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Sample records for 231pa ionizatsionnykh kamer

  1. 231Pa systematics in postglacial volcanic rocks from Iceland

    Science.gov (United States)

    Turner, Simon; Kokfelt, Thomas; Hoernle, Kaj; Lundstrom, Craig; Hauff, Folkmar

    2016-07-01

    Several recent studies have highlighted the potential of combined 238U-230Th and 235U-231Pa systematics to constrain upwelling rates and the role of recycled mafic lithologies in mantle plume-derived basalts. Accordingly, we present measurements of the 231Pa concentrations from 26 mafic volcanic rocks from Iceland, including off-axis basalts from the Snaefellsnes Peninsula, to complement previously published 238U-230Th-226Ra data. 231Pa concentrations vary from 27 to 624 fg/g and (231Pa/235U) ratios from 1.12 to 2.11 with the exception of one anomalous sample from the Southeast Rift which has a 231Pa deficit with (231Pa/235U) = 0.86. An important new result is that basalts from the Southeast Rift and the Snaefellsnes Peninsula define a trend at relatively low (231Pa/235U) for a given (230Th/238U) ratio. Many of the remaining samples fall in or around the global field for ocean island basalts but those from the Mid-Iceland Belt and the Southwest Rift/Reykjanes Peninsula extend to higher (231Pa/235U) ratios at a given (230Th/238U), similar to mid-ocean ridge basalts. In principle, these lavas could result from melting of peridotite at lower pressures. However, there is no reason to suspect that the Mid-Iceland Belt and the Southwest Rift lavas reflect shallower melting than elsewhere in Iceland. In our preferred model, these lavas reflect melting of garnet peridotite whereas those from the Southeast Rift and the Snaefellsnes Peninsula contain a significant contribution (up to 20%) of melt from garnet pyroxenite. This is consistent with incompatible trace element and radiogenic isotope evidence for recycled oceanic crust in these lavas. There is increasing agreement that the displacement of ocean island basalts to lower (231Pa/235U) ratios at a given (230Th/238U), compared to mid-ocean ridge basalts, reflects the role of recycled mafic lithologies such as garnet pyroxenite as well as higher average pressures of melting. It now seems likely that this interpretation may

  2. 231Pa/230Th records of Arctic/Atlantic interchange in Fram Strait

    Science.gov (United States)

    Hoffmann, S. S.; McDermott, K. J.; McManus, J. F.; Mukasa, S. B.

    2014-12-01

    Fram Strait, the Arctic Ocean's only deep passage for exchange with lower latitude oceans, today serves as a conduit for waters flowing north into the Arctic Ocean and south into the Atlantic. Reconstruction of circulation patterns and strength at depth in the strait can help to clarify the history of Arctic/Atlantic deep water exchange and Arctic contributions to global meridional overturning circulation. We will present new sedimentary measurements of radioisotopes 231Pa and 230Th to provide information on this exchange in the past and its relationship to sedimentation and climatic events. Coretop and downcore 231Pa/230Th ratios from Arctic sediments indicate that 231Pa has been exported from the central Arctic basin throughout the Holocene and deglaciation. Fram Strait represents a possible sink for this "missing" 231Pa. Preliminary results from ODP Holes 908A and 909A, at 1274 m and 2519 m water depths respectively in the central strait, suggest that ratios in this region during the Holocene have varied between ~0.106 (above the 231Pa/230Th production ratio of 0.093 in seawater, indicating net import of 231Pa)and ~0.055 (well below the production ratio, indicating net export of 231Pa). Further measurements in cores from the Greenland and Svalbard continental slopes will give a fuller regional picture of 231Pa deposition and transport across the strait.

  3. Radiation protection potential of MOX-fuel doped with 231Pa and Cs radioisotopes.

    Science.gov (United States)

    Kryuchkov, E F; Glebov, V B; Apse, V A; Shmelev, A N

    2005-01-01

    The paper addresses the problem of MOX-fuel self-protection during full cycle of MOX-fuel management. Under conditions of the closed LWR cycle the proliferation-resistance levels were evaluated for fresh and spent MOX-fuel with 231Pa and Cs feed. As it follows from the paper results, combination of these two admixtures being doped into MOX-fuel is able to enhance the inherent radiation barrier and to weaken shortcomings of both proliferation deterrents.

  4. Persistent export of 231Pa from the deep central Arctic Ocean over the past 35,000 years.

    Science.gov (United States)

    Hoffmann, Sharon S; McManus, Jerry F; Curry, William B; Brown-Leger, L Susan

    2013-05-30

    The Arctic Ocean has an important role in Earth's climate, both through surface processes such as sea-ice formation and transport, and through the production and export of waters at depth that contribute to the global thermohaline circulation. Deciphering the deep Arctic Ocean's palaeo-oceanographic history is a crucial part of understanding its role in climatic change. Here we show that sedimentary ratios of the radionuclides thorium-230 ((230)Th) and protactinium-231 ((231)Pa), which are produced in sea water and removed by particle scavenging on timescales of decades to centuries, respectively, record consistent evidence for the export of (231)Pa from the deep Arctic and may indicate continuous deep-water exchange between the Arctic and Atlantic oceans throughout the past 35,000 years. Seven well-dated box-core records provide a comprehensive overview of (231)Pa and (230)Th burial in Arctic sediments during glacial, deglacial and interglacial conditions. Sedimentary (231)Pa/(230)Th ratios decrease nearly linearly with increasing water depth above the core sites, indicating efficient particle scavenging in the upper water column and greater influence of removal by lateral transport at depth. Although the measured (230)Th burial is in balance with its production in Arctic sea water, integrated depth profiles for all time intervals reveal a deficit in (231)Pa burial that can be balanced only by lateral export in the water column. Because no enhanced sink for (231)Pa has yet been found in the Arctic, our records suggest that deep-water exchange through the Fram strait may export (231)Pa. Such export may have continued for the past 35,000 years, suggesting a century-scale replacement time for deep waters in the Arctic Ocean since the most recent glaciation and a persistent contribution of Arctic waters to the global ocean circulation.

  5. Meridional circulation across the Antarctic Circumpolar Current serves as a double 231Pa and 230Th trap

    Science.gov (United States)

    Rutgers van der Loeff, Michiel; Venchiarutti, Celia; Stimac, Ingrid; van Ooijen, Jan; Huhn, Oliver; Rohardt, Gerd; Strass, Volker

    2016-12-01

    Upwelling of Circumpolar Deep Water in the Weddell Gyre and low scavenging rates south of the Antarctic Circumpolar Current (ACC) cause an accumulation of particle reactive nuclides in the Weddell Gyre. A ventilation/reversible scavenging model that successfully described the accumulation of 230Th in this area was tested with other particle reactive nuclides and failed to adequately describe the depth-distributions of 231Pa and 210Pb. We present here a modified model that includes a nutrient-like accumulation south of the Antarctic Polar Front in an upper meridional circulation cell, as well as transport to a deep circulation cell in the Weddell Gyre by scavenging and subsequent release at depth. The model also explains depletion of 231Pa and 230Th in Weddell Sea Bottom Water (WSBW) by ventilation of newly formed deep water on a timescale of 10 years, but this water mass is too dense to leave the Weddell Gyre. In order to quantify the processes responsible for the 231Pa- and 230Th-composition of newly formed Antarctic Bottom Water (AABW) we present a mass balance of 231Pa and 230Th in the Atlantic sector of the Southern Ocean based on new data from the GEOTRACES program. The ACC receives 6.0 ± 1.5 ×106 dpms-1 of 230Th from the Weddell Sea, similar in magnitude to the net input of 4.2 ± 3.0 ×106 dpms-1 from the north. For 231Pa, the relative contribution from the Weddell Sea is much smaller, only 0.3 ± 0.1 ×106, compared to 2.7 ± 1.4 ×106 dpms-1 from the north. Weddell Sea Deep Water (WSDW) leaving the Weddell Gyre northward to form AABW is exposed in the ACC to resuspended opal-rich sediments that act as efficient scavengers with a Th/Pa fractionation factor F ≤ 1. Hydrothermal inputs may provide additional removal with low F. Scavenging in the full meridional circulation across the opal-rich ACC thus acts as a double 231Pa and 230Th trap that preconditions newly formed AABW.

  6. Sediment 231Pa/230Th as a recorder of the rate of the Atlantic meridional overturning circulation: insights from a 2-D model

    Directory of Open Access Journals (Sweden)

    S. E. Allen

    2009-11-01

    Full Text Available A two dimensional scavenging-circulation model is used to investigate the patterns of sediment 231Pa/230Th generated by the Atlantic Meridional Overturning Circulation (AMOC and further advance the application of this proxy for ocean paleocirculation studies. The scavenging parameters and the geometry of the overturning circulation cell have been chosen so that the model generates meridional sections of dissolved 230Th and 231Pa consistent with published water column profiles and an additional 12 previously unpublished profiles measured in the North and Equatorial Atlantic. The processes that generate the meridional sections of dissolved and particulate 230Th, dissolved and particulate 231Pa, dissolved and particulate 231Pa/230Th, and sediment 231Pa/230Th are discussed in detail. The results indicate that the relationship between sediment 231Pa/230Th at any given site and the overturning circulation is very complex. They clearly show that constraining past changes in the strength and geometry of the AMOC requires an extensive data set and they suggest strategies to maximize information from a limited number of samples.

  7. Sediment 231Pa/230Th as a recorder of the rate of the Atlantic meridional overturning circulation: insights from a 2-D model

    Directory of Open Access Journals (Sweden)

    S. E. Allen

    2010-03-01

    Full Text Available A two dimensional scavenging model is used to investigate the patterns of sediment 231Pa/230Th generated by the Atlantic Meridional Overturning Circulation (AMOC and further advance the application of this proxy for ocean paleocirculation studies. The scavenging parameters and the geometry of the overturning circulation cell have been chosen so that the model generates meridional sections of dissolved 230Th and 231Pa consistent with published water column profiles and an additional 12 previously unpublished profiles measured in the North and Equatorial Atlantic. The processes that generate the meridional sections of dissolved and particulate 230Th, dissolved and particulate 231Pa, dissolved and particulate 231Pa/230Th, and sediment 231Pa/230Th are discussed in detail. The results indicate that the relationship between sediment 231Pa/230Th at any given site and the overturning circulation is very complex. They clearly show that constraining past changes in the strength and geometry of the AMOC requires an extensive data set and they suggest strategies to maximize information from a limited number of samples.

  8. 230Th and 231Pa on GEOTRACES GA03, the U.S. GEOTRACES North Atlantic transect, and implications for modern and paleoceanographic chemical fluxes

    Science.gov (United States)

    Hayes, Christopher T.; Anderson, Robert F.; Fleisher, Martin Q.; Huang, Kuo-Fang; Robinson, Laura F.; Lu, Yanbin; Cheng, Hai; Edwards, R. Lawrence; Moran, S. Bradley

    2015-06-01

    The long-lived uranium decay products 230Th and 231Pa are widely used as quantitative tracers of adsorption to sinking particles (scavenging) in the ocean by exploiting the principles of radioactive disequilibria. Because of their preservation in the Pleistocene sediment record and through largely untested assumptions about their chemical behavior in the water column, the two radionuclides have also been used as proxies for a variety of chemical fluxes in the past ocean. This includes the vertical flux of particulate matter to the seafloor, the lateral flux of insoluble elements to continental margins (boundary scavenging), and the southward flux of water out of the deep North Atlantic. In a section of unprecedented vertical and zonal resolution, the distributions of 230Th and 231Pa across the North Atlantic shed light on the marine cycling of these radionuclides and further inform their use as tracers of chemical flux. Enhanced scavenging intensities are observed in benthic layers of resuspended sediments on the eastern and western margins and in a hydrothermal plume emanating from the Mid-Atlantic Ridge. Boundary scavenging is clearly expressed in the water column along a transect between Mauritania and Cape Verde which is used to quantify a bias in sediment fluxes calculated using 230Th-normalization and to demonstrate enhanced 231Pa removal from the deep North Atlantic by this mechanism. The influence of deep ocean ventilation that leads to the southward export of 231Pa is apparent. The 231Pa/230Th ratio, however, predominantly reflects spatial variability in scavenging intensity, complicating its applicability as a proxy for the Atlantic meridional overturning circulation.

