Isolation by distance

In other micrometazoans, either an isolation-by-distance pattern has not been tested or insignificant genetic differences have been found when correlated with geographic distances (for a more detailed analysis of this processes, refer to Chapter 16). 

Mills, S., Lunt, D.H., G6mez, A. (2007). Global isolation by distance despite strong regional phylogeographyin a small metazoan. BMC Evolutionary Biology 7, 225. 

Vos, M., Velicer, G.J. (2008). Isolation by distance in the spore-forming soil bacterium Myxococcus xanthus. Current Biology 18,386-391. 

Controlled risk assessment (4) Barriers adequate, isolation by distance acceptable, and insulated control panels further reduce risk of exposure to hazardous noise levels. A controlled RAC of 3E is assigned because, even if a relief did occur, the distance and isolation would create a marginal, rather than critical, risk. 

Protection against explosions is typically provided by explosion-venting, using panels or membranes which vent an incipient explosion before it can develop dangerous pressures (11,60). Protection from explosions can be provided by isolation, either by distance or barricades. Because of the destmctive effects of explosions, improvement in explosion-prevention instmmentation, control systems, or overpressure protection should receive high priority. 

The preparation and structural characterization of the ions HX2 has been an important feature of such work/ As expected, these H-bonded ions are much less stable than Hp2 though crystalline salts of all three anions and of the mixed anions HXY (except HBrI ) have been isolated by use of large counter cations, typically Cs+ and NR4+ (R = Me, Et, Bu") — see pp. 1313-21, of ref. 23 for further details. Neutron and X-ray diffraction studies suggest that [C1-H - C1] can be either centrosymmetric or non-centrosymmetric depending on the crystalline environment. An example of the latter mode involves interatomic distances of 145 and 178 pm respectively and a bond angle of -168 (Cl- -Cl 321.2pm).( >... 

The magnetostatic potential about an isolated pair of spheres with dipole moments of M, and M2 will now be considered. M, and M2 are vectors. The magnetostatic potential between Mx and M2 separated by distance R is given by Eq. 36. 

The volume properties of crystalline mixtures must be related to the crystal chemical properties of the various cations that occupy the nonequivalent lattice sites in variable proportions. This is particularly true for olivines, in which the relatively rigid [Si04] groups are isolated by Ml and M2 sites with distorted octahedral symmetry. To link the various interionic distances to the properties of cations, the concept of ionic radius is insufficient it is preferable to adopt the concept of crystal radius (Tosi, 1964 see section 1.9). This concept, as we have already noted, is associated with the radial extension of the ion in conjunction with its neighboring atoms. Experimental electron density maps for olivines (Fujino et al., 1981) delineate well-defined minima (cf figure 1.7) marking the maximum radial extension (rn, ,x) of the neighboring ions ... 

Crystal data are available for the salts KAg(CN)23,4 and K3Ag(CN)4.s These salts were isolated by evaporation at room temperature of aqueous solutions containing KCN and AgCN in appropriate molar ratios. K3Ag(CN)4 was anhydrous (not hydrated as originally proposed)6 and isomorphous with the corresponding copper salt. The dicyanoargentate(I) ion was found to be linear, with an Ag—C distance of 213 pm. KAg(CN)2 has UV absorption bands at 236 and 270 nm.7... 

Photopolymerization of the crystals was carried out in a sealed Pyrex ampule under irradiation of UV light using a high-pressure mercury lamp (Toshiba SHL-100-2, 100 W) at a distance of 10 cm. A typical polymerization procedure is described below. Monomer diethyl c ,cA-muconate 1 (200 mg, 1.0 mmol) was placed in an ample, which was then evacuated on a vacuum line. After irradiation, polymer was isolated by removal of the unreacted monomer with chloroform (20 mL) for 5-10 h at room temperature. Photopolymerization was also carried out by direct exposure to sunlight. 

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