Time filter

Source Type

South Kensington, United Kingdom

Rosi F.,University of Perugia | Manuali V.,University of Perugia | Grygar T.,Academy of Sciences of the Czech Republic | Bezdicka P.,Academy of Sciences of the Czech Republic | And 7 more authors.
Journal of Raman Spectroscopy | Year: 2011

The effectiveness of Raman spectroscopy (using a bench-top system on standard pigments) for the characterisation of modified lead antimonate yellows was demonstrated in the already published Part I. The knowledge gained is employed here for the study of yellow glazes on genuine Renaissance plates with the aim of identifying non-invasively lead pyroantimonate compounds by portable micro-Raman equipment. The investigation was carried out directly on site, at the Victoria and Albert Museum (London, UK) and at the Museo Statale d'Arte Medievale di Arezzo (Arezzo, Italy), combining Raman and X-ray fluorescence analyses. In addition to the spectral features of both unmodified Naples yellow and Sn- and Zn-modified lead antimonate compounds, the Raman patterns related to partially modified pyrochlore structures were observed. For this reason, the possible Sn-induced modification of Naples yellow by cassiterite (SnO 2), present within the glaze as opacifier was explored on lead antimonate yellow glaze mock-ups fired at different temperatures. © 2010 John Wiley & Sons, Ltd.

Ellis M.V.,Science Section
Australian Zoologist | Year: 2016

Nest boxes have been widely used across the world to provide shelter for animal species, often to restore areas following the loss of natural tree hollows. While the microclimates of installed nest boxes have been studied, limited attention has been paid to whether microclimate is influenced by nest box size, shape and entrance dimensions. In this study the temperature and humidity patterns were recorded within six nest box designs that were exposed to direct sunshine.AII were constructed of 19 mm plywood but varied in length by a factor of 2X, in volume by 3.5X and in entrance areas by 5X. All next boxes behaved the same thermally, closely following ambient during the night, but during the day they heated to 5 °C warmer than ambient by mid-afternoon. Fluctuations in humidity varied, with small nest boxes with large entrances being closer to ambient humidity than those with small entrances or large volumes. Overall, nest box size and shape had no detectable influence on the internal temperature fluctuations, but did to a slight extent on humidity patterns. Construction material and nest box placement are the likely drivers of the temperature and humidity patterns within nest boxes, and need to be the focus of efforts to keep nest boxes habitable when deployed, and designs should be selected on the basis of the target animal's preferences for size and shape.

Burgio L.,Science Section | Burgio L.,University College London | Cesaratto A.,University of Parma | Derbyshire A.,Paper Conservation Section
Journal of Raman Spectroscopy | Year: 2012

Eighteen English portrait miniatures from the Victoria and Albert Museum collection were analysed using Raman microscopy and optical microscopy. Most had been attributed to well-known artists such as Levina Teerlinc, Nicholas Hilliard and Isaac Oliver, but there were some of uncertain attribution. Each miniature was examined in detail in order to characterise the palette used by the artists, paying attention not only to the identity of the materials but also to the shape, size and distribution of the pigment particles. The different mixtures used in various areas, such as the carnation, used for the skin tones, lips and dark physiognomic detail helped the authors to distinguish between different miniaturists. This approach, associated with conservation, curatorial and art historical expertise, was used to suggest an attribution for three miniatures where previously the artist was uncertain or disputed. This type of analysis should be extended to a larger number of miniatures from the same period and geographical provenance in order to build up a stronger database and reach a statistically significant sample size. © 2012 Victoria and Albert Museum.

Kogou S.,Nottingham Trent University | Lucian A.,Nottingham Trent University | Bellesia S.,Science Section | Burgio L.,Science Section | And 3 more authors.
Applied Physics A: Materials Science and Processing | Year: 2015

