Living mode

For certain nuclides, different physical properties (half-lives, mode of decay) are observed. They are due to different energetic states, the ground state and one or more metastable excited states of the same nuclide. These different states are called isomers or nuclear isomers. Because the transition from the metastable excited states to the ground states is forbidden , they have their own half-lives, which vary between some milliseconds and many years. The excited states (isomers) either change to the ground state by emission of a y-ray photon (isomeric transition IT) or transmutation to other nuclides by emission of cc or particles. Metastable excited states (isomers) are characterized by the suffix m behind the mass number A, for instance Co and Co. Sometimes the ground state is indicated by the suffix g. About 400 nuclides are known to exist in metastable states. 

Hou and Wakatsuki [197] reported a cationic ternary system composed of samarocene aluminate Cp 2Sm( j,-Me)2AlMe2 (95) and TIBA and [PhsC] [B(C6Fs)4], showing living mode for the copolymerization of butadiene and styrene... 

Beside a maximal transmission speed in GSM a rate of transmitted samples (contained measurement results) is very important as well. In our experiment packets (each file containts one 2-byte sample) were transmitted with an effective speed of 2640 b/s using GPRD or HSCSD technology. However, if we transmitted packets consist 1000 samples each the effective speed was 10 times higher, up to 26 kb/s This data mean that single samples from measurement were transmitted in a live mode with a rate of 55 S/s (samples per second) but packets with 1000 samples were transmitted with a rate of 1600 S/s. (Mackowski, 2008). 

The polymerization was found to proceed smoothly to high conversions. The time dependence of logarithmic initial-to-current monomer concentration ratio ln(mo/m) is linear (Figure 2, curve 1), thus indicating the absence of chain termination processes, as case inherent in polymerization proceeding in the living mode. MW of the obtained polymers increases linearly with the conversion (Figure 2). The polydispersity indexes somewhat decrease with the conversion, a fact that is also typical of controlled radical polymerization. GPC... 

Cationic polymerization is a very important procedure that has been adopted to prepare block copolymers consisting of monomeric units that cannot be polymerized by other methods, such as isobutylene (IB) and alkyl vinyl ethers (VEs), thus enhancing the potential of macromolecular engineering. Cationic polymerization proceeds through carbenium (or oxonium) sites in a controlled/living mode if appropriate conditions such as initiation/coinitiation (Lewis acid), additives, solvent, and temperature have been chosen. 

Several approaches involving a combination of cationic and anionic polymerizations have been reported for the synthesis of block copolymers. These approaches are based on the anionic-to-cationic transformation mechanism and vice versa. Regardless of the mechanism, well-defined block polymeric architectures can be prepared by living modes of both polymerization techniques. 

The positron source is usually Na, which releases a positron every 1.5 ms as it decays into Ne. Approximately 3 ps after the positron is emitted from the source, gamma radiation of energy 1.28 MeV is released. This energy release is detected and marks the positron birth. Once inside the sample, the positron annihilates by one of the three possible modes. The first and shortest lived mode results from thepara-positronium,p-Ps, species which is formed when the positron... 

Streletzky and Phillies eventually demonstrated that their results are consistent with the earlier papers of Philhes and Lacroix(63) and Ngai and Phillies(61). The demonstration consists of showing that Phillies and Lacroix had only been able to study the shorter-lived mode of probes in 300 kDa HPC, for which the Ngai-Phillies model is correct(61). In both systems, it is the shorter-lived mode that follows coupling-scaling. 

Brown and Stepanek extended work on polystyrene cyclohexane up to 8(X) g/1 polymer(44). Between 650 and 700 g/1, there is a dramatic change in S(q,t). A rapid-decaying, -dependent mode vanishes from the spectrum. The broad, long-lived mode becomes dominant, and shifts to still longer times. At 35 °C, the relaxation rate of the long-lived mode is nearly independent of at 70 °C, the relaxation rate is far faster and scales with q. At 700 g/1, the VH and VV spectra have nearly the same distributions of relaxation times. 

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