sulphide was determined spectrophotometrically at 628 nm and ph 6.7 based on its catalytic reduction of toluidine blue in the presence of se(iv) using a flow injection system. after optimization of the measuring conditions the calibration curve was found linear up to 25 mg/ml and the detection limit was 0.3 mg/ml (30 ml injections). the relative standard deviation for the determination of 10 mg...

In an attempt to detect an increased bronchial blood flow in man from the earpiece dye-dilution curve, the reliability of three indexes was investigated by comparing them with the values of bronchial blood flow measured from the left atrial dye-dilution curve following dye injection into the aortic root. The first index is obtained from the Cp method, in which the ratio of the peak concentratio...

We consider the evolution of a compact segment of an analytic curve on the unit tangent bundle of a finite volume hyperbolic n-manifold under the geodesic flow. Suppose that the curve is not contained in a stable leaf of the flow. It is shown that under the geodesic flow, the normalized parameter measure on the curve gets asymptotically equidistributed with respect to the normalized natural Rie...

We used the end-tidal concentration of xenon-133 (air curve) to estimate the profile of its arterial concentration in calculating cerebral blood flow. We examined the effects of pulmonary disease and artificial ventilation on the air curve and the calculated cerebral blood flow. We studied the relation between arterial and end-tidal xenon activities in 19 subjects, of whom 15 had pulmonary dysf...

BACKGROUND Accurate functional diagnosis of coronary stenosis is vital for decision making in coronary revascularization. With recent advances in computational fluid dynamics (CFD), fractional flow reserve (FFR) can be derived non-invasively from coronary computed tomography angiography images (FFRCT) for functional measurement of stenosis. However, the accuracy of FFRCT is limited due to the a...

The flow of a curve or surface is said to be inextensible if, in the former case, the arclength is preserved, and in the latter case, if the intrinsic curvature is preserved. Physically, inextensible curve and surface flows are characterized by the absence of any strain energy induced from the motion. In this paper we investigate inextensible flows of curves and developable surfaces in R3. Nece...