lumen

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lumen:

see photometryphotometry
, branch of physics dealing with the measurement of the intensity of a source of light, such as an electric lamp, and with the intensity of light such a source may cast on a surface area.
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Lumen

A unit of light from one source. Light falling on 1 square foot of surface of an imaginary sphere having a 1-foot radius around 1 candle.

Lumen

 

the unit of luminous flux in the International System of Units. Symbol, 1m. One lumen is the luminous flux emitted by an isotropic point source in a with a luminous intensity of 1 candela in a solid angle of 1 steradian.

lumen

[′lü·mən]
(anatomy)
The interior space within a tubular structure, such as within a blood vessel, a duct, or the intestine.
(optics)
The unit of luminous flux, equal to the luminous flux emitted within a unit solid angle (1 steradian) from a point source having a uniform intensity of 1 candela, or to the luminous flux received on a unit surface, all points of which are at a unit distance from such a source. Symbolized lm.
(science and technology)
The space within a tube.

lumen (lm)

The SI unit of luminous flux equal to the luminous flux received on a unit surface, all points of which are equidistant from a point source having a uniform intensity of 1 candela.

lumen

A unit of measurement of the light intensity radiating in the air in all directions from a light source. Lumens define "luminous flux," which is energy within the range of frequencies we perceive as light. For example, a wax candle generates about 13 lumens; a 60-watt bulb approximately 800, and a 100-watt bulb 1,600 lumens.

Lumen Ratings for Data Projectors
When choosing a data projector, the lumen rating is an important specification. In a small, dark room, 500 lumens may be ample; however, in a conference room with normal lighting, 1,000 to 2,000 lumens is required. In a large, well-lit room, at least 2,000 lumens is necessary. This rating is derived by taking the average of photometer readings at several points on a full white image on the screen. See lux, ANSI lumen, Lm/W, candela and spectrum.
References in periodicals archive ?
The production of these immunomodulatory cytokines largely depends on resident DCs that sample the lumenal contents at the epithelial barrier (Cerovic et al.
Das 250 amostras de conteudo lumenal de ileo e jejuno analisadas, 171 (68,4%) demonstraram caracteristicas morfo-tintoriais e bioquimicas compativeis com Cp, apresentando bastonetes gram positivos curtos, colonias arredondadas, umbilicadas, brilhantes com zona de dupla hemolise no ASA e ausencia de crescimento em anaerobiose.
notoides, lumenal oil droplets disappeared slowly, over a period of days (7-8 days in our field-fed squid; 3-4 days in our mysid-fed squid), not hours or minutes.
Yates, "NADPH oxidase activity controls phagosomal proteolysis in macrophages through modulation of the lumenal redox environment of phagosomes," Proceedings of the National Academy of Sciences of the United States of America, vol.
Suggested hypotheses include intrauterine vascular accidents, persistent embryonic diverticula, and aberrant lumenal recanalization.
Molecular modeling of the 3D structure of the lumenal domain of ribophorin I demonstrated that ribophorin I has several [beta]-propeller domains rich in hydrophobic amino acids on its molecular surface.
Defining clinically significant coronary artery disease as lumenal narrowing above 70%, Grinspoon uncovered serious coronary artery trouble in 5 men with HIV (6.
A study with isolated human proximal tubular cells (HK2 cells) in culture (5) demonstrated that radiolabeled albumin enters the cells from the apical pole (the lumenal side).
Effects of colonic lumenal components on AP-1 dependent gene transcription in cultured human colon carcinoma cells.
Numerous individual hemocytes containing India ink were eliminated from the clams by diapedesis over lumenal epithelial surfaces (Fig.
Professor Donald Baim, who recently presented his experience in the animal lab with Cappella, stated that "IVUS, radiography and histology show excellent expansion in both the side-branch and the main vessel, full lumenal patency, and complete wall apposition through the ostial transition segment.
In contrast, most nascent apoB that fails to assemble properly into lipoprotein on the lumenal side of the ER becomes membrane bound and is inefficiently or partially translocated.