Search results for "deformation"
showing 10 items of 515 documents
Deformation of the octahedral coordination of the Sb(III) atom in the structure of bis(1,2,4-triazolium) pentachloroantimonate(III) (C2H4N3)2[SbCl5]
2002
In the title compound the [SbCl 6] 3- octahedra show high variations in their Sb-Cl bond lengths and Cl-Sb-Cl angles. There are two crystallographically non-equivalent (C 2H 4N 3) + 1,2,4-triazolium cations in the crystal structure. They are located inside the cavities formed by the [{SbCl 5} 2-] n inorganic structure. The [{SbCl 5} 2-] n chains and (C 2H 4N 3) + cations are connected with each other by the N-H...Cl and C-H...Cl hydrogen bonds. Only two chloride atoms are involved in the N-H...Cl hydrogen bonds. The N-H...Cl interactions are responsible for the changing of geometries of Sb1-Cl2 and Sb1-Cl4 bonds and corresponding Cl-Sb-Cl angles. Their influence on the geometry of [SbCl 6] …
Limits of Sobolev homeomorphisms
2017
Let X; Y subset of R-2 be topologically equivalent bounded Lipschitz domains. We prove that weak and strong limits of homeomorphisms h: X (onto)-> Y in the Sobolev space W-1,W-p (X, R-2), p >= 2; are the same. As an application, we establish the existence of 2D-traction free minimal deformations for fairly general energy integrals. Peer reviewed
The 15 March 2007 explosive crisis at Stromboli Volcano, Italy: assessing physical parameters through a multidisciplinary approach
2011
Basaltic volcanoes are dominated by lava emission and mild explosive activity. Nevertheless, many basaltic systems exhibit, from time to time, poorly documented and little-understood violent explosions. A short-lived, multiblast explosive crisis (paroxysmal explosion) occurred on 15 March 2007 during an effusive eruptive crisis at Stromboli (Italy). The explosive crisis, which started at 20:38:14 UT, had a total duration of ∼5 min. The combined use of multiparametric data collected by the permanent instrumental networks (seismic, acoustic, and thermal records) and a field survey carried out immediately after the event enabled us to constrain the eruptive dynamics and quantify physical param…
Complex vein systems as a data source in tectonics: An example from the Ugab Valley, NW Namibia
2014
Abstract Neoproterozoic metaturbidites in the Lower Ugab Domain, Namibia, contain a complex network of four sets of quartz-calcite veins, overprinted by km-scale folds associated with four regional foliations. The veins formed by fluid overpressure predating the main deformation. Deformation structures developed at the junction of two mobile belts during the assembly of Gondwana, the NS Kaoko Belt, and the EW trending Damara Belt. Km-scale NS trending folds were initiated during EW constriction in the Kaoko Belt, while their further development and all subsequent events are related to constriction in the EW-Damara Belt, with coeval sinistral strike slip in the Kaoko Belt. Deformation of the…
B-Deformable Superquadrics for 3D Reconstruction
1995
We propose a new model for 3D representation and reconstruction. It is based on deformable superquadrics and parametric B-Splines. The 3D object deformation method uses B-Splines, instead of a Finite Element Method (FEM). This new model exhibits advantages of B-Splines It is significantly faster than deformable superquadrics without loss of generality (no assumption is made on object shapes,).
Bounding principles for elastic-plastic-creeping solids loaded below and above the shakedown limit
1982
Solids of elastic-perfectly plastic creeping material subjected to variable loads are considered within the infinitesimal displacement framework and a bounding principle is presented which holds below and above the shakedown limit. Through the choice of some free parameters, this principle generates a number of deformation bounds with practical meanings, some of wich coincide with known results for creeping and noncreeping material, while others constitute new results or generalizations of known results. The topic will be further studied in a subsequent paper [35].
GPS Monitoring of the Scopello (Sicily, Italy) DGSD Phenomenon: Relationships Between Surficial and Deep-Seated Morphodynamics
2015
The Scopello area, which is located along the north-western Tyrrhenian coastal sector of the Sicilian chain (Italy), is widely affected by Deep-seated Gravitational Slope Deformation (DGSD) phenomena, which are mainly the result of a geomorphologic setting marked by the outcropping of an overthrust plan, limiting a brittle fractured carbonate slab, laid onto a ductile marly-clayey substratum. Due to the very advanced stage of the deformation phenomena, a coupled morphodynamic style has established between shallow landslides and DGSD phenomena, affecting the exhumed ductile substratum and the overlaying rigid dismantled slab, respectively. A GPS network was realized for monitoring the Scopel…
Comparison between topographic and photogrammetric techniques for deformation monitoring of the dome of the Massimo Theatre in Palermo
2012
This paper shows the first results of a study aimed at monitoring the deformations of the dome of the Massimo Theatre in Palermo caused by thermal dilatations, with the use of topographic and photogrammetric integrated techniques. Particularly, two robotic total stations and high precision digital photogrammetric systems were employed. In order to correlate the displacements of the rollers on which the steel structure of the dome rest with the thermal gradients, different thermal images were acquired by a thermal imaging camera. The main goal of the work was to compare the two techniques with reference to very small (submillimeter) deformation measurements. The obtained results show that th…
Monitoraggio delle deformazioni della cupola del Teatro Massimo di Palermo con l’impiego di tecniche topografiche e fotogrammetriche integrate.
2012
L’articolo riporta i primi risultati di uno studio finalizzato al monitoraggio delle deformazioni della cupola del Teatro Massimo di Palermo provocate dalle dilatazioni termiche, con l’impiego di tecniche topografiche e fotogrammetriche integrate. In particolare, sono state utilizzate due stazioni totali robotizzate e sistemi di fotogrammetria digitale di elevata precisione. Per correlare gli spostamenti dei carrelli sui quali poggia la struttura in acciaio della cupola con i gradienti termici, sono state acquisite immagini termiche diversificate. L’obiettivo principale del lavoro consisteva nel confronto delle due tecniche di rilievo in relazione a misure di deformazione di entità molto ri…
Structural properties of GaN quantum dots
2006
The strain state and the deformation profile of GaN quantum dots embedded in AlN have been measured by high resolution electron microscopy, medium energy ion scattering and grazing incidence X-ray diffraction. The results are compared with theoretical calculations, allowing one to conclude that GaN quantum dots experience a non biaxial strain which drastically decreases when going from the basal plane up to the apex of the dots. We also demonstrate that AlN is distorted in the surroundings of the dots, which provides the driving force for vertical correlation of GaN dots when the AlN spacer between successive planes is thin enough.