Phase Fraction Distribution Research Articles

Techniques tomographiques en écoulement diphasique

Impedance tomography consists in reconstructing the conductivity distribution from electrical data which characterise the electrical response of a medium to arbitrary excitations. Impedance tomography is an ill-conditioned problem and designing a tomograph therefore requires the quantitative knowledge of the sensitivity of the reconstruction to the measurements noise. The numerical conditioning of an original and accurate algorithm has studied. This algorithm does not suffer from the shortcomings already identified in the literature. It is shown that for media encompassing inclusions which is a typical situation in two-phase flows, the necessary accuracy for the measurements if far beyond any technological reach. Moreover, within these high requirements for accuracy, some side effects must be carefully controlled or compensated and relevant procedures are provided. Furthennore, reconstruction artefacts are shown and they are found to derive from the unavoidable tridimensional nature of the electric field. For all these reasons, it is concluded that impedance tomography has very low potentialities as an accurate phase fraction distribution measuring technique in any arbitrary two-phase flows.

Immunocytochemical Demonstration of S Phase Cells by Antlbromobeoxyuribine Monoclonal Antibody in Human Prostate Adenocarcinoma

Using a monoclonal antibody to bromodeoxyuridine and immunohistochemistry, we measured the incorporation of this thymidine analogue into the deoxyribonucleic acid of human prostate adenocarcinoma cells exposed in situ. Fifteen patients with prostate cancer were given an intravenous infusion of 500mg. bromodeoxyuridine at needle biopsy to label tumor cells in the deoxyribonucleic acid synthesis phase (S phase). The tumor specimens were fixed with 70 per cent ethanol, embedded in paraffin, sectioned and stained by an indirect immunoperoxidase method using anti-bromodeoxyuridine monoclonal antibody as the first antibody. The results showed that this method demonstrated bromodeoxyuridine-labeled nuclei satisfactorily in tissue section. The bromodeoxyuridine labeling index, S phase fraction, was determined by counting the number of bromodeoxyuridine-labeled cells in the tissue sections. Grade 3 tumors averaged 4.37 ± 0.48 per cent labeling versus 2.41 ± 0.49 per cent in grade 2 tumors, and grade 1 tumor in the series had an S phase fraction of 1.36 ± 0.39 per cent. The average S phase fractions for single gland, cribriform, fused and medullary were 1.16, 2.30, 3.74 and 4.95 per cent, respectively. The results obtained with S phase fraction measured with bromodeoxyuridine labeling proved to be comparable to the results of histological grade and growth pattern. Thus, the higher S phase fraction may indicate biological malignancy. Moreover, the degree of heterogeneity concerning S phase fraction distribution within prostate cancer tissue could be compared to the morphological appearance. Our preliminary results suggest that the measurement of bromodeoxyuridine labeling index in prostate cancer may prove to be a new objective and quantitative assay of biological potential of individual tumor.

Influence of transverse intraphase velocity profiles and phase fraction distributions on the character of two-phase flow equations

Influence of transverse intraphase velocity profiles and phase fraction distributions on the character of two-phase flow equations