  9. SİNANOĞLU’S MASNAVİ ABOUT MIRACLE OF ŞAKKU’L-KAMER

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    Fatma BÜYÜKKARCI YILMAZ

    2013-03-01

    Full Text Available The miracle which is the only evidence that legitimize prophecy is a super-naturalistic / oracular event that its analogue cannot be actualized by another person. One of the miracles which bestowed on Mohammed during his prophecy is dichotomy of moon and its reunification with his sign that is called the miracle of Şakku’l-kamer, one of the most studied topic except the event of Miraj. In masnavis or qasidas belong to folk or classic literature, the Prophet’s miracle of the Şakku’l-kamer is one of the most frequent themes. Some of the works about prophet’s life and miracles are breef narratives which can be read in a few hours. These works were written in order to read in religious meetings. Some of them are anonymous, their language is very simple and they are not literary perfect. One of the most obvious formal features of these short masnavis, introduced into Turkish by the ways of translation, narration and adaptation, is their prosody of fâilâtün fâilâtün fâilün which can quite easily be adapted into Turkish. These short religious works which have been written since 14th century sub-served the process of strengthening and separation of Islamisation. Sinanoğlu wrote a mawlid named Ümîdü’l-müznibîn. He lived in 15th century as regards that mentioned work had been written in 884 (Hijri/1478 (Gregorian. Sinanoğlu’s poetical work about the miracle, Şakku’l-kamer is a little masnavi which is consisted of 272 couplets. Its prosody is fâilâtün fâilâtün fâilün which is frequently seen in this kind of works. If it is taken note of the reason of why work was written, after the parts of eulogy to God and Mohammed, Sinanoğlu maintains that one day, when he read this miracle, he liked that and would like to narrate this in Turkish in verse. After that, Sinanoğlu gives a clue about the function of the text that ordinary people’s faith becomes stronger when they learn Mohammed’s miracle. The story of the work

  10. Schipperen op de Aziatische vaart: de financiering van de VOC kamer Enkhuizen, 1602-1622

    NARCIS (Netherlands)

    R. Schalk; O. Gelderblom; J. Jonker

    2012-01-01

    Negotiating the Asiatic Route: Financing the Dutch East India Company, Enkhuizen Chamber, 1602-1622 During its first twenty years the Dutch East India Company, or voc, struggled with the disadvantages of operations being spread over six local chambers, as imposed by its 1602 charter. Mirroring the D

  11. Schipperen op de Aziatische vaart. De financiering van de voc kamer Enkhuizen, 1602-1622

    Directory of Open Access Journals (Sweden)

    Ruben Schalk

    2012-12-01

    Full Text Available Negotiating the Asiatic Route: Financing the Dutch East India Company, Enkhuizen Chamber, 1602-1622During its first twenty years the Dutch East India Company, orvoc, struggled with the disadvantages of operations being spread over six local chambers, as imposed by its 1602 charter. Mirroring the Dutch Republic’s urban particularism, this operational fragmentation effectively bankrupted chambers if ships failed to return. Using the ledgers of Enkhuizen, one of the smaller chambers, we detail the difficulties with which it grappled and chart the slow process of overcoming them through the harmonisation of administrative procedures and other trust-building measures. These culminated in the company directors claiming limited liability for debt, which until now they were generally thought to have possessed from the start.

  12. Schipperen op de Aziatische vaart. De financiering van de voc kamer Enkhuizen, 1602-1622

    NARCIS (Netherlands)

    Schalk, Ruben; Gelderblom, Oscar; Jonker, Joost

    2012-01-01

    Negotiating the Asiatic Route: Financing the Dutch East India Company, Enkhuizen Chamber, 1602-1622During its first twenty years the Dutch East India Company, orvoc, struggled with the disadvantages of operations being spread over six local chambers, as imposed by its 1602 charter. Mirroring the Dut

  13. Schipperen op de Aziatische vaart. De financiering van de VOC kamer Enkhuizen, 1602-1622

    NARCIS (Netherlands)

    Schalk, R.; Gelderblom, O.C.; Jonker, J.P.B.

    2012-01-01

    Negotiating the Asiatic Route: Financing the Dutch East India Company, Enkhuizen Chamber, 1602-1622 During its first twenty years the Dutch East India Company, or voc, struggled with the disadvantages of operations being spread over six local chambers, as imposed by its 1602 charter. Mirroring the D

  14. De Kamers van Arbeid. Experimenten met politieke vertegenwoordiging in Nederland rond 1900

    NARCIS (Netherlands)

    Veen, Adriejan van

    2013-01-01

    The Chambers of Labour: Experiments with Political Representation in the Netherlands ca. 1900In the historiography of the Netherlands so far relatively little attention has been paid to the history of organs of advice and deliberation from the perspective of the evolution of political representation

  15. De Kamers van Arbeid. Experimenten met politieke vertegenwoordiging in Nederland rond 1900

    Directory of Open Access Journals (Sweden)

    Adriejan van Veen

    2013-06-01

    Full Text Available The Chambers of Labour: Experiments with Political Representation in the Netherlands ca. 1900In the historiography of the Netherlands so far relatively little attention has been paid to the history of organs of advice and deliberation from the perspective of the evolution of political representation. The late nineteenth century Chambers of Labour are one of the earliest examples of advisory organs representing functional interests. In this article it is argued that the Chambers of Labour constituted a new experiment with political representation in the Netherlands. Arising from a fruitful public debate about forms of representation as alternatives to or adjacent to parliamentary representation at the end of the nineteenth century, as well as local experiments with private labour councils, they were instituted as advisory organs complementary to parliament, representing new groups such as women and labourers. The Chambers of Labour should been seen as coming forth from new thinking about representation and as part of a democratic practice that transcended the parliamentary-electoral boundaries.

  16. De Kamers van Arbeid. Experimenten met politieke vertegenwoordiging in Nederland rond 1900

    OpenAIRE

    Adriejan van Veen

    2013-01-01

    The Chambers of Labour: Experiments with Political Representation in the Netherlands ca. 1900In the historiography of the Netherlands so far relatively little attention has been paid to the history of organs of advice and deliberation from the perspective of the evolution of political representation. The late nineteenth century Chambers of Labour are one of the earliest examples of advisory organs representing functional interests. In this article it is argued that the Chambers of Labour cons...

  17. Besluitvorming over verkeersveiligheid in het Nationaal Verkeers- en Vervoersplan NVVP : de inspraakfase, het kabinetsstandpunt en de behandeling in de Tweede Kamer.

    NARCIS (Netherlands)

    Bax, C.A.

    2006-01-01

    Decision making about road safety in the National Traffic and Transport Plan; The participation phase, the cabinet's position and the parliamentary debate. This study examines whether the decision making about the National Traffic and Transport Plan has resulted in a decisive road safety policy and

  18. The word order change in Dutch directional phrases: from the perspective of language typology

    NARCIS (Netherlands)

    Lin, J.

    2012-01-01

    The current study provides an alternative explanation of the word order change observed in Dutch directional phrases from the perspective of typology. This change took place around the end of the 19th century and concerns directional phrases such as 'in de kamer' (‘in(to) the room’) and 'de kamer in

  19. Verantwoording van gegevens en procedures voor de 1e tranche interventiewaarden: van RIVM-rapporten naar de Notitie Interventie-waarden bodemsanering

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    van den Berg R; LBG

    1997-01-01

    In 1994 is de Notitie Interventiewaarden Bodemsanering aangeboden aan de Tweede Kamer en zijn na goedkeuring door de Tweede Kamer de interventiewaarden van kracht geworden. Tijdens het proces van de eerste rapportage van zowel de humaan-toxicologische als ecotoxicologische onderbouwing van voorstel

  20. Corrigendum to "Deep water provenance and dynamics of the (de)glacial Atlantic meridional overturning circulation" [Earth Planet. Sci. Lett. 445 (2016) 68-78

    Science.gov (United States)

    Lippold, Jörg; Gutjahr, Marcus; Blaser, Patrick; Christner, Emanuel; de Carvalho Ferreira, Maria Luiza; Mulitza, Stefan; Christl, Marcus; Wombacher, Frank; Böhm, Evelyn; Antz, Benny; Cartapanis, Olivier; Vogel, Hendrik; Jaccard, Samuel L.

    2017-01-01

    We have reconstructed past modes of the Atlantic Meridional Overturning Circulation (AMOC) by combining two sedimentary proxies, Nd isotopes (εNd) and the 231Pa/230Th ratio over the last deglaciation. Combined down-core 231Pa/230Th and εNd records from six Atlantic Ocean sediment archives are presented (Lippold et al., 2016).

  1. Lilian van den Aarsen in de Havikerpoort; schakelen tussen de regio en de wereld van Den Haag

    NARCIS (Netherlands)

    Hazeleger, B.; Vos, C.C.

    2006-01-01

    Op pad in haar favoriete landschap bij Middachten schetst Lilian van Aaarsen (LNV) met veel overtuiging hoe ze schakelend achtjes draait tussen de concrete inrichting in de regio en het Haagse Tweede-Kamer-Land. Het artikel bevat uitleg over de Havikerpoort: de ecologische verbinding tussen Veluwe e

  2. Eigen rechtsingang voor minderjarigen : Ervaringen met artikel 1:162a BW

    NARCIS (Netherlands)

    Doornhein, L.

    1992-01-01

    In december 1990 is de nieuwe wet houdende een nadere regeling van de omgang in verband met scheiding in werking getreden. De Tweede Kamer is een evaluatie toegezegd van de ervaringen met het nieuwe artikel 1:162a BW, waarmee minderjarigen een (informele) eigen rechtsingang hebben gekregen. Jongeren

  3. Aardkloot in ademnood. Hyperventilerende democratie in de mondiale sferen en netwerken van Peter Sloterdijk en Bruno Latour

    NARCIS (Netherlands)

    Dijstelbloem, H.

    2010-01-01

    Eind 2008 diende professor Schuurman, senator van de ChristenUnie, in de Eerste Kamer een motie in waarin hij het kabinet verzocht scenario’s te ontwikkelen om de verschillende crises waar de wereldbevolking mee kampt, in samenhang te bezien. Niet alleen de financiële crisis baarde hem zorgen, maar

  4. Oriënterende meting van ammoniakemissie Holcim Sleufvloer type B = Explorative ammonia emission measurements on the Holcim grooved floor type B

    NARCIS (Netherlands)

    Dooren, van H.J.C.; Blanken, K.; Gunnink, H.; Huis in 't Veld, J.W.H.

    2010-01-01

    Dit rapport beschrijft de flux kamer metingen die uitgevoerd zijn aan de Holcim Sleufvloer Type B vergeleken met de sleufvloer type A en een standaard betonnen roostervloer als referentie. De ammoniakemissie bedroeg 39% van de emissie die op de roostervloer gemeten is. Het betreft hier oriënterende

  5. Welzijn van dieren in reizende circussen

    NARCIS (Netherlands)

    Hopster, H.; Dierendonck, van M.; Brandt, van den H.; Reemen, van K.

    2009-01-01

    Op verzoek van de minister van LNV onderzocht Wageningen UR Livestock Research het welzijn van circusdieren. In haar brief naar de Tweede Kamer geeft diezelfde minister aan dat zij de aanbevelingen die het onderzoeksinstituut deed, wil overnemen. Na onderzoek stelt Livestock Research van Wageningen

  6. Bereiding van en onderzoek met "primaire" bilirubinestandaarden

    NARCIS (Netherlands)

    Dreumel; H.J. van; Wikkeling; R.H.; Phielix-Strubbe; C.J.; Klaassen; R.; Boink; A.B.T.J.; Koedam; J.C.

    1987-01-01

    De bereiding van primaire bilirubine-standaarden is mogelijk mits ; - gebruik wordt gemaakt van de beste kwaliteit bilirubine ; - HSA (en niet BSA) wordt gebruikt, dat direct voor gebruik wordt gefil- treerd ; - alle bewerkingen gebeuren onder strenge "donkere-kamer" condities ; - de

  7. Consultancyonderzoek naar mogelijke oorzaken uitval bij Mandevilla

    NARCIS (Netherlands)

    Noort, van F.R.; Lieffering, M.

