Luminance ratio

Visual or fighting quality view, illiuninance, luminance ratios, reflection, etc. 

In a given ambient lighting, the luminance varies between the minimal luminance, L min, and the maximal luminance, Umax. The ratio Umax/Umin is the luminance ratio. In order to have similar image appearance with respect to contrast, all display devices should have the same luminance ratio and the same display function. If more than one monitor is used in a workstation, as is usually the case, the luminance responses should be compared and found to be similar within specified limits. 

Brightness Ratio One should also analyze work stations for brightness ratio or luminance ratio. Luminance... 

Opacity or transparency is important when the amount of light to be transmitted is a consideration. These properties are usually measured as haze and luminous transmittance. As reviewed haze is defined as the percentage of transmitted light through a test specimen that is scattered more than 2.5° from the incident beam. Luminous transmittance is the ratio of transmitted light to incident light. Table 5-7 provides the optical and various other properties of different transparent plastics. 

Size Format Resolution Contrast ratio Full white brightness Power consumption Color gamut Luminance uniformity Pixel count... 

The enhancement in luminous efficiency achieved by inserting an ultrathin interlayer between the ITO and NPB is mainly due to the reduction of hole injection from ITO to NPB in OLEDs. For a simple approximation, luminous efficiency (rj) can be related directly to a ratio of the recombination current (/r) to the total current density of OLEDs (/tot). If one denotes the current contributions from holes and electrons in OLEDs as. /h and /e, respectively, then the sum of hole and electron currents, /tot. /h + /e, and tj can be expressed as... 

The luminous efficiency is the simplest to calculate. It is the ratio of the luminance (cd/m2) to the current density (A/m2), and has units of cd/A. Finally, the power efficiency is the ratio of the light output in lumens divided by the electrical input in watts. For reference, a typical incandescent light bulb is 151m/W, while a fluorescent light bulb is 601m/W. 

Ionic liquids are excellent solvents for the Diels-Alder reaction providing significant increases in rate and selectivity. Diels-Alder reactions conducted in chloroa-luminate ionic liquids show considerable promise. For example, the endo.exo ratio for the reaction between cyclopentadiene and methyl acrylate (Scheme 7.5) could be varied by changing the composition of the ionic liquid (see Chapter 4) [11]. Although a high yield was obtained, in order to extract the products it was necessary to quench the ionic liquid in water. This is a considerable disadvantage and for this reason neutral ionic liquids have been the focus of subsequent attention. 

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