Radioactive Lead
Mostrando 1-12 de 29 artigos, teses e dissertações.
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1. Estudo sobre a identificação de hádrons em câmaras de fotoemulsão / Study about hadron identification in emulsion chambers
This work introduces the importance of photoemulsion chambers that remain in use after decades and still offer many advantages for elementary particle physics. We cite OPERA (Oscillation Project with Emulsion-tRacking Apparatus) detector that is the greatest lead photoemulsion chamber detector ever constructed as an example of its application nowadays (nine
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/04/2012
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2. Utilização de líquens como bioindicadores de contaminação atmosférica por radionuclídeos naturais e metais em região impactada por TENORM / The use of lichens as bioindicators of atmospheric contamination by natural radionuclides and metals in a region impacted by TENORM
The main aim of this thesis is to study the possibility of using lichen as bioincicator of atmospheric pollution in regions contaminated by radionuclides, metals and rare earth elements. Two regions were chosen, one in Pirapora do Bom Jesus, where a tin and lead industry is located, and a second one in Cubatão, where a phosphate fertilizer industrial comple
Publicado em: 2010
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3. Espalhamento de Férmions sob Influencia da Violação de Lorentz no Setor Fotônico / Scattering of Fermions under Influence of Violation Lorentz Sector Photonic
The standard model extension is a theoretical framework which includes the possibility of Lorentz symmetry violation in the Standard Model of elementary interactions. In electrodynamics, this possibility is represented by the term, KμFμF, that violates Lorentz symmetry without jeopardizing CPT symmetry, and the term "μvAμ@A, which violate
Publicado em: 2010
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4. Estudo de metais e de substâncias tóxicas em brinquedos
The main goal of the present study is the analysis of toxic elements in plastic toys commercialized in Brazil. Metals like cadmium, lead, chromium, zinc, and aluminum, along with organic substances, such as phthalates, were identified in different toys by quantitative analytical techniques. Traces of thorium were detected in one of the studied samples. Altho
Química Nova. Publicado em: 2009
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5. InfluÃncia do posicionamento da paciente na modificaÃÃo da dose em ÃrgÃos crÃticos na braquiterapia de alta taxa de dose em cÃncer de colo uterino
High dose rate brachytherapy is a medical procedure which uses radioisotopes with dose rate over 0.2 Gy/min. This kind of treatment is commonly used on uterine cancer in more advanced stages of the disease. The brachytherapy of high dose have substituted the low dose rate modality because it is a treatment performed at clinic and without the need for anaesth
Publicado em: 2008
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6. Influencia do metimazol na distribuicao dos radionuclideos 131I E 99m Tc em ratos / Influence of methimazole in distribution of radionuclides131I E 99m Tc in laboratorial rats
Radionuclides, such as 99mTc and 131I, being administered as radiopharmaceuticals have been used in Nuclear Medicine to diagnose and treat many diseases in humans. Syntheticâs drugs as methymazole are used in treatment of hiperthyroidism so as to reduces hormones before the radioactive treatment. Interaction between medicines and radionuclides can modify ra
Publicado em: 2007
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7. "Um estudo sobre o desequilíbrio radioativo da série do urânio em amostras de solo" / A study on radioactive disequilibrium of the uranium series in soil samples.
The specific activities of 238U , 226Ra, 210Pb, 232Th and 40K were measured, and the 226Ra/238U and 210Pb/226Ra activity ratios were calculated for samples collected in a 2.10 m deep soil profile in a preserved area of the São Paulo Botanic Garden. The sampling site is covered by dense vegetation that, together with the upper soil layer, has not been distur
Publicado em: 2006
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8. Óxidos de ferro e monazita de areias de praias do Espírito Santo
Sand samples collected from two sampling sites on Guarapari and Iriri beaches, state of Espírito Santo, Brazil, were studied in an attempt to better describe their chemical and mineralogical compositions and radioactive behaviors. The sands were found to contain about 6 (Guarapari) and 2 dag kg-1 (Iriri) of rare earth and thorium that, if allocated to the m
Química Nova. Publicado em: 2005-03
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9. Pathways of Propionate Degradation by Enriched Methanogenic Cultures
A mixed methanogenic culture was highly enriched in a growth medium containing propionate as the sole organic carbon and energy source. With this culture, the pathways of propionate degradation were studied by use of 14C-radiotracers. Propionate was first metabolized to acetate, carbon dioxide, and hydrogen by nonmethanogenic organisms. Formate was not excre
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10. Suppression of DNA Synthesis in Hepatoma Cells Exposed to Glucocorticoid Hormone In Vitro
Glucocorticoid hormone is shown to markedly suppress DNA synthesis in a line of rat hepatoma cells in vitro. In the presence of 300 nM hydrocortisone or 30 nM dexamethasone the incorporation of radioactive thymidine falls to 50% of control levels by 36 hr, and at higher concentrations of hormone inhibition can be noted as early as 12 hr and is nearly complet
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11. In Vivo Effect of Thiolutin on Cell Growth and Macromolecular Synthesis in Escherichia coli
Thiolutin reversibly inhibits growth and ribonucleic acid synthesis in Saccharomyces cerevisiae. It is now demonstrated that, at 5 μg/ml, thiolutin rapidly inhibits all incorporation of radioactive precursors into ribonucleic acid and protein in Escherichia coli, although the incorporation of deoxythymidine into deoxyribonucleic acid continues for some time
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12. The assessment of doses and effects from intakes of radioactive particles.
The behaviour of radionuclides after entry into the body and the radiation doses received by individual tissues depend on the chemical nature of the element, the physicochemical form of the intake, the radioactive half-life of the isotope and the type and energy of the emissions. Ingestion of radionuclides in insoluble particles will result in radiation dose