Homogeneous processes

Homogeneous catalysis by transition metal clusters has been reviewed from the perspective of the specific transformations.Examples of very mixed-metal clusters catalyzing processes homogeneously are collected in Table IX. As is generally the case with homogeneous catalysis, the catalytic precursor is well defined, but the nature of the active catalyst is unclear. 

Sour-service standards, which specifies alloying and processing, homogeneous microstructure, and segregation control... 

Ripened Ume fruit (P. mume) was taken and the fleshy cover was removed to obtain the seeds. The upper layer of the seeds was cracked with a hammer to give the soft kernels inside. Those kernels were collected and crushed in the process homogenizer at 4 °C, with 10 mM potassium phosphate buffer, pH 6.0, to give a milky suspension. The suspension was filtered through four layers of cheesecloth to remove the insoluble part. The HNL activity shown by P. mume extract was 6.9 U mg in the milky suspension. ... 

Carboxylic acids containing double bonds are easily converted to saturated acids by catalytic hydrogenation over common catalysts. If a new chiral center is generated in the reduction process, homogeneous hydrogenation over a chiral catalyst gave 40-45% enantiomeric excess of one enantiomer [19],... 

Catalysis represents a possible tool to convert selectively carbohydrates through environmentally friendlier processes. Homogeneous catalysts are widely used in industry mainly because of their high activity, thus allowing a minimization of energy, cost, and labor. However, these catalytic processes present some problems... 

It is well established that pasteurization and homogenization of milk reduce its XO activity (Cerbulis and Farrell 1980 Zikakis and Wooters 1980). In a study in which the activity of XO was assayed in 195 commercially processed dairy foods, it was found that commercial processing (homogenization, pasteurization) destroyed about 82% of the XO activity in raw milk (Zikakis and Wooters 1980). 

When other steps are involved in the electrode process, homogeneous or heterogeneous, more complicated circuits have to be utilized, as indicated in Section 11.10. 

At the beginning of this century, attempts were made to understand the mechanisms of chemical oscillations. However, the mechanisms of heterogeneous reactions are too complicated since they involve phase transitions and transport processes. Homogeneous reactions are much simpler, and it was natural to begin theoretical study with them. 

The vigorous mixing regime in the thin films of the SDR has also been exploited for crystallization processes.Homogeneous nucleation in the thin films results in a narrow crystal size distribution for crystals formed in the SDR. Uniformly shaped barium sulfate crystals of 0.5-1 pm have been produced with a reasonably low power dissipation of 115W/kg.f ... 

Integrating chemistry and chemical engineering of industrial processes, homogeneous and heterogeneous catalysis. Somorjai G A 1994 Introduction to Surfaoe Chemistry and Catalysis (New York Wiley)... 

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