Biogenic silica and silicic acid benthic fluxes of a North-eastern Atlantic Abyssal Locality

Within the framework of the EU-funded BENGAL programme, the effects of seasonality on biogenic silica early diagenesis have been studied at the Porcupine Abyssal Plain (PAP), an abyssal locality located in the northeast Atlantic Ocean. Nine cruises were carried out between August 1996 and August 1998. Silicic acid (DSi) increased downward from 46.2 to 213 µM (mean of 27 profiles). Biogenic silica (BSi) decreased from ca. 2% near the sediment-water interface to <1% at depth. Benthic silicic acid fluxes as measured from benthic chambers were close to those estimated from non-linear DSi porewater gradients. Some 90% of the dissolution occurred within the top 5.5 cm of the sediment column, rather than at the sediment-water interface and the annual DSi efflux was close to 0.057 mol Si/m**2/yr. Biogenic silica accumulation was close to 0.008 mol Si/m**2/yr and the annual opal delivery reconstructed from sedimentary fluxes, assuming steady state, was 0.065 mol Si/m**2/yr. This is in good agreement with the mean annual opal flux determined from sediment trap samples, averaged over the last decade (0.062 mol Si/m**2/yr). Thus ca. 12% of the opal flux delivered to the seafloor get preserved in the sediments. A simple comparison between the sedimentation rate and the dissolution rate in the uppermost 5.5 cm of the sediment column suggests that there should be no accumulation of opal in PAP sediments. However, by combining the BENGAL high sampling frequency with our experimental results on BSi dissolution, we conclude that non-steady state processes associated with the seasonal deposition of fresh biogenic particles may well play a fundamental role in the preservation of BSi in these sediments. This comes about though the way seasonal variability affects the quality of the biogenic matter reaching the seafloor. Hence it influences the intrinsic dissolution properties of the opal at the seafloor and also the part played by non-local mixing events by ensuring the rapid transport of BSi particles deep into the sediment to where saturation is reached.

ACE research vignette 021 : does the use of “bricolage” make start-ups more innovative?

This series of research vignettes is aimed at sharing current and interesting research findings from our team of international Entrepreneurship researchers. In this vignette, Professor Per Davidsson and Associate Professor Paul Steffens consider the links between entrepreneurial “bricolage” and innovation.

Teología, 1972/73, Tomo X nº 021-022 (número completo)

1962-1972 / La Dirección -- La Teología al servicio de la Palabra de Dios / Carmelo Giaquinta -- El “Padre Nuestro” en el Evangelio según san Mateo / Luis H. Rivas -- La liberación. Aspectos bíblicos: evaluación crítica / José Mejía -- Matrimonio y sacerdocio: sacramento, fidelidad, castidad / Eduardo Briancesco -- Palabras y gestos en la Reconciliación sacramental / Luis Alessio -- El matrimonio en los Sínodos del Obispo Trejo / José M. Arancibia -- Propiedad de los medios de producción y pensamiento social de la Iglesia / Carmelo Giaquinta -- Reflexiones acerca de la pastoral popular desde el interior de un santuario / Guillermo Rodríguez Melgarejo -- Algunos principios para una teología de la pastoral popular / Ernesto Mai -- Nota bibliográficas -- Libros recibidos -- Crónica de la Facultad -- Índice del Tomo X

Diário da Constituinte [gravação de vídeo] : [programa n. 021]

O Congresso Nacional recebe visita de crianças, que trouxeram propostas aos Constituintes. Ulysses Guimarães, como Presidente da Assembleia Nacional Constituinte (ANC), fala em defesa das crianças e afirma que elas terão papel de destaque nesta Constituição. As Subcomissões de Educação, Cultura e Esporte; e da Ciência, Tecnologia e da Comunicação tratam a questão das verbas para a educação. O constituinte João Calmon (PMDB-ES) defende maiores recursos para a Educação com o maior percentual de arrecadação possível. A Subcomissão da Questão Urbana e Transporte busca definir a jurisdição dos municípios em relação aos transportes urbanos e a urbanização das cidades. A Subcomissão dos Direitos dos Trabalhadores e Servidores Públicos refere-se ao problema da Lei de Greve dos trabalhadores. O constituinte Geraldo Campos (PMDB-DF), relator da Subcomissão afirma que a Lei de Greve é problema para ser resolvido na Assembleia Constituinte, não no Executivo.

Final report on an inventory of flowing artesian wells in Florida: leading to the enforcement of sections 373.021 - 373.061 Florida Statutes 1957

This report published as Information Circular No. 21, together with the interim report published in 1957 as Information Circular No. 10, Florida Geological Survey, illustrates as completely as possible the situation that now exists among the freely flowing wells of the State. (PDF contains 40 pages.)

Orçamento de 2013 : contingenciamento de despesas do Executivo : Decreto nº 8.021 (29/05) : Portaria MP 207 (31/05)

Seguem-se observações preliminares sobre o contingenciamento de 2013, baseadas na 1ª Avaliação de receitas e despesas, anunciada somente em 22 de maio por conta da sanção tardia do orçamento; nos limites de pagamento e de movimentação e empenho das dotações do Executivo do Decreto 8.021/13, de 29 de maio, e da Portaria Ministério do Planejamento 207, de 31 de maio, assim como nas previsões constantes da proposta e da Lei aprovada.

Resolución No. 021: Por la cual se decide un recurso de reposición y en subsidio de apelación

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