    2011-01-01

    Referaat Wageningen UR Glastuinbouw en Marcel Lieffering Kamer- en Perkplantenadviesburo hebben in opdracht van het productschap Tuinbouw oriënterend onderzoek gedaan naar uitval in de teelt van Mandevilla. In de literatuur worden de ziekten Pythium-soorten, Phytopthora-soorten, Fusarium oxysporum e

  8. Toepassing van hoge-Tc supergeleiding in een 7-kanaals hartscanner

    NARCIS (Netherlands)

    Brake, ter Marcel

    1996-01-01

    Op de valreep van 1995 werd in de leerstoel Lage Temperaturen van de Universiteit Twente de laaste hand gelegd aan een 7-kanaals magnetometer, uitgerust met zogenaamde hoge-Tc SQUIDs In januari 1996 werden hiermee de eerste hartslagmetingen in een magnetisch afgeschermde kamer verricht en werden mag

  9. Investigation of applicability of a mid-infrared spectroscopic method using an attenuated total reflection accessory and a new near-infrared transmission method for determination of faecal fat

    NARCIS (Netherlands)

    Volmer, M; Kingma, AW; Borsboom, PCF; Wolthers, BG; Kema, IP

    2001-01-01

    In many laboratories, the titrimetric method of Van de Kamer is used for the analysis of faecal fat content of patients suspected of steatorrhoea. We investigated the applicability of a mid-infrared (MIR) spectroscopic method, using an attenuated total reflection (ATR) accessory, and a new near-infr

  10. A Foreign Martial-Art Expert

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    In an international martial-artcompetition held in Shaolin Temple, Henan Province,inSeptember last year Omran Kamer,executive member of the Interna- tional Martial-Art Federation andinitiator of martial arts in Algeria,won fourth prizes for taiji and sanda(bare-hand fighting),fifth prize forShaolin boxing and two top prizes

  11. Toeristenbelasting en deeleconomie: kansen en bedreigingen voor Nederlandse gemeenten

    NARCIS (Netherlands)

    A.W. Schep (Arjen)

    2016-01-01

    textabstractDe komst van het fenomeen vakantieverhuur via websites en apps als die van Airbnb heeft een grote vlucht genomen. Alleen al in Amsterdam verbleven 575.000 toeristen bij particulieren die hun woning, kamer of appartement via Airbnb hadden aangeboden. Dit heeft niet alleen positieve gevolg

  12. Oriënterende meting van ammoniakemissie Holcim Sleufvloer type B = Explorative ammonia emission measurements on the Holcim grooved floor type B

    OpenAIRE

    Dooren, van, H.J.C.; Blanken, K.; Gunnink, H.; Huis in 'T Veld, J.W.H.

    2010-01-01

    Dit rapport beschrijft de flux kamer metingen die uitgevoerd zijn aan de Holcim Sleufvloer Type B vergeleken met de sleufvloer type A en een standaard betonnen roostervloer als referentie. De ammoniakemissie bedroeg 39% van de emissie die op de roostervloer gemeten is. Het betreft hier oriënterende metingen die gevalideerd moeten worden door metingen op grotere schaal (hele stal).This report describes open flux chamber measurements on the Holcim grooved floor type B for dairy cattle compared ...

  13. Study for 228Th reduction in thermal reactor with Th-U fuel cycls

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    By using computercode WIMS/CENDL, the effects of some parameters, core configuration such as fuel element structure, neutron flux and burn-up, are discussed in thispaper.It is shown that high neutron flux, small fuel rod diameter,large volume ratio of coolant to fuel, seed-blank heterogeneous corearrangement and 231Pa chemical separation are necessary for reducing 228Th production in reactor.

  14. Mantle Plume Upwelling Rates: Evidence from U-Series in Young Ocean Island Basalts

    Science.gov (United States)

    Bourdon, B.; Turner, S. P.; Stracke, A.; Saal, A. E.

    2004-12-01

    U-series disequilibria measured in recent lavas at intraplate volcanoes provide a powerful probe to examine the validity of the plume model. U-Th and U-Pa fractionation produced during melting is a function of the melting rate. In turn, this parameter should scale with mantle upwelling velocities. Simply stated, a larger melting rate (larger mantle upwelling velocity) yields smaller Th and Pa excess relative to their parent nuclides. A number of observations supports this approach: (1) there is a negative correlation between 230Th excess and buoyancy fluxes (2) based on new measurements of 231Pa in the Azores, Iceland and the Galapagos and literature data, we show here that there is also a well defined correlation between 231Pa excess and buoyancy flux (3) For Hawaii, Iceland and the Azores, 230Th excess (or 231Pa excess) increases as a function of the distance from the centre of the `hotspot'. These observations suggests that `hotspot' buoyancy fluxes are associated with a greater melt production per unit of time and that the centre of `hotspot' corresponds to a faster mantle upwelling velocity than its periphery. This is therefore in strong support of a model where ocean islands are associated with faster upwelling at depth. However, there is in fact not a simple relationship between melt productivity and upwelling velocities. Notably, the presence of volatiles, of mafic lithologies or of variably enriched peridotitic source could all affect melting rate and hence U-Th-Pa fractionation. We have considered these issues in great detail using a large data base for the Azores islands. While there are clear variations in mantle source composition, they cannot explain the observations of increasing 231Pa/235U ratio with distance from the centre of the Azores hotspot . If we take into account the effect of water in the source of the Azores, it clearly affects the scaling between U-series fractionation and upwelling velocity but not the overall conclusions.

  15. The influence of source heterogeneity on the U-Th-Pa-Ra disequilibria in post-glacial tholeiites from Iceland

    Science.gov (United States)

    Koornneef, J. M.; Stracke, A.; Bourdon, B.; Grönvold, K.

    2012-06-01

    We investigate the relative influence of mantle upwelling velocity and source heterogeneity on the melting rates recorded by 230Th-238U, 231Pa-235U and 226Ra-230Th disequilibria in post-glacial tholeiites from Iceland's main rift areas. The measured (230Th/238U) ratios range from 1.085 to 1.247, the (231Pa/235U) ratios from 1.333 to 1.925, and the (226Ra/230Th) ratios from 0.801 to 1.218. A general positive correlation between 230Th excesses and distance from the inferred plume centre is consistent with a model of decreasing mantle upwelling velocity with increasing distance from the plume axis. However, the model is not substantiated by the (231Pa/235U) data as the correlation with distance from the plume centre is weak. On the scale of individual eruption centres, the observed U-series are influenced by variations in melt transport time, source porosity, and local variations in mantle upwelling velocity. Broad correlations between (230Th/238U) and (231Pa/235U) and highly incompatible trace element ratios for samples from the Western Volcanic Zone provide, however, evidence for a significant underlying effect of source heterogeneity on the U-series data. Low 230Th and 231Pa excesses in enriched samples from the Western Volcanic Zone with high U/Th, Nb/U and Nb/La indicate that partial melts from an enriched source component, characterised by high melt productivity but low bulk DU/DTh, influence the U-series systematics of the erupted melts. These results re-affirm the presence of comparatively larger abundances of enriched material in the mantle source beneath the South Western Rift of Iceland, which has been suggested based on relationships between highly incompatible element and Pb isotope ratios in Icelandic basalts. Overall, our results highlight the importance of lithological heterogeneity on the melting behaviour of the upper mantle and the composition of oceanic basalts.

  16. Developing Situation and Application of High-temperature Superconductor%高温超导体的发展现状及应用

    Institute of Scientific and Technical Information of China (English)

    杨砚儒; 刘莹莹

    2001-01-01

    @@ 所谓超导,是指一定温度、压力下,一些金属合金和化合物的电阻突然为零的性质.1911年初荷兰物理学家H.KamerLingh-Qnnes发现汞在4.2K附近出现零电阻,1911年2月至5月间他连续发表多篇论文,公布了两项重要发现:一是超导体电流越强,临界转变点越低.

  17. Nuclear program of Iran. Towards de-escalation of a nuclear crisis. Advisory letter; Nucleair programma van Iran. Naar de-escalatie van een nucleaire crisis. Briefadvies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-04-15

    The Dutch government, partly at the request of the House of Representatives (Second Chamber), the AIV asked to give an opinion about the position of Iran in the region and the role of the nuclear program of Iran in the geopolitical relations, in view of the most recent developments [Dutch] De Nederlandse regering heeft, mede op verzoek van de Tweede Kamer der Staten-Generaal, de AIV gevraagd advies uit te brengen over de positie van Iran in de regio en de rol van het nucleaire programma van Iran in de geopolitieke verhoudingen hierin, mede gelet op de meest recente ontwikkelingen.

  18. Basin-Scale nd Isotope Gradients in South Atlantic Marine Sedimentary Records

    Science.gov (United States)

    Ran, W.; Abouchami, W.; Zahn, R.; Masque, P.

    2012-12-01

    Recent 231Pa/230Th and Nd isotopes studies have suggested a slower and re-configured Meridional Overturning Circulation in the Atlantic (AMOC) during the Last Glacial Maximum (LGM) [1]. We have undertaken a Sr and Nd isotope study on sediment core MD02-2594 (34°43'S, 17°20'E, 2440 m) located in the Cape Basin where nutrient-based proxies - δ13C and Cd/Ca ratios - and low 231Pa/230Th, a tracer of deep water overturning rate, indicate the presence of Southern Component Water (SCW) and a weaker AMOC during the LGM [1]. Samples cover the LGM and Holocene sections of the core previously analysed for Pa/Th [1]. Sr and Nd isotope data were obtained on the bulk sediment as well as on the Fe-Mn oxides leachates and the residual detrital fraction extracted using established sequential leaching procedure. Analyses were performed on a ThermoFisher Triton TIMS at MPIC and Nd isotopes measured as NdO. Our results show that the bulk sediment Nd isotope record is, as expected, overprinted by the Nd isotope composition of the lithogenic fraction and follows closely the 231Pa/230Th record. Sr isotope ratios in Fe-Mn leachates have been used as diagnostic of a seawater origin for the Fe-Mn oxides which should yield modern seawater Sr isotopic composition. Our samples have 87Sr/86Sr ratios similar to or slightly higher than those measured for seawater [2]. The Nd isotope composition of the Fe-Mn leachates show, nevertheless, a distinct signature from both the bulk sediment and the detrital fraction, both of which display systematically less radiogenic Nd isotope ratios throughout the whole record. The seawater ɛNd record exhibits a decreasing trend from the LGM into the Bolling-Allerød and Younger Dryas, prior to stabilizing at a value of about -9 during the Holocene. Covariations between Nd isotope ratios of Fe-Mn leachates and 231Pa/230Th reveal contrasted behaviour during the LGM and the Holocene period: low and nearly constant glacial Pa/Th values are associated with

  19. Electron spin resonance (ESR) dating of hominid-bearing deposits in the Caverna delle Fate, Ligure, Italy

    Science.gov (United States)

    Falgueres, Christophe; Yokoyama, Yuji; Bibron, Roland

    1990-07-01

    Stalagmitic floors interstratified with Mousterian deposits from the Caverna delle Fate (Italy) have been dated by the electron spin resonance (ESR) method. Three samples dated fall between 60,000 and 74,000 yr and indicate the age of the Mousterian deposits. They are in good agreement with ages determined by nondestructive γ-ray spectrometry of the human remains from 231Pa/ 235U and 230Th /234U ratios, which are, respectively, 75,000 -14,000+21,000 and 82,000 -25,000+36,000 yr. These dates are consistent with the morphological characteristics of the bones as Neanderthal remains.

  20. Changes in the geometry and strength of the Atlantic meridional overturning circulation during the last glacial (20-50 ka)

    Science.gov (United States)

    Burckel, Pierre; Waelbroeck, Claire; Luo, Yiming; Roche, Didier M.; Pichat, Sylvain; Jaccard, Samuel L.; Gherardi, Jeanne; Govin, Aline; Lippold, Jörg; Thil, François

    2016-11-01

    We reconstruct the geometry and strength of the Atlantic meridional overturning circulation during the Heinrich stadial 2 and three Greenland interstadials of the 20-50 ka period based on the comparison of new and published sedimentary 231Pa / 230Th data with simulated sedimentary 231Pa / 230Th. We show that the deep Atlantic circulation during these interstadials was very different from that of the Holocene. Northern-sourced waters likely circulated above 2500 m depth, with a flow rate lower than that of the present-day North Atlantic deep water (NADW). Southern-sourced deep waters most probably flowed northwards below 4000 m depth into the North Atlantic basin and then southwards as a return flow between 2500 and 4000 m depth. The flow rate of this southern-sourced deep water was likely larger than that of the modern Antarctic bottom water (AABW). Our results further show that during Heinrich stadial 2, the deep Atlantic was probably directly affected by a southern-sourced water mass below 2500 m depth, while a slow, southward-flowing water mass originating from the North Atlantic likely influenced depths between 1500 and 2500 m down to the equator.

  1. Dutch climate and energy policy. Analysis of policy reviews 1989-2012; Het Nederlandse Klimaat- en Energiebeleid. Analyse van beleidsevaluaties 1989-2012

    Energy Technology Data Exchange (ETDEWEB)

    Faber, J.; Blom, M.J.; De Bruyn, S.M.; Nelissen, D.; Aarnink, S.J.; De Buck, A.; Bennink, D. [CE Delft, Delft (Netherlands); Oosterhuis, F.H.; Kuik, O.J. [Instituut voor Milieuvraagstukken IVM, Vrije Universiteit VU, Amsterdam (Netherlands)

    2012-11-15

    The Dutch government has had climate policy in place since 1989. Since 1999 that policy has been intensified with a view to meeting Kyoto commitments for the period 2008-2012. The Dutch Parliament requested a review of the costs and effects of the measures implemented in the context of Dutch climate and energy policy, based on the available review studies, with led to the commissioning of the present report [Dutch] De Nederlandse overheid voert sinds 1989 klimaatbeleid. Vanaf 1999 is het beleid geïntensiveerd met het oog op het halen van de Kyoto-doelstelling in de periode 2008-2012. De Tweede Kamer wil een overzicht hebben van de kosten en effecten van beleidsinstrumenten van het Nederlandse klimaat- en energiebeleid, op basis van bestaande evaluatiestudies en heeft daarom deze studie laten uitvoeren.

