E.coli cells expressing recombinant human interferon-γwas disrupted by sonication anddissolved in 7mol·L~(-1) guanidine hydrochloride.The extract obtained was then renaturated by 70 folddilution with PBS.HulFN γwas purified by affinity chromatography with monoclonal antibody fromthe renaturated crude feed solution.After washing the column with PBS,the adsorbed HulFN γwaseluted with PBS containing 0.5mol·L~(-1) NaCl.The column was regenerated with 2mol·L~(-1) GuHClfor reuse.After one step of affinity purification the purity of interferon-γwas over 95%.and thespecific activity of the HulFN-γreached 1.2×10~7 IU·mg~(-1) protein.92.8% of recovery was obtainedin the elution step.Total recovery of HulFN γactivity in the affinity chromatography was 78%.

A new dynamic non-equilibrium mixing-pool model for simulating start-up and dynamic re-sponse of a distillation column is reported.The proposed model is established on the basis ofconsidering the two dimensional flow/mixing behavior of actual trays in a distillation column.Com-parison is made among the computed results of the start-up time and the dynamic response time bythe proposed and five other typical models.It is found that the computed time for both dynamicprocesses is longer by the model which considers any flow/mixing pattern than by the model withoutsuch concern.The inertia effect of flow/mixing seems to be important and can not be ignored inmodeling the transient process of distillation.The proposed model,which is believed to be suitableto large column,seems somewhat useful in predicting industrial distillation dynamics.

The paradox is well known that the residence time distribution(RTD)is not valid forthe estimation of the conversion of a first order reaction in an open tubular reactor.A casc ofδinjection of reactive species into an open flow system is investigated theoretically in this paper.The analytical solution with the Laplace transform demonstrated that the conversion of a first orderreaction is identical to that in a closed reactor under steady state.The effect of the backgroundreactant concentration gradient addressed by the authors in a previous paper was employed to thiscase.and the numerical solution of the tracer dispersion based on this novel argument gave rise to asimilar value of conversion.suggesting the validity of the concept and the significance of the subtledifference between RTDs determined with or without the presence of a background reactant in anopen flow system.

Solubilities of 2,4-dichlorobenzaldehyde in five single organic solvents,namely,n-propanol,n-butanol.cyclohexane,chloroform and dichloromethane as well as in two mixed solvents,namely,cyclohexane-acetone and cyclohexane n-butanol,have been measured.These data are correlated withWilson,NRTL and UNIQUAC activity coefficient models and can be used for the process design inthe purification of 2,4-dichlorobenzaldehyde.

In order to solve the fouling problems in boiling processes,a boiling system was designedby adding solid particles to the boiling liquid In this paper.both theoretical analyses andexperimental studies on the boiling heat transfer in such a three-phase flow boiling were carried out.Based on the analysis of heat transfer characters of this three-phase flow boiling,a mathematical mod-el for the heat transfer coefficient of flow boiling was developed.The experiments show that,in thepresence of particles the boiling heat transfer is enhanced and is about 2 times that of the vaporliquid two phase one with better flow stability.The fluidized particles rub the heat transfer wall toprevent and to clean the fouling.

This paper presents the application of gamma ray scanning technique to distillation/absorption columns and FCC risers.The flow regime transition.clear liquid height,froth height.crestliquid height over the exit weir on a V-1 type valve tray and downcomer hydraulics were investigatedusing the scanning device previously developed.The solid distribution and coke deposition were experi-mentally simulated in a FCC riser simulator by employing a three dimensional scanning device devel-oped for the present investigation.The success of this investigation should shed a light forquantifying two-phase contact phenomena in various gas liquid and gas solid two phase flow system.

The isobaric vapor-liquid equilibrium data of systems of ethyl acetate_((1))-n-octane_((2)) andisopropyl acetate_((1))-n-octane_((2)) were determined at 0.0709 MPa and 0.1013 MPa by using a modifiedRose-Williams still.The experimental data were tested for thermodynamical consistency and correlatedsatisfactorily with p-T equation of state and Wilson equation.