1,944 research outputs found
Combinatorial synthesis and screening of chalcogenide materials for data storage
No full textFor more than 15 years researchers at the Optoelectronics Research Centre at the University of Southampton have been developing novel compositions of chalcogenide glasses for a wide range of optical applications. Recently this expertise has been combined with those of Ilika Technologies Ltd and the School of Chemistry to focus on the development of enhanced chalcogenide materials for OUM and optical data storage applications. In our talk, we report on our high throughput methodology which allows rapid, reproducible and comprehensive mapping of phase diagrams and screening of optical, thermal and electrical properties. These procedures were initially applied to Ge:Sb:Te compositions where we were able to synthesis and analyse over 4000 sample points spanning the entire ternary system. In order to process such large volumes of compositions, novel screening techniques and strategies have been employed. We are applying this methodology to other novel compositions and our findings are reported
High throughput synthesis and screening of chalcogenide materials for data storage
No full textThe ability to store information through the phase change mechanism is a well established technology for optical data storage, with typically germanium antimony telluride based films forming the active layer of a phase change disc. However, the ever increasing need for greater storage densities, shorter write/erase, duration and longer archival time is driving interest beyond these established materials. A new thin high throughput thin film deposition method provides a well controlled route to the synthesis of a wide range of chalcogenide compositions through simultaneous deposition of the component elements. When combined with fast primary and secondary screening techniques, the amorphous / crystalline phase transition can be characterised across the ternary compositional space. When combined with a full high throughput characterisation of the phases using EDX and XRD, conductivity measurements and ellipsometric characterisation of the optical properties, a better understanding of the desired phenomena for phase change memory applications is accessible. Results of a high throughput study of the GeSbTe system are presented
Material optimisation for optical data storage
No full textHigh throughput synthesis and screening methodologies of optical data storage materials have allowed an in depth study of more than 4000 compositions. We report on the optical and electrical compositional dependence of these materials
Germanium antimony sulphide nano-wires fabricated by chemical vapour deposition and e-beam lithography
No full textGermanium antimony sulphide (Ge-Sb-S) amorphous thin films have been deposited directly onto SiO-on-silicon substrates by means of chemical vapour deposition. The Ge-Sb-S films have been characterized by micro-Raman, scanning electron microscopy, energy dispersive X-ray analysis and static tester techniques. Ge-Sb-S nano wires have been patterned and fabricated by e-beam lithography and dry etching techniques. Modeling results show the potential for fast switching of these Ge-Sb-S nano wire structures, making it a possible candidate for the phase change memory applications
Temperature-driven phenological changes within a marine larval fish assemblage
No full textMost marine teleosts have a pelagic phase during their early life history, but few studies have investigated how the timing of events within the planktonic larval fish assemblage is related to environmental variability. We examined this issue using a data series of 534 larval fish samples collected between 1975 and 1987 in the Western English Channel, near Plymouth, UK. Two sets of species were identified: spring spawning (April to July) and summer spawning (July to September). The timing of appearance of the spring-spawning group in the plankton was significantly dependent on sea temperatures the previous November and December, with earlier appearance during cooler years. We suggest that this could be due to colder years triggering earlier winter migration of adults from cool inshore habitat to warmer offshore overwintering grounds, which in turn results in earlier gonad maturation and spawning. In contrast, the timing of appearance of the summer-spawning group was significantly dependent on sea temperatures the preceding March, with earlier spawning during warmer years. This may be due exclusively to more rapid gonad maturation in offshore waters. These data emphasize that marine fish populations do not always respond uniformly to temperature change. Moreover, since appropriate timing of larval fish appearance in the plankton may be critical for the match or mismatch with essential trophic resources, the thermally induced phenological changes identified have potential to influence annual recruitment success
Poe's biopics : representations of the author in D.W. Griffith's Edgar Allen Poe and James Mcteigue's The raven
No full textLiterary biopics often reinforce romantic images regarding the creative process, emphasizing biographic and author-centered approaches to literature previously denounced by Roland Barthes (1977). Curiously, one of the most famous critics of such romantic conceptions, Edgar Allan Poe, has himself been a victim of this very same treatment, his literary production being taken as part and result of his controversial biography in a number of works. This article analyzes two biographical films, or biopics, about the renowned poet, D.W. Griffith’s Edgar Allen Poe (sic) (1909) and James McTeigue’s The Raven (2012). The analysis of these works indicates that both reinforce the merge of the artist’s life and oeuvre, as well as the blurring of borders between fact and fiction, author and character, high and mass culture, thus contributing to the characterization of the biopic as a fitting example of historiographic metafiction. (Hutcheon, 1988).Cinebiografias literárias frequentemente reforçam visões românticas quanto ao fazer artístico, reiterando a visão biografista e a centralidade do autor há muito denunciadas por Roland Barthes (1977). Curiosamente, um dos mais célebres críticos de tais concepções românticas, Edgar Allan Poe, viu-se vítima desse mesmo tratamento ao ter sua produção literária apropriada como parte e reflexo de sua controversa biografia em diversas obras. O presente artigo debruça-se sobre dois filmes biográficos, ou biopics, acerca do célebre poeta, Edgar Allen Poe (sic), de D.W. Griffith (1909), e O Corvo, de James McTeigue (2012). A análise das obras aponta que ambas reiteram a fusão entre vida e obrado artista, bem como o apagamento das fronteiras entre fato histórico e ficção, entre autor e personagem, alta cultura e cultura de massa, contribuindo para a caracterização do gênero biopic como um dos mais bem-acabados exemplos de metaficção historiográfica (Hutcheon, 1988)
Electrical phase change of Ga:La:S:Cu films
No full textGa:La:S:Cu films have been prepared by sputter deposition. Amorphous thin films were fabricated with Cu concentrations as high as 66 at.%. The electrical phase change properties of these films have been investigated. The electrical resistivity of these materials is 200 µm in the amorphous state and 40 µm in the crystalline state. The crystallisation time was measured using an optical pump probe method and confirmed to be 150 ns. The high resistivity of these films in both their crystalline and amorphous states allows low current, Joule, heating and therefore shows potential for the utilisation as the active layer in electrical phase change memory devices
Author Correction:A cattle graph genome incorporating global breed diversity
No full textThe original version of this Article omitted from the author list the 12th and 13th authors Dennis Muhanguzi and Wilson Amanyire, who are from the ‘School of Biosecurity, Biotechnology and Laboratory Sciences (SBLS), College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O Box 7062, Kampala, Uganda’. Consequently, the final sentence of the Author Contributions incorrectly read ‘D.W., P.T., E.A.J.C., C.E., E.T.O., E.R.A., A. Tijjani, K.M., A.F., B.R.F., A.Q., U.C. and P.W. provided samples and expertise for the studies’. This has been replaced with ‘D.W., P.T., W.A., D.M., E.A.J.C., C.E., E.T.O., E.R.A., A. Tijjani, K.M., A.F., B.R.F., A.Q., U.C. and P.W. provided samples and expertise for the studies’. This has been corrected in both the PDF and HTML versions of the Article
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
No full textIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
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