Proceedings in Radiochemistry最新文献

{"title":"Complete and incomplete fusion in 9Be+124Sn system","authors":"V. Parkar, R. Palit, Sushil Sharma, B. Naidu, P. Joshi, S. Santra, P. Rath, K. Ramachandran, K. Mahata, T. Trivedi, A. Raghav","doi":"10.1524/RCPR.2011.0024","DOIUrl":"https://doi.org/10.1524/RCPR.2011.0024","url":null,"abstract":"Abstract Complete and incomplete fusion cross-sections for the 9Be+124Sn system have been measured around the Coulomb barrier energies (ElabC.B=28 MeV) using the on-line gamma ray detection technique. The complete fusion cross-sections of this system have been compared with the two stable projectiles on the same 124Sn target to provide information on the projectile dependence. The brief comparison of the present 9Be+124Sn data with a comprehensive and recent study of the neighbouring system 9Be+144Sm is also given.","PeriodicalId":338467,"journal":{"name":"Proceedings in Radiochemistry","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123545658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Activities of the 7Be and 137Cs nuclides in mushrooms from southern and western Finland","authors":"T. Lönnroth, J. Lill, A. Björkholm, T. Haavisto, J. Slotte","doi":"10.1524/RCPR.2011.0041","DOIUrl":"https://doi.org/10.1524/RCPR.2011.0041","url":null,"abstract":"Abstract We report the results from activity measurements of 7Be and 137Cs nuclides in mushrooms in Southern and Western Finland. Fifty-three samples were studied, and they showed large variations especially in the 137Cs activity both regionally and between mushroom species.","PeriodicalId":338467,"journal":{"name":"Proceedings in Radiochemistry","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123313332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EXAFS analysis of uranium(IV) and thorium(IV) complexes in concentrated CaCl2 solutions","authors":"A. Uehara, T. Fujii, H. Matsuura, N. Sato, T. Nagai, Kazuo Minato, H. Yamana, Y. Okamoto","doi":"10.1524/rcpr.2011.0030","DOIUrl":"https://doi.org/10.1524/rcpr.2011.0030","url":null,"abstract":"Abstract The coordination of U4+ and Th4+ in concentrated CaCl2 solutions is studied by U and Th LIII edge extended X-ray absorption fine structure (EXAFS) spectroscopy. With the decrease of concentration of CaCl2 from 6.9 to 4 M, the Cl− ion coordination number NCl in the U4+ coordination sphere decreases from 3.4 to 1.3, while the hydration number NO increases from 4.5 to 6.7. The combined coordination number NO+NCl of U4+ in concentrated Cl− solution (8.0), is lower than that in 1.5 M perchloric acid aqueous solution (9.0). For Th4+, the decrease of concentration from 6.9 to 4 M CaCl2, the coordination number NCl in the Th4+ coordination sphere decreased slightly from 1.9 to 1.5, while coordination number NO increased from 7.6 to 8.8. The NO+NCl of Th4+ in concentrated Cl− solution (9.0), is similar to that in 1.5 M perchloric acid. The bond distance of U–Cl (2.67 Å), is shorter than that of Th–Cl (2.76 Å), because of low coordination number NO to U4+. By adding HCl into the system, the U4+ and Th4+ coordination sphere is unchanged. The coordination structures of U4+ and Th4+ in concentrated LiCl is also discussed.","PeriodicalId":338467,"journal":{"name":"Proceedings in Radiochemistry","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124948454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of uranium ore concentrates for origin assessment","authors":"Z. Varga, M. Wallenius, K. Mayer, M. Meppen","doi":"10.1524/RCPR.2011.0004","DOIUrl":"https://doi.org/10.1524/RCPR.2011.0004","url":null,"abstract":"Abstract In this study the most important analytical methodologies are presented for the nuclear forensic investigation of uranium ore concentrates (yellow cakes). These methodologies allow to measure characteristic parameters which may be source material or process inherited. By the combination of the various techniques (e.g. infrared spectrometry, impurity content, rare-earth pattern and U, Sr and Pb isotope ratio analysis by mass spectrometry), the possible provenances of the illicit material can be narrowed down to a few options and its declared origin can be verified. The methodologies serve for nuclear forensic investigations as well as for nuclear safeguards, checking the consistency of information.","PeriodicalId":338467,"journal":{"name":"Proceedings in Radiochemistry","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128578591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of the periodic table in discovery of new elements","authors":"D. Hoffman","doi":"10.1524/RCPR.2011.0000","DOIUrl":"https://doi.org/10.1524/RCPR.2011.0000","url":null,"abstract":"Abstract This year (2009) marks the 140th Anniversary of Mendeleev's original 1869 periodic table of the elements based on atomic weights. It also marks the 175th anniversary of his birth in Tolbosk, Siberia. The history of the development of periodic tables of the chemical elements is briefly reviewed beginning with the presentation by Dmitri Mendeleev and his associate Nikolai Menshutkin of their original 1869 table based on atomic weights. The value, as well as the sometimes negative effects, of periodic tables in guiding the discovery of new elements based on their predicted chemical properties is assessed. It is noteworthy that the element with Z=101 (mendelevium) was identified in 1955 using chemical techniques. The discoverers proposed the name mendelevium to honor the predictive power of the Mendeleev Periodic Table. Mendelevium still remains the heaviest element to have been identified first by chemical rather than nuclear or physical techniques. The