WorldWideScience

Sample records for wechselwirkungspotentiale von helium

  1. Ab initio calculation of the interaction potentials of helium, neon, and methane as well as theoretical studies on their thermophysical properties and those of water vapor; Ab initio-Berechnung der Wechselwirkungspotentiale von Helium, Neon und Methan sowie theoretische Untersuchungen zu ihren thermophysikalischen Eigenschaften und denen von Wasserdampf

    Energy Technology Data Exchange (ETDEWEB)

    Hellmann, Robert

    2009-06-16

    Thermophysical properties of the pure gases helium, neon, methane and water vapor were calculated for low densities over wide temperature ranges. Statistical thermodynamics was used for the determination of the pressure virial coefficients. The kinetic theory of gases was utilized for the calculation of the transport and relaxation properties. So far kinetic theory was limited to linear molecules and has now been extended to molecules of arbitrary geometry to enable calculations on methane and water vapor. The interaction potentials, which are needed for all computations, were determined for helium, neon and methane from the supermolecular approach using quantum chemical ab initio methods. For water the interaction potentials were taken from the literature. The calculated values of the thermophysical properties for the four gases show very good agreement with the best experimental data. At very low and very high temperatures the theoretical values are more accurate than experimental data. (orig.)

  2. Photoionization of helium dimers; Photoionisation von Heliumdimeren

    Energy Technology Data Exchange (ETDEWEB)

    Havermeier, Tilo

    2010-06-09

    The helium dimer is one of the most weakly bound systems in the universe. This makes it an interesting quantum mechanical object for investigation. These Van der Waals Clusters can be produced in an expansion of a cryogenic gas jet through a small nozzle into vacuum. In the present experiment we examine the interaction of He dimers with synchrotron radiation at an energy range from 64 to 78 eV. We observed different pathways leading to single ionization of both He atoms of the dimer compound. This two close standing ions begin now to dissociate in cause of their coulomb potential. All charged fragments were detected in coincidence with a COLTRIMS system. Especially Interatomic Coulombic Decay (ICD) and the two step process (TS1) were clearly identified. Furthermore a distribution of the internuclear distance was obtained from the measured Kinetic Energy Release (KER). (orig.)

  3. Probing quantum and classical turbulence analogy in von Kármán liquid helium, nitrogen, and water experiments

    Energy Technology Data Exchange (ETDEWEB)

    Saint-Michel, B. [Laboratoire SPHYNX, CEA/IRAMIS/SPEC, CNRS URA 2464, F-91191 Gif-sur-Yvette (France); Aix Marseille Université, CNRS, Centrale Marseille, IRPHE UMR 7342, 13384 Marseille (France); Herbert, E. [Laboratoire SPHYNX, CEA/IRAMIS/SPEC, CNRS URA 2464, F-91191 Gif-sur-Yvette (France); Université Paris Diderot – Sorbonne Paris Cité, Laboratoire Interdisciplinaire des Énergies de Demain (LIED) – CNRS UMR 8236, Paris (France); Salort, J.; Castaing, B.; Chevillard, L. [Laboratoire de Physique de l’ÉNS de Lyon, CNRS/Université Lyon- F-69364 Lyon CEDEX 7 (France); Baudet, C.; Bourgoin, M.; Gagne, Y. [Laboratoire des Écoulements Géophysiques et Industriels, CNRS/UJF/INPG, F-38041 Grenoble CEDEX 9 (France); Bon Mardion, M.; Bonnay, P.; Diribarne, P.; Girard, A.; Rousset, B. [Univ. Grenoble Alpes, INAC-SBT, F-38000 Grenoble, France and CEA, INAC-SBT, F-38000 Grenoble (France); Daviaud, F.; Dubrulle, B. [Laboratoire SPHYNX, CEA/IRAMIS/SPEC, CNRS URA 2464, F-91191 Gif-sur-Yvette (France); Gibert, M.; Hébral, B. [Univ. Grenoble Alpes, Inst NEEL, F-38042 Grenoble, France and CNRS, Inst NEEL, F-38042 Grenoble (France); Lehner, Th. [LUTH, Observatoire Paris-Meudon, 5 Pl. Jules Janssen, F-92195 Meudon CEDEX (France)

    2014-12-15

    We report measurements of the dissipation in the Superfluid helium high REynold number von Kármán flow experiment for different forcing conditions. Statistically steady flows are reached; they display a hysteretic behavior similar to what has been observed in a 1:4 scale water experiment. Our macroscopical measurements indicate no noticeable difference between classical and superfluid flows, thereby providing evidence of the same dissipation scaling laws in the two phases. A detailed study of the evolution of the hysteresis cycle with the Reynolds number supports the idea that the stability of the steady states of classical turbulence in this closed flow is partly governed by the dissipative scales. It also supports the idea that the normal and the superfluid components at these temperatures (1.6 K) are locked down to the dissipative length scale.

  4. Liquid helium

    CERN Document Server

    Atkins, K R

    1959-01-01

    Originally published in 1959 as part of the Cambridge Monographs on Physics series, this book addresses liquid helium from the dual perspectives of statistical mechanics and hydrodynamics. Atkins looks at both Helium Three and Helium Four, as well as the properties of a combination of the two isotopes. This book will be of value to anyone with an interest in the history of science and the study of one of the universe's most fundamental elements.

  5. Helium cryogenics

    CERN Document Server

    Van Sciver, Steven W

    2012-01-01

    Twenty five years have elapsed since the original publication of Helium Cryogenics. During this time, a considerable amount of research and development involving helium fluids has been carried out culminating in several large-scale projects. Furthermore, the field has matured through these efforts so that there is now a broad engineering base to assist the development of future projects. Helium Cryogenics, 2nd edition brings these advances in helium cryogenics together in an updated form. As in the original edition, the author's approach is to survey the field of cryogenics with emphasis on helium fluids. This approach is more specialized and fundamental than that contained in other cryogenics books, which treat the associated range of cryogenic fluids. As a result, the level of treatment is more advanced and assumes a certain knowledge of fundamental engineering and physics principles, including some quantum mechanics. The goal throughout the work is to bridge the gap between the physics and engineering aspe...

  6. Antiprotonic helium

    CERN Multimedia

    Eades, John

    2005-01-01

    An exotic atom in w hich an electron and an antiproton orbit a helium nucleus could reveal if there are any differences between matter and antimatter. The author describes this unusual mirror on the antiworld (5 pages)

  7. The helium question.

    Science.gov (United States)

    Cook, E

    1979-12-07

    Helium appears indispensable for certain energy-related uses that may be important 50 years from now, when helium-bearing natural gas, a much cheaper source than air, may be exhausted. Present demand, however, is lower than productive capacity, and much helium is being dissipated into the atmosphere as natural gas is burned for fuel. Controversy over the need for a government-directed helium-conservation program reflects fundamental differences in viewpoints on the economic future of industrial society, on the limits of substitution of labor and capital for a depleting resource, and on intergenerational equity and risk-bearing.

  8. Helium the disappearing element

    CERN Document Server

    Sears, Wheeler M

    2015-01-01

    The subject of the book is helium, the element, and its use in myriad applications including MRI machines, particle accelerators, space telescopes, and of course balloons and blimps. It was at the birth of our Universe, or the Big Bang, where the majority of cosmic helium was created; and stellar helium production continues. Although helium is the second most abundant element in the Universe, it is actually quite rare here on Earth and only exists because of radioactive elements deep within the Earth. This book includes a detailed history of the discovery of helium, of the commercial industry built around it, how the helium we actually encounter is produced within the Earth, and the state of the helium industry today. The gas that most people associate with birthday party balloons is running out. “Who cares?” you might ask. Well, without helium, MRI machines could not function, rockets could not go into space, particle accelerators such as those used by CERN could not operate, fiber optic cables would not...

  9. The core helium flash

    Science.gov (United States)

    Cole, P. W.; Deupree, R. G.

    1980-12-01

    The role of convection in the core helium flash is simulated by two-dimensional eddies interacting with the thermonuclear runaway. These eddies are followed by the explicit solution of the two-dimensional conservation laws with a two-dimensional finite difference hydrodynamics code. Thus, no phenomenological theory of convection such as the local mixing length theory is required. The core helium flash is violent, producing a deflagration wave. This differs from the detonation wave (and subsequent disruption of the entire star) produced in previous spherically symmetric violent core helium flashes as the second dimension provides a degree of relief which allows the expansion wave to decouple itself from the burning front. The results predict that a considerable amount of helium in the core will be burned before the horizontal branch is reached and that some envelope mass loss is likely.

  10. The Descending Helium Balloon

    Science.gov (United States)

    Helseth, Lars Egil

    2014-01-01

    I describe a simple and fascinating experiment wherein helium leaks out of a rubber balloon, thereby causing it to descend. An estimate of the volumetric leakage rate is made by measuring its rate of descent.

  11. von Willebrand Disease

    Science.gov (United States)

    ... for type 1 von Willebrand disease is called desmopressin. It causes a temporary increase in the von ... injection or by being sniffed into the nose. Desmopressin may also help some people with type 2 ...

  12. Interaktive Visualisierung von Strukturmechaniksimulationen

    OpenAIRE

    Sommer, Ove

    2003-01-01

    A) Motivation und Problemstellung Der Computer ist heute eines der wichtigsten Hilfsmittel beim Entwurf und der Entwicklung von Fahrzeugen. Zunächst wurde er von Konstrukteuren für das Computer Aided Design (CAD) von virtuellen Fahrzeugmodellen eingesetzt. Inzwischen ist er in vielen anderen Bereichen der Fahrzeugentwicklung unentbehrlich geworden: der Entwicklungszyklus von Automobilen ist durch die Computer-gestützte numerische Simulation substanziell verkürzt worden. An virtuellen Prot...

  13. Cavitation in flowing superfluid helium

    Science.gov (United States)

    Daney, D. E.

    1988-01-01

    Flowing superfluid helium cavitates much more readily than normal liquid helium, and there is a marked difference in the cavitation behavior of the two fluids as the lambda point is traversed. Examples of cavitation in a turbine meter and centrifugal pump are given, together with measurements of the cavitation strength of flowing superfluid helium. The unusual cavitation behavior of superfluid helium is attributed to its immense thermal conductivity .

  14. Broken symmetry makes helium

    CERN Multimedia

    Gray, P L

    2003-01-01

    "The subatomic pion particle breaks the charge symmetry rule that governs both fusion and decay. In experiments performed at the Indiana University Cyclotron Laboratory, physicists forced heavy hydrogen (1 proton + 1 neutron) to fuse into helium in a controlled, measurable environment" (1 paragraph).

  15. Activities of the enterprise Linde on the field of cryogenics - within the meaning of the bequest of Carl von Linde. Linde-Aktivitaeten auf dem Gebiet der Kryotechnik im Sinne des Vermaechtnisses von Carl von Linde

    Energy Technology Data Exchange (ETDEWEB)

    Patzelt, A. (Linde AG, Werksgruppe Verfahrenstechnik und Anlagenbau, Hoellriegelskreuth (Germany))

    1992-01-01

    The patent for the liquefaction of air and other gases by Carl von Linde was the basis for the set up of a refrigeration industry. In the area of cryogenics at temperatures between liquid hydrogen and liquid helium the actual status will presented by 3 examples. (orig.).

  16. Lernen von und bei Max von Laue

    Science.gov (United States)

    Thiessen, P. A.

    Erinnerungen an die Entstehungsgeschichte und die Frühzeiten der Röntgenstrukturanalyse.Translated AbstractLearning at Max von LaueRemembrances of the historical rise and the early times of X-ray structure analysis.

  17. Applications of Groundwater Helium

    Science.gov (United States)

    Kulongoski, Justin T.; Hilton, David R.

    2011-01-01

    Helium abundance and isotope variations have widespread application in groundwater-related studies. This stems from the inert nature of this noble gas and the fact that its two isotopes ? helium-3 and helium-4 ? have distinct origins and vary widely in different terrestrial reservoirs. These attributes allow He concentrations and 3He/4He isotope ratios to be used to recognize and quantify the influence of a number of potential contributors to the total He budget of a groundwater sample. These are atmospheric components, such as air-equilibrated and air-entrained He, as well as terrigenic components, including in situ (aquifer) He, deep crustal and/or mantle He and tritiogenic 3He. Each of these components can be exploited to reveal information on a number of topics, from groundwater chronology, through degassing of the Earth?s crust to the role of faults in the transfer of mantle-derived volatiles to the surface. In this review, we present a guide to how groundwater He is collected from aquifer systems and quantitatively measured in the laboratory. We then illustrate the approach of resolving the measured He characteristics into its component structures using assumptions of endmember compositions. This is followed by a discussion of the application of groundwater He to the types of topics mentioned above using case studies from aquifers in California and Australia. Finally, we present possible future research directions involving dissolved He in groundwater.

  18. 48 CFR 52.208-8 - Required Sources for Helium and Helium Usage Data.

    Science.gov (United States)

    2010-10-01

    ... Helium and Helium Usage Data. 52.208-8 Section 52.208-8 Federal Acquisition Regulations System FEDERAL... Provisions and Clauses 52.208-8 Required Sources for Helium and Helium Usage Data. As prescribed in 8.505, insert the following clause: Required Sources for Helium and Helium Usage Data (APR 2002) (a) Definitions...

  19. High Efficiency Regenerative Helium Compressor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Helium plays several critical rolls in spacecraft propulsion. High pressure helium is commonly used to pressurize propellant fuel tanks. Helium cryocoolers can be...

  20. Cavitation in liquid helium

    Energy Technology Data Exchange (ETDEWEB)

    Finch, R. D.; Kagiwada, R.; Barmatz, M.; Rudnick, I.

    1963-11-15

    Ultrasonic cavitation was induced in liquid helium over the temperature range 1.2 to 2.3 deg K, using a pair of identical transducers. The transducers were calibrated using a reciprocity technique and the cavitation threshold was determined at 90 kc/s. It was found that this threshold has a sharp peak at the lambda point, but is, at all temperatures quite low, with an approximate range of 0.001 to 0.01 atm. The significance of the results is discussed. (auth)

  1. Electronic properties of physisorbed helium

    Energy Technology Data Exchange (ETDEWEB)

    Kossler, Sarah

    2011-09-22

    This thesis deals with electronic excitations of helium physisorbed on metal substrates. It is studied to what extent the electronic properties change compared to the gas phase due to the increased helium density and the proximity of the metal. Furthermore, the influence of different substrate materials is investigated systematically. To this end, up to two helium layers were adsorbed onto Ru (001), Pt (111), Cu (111), and Ag (111) surfaces in a custom-made cryostat. These samples were studied spectroscopically using synchrotron radiation and a time-of-flight detector. The experimental results were then analyzed in comparison with extensive theoretical model calculations.

  2. Trapping fermionic and bosonic helium atoms

    NARCIS (Netherlands)

    Stas, R.J.W.

    2005-01-01

    This thesis presents experimental and theoretical work performed at the Laser Centre of the Vrije Universiteit in Amsterdam to study laser-cooled metastable triplet helium atoms. Samples containing about 3x10^8 helium atoms-either fermionic helium-3 atoms, bosonic helium-4 atoms or mixtures

  3. von Willebrand Disease

    Science.gov (United States)

    ... the condition. For example, the school nurse, teacher, daycare provider, coach, or any leader of afterschool activities ... MedlinePlus) Von Willebrand Disease (MedlinePlus) Building 31 31 Center Drive Bethesda, MD 20892 Learn more about getting ...

  4. Carl von Clausewitz

    DEFF Research Database (Denmark)

    Højrup, Thomas

    2009-01-01

    Forskningsbaseret præsentation af Carl von Clausewitz' krigsteori og dens betydning for statsbegrebet og udviklingen af teori om statsdannelse og statssystem. Krigsbegrebets betydning for politikbegrebet ekspliciteres, og de indre relationer imellem de to begreber demonstreres med konkrete eksemp...

  5. Ellis Von Creveld Syndrome

    Directory of Open Access Journals (Sweden)

    Afshar H

    1999-01-01

    Full Text Available One patient with Ellis Von Creveld syndrome contains: dwarfism, congenital heart"ndisease, ectodermal dysplasia, polyductyly, an abnormally wide labial frenum and maxillary"nmolars with single root.

  6. Quantum entanglement of helium-like systems with varying-Z: compact state-of-the-art CI wave functions

    Science.gov (United States)

    López-Rosa, S.; Esquivel, R. O.; Plastino, A. R.; Dehesa, J. S.

    2015-09-01

    In this work we have performed state-of-the-art configuration-interaction (CI) calculations to determine the linear and von Neumann entanglement entropies for the helium-like systems with varying nuclear charge Z in the range 1≤slant Z≤slant 10. The focus of the work resides on determining accurate entanglement values for 2-electron systems with the lowest computational cost through compact CI-wave functions. Our entanglement results for the helium atom fully agree with the results obtained with higher quality wave functions of the Kinoshita type (Dehesa [5]). We find that the correlation energy is linearly related to the entanglement measures associated with the linear and von Neumann entropies of the single-particle reduced density matrizes, which sheds new light on the physical implications of entanglement in helium-like systems. Moreover, we report CI-wave-function-based benchmark results for the entanglement values for all members of the helium isoelectronic series with an accuracy similar to that of Kinoshita-type wave functions. Finally, we give parametric expressions of the linear and von Neumann entanglement measures for two-electron systems as Z varies from 1 to 10.

  7. Pierre Gorce working on a helium pump.

    CERN Multimedia

    1975-01-01

    This type of pump was designed by Mario Morpurgo, to circulate liquid helium in superconducting magnets wound with hollow conductors. M. Morpurgo, Design and construction of a pump for liquid helium, CRYIOGENICS, February 1977, p. 91

  8. Von Braun Fountain

    Science.gov (United States)

    1999-01-01

    A fountain representing a rocket launch was dedicated in the Von Braun courtyard outside of Building 4200 at Marshall Space Flight Center during the weekend celebrating the 30th arniversary of the Apollo 11 lunar landing. On hand for the festivities were many of the Saturn and Apollo astronauts.

  9. Rhizostomeen von Manila

    NARCIS (Netherlands)

    Stiasny, G.

    1924-01-01

    Die hier beschriebene kleine Scyphomedusen-Sammlung wurde von Herrn Director P. B. Sivickis, Dept. of Zoology, University of Philippines, Manila, dem Rijksmuseum van Natuurlijke Historie in Leiden überwiesen. Das Material wurde im December 1922 in Manila-bay gefischt und befindet sich in bestem

  10. Karman, Prof. Theodore von

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1961 Honorary. Karman, Prof. Theodore von. Date of birth: 11 May 1881. Date of death: 6 May 1963. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the ...

  11. Schmetterlinge von Madeira

    NARCIS (Netherlands)

    Martin, K.

    1941-01-01

    Wer auf einer ozeanischen Insel Schmetterlinge sammeln will, darf seine Erwartungen nicht zu hoch spannen; aber dennoch waren meine Frau und ich sehr enttäuscht, als uns auf einer Reise nach Madeira von einer dort angesessenen, gebildeten Dame gesagt wurde, sie habe auf der Insel niemals einen

  12. 21 CFR 184.1355 - Helium.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Helium. 184.1355 Section 184.1355 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1355 Helium. (a) Helium (empirical formula He, CAS Reg. No. 7440-59-7) is a...

  13. 21 CFR 582.1355 - Helium.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Helium. 582.1355 Section 582.1355 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS... Helium. (a) Product. Helium. (b) Conditions of use. This substance is generally recognized as safe when...

  14. 30 CFR 256.11 - Helium.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Helium. 256.11 Section 256.11 Mineral Resources... Helium. (a) Each lease issued or continued under these regulations shall be subject to a reservation by the United States, under section 12(f) of the Act, of the ownership of and the right to extract helium...

  15. Simplicity works for superfluid helium

    Energy Technology Data Exchange (ETDEWEB)

    Bowley, Roger [University of Nottingham, Nottingham (United Kingdom)

    2000-02-01

    The famous philosopher Karl Popper once said that ''science is the art of systematic oversimplification''. Indeed, when faced with a new puzzle the trick is to simplify it without losing the essential physics - something that is easier said than done. However, this approach has paid off recently in low-temperature physics. Last year Richard Packard, Seamus Davis and co-workers at the University of California at Berkeley encountered a puzzling new phenomenon in superfluid helium-3, a quantum fluid that remains a liquid close to absolute zero and exhibits unusual properties such as the ability to flow without friction (A Machenkov et al. 1999 Phys. Rev. Lett. 83 3860). Previous experiments had revealed that certain effects in liquid helium are analogous to effects observed in superconductors, materials that lose all resistance to electric current at low temperatures. When the Berkeley researchers connected two reservoirs of superfluid helium-3, the superfluid flowed back and forth through apertures that formed a ''weak link'' between the two containers. This behaviour is similar to the oscillatory current of electrons that can flow across an insulating gap separating two superconductors - a device that is known as a Josephson junction. What was puzzling about the Berkeley results was that the helium-3 had two different stable configurations, both of which behaved in an unconventional way compared with a Josephson junction. This puzzle has now been solved independently by Sidney Yip at the National Center for Theoretical Sciences in Taiwan, and by Janne Viljas and Erkki Thuneberg at the Helsinki University of Technology in Finland (Phys. Rev. Lett. 1999 83 3864 and 3868). In this article the author describes the latest research on superfluid helium. (UK)

  16. Charging dynamics of dopants in helium nanoplasmas

    DEFF Research Database (Denmark)

    Heidenreich, Andreas; Grüner, Barbara; Schomas, Dominik

    2017-01-01

    We present a combined experimental and theoretical study of the charging dynamics of helium nanodroplets doped with atoms of different species and irradiated by intense near-infrared laser pulses (≤1015 W cm−2). In particular, we elucidate the interplay of dopant ionization inducing the ignition...... of a helium nanoplasma, and the charging of the dopant atoms driven by the ionized helium host. Most efficient nanoplasma ignition and charging is found when doping helium droplets with xenon atoms, in which case high charge states of both helium (He2+) and of xenon (Xe21+) are detected. In contrast, only low...

  17. HeREF-2003 : Helium Refrigeration Techniques

    CERN Multimedia

    2003-01-01

    CERN Technical Training 2003: Learning for the LHC ! Theory, Technology, Maintenance and Control of Helium Refrigerators HeREF-2003 is a course in the framework of the 2002 Technical Training Programme, that will provide a complete introduction to Helium refrigeration, with a practical approach to theory, technology, maintenance and control of Helium refrigeration installations. Theoretical aspects and equations will be limited to a minimum. HeREF-2003 targets an audience of technicians and operators of Helium refrigeration plants at CERN, as well as physicists and engineers needing an overview of current Helium refrigeration techniques. HeREF-2003 will address, among other, issues related to component technology, installation maintenance, process control and Helium purity. A commented visit to a couple of CERN Helium refrigeration or liquefaction plants will also take place. • Duration: 7 half days (4 mornings and 3 afternoons), 6-10 October, 2003 • Cost per participant: 500.- CHF ...

  18. HeREF-2003: Helium Refrigeration Techniques

    CERN Multimedia

    2003-01-01

    CERN Technical Training 2003: Learning for the LHC ! Theory, Technology, Maintenance and Control of Helium Refrigerators HeREF-2003 is a course in the framework of the 2002 Technical Training Programme, that will provide a complete introduction to Helium refrigeration, with a practical approach to theory, technology, maintenance and control of Helium refrigeration installations. Theoretical aspects and equations will be limited to a minimum. HeREF-2003 targets an audience of technicians and operators of Helium refrigeration plants at CERN, as well as physicists and engineers needing an overview of current Helium refrigeration techniques. HeREF-2003 will address, among other, issues related to component technology, installation maintenance, process control and Helium purity. A commented visit to a couple of CERN Helium refrigeration or liquefaction plants will also take place. Duration: 7 half days (4 mornings and 3 afternoons), 6-10 October, 2003 Cost per participant: 500.- CHF Language: Bilingual English...

  19. Kommunikative Konstitution von Organisationen

    DEFF Research Database (Denmark)

    Schoeneborn, Dennis; Wehmeier, Stefan

    2014-01-01

    Beiträge zur Unternehmenskommunikation behandeln in der Regel (strategisch) geplante interne oder externe Kommunikation. Der vorliegende Beitrag stellt einen alternativen Theorieansatz vor, der aktuell im nordamerikanischen Forschungsgebiet „Organizational Communication“ vorherrschend ist....... zunehmende Aufmerksamkeit erhält Der sogenannten „CCO-Perspektive“ („Communicative Constitution of Organizations“) zufolge bestehen Unternehmen aus einer Vielzahl von internen und externen Kommunikationspraktiken, die nur in bedingtem Maße strategisch steuerbar sind. Zugleich sind es eben diese...

  20. Kulturelle Aspekte von Textsorten

    Directory of Open Access Journals (Sweden)

    Siegfried Heusinger

    1998-12-01

    Full Text Available Ich fasse meine Überlegungen zu kulturellen Aspekten von Textsorten zusammen: 1. Mit unseren Kulturverständnis ist die terminologisierte Wortgruppe "interkulturelle Kommunikation" nicht zu begreifen als Kommunikation zwischen Menschen verschiedener kultureller Bindungen, sondern sie ist nicht zu begreifen als Kommunikation zwischen Menschen verschiedener kultureller Bindungen, sondern sie ist ethnisch wie auch ethisch angepasstes sprachlichkommunikatives Verhalten an kulturelle Traditionen der jeweils für den Kommunkations- akt vereinbarten Sprache. 2. Das Adjektiv "interkulturell" referiert auf idiomatisierte Wendungen im zwischenmenschlichen Kontakt wie auch auf kulturell gebundene Unterschiede in der Benennungsmotivation (z.B. anloben/österr./, vereidigen /dt./ 3. Das Adjektiv "interkulturell" ist ebenfalls zu beziehen auf den Austausch von Erfahrungen und Ideen, auf den Dialog von Kulturen. 4. Textsorten existieren in ihrer kulturellen in ihrer kulturellen Tradition, wobei das Kulturspezifische vornehmlich in traditionellen (aber entwicklungsoffenen Formulierungs- und Gestaltungsmustern zu suchen iost. Andere Textsortencharakteristika wie die situative Einbettung, die kommunikative Zwecksetzung, die thematische Bindung und die Komposition haben offenbar kaum eine kulturspezifische Prägung. 5. Im Trend zur Internationalisierung der Textsorten erweisen sich die kulturell geprägten Textmustervor allem zwischen angrenzenden Nationen häufig als affin.

  1. Nutzerorientiertes Management von materiellen und immateriellen Informationsobjekten

    OpenAIRE

    Hübsch, Chris

    2001-01-01

    Schaffung einer stabilen, erweiterbaren und skalierbaren Infrastruktur für die Bereitstellung von Diensten im Umfeld von Bibliotheken und ähnlichen wissensanbietenden Einrichtungen unter Verwendung von XML-RPC und Python.

  2. Helium atom scattering from surfaces

    CERN Document Server

    1992-01-01

    High resolution helium atom scattering can be applied to study a number of interesting properties of solid surfaces with great sensitivity and accuracy. This book treats in detail experimental and theoretical aspects ofthis method as well as all current applications in surface science. The individual chapters - all written by experts in the field - are devoted to the investigation of surface structure, defect shapes and concentrations, the interaction potential, collective and localized surface vibrations at low energies, phase transitions and surface diffusion. Over the past decade helium atom scattering has gained widespread recognitionwithin the surface science community. Points in its favour are comprehensiveunderstanding of the scattering theory and the availability of well-tested approximation to the rigorous theory. This book will be invaluable to surface scientists wishing to make an informed judgement on the actual and potential capabilities of this technique and its results.

  3. Investigations of levitated helium drops

    Science.gov (United States)

    Whitaker, Dwight Lawrence

    1999-11-01

    We report on the development of two systems capable of levitating drops of liquid helium. Helium drops of ˜20 mum have been levitated with the radiation pressure from two counter-propagating Nd:YAG laser beams. Drops are produced with a submerged piezoelectric transducer, and could be held for up to three minutes in our optical trap. Calculations show that Brillouin and Raman scattering of the laser light in the liquid helium produces a negligible rate of evaporation of the drop. Evaporation caused by the enhanced vapor pressure of the curved drop surfaces appears to be a significant effect limiting the drop lifetimes. Helium drops as large as 2 cm in diameter have been suspended in the earth's gravitational field with a magnetic field. A commercial superconducting solenoid provides the necessary field, field-gradient product required to levitate the drops. Drops are cooled to 0.5 K with a helium-3 refrigerator, and can be held in the trap indefinitely. We have found that when two or more drops are levitated in the same magnetic trap, the drops often remain in a state of apparent contact without coalescing. This effect is a result of the evaporation of liquid from between the two drops, and is found to occur only for normal fluid drops. We can induce shape oscillations in charged, levitated drops with an applied ac electric field. We have measured the resonance frequencies and damping rates for the l = 2 mode of oscillation as function of temperature. We have also developed a theory to describe the small amplitude shape oscillations of a He II drop surrounded by its saturated vapor. In our theory, we have considered two sets of boundary conditions---one where the drop does not evaporate and another in which the liquid and vapor are in thermodynamic equilibrium. We have found that both solutions give a frequency that agrees well with experiment, but that the data for the damping rate agree better with the solution without evaporation.

  4. Thermodynamic properties of hydrogen-helium plasmas.

    Science.gov (United States)

    Nelson, H. F.

    1972-01-01

    Calculation of the thermodynamic properties of an atomic hydrogen-helium plasma for postulated conditions present in a stagnation shock layer of a spacecraft entering the atmosphere of Jupiter. These properties can be used to evaluate transport properties, to calculate convective heating, and to investigate nonequilibrium behavior. The calculations have been made for temperatures from 10,000 to 100,000 K, densities of 10 to the minus 7th and .00001 g cu cm, and three plasma compositions: pure hydrogen, 50% hydrogen/50% helium, and pure helium. The shock layer plasma consists of electrons, protons, atomic hydrogen, atomic helium, singly ionized helium, and doubly atomized helium. The thermodynamic properties which have been investigated are: pressure, average molecular weight, internal energy, enthalpy, entropy, specific heat, and isentropic speed of sound. A consistent model was used for the reduction of the ionization potential in the calculation of the partition functions.

  5. Critical Landau velocity in helium nanodroplets.

    Science.gov (United States)

    Brauer, Nils B; Smolarek, Szymon; Loginov, Evgeniy; Mateo, David; Hernando, Alberto; Pi, Marti; Barranco, Manuel; Buma, Wybren J; Drabbels, Marcel

    2013-10-11

    The best-known property of superfluid helium is the vanishing viscosity that objects experience while moving through the liquid with speeds below the so-called critical Landau velocity. This critical velocity is generally considered a macroscopic property as it is related to the collective excitations of the helium atoms in the liquid. In the present work we determine to what extent this concept can still be applied to nanometer-scale, finite size helium systems. To this end, atoms and molecules embedded in helium nanodroplets of various sizes are accelerated out of the droplets by means of optical excitation, and the speed distributions of the ejected particles are determined. The measurements reveal the existence of a critical velocity in these systems, even for nanodroplets consisting of only a thousand helium atoms. Accompanying theoretical simulations based on a time-dependent density functional description of the helium confirm and further elucidate this experimental finding.

  6. Ras Laffan helium recovery unit 2

    Science.gov (United States)

    Fauve, Eric Arnaud; Grabié, Veronique; Grillot, David; Delcayre, Franck; Deschildre, Cindy

    2012-06-01

    In May 2010, Air Liquide was awarded a contract for the Engineering Procurement and Construction (Turnkey EPC) for a second helium recovery unit [RLH II] dedicated to the Ras Laffan refinery in Qatar. This unit will come in addition to the one [RLH I] delivered and commissioned by Air Liquide in 2005. It will increase the helium production of Qatar from 10% to 28% of worldwide production. RLH I and RLH II use Air Liquide Advanced Technologies helium liquefiers. With a production of 8 tons of liquid helium per day, the RLH I liquefier is the world largest, but not for long. Thanks to the newly developed turbine TC7, Air Liquide was able to propose for RLH II a single liquefier able to produce over 20 tons per day of liquid helium without liquid nitrogen pre-cooling. This liquefier using 6 Air Liquide turbines (TC series) will set a new record in the world of helium liquefaction.

  7. Backscattered Helium Spectroscopy in the Helium Ion Microscope: Principles, Resolution and Applications

    NARCIS (Netherlands)

    van Gastel, Raoul; Hlawacek, G.; Dutta, S.; Poelsema, Bene

    2015-01-01

    We demonstrate the possibilities and limitations for microstructure characterization using backscattered particles from a sharply focused helium ion beam. The interaction of helium ions with matter enables the imaging, spectroscopic characterization, as well as the nanometer scale modification of

  8. Parameters of helium absorption by porous structures

    Science.gov (United States)

    Bukin, A. N.; Ivanova, A. S.; Marunich, S. A.; Pak, Yu. S.; Rozenkevich, M. B.

    2017-05-01

    Results from investigating the parameters of helium absoption by hollow glass-crystalline cenospheres obtained at the Reftinsky regional power station in the city of Asbest are presented. The permeability coefficients of helium penetrating through shells are determined, and the apparent activation energy is estimated ( E act = 33 ± 5 kJ/mol). The possibility of selectively extracting helium from mixtures of it and nitrogen is shown.

  9. Surface Impact Simulations of Helium Nanodroplets

    Science.gov (United States)

    2015-06-30

    AFRL-RW-EG-TP-2015-001 Surface Impact Simulations of Helium Nanodroplets Robert J. Hinde Department of Chemistry University of...TITLE AND SUBTITLE Surface Impact Simulations of Helium Nanodroplets 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA8651-11-1-0005 5c. PROGRAM ELEMENT...captures atomic delocalization of the helium atoms characteristic of the quantum solvent, but allow the single-particle wavefunctions to vary throughout

  10. Behaviour of helium after implantation in molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Viaud, C. [Commissariat a l' Energie Atomique (CEA), Cadarache (France)], E-mail: viaud@dircad.cea.fr; Maillard, S.; Carlot, G.; Valot, C. [Commissariat a l' Energie Atomique (CEA), Cadarache (France); Gilabert, E. [Chimie Nucleaire Analytique and Bio-environnementale (CNAB), Gradignan (France); Sauvage, T. [CEMHTI-CNRS, Orleans (France); Peaucelle, C.; Moncoffre, N. [Institut de Physique Nucleaire de Lyon (IPNL), Lyon (France)

    2009-03-31

    This study deals with the behaviour of helium in a molybdenum liner dedicated to the retention of fission products. More precisely this work contributes to evaluate the release of implanted helium when the gas has precipitated into nanometric bubbles close to the free surface. A simple model dedicated to calculate the helium release in such a condition is presented. The specificity of this model lays on the assumption that the gas is in equilibrium with a simple distribution of growing bubbles. This effort is encouraging since the calculated helium release fits an experimental dataset with a set of parameters in good agreement with the literature.

  11. Helium resources of the United States, 1989

    Science.gov (United States)

    Miller, Richard D.; Hamak, John E.

    The helium resources base of the United States was estimated by the Bureau of Mines to be 894.6 Bcf as of January 1, 1989. These resources are divided into four categories in decreasing degree of the assurance of their existence: (1) helium in storage and in proved natural gas reserves, 282.4 Bcf; (2) helium in probable natural gas resources, estimated at 237.7 Bcf; (3) helium in possible natural gas resources, estimated to be 263.2 Bcf; and (4) helium in speculative natural gas resources, 111.4 Bcf. These helium resources are further divided into depleting and nondepleting, with the helium in storage being in a separate classification. The depleting resources are those associated with natural gasfields that are, or will be, produced for the natural gas they contain. Almost all of the helium in potential (probable, possible, and speculative) natural gas resources is included in this classification. These depleting resources are estimated to contain 775 Bcf of the total helium resource base.

  12. The helium-graphite interaction

    Energy Technology Data Exchange (ETDEWEB)

    Joly, F.; Lhuillier, C.; Brami, B. (Lab. de Physique Theorique des Liquides, Univ. Pierre et Marie Curie, 75 - Paris (France))

    1992-03-15

    We propose a very simple empirical form of the helium-on-graphite potential, which reproduces the energy of the six known bound states, the experimental average distance of the {sup 4}He atom from the surface in the ground state and the correct asymptotic behaviour of the interaction. This optimized potential is used to compute the binding energy of a {sup 3}He atom on the same substrate. The agreement between the theoretical predictions and the experimental results is a check of the set of variational parameters. (orig.).

  13. Helium transfer line installation details.

    CERN Multimedia

    G. Perinic

    2007-01-01

    A particularity of the 32 m long four in one helium transfer line in between the cold box in USC55 and the cavern UX5 is the fact that the transfer line passes through a hole in the crane rail support beam. In order to ensure the alignment of the suspension rail in the interconnecting tunnel with the hole in the rail support as well as the connection points at both ends required precise measurements of the given geometries as well as the installation of a temporary target for the verification of the theoretical predictions.

  14. John von Neumann Birthday Centennial

    Energy Technology Data Exchange (ETDEWEB)

    Grcar, Joseph F.

    2004-11-12

    In celebration of John von Neumann's 100th birthday, a series of four lectures were presented on the evening of February 10, 2003 during the SIAM Conference on Computational Science and Engineering in San Diego. The venue was appropriate because von Neumann spent much of the later part of his life, in the 1950's, as an unofficial ambassador for computational science. He was then the only senior American scientist who had experience with the new computers (digital, electronic, and programmable) and a vision of their future importance. No doubt he would have relished the chance to attend a meeting such as this. The first speaker, William Aspray, described the ''interesting times'' during which computers were invented. His remarks were based on his history [1] of this period in von Neumann's life. We were honored to have John von Neumann's daughter, Marina von Neumann-Whitman, as our second speaker. Other accounts of von Neumann's life can be found in books by two of his colleagues [2] and [3]. Our third speaker, Peter Lax, provided both mathematical and international perspectives on John von Neumann's career. Finally, Pete Stewart spoke about von Neumann's numerical error analysis [4] in the context of later work; this talk did not lend itself to transcription, but readers may consult the historical notes in [5]. Our thanks to all the speakers for a remarkable evening. We are grateful to the DOE Applied Mathematical Sciences (AMS) program for partially supporting these lectures. Thanks are also due to SIAM and William Kolata, to our emcee, Gene Golub, to Paul Saylor for recording and editing, and to Barbara Lytle for the transcriptions. More about von Neumann's work can be learned from the recent American Mathematical Society proceedings [6].

  15. LOX Tank Helium Removal for Propellant Scavenging

    Science.gov (United States)

    Chato, David J.

    2009-01-01

    System studies have shown a significant advantage to reusing the hydrogen and oxygen left in these tanks after landing on the Moon in fuel cells to generate power and water for surface systems. However in the current lander concepts, the helium used to pressurize the oxygen tank can substantially degrade fuel cell power and water output by covering the reacting surface with inert gas. This presentation documents an experimental investigation of methods to remove the helium pressurant while minimizing the amount of the oxygen lost. This investigation demonstrated that significant quantities of Helium (greater than 90% mole fraction) remain in the tank after draining. Although a single vent cycle reduced the helium quantity, large amounts of helium remained. Cyclic venting appeared to be more effective. Three vent cycles were sufficient to reduce the helium to small (less than 0.2%) quantities. Two vent cycles may be sufficient since once the tank has been brought up to pressure after the second vent cycle the helium concentration has been reduced to the less than 0.2% level. The re-pressurization process seemed to contribute to diluting helium. This is as expected since in order to raise the pressure liquid oxygen must be evaporated. Estimated liquid oxygen loss is on the order of 82 pounds (assuming the third vent cycle is not required).

  16. Helium-cooled high temperature reactors

    Energy Technology Data Exchange (ETDEWEB)

    Trauger, D.B.

    1985-01-01

    Experience with several helium cooled reactors has been favorable, and two commercial plants are now operating. Both of these units are of the High Temperature Graphite Gas Cooled concept, one in the United States and the other in the Federal Republic of Germany. The initial helium charge for a reactor of the 1000 MW(e) size is modest, approx.15,000 kg.

  17. Organ protection by the noble gas helium

    NARCIS (Netherlands)

    Smit, K.F.

    2017-01-01

    The aims of this thesis were to investigate whether helium induces preconditioning in humans, and to elucidate the mechanisms behind this possible protection. First, we collected data regarding organ protective effects of noble gases in general, and of helium in particular (chapters 1-3). In chapter

  18. Nanofabrication with a helium ion microscope

    NARCIS (Netherlands)

    Maas, D.; Van Veldhoven, E.; Chen, P.; Sidorkin, V.; Salemink, H.; Van der Drift, E.; Alkemade, P.

    2009-01-01

    The recently introduced helium ion microscope (HIM) is capable of imaging and fabrication of nanostructures thanks to its sub-nanometer sized ion probe [1,2]. The unique interaction of the helium ions with the sample material provides very localized secondary electron emission, thus providing a

  19. Helium Speech: An Application of Standing Waves

    Science.gov (United States)

    Wentworth, Christopher D.

    2011-01-01

    Taking a breath of helium gas and then speaking or singing to the class is a favorite demonstration for an introductory physics course, as it usually elicits appreciative laughter, which serves to energize the class session. Students will usually report that the helium speech "raises the frequency" of the voice. A more accurate description of the…

  20. Radioactive ions and atoms in superfluid helium

    NARCIS (Netherlands)

    Dendooven, P.G.; Purushothaman, S.; Gloos, K.; Aysto, J.; Takahashi, N.; Huang, W.; Harissopulos, S; Demetriou, P; Julin, R

    2006-01-01

    We are investigating the use of superfluid helium as a medium to handle and manipulate radioactive ions and atoms. Preliminary results on the extraction of positive ions from superfluid helium at temperatures close to 1 K are described. Increasing the electric field up to 1.2 kV/cm did not improve

  1. Alejandro Von Humboldt

    Directory of Open Access Journals (Sweden)

    Gerardo Paz Otero

    1965-09-01

    Full Text Available Diverso fue y sigue siéndolo, el destino de los dos hermanos Humboldt, Guillermo y Alejandro. Sino que se inicia con el nacimiento: Guillermo, el mayor, nace el 22 de junio de 1767 en Potsdam, residencia de los emperadores prusianos, la ciudad de los palacios imperiales, el imperio del militarismo germano; su cuna se meció cerca al palacete de Sans-Soussi, donde Federico el Grande forja ba el poderío de Prusia, cultivaba las ciencias y las artes, anfitrionaba a los intelectuales de Europa, y era "vasallo espiritual de Volta ire", según la aguda frase de Goethe. Alejandro viene al mundo dos años después (14 de septiembre de 1769 en Berlín, en la casa burguesa de la Jagerstrasse (calle del cazador que su madre Elizabeth von Humboldt heredara de su primer esposo.

  2. Der Einfluss von Phlorizin auf den programmierten Zelltod von Erythrozyten

    OpenAIRE

    Meier, Anja Doris

    2013-01-01

    Erythrozyten sind in der Lage, suizidalen Zelltod zu betreiben. Von einigen Substanzen ist bereits bekannt, dass sie die sogenannte Eryptose beeinflussen. Beispiele dafür sind Quecksilber, Monensin, Benzethonium und Oridonin, welche zu den Stimulatoren der Eryptose gehören. Blebbistatin, Koffein und Endothelin, gehören zu den Inhibitoren. In dieser Studie sollte untersucht werden, welchen Einfluss Phlorizin auf den Ablauf des suizidalen Zelltodes von Erythrozyten hat. Es wurde belegt, dass si...

  3. Permeability of Hollow Microspherical Membranes to Helium

    Science.gov (United States)

    Zinoviev, V. N.; Kazanin, I. V.; Pak, A. Yu.; Vereshchagin, A. S.; Lebiga, V. A.; Fomin, V. M.

    2016-01-01

    This work is devoted to the study of the sorption characteristics of various hollow microspherical membranes to reveal particles most suitable for application in the membrane-sorption technologies of helium extraction from a natural gas. The permeability of the investigated sorbents to helium and their impermeability to air and methane are shown experimentally. The sorption-desorption dependences of the studied sorbents have been obtained, from which the parameters of their specific permeability to helium are calculated. It has been established that the physicochemical modification of the original particles exerts a great influence on the coefficient of the permeability of a sorbent to helium. Specially treated cenospheres have displayed high efficiency as membranes for selective extraction of helium.

  4. Global helium particle balance in LHD

    Energy Technology Data Exchange (ETDEWEB)

    Motojima, G., E-mail: motojima.gen@lhd.nifs.ac.jp [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Masuzaki, S.; Tokitani, M.; Kasahara, H.; Yoshimura, Y.; Kobayashi, M.; Sakamoto, R.; Morisaki, T.; Miyazawa, J.; Akiyama, T. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Ohno, N. [Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603 (Japan); Mutoh, T.; Yamada, H. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan)

    2015-08-15

    Global helium particle balance in long-pulse discharges is analyzed for the first time in the Large Helical Device (LHD) with the plasma-facing components of the first wall and the divertor tiles composed of stainless steel and carbon, respectively. During the 2-min discharge sustained by ion cyclotron resonance heating (ICRH) and electron cyclotron heating (ECH), helium is observed to be highly retained in the wall (regarded as both the first wall and the divertor tiles). Almost all (about 96%) puffed helium particles (1.3 × 10{sup 22} He) are absorbed in the wall near the end of the discharge. Even though a dynamic retention is eliminated, 56% is still absorbed. The analysis is also applied to longer pulse discharges over 40 min by ICRH and ECH, indicating that the helium wall retention is dynamically changed in time. At the initial phase of the discharge, a mechanism for adsorbing helium other than dynamical retention is invoked.

  5. Exotic helium molecules; Molecules exotiques d'helium

    Energy Technology Data Exchange (ETDEWEB)

    Portier, M

    2007-12-15

    We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}P{sub 0}) molecule, or a {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 {+-} 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime {tau} = (1.4 {+-} 0.3) {mu}s is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

  6. Einsatz von Nickel-Katalysatoren zum Cracken von Teerprodukten aus der Niederdruckaufkohlung von Stahl mit Ethin

    OpenAIRE

    Mbadinga Mouanda, Gelase

    2009-01-01

    Die Niederdruckaufkohlung von Stahl ist ein modernes Verfahren, das zur Einsatzhärtung von Stahlbauteilen dient. Bei Temperaturen zwischen 900 und 1050 °C und Drücken unter 50 mbar werden Bauteile durch heterogene Pyrolyse von Ethin in einem Ofen einsatzgehärtet. Das während der Pyrolyse erzeugte Abgas enthält aromatische Kohlenwasserstoffe und kann katalytisch behandelt werden. Der Katalysator wird durch Rußablagerung desaktiviert und muss zyklisch durch Verbrennung mit Luft regeneriert werd...

  7. Living with von Willebrand Disease

    Science.gov (United States)

    ... the condition. For example, the school nurse, teacher, daycare provider, coach, or any leader of afterschool activities ... MedlinePlus) Von Willebrand Disease (MedlinePlus) Building 31 31 Center Drive Bethesda, MD 20892 Learn more about getting ...

  8. Ueber einige Coelenterata von Australien

    NARCIS (Netherlands)

    Stiasny, G.

    1931-01-01

    I. Hydromedusen. *Olindias singularis Browne. II. Scyphomedusen. *Atolla wyvillei Haeckel. *Linuche unguiculata O. Swartz. Pelagia noctiluca Péron u. Lesueur. Cyanea capillata var. annaskala von Lendenfeld. Netrostoma coerulescens Maas. *Versura anadyomene (Maas) Mayer. Catostylus mosaicus L.

  9. Kleben von Kunststoff mit Metall

    CERN Document Server

    Brockmann, W; Käufer, H

    1989-01-01

    Das Buch behandelt das Kleben von Kunststoffen mit Metallen in einer fur den Praktiker verstandlichen und umsetzbaren Form. Es leitet zu Klebeverfahren an, die optimale Ergebnisse hinsichtlich Qualitat, Dauerhaftigkeit und Wirtschaftlichkeit liefern.

  10. Unstable Helium Shell Burning on Accreting White Dwarfs

    Science.gov (United States)

    Shen, Ken J.; Bildsten, Lars

    2009-07-01

    AM Canum Venaticorum (AM CVn) binaries consist of a degenerate helium donor and a helium, C/O, or O/Ne white dwarf accretor, with accretion rates of \\dot{M} = 10^{-13}\\--10^{-5} \\, M_\\odot \\; yr^{-1}. For accretion rates thermonuclear supernovae. In this paper, we study the evolution of the He-burning shells in more detail. We calculate maximum achievable temperatures as well as the minimum envelope masses that achieve dynamical burning conditions, finding that AM CVn systems with accretors gsim0.8 M sun will undergo dynamical burning. Triple-α reactions during the hydrostatic evolution set a lower limit to the 12C mass fraction of 0.001-0.05 when dynamical burning occurs, but core dredge-up may yield 12C, 16O, and/or 20Ne mass fractions of ~0.1. Accreted 14N will likely remain 14N during the accretion and convective phases, but regardless of 14N's fate, the neutron-to-proton ratio at the beginning of convection is fixed until the onset of dynamical burning. During explosive burning, the 14N will undergo 14N(α, γ)18F(α, p)21Ne, liberating a proton for the subsequent 12C(p, γ)13N(α, p)16O reaction, which bypasses the relatively slow α-capture onto 12C. Future hydrodynamic simulations must include these isotopes, as the additional reactions will reduce the Zel'dovich-von Neumann-Döring length, making the propagation of the detonation wave more likely.

  11. Fluorido-Komplexe von Technetium

    OpenAIRE

    Mariappan Balasekaran, Samundeeswari

    2013-01-01

    Zusammenfassung Diese Dissertationsschrift befasst sich mit der Synthese und Charakterisierung neuer Technetiumfluoride mit dem Metall in den Oxidationsstufen “+1”, “+2”, “+4” und “+6”. Im ersten Kapitel wird über die Isolierung von unterschiedlichen Salzen von Fluoridonitridotechnetaten(VI) entweder aus Nitridotechnetium(VI)-säure oder aus Pertechnetat durch den Einsatz geeigneter Reduktionsmittel berichtet. Das Cäsiumsalz dieser Verbindung bildet einen oxido-verbrückten, dimeren Kompl...

  12. Effiziente chemoenzymatische Synthese von dhydroartemisinaldehyd

    OpenAIRE

    Demiray, Melodi; Tang, Xiaoping; Wirth, Thomas; Faraldos, Juan A.; Allemann, Rudolf K.

    2017-01-01

    Artemisinin aus der Pflanze Artemisia annua ist das wirkungsvollste Arzneimittel zur Behandlung von Malaria. Die Sesquiterpen-Cyclase Amorphadien-Synthase, ein Cytochrom-abhängiges CYP450 und eine Aldehyd-Reduktase wandeln in der Pflanze Farnesyl-Diphosphat (FDP) in Dihydroartemisinaldehyd (DHAAl) um, welches ein Schlüsselzwischenprodukt in der Biosynthese von Artemisinin und eine halbsynthetische Vorstufe in der chemischen Synthese des Arzneimittels ist. Hier berichten wir über einen chemoen...

  13. Effects of helium ash on fusion reactor operation and analogies with fission reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kamelander, G. [Oesterreichisches Forschungszentrum Seibersdorf GmbH (Austria); Buerbaumer, H. [Technische Univ., Vienna (Austria). Inst. fuer Allgemeine Physik

    1999-08-01

    It is well known from early reactor physics textbooks that fission products, especially xenon 135, have an important impact on fission reactor operation. An excess reactivity must be provided to compensate the reactivity loss due to this highly absorbing isotope and power oscillations must be suppressed by the control system. In the actual paper it is shown that in a magnetically confined fusion reactor the helium emerging from deuterium-tritium reactions will have an impact on reactor operation. It is necessary to provide additional auxiliary heating. Furthermore, it is shown that under certain circumstances in the initial phase of the plasma discharge oscillations of power and temperature are possible. Such oscillations have to be suppressed by a control system. The analogies in fission and fusion systems with respect to reaction products are discussed. (orig.) [German] Es ist bereits aus den ersten Lehrbuechern der Reaktorphysik bekannt, dass Spaltprodukte, insbesondere das Xenon-135, einen wichtigen Einfluss auf den Betrieb von Reaktoren haben. Es muss Ueberschussreaktivitaet bereitgestellt werden, um den Reaktivitaetsverlust durch dieses stark absorbierende Isotop zu kompensieren, und Leistungsschwingungen muessen durch ein Regelungssystem unterdrueckt werden. Im vorliegenden Artikel wird gezeigt, dass in einem auf Magneteinschluss basierenden Fusionsreaktor das aus den Deuterium-Tritium-Reaktionen resultierende Helium ebenfalls einen starken Einfluss auf den Betrieb haben wird. Es muss zusaetzliche Hilfsheizung bereitgestellt werden. Weiters koennen unter bestimmten Umstaenden in der Anfangsphase der Plasmaentladung Leistungsschwingungen entstehen, die durch eine Regelung unterdrueckt werden muessen. Die Analogien von Fissions- und Fusionssystemen im Hinblick auf Reaktionsprodukte werden diskutiert. (orig.)

