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Reflectivity absolute

Urinary excretion of quercetin increased significantly with dose and time after the consumption of fruit juice (blackcurrant and apple juice in a 1 1 mixture) in humans [75]. Ranges from 0.29-0.47% of ingested quercetin were found in the urine. The presence of quercetin in urine shows that it was absorbed by the gut, but the urinary content does not necessarily reflect absolute absorptive efficiency because absorbed quercetin may be metabolized (conjugated), stored and excreted through other routes such as the biliary tract. However, since quercetin is present in a variety of fruit and vegetables, plasma concentrations or urinary excretion of quercetin may potentially be useful as biomarkers of habitual intake of these foods. [Pg.284]

An important interpretation of observed anisotropy centres on whether or not the crust is coupled to the mantle during orogenic episodes (Silver 1996). Silver and coworkers (Silver Chan 1988 Savage Silver 1993) referred to the coupled case as vertically coherent deformation (VCD) and the decoupled case as simple astheno-spheric flow (SAP). In the VCD case it is arped that anisotropy will be frozen into the lithosphere at the time of deformation and the orientation of the anisotropy will mimic trends in the surface geology. In contrast, Vinnik and coworkers have argued that in the SAP case the orientation of the anisotropy will reflect absolute plate motions (Vinnik et al. 1992). Analysis of... [Pg.33]

Sign of rotation reflects absolute configuration (and is often used to assign it), and the magnitude of the rotation is used to determine the optical purity, usually expressed as a percent ... [Pg.50]

We need to consider enantiomorphs in most multivariate analyses which use crystallographic data. Most of the structures are either (a) non-chiral, or (b) chiral molecules for which the absolute chirality has not been determined. In some cases, however, the 3 D coordinate sets in the CSD do reflect absolute chirality either the absolute stereochemistry has been established explicitly by the X-ray experiment, or it is so well known that we expect the coordinates to represent the correct enantiomorph as, for example, in the case of the pyranose sugars. In these instances we might wish to ignore the enantiomorphs. [Pg.135]

Disconnection of strata across a fault and production of fault gauge are linear processes, determined by the actual relative fault movement, whilst mineral reactions like quartz diagenesis are exponential with temperature, i.e. reflecting absolute burial depth and temperature. [Pg.316]

Probes may be absolute, differential, reflection or array and may work at single, dual and multiple frequencies. [Pg.274]

For each combination of atoms i.j, k, and I, c is defined by Eq. (29), where X , y,. and Zj are the coordinates of atom j in Cartesian space defined in such a way that atom i is at position (0, 0, 0), atomj lies on the positive side of the x-axis, and atom k lies on the xy-plaiic and has a positive y-coordinate. On the right-hand side of Eq. (29), the numerator represents the volume of a rectangular prism with edges % , y ., and Zi, while the denominator is proportional to the surface of the same solid. If X . y ., or 2 has a very small absolute value, the set of four atoms is deviating only slightly from an achiral situation. This is reflected in c, which would then take a small absolute value the value of c is conformation-dependent because it is a function of the 3D atomic coordinates. [Pg.424]

X 10 J/kg(10.4 X 10 Btu/lb) in 1990. The shift in coal production toward western coal deposits also reflects the shift in coal utilization patterns (Table 7). Electric utiUties are increasing coal consumption on both absolute and percentage bases, whereas coke plants, other industrial operations, and residential and commercial coal users are decreasing use of this soHd fossil fuel. [Pg.3]

If a molecule contains several asymmetric C atoms, then the diastereomers show diastereotopic shifts. Clionasterol (28a) and sitosterol (28b) for example, are two steroids that differ only in the absolute configuration at one carbon atom, C-24 Differing shifts of C nuclei close to this asymmetric C atom in 28a and b identify the two diastereomers including the absolute configuration of C-24 in both. The absolute configurations of carboxylic acids in pyrrolizidine ester alkaloids are also reflected in diastereotopic H and C shifts which is used in solving problem 54. [Pg.55]

Reduction of the sodium salt of equilenin 17-ethylene ketal with lithium, sodium or potassium in ammonia at —70° occurs predominantly in the B-ring, affording, after acid hydrolysis, equilin (29) in up to 76% yield (55% isolated). The preferential reduction of the B-ring reflects the relative, but not absolute, resistance to reduction conferred on the A-ring by the naphthoxide ion. Some A-ring reduction does compete kinetically with B-ring reduction, since the epimeric 3-hydroxyestra-5,7,9-trien-17-ones are the major reaction by-products. Simple phenoxide ions usually reduce slowly... [Pg.9]

The main difference between the G2 models is tlie way in which tlie electron correlation beyond MP2 is estimated. The G2 method itself performs a series of MP4 and QCISD(T) calculations, G2(MP2) only does a single QCISD(T) calculation with tlie 6-311G(d,p) basis, while G2(MP2, SVP) (SVP stands for Split Valence Polarization) reduces the basis set to only 6-31 G(d). An even more pruned version, G2(MP2,SV), uses the unpolarized 6-31 G basis for the QCISD(T) part, which increases the Mean Absolute Deviation (MAD) to 2.1 kcal/mol. That it is possible to achieve such good performance with tliis small a basis set for QCISD(T) partly reflects the importance of the large basis MP2 calculation and partly the absorption of errors in the empirical correction. [Pg.166]

Thermal insulation is available over a wide range of temperatures, from near absolute zero (-273 C) ( 59.4°F) to perhaps 3,(1()0°C (5,432°F). Applications include residential and commercial buildings, high- or low-temperature industrial processes, ground and air vehicles, and shipping containers. The materials and systems in use can be broadly characterized as air-filled fibrous or porous, cellular solids, closed-cell polymer foams containing a gas other than air, evacuated powder-filled panels, or reflective foil systems. [Pg.674]

Notes 1. Figures are not to be considered as absolute costs, but rather reflect comparisons between various machine options. [Pg.490]

The hydrodynamic radius reflects the effect of coil size on polymer transport properties and can be determined from the sedimentation or diffusion coefficients at infinite dilution from the relation Rh = kBT/6itri5D (D = translational diffusion coefficient extrapolated to zero concentration, kB = Boltzmann constant, T = absolute temperature and r s = solvent viscosity). [Pg.81]


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See also in sourсe #XX -- [ Pg.87 ]




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Absolute reflectance measurements

Absolute reflection spectrum

Absolute specular reflectance

Reflectance, absolute

Reflectance, absolute

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