  2. Novo gênero e espécie de Portanini Linnavuori, e notas taxonômicas (Hemiptera, Cicadellidae, Xestocephalinae New genus and species of Portanini Linnavuori, and taxonomic notes (Hemiptera, Cicadellidae, Xestocephalinae

    Directory of Open Access Journals (Sweden)

    Adenomar Neves de Carvalho

    2009-01-01

    Full Text Available Nove espécies são transferidas de Portanus Ball, 1932 para Paraportanus gen. nov.: Paraportanus longicornis (Osborn, 1923 comb. nov. = Portanus chelatus DeLong, 1976 syn. nov.; Paraportanus elegans (Kramer, 1961 comb. nov.; Paraportanus facetus (Kramer, 1961 comb. nov.; Paraportanus eburatus (Kamer, 1964 comb. nov.; Paraportanus filamentus (DeLong, 1980 comb. nov.; Paraportanus bicornis (Carvalho & Cavichioli, 2003 comb. nov.; Paraportanus bimaculatus (Carvalho & Cavichioli, 2003 comb. nov.; Paraportanus cinctus (Carvalho & Cavichioli, 2003 comb. nov.; Paraportanus variatus (Carvalho & Cavichioli, 2003 comb. nov.. Novos dados de distribuição geográfica são registrados para: P. facetus; P. elegans e P. longicornis. Chave para identificação das espécies é apresentada.A new genus and a new species of Portanini are described: Paraportanus gen. nov. and the type species Paraportanus jenniferae sp. nov. (from Brazil, Maranhão. Nine species formerly described in Portanus Ball, 1932 are transferred into this new genus: Paraportanus longicornis (Osborn, 1923 comb. nov. = Portanus chelatus DeLong, 1976 syn. nov.; Paraportanus elegans (Kramer, 1961 comb. nov.; Paraportanus facetus (Kramer, 1961 comb. nov.; Paraportanus eburatus (Kamer, 1964 comb. nov.; Paraportanus filamentus (DeLong, 1980 comb. nov.; Paraportanus bicornis (Carvalho & Cavichioli, 2003 comb. nov.; Paraportanus bimaculatus (Carvalho & Cavichioli, 2003 comb. nov.; Paraportanus cinctus (Carvalho & Cavichioli, 2003 comb. nov.; Paraportanus variatus (Carvalho & Cavichioli, 2003 comb. nov.. New geographical distribution data are recorded for P. facetus; P. elegans e P. longicornis. A key is presented.

  3. Hybrid fusion-fission reactor with a thorium blanket: Its potential in the fuel cycle of nuclear reactors

    Science.gov (United States)

    Shmelev, A. N.; Kulikov, G. G.; Kurnaev, V. A.; Salahutdinov, G. H.; Kulikov, E. G.; Apse, V. A.

    2015-12-01

    Discussions are currently going on as to whether it is suitable to employ thorium in the nuclear fuel cycle. This work demonstrates that the 231Pa-232U-233U-Th composition to be produced in the thorium blanket of a hybrid thermonuclear reactor (HTR) as a fuel for light-water reactors opens up the possibility of achieving high, up to 30% of heavy metals (HM), or even ultrahigh fuel burnup. This is because the above fuel composition is able to stabilize its neutron-multiplying properties in the process of high fuel burnup. In addition, it allows the nuclear fuel cycle (NFC) to be better protected against unauthorized proliferation of fissile materials owing to an unprecedentedly large fraction of 232U (several percent!) in the uranium bred from the Th blanket, which will substantially hamper the use of fissile materials in a closed NFC for purposes other than power production.

  4. Non-destructive γ spectrum analysis of polymetallic nodules from the eastern Pacific

    Institute of Scientific and Technical Information of China (English)

    刘广山; 黄奕普; 蔡毅华; 陈敏

    2002-01-01

    -- Non-destructive γ spectrum analyses of 20 polymetallic nodules from the eastern Pacific were carried out. Numerous nuclides, such as 238 U, 230 Th, 226 Ra, 210 Pb, 228 Ra, 228 Th, 235 U, 227 Ac ( or 231pa) and 40K were detected. The count rates of the nuclides in the top or bottom side of nodules facing detector were measured and the ratio R of the count rates of nuclides in the top and the bottom sides was obtained. From counts and ratios, some useful information relating to the growth and movement of the nodules, the source of nuclide and relationship between those and environment can be gotten. A new method for clear distinction between the top and bottom sides of the nodule based on the R value of 226Ra or 210pb was developed. In addition, one can infer the turnover of nodules according to the R value of 230Th.

  5. Mound Facility activities in chemical and physical research: July--December 1977. [Kr-Xe and Kr-Ar diffusion; Ne-Ar thermal diffusion

    Energy Technology Data Exchange (ETDEWEB)

    1978-05-01

    Isotope separation of Ar, C, /sup 3/He, Kr, Ne, O, and Xe isotopes is reported. TiFeH/sub x/, TiCoH/sub x/, TiCuH/sub x/, and VH/sub x/ were studied using NMR (proton relaxation times). VD/sub x/ and VT/sub x/ were synthesized. The problem of calculating the valence state of Pu is discussed. A series solution to the plutonium (N,H) characteristic equation is suggested. Shipments of /sup 231/Pa, /sup 230/Th, and /sup 229/Th are reported. Separation and processing of /sup 234/U are also reported. Theoretical methods were developed to calculate temperature distributions as functions of water flow rate in liquid thermal diffusion columns. Diffusion coefficients were measured from 300 to 1200/sup 0/K for Kr-Xe and Kr-Ar. New thermal diffusion factors are submitted for Ne-Ar.

  6. U—Series Dating of Fossil Bones:Results from Chinese Sites and Discussions on Its Reliability

    Institute of Scientific and Technical Information of China (English)

    沈冠军

    1996-01-01

    Calculations,according to some open-system models,point out that while a statistically significant discrepancy between the results of two U-series methods,230Th/234U and 227Th/220Th(or 231Pa/235U),attests a relatively recent and important uranium migration,concordant dates cannot guarantee closes-system behavior of sample.The results of 20 fossil bones from 10 Chinese sites,19 of which are determined by two U-series methods,are given,Judging from independent age controls,8 out of the 11 concordant age sets are unacceptable,The results in this paper suggest that uranium may cycle into or out of fossil bones,such geochemical events may take place at any time and no known preserving condition may securely protect them from being affected.So for the sitew we have studied,the U-series dating of fossil bones is of limited reliability.

  7. Extraction and purification of {sup 227}Ac and development of solid {sup 219}Rn source

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Quan; Qiu, Shoukang; Xiao, Detao; Zhou, Yaohui; An, Xiaogang [University of South China, Hengyang (China). Radon Key Laboratory of Hunan Province/School of Nuclear Science and Technology

    2014-04-01

    The method of {sup 227}Ac extraction and purification from high-grade uranium ore and the test results of solid {sup 219}Rn source made from {sup 227}Ac are reported in this paper. With five years of follow-up monitoring, radiochemical purity of {sup 227}Ac and the emanation power of solid {sup 219}Rn source has been checked by emanation method and γ-spectrometry, the results showed that {sup 228}Th, {sup 231}Pa and {sup 226}Ra have been effectively removed and the emanation power of {sup 219}Rn source is about 80%. The long-term test results also showed that the {sup 219}Rn emanation rate remains stable in a wide air humidity range (40% ∝ 90%). Though the {sup 219}Rn source has not been accurately calibrated yet, it has been applied in the research for delay coincidence measurement of {sup 223}Ra. (orig.)

  8. Parliamentary study on Cost and Effects of Climate and Energy Policy [in the Netherlands]; Parlementair onderzoek Kosten en effecten klimaat- en energiebeleid

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-15

    Nederlandse klimaatbeleid te kunnen duiden, hebben de vaste commissies voor Infrastructuur en Milieu (IenM) en voor Economische Zaken, Landbouw en Innovatie (ELI) van de Tweede Kamer behoefte aan een integraal overzicht van de kosten en effecten van klimaatbeleidsinstrumenten. In de afgelopen jaren is een groot aantal evaluaties uitgevoerd naar de bijdrage van diverse klimaat- en energiebeleidsinstrumenten in verschillende sectoren van de economie aan het realiseren van beleidsdoelen. Deze studies zijn zowel voorafgaand aan het introduceren van instrumenten (ex-ante evaluaties) als achteraf gedaan (ex-post evaluaties). Het doel van deze studie is om een overzicht te geven van de kosten en baten van beleidsinstrumenten van het Nederlandse klimaat- en energiebeleid aan de hand van de gepubliceerde ex-ante en ex-post evaluaties. Dit geeft de Tweede Kamer inzicht in de voor- en nadelen van mogelijk in te zetten instrumenten. Het biedt daarmee een basis voor de Tweede Kamer om toekomstige inzet van beleidsinstrumenten te kunnen beoordelen en de kwaliteit van het evaluatie-instrument zelf te helpen verbeteren.

  9. On the role of fusion neutron source with thorium blanket in forming the nuclide composition of the nuclear fuel cycle of the Russian Federation

    Science.gov (United States)

    Shmelev, A. N.; Kulikov, G. G.

    2016-12-01

    The possible role of available thorium resources of the Russian Federation in utilization of thorium in the closed (U-Pu)-fuel cycle of nuclear power is considered. The efficiency of application of fusion neutron sources with thorium blanket for economical use of available thorium resources is demonstrated. The objective of this study is the search for a solution of such major tasks of nuclear power as reduction of the amount of front-end operations in the nuclear fuel cycle and enhancement of its protection against uncontrolled proliferation of fissile materials with the smallest possible alterations in the fuel cycle. The earlier results are analyzed, new information on the amount of thorium resources of the Russian Federation is used, and additional estimates are made. The following basic results obtained on the basis of the assumption of involving fusion reactors with Th-blanket in future nuclear power for generation of the light uranium fraction 232+233+234U and 231Pa are formulated. (1) The fuel cycle would shift from fissile 235U to 233U, which is more attractive for thermal power reactors. (2) The light uranium fraction is the most "protected" in the uranium fuel component, and being mixed with regenerated uranium, it would become reduced-enrichment uranium fuel, which would relieve the problem of nonproliferation of the fissile material. (3) The addition of 231Pa into the fuel would stabilize its neutron-multiplying properties, thus making it possible to implement a long fuel residence time and, as a consequence, increase the export potential of the whole nuclear power technology. (4) The available thorium resource in the vicinity of Krasnoufimsk is sufficient for operation of the large-scale nuclear power industry of the Russian Federation with an electric power of 70 GW for more than one quarter of a century. The general conclusion is that involvement of a small number of fusion reactors with Th-blanket in the future nuclear power industry of the Russian

  10. Closed fuel cycle with increased fuel burn-up and economy applying of thorium resources

    Science.gov (United States)

    Kulikov, G. G.; Apse, V. A.

    2017-01-01

    The possible role of existing thorium reserves in the Russian Federation on engaging thorium in being currently closed (U-Pu)-fuel cycle of nuclear power of the country is considered. The application efficiency of thermonuclear neutron sources with thorium blanket for the economical use of existing thorium reserves is demonstrated. The aim of the work is to find solutions of such major tasks as the reduction of both front-end and back-end of nuclear fuel cycle and an enhancing its protection against the uncontrolled proliferation of fissile materials by means of the smallest changes in the fuel cycle. During implementation of the work we analyzed the results obtained earlier by the authors, brought new information on the number of thorium available in the Russian Federation and made further assessments. On the basis of proposal on the inclusion of hybrid reactors with Th-blanket into the future nuclear power for the production of light uranium fraction 232+233+234U, and 231Pa, we obtained the following results: 1. The fuel cycle will shift from fissile 235U to 233U which is more attractive for thermal power reactors. 2. The light uranium fraction is the most "protected" in the uranium component of fuel and mixed with regenerated uranium will in addition become a low enriched uranium fuel, that will weaken the problem of uncontrolled proliferation of fissile materials. 3. 231Pa doping into the fuel stabilizes its multiplying properties that will allow us to implement long-term fuel residence time and eventually to increase the export potential of all nuclear power technologies. 4. The thorium reserves being near city Krasnoufimsk (Russia) are large enough for operation of large-scale nuclear power of the Russian Federation of 70 GWe capacity during more than a quarter century under assumption that thorium is loaded into blankets of hybrid TNS only. The general conclusion: the inclusion of a small number of hybrid reactors with Th-blanket into the future nuclear

  11. Investigation of applicability of a mid-infrared spectroscopic method using an attenuated total reflection accessory and a new near-infrared transmission method for determination of faecal fat.

