. The black hole appears to be near the edge, rather than at the center, of the giant gas reservoir, indicating, the astronomers say

  5. High velocity collisions - probing the edge of planetesimal growth

    NASA Astrophysics Data System (ADS)

    Teiser, J.; Wurm, G.


    field damage around the direct impact site. This near field damage can range from a thin circular trench around the sticking projectile material to a crater which also includes the impact site as material loss. Figure 1 gives an example for a collision with near field damage leading to mass loss. The balance between these two processes determines the mass balance of a collision. (3) When the impact energies are too high a large area of the target surface can be eroded away. This far field damage depends on the target size and thus is not important for realistic conditions. Due to the size dependance of the balance between near and far field damage small projectiles can lead to a net growth even with high velocities. Conclusions Based on experimental results we present a growth model which can be a solution to the question how planetesimal growth is possible once dust aggregates are compact and velocities tend to be destructive. Projectiles of a few mm in size hit a larger aggregate with a size of ~30 cm and leave a crater in the target surface which leads to a slight mass loss. In this colision the projectiles fragment into smaller pieces whereas the target mass hardly changes. In processes of this kind a large amount of sub-mm particles is formed which can lead to a mass gain in a following collisions. Although fragmentation plays a significant role in the high velocity range planetesimal growth via mutual collisions is possible. References [1] Blum, J. and Wurm, G. (2008) ARAA, in press. [2] Dominik, C. and Tielens, A. G. G. M. (1997) ApJ,480, 647-673. [3] Weidenschilling, S. J. and Cuzzi, J. N. (1993) in Levy, E. H. and Lunine, J. I., Protostars and Planets III, 1031-1060. [4] Blum, J. and Münch, (1993) Icarus, 106, 98-116. [5] Wurm, G. et al. (2005) Icarus, 178, 253-263.

  6. PAHs in circumstellar disks around T Tauri stars

    NASA Astrophysics Data System (ADS)

    Geers, Vincent C.; Augereau, Jean-Charles; Pontoppidan, Klaus M.; Dullemond, Cornelis P.; Visser, Ruud; van Dishoeck, Ewine F.; C2d Irs Team

    3D axi-symmetric radiative transfer models of circumstellar disks (Dullemond & Dominik 2004), to study the relation between disk structure and PAH feature strength. In this poster we present our first Spitzer spectra of PAH features in T Tauri stars and first results from the PAHs in disks modeling.

  7. Coming Home at Paranal

    NASA Astrophysics Data System (ADS)


    , won by Auer and Weber Freie Architekten from Munich (Germany), and with Dominik Schenkirz as principal designer. The interior furnishing and decoration was awarded to the Chilean architect Paula Gutierrez . The construction began in late 1998. Information about this work and several photos illustrating the progress have been published as PR Photos 31a-d/99 , PR Photo 43h/99 and PR Photos 04b-d/01 . Taking advantage of an existing depression in the ground, the architects created a unique subterranean construction with a single facade opening towards the Pacific Ocean , far below at a distance of about 12 km. It has the same colour as the desert and blends perfectly into the surroundings. The Paranal Residencia is elegant, with robust and inexpensive materials. Natural daylight is brought into the building through a 35-m wide glass-covered dome, a rectangular courtyard roof and various skylight hatches. The great originality of this design has made it possible to create an interior with a feeling of open space, despite the underground location. Some building characteristics are indicated below Facilities at the Residencia To the visitor who arrives at the Paranal Residencia from the harsh natural environment, the welcoming feeling under the dome is unexpected and instantly pleasant. This is a true "oasis" within coloured concrete walls and the air is agreeably warm and moist. There is a strong sense of calm and serenity and, above all, a feeling of coming home . At night, the lighting below the roofing closure fabric is spectacular and the impression on the mind is overwhelming. The various facilities are integrated over four floors below ground level. They include small, but nice and simple bedrooms, offices, meeting points, a restaurant, a library, a reception area, a cinema and other recreational areas. The natural focal point is located next to the reception at the entrance. The dining room articulates the building at the -2 level and view points through the facade

  8. It's Far, It's Small, It's Cool: It's an Icy Exoplanet!

    NASA Astrophysics Data System (ADS)


    gravitational microlensing" by J.-P. Beaulieu, D. P. Bennett, P. Fouqué, A. Williams, M. Dominik, U. G. Jørgensen, D. Kubas et al.). High resolution images and their captions are available on this page. This press release is also accompanied by Broadcast quality material.

  9. VLT Spectra "Resolve" a Stellar Disk at 25,000 Light-Years Distance

    NASA Astrophysics Data System (ADS)


    " ) that appeared in the April 1, 2001 issue of the "Astrophysical Journal" (available on the web at ApJL 550, L173 or astro-ph0011380). Notes [1] Note the recent ESO Press Release 06/01 about the VLT Interferometer. Observations of binary stars that undergo eclipses from time to time also allow indirect studies of the surfaces of the two components; such objects, however, influence each other and cannot be characterized as "normal" stars. [2] The team (the PLANET collaboration) consists of Michael Albrow , Kailash C. Sahu (Space Telescope Science Institute, Baltimore, MD, USA) Jin H. An (Dept. of Astronomy, Ohio State University, Columbus, OH, USA), Jean-Philippe Beaulieu (Institut d'Astrophysique de Paris, France), John A. R. Caldwell , John W. Menzies , Pierre Vermaak (South African Astronomical Observatory, Cape Town, South Africa), Martin Dominik , Penny D. Sackett (Kapteyn Astronomical Institute, Groningen, The Netherlands) , John Greenhill , Kym Hill , Stephen Kane , Robert Watson (University of Tasmania, Hobart, Tasmania, Australia), Ralph Martin , Andrew Williams (Perth Observatory, Australia), Karen Pollard (Physics Dept., Gettysburg College, PA, USA) and Peter H. Hauschildt (Dept. of Physics and Astronomy & Center for Simulational Physics, University of Georgia, Athens, GA, USA). [3] The distance to the Sun is 149.6 million kilometres; 25,000 light-years = 240,000,000,000,000,000 kilometres. 1 billion = 1000 million. [4] The diameter of the cool giant star is approx. 15 million km (about ten times that of the Sun). At the indicated distance, 25,000 light-years, this corresponds to a very small angle, about 10 micro-arcsec. This is equal to the angle subtended by a human hair (diameter 50 microns = 0.05 mm) at a distance of 1000 km. Technical information about the photos PR Photo 16b/01 shows a 0.25-sec acquisition exposure of EROS-BLG-2000-5 , obtained with VLT ANTU + FORS1 in order to set up the spectrograph slit for the subsequent spectral exposures. The