Search results for "Light"
showing 10 items of 3575 documents
Environmental Organic Photochemistry: Advances and Perspectives
2013
This review is a survey of recent advances in environment related aspects of organic photochemistry. Besides presenting gen- eral concepts, the manuscript is mainly focused on the photoreactivity of natural organic matter, and on the photochemistry of anthropo- genic substances under natural light irradiation.
Study of scintillation light collection, production and propagation in a 4 tonne dual-phase LArTPC
2020
The $3 \times 1 \times 1$ m$^3$ demonstrator is a dual phase liquid argon time projection chamber that has recorded cosmic rays events in 2017 at CERN. The light signal in these detectors is crucial to provide precise timing capabilities. The performances of the photon detection system, composed of five PMTs, are discussed. The collected scintillation and electroluminescence light created by passing particles has been studied in various detector conditions. In particular, the scintillation light production and propagation processes have been analyzed and compared to simulations, improving the understanding of some liquid argon properties.
The role of light in the emergence of weeds: using Camelina microcarpa as an example
2015
When modelling the emergence of weeds, two main factors are considered that condition this process: temperature and soil moisture. Optimum temperature is necessary for metabolic processes that generate energy for growth, while turgor pressure is necessary for root and shoot elongation which eventually leads to seedling emergence from the soil. Most emergence models do not usually consider light as a residual factor, but it could have an important role as it can alter directly or indirectly the dormancy and germination of seeds. In this paper, inclusion of light as an additional factor to photoperiod and radiation in emergence models is explored and compared with the classical hydrothermal t…
The effect of light quality on anther culture of Citrus clementina Hort. ex Tan.
2005
This pre lim i nary re search re ports re sults on the in flu ence of light qual ity on an ther cul ture of Cit rus clementina Hort. ex Tan., cultivar Nules. Af ter one month of cul ti va tion in dark - ness, four light quali ties were tested: White, Red, Far-Red and Blue. Con tin u ous Dark ness and White light un der photoperiod of 16 hrs were used as a con trol con di tions. Ga metic embryoids and embryogenic cal lus were ob tained only un der photoperiodic con di tions of White light, sug gest ing that the al - ter na tion of light and dark can be used for the pro cess of ga - metic embryogenesis in Cit rus.
Simulation analysis of Ruthenium-based Dye Sensitized Solar Cells
2016
Dye Sensitized Solar Cell (DSSC), usually referred as one of the most promising third generation photovoltaic devices, is an electrochemical device in which a molecule (i.e., the dye) chemisorbed onto the surface of a porous material absorbs the incident light and, thus, transfers an electron to the wide band gap semiconductor material. The injected electrons can diffuse through the semiconductor up to the collecting anode without the risk of recombination. The roles of the electrolyte which permeates the cell are to regenerate the ionized molecule and to implement a hole-transporting layer, allowing to repeat the abovementioned process. Thanks to this behaviour, semiconductors with large a…
A giant planet beyond the snow line in microlensing event OGLE-2011-BLG-0251
2013
We present the analysis of the gravitational microlensing event OGLE-2011-BLG-0251. This anomalous event was observed by several survey and follow-up collaborations conducting microlensing observations towards the Galactic Bulge. Based on detailed modelling of the observed light curve, we find that the lens is composed of two masses with a mass ratio q=1.9 x 10^-3. Thanks to our detection of higher-order effects on the light curve due to the Earth's orbital motion and the finite size of source, we are able to measure the mass and distance to the lens unambiguously. We find that the lens is made up of a planet of mass 0.53 +- 0.21,M_Jup orbiting an M dwarf host star with a mass of 0.26 +- 0.…
The relationship between visible light emission and species fraction of the hydrogen ion beams extracted from 2.45 GHz microwave discharge.
2015
The relationship between Balmer-α and Fulcher-band emissions with extracted H + , H + 2 , and H + 3 ions is demonstrated for a 2.45 GHz microwave discharge. Ion mass spectra and optical measurements of Balmer-α and Fulcher-band emissions have been obtained with a Wien Filter having an optical viewport on the plasma chamber axis. The beam of approximately 1 mA is analyzed for different plasma conditions simultaneously with the measurement of light emissions both with temporal resolution. The use of visible light emissions as a valuable diagnostic tool for monitoring the species fraction of the extracted beams is proposed. peerReviewed
Slight variations in components ratio affect odor pleasantness of a blending mixture
2009
International audience; Odors rely mainly on the perception of odorants mixtures but are commonly perceived as single undivided entities; nevertheless, the processes involved remain poorly explored. It has been reported that perceptual blending, based on configural olfactory processing, can lead odorant mixtures to give rise to an emergent odor quality not present in the components. Furthermore, very slight variations (just noticeable differences, jnd) in components concentrations were shown to be sufficient to modify the odor quality of a blending mixture. In the present study, we set out to examine whether jnd in components concentrations could also affect the odor pleasantness of a blend…
Active lighting applied to three-dimensional reconstruction of specular metallic surfaces by polarization imaging
2006
International audience; In the field of industrial vision, the three-dimensional inspection of highly reflective metallic objects is still a delicate task. We deal with a new automated three-dimensional inspection system based on polarization analysis. We first present an extension of the shape-from-polarization method for dielectric surfaces to metallic surfaces. Then, we describe what we believe to be a new way of solving the ambiguity concerning the normal orientation with an active lighting system. Finally, applications to shape-defect detection are discussed, and the efficiency of the system to discriminate defects on specular metallic objects made by stamping and polishing is presente…
Cristianismo, revolución y renovación en Chile. El movimiento de acción popular unitaria (MAPU) 1969-1989
2011
El Movimiento de Acción Popular Unitaria (MAPU) fue un pequeño, pero influyente partido de la política chilena entre 1969 y 1989, nacido de la escisión de parlamentarios “comunitaristas” y los jóvenes “rebeldes” de la Democracia Cristiana. El nuevo partido fue protagonista de los dos principales procesos históricos de la izquierda a fines del siglo XX: a.- la creación de la Unidad Popular que llevó a Salvador Allende al poder en 1970, el que fracasó en medio del complot a dicho gobierno y las fuertes divisiones de la izquierda entre revolucionarios y reformistas, que llevó al propio MAPU a su escisión previa al golpe de estado en 1973 (nace el MAPU-Obrero Campesino, moderado), b.- el proces…