Effect Of Hydrodynamic Conditions Research Articles

Vplyv hydrodynamických podmienok na hydrolýzu sacharózy v nehybnej vrstve imobilizovaných kvasiniek.

V poslednĂ˝ch rokov je čoraz väčší zĂĄujem o aplikĂĄciu imobilizovanĂ˝ch kvasiniek s invertĂĄzovou aktivitou. ChĂ˝bajĂş vĹĄak seriĂłzne bioinĹžinierske prĂĄce pre nĂĄvrh bioreaktorov. V tejto prĂĄci sme sa zamerali na ĹĄtĂşdium bioreaktora s nehybnou vrstvou imobilizovanĂ˝ch kvasiniek v Ca-alginĂĄtovom geli. Pre danĂŠ podmienky hydrolĂ˝zy je treba v bioreaktore zachovaĹĽ laminĂĄrny reĹžim s Re číslom do 0,3 resp. zdĹžnĂ˝ čas 20 minĂşt.

On discrepancies between theory and practice of electropolishing

An attempt has been made to clarify some discrepancies in the field of electropolishing. First, existence and meaning of the ‘current plateau’ in the electropolishing of steels is analysed. Although for most steels the current plateau exists, it is not applicable in the way known for the electropolishing of copper. The effect of hydrodynamic conditions and potential applied on the surface finish attainable is presented. In contradiction to up-to-date reports, a regularity is observed. Mass transfer during the electropolishing of steels was also studied, showing the effect of rotation speed on the mass loss distribution.

Composition of minerals and their formation mechanism of lateritic weathering crust in Hainan Island

This paper discusses the composition of minerals and their formation mechanism of two types of the lateritic weathering crust on Early Pleistocene basalts in the northern part of Hainan Island. At first, the mineralogy of various weathering zones is described. Then, three main physicochemical processes in microscopic range (replacement as pseudomorph, dissolution and illuviation) and the effect of hydrodynamic conditions in the same range on these processes are inferred on the basis of the study of microfabric characters of the weathered rocks. Finally, weathered sequence of minerals in the lateritic processes of basalts is proposed.

Effect of hydrodynamic conditions on the hydrocracking process

1. Model studies of the three-phase fluidized bed, under conditions where the physical properties of the cold system are approximately similar to properties of the real system under operating conditions, have shown the necessity for including recirculation of the hydraulic recycle in the scheme of hydrocracking in a three-phase fluidized bed. 2. In operating the three-phase fluidized-bed hydrocracking pilot installation with different kinds of charging stock, the cold model indices for phase velocities including velocities in holes of the distributing grid were substantiated, and isotropic condition of the temperature field in the pilot installation reactor was determined. 3. The technical feasibility of three-phase fluidized bed hydrocracking was demonstrated both in the case of distilling the heavy distillates and run-down distillation of residuals,and prospects for commercial hydrocracking of residuals from crudes with high sulfur content were revealed.