Search results for "RECESS"

Contratti a tempo indeterminato

2013

Recesso del consumatore

2013

Structure of the new mineral sarrabusite, Pb5CuCl4(SeO3)4, solved by manual electron-diffraction tomography.

2012

The new mineral sarrabusite Pb5CuCl4(SeO3)4 has been discovered in the Sardinian mine of Baccu Locci, near Villaputzu. It occurs as small lemon–yellow spherical aggregates of tabular crystals (< 10 µm) of less than 100 µm in diameter. The crystal structure has been solved from and refined against electron diffraction of a microcrystal. Data sets have been measured by both a manual and an automated version of the new electron-diffraction tomography technique combined with the precession of the electron beam. The sarrabusite structure is monoclinic and consists of (010) layers of straight chains formed by alternating edge-sharing CuO4Cl2 and PbO8 polyhedra parallel to the c axis, which sha…

The “Big Bang” of the populist parties in the European Union: The 2014 European Parliament election

2018

A significant number of voters are turning their backs on traditional parties. The stability of European party systems is being defied by a growing number of (new) radical parties, whose presence i...

Survival rates of a lithium disilicate-based core ceramic for three-unit esthetic fixed partial dentures: a 10-year prospective study.

2013

Purpose The aim of this prospective study was to evaluate the clinical efficacy and long-term survival rate of three-unit fixed partial dentures (FPDs) made from lithium disilicate-based core ceramic. Materials and methods Twenty-one three-unit FPDs were placed in 19 patients to replace single lost teeth in the esthetic area, following a study protocol that took clinical, esthetic, and radiologic aspects into consideration. Each case was reviewed at 1 week following placement, at 6 months, and then annually for 10 years. Statistical analysis was performed using Kaplan-Meier survival analysis. Results Out of the 19 patients, 14.3% presented reversible postoperative sensitivity. Recession was…

Treatment of Gingival Recession: When and How?

2021

Gingival recession is a common finding in daily clinical practice. Several issues may be associated with the apical shift of the gingival margin such as dentine hypersensitivity, root caries, non-carious cervical lesions (NCCLs), and compromised aesthetics. The first step in an effective management and prevention program is to identify susceptibility factors and modifiable conditions associated with gingival recession. Non-surgical treatment options for gingival recession defects include establishment of optimal plaque control, removal of overhanging subgingival restorations, behaviour change interventions, and use of desensitising agents. In cases where a surgical approach is indicated, co…

"Ab initio" structure solution from electron diffraction data obtained by a combination of automated diffraction tomography and precession technique

2009

Using a combination of our recently developed automated diffraction tomography (ADT) module with precession electron technique (PED), quasi-kinematical 3D diffraction data sets of an inorganic salt (BaSO(4)) were collected. The lattice cell parameters and their orientation within the data sets were found automatically. The extracted intensities were used for "ab initio" structure analysis by direct methods. The data set covered almost the complete set of possible symmetrically equivalent reflections for an orthorhombic structure. The structure solution in one step delivered all heavy (Ba, S) as well as light atoms (O). Results of the structure solution using direct methods, charge flipping …

Elektrónová a pásová štruktúra CuMnAs študovaná optickou a fotoemissinou spektroskopiou

2017

Tetragonal phase of CuMnAs progressively appears as one of the key materials for antiferromagnetic spintronics due to efficient current-induced spin-orbit torques whose existence can be directly inferred from crystal symmetry. Theoretical understanding of spintronic phenomena in this material, however, relies on the detailed knowledge of electronic structure (band structure and corresponding wave functions) which has so far been tested only to a limited extent. We show that AC permittivity (obtained from ellipsometry) and UV photoelectron spectra agree with density functional calculations. Together with the x-ray diffraction and precession electron diffraction tomography, our analysis confi…

A multi-technique, micrometer- to atomic-scale description of a synthetic analogue of chukanovite, Fe-2(CO3)(OH)(2)

2014

International audience; A synthetic analogue of chukanovite Fe-2(CO3)(OH)(2) is formed during experimental work on iron-clay interactions simulating the cooling of containers in radioactive waste repositories. Despite its small size and the mixture with other minerals it is undoubtedly identified by X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy and Transmission Electron Microscopy. For the first time, the structural characterisation of a synthetic chukanovite is carried out thanks to the combination of Automated Diffraction Tomography and Precession Electron Diffraction. Refinement results and comparison with literature data show that the structure…

Towards automated diffraction tomography. Part II--Cell parameter determination.

2008

Automated diffraction tomography (ADT) allows the collection of three-dimensional (3d) diffraction data sets from crystals down to a size of only few nanometres. Imaging is done in STEM mode, and diffraction data are collected with quasi-parallel beam nanoelectron diffraction (NED). Here, we present a set of developed processing steps necessary for automatic unit-cell parameter determination from the collected 3d diffraction data. Cell parameter determination is done via extraction of peak positions from a recorded data set (called the data reduction path) followed by subsequent cluster analysis of difference vectors. The procedure of lattice parameter determination is presented in detail f…