Polarizers efficiencies

FIGURE 10.7 Power consumption simulation for a 2.2-in. full-color OLED display using Universal Display s phosphorescent OLEDs, small-molecule fluorescent devices, and polymer OLEDs along with a comparison of the power consumed by an active-matrix liquid crystal display backlight. R G B= 3 6 1, 50% polarizer efficiency, and 30% of pixels lit. (From Mahon, J.K., Adv. Imaging, June, 28, 2003. With permission.)... 

A polarized beam apparatus is shown schematically in Fig. 10. The polarized beam is produced by reflection from a crystal for which b=p da fdQ = 0, Eq. (3.34)]. The (111) plane of Coo.92Feo.08 is frequently used, and polarization efficiencies of >99 percent may be obtained. The polarization may be reversed... 

Once Lhe vapor- and liquid-phase transfer units have been determined, they are combined to obtain the number of overall transfer units (vapor concentration basis) by Eq. (5.9-19). Finally, the leeal, or polar, efficiency is computed ... 

Figure 5.12 shows the CPMAS/DD NMR spectra of semi-crystalline a-PBT [poly(butylene terephthalate)] recorded [22] below (a) and well above (b) its 7g of 55°C. At ambient temperatures, both crystalline and amorphous carbons are sufficiently rigid to cross-polarize efficiently, but at 105°C the amorphous carbons are mobile and conformationally averaging. The ambient spectrum is broadened by the rigid and conformationally diverse amorphous carbon nuclei which resonate at a variety of frequencies. At lOS C the amorphous carbons, which are mobile with small 7, are conformationaUy averaging to (Ti, and no longer cross-polarize efficiently. Thus at elevated temperatures, only the crystalline carbons in the sample are contributing to the CPMAS/DD spectrum. 

The two spin states of the neutron can be distinguished by considering their response to an external magnetic held a spin + would be aligned parallel to the field direction (B), whereas a spin would be antiparallel to it. In a non-polarized beam of neutrons the frequency of + (and of — ) spins is 50%. The polarization of a neutron beam (in the direction of B), as well as the polarizing efficiency of a polarizer, may be characterized by the parameter P defined as P = N+-N )/ N++N-), where N+ and NL are the numbers of neutrons with spin + and respectively. 

Figure 4. Upper limits on detector half-angle as a function of polarizer efficiency To test the BCHSH inequality, the experiment must be performed with apparatus parameters chosen in the region below the appropriate curve— the upper curve for a 0-1-0 cascade, the lower for a 1-1-0 cascade. (From Clauser et...

Polyaniline also presents an additional potential advantage because uniaxially oriented blends of polyaniline doped with dode-cylbenzenesulfonic acid or CSA and common bulk polymers such as polyacrylonitrile, polyethylene, and poly(vinyl alcohol) display a polarizing efficiency over the range from 400 to 4000 cm that matches, or surpasses, that of commercial wire grid polarizers [211]. These characteristics permit the use of polyaniline simultaneously as a polarizer and as an anode. 

Fig. 16. The experimental CP/MAS spectrum of solid glassy aPP (top) is compared with simulations for the various groups (rows 2-4). For all groups the shape is satisfactorily matched. Note that for all spectra - experiment and theory - the width of the spectrum is 50 ppm. The absolute position is not correctly reproduced by the quantum chemical simulations due to the small atomic basis employed and has been adjusted for better comparison. The absolute height of the peaks does not convey any information since, experimentally, different cross polarization efficiencies tend to distort the stoicheometric relations. Thus, the simulated spectra were all scaled to the same peak height. The fine line shows the contributions of the various conformations, Eq. (3.15) (slightly broadened for typographical reasons), the hold line is the simulation with the d-function being replaced by a Gaussian function s, Eq. (3.16)...

In this technique one standard polarizer is replaced by a dichroic color sensitive polarizer. For the yellow mode this results in a compensation of the off state and only slight influence on the on state. This mode of operation is called the neutral STN-mode (NSTN). For the complementary blue mode a compensation of the on state is achieved. A disadvantage of this technique is the low polarization efficiency of only (50-75)%. This limits its use to low-multiplexed displays with moderate requirements of contrast and viewing angle. 

The threshold characteristic of the dye-doped TN display is very similar to that of a TN display (see Fig. 4). The contrast ratio of a dye-doped TN LCD is heavily dependent on the polarization efficiency of the polarizer, and thus polarizers with very high polarization efficiency (>99%) should be used. The threshold and operating voltages also increase slightly with an increase in thickness. The contrast ratio shows a similar effect to the Gooch Tarry curve in TN displays. The contrast ratio has been found to maximize at the first and second Gooch Tarry minima [16, 88]. It has been found that the incorporation of dyes broadens the Gooch Tarry minima [16, 27]. The addition of a small amount of dichroic dye decreases the values of the maxima and increases... 

CIDNP is not a direct method of detection of the structure of radical species the information of hy-perfine interaction (hfi) constants, g-factors, and lifetimes of paramagnetic intermediates, is obtained on the basis of the analysis of the phases and intensities of polarized lines in NMR spectra, as well as from CIDNP kinetics, and the dependence of polarization efficiency on the magnetic field strength applied to the sample during reaction. However, the simplicity and reliability of the identification of polarized lines in the NMR spectra ensure high plausibility of CIDNP-based structural and kinetic information. 

MAS does have an effect on the cross-polarization efficiency for mobile systems like elastomers [72]. For a static sample, the transfer rate is a function of u>c and has a maximum polarization-transfer rate at the Hartman-Hahn match and a slower polarization transfer with increasing mismatch. However, when the sample is spun with MAS, there is a very slow transfer of polarization at the Hartman-Hahn match, where the transfer is expected to be most rapid. A series of maxima in the transfer rate occurs when co c and co w are mismatched by a multiple of the spinning firequency. Thus, mismatching the cuic and )ih produces high signals at multiples of the MAS firequency. A series of maxima in Tch are observed as a result of an amplitude-modulated pattern due to C-H heteronuclear coupling [73]. 

The polarimeter was commissioned on the nights 1993, May 4 5. The results show that (1). The polarization efficiency is 100% from 1 to 2.4/im (as measured using a Gian prism). (2). The instrumental polarization is (0.02 0.06)%. (3). The polarization measurements for a number of standard polarized stars taken from Whittet et al. (1992) gave excellent agreement with an rms scatter of 0.15%. 

---