Shielding mechanism

Fig. 8. Process-2one shielding mechanisms (a) Microcrack cloud (b) phase transformation (c) yielding of ductile reinforcements.

Schreckenbach, G., 1999, The 57Fe NMR Shielding in Ferrocene Revisited. A Density-Functional Study of Orbital Energies, Shielding Mechanisms, and the Influence of the Exchange-Correlation Functional , J. Chem. Phys., 110, 11936. 

The chemical shift of the angular proton in benzo[c]quinolizidines will differ from that in quinolizidine itself as a result of delocalization of the lone pair electrons over the aromatic ring in certain conformations. Examples are provided by 29 and 30. In trans-fused 29, the nitrogen lone pair is delocalized over the aromatic ring and thus the anti-coplanar shielding mechanism is lost and the angular proton absorbs to low field of that in the cis conformation 30.51... 

For n < 3, as r—> 0, 0(ke) > 0(ec) and, therefore, the elastic field, Eqn. (3), dominates at the crack tip. In this case, the near-tip and far-fields are both of the type cr °c K/V7 where Ktip generally differs from Kappiied.43,44 This leads to a shielding mechanism. Nevertheless, an intermediate field of the HRR type can also exist for n > 1, but this case (1 < n < 3) which is important for ceramics has not received much attention. The case of n>3 has been widely investigated. 

While the main focus of the present article is on ozone, we note briefly in passing that several mechanisms have been postulated for the MIF in the CAIs, in particular an on-dust chemical mechanism [27] that is a surface reaction analog of the ozone formation mechanism discussed here, depicted schematically in Figure 2.6, and spectral self-shielding mechanisms [28-30]. In the latter, CO is dissociated photochemically in the early solar system, so producing a domain that is largely physically separated from that of the less abundant isotopes... 

Bonded M0S2 film Mariner3,4 Nimbus 1 Mercury Apollo Solar panel actuator Panel hinge pins Heat shield mechanism Legs on Lunar Module... 

Studying ultra-violet spectrums of indan derivatives let us make a supposition about their "shield" mechanism, which causes light stabilizing effect, as indan sulphuryl amide additions (as carbazolsulphonamides) absorb radiation in the same wave length interval as cellulose diacetate. 

It is very important to note that indan - sulphonamides absorb light in the same field as CDA. The last fact allows to make a conclusion about shielding mechanism of the action of this set of compounds. 

C shifts of bipy carbons fairly a constant for the series C shifts of the C-2 atom of b py in the complexes correlates with a charge-transfer Pt- py transition. Linear correlation between C shifts of 4R-py and both the corresponding benzenes and the Pt complexes suggests similar shielding mechanisms Pt shifts shown to be c... 

Values of the shifts of some 4-substituted pyridines are shown in Table VII.Substituent effects were generally within +3 p.p.m. of those found in the corresponding monosubstituted benzenes, and therefore suggested similar shielding mechanisms for the two classes of compounds. This hypothesis receives support in a more recent study of 2-substituted pyridines. The shift of C5 is directly dependent upon the ftp parameters of the 2-substituent and consequently the shielding mechanisms for carbon atoms para to substituents are similar for both the pyridine and benzene systems. 

As already mentioned and shown in Figure 9.1, the primary shielding mechanism is reflection for which shield should possess free charge carriers (electrons/holes) that can interact with incident EM field. Therefore, electrical properties of ICP-based blends and composites are extremely important and their detailed understanding is of paramount importance, for regulation of attenuation as well as shielding mechanism. 

M. H. Al-Saleh, U. Sundararaj, Electromagnetic Interference Shielding Mechanisms of CNT/Polymer Composites. Carbon 2009,47,1738-1746. 

Alkalis can modify the viscosity of xanthan solutions in many ways. First, alkalis provide cations into the polymer solution. These cations can reduce the viscosity of polymer solutions through the charge-shielding mechanism explained earlier. Secondly, the acetyl groups in the side chains of xanthan can be removed by strong alkalis [83]. The elimination of the acetyl groups may have no effect on viscosity [84] or may increase the viscosity of xanthan solutions [28]. Finally, alkalis can hydrolyze the xanthan backbone, which can be very detrimental to the solution viscosity. 

The effect of sodium hydroxide on the xanthan flow curves is more than that expected from the charge shielding mechanism observed with sodium chloride. One possible explanation of this effect is base-catalyzed fragmentation reactions [26,32]. Fragmentation reactions break the biopolymer backbone (cellulose-like structure) to smaller saccharide units. Consequently, the hydrodynamic radius of the biopolymer would decrease and the viscosity of the polymer solution would diminish. 

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