Made available in DSpace on 2014-10-09T12:27:46Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:03Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

abstract: The presence of a number of extinct radionuclides in the early Solar System (SS) is known from geochemical and isotopic studies of meteorites and their components. The half-lives of these isotopes are short relative to the age of the SS, such that they have now decayed to undetectable levels. They can be inferred to exist in the early SS from the presence of their daughter nuclides in meteoritic materials that formed while they were still extant. The extinct radionuclides are particularly useful as fine-scale chronometers for events in the early SS. They can also be used to help constrain the astrophysical setting of the formation of the SS because their short half-lives and unique formation environments yield information about the sources and timing of delivery of material to the protoplanetary disk. Some extinct radionuclides are considered evidence that the Sun interacted with a massive star (supernova) early in its history. The abundance of 60Fe in the early SS is particularly useful for constraining the astrophysical environment of the Sun's formation because, if present in sufficient abundance, its only likely source is injection from a nearby supernova. The initial SS abundance of 60Fe is poorly constrained at the present time, with estimates varying by 1-2 orders of magnitude. I have determined the 60Fe-60Ni isotope systematics of ancient, well-preserved meteorites using high-precision mass spectrometry to better constrain the initial SS abundance of 60Fe. I find identical estimates of the initial 60Fe abundance from both differentiated basaltic meteorites and from components of primitive chondrites formed in the Solar nebula, which suggest a lower 60Fe abundance than other recent estimates. With recent improved meteorite collection efforts there are more rare ungrouped meteorites being found that hold interesting clues to the origin and evolution of early SS objects. I use the 26Al-26Mg extinct radionuclide chronometer to constrain the ages of several recently recovered meteorites that sample previously unknown asteroid lithologies, including the only know felsic meteorite from an asteroid and two other ungrouped basaltic achondrites. These results help broaden our understanding of the timescales involved in igneous differentiation processes in the early SS. / Dissertation/Thesis / Ph.D. Geological Sciences 2012

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-08-07T13:29:58Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE PAULA FRASSINETTI.pdf: 2414745 bytes, checksum: 4d824cc24f314359b8a18d0aa19140aa (MD5) / Made available in DSpace on 2017-08-07T13:29:58Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) TESE PAULA FRASSINETTI.pdf: 2414745 bytes, checksum: 4d824cc24f314359b8a18d0aa19140aa (MD5) Previous issue date: 2016-08-02 / CAPES / Atualmente tem-se evidenciado um aumento dos níveis da radioatividade ambiental, em decorrência de atividades antrópicas, tendo como exemplo as indústrias de petróleo que produzem por ano cerca de 2,5x104 a 2,25x105 toneladas de materiais contaminados, que contêm níveis elevados de elementos das séries radioativas naturais do 238U,235U, 232Th e 40K, contribuindo para a formação do “TENORM” (Technologically Enhanced Naturally Ocurring Radioactive Material). Assim, o objetivo principal deste estudo foi avaliar as concentrações do 238U, 226Ra, 232Th, 40K e 210Pb em amostras de solos, sedimentos, peixes e folhas de mangue coletadas no percurso dos rios Ipojuca Massangana e Tatuoca localizados na Região Estuarina do Complexo Industrial de SUAPE, devido à instalação de uma refinaria de petróleo e à consequente introdução no meio ambiente de materiais radioativos naturais oriundos de outras regiões. Para isto, foram determinadas as concentrações do 238U, 226Ra, 232 Th, 40K em amostras de solos, sedimentos, peixes e folhas, utilizando o método da espectrometria gama. Além disso, determinou-se