  14. Helium Detonations on Neutron Stars

    Science.gov (United States)

    Zingale, M.; Timmes, F. X.; Fryxell, B.; Lamb, D. Q.; Olson, K.; Calder, A. C.; Dursi, L. J.; Ricker, P.; Rosner, R.; Truran, J. W.; MacNeice, P.; Tufo, H.

    2000-05-01

    We present the results of a numerical study of helium detonations on the surfaces of neutron stars. We analyze the evolution of a detonation as it breaks through the envelope of the neutron star and propagates across its surface. A series of surface waves propagate across the pool of hot ash with a speed of 1.3 x 109 \\ cm \\ s-1, matching the speed expected from shallow water wave theory. The entire envelope bounces in the gravitational potential well of the neutron star with a period of 50 μ s. The photosphere reaches a height of 15 km above the surface of the neutron star. The sensitivity of the results to the spatial resolution and assumed initial conditions are analyzed, and the relevance of this model to Type I X-ray bursts is discussed. This work is supported by the Department of Energy under Grant No. B341495 to the Center for Astrophysical Thermonuclear Flashes at the University of Chicago.

  15. Electric response in superfluid helium

    Science.gov (United States)

    Chagovets, Tymofiy V.

    2016-05-01

    We report an experimental investigation of the electric response of superfluid helium that arises in the presence of a second sound standing wave. It was found that the signal of the electric response is observed in a narrow range of second sound excitation power. The linear dependence of the signal amplitude has been derived at low excitation power, however, above some critical power, the amplitude of the signal is considerably decreased. It was established that the rapid change of the electric response is not associated with a turbulent regime generated by the second sound wave. A model of the appearance of the electric response as a result of the oscillation of electron bubbles in the normal fluid velocity field in the second sound wave is presented. Possible explanation for the decrease of the electric response are presented.

  16. In Beam Tests of Implanted Helium Targets

    CERN Document Server

    McDonald, J E; Ahmed, M W; Blackston, M A; Delbar, T; Gai, M; Kading, T J; Parpottas, Y; Perdue, B A; Prior, R M; Rubin, D A; Spraker, M C; Yeomans, J D; Weissman, L; Weller, H R; Delbar, Th.; Conn, LNS/U; Duke, TUNL/

    2006-01-01

    Targets consisting of 3,4He implanted into thin aluminum foils (approximately 100, 200 or 600 ug/cm^2) were prepared using intense (a few uA) helium beams at low energy (approximately 20, 40 or 100 keV). Uniformity of the implantation was achieved by a beam raster across a 12 mm diameter tantalum collimator at the rates of 0.1 Hz in the vertical direction and 1 Hz in the horizontal direction. Helium implantation into the very thin (approximately 80-100 ug/cm^2) aluminum foils failed to produce useful targets (with only approximately 10% of the helium retained) due to an under estimation of the range by the code SRIM. The range of low energy helium in aluminum predicted by Northcliffe and Shilling and the NIST online tabulation are observed on the other hand to over estimate the range of low energy helium ions in aluminum. An attempt to increase the amount of helium by implanting a second deeper layer was also carried out, but it did not significantly increase the helium content beyond the blistering limit (ap...

  17. Helium implanted AlHf as studied by Ta TDPAC

    Indian Academy of Sciences (India)

    Unknown

    TDPAC; electric field gradient; Hf solute clusters; helium-vacancy complex; defect recovery. 1. Introduction. In recent years a considerable effort has been directed to the behaviour of helium in metals as helium is produced by (n, α) reaction in nuclear materials. Helium atoms are insoluble in metals and are strongly attracted ...

  18. 21 CFR 868.1640 - Helium gas analyzer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Helium gas analyzer. 868.1640 Section 868.1640...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1640 Helium gas analyzer. (a) Identification. A helium gas analyzer is a device intended to measure the concentration of helium in a gas...

  19. Development of a transferline connecting a helium liquefier coldbox and a liquid helium Dewar

    Science.gov (United States)

    Menon, Rajendran S.; Rane, Tejas; Chakravarty, Anindya; Joemon, V.

    2017-02-01

    A helium liquefier with demonstrated capacity of 32 1/hr has been developed by BARC. Mumbai. A transferline for two way flow of helium between the helium liquefier coldbox and receiver Dewar has been developed in-house at BARC. Further, a functionally similar, but structurally improved transferline has been developed through a local fabricator. This paper describes and discusses issues related to the development of these cryogenic transferlines. The developed transferlines have been tested with a flow of liquid nitrogen and successfully utilised later in the helium liquefier plant.

  20. ASACUSA Anti-protonic Helium_Final

    CERN Multimedia

    CERN Audiovisual Production Service; CERN AD; Paola Catapano; Julien Ordan, Arzur Catel; Paola Catapano; ASACUSA COLLABORATION

    2016-01-01

    Latest precision measurement of the mass of the proton and the anti proton though the production of antiprotonic helium by the ASACUSA experiment at CERN's antimatter factory, with a beam from the Antiproton Decelerator

  1. Realization of mechanical rotation in superfluid helium

    Science.gov (United States)

    Gordon, E. B.; Kulish, M. I.; Karabulin, A. V.; Matyushenko, V. I.; Dyatlova, E. V.; Gordienko, A. S.; Stepanov, M. E.

    2017-09-01

    The possibility of using miniaturized low-power electric motors submerged in superfluid helium for organization of rotation inside a cryostat has been investigated. It has been revealed that many of commercial micromotors can operate in liquid helium consuming low power. Turret with 5 sample holders, assembled on the base of stepper motor, has been successfully tested in experiments on the nanowire production in quantized vortices of superfluid helium. Application of the stepper motor made it possible in a single experiment to study the effect of various experimental parameters on the yield and quality of the nanowires. The promises for continuous fast rotation of the bath filled by superfluid helium by using high-speed brushless micromotor were outlined and tested. Being realized, this approach will open new possibility to study the guest particles interaction with the array of parallel linear vortices in He II.

  2. Helium-Hydrogen Recovery System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Immense quantities of expensive liquefied helium are required at Stennis and Kennedy Space Centers for pre-cooling rocket engine propellant systems prior to filling...

  3. Helium behaviour in implanted boron carbide

    Directory of Open Access Journals (Sweden)

    Motte Vianney

    2015-01-01

    Full Text Available When boron carbide is used as a neutron absorber in nuclear power plants, large quantities of helium are produced. To simulate the gas behaviour, helium implantations were carried out in boron carbide. The samples were then annealed up to 1500 °C in order to observe the influence of temperature and duration of annealing. The determination of the helium diffusion coefficient was carried out using the 3He(d,p4He nuclear reaction (NRA method. From the evolution of the width of implanted 3He helium profiles (fluence 1 × 1015/cm2, 3 MeV corresponding to a maximum helium concentration of about 1020/cm3 as a function of annealing temperatures, an Arrhenius diagram was plotted and an apparent diffusion coefficient was deduced (Ea = 0.52 ± 0.11 eV/atom. The dynamic of helium clusters was observed by transmission electron microscopy (TEM of samples implanted with 1.5 × 1016/cm2, 2.8 to 3 MeV 4He ions, leading to an implanted slab about 1 μm wide with a maximum helium concentration of about 1021/cm3. After annealing at 900 °C and 1100 °C, small (5–20 nm flat oriented bubbles appeared in the grain, then at the grain boundaries. At 1500 °C, due to long-range diffusion, intra-granular bubbles were no longer observed; helium segregates at the grain boundaries, either as bubbles or inducing grain boundaries opening.

  4. Die Wertigkeit von Bildinformationskategorien und ihre Rolle bei der Beurteilung von Bildern als Medien

    OpenAIRE

    Wieczorek, Ulrich

    1997-01-01

    Die Wertigkeit von Bildinformationskategorien und ihre Rolle bei der Beurteilung von Bildern als Medien. - In: Die Geographiedidaktik ist tot, es lebe die Geographiedidaktik : Festschr. zur Emeritierung von Josef Birkenhauer / hrsg. von Friedhelm Frank ... - München, 1997. - S. 253-271. - (Münchner Studien zur Didaktik der Geographie ; 8)

  5. Ethnographische Filme und die Darstellung von Frauen

    Directory of Open Access Journals (Sweden)

    Judith Keilbach

    2002-03-01

    Full Text Available In dieser Filmographie werden ethnographische und koloniale Filme aus dem Bestand des Nederlands Filmmuseum kommentiert, die für die Frage nach der Darstellung von Frauen und Geschlechterverhältnissen von Interesse sind.

  6. John von Neumann selected letters

    CERN Document Server

    2005-01-01

    John von Neuman was perhaps the most influential mathematician of the twentieth century, especially if his broad influence outside mathematics is included. Not only did he contribute to almost all branches of mathematics and created new fields, but he also changed post-World War II history with his work on the design of computers and with being a sought-after technical advisor to many figures in the U.S. military-political establishment in the 1940s and 1950s. The present volume is the first substantial collection of (previously mainly unpublished) letters written by von Neumann to colleagues, friends, government officials, and others. The letters give us a glimpse of the thinking of John von Neumann about mathematics, physics, computer science, science management, education, consulting, politics, and war. Readers of quite diverse backgrounds will find much of interest in this fascinating first-hand look at one of the towering figures of twentieth century science.

  7. Helium and Neon in Comets

    Science.gov (United States)

    Jewitt, David

    1996-01-01

    Two comets were observed with EUVE in late 1994. Both comet Mueller and comet Borrelly are short-period comets having well established orbital elements and accurate ephemerides. Spectra of 40 ksec were taken of each. No evidence for emission lines from either Helium or Neon was detected. We calculated limits on the production rates of these atoms (relative to solar) assuming a standard isotropic outflow model, with a gas streaming speed of 1 km/s. The 3-sigma (99.7% confidence) limits (1/100,000 for He, 0.8 for Ne) are based on a conservative estimate of the noise in the EUVE spectra. They are also weakly dependent on the precise pointing and tracking of the EUVE field of view relative to the comet during the integrations. These limits are consistent with ice formation temperatures T greater than or equal to 30 K, as judged from the gas trapping experiments of Bar-Nun. For comparison, the solar abundances of these elements are He/O = 110, Ne/O = 1/16. Neither limit was as constraining as we had initially hoped, mainly because comets Mueller and Borrelly were intrinsically less active than anticipated.

  8. Helium Detonations on Neutron Stars

    Science.gov (United States)

    Zingale, M.; Timmes, F. X.; Fryxell, B.; Lamb, D. Q.; Olson, K.; Calder, A. C.; Dursi, L. J.; Ricker, P.; Rosner, R.; MacNeice, P.; Tufo, H. M.

    2001-03-01

    We present the results of a numerical study of helium detonations on the surfaces of neutron stars. We describe two-dimensional simulations of the evolution of a detonation as it breaks through the accreted envelope of the neutron star and propagates laterally through the accreted material. The detonation front propagates laterally at nearly the Chapman-Jouguet velocity, v=1.3×109 cm s-1. A series of surface waves propagate across the pool of hot ash behind the detonation front with the same speed, matching the speed expected from shallow water wave theory. The entire envelope oscillates in the gravitational potential well of the neutron star with a period of ~50 μs. The photosphere reaches an estimated height of 10 km above the surface of the neutron star. Our study confirms that such a detonation can insure the spread of burning over the entire neutron star surface on a timescale consistent with burst rise times. We analyze the sensitivity of the results to the spatial resolution and the assumed initial conditions. We conclude by presenting a comparison of this model to type I X-ray bursts.

  9. An Invitation from Lars von Trier

    DEFF Research Database (Denmark)

    Skadhauge, Troels; Tønder, Lars

    2015-01-01

    Translation of Martin Krasnik interview with Lars von Trier broadcast on DR2, January 12, 2015. The following is an interview of Lars von Trier (LvT) by the Danish journalist Martin Krasnik (MK). The interview took place in Lars von Trier’s home in Brede, a small town just outside Copenhagen...

  10. Management von Anforderungsdokumenten mittels semantischer Wikis

    OpenAIRE

    Decker, B.

    2005-01-01

    Im Projekt RISE wird untersucht, wie durch den Einsatz von Wikis das Anforderungsmanagement von Software Projekten agil unterstützt werden kann. Um das oftmals chaotische Wachstum von Inhalten in den Griff zu bekommen, werden maschinelle Lernverfahren genutzt, um Inhalte zu strukturieren und dem Benutzer zugänglich zum machen.

  11. Multivariat-statistische Auswertung von energiedispersiven Röntgenfluoreszenzspektren zur Identifizierung von Substanzen

    OpenAIRE

    Kessler, Thorsten

    2001-01-01

    Es wurde der Einsatz von multivariater Auswertung von energiedispersiven Röntgenfluoreszenzanalyse (EDRFA) -Spektren für die Zuordnung von Substanzen getestet. Hierbei erfolgten u. a. Untersuchungen zur Zuordnungsanalytik von Chemikalien ohne und mit Verpackungen. Zur Untersuchung von Chemikalien mit Verpackung wurden ausschließlich anorganische, feste Chemikalien in z.T. unterschiedlicher Verpackung herangezogen. Zusätzlich sollte ein Vergleich zwischen Messungen durch gleiche Verpackungen u...

  12. Homopteren von Java, gesammelt von Herrn Edw. Jacobson

    NARCIS (Netherlands)

    Melichar, L.

    1914-01-01

    Herr Edw. Jacobson hat auf Java in den Jahren 1908— 1910 Homopteren gesammelt und mir die Bearbeitung des gesammelten Materiales übertragen. Die Jacobson’sche Ausbeute ist insoferne bemerkenswert, als dieselbe viele Mikrohomopteren enthält, welche von nichtfachkundigen Sammlern gewöhnlich nicht

  13. Standard Guide for Simulation of Helium Effects in Irradiated Metals

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1996-01-01

    1.1 This guide provides advice for conducting experiments to investigate the effects of helium on the properties of metals where the technique for introducing the helium differs in some way from the actual mechanism of introduction of helium in service. Simulation techniques considered for introducing helium shall include charged particle implantation, exposure to α-emitting radioisotopes, and tritium decay techniques. Procedures for the analysis of helium content and helium distribution within the specimen are also recommended. 1.2 Two other methods for introducing helium into irradiated materials are not covered in this guide. They are the enhancement of helium production in nickel-bearing alloys by spectral tailoring in mixed-spectrum fission reactors, and isotopic tailoring in both fast and mixed-spectrum fission reactors. These techniques are described in Refs (1-5). Dual ion beam techniques (6) for simultaneously implanting helium and generating displacement damage are also not included here. This lat...

  14. Replikation von µ-Peptidarrays

    OpenAIRE

    Striffler, Jakob

    2014-01-01

    In der vorliegen Arbeit wurde ein Verfahren erarbeitet und mit Photometrie, XPS und ToF-SIMS charakterisiert, mit dem durch mikropartikelbasierte Verfahren hergestellte µ-Peptidarrays von Syntheseoberflächen abgespalten und auf beliebige Zieloberflächen transferiert werden können.

  15. Von Krahl ON! / Terje Metsavas

    Index Scriptorium Estoniae

    Metsavas, Terje

    2008-01-01

    Madli Pesti ja Terje Metsavas kohtusid Von Krahli teatri tehnilise meeskonnaga teatri black-box-saalis. Teatri tehniline meeskond on tehnikadirektor Enar Tarmo, video- ja multimeediaga tegelev Lauri Sepp, tehnikud Janno "John" Jaanus, Oliver Kulpsoo ja Allan Räim. Selles, kuidas sünnivad "tehnikaimed" ja kuidas lahendatakse lavastuslikke projekte

  16. Integration von Produktion und Instandhaltung

    OpenAIRE

    Hans-Böckler-Stiftung

    2003-01-01

    Die Faktoren Produktqualität und Kosten-Nutzen-Verhältnis sind entscheidend im Wettbewerb. Um diese Faktoren zu optimieren, suchen die Unternehmen nach innovativen Modellen der Integration von Produktion und Instandhaltung. Über Konzeption und Erprobung solcher Modelle berichtet eine Arbeitsgruppe der Engeren Mitarbeiter der Arbeitsdirektoren Stahl Fachausschuss 1/00.

  17. Suicide by asphyxiation due to helium inhalation.

    Science.gov (United States)

    Howard, Matthew O; Hall, Martin T; Edwards, Jeffrey D; Vaughn, Michael G; Perron, Brian E; Winecker, Ruth E

    2011-03-01

    Suicide by asphyxiation using helium is the most widely-promoted method of "self-deliverance" by right-to-die advocates. However, little is known about persons committing such suicides or the circumstances and manner in which they are completed. Prior reports of suicides by asphyxiation involving helium were reviewed and deaths determined by the North Carolina Office of the Chief Medical Examiner to be helium-associated asphyxial suicides occurring between January 1, 2000 and December 31, 2008 were included in a new case series examined in this article. The 10 asphyxial suicides involving helium identified in North Carolina tended to occur almost exclusively in non-Hispanic, white men who were relatively young (M age = 41.1 T 11.6). In 6 of 10 cases, decedents suffered from significant psychiatric dysfunction; in 3 of these 6 cases, psychiatric disorders were present comorbidly with substance abuse. In none of these cases were decedents suffering from terminal illness. Most persons committing suicide with helium were free of terminal illness but suffered from psychiatric and/or substance use disorders.

  18. Helium release from radioisotope heat sources

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.E.; Early, J.W.; Starzynski, J.S.; Land, C.C.

    1984-05-01

    Diffusion of helium in /sup 238/PuO/sub 2/ fuel was characterized as a function of the heating rate and the fuel microstructure. The samples were thermally ramped in an induction furnace and the helium release rates measured with an automated mass spectrometer. The diffusion constants and activation energies were obtained from the data using a simple diffusion model. The release rates of helium were correlated with the fuel microstructure by metallographic examination of fuel samples. The release mechanism consists of four regimes, which are dependent upon the temperature. Initially, the release is controlled by movement of point defects combined with trapping along grain boundaries. This regime is followed by a process dominated by formation and growth of helium bubbles along grain boundaries. The third regime involves volume diffusion controlled by movement of oxygen vacancies. Finally, the release at the highest temperatures follows the diffusion rate of intragranular bubbles. The tendency for helium to be trapped within the grain boundaries diminishes with small grain sizes, slow thermal pulses, and older fuel.

  19. Commissioning of a new helium pipeline

    Science.gov (United States)

    2000-01-01

    At the commissioning of a new high-pressure helium pipeline at Kennedy Space Center, participants cut the lines to helium-filled balloons. From left, they are Center Director Roy Bridges; Michael Butchko, president, SGS; Pierre Dufour, president and CEO, Air Liquide America Corporation; David Herst, director, Delta IV Launch Sites; Pamela Gillespie, executive administrator, office of Congressman Dave Weldon; and Col. Samuel Dick, representative of the 45th Space Wing. The nine-mile-long buried pipeline will service launch needs at the new Delta IV Complex 37 at Cape Canaveral Air Force Station. It will also serve as a backup helium resource for Shuttle launches. Nearly one launch's worth of helium will be available in the pipeline to support a Shuttle pad in an emergency. The line originates at the Helium Facility on KSC and terminates in a meter station at the perimeter of the Delta IV launch pad. Others at the ceremony were Jerry Jorgensen, pipeline project manager, Space Gateway Support (SGS), and Ramon Lugo, acting executive director, JPMO.

  20. [Friedrich Ludwig von Maydelli pildid Baltimaade ajaloost = Friedrich Ludwig von Maydells Baltische Geschichte in Bildern = Friedrich Ludwig von Maydell ́s Baltic history in images] / Ulrike Plath

    Index Scriptorium Estoniae

    Plath, Ulrike, 1972-

    2014-01-01

    Arvustus: Friedrich Ludwig von Maydelli pildid Baltimaade ajaloost = Friedrich Ludwig von Maydells Baltische Geschichte in Bildern = Friedrich Ludwig von Maydell ́s Baltic history in images. Eesti kunstimuuseum, Kadrioru kunstimuuseum. Tallinn 2013

  1. Screw Compressor Characteristics for Helium Refrigeration Systems

    Science.gov (United States)

    Ganni, V.; Knudsen, P.; Creel, J.; Arenius, D.; Casagrande, F.; Howell, M.

    2008-03-01

    The oil injected screw compressors have practically replaced all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, minimal vibration, reliability and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium systems, typically two-thirds of the lost input power is due to the compression system. Therefore it is important to understand the isothermal and volumetric efficiencies of these machines to help properly design these compression systems to match the refrigeration process. This presentation summarizes separate tests that have been conducted on Sullair compressors at the Superconducting Super-Collider Laboratory (SSCL) in 1993, Howden compressors at Jefferson Lab (JLab) in 2006 and Howden compressors at the Spallation Neutron Source (SNS) in 2006. This work is part of an ongoing study at JLab to understand the theoretical basis for these efficiencies and their loss mechanisms, as well as to implement practical solutions.

  2. Feasibility of lunar Helium-3 mining

    Science.gov (United States)

    Kleinschneider, Andreas; Van Overstraeten, Dmitry; Van der Reijnst, Roy; Van Hoorn, Niels; Lamers, Marvin; Hubert, Laurent; Dijk, Bert; Blangé, Joey; Hogeveen, Joel; De Boer, Lennaert; Noomen, Ron

    With fossil fuels running out and global energy demand increasing, the need for alternative energy sources is apparent. Nuclear fusion using Helium-3 may be a solution. Helium-3 is a rare isotope on Earth, but it is abundant on the Moon. Throughout the space community lunar Helium-3 is often cited as a major reason to return to the Moon. Despite the potential of lunar Helium-3 mining, little research has been conducted on a full end-to-end mission. This abstract presents the results of a feasibility study conducted by students from Delft University of Technology. The goal of the study was to assess whether a continuous end-to-end mission to mine Helium-3 on the Moon and return it to Earth is a viable option for the future energy market. The set requirements for the representative end-to-end mission were to provide 10% of the global energy demand in the year 2040. The mission elements have been selected with multiple trade-offs among both conservative and novel concepts. A mission architecture with multiple decoupled elements for each transportation segment (LEO, transfer, lunar surface) was found to be the best option. It was found that the most critical element is the lunar mining operation itself. To supply 10% of the global energy demand in 2040, 200 tons of Helium-3 would be required per year. The resulting regolith mining rate would be 630 tons per second, based on an optimistic concentration of 20 ppb Helium-3 in lunar regolith. Between 1,700 to 2,000 Helium-3 mining vehicles would be required, if using University of Wisconsin’s Mark III miner. The required heating power, if mining both day and night, would add up to 39 GW. The resulting power system mass for the lunar operations would be in the order of 60,000 to 200,000 tons. A fleet of three lunar ascent/descent vehicles and 22 continuous-thrust vehicles for orbit transfer would be required. The costs of the mission elements have been spread out over expected lifetimes. The resulting profits from Helium

  3. Electron correlation for helium-like atoms

    Energy Technology Data Exchange (ETDEWEB)

    Roy, U. [Visvabharati Univ., Santiniketan (India). Dept. of Comput. Sci.; Talukdar, B. [Visvabharati Univ., Santiniketan (India). Dept. of Physics

    1999-02-01

    A recently proposed analytical approach to the ground-state energy of helium atom is generalised to study the effect of electron-electron correlation on the properties of helium isoelectronic sequence. The expectation values of the Hamiltonian and some important functions of radial distances are expressed in terms of derivatives of Lewis integrals which not only permit the straightforward variational calculation to get numerical results but also help one derive interesting recurrence relations for radial expectation values. The results presented for atoms from H{sup -} to Si{sup 12+} indicate that the present analytical model will have quantitative applicability for the study of electronic correlation in high-Z helium-like atoms within the framework of non-relativistic quantum mechanics. (orig.) 22 refs.

  4. Superfluid helium-4 in one dimensional channel

    Science.gov (United States)

    Kim, Duk Y.; Banavar, Samhita; Chan, Moses H. W.; Hayes, John; Sazio, Pier

    2013-03-01

    Superfluidity, as superconductivity, cannot exist in a strict one-dimensional system. However, the experiments employing porous media showed that superfluid helium can flow through the pores of nanometer size. Here we report a study of the flow of liquid helium through a single hollow glass fiber of 4 cm in length with an open id of 150 nm between 1.6 and 2.3 K. We found the superfluid transition temperature was suppressed in the hollow cylinder and that there is no flow above the transition. Critical velocity at temperature below the transition temperature was determined. Our results bear some similarity to that found by Savard et. al. studying the flow of helium through a nanohole in a silicon nitrite membrane. Experimental study at Penn State is supported by NSF Grants No. DMR 1103159.

  5. Experimental helium liquefier with a GM cryocooler

    Science.gov (United States)

    Choudhury, Anup; Sahu, Santosh

    2017-06-01

    A helium liquefier has been developed with a Gifford-McMahon cryocooler using the cold enthalpy available at the first stage, the inter-stage, and the second stage of the cryocooler. Most of the enthalpy of the helium gas at 300 K is absorbed in the first stage by a coaxial heat exchanger and inter-stage region of the cryocooler. Pre-cooled helium gas is liquefied at the second stage heat exchanger where the final cooldown and condensation happens. The measured production capacity of the liquefier is 17.4 l/day at atmospheric pressure. The whole setup has been designed to work in a coaxial configuration where the two heat exchangers, the cryostat, and the dewar are symmetrically placed around the central axis.

  6. Temperature Rises In Pumps For Superfluid Helium

    Science.gov (United States)

    Kittel, Peter

    1990-01-01

    Report discusses increases in temperature of superfluid helium in centrifugal and fountain-effect pumps. Intended for use in transfers of superfluid helium in outer space. Increases in temperature significantly affect losses during transfers and are important in selection of temperatures of supply tanks. Purpose of study, increase in temperature in fountain-effect pump calculated on basis of thermodynamic considerations, starting from assumption of ideal pump. Results of recent tests of ceramic material intended for use in such pumps support this assumption. Overall, centrifugal pumps more effective because it produces smaller rise in temperature.

  7. Von den Veranschaulichungsmethoden in den Rundfunkpredigten von der Heiligkreuz- Kirche

    Directory of Open Access Journals (Sweden)

    Witold Ostafiński

    2004-12-01

    Full Text Available In der gegenwärtigen Verkündigung des Wortes Gottes spielt die Veranschaulichung der Überlieferung eine nicht zu überschätzende Rolle. Vor diesem Hintergrund wird es sehr wichtig, dass man den Predigern nicht nur auf die Funktion des Bildes in der Verkündigung, sondern auch auf die Art und Weise seines Entstehens auf der narrativen Ebene aufmerksam macht. Während die Kenner der Homiletik die Notwendigkeit des Auftretens der Bildeigenschaften in den Predigten betonen, erinnern sie gleichzeitig daran, dass der moderne, von der „Bild-Zivilisation“ gestaltete Mensch, „immer mehr sehen als hören“ möchte. Der vorliegende, die Rundfunkpredigten von der Heiligkreuz-Kirche analysierende Aufsatz, nimmt auf und bringt zugleich nahe die Problematik der Notwendigkeit des Bildes in der Wort-Gottes-Verkündigung. Der Artikel stellt die Erzählungsform als eine wichtige Möglichkeit der Glaubensüberlieferung dar, behandelt das Problem der Aktualisierung evangelischen Werte, bringt das von den Predigten gestaltete synästhetische Weltbild nahe und analysiert die Rolle des Zitats und Beispiels (exemplum bei der Gestaltung der Bildhaftigkeit einer Predigt. Darüber hinaus überprüft der Aufsatz in seinem letzten Teil die in den gegenwärtigen Rundfunkpredigten meist verwendeten Redefiguren

  8. Analyse von Schnittstellenkompatibilität von Steuergeräten auf Basis von MSC-Beschreibungen

    OpenAIRE

    Ma, Zheng

    2008-01-01

    In modernen Fahrzeugen befindet sich eine Vielzahl von Steuergeräten, die verschiedenste Funktionen, wie z.B. das Antiblockiersystem (ABS) realisieren. Die Funktionalitäten von Steuergeräten werden heute mit unterschiedlichen Methoden beschrieben. Eine dieser Methoden sind Message Sequence Charts (MSCs). Aufgrund der Freiheitsgrade von MSCs gibt es verschiedene Möglichkeiten gleiche Funktionalität unterschiedlich zu beschreiben. In dieser Arbeit wird eine Methode definiert, wie...

  9. Männlichkeiten von rechts

    Directory of Open Access Journals (Sweden)

    Marc Gärtner

    2004-11-01

    Full Text Available Oliver Geden, Doktorand am Institut für europäische Ethnologie der Humboldt Universität Berlin untersucht Männlichkeitskonzepte im zeitgenössischen Rechtspopulismus – ein Thema, zu dem überraschend lange keine einschlägigen Studien vorlagen. Anhand von Parteimedien und Interviews rekonstruiert er strategische Positionen zu Männlichkeit und Geschlechterverhältnissen auf unterschiedlichen Organisationsebenen der Österreichischen „Haider-Partei“ FPÖ. Statt eines monolithischen „Neo-Macho-Projektes“ findet er im Kern zwar ähnliche Traditionalisierungsbemühungen auf allen Ebenen, je nach Kontext aber differenzierbare pragmatische, verunsicherte und neo-naturalistische Perspektiven auf die Geschlechterthematik. Durch die Einbeziehung von Gruppeninterviews im Nachwuchsverband der Partei erhält die Publikation eine besondere Brisanz. Geden analysiert die methodischen und forschungsethischen Implikationen ebenso hervorragend wie das Kernthema selbst.

  10. Von Willebrand factor and aging.

    Science.gov (United States)

    Konkle, Barbara A

    2014-09-01

    von Willebrand factor (VWF) plays critical roles in initiating primary hemostasis and extending the half-life of coagulation factor VIII in circulation. VWF levels increase with age and elevated levels are associated with an increased risk of venous thromboembolism and cardiovascular disease (CVD). Patients with von Willebrand disease (VWD) due to a deficiency or dysfunction of VWF may have symptoms that ameliorate with aging or may have exacerbation of their disease. Bleeding sites of particular challenge in the aging patient include gastrointestinal bleeding and hematuria. Some medications used to treat VWD should be used with special precaution in older patients, including desmopressin and VWF-containing factor concentrates. Patients with VWD may have some protection from CVD, but in those patients who develop CVD, management is very challenging, given the role of antiplatelet therapy as the mainstay of treatment. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  11. von Hippel-Lindau disease

    DEFF Research Database (Denmark)

    Binderup, Marie Louise Mølgaard; Gimsing, Steen; Kosteljanetz, Michael

    2013-01-01

    Endolymphatic sac tumours (ELSTs) of the inner ear occur in 16% of patients with the hereditary tumor syndrome von Hippel-Lindau disease (vHL). ELSTs of all sizes can cause irreversible hearing loss which can, however, be prevented through early diagnosis and treatment. We aim to emphasize the ch...... the challenges of prophylactic ELST screening and to explore the role of audiometry in pre-symptomatic ELST screening....

  12. Methode zur Entwicklung von Prozessportalen

    OpenAIRE

    Alt, Rainer; Caesar, Marc; Leser, Florian; Österle, Hubert; Puschmann, Thomas; Reichmayr, Christian; Zurmuehlen, Rudolf

    2004-01-01

    Die in Kapitel 2 dargestellte Architektur zeigt Gestaltungselemente auf den drei Ebenen Strategie, Prozess und System. Zahlreiche Beispiele in den darauf folgenden Kapiteln haben die Anwendung dieser Architektur gezeigt. Um ein intuitives Vorgehen bei Entwurf und der Umsetzung von Echtzeit-Portalen zu vermeiden, sollen die bei den Fallbeispielen erzielten Erkenntnisse und Erfahrungen in ein systematisches Vorgehen einfliessen. Obgleich sich der Entwurf einer Architektur für das Echtzeit-Unter...

  13. Photoassociation of cold metastable helium atoms

    NARCIS (Netherlands)

    Woestenenk, G.R.

    2001-01-01

    During the last decades the study of cold atoms has grown in a great measure. Research in this field has been made possible due to the development of laser cooling and trapping techniques. We use laser cooling to cool helium atoms down to a temperature of 1 mK and we are able to

  14. Parametric study of radiofrequency helium discharge under ...

    Indian Academy of Sciences (India)

    The excitation temperatures in the α and γ modes were 3266 and 4500 K respectively, evaluated by Boltzmann's plot method. The estimated gas temperature increased from 335 K in the α mode to 485 K in the γ mode, suggesting that the radio frequency atmospheric pressure helium discharge can be used for surface ...

  15. Critical Landau Velocity in Helium Nanodroplets

    NARCIS (Netherlands)

    Brauer, N.B.; Smolarek, S.; Loginov, E.; Mateo, D.; Hernando, A.; Pi, M.; Barranco, M.; Buma, W.J.; Drabbels, M.

    2013-01-01

    The best-known property of superfluid helium is the vanishing viscosity that objects experience while moving through the liquid with speeds below the so-called critical Landau velocity. This critical velocity is generally considered a macroscopic property as it is related to the collective

  16. Helium and Sulfur Hexafluoride in Musical Instruments

    Science.gov (United States)

    Forinash, Kyle; Dixon, Cory L.

    2014-01-01

    The effects of inhaled helium on the human voice were investigated in a recent article in "The Physics Teacher." As mentioned in that article, demonstrations of the effect are a popular classroom activity. If the number of YouTube videos is any indication, the effects of sulfur hexafluoride on the human voice are equally popular.…

  17. Interatomic Coulombic decay in helium nanodroplets

    DEFF Research Database (Denmark)

    Shcherbinin, Mykola; Laforge, Aaron; Sharma, Vandana

    2017-01-01

    Interatomic Coulombic decay (ICD) is induced in helium nanodroplets by photoexciting the n=2 excited state of He+ using XUV synchrotron radiation. By recording multiple-coincidence electron and ion images we find that ICD occurs in various locations at the droplet surface, inside the surface region...

  18. Messer to provide helium for LHC

    CERN Multimedia

    2008-01-01

    Over the course of the next few years, industrial gas specialist The Messer Group, through its Swiss subsidiary Messer Schweiz AG, is to provide a 160,000kg supply of helium to the European Organisation for Nuclear Research (CERN) for the operation of the world's largest particle accelerator.

  19. Messer to provide helium for LHC project

    CERN Multimedia

    2008-01-01

    Over the course of the next few years, industrial gas specialist The Messer Group, through its Swiss subsidiary Messer Schweiz AG, is to provide a 160,000kg supply of helium to the European Organisation for Nuclear Research (CERN) for the operation of the world's largest particle accelerator.

  20. Near field characteristics of buoyant helium plumes

    Indian Academy of Sciences (India)

    affects the combustion. Puffing is also observed in low density gas plumes when the ratio of inlet ... generated using helium and helium–air mixtures, hot gases were used to understand the flow dynamics associated .... The glass lens acts as a filter to block any UV light and prevents fluorescence signal contamination. Since.

  1. Near field characteristics of buoyant helium plumes

    Indian Academy of Sciences (India)

    ... Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Sadhana; Volume 40; Issue 3. Near field characteristics of buoyant helium plumes. Kuchimanchi K Bharadwaj Debopam Das Pavan K Sharma. Section I – Fluid Mechanics and Fluid Power (FMFP) Volume 40 Issue 3 May 2015 pp 757- ...

  2. Refraction of cylindrical converging shock wave at an air/helium gaseous interface

    Science.gov (United States)

    Zhai, Zhigang; Li, Wei; Si, Ting; Luo, Xisheng; Yang, Jiming; Lu, Xiyun

    2017-01-01

    Refraction of a cylindrical converging shock wave at an inclined air/helium interface is investigated. Experimentally, based on the shock dynamics theory, a special wall profile is designed to generate a perfectly cylindrical converging shock wave. A soap film technique is developed to form an inclined discontinuous air/helium interface, and high-speed schlieren photography is adopted to capture the flow. Numerical simulations are also performed to compare with the experimental counterparts and to show details of refraction. In this work, two initial incident angles (45° and 60°) are considered. As the incident shock converges inward, the shock intensity increases while the incident angle decreases, causing possible transitions among the wave patterns. For the case of 45°, an irregular refraction of free precursor refraction (FPR) first occurs and gradually transits into regular refraction, while for the case of 60°, various irregular refractions of twin von Neumann refraction (TNR), twin regular refraction (TRR), free precursor von Neumann refraction (FNR), and FPR occur in sequence. The transition sequences do not belong to any groups described in the planar counterpart, indicating that the classification of the refraction phenomenon in the planar case is not exhaustive or cannot be applied to the converging case. It is also the first time to observe the transition from FNR to FPR, providing an experimental evidence for the previous numerical results. It is deemed that the difference between the velocities of the incident and transmitted shocks propagating along the interface is the primary factor that induces the transitions among wave patterns.

  3. Thirty years of screw compressors for helium; Dreissig Jahre Schraubenkompressoren fuer Helium

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, H. [Kaeser Kompressoren GmbH, Coburg (Germany). Technisches Buero/Auftragskonstruktion

    2007-07-01

    KAESER helium compressors, as well as their other industrial compressors, will be further developed with the intention to improve the availability and reliability of helium liquefaction systems. Further improvement of compressor and control system efficiency will ensure a low and sustainable operating cost. Fast supply of replacement parts with several years of warranty is ensured by a world-wide distribution system and is also worked on continuously. (orig.)

  4. Femtosecond spectroscopy on alkali-doped helium nanodroplets; Femtosekundenspektroskopie an alkalidotierten Helium-Nanotroepfchen

    Energy Technology Data Exchange (ETDEWEB)

    Claas, P.

    2006-01-15

    In the present thesis first studies on the short-time dynamics in alkali dimers and microclusters, which were bound on the surface of superfluid helium droplets, were presented. The experiments comprehended pump-probe measurements on the fs scale on the vibration dynamics on the dimers and on the fragmentation dynamics on the clusters. Generally by the studies it was shown that such extremely short slopes can also be observed on helium droplets by means of the femtosecond spectroscopy.

  5. Einfluss von Hypoxie auf das Transkriptom und das mitochondriale Proteom von Arabidopsis thaliana

    OpenAIRE

    Willeke, Claudia

    2011-01-01

    Hypoxie beeinflusst Wachstum und Entwicklung von Pflanzen. Da Sauerstoff als finaler Elektronenakzeptor der Atmungskette dient, sind Mitochondrien möglicherweise an der Wahrnehmung von Hypoxie und der Weiterleitung des Signals durch retrograde Regulierung beteiligt. In dieser Arbeit wurden daher die Auswirkungen von Hypoxie auf das Transkriptom und das mitochondriale Proteom von Arabidopsis thaliana untersucht. Zu diesem Zweck wurden Inkubationssysteme für Zellkulturen, Keimlinge und Pflanzen...

  6. Dr. von Braun Briefing Walt Disney

    Science.gov (United States)

    1965-01-01

    Dr. von Braun began his association with Walt Disney in the 1950s when the rocket scientist appeared in three Disney television productions related to the exploration of space. Years later, Dr. von Braun invited Disney and his associates to tour the Marshall Space Flight Center (MSFC) in Huntsville, Alabama. This photograph is dated April 13, 1965. From left are R.J. Schwinghamer from the MSFC, Disney, B.J. Bernight, and Dr. von Braun.

  7. Offenes Baukastensystem zur effizienten Dimensionierung von Materialflusssystemen

    OpenAIRE

    Meinhardt, Ingolf; Marquardt, Hans-Georg

    2007-01-01

    Die optimale Gestaltung logistischer Systeme und Prozesse bekommt eine immer größere Bedeutung für die Wirtschaftlichkeit und Wettbewerbsfähigkeit von Unternehmen. Für Einzelkomponenten von Materi-alflusssystemen sind neben exakten analytischen Verfahren auch Näherungslösungen und Ersatzmodelle in Form von Polynomen, neuronalen Netzen oder zeitdiskreten Verfahren vorhanden, mit denen eine gute Nachbildung des Verhaltens dieser Komponenten möglich ist. Ziel des Baukastensystems ist es, für...

  8. Evaluation of helium cooling for fusion divertors

    Energy Technology Data Exchange (ETDEWEB)

    Baxi, C.B.

    1993-09-01

    The divertors of future fusion reactors will have a power throughput of several hundred MW. The peak heat flux on the diverter surface is estimated to be 5 to 15 MW/m{sup 2} at an average heat flux of 2 MW/m{sup 2}. The divertors have a requirement of both minimum temperature (100{degrees}C) and maximum temperature. The minimum temperature is dictated by the requirement to reduce the absorption of plasma, and the maximum temperature is determined by the thermo-mechanical properties of the plasma facing materials. Coolants that have been considered for fusion reactors are water, liquid metals and helium. Helium cooling has been shown to be very attractive from safety and other considerations. Helium is chemically and neutronically inert and is suitable for power conversion. The challenges associated with helium cooling are: (1) Manifold sizes; (2) Pumping power; and (3) Leak prevention. In this paper the first two of the above design issues are addressed. A variety of heat transfer enhancement techniques are considered to demonstrate that the manifold sizes and the pumping power can be reduced to acceptable levels. A helium-cooled diverter module was designed and fabricated by GA for steady-state heat flux of 10 MW/m{sup 2}. This module was recently tested at Sandia National Laboratories. At an inlet pressure of 4 MPa, the module was tested at a steady-state heat flux of 10 MW/m{sup 2}. The pumping power required was less than 1% of the power removed. These results verified the design prediction.

  9. von Willebrand disease phenotype and von Willebrand factor marker genotype in Doberman Pinschers.

    Science.gov (United States)

    Brooks, M B; Erb, H N; Foureman, P A; Ray, K

    2001-03-01

    To define the relationship between clinical expression of a type-1 von Willebrand disease phenotype and genotype at 2 von Willebrand factor marker loci in Doberman Pinschers. 102 client-owned Doberman Pinschers. Dogs were recruited on the basis of plasma von Willebrand factor concentration, clinical history, and pedigree. Blood samples and response to a history questionnaire were obtained for each dog. Plasma von Willebrand factor concentration was measured by use of an ELISA, and genotyping was performed via polymerase chain reaction for 1 intragenic and 1 extragenic von Willebrand factor marker. Amplification product size was determined by use of polyacrylamide gel electrophoresis (intragenic marker) or automated sequence analysis (extragenic marker). Western blots were prepared from a subset of dogs with low plasma von Willebrand factor concentration to evaluate multimer distribution. Strong associations were detected between plasma von Willebrand factor concentration and von Willebrand factor marker genotype. Twenty-five dogs had substantial reduction in plasma von Willebrand factor concentration and multiple hemorrhagic events. All were homozygous for a 157-base-pair intragenic marker allele and homozygous or compound heterozygous for 1 of 4 extragenic marker alleles. These marker genotypes were exclusively detected in dogs with low plasma von Willebrand factor concentration, although some dogs with these genotypes did not have abnormal bleeding. Type-1 von Willebrand disease in Doberman Pinschers is associated with the von Willebrand factor gene locus; however, the expression pattern in this breed appears more complex than that of a simple recessive trait.

  10. Modellierung von Anwenderverhalten im Social Semantic Web

    Science.gov (United States)

    Ulbrich, Armin; Höfler, Patrick; Lindstaedt, Stefanie

    Ziel dieses Kapitels ist es, gemeinsame Verwendungsszenarien des Semantic Web und des Social Web zu identifizieren und zu benennen. Dabei wird ein Teilaspekt des Themengebiets im Detail betrachtet: die Nutzung von Services, die Beobachtungen des Verhaltens von Anwendern analysieren, um daraus maschinell interpretierbare Informationen zu erhalten und diese als Modelle zu organisieren. Es werden zunächst einige Eigenschaften und Unterscheidungsmerkmale von Anwenderverhalten und organisierten Modellen dargestellt. Anschließend wird der mögliche wechselseitige Nutzen von Anwenderverhalten und Modellen diskutiert. Den Abschluss bildet eine Betrachtung einiger exemplarischer Software-Services, die heute schon verwendet werden, um Anwenderverhalten in Modelle überzuführen.

  11. The Social Science of Carl von Clausewitz

    Science.gov (United States)

    2006-01-01

    The Social Science of Carl von Clausewitz JANEEN KLINGER C arl von Clausewitz’s great, unfinished book On War is well-known as be- ing prone to...COVERED 00-00-2006 to 00-00-2006 4. TITLE AND SUBTITLE The Social Science of Carl von Clausewitz 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...Raymond Aron, Clausewitz: Philos- opher of War (New York: Simon and Schuster, 1983), p. 206. 88 Parameters 2. Carl Von Clausewitz , On War, ed. and trans

  12. Die naturräumliche Gliederung von Schwaben

    OpenAIRE

    Fischer, Klaus

    1985-01-01

    Die naturräumliche Gliederung von Schwaben. - In: Historischer Atlas von Bayerisch-Schwaben / hrsg. von Hans Frei ... - 2., neu bearb. u. erg. Aufl. - Augsburg : Schwäb. Forschungsgem. - Lifg. 2. (1985). - Kt. II, 7.

  13. The future of helium as a natural resource

    CERN Document Server

    Glowacki, Bartek A; Nuttall, William J

    2012-01-01

    The book reveals the changing dynamics of the helium industry on both the supply-side and the demand-side. The helium industry has a long-term future and this important gas will have a role to play for many decades to come. Major new users of helium are expected to enter the market, especially in nuclear energy (both fission and fusion). Prices and volumes supplied and expected to rise and this will prompt greater efforts towards the development of new helium sources and helium conservation and recycling.

  14. Review of Membranes for Helium Separation and Purification

    Science.gov (United States)

    Scholes, Colin A.; Ghosh, Ujjal K.

    2017-01-01

    Membrane gas separation has potential for the recovery and purification of helium, because the majority of membranes have selectivity for helium. This review reports on the current state of the research and patent literature for membranes undertaking helium separation. This includes direct recovery from natural gas, as an ancillary stage in natural gas processing, as well as niche applications where helium recycling has potential. A review of the available polymeric and inorganic membranes for helium separation is provided. Commercial gas separation membranes in comparable gas industries are discussed in terms of their potential in helium separation. Also presented are the various membrane process designs patented for the recovery and purification of helium from various sources, as these demonstrate that it is viable to separate helium through currently available polymeric membranes. This review places a particular focus on those processes where membranes are combined in series with another separation technology, commonly pressure swing adsorption. These combined processes have the most potential for membranes to produce a high purity helium product. The review demonstrates that membrane gas separation is technically feasible for helium recovery and purification, though membranes are currently only applied in niche applications focused on reusing helium rather than separation from natural sources. PMID:28218644

  15. Planung von CLIL-Unterricht

    Directory of Open Access Journals (Sweden)

    Josef Leisen

    2015-10-01

    Full Text Available Der Beitrag formuliert die Sprachlernbedingungen und die Leitlinien des Sprachlernens im Fach und nennt Merkmale des guten integrierten Fach- und Sprachlehrens. Ausgehend von den Sprachproblemen, die sich im CLIL-Unterricht auftun, wird der sprachsensible CLIL-Unterricht definiert, und es werden Anregungen zur Gestaltung gegeben. Sprachliche Standardsituationen umfassen die kommunikativen Situationen im CLIL-Unterricht, die beim fachlichen Lernen auftreten und von der CLIL-Lehrkraft professionell bewältigt werden müssen. Im Beitrag wird ein Lehr-Lern-Modell ausführlich beschrieben und erläutert. Die Steuerungen von Sprachlernprozessen im CLIL durch Aufgabenstellungen, Methoden-Werkzeuge, Moderation und Diagnose/Rückmeldung werden ausführlich beschrieben. Die Planung einer Lernlinie in sechs Schritten wird dargestellt und erläutert. Planungsraster für CLIL-Lernlinien schließen den Beitrag ab. The article sets out the conditions for language learning in general as well as guiding principles of language learning in the subject and puts forward criteria for successfully integrated content and language learning. Based on typical language problems arising in CLIL-classrooms, the language-sensitive CLIL-classroom is defined and organisational suggestions are given. Linguistic standard situations comprise the communicative situations in the CLIL-classroom which are encountered in subject-related learning and have to be professionally mastered by the CLIL-teacher. The article extensively describes and explains a model of teaching and learning that can be used for the CLIL-classroom. It gives detailed information on managing language learning processes in CLIL by means of tasks, resources and methods as well as discourse facilitation, evaluation and feedback. In addition, a six-step lesson unit is outlined and explained. The article concludes by giving a planning matrix for CLIL lesson units.

  16. Homoepitaxie von ZnO

    OpenAIRE

    Neumann, Christian

    2006-01-01

    Die Arbeit beschäftigt sich mit der homoepitaktischen Darstellung von ZnO-Dünnschichten. Die Arbeit beginnt mit einer theoretischen Betrachtung des Materialsystems und den daraus für eine erfolgreiche Epitaxie zu ziehenden Schlüssen. Es wurde eine Temperbehandlung zur Oberflächenmodifikation kommerziell erhältlicher ZnO-Einkristallsubstrate erarbeitet, die für eine erfolgreiche Epitaxie erforderlich ist. Im Anschluß daran wird die Entwicklung eines CVD-Prozesses mit metallischer Zin...

  17. Riidaja mõis / Elma von Stryk

    Index Scriptorium Estoniae

    Stryk, Elma von

    2006-01-01

    renoveerimise ootel barokne puithäärber (1762), kompleksi ümbritsev kivimüür, maakividest hobusetall, pargivaade, punastest tellistest neogooti stiilis kabel (1864), mis taastati von Strykkide perekonna toel. 11 ill.; fotod: Raivo Tasso; kabelis on Elma von Stryki loodud Kristust kujutav altarimaal

  18. Sorten- und Nachbaueignung von Hafer und Weizen

    OpenAIRE

    Spieß, Hartmut

    2000-01-01

    Der Beitrag gibt anhand alter und neuer Sortenvergleiche von Hafer und Weizen Einblick in die Problematik ökologischer Züchtung und Sortenwahl. Dabei geht es neben spezifischen Sorteneigenschaften um die Ausgewogenheit von Ertrags- und Qualitätsbildung im Verhältnis zur Pflanzengesundheit.

  19. Survivor from asphyxiation due to helium inhalation

    Directory of Open Access Journals (Sweden)

    Massimiliano Etteri

    2016-06-01

    Full Text Available In this rare case report we describe a 27- year-old white man survived to suicide by asphyxiation using the so-called suicide bag (or exit bag filled with helium supplied through a plastic tube. He had no previous psychiatric or organic illnesses. At the time of presentation to our Emergency Department he was awake and reported severe dyspnea with a clinical pattern of acute respiratory failure. Imaging studies showed pulmonary edema and the patient was treated with non-invasive ventilation in Intensive Care Unit. After 15 days the patient was discharged from hospital in optimal conditions. These rare cases of survivor might suggest the possible causes of death from inhaling helium.

  20. Detection of charged particles in superfluid helium

    Energy Technology Data Exchange (ETDEWEB)

    Bandler, Simon R. [Brown Univ., Providence, RI (United States)

    1994-12-01

    This thesis is concerned with the use of a large superfluid helium detector for the detection of solar neutrinos. A small-scale prototype of this type of detector has been constructed and tested. In this thesis the author discussed in detail the design of the apparatus, the experiments which have been carried out, and what has been learned about the important physical processes involved in this type of detector. These processes include the anisotropic generation of phonons and rotons by the recoiling particle, the propagation of the phonons and rotons in the liquid, the evaporation process at the liquid surface, and the adsorption of the helium atoms onto the wafers. In addition he discusses the generation and detection of fluorescent photons from recoiling particles. The implications of these results to the design of a full-scale detector of neutrinos are discussed.

  1. THERMAL OSCILLATIONS IN LIQUID HELIUM TARGETS.

    Energy Technology Data Exchange (ETDEWEB)

    WANG,L.; JIA,L.X.

    2001-07-16

    A liquid helium target for the high-energy physics was built and installed in the proton beam line at the Alternate Gradient Synchrotron of Brookhaven National Laboratory in 2001. The target flask has a liquid volume of 8.25 liters and is made of thin Mylar film. A G-M/J-T cryocooler of five-watts at 4.2K was used to produce liquid helium and refrigerate the target. A thermosyphon circuit for the target was connected to the J-T circuit by a liquid/gas separator. Because of the large heat load to the target and its long transfer lines, thermal oscillations were observed during the system tests. To eliminate the oscillation, a series of tests and analyses were carried out. This paper describes the phenomena and provides the understanding of the thermal oscillations in the target system.

