Search results for " Reflection"

Temperature dependence of the absorption properties of silanol groups in amorphous SiO2: Are silanol groups organized in clusters?

2011

Mapováni spinů povrchových a bulkových Rashba stavů v tenkých vrstvách feroelektrického α-GeTe(111)

2015

Rozbíjení inverzní symetrie ve fereeleRashba efekt; Fotoemisse; DFTktrickém polovodiči způsobuje děleni stavů, tzv Rashba efekt. V tomto článku ukazujeme kompletně mapování spinové polarizace těchto Rashba stavů za pomoci spinovo rozlišené fotoemisse. The breaking of bulk inversion symmetry in ferroelectric semiconductors causes a Rashba-type spin splitting of electronic bulk bands. This is shown by a comprehensive mapping of the spin polarization of the electronic bands in ferroelectric α- GeTe(111) films using a time-of-flight momentum microscope equipped with an imaging spin filter that enables a simultaneous measurement of more than 10 000 data points. The experiment reveals an opposite…

Conclusione generale

2009

Le ipotesi relative alla congruenza delle attività formative progettate con gli obiettivi che ci si prefiggeva di raggiungere sono state verificate in un campione di livello medio-alto per la competenza metacognitiva.

A Critical Reflection on Relationship between ICT and Change Management in Enhancing Teaching and Learning Performances

2019

Abstract Numerous studies have pointed out direct positive impacts of Information Communication Technology (ICT) on education quality. From just tool, ICT is being viewed in itself as quality or as catalyst for quality improvement. These findings have led universities worldwide to adopt ICT regardless of uncertainties. Consequently, not all of them succeeded. Proofs from cases around the world show that ICT produces positive impact only in the environment that fits. Such environment is fostered by an effective change management approach. The main aim of this paper is therefore to present the symbiotic relationship between ICT and change management, zeroing on how changes are managed to atta…

Study of the imaging conditions and processing for the aspect control of specular surfaces

2001

A vision system capable of imaging and detecting defects on reflective nonplanar surfaces in the production line at a high cadence is presented in this paper. Defects are typically dust located under the metallic layer of packaging products used in cosmetic industries. To realize this processing, structured lighting which reveals the defects in the image is proposed. Defects appear clearly in the images like a set of brilliant pixels in dark zones. The signature of the defect is then obtained. The size of this signature does not depend linearly on the size of the defect. It is a function of the observation angle. In order to realize a precise and robust process, the necessity of acquiring s…

Quantification de l’ablation d’un bassin versant marno-calcaire alpin durant le Petit Age Glaciaire par l’étude d’un système lacustre (cas du lac du «…

2002

Measurements of present-day erosion may give heterogeneous results according to the methods used. This article proposes an approach to erosion during the Little Ice Age by the quantitative analysis of detritical materials trapped in a dammed lake. This infill is recognized through two drillings, and these specific observations are supplemented by a seismic reflexion survey which provided a reliable estimate of the geometry of the lake infill. The sedimentary production is calculated from three pieces of data: (1) the surface of the drainage area, (2) duration of the lake system activity and (3) the volume of trapped sediments. From the three determined variables, we propose a detritical product…

Classification of pumpkin seed oils according to their species and genetic variety by attenuated total reflection Fourier-transform infrared spectros…

2011

Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), followed by multivariate treatment of the spectral data, was used to classify seed oils of the genus Cucurbita (pumpkins) according to their species as C. maxima, C. pepo, and C. moschata. Also, C. moschata seed oils were classified according to their genetic variety as RG, Inivit C-88, and Inivit C-2000. Up to 23 wavelength regions were selected on the spectra, each region corresponding to a peak or shoulder. The normalized absorbance peak areas within these regions were used as predictors. Using linear discriminant analysis (LDA), an excellent resolution among all categories concerning both Cucurbita species a…

Determination of sugars in depilatory formulations: a green analytical method employing infrared detection and partial least squares regression.

2011

A green analytical method was developed for the analysis of sugar-based depilatories. Three independent partial least squares (PLS) regression models were built for the direct determination of glucose, fructose and maltose without any sample pretreatment based on their attenuated total reflectance - Fourier transform infrared (ATR-FTIR) spectra. The models showed adequate prediction capabilities with root-mean-square-errors of prediction ranging from 7.04 to 12.55 mg sugar g(-1) sample. As a reference procedure, gradient liquid chromatography with on-line infrared detection, employing background correction based on cubic smoothing splines, was used. The analysis revealed changes in the suga…

ATR-FTIR spectroscopy as a quality control system for monitoring the storage of blood products

2021

Blood screening is a fundamental part of disease diagnosis and monitoring health. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy offers an innovative solution to streamlining the process, especially for multianalyte detection in aqueous samples. However, samples always undergo a storage phase before they are processed for testing and blood transfusion. In this study, we investigated the effect of standard storage procedures on the macromolecular composition of whole blood, and plasma collected in blood tubes for diagnostic purposes and initial screening of blood products. Periphery blood samples were collected from 10 volunteers and then stored for 14 days a…

Comparison of two partial least squares infrared spectrometric methods for the quality control of pediculosis lotions.

2006

Two vibrational spectroscopy procedures have been developed and compared for the direct and simultaneous determination of piperonyl butoxide and tetramethrin, the active ingredients of alcoholic capillary lotions, for hair pediculosis diseases. Nine lotions, purchased from the Spanish market, were analyzed using both, attenuated total reflectance (ATR) and transmission FT-IR measurements, and based on the use of partial least squares (PLS) multivariate calibration. A reduced set of 15 matched standards (11 for calibration and 4 for validation) was employed using both measurement modes. The spectral wave number ranges between 1757 and 1712 cm(-1) was selected to determine tetramethrin by bot…