também as concentrações de 210Pb em amostras de peixes e folhas de mangue também pelo método da espectrometria gama e em amostras de solos e sedimentos pela técnica da troca iônica. As concentrações de 238U, 226Ra, 232 Th, 40K e 210Pb em solos, sedimentos, peixes e folhas de mangue variaram respectivamente de < LD – 622,89 Bq.kg-1; 13,57 – 872,62 Bq.kg-1; 16,6 – 989,17 Bq.kg-1; < LD – 992,35 Bq.kg-1. Os resultados obtidos mostraram que a área relativa à situação pré-operacional encontra-se com valores acima dos estimados pela UNSCEAR para regiões consideradas naturais, apresentando interferência antropogênica. / Now a days it has been evidenced increase in environmental radioactivity levels, as a result of human activities, taking as an example the petroleum industry that produces annually 2,5x104 the 2,25x105 tons of contaminated materials which contain high levels of natural radioactive elements from the 238U, 235U, 232Th and 40K natural series, contributing to the formation of "TENORM" (Technologically Enhanced Naturally ocurring radioactive Material). Then, the main objective of this study was to evaluate the concentrations 238U, 226 Ra, 232Th, 40K and 210Pb in soil samples, sediments, fish and mangrove leaves collected in the course of Ipojuca, Massangana and Tatuoca rivers located in the estuarine region of the Industrial Complex of SUAPE, due to the installation of an oil refinery and the consequent introduction into the environment of natural radioactive materials from other regions. With this purpose the concentrations of 238U, 226Ra, 232Th and 40K were determined in soil samples, sludge, leaves and fish, using gamma spectrometry. Also concentrations were determined 210 Pb in samples of fish and mangrove leaves were determined by the method of gamma spectrometry and in soil and sediment samples by the technique of ion exchange. The concentrations in soils , sediments, fish and mangrove leaves obtained for 238U, 226Ra, 232Th, 40 K and 210Pb ranged respectively from < LD - 622.89 Bq.kg-1; 13.57 to 872.62 Bq.kg-1; 16.6 to 989.17 Bq.kg-1; < LD - 992.35 Bq.kg-1. The results showed that the area studied presented radioactivity concentration values estimated by UNSCEAR to regions considered natural, with anthropogenic interference.

Made available in DSpace on 2014-10-09T12:27:46Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:03Z (GMT). No. of bitstreams: 0 / Leishmanioses são um complexo de doenças infecciosas causadas por protozoários intramacrofágicos do gênero Leishmania, fatal se não tratadas adequadamente. Os antimoniais pentavalentes são os medicamentos de primeira escolha para o tratamento, apesar de sua toxicidade e seu mecanismo de ação pouco esclarecido. Uma terapia mais eficaz pode ser conseguida pelo direcionamento de fármacos antileishmania para os locais de infecção. Os lipossomas são vesículas lipídicas que promovem melhora na eficácia e na ação de fármacos na célula alvo. Os lipossomas são capturados preferencialmente pelas células do sistema mononuclear fagocitário (SMF). O objetivo deste estudo foi desenvolver uma formulação de antimoniato de meglumina lipossomal, constituído por fosfatidilserina e estudar sua farmacocinética em animais sadios para esclarecer seu metabolismo e distribuição. As análises quantitativas de antimônio em lipossomas demonstram que Análise por Ativação Neutrônica foi a técnica mais sensível com cerca de 100 % de precisão. Todas as formulações de lipossomas apresentaram um tamanho de diâmetro médio de 150 nm. A determinação da CE50 em macrófagos infectados mostrou que as formulações de antimoniato de meglumina encapsulado em lipossomas foram entre 10 - 63 vezes mais eficazes do que a fármaco livre, indicando maior índice de seletividade. Por microscopia de fluorescência, foi verificada uma maior internalização de lipossomas fluorescentes em macrófagos infectados durante um curto tempo de incubação em comparação com macrófagos não infectados. A biodistribuição do antimoniato de meglumina irradiado encapsulado em lipossomas contendo fosfatidilserina