Prediction of multicomponent distillation efficiencies

The prediction of multicomponent distillation efficiencies from binary data is highly desirable as it is physically impossible to perform the experimental study of all the systems of industrial importance.In the present work a new method of predicting ternary efficiencies is presented. The validity of the method is assessed comparing experimental ternary distillation lines with predicted distillation lines. Experimental results obtained in a 38mm diameter seven plate sieve-plate column with the binary systems cyclohexane/n-heptane, cyclohexane/toluene and n-heptane/toluene and the ternary system cyclohexane/n-heptane/toluene are used for such comparison.Experimental results obtained with the ternary system show the existence of Murphree efficiencies greater than unity for the intermediate component. Such interesting physical situations are also predicted using the new method.     

Coronary artery perforation and delayed cardiac tamponade following balloon coronary angioplasty

A 62-year-old woman who had coronary artery disease and hypertrophic cardiomyopathy received percutaneous transluminal coronary angioplasty and endomyocardial biopsy. She withstood the procedure well. However, delayed pericardial tamponade occurred 2 hours after discharge from the cardiac catheterization laboratory. Despite pericardial drainage with a pigtail catheter and blood transfusion, the patient required emergency surgery. An oozing diagonal branch of the left anterior descending coronary artery was found. Ligation of this small branch stabilized the hemodynamics. Avoidance of improper positioning of the guide wire in the small coronary artery branch is important in preventing arterial wall trauma and subsequent perforation.     

Molecular topology of the photosynthetic light-harvesting pigment complex, peridinin-chlorophyll a-protein, from marine dinoflagellates

The photosynthetic light-harvesting complex, peridinin-chlorophyll a-protein, was isolated from several marine dinoflagellates including Glenodinium sp. by Sephadex and ion-exchange chromatography. The carotenoid (peridinin)-chlorophyll a ratio in the complex is estimated to be 4:1. The fluorescence excitation spectrum of the complex indicates that energy absorbed by the carotenoid is transferred to the chlorophyll a molecule with 100% efficiency. Fluorescence lifetime measurements indicate that the energy transfer is much faster than fluorescence emission from chlorophyll a. The four peridinin molecules within the complex appear to form two allowed exciton bands which split the main absorption band of the carotenoid into two circular dichronic bands (with negative ellipticity band at 538 nm and positive band at 463 nm in the case of peridinin-chlorophyl a-protein complex from Glenodinium sp.). The fluorescence polarization of chlorophyll a in the complex at 200 K is about 0.1 in both circular dichroic excitation bands of the carotenoid chromophore. From these circular dichroic and fluorescence polarization data, a possible molecular arrangement of the four peridinin and chlorophyll molecules has been deduced for the complex. The structure of the complex deduced is also consistent with the magnitude of the exciton spliting (ca. greater than 3000 cm-1) at the intermolecular distance in the dimer pair of peridinin (ca. 12 A). This structural feature accounts for the efficient light-harvesting process of dinoflagellates as the exciton interaction lengthens the lifetime of peridinin (radiative) and the complex topology increases the energy transfer probability. The complex is, therefore, a useful molecular model for elucidating the mechanism and efficiency of solar energy conversion in vivo as well as in vitro.     

Surface tension effects in binary and multicomponent distillation

Surface tension effects play an important role in the performance of distillation columns. In the present work they are analysed using experimental resIt is shown that marked differences exist between the behaviour of the different binary systems and that the observed binary efficiency differences canSo far as the ternary system is concerned it is clear that for most of the experimental duration lines two distinct zones have to be considered as theIt is pointed out that in the ternary diagram the region of high values of foam height corresponds to the region of larger values of component efficien