On the determination of the rate constants of chain initiation, propagation, and limitation in the steady-state catalytic polymerization of propylene

1964 ◽  
Vol 13 (11) ◽  
pp. 1863-1869 ◽  
Author(s):  
A. P. Firsov ◽  
V. I. Tsvetkova ◽  
N. M. Chirkov
Keyword(s):  
Steady State ◽  
Rate Constants ◽  
Catalytic Polymerization ◽  
Chain Initiation

scholarly journals Determination of the steady-state turnover rates of the metabolically active pools of phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate in human erythrocytes

1989 ◽  
Vol 259 (3) ◽  
pp. 893-896 ◽  
Author(s):  
C E King ◽  
P T Hawkins ◽  
L R Stephens ◽  
R H Michell
Keyword(s):  
Steady State ◽  
Rate Constants ◽  
Human Erythrocytes ◽  
Turnover Rates ◽  
Metabolic Fluxes ◽  
Metabolic Pool ◽  
Phosphatidylinositol 4 ◽  
Kinetics Of ◽  
Phosphate Groups

When intact human erythrocytes are incubated at metabolic steady state in a chloride-free medium containing [32P]Pi, there is rapid labelling of the gamma-phosphate of ATP, followed by a slower labelling of the monoester phosphate groups of phosphatidylinositol 4-phosphate (PtdIns4P) and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] [King, Stephens, Hawkins, Guy & Michell (1987) Biochem. J. 244, 209-217]. We have analysed the early kinetics of the labelling of these phosphate groups, in order to determine: (a) the steady-state rates of the interconversions of phosphatidylinositol, PtdIns4P and PtdIns(4,5)P2; and (b) the fractions of the total cellular complement of PtdIns4P and PtdIns(4,5)P2 that participate in this steady-state turnover. The experimental data most closely fit a pattern of PtdIns4P and PtdIns(4,5)P2 turnover in which one-quarter of the total cellular complement of each lipid is in the metabolic pool that participates in rapid metabolic turnover, with rate constants of 0.028 min-1 for the interconversion of PtdIns and PtdIns4P, and of 0.010 min-1 for the PtdIns4P/PtdIns(4,5)P2 cycle. These rate constants represent metabolic fluxes of approx. 2.1 nmol of lipid/h per ml of packed erythrocytes between PtdIns and PtdIns4P and of approx. 5.7 nmol/h per ml of cells between PtdIns4P and PtdIns(4,5)P2.

Steady-state voltammetry with microelectrodes: determination of heterogeneous charge transfer rate constants for metalloporphyrin complexes

1991 ◽  
Vol 30 (8) ◽  
pp. 1682-1685 ◽  
Author(s):  
Y. Zhang ◽  
C. D. Baer ◽  
C. Camaioni-Neto ◽  
P. O'Brien ◽  
D. A. Sweigart
Keyword(s):  
Charge Transfer ◽  
Steady State ◽  
Rate Constants ◽  
Transfer Rate ◽  
Charge Transfer Rate

The Well Stirred Liquid Phase Photochemical Reactor: Laboratory Tool or Master of Disguises?

2016 ◽  
Vol 19 (2) ◽  
Author(s):  
David Ollis
Keyword(s):  
Steady State ◽  
Liquid Phase ◽  
Rate Constants ◽  
Light Flux ◽  
Kinetic Studies ◽  
Prior Work ◽  
True Rate ◽  
Phase Data ◽  
Laboratory Tool

AbstractSince the early 1980s, liquid phase kinetic studies of homogeneous and heterogeneous photochemistry (especially including photocatalysis), have routinely utilized well stirred laboratory scale photoreactors. Convenient as these reactors are, their operation may be limited by reactant concentration, or by a transport limitation for light flux or dissolved oxygen. Similarly, the mechanistic interpretation of most phootocatalyzed liquid phase data has assumed the validity of Langmuir-Hinshelwood kinetics, whereas recent papers have demonstrated decisively that a pseudo steady state prevails, rather than equilibrium adsorption circumstance. We briefly review these circumstances which have led to kinetic disguises, and offer simple recommendations for future homogeneous and heterogeneous photochemical liquid phase studies which will allow determination of true rate constants and avoid the transport phenomena and mechanistic disguises evident in prior work.

STEADY-STATE DETERMINATION OF FUEL-BOND NITROGEN IN DIESEL AND INDUSTRIAL GAS OIL

Clean Air ◽  
2007 ◽  
Vol 8 (4) ◽  
pp. 359-371
Author(s):  
A. Medeiros ◽  
R. Edenhofer ◽  
K. Lucka ◽  
H. Kohne
Keyword(s):  
Steady State ◽  
Gas Oil ◽  
State Determination
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