mostrou que a formulação lipossomal promoveu um direcionamento seletivo do antimônio para tecidos do SMF, além do que manteve as doses elevadas nos órgãos por um período prolongado. Em conclusão, estes dados sugerem que o antimoniato de meglumina encapsulado em lipossomas apresentou maior eficácia do que a fármaco não lipossomal contra a infecção por Leishmania. O desenvolvimento de formulações lipossomais pode ser uma nova alternativa para a quimioterapia de doenças infecciosas, especialmente Leishmanioses, já que são usados como sistemas carreadores para entrega sustentada e direcionada de fármacos ao local da infecção. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

It is government policy that the UK’s intermediate level radioactive wastes (ILW) will be disposed of in a deep geological disposal facility (GDF), where cementitious materials will be ubiquitous. After ILW disposal, groundwater ingress through the engineered facility is expected, forming a hyperalkaline plume from the cementitious materials into the surrounding host rock. This will form a persistent, high pH, “chemically disturbed zone” over timescales of 105 - 106 years, that will evolve from pH >13 to pH 10 over time. In the deep subsurface, microbial processes, particularly metal reduction may immobilise redox active radioactive contaminants in the waste, yet these reactions remain poorly characterised under these extreme conditions. In this project, microbiologically-mediated Fe(III) reduction was explored under alkaline conditions in sediment from a lime workings site in Buxton, UK, as an analogue for an ILW impacted subsurface environment. In addition, the impact of these processes on radionuclide (U, Tc and Np) behaviour was considered. Microcosms were set up using sediments taken from the site, adjusted to pH 10, augmented with electron donor (organic acids with yeast extract) and Fe(III), U(VI), Tc(VII) or Np(V) as electron acceptors. Biogeochemical processes were monitored using geochemistry, microbial ecology and X-ray absorption spectroscopy (XAS) techniques. A cascade of microbial reduction processes occurred at pH 10 – 10.5 in all microbially active systems. In Fe(III) enriched systems, the dominant post-reduction mineral phase was magnetite and the rate and extent of Fe(III) reduction was increased in the presence of extracellular (AQDS, Aldrich humic acid) and endogenous (riboflavin) electron shuttles. In U(VI) supplemented sediment systems, partial U(VI) reduction occurred to a non-uraninite phase, which was susceptible to reoxidation by air (O2) and nitrate. By contrast, in Fe(III)-augmented microcosms, more complete U removal to solids was noted, with uraninite identified as the end product, which was also reoxidised by air (O2) and nitrate. In these experiments there was, however, evidence to suggest that uranium was associated with the reoxidised Fe(III) mineral. In Tc supplemented microcosm experiments, complete Tc(VII) reduction occurred in systems with and without added Fe(III). In the microcosms with no added Fe(III) however, only partial Tc removal from solution occurred, despite evidence for complete reduction, suggesting that soluble or colloidal Tc(IV) may be present. Moderate Tc reoxidation occurred with air (O2) in both systems with and without added Fe(III) however no Tc remobilisation occurred during reoxidation with added nitrate. XAS on Fe(III) enriched sediments that had been microbially reduced and then re-oxidised by air, indicated that Tc may be associated with the reoxidised Fe mineral phase in these experiments. In the Np experiments, significant Np(V) sorption to sediments with and without added Fe(III) occurred initially, followed by Np(V) bioreduction to Np(IV). In all experiments, microbial (16S rRNA gene) profiling suggested a role for novel Gram-positive bacteria in Fe(III) and radionuclide reduction. These results highlight the significance of microorganisms on radionuclide biogeochemistry at high pH and have implications for the safe disposal of intermediate level nuclear wastes.

