Search results for "reflection"

De la performance musicale dans la Guyane traditionnelle : expression cognitive singulière d?une musique-verbe

2021

Guianese culture and traditional music, here evoked, are various. It is more a transcultural process that, along centuries, gave an original result born in the Americas, in Guiana in this case. It is a form of refoundation, of recreation of cultures and new human beings generally called Creoles. The musical performance, that I study here, is the echo of social and cultural space of this reformulation of thought, life, and conception of the world. It is, as well, a mean of transposition and transformation of the values issued of diverse sources and categories. It is in no way a second-rate cultural practice, as it is the place where were born philosophies and actions for common life as well …

Multispectral and autofluorescence RGB imaging for skin cancer diagnostics

2019

This paper presents the results of statistical clinical data, combining two diagnostic methods. A combination of two skin imaging methods – diffuse reflectance and autofluorescence – has been applied for skin cancer diagnostics. Autofluorescence (AF) and multispectral diffuse reflectance images were acquired by custom made prototype with 405 nm, 526 nm, 663 nm and 964 nm LEDs and RGB CMOS camera. Parameter p’ was calculated from diffuse reflectance images under green, red and infrared illumination, AF intensity (I’) was calculated from AF images exited at 405nm wavelength. Obtained results show that criterion p` > 1 gives possibility to discriminate melanomas and different kind of keratosis…

Gianfrancesco Maineri, Paolo da San Leocadio i la gènesi d?un model de Crist portacreu

2020

[CA] El present article es centra en la vinculació entre els diversos exemplars de Crist portacreu de Gianfrancesco Maineri i els homònims de Paolo da San Leocadio. A través de diverses comparacions, tractarà d¿explicar-se la gènesi d¿aquest model, aportant, a més, dades que permetran una millor classificació dels exemplars leocadians. Finalment, es realitzen una sèrie de reflexions entorn de l¿hipotètic retorn de San Leocadio a Itàlia (1485-1489) i a la seua possible vinculació amb Maineri.

Combining EXAFS and XRay Powder Diffraction to Solve Structures Containing Heavy Atoms

2005

Determination of structures using x-ray powder diffraction is complicated if the reflection intensities are mainly influenced by the scattering from heavy atoms and the atomic coordinates of light atoms remain uncertain. A method like EXAFS, which is sensitive to short range order, gives reliable atomic distances in the surroundings of heavy atoms with a precision of ±0.02 A. The probability for obtaining the complete structure from x-ray powder diffraction increases if one includes parameters derived from EXAFS measurements as restraints during the procedure of structure solving. We demonstrate the potential of combining EXAFS and x-ray powder diffraction by solving the structure UO2[H2AsO…

A penetration depth study on the non-centrosymmetric superconductors Li2(Pd1−xPtx)3B

2008

Abstract We study the superconducting order parameter in the non-centrosymmetric compounds Li 2 (Pd 1− x Pt x ) 3 B ( x =0, 0.3, 0.7 and 1) by measuring magnetic penetration depth λ ( T ). The low temperature λ ( T ) shows a linear temperature dependence for x ⩾0.3, but follows exponential-like behavior for lower Pt contents. These findings suggest that a spin-triplet state might gradually develop with increasing x due to the broken inversion symmetry.

Global-Local model for guided wave scattering problems with application to defect characterization in built-up composite structures

2020

Abstract Predicting scattering of elastic guided waves in multi-layered solid plates with geometrical and/or material discontinuities is of great interest to many fields, including ultrasonic-based Non-Destructive Testing (NDT) and health monitoring of critical structural components (SHM). The problem is complicated by the multimode and dispersive behaviour of the guided waves. This paper describes a unified Global-Local (GL) approach that is computationally efficient in cases that can be very complex in terms of geometry and/or material properties. One example of this is a composite built-up structure. The proposed GL procedure discretizes the “local” region with the scattering discontinui…

Controlled time integration for the numerical simulation of meteor radar reflections

2016

We model meteoroids entering the Earth[U+05F3]s atmosphere as objects surrounded by non-magnetized plasma, and consider efficient numerical simulation of radar reflections from meteors in the time domain. Instead of the widely used finite difference time domain method (FDTD), we use more generalized finite differences by applying the discrete exterior calculus (DEC) and non-uniform leapfrog-style time discretization. The computational domain is presented by convex polyhedral elements. The convergence of the time integration is accelerated by the exact controllability method. The numerical experiments show that our code is efficiently parallelized. The DEC approach is compared to the volume …

2020

Abstract Interest in studying information systems discontinuance has been increasing lately, yet there is no consensus on what it means. To improve the situation, we conduct a comprehensive review of current literature on IS discontinuance and identify 55 studies published during 1991–2017 that specifically focus on the topic. Our conceptual analysis disentangles the process, content, and context of the phenomenon, revealing that over the course of a typical IS lifecycle, IS discontinuance may materialize at least in five distinct forms: rejection, regressive discontinuance, quitting, temporary discontinuance, and replacement. After elaborating their distinctions, we discuss their theoretic…

The relevance of biographic narratives for social workers’ professional memory, reflexivity and identity

2020

The present article is about the use of biographic methods and oral history, and its contribution to developing processes of critical reflection and reflexivity. It is based on a set of oral data collected from Portuguese social workers who played an active role in the revolutionary phase during the transition from dictatorship to democracy in Portugal (following the 25th April 1974 military coup). The article explores how the use of biographic methods (integrated within a historical methodological framework), other than simply producing accounts of past experiences, allowed interviewees to re-capture, re-interpret and re-signify their own experiences in the light of changing professional …

Generation of radiative knots in a randomly pulsed protostellar jet

2009

HH objects are characterized by a complex knotty morphology detected mainly along the axis of protostellar jets in a wide range of bands. Evidence of interactions between knots formed in different epochs have been found, suggesting that jets may result from the ejection of plasma blobs from the source. We aim at investigating the physical mechanism leading to the irregular knotty structure observed in jets in different bands and the complex interactions occurring among blobs of plasma ejected from the stellar source. We perform 2D axisymmetric HD simulations of a randomly ejected pulsed jet. The jet consists of a train of blobs which ram with supersonic speed into the ambient medium. The in…