22,634 research outputs found
Distinguishing damages from two earthquakes —Archaeoseismology of a Crusader castle (Al-Marqab citadel, Syria)
No full textDamages from two major earthquakes are identified in medieval Al-Marqab citadel (Latin: Margat) in coastal Syria. Built by the Order of St. John (Hospitallers) in the twelfth–thirteenth centuries, the hilltop fortification has masonry walls made with and without mortar, using the opus caementum technology (Roman concrete). V-shaped and U-shaped failures, single-corner and symmetrical corner collapses, and in-plane shifts of ashlar masonry walls are identified and dated by historical and archaeological methods. The azimuth of displacement is NE-SW for the older
damages of the Crusader period (A.D. 1170–1285), possibly related to the A.D. 1202 earthquake. A later, NW-SE displacement occurred during the Muslim period (post-
1285). The 1202 earthquake produced at least VIII intensity on the MSK scale at Al-Marqab, which is higher than previously considered
Finite Differential Speed-Gradient Algorithms for Direct Adaptive Control of Nonminimum Phase Systems
No full textNiemcza diorites and moznodiorites (Sudetes, SW Poland): a record of changing geotectonic setting at ca. 340 Ma
No full textGranites sensu lato in the Sudetes intruded in several episodes during the Variscan orogeny recording different stages of crust and mantle evolution. Correlating precise ages with geochemistry of the Variscan granites provides information on the evolution of these sources within the Variscan orogen. The Variscan intrusive rocks from the Niemcza Zone (Bohemian Massif, Sudetes, SW Poland) include undeformed dioritic to syenitic rocks and magmatically foliated granodiorites. In this study we analysed low SiO2 (48–53 wt.%) monzodioritic rocks from Przedborowa and Koźmice. The monzodiorites contain late-magmatic zircons with ages of 341.8 ± 1.9 Ma for Przedborowa and 335.6 ± 2.3 Ma for Koźmice, interpreted as emplacement ages of the dioritic magmas. Older Przedborowa rocks are lower in K, Mg, Rb and Ni than the Koźmice rocks and similar compositional trend is also observed in the Central Bohemian Plutonic Complex. The implication is that the mantle underlying the Niemcza Zone became more enriched from ca. 342 to ca. 336 Ma, probably following the collision of the Saxothuringian and Moldanubian/Lugian domains. The magmatism related to the collision occurred ca. 12 Ma later than that in the Central Bohemian Plutonic Complex, but was accompanied by a similar change in magma chemistry from high-K (Przedborowa) to shoshonitic (Koźmice, Kośmin enclaves) and probably to ultrapotassic (Wilków Wielki)
Automatic document-level semantic metadata annotation using folksonomies and domain ontologies
No full textThe last few years have witnessed a fast growth of the concept of Social Software. Be it video sharing such as YouTube, photo sharing such as Flickr, community building such as MySpace, or social bookmarking such as del.icio.us. These websites contain valuable user-generated metadata called folksonomies. Folksonomies are ad hoc, light-weight knowledge representation artefacts to describe web resources using people’s own vocabulary. The cheap metadata contained in such websites presents potential opportunities for us (researchers) to benefit from. This thesis presents a novel tool that uses folksonomies to automatically generate metadata with educational semantics in an attempt to provide semantic annotations to bookmarked web resources, and to help in making the vision of the Semantic Web a reality. The tool comprises two components: the tags normalisation process and the semantic annotation process. The tool uses the del.icio.us social bookmarking service as a source for folksonomy tags. The tool was applied to a case study consisting of a framework for evaluating the usefulness of the generated semantic metadata within the context of a particular eLearning application. This implementation of the tool was evaluated over three dimensions: the quality, the searchability and the representativeness of the generated semantic metadata. The results show that folksonomy tags were acceptable for creating semantic metadata. Moreover, folksonomy tags showed the power of aggregating people’s intelligence. The novel contribution of this work is the design of a tool that utilises folksonomy tags to automatically generate metadata with fine gained and extra educational semantics
Electronic characterization of Al/PMMA[poly(methyl methacrylate)]/p-Si and Al/CEP(cyanoethyl pullulan)/p-Si structures
No full textThin films of poly(methyl methacrylate) (PMMA) and cyanoethyl pullulan (CEP) were prepared by spin coating on p-Si substrate. Capacitance-voltage (C-V) and current-voltage (I-V) behavior of the aluminum/PMMA/p-Si and A1/CEP(cyanoethyl pullulan)/p-Si MIS (metal-insulator-semiconductor) structures was studied at various frequencies ranging from 20 kHz to 1 MHz and for a bias voltage range of -50 V to +20 V. No hysteresis was observed in the C-V curve for both films as deposited and annealed (70-200 degrees C). Flat band voltage (V-FB) of aluminum/PMMA/p-Si structure with as deposited films was about -15 V and increased up to -30 V with annealing. This suggested that a large amount of positive charge was generated in the film. Electronic properties of the annealed PMMA film at above glass transition temperature were degraded substantially with larger shift in flat band voltage, low dielectric constant and low breakdown voltage. Al/CEP(eyanoethyl pullulan)/p-Si showed VF B about - 1 V for both as deposited or annealed film and CEP is more stable than PMMA. Frequency dependence of the electronic properties was also studied. (c) 2006 Elsevier B.V. All rights reserved.X1159sciescopu
Hymenophyllum polyanthos (Sw.) Sw.
No full textHonduras, Francisco Morazan, San Juancito Montana de La Tigra. LAT (14°12'10' ); LONG (87°06'53' ); ALT (2000). Honduras. Sobre Quercus sp. Bosque nebuloso, denso y húmedo de ìMontaña La Tigra al S. O. de San Juancito, Dept. Morazán. Alt. ì2000 m
Deposition of Al-doped ZnO thin-films with radio frequency magnetron sputtering for a source/drain electrode for pentacene thin-film transistor
No full textAl-doped ZnO thin-films were deposited with the radio frequency magnetron sputtering technique at various temperatures and sputtering powers for a source/drain electrode in the pentacene thin-film transistor. With the increase in the deposition temperature and the decrease in the radio frequency sputtering power, the crystallinity was increased and the surface roughness was decreased, which lead to the decrease in the electrical resistivity of the film. Al-doped ZnO film deposited at 200 degrees C and sputtering power of 50 W showed a low resistivity (9.73 x 10(4) mu Omega cm), high crystallinity, low roughness and uniform surface morphology. The pentacene thin-film transistor fabricated with Al-doped ZnO film as a source/drain electrode showed a device performance, (mobility: 7.89x 10(-3) cm(2)/Vs and on/off ratio: similar to 5x10(4)) which is comparable with an indium tin oxide electrode grown at room temperature. (C) 2009 Elsevier B.V. All rights reserved.X113735sciescopu
Dynamical reordering of charge stripes in (Bi, Ca) MnO3 driven by electron beam irradiation
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