38,182 research outputs found
Sampling problems in the radiocarbon dating of old mortars and plasters with the "pure lime lumps" technique.
No full textSeveral scientific papers describe the radiocarbon dating of lime mortars and plasters [Folk and Valastro, 1976; Van Strydonck et al., 1992; Hale et al., 2003; Nawrocka et al., 2005] carried out using the 14C dating contained in the calcium carbonate precipitated during the hardening process of lime. As the content of 14C contained in the newly formed calcium carbonate reflects the 14C concentration in the atmosphere at the time of hardening, this material can be used for the radiocarbon dating of old mortars and plasters. Although the method is quite simple in its basis principle, relevant issues come from the contamination problems with other carbon sources. Grains of carbonate sand or underburned pieces of the same limestone used to produce the lime, that are originally mixed with the binder cannot be, in fact, completely removed from the mixtures. These materials do not contain radioactive carbon but behave as the carbonated lime during the analyses.
For overcoming this problem, over the past years, new techniques for the sample preparation have been developed and among these techniques, the so called “pure lime lumps” represents a fast and reliable method. The technique is based on the use of lumps of pure lime, very often embedded in old lime based mixtures as material for the radiocarbon dating. Because these lumps are made of pure lime any contamination problem is avoided. However, despite the remarkable results already achieved with this technique [Pesce et al., 2009; Pesce et al., 2012; Pesce et al., 2013], the sample collection is still a very important issue for a successful application of the radiocarbon dating.
This contribute describes the main sampling problems faced during a research on the accuracy and precision of the "pure lime lumps" technique, founded by the University of Genoa2 and carried out together by the University of Genoa and the and CEDAD in Italy and the University of Bath in United Kingdom
New localities of Elaphoidella nuragica Pesce & Galassi, with a description of the female (Copepoda Harpacticoida: Canthocamptidae).
No full textFrazione lipidica di uova di pesce. Nota I: semiconserve.
No full textSono state analizzate le frazioni lipidiche di semi-conserve di uova di pesce di uso alimentare. In particolare si sono utilizzati campioni commerciali e artigianali di bottarga di muggine, tonno e molva (prodotti essicati) e campioni commerciali di caviale, uova di lompo, capelan e salmone (in salamoia)....
Un nuovo Diacyclops del gruppo "languidoides" di acque freatiche dl Lazio: Diacyclops cristinae n. sp.(Crustacea Copapoda: Cyclopidae).
No full textThe genus Neocyclops Gurney in the West Indies: an update including the description of Neocyclops (Protoneocyclops) geltrudae n. sp. (Crustacea, Copepoda, Cyclopidae).
No full textUna nuova Attheyella di acque sotterranee italiane: Attheyella (Brehemiella) paranaphtalica n.sp. (Crustacea Copepoda: Canthocamptidae).
No full textFirst record of the family Microparasellidae in Turkey, and description of two new species of the genus Microcharon Karaman (Crustacea Isopoda: Janiroidea).
No full textStandardization and Quality Assessment Under the Perspective of Automated Computer-Assisted HEp-2 Immunofluorescence Assay Systems
No full textThe recent availability of automated computer-assisted diagnosis (CAD) systems for the reading and interpretation of the anti-nuclear antibody (ANA) test performed with the indirect immunofluorescence (IIF) method on HEp-2 cells, has improved the reproducibility of the results and initiated a process of harmonization of this test. Furthermore, CAD systems provide quantitative expression of fluorescence intensity, allowing the introduction of objective quality control procedures to the monitoring of the entire process. The calibration of the reading systems and the automated image interpretation are essential prerequisites for obtaining reproducible and harmonized IIF test results and form the basis for standardization, regardless of the computer algorithms used in the different systems. The use of automated CAD systems, facilitating control procedures, represents a step forward for the quality certification of the laboratory
Elaphoidella plesai n.sp., from ground waters of Austria (Copepoda Harpacticoida: Canthocamptidae). Annls Limnol., 30 (2): 91-94
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