    Science.gov (United States)

    Volmer, M; Kingma, A W; Borsboom, P C; Wolthers, B G; Kema, I P

    2001-05-01

    In many laboratories, the titrimetric method of Van de Kamer is used for the analysis of faecal fat content of patients suspected of steatorrhoea. We investigated the applicability of a mid-infrared (MIR) spectroscopic method, using an attenuated total reflection (ATR) accessory, and a new near-infrared (NIR) spectroscopic method. For the NIR method, sealed plastic bags containing the stool samples were used as transmission cells. Standardization was obtained using a previously described MIR method, with a NaCl flow-cell, as reference method. Partial least-squares regression was used for the calibration of each method. Full cross-validation of the calibration set was used for the internal validation of each method. Fifteen per cent of the stool samples could not be estimated with the ATR method within reasonable accuracy limits compared with the reference. The standard error of prediction of the NIR method was 1.1 g/dL. We conclude that the new NIR method is a promising technique for routine use. However, further experiments need to be done with triplicate measurements of each sample and the use of an external validation set.

  12. Jonu sastāva spektrometriski pētījumi koronas izlādei ūdens tvaika/gaisa atmosfērā

    OpenAIRE

    Volkovs, Artis

    2015-01-01

    Šajā darbā ar spektroskopiskām metodēm tiek pētīts, kādas vielas tiek iegūtas, jonizējot mitrinātu gaisu ar koronizlādes palīdzību. Jonizēta gaisa reaktora darbība ir balstīta uz augstenerģētisku atmosfēras modificēšanu - izmantojot plazmas tehnoloģiju, tiek mainīts atmosfērā esošo gāzu sastāva, pārveidojot tās par aktīvākiem oksidantiem. Ar augstsprieguma impulsu ģeneratoru tiek ierosināta koronas izlāde starp diviem elektrodiem speciālā izlādes kamerā, kurai tiek pievadīts mitrināts gaiss....

  13. Intertekstualiteit en die Bose in Kroniek van Perdepoort (Anna M. Louw

    Directory of Open Access Journals (Sweden)

    E. Linde

    1986-05-01

    Full Text Available In Anna M. Louw’s novel Kroniek van Perdepoort the primal conflict between good and evil is an important constituent element. Well-known authors in world literature have been fascinated by this problem, and it is an enriching experience to bring together allusions and to investigate points of contact with authors such as Feodor Dostoyevsky, Thomas Mann. William Faulkner and Patrick White. In Kroniek van Perdepoort there is a meeting between Klaas Kamer and the devil. Similarities between this meeting and similar meetings in Dr Faustus (Thomas Mann and The Brothers Karamazov (Dostoyevsky are pointed out.Subsequently the portrayal of sin in Kroniek van Perdepoort is compared with Faulkner’s novels The Sound and the Fury and Absalom, Absalom!, in which a similar theme is represented.Patrick White is also an author of religious literature to whom Anna M. Louw is attracted by her own admission. His novels. The solid Mandala and Riders in the Chariot are studied, and similarities with Kroniek van Perdepoort indicated.

  14. Considerations on pancreatic exocrine function after pancreaticoduodenectomy

    Institute of Scientific and Technical Information of China (English)

    Francisco; José; Morera-Ocon; Luis; Sabater-Orti; Elena; Muoz-Forner; Jaime; Pérez-Griera; Joaquín; Ortega-Serrano

    2014-01-01

    The pancreaticoduodenectomy(PD) procedure may lead to pancreatic exocrine and endocrine insufficiency. There are several types of reconstruction for this kind of operation. Pancreaticogastrostomy(PG) was introduced to reduce the rate of postoperative pancreatic fistula. Although some randomized control trials have shown no differences regarding pancreatic leakage between PG and pancreaticojejunostomy(PJ), recently some reports reveal benefits from the PG over the PJ. Some surgeons concern about the performing of the PG and inactivation of pancreatic enzymes being in contact with the gastric juice, and the detrimental results over the exocrine pancreatic function. The pancreatic exocrine function can be measured with direct and indirect tests. Direct tests have the highest sensitivity and specificity for detection of exocrine insufficiency but require tube placement. Among the tubeless indirect tests, the van de Kamer stool fat analysis remains the standard to diagnose fat malabsorption. The patient compliance and time consuming makes it not so suitable for its clinical use. Fecal immunoreactive elastase test is employed for screening of exocrine insufficiency, is not cumbersome, and has been used to study pancreatic function after resection. We analyze the FE1 levels in our patients after the PD with two types of reconstruction, PG and PJ, and we discuss some considerations about the pancreaticointestinal drainage method after pancreaticoduodenectomy.

  15. Die verhaal as mitiese vraagstelling: die verhaalkuns van Henriette Grové

    Directory of Open Access Journals (Sweden)

    Heilna du Plooy

    1996-03-01

    Full Text Available Story as mythical questioning: The narrative art of Henriette GrovéHenriette Grove's stories are mostly concerned with the nature and meaning of human experience, especially human suffering. In this article an effort is made to characterize these stories, indicating the relation between the stories and a way of thinking that is primarily concerned with metaphysical, mythical and religious issues. Texts like In die kamer was ’n kas and Die kêrel van die Pêrel and some short stories are examined to find indications of the underlying vision of man from which the stories generate. Special attention will be given to focalization in the stories, indicating the need to extend the meaning and use of the term so that textual as well as extratextual modal relations can be described. These relations may provide an indication of the vision of man which is favoured by the “abstract author" and which in this case seems to encompass much more than mere ideological thought patterns. Grové's stories posit questions which, being mythical questions, can only be answered in a religious manner. The stories do not provide solutions to the problematic nature o f experience and suffering, but insist on asking the type of questions with which religion concerns itself.

  16. Program pro inovaci řídicího systému SORT

    OpenAIRE

    Šulc, Martin

    2014-01-01

    Analýza zadání pro rozšíření řídicího systému a návrhu ovládacího programu pro pozorovací kamery a s tím spojený teoretický rozbor nezbytný pro pochopení problematiky. Návrh komunikačního protokolu pro zpřístupnění všech funkcí systému přes TCP/IP komunikaci. Následná implementace protokolu do ovládacího programu a do řídicího programovatelného automatu. Naprogramování aplikace s uživatelským rozhraním pro ovládání kamer a zpracování obrazových dat. Program také představuje server pro TCP/IP ...

  17. Level Densities in the actinide region and indirect n,y cross section measurements using the surrogate method

    Directory of Open Access Journals (Sweden)

    Wiedeking M.

    2012-02-01

    Full Text Available Results from a program of measurements of level densities and gamma ray strength functions in the actinide region are presented. Experiments at the Oslo cyclotron involving the Cactus/Siri detectors and 232Th(d,x and 232Th(3He,x reactions were carried out to help answer the question of which level density model is the most appropriate for actinide nuclei, since it will have an impact on cross section calculations important for reactor physics simulations. A new technique for extracting level densities and gamma ray strength functions from particle-gamma coincidence data is proposed and results from the development of this technique are presented. In addition, simultaneous measurements of compound nuclear gamma decay probabilities have been performed for the key thorium cycle nuclei 233Th, 231Th and 232Pa up to around 1MeV above the neutron binding energy and have enabled extraction of indirect neutron induced capture cross sections for the 232Th, 231Pa and 230Th nuclei using the surrogate reaction method. Since the neutron capture cross section for 232Th is already well known from direct measurements a comparison provides a stringent test of the applicability of the surrogate technique in the actinide region.

  18. Direct determination of the timing of sea level change during termination II.

    Science.gov (United States)

    Gallup, Christina D; Cheng, H; Taylor, F W; Edwards, R L

    2002-01-11

    An outcrop within the last interglacial terrace on Barbados contains corals that grew during the penultimate deglaciation, or Termination II. We used combined 230Th and 231Pa dating to determine that they grew 135.8 +/- 0.8 thousand years ago, indicating that sea level was 18 +/- 3 meters below present sea level at the time. This suggests that sea level had risen to within 20% of its peak last-interglacial value by 136 thousand years ago, in conflict with Milankovitch theory predictions. Orbital forcing may have played a role in the deglaciation, as may have isostatic adjustments due to large ice sheets. Other corals in the same outcrop grew during oxygen isotope (delta18O) substage 6e, indicating that sea level was 38 +/- 5 meters below present sea level, about 168.0 thousand years ago. When compared to the delta18O signal in the benthic V19-30/V19-28 record at that time, the coral data extend to the previous glacial cycle the conclusion that deep-water temperatures were colder during glacial periods.

  19. A test of uranium-series dating of fossil tooth enamel: results from Tournal Cave, France

    Science.gov (United States)

    Bischoff, J.L.; Rosenbauer, R.J.; Tavoso, A.; de Lumley, Henry

    1988-01-01

    A series of well preserved mammal bones and horse teeth was analyzed from archaeological levels of Tournal Cave (Magdalenian, Aurignacian, and Mousterain) to test the hypothesis that well-crystallized enamel behaves more as a closed system than does whole bone. The isotopic composition of bones and tooth enamels from this deposit meet criteria for confidence, and gave no reasons to suspect contamination or open-system behavior. Two samples for which 231Pa could be analyzed showed internal concordance with the respective 230Th ages. In spite of the favourable isotopic criteria, however, comparison of the U-series ages of the bones and the tooth enamel with stratigraphic position and 14C control indicated the dates were not meaningful. In general, both bones and tooth enamels gave ages too young, although some were clearly too old. Neither group showed any systematic increase of age with stratigraphic depth. Tooth enamel, therefore, shows no advantage over bone for U-series dating for this site. In Tournal cave both bones and enamel are apparently open to U, which is probably cycling as a consequences of post-depositional groundwater movement. ?? 1988.

  20. LAFARA: a new underground laboratory in the French Pyrénées for ultra low-level gamma-ray spectrometry.

    Science.gov (United States)

    van Beek, P; Souhaut, M; Lansard, B; Bourquin, M; Reyss, J-L; von Ballmoos, P; Jean, P

    2013-02-01

    We describe a new underground laboratory, namely LAFARA (for "LAboratoire de mesure des FAibles RAdioactivités"), that was recently created in the French Pyrénées. This laboratory is primarily designed to analyze environmental samples that display low radioactivity levels using gamma-ray spectrometry. Two high-purity germanium detectors were placed under 85 m of rock (ca. 215 m water equivalent) in the tunnel of Ferrières (Ariège, France). The background is thus reduced by a factor of ∼20 in comparison to above-ground laboratories. Both detectors are fully equipped so that the samples can be analyzed in an automatic mode without requiring permanent presence of a technician in the laboratory. Auto-samplers (twenty positions) and systems to fill liquid nitrogen automatically provide one month of autonomy to the spectrometers. The LAFARA facility allows us to develop new applications in the field of environmental sciences based on the use of natural radionuclides present at low levels in the environment. As an illustration, we present two of these applications: i) dating of marine sediments using the decay of (226)Ra in sedimentary barite (BaSO(4)), ii) determination of (227)Ac ((231)Pa) activities in marine sediment cores.

  1. Boundary processes traced by neodymium isotopes

    Science.gov (United States)

    Jeandel, C.; Lacan, F.

    2003-04-01

    Continental margins have been identified as preferential sites for removing of reactive elements from the ocean, on the base of U-series measurements (more specifically 231Pa/230Th). This process is called boundary scavenging (Bacon, 1988). Five years of neodymium isotopes data in water masses along the ocean margins (Indonesia, Papua New Guinea, Greenland-Scotland ridge and Labrador Sea) suggests that Nd is transferred from the sediments to the ocean but the reverse also occurs via the so-called boundary scavenging. These processes are only detectable by isotopic ratio measurements because they affect the isotopic signature of the water mass coming in contact with the margin, without changing its concentration. They can involve much higher fluxes than net input processes: for example, the modification of the AAIW signature along the Papua New Guinea slope involves exchange processes only (Lacan and Jeandel, 2001). Since we suspect that such processes not only affect the Nd oceanic chemistry but also the chemical fate of other reactive elements in the ocean, we suggest that the concept of boundary scavenging should be extended to "boundary exchange".