  2. Tritium decay helium-3 effects in tungsten

    Directory of Open Access Journals (Sweden)

    M. Shimada

    2017-08-01

    Full Text Available Tritium (T implanted by plasmas diffuses into bulk material, especially rapidly at elevated temperatures, and becomes trapped in neutron radiation-induced defects in materials that act as trapping sites for the tritium. The trapped tritium atoms will decay to produce helium-3 (3He atoms at a half-life of 12.3 years. 3He has a large cross section for absorbing thermal neutrons, which after absorbing a neutron produces hydrogen (H and tritium ions with a combined kinetic energy of 0.76 MeV through the 3He(n,HT nuclear reaction. The purpose of this paper is to quantify the 3He produced in tungsten by tritium decay compared to the neutron-induced helium-4 (4He produced in tungsten. This is important given the fact that helium in materials not only creates microstructural damage in the bulk of the material but alters surface morphology of the material effecting plasma-surface interaction process (e.g. material evolution, erosion and tritium behavior of plasma-facing component materials. Effects of tritium decay 3He in tungsten are investigated here with a simple model that predicts quantity of 3He produced in a fusion DEMO FW based on a neutron energy spectrum found in literature. This study reveals that: (1 helium-3 concentration was equilibrated to ∼6% of initial/trapped tritium concentration, (2 tritium concentration remained approximately constant (94% of initial tritium concentration, and (3 displacement damage from 3He(n,HT nuclear reaction became >1 dpa/year in DEMO FW.

  3. Laser-Induced Breakdown in Liquid Helium

    Science.gov (United States)

    Sirisky, S.; Yang, Y.; Wei, W.; Maris, H. J.

    2017-10-01

    We report on experiments in which focused laser light is used to induce optical breakdown in liquid helium-4. The threshold intensity has been measured over the temperature range from 1.1 to 2.8 K with light of wavelength 1064 nm. In addition to the measurement of the threshold, we have performed experiments to study how the breakdown from one pulse modifies the probability that a subsequent pulse will result in breakdown.

  4. Combined cold compressor/ejector helium refrigerator

    Science.gov (United States)

    Brown, Donald P.

    1985-01-01

    A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

  5. Correlation of Helium Solubility in Liquid Nitrogen

    Science.gov (United States)

    VanDresar, Neil T.; Zimmerli, Gregory A.

    2012-01-01

    A correlation has been developed for the equilibrium mole fraction of soluble gaseous helium in liquid nitrogen as a function of temperature and pressure. Experimental solubility data was compiled and provided by National Institute of Standards and Technology (NIST). Data from six sources was used to develop a correlation within the range of 0.5 to 9.9 MPa and 72.0 to 119.6 K. The relative standard deviation of the correlation is 6.9 percent.

  6. Helium refrigeration system for hydrogen liquefaction applications

    Science.gov (United States)

    Nair, J. Kumar, Sr.; Menon, RS; Goyal, M.; Ansari, NA; Chakravarty, A.; Joemon, V.

    2017-02-01

    Liquid hydrogen around 20 K is used as cold moderator for generating “cold neutron beam” in nuclear research reactors. A cryogenic helium refrigeration system is the core upon which such hydrogen liquefaction applications are built. A thermodynamic process based on reversed Brayton cycle with two stage expansion using high speed cryogenic turboexpanders (TEX) along with a pair of compact high effectiveness process heat exchangers (HX), is well suited for such applications. An existing helium refrigeration system, which had earlier demonstrated a refrigeration capacity of 470 W at around 20 K, is modified based on past operational experiences and newer application requirements. Modifications include addition of a new heat exchanger to simulate cryogenic process load and two other heat exchangers for controlling the temperatures of helium streams leading out to the application system. To incorporate these changes, cryogenic piping inside the cold box is suitably modified. This paper presents process simulation, sizing of new heat exchangers as well as fabrication aspects of the modified cryogenic process piping.

  7. Optical traps for ultracold metastable helium atoms

    Energy Technology Data Exchange (ETDEWEB)

    Simonet, Juliette [LKB ENS, Paris (France)

    2009-07-01

    One of the main characteristics of metastable helium atoms is their high internal energy (20 eV). This energy can be released when a metastable atom hits a surface, ejecting one electron. Therefore, using a Channeltron Electron Multiplier (CEM), one can detect atoms with a time resolution of up to 5 ns. However, this high internal energy raises the problem of inelastic Penning ionizations, following: He{sup *}+He{sup *}{yields}He+He{sup +}+e{sup *}. This process has a rate of the order of 10 x 10 cm{sup 3} cot s{sup -}1 but is reduced by four orders of magnitude if the atoms are spin polarized due to total spin conservation. We report on the progress of the set up of a dipole trap for ultracold metastable helium using a red detuned fiber laser at 1560 nm. One of the aims of this optical trap is to release the constraint on the magnetic field value. We plan to measure the magnetic field dependance of inelastic collision rates for temperatures smaller than 10 {mu}K. In a spin polarized gas of helium, the spin-spin interaction produces spin relaxation and relaxation induced Penning ionization if the polarization condition is no longer maintained. We also present the development of a optical lattices in 1D and later in 3D. We intend to monitor the Penning ionization rate in order to follow the real-time dynamics of the superfluid-Mott insulator quantum phase transition.

  8. Laser Spectroscopy of Antiprotonic Helium Atoms

    CERN Multimedia

    2002-01-01

    %PS205 %title\\\\ \\\\Following the discovery of metastable antiprotonic helium atoms ($\\overline{p}He^{+} $) at KEK in 1991, systematic studies of their properties were made at LEAR from 1991 to 1996. In the first two years the lifetime of $\\overline{p}He^{+}$ in liquid and gaseous helium at various temperatures and pressures was measured and the effect of foreign gases on the lifetime of these atoms was investigated. Effects were also discovered which gave the antiproton a 14\\% longer lifetime in $^4$He than in $^3$He, and resulted in important differences in the shape of the annihilation time spectra in the two isotopes.\\\\ \\\\Since 1993 laser spectroscopy of the metastable $\\overline{p}He^{+}$ atoms became the main focus of PS205. Transitions were stimulated between metastable and non-metastable states of the $\\overline{p}He^{+}$ atom by firing a pulsed dye laser beam into the helium target every time an identified metastable atom was present (Figure 1). If the laser frequency matched the transition energy, the...

  9. In situ controlled modification of the helium density in single helium-filled nanobubbles

    Energy Technology Data Exchange (ETDEWEB)

    David, M.-L., E-mail: marie-laure.david@univ-poitiers.fr; Pailloux, F. [Institut Pprime, UPR 3346 CNRS-Université de Poitiers, SP2MI, 86962 Futuroscope-Chasseneuil cedex (France); Canadian Centre for Electron Microscopy, Mc Master University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Alix, K.; Mauchamp, V.; Pizzagalli, L. [Institut Pprime, UPR 3346 CNRS-Université de Poitiers, SP2MI, 86962 Futuroscope-Chasseneuil cedex (France); Couillard, M.; Botton, G. A. [Canadian Centre for Electron Microscopy, Mc Master University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada); Department of Materials Science and Engineering, Mc Master University, 1280 Main Street West, Hamilton, Ontario L8S 4M1 (Canada)

    2014-03-28

    We demonstrate that the helium density and corresponding pressure can be modified in single nano-scale bubbles embedded in semiconductors by using the electron beam of a scanning transmission electron microscope as a multifunctional probe: the measurement probe for imaging and chemical analysis and the irradiation source to modify concomitantly the pressure in a controllable way by fine tuning of the electron beam parameters. The control of the detrapping rate is achieved by varying the experimental conditions. The underlying physical mechanisms are discussed; our experimental observations suggest that the helium detrapping from bubbles could be interpreted in terms of direct ballistic collisions, leading to the ejection of the helium atoms from the bubble.

  10. Retention of hydrogen isotopes and helium in nickel

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Mitsumasa; Sato, Rikiya; Yamaguchi, Kenji; Yamawaki, Michio [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

    1996-10-01

    In the present study, a thin foil of nickel was irradiated by H{sub 2}{sup +}, D{sub 2}{sup +} and He{sup +} to a fluence of 1.2-6.0x10{sup 20}/m{sup 2} using the TBTS (Tritium Beam Test System) apparatus. The thermal desorption spectroscopy (TDS) technique was employed to evaluate the total amount of retained hydrogen isotope and helium atoms in nickel. In the spectra, two peaks appeared at 440-585K and 720-735K for helium. Hydrogen isotopes irradiation after helium preirradiation were found to enhance the helium release and to decrease the peak temperatures. Helium irradiation after hydrogen isotopes preirradiation were found to enhance the helium release, but the peak temperature showed little difference from that without preirradiation. (author)

  11. Capacity enhancement of indigenous expansion engine based helium liquefier

    Science.gov (United States)

    Doohan, R. S.; Kush, P. K.; Maheshwari, G.

    2017-02-01

    Development of technology and understanding for large capacity helium refrigeration and liquefaction at helium temperature is indispensable for coming-up projects. A new version of helium liquefier designed and built to provide approximately 35 liters of liquid helium per hour. The refrigeration capacity of this reciprocating type expansion engine machine has been increased from its predecessor version with continuous improvement and deficiency debugging. The helium liquefier has been built using components by local industries including cryogenic Aluminum plate fin heat exchangers. Two compressors with nearly identical capacity have been deployed for the operation of system. Together they consume about 110 kW of electric power. The system employs liquid Nitrogen precooling to enhance liquid Helium yield. This paper describes details of the cryogenic expander design improvements, reconfiguration of heat exchangers, performance simulation and their experimental validation.

  12. Dynamic imaging of the nasal cavity and the paranasal sinuses with polarized {sup 3}helium MRI; Dynamische Bildgebung der Nasenhaupthoehle und der Nasennebenhoehlen im MR mittels polarisiertem {sup 3}Helium

    Energy Technology Data Exchange (ETDEWEB)

    Hanke, A.; Gast, K.; Viallon, M.; Thelen, M.; Kauczor, H.U. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Markstaller, K. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Klinik fuer Anaesthesiologie, Univ. Mainz (Germany); Eberle, B. [Klinik fuer Anaesthesiologie, Univ. Mainz (Germany)

    2001-12-01

    left frontal sinus and 7.8 for the right side. (orig.) [German] Ziel: Im Rahmen dieser Studie sollte untersucht werden, ob die Inhalation von polarisiertem {sup 3}Helium und Bildgebung mittels MRT zu einer Anreicherung des Edelgases in der Nasenhaupthoehle und den Nasennebenhoehlen fuehrt. Ziel war es, durch die {sup 3}Helium-MRT eine Darstellung der Nasenhaupthoehle und der Nasennebenhoehlen zu ermoeglichen und Verteilungsstoerungen der Ventilation der Nasennebenhoehlen zu beurteilen. Probanden und Methoden: Untersucht wurden drei Probanden. {sup 3}Helium-Gas wurde durch optisches Pumpen auf einen Polarisationsgrad von 40 - 50% polarisiert. Ueber ein Glasroehrchen wurden 300 ml 100% {sup 3}Helium in die linke Nasenoeffnung bei verschlossener kontralateraler Nasenoeffnung und anschliessendem zweimaligen Valsalva Manoever appliziert. Durch die Verwendung einer im Rahmen der Lungenforschung erprobten computerunterstuetzten Applikationseinheit konnte ein vorwaehlbares Gasvolumen bei korrekter Abgabe des {sup 3}Heliums waehrend der Inspiration gewaehrleistet werden. Die Aufnahmen wurden an einem 1,5-T-MRT-System angefertigt. Die Messungen erfolgten mit einer ultraschnellen zweidimensionalen FLASH-Sequenz (TR = 2 ms, TE = 0,7 ms, FA < 2, Matrix 75 x 128, FOV = 500 mm) mit einer zeitlichen Aufloesung von 130 ms. Ergebnisse: Der linke Sinus maxillaris zeigt sich nach Gabe des {sup 3}He-Gases signalintensiver als der rechte. Die mittlere Signalintensitaet war mit 526{+-}86 links groesser als rechts (336{+-}102). Der Sinus frontalis und der Sinus ethmoidalis links und rechts zeigten nur eine Aufnahme des {sup 3}Helium-Gases nach zweimaligem Valsalva-Manoever. Durch die niedrige Signalintensitaet der Ethmoidal- und Frontalzellen kamen diese nur flau zur Darstellung. Das Signal/Rauschverhaeltnis betrug fuer den Sinus maxillaris links 14,1, rechts 8,9, den Sinus ethmoidalis links 6,3, rechts 5,8 und den Sinus frontalis links 6,6 und rechts 7,8. (orig.)

  13. Helium induces preconditioning in human endothelium in vivo.

    Science.gov (United States)

    Smit, Kirsten F; Oei, Gezina T M L; Brevoord, Daniel; Stroes, Erik S; Nieuwland, Rienk; Schlack, Wolfgang S; Hollmann, Markus W; Weber, Nina C; Preckel, Benedikt

    2013-01-01

    Helium protects myocardium by inducing preconditioning in animals. We investigated whether human endothelium is preconditioned by helium inhalation in vivo. Forearm ischemia-reperfusion (I/R) in healthy volunteers (each group n = 10) was performed by inflating a blood pressure cuff for 20 min. Endothelium-dependent and endothelium-independent responses were measured after cumulative dose-response infusion of acetylcholine and sodium nitroprusside, respectively, at baseline and after 15 min of reperfusion using strain-gauge, venous occlusion plethysmography. Helium preconditioning was applied by inhalation of helium (79% helium, 21% oxygen) either 15 min (helium early preconditioning [He-EPC]) or 24 h before I/R (helium late preconditioning). Additional measurements of He-EPC were done after blockade of endothelial nitric oxide synthase. Plasma levels of cytokines, adhesion molecules, and cell-derived microparticles were determined. Forearm I/R attenuated endothelium-dependent vasodilation (acetylcholine) with unaltered endothelium-independent response (sodium nitroprusside). Both He-EPC and helium late preconditioning attenuated I/R-induced endothelial dysfunction (max increase in forearm blood flow in response to acetylcholine after I/R was 180 ± 24% [mean ± SEM] without preconditioning, 573 ± 140% after He-EPC, and 290 ± 32% after helium late preconditioning). Protection of helium was comparable to ischemic preconditioning (max forearm blood flow 436 ± 38%) and was not abolished after endothelial nitric oxide synthase blockade. He-EPC did not affect plasma levels of cytokines, adhesion molecules, or microparticles. Helium is a nonanesthetic, nontoxic gas without hemodynamic side effects, which induces early and late preconditioning of human endothelium in vivo. Further studies have to investigate whether helium may be an instrument to induce endothelial preconditioning in patients with cardiovascular risk factors.

  14. Jacob Stael von Holstein ja palladionism eesti arhitektuuris / Ants Hein

    Index Scriptorium Estoniae

    Hein, Ants, 1952-

    2005-01-01

    Sõjaväeinsenerist ja arhitektist Jacob Stael von Holsteinist (1628, Pärnu-1679), tema kavandatud hoonetest ja rollist 17. sajandi II poole arhitektuuris. Fabian von Ferseni Toompeal Lossiplatsil asunud elamust (lammutati 1894) ja Maardu mõisahoonest, Hans von Ferseni Mäo mõisahoonest Järvamaal, Otto Wilhelm von Ferseni majast Toompeal, Axel von Roseni majast Tallinnas Pikk t. 28 (1670-74), Otto Reinhold von Taube majast Tartus (hävinud), J. S. von Holsteini enda hoonetest: majast Tallinnas Toompea 1, Anija mõisahoonest, elamust Riias jm. Bibliograafia lk. 452

  15. Asteroseismic estimate of helium abundance of 16 Cyg A, B

    Directory of Open Access Journals (Sweden)

    Verma Kuldeep

    2015-01-01

    Full Text Available The helium ionization zone in a star leaves a characteristic signature on its oscillation frequencies, which can be used to estimate the helium content in the envelope of the star. We use the oscillation frequencies of 16 Cyg A and B, obtained using 2.5 years of Kepler data, to estimate the envelope helium abundance of these stars. We find the envelope helium abundance to lie in the range 0.231–0.251 for 16 Cyg A and 0.218–0.266 for 16 Cyg B.

  16. Helium vs. Proton Induced Displacement Damage in Electronic Materials

    Science.gov (United States)

    Ringo, Sawnese; Barghouty, A. F.

    2010-01-01

    In this project, the specific effects of displacement damage due to the passage of protons and helium nuclei on some typical electronic materials will be evaluated and contrasted. As the electronic material absorbs the energetic proton and helium momentum, degradation of performance occurs, eventually leading to overall failure. Helium nuclei traveling at the same speed as protons are expected to impart more to the material displacement damage; due to the larger mass, and thus momentum, of helium nuclei compared to protons. Damage due to displacement of atoms in their crystalline structure can change the physical properties and hence performance of the electronic materials.

  17. Neues über das Tertiär von Java und die mesozoischen Schichten von West-Borneo

    NARCIS (Netherlands)

    Martin, K.

    1888-01-01

    Die Monographie, welche unter dem Titel Die Fossilien von Java herausgegeben wird ¹), ist so weit fortgeschritten, dass sich aus den in ihr beschriebenen Gastropoden bereits eine Anzahl von Schlussfolgerungen ableiten lässt, welche für die in Bearbeitung begriffene, geologische Karte von Java von

  18. Indikatorenbasierte Bewertung von Entwurfsentscheidungen auf Systemebene

    Science.gov (United States)

    Freier, M.; Wenzler, A.; Mayer, T.; Gerlach, J.; Rosenstiel, W.

    2013-07-01

    Bei dem Entwurf von anwendungsspezifischen integrierten Schaltungen muss ein Entwickler zusätzliche Funktionen integrieren und die zunehmende Komplexität bewältigen. Für die Reduzierung der Kosten bleibt weiterhin die Verkürzung der benötigten Entwicklungszeit ein Ziel. Ein entscheidender Faktor dabei ist die zuverlässige Absicherung von Entwurfsentscheidungen in einer frühen Entwurfsphase. In der vorliegenden Arbeit wird eine Methode vorgestellt, die eine Bewertung von Entwurfsentscheidungen bei Systemmodellen mittels automatisch ermittelter Indikatoren ermöglichen soll. Die Systemmodelle können mit der Entwurfsumgebung MATLAB/Simulink oder in SystemC beschrieben sein.

  19. The Digital Von Fahrenheid Pyramid

    Science.gov (United States)

    Bura, M.; Janowski, J.; Wężyk, P.; Zięba, K.

    2017-08-01

    3D Scanners Lab from Digital Humanities Laboratory at the University of Warsaw initiated the scientific project, the purpose of which was to call attention to systematically penetrated and devastated pyramid-shaped tomb from the XVIII/XIX century, of family von Fahrenheid in Rapa in Banie Mazurskie commune (NE Poland). By conducting a series of non-invasive studies, such as 3D inventory using terrestrial laser scanning (TLS), thermal imaging, georadar measurements (around and inside the tomb) and anthropological research of mummified remains as well - the complete dataset was collected. Through the integration of terrestrial (TLS) and airborne laser scanning (ALS) authors managed to analyse the surroundings of Fahrenheid pyriamid and influence of some objects (like trees) on the condition and visibility of the Pyramids in the landscape.

  20. Khazanah: Friedrich Karl von Savigny

    Directory of Open Access Journals (Sweden)

    Atip Latipulhayat

    2015-04-01

    Full Text Available Friedrich Karl von Savigny (1779-1861 adalah ahli hukum Jerman yang juga dianggap sebagai salah satu Bapak hukum Jerman. Savigny adalah tokoh mazhab sejarah (historical school jurisprudence yang dikembangkannya pada paruh pertama abad ke 19. Dia juga dianggap sebagai pelopor kajian mengenai relasi antara perkembangan hukum dan sosial. Sebagai seorang pemikir hukum yang senantiasa kreatif dalam membuat terobosan-terobosan (trail-blazing legal scientist, Savigny memberikan kontribusi penting dalam perkembangan ilmu hukum dan bahkan terhadap ilmu sosial. Dari sekian banyak kontribusinya antara lain teorinya mengenai kontinuitas antara institusi hukum saat ini dengan institusi hukum masa lalu, meletakkan fondasi bagi kajian sosiologi hukum, dan menegaskan mengenai urgensi metode historis dalam kajian hukum.

  1. Evaluierung und Entwicklung von Methoden zur automatisierten Erfassung von Waldstrukturen aus Daten flugzeuggetragener Fernerkundungssensoren

    OpenAIRE

    Heurich, Marco

    2006-01-01

    Auf Grund der rasanten technologischen Entwicklung im Bereich der Sensorik sowie der Computerhard- und -software haben sich in den letzten Jahren neue Perspektiven zur Erforschung von Wäldern ergeben. Im Rahmen dieser durch die High-Tech-Offensive Bayern geförderten Arbeit wurde deshalb untersucht, inwieweit sich der Einsatz neuer Technologien zur automatisierten Erfassung von Waldstrukturen eignet. Als Voraussetzung dafür wurde zunächst ein Referenzgebiet zum Testen von Fernerkundungssensore...

  2. Spezifische Bindung von Aluminium und Eisen an den kationenselektiven Kanal MppA von Microthrix parvicella

    OpenAIRE

    Knaf, Tobias

    2013-01-01

    Schwermetallsalze wie beispielsweise Aluminium- oder Eisensalze werden in der Abwasserbehandlung zur Prävention und Bekämpfung von Blähschlamm, Schwimmschlamm und Schaumbildung verwendet. Dadurch kann eine Verbesserung der Schlammabsetzeigenschaften im Nachklärbecken erreicht werden. Übermäßiges Wachstum des grampositiven Bakteriums Microthrix parvicella gilt dabei als Hauptursache von Schlammabsetzproblemen und kann ebenfalls durch die Dosierung von schwermetallhaltigen Flockungs- und Fällun...

  3. Das Tumorsuppressorprotein p53 - Rolle bei der Induktion von Apoptose und bei der Replikation von Adenoviren

    OpenAIRE

    Koch, Philipp

    2003-01-01

    Das Tumorsuppressorgen p53 gehört zu den zentralen Steuereinheiten von Proliferation und Wachstum in der Zelle. Mutationen und funktioneller Verlust bei diesem Protein ist eng mit der Entstehung maligner Tumoren assoziiert. So kann man in über 50% aller soliden Tumoren Mutationen von p53 nachweisen. Es vermittelt seine Funktion hauptsächlich durch transkriptionelle Aktivierung p53-responsiver Gene. Folge der Aktivierung von p53 is...

  4. Helium-3 and Helium-4 acceleration by high power laser pulses for hadron therapy

    CERN Document Server

    Bulanov, S S; Schroeder, C B; Leemans, W P; Bulanov, S V; Margarone, D; Korn, G; Haberer, T

    2015-01-01

    The laser driven acceleration of ions is considered a promising candidate for an ion source for hadron therapy of oncological diseases. Though proton and carbon ion sources are conventionally used for therapy, other light ions can also be utilized. Whereas carbon ions require 400 MeV per nucleon to reach the same penetration depth as 250 MeV protons, helium ions require only 250 MeV per nucleon, which is the lowest energy per nucleon among the light ions. This fact along with the larger biological damage to cancer cells achieved by helium ions, than that by protons, makes this species an interesting candidate for the laser driven ion source. Two mechanisms (Magnetic Vortex Acceleration and hole-boring Radiation Pressure Acceleration) of PW-class laser driven ion acceleration from liquid and gaseous helium targets are studied with the goal of producing 250 MeV per nucleon helium ion beams that meet the hadron therapy requirements. We show that He3 ions, having almost the same penetration depth as He4 with the ...

  5. The antimicrobial effects of helium and helium-air plasma on Staphylococcus aureus and Clostridium difficile.

    Science.gov (United States)

    Galvin, S; Cahill, O; O'Connor, N; Cafolla, A A; Daniels, S; Humphreys, H

    2013-08-01

    Healthcare-associated infections (HCAI) affect 5-10% of acute hospital admissions. Environmental decontamination is an important component of all strategies to prevent HCAI as many bacterial causes survive and persist in the environment, which serve as ongoing reservoirs of infection. Current approaches such as cleaning with detergents and the use of chemical disinfectant are suboptimal. We assessed the efficacy of helium and helium-air plasma in killing Staphylococcus aureus and Clostridium difficile on a glass surface and studied the impact on bacterial cells using atomic force microscopy (AFM). Both plasma types exhibited bactericidal effects on Staph. aureus (log3·6 - >log7), with increased activity against methicillin-resistant strains, but had a negligible effect on Cl. difficile spores (helium and helium-air plasma as a decontaminant and demonstrated a significant reduction in bacterial counts of Staphylococcus aureus on a glass surface. Atomic force microscopy morphologically confirmed the impact on bacterial cells. This approach warrants further study as an alternative to current options for hospital hygiene. © 2013 The Society for Applied Microbiology.

  6. Helium-3 and helium-4 acceleration by high power laser pulses for hadron therapy

    Directory of Open Access Journals (Sweden)

    S. S. Bulanov

    2015-06-01

    Full Text Available The laser driven acceleration of ions is considered a promising candidate for an ion source for hadron therapy of oncological diseases. Though proton and carbon ion sources are conventionally used for therapy, other light ions can also be utilized. Whereas carbon ions require 400 MeV per nucleon to reach the same penetration depth as 250 MeV protons, helium ions require only 250 MeV per nucleon, which is the lowest energy per nucleon among the light ions (heavier than protons. This fact along with the larger biological damage to cancer cells achieved by helium ions, than that by protons, makes this species an interesting candidate for the laser driven ion source. Two mechanisms (magnetic vortex acceleration and hole-boring radiation pressure acceleration of PW-class laser driven ion acceleration from liquid and gaseous helium targets are studied with the goal of producing 250 MeV per nucleon helium ion beams that meet the hadron therapy requirements. We show that He^{3} ions, having almost the same penetration depth as He^{4} with the same energy per nucleon, require less laser power to be accelerated to the required energy for the hadron therapy.

  7. Helium passage through homogeneous ultrafine hydrocarbon layers

    Directory of Open Access Journals (Sweden)

    Bubenchikov Michael A.

    2017-01-01

    Full Text Available The present paper deals with the problem of helium atoms and methane molecules moving through a hydrocarbon layer of evenly distributed energy sources. A computational technique for integrating the Schrödinger equation based on formulation of two fundamental numerical solutions to the problem of waves passing through a barrier is suggested. A linear combination of these solutions defines the required wave function, while cross-linking with asymptotic boundary conditions allows determining the coefficients of transmission and particle reflection from the potential layer barrier.

  8. Linde standard helium plant of medium capacity

    Energy Technology Data Exchange (ETDEWEB)

    Patzelt, A.; Stephan, A.; Nienaber, U.; Weber, J.

    1991-01-01

    The unit is designed to deliver up to 70 l/h of liquid helium (LHe) without precooling by liquid nitrogen (LN{sub 2}), up to 105 l/h with LN{sub 2} precooling, or up to 210 W cryo-refrigeration output at 4.5 K. Its principal components are an oil-flooded screw compressor, gas-bearing expansion turbines, vacuum-brazed aluminium plate-fin heat exchangers, an automatic feed gas purifier, and a process control system. Descriptions are given of the process layout, the main system components, and operation of the unit. (orig.).

  9. Heuristic theory of positron-helium scattering.

    Science.gov (United States)

    Drachman, R. J.

    1971-01-01

    An error in a previous modified adiabatic approximation (Drachman, 1966), due to a lack of generality in the form of the short-range correlation part of the wave function for L greater than zero, is corrected heuristically by allowing the monopole suppression parameter to depend on L. An L-dependent local potential is constructed to fit the well-known positron-hydrogen s, p, and d wave phase shifts below the rearrangement threshold. The same form of potential yields a positron-helium cross-section in agreement with a recent experimental measurement near threshold.

  10. Production of thorium-229 using helium nuclei

    Science.gov (United States)

    Mirzadeh, Saed [Knoxville, TN; Garland, Marc Alan [Knoxville, TN

    2010-12-14

    A method for producing .sup.229Th includes the steps of providing .sup.226Ra as a target material, and bombarding the target material with alpha particles, helium-3, or neutrons to form .sup.229Th. When neutrons are used, the neutrons preferably include an epithermal neutron flux of at least 1.times.10.sup.13 n s.sup.-1cm.sup.-2. .sup.228Ra can also be bombarded with thermal and/or energetic neutrons to result in a neutron capture reaction to form .sup.229Th. Using .sup.230Th as a target material, .sup.229Th can be formed using neutron, gamma ray, proton or deuteron bombardment.

  11. Quantum entanglement in helium-like ions

    Science.gov (United States)

    Lin, Y.-C.; Ho, Y. K.

    2012-06-01

    Recently, there have been considerable interests to investigate quantum entanglement in two-electron atoms [1-3]. Here we investigate quantum entanglement for the ground and excited states of helium-like ions using correlated wave functions, concentrating on the particle-particle entanglement coming from the continuous spatial degrees of freedom. We use the two-electron wave functions constructed by employing B-spline basis to calculate the linear entropy of the reduced density matrix L=1-TrA(ρA^2 ) as a measure of the spatial entanglement. HereρA=TrB(| >AB ABDehesa et. al., J. Phys. B 45, 015504 (2012)

  12. Variable helium diffusion characteristics in fluorite

    Science.gov (United States)

    Wolff, R.; Dunkl, I.; Kempe, U.; Stockli, D.; Wiedenbeck, M.; von Eynatten, H.

    2016-09-01

    Precise analysis of the diffusion characteristics of helium in fluorite is crucial for establishing the new fluorite (U-Th-Sm)/He thermochronometer (FHe), which potentially provides a powerful tool for dating ore deposits unsuitable for the application of conventional geochronometers. Incremental helium outgassing experiments performed on fluorites derived from a spectrum of geological environments suggest a thermally activated volume diffusion mechanism. The diffusion behaviour is highly variable and the parameters range between log D0/a2 = 0.30 ± 0.27-7.27 ± 0.46 s-1 and Ea = 96 ± 3.5-182 ± 3.8 kJ/mol. Despite the fact that the CaF2 content of natural fluorites in most cases exceeds 99 weight percent, the closure temperature (Tc) of the fluorite (U-Th-Sm)/He thermochronometer as calculated from these diffusion parameters varies between 46 ± 14 °C and 169 ± 9 °C, considering a 125 μm fragment size. Here we establish that minor substitutions of calcium by rare earth elements and yttrium (REE + Y) and related charge compensation by sodium, fluorine, oxygen and/or vacancies in the fluorite crystal lattice have a significant impact on the diffusivity of helium in the mineral. With increasing REE + Y concentrations F vacancies are reduced and key diffusion pathways are narrowed. Consequently, a higher closure temperature is to be expected. An empirical case study confirms this variability: two fluorite samples from the same deposit (Horni Krupka, Czech Republic) with ca. 170 °C and ca. 43 °C Tc yield highly different (U-Th-Sm)/He ages of 290 ± 10 Ma and 79 ± 10 Ma, respectively. Accordingly, the fluorite sample with the high Tc could have quantitatively retained helium since the formation of the fluorite-bearing ores in the Permian, despite subsequent Mesozoic burial and associated regional hydrothermal heating. In contrast, the fluorite with the low Tc yields a Late Cretaceous age close to the apatite fission track (AFT) and apatite (U-Th)/He ages (AHe

  13. Temperature rise in superfluid helium pumps

    Science.gov (United States)

    Kittel, Peter

    1988-01-01

    The temperature rise of a fountain effect pump (FEP) and of a centrifugal pump (CP) are compared. Calculations and estimates presented here show that under the operating conditions expected during the resupply of superfluid helium in space, a centrifugal pump will produce a smaller temperature rise than will a fountain effect pump. The temperature rise for the FEP is calculated assuming an ideal pump, while the temperature rise of the CP is estimated from the measured performance of a prototype pump. As a result of this smaller temperature rise and of the different operating characteristics of the two types of pumps, transfers will be more effective using a centrifugal pump.

  14. How Is von Willebrand Disease Treated?

    Science.gov (United States)

    ... the condition. For example, the school nurse, teacher, daycare provider, coach, or any leader of afterschool activities ... MedlinePlus) Von Willebrand Disease (MedlinePlus) Building 31 31 Center Drive Bethesda, MD 20892 Learn more about getting ...

  15. How Is von Willebrand Disease Diagnosed?

    Science.gov (United States)

    ... the condition. For example, the school nurse, teacher, daycare provider, coach, or any leader of afterschool activities ... MedlinePlus) Von Willebrand Disease (MedlinePlus) Building 31 31 Center Drive Bethesda, MD 20892 Learn more about getting ...

  16. Johann Friedrich Wilhelm Adolf von Baeyer

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 6. Johann Friedrich Wilhelm Adolf von Baeyer: A Pioneer of Synthetic Organic Chemistry. Gopalpur Nagendrappa. General Article Volume 19 Issue 6 June 2014 pp 489-522 ...

  17. Genetics Home Reference: von Willebrand disease

    Science.gov (United States)

    ... Jun;5(6):1165-9. Citation on PubMed Kessler CM. Diagnosis and treatment of von Willebrand disease: ... consult with a qualified healthcare professional . About Selection Criteria for Links Data Files & API Site Map Customer ...

  18. Von Onlineplattformen und mittelalterlichen Märkten

    Directory of Open Access Journals (Sweden)

    Claudius Gräbner

    2017-12-01

    Full Text Available Mit der zunehmenden Digitalisierung und Vernetzung ökonomischer Systeme haben plattformbasierte Interaktionsbeziehungen stark an Bedeutung gewonnen. Hier werden zwei oder mehr Nutzungsgruppen durch eine dritte Seite, die Plattform, zusammengebracht. Die Interaktion wird in solchen zweiseitigen Märkten von den Plattformbetreibern kontrolliert. Kreditkartensysteme, Softwaremärkte oder werbefinanzierte Online-Communities stellen typische Beispiele dar. Da die Analyse von zweiseitigen Märkten mit Gleichgewichtsmodellen aufgrund der algebraischen Struktur des Problems in der Regel nicht praktikabel ist, präsentieren wir im vorliegenden Beitrag ein agentenbasiertes Modell, welches in einem kürzlich erschienenen Artikel ausführlicher diskutiert wird. Anhand von illustrativen Beispielen verdeutlichen wir die Implikationen eines agentenbasierten Ansatzes für die Innovationsökonomik im Allgemeinen und das Studium von Technologieentwicklung im Besonderen.

  19. Ist Pop die Volksmusik von heute?

    OpenAIRE

    Arbeitskreis Studium Populärer Musik

    1986-01-01

    Zugegeben, die Frage, ob Pop die Volksmusik von heute sei, ist provokant. Genau das war beabsichtigt. Sehr schnell erhielten wir auf unser Vorhaben, ein Seminar zu diesem Thema zu veranstalten, eine Vielzahl von Rückmeldungen. Pop-, Rock- und Jazzspezialisten, Musikwissenschaftler und Musikotiunologen fühlten sich animiert, Stellung zu beziehen und ein Referat zu halten. Intensive Diskussionen schlossen sich an, beflügelt auch durch die ansprechende Atmosphdre in der stil...

  20. Begehrte Körper jenseits von Geschlecht?

    Directory of Open Access Journals (Sweden)

    Corinna Tomberger

    2001-03-01

    Full Text Available Obwohl die visuelle Konstruktion des männlichen Körpers im Mittelpunkt von Daniel Wildmanns Studie steht, gelingt es ihm paradoxerweise, die Kategorie Geschlecht weitgehend zu ignorieren. In seiner Analyse des Films Olympia von Leni Riefenstahl zeigt der Autor auf, wie der ‚arische‘ Körper als Objekt des Begehrens für das Publikum entworfen wird.

  1. Dr. von Braun With German Rocket Experimenters

    Science.gov (United States)

    1930-01-01

    Dr. von Braun was among a famous group of rocket experimenters in Germany in the 1930s. This photograph is believed to be made on the occasion of Herman Oberth's Kegelduese liquid rocket engine being certified as to performance during firing. From left to right are R. Nebel, Dr. Ritter, Mr. Baermueller, Kurt Heinish, Herman Oberth, Klaus Riedel, Wernher von Braun, and an unidentified person.

  2. 50th birthday of Christian von Ferber

    Directory of Open Access Journals (Sweden)

    2011-06-01

    Full Text Available On May 15, 2011 Christian von Ferber - member of the Editorial Board of "Condensed Matter Physics" and renowned expert in the fields of soft matter physics and complex systems - celebrated his 50th birthday. The Editorial board of CMP, colleagues and friends warmy congratulate Christian von Ferber and wish him and his family continuing good health and to enjoy many adventures and discoveries in his future scientific travels!

  3. Dr. von Braun With Management Team

    Science.gov (United States)

    1961-01-01

    Dr. von Braun is shown in this photograph, which was probably taken in the early 1960s, with members of his management team. Pictured from left to right are, Werner Kuers, Director of the Manufacturing Engineering Division; Dr. Walter Haeussermarn, Director of the Astrionics Division; Dr. William Mrazek, Propulsion and Vehicle Engineering Division; Dr. von Braun; Dieter Grau, Director of the Quality Assurance Division; Dr. Oswald Lange, Director of the Saturn Systems Office; and Erich Neubert , Associate Deputy Director for Research and Development.

  4. Hullud päevad von Krahlis

    Index Scriptorium Estoniae

    2006-01-01

    Von Krahli Teatris mängitakse neil päevi neli korda Peeter Jalaka lavastuses Tõnu Kõrvitsa kammeroopereid "Tuliaed" ja "Mu luiged, mu mõtted", mille aluseks on luuletaja Marie Heibergi saatus. Libreto autor on Maarja Kangro. Kammerooperid tulevad lavale Von Krahli Teatri ja Nargen Opera koostöös. Esitavad Kädy Plaas, Helen Lokuta, Nargen Opera koor ja Tallinna Kammerorkester, dirigent Tõnu Kaljuste

  5. Visualisierung von typisierten Links in Linked Data

    Directory of Open Access Journals (Sweden)

    Georg Neubauer

    2017-09-01

    Full Text Available Das Themengebiet der Arbeit behandelt Visualisierungen von typisierten Links in Linked Data. Die wissenschaftlichen Gebiete, die im Allgemeinen den Inhalt des Beitrags abgrenzen, sind das Semantic Web, das Web of Data und Informationsvisualisierung. Das Semantic Web, das von Tim Berners Lee 2001 erfunden wurde, stellt eine Erweiterung zum World Wide Web (Web 2.0 dar. Aktuelle Forschungen beziehen sich auf die Verknüpfbarkeit von Informationen im World Wide Web. Um es zu ermöglichen, solche Verbindungen wahrnehmen und verarbeiten zu können sind Visualisierungen die wichtigsten Anforderungen als Hauptteil der Datenverarbeitung. Im Zusammenhang mit dem Sematic Web werden Repräsentationen von zuhammenhängenden Informationen anhand von Graphen gehandhabt. Der Grund des Entstehens dieser Arbeit ist in erster Linie die Beschreibung der Gestaltung von Linked Data-Visualisierungskonzepten, deren Prinzipien im Rahmen einer theoretischen Annäherung eingeführt werden. Anhand des Kontexts führt eine schrittweise Erweiterung der Informationen mit dem Ziel, praktische Richtlinien anzubieten, zur Vernetzung dieser ausgearbeiteten Gestaltungsrichtlinien. Indem die Entwürfe zweier alternativer Visualisierungen einer standardisierten Webapplikation beschrieben werden, die Linked Data als Netzwerk visualisiert, konnte ein Test durchgeführt werden, der deren Kompatibilität zum Inhalt hatte. Der praktische Teil behandelt daher die Designphase, die Resultate, und zukünftige Anforderungen des Projektes, die durch die Testung ausgearbeitet wurden.

  6. Nano-engineering with a focused helium ion beam

    NARCIS (Netherlands)

    Maas, D.J.; Drift, E.W. van der; Veldhoven, E. van; Meessen, J.; Rudneva, M.; Alkemade, P.F.A.

    2011-01-01

    Although Helium Ion Microscopy (HIM) was introduced only a few years ago, many new application fields are budding. The connecting factor between these novel applications is the unique interaction of the primary helium ion beam with the sample material at and just below its surface. In particular,

  7. Turnkey Helium Purification and Liquefaction Plant for DARWIN, Australia

    Science.gov (United States)

    Lindemann, U.; Boeck, S.; Blum, L.; Kurtcuoglu, K.

    2010-04-01

    The Linde Group, through its Australian subsidiary BOC Limited, has signed an agreement with Darwin LNG Pty Ltd for the supply of feed-gas to Linde's new helium refining and liquefaction facility in Darwin, Australia. Linde Kryotechnik AG, located in Switzerland, has carried out the engineering and fabrication of the equipment for the turn key helium plant. The raw feed gas flow of 20'730 Nm3/h contains up to of 3 mol% helium. The purification process of the feed gas consists of partial condensation of nitrogen in two stages, cryogenic adsorption and finally catalytic oxidation of hydrogen followed by a dryer system. Downstream of the purification the refined helium is liquefied using a modified Bryton process and stored in a 30'000 gal LHe tank. For further distribution and export of the liquid helium there are two stations available for filling of truck trailers and containers. The liquid nitrogen, required for refrigeration capacity to the nitrogen removal stages in the purification process as well as for the pre-cooling of the pure helium in the liquefaction process, is generated on site during the feed gas purification process. The optimized process provides low power consumption, maximum helium recovery and a minimum helium loss.

  8. Thermal stability of helium-vacancy clusters in iron

    CERN Document Server

    Morishita, K; Wirth, B D; Díaz de la Rubia, T

    2003-01-01

    Molecular dynamics calculations were performed to evaluate the thermal stability of helium-vacancy clusters (He sub n V sub m) in Fe using the Ackland Finnis-Sinclair potential, the Wilson-Johnson potential and the Ziegler-Biersack-Littmark-Beck potential for describing the interactions of Fe-Fe, Fe-He and He-He, respectively. Both the calculated numbers of helium atoms, n, and vacancies, m, in clusters ranged from 0 to 20. The binding energies of an interstitial helium atom, an isolated vacancy and a self-interstitial iron atom to a helium-vacancy cluster were obtained from the calculated formation energies of clusters. All the binding energies do not depend much on cluster size, but they primarily depend on the helium-to-vacancy ratio (n/m) of clusters. The binding energy of a vacancy to a helium-vacancy cluster increases with the ratio, showing that helium increases cluster lifetime by dramatically reducing thermal vacancy emission. On the other hand, both the binding energies of a helium atom and an iron ...

  9. Proton-Helium Elastic Electromagnetic Cross-Section

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Burn [Chinese Academy of Sciences (CAS), Lanzhou (China); Ng, Kingyuen B. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-11-01

    In the test facility of the C-ADS project, A 25-MeV proton beam is directed to hit a target consisting of 1-mm tungsten balls lubricated by 100-Pa helium gas. To estimate the power loss to the helium gas, an accurate collision cross section is computed.

  10. Nuclear polarizability of helium isotopes in atomic transitions

    OpenAIRE

    Pachucki, K.; Moro, A. M.

    2006-01-01

    We estimate the nuclear polarizability correction to atomic transition frequencies in various helium isotopes. This effect is non-negligible for high precision tests of quantum electrodynamics or accurate determination of the nuclear charge radius from spectroscopic measurements in helium atoms and ions. In particular, it amounts to $28(3)$ kHz for 1S-2S transition in 4He+.

  11. Deposition, milling, and etching with a focused helium ion beam

    NARCIS (Netherlands)

    Alkemade, P.F.A.; Veldhoven, E. van

    2012-01-01

    The recent successful development of the helium ion microscope has produced both a new type of microscopy and a new tool for nanoscale manufacturing. This chapter reviews the first explorations in this new field in nanofabrication. The studies that utilize the Orion helium ion microscope to grow or

  12. Low Temperature Gaseous Helium and very High Turbulence Experiments

    CERN Document Server

    Pietropinto, S; Castaing, B; Chabaud, B; Gagne, Y; Hébral, B; Ladam, Y; Lebrun, P; Pirotte, O; Poulain, C; Roche, P E

    2002-01-01

    Cryogenic gaseous helium gives access to extreme turbulent experimental conditions. The very high cooling helium flow rates available at CERN have been used to reach Reynolds numbers up to Re ~ 10**7 in a round jet experiment. First results are discussed.

  13. Search for Dislocation Free Helium 4 Crystals.

    Science.gov (United States)

    Souris, F; Fefferman, A D; Haziot, A; Garroum, N; Beamish, J R; Balibar, S

    The giant plasticity of [Formula: see text]He crystals has been explained as a consequence of the large mobility of their dislocations. Thus, the mechanical properties of dislocation free crystals should be quite different from those of usual ones. In 1996-1998, Ruutu et al. published crystal growth studies showing that, in their helium 4 crystals, the density of screw dislocations along the c-axis was less than 100 per cm[Formula: see text], sometimes zero. We have grown helium 4 crystals using similar growth speeds and temperatures, and extracted their dislocation density from their mechanical properties. We found dislocation densities that are in the range of 10[Formula: see text]-10[Formula: see text] per cm[Formula: see text], that is several orders of magnitude larger than Ruutu et al. Our tentative interpretation of this apparent contradiction is that the two types of measurements are somewhat indirect and concern different types of dislocations. As for the dislocation nucleation mechanism, it remains to be understood.

  14. Helium enrichment during convective carbon dioxide dissolution

    Science.gov (United States)

    Larson, T.; Hesse, M. A.

    2013-12-01

    Motivated by observed variations of the CO2/He ratios in natural carbon dioxide (CO2) reservoirs, such as the Bravo Dome field in northeastern New Mexico, we have performed laboratory experiments equilibrating gas mixtures containing Helium (He) and CO2 with water, at close to ambient conditions in a closed system. The experimental design allows for continuous measurement of headspace pressure as well as timed interval measurements of the CO2/He ratios and the δ13C value of CO2 in the headspace. Results from three dissolution experiments are reported: 1) pure Helium system, 2) 98% CO2 + 2% Nitrogen system, and 3) 97% CO2 and 3% Helium. Final equilibrated experimental results are compared to theoretical results obtained using Henry's Law relationships. The evolution of the amount of dissolved CO2 computed from gas pressure and gas compositions are in good agreement with Henry's Law relationships. For example, the CO2 + N2 system was initially pressurized with pure CO2 to 1323 mbar and after six days it equilibrated to a measured headspace pressure of 596 mbar. This compares very well with a calculated equilibrium headspace pressure of 592 mbar for this system. The CO2 + He system was pressurized to 1398 mbar CO2 and after six days equilibrated to a measured headspace pressure of 397 mbar. This measured pressure is slightly higher than the predicted equilibrated headspace pressure of 341 mbar, indicating a possible leak in the system during this particular experiment. In both experiments the initial pH of the water was 9.3 and the final equilibrated pH was 5.4. The δ13C value of equilibrated headspace CO2 was within 0.25‰ of its starting δ13C value, demonstrating insignificant carbon isotope fractionation at low pH. Measured Helium/ CO2 ratios throughout the CO2+Helium experiment preserve a non-linear trend of increasing He/ CO2 ratios through time that correlate very well with the measured pressure drop from CO2 dissolution. This indicates that gas composition

  15. Binary helium dwarf supernovae. [numerical hydrodynamic investigation of evolution

    Science.gov (United States)

    Mazurek, T. J.

    1973-01-01

    The possibility of helium dwarf evolution to sufficiently high densities for violent helium ignition in low-massed binary systems is investigated. During accretional evolution the occurrence of thermonuclear runaway is found to be probable when the dwarf's mass approaches 1 solar mass, and steady-state discontinuous wave propagation considerations indicate that the dwarf is totally incinerated (i.e., its total mass burns to nuclear equilibrium) by a detonation wave. A numerical stellar dynamic investigation, including the full effects of nuclear statistical equilibrium and electron capture indicates total disruption for all reasonable dwarf central densities. For consistency with the cosmic element abundances, the conclusion of total disruption requires a low frequency for helium supernova events, implying that helium ignition in mass-exchanging binaries must occur at the lower densities of the relatively mild helium flash.

  16. Using Uncertainty Principle to Find the Ground-State Energy of the Helium and a Helium-like Hookean Atom

    Science.gov (United States)

    Harbola, Varun

    2011-01-01

    In this paper, we accurately estimate the ground-state energy and the atomic radius of the helium atom and a helium-like Hookean atom by employing the uncertainty principle in conjunction with the variational approach. We show that with the use of the uncertainty principle, electrons are found to be spread over a radial region, giving an electron…

  17. Helium processing for deuterium/helium burns in ITER's physics phase

    Energy Technology Data Exchange (ETDEWEB)

    Finn, P.A.; Sze, D.K.

    1991-01-01

    The requirements for vacuum pumping and fuel processing for deuterium/helium (D/{sup 3}He) burns in the physics operating phase for the International Thermonuclear Experimental Reactor (ITER) were assessed. These burns are expected to have low fusion power (100 MW), short burn times ({le}30 s), limited operation (2000 shots), and a fractional burn {approximately}0.3%. For the physics phase, the fuel processing system will include several units to separate deuterium and helium (activated charcoal bed, SAES getter and a Pd/Ag diffuser), as well as an isotopic separation system to separate {sup 3}He and {sup 4}He. The needed vacuum system's cryosorption surface area may be as large as 10 m{sup 2} if the burn time is {approximately}200 s, the fractional burn is <0.3%, or the fusion power is >100 MW. 8 refs., 1 fig., 4 tabs.

  18. Imprints from the solar cycle on the helium atom and helium pickup ion distributions

    Directory of Open Access Journals (Sweden)

    D. Rucinski

    2003-06-01

    Full Text Available Neutral interstellar helium atoms penetrate into the solar system almost unaffected by gas–plasma interactions in the heliospheric interface region, and thus can be considered as carriers of original information on the basic parameters (like density, temperature, bulk velocity of the Very Local Interstellar Medium (VLISM. Such information can nowadays be derived from analysis of data obtained from different experimental methods: in situ measurements of He atoms (Ulysses, observations of the solar backscattered He 584 A radiation (EUVE, in situ measurements of He + pickup ions (AMPTE, Ulysses, Wind, SOHO, ACE. In view of the current coordinated international ISSI campaign devoted to the study of the helium focusing cone structure and its evolution, we analyze expected variations of neutral He density, of He + pickup fluxes and of their phase space distributions at various phases of the solar activity cycle based on a realistic time-dependent modelling of the neutral helium and He + pickup ion distributions, which reflect solar cycle-induced variations of the photoionization rate. We show that the neutral helium density values are generally anticorrelated with the solar activity phase and in extreme cases (near the downwind axis the maximum-to-minimum density ratio may even exceed factors of ~ 3 at 1 AU. We also demonstrate that in the upwind hemisphere (at 1 AU and beyond the He + fluxes are correlated with the solar cycle activity, whereas on the downwind side the maximum of the expected flux up to distances of ~ 3 AU occurs around solar minimum epoch, and only further away does the correlation with solar activity become positive. Finally, we present the response of the phase space distribution spectra of He + pickup ions (in the solar wind frame for different epochs of the solar cycle and heliocentric distances from 1 to 5 AU covering the range of Ulysses, Wind and ACE observations.Key words. Solar physics, astrophysics and astronomy

  19. Helium and Sulfur Hexafluoride in Musical Instruments

    Science.gov (United States)

    Forinash, Kyle; Dixon, Cory L.

    2014-11-01

    The effects of inhaled helium on the human voice were investigated in a recent article in The Physics Teacher.1 As mentioned in that article, demonstrations of the effect are a popular classroom activity. If the number of YouTube videos is any indication, the effects of sulfur hexafluoride on the human voice are equally popular. However, there appears to be little information available on the effects of either of these gases on musical instruments.2 We describe here the results of a student project that involved measuring the frequency shifts in an organ pipe, a trumpet, and a trombone as the result of filling the instruments with these two gases. The project was one of several possible end-of-semester projects required in an elective science of sound course for non-science majors.

  20. Frequency metrology in quantum degenerate helium

    Directory of Open Access Journals (Sweden)

    Vassen Wim

    2013-08-01

    Full Text Available We have measured the absolute frequency of the 1557-nm doubly forbidden transition between the two metastable states of helium, 2 3S1 (lifetime 8000 s and 2 1S0 (lifetime 20 ms, with 1 kHz precision. With an Einstein coefficient of 10−7 s−1 this is one of weakest optical transitions ever measured. The measurement was performed in a Bose-Einstein condensate of 4He* as well as in a Degenerate Fermi Gas of 3He*, trapped in a crossed dipole trap. From the isotope shift we deduced the nuclear charge radius difference between the α-particle and the helion. Our value differs by 4σ with a very recent result obtained on the 2 3S → 2 3P transition.

  1. An Update of the Primordial Helium Abundance

    Science.gov (United States)

    Peimbert, Antonio; Peimbert, Manuel; Luridiana, Valentina

    2015-08-01

    Three of the best determinations of the primordial helium abundance (Yp) are those obtained from low metallicity HII regions by Aver, Olive, Porter, & Skillman (2013); Izotov, Thuan, & Guseva (2014); and Peimbert, Peimbert, & Luridiana (2007). In this poster we update the Yp determination by Peimbert et al. taking into account, among other aspects, recent advances in the determination of the He atomic physical parameters, the temperature structure, the collisional effects of high temperatures on the Balmer lines, as well as the effect of H and He bound-bound absorption.We compare our results with those of Aver et al. and Izotov et al. and point out possible explanations for the differences among the three determinations. We also compare our results with those obtained with the Plank satellite considering recent measurements of the neutron mean life; this comparison has implications on the determination of the number of light neutrino families.