A holistic approach using non-invasive multimodal imaging and spectroscopic techniques to study the materials (pigments, drawing materials and paper) and painting techniques of watercolour paintings is presented. The non-invasive imaging and spectroscopic techniques include VIS–NIR reflectance spectroscopy and multispectral imaging, micro-Raman spectroscopy, X-ray fluorescence spectroscopy (XRF) and optical coherence tomography (OCT). The three spectroscopic techniques complement each other in pigment identification. Multispectral imaging (near-infrared bands), OCT and micro-Raman complement each other in the visualisation and identification of the drawing material. OCT probes the micro-structure and light scattering properties of the substrate, while XRF detects the elemental composition that indicates the sizing methods and the filler content. The multiple techniques were applied in a study of forty-six nineteenth-century Chinese export watercolours from the Victoria and Albert Museum (V&A) and the Royal Horticultural Society (RHS) to examine to what extent the non-invasive analysis techniques employed complement each other and how much useful information about the paintings can be extracted to address art conservation and history questions. A micro-destructive technique of micro-fade spectrometry was used to assess the vulnerability of the paintings to light exposure. Most of the paint and paper substrates were found to be more stable than ISO Blue Wool 3. The palette was found to be composed of mostly traditional Chinese pigments. While the synthetic pigment, Prussian blue, made in Europe, was found on some of the paintings, none was found on the RHS paintings accurately recorded as being between 1817 and 1831 even though it is known that Prussian blue was imported to China during this period. The scale insect dyes, lac and cochineal, were detected on nearly every painting including those that fall within the identified date range. Cochineal is known to have been imported to China in the same period. While carbon-based ink was used for the drawings in the V&A paintings, graphite pencil was used in most of the RHS paintings. The majority of RHS paintings were on Western papers, but nearly all of the V&A paintings were on Chinese papers. Nearly all of the V&A painting substrates and hardly any of the RHS paintings were sized with alum. Elements such as Cu, Zn, Ti and Pb were detected on nearly all of the RHS papers regardless of whether they were Chinese or Western papers. These elements were largely absent from the V&A papers. The differences between the two collections reflect their discrete origins and intended purposes. © 2015 Springer-Verlag Berlin Heidelberg

A five-member team of researchers from the U.S. Naval Research Laboratory (NRL) Center for Corrosion Science and Engineering received the Office of Naval Research (ONR) Prize for Affordability, Aug. 26, at an award ceremony held at ONR in Alexandria, Va. The award honors materials research engineers James Martin, head of the Marine Coatings Science Section, Jimmy Tagert, and John Wegand; research chemist, Dr. Erick Iezzi; and physical scientist technician, Paul Slebodnick for significant contributions to an overall reduction in the total ownership costs associated with corrosion control of Navy ships and submarines and achievements in the development and transition of nonskid and topside coatings to the fleet. The team formulated, synthesized, and commercialized topside and nonskid coatings having longer life, high durability, improved weathering resistance and color stability, to replace both legacy nonskid decking and topside coatings. The Navy installs nearly 3.7 million square feet of non-skid coatings per year that typically cost over $56 million annually. Conventional epoxy based nonskids have a 12 to 36 month lifecycle, while topside coatings have a 24 to 36 month life. The new NRL-developed polysiloxane system doubles or triples the life expectancy of this system. For topside coatings, not only are lifetimes increased, but also installation costs are reduced by up to 28 percent through the reduced number of coats over conventional systems. As a result, polysiloxane coatings systems have been qualified and approved for use by Naval Sea Systems Command (NAVSEA) and have been mandated for all topside depot level maintenance availabilities. The NRL polysiloxane nonskid decking system is planned for qualification in 2015. At present, the nonskid coatings system has exceeded the one-year flight deck requirement on-board the USS Theodore Roosevelt (CVN 71), has outperformed all previous nonskids on-board the USS Michigan (SSGN 727), and is still performing well on-board the USS Bulkeley (DDG 84). On Navy submarines, this system is the only system ever to pass the submarine nonskid requirements. The Center for Corrosion Science and Engineering (CCSE) conducts broad scientific and engineering programs to understand and reduce the effects of the marine environment on naval systems. Within the CCSE, the Marine Coatings Science Section conducts basic and applied research to synthesize and produce advanced, multi-functional marine coatings technology for all naval environments including immersion, alternate immersion and atmospheric exposures typical of Navy and Marine Corps platforms. About the U.S. Naval Research Laboratory The U.S. Naval Research Laboratory provides the advanced scientific capabilities required to bolster our country's position of global naval leadership. The Laboratory, with a total complement of approximately 2,500 personnel, is located in southwest Washington, D.C., with other major sites at the Stennis Space Center, Miss., and Monterey, Calif. NRL has served the Navy and the nation for over 90 years and continues to advance research further than you can imagine. For more information, visit the NRL website or join the conversation on Twitter, Facebook, and YouTube.

Discover hidden collaborations