question concerning whether there will be a future role for the current form of the periodic table in predicting chemical properties and aid in the identification of elements beyond those currently known is considered.","PeriodicalId":338467,"journal":{"name":"Proceedings in Radiochemistry","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130414046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring fluorine in uranium oxyfluoride particles using secondary ion mass spectrometry for nuclear forensics","authors":"Kips Ruth, M. Kristo, Hutcheon Ian, Z. Wang, Johnson Tim, Gerlach David, Amonette Jim, Olsen Khris, Stefaniak Elzbieta","doi":"10.1524/RCPR.2011.0001","DOIUrl":"https://doi.org/10.1524/RCPR.2011.0001","url":null,"abstract":"Abstract Gaseous uranium hexafluoride (UF6) is used for the enrichment of uranium and is known to be a very reactive and volatile gas. When a small amount of UF6 is released in the environment, it forms uranium oxyfluoride (UO2F2) particles and hydrogen fluoride from the reaction with atmospheric moisture. The UO2F2 particles settle on various surfaces within the enrichment facility where they are collected by safeguards organizations such as the International Atomic Energy Agency (IAEA) through a technique called environmental sampling. Despite their small size, the uranium isotopic composition of these particles is used to determine whether an enrichment facility is compliant with its declarations. Additional and complementary information on the particles' source, formation process and exposure history can be obtained from elemental, molecular and morphological analysis. As fluorine is not always detected in uranium particles originating from enrichment facilities, it is assumed that UO2F2 is unstable under certain environmental conditions. This study aims to determine how those environmental conditions affect the relative amount of fluorine in UO2F2 particles. Expressly for the purpose of this work, we prepared a set of UO2F2 particle samples from the hydrolysis of UF6 and stored these samples in environmental chambers at different temperature, humidity and lighting conditions. The NanoSIMS secondary ion mass spectrometer, with a nanometer-scale spatial resolution, was used to measure the F+/U+ secondary ion ratio of individual particles immediately after sample preparation, and at different time intervals. NanoSIMS analyses on single particles stored up to 7 months in dry air did not detect a significant decrease in the relative amount of fluorine. The exposure to high humidity however, resulted in a much lower F+/U+ ratio, up to 2 orders of magnitude below that of the particles stored in dry air. It should be noted that fluorine was still detected in these samples, even after 7 months of high humidity exposure.","PeriodicalId":338467,"journal":{"name":"Proceedings in Radiochemistry","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122926695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of air particulate matter in Teflon™ and quartz filters by short-irradiation, epithermal-neutron activation with Compton suppression","authors":"M. Freitas, S. Almeida, H. M. Dung, I. Dionísio, A. Pacheco","doi":"10.1524/RCPR.2011.0065","DOIUrl":"https://doi.org/10.1524/RCPR.2011.0065","url":null,"abstract":"Abstract This work aimed at developing methodologies to characterize the elemental composition of air particulate matter (APM) collected in Portugal, at an urban area (Lisboa, mainland Portugal) and at a remote location (Terceira island, Azores, Portugal). The Azores' collections were based on quartz filters; Teflon™ filters were used at the urban area. The main components of Teflon™ and quartz filters are fluorine and silica, respectively, the latter featuring higher levels of elements in the blanks. Al and Ti are reduced to null values when the blanks are subtracted. Epithermal short irradiation associated to Compton suppression in the measurement allowed the determination of a set of elements potentially representative of important emission sources: sea-spray (Cl, Br, Na, Mg), fuel burning (V), incineration (Cl), soil resuspension (Mg, Mn, Na, U, V), and traffic (Br, Mn). The analysis was fast due to the use of an automatic system. In some cases, the same element had different origins in the urban and remote oceanic areas.","PeriodicalId":338467,"journal":{"name":"Proceedings in Radiochemistry","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134040018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uranium resonance ionization mass spectrometry in natural U-silicate","authors":"K. B. Knight, M. Savina, B. Isselhardt, I. Hutcheon, S. Prussin, M. Pellin","doi":"10.1524/RCPR.2011.0006","DOIUrl":"https://doi.org/10.1524/RCPR.2011.0006","url":null,"abstract":"Abstract A natural uranium silicate mineral, cuprosklodowskite, has been analyzed by Resonance Ionization Mass Spectrometry (RIMS) for uranium isotope composition under a variety of experimental conditions. While no significant isobaric interferences are observed in the mass regions of interest, molecular supression is incomplete, and varies with the method of neutral U atom production. Despite low measured useful yields under the present analytical arrangement, it is possible to measure uranium isotope composition directly from the sample surface with only a minimum of sample preparation. U-RIMS is a method deserving further development for analyses of environmental materials.","PeriodicalId":338467,"journal":{"name":"Proceedings in Radiochemistry","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121630620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}