Search results for " lighting"

Solid-State Lighting: Simple, Fast, Bright, and Stable Light Sources (Adv. Mater. 7/2012)

2012

The colour of light for urban spaces

2013

Light in urban spaces was first introduced to prevent crimes against both people and properties and, while there is no study that confirms crimes' reduction in lit spaces, it is undeniable that people feel safer in lit urban spaces. Over the years it became evident that light can also improve the liveability of cities and enhance their characteristics, therefore in the last years a growing attention was paid to urban lighting design taking into account the environmental impact and energy saving requirements too. The will to use the lighting design project to improve the liveability of historical centres it’s clear: the city during the night is no more conceived like a sum of lit architectur…

Direct assessment of the sensitivity drift of SQM sensors installed outdoors

2021

Long-term monitoring of the evolution of the artificial night sky brightness is a key tool for developing science-informed public policies and assessing the efficacy of light pollution mitigation measures. Detecting the underlying artificial brightness trend is a challenging task, since the typical night sky brightness signal shows a large variability with characteristic time scales ranging from seconds to years. In order to effectively isolate the weak signature of the effect of interest, determining the potential long term drifts of the radiance sensing systems is crucial. If these drifts can be adequately characterized, the raw measurements could be easily corrected for them and transfor…

Protocolo técnico para la fotografía de fuentes filológicas primarias

2014

con fines documentales, proyectado para garantizar la máxima fidelidad posible al motivo original representado. Tras una descripción detallada del material necesario, seleccionado específicamente en función de las necesidades particulares de la fotografía de textos manuscritos o impresos, se desarrolla un procedimiento adaptado a las nuevas circunstancias de la fotografía digital, concebido en dos fases: la captación de la imagen en formato RAW, y su posterior edición. En este estudio se trata la primera parte, describiendo sistemáticamente, paso a paso, las decisiones técnicas relativas a los ajustes fotográficos de la toma en diferentes situaciones lumínicas, encaminadas a maximizar la ca…

Getting night lighting right taking account of nocturnal urban uses for better-lit cities

2018

Translated by Oliver Waine; International audience; Innovation in contemporary urban lighting has increasingly been driven by issues of sustainability. While environmental concerns focus attention on energy savings and reducing light pollution, taking account of how people use public spaces is important too, as artificial light can then be adjusted to actual needs. Following the pioneering work of Roger Narboni and Luc Gwiazdzinski, Samuel Challéat and Dany Lapostolle make the case for dedicated nocturnal city planning.

3D acquisition system for transparent objects

2010

This thesis deals with a new automated tridimensional inspection system for transparent surfaces, based on polarization analysis. We first present an extension of the ‘Shape from Polarization’ method for transparent surfaces. After being reflected, an unpolarized light wave becomes partially linearly polarized, depending on the surface normal and on the refractive index of the media it impinges on. Hence, by measuring the polarization parameters of the reflected light, the surface normals are computed. The ambiguity concerning the normal orientation is solved here with a multispectral lighting system. Finally, the description of the whole acquisition prototype is given as well as some exper…

Blaming the Light, Claiming the Night. Actors, Issues and Effects of Lighting Conflicts in France since the 1980's

2014

International audience; Regarding environmental issues, conflictuality is a privileged way to reach the political arena. "Naming, Blaming, Claiming": three steps that make the controversy emerge, constitute the public issue, then bring it to the politi- cal agenda. These three stages are clearly identifiable in the history of night protection associative movements. These movements emerged in the 1970's in the United States of America, quickly disseminated enjoying a broader context of environmental thinking. Conflicts related to artificial lighting are structurally akin to conflicts of contradictory uses of a single resource: the night. For some - the technicists -, the night is the "good-s…

Embedding energy consumption for lighting in the evaluation methods of the energy performance of buildings

2009

Stable Light-Emitting Electrochemical Cells Using Hyperbranched Polymer Electrolyte

2021

The choice of an adequate electrolyte is a fundamental aspect in polymer light-emitting electrochemical cells (PLECs) as it provides the in situ electrochemical doping and influences the performance of these devices. In this study, a hyperbranched polymer (Hybrane DEO750 8500) blended with a Li salt is used as a novel electrolyte in state-of-the-art Super Yellow (a polyphenylenevinylene) based LECs. Due to the desirable properties of the hyperbranched polymer and the homogeneous and smooth films that it forms with the emitting polymer, PLEC with excellent electroluminescent properties are obtained using a pulsed current bias scheme. The devices are very stable, with lifetimes in excess of 2…

(Ré)concilier éclairage urbain et environnement nocturne : les enjeux d’une controverse sociotechnique

2014

International audience; Our paper explains the birth of an environmental problem, i.e. light pollution, viewed as a socio-technical controversy. Supported by the actor-network approach, it traces over forty years the conditions of its emergence, transformation and dissemination to local, national and transnational levels and through various professional disciplines. Schematically, “environmentalists” uphold a holistic approach of “nocturnality” and define artificial light as a pollutant. Facing them, the “technicist” defends a segmented approach and defines artificial light as a nuisance. The introduction of this controversy into the political agenda leads to institutional decisions that gr…