  2. Cluster counting in helium based gas mixtures

    Science.gov (United States)

    Cataldi, G.; Grancagnolo, F.; Spagnolo, S.

    1997-02-01

    The statistical advantages deriving from counting primary ionization, as opposed to the conventional energy loss measurement, are extensively discussed. A primary ionization counting method is proposed for a "traditional", cylindrical, single sense wire cell drift chamber, which makes use of a helium based gas mixture. Its conceptual feasibility is proven by means of a simple Monte Carlo simulation. A counting algorithm is developed and tested on the simulation output. A definition of the parameters of the read-out and of the digitizing electronics is given, assuming the described counting algorithm applied to a general detector design, in order to have a complete and realistic planning of a cluster counting measurement. Finally, some interesting results from a beam test, performed according to the described parameters, on primary ionization measurements and on {π}/{μ} separation are shown.

  3. Helium Inventory Management For LHC Cryogenics

    CERN Document Server

    Pyarali, Maisam

    2017-01-01

    The LHC is a 26.7 km circumference ring lined with superconducting magnets that operate at 1.9 K. These magnets are used to control the trajectory of beams of protons traveling in opposite directions and collide them at various experimental sites across the LHC where their debris is analyzed. The focus of this paper is the cryogenic system that allows the magnets to operate in their superconducting states. It aims to highlight the operating principles of helium refrigeration and liquefaction, with and without nitrogen pre-cooling; discuss the various refrigerators and liquefiers used at CERN for both LHC and Non-LHC applications, with their liquefaction capacities and purposes; and finally to deliberate the management of the LHC inventory and how it contributes to the strategic decision CERN makes regarding the inventory management during the Year-End Technical Stop (YETS), Extended Year-End Technical Stop (EYETS) and long shutdowns.

  4. Positronium and Electron Scattering on Helium

    Science.gov (United States)

    DiRienzi, Joseph

    2011-01-01

    A recent work [1] establishes experimentally that Positronium scattering by atoms of various elements is surprisingly close in total cross-section to that of an isolated electron of the same velocity. In this work we will look at the scattering of Ps on Helium and compare it to a determination of the scattering of an e- with the same element. For both the Ps scattering and the e- scattering on He, we assume the symmetrization of the e- with the closed shell He electrons is the dominant interaction. A local effective potential employed in [2] and [3] is used to model the electron exchange and cross- sections are determined for a set of partial waves. For the Ps scattering we include as a secondary effect the Van der Waals interaction. For single e- scattering of He, we also employ a short range Coulomb potential and dispersion as contributing effects. Results of the cross-sections determined in each case are then compared

  5. Observation of the antimatter helium-4 nucleus.

    Science.gov (United States)

    2011-05-19

    High-energy nuclear collisions create an energy density similar to that of the Universe microseconds after the Big Bang; in both cases, matter and antimatter are formed with comparable abundance. However, the relatively short-lived expansion in nuclear collisions allows antimatter to decouple quickly from matter, and avoid annihilation. Thus, a high-energy accelerator of heavy nuclei provides an efficient means of producing and studying antimatter. The antimatter helium-4 nucleus (4He), also known as the anti-α (α), consists of two antiprotons and two antineutrons (baryon number B = -4). It has not been observed previously, although the α-particle was identified a century ago by Rutherford and is present in cosmic radiation at the ten per cent level. Antimatter nuclei with B antimatter nuclei and a benchmark for possible future observations of 4He in cosmic radiation.

  6. Liquid Oxygen Thermodynamic Vent System Testing with Helium Pressurization

    Science.gov (United States)

    VanDresar, Neil T.

    2014-01-01

    This report presents the results of several thermodynamic vent system (TVS) tests with liquid oxygen plus a test with liquid nitrogen. In all tests, the liquid was heated above its normal boiling point to 111 K for oxygen and 100 K for nitrogen. The elevated temperature was representative of tank conditions for a candidate lunar lander ascent stage. An initial test series was conducted with saturated oxygen liquid and vapor at 0.6 MPa. The initial series was followed by tests where the test tank was pressurized with gaseous helium to 1.4 to 1.6 MPa. For these tests, the helium mole fraction in the ullage was quite high, about 0.57 to 0.62. TVS behavior is different when helium is present than when helium is absent. The tank pressure becomes the sum of the vapor pressure and the partial pressure of helium. Therefore, tank pressure depends not only on temperature, as is the case for a pure liquid-vapor system, but also on helium density (i.e., the mass of helium divided by the ullage volume). Thus, properly controlling TVS operation is more challenging with helium pressurization than without helium pressurization. When helium was present, the liquid temperature would rise with each successive TVS cycle if tank pressure was kept within a constant control band. Alternatively, if the liquid temperature was maintained within a constant TVS control band, the tank pressure would drop with each TVS cycle. The final test series, which was conducted with liquid nitrogen pressurized with helium, demonstrated simultaneous pressure and temperature control during TVS operation. The simultaneous control was achieved by systematic injection of additional helium during each TVS cycle. Adding helium maintained the helium partial pressure as the liquid volume decreased because of TVS operation. The TVS demonstrations with liquid oxygen pressurized with helium were conducted with three different fluid-mixer configurations-a submerged axial jet mixer, a pair of spray hoops in the tank

  7. The primordial helium abundance from updated emissivities

    Energy Technology Data Exchange (ETDEWEB)

    Aver, Erik [Department of Physics, Gonzaga University, 502 E Boone Ave, Spokane, WA, 99258 (United States); Olive, Keith A.; Skillman, Evan D. [School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN, 55455 (United States); Porter, R.L., E-mail: aver@gonzaga.edu, E-mail: olive@umn.edu, E-mail: ryanlporter@gmail.com, E-mail: skillman@astro.umn.edu [Department of Physics and Astronomy, University of Georgia, Athens, GA, 30602 (United States)

    2013-11-01

    Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Y{sub p}. The He I emissivities are the foundation of the model of the H II region's emission. Porter, Ferland, Storey, and Detisch (2012) have recently published updated He I emissivities based on improved photoionization cross-sections. We incorporate these new atomic data and update our recent Markov Chain Monte Carlo analysis of the dataset published by Izotov, Thuan, and Stasi'nska (2007). As before, cuts are made to promote quality and reliability, and only solutions which fit the data within 95% confidence level are used to determine the primordial He abundance. The previously qualifying dataset is almost entirely retained and with strong concordance between the physical parameters. Overall, an upward bias from the new emissivities leads to a decrease in Y{sub p}. In addition, we find a general trend to larger uncertainties in individual objects (due to changes in the emissivities) and an increased variance (due to additional objects included). From a regression to zero metallicity, we determine Y{sub p} = 0.2465 ± 0.0097, in good agreement with the BBN result, Y{sub p} = 0.2485 ± 0.0002, based on the Planck determination of the baryon density. In the future, a better understanding of why a large fraction of spectra are not well fit by the model will be crucial to achieving an increase in the precision of the primordial helium abundance determination.

  8. Suicidal asphyxiation with helium: report of three cases.

    Science.gov (United States)

    Grassberger, Martin; Krauskopf, Astrid

    2007-01-01

    Helium is an inert gas that among other things is used medically to alleviate the symptoms of airway obstruction, as part of a diving mix in deep-sea diving or as balloon gas. In recent years the so-called right-to-die literature has suggested suffocation with inhaled helium as an effective and peaceful means of self-deliverance for terminally ill patients. Helium displaces oxygen and carbon dioxide and can thus lead to asphyxia. We report three cases of suicidal asphyxiation with helium gas that were examined at the Department of Forensic Medicine Vienna within three months in 2006. In all three cases, autopsy was unrewarding from the point of view of gross pathology. Special autopsy techniques and devices are required for collection of the gas from the lungs. Gas-chromatography is used to examine the gas for helium; however, this requires replacement of the carrier gas, which is itself usually helium. The fact that three people in Vienna committed suicide using this method within a short period of time, together with the abundance of detailed how-to literature on the Internet, suggests a possible future increase in the number of deaths associated with the inhalation of inert gases, particularly helium. Because of the diagnostic obstacles involved, it is necessary to rely on good death-scene investigation for situational evidence when the body is discovered.

  9. Privatiserung von Geschichte. Probleme einer differenzierten Aufarbeitung

    Directory of Open Access Journals (Sweden)

    Birthe Kundrus

    2000-11-01

    Full Text Available Ausgangspunkt der Untersuchung von Vera Neumann ist die These, daß im Krieg Erlebtes und Erlittenes in den Wiederaufbau- und Wirtschaftswunderjahren Westdeutschlands einem Thematisierungstabu unterlegen sei. Anhand von 50 Interviews, die in den 80er Jahren im Rahmen des von Lutz Niethammer geleiteten Projekts „Lebensgeschichte und Sozialgeschichte im Ruhrgebiet 1930–1960“ (LUSIR entstanden sind und die sie jetzt anhand der Tonbandprotokolle und Abschriften ein zweites Mal auswertet, möchte die Historikerin diese Verschüttungen aufspüren. Im Anschluß an Niethammers These der „Privatisierung von Geschichte“ will sie zeigen, daß seelische und körperliche Kriegsfolgen wie Deprivations- und Überlastungsgefühle, der Verlust von Angehörigen und Kriegsbeschädigungen „privatisiert“, d.h. an die Familien übertragen wurden. Dort seien dann in erster Linie die weiblichen Familienmitglieder mit der Versorgungs- und Pflegearbeit konfrontiert worden. An vier Fallbeispiele schließt sich eine detaillierte Auswertung des gesamten Interviewmaterials an. Diesen Teilen folgt ein Abschnitt zur staatlichen Kriegsopferversorgung in der frühen Bundesrepublik.

  10. An MRI Von Economo - Koskinas atlas.

    Science.gov (United States)

    Scholtens, Lianne H; de Reus, Marcel A; de Lange, Siemon C; Schmidt, Ruben; van den Heuvel, Martijn P

    2016-12-28

    The cerebral cortex displays substantial variation in cellular architecture, a regional patterning that has been of great interest to anatomists for centuries. In 1925, Constantin von Economo and George Koskinas published a detailed atlas of the human cerebral cortex, describing a cytoarchitectonic division of the cortical mantle into over 40 distinct areas. Von Economo and Koskinas accompanied their seminal work with large photomicrographic plates of their histological slides, together with tables containing for each described region detailed morphological layer-specific information on neuronal count, neuron size and thickness of the cortical mantle. Here, we aimed to make this legacy data accessible and relatable to in vivo neuroimaging data by constructing a digital Von Economo - Koskinas atlas compatible with the widely used FreeSurfer software suite. In this technical note we describe the procedures used for manual segmentation of the Von Economo - Koskinas atlas onto individual T1 scans and the subsequent construction of the digital atlas. We provide the files needed to run the atlas on new FreeSurfer data, together with some simple code of how to apply the atlas to T1 scans within the FreeSurfer software suite. The digital Von Economo - Koskinas atlas is easily applicable to modern day anatomical MRI data and is made publicly available online. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Toxicological findings in three cases of suicidal asphyxiation with helium.

    Science.gov (United States)

    Oosting, Roelof; van der Hulst, Rogier; Peschier, Leo; Verschraagen, Miranda

    2015-11-01

    Toxicological findings in deaths by asphyxiation due to a pure inert gas like helium are rare. We present three suicide cases of asphyxial death attributed to anoxia caused by inhalation of helium in a plastic bag positioned over the head. In one case, lung tissue, brain tissue and heart blood were obtained during standard autopsy procedures. In two cases, samples were obtained differently: heart blood, femoral blood, brain tissue, lung tissue and/or air from the lungs were directly sealed into headspace vials during autopsy. Air from the lungs was collected using a syringe and transferred into an aluminum gas sampling bag which was heat sealed as soon as possible. Semi-quantitative gas analyses were performed using headspace gas chromatography-thermal conductivity detection (HS-GC/TCD) with a molsieve column capable of separating permanent gasses. Nitrogen was used as carrier gas. In the first case no helium was detected in lung tissue, brain tissue and heart blood. In the second case the presence of helium was detected in lung tissue (approximately 5% helium in gaseous phase) but not in femoral blood. In the third case the presence of helium was detected in air from the lungs (0.05%), lung tissue (0.4%), brain tissue (0.1%) and heart blood (0.04%). Helium is easily lost if sampling is not performed properly. The presented cases suggest that quick sample collection of various matrices during autopsy is suitable to detect gasses like helium in postmortem cases. Use of HS-GC/TCD enables to detect an inert gas like helium. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Doença de von Willebrand e anestesia Enfermedad de von Willebrand y anestesia Von Willebrand's disease and anesthesia

    Directory of Open Access Journals (Sweden)

    Fabiano Timbó Barbosa

    2007-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A doença de von Willebrand ocorre devido à mutação no cromossomo 12 e é caracterizada por deficiência qualitativa ou quantitativa do fator de von Willebrand. A diversidade de mutações leva ao aparecimento das mais variadas manifestações clínicas possibilitando a divisão dos pacientes em vários tipos e subtipos clínicos. A coagulopatia se manifesta basicamente através da disfunção plaquetária associada à diminuição dos níveis séricos do fator VIII coagulante. O objetivo dessa revisão foi mostrar os cuidados relacionados aos pacientes portadores da doença de von Willebrand durante o período perioperatório. CONTEÚDO: Foram definidas as características da doença de von Willebrand quanto à fisiopatologia, à classificação, ao diagnóstico laboratorial, ao tratamento atual e aos cuidados com o manuseio do paciente no período perioperatório. CONCLUSÕES: A doença de von Willebrand é o distúrbio hemorrágico hereditário mais comum, porém ela é subdiagnosticada pela complexidade da própria doença. A correta classificação do paciente, o uso apropriado da desmopressina e a transfusão do fator de von Willebrand são medidas fundamentais para a realização do procedimento anestésico bem-sucedido.JUSTIFICATIVA Y OBJETIVOS: La enfermedad de von Willebrand ocurre debido a la mutación en el cromosoma 12 y se caracteriza por la deficiencia cualitativa o cuantitativa del factor de von Willebrand. La diversidad de mutaciones conlleva al aparecimiento de las más variadas manifestaciones clínicas posibilitando la división de los pacientes en varios tipos y subtipos clínicos. La coagulopatía se manifiesta básicamente a través de la disfunción plaquetaria asociada con la disminución de los niveles séricos del factor VIII coagulante. El objetivo de esa revisión fue mostrar los cuidados relacionados con las pacientes portadoras de la enfermedad de von Willebrand durante el per

  13. Von der Universitätsbibliothek Regensburg zum Bayerischen Bibliotheksverbund

    OpenAIRE

    Frankenberger, Rudolf

    1989-01-01

    Von der Universitätsbibliothek Regensburg zum Bayerischen Bibliotheksverbund : d. Entwicklung d. Bayer. Bibliotheksverbundes. - In: Bibliothekslandschaft Bayern : Festschr. für Max Pauer zum 65. Geburtstag / hrsg. von Paul Niewalda. - Wiesbaden : Harrassowitz, 1989. - S. 84-96

  14. Kerttu Wagner. Die historischen romane von Jaan Kross / Wolfgang Drechsler

    Index Scriptorium Estoniae

    Drechsler, Wolfgang, 1963-

    2001-01-01

    Arvustus: Wagner, Kerttu. Die historischen Romane von Jaan Kross : am Beispiel einer Untersuchung der deutschen und englischen Übersetzungen von "Professor Martensi ärasõit" (1984). Frankfurt am Main [etc.] : P. Lang, 2001.

  15. Performance of Oil-Injected Scroll Compressors for Helium Refrigerators

    Science.gov (United States)

    Shiibayashi, Masao; Izunaga, Yasushi; Sado, Shintaro

    In recent years there arises growing demand of helium liquefaction refrigerators for the magnetic resonance imaging systems, magnetically levitated vehicles and other systems using superconducting magnet. From this background, a small size, scroll type of hermetic helium compressor capable of compressing helium gas to the pressure ratio of 20 in a single stage is developed. Main features of this compressor are as follows. 1) Discharge capacity can be varied from 7 to 20 Nm3/h by changing driving motor frequency from 30 to 80 Hz. 2) The overall adiabatic efficiency showed 72%∼79% under the pressure ratio range of 11∼20 at 60 Hz using oil injection cooling device.

  16. European standardization activities on safety of liquid helium cryostats

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    This talk gives a general overview on the challenges of designing safety units for liquid helium cryostats with regard to existing industry standards. It reviews the work of a national working group that published the technical guideline DIN SPEC 4683 in April 2015, which is dedicated to the particular conditions in liquid helium cryostats. Based on both this guideline and equivalent documents from e.g. CEA, CERN, a working group is being formed at the European Committee for Standardization, associated to CEN/TC 268, which will work on a European standard on safety of liquid helium cryostats. The actual status and the schedule of this project are presented.

  17. International thermodynamic tables of the fluid state helium-4

    CERN Document Server

    Angus, S; McCarty, R D

    2013-01-01

    International Thermodynamic Tables of the Fluid State Helium-4 presents the IUPAC Thermodynamic Tables for the thermodynamic properties of helium. The IUPAC Thermodynamic Tables Project has therefore encouraged the critical analysis of the available thermodynamic measurements for helium and their synthesis into tables. This book is divided into three chapters. The first chapter discusses the experimental results and compares with the equations used to generate the tables. These equations are supplemented by a vapor pressure equation, which represents the 1958 He-4 scale of temperature that is

  18. Multi-objective Optimization on Helium Liquefier Using Genetic Algorithm

    Science.gov (United States)

    Wang, H. R.; Xiong, L. Y.; Peng, N.; Meng, Y. R.; Liu, L. Q.

    2017-02-01

    Research on optimization of helium liquefier is limited at home and abroad, and most of the optimization is single-objective based on Collins cycle. In this paper, a multi-objective optimization is conducted using genetic algorithm (GA) on the 40 L/h helium liquefier developed by Technical Institute of Physics and Chemistry of the Chinese Academy of Science (TIPC, CAS), steady solutions are obtained in the end. In addition, the exergy loss of the optimized system is studied in the case of with and without liquid nitrogen pre-cooling. The results have guiding significance for the future design of large helium liquefier.

  19. Gemeinsam hilfreich oder einsam lästig? Beurteilung von praktikumsbegleitenden Weblogs von angehenden Lehrpersonen

    Directory of Open Access Journals (Sweden)

    Nives Egger

    2017-02-01

    Full Text Available Weblogs werden an Hochschulen vermehrt zur Unterstützung von Lern- und Reflexionsprozessen eingesetzt, in der Lehrer/innenbildung auch zunehmend während der berufspraktischen Ausbildung. Die Studierenden beurteilen den Einsatz von Weblogs jedoch unterschiedlich. Dabei ist wenig bekannt, welchen Einfluss die Vergabe und das Erhalten von Peerfeedback auf den Beurteilungsprozess von praktikumsbegleitenden Weblogs sowie auf den Umfang von Blogpostings haben. Im folgenden Beitrag wird dieser Frage mittels einer Befragung von 74 angehenden Lehrpersonen nachgegangen, die praktikumsbegleitende Weblogs mit oder ohne Peerfeedback nutzten, um über herausfordernde Ereignisse im Praktikum zu reflektieren. Die Ergebnisse zeigen, dass Studierende, die Peerfeedback erhielten und andere Blogbeiträge kommentierten, den Weblogeinsatz nützlicher einschätzen sowie eine höhere Motivation und positivere Einstellung gegenüber den Einsatz von Weblogs aufweisen als Studierende, die ohne Peerfeedback bloggen. Keinen Einfluss hat Peerfeedback auf den Umfang der Blogbeiträge und auf die dafür aufgewendete Zeit.

  20. Polylaktidbeschichtung zur antithrombogenen Ausrüstung von Biomaterialien

    OpenAIRE

    Mebus, Siegrun

    2007-01-01

    In der Klinik etablierte Biomaterialien wurden mit einer Polylaktidbeschichtung und eingearbeiteten Antikoagulanzien ausgerüstet. Die mit einem in-vitro-Modell erarbeiteten Daten zeigen, daß der Arzneistoffträger innerhalb von 90 Tagen nicht abgebaut wurde. Die Freisetzung der Arzneistoffe erfolgte abhängig von deren Konzentration und dem Mischungsverhältnis von Iloprost und Hirudin. Iloprost beeinflußt die Freisetzungsrate von PEG-Hirudin bzw. r-Hirudin. Es konnte mit mikrobiologischen Metho...

  1. Nutzung der Eisenkorrosion zur Entfernung von Arsen aus Trinkwasser

    OpenAIRE

    Karschunke, Karsten

    2005-01-01

    In dieser Arbeit werden experimentelle Untersuchungen zur Nutzung von Eisenkorrosionsprozessen zur Entfernung von Arsen aus Trinkwasser vorgestellt. Auch in geringen Konzentrationen stellt diese Verunreinigung auf Grund der krebserregenden Wirkung von Arsen langfristig eine Gefahr für die menschliche Gesundheit dar. Verschiedene Entfernungsmethoden sind bekannt und in der Praxis der Trinkwasseraufbereitung bewährt, beispielsweise Flockungsverfahren unter Einsatz von Eisensalzen oder die Adsor...

  2. Liouville-von Neumann molecular dynamics.

    Science.gov (United States)

    Jakowski, Jacek; Morokuma, Keiji

    2009-06-14

    We present a novel first principles molecular dynamics scheme, called Liouville-von Neumann molecular dynamics, based on Liouville-von Neumann equation for density matrices propagation and Magnus expansion of the time-evolution operator. The scheme combines formally accurate quantum propagation of electrons represented via density matrices and a classical propagation of nuclei. The method requires a few iterations per each time step where the Fock operator is formed and von Neumann equation is integrated. The algorithm (a) is free of constraint and fictitious parameters, (b) avoids diagonalization of the Fock operator, and (c) can be used in the case of fractional occupation as in metallic systems. The algorithm is very stable, and has a very good conservation of energy even in cases when a good quality conventional Born-Oppenheimer molecular dynamics trajectories is difficult to obtain. Test simulations include initial phase of fullerene formation from gaseous C(2) and retinal system.

  3. Gasification of liquid manure; Vergasung von Guelle

    Energy Technology Data Exchange (ETDEWEB)

    Gudenau, H.W.; Hoberg, H.; Hirsch, U. [Technische Hochschule Aachen (Germany). Inst. fuer Eisenhuettenkunde

    1996-12-31

    The potential of thermal use of liquid manure is investigated. It is recommended to separate the liquid and solid fraction. While the liquid fraction can be used as fertilizer, the solid fraction can be used for generating a fuel gas for combined heat and power generation. (orig) [Deutsch] Die Untersuchungen haben ergeben, dass in der thermischen Verwertung von Guelle ein bisher nur wenig genutztes Potential vorliegt. Die zum Anbau von Getreide notwendige Duengung kann durch Separation von Guelle in Fest- und Duennfraktion effektiver und kostenguenstiger durchgefuehrt werden. Der Naehrstoffgehalt des Guellefeststoffs sollte durch thermische Aufbereitung aufkonzentriert werden, so dass eine Vermarktung auch mit laengeren Transpoertwegen darstellbar ist. Die bei der thermischen Behandlung gewonnene Waerme kann prozessintern genutzt und ueberschuessige Waerme an Abnehmer in der naeheren Umgebung geliefert werden. Genauso besteht die Moeglichkeit, ein Brenngas zu erzeugen und die Energie mit Kraft-Waerme-Kopplung zu nutzen. (orig)

  4. New experimental device for VHTR structural material testing and helium coolant chemistry investigation - High Temperature Helium Loop in NRI Rez

    Energy Technology Data Exchange (ETDEWEB)

    Berka, Jan, E-mail: bej@cvrez.cz [Research Centre Rez, Ltd, Husinec-Rez 130, 25068 Rez (Czech Republic); Institute of Chemical Technology Prague, Technicka 1905, 16628 Prague 6 (Czech Republic); Matecha, Josef, E-mail: josef.matecha@ujv.cz [Nuclear Research Institute Rez plc., Husinec-Rez 130, 25068 Rez (Czech Republic); Cerny, Michal [Institute of Chemical Technology Prague, Technicka 1905, 16628 Prague 6 (Czech Republic); Viden, Ivan, E-mail: ivan.viden@vscht.cz [Institute of Chemical Technology Prague, Technicka 1905, 16628 Prague 6 (Czech Republic); Sus, Frantisek [Research Centre Rez, Ltd, Husinec-Rez 130, 25068 Rez (Czech Republic); Nuclear Research Institute Rez plc., Husinec-Rez 130, 25068 Rez (Czech Republic); Hajek, Petr [Nuclear Research Institute Rez plc., Husinec-Rez 130, 25068 Rez (Czech Republic)

    2012-10-15

    The High Temperature Helium Loop (HTHL) is an experimental device for simulation of VHTR helium coolant conditions. The purpose of the HTHL is structural materials testing and helium coolant chemistry investigation. In the HTHL pure helium will be used as working medium and its main physical parameters are 7 MPa, max. temperature in the test section 900 Degree-Sign C and flow rate 37.8 kg/h. The HTHL consists of an active channel, the helium purification system, the system of impurities dosage (e.g. CO, CO{sub 2}, H{sub 2}, H{sub 2}O, O{sub 2}, N{sub 2}, and CH{sub 4}) and the helium chemistry monitoring system (sampling and on-line analysis and determination of impurities in the helium flow). The active channel is planned to be placed into the core of the experimental reactor LVR-15 which will serve as a neutron flux source (max. 2.5 Multiplication-Sign 10{sup 18} n/m{sup 2} s for fast neutrons). The HTHL is now under construction. Some of its main parts are finished, some are still being produced (active channel internals, etc.), some should be improved to work correctly (the helium circulatory compressor); certain sub-systems are planned to be integrated to the loop (systems for the determination of moisture and other impurities in helium, etc.). The start of the HTHL operation is expected during 2011 and the integration of the active channel into the LVR-15 core during 2012.

  5. [Anja Wilhelmi. Lebensweltlen von Frauen der deutschen Oberschicht im Baltikum (1800-1939). Eine Untersuchung anhand von Autobiographien] / Alexander Ewig

    Index Scriptorium Estoniae

    Ewig, Alexander, 1980-

    2011-01-01

    Arvustus: Wilhelmi, Anja. Lebenswelten von Frauen der deutschen Oberschicht im Baltikum (1800-1939). Eine Untersuchung anhand von Autobiographien. (Veröffentlichungen des Nordost-Instituts, 10.) (Wiesbaden : HArrassowitz 2008)

  6. Wachstum und Aufbau von Spongomorpha aeruginosa (Chlorophyta, Acrosiphoniales)

    NARCIS (Netherlands)

    Kornmann, Peter

    1967-01-01

    In zahlreichen Arbeiten dienten Algen als Objekte für das Studium von Regenerationsvorgängen und Erscheinungen der Polarität. Dagegen ist — von Chara abgesehen — über das normale Wachstum, den zeitlichen Ablauf von Teilung und Streckung der Zellen und die Entstehungsgeschichte des typischen Thallus

  7. Modellierung von Dienstleistungen mittels Business Service Blueprinting Modeling

    OpenAIRE

    Meis, Jochen; Menschner, Philipp; Leimeister, Jan Marco

    2010-01-01

    Der Beitrag stellt mit Business Service Blueprint Modeling (BSBM) einen konzeptionellen Ansatz zur Modellierung von Dienstleistungen vor, der ein systematisches und standardisiertes Vorgehen zur Modellierung von Dienstleistungen mit Kundeninteraktion anstrebt. BSBM verwendet hierzu die Business Process Modeling Notation (BPMN) in einem Service Blueprint (SB). Somit wird ein Modellierungskonzept geschaffen, das sowohl Kundeninteraktionspunkte berücksichtigt als auch von aktuellen Werkzeugen un...

  8. Spectral theory and quotients in Von Neumann algebras | West ...

    African Journals Online (AJOL)

    In this note we consider to what extent the functional calculus and the spectral theory in von Neumann algebras are preserved by the taking of quotients relative to two-sided ideals of the von Neumann algebra. Keywords:von Neumann algebra, functional calculus, spectral theory, quotient algebras. Quaestiones ...

  9. Market Timing und Finanzierungsentscheidungen: Unterscheidet sich Europa von den USA?

    NARCIS (Netherlands)

    Sautner, Z.; Spranger, J..

    2009-01-01

    Seit der Arbeit von Baker/Wurgler (2002) hat sich die Market-Timing-Theorie als alternative Kapitalstrukturtheorie etabliert. Sie impliziert, dass die Kapitalstruktur von Unternehmen das kumulierte Ergebnis von Versuchen des Equity Market Timing ist. Im Rahmen dieser Studie wird untersucht,

  10. How to make Raman-inactive helium visible in Raman spectra of tritium-helium gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Schloesser, M.; Pakari, O.; Rupp, S.; Mirz, S.; Fischer, S. [Institute of Technical Physics, Tritium Laboratory Karlsruhe - TLK, Karlsruhe Institute of Technology - KIT, Karlsruhe (Germany)

    2015-03-15

    Raman spectroscopy, a powerful method for the quantitative compositional analysis of molecular gases, e.g. mixtures of hydrogen isotopologues, is not able to detect monoatomic species like helium. This deficit can be overcome by using radioluminescence emission from helium atoms induced by β-electrons from tritium decay. We present theoretical considerations and combined Raman/radioluminescence spectra. Furthermore, we discuss the linearity of the method together with validation measurements for determining the pressure dependence. Finally, we conclude how this technique can be used for samples of helium with traces of tritium, and vice versa. (authors)

  11. Bewertung von Fahrzeuggeräuschen

    Science.gov (United States)

    Genuit, Klaus; Schulte-Fortkamp, Brigitte; Fiebig, André; Haverkamp, Michael

    Bei der Wahrnehmung und Beurteilung eines Automobils sind unzählige Merkmale und Eigenschaften von Bedeutung. Dabei können Merkmale objektiv-technisch beschrieben werden, wie Angaben zur Motorisierung, Höchstgeschwindigkeit, Drehmoment, zulässige Zuladung, Verbrauch usw. Daneben sind weitere Eigenschaften von Bedeutung, die sich einer einfachen objektiv-technischen Beschreibung entziehen. Hier sind Begriffe zu nennen, wie Sicherheit, allgemeine Qualitätsanmutung, Design, Ergonomie, Komfort, Haptik, Fahrdynamik, Zuverlässigkeit, die deutlich schwieriger objektiv erfassbar und beschreibbar sind (Abb. 4.1).

  12. [Von Recklinghausen disease and hepatic neurofibromatosis].

    Science.gov (United States)

    Guzman Toro, F; Hinestroza, D; Colmenares, D

    1995-01-01

    Von Recklinghausen's neurofibromatosis is one of the most common autosomal dominant disease with an estimated frecuency of 1:3000 live births. Characteristic lesions include cafe-au-lait spots and neurofibromas following the path of peripheral nerves. Liver involvement by neurofibromatosis is rare and very few cases have been reported. We present a case of a young man with Von Recklinhausen's disease and hepatic neurofibromatosis with multiple caf-au-lait spots, cutaneous neurofibromas, short stature and osseous lesions and compare the clinical, radiological, surgical and anatomopathological findings with others describe previously in the literature.

  13. Zur Aktivierung des Verbundtragverhaltens von Glaslaminaten

    OpenAIRE

    Sastré-Terrasa, Johannes (Hanno)

    2007-01-01

    Für jedes konstruktiv planerische Handeln ist ein fundiertes Wissen über die Baustoffe primäre Voraussetzung. Das trifft für Glas, auf Grund der Komplexität des Materialverhaltens, im besonderen Maße zu. Diese Arbeit beschäftigt sich deshalb zunächst mit dem Werkstoff Glas, den Grundlagen zum schadensfreien Fügen von Glas sowie dem Verhalten seiner Fügepartner. Die wichtigste Methode, das Kleben von Glas, wird im Wesentlichen durch die viskoelastischen und temperaturabhängig...

  14. Performance of Screw Compressor for Small-Capacity Helium Refrigerators

    Science.gov (United States)

    Urashin, Masayuki; Matsubara, Katsumi; Izunaga, Yasushi

    A helium compressor is one of the important components comprising a cryogenic refrigerator. The purpous of this investigation is to develop a new small-capacity helium screw compressor. The performance of a single-stage compressor at high compression ratio and the cooling performance of the compressor are investigated. A semi-hermetic screw compressor with new profile screw rotors, with which high performance can be obtained, is utilized in this investigation. Lubricating oil is applied to cool the compressor motor and the compressed gas. As a result, an overall isentropic efficiency of 80% is obtained when helium is compressed to a compression ratio of 19.8 with a single-stage screw compressor. At the same time, the temperature of a compressor motor and discharge gas can be maintained at low levels. Therefore, it is found that a single-stage screw compressor can compress helium to high compression ratio.

  15. Gaseous Helium Reclamation at Rocket Test Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — GHe reclamation is critical in reducing operating costs at rocket engine test facilities. Increases in cost and shortages of helium will dramatically impact testing...

  16. One of the Helium Liquifiers in the North Area

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    Several Helium Liquifiers were installed in the North Area to cool superconducting magnets used in the experiments. At center top is M.Dykes, at bottom right J.Dozio. See CERN Annual Report 1979 p.82.

  17. General mechanism for helium blistering involving displaced atom transport

    Energy Technology Data Exchange (ETDEWEB)

    McDonell, W.R.

    1979-01-01

    A mechanism developed to account for formation of vertically elongated blisters in high displacement environments produced by /sup 252/Cf alpha particles and fission fragments has been extended to formation of done-shaped blisters in the low displacement environments produced by simple helium ion beams. In this mechanism, transport of displaced atoms to relieve compressive stresses in the helium-implanted layer allows interconnections of small, subsurface bubbles to form the blister cavity. The same transport may cause thickening of the blister caps at low implantation energies. The transition from dome-shaped to vertically elongated blistering occurs between the 300 and 3000 displacements per helium atom produced by simple helium ions and /sup 252/Cf radiations respectively.

  18. Self-Calibrating Vector Helium Magnetometer (SVHM) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR proposal describes proposed development of a conceptual design for a Self-Calibrating Vector Helium Magnetometer (SVHM) for design and fabrication...

  19. High-Range Scalar Helium Magnetometer (HSHM) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes development of a conceptual design for a High-range Scalar Helium Magnetometer (HSHM) for the field range +/-16 Gauss. The HSHM...

  20. Helium, hydrogen, and fuzz in plasma-facing materials

    Science.gov (United States)

    Hammond, Karl D.

    2017-10-01

    Tungsten, the primary material under consideration as the divertor material in magnetic-confinement nuclear fusion reactors, has been known for the last decade to form ‘fuzz’—a layer of microscopic, high-void-fraction features on the surface—after only a few hours of exposure to helium plasma. Fuzz has also been observed in molybdenum, tantalum, and several other metals. Helium bubbles in tungsten and other metals are also known to change the hardness of the surface, accumulate at grain boundaries and dislocations, and increase hydrogen isotope retention. This article reviews helium- and hydrogen-induced surface evolution, including fuzz formation, in tungsten and other plasma-facing materials, as well as modeling and experimental efforts that have been undertaken to understand the mechanisms of fuzz formation, helium and hydrogen transport in plasma-facing materials, and relevant atomic-scale and electronic effects relevant to plasma-facing materials.

  1. Dark Matter Detection Using Helium Evaporation and Field Ionization

    Science.gov (United States)

    Maris, Humphrey J.; Seidel, George M.; Stein, Derek

    2017-11-01

    We describe a method for dark matter detection based on the evaporation of helium atoms from a cold surface and their subsequent detection using field ionization. When a dark matter particle scatters off a nucleus of the target material, elementary excitations (phonons or rotons) are produced. Excitations which have an energy greater than the binding energy of helium to the surface can result in the evaporation of helium atoms. We propose to detect these atoms by ionizing them in a strong electric field. Because the binding energy of helium to surfaces can be below 1 meV, this detection scheme opens up new possibilities for the detection of dark matter particles in a mass range down to 1 MeV /c2 .

  2. Advances in molecular mechanism of cardioprotection induced by helium

    Science.gov (United States)

    Ding, Yi-ping; Zhang, Ju-yi; Feng, Dong-xia; Kong, Yan; Xu, Zhuan; Chen, Gang

    2017-01-01

    Helium has been classified as a kind of inert gas that is not effortless to spark chemical reactions with other substances in the past decades. Nevertheless, the cognition of scientists has gradually changed accompanied with a variety of studies revealing the potential molecular mechanism underlying organ-protection induced by helium. Especially, as a non-anesthetic gas which is deficient of relevant cardiopulmonary side effects, helium conditioning is recognized as an emerging and promising approach to exert favorable effects by mimicking the cardioprotection of anesthetic gases or xenon. In this review we will summarize advances in the underlying biological mechanisms and clinical applicability with regards to the cardioprotective effects of helium. PMID:28744366

  3. Gaseous Helium Reclamation at Rocket Test Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The ability to restore large amounts of vented gaseous helium (GHe) at rocket test sites preserves the GHe and reduces operating cost. The used GHe is vented into...

  4. Self-Calibrating Vector Helium Magnetometer (SVHM) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase 2 SBIR proposal describes the design, fabrication and calibration of a brass-board Self-Calibrating Vector Helium Magnetometer (SVHM). The SVHM instrument...

  5. Transport and extraction of radioactive ions stopped in superfluid helium

    CERN Document Server

    Huang Wan Xia; Gloos, K; Takahashi, N; Arutyunov, K; Pekola, J P; Äystö, J

    2003-01-01

    A new approach to convert a high energy beam to a low energy one, which is essential for the next generation radioactive ion beam facilities, has been proposed and tested at Jyvaeskylae, Finland. An open sup 2 sup 2 sup 3 Ra alpha-decay-recoil source has been used to produce radioactive ions in superfluid helium. The alpha spectra demonstrate that the recoiling sup 2 sup 1 sup 9 Rn ions have been extracted out of liquid helium. This first observation of the extraction of heavy positive ions across the superfluid helium surface was possible thanks to the high sensitivity of radioactivity detection. An efficiency of 36% was obtained for the ion extraction out of liquid helium.

  6. Dark Matter Detection Using Helium Evaporation and Field Ionization.

    Science.gov (United States)

    Maris, Humphrey J; Seidel, George M; Stein, Derek

    2017-11-03

    We describe a method for dark matter detection based on the evaporation of helium atoms from a cold surface and their subsequent detection using field ionization. When a dark matter particle scatters off a nucleus of the target material, elementary excitations (phonons or rotons) are produced. Excitations which have an energy greater than the binding energy of helium to the surface can result in the evaporation of helium atoms. We propose to detect these atoms by ionizing them in a strong electric field. Because the binding energy of helium to surfaces can be below 1 meV, this detection scheme opens up new possibilities for the detection of dark matter particles in a mass range down to 1  MeV/c^{2}.

  7. Future Energy Source. [Mining Helium-3 on the Moon

    Science.gov (United States)

    1990-01-01

    This video describes the efforts of the Center for the Commercial Development of Space in Wisconsin to develop a strategy for mining Helium-3, an efficient, environmentally safe alternative to fossil fuels that exists on the moon. Animated sequences depict the equipment that could mine the lunar surface, boil away Helium-3 to be transported back to earth, and return the soil to the moon without destroying the lunar surface.

  8. Pulsed extraction of ionization from helium buffer gas

    OpenAIRE

    Morrissey, D. J.; Bollen, G.; Facina, M.; Schwarz, S.

    2008-01-01

    The migration of intense ionization created in helium buffer gas under the influence of applied electric fields is considered. First the chemical evolution of the ionization created by fast heavy-ion beams is described. Straight forward estimates of the lifetimes for charge exchange indicate a clear suppression of charge exchange during ion migration in low pressure helium. Then self-consistent calculations of the migration of the ions in the electric field of a gas-filled cell at the Nationa...

  9. Using Electrons on Liquid Helium for Quantum Computing

    OpenAIRE

    Dahm, A. J.; Goodkind, J. M.; Karakurt, I.; Pilla, S.

    2001-01-01

    We describe a quantum computer based on electrons supported by a helium film and localized laterally by small electrodes just under the helium surface. Each qubit is made of combinations of the ground and first excited state of an electron trapped in the image potential well at the surface. Mechanisms for preparing the initial state of the qubit, operations with the qubits, and a proposed readout are described. This system is, in principle, capable of 100,000 operations in a decoherence time.

  10. Robust Ferromagnetism of Chromium Nanoparticles Formed in Superfluid Helium.

    Science.gov (United States)

    Yang, Shengfu; Feng, Cheng; Spence, Daniel; Al Hindawi, Aula M A A; Latimer, Elspeth; Ellis, Andrew M; Binns, Chris; Peddis, Davide; Dhesi, Sarnjeet S; Zhang, Liying; Zhang, Yafei; Trohidou, Kalliopi N; Vasilakaki, Marianna; Ntallis, Nikolaos; MacLaren, Ian; de Groot, Frank M F

    2017-01-01

    Chromium nanoparticles are formed using superfluid helium droplets as the nanoreactors, which are strongly ferromagnetic. The transition from antiferromagentism to ferromagnetism is attributed to atomic-scale disorder in chromium nanoparticles, leading to abundant unbalanced surface spins. Theoretical modeling confirms a frustrated aggregation process in superfluid helium due to the antiferromagnetic nature of chromium. © 2016 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Erwachsenenbildung im Spannungsfeld von Wissenschaft, Politik und Praxis: Heide von Felden, Christiane Hof und Sabine Schmidt-Lauff (Hrsg.). [Rezension

    OpenAIRE

    Filla, Wilhelm

    2016-01-01

    Rezension von: Felden, Heide von/Hof, Christiane/Schmidt-Lauff, Sabine (Hrsg.) (2013): Erwachsenenbildung im Spannungsfeld von Wissenschaft, Politik und Praxis. Dokumentation der Jahrestagung der Sektion Erwachsenenbildung der Deutschen Gesellschaft für Erziehungswissenschaften vom 27. bis 29. September 2012. Baltmannsweiler: Schneider Verlag Hohengehren.

  12. Die Verteilung und Eigenschaften von Bodenformen in der Deutschen Bucht, eine Rekonstruktion der Karten von Ulrich (1973)

    DEFF Research Database (Denmark)

    Winter, Christian; Lefebvre, Alice; Benninghoff, Markus

    2015-01-01

    Entstehung, Gestalt und Dynamik von Bodenformen in vergleichsweise kleinen Untersuchungsgebieten ist die Arbeit von ULRICH (1973) über die Verteilung von Bodenformen in der Deutschen Bucht bis heute die einzige verfügbare zusammenhängende Darstellung für die deutsche Nordseeküste. Die analogen Karten und die...

  13. Der Briefwechsel zwischen Alexander von Humboldt und Karl Ernst von Baer

    Directory of Open Access Journals (Sweden)

    Thomas Schmuck

    2012-10-01

    Full Text Available Zusammenfassung Der kurze, nicht vollständig erhaltene Briefwechsel zwischen Alexander von Humboldt und Karl Ernst von Baer behandelt sehr verschiedene Themen: Politik, Kriegsgefahr, den Wissenschaftsbetrieb, Auszeichnungen und Tagungen, Embryologie und Cholera. Gemeinsam mit Briefen und Reden ergibt sich dabei ein differenziertes Bild der Beurteilung der beiden Wissenschaftler durch den jeweils anderen. Während Baer sich als Bewunderer Humboldts erweist, erscheint umgekehrt Humboldts Einschätzung Baers als ambivalent. Abstract The short, not completely preserved correspondence between Alexander von Humboldt and Karl Ernst von Baer deals with a wide range of subjects: politics and the danger of war, academic activities, scientific awards and conferences, aspects of embryology and the cholera. Letters to third persons and speeches, together with the correspondence between Humboldt and Baer show a differentiated pattern of mutual appraisal: While Baer always remained an admirer of the elder naturalist, Humboldt’s estimation was characterized by ambivalence.

  14. Helium penetrates into silica glass and reduces its compressibility.

    Science.gov (United States)

    Sato, Tomoko; Funamori, Nobumasa; Yagi, Takehiko

    2011-06-14

    SiO(2) glass has a network structure with a significant amount of interstitial voids. Gas solubilities in silicates are expected to become small under high pressure due to compaction of voids. Here we show anomalous behaviour of SiO(2) glass in helium. Volume measurements clarify that SiO(2) glass is much less compressible than normal when compressed in helium, and the volume in helium at 10 GPa is close to the normal volume at 2 GPa. X-ray diffraction and Raman scattering measurements suggest that voids are prevented from contracting when compressed in helium because helium penetrates into them. The estimated helium solubility is very high and is between 1.0 and 2.3 mol per mole of SiO(2) glass at 10 GPa, which shows marked contrast with previous models. These results may have implications for discussions of the Earth's evolution as well as interpretations of various high-pressure experiments, and also lead to the creation of new materials.

  15. Atomistic simulation of helium bubble nucleation in palladium

    Energy Technology Data Exchange (ETDEWEB)

    Wang Liang [Department of Applied Physics, Hunan University, Changsha 410082 (China); Hu, Wangyu [Department of Applied Physics, Hunan University, Changsha 410082 (China)], E-mail: wangyuhu2001cn@yahoo.com.cn; Xiao Shifang [Department of Applied Physics, Hunan University, Changsha 410082 (China)], E-mail: sfxiao@yahoo.com.cn; Yang Jianyu [Department of Maths and Physics, Hunan Institute of Engineering, Xiangtan 411104 (China); Deng Huiqiu [Department of Applied Physics, Hunan University, Changsha 410082 (China)

    2009-09-15

    A palladium crystal has been constructed with 11808 atoms. 55 helium atoms occupied the octahedral position of palladium crystal are introduced and retained in a spherical region. Molecular dynamic simulations are performed in a constant temperature and constant volume ensemble (NVT) with temperature controlled by Nose-Hoover thermostat. The interactions between palladium atoms are described with modified analytic embedded atom method (MAEAM), the interactions between palladium atom and helium atom are in the form of Morse potential, and the interactions between helium atoms are in the form of L-J potential function. With the analysis of the radial distribution function (RDF) and microstructure, it reveals that some of helium atoms form a series of clusters with different size, and the nucleation core is random at low temperature, and which is the embryo of helium bubble. Increasing temperature can accelerate the process of bubble nucleation, and the clusters will aggregate and coalesce into a bigger one in which there are no palladium atoms, and it is considered as a helium bubble.

  16. Measurement of helium production cross sections of iron for d-T neutrons by helium accumulation method

    Energy Technology Data Exchange (ETDEWEB)

    Takao, Yoshiyuki; Kanda, Yukinori; Nagae, Koji; Fujimoto, Toshihiro [Kyushu Univ., Fukuoka (Japan); Ikeda, Yujiro

    1997-03-01

    Helium production cross sections of Iron were measured by helium accumulation method for neutron energies from 13.5 to 14.9 MeV. Iron samples were irradiated with FNS, an intense d-T neutron source of JAERI. As the neutron energy varies according to the emission angle at the neutron source, the samples were set around the neutron source and were irradiated by neutrons of different energy depending on each sample position. The amount of helium produced in a sample was measured by Helium Atoms Measurement System at Kyushu University. The results of this work are in good agreement with other experimental data in the literature and also compared with the evaluated values in JENDL-3. (author)

  17. Quantum interference spectroscopy of rubidium-helium exciplexes formed on helium nanodroplets.

    Science.gov (United States)

    Mudrich, M; Stienkemeier, F; Droppelmann, G; Claas, P; Schulz, C P

    2008-01-18

    Femtosecond multiphoton pump-probe photoionization is applied to helium nanodroplets doped with rubidium (Rb). The yield of Rb+ ions features pronounced quantum interference (QI) fringes demonstrating the coherence of a superposition of electronic states on a time scale of tens of picoseconds. Furthermore, we observe QI in the yield of formed RbHe exciplex molecules. The quantum interferogram allows us to determine the vibrational structure of these unstable molecules. From a sliced Fourier analysis one cannot only extract the population dynamics of vibrational states but also follow their energetic evolution during the RbHe formation.

  18. Interpenetration bei Parsons und Luhmann : Von der Integration zur Produktion von Unordnung

    OpenAIRE

    Künzler, Jan

    2010-01-01

    Talcott Parsons hatte den Interpenetrationsbegriff eingeführt, um strukturelle Beziehungen zwischen verschiedenen System arten erfassen zu können. Niklas Luhmann übernimmt den Begriff von Parsons und benutzt ihn nach weitreichenden Revisionen v. a. dazu, das Verhältnis von psychischen und sozialen Systemen auf den Begriff zu bringen. In dieser Intersystembeziehung spielt Sprache eine entscheidende Rolle. Ein systemtheoretisches Sprachkonzept, das dieser Vermittlungsleistung Rechnung trägt, st...

  19. Dentinhaftung von Zementen. Der Haftverbund von Zementen mit Dentin in Kombination mit verschiedenen indirekten Restaurationsmaterialien

    OpenAIRE

    Peutzfeldt, Anne; Sahafi, Alireza; Flury, Simon

    2011-01-01

    Einleitung: Die Anzahl zahnärztlicher Zemente sowie Restaurationsmaterialien steigt stetig. Die richtige Zementwahl für einen zuverlässigen Haftverbund zwischen Restaurationsmaterial und Zahnsubstanz ist von Interesse für den Kliniker. Ziel der vorliegenden in vitro-Studie war es daher, den Dentinhaftverbund von verschiedenen Zementen in Kombination mit verschiedenen indirekten Restaurationsmaterialien zu untersuchen. Material und Methoden: Zylindrische Probekörper aus sechs Restaurations...

  20. Identifizierung von Mikrodomän-Proteinen und funktionelle Charakterisierung von Cholesterin im Golgi-Apparat

    OpenAIRE

    Stüven, Ernstpeter

    2002-01-01

    Mittels Detergenzextraktion von Golgimembranen bei 0°C mit anschließender Dichtegradientenzentrifugation wurden sphingolipid- und cholesterinreiche Mikrodomänen isoliert, die zehn Proteine entsprechend der Coomassiefärbung in der SDS-PAGE enthalten. Im Rahmen dieser Arbeit wurden die zwei bisher nicht charakterisierten Proteine mit Molekulargewichten von 72 und 56 kDa als Untereinheiten A und B der vakuolären ATPase identifiziert. Daneben konnte mit NAP-22 eine elfte Komponente identifiziert ...

  1. Der "Bindungsfragebogen" von Grau und der "Bielefelder Fragebogen zu Partnerschaftserwartungen" von Hoger und Buschkamper im Vergleich

    National Research Council Canada - National Science Library

    Ina Grau; Ulrich Clashausen; Diether Hoger

    2003-01-01

    ...". Das Bindungsmuster ergibt sich aus der speziellen anhand von Clusteranalysen ermittelten Konfiguration der Skalen. In Clusteranalysen mit dem BinFB wurden vier Cluster aufgefunden, mit dem BFPE funf Cluster. Wahrend vier der BFPE-Cluster recht gut mit den vier BinFB-Clustern ubereinstimmen, wird eine funfte Personengruppe vom BFPE als "vermeidend-offnungsbereit" und von BinFB als "sicher" klassifiziert. Beide Interprctationsmoglichkeiten werden unter besonderer Berucksichtigung der Skala "Zuwendungsbedurfn...

  2. Authentizität von Milch und Fisch – Erkennung von Bioprodukten im Labor

    OpenAIRE

    Molkentin, Joachim

    2008-01-01

    Die Nachfrage nach Bio-Lebensmitteln ist in Deutschland in den letzten Jahren stetig gestiegen. So erhöhte sich der Absatz von Bio-Trinkmilch in 2007 im Vergleich zum Vorjahr erneut um 34 %. Aufgrund sporadisch resultierender Lieferengpässe bei Bio-Milch aber auch der erheblichen Handelspreisdifferenz – wie z. B. insbesondere bei Bio-Lachs – besteht ein potenzielles Risiko der Falschdeklaration konventioneller Produkte als Bio-Ware. Zum Schutz von Verbrauchern wie auch Erzeugern werden dah...

  3. Die Rezeptionsgeschichte von Ulrich Schmidels Wahrhaftige Beschreibung von 1567 bis heute

    OpenAIRE

    Obermeier, Franz

    2001-01-01

    Schmidels Werk hat bisher nur in Ansätzen die ihm zustehende Würdigung als eines der wichtigsten Quellenwerke der frühen Kolonialzeit Südamerikas erfahren. Es stand lange Zeit im Schatten des bekannteren und auch literarisch ansprechenderen Reisebuchs von Hans Staden (Wahrhaftige Historia, Marburg 1557), dessen persönliche Schilderung seiner Gefangenschaft dem modernen Leser durch den geschickten Einsatz von narrativen Elementen entsprechend der heutigen Genretradition des persönlich gefasste...

