Formation, Reactivity Tuning and Kinetic Investigations of Iron “Dioxygen” Intermediate Complexes and Derivatives in Multiphase Flow Reactions

The transient multiphase flow behavior in a single-strand tundish during ladle change was studied using physical modeling. The water and silicon oil were employed to simulate the liquid steel and slag. The effect of the turbulence inhibitor on the slag entrainment and the steel exposure during ladle change were evaluated and discussed. The effect of the slag carry-over on the water-oil-air flow was also analyzed. For the original tundish, the top oil phase in the impact zone was continuously dragged into the tundish bath and opened during ladle change, forming an emulsification phenomenon. By decreasing the liquid velocities in the upper part of the impact zone, the turbulence inhibitor decreased considerably the amount of entrained slag and the steel exposure during ladle change, thereby eliminating the emulsification phenomenon. Furthermore, the use of the TI-2 effectively lowered the effect of the slag carry-over on the steel cleanliness by controlling the movement of slag droplets. The results from industrial trials indicated that the application of the TI-2 reduced considerably the number of linear inclusions caused by ladle change in hot-rolled strip coils.

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Chromatographic Isolation of the LDH-Isoenzymes of Human Blood Platelets and an Investigation of Their Enzyme Kinetics

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651273 ◽

1968 ◽

Vol 20 (03/04) ◽

pp. 301-313 ◽

Cited By ~ 2

Author(s):

W Schneider ◽

K Schumacher ◽

B Thiede ◽

R Gross

Keyword(s):

Human Blood ◽

Blood Platelets ◽

Deae Cellulose ◽

Order Reaction ◽

Kinetic Properties ◽

Ldh Isoenzymes ◽

Kinetic Investigations ◽

Substrate Concentrations ◽

Chromatographic Isolation ◽

Human Blood Platelets

SummaryThe LDH-isoenzymes of human blood platelets show a distinct predominance of the isoenzymes 2 and 3 upon chromatography on DEAE-cellulose. Small amounts of LDH-1 are also present, while only traces of LDH-4 and -5 can be detected.Enzyme kinetic investigations of the principal isoenzymes LDH-1, -2 and -3 clearly show that the differences in inhibition constants with pyruvate as substrate which are demonstrable at 25° largely disappear at 37°. On the other hand, the differences among the isoenzymes in their affinity for pyruvate and lactate as substrate as well as in with respect to the optimal substrate concentrations of pyruvate are more marked at 37° than at 25°. Also, the type of inhibition found with lactate as substrate is increasingly the expression of a higher order reaction in going from LDH-1 to LDH-3. A dependence of the LDH distribution pattern upon the metabolism of the cell is discussed. A comparison of our results with thrombocytes with those of other workers with erythrocytes and leucocytes makes it unlikely that the LDH pattern is directly dependent upon the existence of an oxidative metabolism. Rather, the redox potential of the cell could be of importance for the nature of the pattern of isoenzymes and for their differing kinetic properties.

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