Lumen equivalent

Figure 4. Lumen equivalent values of several spectral distributions having the color coordinates x = 0.65, y = 0.35 (1-5)...

However, the (Zn,Cd)S system has several disadvantages. In the first place, the use of cadmium has become inacceptable for environmental reasons. The red phosphor on this basis has still another large disadvantage, viz. in order to obtain red emission the larger part of the broad band emission of this phosphor is situated in the near infrared. The maximum of the emission band is close to 680 nm. This implies that the lumen equivalent of this phosphor is low (2S%). For Y2O2S Eu with line emission this is 55% [ I ]. 

Lumen equivalent relative to monochromatic light of 611 nm wavelength. 

It is important that the Do - F4 emission of at about 700 nm is as weak as possible, since this will decrease the lumen equivalent. The high value of the lumen equivalents of Y203 Eu " and Y2(W04)3 Eu " are actually due to the low Do - F4 intensity. Further, the D emission of Eu should be quenched by cross relaxation as in the lamp phosphor (see Sect, 6.4.1.4). This makes a Eu concentration of some 3% necessary. 

Figure 6, Polarized epithelial cells in culture. Epithelial cells in culture possess an apical surface with microvilli that faces the tissue culture medium (equivalent to the lumenal side of the cells in vivo), and a basolateral surface that faces the tissue culture dish (equivalent to the blood side of the cells in vivo).

Figure 46-8. Fusion of a vesicle with the plasma membrane preserves the orientation of any integral proteins embedded in the vesicle bilayer. Initially, the amino terminal of the protein faces the lumen, or inner cavity, of such a vesicle. After fusion, the amino terminal is on the exterior surface of the plasma membrane. That the orientation of the protein has not been reversed can be perceived by noting that the other end of the molecule, the carboxyl terminal, is always immersed in the cytoplasm. The lumen of a vesicle and the outside of the cell are topologically equivalent. (Re drawn and modified, with permission, from Lodish HF, Rothman JE The assembly of cell membranes. Sci Am [Jan] 1979 240 43.)...

For the sake of simplicity, we may replace the packed segment by a hypothetical open tube of length, Le, that is the same as the distance traveled by the neutral and inert tracer in the packed segment. The lumen of this hypothetical tube, A packed, is assumed to be the same as the free cross-sectional area of the packed column so that Apacked = 7rae, where, ae is the radius of the hypothetical tube. The equivalent length, Le, is determined from the ratio of the conductivities of the packed and the open... 

Various theoretical cases of polymer properties were considered in Fig. 6. The values of Ep or Tp used in the simulation are not necessarily those of existing polymers. They were tried in order to illustrate the limits of properties modified by treatments involving no modifications of the cell walls. The case (f), for instance, equivalent to filling the lumens with pure cellulose, is the only one inducing an increase of E /y and a decrease of tan 8 at the same time. 

A lux is the standard of illuminance equivalent to one lumen per square meter (Im/m ). This is a lighting term and not very applicable to photochemical uses. 

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