  4. Analyse von Arbeitsplätzen auf halbautomatischen Pflanzmaschinen mit Hilfe von MTM (Methods Time Measurement)

    OpenAIRE

    Remmele, Edgar

    2017-01-01

    Mit Hilfe von MTM (Methods Time Measurement), einem System vorbestimmter Zeiten, werden Bewegungsstudien an drei verschiedenen halbautomatischen Pflanzmaschinen durchgeführt. Hauptunterscheidungsmerkmal der untersuchten Pflanzmaschinen ist die Methode der Übergabe der Pflanze von der Pflanzperson an die Pflanzmaschine. Analysiert wird der Arbeitsplatz der Pflanzmaschine ACCORD-Standard mit der Methode Klemmscheibe, PES-Beetpflanzer 1500/1900 mit der Methode Pflanzfinger und Lännen RT-2 mit de...

  5. Cavity optomechanics in a levitated helium drop

    Science.gov (United States)

    Childress, L.; Schmidt, M. P.; Kashkanova, A. D.; Brown, C. D.; Harris, G. I.; Aiello, A.; Marquardt, F.; Harris, J. G. E.

    2017-12-01

    We describe a proposal for a type of optomechanical system based on a drop of liquid helium that is magnetically levitated in vacuum. In the proposed device, the drop would serve three roles: its optical whispering-gallery modes would provide the optical cavity, its surface vibrations would constitute the mechanical element, and evaporation of He atoms from its surface would provide continuous refrigeration. We analyze the feasibility of such a system in light of previous experimental demonstrations of its essential components: magnetic levitation of mm-scale and cm-scale drops of liquid He , evaporative cooling of He droplets in vacuum, and coupling to high-quality optical whispering-gallery modes in a wide range of liquids. We find that the combination of these features could result in a device that approaches the single-photon strong-coupling regime, due to the high optical quality factors attainable at low temperatures. Moreover, the system offers a unique opportunity to use optical techniques to study the motion of a superfluid that is freely levitating in vacuum (in the case of 4He). Alternatively, for a normal fluid drop of 3He, we propose to exploit the coupling between the drop's rotations and vibrations to perform quantum nondemolition measurements of angular momentum.

  6. Helium irradiation induced hardening in MNHS steels

    Science.gov (United States)

    Cui, Minghuan; Wang, Ji; Wang, Zhiguang; Shen, Tielong; Wei, Kongfang; Yao, Cunfeng; Sun, Jianrong; Gao, Ning; Zhu, Yabin; Pang, Lilong; Wang, Dong; Zhu, Huiping; Han, Yi; Fang, Xuesong

    2017-09-01

    A recently developed reduced activation martensitic MNHS steel was irradiated with 200 keV helium (He) ions to a fluence of 1.0 × 1020 ions/m2 at 300 °C and 1.0 × 1021 ions/m2 at 300 °C and 450 °C. After irradiation, transmission electron microscopy (TEM) and nano-indentation measurements were used to investigate the hardness change and defects induced by He irradiation. Two kinds of defects including He bubbles and dislocation loops are observed by TEM. Irradiation induces hardening of MNHS steels and peak hardness values occur in all irradiated samples. Hardness increments induced by He bubbles and dislocation loops are predicted and fitted with the experimental peak hardness increment, based on the dispersed barrier-hardening (DBH) model and the size and number density of the two defects. A good agreement is got between the predicted and experimental hardness increment and the obstacle strength factor of He bubbles is a little stronger than the obstacle strength of dislocation loops. Other possible contributions to irradiation induced hardening are also discussed.

  7. Helium-Shell Nucleosynthesis and Extinct Radioactivities

    Science.gov (United States)

    Meyer, B. S.; The, L.-S.; Clayton, D. D.; ElEid, M. F.

    2004-01-01

    Although the exact site for the origin of the r-process isotopes remains mysterious, most thinking has centered on matter ejected from the cores of massive stars in core-collapse supernovae [13]. In the 1970's and 1980's, however, difficulties in understanding the yields from such models led workers to consider the possibility of r-process nucleosynthesis farther out in the exploding star, in particular, in the helium burning shell [4,5]. The essential idea was that shock passage through this shell would heat and compress this material to the point that the reactions 13C(alpha; n)16O and, especially, 22Ne(alpha; n)25Mg would generate enough neutrons to capture on preexisting seed nuclei and drive an "n process" [6], which could reproduce the r-process abundances. Subsequent work showed that the required 13C and 22Ne abundances were too large compared to the amounts available in realistic models [7] and recent thinking has returned to supernova core material or matter ejected from neutron star-neutron star collisions as the more likely r-process sites.

  8. Zur Entwicklung von Containerschiffsflotten : eine Paneldatenanalyse

    OpenAIRE

    Prinz, Alexander; Schulze, Peter M.

    2004-01-01

    Diese Arbeit untersucht die regional aggregierten Containerschiffsflotten der wichtigsten Wirtschaftsräume entlang der Hauptverkehrsrouten der Seeschifffahrt. Anhand einer Paneldatenanalyse mit festen Effekten werden die positive Abhängigkeit der Containerschifffahrt von Weltwirtschaft und Welthandel quantifiziert und erklärende Variablen für die Entwicklung der Containerschifffahrt identifiziert.

  9. Von Kalifornien nach Taxham / Katri Soe

    Index Scriptorium Estoniae

    Soe, Katri, 1971-

    2005-01-01

    Neljas osa magistritööst "Von Kalifornien nach Taxham: Formen und Strukturen der Kommunikation in Peter Handkes Romanen "Der kurze Brief zum langen Abschied" und "In einer dunklen Nacht ging ich aus meinem stillen Haus"" (Tartu, 2000. Juhendaja: Claus Sommerhage)

  10. Euler-Chelpin, Prof. Hans von

    Indian Academy of Sciences (India)

    Euler-Chelpin, Prof. Hans von. Nobel Laureate (Chemistry) - 1929. Date of birth: 15 February 1873. Date of death: 6 November 1964 ... Posted on 21 December 2017. ASTROPHYSICS: An Observational View of the Universe. Math Art and Design: MAD about Math, Math Education and Outreach. Math and Finance ...

  11. Ueberreste vorweltlicher Proboscidier von Java und Banka

    NARCIS (Netherlands)

    Martin, K.

    1884-01-01

    Junghuhn führte in seinem Werke über Java nur einen einzigen Wirbelthierrest, Carcharias megalodon, an (7, IV, pag. 97); es war ihm nicht gelungen bei seinem ersten Aufenthalte auf der Insel Reste von Säugethieren zu finden, so eifrig er auch darnach in den Höhlen des Tertiaergebirges suchte (7, IV,

  12. Alte und neue Scyphomedusen von Australien

    NARCIS (Netherlands)

    Stiasny, G.

    1926-01-01

    In einer Collection Coelenterata, von verschiedenen australischen Fundorten herrührend, die mir vom Direktor des Australian Museum in Sydney, Dr. Ch. Anderson, zur Untersuchung übersendet wurden, fanden sich auch einige Scyphomedusen, die in den australischen Gewässern bisher noch nicht nachgewiesen

  13. Eigenschaften von Gott. Eine quantitative Analyse

    Directory of Open Access Journals (Sweden)

    Thomas Benesch

    2016-12-01

    Full Text Available ENGLISH: A quantitative research on 32 pupils of an elementary school (third and fourth class was performed. The questions regarded to socio-demographic issues as well as so called opposition pairs for God. These opposition pairs include the semantic differential of the loving God combined with the selection of 27 opposition pairs which were derived from literature. The image of God has been developed due to a factor analysis with respect to human and divine properties. These characteristics are depending on the religious education of children as well as their habits of reading in the Holy Bible. DEUTSCH: Eine quantitative Erhebung von 32 Volksschulkindern einer 3. und 4. Klasse wurde einerseits mit erweiterten sozio-demographischen Fragen und gleichzeitig mit Gegensatzpaaren für Gott beschrieben. Die Gegensatzpaare beinhalteten das semantische Differential des liebenden Gottes zusammen mit einer Auswahl von 27 Gegensatzpaaren, die deduktiv aus der Literatur abgeleitet wurden. Das Gottesbild hat sich anhand einer Faktorenanalyse darin entwickelt, dass Gott einerseits mit menschlichen Attributen versehen wird und andererseits mit Eigenschaften von Gott. Diese Eigenschaften von Gott sind abhängig davon, ob die Kinder religiös erzogen werden und ob sie gerne die Heilige Schrift lesen.

  14. Active Von Willebrand Factor, thrombocytopenia and thrombosis

    NARCIS (Netherlands)

    Hulstein, J.J.J.

    2006-01-01

    Platelets and von Willebrand factor (VWF) are unable to interact in circulation. To induce an interaction, a conversion of VWF to a platelet-binding conformation is required. At higher shear stresses, the first step in thrombus formation is binding of VWF to the subendothelium. This results in

  15. Molecular mechanisms of von Willebrand Factor mechanoregulation

    NARCIS (Netherlands)

    Jakobi, A.J.|info:eu-repo/dai/nl/311489621

    2012-01-01

    Von Willebrand factor (VWF) multimers mediate primary adhesion and aggregation of platelets. The potency to recruit platelets critically depends on the size of VWF multimers, which is regulated by a feedback mechanism involving shear-induced unfolding of the A2 domain in VWF and cleavage by the

  16. Measurements and von Neumann projection/collapse

    Indian Academy of Sciences (India)

    unwanted superpositions of (system + apparatus)-states can be shown to be suppressed, leading eventually to the projection/collapse rule postulated in von Neumann's treatment of measurements [3]. In the next section, the measurement problem in quantum mechanics (QM) is recalled. In §3, some proposed improvements ...

  17. Guido von Pirquet: Austrian pioneer of astronautics

    Science.gov (United States)

    Sykora, F.

    1977-01-01

    The works of Guido von Pirquet, Austrian pioneer of rocketry, were assessed. Major emphasis was given to Pirquet's calculation of the route to Venus which in fact was followed by the first Russian rocket to Venus. Of interest also is Pirquet's valuable construction of a space station and his analysis of interstellar space flight.

  18. Soolopartiid Von Krahli katuse all / Kristi Eberhart

    Index Scriptorium Estoniae

    Eberhart, Kristi

    2007-01-01

    Von Krahli Teatri kolmest lavastusest: "Erki ja Tiina" (lavastaja Mart Kangro, tantsivad Erki Laur ja Tiina Tauraite), "Faust" (J. W. Goethe ainetel tekst ja lavastus Taavi Eelmaa, muusika ja laulud Chalice, osades Jarek Kasar ja Rein Pakk), "Hamletid" (William Shakespeare'i ainetel kontseptsiooni, lavastuse, koreograafia, kujunduse, valguse autor Sasha Pepeljajev, video- ja helikunstnik Taavet Jansen. Esitaja Juhan Ulfsak)

  19. De ziekte van Von Hippel-Lindau

    NARCIS (Netherlands)

    Los, M.; Links, T.P.; Lenders, J.W.M.; Voest, E.E.

    2000-01-01

    Von Hippel-Lindau disease (VHL) is an autosomal dominant inherited cancer syndrome. The disease was diagnosed in three patients: a 22-year-old woman who presented with decreased vision due to retinal angiomatosis and in whom a renal carcinoma was diagnosed five years later at a routine VHL analysis,

  20. Ueber eine Anomalie von Acromitus flagellatus (Stiasny)

    NARCIS (Netherlands)

    Stiasny, G.

    1934-01-01

    Bei erneuter Durchsicht des reichhaltigen Materiales von Acromitus flagellatus (Stiasny) in der Scyphomedusen-Sammlung des Rijksmuseum van Natuurlijke Historie in Leiden (vergl. meine Mitteilungen daruber, 1920, Uebersichtstabelle III und 1921, p. 131/136) fand ich ein Exemplar, das eine

  1. Laue, Prof. Max Theodor Felix von

    Indian Academy of Sciences (India)

    Home; Fellowship. Fellow Profile. Elected: 1954 Honorary. Laue, Prof. Max Theodor Felix von. Nobel Laureate (Physics) - 1914. Date of birth: 9 October 1897. Date of death: 24 April 1960. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the ...

  2. Ueber zwei neue Vogelarten von Java

    NARCIS (Netherlands)

    Finsch, O.

    1902-01-01

    Die beiden nachstehend beschriebenen Vögel wurden mir von Herrn Max Bartels als muthmasslich neu zugesandt. Die genaue Untersuchung hat dies bestätigt. Ich freue mich daher eine der Arten zu Ehren des Entdeckers benennen zu können. Seit einigen Jahren als Leiter der Plantage Pangerango bei Pasir

  3. Classical diagnostic radiological features of Von Recklinghausen's ...

    African Journals Online (AJOL)

    Neurofibromatosis type 1(NF-1, Von Recklinghausen disease or peripheral NF) is a rare autosomal dominant disorder with varied clinical manifestations involving the skin, nerves and bones. It is the most common of the neurocutaneous syndromes, with variable pathological and clinical expression. Approximately half of all ...

  4. Joint bleeding in von Willebrand disease

    NARCIS (Netherlands)

    Galen, K.P.M. van

    2017-01-01

    Von Willebrand disease (VWD) is the most common inherited bleeding disorder occurring in approximately 1/100 people. Until now, joint bleeds did not get much attention in clinical research on VWD, since mucocutaneous bleeding is predominant. However, recurrent joint bleeds lead to arthropathy, the

  5. Das Druckprofil von Sportkompressionsstrümpfen.

    Science.gov (United States)

    Reich-Schupke, Stefanie; Surhoff, Stefan; Stücker, Markus

    2016-05-01

    Zunehmend werden Sportkompressionsstrümpfe (SKS) eingesetzt, doch fehlt eine Norm in Analogie zu medizinischen Kompressionsstrümpfen (MKS). Ziel dieser Pilotstudie war der Vergleich der Druckprofile von fünf SKS ex vivo und in vivo miteinander sowie mit MKS-Normen. CEP Running-Progressive-Socks, Falke Running--Energizing, Sigvaris Performance, X-Socks Speed-Metal-Energizer und 2XU Compression--Race-Socks wurden an zehn Leistungssportlern (standardisiert in vivo, Kikuhime--Sensor) sowie im Hohenstein Institut (ex vivo) hinsichtlich ihres Druckprofils getestet. Die Ex-vivo-Messungen im Fesselbereich von CEP (25,6 mmHg) und 2XU (23,2 mmHg) entsprachen der deutschen MKS-Klasse 2, von Sigvaris-SKS (20,8 mmHg) der deutschen MKS-Klasse 1. Die übrigen SKS lagen darunter. Die ermittelten Druckprofile differierten stark und entsprachen nicht der MKS-Norm. Die In-vivo-Messungen zeigten für drei SKS (2XU, CEP, Sigvaris) durchschnittlich einen höheren Anpressdruck als die SKS von Falke und X-Socks. Alle SKS lagen in vivo jedoch unter der deutschen MKS-Klasse 1. Kein SKS bot den für MKS geforderten Druckabfall vom Messpunkt B nach D. Die in vivo und ex vivo ermittelten SKS-Druckprofile zeigten heterogene Ergebnisse und folgten kaum den MKS-Anforderungen. Entsprechend sind auch die klinisch-praktischen Effekte von SKS nicht vergleichbar. Wünschenswert wäre eine SKS-Klassifikation, die erlaubt, Produkte einzuordnen, zu vergleichen und nach konkreten Vorlieben und Bedürfnissen (hoher vs. geringer Druck, progressiver vs. degressiver Gradient) auszuwählen. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  6. Thermal vacancies and phase separation in bcc mixtures of helium-3 and helium-4

    Energy Technology Data Exchange (ETDEWEB)

    Fraass, Benedick Andrew [Univ. of Illinois, Urbana-Champaign, IL (United States). Dept. of Physics

    1980-01-01

    Thermal vacancy concentrations in crystals of 3He-4He mixtures have been determined. A new x-ray diffractometer-position sensitive detector system is used to make measurements of the absolute lattice parameter of the helium crystals with an accuracy of 300 ppM, and measurements of changes in lattice parameters to better than 60 ppM. The phase separation of the concentrated3He-4He mixtures has been studied in detail with the x-ray measurements. Vacancy concentrations in crystals with 99%, 51%, 28%, 12%, and 0% 3He have been determined. Phase separation has been studied in mixed crystals with concentrations of 51%, 28%, and 12% 3He and melting pressures between 3.0 and 6.1 MPa. The phase separation temperatures determined in this work are in general agreement with previous work. The pressure dependence of Tc, the phase separation temperature for a 50% mixture, is found to be linear: dTc/dP = -34 mdeg/MPa. The x-ray measurements are used to make several comments on the low temperature phase diagram of the helium mixtures.

  7. LRO-LAMP Observations of Lunar Exospheric Helium

    Science.gov (United States)

    Grava, Cesare; Retherford, Kurt D.; Hurley, Dana M.; Feldman, Paul D.; Gladstone, Randy; Greathouse, Thomas K.; Cook, Jason C.; Stern, Alan; Pryor, Wayne R.; Halekas, Jasper S.; Kaufmann, David E.

    2015-11-01

    We present results from Lunar Reconnaissance Orbiter’s (LRO) UV spectrograph LAMP (Lyman-Alpha Mapping Project) campaign to study the lunar atmosphere. Two kinds of off-nadir maneuvers (lateral rolls and pitches towards and opposite the direction of motion of LRO) were performed to search for resonantly scattering species, increasing the illuminated line-of-sight (and hence the signal from atoms resonantly scattering the solar photons) compared to previously reported LAMP “twilight observations” [Cook & Stern, 2014]. Helium was the only element distinguishable on a daily basis, and we present latitudinal profiles of its line-of-sight column density in December 2013. We compared the helium line-of-sight column densities with solar wind alpha particle fluxes measured from the ARTEMIS (Acceleration, Reconnection, Turbulence, & Electrodynamics of Moon’s Interaction with the Sun) twin spacecraft. Our data show a correlation with the solar wind alpha particle flux, confirming that the solar wind is the main source of the lunar helium, but not with a 1:1 relationship. Assuming that the lunar soil is saturated with helium atoms, our results suggest that not all of the incident alpha particles are converted to thermalized helium, allowing for a non-negligible fraction (~50 %) to escape as suprathermal helium or simply backscattered from the lunar surface. We also support the finding by Benna et al. [2015] and Hurley et al. [2015], that a non-zero contribution from endogenic helium, coming from radioactive decay of 232Th and 238U within the mantle, is present, and is estimated to be (4.5±1.2) x 106 He atoms cm-2 s-1. Finally, we compare LAMP-derived helium surface density with the one recorded by the mass spectrometer LACE (Lunar Atmospheric Composition Experiment) deployed on the lunar surface during the Apollo 17 mission, finding good agreement between the two measurements. These LRO off-nadir maneuvers allow LAMP to provide unique coverage of local solar time and

  8. Theoretical model of the helium zone plate microscope

    Science.gov (United States)

    Salvador Palau, Adrià; Bracco, Gianangelo; Holst, Bodil

    2017-01-01

    Neutral helium microscopy is a new technique currently under development. Its advantages are the low energy, charge neutrality, and inertness of the helium atoms, a potential large depth of field, and the fact that at thermal energies the helium atoms do not penetrate into any solid material. This opens the possibility, among others, for the creation of an instrument that can measure surface topology on the nanoscale, even on surfaces with high aspect ratios. One of the most promising designs for helium microscopy is the zone plate microscope. It consists of a supersonic expansion helium beam collimated by an aperture (skimmer) focused by a Fresnel zone plate onto a sample. The resolution is determined by the focal spot size, which depends on the size of the skimmer, the optics of the system, and the velocity spread of the beam through the chromatic aberrations of the zone plate. An important factor for the optics of the zone plate is the width of the outermost zone, corresponding to the smallest opening in the zone plate. The width of the outermost zone is fabrication limited to around 10 nm with present-day state-of-the-art technology. Due to the high ionization potential of neutral helium atoms, it is difficult to build efficient helium detectors. Therefore, it is crucial to optimize the microscope design to maximize the intensity for a given resolution and width of the outermost zone. Here we present an optimization model for the helium zone plate microscope. Assuming constant resolution and width of the outermost zone, we are able to reduce the problem to a two-variable problem (zone plate radius and object distance) and we show that for a given beam temperature and pressure, there is always a single intensity maximum. We compare our model with the highest-resolution zone plate focusing images published and show that the intensity can be increased seven times. Reducing the width of the outermost zone to 10 nm leads to an increase in intensity of more than 8000

  9. Optomechanics in a Levitated Droplet of Superfluid Helium

    Science.gov (United States)

    Brown, Charles; Harris, Glen; Harris, Jack

    2017-04-01

    A critical issue common to all optomechanical systems is dissipative coupling to the environment, which limits the system's quantum coherence. Superfluid helium's extremely low optical and mechanical dissipation, as well as its high thermal conductivity and its ability cool itself via evaporation, makes the mostly uncharted territory of superfluid optomechanics an exciting avenue for exploring quantum effects in macroscopic objects. I will describe ongoing work that aims to exploit the unique properties of superfluid helium by constructing an optomechanical system consisting of a magnetically levitated droplet of superfluid helium., The optical whispering gallery modes (WGMs) of the droplet, as well as the mechanical oscillations of its surface, should offer exceptionally low dissipation, and should couple to each other via the usual optomechanical interactions. I will present recent progress towards this goal, and also discuss the background for this work, which includes prior demonstrations of magnetic levitation of superfluid helium, high finesse WGMs in liquid drops, and the self-cooling of helium drops in vacuum.

  10. Rotovibrational spectroscopy of hydrogen peroxide embedded in superfluid helium nanodroplets.

    Science.gov (United States)

    Raston, Paul L; Knapp, Chrissy J; Jäger, Wolfgang

    2011-11-14

    We report the infrared depletion spectrum of para- and ortho-hydrogen peroxide embedded in superfluid helium nanodroplets in the OH stretching region. Six transitions were observed in the antisymmetric stretching band (v(5)) of H(2)O(2), and three in the weaker symmetric stretching band (v(1)). While rotations about the b- and c-axes are slowed by a factor of ∼0.4 relative to the gas phase, rotations about the a-axis are not significantly affected; this relates to the rotational speed about the a-axis being too fast for helium density to adiabatically follow. The trans tunneling splitting does not appear to be considerably affected by the helium droplet environment, and is reduced by only 6% relative to the gas phase, under the assumption that the vibrational shifts of the v(5) and v(1) torsional subbands are the same. The linewidths increase with increasing rotorsional energies, and are significantly narrower for energies which fall within the "phonon gap" of superfluid helium. These narrower lines are asymmetrically broadened, indicative of a dynamical coupling between the H(2)O(2) rotor and surrounding helium density.

  11. Validation of Helium Inlet Design for ITER Toroidal Field Coil

    CERN Document Server

    Boyer, C; Hamada, K; Foussat, A; Le Rest, M; Mitchell, N; Decool, P; Savary, F; Sgobba, S; Weiss, K-P

    2014-01-01

    The ITER organization has performed design and its validation tests on a helium inlet structure for the ITER Toroidal Field (TF) coil under collaboration with CERN, KIT, and CEA-Cadarache. Detailed structural analysis was performed in order to optimize the weld shape. A fatigue resistant design on the fillet weld between the shell covers and the jacket is an important point on the helium inlet structure. A weld filler material was selected based on tensile test at liquid helium temperature after Nb3Sn reaction heat treatment. To validate the design of the weld joint, fatigue tests at 7 K were performed using heat-treated butt weld samples. A pressure drop measurement of a helium inlet mock-up was performed by using nitrogen gas at room temperature in order to confirm uniform flow distribution and pressure drop characteristic. These tests have validated the helium inlet design. Based on the validation, Japanese and European Union domestic agencies, which have responsibilities of the TF coil procurement, are pr...

  12. Development of Stirling cycle refrigerators as an alternative to cold-vapour refrigerators; Entwicklung von Stirling-Kaeltemaschinen alternativ zu Kaltdampf-Kaeltemaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Schikora, H.; Siegel, A.; Schiefelbein, K. [Essen Univ. (Gesamthochschule) (Germany). Inst. fuer Angewandte Thermodynamik und Klimatechnik

    1998-10-01

    For some years already, the Institut fuer Angewandte Thermodynamik und Klimatechnik has been studying Stirling cycle refrigerators using helium, a technical gas causing no environmental harm whatsoever. As calculations show, a Stirling refrigerator`s energetic performance is on a par with that of a single-stage, cold-vapour refrigerator if the heat emission temperature differs from the cold generation temperature by more than 55 K. As part of a research project sponsored by the federal ministry of science and technology which has been under way since January 1998, a Stirling refrigerator for deep-freezing at supermarkets is being developed. The results of this work are to demonstrate whether the theoretical calculations are correct and to mature, moreover, into a design not too remote from transfer to market. (orig.) [Deutsch] Das Institut fuer Angewandte Thermodynamik und Klimatechnik beschaeftigt sich seit einigen Jahren mit Stirling-Kaeltemaschinen, in denen das in jeder Beziehung umweltunschaedliche Arbeitsgas Helium eingesetzt wird. Die berechneten Leistungsdaten einer Stirling-Kaeltemaschine zeigen, dass bei Differenzen zwischen der Temperatur der Waermeabgabe und der Temperatur der Kaelteerzeugung von mehr als 55 K die Stirling-Kaeltemaschine mit einer einstufigen Kaltdampf-Kaeltemaschine in energetischer Hinsicht konkurrieren kann. Aus diesem Grund wird, in einem seit Januar 1998 laufenden BMBf-Forschungsvorhaben, eine Stirling-Kaeltemaschine fuer das Anwendungsgebiet `Tiefkuehlung in Supermaerkten` entwickelt. Die Ergebnisse dieser Entwicklungsarbeit sollen zum einen zeigen, ob die theoretischen Berechnungen richtig waren und zum anderen in einer Maschinenkonstruktion muenden, die nicht allzuweit von der Marktreife entfernt ist. (orig.)

  13. Integrales Lernen in und von Organisationen

    Directory of Open Access Journals (Sweden)

    Wendelin Kupers

    2006-06-01

    Full Text Available Bezogen auf das integrale Models von Ken Wilber untersucht der Beitrag die Bedeutung des Lernens in und von Organisationen. Nach einer Darstellung der Relevanz und des Grundverständnisses des Lernens im Organisationskontext, werden integrale Dimensionen des Lernens dargestellt. Im Einzelnen werden die verschiedenen Sphären eines inneren-subjektiven und äusseren-„objektiven“ Lernens des Einzelnen als auch ein gemeinschaftliches Lernen und Lernen im System auf der kollektiven Ebene dargestellt sowie deren interrelationaler Zusammenhang diskutiert. Schließlich beschreibt der Beitrag noch integrale Lernprozesse sowie integrale Gestaltungsfelder zur Förderung des Lernens in den verschiedenen Bereichen. Abschließend spricht der Artikel noch Schwierigkeiten und Probleme an sowie nimmt im Fazit ein perspektivischen Ausblick vor.

  14. Laboratory Testing for Von Willebrand Factor Multimers.

    Science.gov (United States)

    Oliver, Susan; Lau, Kun Kan Edwin; Chapman, Kent; Favaloro, Emmanuel J

    2017-01-01

    Von Willebrand disease (VWD) is reportedly the most common inherited bleeding disorder and can also arise as an acquired syndrome (AVWS). These disorders develop due to defects and/or deficiency of the plasma protein von Willebrand factor (VWF). Laboratory testing for the VWF-related disorders requires assessment of both VWF level and VWF activity, the latter requiring multiple assays because of the many functions carried out by VWF to help prevent bleeding. As an additional step, an evaluation of VWF structural features by multimer analysis is useful in selective investigations. The current paper therefore describes a protocol for assessment of VWF multimers by gel electrophoresis, thus enabling identification of protein bands that represent differently sized multimers. The sample protocol described in this chapter is the methodology developed by Sebia.

  15. Wir zeigen andere Bilder von Frauen ...

    Directory of Open Access Journals (Sweden)

    Bettina Rulofs

    2010-03-01

    Full Text Available Der vorliegende Beitrag beleuchtet die Bedeutung der Geschlechterordnung im Prozess der sportmedialen Kommunikation. Im Kern geht es um die Frage, inwiefern im Prozess der medialen Vermittlung von Sport traditionelle Geschlechterstereotype aufrechterhalten werden oder Möglichkeiten der Irritation solcher Stereotype bestehen. Dazu werden verschiedene Ebenen des massenmedialen Kommunikationsprozesses in den Blick genommen: die Medienprodukte, die Öffentlichkeitsarbeit und Selbst-Präsentation der Sportler/innen, die Medienrezeption und die Herstellungsprozesse von Medien in den Sportredaktionen. This article illustrates the relevance of gender in processes of sports media communication. The question in focus is in what way traditional gender stereotypes are perpetuated in the process of media communication in sport and how such stereotypes can be irritated. Therefore different levels of mass media communication are considered: the media products, the public relations of athletes and the presentation of themselves as athletes, the media-reception and the production processes in sport departments of media institutions.

  16. Virchow's triad: Kussmaul, Quincke and von Recklinghausen.

    Science.gov (United States)

    Stanifer, John W

    2016-02-01

    For most of the 19th century, Germany was the centre of the medical world. From there the most innovating research came and many of the physicians of that era are known to nearly every medical student and physician of today. Virchow, Kussmaul, Quincke, von Recklinghausen, Müller and Schönlein are familiar names in today's medicine but insofar as they are merely eponyms associated with signs, symptoms, disease and anatomy. The story of their lives, their research and their influence on each other has been little examined. This is an essay about Virchow's relationship with his mentors Müller and Schönlein and how these relationships shaped the development of Kussmaul, Quincke and von Recklinghausen as students of Virchow and their work in medicine and clinical observation after leaving Virchow's laboratory. © The Author(s) 2014.

  17. Evolution equations of von Karman type

    CERN Document Server

    Cherrier, Pascal

    2015-01-01

    In these notes we consider two kinds of nonlinear evolution problems of von Karman type on Euclidean spaces of arbitrary even dimension. Each of these problems consists of a system that results from the coupling of two highly nonlinear partial differential equations, one hyperbolic or parabolic and the other elliptic. These systems take their name from a formal analogy with the von Karman equations in the theory of elasticity in two dimensional space. We establish local (respectively global) results for strong (resp., weak) solutions of these problems and corresponding well-posedness results in the Hadamard sense. Results are found by obtaining regularity estimates on solutions which are limits of a suitable Galerkin approximation scheme. The book is intended as a pedagogical introduction to a number of meaningful application of classical methods in nonlinear Partial Differential Equations of Evolution. The material is self-contained and most proofs are given in full detail. The interested reader will gain a ...

  18. La Medea de Lars von Trier

    Directory of Open Access Journals (Sweden)

    Iratxe Fresneda Delgado

    2013-04-01

    Full Text Available El presente artículo analiza el modo en el que Lars von Trier recrea para el cine el estereotipo de Medea. Mediante el análisis fílmico de la película y apoyándose en los estudios culturales, el texto se interroga acerca de la importancia y el poder potencial del cine a la hora recuperar el antiguo mito y demostrar su vigencia. El análisis amplía horizontes para la compresión de los mecanismos que articulan el entramado de significados de la película, donde Von Trier aporta una nueva visión del arquetipo de Medea uniéndola, a la tradición pictórica del Romanticismo. Una influencia que habita en las posteriores obras del director danés, donde el paisaje, la naturaleza, se erige en elemento catalizador de las pulsiones humanas, en su cómplice y testigo.This paper explores the way that Lars von Trier’s film recreates the stereotype of Medea. Using film analysis and based on cultural studies the article asks about the importance and potential power of cinema to recover the ancient myth and show their effects. The analysis expands horizons for the understanding of the mechanisms that link the network of meanings of the film, where the author offers a new vision of Medea's archetype attaching it to the pictorial tradition tied to the Romanticism. An influence that can be seen in the later works of Lars von Trier, where the landscape, the nature, stands as a catalyst of human drives, as his accomplice and witness.

  19. Von Medien, Übertragungen und Automaten

    Directory of Open Access Journals (Sweden)

    Alessandro Barberi

    2013-12-01

    Full Text Available Im Zuge der Debatten zum Medialen Habitus wurde vielfach betont, dass die >Theorie der Praxispraxeologischen Medientheorie< des Medialen Habitus avant la lettre gesprochen werden kann. Dieser Artikel untersucht – ausgehend von den Debatten zur "Medienkompetenz" – wie Bourdieu Sprache, Sprechen und Diskurs, sowie Akteure, Felder und Habitus als Medien begreift und betont dabei die Nützlichkeit der Bourdieuschen Bildungssoziologie im Rahmen einer sozialwissenschaftlichen Grundlegung der Medienpädagogik.

  20. Untersuchungen von Nanostrukturen magnetischer Kolloide mit Kleinwinkelstreuung

    OpenAIRE

    Kammel, Martin

    2005-01-01

    Mit Hilfe der Neutronenkleinwinkelstreuung mit polarisieren Neutronen wird eine Analyse so genannter Ferrofluide durchgeführt. Ferrofluide sind Dispersionen magnetisierbarer Teilchen, welche durch in den meisten Fällen organische Hüllen gegen irreversibler Aggregation geschützt sind. Anhand von verdünnten Magnetit-Kolloidlösungen wurden als Stabilisierung Dextran, Tenside (Laurinsäure/Marlipal) und elektrostatisch stabilisierte Magnetitteilchen untersucht. Dabei fanden sich in jedem dieser Fl...

  1. Maschinelle Erkennung von Verkehrsteilnehmern mittels heterogener Sensorik

    OpenAIRE

    Walchshäusl, Leonhard

    2009-01-01

    In modernen Fahrzeugen halten verstärkt Fahrerassistenzsysteme zum Insassenschutz und zum Schutz anderer Verkehrsteilnehmer Einzug. Typische, bereits seit längerem verfügbare Systeme, wie Airbag und Antiblockiersystem, erreichen schon heute eine hohe Marktdurchdringung. Künftige aktive Sicherheitssysteme, die von der Kollisionswarnung bis hin zur autonomen Gefahrenbremsung reichen, sind Gegenstand aktueller Forschung. Insbesondere Systeme, die aktiv in das Fahrgeschehen eingreifen, erfordern ...

  2. Mikrobieller Befall von Elektrotauchlack in der Automobilindustrie

    OpenAIRE

    Gühring, Ina Katrin

    2000-01-01

    Nach Umstellung auf umweltverträglichere Lackmaterialien (Reduzierung biozid wirkender Lösemittel, Schwermetalle) traten in Elektrotauchanlagen verschieder Werke der DaimlerChrysler AG vermehrt Beschichtungsstörungen bei Karossen auf. Dabei war ein pH-Anstieg des Lackmaterials, Schichtdickenanstieg, Abblättern des Lacks („Striptease“ Effekt), Oberflächenstörungen (Pusteln, Blasen, Krater), schlechter Umgriff, eine Bildung von Lackschlamm und geringerer Schichtwiderstand zu beobachten. Gleichz...

  3. Die Usability von Rich Internet Applications

    Science.gov (United States)

    Linder, Jörg

    Interaktiven Services, die dem Themenkreis Web 2.0 zugeordnet werden, haftet unter anderem das Attribut an, besonders leicht bedienbar zu sein. Flickr, Youtube und Wikipedia gelten als Erfolgsprojekte dieser neuen Art von interaktiven Websites. Wodurch zeichnet sich nun eine Usability 2.0 (so es sie überhaupt geben sollte) aus? Was ist zu beachten, wenn so genannte Rich Internet Applications gestaltet werden?

  4. Therapie von Vorhofflimmern: Rolle der Katheterablation

    OpenAIRE

    Hindricks G; Kircher S; Gaspar T.; Arya A

    2009-01-01

    Vorhofflimmern ist die häufigste Herzrhythmusstörung in der Gesamtbevölkerung und geht einher mit erhöhter Morbidität und Mortalität. Als prinzipielle Behandlungskonzepte stehen die "Frequenzkontrolle" und die "Rhythmuskontrolle" zur Verfügung. Während sich die medikamentöse Rhythmuskontrolle als insgesamt unzureichend erwiesen hat, stellt die Katheterablation von Vorhofflimmern einen etablierten, potenziell kurativen Therapieansatz mit beachtlichen Erfolgsraten dar. Obwohl hinsichtlich d...

  5. Modellierung von Preiserwartungen durch neuronale Netze

    OpenAIRE

    Heinemann, Maik; Lange, Carsten

    1997-01-01

    Das Papier untersucht, wie Erwartungsbildung mit Hilfe neuronaler Netze modelliert werden kann. Die Grundlage bildet ein Cobweb-Modell, in dem Firmen Preiserwartungen auf Basis eines Feedforward-Netzes bilden.Zunächst wird anhand von Simulationen gezeigt, daß Firmen durch neuronale Erwartungsbildung approximativ rationale Erwartungen bilden können. Im Gegensatz zur Hypothese rationaler Erwartungen ist dafür die Kenntnis des relevanten Modells nicht mehr erforderlich, lediglich Beobachtungen d...

  6. Expression von Blutgruppenantigenen durch humane mesenchymale Stammzellen

    OpenAIRE

    Schüle, Michael Christian

    2013-01-01

    Die vorliegende experimentelle Arbeit befasst sich mit der Untersuchung der Expression von Blutgruppenantigenen durch humane mesenchymale Stammzellen (MSC) aus dem Knochenmark. Der Fokus lag hierbei auf den klinisch bedeutsamen Antigenen A, B, H, Rhesus-D, -C, -c, -E, -e, RhAG, K, k, Jka, Jkb und DARC. Die Expression wurde systematisch auf Genom-, Transkriptom- und Proteinebene evaluiert. Alle untersuchten MSC Populationen exprimierten FUT1, RHCE, KEL und Kidd (HUT11) mRNA. mRNA der AB0-Gl...

  7. Weitere Vorkommen von Impatiens capensis in Hessen

    OpenAIRE

    Nawrath, Stefan

    1996-01-01

    Neue hessische Fundorte von Impatiens capensis aus dem Taunus und dessen Vorland sowie aus der Rheinebene werden berichtet. Die insbesondere im Schwarzbach-System zahlreichen Fundorte werden beschrieben und in einer Verbreitungskarte dargestellt. New Hessian stations of Impatiens capensis in the Taunus mountains as well as their foothills and in the Rhine valley are reported on. The stations which are particularly numerous in the Schwarzbach system, are described and demonstrated on a dist...

  8. Photoionization Energies and Oscillator Strengths of Helium and Helium-like Ions

    Science.gov (United States)

    Faye, N. A. B.; Ndao, A. S.; Konte, A.; Biaye, M.; Wague, A.

    2005-10-01

    We first studied the resonant photoionization of helium-like ions, such as C4+, N5+, and O6+, and determined the wave functions, the excitation energies, and the partial and total widths of the autoionizing states of these ions lying under the n = 3 thresholds of the residual ion. For more detailed analysis of the theory, and a better comprehension of the internal dynamics of atomic resonances and electronic phenomena of correlation, we extended these calculations to other helium-like ions, under higher thresholds (n = 4 and 5) of the hydrogen ions H-, and of Li+, C4+, N5+, and O6+. We were also interested in oscillator strengths. These parameters are important for interpreting the spectra and diagnosing astrophysical and laboratory plasmas, as well as for analyzing the spectra coming from space and determining the composition and relative abundance from the various elements of the stellar and interstellar environment. We sought a better comprehension of the coupling between autoionizing and continuum states and of the phenomena of electronic correlations. We used the method of diagonalization that has been used below the n = 2 threshold of the residual ion. The results are important for astrophysicists and physicists studying matter-radiation interaction and for the invention of new laser systems. We also measured laser-induced chlorophyll fluorescence (LICF) emission spectra of the leaves of some tropical plants using a compact fiber-optic fluorosensor with a continuous-wave violet diode laser as the exciting source and an integrated digital spectrometer to analyze the state of stress of the plants.

  9. Helium heater design for the helium direct cycle component test facility. [for gas-cooled nuclear reactor power plant

    Science.gov (United States)

    Larson, V. R.; Gunn, S. V.; Lee, J. C.

    1975-01-01

    The paper describes a helium heater to be used to conduct non-nuclear demonstration tests of the complete power conversion loop for a direct-cycle gas-cooled nuclear reactor power plant. Requirements for the heater include: heating the helium to a 1500 F temperature, operating at a 1000 psia helium pressure, providing a thermal response capability and helium volume similar to that of the nuclear reactor, and a total heater system helium pressure drop of not more than 15 psi. The unique compact heater system design proposed consists of 18 heater modules; air preheaters, compressors, and compressor drive systems; an integral control system; piping; and auxiliary equipment. The heater modules incorporate the dual-concentric-tube 'Variflux' heat exchanger design which provides a controlled heat flux along the entire length of the tube element. The heater design as proposed will meet all system requirements. The heater uses pressurized combustion (50 psia) to provide intensive heat transfer, and to minimize furnace volume and heat storage mass.

  10. A cryogenic axial-centrifugal compressor for superfluid helium refrigeration

    CERN Document Server

    Decker, L; Schustr, P; Vins, M; Brunovsky, I; Lebrun, P; Tavian, L

    1997-01-01

    CERN's new project, the Large Hadron Collider (LHC), will use superfluid helium as coolant for its high-field superconducting magnets and therefore require large capacity refrigeration at 1.8 K. This may only be achieved by subatmospheric compression of gaseous helium at cryogenic temperature. To stimulate development of this technology, CERN has procured from industry prototype Cold Compressor Units (CCU). This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating under low-pressure helium at ambient temperature. The machine has been commissioned and is now in operation. After describing basic constructional features of the compressor, we report on measured performance.

  11. Helium and neon isotopes in deep Pacific Ocean sediments

    Science.gov (United States)

    Nier, A. O.; Schlutter, D. J.; Brownlee, D. E.

    1990-01-01

    Helium and neon concentration measurements, along with isotope ratio determinations, have been made for particles collected in the deep Pacific with a magnetic sled, and they are believed to be of extraterrestrial origin. Analyses were made for samples consisting of composites of many extremely fine particles and for several individual particles large enough to contain sufficient gas for analysis but small enough to escape melting in their passage through the atmosphere. Step-heating was employed to extract the gas. Cosmic-ray spallation products or solar-wind helium and neon, if present, were not abundant enough to account for the isotopic compositions measured. In the case of the samples of magnetic fines, the low temperature extractions provided elemental and isotopic ratios in the general range found for the primordial gas in carbonaceous chondrites and gas-rich meteorites. The isotopic ratios found in the high temperature extractions suggest the presence of solar-flare helium and neon.

  12. The Story of Helium and the Birth of Astrophysics

    CERN Document Server

    Nath, Biman B

    2013-01-01

    Biman Nath The Story of Helium and the Birth of Astrophysics Helium was the first element ever discovered by astronomers. Its presence was first indicated in the Sun and not on Earth. Further, its discovery marked the birth of the new science of astrophysics. However, it turns out that the events leading to the discovery of helium have been rather misrepresented in books, journals, and even encyclopedias. The usual story about its joint discovery during a solar eclipse in 1868 by French astronomer Pierre Janssen and late in England by Norman Lockyer, is far from the truth. Janssen never mentioned any new spectral line in his reports. The actual story turns out to be as dramatic as in fiction. This book tells the story without jargon, using the words of the scientists themselves (from their letters and reports), and rescues the real story from the backwaters of history.

  13. Commissioning of the JT-60SA helium refrigerator

    Science.gov (United States)

    Kamiya, Koji; Natsume, Kyohei; Ohtsu, Kiichi; Oishi, Makoto; Honda, Atsushi; Kashiwa, Yoshitoshi; Kizu, Kaname; Koide, Yoshihiko; Hoa, Christine; Michel, Frederic; Roussel, Pascal; Lamaison, Valerie; Bonne, Francois; Dipietro, Enrico; Cardella, Antonino; Wanner, Manfred; Legrand, Jerome; Pudys, Vincent; Langevin, Baptiste

    2017-09-01

    The JT-60SA project will use superconducting magnets to confine the plasma and achieve a plasma current with a typical flat top duration of 100 second in purely inductive mode. The helium refrigerator has an equivalent cooling power of 9 kW at 4.5 K providing 3.7 K, 4.5 K, 50 K and 80 K for the diverter cryopump, the superconducting magnets, the HTS current leads, and the thermal shields, respectively. This paper summarizes the JT-60SA helium refrigerator commissioning activities aiming at successful operation of heat load smoothing technology to manage the 12 kW heat pulses by 9 kW cooling power using a 7000 liter liquid helium.

  14. A quantitative experiment on the fountain effect in superfluid helium

    Science.gov (United States)

    Amigó, M. L.; Herrera, T.; Neñer, L.; Peralta Gavensky, L.; Turco, F.; Luzuriaga, J.

    2017-09-01

    Superfluid helium, a state of matter existing at low temperatures, shows many remarkable properties. One example is the so called fountain effect, where a heater can produce a jet of helium. This converts heat into mechanical motion; a machine with no moving parts, but working only below 2 K. Allen and Jones first demonstrated the effect in 1938, but their work was basically qualitative. We now present data of a quantitative version of the experiment. We have measured the heat supplied, the temperature and the height of the jet produced. We also develop equations, based on the two-fluid model of superfluid helium, that give a satisfactory fit to the data. The experiment has been performed by advanced undergraduate students in our home institution, and illustrates in a vivid way some of the striking properties of the superfluid state.

  15. Helium and mercury in the central Seward Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Wescott, E.; Ruscetta, C.A.; Foley, D. (eds.)

    1981-05-01

    The central Seward Peninsula, Alaska, has one Known Geothermal Resource Area (KGRA) at Pilgrim Springs, and has recent volcanic flows, fault systems, topographic and tectonic features which can be explained by a rift model. As part of a geothermal reconnaissance of the area we used helium and mercury concentrations in soil as indicators of geothermal resources. The largest helium concentrations were found in the vicinity of the Pilgrims Springs KGRA, and indicate prime drilling sites. Five profile lines were run across the suspected rift system. Significant helium anomalies were found on several of the traverses, where future exploration might be concentrated. Mercury values showed a great range of variability on the traverses, and seem unreliable as geothermal indicators except in the vicinity of the Pilgrim Springs. Permafrost at the surface resulting in variations in sampling depth may contribute to the mercury variations.

  16. Supersonic jets of hydrogen and helium for laser wakefield acceleration

    CERN Document Server

    Svensson, K.; Wojda, F.; Senje, L.; Burza, M.; Aurand, B.; Genoud, G.; Persson, A.; Wahlström, C.-G.; Lundh, O.

    2016-01-01

    The properties of laser wakefield accelerated electrons in supersonic gas flows of hydrogen and helium are investigated. At identical backing pressure, we find that electron beams emerging from helium show large variations in their spectral and spatial distributions, whereas electron beams accelerated in hydrogen plasmas show a higher degree of reproducibility. In an experimental investigation of the relation between neutral gas density and backing pressure, it is found that the resulting number density for helium is ∼30% higher than for hydrogen at the same backing pressure. The observed differences in electron beam properties between the two gases can thus be explained by differences in plasma electron density. This interpretation is verified by repeating the laser wakefield acceleration experiment using similar plasma electron densities for the two gases, which then yielded electron beams with similar properties.

  17. HEATHER - HElium Ion Accelerator for RadioTHERapy

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Jordan [Huddersfield U.; Edgecock, Thomas [Huddersfield U.; Green, Stuart [Birmingham U.; Johnstone, Carol [Fermilab

    2017-05-01

    A non-scaling fixed field alternating gradient (nsFFAG) accelerator is being designed for helium ion therapy. This facility will consist of 2 superconducting rings, treating with helium ions (He²⁺ ) and image with hydrogen ions (H + 2 ). Currently only carbon ions are used to treat cancer, yet there is an increasing interest in the use of lighter ions for therapy. Lighter ions have reduced dose tail beyond the tumour compared to carbon, caused by low Z secondary particles produced via inelastic nuclear reactions. An FFAG approach for helium therapy has never been previously considered. Having demonstrated isochronous acceleration from 0.5 MeV to 900 MeV, we now demonstrate the survival of a realistic beam across both stages.

  18. [Orthopaedic manifestations of Von Recklinghausen's neurofibromatosis].

    Science.gov (United States)

    Trigui, Moez; Ayadi, Kamel; Sakka, Mourad; Zribi, Wassim; Frikha, Faten; Gdoura, Fakher; Sallemi, Sami; Zribi, Mohamed; Keskes, Hassib

    2011-03-01

    Von Recklinghausen's neurofibromatosis is a dominant autosomic genetic disease characterized by different clinical manifestations. The goal of this work was to study its orthopaedic manifestations and to show the characteristics of their management. A retrospective study was carried out on 15 patients having a Von Recklinghausen's neurofibromatosis. For each patient, different orthopaedic manifestations and their evolution after treatment were analyzed. These manifestations were classified in spinal deformities, pseudarthrosis of long bones and tumours of the peripheral nerves. The spinal deformities were observed in 9 cases. A dystrophic scoliosis was observed in 6 patients with an average angle of 50° and was associated to a kyphosis in 5 patients. The treatment was surgical by posterior arthrodesis in 2 cases and circumferential arthrodesis in 2 cases. The congenital curves and pseudarthroses of leg were observed in 5 cases, localized at the lower third of the leg in all cases. An Ilizarov external fixator with segmental osseous transport was carried out in 2 patients. The duration of the external fixator was 23 months ½ with 5 interventions in each case. Four plexiform neurofibromas and 3 nodular neurofibromas were observed. A transformation into neurofibrosarcoma was found in 2 patients. In one case, a resection without functional sacrifice was carried out and in the other case the patient was dead before the resection. The orthopaedic manifestations of Von Recklinghausen's neurofibromatosis are frequent, varied and have a difficult management. The functional and sometimes vital prognoses are challenging. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  19. Treatment of patients with von Willebrand disease

    Directory of Open Access Journals (Sweden)

    Tuohy E

    2011-04-01

    Full Text Available Emma Tuohy1, Emma Litt1, Raza Alikhan1,21Department of Haematology, University Hospital of Wales, Cardiff, UK; 2Haemophilia and Thrombosis Centre, University Hospital of Wales, Cardiff, UKAbstract: Von Willebrand disease (vWD is the most common hereditary bleeding disorder. The aim of therapy is to correct the dual hemostatic defect, due to defective platelet adhesion-aggregation and abnormal coagulation due to Factor VIII (FVIII deficiency. The choice of treatment depends on a number of factors, including the severity of the bleed, the procedure planned, the subtype and severity of the disease and the age and morbidity of the patient. Desmopressin (DDAVP is the treatment of choice for type 1 vWD as it increases endogenous release of FVIII and von Willebrand factor (vWF and is also used in some subtypes of type 2 vWD. In those patients in whom DDAVP is ineffective or contraindicated, levels can be restored by infusing vWF:FVIII concentrates. The role of antifibrinolytic treatment is an important adjunct to replacement therapy during minor or major surgery involving mucosal surfaces. The dosing and timing of vWF:FVIII concentrates is important depending on the nature of the surgical procedure. The role of secondary prophylaxis needs to be further defined.Keywords: von Willebrand disease, treatment, DDAVP 

  20. 3D CFD Transient Numerical Simulation of Superfluid Helium

    Science.gov (United States)

    Bruce, R.; Reynaud, J.; Pascali, S.; Baudouy, B.

    2017-12-01

    Numerical simulations of superfluid helium are necessary to design the next generation of superconducting accelerator magnets at CERN. Previous studies have presented the thermodynamic equations implemented in the Fluent CFD software to model the thermal behavior of superfluid helium. Momentum and energy equations have been modified in the solver to model a simplified two-fluid model. In this model, the thermo-mechanical effect term and the Gorter-Mellink mutual friction term are the dominant terms in the momentum equation for the superfluid component. This assumption is valid for most of superfluid applications. Transient thermal and dynamic behavior of superfluid helium has been studied in this paper. The equivalent thermal conductivity in the energy equation is represented by the Gorter-Mellink term and both the theoretical and the Sato formulation of this term have been compared to unsteady helium superfluid experiments. The main difference between these two formulations is the coefficient to the power of the temperature gradient between the hot and the cold part in the equivalent thermal conductivity. The results of these unsteady simulations have been compared with two experiments. The first one is a Van Sciver experiment on a 10 m long, and 9 mm diameter tube at saturation conditions and the other, realized in our laboratory, is a 150×50×10 mm rectangular channel filled with pressurized superfluid helium. Both studies have been performed with a heating source that starts delivering power at the beginning of the experiment and many temperature sensors measure the transient thermal behavior of the superfluid helium along the length of the channel.

  1. Application of helium isotopes to studies of ocean circulation

    Science.gov (United States)

    Schlosser, P.; Newton, R.; Winckler, G.; Lupton, J.; Jenkins, W.; Top, Z.; Roether, W.; Jean-Baptiste, P.

