26 resultados para Tin diselenide
em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain
Resumo:
A study of tin deposits from Priamurye (Russia) is performed to analyze the differencesbetween them based on their origin and also on commercial criteria. A particularanalysis based on their vertical zonality is also given for samples from Solnechnoedeposit. All the statistical analysis are made on the subcomposition formed by seventrace elements in cassiterite (In, Sc, Be, W, Nb, Ti and V) using the Aitchison’methodology of analysis of compositional data
Resumo:
A problem in the archaeometric classification of Catalan Renaissance pottery is the fact, thatthe clay supply of the pottery workshops was centrally organized by guilds, and thereforeusually all potters of a single production centre produced chemically similar ceramics.However, analysing the glazes of the ware usually a large number of inclusions in the glaze isfound, which reveal technological differences between single workshops. These inclusionshave been used by the potters in order to opacify the transparent glaze and to achieve a whitebackground for further decoration.In order to distinguish different technological preparation procedures of the single workshops,at a Scanning Electron Microscope the chemical composition of those inclusions as well astheir size in the two-dimensional cut is recorded. Based on the latter, a frequency distributionof the apparent diameters is estimated for each sample and type of inclusion.Following an approach by S.D. Wicksell (1925), it is principally possible to transform thedistributions of the apparent 2D-diameters back to those of the true three-dimensional bodies.The applicability of this approach and its practical problems are examined using differentways of kernel density estimation and Monte-Carlo tests of the methodology. Finally, it istested in how far the obtained frequency distributions can be used to classify the pottery
Resumo:
Tin-oxide nanoparticles with controlled narrow size distributions are synthesized while physically encapsulated inside silica mesoporous templates. By means of ultraviolet-visible spectroscopy, a redshift of the optical absorbance edge is observed. Photoluminescence measurements corroborate the existence of an optical transition at 3.2 eV. The associated band of states in the semiconductor gap is present even on template-synthesized nanopowders calcined at 800°C, which contrasts with the evolution of the gap states measured on materials obtained by other methods. The gap states are thus considered to be surface localized, disappearing with surface faceting or being hidden by the surface-to-bulk ratio decrease.
Resumo:
Low-cost tin oxide gas sensors are inherently nonspecific. In addition, they have several undesirable characteristics such as slow response, nonlinearities, and long-term drifts. This paper shows that the combination of a gas-sensor array together with self-organizing maps (SOM's) permit success in gas classification problems. The system is able to determine the gas present in an atmosphere with error rates lower than 3%. Correction of the sensor's drift with an adaptive SOM has also been investigated
Resumo:
The aim of this article is to show which are the dramatic "yields" of the inclusion of the reference to the goddess Diana in Tennessee Williams's Cat on a Hot tin Roof. In the author's opinion, it does not deal simply with a meaningful reference; on the contrary, the accurate analysis of Williams's text proves that it is a true nuclear and cohesive element of the whole drama.
Resumo:
Dado que el referente clásico "Edipo en busca de su identidad" ha sido siempre reconocido para Suddenly Last Summer , el autor de este artículo, mediante un análisis minucioso del texto del dramaturgo americano, propone leer en este caso Cat on a Hot Tin Roof desde el modelo Edipo Rey de Sófocles y descubrir en él igualmente la tradicional ironía clásica tanto desde el punto de vista del espectador como de los mismos personajes principales, Brick y su padre, ambos en busca de su verdad, una verdad, claro está, contraria a la esperada.
Resumo:
Atès que el referent clàssic "Èdip en cerca de la seva identitat" ha estat sempre reconegut per a Suddenly Last Summer, l'autor d'aquest article, mitjançant una anàlisi acurada del text del dramaturg americà, proposa de llegir en aquest cas Can on a Hot tin Roof des del model Èdip Rei de Sòfocles i descobrir-hi igualment la tradicional ironia clàssica tant des del punt de vista de l'espectador com dels mateixos personatges principals, Brick i el seu pare, ambdós en cerca de la seva veritat, una veritat, és clar, contrària a la que esperaven.
Resumo:
L'objectiu d'aquest article és mostrar quins són els rèdits dramàtics de la inclusió de la referència a la deessa Diana a Cat on a Hot Tin Roof de Tennessee Williams. En opinió del autor, no es tracta simplement d'una referència significativa, sinó que l'anàlisi acurada del text de Williams demostra que és un element vertaderament nuclear i cohesionador de tot el drama.
