Graphitization of Small Carbonate Samples for Paleoceanographic Research at the Godwin Radiocarbon Laboratory, University of Cambridge

A new radiocarbon preparation facility was set up in 2010 at the Godwin Laboratory for Palaeoclimate Research, at the University of Cambridge. Samples are graphitized via hydrogen reduction on an iron powder catalyst before being sent to the Chrono Centre, Belfast, or the Australian National University for accelerator mass spectrometry (AMS) analysis. The experimental setup and procedure have recently been developed to investigate the potential for running small samples of foraminiferal carbonate. By analyzing background values of samples ranging from 0.04 to 0.6 mg C along with similar sized secondary standards, the setup and experimental procedures were optimized for small samples. “Background” modern 14C contamination has been minimized through careful selection of iron powder, and graphitization has been optimized through the use of “small volume” reactors, allowing samples containing as little as 0.08 mg C to be graphitized and accurately dated. Graphitization efficiency/fractionation is found not to be the main limitation on the analysis of samples smaller than 0.07 mg C, which rather depends primarily on AMS ion beam optics, suggesting further improvements in small sample analysis might yet be achieved with our methodology.

Songs of ourselves : the University of Cambridge International Examinations anthology of poetry in english.

Antología de poesías pertenecientes a cien poetas de todo el mundo de habla inglesa. Es una introducción a una gran variedad de formas, estilos y contenidos de versos de los últimos cuatro siglos, desde el siglo XVI hasta la actualidad. Su contenido se adapta al estudio del CIE, IGCSE y al programa de estudios del nivel AS y nivel avanzado de literatura en inglés.

Stories of ourselves : the University of Cambridge International Examinations anthology of stories in english.

Antología de relatos de escritores de diferentes países y culturas, como Charles Dickens, H.G. Wells, Virginia Woolf, Graham Greene, V.S. Naipaul, Raymond Carver, Jhumpa Lahiri y Annie Proulx. Su contenido se adapta al estudio del CIE, IGCSE y a los exámenes del nivel AS y nivel A de literatura en inglés.