37,125 research outputs found

    Slavnov-Taylor identities for noncommutative QED4_4

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    In this work we present an analysis of the one-loop Slavnov-Taylor identities in noncommutative QED4_4. The vectorial fermion-photon and the triple photon vertex functions were studied, with the conclusion that no anomalies arise.Comment: 24 pages, revtex4, v2: typos correcte

    Thorium content in soil, water and sediment samples and fluvial sediment-associated transport in a catchment system with a semi-arid interface, Brazil

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    Thorium (Th) is one of the main sources of natural radiation to ecosystems. However, data regarding Th concentrations in rocks, soil, water and sediments are currently scarce. Accordingly, this study aimed to establish background concentrations and quality reference values (QRVs) for Th in the environmentally impacted Ipojuca River catchment in Brazil, where the weathering of granites releases Th into the environment. Additionally, the study aimed to calculate Th fluxes in water, and both bed and suspended sediment. The mean Th concentration in the study catchment soils was 28.6 mg kg−1. The QRV for Th was estimated to be 21 mg kg−1 and 86.3 Bq kg−1. Bed and suspended sediment–associated concentrations ranged from 2.8 to 32.9 mg kg−1. Suspended sediment–associated discharge (3.42 t year−1) accounted for more than 99% of the total Th flux, while the dissolved phase transport was negligible in comparison. At the downstream cross section in the study catchment, suspended sediment samples exhibited Th concentrations similar to those observed in rivers impacted by mining activities. The discharge of sediment to the ocean from the study area is mainly triggered by soil erosion processes in the hotspot region (middle-inferior course). It is essential to identify Th hotspots before establishing environmental policies regarding human health and environmental protection

    Efeito de antídotos na atividade das cloroacetanilidas sobre as plantas de sorgo (Sorghum bicolor (L.) Moench.

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    Foram conduzidos dois experimentos, no ano agricola 1983/84, objetivando estudar a eficiencia dos antidotos CGA 92194 CGA 43089 sobre a tolerancia dos cultivares de sorgo BR 300 (granifero) e BR 501 (sacarino) as cloroacetanilidas e ao atrazine, bem como os respectivos efeitos desses herbicidas sobre a s plantas daninhas. O solo do local escolhido para a instalacao dos ensaios, em 1983/84, foi um Latossolo Vermelho-Escuro, fase cerrado, com textura argilosa e materia organica entre 2,57 e 2,90%. O delineamento experimental foi em blocos ao acaso, em esquema fatorial completo, com quatro repeticoes. Os tratamentos foram: atrazine a 1,5 kg/ha, aplicado isoladamente e em mistura com metolachlor, alachlor, acetochlor e propachlor, com e sem antidoto, mais uma testemunha, sem herbicida, capinada e sem capina. Os antidotos foram aplicados na forma de tratamento de sementes. As caracteristicas avaliadas foram: stand, inicial e final, altura de plantas, numero de paniculas, peso de paniculas, producao de graos, densidade de plantas daninhas e peso da materia seca da parte aerea aos 34 e 64 dias apos a aplicacao dos produtos. Para o sorgo sacarino, alem dessas caracteristicas, avaliaram-se ainda o peso da massa verde total da parte aerea, o peso total dos colmos despalhados, o diametro do colmo despalhado, a percentagem de caldo extraido, acucares redutores, acucares redutores totais, sacarose total sacarose e brix, determinados segundo metodo proprio do CNPMS, Sete Lagoas, MG

    Populações de plantas e adubação orgânica em solo degradado na cultura do amendoim

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    Avaliação Bioeconômica de Antiparasitários Fitoterápicos e Homeopáticos em Bovinos de Corte.

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