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Internal displacements tables

Chemla and Ferreira effected lithiozincation of TMS propargyl chloride to prepare chloroal-lenylzinc bromide reagents (Table 21)33. Subsequent reaction of these reagents with N-t-butyl-substituted sulfoximines yielded the related traws-sulfoxinyl aziridines, arising from internal displacement of the chloride substituent of the anti sulfinamide adduct. A transition state in which the f-BuSO group is eclipsed with the alkynyl (vs R) substituent accounts for the preferred formation of the major A-sulfinyl diastereomer (equation 41). [Pg.451]

Except for LiC104, which is stable for some distance above its melting point, no molten salt densities seem to have been measured. Most ambient- temperature measurements are of fairly low accuracy. The most reasonable values have been listed for convenience. These are obtained either experimentally (usually pycnometrically, by displacement of a liquid such as CC14) or calculated from X-ray data. Solids frequently exhibit voids and/or occlude solvent so that reported values may scatter considerably. X-ray values are those for a perfect lattice and thus are only approximate guides to densities of real crystals. Whenever recent data are not available, the evaluation from International Critical Tables has been accepted. [Pg.200]

Sokel carried out the variational calculations necessary to calculate C44 for a few materials. In a similar way Chadi and Martin used the special points method to calculate C44 with the artificial restriction that all nearest-neighbor distances remain fixed. They then did a valence force field calculation, such as will be discussed in the next section, to correct for internal displacements. The results of these calculations are listed in Table 8-3. In spite of the extra complications, the theory seems to be about as accurate as it was for the calculation of c, — c,2. [Pg.193]

This expression has been evaluated by using the internal displacement parameter of Table 8-4 and, in Table 9-4, the resulting e, are compared with values derived from experimental piezoelectric constants compiled by Martin (1972a). The... [Pg.224]

Kinetic energy of electrons, 3 free-electron gas, 348f local approximation, 351, 377f, 541 Kleinman s internal displacement parameter, 198f tables, 196, 208, 220 Kohn anomalies, 395f Kohn-Sham exchange, 540 Koster-Slaler tables, 481 Kramers-Kronig relations, 99 Krypton, properties of. See Inert gas solids... [Pg.303]

Table 2. v, g and are, respectively, the ftequency of the zone-center optic phonon, the coupling coefficent vdth the transverse acoustic phonon and the internal displacement parameter of Kleinman. The experimental data are given between parenthesis (see Ref. 16). [Pg.186]

Tables 45.1 and 45.2 do not show the dynamics of the displacement which has taken place in the region over time, or how individuals and families have responded to the conflict situations which have prompted displacement both inside their respective countries and into the neighbouring MENA countries. Iraqis, for example, constituted the largest group of newly displaced people in the second half of the 2010s. As of September 2007, there were estimated to be over 4.4 million displaced Iraqis around the world, including some 2.2 million internally displaced in Iraq and a similar number in neighbouring countries Jordan and Syria received the largest numbers, an estimated 450,000-500,000 and 800,000 respectively (Eafo 2007), while some 200,000 are hosted further afield (UNHCR 2007). Tables 45.1 and 45.2 do not show the dynamics of the displacement which has taken place in the region over time, or how individuals and families have responded to the conflict situations which have prompted displacement both inside their respective countries and into the neighbouring MENA countries. Iraqis, for example, constituted the largest group of newly displaced people in the second half of the 2010s. As of September 2007, there were estimated to be over 4.4 million displaced Iraqis around the world, including some 2.2 million internally displaced in Iraq and a similar number in neighbouring countries Jordan and Syria received the largest numbers, an estimated 450,000-500,000 and 800,000 respectively (Eafo 2007), while some 200,000 are hosted further afield (UNHCR 2007).
Slurries of free-filtering sohds that are difficult to suspend are sometimes filtered on a top-feed drum filter or filter-diyer. An example application is in the production of table salt. An alternative for slurries of extremely coarse, dense solids is the internal drum filter. In the chemical-process industiy both top-feed and internal drums (which are described briefly by Emmett in Schweitzer, op. cit., p. 4-41) have largely been displaced by the horizontal vacuum filter (q.v). [Pg.1714]

