Search results for "Reflectivity"

Effect of Mn Doping on the Optical Properties of Chalcogenide Compounds ZnS and ZnTe

2020

In this paper, the influence of the addition of Mn on the optical properties of the binary compounds ZnS and ZnTe deposited by a close-spaced vacuum sublimation method onto nonoriented glass at different substrate temperatures was considered. The spectral dependences of the transmittance T (λ), reflectance R (λ) and the absorption α (λ), as well as the bandgap for each material (Eg) were measured and calculated.

Sex and population variation in ultraviolet reflectance of colour patches in Gallotia galloti (Fam. Lacertidae) from Tenerife (Canary Islands)

2005

Sex and population differences in the ultraviolet (UV) reflectance patterns of two phenotypically divergent lacertids from Tenerife, Gallotia galloti eisentrauti and G. g. galloti, are described. Adults in both populations have rows of lateral and ventro-lateral blue patches on either side of the trunk that show a single peak of reflectance in the near UV. The lateral patches of males are more intensely reflective than those of females, but females have more chromatic and UV-shifted lateral patches than males. Most G. g. eisentrauti and some G. g. galloti also have blue cheek patches on either side of the gular area. Male cheek patches have reflectance peaks in the near UV, whereas those of…

Ultraviolet reflectance of male nuptial colouration in sand lizards (Lacerta agilis) from the Pyrenees

2007

Abstract The evolutionary significance of lacertid colourations is relatively unexplored. However, several studies have demonstrated signalling by means of bright green colouration in Swedish Lacerta agilis males during the breeding season. Unfortunately, most of these studies have been based on human colour perception that differs in several ways from that of lizard. An important difference between human and lizard colour vision is the presence of an ultraviolet (UV) sensitive cone in lizards. The available evidence suggests that male sand lizards colorations do not reflect UV wavelengths, at least in Swedish populations. However, this study, based on objective (spectrophotometric) measur…

Kohti reflektiivistä katsomuskasvatusta

2023

Tässä artikkelissa käsitellään reflektiivisyyttä katsomuskasvatuksen kontekstissa filosofisista ja teoreettisista näkökulmista. Katsomuskasvatus tulkitaan tässä laajasti: se kattaa elämänkatsomustiedon ja uskontojen opetuksen lisäksi kaiken kasvatuksen, joka tukee katsomuksen muodostumista ja identiteettityötä. Reflektiivinen katsomuskasvatus asettuu vastakohdaksi indoktrinatiiviselle kasvatukselle, jossa pyritään iskostamaan tietynlaiseen oppiin tai uskomusjärjestelmään perustuva ajattelutapa oppilaiden mieliin. Reflektiivisen katsomuskasvatuksen tarkoitus on antaa lapselle ja nuorelle välineitä määritellä identiteettiään ja maailmankuvaansa. Artikkelissa esitetään uusi reflektiivisen kats…

Determination of reflectance spectra model of skin phototypes V

2012

In dermatology, skin is assessed for its response to UV light and is categorised under the Fitzpatrick skin type (FST). The FST is commonly applied as a predictor of skin cancer. The FST classification however is subjective. To enable an objective assessment, a pattern model of skin colour taken from normal subjects is required. In this paper, a model for skin phototype (SPT) V is developed and presented. We conducted an observational study involving 41 participants with FST V. The study analysed the reflectance spectra of facultative skin and constitutive skin which was captured using spectrophotometer and multispectral camera. Using piecewise linear regression, we modelled the reflectance…

"Voi ei, nää on tosi hyviä verrattuna muhun!" : uudenlaisen arviointimenetelmän toimivuus ranskan suullisen kielitaidon itsearvioinnissa

2013

The Coaching Maps as a Tool for Developing Reflectivity in Organisations

2019

Our view of organizations, labour and the competencies of managers will soon need to change. In the postmodern and post-Fordist world, economy and organizations function differently than they did in the 20th century. Workers and managers will have to face new expectations. Not only has reflectivity become one of the key organisational factors; it is also taught, learnt and shaped. Drawing on an authoethnographic model and action-research, authors of this paper provide an education and development tool that managers and workers can use to develop and trigger reflectivity. Picture ethnography, coaching philosophy and hermeneutics are theoretical bases for the construction of a new model of se…

Unsupervised Numerical Characterization in Determining the Borders of Malignant Skin Tumors from Spectral Imagery

2021

For accurate removal of malignant skin tumors, it is crucial to assure the complete removal of the lesions. In the case of certain ill-defined tumors, it is clinically challenging to see the true borders of the tumor. In this paper, we introduce several computationally efficient approaches based on spectral imaging to guide clinicians in delineating tumor borders. First, we present algorithms that can be used effectively with simulated skin reflectance data. By using simulated data, we gain detailed information about the sensitivity of the different approaches and how variables defined by algorithms act in the skin model. Second, we demonstrate the performance of the algorithms with spectra…

Photoaging evaluation by RGB images using a smartphone for photodynamic therapy assessment

2017

In this study was evaluated the photoaging of patients' skins by the processing of RGB images acquired with an optical system based on a smartphone. Two groups were approached: a younger and an older.

Unravelling the Intertwined Atomic and Bulk Nature of Localised Excitons by Attosecond Spectroscopy

2021

The electro-optical properties of most semiconductors and insulators of technological interest are dominated by the presence of electron-hole quasi-particles, called excitons. The manipulation of excitons in dielectrics has recently received great attention, with possible applications in different fields including optoelectronics and photonics. Here, we apply attosecond transient reflection spectroscopy in a sequential two-foci geometry and observe sub-femtosecond dynamics of a core-level exciton in bulk MgF2 single crystals. Furthermore, we access absolute phase delays, which allow for an unambiguous comparison with theoretical calculations. Our results show that excitons surprisingly exhi…