Resumo:
El objetivo de este artículo es mostrar cuáles son los réditos dramáticos de la inclusión de la referencia a la diosa Diana en Cat on a Hot Tin Roof de Tennessee Williams. En opinión del autor, no se trata simplemente de una referencia significativa, sino que el análisis minucioso del texto de Williams demuestra que es un elemento verdaderamente nuclear y cohesionador de todo el drama.
Resumo:
In this work, zinc indium tin oxide layers with different compositions are used as the active layer of thin film transistors. This multicomponent transparent conductive oxide is gaining great interest due to its reduced content of the scarce indium element. Experimental data indicate that the incorporation of zinc promotes the creation of oxygen vacancies. In thin-film transistors this effect leads to a higher threshold voltage values. The field-effect mobility is also strongly degraded, probably due to coulomb scattering by ionized defects. A post deposition annealing in air reduces the density of oxygen vacancies and improves the fieldeffect mobility by orders of magnitude. Finally, the electrical characteristics of the fabricated thin-film transistors have been analyzed to estimate the density of states in the gap of the active layers. These measurements reveal a clear peak located at 0.3 eV from the conduction band edge that could be attributed to oxygen vacancies.
Resumo:
In this work, zinc indium tin oxide layers with different compositions are used as the active layer of thin film transistors. This multicomponent transparent conductive oxide is gaining great interest due to its reduced content of the scarce indium element. Experimental data indicate that the incorporation of zinc promotes the creation of oxygen vacancies. In thin-film transistors this effect leads to a higher threshold voltage values. The field-effect mobility is also strongly degraded, probably due to coulomb scattering by ionized defects. A post deposition annealing in air reduces the density of oxygen vacancies and improves the fieldeffect mobility by orders of magnitude. Finally, the electrical characteristics of the fabricated thin-film transistors have been analyzed to estimate the density of states in the gap of the active layers. These measurements reveal a clear peak located at 0.3 eV from the conduction band edge that could be attributed to oxygen vacancies.
Resumo:
The deuteric alteration processes undergone by the granites of the Ricobayo Batholith were: microclinization, chloritization, albitization, muscovitization, tourmalinization and garnetization. These processes must be interpreted in a dynamic context so that the different reactions that take place are the consequence of a successive interaction between rock and fluids. The physicochemical conditions deduced from these fluids are: temperature lower than 600 OC, pressure between 1.5 and 1 Kb, fugacity of oxygen between 10-25 and 10-35 bars, fugacity of sulphur lower than 10-l5 bars, the composition was kept stable and their log (a(K+)/a(Ht)) and log (a(Na+)/a(H+)) varied between 3.8 and 3.2 and between 3.5 and 4.6, respectively, and the pH of the fluids was higher than 5 during the microclinization, muscovitization and tourmalinization, and lower during chloritization and albitization. The deposition of cassiterite occurs with pH episodes that exceed 5.
Resumo:
Zinc indium tin oxide (ZITO) transparent conductive oxide layers were deposited via radio frequency (RF) magnetron co-sputtering at room temperature. A series of samples with gradually varying zinc content was investigated. The samples were characterized with x-ray and ultraviolet photoemission spectroscopy (XPS, UPS) to determine the electronic structure of the surface. Valence and conduction bands maxima (VBM, CBM), and work function were determined. The experiments indicate that increasing Zn content results in films with a higher defect rate at the surface leading to the formation of a degenerately doped surface layer if the Zn content surpasses 50%. Furthermore, the experiments demonstrate that ZITO is susceptible to ultraviolet light induced work function reduction, similar to what was earlier observed on ITO and TiO2 films.
Resumo:
Majolica pottery was the most characteristic tableware produced in Spain during the Medieval and Renaissance periods. A study of the three main production centers in the historical region of Aragon during Middle Ages and Renaissance was conducted on a set of 71 samples. The samples were analyzed by instrumental neutron activation analysis (INAA), and the resulting data were interpreted using an array of multivariate statistical procedures. Our results show a clear discrimination among different production centers allowing a reliable provenance attribution of ceramic sherds from the Aragonese workshops.