L'énergie nucléaire est l’un des moteurs de notre société moderne et, malgré des controverses, est considérée comme la forme d'énergie la plus efficace et la plus écologique. Néanmoins, elle est également à l'origine de nombreuses craintes : de part les déchets fortement radiotoxiques produits par les réacteurs et aussi les risques éventuels d’accidents nucléaires qui posent, sur la santé publique et l'environnement, de graves problèmes. Dans ce contexte, l'objectif de ce projet était de proposer de nouveaux matériaux innovants, capables de piéger efficacement les radionucléides dans les milieux aqueux contaminés. Un nouveau polymère est décrit et a été synthétisé à la fois en solution en utilisant la polymérisation radicalaire contrôlée de type Cu0-CRP mais également à partir de différents substrats comme le PET et le PVC, ce dernier s’étant révélé le plus efficace. Ces nouveaux matériaux ont ensuite été testés et se sont avérés très performants dans le piégeage de l'uranium et de nombreux lanthanides dans l'eau. Ces résultats ont de nombreuses applications potentielles dans l'industrie nucléaire. Ils peuvent être utilisés pour récupérer l'uranium de l'eau de mer comme une future source d'énergie renouvelable. Ils peuvent également contribuer à l'industrie de la gestion des déchets nucléaires, en permettant d’extraire les actinides et/ou lanthanides des effluents radioactifs. En plus, ces matériaux sont prometteurs dans le domaine du traitement des eaux radio-contaminées et la radiodétoxification des organismes vivants, y compris les humains. / Nuclear energy is the true engine of our modern day society and seen as the most efficient and clean form of energy. At the same time, it is the source of many concerns, with its highly radiotoxic waste produced by nuclear reactors and the public health and environmental risks that follow nuclear accidents. In this context, the aim of this project was to come up with new innovative materials, capable of efficiently trap radionuclides in contaminated aqueous media. A new polymer is reported and synthesized in solution as a free polymer, using the easy, cheap and fast metallic copper-mediated controlled radical polymerization (Cu0-CRP). The new polymer was also built from different substrates like PET and PVC, the latter being the most efficient. These new materials were later put to test and proved to be highly performing in trapping uranium and many lanthanides in water. These results have many implications in the nuclear industry. They can be used to harvest uranium from seawater as a future renewable energy source. They can also help the nuclear waste management industry. They are also a potential candidate for treating radio-contaminated environments and for radiodetoxification of living species, including humans.

Title: The Preparation of Porous Materials for Radionuclide Capture Author: Bc. Anna Bajzíková Curriculum: Teaching of Chemistry and Biology for Secondary Schools Type of thesis: Master's Department: Department of Teaching and Didactics of Chemistry, Faculty of Science, Charles University in Prague Elaborated: Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Psysical Engineering, Czech Technical University in Prague Advisor: Doc. Ing. Stanislav Smrček, CSc. Consultant: RNDr. Ján Kozempel, Ph.D. Abstract: The use of radionuclides is still increasing and with it also increases the amount of radioactive waste and this waste have to be processed. This thesis is focused on the preparation, characterization and testing of porous materials which could be used for the process of this waste. There were prepared and characterized materials based on silica and zirkonia with a modified surface. For the modification were used styren with divinilbenzene, polyacrilonitrile and diglycolamides at different configurations of these materials. Furthermore, there were prepared materials based on hydroxyapatite and its modifications. Prepared sorbents were tested for radionuclide capture - flow through the column and also in the static experiments. The capture of 227Ac and its daughter's radionuclides...

Soon after the discovery of radioactivity it was shown that radionuclides can be used both for diagnostic and therapeutic studies, depending on the characteristic radiations emitted by them. By 1960’s the radionuclide production technology using nuclear reactors was well established. In early 1970’s a renaissance of the cyclotrons occurred because many of the neutron deficient radionuclides could only be produced using irradiations with charged particles, like protons, deuterons, α-particles, etc. Initially, interest was directed towards radioactive gases for inhalation studies and other radionuclides for scintigraphy. Later, with the advent of emission tomography, i.e. Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET), the emphasis shifted to 123I and positron emitters [cf. 1–3], and tremendous progress ensued. In order to keep abreast of the fast developments, a Symposium was organized at the Brookhaven National Laboratory (BNL), USA, in 1976, with the title “Radiopharmaceutical Chemistry”. This became a biennial event, with alternate meetings in North America and Europe. It included all aspects of radionuclide and radiopharmaceutical research. About a decade later, however, it was realized that for discussion of technical aspects, a separate forum would be more appropriate. A group of experts therefore convened the first Targetry Workshop in Heidelberg in 1985. Thereafter it was established as a recurring Workshop, with its scope enlargened to include also nuclear and radiochemical problems. Today, the major conference on Radiopharmaceutical Sciences and the specialist International Workshop on Target-ry and Target Chemistry are held in alternate years. The present Workshop is No. 15 in the series and it is being jointly held by the research groups in Dresden and Prague, both of which have a long tradition of cyclotron production of radionuclides. In this talk, some personal reminiscences and impressions of the historical de-velopments in the field over the last 40 years will be briefly described.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24104号 / 工博第5026号 / 新制||工||1784(附属図書館) / 京都大学大学院工学研究科原子核工学専攻 / (主査)教授 佐々木 隆之, 教授 横峯 健彦, 准教授 小林 大志 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

