Search results for "layer"
showing 10 items of 2667 documents
Music Performance Anxiety : Use of Coping Strategies by Tertiary Flute Players
2013
This article presents part of a master´s degree research, which focused on investigating causes, symptoms, and strategies used by tertiary flute players to cope with music performance anxiety in the performance of an unaccompanied flute work in recital of evaluative character. However, it will present only the results on strategies of twelve flute students from three music colleges in Brazil to cope with music performance anxiety. Seven of participants were male, and five were female. The procedures of collection and analyses of data occurred as in the study by Siw Nielsen (1999), that is, through the behavioral observation of the participants in the recital, and verbal reports by semi-stru…
The influence of soft acidic drinks in exposing dentinal tubules after non-surgical periodontal treatment: a SEM investigation on the protective effe…
2007
Objective: The aim of this study was to investigate the different smear layer morphologies produced by instrumentation with a hand curette and a periodontal sonic scaler for potential removal by soft acidic solution. The effect of a new oxalate-containing phytocomplex spray in preventing tubules exposure after citric acid solution application was also evaluated. Methods: Thirty recently extracted human teeth were used to obtain root dentinal fragments and divided in two groups: Curette treatment (CRT) root planed applying 30 working strokes to each surface using a Gracey?s curette 5-6 and Ultrasonic scaler (USC) treated using a periodontal scaler mounted on an ultrasonic hand-piece for 30 s…
Monitoring water and carbon fluxes at fine spatial scales using HyspIRI-like measurements
2012
Remotely sensed observations in the visible to the shortwave infrared (VSWIR) and thermal infrared (TIR) regions of the electromagnetic spectrum can be used synergistically to provide valuable products of land surface properties for reliable assessments of carbon and water fluxes. The high spatial, spectral and temporal resolution VSWIR and TIR observations provided by the proposed Hyperspectral - InfraRed (HyspIRI) mission will enable a new era of global agricultural monitoring, critical for addressing growing issues of food insecurity. To enable predictions at fine spatial resolution (<100m), modeling efforts must rely on a combination of high-frequency temporal and highresolution spa…
Direct Measurement of Mammographic X-Ray Spectra with a Digital CdTe Detection System
2012
In this work we present a detection system, based on a CdTe detector and an innovative digital pulse processing (DPP) system, for high-rate X-ray spectroscopy in mammography (1–30 keV). The DPP system performs a height and shape analysis of the detector pulses, sampled and digitized by a 14-bit, 100 MHz ADC. We show the results of the characterization of the detection system both at low and high photon counting rates by using monoenergetic X-ray sources and a nonclinical X-ray tube. The detection system exhibits excellent performance up to 830 kcps with an energy resolution of 4.5% FWHM at 22.1 keV. Direct measurements of clinical molybdenum X-ray spectra were carried out by using a pinhole…
Crystal growth and characterization of Zn1-xMgxO advanced micro- and nanostructures
2018
Dentro de la creciente área de investigación de la física de semiconductores, los pertenecientes a la familia II-VI se han convertido en un campo fundamental de la física de materiales debido a que sus propiedades fotofísicas son únicas para crear una nueva generación de dispositivos en el campo de la fotónica y la microelectrónica. Entre ellos, los semiconductores basados en ZnO han ganado un considerable interés en la comunidad científica en parte debido a su alta energía de enlace del excitón (60 meV) la cual es 2.4 veces más alta que la energía térmica a temperatura ambiente. Este hecho puede dar lugar a emisión laser excitónica a temperaturas incluso mayores que la ambiente. Además, gr…
Hartree - Fock simulation of the Ag/MgO interface structure
1996
The atomic and electronic structure of the Ag/MgO interface are calculated using an ab initio Hartree - Fock computer code and a supercell model of a silver monolayer atop three layers of MgO substrate. The band structure, electronic density distribution and densities of states are analysed in detail for isolated and interacting slabs of a metal and MgO. The energetically most favoured adsorption position for Ag atoms is found to be above the O atoms, with the binding energy of 0.20 eV and the equilibrium Ag - O distance of 2.64 A. Neither appreciable charge transfer in the interfacial region, nor considerable population of bonds between the silver monolayer and the insulating substrate tak…
Origin of the large spectral shift in electroluminescence in a blue light emitting cationic iridium(III) complex
2007
A new, but archetypal compound [ Ir( ppy- F-2) (2)Me(4)phen] PF6, where ppy- F2 is 2-(2',4'- fluorophenyl) pyridine and Me(4)phen is 3,4,7,8- tetramethyl- 1,10- phenanthroline, was synthesized and used to prepare a solid-state light-emitting electrochemical cell (LEEC). This complex emits blue light with a maximum at 476 nm when photoexcited in a thin film, with a photoluminescence quantum yield of 52%. It yields an efficient single-component solid-state electroluminescence device with a current efficiency reaching 5.5 cd A(-1) and a maximum power efficiency of 5.8 Lm Watt(-1). However, the electroluminescence spectrum is shifted with respect to the photoluminescence spectrum by 80 nm resul…
Optimising Lactic Acid Cheese Packaging Systems
2016
On the basis of a previous research, it seems that foil-wrapped tray solutions are not particularly chosen by lactic acid cheese consumers. With relation to this study, almost half of the respondent population would have expressed the desire of different packages. Parchment packages and poly(ethylene-co-vinyl acetate)/polyvinylidene chloride/poly(ethylene-co-vinyl acetate) laminates would be removed by 25.0 and 12.5% of customers, respectively. Polyamide/polyethylene double and single packaging would be removed from the market only by 5.0% of respondents. Data have shown that cheese and packaging quality are dependent on lactic acid cheese surface microflora. The type of this microflora is …
A short story of 3AB-OS Cancer Stem Cells, a possible model for studying cancer stemness
2014
All tumors contain a population of Cancer Stem Cells (CSCs) responsible for the initiation, growth and development of the tumor and a challenge in cancer research is their identification and eradication. In our laboratory, by chemical treatment of the human osteosarcoma MG63 cell line, we have isolated and characterized the human OS CSC line (3AB-OS). 3AB-OS CSCs have a significant chromosomal complexity and a large number of molecular abnormalities which appear to be strongly congruent with those described in a large number of pediatric and adult osteosarcomas. 3AB-OS cells transdifferentiated in vitro into cells of all three primary germ layers and, when xenografted in athymic mice they w…
First-principles calculations on surface hydroxyl impurities in BaF2
2012
Abstract OH − impurities located near the (1 1 1) BaF 2 surface have been studied by using density functional theory (DFT) with hybrid exchange potentials, namely DFT-B3PW. Twenty surface OH − configurations were studied, and the hydroxyls located on the first surface layer are the energetically most favorable configurations. For the (1 1 1) BaF 2 surface atomic layers, the surface hydroxyls lead to a remarkable XY -translation and a dilating effect in the Z -direction, overcoming the surface shrinking effect in the perfect slab. Bond population analysis shows that the surface effect strengthens the covalency of surface OH − impurities. The studies on band structures and density of states (…