Mass correlation

We show in Chapter 2 that the periodic table is based on the structure of atoms rather than on their masses. Elemental masses correlate closely with atomic structure, however, so ordering by mass is almost the same as ordering by structure. There are... 

El-Shanaway measured 70 pm and his Eq. (14-199) predicted 76 pm. The power/mass correlation [Eq. (14-198)] predicts 102 pm. The agreement between both correlations and the measurement is much better than normally achieved. 

Pinczewski and Fell [Trans. Inst. Chem Eng., 55, 46 (1977)] show that the velocity at which vapor jets onto the tray sets the droplet size, rather than the superficial tray velocity. The power/mass correlation predicts an average drop size close to that measured by Pinczewski and Fell. Combination of this prediction with the estimated fraction of the droplets entrained gave a relationship for entrainment, Eq. (14-202). The dependence of entrainment with the eighth power of velocity even approximates the observed velocity dependence, as flooding is approached. 

For compounds of low molar mass, correlations are available. Satoh (1948) proposed a method for the prediction of between Cp at 200, 300 and 400 K by the addition of group contributions. Shaw (1969) used the same method for Cp(298) whereas Johnson and Huang (1955) used it for Cp(293). The question was whether these increments are applicable to polymers. 

Turbulent mixing and dust disk evolution models for a range of stellar and disk masses correlations are much easier to observe and more difficult to fit than simulations restricted to the minimum-mass solar nebula... 

Buadu, L.D., Murakami, J., Murayama, S., et al. (1997) Patterns of peripheral enhancement in breast masses correlation of findings on contrast mediiun enhanced MRI with histologic features and tumor angiogenesis. Journal of Computer Assisted Tomography, 21, 421 30. 

GPC Elution Behavior for Aromatic Compound Types. To predict molecular weight and the chemical structure of fractions separated by GPC, we must understand the elution behavior for characteristic compound types. However, it was very difficult to gain information on these relations because of the limited studies on coal products. Dooley and co-workers (12, 13) extensively studied GPC mass correlations for petroleum heavy oil. 

Ei before and after the time-delayed extraction pulse, (b) Implementation of the mass-correlated acceleration scheme on a miniaturized instrument. 

Figure 13.10 Schematic and picture of the 4-inch TOF mass spectrometer using the mass-correlated acceleration (MCA) technique.

Figure 13.11 Mass spectra of a peptide mixture using (a) time-delayed extraction and (b) mass-correlated acceleration.

Table 13.1 BSA (66 432.96 Da) tryptic digest comparison of peak widths using delayed extraction and mass-correlated acceleration (MCA).28...

Grinstein Because our (MILES) simulation approach does not require explicit filtering, we do not need to use Favre-averaged variables the impact of pressure and mass correlations can be thus evaluated directly (at least in principle) based on the database generated in the simulations. 

Figure 3.17 shows an example of an ion mobility-mass spectrum for a sample of peptides, lipids, and nucleotides demonstrating one of the strengths of combining IMS with mass spectrometry, the formation of mobility-mass correlated trend lines . 

But, biomolecules are not rigid spheres they have different shapes that prodnce different collision cross sections d. To a first approximation, when d is plotted as a function of m, unique mobility-to-mass correlation curves (often called trend lines) are generated for different classes of compounds. Trend lines were first observed by... 

FIGURE 9.1 Mobility-mass correlation curves (trend lines). (From McLean et al Ion mobility-mass spectrometry a new paradigm for proteomics, Int. J. Mass Spectrom. 2005 240, 301-315. With permission.)... 

An important qualitative indicator for ions based on the position that they occupy in mobility-mass correlation space is the specific cross section (SCS). Analogous to specific volume in three dimensions, this value is the 2D ratio of the measured collision cross section in to the mass in daltons of the ion for which the collision cross section was measured (fl/m). This quantity is reported in A /daltons and is essentially the slope of the trend lines for a given class of compounds. Ions that fall into a specific class will have similar fl/m values. As noted above with respect to peptides, small differences in fl/m values for compounds in a class from the average Him for a class provide information on the structure of ion. 

Accurate mass scales (or calibration curves) are generally established by measuring the mass spectrum of a reference compound simultaneously with the spectrum of the sample. The precise mass of every ion in the spectrum of the reference compound is known, so a precise mass correlation is thereby provided. Common reference materials are perfluorokerosene (PFK) and perfluorotributylamine (PFTBA), the mass spectra of which are shown in Figures 3.1 and 3.2, respectively. Since all the ions formed from these compounds contain several fluorine atoms (18.9984) and no hydrogen atoms (1.0078), they have negative mass defects and are well separated from organic ions that normally have positive mass defects. Of course, other chemicals may be used to provide reference masses, as long as the exact masses in its spectrum are known. 

Does molar mass correlate with nonideal-gas behavior below 200 atm ... 

Viscosity average molecular mass correlates with the ability of the polymer solution to flow because "a" is a crude measure of hydrodynamic volume of the polymer molecules in the solution and this volume controls solution viscosity. When the capacity of the polymer solution to scatter light is measured, it will not depend on... 

This can be measured by monitoring fluorescently labeled peptides (here FAM-PDP2) using fluorescence in-gel detection. Cells are incubated with the peptides for different amounts of time. The resulting fluorescence intensity of the samples at the expected peptide retention time in the gel (correlating with its mass) correlates with the amount of peptide left after a certain amount of incubation time. 

Smectics exhibit positional disorder in two dimensions but have a center-of-mass correlation along the third dimension. Each layer can be likened to a two-dimensional fluid. There are various smectic phases. The smectic A and C phases are represented in Fig. Ic and d. The direction of molecular alignment is perpendicular to the layer planes in the smectic-A and is at a tilt to the layer normal in the smectic C phase. Numerous other smectic phases have been identified and are distinguished by various in-plane order and correlations between the layers. 

Both cholesteric and smectic mesophases are layered. In the former case, the periodicity arises from a natural twist to the director field, and in the latter, from a center-of-mass correlation in one dimension. There are many types of smectic phases distinguished by their symmetry and order. The set of field-induced phenomena is quite different for these two materials, owing primarily to the very different layer compressibility. That is, the cholesteric pitch can be unwound by an external field, whereas the smectic layering is typically too strong to be altered significantly. However, because of the common layered structure, there are also strong similarities. 

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