Search results for "reflection"
showing 10 items of 645 documents
Experimental measurements for studying angular and spectral variation of thermal infrared emissivity
2004
One condition for precise multiangle algorithms for estimating sea and land surface temperature with the data from the Advanced Along Track Scanning Radiometer is accurate knowledge of the angular variation of surface emissivity in the thermal IR spectrum region. Today there are very few measurements of this variation. The present study is conducted to provide angular emissivity measurements for five representative samples (water, clay, sand, loam, gravel). The measurements are made in one thermal IR broadband (8-13 microm) and three narrower bands (8.2-9.2, 10.3-11.3, and 11.5-12.5 microm) at angles of 0 degrees-60 degrees (at 5 degrees increments) to the surface normal. The results show a…
Resolution of the photon scanning tunneling microscope: influence of physical parameters
1992
Abstract The photon scanning tunneling microscope (PSTM) is the photon analogue of the electron scanning tunneling microscope (ESTM). It uses the evanescent field due to total internal reflection (TIR) of a light beam in a prism modulated by a sample placed on the base of the prism. Our experimental results shown details which present a lateral size as small as 200 A. The PSTM axial resolution is more difficult to evaluate. It is a function of the roughness of the sample. For very smooth samples, images shown an axial resolution of about 10 A. At last we discuss how both lateral and axial resolution can be affected by several parameters such as the tip surface distance and the roughness of …
Prediction of organic carbon and total nitrogen contents in organic wastes and their composts by Infrared spectroscopy and partial least square regre…
2017
Middle and near infrared (MIR and NIR) were employed to determine organic carbon (OC) and total nitrogen (TN) in different soil organic amendments including wastes, composts and mixtures of composts and organic wastes. Prediction models based on partial least squares (PLS) regression from the spectra of untreated samples were built. Different spectra preprocessing strategies were adopted and the best number of latent variable was evaluated using leave-one-out cross-validation. Attenuated total reflectance (PLS-ATR-MIR) and diffuse reflectance (PLS-DR-NIR) models were built and evaluated from root mean square error of cross validation and prediction (RMSECV and RMSEP), coefficients of determ…
ENTREACTO / ENTR?ACTE Un film / A Film Chopin y los Sand, amor a cuatro bandas. Aproximación a la esfera privada de Fryderyk Chopin a partir de la pe…
2021
Two centuries later, the legend Chopin-Sand continues to supply the collective imaginary with vague readings, where historical truthfulness, let alone musical truth, is often contingent on the literary. The much discussed and bellicose romance between the Polish composer and the French novelist, George Sand, tends to some reductionism and evades an obvious reality: Fryderyk Chopin meets George Sand when she was already the mother of two children. This circumstance suggests reformulating certain romantic stereotypes. Jerzy Antczak?s biographical film Pragnienie Mi?o?ci (Chopin: Desire for Love, 2002) does not overlook this detail and makes it one of its narrative axes. The relationship betwe…
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.
In situ ATR-IR studies in aqueous phase reforming of hydroxyacetone on Pt/ZrO2 and Pt/AlO(OH) catalysts: The role of aldol condensation
2018
Abstract In situ Attenuated Total Reflection Infrared (ATR-IR) spectroscopy was used to study Aqueous Phase Reforming of hydroxyacetone on Pt/AlO(OH) and Pt/ZrO2 catalysts at 230 °C/ 30 bar. Formation of strongly adsorbed aldol condensation products was observed on the surface of Pt/ZrO2 and ZrO2 in contrast to Pt/AlO(OH) and AlO(OH). Peak assignments were supported by DFT calculations of the IR spectra of the condensation products in vacuum and in the presence of water. Aldol condensation of hydroxyacetone leading to compounds with high molecular weight with unsaturated bonds was suggested as a first step in coke formation. Carbonaceous deposits on the surface of the ZrO2 support are oxyge…
Professionals’ views on children’s service user involvement
2021
Purpose Children are gradually attaining recognition as service users and their involvement in service development has been advanced in recent years. This study draws on empirical research in social and health-care services designed for children and families. The purpose of this paper is to analyse how professionals understand children’s involvement as experts by experience. The focus is on professionals’ views and intergenerational relations. Design/methodology/approach The research data comprise 25 individual and 10 group interviews with managers and professionals working in social and health-care services in one Finnish province. The data were analysed using qualitative thematic analysi…
Ventricular-vascular coupling in hypertension: methodological considerations and clinical implications.
2014
The present review is addressed to analyse the complex interplay between left ventricle and arterial tree in hypertension. The different methodological approaches to the analysis of ventricular vascular coupling in the time and frequency domain are discussed. Moreover, the role of hypertension-related changes of arterial structure and function (stiffness and wave reflection) on arterial load and how ventricular-vascular coupling modulates the process of left ventricular adaptation to hypertension are analysed.The different interplay between vascular bed and left ventricle emerges as the pathophysiological basis for the development of the multiple patterns of ventricular structural adaptatio…
Interpretation of PEA Output Signal in a Multilayer Specimen
2018
The aim of the present work is to evaluate the acoustic waves behavior within the Pulsed Electro-Acoustic (PEA) cell, in case of a multilayer specimen, in order to avoid misinterpretation of the output signal. Due to the reflection phenomenon of the acoustic waves travelling within the PEA cell, the output signal could be distorted. Because this aspect, for a given PEA cell with certain ground electrode and absorber thicknesses, depends on the sound velocity and thickness of the specimen under test, the latter must be carefully sized. For this aim, some useful relationships, that must be taken into account are given and described. In particular, a three layers sample simulating an air void …
On-line database of voltammetric data of immobilized particles for identifying pigments and minerals in archaeometry, conservation and restoration (E…
2016
[EN] A web-based database of voltammograms is presented for characterizing artists' pigments and corrosion products of ceramic, stone and metal objects by means of the voltammetry of immobilized particles methodology. Description of the website and the database is provided. Voltammograms are, in most cases, accompanied by scanning electron microphotographs, X-ray spectra, infrared spectra acquired in attenuated total reflectance Fourier transform infrared spectroscopy mode (ATR-FTIR) and diffuse reflectance spectra in the UV-Vis-region. For illustrating the usefulness of the database two case studies involving identification of pigments and a case study describing deterioration of an archae…