    2004-12-01

    Since the discovery of excess He-3 in the ocean by Clarke and Craig in the 1960's helium isotopes have been used in local, regional and global studies of circulation patterns and water mass transformation in the world ocean. From initial pilot studies through systematic exploration of these tracers during the GEOSECS (Geochemical Ocean Sections) program to the recent global survey as part of the WOCE (World Ocean Circulation Experiment) hydrographic program (WHP) we obtained more detailed information on the distribution of helium isotopes, as well as their sources and sinks in the ocean. This information can now be applied to construct global fields of helium isotopes and to extract unique information on the circulation patterns at different depth levels in the ocean, as well as on local and regional processes such as ventilation of water masses in deep water formation regions. Additionally, the data sets are now sufficiently large to be useful for validation of Ocean General Circulation Models (OGCM's). In this contribution we present examples of global helium isotope fields constructed from major programs such as GEOCECS, TTO (Transient Tracers in the Ocean), SAVE (South Atlantic Ventilation Experiment) and WOCE, as well as from individual ocean sections. We use the data to delineate circulation patterns in the major ocean basins at several depth levels, especially mid-depth waters. Additionally, we outline the use of helium isotopes in studies of ocean ventilation. Finally, we compare observed and simulated helium isotope fields to highlight OGCM capabilities and deficiencies to reproduce internal He-3 excesses in the ocean and the related ventilation processes.

  2. Gestalt und Funktion von Animal Design : Versuch einer semiotischen Analyse

    OpenAIRE

    Schlüter, Wolfgang

    2009-01-01

    Dissertation zur Gestalt und Funktion von Animal Design (tieranaloges Design). Untersucht wird eine Auswahl an Produkten, die in ihrem Äußeren an Tiere erinnern. Hierbei stehen Aspekte wie die Emotionalisierung von Produkten, demonstrativer Konsum und die soziale Funktion im Fokus der Analyse. Anhand von Abbildungen und Zeichnungen wird u.a. dargestellt, welche Bedeutung die Tiergestalt für das jeweilige Produktdesign hat. Die Objekte werden jeweils unter phänomenologischen, hermeneutischen u...

  3. Bioethik in der Ukraine: Von Medizinischer zur Integrativen Bioethik

    OpenAIRE

    Gubenko, Anna

    2014-01-01

    Im Artikel wird die Chronologie der Entstehung und Entwicklung der Bioethik in der Ukraine analysiert. Dabei werden drei Hauptetappen der Herausbildung von Bioethik als a) einer gesellschaftlichen Organisation, b) einer Lerndisziplin und c) einer integrativen Wissenschaft unterschieden. Der Autor hat den Vektor von medizinischer zur integrativen Bioethik durch Ausbildung und soziale sowie pädagogische Praktiken bezeichnet. In diesem Sinne wird der Begriff von “pädagogischer Bioethik“ einge...

  4. Portrait of Dr. Von Braun with Walt Disney, 1954.

    Science.gov (United States)

    1954-01-01

    Marshall Center Director Dr. Wernher Von Braun is pictured with Walt Disney during a visit to the Marshall Space Flight Center in 1954. In the 1950s, Dr. Von Braun while working in California on the Saturn project, also worked with Disney studios as a technical director in making three films about Space Exploration for television. Disney's tour of Marshall in 1965 was Von Braun's hope for a renewed public interest in the future of the Space Program at NASA.

  5. Risiko und Akzeptanz von Industrieansiedlungen: Eine empirische Studie

    OpenAIRE

    Burgemeister, Jörg; Weber, Martin

    1992-01-01

    In der Bundesrepublik Deutschland stoßen Industrieansiedlungen oft auf den Widerstand der Bevölkerung. Bei der Akzeptanz einer Ansiedlung sind von den Bürgern subjektiv wahrgenommene Risiken und Nutzen der Ansiedlung von erheblicher Bedeutung. In einer Fragebogenstudie haben wir untersucht, wie Personen die Nutzen und Risiken von Industrieansiedlungen einschätzen, inwieweit sie Absiedlungen akzeptieren, welche Bestimmungsfaktoren ihren Risiko- und Akzeptanzurteilen zugrundeliegen, und wie sic...

  6. Erfolgsfaktoren von Internet-Auktionen: Eine empirische Analyse in PLS

    OpenAIRE

    Fritz, Wolfgang; Möllenberg, Antje; Dees, Heiko

    2004-01-01

    Internet-Auktionen haben sich zu einem der erfolgreichsten Geschäftsmodelle im E-Commerce entwickelt. Die stetig steigende Anzahl von Auktionen beim Marktführer eBay zeugen von einer zunehmenden Beliebtheit solcher Auktionen. Doch welche Determinanten beeinflussen den Erfolg einer Internet-Auktion? Im vorliegenden Beitrag wird dieses Thema aus dem Blickwinkel des Verkäufers am Beispiel von Ticket-Auktionen empirisch untersucht. Im Mittelpunkt steht dabei eine Kausalanalyse, die den Einfluss v...

  7. Saage tuttavaks : Elisabeth ja Karl von Hoerschelmann / Mai Levin

    Index Scriptorium Estoniae

    Levin, Mai, 1942-

    2004-01-01

    Kuraator M. Levin kuni 10. X 2004 Adamson-Ericu muuseumis avatud näitusest "Tuntud ja tundmatud Elisabeth von Rosendorff-Hoerschelmann ja Karl von Hoerschelmann". Enamik töid on kunstnike laste Konstantin Hoerschelmanni ja Anna Röder-Hoerschelmanni omand. Elisabeth Rosendorff (1898-1984) sündis Virumaal Maidlas eesti perekonnas, Karl von Hoerschelmann (1899-1951) Sevastoopolis saksa perekonnas

  8. Abbaukinetiken - und mechanismen von Lignin und Vanillin unter hydrothermalen Bedingungen

    OpenAIRE

    Curtze, Jan Henning

    2017-01-01

    Eine Methode zur energetischen Aufkonzentrierung von feuchten Abfallbiomassen ist die Hydrothermale Carbonisierung (HTC). Um technische HTC-Reaktoren rational auslegen zu können, sollte die Formalkinetik der vier Hauptkomponenten von Biomasse - Kohlenhydrate, Lignin, Fette/Öle und Proteine – bekannt sein. Des Weiteren spielt die Änderungskinetik des Feststoffes während der HTC eine wichtige Rolle. Der Fokus dieser Arbeit liegt auf der Untersuchung der HTC von Lignin, was ein hochkomplexes, ch...

  9. Studien zur Kinetik der Fehlfaltung un Aggregation von Proteinen

    OpenAIRE

    Modler, Andreas Johannes

    2003-01-01

    Diese Arbeit befasst sich mit der Kinetik der Fehlfaltung und Aggregation von Proteinen. Anhand dreier Beispiele, der Phosphoglyceratkinase (PGK) aus Hefe, einer Variante von Barstar und des Prion-Proteins des Syrischen Hamsters (SHaPrP(90-232)) wurde insbesondere die Kinetik der Bildung von Amyloidfibrillen und deren kinetischer Vorläuferstrukturen mittels dynamischer und statischer Lichtstreuung, Circulardichroismus, Infrarotspektroskopie, Elektronenmikroskopie und teilweise analytischer Ch...

  10. Radioactive core ions of microclusters, ``snowballs`` in superfluid helium

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, N. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Shimoda, T. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Fujita, Y. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Miyatake, H. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Mizoi, Y. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Kobayashi, H. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Sasaki, M. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Shirakura, T. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Itahashi, T. [Research Center for Nuclear Physics, Osaka Univ., Ibaraki (Japan); Mitsuoka, S. [Research Center for Nuclear Physics, Osaka Univ., Ibaraki (Japan); Matsukawa, T. [Naruto Univ. of Education, Tokushima (Japan); Ikeda, N. [Kyushu Univ., Fukuoka (Japan). Dept. of Physics; Morinobu, S. [Kyushu Univ., Fukuoka (Japan). Dept. of Physics; Hinde, D.J. [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences; Asahi, K. [Tokyo Inst. of Tech. (Japan). Dept. of Physics; Ueno, H. [Tokyo Inst. of Tech. (Japan). Dept. of Physics; Izumi, H. [Tokyo Inst. of Tech. (Japan). Dept. of Physics

    1996-12-01

    Short-lived beta-ray emitters, {sup 12}B, sustaining nuclear spin polarization were introduced into superfluid helium. The nuclear polarization of {sup 12}B was observed via measurement of beta-ray asymmetry. It was found that the nuclear polarization was preserved throughout the lifetime of {sup 12}B (20.3 ms). This suggests that the ``snowball``, an aggregation of helium atoms produced around an alien ion, constitutes a suitable milieu for freezing-out the nuclear spin of the core ion and that most likely the solidification takes place at the interior of the aggregation. (orig.).

  11. High temperature indentation of helium-implanted tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, James S.K.-L., E-mail: james.gibson@materials.ox.ac.uk [Oxford University, Department of Materials, Parks Road, Oxford OX1 3PH (United Kingdom); Roberts, Steve G. [Oxford University, Department of Materials, Parks Road, Oxford OX1 3PH (United Kingdom); Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Armstrong, David E.J. [Oxford University, Department of Materials, Parks Road, Oxford OX1 3PH (United Kingdom)

    2015-02-11

    Nanoindentation has been performed on tungsten, unimplanted and helium-implanted to ~600 appm, at temperatures up to 750 °C. The hardening effect of the damage was 0.90 GPa at 50 °C, but is negligible above 450 °C. The hardness value at a given temperature did not change on re-testing after heating to 750 °C. This suggests that the helium is trapped in small vacancy complexes that are stable to at least 750 °C, but which can be bypassed due to increased dislocation mobility (cross slip or climb) above 450 °C.

  12. Supercritical Helium Cooling of the LHC Beam Screens

    CERN Document Server

    Hatchadourian, E; Tavian, L

    1998-01-01

    The cold mass of the LHC superconducting magnets, operating in pressurised superfluid helium at 1.9 K, must be shielded from the dynamic heat loads induced by the circulating particle beams, by means of beam screens maintained at higher temperature. The beam screens are cooled between 5 and 20 K by forced flow of weakly supercritical helium, a solution which avoids two-phase flow in the long, narr ow cooling channels, but still presents a potential risk of thermohydraulic instabilities. This problem has been studied by theoretical modelling and experiments performed on a full-scale dedicated te st loop.

  13. Hydrogen-Helium shock Radiation tests for Saturn Entry Probes

    Science.gov (United States)

    Cruden, Brett A.

    2016-01-01

    This paper describes the measurement of shock layer radiation in Hydrogen/Helium mixtures representative of that encountered by probes entering the Saturn atmosphere. Normal shock waves are measured in Hydrogen-Helium mixtures (89:11% by volume) at freestream pressures between 13-66 Pa (0.1-0.5 Torr) and velocities from 20-30 km/s. Radiance is quantified from the Vacuum Ultraviolet through Near Infrared. An induction time of several centimeters is observed where electron density and radiance remain well below equilibrium. Radiance is observed in front of the shock layer, the characteristics of which match the expected diffusion length of Hydrogen.

  14. A Neutron Scattering Study of Collective Excitations in Superfluid Helium

    DEFF Research Database (Denmark)

    Graf, E. H.; Minkiewicz, V. J.; Bjerrum Møller, Hans

    1974-01-01

    Extensive inelastic-neutron-scattering experiments have been performed on superfluid helium over a wide range of energy and momentum transfers. A high-resolution study has been made of the pressure dependence of the single-excitation scattering at the first maximum of the dispersion curve over...... of the multiexcitation scattering was also studied. It is shown that the multiphonon spectrum of a simple Debye solid with the phonon dispersion and single-excitation cross section of superfluid helium qualitatively reproduces these data....

  15. K2 spots rotation in the helium star HD144941

    Science.gov (United States)

    Jeffery, C. Simon; Ramsay, Gavin

    2018-02-01

    HD144941 is an evolved early-type metal-poor low-mass star with a hydrogen-poor surface. It is frequently associated with other intermediate helium-rich subdwarfs and extreme helium stars. Previous photometric studies have failed to detect any variability. New observations with the K2 mission show complex but periodic variations with a full amplitude of 4 parts per thousand. It is proposed that these are due to an inhomogeneous surface brightness distribution (spots) superimposed on a rotation period of 13.9 ± 0.2 d. The cause of the surface inhomogeneity is not identified, although an oblique dipolar magnetic field origin is plausible.

  16. Conductivity change of defective graphene by helium ion beams

    Directory of Open Access Journals (Sweden)

    Yuichi Naitou

    2017-04-01

    Full Text Available Applying a recently developed helium ion microscope, we demonstrated direct nano-patterning and Anderson localization of single-layer graphene (SLG on SiO2/Si substrates. In this study, we clarified the spatial-resolution-limitation factor of direct nano-patterning of SLG. Analysis of scanning capacitance microscopy measurements reveals that the conductivity of helium ion (H+-irradiated SLG nanostructures depends on their geometrical size, i.e., the smaller the H+-irradiated SLG region, the higher its conductivity becomes. This finding can be explained by the hopping carrier transport across strongly localized states of defective SLG.

  17. REVIEWS OF TOPICAL PROBLEMS: Optical polarization of helium-3 nuclei

    Science.gov (United States)

    Laloë, F.; Leduc, M.; Nacher, P.-J.; Novikov, L. N.; Tastevin, G.

    1985-11-01

    The present state of the problem of producing highly polarized systems of helium-3 by laser optical pumping over a broad temperature range is reviewed. The physical principles underlying the polarization of 3He nuclei during optical pumping and the exchange of metastability are described. Particular features of laser pumping at low temperatures are discussed. The possible use of polarized helium atoms in research on exchange and relaxation processes, in quantum magnetometry, and in nuclear physics to produce polarized targets and particle beams is discussed. The results of theoretical and experimental research on the quantum properties of highly polarized systems at low temperatures, near the temperature of quantum degeneracy, are reviewed.

  18. Heat transport of nitrogen in helium atmospheric pressure microplasma

    CERN Document Server

    Xu, Shaofeng

    2013-01-01

    Stable DC atmospheric pressure normal glow discharges in ambient air were produced between the water surface and the metallic capillary coupled with influx of helium gas. Multiple independent repeated trials indicated that vibrational temperature of nitrogen rises from 3200 to 4622 K, and rotational temperature of nitrogen decreases from 1270 to 570 K as gas flux increasing from 20 to 80 sccm and discharge current decreasing from 11 to 3 mA. Furthermore, it was found that the vibrational degree of the nitrogen molecule has priority to gain energy than the rotational degree of nitrogen molecule in nonequilibrium helium microplasma.

  19. Methods of Helium Injection and Removal for Heat Transfer Augmentation

    Science.gov (United States)

    Haight, Harlan; Kegley, Jeff; Bourdreaux, Meghan

    2008-01-01

    While augmentation of heat transfer from a test article by helium gas at low pressures is well known, the method is rarely employed during space simulation testing because the test objectives usually involve simulation of an orbital thermal environment. Test objectives of cryogenic optical testing at Marshall Space Flight Center's X-ray Cryogenic Facility (XRCF) have typically not been constrained by orbital environment parameters. As a result, several methods of helium injection have been utilized at the XRCF since 1999 to decrease thermal transition times. A brief synopsis of these injection (and removal) methods including will be presented.

  20. Detectability of Light Dark Matter with Superfluid Helium.

    Science.gov (United States)

    Schutz, Katelin; Zurek, Kathryn M

    2016-09-16

    We show that a two-excitation process in superfluid helium, combined with sensitivity to meV energy depositions, can probe dark matter down to the ∼keV warm dark matter mass limit. This mass reach is 3 orders of magnitude below what can be probed with ordinary nuclear recoils in helium at the same energy resolution. For dark matter lighter than ∼100  keV, the kinematics of the process requires the two athermal excitations to have nearly equal and opposite momentum, potentially providing a built-in coincidence mechanism for controlling backgrounds.

  1. Sodium dopants in helium clusters: Structure, equilibrium and submersion kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, F. [Laboratoire Interdisciplinaire de Physique, Rue de La Piscine, Campus Saint Martin d’Hères, 38000 Grenoble (France)

    2015-12-31

    Alkali impurities bind to helium nanodroplets very differently depending on their size and charge state, large neutral or charged dopants being wetted by the droplet whereas small neutral impurities prefer to reside aside. Using various computational modeling tools such as quantum Monte Carlo and path-integral molecular dynamics simulations, we have revisited some aspects of the physical chemistry of helium droplets interacting with sodium impurities, including the onset of snowball formation in presence of many-body polarization forces, the transition from non-wetted to wetted behavior in larger sodium clusters, and the kinetics of submersion of small dopants after sudden ionization.

  2. Dr. von Braun and Army Ballistics Missile Agency (ABMA) Group

    Science.gov (United States)

    1959-01-01

    This photograph of Dr. von Braun, shown here to the left of General Bruce Medaris, was taken in the fall of 1959, immediately prior to Medaris' retirement from the Army. At the time, von Braun and his associates worked for the Army Ballistics Missile Agency in Huntsville, Alabama. Those in the photograph have been identified as Ernst Stuhlinger, Frederick von Saurma, Fritz Mueller, Hermarn Weidner, E.W. Neubert (partially hidden), W.A. Mrazek, Karl Heimburg, Arthur Rudolph, Otto Hoberg, von Braun, Oswald Lange, Medaris, Helmut Hoelzer, Hans Maus, E.D. Geissler, Hans Heuter, and George Constan.

  3. Einfluss von rekombinantem Adiponektin auf die monozytäre Expression von Annexin A6

    OpenAIRE

    Stögbauer, Fabian

    2009-01-01

    In der vorliegenden Arbeit wurden zunächst die CD14 Micro Beads titriert und so die Menge an CD14 Micro Beads bestimmt, die nötig ist, um eine große Anzahl Monozyten mit einem hohen Reinheitsgrad, verbunden mit geringen Kosten, aus Vollblut isolieren zu können. In den folgenden in vitro Untersuchungen wurden dann periphere Monozyten von humanen Spendern isoliert, um die dosis- und zeitabhängige Veränderung der Annexin A6-Proteinexpression unter dem Einfluss von Adiponektin feststellen zu k...

  4. Einfluss von Eugenol und Silikonöl auf die Dentinhaftung von adhäsiven Befestigungsmaterialien

    OpenAIRE

    Bigdali, Puria

    2015-01-01

    Zielsetzung Eugenolhaltige Zemente und Silikone stehen in Verdacht den Verbund von Kompositzementen zu beeinflussen. Ziel dieser Arbeit war es den Einfluss eugenolhaltiger und eugenolfreier Zemente und von Additions- und Kondensationssilikonen auf konventionell adhäsive und selbstadhäsive Kompositzemente zu untersuchen. Material und Methode Aus 200 extrahierten Rinderzähnen wurden 200 Dentinscheiben mit einer Dicke von 1 mm hergestellt, in welche eine definierte Kavität mit einem ...

  5. Automatisierte Generierung von Postleitzahlgebieten aus OpenStreetMap-Daten unter Verwendung von Open Source GIS Software

    OpenAIRE

    Hauck, Christian

    2011-01-01

    Das Projekt OpenStreetMap als freie Wiki-Weltkarte gewinnt als Quelle von Geodaten für unter-schiedlichste Bedürfnisse innerhalb der Geowissenschaften, des Geomarketings und auch im Alltag immer mehr an Bedeutung. Die kostenlosen, von Freiwilligen einer Community gesammelten geo-graphischen Daten, sogenannte nutzergenerierte Daten, dienen heute vielen Anwendern als Daten-grundlage und stehen in der Konkurrenz zu proprietären Geodaten von kommerziellen Anbietern. Neben Straßendaten sind zahlre...

  6. 43 CFR 16.1 - Agreements to dispose of helium in natural gas.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Agreements to dispose of helium in natural gas. 16.1 Section 16.1 Public Lands: Interior Office of the Secretary of the Interior CONSERVATION OF HELIUM § 16.1 Agreements to dispose of helium in natural gas. (a) Pursuant to his authority and...

  7. Helium inhalation in adolescents: characteristics of users and prevalence of use.

    Science.gov (United States)

    Whitt, Ahmed; Garland, Eric L; Howard, Matthew O

    2012-01-01

    Although helium-related fatalities and concerns about potentially harmful effects of helium use have increased in recent years, virtually nothing is known about the epidemiology of helium inhalation in adolescents. This exploratory investigation examined the prevalence and correlates of helium inhalation in a large sample of at-risk youth. Study participants were 723 Missouri adolescents (M age = 15.5, SD = 1.2) in residential treatment for delinquent behavior. More than one-in-nine (N = 81, 11.5%) adolescents had inhaled helium with the intention of getting high, and one-third (N = 27, 34.2%) of helium users reported they actually did get high when they inhaled helium. Helium users were significantly more likely to be Caucasian, to live in rural/small town areas, and to have histories of mental illness, auditory hallucinations, and alcohol and marijuana use than nonusers. Helium users also reported significantly more current psychiatric distress, suicidality, traumatic life experiences, and antisocial attitudes, traits, and behaviors than nonusers. Helium inhalation was prevalent in this sample and many such users reported getting high while using helium. Helium users had psychosocial profiles similar to those of volatile solvent users, suggesting that they may be at substantial risk for a variety of adverse health outcomes.

  8. 76 FR 30362 - Federal Acquisition Regulation; Submission for OMB Review; Acquisition of Helium

    Science.gov (United States)

    2011-05-25

    ...; Submission for OMB Review; Acquisition of Helium AGENCY: Department of Defense (DOD), General Services... approved information collection requirement concerning acquisition of helium. Public comments are... Collection 9000- 0113, Acquisition of Helium, by any of the following methods: Regulations.gov : http://www...

  9. 76 FR 12357 - Federal Acquisition Regulation; Information Collection; Acquisition of Helium

    Science.gov (United States)

    2011-03-07

    ... Helium AGENCY: Department of Defense (DOD), General Services Administration (GSA), and National... requirement concerning acquisition of helium. Public comments are particularly invited on: Whether this...: A. Purpose The Helium Act (Pub. L. 86-777) (50 U.S.C. 167a, et seq.) and the Department of the...

  10. Helium implanted AlHf as studied by 181 Ta TDPAC

    Indian Academy of Sciences (India)

    Measurements on helium implanted sample indicate the binding of helium associated defects by Hf solute clusters. Isochronal annealing measurements indicate the dissociation of the helium implantation induced defects from Hf solute clusters for annealing treatments beyond 650 K. On comparison of the present results ...

  11. Path integral Monte Carlo calculations of helium and hydrogen-helium plasma thermodynamics and of the deuterium shock Hugoniot

    Energy Technology Data Exchange (ETDEWEB)

    Levashov, P R [Institute for High Energy Densities, RAS, Izhorskaya 13/19, Moscow 125412 (Russian Federation); Filinov, V S [Institute for High Energy Densities, RAS, Izhorskaya 13/19, Moscow 125412 (Russian Federation); Bonitz, M [Christian-Albrechts-Universitaet zu Kiel, Institut fuer Theoretische Physik und Astrophysik, Leibnizstr. 15, 24098 Kiel (Germany); Fortov, V E [Institute for High Energy Densities, RAS, Izhorskaya 13/19, Moscow 125412 (Russian Federation)

    2006-04-28

    In this work, we calculate the thermodynamic properties of hydrogen-helium plasmas with different mass fractions of helium by the direct path integral Monte Carlo method. To avoid unphysical approximations, we use the path integral representation of the density matrix. We pay special attention to the region of weak coupling and degeneracy and compare the results of simulation with a model based on the chemical picture. Further with the help of calculated deuterium isochors, we compute the shock Hugoniot of deuterium. We analyse our results in comparison with recent experimental and calculated data on the deuterium Hugoniot.

  12. Dissolved helium and TDS in groundwater from Bhavnagar in Gujarat

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    2003-01-02

    Jan 2, 2003 ... quake related or induced by other environmental. Keywords. Groundwater; Helium; TDS; Bhavnagar; seismicity. Proc. Indian Acad. Sci. (Earth Planet. Sci.) .... (ppm AEU) surface. Sample. Well type. Location lithology. Depth. Sept. Jan. March. Sept. Jan. March. Sept. Jan. March code. TW/HP name. AL/BAS.

  13. Molecular Iodine Fluorescence Using a Green Helium-Neon Laser

    Science.gov (United States)

    Williamson, J. Charles

    2011-01-01

    Excitation of molecular iodine vapor with a green (543.4 nm) helium-neon laser produces a fluorescence spectrum that is well suited for the upper-level undergraduate physical chemistry laboratory. Application of standard evaluation techniques to the spectrum yields ground electronic-state molecular parameters in good agreement with literature…

  14. Apparatus to measure low level helium for neutron dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, Shuji; Takao, Yoshiyuki; Muramasu, Masatomo; Hida, Tomoya; Sou, Hirofumi; Nakashima, Hideki [Kyushu Univ., Fukuoka (Japan); Kanda, Yukinori

    1998-03-01

    An apparatus to measure low level helium in a solid sample for neutron dosimetry in the practical use such as area monitoring in the long-term and reactor surveillance was reported. In our previous work, the helium atoms measurement system (HAMS) was developed. A sample was evaporated in the furnace and the released gas from the sample was analyzed with the mass spectrometer of the system to determine the amount of helium contained in it. The system has been improved to advance the lower helium measurement limit in a solid sample for its application to an area monitoring system. The mass of a solid is up to 100mg. Two important points should be considered to advance the lower limit. One was to produce a high quality vacuum in the system chamber for suppressing background gases during the sample measurement. The other important point was to detect very small output from the mass spectrometer. A pulse counting system was used to get high sensitivity in the mass 4 analyzing. (author)

  15. TRANSMISSION ELECTRON MICROSCOPY STUDY OF HELIUM BEARING FUSION WELDS

    Energy Technology Data Exchange (ETDEWEB)

    Tosten, M; Michael Morgan, M

    2008-12-12

    A transmission electron microscopy (TEM) study was conducted to characterize the helium bubble distributions in tritium-charged-and-aged 304L and 21Cr-6Ni-9Mn stainless steel fusion welds containing approximately 150 appm helium-3. TEM foils were prepared from C-shaped fracture toughness test specimens containing {delta} ferrite levels ranging from 4 to 33 volume percent. The weld microstructures in the low ferrite welds consisted mostly of austenite and discontinuous, skeletal {delta} ferrite. In welds with higher levels of {delta} ferrite, the ferrite was more continuous and, in some areas of the 33 volume percent sample, was the matrix/majority phase. The helium bubble microstructures observed were similar in all samples. Bubbles were found in the austenite but not in the {delta} ferrite. In the austenite, bubbles had nucleated homogeneously in the grain interiors and heterogeneously on dislocations. Bubbles were not found on any austenite/austenite grain boundaries or at the austenite/{delta} ferrite interphase interfaces. Bubbles were not observed in the {delta} ferrite because of the combined effects of the low solubility and rapid diffusion of tritium through the {delta} ferrite which limited the amount of helium present to form visible bubbles.

  16. Helium Neon laser therapy for post mastectomy lymphedema and ...

    African Journals Online (AJOL)

    The aim of this work was to evaluate the efficacy of Helium Neon (He–Ne) laser therapy on post mastectomy lymphedema and shoulder mobility. Thirty female patients with axillary lymph node dissection (ALND), with or without radiotherapy had been participated in this study. The patients were randomly divided into two ...

  17. Turbulent Mixing on Helium-accreting White Dwarfs

    Science.gov (United States)

    Piro, Anthony L.

    2015-03-01

    An attractive scenario for producing Type Ia supernovae (SNe Ia) is a double detonation, where detonation of an accreted helium layer triggers ignition of a C/O core. Whether or not such a mechanism can explain some or most SNe Ia depends on the properties of the helium burning, which in turn is set by the composition of the surface material. Using a combination of semi-analytic and simple numerical models, I explore when turbulent mixing due to hydrodynamic instabilities during the accretion process can mix C/O core material up into the accreted helium. Mixing is strongest at high accretion rates, large white dwarf (WD) masses, and slow spin rates. The mixing would result in subsequent helium burning that better matches the observed properties of SNe Ia. In some cases, there is considerable mixing that can lead to more than 50% C/O in the accreted layer at the time of ignition. These results will hopefully motivate future theoretical studies of such strongly mixed conditions. Mixing also has implications for other types of WD surface explosions, including the so-called .Ia supernovae, the calcium-rich transients (if they arise from accreting WDs), and metal-enriched classical novae.

  18. Resonances of the helium atom in a strong magnetic field

    DEFF Research Database (Denmark)

    Lühr, Armin Christian; Al-Hujaj, Omar-Alexander; Schmelcher, Peter

    2007-01-01

    We present an investigation of the resonances of a doubly excited helium atom in a strong magnetic field covering the regime B=0–100  a.u. A full-interaction approach which is based on an anisotropic Gaussian basis set of one-particle functions being nonlinearly optimized for each field strength...

  19. Suicidal asphyxiation by using helium – two case reports

    Directory of Open Access Journals (Sweden)

    Anna Smędra

    2015-05-01

    Full Text Available Helium is one of inert gases causing physical asphyxiation, whose excess content in the breathing atmosphere reduces the partial pressure of oxygen and may be fatal after short-term exposure. When breathing a mixture of an inert gas (helium, nitrogen, argon with a small amount of oxygen, with the possibility of exhaling carbon dioxide, no warning signs characteristic of suffocation are perceived by the subject. Freedom from discomfort and pain, effectiveness, rapid effect and relatively easy availability of required accessories have resulted in the use of inert gases for suicidal purposes. The paper reports two cases of suicide committed by using a special kit consisting of the so-called “suicide bag” (or “exit bag” filled with helium supplied through a plastic tube. In both cases, examination of the sites where the corpses were found and analysis of collected material allowed to establish that before their death the subjects had searched the Internet for instructions on how to commit suicide using helium. Due to the advanced putrefaction process, the autopsies failed to determine the causes of their death unequivocally. However, the circumstances surrounding the deaths suggested rapid asphyxiation as a result of oxygen deficiency in the breathing mixture. Since in cases of the type discussed here the cause of death cannot generally be established by autopsy, knowledge of the circumstances of disclosure of the corpse, as well as examination of the cadaver and the death scene is of utmost importance.

  20. LOW-FIELD DIAMAGNETISM IN HELIUM RYDBERG STATES

    NARCIS (Netherlands)

    Vanderveldt, T.; Vassen, W.; Hogervorst, W.

    1992-01-01

    In a CW laser-atomic beam experiment metastable helium atoms are excited to Rydberg states (n = 58) in a magnetic field (= 0.1 T) The observed l-mixing spectra are reproduced using the method of diagonalization of the energy matrix as well as semiclassical theories. Also the first anticrossing

  1. QUASI-LANDAU STRUCTURE OF DIAMAGNETIC HELIUM RYDBERG ATOMS

    NARCIS (Netherlands)

    Vanderveldt, T.; Vassen, W.; Hogervorst, W.

    1993-01-01

    Diamagnetism in helium Rydberg atoms is studied near the ionisation threshold using constant scaled-energy laser spectroscopy. Quasi-Landau resonances in the Fouriertransform of the energy spectrum are explained using the classical periodic-orbit theory. Longlaser scans combined with a

  2. Dissolved helium and TDS in groundwater from Bhavnagar in ...

    Indian Academy of Sciences (India)

    The increase in basaltic aquifers has been explained by enhanced pumping of old groundwater with relatively higher concentration of dissolved helium and salt, whereas the decrease in alluvial aquifers has been explained by dilution from the post monsoon groundwater recharge. Therefore, the observed temporal ...

  3. Lattice location of helium in uranium dioxide single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Garrido, F.; Nowicki, L. E-mail: lech.nowicki@fuw.edu.pl; Sattonnay, G.; Sauvage, T.; Thome, L

    2004-06-01

    Lattice location of {sup 3}He atoms implanted into UO{sub 2} single crystals was performed by means of the channeling technique combined with nuclear reaction analysis (NRA) and Rutherford backscattering spectrometry (RBS). The {sup 3}He(d,p){sup 4}He reaction was used. The experimental angular scans show that helium atoms occupy octahedral interstitial positions.

  4. Automated liquid-helium transfer tube lifting system

    Science.gov (United States)

    Kato, Kiyonori; Suzui, Mitsukazu

    1990-07-01

    An automatic liquid-helium transfer tube lifting system has been developed, in which the transfer tube can be raised or lowered very slowly by remote control. This system relieves the operator of considerable manual labor, and protects the O-ring seals from damage at low temperature.

  5. Electronic spectroscopy of aniline ions embedded in helium nanodroplets

    NARCIS (Netherlands)

    Brauer, N.B.; Smolarek, S.D.; Zhang, X.; Buma, W.J.; Drabbels, M.

    2011-01-01

    Excitation spectra of the Ã2A2←X̃2B1 and B̃2B1←X̃2B1 transitions of aniline cations embedded in helium nanodroplets are reported. The spectra are characterized by broad asymmetric resonances that consist of an intrinsically broadened zero-phonon line, which partially overlaps with the accompanying

  6. Numerical simulation of losses along a natural circulation helium loop

    Energy Technology Data Exchange (ETDEWEB)

    Knížat, Branislav, E-mail: branislav.knizat@stuba.sk; Urban, František, E-mail: frantisek.urban@stuba.sk; Mlkvik, Marek, E-mail: marek.mlkvik@stuba.sk; Ridzoň, František, E-mail: frantisek.ridzon@stuba.sk; Olšiak, Róbert, E-mail: robert.olsiak@stuba.sk [Slovak University of Technology in Bratislava, Faculty of Mechanical Engineering, Nám. slobody 17, 812 31 Bratislava, Slovak Republik (Slovakia)

    2016-06-30

    A natural circulation helium loop appears to be a perspective passive method of a nuclear reactor cooling. When designing this device, it is important to analyze the mechanism of an internal flow. The flow of helium in the loop is set in motion due to a difference of hydrostatic pressures between cold and hot branch. Steady flow at a requested flow rate occurs when the buoyancy force is adjusted to resistances against the flow. Considering the fact that the buoyancy force is proportional to a difference of temperatures in both branches, it is important to estimate the losses correctly in the process of design. The paper deals with the calculation of losses in branches of the natural circulation helium loop by methods of CFD. The results of calculations are an important basis for the hydraulic design of both exchangers (heater and cooler). The analysis was carried out for the existing model of a helium loop of the height 10 m and nominal heat power 250 kW.

  7. Sputtering of solid nitrogen by keV helium ions

    DEFF Research Database (Denmark)

    Ellegaard, O.; Schou, Jørgen; Sørensen, H.

    1993-01-01

    Solid nitrogen has become a standard material among the frozen molecular gases for electronic sputtering. We have combined measurements of sputtering yields and energy spectra from nitrogen bombarded by 4-10 keV helium ions. The data show that the erosion is electronic rather than knockon...

  8. Conceptual design of a helium heater for high temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xue Zhou, E-mail: jin@kit.edu; Chen, Yuming; Ghidersa, Bradut-Eugen

    2014-10-15

    Highlights: •A special design of heater with two vessels is introduced for the operation at 10 MPa and 800 °C. •The additional coupling between the cold leg and the hot leg of the loop due to the heater design has an impact on the loop energy budget. •Reducing the heat transfer between the two flow channels inside the heater by means of a helium gap in the inlet nozzle is proven to be effective. -- Abstract: The Karlsruhe Advanced Technologies Helium Loop (KATHELO) has been designed for testing divertor modules as well as qualifying materials for high heat flux, high temperature (up to 800 °C) and high pressure (10 MPa) applications. The test section inlet temperature level is controlled using a process electrical heater. To cope with the extreme operating conditions, a special design of this unit has been proposed. In this paper the conceptual design of the unit will be presented and the impact of the coupling between the cold and hot helium gas on the overall efficiency of the loop will be investigated. The detailed thermal-hydraulic analysis of the feed through of the hot helium into the low temperature pressure vessel using ANSYS CFX will be presented. The impact of the design choices on the overall energy budget of the loop will be analyzed using RELAP5-3D.

  9. The Erosion of Frozen Argon by Swift Helium Ions

    DEFF Research Database (Denmark)

    Besenbacher, F.; Bøttiger, Jørgen; Graversen, O.

    1981-01-01

    The temperature, energy, and thickness dependence of the erosion rates of frozen argon films when irradiated with 0.1–3 MeV helium ions have been measured. The erosion yields Y are much too high to be explained by the concentional collisional cascade-sputtering theory and are furthermore...

  10. Impulsive Laser Induced Alignment of Molecules Dissolved in Helium Nanodroplets

    DEFF Research Database (Denmark)

    Pentlehner, Dominik; H. Nielsen, Jens; Slenczka, Alkwin

    2013-01-01

    We show that a 450 fs nonresonant, moderately intense, linearly polarized laser pulse can induce field-free molecular axis alignment of methyliodide (CH3I) molecules dissolved in a helium nanodroplet. Time-resolved measurements reveal rotational dynamics much slower than that of isolated molecule...

  11. The Helium Atom and Isoelectronic Ions in Two Dimensions

    Science.gov (United States)

    Patil, S. H.

    2008-01-01

    The energy levels of the helium atom and isoelectronic ions in two dimensions are considered. The difficulties encountered in the analytical evaluation of the perturbative and variational expressions for the ground state, promote an interesting factorization of the inter-electronic interaction, leading to simple expressions for the energy. This…

  12. Accurate Determination of the Volume of an Irregular Helium Balloon

    Science.gov (United States)

    Blumenthal, Jack; Bradvica, Rafaela; Karl, Katherine

    2013-01-01

    In a recent paper, Zable described an experiment with a near-spherical balloon filled with impure helium. Measuring the temperature and the pressure inside and outside the balloon, the lift of the balloon, and the mass of the balloon materials, he described how to use the ideal gas laws and Archimedes' principal to compute the average molecular…

  13. Maintenance free gas bearing helium blower for nuclear plant

    Science.gov (United States)

    Molyneaux, A., Dr; Harris, M., Prof; Sharkh, S., Prof; Hill, S.; de Graaff, T.

    2017-08-01

    This paper describes the design, testing and operation of novel helium blowers used to recirculate the helium blanketing gas in the nuclear reactor used as a neutron source at the Institut Laue Langevan, Grenoble, France. The laser sintered shrouded centrifugal wheel operates at speeds up to 45000 rpm supported on helium lubricated hydrodynamic spiral groove bearings, and is driven by a sensorless permanent magnet motor. The entire machine is designed to keep the helium gas (polluted by a small amount of D2O) out of contact with any iron or copper materials which would contribute to the corrosion of parts of the circuit. It is designed to have zero maintenance during a lifetime of 40,000 hours of continuous operation. This paper will describe the spiral groove journal and thrust bearings. Design and manufacture of the 1 kW motor and centrifugal wheel will be explained including their CFD and FEA analyses. Measurements of rotor displacement will be presented showing the behaviour under factory testing as well as details of the measured centrifugal wheel and motor performances. Two machines are incorporated into the circuit to provide redundancy and the first blower has been in continuous operation since Jan 2015. The blower was designed, manufactured, assembled and tested in the UK using predominantly UK suppliers.

  14. Subsurface analysis of semiconductor structures with helium ion microscopy

    NARCIS (Netherlands)

    van Gastel, Raoul; Hlawacek, G.; Zandvliet, Henricus J.W.; Poelsema, Bene

    2012-01-01

    We have used helium ion microscopy to directly track the subsurface diffusion of Pd through a Si stack in a non-invasive manner. The imaging and analysis of semiconductor structures along a direction perpendicular to the substrate is traditionally performed by making cross sections of a sample and

  15. US Congress considers bill to relieve helium shortage

    Science.gov (United States)

    Gwynne, Peter

    2013-04-01

    A bill to alleviate the threat of a significant shortage of helium was set to be debated in the US House of Representatives as Physics World went to press with the House's Natural Resources Committee putting the finished touches to the motion.

  16. Ööklubi Club von Überlingen = Club von Überlingen

    Index Scriptorium Estoniae

    2008-01-01

    Ööklubi Club von Überlingen (Madara 22A, Tallinn) sisekujundusest. Sisearhitekt: Taavi Aunre (Boom.ee OÜ). Taavi Aunrest, tema tähtsamad tööd. I-II korruse plaan, 11 värv. vaadet, foto T. Aunrest

  17. Von den Liven von Oesel / August Ludwig Schlözer

    Index Scriptorium Estoniae

    Schlözer, August Ludwig

    2008-01-01

    Avaldatud Eberhard Winkleri initsiatiivil A. L. Schlözeri teose põhjal: Gesammelte Nachrichten von den Ueberresten der Liven, in Livland und Kurland. (1770), mis moodustab osa teosest: Schlözer, August Ludwig. M. Johann Joseph Haigold's Beylagen zum Neuveränderten Russland. Zweiter Theil. Riga und Leipzig, 1770

  18. Aino Lepik von Wiren / Aino Lepik von Wiren ; interv. Kadi Alatalu

    Index Scriptorium Estoniae

    Lepik von Wirén, Aino, 1961-

    2007-01-01

    Heinrich Marga eksiilvalitsuse (20.06.1990-7.10.1992) kohtuminister Aino Lepik von Wiren pagulaslapse elust Rootsis, haridusest ja elukutse valikust, tööst eksiilvalitsuses, tööleasumisest Eestisse 1992. aastal, seadusandlikust tegevusest ning aluse panekust välismaalaste- ja kodakondsuspoliitikale, naiste võimalustest poliitilisse tippu tõusmiseks, kodu- ja väliseestlaste vastandamisest

  19. Rezension: Träume von Räumen von Georges Perec

    Directory of Open Access Journals (Sweden)

    Thomas Ballhausen

    2015-12-01

    Full Text Available Mit "Träume von Räumen" liegt ein zentraler Text aus dem umfangreichen Œuvre Geroges Perecs vor, der zuletzt 1990 als Übersetzung greifbar war. Der ursprünglich 1974 erschienene Band ist in mehrfacher Hinsicht wesentlich für das Verständnis Perecs und seiner literarisch-philosophische Wunderwelt ...

  20. Cold Helium Gas Pressurization For Spacecraft Cryogenic Propulsion Systems

    Science.gov (United States)

    Morehead, Robert L.; Atwell. Matthew J.; Hurlbert, Eric A.; Melcher, J. C.

    2017-01-01

    To reduce the dry mass of a spacecraft pressurization system, helium pressurant may be stored at low temperature and high pressure to increase mass in a given tank volume. Warming this gas through an engine heat exchanger prior to tank pressurization both increases the system efficiency and simplifies the designs of intermediate hardware such as regulators, valves, etc. since the gas is no longer cryogenic. If this type of cold helium pressurization system is used in conjunction with a cryogenic propellant, though, a loss in overall system efficiency can be expected due to heat transfer from the warm ullage gas to the cryogenic propellant which results in a specific volume loss for the pressurant, interpreted as the Collapse Factor. Future spacecraft with cryogenic propellants will likely have a cold helium system, with increasing collapse factor effects as vehicle sizes decrease. To determine the collapse factor effects and overall implementation strategies for a representative design point, a cold helium system was hotfire tested on the Integrated Cryogenic Propulsion Test Article (ICPTA) in a thermal vacuum environment at the NASA Glenn Research Center Plum Brook Station. The ICPTA vehicle is a small lander-sized spacecraft prototype built at NASA Johnson Space Center utilizing cryogenic liquid oxygen/liquid methane propellants and cryogenic helium gas as a pressurant to operate one 2,800lbf 5:1 throttling main engine, two 28lbf Reaction Control Engines (RCE), and two 7lbf RCEs (Figure 1). This vehicle was hotfire tested at a variety of environmental conditions at NASA Plum Brook, ranging from ambient temperature/simulated high altitude, deep thermal/high altitude, and deep thermal/high vacuum conditions. A detailed summary of the vehicle design and testing campaign may be found in Integrated Cryogenic Propulsion Test Article Thermal Vacuum Hotfire Testing, AIAA JPC 2017.

  1. Saturn's Helium Abundance from Cassini CIRS and RSS Data

    Science.gov (United States)

    Achterberg, Richard K.; Schinder, Paul J.; Flasar, F. Michael

    2016-10-01

    The ratio of helium to hydrogen in Saturn's atmosphere provides an important constraint on models of Saturn's formation and evolution, but has been poorly constrained by available data. Measurements combining Voyager infrared and radio data [1] gave a He/H2 mole ratio of 0.034 ± 0.024, far below the protosolar value and requiring either significant helium loss or sequestration in the interior. Prompted by discrepancies between the Voyager infrared/radio and Galileo probe measurements of helium on Jupiter, Conrath and Gautier [2] reevaluated the helium abundance on Saturn from Voyager infrared data only, obtaining a He/H2 mole ratio of 0.135 ± 0.025, inconsistent with the previous results. Because of this discrepancy, estimating Saturn's atmospheric helium abundance has been a major goal of the Cassini mission.We are estimating the He/H2 mole ratio in Saturn's atmosphere using a combination of data from the Cassini Radio Science Subsystem (RSS) and Composite InfraRed Spectrometer (CIRS). Radio occultations, in which a carrier signal is observed as Cassini passed behind Saturn as seen from antennas on Earth, give a vertical profile of atmospheric refractivity, which can be converted to temperature as a function of pressure assuming a mean molecular weight. The assumed molecular weight is adjusted until synthetic thermal infrared spectra match spectra observed by CIRS at the same latitude and time. Preliminary results from a set of eleven near-equatorial occultations taken in 2005 give He/H2 mole ratios varying between ~0.060 and 0.085.[1] Conrath, B. J., et al., 1984, Ap. J., 282:807-815[2] Conrath, B. J. and D. Gautier, 2000, Icarus, 144:124-134

  2. Thermophysicochemical Reaction of ZrCo-Hydrogen-Helium System

    Science.gov (United States)

    Jung, Kwangjin; Kang, Hee-Seok; Yun, Sei-Hun; Chung, Hongsuk

    2017-11-01

    Nuclear fusion energy, which is clean and infinite, has been studied for more than half a century. Efforts are in progress worldwide for the demonstration and validation of nuclear fusion energy. Korea has been developing hydrogen isotope storage and delivery system (SDS) technologies including a basic scientific study on a hydrogen storage medium. An SDS bed, which is a key component of the SDS, is used for storing hydrogen isotopes in a metal hydride form and supplying them to a tokamak. Thermophysicochemical properties of the ZrCo-H2-He system are investigated for the practical utilization of a hydriding alloy system. The hydriding reaction, in which ZrCoHx is composed as ZrCo absorbing hydrogen, is exothermic. The dehydriding reaction, in which ZrCoHx decomposes into ZrCo and hydrogen, is endothermic. The heat generated through the hydriding reaction interrupts the hydriding progress. The heat loss by a dehydriding reaction impedes the dehydriding progress. The tritium decay product, helium-3, covers the ZrCo and keeps the hydrogen from contact with ZrCo in the SDS bed. In this study, we designed and fabricated a ZrCo bed and its performance test rig. The helium blanketing effect on a ZrCo hydrogen reaction with 0 % to 20 % helium content in a gaseous phase and a helium blanket removal method were studied experimentally. In addition, the volumetric flow rates and temperature at the beginning of a ZrCo hydrogen reaction in a hydrogen or helium atmosphere, and the cooling of the SDS bed by radiation only and by both radiation and natural convection related to the reuse cycle, were obtained.

  3. Effect of weld thermal cycle on helium bubble formation in stainless steel

    Science.gov (United States)

    Kano, F.; Nakahigashi, S.; Nakamura, H.; Uesugi, N.; Mitamura, T.; Terasawa, M.; Irie, H.; Fukuya, K.

    1998-10-01

    Helium bubble structure was examined on a helium-implanted stainless steel after applying two kinds of heat input. Helium ions were implanted on Type 304 stainless steel at 573 K from 2 to 200 appm to a peak depth of 0.5 μm from the surface. After that, weld thermal history was applied by an electron beam. The cooling rates were selected to be 370 and 680 K/s from 1023 to 773 K. TEM observation revealed that nucleation and growth of helium bubbles were strongly dependent on the cooling rate after welding and the helium concentration.

  4. Probing helium interfaces with light scattering: from fluid mechanics to statistical physics.

    Science.gov (United States)

    Wolf, P E; Bonnet, F; Guyon, L; Lambert, T; Perraud, S; Puech, L; Rousset, B; Thibault, P

    2009-02-01

    We have investigated the formation of helium droplets in two physical situations. In the first one, droplets are atomised from superfluid or normal liquid by a fast helium vapour flow. In the second, droplets of normal liquid are formed inside porous glasses during the process of helium condensation. The context, aims, and results of these experiments are reviewed, with focus on the specificity of light scattering by helium. In particular, we discuss how, for different reasons, the closeness to unity of the index of refraction of helium allows in both cases to minimise the problem of multiple scattering and obtain results which it would not be possible to get using other fluids.

  5. Wege des Exports von Glutathion aus Astrocyten

    OpenAIRE

    Minich, Tobias Florian

    2008-01-01

    Vorliegender Arbeit lag die Aufgabe zugrunde herauszufinden, welche(s) Transportsystem(e) außer dem Multidrug-Transporter 1 (multidrug resistance protein 1, MRP1) zum Austritt des Tripeptides Glutathion aus Primärkulturen von Astrogliazellen in das extrazelluläre Milieu beitragen. Als Grundlage für die Untersuchungen wurde zunächst an zwei Wildtyp Mausstämmen (NMRI und FVB/N) sichergestellt, dass astrogliareiche Primärkulturen aus Mäusen sowohl reduziertes als auch oxidiertes Glutathion expor...

  6. Die Behandlung von Intersexuellen in der Diskussion

    Directory of Open Access Journals (Sweden)

    Heinz-Jürgen Voß

    2008-11-01

    Full Text Available Wissenschaftler/-innen aus unterschiedlichen Fachdisziplinen und mit unterschiedlichen Ansichten zum Umgang mit intersexuellen Menschen kommen zu Wort – in diesem Sinne ist der Sammelband sehr heterogen. Es werden Erfahrungen mit Geschlechtsanpassung dargestellt, Begrifflichkeiten analysiert und Probleme bei der Therapie und in der Forschung erörtert. Vorangestellt, aber erfreulicherweise nicht abgetrennt, äußern sich Betroffene. Bereits wegen der sich im Abschluss des Bandes befindlichen Handlungsempfehlungen zur Behandlung von Säuglingen und Kindern mit ‚abweichenden‘ bzw. ‚uneindeutigen‘ Geschlechtsmerkmalen, die sich insbesondere an Eltern, Mediziner/-innen und Sozialpädagog/-innen wenden, ist das Buch unbedingt empfehlenswert.

  7. Electronic Resource Management System. Vernetzung von Lizenzinformationen

    OpenAIRE

    Michaela Selbach; Daniel Armin Rupp

    2014-01-01

    In den letzten zehn Jahren spielen elektronische Ressourcen im Bereich der Erwerbung eine zunehmend wichtige Rolle: Eindeutig lässt sich hier ein Wandel in den Bibliotheken (fort) vom reinen Printbestand zu immer größeren E-Only-Beständen feststellen. Die stetig wachsende Menge an E-Ressourcen und deren Heterogenität stellt Bibliotheken vor die Herausforderung, die E-Ressourcen effizient zu verwalten. Nicht nur Bibliotheken, sondern auch verhandlungsführende Institutionen von Konsortial- und ...

  8. Authentifizierung von Bio-Milch im Labor

    OpenAIRE

    Molkentin, Joachim

    2008-01-01

    In Deutschland ist die Nachfrage nach Bio-Lebensmitteln in den letzten Jahren stetig gestiegen. So erhöhte sich der Absatz von Bio-Trinkmilch in 2007 im Vergleich zum Vorjahr erneut kräftig um 34 Prozent (ZMP, Bonn) und der Bio-Anteil beträgt inzwischen bei Frischmilch knapp elf Prozent. Aufgrund sporadisch resultierender Lieferengpässe bei Bio-Milch sowie der vorhandenen Handelspreisdifferenz besteht zunehmend ein potenzielles Risiko der Falschdeklaration konventionell erzeugter Milch als Bi...

  9. Der Denkmalwert von Illegalität

    OpenAIRE

    Beyer, Dennis

    2012-01-01

    Kunst oder Schmiererei - Graffiti spalten die Gesellschaft. Für die einen sind sie illegale Schmierereien und Ausdruck von Vandalismus, für die anderen gelten sie als Kunst am Bau einer verkannten Avantgarde. Das Spektrum an Motivationen und Produkten innerhalb der Sprayer-Gemeinschaft ist tatsächlich derart vielfältig, dass eine sachliche Debatte ohne Polarisation kaum möglich scheint. Dennoch stellt sich die Frage, welche Bedeutung diese flüchtigen und illegalen Zeugnisse einer Minderheit i...

  10. Comparison of automated von Willebrand factor activity assays

    DEFF Research Database (Denmark)

    Timm, Annette; Hillarp, Andreas; Philips, Malou

    2015-01-01

    INTRODUCTION: Von Willebrand Disease (VWD) is the most common inherited bleeding disorder. Measurement of von Willebrand factor (VWF) activity in plasma is often based on platelet agglutination stimulated by the ristocetin cofactor activity. Novel assays, based on latex beads with recombinant...

  11. Illustrierte Bestimmungshilfe zur Unterscheidung von Candelaria concolor und Candelaria pacifica

    OpenAIRE

    Stapper, Norbert J.

    2012-01-01

    Unterscheidungsmerkmale von Candelaria concolor und C. pacifica werden anhand von Makro- und Mikrofotos dargestellt. Im Gelände kann C. pacifica anhand der fehlenden Unterrinde erkannt werden. Characteristic features separating Candelaria concolor from C. pacifica are presented on macro and micro photographs. The lack of a lower cortex can be used to identify C. pacifica in the field.

