Reflectance ratio

After merging of the single zones, data sets of approx. 100-300 independent reflections can be obtained as described in chapter 2.5. In a first step a kinematical structure refinement should be performed using the program SHELXL [13]. The temperature factors for FAPPO were chosen as U = 0.06 for C, N and O as U = 0.10 for H atoms apart from H atoms situated at N with U = 0.12 A (Electron scattering factors [20]). To prevent the molecules from being distorted a refinement, where the whole molecule was kept rigid, was performed. This also improves the usually bad parameter/reflection ratio. In the case of modification I we obtained R-values of 31% (481 unique reflections with I > 2cr) for the 100 kV data and of 25% (385 unique reflections with I > 2a). The sparse 100 kV data of modification II was not analysed quantitatively. From 300 kV data we obtained an R-value of 23% (226 unique reflections with I > 2a). 

If the blackness of the particulate matter collected on a filter is due to the graphitic carbon content of the sample, then the Km unit should convert to ambient elemental carbon concentrations. The form of that translation is apparent from the definition of the Km unit. Elemental carbon concentration measurements made by laboratory reflactometers calibrated against heated butane soot standards show that elemental carbon concentrations are linearly related to the log of the reflectance ratio R /R. Aerosol loadings stated in Km units should be directly proportional to elemental carbon concentrations sampled. 

Essentially, this operation computes the average reflectance ratio between the reflectance of the current point and the average reflectance of random samples surrounding the point (Brainard and Wandell 1992 Hurlbert 1986). If the threshold operation is used and the paths are assumed to pass through all of the image pixels then the retinex algorithm is simply normalization with respect to the response at the largest location (Brainard and Wandell 1992). 

Weersink R, Patterson MS, Diamond K, Silver S, Padgett N. Noninvasive measurement of fluorophore concentration in turbid media with a simple fluorescence/reflectance ratio technique. Applied Optics 2001, 40, 6389-6395. 

Fic. 5. Reflection ratio of textured a-Si versus laser pulse energy. Data for three different pulse widths are given. , 100 nsec , 200 nsec 1 fisec. [After Craighead et al. (1982).]... 

Using 8 0. Atmospheric sulfate (aerosol and rainfall) has recently been found to have a mass independent isotopic composition, with excess over what would have been expected based on the 5 0 of sulfate (Lee et al., 2001). On a three-isotope plot with on the x-axis and 5 0 on the y-axis, mass-dependent fractionation (MDF) result in sulfate values defined by the relation = 0.525 0, whereas MIF causes values that deviate from this relation. For sulfate, the mass-independent relation is described by -0.525 O (Lee et al., 2001). Hence, MDF results in = 0, whereas an MIF results in A O 5 0. and A O values reflect ratios, and are reported in per mil... 

Schebece examined several commercial hairsprays for hair luster before and after soaking fibers in different concentrations of the product concentrates. In all cases, the specular/diffuse reflectance ratios decreased (from 2 to 14%), depending on the concentration and type of resin used. In addition, combing and other physical manipulations of the resin on the hair produced cracks in the hairspray resins, increasing the diffuse scattering and further dulling the hair. 

The classical generation of an activity-sensitive voltage is spontaneous in a solution containing both non redox ions and redox ions. Classical electrodes of types 1,2, and 3 respond by ion exchange directly or indirectly to ions of the same material as the electrode. Inert metal electrodes (sometimes called type 0)—Pt, Ir, Rh, and occasionally carbon C—respond by electrons exchange from redox pairs in solution. Potential differences are interfacial and reflect ratios of activities of oxidized to reduced forms. 

Here the factor 1/2 is due to the temporal averaging by the detector over the oscillations of the electric field of the light. If the reflectivity ratio is... 

The ellipsometric method has been developed by Yukioka and Inoue (1991, 1994). The principles of the technique and the model used for calculating the thickness of the interphase are schematically illustrated in Figs. 4.13 and 4.14, respectively. The retardation (A) and reflection ratio (tan(i/<)) can be determined from the ellipsometric readings. The adopted model assumes the existence of four layers air, thin polymer-1, interphase, and thick polymer-2 (see Fig. 4.14). In the interphase the refractive index is assumed to be an average n = iti+ ni)H. Thus, one can compute the best value of the interfacial thickness, do, to fit the observed values of A and tan( ). The following relations were derived for the computation of d ... 

Multilayer dielectric film is a well-developed technique in thin-film optics, but only very recently was it incorporated in transflective LCDs [16]. As illustrated in Figure 9.4(c), two dielectric inorganic materials with refractive indices and 2 are periodically deposited as thin films on the substrate. By controlling the refractive index and thickness of each thin layer, as well as the total number of layers, one can obtain the desired reflectivity and transmissivity. Similar to the half-mirror transflector, the transmittance/reflectance ratio of the multilayer dielectric film is sensitive to each layer s thickness. In addition, to produce several layers successively increases the manufacmring cost. Therefore, the multilayer dielectric film transflector is rarely used in commercial transflective LCDs. 

Reflection factor (reflectivity) Ratio of reflected light flux to the incident light flux... 

Reflectance (relative spectral directional reflectance) Ratio of the radiant flux reflected from a light-diffusing specimen to that reflected from a light-diffusing standard. 

The change in ellipsoidal shape between the incident and reflected hghts is determined by a ratio of to described in Eqs. (3) and (4). The change is described by the following relative reflection ratio ... 

Figure 6 The complex reflection ratio p for the system described in Figure 5.

Figure 7 The spectroscopic values of the complex reflection ratio p for three samples of Si02 films grown on silicon as measured by spectroscopic ellipsometry. The three different thicknesses are (A) 66nm, (B) 190nm, and (C) 321 nm.

Tp, Tj, etc. = complex reflection coefficients 5 = sin(2 /) sin(A) 5 = Stokes vector V = voltage, element of Stokes vector z = vector of fitted parameters (Eqn [14]) a = absorption coefficient 8c = constant phase shift A = ellipsometry angle 0 = azimuthal angle X = wavelength p = complex reflection ratio ( ) = angle of incidence ( )f, = complex... 

Surface activity in 1,4-polyisoprene-polyacetylene, AB, block copolymer solutions was to be expected from the amphiphilic properties of such a diblock system with one moiety so insoluble because of the strong polyacetylene-polyacetylene attractive interactions. The present experiments allow access, for the first time, to some of the thermodynamic parameters of these interactions and give a structural model for the surface excess above and below the critical micelle concentration. This has been identified as about 10" moles/L for the lelated polymer 1,4-polyisoprene-polyacetylene (MW 8000 520) in toluene at 20 C using the drop weight method to determine surface tension. From ca. 10" molar to molar the surface tension drops by about 3.5% to a constant value of ca. 28.4 dyne cm at concentrations above 10 3 molar (ca. 1% w/w). Referring to Figure 3 we see that it is above ca 1% that a broad peak develops in the solution/solvent reflectivity ratio for 0.15 < k / < 0.25. The area per... 

Since the emissivity of a surface is one minus the square of the amplitude ratio, (R f or (i ), the thermal emissivity depends also on the refractive index and the emission angle. Consider the case of a nonmagnetic homogeneous layer of refractive index no = n bounded by a vacuum, n i = 1. With the help of Eq. (1.6.6) we can eliminate 0o from the reflection ratios, Eqs. (1.6.12) and (1.6.14) calling 0j = 0 we obtain for the emissivities... 

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