  2. Chuck Palahniuk: Negdje mora puknuti / S engleskog prevela Valentina Lisak

    Directory of Open Access Journals (Sweden)

    Chuck Palahniuk

    2011-12-01

    Full Text Available Iza zaključanih vrata zahoda u stražnjem dijelu antikvarnice Claire Upton razgovara na telefon. Glas joj odjekuje od poda i zidova: Koliko je teško provaliti nadzornu kameru? Ukrasti snimku? upita svog muža i počne plakati.U zadnjih tjedan dana bila je u tom dućanu već tri ili četiri puta. Jedan od onih gdje moraš ostaviti torbu na blagajni, inače te ne puste unutra. Moraš ostaviti i kaput, ako ima duboke, prostrane džepove. I kišobran, jer bi ljudi u nabore mogli ubacivati sitne predmete, češljeve, nakit i druge drangulije. Kraj starog blagajnika stoji sivi karton na kojem crnim markerom piše: “Ne volimo kad nas kradete!”Skidajući kaput, Claire reče: “Ja nisam lopov.”Stari blagajnik pogledom ju je odmjerio od glave do pete. Coknuo je jezikom i pitao: “Po čemu ste vi iznimka?”Za svaki ostavljeni predmet dao je Claire polovicu karte. Za torbicu hercova asa. Za kaput trefovu devetku. Za kišobran pikovu trojku.Pogledom je prešao preko Claireinih ruku, obrisa džepova na prsima i najlonki tražeći izbočine, nešto ukradeno. Iza prednjeg pulta po cijeloj su trgovini visjeli mali natpisi koji su upozoravali da je ovdje zabranjeno krasti. Kamere su nadzirale svaki prolaz, svaki kutak i sve prikazivale na malenom ekranu punom drugih ekrana. Trezor malih, crno-bijelih tv-ekrana iza blagajne gdje je sjedio starac i sve ih promatrao.

  3. Radionuclide studies in the North Atlantic as a contribution to a better understanding of particle dynamics in the water column. Final report; Radionukliduntersuchungen im Nordatlantik als Beitrag zum Verstaendnis der Partikeldynamik in der Wassersaeule. Endbericht

    Energy Technology Data Exchange (ETDEWEB)

    Scholten, J.C.; Vogler, S.; Fietzke, J.; Mangini, A.; Stoffers, P.

    1997-12-31

    As part of the German Joint Global Ocean Flux Study (JGOFS) the distribution of natural radionuclides in the water column and in sediment traps have been investigated. The main objective was to estimate the trapping efficiency of sediment traps deployed at three locations in the eastern North Atlantic (L1: 33 N, L2: 47 N; L3: 54 N; all situated at about 20 W) and to obtain information about particle exchange processes in the water column. In the upper water column the {sup 230}Th concentrations are similar at all locations investigated and a reversible scavenging model was able to describe the {sup 230}Th distribution. In the deep water-column at L2 and L3, however, the {sup 230}Th concentrations were significantly lower than predicted from the reversible scavenging model. The {sup 230}Th concentrations here could be described by a scavenging-mixing model which assumes an advection of {sup 230}Th depleted water masses and a rapid ventilation between 3 and 25 years. Seasonal variations in the radionuclide fluxes were observed in the sediment traps. The {sup 228}Th/{sup 230}Th ratios in the traps indicate particle exchange rates (aggregation/disaggregation) to be higher during the spring blooms. Based on the {sup 230}Th and {sup 231}Pa distribution in the water column and in the sediment traps, trapping efficiencies were calculated to be between 15% and 181%. Overtrapping was observed in a trap deployed near the seafloor. The lowest efficiencies (15%-26%) were determined in the 500 m and 1000 m traps. No direct relation between water currents and trapping biases were observed in this study. (orig.) [Deutsch] Im Rahmen der Deutschen JOINT GLOBAL OCEAN FLUX STUDY wurde die Verteilung natuerlicher Radionuklide in der Wassersaeule und in Sinkstoffallen an drei Lokationen (L1: 34 N, L2: 47 N, L3: 54 N; alle bei 20 W) im oestlichen Nordatlantik untersucht. Wesentliche Ziele des Projektes waren, die Fangeffizienz von Sinkstoffallen und die Partikeldynamik (Partikel

  4. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    P. Bernot

    2005-07-13

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this activity is to predict dissolved concentrations or solubility limits for elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) relevant to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are provided in the form of tabulated functions with pH and log fCO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. Even though selection of an appropriate set of radionuclides documented in Radionuclide Screening (BSC 2002 [DIRS 160059]) includes actinium, transport of Ac is not modeled in the total system performance assessment for the license application (TSPA-LA) model because of its extremely short half-life. Actinium dose is calculated in the TSPA-LA by assuming secular equilibrium with {sup 231}Pa (Section 6.10); therefore, Ac is not analyzed in this report. The output data from this report are fundamental inputs for TSPA-LA used to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for the actinides discussed in this report. These models cover broad ranges of environmental conditions so they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or

  5. REIMEP-22 inter-laboratory comparison. ''U Age Dating - determination of the production date of a uranium certified test sample''

    Energy Technology Data Exchange (ETDEWEB)

    Venchiarutti, Celia; Richter, Stephan; Jakopic, Rozle; Aregbe, Yetunde [European Commission, Joint Research Centre (JRC), Geel (Belgium). Institute for Reference Materials and Measurements (IRMM); Varga, Zsolt; Mayer, Klaus [European Commission, Joint Research Centre (JRC), Karlsruhe (Germany). Institute for Transuranium Elements (ITU)

    2015-07-01

    The REIMEP-22 inter-laboratory comparison aimed at determining the production date of a uranium certified test sample (i.e. the last chemical separation date of the material). Participants in REIMEP-22 on ''U Age Dating - Determination of the production date of a uranium certified test sample'' received one low-enriched 20 mg uranium sample for mass spectrometry measurements and/or one 50 mg uranium sample for a-spectrometry measurements, with an undisclosed value for the production date. They were asked to report the isotope amount ratios n({sup 230}Th)/n({sup 234}U) for the 20 mg uranium sample and/or the activity ratios A({sup 230}Th)/A({sup 234}U) for the 50 mg uranium sample in addition to the calculated production date of the certified test samples with its uncertainty. Reporting of the {sup 231}Pa/{sup 235}U ratio and the respective calculated production date was optional. Eleven laboratories reported results in REIMEP-22. Two of them reported results for both the 20 mg and 50 mg uranium certified test samples. The measurement capability of the participants was assessed against the independent REIMEP-22 reference value by means of z- and zeta-scores in compliance with ISO 13528:2005. Furthermore a performance assessment criterion for acceptable uncertainty was applied to evaluate the participants' results. In general, the REIMEP-22 participants' results were satisfactory. This confirms the analytical capabilities of laboratories to determine accurately the age of uranium materials with low amount of ingrown thorium (young certified test sample). The Joint Research Centre of the European Commission (EC-JRC) organised REIMEP-22 in parallel to the preparation and certification of a uranium reference material certified for the production date (IRMM-1000a and IRMM-1000b).

  6. Origin of elements of the Uranium-235 family observed in the Ellez river near the EL-4 experimental nuclear reactor in dismantling (Monts d'Arree- Finistere department); Origine des elements de la famille de l'uranium-235 observes dans la riviere Ellez a proximite du reacteur nucleaire experimental EL4 en cours de demantelement (Mont d'Arree - departement du Finistere). Resultats et premiers constats annee 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    In a previous study which concerned the catchment basin of the harbour of Brest, the A.C.R.O. put in evidence a marking by artificial radioelements around the power plant of Brennilis which can be imputed without ambiguities to the nuclear installation. It also put in evidence abnormalities concerning the natural radioactivity which justifies this new study. In the area of the Monts d'Arree, actinium 227 ({sup 227}Ac), non born by its ascendents which are {sup 235}U and {sup 231}Pa is observed. This phenomenon is characterized by mass activities superior to these ones of {sup 235}U and able to reach these ones of {sup 238}U. Its presence corresponds with the drainage of the Ellez river since the former channel of radioactive effluents releases from the nuclear power plant EL-4 up to the reservoir Saint-Herblot situated 6 km downstream. The strongest values of radioactivity are registered near the disused power plant, at this place a relationship exists between the level of actinium 227 and this one of the artificial radioactivity as it exists a relationship with the decay products of radon exhaled from the subsoil ({sup 210}Pb). But its presence is not limited to a part of the Ellez river, it is equally observed in terrestrial medium, in places in priori not influenced by the direct liquid effluents of the power plant. This place is situated at more than 4 km and without any connection with the Ellez waters. At this stage of the study, it is not possible to answer with certainty the question of the origin of this phenomenon. A new reorientation is considered indispensable to clarify definitively the origin of this unknown phenomenon in the scientific publications and the environmental monitoring. (N.C.)

  7. Application of the Spanish methodological approach for biosphere assessment to a generic high-level waste disposal site.

    Science.gov (United States)

    Agüero, A; Pinedo, P; Simón, I; Cancio, D; Moraleda, M; Trueba, C; Pérez-Sánchez, D

    2008-09-15

    A methodological approach which includes conceptual developments, methodological aspects and software tools have been developed in the Spanish context, based on the BIOMASS "Reference Biospheres Methodology". The biosphere assessments have to be undertaken with the aim of demonstrating compliance with principles and regulations established to limit the possible radiological impact of radioactive waste disposals on human health and on the environment, and to ensure that future generations will not be exposed to higher radiation levels than those that would be acceptable today. The biosphere in the context of high-level waste disposal is defined as the collection of various radionuclide transfer pathways that may result in releases into the surface environment, transport within and between the biosphere receptors, exposure of humans and biota, and the doses/risks associated with such exposures. The assessments need to take into account the complexity of the biosphere, the nature of the radionuclides released and the long timescales considered. It is also necessary to make assumptions related to the habits and lifestyle of the exposed population, human activities in the long term and possible modifications of the biosphere. A summary on the Spanish methodological approach for biosphere assessment are presented here as well as its application in a Spanish generic case study. A reference scenario has been developed based on current conditions at a site located in Central-West Spain, to indicate the potential impact to the actual population. In addition, environmental change has been considered qualitatively through the use of interaction matrices and transition diagrams. Unit source terms of (36)Cl, (79)Se, (99)Tc, (129)I, (135)Cs, (226)Ra, (231)Pa, (238)U, (237)Np and (239)Pu have been taken. Two exposure groups of infants and adults have been chosen for dose calculations. Results are presented and their robustness is evaluated through the use of uncertainty and

  8. Geologic evidence for age of deposits at Hueyatlaco archeological site, Vasequillo, Mexico

    Science.gov (United States)

    Steen-McIntyre, Virginia; Fryxell, Roald; Malde, Harold E.

    1981-07-01

    Direct tracing of beds during excavation in May 1973, confirmed that the artifact-bearing layers at Hueyatlaco underlie 10 m of fine-grained, water-laid deposits that constitute part of the wide-spread Valsequillo gravels. Dissection of these deposits by the adjacent Río Atoyac has reached a depth of 50 m. The stratigraphic section at Hueyatlaco includes four distinctive tephra units. The oldest one occupies a small channel in a series of cut-and-fill stream deposits that have yielded bifacial tools. It lies more than a meter above flat-lying, fine-grained beds from which edge-retouched tools have been recovered. The three other tephra units occur higher in the section. Fission-track ages on zircon phenocrysts from two of the younger tephra layers (370,000 ± 200,000 and 600,000 ± 340,000 yr, 2σ) agree with concordant uranium-series dates for a camel pelvis that was found associated with bifacial tools at Hueyatlaco (245,000 ± 40,000 yr by 230Th and > 180,000 yr by 231Pa). These dates are compatible with the depth of burial and subsequent dissection of the Hueyatlaco deposits, as well as with the degree of hydration of volcanic glass shards and with the extent of etching of heavy-mineral phenocrysts from within the tephra layers. These findings suggest to us that further search for archaeological remains in deposits as old as those at Hueyatlaco would be warranted.