  12. On two matrix derivatives by Kollo and von Rosen

    OpenAIRE

    Neudecker, Heinz

    2003-01-01

    The article establishes relationships between the matrix derivatives of Fwith respect to Xas introduced by von Rosen (1988), Kollo and von Rosen (2000) and the Magnus-Neudecker (1999) matrix derivative. The usual transformations apply and the Moore-Penrose inverse of the duplication matrix is used. Both Xand F have the same dimension. Peer Reviewed

  13. A New Generalization of von Neumann Relative Entropy

    Science.gov (United States)

    Li, Jing; Cao, Huaixin

    2017-11-01

    In quantum information, von Neumann relative entropy has a great applications and operational interpretations in diverse fields, and von Neumann entropy is an important tool for describing the uncertainty of a quantum state. In this paper, we generalize the classical von Neumann relative entropy S( ρ|| σ) and von Neumann entropy S( ρ) to f-von Neumann relative entropy \\widetilde {S}f(ρ ||σ ) and f-von Neumann entropy \\widetilde {S}f(ρ ) induced by a logarithm-like function f, respectively, and explore their properties. We prove that \\widetilde {S}f(ρ ||σ ) is nonnegative and then prove that \\widetilde {S}f(ρ ) has nonnegativity, boundedness, concavity, subadditivity and so on. Later, we show the stability and continuity of the \\widetilde {S}f(ρ ) with respect to the trace distance. In the case that f( x) = -log x, the resulted entropies reduce the classical von Neumann relative entropy and von Neumann entropy, respectively. This means that our results extend the usual results to a more general setting and then have some potential applications in quantum information.

  14. An accurate von Neumann's law for three-dimensional foams

    NARCIS (Netherlands)

    Hilgenfeldt, Sascha; Kraynik, Andrew M.; Koehler, Stephan A.; Stone, Howard A.

    2001-01-01

    The diffusive coarsening of 2D soap froths is governed by von Neumann's law. A statistical version of this law for dry 3D foams has long been conjectured. A new derivation, based on a theorem by Minkowski, yields an explicit analytical von Neumann's law in 3D which is in very good agreement with

  15. Minimum Moduli in Von Neumann Algebras | Gopalraj | Quaestiones ...

    African Journals Online (AJOL)

    Minimum Moduli in Von Neumann Algebras. Perumal Gopalraj, Anton Ströh. Abstract. In this paper we answer a question raised in [12] in the affirmative, namely that the essential minimum modulus of an element in a von. Neumann algebra, relative to any norm closed two-sided ideal, is equal to the minimum modulus of the ...

  16. Spin–momenta entanglement in moving frames: Properties of von ...

    Indian Academy of Sciences (India)

    well as locality, of information [9–11]. Expressed differently, the von Neumann entropy measures the stored qubits of information per states of the combined system while the reduced one quantifies the qubits per states that may be stored in one of the subsystems. [1]. It is then obvious that a deeper understanding of von ...

  17. Victor or Villain? Wernher von Braun and the Space Race

    Science.gov (United States)

    O'Brien, Jason L.; Sears, Christine E.

    2011-01-01

    Set during the Cold War and space race, this historical role-play focuses on Wernher von Braun's involvement in and culpability for the use of slave laborers to produce V-2 rockets for Nazi Germany. Students will grapple with two central questions. Should von Braun have been allowed to emigrate to the United States given his affiliation with the…

  18. Von Krahli teatris etenduvad Tõnu Kõrvitsa kammerooperid / Esme Kassak

    Index Scriptorium Estoniae

    Kassak, Esme

    2006-01-01

    20. apr. esietenduvad Von Krahli Teatris Peeter Jalaka lavastuses Tõnu Kõrvitsa uued kammerooperid "Tuleaed" ja "Mu luiged, mu mõtted", mille aluseks on luuletaja Marie Heibergi saatus. Libretode autor on Maarja Kangro. Kammerooperid tulevad lavale Von Krahli Teatri ja Nargen Opera koostöös. Esitavad Kädy Plaas, Helen Lokuta, Nargen Opera koor ja Tallinna Kammerorkester, dirigent Tõnu Kaljuste

  19. von Willebrand disease and aging : an evolving phenotype

    NARCIS (Netherlands)

    Sanders, Y. V.; Giezenaar, M. A.; Laros-van Gorkom, B. A. P.; Meijer, K.; van der Bom, J. G.; Cnossen, M. H.; Nijziel, M. R.; Ypma, P. F.; Fijnvandraat, K.; Eikenboom, J.; Mauser-Bunschoten, E. P.; Leebeek, F. W. G.

    Background: Because the number of elderly von Willebrand disease (VWD) patients is increasing, the pathophysiology of aging in VWD has become increasingly relevant. Objectives: To assess age-related changes in von Willebrand factor (VWF) and factor VIII (FVIII) levels and to compare age-related

  20. CERN Technical Training 2002: Learning for the LHC! HEREF-2002 : HELIUM REFRIGERATION TECHNIQUES

    CERN Multimedia

    Davide Vitè

    2002-01-01

    Theory, Technology, Maintenance and Control of Helium Refrigerators HeREF-2002 is a new course, in the framework of the 2002 Technical Training Programme, that will provide a complete introduction to Helium refrigeration, with a practical approach to theory, technology, maintenance and control of Helium refrigeration installations. Theoretical aspects and equations will be limited to a minimum. HeREF-2002 targets an audience of technicians and operators of Helium refrigeration plants at CERN, as well as physicists and engineers needing an overview of current Helium refrigeration techniques. HeREF-2002 will address, among other, issues related to component technology, installation maintenance, process control and Helium purity. A commented visit to a couple of CERN Helium refrigeration or liquefaction plants will also take place. Duration: 7 half days (5 mornings and 2 afternoons), 21-25 October, 2002. Estimated cost: 300.- CHF Language: Bilingual English-French. The course support will be in English, the ...

  1. CERN Technical Training 2002: Learning for the LHC ! HeREF-2002 : Helium Refrigeration Techniques

    CERN Multimedia

    Davide Vitè

    2002-01-01

    Theory, Technology, Maintenance and Control of Helium Refrigerators HeREF-2002 is a new course, in the framework of the 2002 Technical Training Programme, that will provide a complete introduction to Helium refrigeration, with a practical approach to theory, technology, maintenance and control of Helium refrigeration installations. Theoretical aspects and equations will be limited to a minimum. HeREF-2002 targets an audience of technicians and operators of Helium refrigeration plants at CERN, as well as physicists and engineers needing an overview of current Helium refrigeration techniques. HeREF-2002 will address, among other, issues related to component technology, installation maintenance, process control and Helium purity. A commented visit to a couple of CERN Helium refrigeration or liquefaction plants will also take place. Duration: 7 half days (5 mornings and 2 afternoons), 21-25 October 2002. Estimated cost: 300.- CHF Language: Bilingual English-French. The course support will be in English, the...

  2. [Heinz von zur Mühlen. Das Bürgertum Fordert Blut. Ein Bolschewistiches Flugblatt von 1918] / Paul Kaegbein

    Index Scriptorium Estoniae

    Kaegbein, Paul

    2007-01-01

    Arvustus: Heinz von zur Mühlen. Das Bürgertum Fordert Blut. Ein Bolschewistiches Flugblatt von 1918. In : Ostseeprovinzen, baltische Staaten und das Nationale. Münster : LIT, 2005, lk. 403-414. 1918. aastast pärit lendlehest, mille käekirja järgi otsustades on kirjutanud Viktor Kingissepp

  3. Kontextualisierung von Queer Theory Contextualizing Queer Theory

    Directory of Open Access Journals (Sweden)

    Anna Voigt

    2008-03-01

    Full Text Available Christine M. Klapeer legt in diesem Einführungsband dar, aus welchen politischen und theoretischen Kontexten heraus sich ‚queer‘ zu einem Begriff mit besonderem politischem und theoretischem Gehalt entwickelt hat. Wesentlich zielt sie dabei auf eine kritische Kontextualisierung von „queer theory”. Die Autorin geht zunächst auf das Gay Liberation Movement ein, grenzt die Queer Theory vom Poststrukturalismus, von feministischen Theorien und den Lesbian and Gay Studies ab, beleuchtet Eckpunkte queeren Denkens und zeichnet schließlich die Entwicklungen in Österreich sowohl politisch-rechtlich als auch bewegungsgeschichtlich und in der Wissenschaftslandschaft nach.Christine M. Klapeer’s introductory volume demonstrates the manner in which ‘queer’ grew out of various political and theoretical contexts to become a term with special political and theoretical content. She focuses primarily on a critical contextualization of “queer theory.” The author begins by approaching the Gay Liberation Movement and then distinguishes Queer Theory from poststructuralism, from feminist theories, and from Lesbian and Gay Studies. She continues on to illuminate the key aspects of queer thought and concludes by sketching the development in Austria in terms of politics and the law, the history of movements, and within the landscape of knowledge.

  4. Guy von Dardel 1919-2009

    CERN Multimedia

    2009-01-01

    Guy von Dardel, a well-known figure at CERN and in the international particle physics community, passed away on 28 August. Guy von Dardel came to CERN when it was founded in 1954 and was a full-time staff member until 1964, performing several experiments and working on technical developments. These included the first measurement of the neutral pion’s life-time. Called to Lund University in 1964, he became professor there in 1965 and director of the 1.2 GeV electron accelerator. In the late 1960s, he performed an experiment at CERN’s PS that measured the decays of the Λ. Then, in the early 1970s, he involved the Lund group in a series of experiments at the Intersecting Storage Rings (ISR), where he measured the production of various types of particles. In particular, he participated in a series of experiments that observed the production of a high abundance of particles with large transverse momenta. This required an explanation...

  5. Suitability of tracers; Eignung von Tracern

    Energy Technology Data Exchange (ETDEWEB)

    Klotz, D. [GSF - Forschungszentrum fuer Umwelt und Gesundheit GmbH, Neuherberg (Germany). Inst. fuer Hydrologie

    1999-02-01

    Hydrological tracer techniques are a means of making statements on the direction and speed of underground water. One of the simpler tasks is to find out whether there is hydrological communication between two given points. This requires a determination of the direction of flow, which places less exacting demands on the properties of the tracer than does the task of determining the flow velocity of underground water. Tracer methods can serve to infer from flow velocity the distance (flow) velocity, which is defined as the ratio between the distance between two points located in flow direction and the actual time it takes water to flow from one to the other. [Deutsch] Mit Hilfe der hydrologischen Markierungstechniken koennen Aussagen ueber die Richtung und die Geschwindigkeit von Bewegungen des unterirdischen Wassers gemacht werden. Der einfachere Fall liegt vor, wenn festgestellt werden soll, ob zwischen zwei Punkten eine hydrologische Verbindung besteht. Bei dieser Fliessrichtungsbestimmung sind die Forderungen an die Eigenschaften der einzusetzenden Tracer geringer als bei der Bestimmung der Geschwindigkeit des unterirdischen Wassers. Von den Geschwindigkeiten des unterirdischen Wassers ist die Abstands-(Fliess)geschwindigkeit, die definiert ist durch das Verhaeltnis aus dem Abstand und der wahren Fliesszeit zwischen zwei in Bewegungsrichtung gelegenen Punkten, durch Tracermethoden zu bestimmen. (orig.)

  6. Die Krakauer Kirche von Karmeliten und Karmelitaninnen

    Directory of Open Access Journals (Sweden)

    Józef Szymon Wronski

    2004-12-01

    Full Text Available 1. Die Klosterkirche der unbeschuhten Karmelitinnen Zum Heiligen Josef. Ein glücklicher Auftakt und somit die charakteristische Einführung in das 20. Jh. für den Kirchenbau von Krakau war die Errichtung der Karmeliterinnen St. Josephs-Kirche an der Lobzowska-Straße 40, in der die Architekten (Tadeusz Stryjeński (1849-1943 - Projektant der Kirche und Franciszek Mączyński (1874-1947 - Ausführer des Bauprojektes mit eigenen Verbesserungen die historisch- eklektizistischen Formen d.h. die mittelalterlichen Formen vor allem des sog. Übergangsstils vereinfachten. Die Kirche, die in den Jahren 1903-1905 errichtet wurde, steht inmitten vom Baukomplex des Klosters, dessen Grundriss das Quadrat ist49. Der Kirchenbau ist ein dem Gesamtbau des Klosters eingefügter Längsraum. Hinter dem Chor liegt das Oratorium des Konvents. Das Material Backstein (mit Verwendung von Stein erinnert an die Baukunst eines der besten Architekten jener Zeit, nämlich Teodor Talowskis (1857-1910, der viele Kirchen in Südpolen, aber auch viele Bürgerhäuser nicht nur in Krakau im ausgehenden 19. Jh. baute. Die Architektur der Karmeliterinnen St. Josephs-Kirche ist immer noch im Malerischen begriffen. Aber die Vereinfachung der historischen Formen führt zu ihrer „Beruhigung” und dadurch zur Wuchtigkeit des Ausdrucks. Bemerkenswert ist die in dieser Zeit (in der Anlage noch seltene ausgewogene Proportionierung des Baukörpers. Das methodische Prinzip jener Zeit ist der Kontrast. Im Kontrast zu den gedrungenen und wuchtigen Formen des Baukörpers stehen z.B. die sich verjüngenden obeliskenförmigen und pylonenartigen Türmchen, die nicht nur die Eingangsfassade der Kirche flankieren, sondern auch an den Ecken des Querhauses der Kirche stehen. Die ingravierten weißen Steine an der Fassade in der Zahl von Zehn erinnern an das Gebot des Karmelterinnenordens: Bete täglich den Rosenkranz und sind zugleich ein Vanitativmotiv. 2. Die Klosterkirche der unbeschuhten

  7. Von Neumann's quantization of general relativity

    Science.gov (United States)

    Arbuzov, A. B.; Cherny, A. Yu.; Cirilo-Lombardo, D. J.; Nazmitdinov, R. G.; Han, Nguyen Suan; Pavlov, A. E.; Pervushin, V. N.; Zakharov, A. F.

    2017-05-01

    Von Neumann's procedure is applied to quantizing general relativity. Initial data for dynamical variables in the Planck epoch, where the Hubble parameter value coincided with the Planck mass are quantized. These initial data are defined in terms of the Fock orthogonal simplex in the tangent Minkowski spacetime and the Dirac conformal interval. The Einstein cosmological principle is used to average the logarithm of the determinant of the spatial metric over the spatial volume of the visible Universe. The splitting of general coordinate transformations into diffeomorphisms and transformations of the initial data is introduced. In accordance with von Neumann's procedure, the vacuum state is treated is a quantum ensemble that is degenerate in quantum numbers of nonvacuum states. The distribution of the vacuum state leads to the Casimir effect in gravidynamics in just the same way as in electrodynamics. The generating functional for perturbation theory in gravidynamics is found by solving the quantum energy constraint. The applicability range of gravidynamics is discussed along with the possibility of employing this theory to interpret modern observational data.

  8. Translational medicine advances in von Willebrand disease.

    Science.gov (United States)

    Lillicrap, D

    2013-06-01

    Following the recognition of von Willebrand disease (VWD) in 1926 and the cloning of the gene for von Willebrand factor (VWF) in 1985, significant advances have been made in our fundamental knowledge of both the disease and the protein. Some of this new knowledge has also begun to impact the clinical management of VWD. First, the progressive increase in our understanding of the molecular genetic basis of VWD has resulted in rational applications of molecular testing to complement the current range of phenotypic tests for VWD. These molecular genetic strategies are most effectively directed at the prenatal diagnosis of type 3 VWD and confirmatory testing for types 2B and 2N disease. In contrast, the use of molecular testing to clarify the diagnosis of type 1 VWD is of marginal benefit, at best. In terms of VWD therapies, a new recombinant VWF concentrate has recently completed successful clinical trials and is now awaiting more widespread application. There have even been some preclinical successes with VWF gene transfer although the clinical rationale for this therapeutic strategy needs careful consideration. Much more remains to be learnt about the biology of VWF and further translational advances for the enhancement of VWD care will inevitably be realized. © 2013 International Society on Thrombosis and Haemostasis.

  9. Entwicklung von Nickel-Trägerkatalysatoren für die Methanisierung von Kohlenstoffdioxid unter Anwendung von Parallelpräparation und statistischer Versuchsplanung

    OpenAIRE

    Thomys, Oliver Dieter

    2017-01-01

    Die Methanisierung von Kohlenstoffdioxid (Sabatier-Reaktion) gilt als aussichtsreiche Technologie für die chemische Speicherung überschüssigen elektrischen Stroms aus erneuerbaren Energien. Diese Arbeit befasst sich mit der Präparation von Nickel-Trägerkatalysatoren mit hoher Niedrigtemperatur-Aktivität und Langzeitstabilität. Durch Parallelsynthese-Konzepte und Methoden der statistischen Versuchsplanung konnten entsprechende Katalysatoren mit niedriger Metallbeladung präpariert werden, deren...

  10. Alexander von Humboldt in Daniel Kehlmanns Welt

    Directory of Open Access Journals (Sweden)

    Ottmar Ette

    2012-12-01

    Full Text Available Zusammenfassung Wie stark sich im Verlauf des zurückliegenden Vierteljahrhunderts der Bekanntheitsgrad Alexander von Humboldts in der deutschsprachigen Öffentlichkeit verändert hat, zeigen nicht nur Fernsehumfragen zu den berühmtesten Deutschen, in denen Alexander von Humboldt mittlerweile figuriert, oder Fernsehserien, die über aktuelle Expeditionen berichten und auf Humboldts Namen zurückgreifen. Am deutlichsten vielleicht belegt dies der enorme Erfolg von Daniel Kehlmanns Roman Die Vermessung der Welt, der ohne die zuvor skizzierte Entwicklung nicht denkbar gewesen wäre. Es ist vor diesem Hintergrund nicht nur reizvoll, sondern aufschlußreich, sich mit dem großen Erfolg dieses kleinen Romans zu beschäftigen. Worum geht es in Die Vermessung der Welt? Und wie läßt sich das „Phänomen Kehlmann“ aus etwas größerer Distanz erklären? Abstract In the last 25 years, Alexander von Humboldt‘s popularity has radically changed in the german-speaking public opinion. Proof of this are not only television surveys about the most famous germans - in which Alexander von Humboldt now regularly figures - or television series about contemporary expeditions, which constantly refer to Humboldt‘s name; perhaps what most clearly verifies this change is the great success of Daniel Kehlmann‘s novel Die Vermessung der Welt. Without the recent developments outlined above, this novel‘s degree of impact would have been unimaginable. To study the great success of this text against this backdrop is not only attractive, but also revealing. What is Die Vermessung der Welt really about? And how can we explain the „Kehlmann phenomenon“ from a greater distance? Resumen La popularidad de Alejandro de Humboldt ha cambiado profundamente dentro del último cuarto de siglo en la opinión pública de habla alemana. Prueba de esto son no sólo las encuestas televisivas sobre los alemanes más famosos, dentro de las cuales figura en estos momentos Alejandro

  11. Explosive Hydrogen and Helium Burning in Astrophysical Events.

    Science.gov (United States)

    Wallace, Richard Kent

    The nuclear energy generation and nucleosynthesis that occur in hydrogen-rich compositions at temperatures substantially greater than 10('8) K are examined in detail. At these high temperatures, a new kind of nucleosynthetic process (the "rp-process") involving the rapid capture of protons on seed nuclei (or on the products of helium burning in a situation with zero initial metallicity) can lead to the production of heavy elements up to and beyond the iron group with an accompanying energy generation rate greatly modified from that of the (beta)-limited CNO cycle customarily employed in such calculations. New nuclear reaction rates of interest are tabulated, and reaction network calculations are presented to illustrate the application of this process to exploding supermassive stars, accreting neutron stars, novae, and certain chaotic cosmologies. Implications for (gamma)-line astronomy and x-ray burst models are discussed. To further explore the importance of thermonuclear instabilities for accreting neutron stars, the evolution of a 1.41 M(,(CIRCLE)) neutron star accreting both solar and metal-deficient mixtures of hydrogen, helium, and heavy elements at rates ranging from about 10('-11) to 10('-10) M(,(CIRCLE)) per year is examined using a one-dimensional numerical model. The metal deficient compositions may result either from placement of the neutron star in a binary system with a Population II Red Giant or from gravitational settling of heavy ions in the accreted material. For such accretion rates and metallicities, hydrogen burning, mediated by the (beta)-limited CNO cycle, is stable and leads to the accumulation of a thick helium layer with mass 10('23) to 10('25) g and temperature 0.7 (LESSTHEQ) T(,8) (LESSTHEQ) 1.2. Helium ignition occurs under extremely degenerate circumstances and is catastrophically violent. In the lower mass helium shells this runaway is propagated as a convective deflagration; for the thicker layers a detonation front is set up which

  12. Purge Monitoring Technology for Gaseous Helium (GHe) Conservation

    Science.gov (United States)

    Dickey, Jonathan; Lansaw, John

    2010-01-01

    John C. Stennis Space Center provides rocket engine propulsion testing for the NASA space programs. Since the development of the Space Shuttle, every Space Shuttle Main Engine (SSME) has gone through acceptance testing before going to Kennedy Space Center for integration into the Space Shuttle. The SSME is a large cryogenic rocket engine that used Liquid Oxygen (LO2) and Liquid Hydrogen (LH2) as propellants. Due to the extremely cold cryogenic conditions of this environment, an inert gas, helium, is used as a purge for the engine and propellant lines since it can be used without freezing in the cryogenic environment. As NASA moves forward with the development of the new ARES V launch system, the main engines as well as the upper stage engine will use cryogenic propellants and will require gaseous helium during the development testing of each of these engines. The main engine for the ARES V will be similar in size to the SSME.

  13. The maintenance record of the KSTAR helium refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Moon, K. M.; Joo, J. J.; Kim, N. W. [National Fusion Research Institute, Daejeon (Korea, Republic of); and others

    2013-12-15

    Korea Superconducting Tokamak Advanced Research (KSTAR) has a helium refrigeration system (HRS) with the cooling capacity of 9 kW at 4.5 K. Main cold components are composed of 300 tons of superconducting (SC) magnets, main cryostat thermal shields, and SC current feeder system. The HRS comprises six gas storage tanks, a liquid nitrogen tank, the room temperature compression sector, the cold box (C/B), the 1st stage helium distribution box (DB no.1), the PLC base local control system interconnected to central control tower and so on. Between HRS and cold components, there is another distribution box (DB#2) nearby the KSTAR device. The entire KSTAR device was constructed in 2007 and has been operated since 2008. This paper will present the maintenance result of the KSTAR HRS during the campaign and discuss the operation record and maintenance history of the KSTAR HRS.

  14. Boron gettering on cavities induced by helium implantation in Si

    Science.gov (United States)

    Roqueta, F.; Alquier, D.; Ventura, L.; Dubois, Ch.; Jérisian, R.

    2001-10-01

    In this paper, we shed light on the strong interaction between the cavity layer induced by helium implantation and boron. First of all, we evidence the impact of He gettering step on a boron-diffused profile. In order to study the boron-cavity interaction, we had used uniformly boron-doped wafers implanted with helium at high dose and anneal using usual furnace annealing (FA) as well as rapid thermal annealing. Then, to avoid any precipitation phenomena, conditions were chosen to not exceed the boron solid solubility value. Our experimental results exhibit a large trapping of boron within the cavity layer. This trapping occurs since the early stage of the annealing. These results enable us to have better understanding of this He gettering step as well as its interaction with boron atoms, which are of great interest for device.

  15. A stable compound of helium and sodium at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Xiao; Oganov, Artem R.; Goncharov, Alexander F.; Stavrou, Elissaios; Lobanov, Sergey; Saleh, Gabriele; Qian, Guang-Rui; Zhu, Qiang; Gatti, Carlo; Deringer, Volker L.; Dronskowski, Richard; Zhou, Xiang-Feng; Prakapenka, Vitali B.; Konôpková, Zuzana; Popov, Ivan A.; Boldyrev, Alexander I.; Wang, Hui-Tian

    2017-02-06

    Helium is generally understood to be chemically inert and this is due to its extremely stable closed-shell electronic configuration, zero electron affinity and an unsurpassed ionization potential. It is not known to form thermodynamically stable compounds, except a few inclusion compounds. Here, using the ab initio evolutionary algorithm USPEX and subsequent high-pressure synthesis in a diamond anvil cell, we report the discovery of a thermodynamically stable compound of helium and sodium, Na2He, which has a fluorite-type structure and is stable at pressures >113 GPa. We show that the presence of He atoms causes strong electron localization and makes this material insulating. This phase is an electride, with electron pairs localized in interstices, forming eight-centre two-electron bonds within empty Na8 cubes. We also predict the existence of Na2HeO with a similar structure at pressures above 15 GPa.

  16. Neutrino-induced Neucleosynthesis in Supernova Helium Shells

    Science.gov (United States)

    Banerjee, Projjwal

    We re-examine a neutrino-driven r-process mechanism in the helium shell of a core-collapse supernova. We analyze the pre-shock evolution in detail using recent stellar models. In addition we perform full hydrodynamic simulations including the effect of shock, finding that the outer helium shells can be the site for an r-process. We find that this mechanism could succeed in early stars of metallicity ≲ 10-3 the solar value, at relatively low temperatures and neutron densities, producing A ˜ 130 and 195 abundance peaks over ˜ 50--60 s. The mechanism is extremely sensitive to the neutrino emission model and to neutrino oscillations. While this mechanism is not very sensitive to the explosion energy, mixing of the ejecta can be different for different explosion energies. We discuss the implications of an r-process that could alter interpretations of abundance data from metal-poor stars.

  17. Communication: Electron diffraction of ferrocene in superfluid helium droplets

    Science.gov (United States)

    Zhang, Jie; He, Yunteng; Kong, Wei

    2016-06-01

    We report electron diffraction of ferrocene doped in superfluid helium droplets. By taking advantage of the velocity slip in our pulsed droplet beam using a pulsed electron gun, and by doping with a high concentration of ferrocene delivered via a pulsed valve, we can obtain high quality diffraction images from singly doped droplets. Under the optimal doping conditions, 80% of the droplets sampled in the electron beam are doped with just one ferrocene molecule. Extension of this size selection method to dopant clusters has also been demonstrated. However, incomplete separation of dopant clusters might require deconvolution and modeling of the doping process. This method can be used for studies of nucleation processes in superfluid helium droplets.

  18. The Astro-E2/XRS-2 helium insert system

    Science.gov (United States)

    Shirron, P. J.; DiPirro, M. J.; Panek, J.; Kelley, R.; Mitsuda, K.; Fujimoto, R.; Hirabayashi, M.; McCammon, D.

    2006-04-01

    The X-ray Spectrometer (XRS-2) instrument on the Japanese Space Agency (JAXA) Astro-E2 spacecraft will measure faint X-ray emissions in the energy range of 0.2-10 keV. A square array of 32 X-ray microcalorimeters used will be able to distinguish individual photons to better than 10 eV at 6 keV, with a quantum efficiency near 100%. The detectors are cooled to 60 mK by means of an adiabatic demagnetization refrigerator (ADR). The ADR rejects heat to a 1.3 K superfluid helium tank, which is surrounded by a 17 K solid neon tank. A Stirling cycle cryocooler precools an outer shield around the neon tank. This system will provide an estimated 3 years of on-orbit lifetime. This paper describes the helium insert, the ADR, the high temperature superconducting leads, and early on-orbit performance.

  19. submitter Data-driven RBE parameterization for helium ion beams

    CERN Document Server

    Mairani, A; Dokic, I; Valle, S M; Tessonnier, T; Galm, R; Ciocca, M; Parodi, K; Ferrari, A; Jäkel, O; Haberer, T; Pedroni, P; Böhlen, T T

    2016-01-01

    Helium ion beams are expected to be available again in the near future for clinical use. A suitable formalism to obtain relative biological effectiveness (RBE) values for treatment planning (TP) studies is needed. In this work we developed a data-driven RBE parameterization based on published in vitro experimental values. The RBE parameterization has been developed within the framework of the linear-quadratic (LQ) model as a function of the helium linear energy transfer (LET), dose and the tissue specific parameter ${{(\\alpha /\\beta )}_{\\text{ph}}}$ of the LQ model for the reference radiation. Analytic expressions are provided, derived from the collected database, describing the $\\text{RB}{{\\text{E}}_{\\alpha}}={{\\alpha}_{\\text{He}}}/{{\\alpha}_{\\text{ph}}}$ and ${{\\text{R}}_{\\beta}}={{\\beta}_{\\text{He}}}/{{\\beta}_{\\text{ph}}}$ ratios as a function of LET. Calculated RBE values at 2 Gy photon dose and at 10% survival ($\\text{RB}{{\\text{E}}_{10}}$ ) are compared with the experimental ones. Pearson's correlati...

  20. SNS Central Helium Liquefier spare Carbon Bed installation and commissioning

    Science.gov (United States)

    DeGraff, B.; Howell, M.; Kim, S.; Neustadt, T.

    2017-12-01

    The Spallation Neutron Source (SNS) Central Helium Liquefier (CHL) at Oak Ridge National Laboratory (ORNL) has been without major operations downtime since operations were started back in 2006. This system utilizes a vessel filled with activated carbon as the final major component to remove oil vapor from the compressed helium circuit prior to insertion into the system’s cryogenic cold box. The need for a spare carbon bed at SNS due to the variability of carbon media lifetime calculation to adsorption efficiency will be discussed. The fabrication, installation and commissioning of this spare carbon vessel will be presented. The novel plan for connecting the spare carbon vessel piping to the existing infrastructure will be presented.

  1. Phase separation of metallic hydrogen-helium alloys

    Science.gov (United States)

    Straus, D. M.; Ashcroft, N. W.; Beck, H.

    1977-01-01

    Calculations are presented for the thermodynamic functions and phase-separation boundaries of solid metallic hydrogen-helium alloys at temperatures between zero and 19,000 K and at pressures between 15 and 90 Mbar. Expressions for the band-structure energy of a randomly disordered alloy (including third order in the electron-ion interaction) are derived and evaluated. Short- and long-range orders are included by the quasi-chemical method, and lattice dynamics in the virtual-crystal harmonic approximation. It is concluded that at temperatures below 4000 K, there is essentially complete phase separation of hydrogen-helium alloys and that a miscibility gap remains at the highest temperatures and pressures considered. The relevance of these results to models of the deep interior of Jupiter is briefly discussed.

  2. Anderson localization of graphene by helium ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Naitou, Y., E-mail: yu-naitou@aist.go.jp [Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305–8562 (Japan); Ogawa, S. [Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba 305–8569 (Japan)

    2016-04-25

    Irradiation of a single-layer graphene (SLG) with accelerated helium ions (He{sup +}) controllably generates defect distributions, which create a charge carrier scattering source within the SLG. We report direct experimental observation of metal-insulator transition in SLG on SiO{sub 2}/Si substrates induced by Anderson localization. This transition was investigated using scanning capacitance microscopy by monitoring the He{sup +} dose conditions on the SLG. The experimental data show that a defect density of more than ∼1.2% induced Anderson localization. We also investigated the localization length by determining patterned placement of the defects and estimated the length to be several dozen nanometers. These findings provide valuable insight for patterning and designing graphene-based nanostructures using helium ion microscopy.

  3. A High Reliability Gas-driven Helium Cryogenic Centrifugal Compressor

    CERN Document Server

    Bonneton, M; Gistau-Baguer, Guy M; Turcat, F; Viennot, P

    1998-01-01

    A helium cryogenic compressor was developed and tested in real conditions in 1996. The achieved objective was to compress 0.018 kg/s Helium at 4 K @ 1000 Pa (10 mbar) up to 3000 Pa (30 mbar). This project was an opportunity to develop and test an interesting new concept in view of future needs. The main features of this new specific technology are described. Particular attention is paid to the gas bearing supported rotor and to the pneumatic driver. Trade off between existing technologies and the present work are presented with special stress on the bearing system and the driver. The advantages are discussed, essentially focused on life time and high reliability without maintenance as well as non pollution characteristic. Practical operational modes are also described together with the experimental performances of the compressor. The article concludes with a brief outlook of future work.

  4. Electrical heater for very-low pressure helium gas

    CERN Document Server

    Benda, V; Vuillierme, B

    1996-01-01

    Testing superconducting magnets for the Large Hadron Collider (LHC) in superfluid helium requires large-capacity refrigeration at 1.8K. At CERN, this is provided by a combination of a cold compressor and a set of warm vacuum pumps capable of handling up to 18g/s at 1 kPa suction pressure. The cold helium vapour, after the cold compressor, is warmed up from about 5K to ambient temperature in a 32 kW electrical heater. The device is designed to operate reliably at flow rates varying from 1 to 18g/s, inlet pressure of 1 kPa to 3 kPa, with pressure drop 100 Pa. Design and construction of the heater, completely realised at CERN, are presented, as well as measured performance. Some technological problems are discussed.

  5. Argon metastable production in argon-helium microplasmas

    Science.gov (United States)

    Hoskinson, Alan R.; Gregorío, José; Hopwood, Jeffrey; Galbally-Kinney, Kristin; Davis, Steven J.; Rawlins, Wilson T.

    2016-06-01

    Microwave resonator-driven microplasmas are a promising technology for generating the high density of rare-gas metastable states required for optically pumped rare gas laser systems. We measure the density of argon 1s5 states (Paschen notation) in argon-helium plasmas between 100 Torr and atmospheric pressure using diode laser absorption. The metastable state density is observed to rise with helium mole fraction at lower pressures but to instead fall slightly when tested near atmospheric pressure. A 0-D model of the discharge suggests that these distinct behaviors result from the discharge being diffusion-controlled at lower pressures, but with losses occurring primarily through dissociative recombination at high pressures. In all cases, the argon metastable density falls sharply when the neutral argon gas fraction is reduced below approximately 2%.

  6. The Thermodynamical Instability Induced by Pressure Ionization in Fluid Helium

    CERN Document Server

    Li, Qiong; Zhang, Gong-Mu; Zhao, Yan-Hong; Lu, Guo; Tian, Ming-Feng; Song, Hai-Feng

    2016-01-01

    A systematic study of pressure ionization is carried out in the chemical picture by the example of fluid helium. By comparing the variants of the chemical model, it is demonstrated that the behavior of pressure ionization depends on the construction of the free energy function. In the chemical model with the Coulomb free energy described by the Pad\\'e interpolation formula, thermodynamical instability induced by pressure ionization is found to be manifested by a discontinuous drop or a continuous fall and rise along the pressure-density curve as well as the pressure-temperature curve, which is very much like the first order liquid-liquid phase transition of fluid hydrogen from the first principles simulations. In contrast, in the variant chemical model with the Coulomb free energy term empirically weakened, no thermodynamical instability is induced when pressure ionization occurs, and the resulting equation of state achieves good agreement with the first principles simulations of fluid helium.

  7. Mechanisms of void coarsening in helium implanted silicon

    CERN Document Server

    Evans, J H

    2002-01-01

    There has been recent discussion of the mechanisms that give rise to the observed coarsening of void populations introduced into silicon by implanting helium and then annealing to remove the helium. Over the temperature range from approximately 700 to 1000 degree sign C and beyond, further annealing leads to an increase of the average void size and decrease in void density. This paper sets out to calculate the coarsening expected from the two primary potential mechanisms, migration and coalescence (M and C) and Ostwald ripening (OR). The methodology of the calculations is carefully set out together with the surface diffusion and vacancy diffusion parameters on which the mechanisms depend. For moderate anneal temperatures, up to 1000 degree sign C, it would seem unlikely that OR can play any part in void coarsening. On the other hand, M and C calculations show that this mechanism gives results consistent with the size range found in experimental results.

  8. The Effects of the Pauli Exclusion Principle in Determining the Ionization Energies of the Helium Atom and Helium-Like Ions

    Science.gov (United States)

    Deeney, F. A.; O'Leary, J. P.

    2012-01-01

    For helium and helium-like ions, we have examined the differences between the values of the ionization energies as calculated from the Bohr theory and those measured in experiments. We find that these differences vary linearly with the atomic number of the system. Using this result, we show how the Bohr model for single-electron systems may be…

  9. Die Rolle von RANK-Ligand und Osteoprotegerin bei Osteoporose

    Directory of Open Access Journals (Sweden)

    Hofbauer LC

    2004-01-01

    Full Text Available Receptor activator of nuclear factor (NF- κB ligand (RANKL, sein zellulärer Rezeptor RANK und der Decoy-Rezeptor Osteoprotegerin (OPG stellen ein essentielles Zytokinsystem für die Zellbiologie von Osteoklasten dar. Verschiedene Untersuchungen belegen die Bedeutung von Störungen des OPG/RANKL/RANK-Systems bei der Pathogenese metabolischer Knochenerkrankungen. In dieser Arbeit werden die wichtigsten Störungen des OPG/RANKL/RANK-Systems bei verschiedenen Osteoporoseformen dargestellt. Östrogenrezeptor- (ER- Agonisten wie 17 β-Östradiol, Raloxifen und Genistein stimulieren die osteoblastäre Produktion von OPG durch Aktivierung von ER- α in vitro, während Lymphozyten von Patientinnen mit Östrogenmangel RANKL überexprimieren. Die parenterale Gabe von OPG vermag den mit Östrogenmangel assoziierten Knochenverlust im Tiermodell und in einer kleineren klinischen Studie zu verhindern. Glukokortikoide und Immunsuppressiva steigern gleichzeitig die RANKL-Expression und hemmen die OPG-Produktion in osteoblastären Zellen in vitro. Glukokortikoide sind auch in vivo imstande, die OPG-Serumspiegel deutlich zu reduzieren. Dagegen hemmen biomechanische Reize in vitro die RANKL-Produktion und steigern die OPG-Produktion. Ein Fehlen dieser biomechanischen Reize bei längerer Immobilisierung kann daher den RANKL/OPG-Quotienten steigern, während die tierexperimentelle Immobilisierungs-Osteoporose durch die parenterale Gabe von OPG gemildert werden kann.

  10. Drei Dimensionen von filmischem Archivmaterial. Die Untersuchung von Archivfilmen aus der Zeit des Holocaust

    Directory of Open Access Journals (Sweden)

    Tobias Ebbrecht-Hartmann

    2017-04-01

    Full Text Available Filmisches Archivmaterial aus der Zeit des Holocaust ist eine ambivalente Quelle. Daher sind spezifische Ansätze notwendig, um dieses Material zu ‘lesen’. Es geht darum, den besonderen Inhalt der Bilder zu analysieren, den Kontext ihrer Entstehung zu bestimmen, aber auch, ihre spätere Verwendung und Zirkulation in der visuellen Kultur und damit auch ihren wechselnden Status mit einzubeziehen. Am Beispiel ausgewählter Filmfragmente aus dem Warschauer Ghetto und dem Ghetto Theresienstadt skizziert der Artikel einen Ansatz, wie man diese drei Dimensionen von filmischem Archivmaterial analysieren kann und schlägt damit eine entsprechende Historiographie von Archivfilmen aus der Zeit des Holocaust vor.

  11. Investigation of Cellular Interactions of Nanoparticles by Helium Ion Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Arey, Bruce W.; Shutthanandan, V.; Xie, Yumei; Tolic, Ana; Williams, Nolann G.; Orr, Galya

    2011-06-01

    The helium ion mircroscope (HIM) probes light elements (e.g. C, N, O, P) with high contrast due to the large variation in secondary electron yield, which minimizes the necessity of specimen staining. A defining characteristic of HIM is its remarkable capability to neutralize charge by the implementation of an electron flood gun, which eliminates the need for coating non-conductive specimens for imaging at high resolution. In addition, the small convergence angle in HeIM offers a large depth of field (~5x FE-SEM), enabling tall structures to be viewed in focus within a single image. Taking advantage of these capabilities, we investigate the interactions of engineered nanoparticles (NPs) at the surface of alveolar type II epithelial cells grown at the air-liquid interface (ALI). The increasing use of nanomaterials in a wide range of commercial applications has the potential to increase human exposure to these materials, but the impact of such exposure on human health is still unclear. One of the main routs of exposure is the respiratory tract, where alveolar epithelial cells present a vulnerable target at the interface with ambient air. Since the cellular interactions of NPs govern the cellular response and ultimately determine the impact on human health, our studies will help delineating relationships between particle properties and cellular interactions and response to better evaluate NP toxicity or biocompatibility. The Rutherford backscattered ion (RBI) is a helium ions imaging mode, which backscatters helium ions from every element except hydrogen, with a backscatter yield that depends on the atomic number of the target. Energy-sensitive backscatter analysis is being developed, which when combined with RBI image information, supports elemental identification at helium ion nanometer resolution. This capability will enable distinguishing NPs from cell surface structures with nanometer resolution.

  12. Atmospheric helium isotope ratio: Possible temporal and spatial variations

    Science.gov (United States)

    Sano, Yuji; Furukawa, Yukiko; Takahata, Naoto

    2010-09-01

    The atmospheric 3He/ 4He ratio has been considered to be constant on a global scale, because the residence time of helium is significantly longer than the mixing time in the atmosphere. However, this ratio may be decreasing with time owing to the anthropogenic release of crustal helium from oil and natural gas wells, although this observation has been disputed. Here, we present the 3He/ 4He ratios of old air trapped in historical slags in Japan and of modern surface air samples collected at various sites around the world, measured with a newly developed analytical system. In air helium extracted from metallurgical slag found at refineries in operation between AD 1603 and 1907 in Japan, we determined a mean 3He/ 4He ratio of (5106 ± 108) × 10 -5 R HESJ (where R HESJ is the 3He/ 4He ratio of the Helium Standard of Japan), which is consistent with the previously reported value of (5077 ± 59) × 10 -5 R HESJ for historical slags in France and United Arab Emirates and about 4% higher than that of average modern air, (4901 ± 4) × 10 -5 R HESJ. This result implies that the air 3He/ 4He ratio has decreased with time as expected by anthropogenic causes. Our modern surface air samples revealed that the 3He/ 4He ratio increases from north to south at a rate of (0.16 ± 0.08) × 10 -5 R HESJ/degree of latitude, suggesting that the low 3He/ 4He ratio originates in high-latitude regions of the northern hemisphere, which is consistent with the fact that most fossil fuel is extracted and consumed in the northern hemisphere.

  13. A quantum computer based on electrons floating on liquid helium

    OpenAIRE

    Dykman, M. I.; Platzman, P. M.

    2001-01-01

    Electrons on a helium surface form a quasi two-dimensional system which displays the highest mobility reached in condensed matter physics. We propose to use this system as a set of interacting quantum bits. We will briefly describe the system and discuss how the qubits can be addressed and manipulated, including interqubit excitation transfer. The working frequency of the proposed quantum computer is ~1GHz. The relaxation rate can be at least 5 orders of magnitude smaller, for low temperatures.

  14. 10 atm helium-methane streamer chamber with holographic registration

    Energy Technology Data Exchange (ETDEWEB)

    Falomkin, I.V.; Ivanov, I.Ts.; Khovansky, N.N.; Lyashenko, V.I.; Pontecorvo, G.B.; Tudor, T.; Shcherbakov, Yu.A.; Yani, Ya.; Trifonov, A.; Troshev, T. (Joint Inst. for Nuclear Research, Dubna (USSR))

    1985-05-15

    Electron track holograms were registered in a 10 atm helium-methane (3/1) self-shunted streamer chamber. From the Gabor holograms tracks were reconstructed: a streamer density of (14 +- 1) str/cm and streamer images of about 150 ..mu..m in diameter were obtained. The density and diameter values remain constant for delay times of the laser pulse with respect to the high voltage pulse within the range of 200 to 9000 ns.

  15. 10 atm helium-methane streamer chamber with holographic registration

    Energy Technology Data Exchange (ETDEWEB)

    Falomkin, I.V.; Ivanov, I.Ts.; Khovansky, N.N.; Lyashenko, V.I.; Pontecorvo, G.B.; Tudor, T.; Shcherbakov, Yu.A.; Yani, Ya.; Trifonov, A.; Troshev, T.; Khristov, V.

    1985-05-15

    Electron track holograms were registered in a 10 atm helium-methane (3/1) self-shunted streamer chamber. From the Gabor holograms tracks were reconstructed: a streamer density of (14+-1) str/cm and streamer images of about 150 ..mu..m in diameter were obtained. The density and diameter values remain constant for delay times of the laser pulse with respect to the high voltage pulse within the range of 200 to 9000 ns. (orig.).

  16. Tritium and helium retention and release from irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; Longhurst, G.R.; Oates, M.A.; Pawelko, R.J. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental effort to anneal irradiated beryllium specimens and characterize them for steam-chemical reactivity experiments. Fully-dense, consolidated powder metallurgy Be cylinders, irradiated in the EBR-II to a fast neutron (>0.1 MeV) fluence of {approx}6 x 10{sup 22} n/cm{sup 2}, were annealed at temperatures from 450degC to 1200degC. The releases of tritium and helium were measured during the heat-up phase and during the high-temperature anneals. These experiments revealed that, at 600degC and below, there was insignificant gas release. Tritium release at 700degC exhibited a delayed increase in the release rate, while the specimen was at 700degC. For anneal temperatures of 800degC and higher, tritium and helium release was concurrent and the release behavior was characterized by gas-burst peaks. Essentially all of the tritium and helium was released at temperatures of 1000degC and higher, whereas about 1/10 of the tritium was released during the anneals at 700degC and 800degC. Measurements were made to determine the bulk density, porosity and specific surface area for each specimen before and after annealing. These measurements indicated that annealing caused the irradiated Be to swell, by as much as 14% at 700degC and 56% at 1200degC. Kr gas adsorption measurements for samples annealed at 1000degC and 1200degC determined specific surface areas between 0.04 m{sup 2}/g and 0.1 m{sup 2}/g for these annealed specimens. The tritium and helium gas release measurements and the specific surface area measurements indicated that annealing of irradiated Be caused a porosity network to evolve and become surface-connected to relieve internal gas pressure. (author)

  17. Modellierung von Angebots- und Nachfrageverhalten zur Analyse von Agrarpolitiken: Theorie, Methoden und empirische Anwendungen

    OpenAIRE

    Henningsen, Arne

    2006-01-01

    Die Analyse der Auswirkungen von Agrarpolitiken ist in der Regel sehr komplex und erfordert eine detaillierte Modellierung des Angebots- und Nachfrageverhaltens im Agrarsektor. Eine empirische Anwendung setzt daher eine angemessene ökonomische Theorie sowie fortgeschrittene quantitative Methoden voraus. Alle neun Aufsätze dieser Dissertation lassen sich in diese Themengebiete einordnen. Zunächst werden die Nachfrage nach Bananen und die Folgen der EU Bananenmarktordnung für deutsche Konsument...

  18. Charakterisierung von Mutanten im Lösungsmittelstoffwechsel von Clostridium acetobutylicum

    OpenAIRE

    Hönicke, Daniel

    2015-01-01

    Im Rahmen dieser Arbeit wurden insgesamt neun durch ClosTron-basierte Mutagenese erhaltene Insertionsmutanten von C. acetobutylicum ATCC 824 einer umfangreichen Charakterisierung unterzogen. Für alle im Batch-Fermentationsmaßstab und/oder in kontinuierlicher Kultur fermentierten Stämme erfolgte eine globale Analyse des Transkriptoms unter Verwendung der DNA-Microarray-Technologie. Für eine Analyse des Acetat- und Aceton-Stoffwechsels wurden Stämme mit einer inaktivierten Phosphotransacetyl...

  19. Transition to ballistic regime for heat transport in helium II

    Energy Technology Data Exchange (ETDEWEB)

    Sciacca, Michele, E-mail: michele.sciacca@unipa.it [Dipartimento Scienze Agrarie e Forestali, Università degli studi di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Sellitto, Antonio, E-mail: ant.sellitto@gmail.com [Dipartimento di Matematica, Informatica ed Economia, Università della Basilicata, Campus Macchia Romana, 85100 Potenza (Italy); Jou, David, E-mail: david.jou@uab.cat [Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Institut d' Estudis Catalans, Carme 47, 08001 Barcelona, Catalonia (Spain)

    2014-07-04

    The size-dependent and flux-dependent effective thermal conductivity of narrow capillaries filled with superfluid helium is analyzed from a thermodynamic continuum perspective. The classical Landau evaluation of the effective thermal conductivity of quiescent superfluid, or the Gorter–Mellinck regime of turbulent superfluids, is extended to describe the transition to ballistic regime in narrow channels wherein the radius R is comparable to (or smaller than) the phonon mean-free path ℓ in superfluid helium. To do so, we start from an extended equation for the heat flux incorporating non-local terms, and take into consideration a heat slip flow along the walls of the tube. This leads from an effective thermal conductivity proportional to R{sup 2} (Landau regime) to another one proportional to Rℓ (ballistic regime). We consider two kinds of flows: along cylindrical pipes and along two infinite parallel plates. - Highlights: • Heat transport in counterflow helium in the ballistic regime. • The one-fluid model based on the Extended Thermodynamics is used. • The transition from the Landau regime to the ballistic regime. • The transition from quantum turbulence to ballistic regime.

  20. Simulation of Helium-3 Extraction from Lunar Ilmenite

    Science.gov (United States)

    Kuhlman, K. R.; Kulcinski, G. L.; Schmitt, H. H.

    2004-01-01

    Knowledge of the trapping mechanisms and diffusion characteristics of solar-wind implanted isotopes in the minerals of the lunar regolith will enable the optimization of the processes to extract solar wind gases from regolith particles. Extraction parameters include the temperature and duration of extraction, particle size, and gas yield. Diffusion data will increase the efficiency and profitability of future mining ventures. This data will also assist in optimizing the evaluations of various potential mining sites based on remote sensing data. For instance, if magnesian ilmenite (Mg,Fel.,Ti03) is found to retain He better than stoichiometric ilmenite (FeTi03), remote sensing data for Mg could be considered in addition to Ti and maturity data. The context of the currently discussed work is the mining of helium-3 for potential use as a fuel for fusion energy generation. However, the potential resources deposited by the solar wind include hydrogen (and derived water), helium-4, nitrogen and carbon. Implantation experiments such as those performed for helium isotopes in ilmenite are important for the optimized extraction of these additional resources. These experiments can easily be reproduced for most elements or isotopes of interest.

  1. Helium abundances on the moon: Assumptions and estimates

    Science.gov (United States)

    Taylor, Lawrence A.

    1991-01-01

    Nuclear energy is a highly desirable source of energy, and He-3 is the most prized of the fusion reactants. As the Wisconsin Group has emphasized, He-3 may be the only true economic ore on the Moon. The lack of a shielding atmosphere on the Moon permits solar-wind alpha particles to impinge upon the lunar regolith and become implanted into the various solid components. In particular, large quantities of helium (5 to 50 ppm) are presented. The measured parameter of I(sub s)/FeO, a direct indicator of maturity and exposure age, can be used as a first approximation to predict the abundances of many solar-wind components in the soils. However, because ilmenite has a much higher retentivity for helium than the other phases, the TiO2 contents of the soils are better indicators of helium contents (Taylor, Space 90). High-Ti mare bassalt regions, such as at the Apollo 17 locale, appear to be the best areas for He mining (15 to 50 ppm He(sub T)), versus 3 to 9 ppm in the Highlands. However, the relationships between I(sub s)/FeO, TiO2 and He-3 contents are complicated - e.g., many of the most He-rich soils are immature to submature. The amount of He-3 in the regolith of the moon is estimated at 220,000 tons in the outer 2 m of the Maria.

  2. Helium-neon laser improves skin repair in rabbits.

    Science.gov (United States)

    Peccin, Maria Stella; Renno, Ana Claudia Muniz; de Oliveira, Flavia; Giusti, Paulo Ricardo; Ribeiro, Daniel Araki

    2012-12-01

    The purpose of this study was to evaluate the influence of helium-neon laser on skin injury in rabbits. For this purpose, 15 New Zealand rabbits underwent bilateral skin damage in leg. Helium-neon laser light, at a fluence of 6 J∕cm2 and wavelength of 632.8 nm, was applied on the left legs (laser group). The right leg lesions (control group) served as negative control. All sections were histopathologically analyzed using HE sections. The results showed little infiltration of inflammatory cells, with proliferation of fibroblasts forming a few fibrous connective tissue after 1 week post-injury. The lesion on the 3rd week was characterized by granulation tissue, which formed from proliferated fibrous connective tissue, congested blood vessels and mild mononuclear cell infiltration. On the 5th week, it was observed that debris material surrounded by a thick layer of connective tissue and dense collage, fibroblasts cells present in the dermis covered by a thick epidermal layer represented by keratinized epithelium. Taken together, our results suggest that helium-neon laser is able to improve skin repair in rabbits at early phases of recovery.

  3. Helium measurements in support of MHTGR lithium target testing

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, B.M. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.; Rogers, J.W. [EG and G-Idaho, Inc., Idaho Falls, ID (United States). Idaho National Engineering Lab.

