Publications associées à Efficacité lumineuse d'un rayonnement

Discomfort glare from daylight: Influence of transmitted color and the eye's macular pigment

Designing architectural façades that allow sufficient daylight to create visually comfortable and pleasant environments is a challenging aspect of building design. It requires accounting for visual comfort and discomfort glare risks and understanding the f ...

EPFL2023

Comparison between CIE 2° and 10° field photopic luminosity functions V(λ) for calculating daylight discomfort glare metrics

Marilyne Andersen, Jan Wienold, Sneha Jain

The spectral sensitivity of the average human eye in photopic conditions is represented by the photopic luminosity function V (λ). The CIE has established the photopic luminosity functions for the 2o and 10o visual fields for a standard observer applicable ...

2022

Visual comfort without borders: Extending daylight glare prediction to dim daylit environments

Geraldine Cai Ting Quek

Avoiding discomfort glare is one of the critical aspects of maintaining visual comfort, which significantly influences occupants' overall satisfaction with their indoor environment. Discomfort glare prediction models have been developed for various lightin ...

EPFL2022

Validation of Spectral Simulation Tools for the Prediction of Indoor Daylight Exposure

Marilyne Andersen, Clotilde Marie A Pierson

A growing area of research focuses on the relationship between ocular light exposure and the non-visual responses. In order to accelerate research on this topic and improve building design, reliable spectral simulation tools are needed. This study aims at ...

2021

Proton-transfer-induced 3D/2D hybrid perovskites suppress ion migration and reduce luminance overshoot

Mohammad Khaja Nazeeruddin, Emad Oveisi, Hobeom Kim

Perovskite light-emitting diodes (PeLEDs) based on three-dimensional (3D) polycrystalline perovskites suffer from ion migration, which causes overshoot of luminance over time during operation and reduces its operational lifetime. Here, we demonstrate 3D/2D ...

Nature Research2020

Application of Fundamental In-Body Radiation Limitations to Practical Design of Antennas for Implantable Bioelectronics

Anja Skrivervik, Denys Nikolayev

Fundamental in-body limitations on achievable radiation efficiency could provide decision-making assistance to engineers working on antennas for implantable bioelectronics. In this study, proof-of-concept conformal microstrip antennas are proposed based on ...

IEEE2020

A smart luminaire in an office environment: impact on light distribution, user interactions and comfort

Jérôme Henri Kämpf

A smart luminaire able to change the direction of its light beam is installed in an office environment and compared to the available LEDs fixtures. Standard lighting measures are performed and a controlled user experiment is conducted, involving 22 subject ...

IOP Publishing Ltd2019

Biocompatible Amphiphilic Hydrogel–Solid Dimer Particles as Colloidal Surfactants

Esther Amstad, Jing Fan

Emulsions of two immiscible liquids can slowly coalesce over time when stabilized by surfactant molecules. Pickering emulsions stabilized by colloidal particles can be much more stable. Here, we fabricate biocompatible amphiphilic dimer particles using a h ...

2017

Ion cyclotron resonance heating for tungsten control in various JET H-mode scenarios

Jonathan Graves, Javier García Hernández

Ion cyclotron resonance heating (ICRH) in the hydrogen minority scheme provides central ion heating and acts favorably on the core tungsten transport. Full wave modeling shows that, at medium power level (4MW), after collisional redistribution, the ratio o ...

2017

Design, simulation, and quality evaluation of micro-optical freeform beam shapers at different illumination conditions

Hans Peter Herzig, Daniel Infante Gómez

A design method to generate thin micro-optical freeform (MOF) beam shapers by clipping or wrapping an original and much thicker freeform surface is provided. MOF elements are situated at the border between refractive and diffractive optical elements. The i ...

Optical Soc Amer2016

Electrically Pumped Vertical-External-Cavity Surface-Emitting Lasers With Patterned Tunnel Junction for Single Transversal-Mode Emission

Elyahou Kapon, Alexei Sirbu

This paper reports on a numerical analysis of methods for current injection into AlInGaAs/InP tunnel-junction electrically pumped vertical-external-cavity surface-emitting lasers. The tunnel junction is patterned to minimize the current crowding effect and ...

Ieee-Inst Electrical Electronics Engineers Inc2015

A micro particle shadow velocimetry (mu PSV) technique to measure flows in microchannels

John Richard Thome, Sepideh Khodaparast, Giulia Tagliabue, Navid Borhani

A micro particle shadow velocimetry (mu PSV) system based on back-lit illumination and forward scatter observation of light from non-fluorescent particles has been developed. Relatively high luminous efficiencies and particle image contrasts were achieved ...

Springer-Verlag2013

The Impact of Light Including Non-Image Forming Effects on Visual Comfort

Apiparn Borisuit

Visual comfort at workplaces has often been considered in terms of discomfort glare, luminance distribution and task visibility. Besides visual effects, the lighting environment has also impact on human physiology and behaviour. These effects of light are ...

EPFL2013

Advanced Window and Lighting Technologies in net Zero Energy Buildings

Jean-Louis Scartezzini

Light has an important visual and non-visual impact on humans. Most of our information exchange, especially within office working spaces, occurs through it, our circadian rhythms are directly influenced by its presence. On the other hand, artificial lighti ...

2011

Ray-tracing simulation of complex fenestration systems based on digitally processed BTDF data

Jean-Louis Scartezzini, Jérôme Henri Kämpf

The implementation of Complex Fenestration Systems (CFS) in the day-to-day life by practitioners, such as lighting designers, architects and façade makers is not an easy task. However, computer design tools can reinforce their usage through the determinati ...

EPFL2011

High Performance Integrated Lighting Systems: Recent Achievements within the Framework of the "Green Lighting" project

Jean-Louis Scartezzini, Friedrich Linhart, Stephen Wittkopf

The „Green Lighting“ project (LESO-PB/EPFL and Swiss Federal Office of Energy) explores different ways to combine advanced day- and artificial lighting technologies for achieving highly energy-efficient office lighting scenarios. This communication gives a ...

EPFL2009

Illuminant estimation and detection using near infrared

Sabine Süsstrunk

Digital camera sensors are sensitive to wavelengths ranging from the ultraviolet (200-400nm) to the near-infrared (700-100nm) bands. This range is, however, reduced because the aim of photographic cameras is to capture and reproduce the visible spectrum (4 ...

2009

Daylight Exposure and Circadian Efficiency in Office Rooms Equipped with Anidolic Daylighting Systems

Jean-Louis Scartezzini, Mirjam Münch, Friedrich Linhart

Anidolic Daylighting Systems (ADS) typically reduce the daylight flux reaching an office room‟s window section and increase it in the rear of the room. They offer interesting possibilities for the combination of comfortable daylighting and highly energy-ef ...

EPFL2009

Doping-induced charge trapping in organic light-emitting devices

Frank Nüesch, Libero Zuppiroli, Detlef Berner, Eduard Tutis, Xiao Wang

By using pyran-containing donor-acceptor dyes as doping molecules in organic light-emitting devices (OLEDs), we scrutinize the effects of charge trapping and polarization induced by the guest molecules in the electro-active host material. Laser dyes 4-(dic ...

Wiley-VCH2005

Microcavity light emitting diodes in the visible red and near infrared wavelength range

It was about 125 years ago that the light bulb was commercialized by Thomas Edison. No doubt a brilliant invention at the time, today its low power conversion efficiency is one of the reasons why lighting in the western world has such high energy consumpti ...

EPFL2005