  9. The consequences of the proposed amendment of the Dutch Bankruptcy Code for the supply and transport of natural gas and electricity in a liberalized market; De gevolgen van de voorgenomen wijziging van de Faillisementswet voor de levering en transport van gas en elektriciteit in een geliberaliseerde markt

    Energy Technology Data Exchange (ETDEWEB)

    Keijsers, P.; Hartendorp, R.C. [Sectie Energy and Utilities, Clifford Chance LLP, Amsterdam (Netherlands)

    2003-06-01

    Pursuant to the legislative proposal to amend the Bankruptcy Act, suppliers of energy can no longer terminate or suspend agreements for the supply of energy in case of bankruptcy of such customer. In addition, default under such an agreement relating to the period prior to bankruptcy is no ground to dissolve such an agreement. Furthermore, (a request for) bankruptcy or seizure of assets may no longer lead to termination by operation of law, unless approved by the receiver. The above applies as well to moratorium of payment. This legislative proposal will probably enter into force at some point during this year. The background of the legislative proposal is that suppliers of energy are 'essential suppliers' who should not be able to abuse their monopolistic position to suspend delivery of energy in order to force payment of unpaid bills relating to the period prior to bankruptcy. There is no justification for such a restriction to only apply to energy companies instead of to all 'essential suppliers'. If the regime were to apply to energy companies, it should only apply to network managers: these parties are the only energy-related parties who remain essential suppliers. In principle, the gas and electricity itself can also be obtained from other parties than the current supplier, although certain problems may arise in relation to switching supplier. In addition, the legislative proposal will probably lead to a situation where energy companies will require security or terminate the agreement in an earlier stage, as soon as they realise that there are problems with the payment of invoices for the supply/transport of electricity. The costs in relation thereto and in relation to the obligation to continue the supply during bankruptcy, may lead to higher costs of energy distribution companies which will probably be included in the terms for the supply of electricity. [Dutch] Onlangs heeft de Tweede Kamer het wetvoorstel met betrekking tot de

  10. The relationship between anomie and participation of Latvian inhabitants in social activities

    Directory of Open Access Journals (Sweden)

    Levina J.

    2016-01-01

    Full Text Available The purpose of this research was to investigate relations between different dimensions of anomie of Latvian inhabitants and their participation in social activities, as well as to find what social activities of Latvian inhabitants best predict their sense of anomie. In this research the secondary data from the third European Quality of Life Survey (European Quality of Life Survey (EQLS, 2012 was used. The Latvian sample consisted of respondents (n = 1009, aged from 18 to 92 years (male – 34.9%, female – 65.1%. To assess anomie three subscales of anomie – Social distrust, Social isolation and Meaninglessness – were used. These subscales [1, 2, 3, 4, 5] were constructed basing on the integrative multidimensional model of anomie, developed by Ļevina, Mārtinsone and Kamerāde [1, 2, 3, 4, 5, 6], and using questions from the third European Quality of Life Survey [7]. To measure social activities, twenty questions of the third European Quality of Life Survey were used. It was found that all three aspects of anomie – social distrust, social isolation and meaninglessness – were negatively associated with such social activities as interaction with others without doing a specific activity with them, doing an activity with others, helping others and contributing to society (civic activities. Contact by phone, the Internet or by post with a brother, sister or other relative best of all predicted social distrust. Contact by phone, the Internet or by post with any of friends or neighbours, as well as with a brother, sister or other relative together with participation in social activities in a club, society, or an association and attending a meeting of a trade union, a political party or political action group best of all predicted social isolation. Meaninglessness best of all could be predicted by contact by phone, the Internet or by post with any of friends or neighbours as well as with brother, sister or other relative and by

  11. Inorganic, radioisotopic and organic analysis of 241-AP-101 tank waste

    Energy Technology Data Exchange (ETDEWEB)

    SK Fiskum; PR Bredt; JA Campbell; LR Greenwood; OT Farmer; GJ Lumetta; GM Mong; RT Ratner; CZ Soderquist; RG Swoboda; MW Urie; JJ Wagner

    2000-06-28

    Battelle received five samples from Hanford waste tank 241-AP-101, taken at five different depths within the tank. No visible solids or organic layer were observed in the individual samples. Individual sample densities were measured, then the five samples were mixed together to provide a single composite. The composite was homogenized and representative sub-samples taken for inorganic, radioisotopic, and organic analysis. All analyses were performed on triplicate sub-samples of the composite material. The sample composite did not contain visible solids or an organic layer. A subsample held at 10 C for seven days formed no visible solids. The characterization of the 241-AP-101 composite samples included: (1) Inductively-coupled plasma spectrometry for Ag, Al, Ba, Bi, Ca, Cd, Cr, Cu, Fe, K, La, Mg, Mn, Na, Nd, Ni, P, Pb, Pd, Ru, Rh, Si, Sr, Ti, U, Zn, and Zr (Note: Although not specified in the test plan, As, B, Be, Co, Li, Mo, Sb, Se, Sn, Tl, V, W, and Y were also measured and reported for information only) (2) Radioisotopic analyses for total alpha and total beta activities, {sup 3}H, {sup 14}C, {sup 60}Co, {sup 79}Se, {sup 90}Sr, {sup 99}Tc as pertechnetate, {sup 106}Ru/Rh, {sup 125}Sb, {sup 134}Cs, {sup 137}Cs, {sup 152}Eu, {sup 154}Eu, {sup 155}Eu, {sup 238}Pu, {sup 239+240}Pu, {sup 241}Am, {sup 242}Cm, and {sup 243+244}Cm; (3) Inductively-coupled plasma mass spectrometry for {sup 237}Np, {sup 239}Pu, {sup 240}Pu, {sup 99}Tc, {sup 126}Sn, {sup 129}I, {sup 231}Pa, {sup 233}U, {sup 234}U, {sup 235}U, {sup 236}U, {sup 238}U, {sup 241}AMU, {sup 242}AMU, {sup 243}AMU, As, B, Be, Ce, Co, Cs, Eu, I, Li, Mo, Pr, Rb, Sb, Se, Ta, Te, Th, Tl, V, and W; (4) total U by kinetic phosphorescence analysis; (5) Ion chromatography for Cl, F, NO{sub 2}, NO{sub 3}, PO{sub 4}, SO{sub 4}, acetate, formate, oxalate, and citrate; (6) Density, inorganic carbon and organic carbon by two different methods, mercury, free hydroxide, ammonia, and cyanide. The 241-AP-101 composite met all

  12. Thermodynamic and structural properties in complexing media; Comportement chimique du protactinium (V) en presence d'ions sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Di Giandomenico, M.V

    2007-10-15

    Protactinium is experiencing a renewal of interest in the frame of long-term energy production. Modelling the behaviour of this element in the geosphere requires thermodynamic and structural data relevant to environmental conditions. Now deep clayey formation are considered for the disposal of radioactive waste and high values of natural sulphate contents have been determined in pore water in equilibrium with clay surface. Because of its tendency to polymerisation, hydrolysis and sorption on all solid supports, the equilibria constants relative to monomer species were determined at tracer scale (ca. 10 - 12 M) with {sup 233}Pa. The complexation constants of Pa(V) and sulphate ions were calculated starting from a systematic study of the apparent distribution coefficient D in the system TTA/Toluene/H{sub 2}O/Na{sub 2}SO{sub 4}/HClO{sub 4}/NaClO{sub 4} and as a function of ionic strength, temperature, free sulphate, protons and chelatant concentration. First of all, the interaction between free species H{sup +}, SO{sub 4}{sup -}, Na{sup +} leads to the formation of HSO{sub 4}{sup -} and NaSO{sub 4}{sup -}, for which concentrations depend upon the related thermodynamic constants. For this purpose a computer code was developed in order to determine all free species concentration. This iterative code takes into account the influence of temperature and ionic strength (SIT modelling) on thermodynamic constants. The direct measure of Pa(V) in the organic and aqueous phase by g-spectrometry had conducted to estimate the apparent distribution coefficient D as function of free sulphate ions. Complexation constants have been determined after a mathematical treatment of D. The extrapolation of these constants at zero ionic strength have been realized by SIT modelling at different temperatures. Besides, enthalpy and entropy values were calculated. Parallelly, the structural study of Pa(V) was performed using 231 Pa. XANES and EXAFS spectra show unambiguously the absence of the

  13. No iron fertilization in the equatorial Pacific Ocean during the last ice age.

    Science.gov (United States)

    Costa, K M; McManus, J F; Anderson, R F; Ren, H; Sigman, D M; Winckler, G; Fleisher, M Q; Marcantonio, F; Ravelo, A C

    2016-01-28

    The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron. Greater atmospheric dust deposition could have fertilized the equatorial Pacific with iron during the last ice age--the Last Glacial Period (LGP)--but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the (232)Th proxy), phytoplankton productivity (using opal, (231)Pa/(230)Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound δ(15)N) from six cores in the central equatorial Pacific for the Holocene (0-10,000 years ago) and the LGP (17,000-27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region. Thus, ice-age iron fertilization in the

  14. A Nd Isotopic Composition Modeling Approach of the Oceanic Thermohaline Circulation Change During LGM

    Science.gov (United States)

    Arsouze, T.; Dutay, J.; Lacan, F.; Jeandel, C.; Alkama, R.; Kageyama, M.; Piotrowski, A.

    2006-12-01

    The role of thermohaline circulation in climate change has been a matter of debate for a long time. Proxies of past ocean circulation such as δ13C or 231Pa/230Th suggest a relationship between North Atlantic Deep Water (NADW) strength and rapid climate change. Neodymium isotopic composition (Nd IC) is a quasi conservative geochemical tracer of water masses in the ocean interior and thus can be used as a proxy for NADW. Seawater Nd IC being recorded in marine sediments, this proxy is used to infer paleo-circulations on various time scales. Recent studies of Nd IC records, in the ferromanganese oxide components of a South Atlantic core, confirm the close relation between thermohaline circulation and North Atlantic climate changes through the last deglaciation (Piotrowski et al., 2004). Our purpose here is to model the Nd IC during the LGM and the Holocene with the Ocean Global Circulation Model NEMO, in the ORCA2 (2°) configuration. The explicit simulation of this proxy in the model allows to investigate and quantify the circulation change that corresponds to the Nd isotopic composition variation recorded in the sediments. We consider that the main source of Nd into the ocean is the interaction between water masses and continental margins (Boundary Exchange process; (Lacan and Jeandel, 2005). Boundary exchange is parameterized using a relaxing term (Arsouze et al., 2006). Simulated Nd IC distributions are evaluated by comparison with available records for the LGM and Holocene. References: Arsouze, T., Dutay, J.-C., Lacan, F. and Jeandel, C., 2006. Modeling the neodymium isotopic composition with a global ocean circulation model Chemical Geology, in press. Lacan, F. and Jeandel, C., 2005. Neodymium isotopes as a new tool for quantifying exchange fluxes at the continent - ocean interface. Earth and Planetary Science Letters, 232(3-4): 245-257. Piotrowski, A.M., Goldstein, S.L., Hemming, S.R. and Fairbanks, R.G., 2004. Intensification and variability of ocean

  15. No iron fertilization in the equatorial Pacific Ocean during the last ice age

    Science.gov (United States)

    Costa, K. M.; McManus, J. F.; Anderson, R. F.; Ren, H.; Sigman, D. M.; Winckler, G.; Fleisher, M. Q.; Marcantonio, F.; Ravelo, A. C.

    2016-01-01

    The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron. Greater atmospheric dust deposition could have fertilized the equatorial Pacific with iron during the last ice age—the Last Glacial Period (LGP)—but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the 232Th proxy), phytoplankton productivity (using opal, 231Pa/230Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound δ15N) from six cores in the central equatorial Pacific for the Holocene (0-10,000 years ago) and the LGP (17,000-27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region. Thus, ice-age iron fertilization in the

  16. A Record of Uranium-Series Transport in Fractured, Unsaturated Tuff at Nopal I, Sierra Peña Blanca, Chihuahua, Mexico

    Science.gov (United States)

    Denton, J.; Goldstein, S. J.; Paviet, P.; Nunn, A. J.; Amato, R. S.; Hinrichs, K. A.

    2015-12-01

    In this study we utilize U-series disequilibria measurements to investigate mineral fluid interactions and the role fractures play in the geochemical evolution of an analogue for a high level nuclear waste repository, the Nopal I uranium ore deposit. Samples of fracture-fill materials have been collected from a vertical drill core and surface fractures. High uranium concentrations in these materials (12-7700 ppm) indicate U mobility and transport from the deposit in the past. U concentrations generally decrease with horizontal distance away from the ore deposit but show no trend with depth. Isotopic activity ratios indicate a complicated geochemical evolution in terms of the timing and extent of actinide mobility, possibly due to changing environmental (redox) conditions over the history of the deposit. 234U/238U activity ratios are generally distinct from secular equilibrium and indicate some degree of open system U behavior during the past 1.2 Ma. However, calculated closed system 238U-234U-230Th model ages are generally >313 ka and >183 ka for the surface fracture and drill core samples respectively, suggesting closed system behavior for U and Th over this most recent time period. Whole rock isochrons drawn for the drill core samples show that at two of three depths fractures have remained closed with respect to U and Th mobility for >200 ka. However, open system behavior for U in the last 350 ka is suggested at 67 m depth. 231Pa/235U activity ratios within error of unity suggest closed system behavior for U and Pa for at least the past 185 ka. 226Ra/230Th activity ratios are typically <1 (0.7-1.2), suggesting recent (<8 ka) radium loss and mobility due to ongoing fluid flow in the fractures. Overall, the mainly closed system behavior of U-Th-Pa over the past ~200 ka provides one indicator of the geochemical immobility of these actinides over long time-scales for potential nuclear waste repositories sited in fractured, unsaturated tuff.

