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Concept

Electric light

Publications associées (28)

III-N blue-emitting epi-structures with high densities of dislocations: Fundamental mechanisms for efficiency improvement and applications

Pierre Christophe Lottigier

Since the dawn of humanity, human beings seeked to light their surroundings for their well-being, security and development. The efficiency of ancient lighting devices, e.g. oil lamps or candles, was in the order of 0.03-0.04% and jumped to 0.4-0.6% with th ...

EPFL2024

Perceived glare from the sun behind tinted glazing: Comparing blue vs. color-neutral tints

Marilyne Andersen, Andreas Schueler, Jan Wienold, Sneha Jain, Maxime Lagier

While the influence of a glare source's spectrum on sensitivity to discomfort glare has been demonstrated repeatedly under electric light conditions, it has not yet been studied under actual daylit conditions. To investigate the influence of spectral alter ...

2023

The mesoglea buffers the physico-chemical microenvironment of photosymbionts in the upside-down jellyfish Cassiopea sp

Anders Meibom, Niclas Heidelberg Lyndby

IntroductionThe jellyfish Cassiopea has a conspicuous lifestyle, positioning itself upside-down on sediments in shallow waters thereby exposing its photosynthetic endosymbionts (Symbiodiniaceae) to light. Several studies have shown how the photosymbionts b ...

FRONTIERS MEDIA SA2023

Ion-Dipole Interaction Enabling Highly Efficient CsPbI3 Perovskite Indoor Photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Haizhou Lu

Metal halide perovskites are ideal candidates for indoor photovoltaics (IPVs) because of their easy-to-adjust bandgaps, which can be designed to cover the spectrum of any artificial light source. However, the serious non-radiative carrier recombination und ...

Wiley-V C H Verlag Gmbh2023

Validation of spectral simulation tools in the context of ipRGC-influenced light responses of building occupants

Marilyne Andersen, Clotilde Marie A Pierson

With the growing awareness about ipRGC-influenced light (IIL) responses, design applications related to these responses are flourishing. To compare design options and optimize lighting conditions for building occupants, lighting simulations are typically u ...

2023

Optimized office lighting advances melatonin phase and peripheral heat loss prior bedtime

Jean-Louis Scartezzini, Mirjam Münch, Marta Benedetti, Lenka Maierova

Improving indoor lighting conditions at the workplace has the potential to support proper circadian entrainment of hormonal rhythms, sleep, and well-being. We tested the effects of optimized dynamic daylight and electric lighting on circadian phase of mela ...

Nature Research2022

Effects of illuminance intensity on the green channel of remote photoplethysmography (rPPG) signals

Ata Jedari Golparvar

Point-of-care remote photoplethysmography (rPPG) devices that utilize low-cost RGB cameras have drawn considerable attention due to their convenience in contactless and non-invasive vital signs monitoring. In rPPG, sufficient lighting conditions are essent ...

SPRINGER2022

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 Electric Light Exposure

Marilyne Andersen, Clotilde Marie A Pierson

As the interest in design applications related to responses to light beyond vision is growing, two simulation tools, ALFA and Lark, have been developed to incorporate spectral characteristics of light in the evaluation of indoor lighting conditions. The sp ...

Commission Internationale de L'Eclairage2021

Integrating non-visual effects of light in the automated daylight-responsive control of blinds and electric lighting

Marta Benedetti

The use of daylight in buildings is important because it contributes to energy savings by reducing the use of electric lighting and space heating. It also impacts on biological functions and on well-being. Indeed, light not only allows vision, but has non- ...

EPFL2021

Self-commissioning glare-based control system for integrated venetian blind and electric lighting

Jean-Louis Scartezzini, Laurent Deschamps, Ali Motamed

Rule-based control logics have proven to be efficient for automation of shading and lighting systems. However, successful commissioning of these systems for multiple stores non-residential buildings, regardless of the control logic, requires time-consuming ...

2020

Effect of Indoor Temperature and Glazing with Saturated Color on Visual Perception of Daylight

Marilyne Andersen, Jan Wienold, Giorgia Chinazzo

This paper presents the combined effect of indoor temperature (19 degrees C, 22 degrees C, and 26 degrees C) and colored glazing (blue, orange, and neutral) on visual perception of daylight. Experiments were performed in an office-like test room, in which ...

TAYLOR & FRANCIS INC2021

Illumination-Dependent Requirements for Heterojunctions and Carrier-Selective Contacts on Silicon

Mathieu Gérard Boccard, Jakub Holovsky, Luca Massimiliano Antognini

High efficiency silicon solar cells generally feature heterojunction or carrier-selective contact architectures, for which there is current interest in developing structures using a wide range of materials. The electrical and optical requirements that thes ...

2020

Calibration and Validation of Climate-Based Daylighting Models Based on One-Time Field Measurements: Office Buildings in the Tropics

Geraldine Cai Ting Quek

Calibrated climate-based lighting simulation models of buildings have the capacity to perform an essential role in postoccupancy evaluations, such as annual frequency assessments of daylighting quality and visual discomfort. However, in most postoccupancy ...

2021

Elucidating the role of the InGaN UL in the efficiency of InGaN based light-emitting diodes

Camille Haller

Blue III-nitride light-emitting diodes (LEDs) are widely used nowadays in solid-state lighting, as white light can be produced by combining yellow phosphors and blue LEDs. This technology has the advantage to have a higher luminous efficiency than incandes ...

EPFL2019

Tailoring Triple-Anion Perovskite Material for Indoor Light Harvesting with Restrained Halide Segregation and Record High Efficiency Beyond 36%

Hong Zhang, Zhiwen Zhou

Indoor photovoltaics are promising to enable self-powered electronic devices for the Internet of Things. Here, reported is a triple-anion CH3NH3PbI2-xBrClx perovskite film, of which the bandgap is specially designed for indoor light harvesting to achieve a ...

2019

Daylight and temperature in buildings: interaction effects on human responses

Giorgia Chinazzo

Over the past years, increasing efforts have been devoted to understand how people perceive the indoor environment with the goal to improve building design and operation. Studies have separately addressed the effects of the four main aspects that influence ...

EPFL2019

Daylight affects human thermal perception

Marilyne Andersen, Jan Wienold, Giorgia Chinazzo

Understanding the factors that affect human thermal responses is necessary to properly design and operate low-energy buildings. It has been suggested that factors not related to the thermal environment can affect thermal responses of occupants, but these f ...

Nature Research2019

Influence of indoor temperature and daylight illuminance on visual perception

Marilyne Andersen, Jan Wienold, Giorgia Chinazzo

This paper details the results of an experimental study investigating the combined effect of indoor temperature (19 ℃, 23 ℃ and 27 ℃) and horizontal illuminances (∼140 lx, ∼610 lx and ∼1440 lx) on visual perception, with daylight as the only source of ligh ...

2019

High power ultraviolet LED illumination systems: coherence properties and applications in photolithography

Johana Bernasconi

Mask-aligner photolithography is a technology used to replicate patterns from a mask to a photosensitive substrate. It is widely used in the fabrication of MEMS and micro-optical components, and for other applications with dimensions in the micrometer rang ...

EPFL2018