    1994-12-31

    The New Production-Modular High Temperature Gas Cooled Reactor (NP-MHTGR) development program sponsored by the US Department of Energy (DOE) has as part of its task the irradiation testing of the lithium target material. The lithium target material tritium ({sup 3}H) production is predominantly through the {sup 6}Li (n,{alpha}){sup 3}H reaction which also produces equal amounts of {sup 4}He ({alpha}). The tritium produced decays to {sup 3}He (12.38 year half-life), with some of this {sup 3}He being converted back to tritium during irradiation via the {sup 3}He(n,p){sup 3}H reaction. From these reactions, and the irradiation time-history, the measurement of the {sup 4}He and {sup 3}He content of a lithium monitor or target material sample can be used to determine several important variables associated with the target material performance, as well as to independently determine the neutron fields associated with the test environment. Helium measurements have been used to determine lithium burnup, tritium retention in target pellets, pellet material composition and variation and threshold temperature for helium release from the pellets. The present paper presents selected results obtained form the various helium measurements and discusses their relevance and importance to the MHTGR target development program.

  4. Lung Function Measurement with Multiple-Breath-Helium Washout System

    CERN Document Server

    Wang, Jau-Yi; Owers-Bradley, John; Mellor, Chris

    2011-01-01

    Multiple-breath-washout (MBW) measurements are regarded as a sensitive technique which can reflect the ventilation inhomogeneity of respiratory airways. Typically nitrogen is used as the tracer gas and is washed out by pure oxygen in multi-breath-nitrogen (MBNW) washout tests. In this work, instead of using nitrogen, helium is used as the tracer gas and a multiple-helium-breath-washout (MBHW) system has been developed for the lung function study. A commercial quartz tuning fork with a resonance frequency of 32768 Hz has been used for detecting the change of the respiratory gas density. The resonance frequency of the tuning fork decreases linearly with increasing density of the surrounding gas. Knowing the CO2 concentration from the infrared carbon dioxide detector, the helium concentration can be determined. Results from 12 volunteers (3 mild asthmatics, 2 smokers, 1 with asthma history, 1 with COPD history, 5 normal) have shown that mild asthmatics have higher ventilation inhomogeneity in either conducting o...

  5. SWCX Emission from the Helium Focusing Cone - Preliminary Results

    Science.gov (United States)

    Snowden, S. L.; Kuntz, K. D.; Collier, M. R.

    2008-01-01

    Preliminary results from an XMM-Newton campaign to study solar wind charge exchange (SWCX) emission from the heliospheric focusing cone of interstellar helium are presented. The detections of enhanced O VII and O VIII emission from the cone are at the 2(sigma) and 4(sigma) levels. The solar wind charge exchange (SWCX) emission in the heliosphere not associated with distinct objects (e.g., comets and planets including exospheric material in and near Earth s magnetosheath) is proportional to the flux of the solar wind and the space density of neutral material. The neutral material originates in the interstellar medium (ISM) and passes through the solar system due to the relative motion of the Sun and the ISM. The flow of the neutral material through the solar system is strongly perturbed by the Sun both by gravity and by radiation pressure. Because of the relative radiative scattering cross sections and the effect of solar gravitation the density of interstellar hydrogen near the Sun is reduced while interstellar helium is gravitationally focused. This creates a helium focusing cone downstream of the Sun [e.g., 1, and references therein].

  6. Pulmonary Kinematics From Tagged Hyperpolarized Helium-3 MRI

    Science.gov (United States)

    Tustison, Nicholas J.; Awate, Suyash P.; Cai, Jing; Altes, Talissa A.; Miller, G. Wilson; de Lange, Eduard E.; Mugler, John P.; Gee, James C.

    2010-01-01

    Purpose To propose and test the feasibility of a novel method for quantifying 3-D regional pulmonary kinematics from hyperpolarized helium-3 tagged MRI in human subjects using a tailored image processing pipeline and a recently developed nonrigid registration framework. Materials and Methods Following image acquisition, inspiratory and expiratory tagged helium-3 MR images were preprocessed using various image filtering techniques to enhance the tag surfaces. Segmentation of the three orthogonal sets of tag planes in each lung produced distinct point-set representations of the tag surfaces. Using these labeled point-sets, deformation fields and corresponding strain maps were obtained via nonrigid point-set registration. Kinematic analysis was performed on three volunteers. Results Tag lines in inspiratory and expiratory images were co-registered producing a continuous 3-D correspondence mapping. Average displacement and directional strains were calculated in three subjects in the inferior, mid, and superior portions of the right and left lungs. As expected, the predominant direction of displacements with expiration is from inferior to superior. Conclusion Kinematic quantitation of pulmonary motion using tagged helium-3 MRI is feasible using the applied image preprocessing filtering techniques and nonrigid point-set registration. Potential benefits from regional pulmonary kinematic quantitation include the facilitation of diagnosis and local assessment of disease progression. PMID:20432362

  7. Formation of Au and tetrapyridyl porphyrin complexes in superfluid helium.

    Science.gov (United States)

    Feng, Cheng; Latimer, Elspeth; Spence, Daniel; Al Hindawi, Aula M A A; Bullen, Shem; Boatwright, Adrian; Ellis, Andrew M; Yang, Shengfu

    2015-07-14

    Binary clusters containing a large organic molecule and metal atoms have been formed by the co-addition of 5,10,15,20-tetra(4-pyridyl)porphyrin (H2TPyP) molecules and gold atoms to superfluid helium nanodroplets, and the resulting complexes were then investigated by electron impact mass spectrometry. In addition to the parent ion H2TPyP yields fragments mainly from pyrrole, pyridine and methylpyridine ions because of the stability of their ring structures. When Au is co-added to the droplets the mass spectra are dominated by H2TPyP fragment ions with one or more Au atoms attached. We also show that by switching the order in which Au and H2TPyP are added to the helium droplets, different types of H2TPyP-Au complexes are clearly evident from the mass spectra. This study suggests a new route for the control over the growth of metal-organic compounds inside superfluid helium nanodroplets.

  8. Lung function measurement with multiple-breath-helium washout system.

    Science.gov (United States)

    Wang, J-Y; Suddards, M E; Mellor, C J; Owers-Bradley, J R

    2013-04-01

    Multiple-breath-washout (MBW) measurements are regarded as a sensitive technique which can reflect the ventilation inhomogeneity of respiratory airways. Typically nitrogen is used as the tracer gas and is washed out by pure oxygen in multiple-breath-nitrogen washout (MBNW) tests. In this study, instead of using nitrogen, (4)He is used as the tracer gas with smaller gas density which may be able to reach deeper into our lungs in a given time and the helium washout results may be more sensitive to the ventilation inhomogeneity in small airways. A multiple-breath-helium-washout (MBHW) system developed for the lung function study is also presented. Quartz tuning forks with a resonance frequency of 32,768Hz have been used for detecting the change of the respiratory gas density. The resonance frequency of the quartz tuning fork decreases linearly with increasing density of the surrounding gas. Knowing the CO2 concentration from the infrared carbon dioxide detector, the helium concentration can be determined. Results from 14 volunteers (3 mild asthmatics, 4 tobacco smokers, 1 with asthma history, 1 with COPD history, 5 normal) have shown that mild asthmatics have higher ventilation inhomogeneity in either conducting or acinar airways (or both). A feature has been found in washout curve of single breaths from 4 tobacco smokers with different length of smoking history which may indicate the early stage of respiratory ventilation inhomogeneity in acinar airways. Copyright © 2012 IPEM. All rights reserved.

  9. Online helium inventory monitoring of JLab cryogenic systems

    Science.gov (United States)

    Hasan, N.; Knudsen, P.; Wright, M.

    2017-12-01

    There are five cryogenic plants at Jefferson Lab which support the LINAC, experiment hall end-stations and test facility. The majority of JLab’s helium inventory, which is around 15 tons, is allocated in the LINAC cryo-modules, with the majority of the balance of helium distributed at the cryogenic-plant level mainly as stored gas and liquid for stable operation. Due to the organic evolution of the five plants and independent actions within the experiment halls, the traditional inventory management strategy suffers from rapid identification of potential leaks. This can easily result in losses many times higher than the normally accepted (average) loss rate. A real-time program to quickly identify potential excessive leakage was developed and tested. This program was written in MATLAB© for portability, easy diagnostics and modification. It interfaces directly with EPICS to access the cryogenic system state, and with and NIST REFPROP© for real fluid properties. This program was validated against the actual helium offloaded into the system. The present paper outlines the details of the inventory monitoring program, its validation and a sample of the achieved results.

  10. Proton and Helium Spectra from the CREAM-III Flight

    Science.gov (United States)

    Yoon, Y. S.; Anderson, T.; Barrau, A.; Conklin, N. B.; Coutu, S.; Derome, L.; Han, J. H.; Jeon, J. A.; Kim, K. C.; Kim, M. H.; Lee, H. Y.; Lee, J.; Lee, M. H.; Lee, S. E.; Link, J. T.; Menchaca-Rocha, A.; Mitchell, J. W.; Mognet, S. I.; Nutter, S.; Park, I. H.; Picot-Clemente, N.; Putze, A.; Seo, E. S.; Smith, J.; Wu, J.

    2017-04-01

    Primary cosmic-ray elemental spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment since 2004. The third CREAM payload (CREAM-III) flew for 29 days during the 2007-2008 Antarctic season. Energies of incident particles above 1 TeV are measured with a calorimeter. Individual elements are clearly separated with a charge resolution of ˜0.12 e (in charge units) and ˜0.14 e for protons and helium nuclei, respectively, using two layers of silicon charge detectors. The measured proton and helium energy spectra at the top of the atmosphere are harder than other existing measurements at a few tens of GeV. The relative abundance of protons to helium nuclei is 9.53 ± 0.03 for the range of 1 TeV/n to 63 TeV/n. This ratio is considerably smaller than other measurements at a few tens of GeV/n. The spectra become softer above ˜20 TeV. However, our statistical uncertainties are large at these energies and more data are needed.

  11. Proton and Helium Spectra from the CREAM-III Flight

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Y. S.; Han, J. H.; Kim, K. C.; Kim, M. H.; Lee, M. H.; Lee, S. E. [Institute for Physical Science and Technology, University of Maryland, College Park, MD, 20742 (United States); Anderson, T.; Conklin, N. B.; Coutu, S.; Mognet, S. I. [Department of Physics, Penn State University, University Park, PA 16802 (United States); Barrau, A.; Derome, L. [Laboratoire de Physique Subatomique et Cosmologie, Grenoble (France); Jeon, J. A.; Lee, H. Y.; Lee, J.; Park, I. H. [Department of Physics, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Link, J. T.; Mitchell, J. W. [Astrophysics Space Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Menchaca-Rocha, A. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico (Mexico); Nutter, S. [Department of Physics, Northern Kentucky University, Highland Heights, KY 41099 (United States); and others

    2017-04-10

    Primary cosmic-ray elemental spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment since 2004. The third CREAM payload (CREAM-III) flew for 29 days during the 2007–2008 Antarctic season. Energies of incident particles above 1 TeV are measured with a calorimeter. Individual elements are clearly separated with a charge resolution of ∼0.12 e (in charge units) and ∼0.14 e for protons and helium nuclei, respectively, using two layers of silicon charge detectors. The measured proton and helium energy spectra at the top of the atmosphere are harder than other existing measurements at a few tens of GeV. The relative abundance of protons to helium nuclei is 9.53 ± 0.03 for the range of 1 TeV/n to 63 TeV/n. This ratio is considerably smaller than other measurements at a few tens of GeV/n. The spectra become softer above ∼20 TeV. However, our statistical uncertainties are large at these energies and more data are needed.

  12. Informationssuchverhalten als Grundlage für die Gestaltung von Veranstaltungen zum Erwerb von Informationskompetenz

    Directory of Open Access Journals (Sweden)

    Martin Wollschläger-Tigges

    2015-09-01

    Full Text Available Für die Gestaltung bibliothekarischer Veranstaltungen zum Erwerb von Informationskompetenz stellen die bisherigen Ergebnisse und Befunde der Forschung zum Informationssuchverhalten eine wertvolle Grundlage dar, indem bestimmte und v.a. typische Verhaltensmuster, Routinen und Präferenzen im Umgang mit Informationsressourcen und Informationen in konzeptionelle und inhaltliche Anpassungen von IK- Veranstaltungen eingebracht und eingesetzt werden. Das Informationssuchverhalten untersucht sowohl individuelle als auch kollektive Informationsprozesse und Faktoren, die diese maßgeblich beeinflussen. Hierzu werden der gesamte Informationsprozess oder einzelne Abschnitte untersucht, die den Information Need, Seeking und Using (INSU-Prozess bilden. Die Befunde der einzelnen INSU-Prozesses-Einheiten zeigen, dass Faktoren wie Informationsbedarf, Informationsart und -form sowie die Einbindung in übergeordnete Arbeitsprozesse wesentlichen Einfluss auf das Informationssuchverhalten haben. Des Weiteren konnte die ISB-Forschung eine Klassifizierung von Benutzergruppen entwickeln und z.B. Fast Surfers, Broad Scanners und Deep Divers charakterisieren bzw. auch das Bouncing oder Flicking Behavior beschreiben. Hinzu kommen mehrere Modelle, die Informationssuchverhalten und Informationsverhalten in bestimmten Situationen nachbilden und darstellen können.

  13. Tragverhalten von Verbunddübeln unter Zugbelastung

    OpenAIRE

    Appl, Jörg-Jochen

    2009-01-01

    Im Bauwesen werden in zunehmendem Maße Dübel zur Einleitung von Lasten in den erhärteten Beton eingesetzt. Vor allem Befestigungssysteme auf der Grundlage chemischer Mörtel werden vermehrt verwendet. Allerdings fehlte bisher ein genügend genaues Berechnungsmodell zur Bemessung von beliebigen Befestigungen mit Verbunddübeln für unterschiedliche Verankerungstiefen und für verschiedene Verbundfestigkeiten. In der vorliegenden Arbeit wurde das Tragverhalten von Verbundübeln unter Zugbelastung...

  14. A von Bertalanffy growth model with a seasonally varying coefficient

    Science.gov (United States)

    Cloern, James E.; Nichols, Frederic H.

    1978-01-01

    The von Bertalanffy model of body growth is inappropriate for organisms whose growth is restricted to a seasonal period because it assumes that growth rate is invariant with time. Incorporation of a time-varying coefficient significantly improves the capability of the von Bertalanffy equation to describe changing body size of both the bivalve mollusc Macoma balthicain San Francisco Bay and the flathead sole, Hippoglossoides elassodon, in Washington state. This simple modification of the von Bertalanffy model should offer improved predictions of body growth for a variety of other aquatic animals.

  15. Abenteuer Alexander-von-Humboldt-Bibliographie

    Directory of Open Access Journals (Sweden)

    Christian Suckow

    2002-04-01

    Full Text Available Article in German; Abstracts in English and German.The two attempts (1860 and 1872 to compile a bibliography of all works of Alexander von Humboldt have to be regarded as failures. Due to Humboldt’s scientific methods, the contemporary popularity of his writings, and the conditions of book publishing and selling, it has been difficult to achieve an overview of his œuvre. Thus each attempt to write a reliable or at least partially complete bibliography of Humboldt’s works constituted an adventure. Horst Fiedler and Ulrike Leitner have mastered this undertaking. As a result of their efforts over more than two decades, a bibliography of those works by Humboldt which were published in book form appeared in the year 2000.

  16. Johann von Lamont: A Pioneer in Geomagnetism

    Science.gov (United States)

    Soffel, Heinrich

    2006-06-01

    The 200th birthday of John Lamont (1805-1879, Figure 1), a pioneer in the study of geomagnetism, was marked on 13 December 2005. Lamont founded the Munich Geomagnetic Observatory in 1840 and was a member of the group of scientists including Carl Friedrich Gauss, Alexander von Humboldt, Eduard Sabine, Jonas Angstrøm, Humphret Lloyd, Adolf Kupffer, Karl Kreil, and Adolphe Quetelet who composed the Göttingen Magnetic Union. They organized an international network of geomagnetic observatories [Barraclough et al., 1992]. The present knowledge of the geomagnetic field and its secular variation is largely based on the data collected by the global network of geomagnetic observatories during the last 170 years. Lamont's talents and his dedication and enthusiasm for discovery are reflected in the depth and scope of his contributions to a broad variety of natural sciences such as astronomy, meteorology, geomagnetism, and geodesy. However, this article just touches on his merits in geomagnetism.

  17. Bertha von Suttner 1843-1914

    OpenAIRE

    Hoock-Demarle, Marie-Claire; Hessel, Stéphane

    2016-01-01

    Née dans « le monde d'hier » cher à son compatriote Stefan Zweig, morte le 21 juin 1914 à la veille du déclenchement d’une guerre qu’elle appelle Weltkrieg, Bertha von Suttner témoigne d’un parcours hors du commun dans un moment crucial où s’amorcent les conflits générés par les militarismes et les nationalismes menant inexorablement à la catastrophe. Arpenteuse d’Europe, voyageuse du Nouveau Monde, elle voit dans « l’américanisation du monde » une raison de construire dans la paix et la coop...

  18. Modernisation of ventilation systems; Modernisierung von Lueftungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Richter, W. [Technische Univ. Dresden (Germany). Inst. fuer Thermodynamik und Technische Gebaeudeausruestung

    1997-12-31

    When redeveloping buildings it is common to use window constructions with air-tight rabbets which obviate the inflow of fresh air almost entirely. This leads to the well-known structural-physics and hygienic consequences. As an added effect, the distinctly enhanced thermal insulation results in changes in dynamic heat loss. The paper focuses on the issues of how to safeguard the inflow of fresh air, and the heating capacity of radiators. (MSK) [Deutsch] Da die bei Gebaeudesanierungen eingesetzten fugendichten Fensterkonstruktionen die Nachstroemmoeglichkeiten fuer die Zuluft fast ganz unterbinden, fuehrt das zu den bekannten bauphysikalischen und hygienischen Konsequenzen. Dazu kommen veraenderte dynamische Waermverlustverhaeltnisse aufgrund der deutlich verbesserten Waermedaemmung. Im Folgenden wird schwerpunktmaessig auf die Probleme Zuluftsicherung und Waermeleistung von Heizkoerpern eingegangen.

  19. Effective potentials for charge-helium and charge-singly-ionized helium interactions in a dense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ramazanov, T.S.; Amirov, S.M.; Moldabekov, Zh.A. [Institute for Experimental and Theoretical Physics, Al-Farabi Kazakh National University, Almaty (Kazakhstan)

    2016-06-15

    The effective electron (proton)-He and electron (proton)-He{sup +} screened pair interaction potentials arising as a result of partial screening of the helium nucleus field by bound electrons, taking into account both screening by free charged particles and quantum diffraction effect in dense plasmas were derived. The impact of quantum effects on screening was analyzed. It was shown that plasma polarization around the atom leads to the additional repulsion (attraction) between the electron (proton) and the helium atom. The method of constructing the full electron (proton)-He and electron (proton)-He{sup +} screened pair interaction potentials as the sum of the derived potentials with the polarization potential and exchange potential is discussed. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Tritium and helium release from beryllium pebbles neutron-irradiated up to 230appm tritium and 3000appm helium

    Directory of Open Access Journals (Sweden)

    Vladimir Chakin

    2016-12-01

    Full Text Available Study of tritium and helium release from beryllium pebbles with diameters of 0.5 and 1mm after high-dose neutron irradiation at temperatures of 686–968K was performed. The release rate always has a single peak, and the peak temperatures at heating rates of 0.017K/s and 0.117K/s lie in the range of 1100–1350K for both tritium and helium release. The total tritium release from 1mm pebbles decreases considerably by increasing the irradiation temperature. The total tritium release from 0.5mm pebbles is less than that from 1mm pebbles and remains constant regardless of the irradiation temperature. At high irradiation temperatures, open channels are formed which contribute to the enhanced tritium release.

  1. Using uncertainty principle to find the ground-state energy of the helium and a helium-like Hookean atom

    Energy Technology Data Exchange (ETDEWEB)

    Harbola, Varun, E-mail: varunh@iitk.ac.in [Kendriya Vidyalaya (Central School) Indian Institute of Technology, Kanpur-208 016 (India)

    2011-11-15

    In this paper, we accurately estimate the ground-state energy and the atomic radius of the helium atom and a helium-like Hookean atom by employing the uncertainty principle in conjunction with the variational approach. We show that with the use of the uncertainty principle, electrons are found to be spread over a radial region, giving an electron cloud. Our calculation also shows how the Coulomb interaction between electrons affects their distribution. This leads to a physical picture of how electrons are located with respect to each other in these atoms. Finally, we also obtain through our calculations a general formula for the estimate of ground-state energy and radius of two electron atoms and ions with atomic number Z.

  2. Hepatische Effekte von Wachstumshormon auf den Glukosestoffwechsel

    Directory of Open Access Journals (Sweden)

    Rufinatscha K

    2015-01-01

    Full Text Available Untherapierter Wachstumshormonmangel im Erwachsenenalter (AGHD ist mit viszeraler Adipositas, Dyslipidämie, Insulinresistenz und Fettleber verbunden. Interessanterweise finden sich viele der AGHD-Merkmale auch bei Patienten mit metabolischem Syndrom. Die nichtalkoholische Fettlebererkrankung (NAFLD gilt als hepatische Manifestation des metabolischen Syndroms. In einigen Studien wurden bei Patienten mit NAFLD verminderte Konzentrationen von zirkulierendem IGF-1, dessen Synthese zu einem großen Teil durch Wachstumshormon (GH reguliert wird, beschrieben. Mäuse, welche eine hepatische Wachstumshormondefizienz aufweisen, zeigen zahlreiche phänotypische Charakteristika des metabolischen Syndroms, unter anderen auch eine Fettlebererkrankung. Dies legt einen Zusammenhang zwischen dem Wachstumshormon und der Entstehung einer NAFLD nahe. Ziel unserer Studie ist es, in einem Zellkulturmodell die Effekte des Wachstumshormons auf den intrazellulären Glukosestoffwechsel näher zu untersuchen. Im Detail sollen Auswirkungen einer verminderten Wachstumshormonrezeptorexpression auf den Insulinsignaltransduktionsweg, den Glykogengehalt und auf Schlüsselenzyme der Glukoneogenese untersucht werden. Präliminäre Daten zeigen, dass eine verminderte Wachstumshormonrezeptorexpression mit intrazellulären Veränderungen des hepatischen Glukosestoffwechsels verbunden ist. Die verminderte Insulinsensitivität könnte auf Alterationen im Insulinsignaltransduktionsweg und Änderungen der Glukoneogenese zurückzuführen sein. Diese präliminären Daten weisen darauf hin, dass Wachstumshormon einen direkten Einfluss auf den Glukosestoffwechsel in der Leber hat. Zudem legen sie nahe, dass Veränderungen im Wachstumshormonstoffwechsel einen wichtigen pathophysiologischen Mechanismus in der Entstehung der Fettlebererkrankung bei Patienten mit metabolischem Syndrom darstellen könnten. Der folgende Artikel soll einen kurzen Überblick über die Effekte von Wachstumshormon

  3. VON WILLEBRAND DISEASE: DIAGNOSIS AND TREATMENT

    Directory of Open Access Journals (Sweden)

    Majda Benedik Dolničar

    2004-12-01

    Full Text Available Background. Von Willebrand disease (VWD is a most frequently inborn bleeding disorder caused by quantitative or qualitative defects of von Willebrand factor (VWF. VWF promotes platelet-vessel wall (adhesion and plateletplatelet interaction (aggregation. It is also the carrier for factor VIII (F VIII in plasma. A deficiency of VWF may results in impairment of both, primary and secondary haemostasis. Therefore, patients with VWD can have bleeding symptoms typical fot the defect in primary haemostasis (mucocutaneous haemorrhages. In severe deficiency of VWF there are also haemarthroses and haematomas typical for patients with coagulation defects. Several types and subtypes of VWD have been described. The diagnosis is based on measurements of VWF concentration and activity and F VIII activity in plasma. The tests identifying VWD subtypes are ristocetin induced platelet agglutination (RIPA, multimeric analysis of VWF and measurement of the binding of VWF to F VIII.Conclusions. Due to heterogeneity of VWF defects, the correct diagnosis of types and subtypes is sometimes difficult but is important for appropriate treatment. There are two main therapeutic options for patients with VWD: desmopressin and blood derived concentrates of F VIII/VWF. In certain cases antifibrinolytics and hormones can be suitable treatment. Desmopressin is the treatment of choice in patients with type 1 VWD. It raises endogenous F VIII and VWF and thereby corrects the intrinsic coagulation defect as well as the prolonged bleeding time (BT or closure time (CT-PFA100 in most type 1 VWD patients. In type 3 and in the majority of type 2 patients desmopressin is not effective and it is necessary to use concentrates containing F VIII and VWF. These are always effective in raising of F VIII activity, whereas the BT/CT may not be completely corrected, but the normalisation of the BT/CT is not always necessary.

  4. Lightweight Liquid Helium Dewar for High-Altitude Balloon Payloads

    Science.gov (United States)

    Kogut, Alan; James, Bryan; Fixsen, Dale

    2013-01-01

    Astrophysical observations at millimeter wavelengths require large (2-to-5- meter diameter) telescopes carried to altitudes above 35 km by scientific research balloons. The scientific performance is greatly enhanced if the telescope is cooled to temperatures below 10 K with no emissive windows between the telescope and the sky. Standard liquid helium bucket dewars can contain a suitable telescope for telescope diameter less than two meters. However, the mass of a dewar large enough to hold a 3-to-5-meter diameter telescope would exceed the balloon lift capacity. The solution is to separate the functions of cryogen storage and in-flight thermal isolation, utilizing the unique physical conditions at balloon altitudes. Conventional dewars are launched cold: the vacuum walls necessary for thermal isolation must also withstand the pressure gradient at sea level and are correspondingly thick and heavy. The pressure at 40 km is less than 0.3% of sea level: a dewar designed for use only at 40 km can use ultra thin walls to achieve significant reductions in mass. This innovation concerns new construction and operational techniques to produce a lightweight liquid helium bucket dewar. The dewar is intended for use on high-altitude balloon payloads. The mass is low enough to allow a large (3-to-5-meter) diameter dewar to fly at altitudes above 35 km on conventional scientific research balloons without exceeding the lift capability of the balloon. The lightweight dewar has thin (250- micron) stainless steel walls. The walls are too thin to support the pressure gradient at sea level: the dewar launches warm with the vacuum space vented continuously during ascent to eliminate any pressure gradient across the walls. A commercial 500-liter storage dewar maintains a reservoir of liquid helium within a minimal (hence low mass) volume. Once a 40-km altitude is reached, the valve venting the vacuum space of the bucket dewar is closed to seal the vacuum space. A vacuum pump then

  5. Helium turbine power generation in high temperature gas reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Yasuo [Tokyo Inst. of Tech. (Japan)

    1995-03-01

    This paper presents studies on the helium turbine power generator and important components in the indirect cycle of high temperature helium cooled reactor with multi-purpose use of exhaust thermal energy from the turbine. The features of this paper are, firstly the reliable estimation of adiabatic efficiencies of turbine and compressor, secondly the introduction of heat transfer enhancement by use of the surface radiative heat flux from the thin metal plates installed in the hot helium and between the heat transfer coil rows of IHX and RHX, thirdly the use of turbine exhaust heat to produce fresh water from seawater for domestic, agricultural and marine fields, forthly a proposal of plutonium oxide fuel without a slight possibility of diversion of plutonium for nuclear weapon production and finally the investigation of GT-HTGR of large output such as 500 MWe. The study of performance of GT-HTGR reduces the result that for the reactor of 450 MWt the optimum thermal efficiency is about 43% when the turbine expansion ratio is 3.9 for the turbine efficiency of 0.92 and compressor efficiency of 0.88 and the helium temperature at the compressor inlet is 45degC. The produced amount of fresh water is about 8640 ton/day. It is made clear that about 90% of the reactor thermal output is totally used for the electric power generation in the turbine and for the multi-puposed utilization of the heat from the turbine exhaust gas and compressed helium cooling seawater. The GT-Large HTGR is realized by the separation of the pressure and temperature boundaries of the pressure vessel, the increase of burning density of the fuel by 1.4 times, the extention of the nuclear core diameter and length by 1.2 times, respectively, and the enhancement of the heat flux along the nuclear fuel compact surface by 1.5 times by providing riblets with the peak in the flow direction. (J.P.N.).

  6. Evolution Law of Helium Bubbles in Hastelloy N Alloy on Post-Irradiation Annealing Conditions

    Directory of Open Access Journals (Sweden)

    Jie Gao

    2016-10-01

    Full Text Available This work reports on the evolution law of helium bubbles in Hastelloy N alloy on post-irradiation annealing conditions. After helium ion irradiation at room temperature and subsequent annealing at 600 °C (1 h, the transmission electron microscopy (TEM micrograph indicates the presence of helium bubbles with size of 2 nm in the depth range of 0–300 nm. As for the sample further annealed at 850 °C (5 h, on one hand, a “Denuded Zone” (0–38 nm with rare helium bubbles forms due to the decreased helium concentration. On the other hand, the “Ripening Zone” (38–108 nm and “Coalescence Zone” (108–350 nm with huge differences in size and separation of helium bubbles, caused by different coarsening rates, are observed. The mechanisms of “Ostwald ripening” and “migration and coalescence”, experimentally proved in this work, may explain these observations.

  7. Effects of sequential tungsten and helium ion implantation on nano-indentation hardness of tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, D. E. J.; Edmondson, P. D.; Roberts, S. G. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

    2013-06-24

    To simulate neutron and helium damage in a fusion reactor first wall sequential self-ion implantation up to 13 dpa followed by helium-ion implantation up to 3000 appm was performed to produce damaged layers of {approx}2 {mu}m depth in pure tungsten. The hardness of these layers was measured using nanoindentation and was studied using transmission electron microscopy. Substantial hardness increases were seen in helium implanted regions, with smaller hardness increases in regions which had already been self-ion implanted, thus, containing pre-existing dislocation loops. This suggests that, for the same helium content, helium trapped in distributed vacancies gives stronger hardening than helium trapped in vacancies condensed into dislocation loops.

  8. Production of carbon monoxide-free hydrogen and helium from a high-purity source

    Science.gov (United States)

    Golden, Timothy Christopher [Allentown, PA; Farris, Thomas Stephen [Bethlehem, PA

    2008-11-18

    The invention provides vacuum swing adsorption processes that produce an essentially carbon monoxide-free hydrogen or helium gas stream from, respectively, a high-purity (e.g., pipeline grade) hydrogen or helium gas stream using one or two adsorber beds. By using physical adsorbents with high heats of nitrogen adsorption, intermediate heats of carbon monoxide adsorption, and low heats of hydrogen and helium adsorption, and by using vacuum purging and high feed stream pressures (e.g., pressures of as high as around 1,000 bar), pipeline grade hydrogen or helium can purified to produce essentially carbon monoxide -free hydrogen and helium, or carbon monoxide, nitrogen, and methane-free hydrogen and helium.

  9. Modeling of helium bubble nucleation and growth in neutron irradiated boron doped RAFM steels

    Energy Technology Data Exchange (ETDEWEB)

    Dethloff, Christian, E-mail: christian.dethloff@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Gaganidze, Ermile [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Svetukhin, Vyacheslav V. [Ulyanovsk State University, Leo Tolstoy Str. 42, 432970 Ulyanovsk (Russian Federation); Aktaa, Jarir [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2012-07-15

    Reduced activation ferritic/martensitic (RAFM) steels are promising candidates for structural materials in future fusion technology. In addition to other irradiation defects, the transmuted helium is believed to strongly influence material hardening and embrittlement behavior. A phenomenological model based on kinetic rate equations is developed to describe homogeneous nucleation and growth of helium bubbles in neutron irradiated RAFM steels. The model is adapted to different {sup 10}B doped EUROFER97 based heats, which already had been studied in past irradiation experiments. Simulations yield bubble size distributions, whereby effects of helium generation rate, surface energy, helium sinks and helium density are investigated. Peak bubble diameters under different conditions are compared to preliminary microstructural results on irradiated specimens. Helium induced hardening was calculated by applying the Dispersed Barrier Hardening model to simulated cluster size distributions. Quantitative microstructural investigations of unirradiated and irradiated specimens will be used to support and verify the model.

  10. Gaseous Helium storage and management in the cryogenic system for the LHC

    CERN Document Server

    Barranco-Luque, M

    2000-01-01

    The Large Hadron Collider (LHC) is presently under construction at CERN. Its main components are superconducting magnets which will operate in superfluid helium requiring cryogenics on a length of about 24 km around the machine ring with a total helium inventory of about 100 tonnes. As no permanent liquid helium storage is foreseen and for reasons of investment costs, only half of the total helium content can be stored in gaseous form in medium pressure vessels. During the LHC operation part of these vessels will be used as helium buffer in the case of multiple magnet quenches. This paper describes the storage, distribution and management of the helium, the layout and the connection to the surface and underground equipment of the cryogenic system.

  11. Von Krahli Teatri lavastus pääses tippfestivalile

    Index Scriptorium Estoniae

    1999-01-01

    Von Krahli Teatri uuendatud lavastus "Eesti mängud. Pulm" esietendub festivalil Theater Der Welt Berliinis. Peeter Jalaka multimeediaetendus Eesti ajaloost ja traditsioonidest osaleb ka suveteatrite festivalil Hamburgis, seejärel antakse kuus etendust Amsterdamis

  12. La actualidad del pensamiento de Carl von Clausewitz

    National Research Council Canada - National Science Library

    Borrero Mansilla, Armando

    2003-01-01

    The article presents the validity of the thought of Carl von Clausewitz, which application, beyond the wars among national States, can be extended to the analysis of the confrontation among political...

  13. Lexikon lesbischer Frauen im Film von Daniela Sobek

    Directory of Open Access Journals (Sweden)

    Karin Windt

    2002-03-01

    Full Text Available Das Lexikon stellt ein neues Basiswerk über lesbische Figuren im Film dar. Neben zahlreichen Artikeln von Anbeginn der Filmgeschichte bis heute gibt es Features über bekannte Schauspielerinnen und lesbische role models.

  14. Magnus Georg von Paucker (1787-1855) / Eckhard Spring

    Index Scriptorium Estoniae

    Spring, Eckhard

    2013-01-01

    Eestis sündinud ja Tartu Ülikoolis õppinud silmapaistvast baltisaksa teadlasest ja tema lapselapsest Alexandrine Pauckerist. 23. novembril 2012 Jelgavas/Mitaus toimunud Magnus Georg von Pauckerile pühendatud teaduskonverentsist

  15. Von Krahli Teater toob Eestisse erakordse auhinna / Tiit Tuumalu

    Index Scriptorium Estoniae

    Tuumalu, Tiit, 1971-

    2004-01-01

    Bessie-auhinna puhul, millega New Yorgis pärjati Von Krahli Teatri lavastust "Luikede järv." Mõjukuselt on seda võrreldud Broadway teatriauhinna Tonyga. Lisatud lühiandmed P. Jalaka ja S. Pepeljajevi kohta

  16. Politische Bildung im Kontext von Regierung, Unterricht und Zucht

    National Research Council Canada - National Science Library

    Thomas Rucker

    2014-01-01

    .... In diesem Beitrag wird zu zeigen versucht, dass Herbart die Unterstützung politischer Bildung als eine Aufgabe von Regierung, Unterricht und Zucht bestimmt und in seinem Werk wichtige „Bausteine...

  17. Revascularization Operation for Moyamoya Disease with Concurrent von Willebrand Disease.

    Science.gov (United States)

    Miki, Kenji; Arimura, Koichi; Nishimura, Ataru; Yoshimoto, Koji; Sayama, Tetsuro; Iihara, Koji

    2017-12-01

    Although extracranial-intracranial (EC-IC) bypass is an effective treatment strategy for symptomatic moyamoya disease, surgeons need to be cautious regarding the possibility of postoperative hemorrhagic complications in patients with a concurrent coagulation disorder. Here, we describe a case of EC-IC bypass for moyamoya disease concurrent with von Willebrand disease type 1. Following perioperative replacement of the von Willebrand factor, the patient showed an uneventful and uncomplicated clinical course. This is the first reported case of EC-IC bypass being performed for moyamoya disease in a patient with concurrent von Willebrand disease. We emphasize the importance of appropriate management with replacement of the von Willebrand factor during the perioperative period to avoid hemorrhagic complications. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Die zentrale Wirkung von Candesartan in der Schlaganfalltherapie

    OpenAIRE

    Maydowski, Katja

    2011-01-01

    Ziel der vorliegenden Arbeit war es, die Auswirkungen des AT1-Blockers Candesartan auf einen ischämischen Insult durch eine rein zentrale AT1-Blockade am Tiermodell mit direkter intracerebroventrikulärer Applikation von Candesartan zu untersuchen.

  19. Zur sportlichen Laufbahn von Marathonläufern

    OpenAIRE

    Rümmele, Edgar

    1984-01-01

    Zur sportlichen Laufbahn von Marathonläufern : e. Beitr. zur Psychologie d. Marathonläufers. - Thun u.a. : Deutsch, 1984. - 253, 14 S. - Zugl.: Tübingen, Univ., Diss. - (Beiträge zur Sportwissenschaft ; 1)

  20. Warum das Controlling den systematischen Einsatz von Simulationen vorantreiben sollte

    DEFF Research Database (Denmark)

    Spitzner, Jan; Schneider, Melanie L.

    2017-01-01

    Simulationen werden in der Unternehmenssteuerung heutzutage noch nicht systematisch eingesetzt. Dass sich jedoch die existierenden Hemmnisse durchaus überwinden lassen, legen die Antworten von Studienteilnehmern nahe, die Simulationen häufig einsetzen. Dabei kann Controlling eine Vorreiterrolle e...

  1. Von Krahli Teater viis Helsingisse kaks menulavastust / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2003-01-01

    Von Krahli Teater esineb 29. nov. Helsingis "Baltic Circle" festivalil lavastustega "Luikede järv" ja "Taksojuhid". Tutvustatakse lühidalt ka paari olulisemat soome lavastust ("Puksiirabi" ja "Hamlet"), mis tulevad festivalil esitamisele

  2. Stopping-Power and Range Tables for Electrons, Protons, and Helium Ions

    Science.gov (United States)

    SRD 124 Stopping-Power and Range Tables for Electrons, Protons, and Helium Ions (Web, free access)   The databases ESTAR, PSTAR, and ASTAR calculate stopping-power and range tables for electrons, protons, or helium ions. Stopping-power and range tables can be calculated for electrons in any user-specified material and for protons and helium ions in 74 materials.

  3. Zur Dialektik von Soft Skills und fachlicher Kompetenz

    OpenAIRE

    Jendrowiak, Hans-Werner

    2010-01-01

    [Der Autor stellt folgende Thesen zur Dialektik von Soft Skills und fachlicher Bildung auf:] 1. Soft Skills sind normale Bildungskategorien und Teil einer Allgemeinen Bildung. […] 2. Soft Skills sind als personalgebundene Kriterien auch immer schon Gegenstand bildungstheoretischer Debatten. […] 3. Soft Skills ist eine trendorientierte Bezeichnung für Bildung. […] 4. Soft Skills sind Ausdruck von Vorstellungen, Ideen und Theorien (Schulkultur, Unternehmenskultur, Unternehmensphilosophie). 5. S...

  4. Behandlung von Cybermobbing durch die Soziale Arbeit in der Schule

    OpenAIRE

    Dill, Irina; Wahl, Lisa

    2015-01-01

    Gegenstand dieser Arbeit ist die Behandlung von Cybermobbing durch die Soziale Arbeit in der Schule. Cybermobbing ist eine neuere Form von schulischer Gewalt und verlangt nach neuen Formen der Beratung und Intervention der Sozialen Arbeit in der Schule. Anhand einer Literaturrecherche gehen die Autorinnen Lisa Wahl und Irina Dill der Frage nach, inwiefern die Soziale Arbeit in der Schule Cybermobbing behandeln kann. Die Konzipierung der Sozialen Arbeit in der Schule fundiert primär auf dem Bu...

  5. Zusammenhang von Prozess, Mikrostruktur, Eigenspannungen und Eigenschaften bei Aluminiumverbundwerkstoffen

    OpenAIRE

    Kachold, Franziska

    2016-01-01

    Wo die mechanische Leistungsfähigkeit von monolithischen Materialien an ihre Grenzen stößt, bieten Verbundwerkstoffe neue Perspektiven. Besonders wenn hohe Festigkeit oder Steifigkeit bei gleichzeitig niedrigem spezifischen Gewicht gefordert ist, kommen Faserverbundwerkstoffe zum Einsatz. Faserverstärkte Polymere existieren bereits seit ca. 1900 und werden heute für ein breites Spektrum von Bauteilen und Produkten im Automobil-, Flugzeug- und auch Sportgerätebau verwendet. Die geringe T...

  6. Von Neumann's impossibility proof: Mathematics in the service of rhetorics

    Science.gov (United States)

    Dieks, Dennis

    2017-11-01

    According to what has become a standard history of quantum mechanics, in 1932 von Neumann persuaded the physics community that hidden variables are impossible as a matter of principle, after which leading proponents of the Copenhagen interpretation put the situation to good use by arguing that the completeness of quantum mechanics was undeniable. This state of affairs lasted, so the story continues, until Bell in 1966 exposed von Neumann's proof as obviously wrong. The realization that von Neumann's proof was fallacious then rehabilitated hidden variables and made serious foundational research possible again. It is often added in recent accounts that von Neumann's error had been spotted almost immediately by Grete Hermann, but that her discovery was of no effect due to the dominant Copenhagen Zeitgeist. We shall attempt to tell a story that is more historically accurate and less ideologically charged. Most importantly, von Neumann never claimed to have shown the impossibility of hidden variables tout court, but argued that hidden-variable theories must possess a structure that deviates fundamentally from that of quantum mechanics. Both Hermann and Bell appear to have missed this point; moreover, both raised unjustified technical objections to the proof. Von Neumann's argument was basically that hidden-variables schemes must violate the ;quantum principle; that physical quantities are to be represented by operators in a Hilbert space. As a consequence, hidden-variables schemes, though possible in principle, necessarily exhibit a certain kind of contextuality. As we shall illustrate, early reactions to Bohm's theory are in agreement with this account. Leading physicists pointed out that Bohm's theory has the strange feature that pre-existing particle properties do not generally reveal themselves in measurements, in accordance with von Neumann's result. They did not conclude that the ;impossible was done; and that von Neumann had been shown wrong.

  7. Möglichkeiten und Grenzen von Social Media Marketing

    OpenAIRE

    Kreutzer, Ralf T.; Hinz, Jule

    2010-01-01

    In diesem Arbeitspapier wird das Konzept des Social Media Marketing theoretisch dargestellt und seine Möglichkeiten und Grenzen analysiert. Dabei werden die einzelnen Instrumente des Social Media Marketings sowie die verschiedenen Nutzertypen erläutert und auf die Erfolgsmessung von Methoden des Social Media Marketings eingegangen. Schließlich wird an den Beispielen HUGO BOSS, Starbucks und Nestlé auf die Umsetzung von Maßnahmen des Social Media Marketings eingegangen und aufgezeigt, welche E...

  8. Rekonstruktion von Gletscherschwankungen mit Hilfe fossiler Hölzer

    OpenAIRE

    Holzhauser, H.

    1984-01-01

    Im vorliegenden Artikel wird gezeigt, wie mit Hilfe von fossilen Hölzern aus dem Gletschervorfeld minimale Gletscherausdehnungen und Gletschervorstöße erfaßt werden können. Einige zeitgenössische Berichte und Zeichnungen aus der Zeit um 1850, als die Alpengletscher ihren letzten neuzeitlichen Hochstand erreichten, sollen veranschaulichen, wie Gletscher in bewaldetes Gebiet vordrangen und Bäume umdrückten. Es wird im weiteren kurz auf die Lage von fossilem Holz im Gletschervo...

  9. Nationale Kapitalanlagengarantien als Instrumente zur Förderung von Direktinvestitionen

    OpenAIRE

    Stern, Thomas

    1988-01-01

    Wegen ihres hohen entwicklungspolitischen Stellenwertes ist die Steigerung von Direktinvestitionen als langfristiges Instrument zur Verbesserung der Verschuldenssituation der Länder der Dritten Welt anerkannt. Trotz dieser Erkenntnis blieben die Direktinvestitionen in Richtung der Entwicklungsländer in den letzten fünf Jahren hinter den Erwartungen zurück und erreichten lediglich einen Anteil von ca. 12 % an den Gesamtkapitalströmen. Wichtige Motive für die Zurückhaltung der Investoren in die...

  10. Kommunale Versorgung, Verortung und Steuerung von Risiken psychischer Gesundheit

    OpenAIRE

    Warner, Joanne

    2006-01-01

    Das Risikokonzept ist heute zentral für alle Bereiche von gesundheitlicher und sozialer Wohlfahrt in Großbritannien. Im Bereich psychischer Gesundheit und insbesondere seit den Maßnahmen zur kommunalen Versorgung in den 1990er Jahren kommt dem Konzept jedoch besondere Aufmerksamkeit zu. Dabei kamen bisher vor allem die Risiken in den Blick, die von Personen mit psychischen Erkrankungen oder in psychischer Not ausgehen, aber nicht die Risiken, mit denen diese selbst konfrontiert sind. Der vorl...

  11. Untersuchung der verfahrenstechnischen Potentiale von CO2-Minderungsoptionen

    OpenAIRE

    Geng, Jin

    2017-01-01

    Die vorliegende Arbeit beschäftigt sich mit der Untersuchung der verfahrenstechnischen Potentiale von CO2-Minderungsoptionen. CO2 ist ein Treibhausgas und führt zu Klimaproblemen. Wie erfolgreich der Kampf gegen den Klimawandel ist, hängt stark von den politischen Entscheidungen ab, welche auf internationalen Vereinbarungen und der wirtschaftlichen Situation basieren. Allerdings ist die technische Machbarkeit die Voraussetzung aller Entscheidungen. In der Arbeit wird diskutiert, welches P...

  12. CyLaw-Report V : "Sicherheit von ec-Karten"

    OpenAIRE

    Schmid, Viola

    2008-01-01

    Entscheidung des BGH vom 05.10.2004 - XI ZR 210/03 Die vorliegende Entscheidung des Bundesgerichtshof (BGH) bringt - nach jahrelanger juristischer Diskussion und divergierender Rechtsprechung verschiedener Gerichte - weiteren Aufschluss bei beweis- und haftungsrechtlichen Fragen von ec-Karten. Die besondere Bedeutung bargeldloser Zahlungsverfahren im Bereich von eCommerce, eGovernment etc. machen das Urteil des BGH zu einer für das Cyberlaw interessanten Entscheidung.

  13. Hochtemperaturverhalten von Stahlbetonplatten mit Textilbetonverstärkung

    OpenAIRE

    Hothan, Sascha; Ehlig, Daniel

    2011-01-01

    Die Verwendung von Endlosfilamenten aus Carbon als Bewehrungsmaterial für Beton, sogenannter Textilbeton, bietet die Möglichkeit der Sanierung und der Verstärkung bestehender Stahlbetonkonstruktionen. Dabei muss die Frage nach dem Feuerwiderstand von derart verstärkten Tragwerken beantwortet werden. Aufschluss darüber liefern Brandversuche. Mit Textilbeton verstärkte Stahlbetonplatten haben in Brandversuchen nach der Einheits- Temperaturzeitkurve bei 33 % der Traglast mehr als 60 Minuten stan...

  14. Expression von Wachstumsfaktoren unter Vakuumversiegelungstherapie in chronischen Wunden

    OpenAIRE

    Rosenberg, Birgit

    2012-01-01

    Hintergründe und Zielsetzung Die Vakuumversiegelungsmethode (V.A.C.® = Vac.) ist ein von M. Morykwas und C. Argenta 1988 entwickeltes Verfahren zur Konditionierung von akuten und chronischen Wunden, das sich in den letzten Jahren klinisch etabliert und dessen Anwendungsspektrum kontinuierlich zugenommen hat. In vielen klinischen Studien konnte die Wirksamkeit dieses Therapieverfahrens in der Wundbehandlung nachgewiesen werden, unklar ist jedoch bislang welche physiologischen Veränderungen auf...

  15. Nash y von Neumann: mundos posibles y juegos de lenguaje

    Directory of Open Access Journals (Sweden)

    Salazar , Boris

    2004-06-01

    Full Text Available Este ensayo emplea las nociones de juego de lenguaje y de equivalencia entre juegos para examinar la decisión de John Nash de no jugar el juego coalicional que propuso John von Neumann. El argumento central es que Nash concibió una clase de mundos posibles incompatible con la de von Neumann, y que en el origen de esa divergencia estarían sus distintas nociones de racionalidad.

  16. Entwicklung von Cellulosefaser-Leichtbeton und Untersuchung des bruchmechanischen Verhaltens

    OpenAIRE

    Thiel, Thomas

    2016-01-01

    Im Zentrum der vorliegenden Arbeit steht ein zementgebundener Leichtbeton auf der Basis von aus Altpapier herausgelösten Cellulosefasern; hierfür wird im Folgenden die Bezeichnung CFLC (Cellulose-Fibre Lightweight Concrete) verwendet. Die Intention zur Untersuchung dieses mitunter auch als Papercrete bezeichneten und bislang nur verhältnismäßig wenig erforschten Materials beruht insbesondere darauf, dass von einer Kombination eines leicht verfügbaren pflanzlichen Faserstoffs mit einem mineral...

  17. Ludwig von Bertalanffy Forerunner of Evolutionary Systems Theory

    OpenAIRE

    Wolfgang, Hofkirchner

    2005-01-01

    Ludwig von Bertalanffy is known as founding father of the General System Theory (GST). When Ludwig von Bertalanffy created his GST amidst the last century, he was able to overcome the deep cleft between the controversial theoretical approaches to biology - mechanicism and vitalism. He did so by formulating laws of organisation ruling biota and after generalising them he successfully applied them to different domains such as medicine, psychology, psychotherapy. Methodologically, Bertalanffy re...

  18. Prodigious degassing of a billion years of accumulated radiogenic helium at Yellowstone

    Science.gov (United States)

    Lowenstern, Jacob B.; Evans, William C.; Bergfeld, D.; Hunt, Andrew G.

    2014-01-01

    Helium is used as a critical tracer throughout the Earth sciences, where its relatively simple isotopic systematics is used to trace degassing from the mantle, to date groundwater and to time the rise of continents1. The hydrothermal system at Yellowstone National Park is famous for its high helium-3/helium-4 isotope ratio, commonly cited as evidence for a deep mantle source for the Yellowstone hotspot2. However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by α-decay of uranium and thorium. Here we show, by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust. It seems that helium has accumulated for (at least) many hundreds of millions of years in Archaean (more than 2.5 billion years old) cratonic rocks beneath Yellowstone, only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot. Our results demonstrate the extremes in variability of crustal helium efflux on geologic timescales and imply crustal-scale open-system behaviour of helium in tectonically and magmatically active regions.

  19. Development of an Agent-based Model to Analyze Contemporary Helium Markets

    Energy Technology Data Exchange (ETDEWEB)

    Riddle, Matthew E. [Argonne National Lab. (ANL), Argonne, IL (United States); Uckun, Canan [Argonne National Lab. (ANL), Argonne, IL (United States); Conzelmann, Guenter [Argonne National Lab. (ANL), Argonne, IL (United States); Macal, Charles M. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-01

    Although U.S. helium demand has remained relatively flat since 2009, exports of helium have increased significantly since then, driven primarily by demand for electronic and semiconductor manufacturing in Asia. In the midst of this global demand shift, the Helium Act dictates a new procedure for pricing and distributing the gas through a reserve that historically functioned as a loose “oligarchy.” The new procedure requires prices to be determined by the open market through auctions and a survey of market prices, as opposed to increasing prices according to the consumer price index. Response to these changes has caused temporary shortages, price increases, and a significant increase in the development of the helium extraction technologies used to produce helium from formerly marginal sources. Technologies are being developed and refined to extract helium from formerly low-yielding natural gas fields containing much lower amounts of helium than the previously considered economic threshold of 0.3%. Combining these transformative policies with the potential for new and significant global supplies from Qatar, Algeria, and Russia could lead to new and unforeseen market behaviors and reactions from global helium markets. The objective of the project is to analyze the global helium markets.

  20. Energy-related applications of helium: a revision of the ERDA-13 data base

    Energy Technology Data Exchange (ETDEWEB)

    Hammel, E.F.; Krupka, M.C.

    1980-08-01

    A re-examination, revision, and re-evaluation of the data base contained within the 1975 document, ERDA-13, The Energy-Related Applications of Helium, were completed and results are presented in this report. New technical and resource data, current legislative proposals, updated supply-and-demand relationships, latest legal developments, programmatic changes affectng the future demand for helium, socio-economic aspects, and the effects of the latest energy-consumption projections were considered and are discussed. In contrast to ERDA-13, however, explicit recommendations with respect to the formulation of Federal helium policy, as it pertains to the energy-related applications of helium, are not given.