Temperature controlled light-emitting diode lamp for photovoltaic rural applications

In recent years, interest in light-emitting diode (LED) lighting has been growing because of its high efficacy, lifetime and ruggedness. This paper proposes a better adaptation of LED lamps to the technical requirements of photovoltaic lighting domestic systems, whose main quality criteria are reliability and that behave as voltage power supplies. As the key element of reliability in LED lamps is temperature, a solution is proposed for driving LED lamps using voltage sources, such as photovoltaic system batteries, with a control architecture based on pulse width modulation signal that regulates the current applied according to the LED lamp temperature. A prototype of the LED lamp has been implemented and tested to show its good performance at different temperatures and at different battery voltages.

Aladdin's Magic Lamp: Developing Methods for Calibration and Geolocation Accuracy Assessment of the DMSP OLS

Nighttime satellite imagery from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) has a unique capability to observe nocturnal light emissions from sources including cities, wild fires, and gas flares. Data from the DMSP OLS is used in a wide range of studies including mapping urban areas, estimating informal economies, and estimating urban populations. Given the extensive and increasing list of applications a repeatable method for assessing geolocation accuracy, performing inter-calibration, and defining the minimum detectable brightness would be beneficial. An array of portable lights was designed and taken to multiple field sites known to have no other light sources. The lights were operated during nighttime overpasses by the DMSP OLS and observed in the imagery. A first estimate of the minimum detectable brightness is presented based on the field experiments conducted. An assessment of the geolocation accuracy was performed by measuring the distance between the GPS measured location of the lights and the observed location in the imagery. A systematic shift was observed and the mean distance was measured at 2.9km. A method for in situ radiance calibration of the DMSP OLS using a ground based light source as an active target is presented. The wattage of light used by the active target strongly correlates with the signal measured by the DMSP OLS. This approach can be used to enhance our ability to make inter-temporal and inter-satellite comparisons of DMSP OLS imagery. Exploring the possibility of establishing a permanent active target for the calibration of nocturnal imaging systems is recommended. The methods used to assess the minimum detectable brightness, assess the geolocation accuracy, and build inter-calibration models lay the ground work for assessing the energy expended on light emitted into the sky at night. An estimate of the total energy consumed to light the night sky globally is presented.

Les deux chemins opposés de la cartographie arabo-islamique médiévale: la mappemonde «islamique» («L'école d’al-Balḫī», Xe siècle) ou le monde en sa diversité (al-Šarīf al Idrīsī, XIIe siècle)

Cette étude fait partie du Projet «Biblioteca Digital Multilingue del Mediterráneo-IVITRA», du programme PROMETEO de la Generalitat Valenciana para Grups de Recerca d’I+D d'Excel·lència, réf. PROMETEO-2009-042, que nous développons dans le projet IVITRA (http://ivitra.ua.es).

The development and structure of the U.S. electric lamp industry : staff report of the Federal Trade Commission /

Cover title: Staff report on the development and structure of the U.S. electric lamp industry.

Driver perception of just-noticeable differences of automotive signal lamp intensities. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Mosque Lamp

Glass, Islamic, Mamluk; 10 5/16 in. x 8 17/64 in.; glass, brownish; blown, folded foot, applied handles; enameled and gilded

Mosque Lamp, from the Suleymaniye Mosque

Pottery, Turkey, Ottoman; 1 ft. 6 31/32 in. x 1 ft. 13/32 in.; glazed fritware, polychrome underglazed painted

The lamp in the desert,

Mode of access: Internet.

Recherches sur les premiers papiers employés en Occident et en Orient du Xe au XIVe siècle,

"Extrait des Mémoires de la Société nationale des antiquaires de France. t. XLVI.'

The lamp of poor souls, and other poems,

"The greater number of these poems appeared in an earlier volume, "The drift of pinions'."

Les origines de l'ancienne France: Xe et XIe siècles ...

Imprint varies slightly.