Chain Termination (in a Chain Polymerization)

2016 ◽  
Author(s):  
Stanisław Penczek ◽  
Graeme Moad
Keyword(s):  
Chain Termination ◽  
Chain Polymerization ◽  
A Chain

Active Center (in a Chain Polymerization)

2016 ◽  
Author(s):  
Stanisław Penczek ◽  
Graeme Moad
Keyword(s):  
Active Center ◽  
Chain Polymerization ◽  
A Chain

scholarly journals Transacylation as a chain-termination mechanism in fatty acid synthesis by mammalian fatty acid synthetase. Synthesis of butyrate and hexanoate by lactating cow mammary gland fatty acid synthetase

1980 ◽  
Vol 186 (1) ◽  
pp. 287-294 ◽  
Author(s):  
J K Hansen ◽  
J Knudsen
Keyword(s):  
Fatty Acids ◽  
Mammary Gland ◽  
Fatty Acid ◽  
Fatty Acid Synthetase ◽  
Short Chain Fatty Acids ◽  
Acid Synthesis ◽  
Chain Termination ◽  
Short Chain ◽  
Esterified Fatty Acids ◽  
A Chain

1. Purified cow mammary gland fatty acid synthetase synthesized long-chain unesterified and short-chain esterified fatty acids. 2. A direct relationship was observed between the amount of short-chain products synthesized and the concentration of acetyl-CoA in the incubation medium. 3. The short-chain products were identified as butyryl-CoA and hexanoyl-CoA. 4. Inhibition of the terminating thioester hydrolase of the fatty acid synthetase complex with phenylmethanesulphonyl fluoride did not inhibit the synthesis of short-chain products. 5. It is suggested that the synthesis of short-chain fatty acids involves the reverse of the ‘loading’ reaction.

On the nonlinear stability and detonability limit of a detonation wave for a model three-step chain-branching reaction

1997 ◽  
Vol 339 ◽  
pp. 89-119 ◽  
Author(s):  
MARK SHORT ◽  
JAMES J. QUIRK
Keyword(s):  
Detonation Wave ◽  
Single Mode ◽  
Chain Termination ◽  
Shock Pressure ◽  
Chain Branching ◽  
Detonation Structure ◽  
Detonation Shock ◽  
A Chain ◽  
Steady Detonation ◽  
Recombination Zone

The nonlinear stability of a pulsating detonation wave driven by a three-step chain-branching reaction is studied. The reaction model consists sequentially of a chain-initiation step and a chain-branching step, both governed by Arrhenius kinetics, followed by a temperature-independent chain-termination step. The model mimics the essential dynamics of a real chain-branching chemical system, but is sufficiently idealized that a theoretical analysis of the instability is possible. We introduce as a bifurcation parameter the chain-branching cross-over temperature (TB), which is the temperature at which the chain-branching and chain-termination rates are equal. In the steady detonation structure, this parameter controls the ratio of the chain-branching induction length to the length of the recombination zone. When TB is at the lower end of the range studied, the steady detonation structure, which is dominated by the temperature-independent recombination zone, is found to be stable. Increasing TB increases the length of the chain-branching induction region relative to the length of the recombination zone, and a critical value of TB is reached where the detonation becomes unstable, with the detonation shock pressure evolving as a single-mode low-frequency pulsating oscillation. This single-mode nonlinear oscillation becomes progressively less stable as TB is increased further, persisting as the long-term dynamical behaviour for a significant range of TB before eventually undergoing a period-doubling bifurcation to a two-mode oscillation. Further increases in TB lead to a chaotic behaviour, where the detonation shock pressure history consists of a sequence of substantive discontinuous jumps, followed by lower-amplitude continuous oscillations. Finally, for further increases in TB a detonability limit is reached, where during the early onset of the detonation instability, the detonation shock temperature drops below the chain-branching cross-over temperature causing the wave to quench.

scholarly journals Translation of the genetic message, IV. UAA as a chain termination codon.

1967 ◽  
Vol 57 (4) ◽  
pp. 1062-1067 ◽  
Author(s):  
J. A. Last ◽  
W. M. Stanley ◽  
M. Salas ◽  
M. B. Hille ◽  
A. J. Wahba ◽  
...  
Keyword(s):  
Chain Termination ◽  
Termination Codon ◽  
A Chain ◽  
Genetic Message
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