  17. Compressive Test and Simulation of Cassava Stems Based on ANSYS%基于ANSYS的木薯茎秆静力学仿真研究

    Institute of Scientific and Technical Information of China (English)

    薛忠; 张衍林; 张劲; 陈实

    2016-01-01

    In this paper , on the basis of cassava stalk mechanical test , application of computer simulation to simulate and analyze the mechanics of cassava stalk in the failure limit state .During the dissertation , analysed composite structure of cassava stalk , gave the relationship of various types of material between the flexible matrix and the engineering constants ,and assumed material types of cassava stalk .Result show:( 1 ) The shear stress of the XY direction on phloem fiber is in the range of -0.002 195~-0.000 231Pa,the shear stress of the XY direction on xylem is in the range of -0.000 231~0.000 014Pa, the maximum shear stress of the XY direction is at the junction of the xylem and phloem fiber which value is -0.002 195Pa, the minimum shear stress of the XY direction is on the xylem which value is 0.000 14Pa;shear stress of YZ direction and XZ direction has the symmetry , the shear stress of stalk at direction of YZ and XZ are concentrated on -3.07E-10~-4.58E-11Pa,the maximum shear stress of YZ or XZ direction is -2.42E-9Pa,the minimum shear stress of YZ or XZ direction is 4.59E-11Pa.(2) The shear stress of XY、YZ、XZ direction present their different laws when pressure model on the lateral , but they all distribute symmetrically .The maximum shear stress of the XY direction is ±1.746 49Pa,the minimum shear stress is ±0.194 054Pa;the maximum shear stress of the YZ direction is ±0.456 2Pa, the minimum shear stress is ±0.005 063Pa, the maximum shear stress of the XZ direction is ±0.260 701Pa, the minimum shear stress is ±0.028 967Pa.%以木薯茎秆力学试验为基础,应用计算机仿真手段模拟分析了木薯茎秆在失效极限状态下的力学状况. 使用万能试验机对木薯茎秆的主要力学成分(木质部、韧皮纤维)进行拉压试验,分别测定了木质部和韧皮纤维的多组弹性模量数据. 研究表明:①韧皮纤维处的 XY 方向切应力在-0 .002 195 ~-0 .000 231 Pa 范围内,

  18. Analýza záběru vpřed na kajaku pro jízdu na divoké vodě v přírodních podmínkách An analysis of the forward stroke as used in a wild water kayak on flat waters

    Directory of Open Access Journals (Sweden)

    František Vaverka

    2005-02-01

    Full Text Available Přímý záběr vpřed je jedna ze základních pohybových činností, jejichž zvládnutí je nezbytné pro dosažení kvalitní výkonnosti v kanoistice na divoké vodě. Analýzou záznamů přímého záběru (4 ženy, 5 mužů; juniorští reprezentanti a talentovaní závodníci jsme ze tří kamer, pomocí systému APAS, určili základní kinematické parametry této pohybové činnosti na pravé a levé straně lodi. Pohyb lodi ve sledovaném úseku byl realizován maximální rychlostí. Pro provedení záběru u lepších kajakářů je typická: menší ztráta rychlosti ve fázi zasazení a přenosu pádla, zkrácení doby trvání fáze tažení, větší frekvence záběrů. U těchto závodníků jsme dále nalezli lepší symetrii pohybu pravé a levé horní končetiny, minimální pohyb trupu v předozadním směru a zmenšení výchylek lodi do stran. The forward stroke is one of the basic motion activities that are typically used for canoeing in white water. Kinematic analysis (4 women, 5 men; junior representatives and talented competitors of records from three cameras was used. The movement of the kayak was carried out with maximal velocity. General parameters of the stroke on the left and right side of the kayak were determined utilizing the APAS system. Lower velocity losses in the catch and pull phase of the paddle, a shorter time of the pull phase, higher frequency of the strokes are typical for kayakers with better levels of efficiency. The movement of the right and left wrist of these competitors in the frontal plane is more symmetrical. The deviation of the trunk is less in the sagittal plane as well as the sideways movement of the kayak.

  19. 一种用于铀同位素比值α能谱分析的磷化膜制源新技术%A New Source-preparation Technique of Phosphate Conversion Coating Used in the Determination of Uranium Isotope Ratio by Alpha Spectrometry

    Institute of Scientific and Technical Information of China (English)

    王哲; 王玉学; 郭冬发; 付琳; 黄秋红; 孙伟; 陈春军

    2016-01-01

    A new source-preparation technique of uranium phosphate conversion coating was developed for the determination of uranium isotope ratio by alpha spectrometry. It was found experimentally that under the conditions of 3.14 cm2 Ni-foil,0.5 mol/L HCl,2.5 mol/L NaCl ,0.08 mol/L KH 2 PO 4 ,20 g/L ascorbic acid ,25 mL initial solution,90℃ constant experiment temperature,1 60 r/min vibration frequency ,20 mm vibration amplitude,and 70min deposition time ,uranium less than 200 μg can be quantitatively and spontaneously converted into phosphorization film on Ni-foil. Compared to the tradi-tional source-preparation technique of electro-deposition,the technique of uranium phosphate conversion coating has the advantage of simple in electro-deposition device, easy in operation, high working-efficiency ,no interference in measuring lots of coexisting radionuclides such as 2 3 2 Th ,2 30 Th,22 6 Ra,2 3 1 Pa and so on in phosphating solution. The total spike recovery rate of uranium reaches 100% nearly,and the spectrum resolution is good in determing uranium isotope ratio by alpha spectrometry.%研发了一种用于铀同位素比值α能谱分析的磷化膜制源新技术.试验发现,当镍镀片面积为3.14 cm2,盐酸浓度为0.5 mol/L ,氯化钠浓度为2.5 mol/L ,磷酸二氢钾浓度为0.08 mol/L,抗坏血酸浓度为20 g/L,溶液体积为25 mL,恒温90℃,振荡速率为160次/min,振程20 mm 时,磷化膜制源70 min,200μg 以下的铀可在镍箔上定量转化为磷化膜.与传统的电沉积制源技术相比较,应用磷化膜制源技术进行测量源制备时无需电沉积装置,制源过程简单快速,工效高,大量共存的232 Th 、230 Th、226 Ra、231 Pa 等核素均不产生干扰,铀的全程回收率接近100%,α能谱峰分辨率较好.

  20. Rates of carbonate soil evolution from carbon, U- and Th-series isotope studies: Example of the Astian sands (SE France)

    Science.gov (United States)

    Barbecot, Florent; Ghaleb, Bassam; Hillaire-Marcel, Claude

    2015-04-01

    In carbonate rich soils, C-isotopes (14C, 13C) and carbonate mass budget may inform on centennial to millennial time scale dissolution/precipitation processes and weathering rates, whereas disequilibria between in the U- and Th-decay series provide tools to document high- (228Ra-228Th-210Pb) to low- (234U, 230Th, 231Pa, 226Ra) geochemical processes rate, covering annual to ~ 1Ma time scales, governing both carbonate and silicate soil fractions. Because lithology constitutes a boundary condition, we intend to illustrate the behavior of such isotopes in soils developed over Astian sands formation (up to ~ 30% carbonate) from the Béziers area (SE France). A >20 m thick unsaturated zone was sampled firstly along a naturally exposed section, then in a cored sequence. Geochemical and mineralogical analyses, including stable isotopes and 14C-measurements, were complemented with 228U, 234U, 230Th, 226Ra, 210Pb and 228Th, 232Th measurements. Whereas the upper 7 m depict geochemical and isotopic features forced by dissolution/precipitation processes leading to variable radioactive disequilibria, but overall deficits in more soluble elements of the decay series, the lower part of the sequence shows strong excesses in 234U and 230Th over parent isotopes (i.e., 238U and 234U, respectively). These features might have been interpreted as the result of successive phases of U-loss and gains. However, 226Ra and 230Th are in near-equilibrium, thus leading to conclude at a more likely slow enrichment process in both 234Th(234U) and 230Th, which we link to dissolved U-decay during groundwater recharge events. In addition, 210Pb deficits (vs parent 226Ra) are observed down to 12 m along the natural outcropping section and below the top-soil 210Pb-excess in the cored sequence, due to gaseous 222Rn-diffusion over the cliff outcrop. Based on C-isotope and chemical analysis, reaction rates at 14C-time scale are distinct from those estimates at the short- or long-lived U-series isotopes

  1. Using U-series and beryllium isotopes to reveal the occurrence and relative timing of crustal and mantle processes in the Southern Volcanic Zone of Chile

    Science.gov (United States)

    Cooper, L. B.; Reubi, O.; Dungan, M. A.; Bourdon, B.; Langmuir, C. H.; Turner, S. J.; Schaefer, J. M.

    2012-12-01

    the main edifice have been mixed with magma compositions similar to those at surrounding minor eruptive centers (Hickey-Vargas et al., 2002). The latter appear to be decompression melts of enriched mantle which manifest moderate U-Th-Ra disequilibrium and substantial 231Pa-excesses, whereas melts from Villarrica have substantial U- and Ra-excesses. Magmas from Osorno reflect a greater influence of sediments originating from the incoming slab. After discounting assimilated samples, all primary melts have uniformly high Pa-excesses (1.7-2.2) coincident with large variations in 238U-230Th disequilibria. Fluid addition-aging-melting successions at Antuco and Chillán may have led to compositions near U-Th equilibrium or with Th-excesses, respectively. Primary Ra-deficits at Chillán, Lonquimay, and Osorno are under investigation and potentially reflect melting of a cumulate body. Forthcoming 10Be data for select U-series samples will enable further clarification of the regional trend. Preliminary analyses of nine Llaima samples erupted between 1850 and 2009 confirm the successful elimination of a meteoric 10Be component and produce a data array consistent with assimilation. The invocation of radioactive decay to produce U-Th equilibrium (duration of at least 380 ky) could also explain the low 10Be/9Be compositions (half-life of 10Be=1,390 ky). Our comprehensive dataset may shed new light on melting processes in subduction zone systems.

  2. Analysis of the beginning of the early flight phase of the ski jump in athletes with different performance levels [Analýza fáze přechodu do letu ve skoku na lyžích u skupin závodníků s různou výkonností

    Directory of Open Access Journals (Sweden)

    Eva Janurová

    2011-09-01

    mezi závodníky s různou výkonností, ale i uvnitř skupin se srovnatelnou délkou skoku. CÍLE: Cílem studie bylo porovnat provedení zahájení přechodové fáze skoku mezi skupinami závodníků v severské kombinaci s různou výkonností. Určit rozdíly v provedení této fáze skoku mezi závodníky v severské kombinaci a ve skoku na lyžích. METODIKA: Odrazová a přechodová fáze skoku na můstku HS-134 m při závodech MS v klasickém lyžování v Liberci v r. 2009 byla zaznamenána s využitím tří kamer (50 Hz. Kamery byly umístěny tak, že jejich optické osy byly kolmé na rovinu pohybu závodníků. Vybrané body na těle a na lyžích závodníků byly vyhodnoceny manuálně. Ze souřadnic těchto bodů jsme určili základní úhlové a rychlostní charakteristiky pro polohu segmentů a lyží. Ze všech startujících závodníků v severské kombinaci jsme vybrali a porovnali skupiny, které dosáhly nejlepší (B, průměrné (M a nejkratší (P délky skoku. VÝSLEDKY: Nájezdová rychlost byla při porovnání skupiny závodníků severské kombinace (NC a skoku na lyžích (SJ významně vyšší u skupiny NC (p < 0,01. Skupina SJ měla na hraně můstku větší posun těla dopředu (p < 0,05. Velikost úhlové rychlosti v kolenním kloubu v úseku 0 až 5 m za hranou můstku byla vyšší u skupiny SJ (p < 0,05. Při porovnání skupin nejlepších závodníků v obou disciplínách byl nalezen rozdíl v poloze bérců na hraně můstku i v celém úseku za hranou. Skupina SJ se vyznačovala větším posunem dolních končetin dopředu (hrana, p < 0,05; 5 m za hranou, p < 0,01, úhlová rychlost v kolenním kloubu byla vyšší. V tomto parametru jsme také zjistili rozdíl mezi skupinami závodníků s průměrnou výkonností, s větší úhlovou rychlostí u skupiny SJ (p < 0,05. ZÁVĚRY: Závodníci ve skoku na lyžích mají ve sledovaném úseku za hranou můstku výhodnější aerodynamickou polohu těla, s v