This table gives the displacements for the normal mode corresponding to the imaginary frequency in terms of redundant internal coordinates (several zero-valued coordinates have been eliminated). The most significant values in this list are for the dihedral angles D1 through D6. When we examine the standard orientation, we realize that such motion corresponds to a rotation of the methyl group. [Pg.74]

In general, dw is written in the form (intensive variable)-d(extensive variable) or as a product of a force times a displacement of some kind. Several types of work terms may be involved in a single thermodynamic system, and electrical, mechanical, magnetic and gravitational fields are of special importance in certain applications of materials. A number of types of work that may be involved in a thermodynamic system are summed up in Table 1.1. The last column gives the form of work in the equation for the internal energy. [Pg.5]

The anomalous phase-displacement method detects essentially a polar axis this means that it can detect lack of centrosymmetry in general, for all non-centrosymmetric crystals have polar directions. For instance, although crystal class 4 is not usually referred to as a polar class (for its fourfold axis is not polar), nevertheless, except for the fourfold axis and all directions normal to it, all other directions are polar (see International Tables, 1952, p. 43), and the corresponding regions of the reciprocal lattice will therefore show the intensity differences which have been described. [Pg.263]

Such molecules belong to the point group Olt. They have 3(7) - 6 = 15 degrees of internal freedom. The 21 Cartesian displacement vectors generate the representation T given in the table below ... [Pg.337]

Table 12 shows the normal co-ordinate force constants for H20, calculated from the force field of Table 10, and it shows the major contributions of the internal co-ordinate force constants / to each . This table illustrates one important and general point that large contributions to the cubic and quartic values come from the quadratic / values. For example, the bending coordinate Q2, in which the atoms move in straight-line displacements, involves a positive displacement in the bond stretch Sr which increases as the square of... [Pg.153]

Table II also includes an estimate of the elevated temperatures reached in the contact areas. These estimates were developed on the basis of the TGA analysis as well as the IR data and appearance of the damage. Any evidence of thermal flow, charring, or chemical change in the impacted area of the film was taken as an indication that the T min of the TGA analysis was exceeded. As shown, these estimated local temperatures are quite high, and the question immediately arises as to their sources under impact conditions. There are three possible sources for this increase in temperature (a) internal damping, (b) differential surface displacement resulting from contact, or (c) fretting motion at the interface induced by the impact. Table II also includes an estimate of the elevated temperatures reached in the contact areas. These estimates were developed on the basis of the TGA analysis as well as the IR data and appearance of the damage. Any evidence of thermal flow, charring, or chemical change in the impacted area of the film was taken as an indication that the T min of the TGA analysis was exceeded. As shown, these estimated local temperatures are quite high, and the question immediately arises as to their sources under impact conditions. There are three possible sources for this increase in temperature (a) internal damping, (b) differential surface displacement resulting from contact, or (c) fretting motion at the interface induced by the impact.
In Table 4.13 an example is worked out for the determination of the sample-displacement error without an internal standard. Other errors should be excluded before if possible. For example, the zero-point error should be corrected by using an external standard. If the reflections can be indexed unequivocally (uncertain reflections must be omitted), the sample-displacement error - the most important error changing from sample to sample - can be easily refined with the lattice constants. The author s program, LATCO, refines the lattice constants twice, with and without sample-displacement error, and one has to decide oneself which of the two refinements is to be preferred. The main criterion for accepting the refinement with sample-position error is the size of the error in comparison with its standard deviation it must amount to at least twice the standard deviation. Furthermore jfi should be significantly... [Pg.130]


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See also in sourсe #XX -- [ Pg.196 , Pg.208 , Pg.220 ]




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Displacement internal

Internal displacement parameter tables

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