{"id":7958,"date":"2016-03-04T23:58:37","date_gmt":"2016-03-04T22:58:37","guid":{"rendered":"http:\/\/karmaka.de\/?p=7958"},"modified":"2016-03-05T00:08:02","modified_gmt":"2016-03-04T23:08:02","slug":"origin-of-uranium-isotope-variations-in-early-solar-nebula-condensates","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=7958","title":{"rendered":"Origin of uranium isotope variations in early solar nebula condensates"},"content":{"rendered":"<p>By Fran\u00e7ois L. H. Tissot, Nicolas Dauphas, Lawrence Grossman<\/p>\n<p>Science Advances  04 Mar 2016:<br \/>\nVol. 2, no. 3, e1501400<br \/>\nDOI: 10.1126\/sciadv.1501400 <\/p>\n<p><a href=\"http:\/\/advances.sciencemag.org\/content\/advances\/2\/3\/e1501400.full.pdf\" target=\"_blank\"><strong>PDF (open access)<\/strong><\/a><br \/>\n<a href=\"http:\/\/advances.sciencemag.org\/content\/2\/3\/e1501400.abstract\" target=\"_blank\"><strong>abstract<\/strong><\/a><br \/>\n<a href=\"http:\/\/advances.sciencemag.org\/highwire\/filestream\/188765\/field_highwire_adjunct_files\/0\/1501400_SM.pdf\" target=\"_blank\"><strong>Supplementary Materials (PDF)<\/strong><\/a><\/p>\n<p>&#8220;High-temperature condensates found in meteorites display uranium isotopic variations (235U\/238U), which complicate dating the solar system\u2019s formation, the origin of which remains mysterious. It is possible that these variations are due to the decay of the short-lived radionuclide 247Cm (t1\/2 = 15.6 My) into 235U, but they could also be due to uranium kinetic isotopic fractionation during condensation. We report uranium isotope measurements of meteoritic refractory inclusions that reveal excesses of 235U reaching ~6% relative to average solar system composition, which can only be due to the decay of 247Cm. This allows us to constrain the 247Cm\/235U ratio at solar system formation to (1.1 \u00b1 0.3) \u00d7 10\u22124. This value provides new clues on the universality of the rapid neutron capture r-process of nucleosynthesis.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>By Fran\u00e7ois L. H. Tissot, Nicolas Dauphas, Lawrence Grossman Science Advances 04 Mar 2016: Vol. 2, no. 3, e1501400 DOI: 10.1126\/sciadv.1501400 PDF (open access) abstract Supplementary Materials (PDF) &#8220;High-temperature condensates found in meteorites display uranium&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[66,9,14,72,586,68,57,71],"tags":[2562,465,2559,2560,108,106,2558,1812,2564,125,1807,2563,2561],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/7958"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7958"}],"version-history":[{"count":4,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/7958\/revisions"}],"predecessor-version":[{"id":7960,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/7958\/revisions\/7960"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7958"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7958"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7958"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}