The Pacific-North America plate boundary in central and southern California has a complex tectonic history, and constraints are poor for inception of an extensional fault system linked to the southern San Andreas fault, a major tectonic element of this plate boundary. Furthermore, decades of research has shown relationships between climate, tectonics, and surface processes in most orogens across the globe (e.g. Alps, Himalaya, Andes, Alaska Ranges), however the role climate plays in modulating erosion and mass fluxes from extensional mountains blocks to sedimentary basins over 104-5 yr timescales is debated. In the eastern California-Walker Lane shear zone, exposures of sedimentary basin fill allow inversion of erosion- and sediment-flux rates from a linked catchment-fan system within an extensional block. In this dissertation, I present two field and geo-thermochronology based studies that explore research topics related by common tectonic setting and geography within the Pacific-North America plate boundary. First I present new low-temperature thermochronology (apatite U-Th-Sm/He) and thermal history modeling to document the kinematic evolution of the Santa Rosa mountains, where the cooling history constrains initiation timing of the west Salton Detachment fault, and the southern San Andreas fault system. I document an age of ca. 8 Ma for exhumation initiation of the Santa Rosa block, from paleodepths of ~4.5–3 km, at vertical rates of ~0.15–0.36 mm/yr, accelerating to ~1.3 km/Ma since ca. 1.2 Ma during initiation of the San Jacinto fault zone. Second, I present a new data set of cosmogenic radionuclide-derived burial ages and paleodenudation rates (26Al/10Be) from the Pleasant Canyon complex in the Panamint Range, and show that denudation rate and sediment flux have varied by a factor of ~2x since the middle Pleistocene. I conclude high frequency variability is driven by climate change, and not tectonic perturbations, as supported by published constraints for exhumation timing. The middle Pleistocene transition from 40–100 ka periodicity may drive the observed changes, a tentative conclusion that makes testable predictions for stratigraphic records of past climate in other locations. Empirical evidence for climate-modulated erosion and sediment flux provides valuable constraints for numerical models of landscape evolution and sedimentary basin architecture. / Ph. D. / Vertical motions along faults produce uplift of mountain blocks, often with steep high topography, which is accompanied by subsidence of adjacent sedimentary basins. Understanding cycles of fault initiation, uplift, and eventual degradation of mountainous fault blocks through erosion is a fundamental goal of the geoscience community, as is inversion of records of past environmental conditions preserved in sedimentary basins. The Pacific-North America plate boundary in California, USA, is composed of several major fault systems that provide an opportunity to study vertical uplift and erosion of mountains, and the sedimentary basins that preserve records of changes in erosion rates through time. In this context, I present a dissertation composed of two original research articles. In Chapter Two, I use thermochronometry in the Santa Rosa Mountains, Coachella Valley, to constrain initiation timing and vertical uplift rates for an extensional fault system called the west Salton detachment fault (WSDF). Localization of the plate boundary in Coachella Valley led to initiation of the WSDF and the southern San Andreas fault system at ca. 8 Myr ago, timing which may reflect a global plate-tectonic driver. Vertical uplift of the Santa Rosa Mountains via the WSDF was moderate during the time between ca. 8–1.2 Myr, then vertical uplift increased four-fold during the initiation of a new strike-slip fault within the southern San Andreas system. In Chapter Two, I use rare isotopes called cosmogenic radionuclides in sediment from basin stratigraphy to constrain the magnitude and variability of erosion in the Pleasant Canyon catchment of the Panamint Mountains since ca. 1.5 Myr ago. The mean erosion rate for Pleasant Canyon is 36 ± 8 mm/kyr, and individual samples vary by up to 2x, indicating erosion rates were not constant through time. The timescales of variability, and evidence from basin stratigraphy suggest that glacial-interglacial climate change produced the observed changes in erosion in this mountain block. This conclusion makes testable predictions for other unglaciated catchments in extensional fault blocks, while evidence of climate-induced changes in sediment fluxes from mountains to basins has potential implications to recovering information about past climate change from stratigraphy.