Measurement of the dielectric constant of highly absorbing polar liquids at microwave frequencies

Nomograms are given for claculating the dielectric constant and dielectric loss of polar liquids by measuring the standing wave ratio for an infinitely thick layer of fluid and the layer thickness at which wave reflection is minimum. Translated from Izmeritel'naya Tekhnika, No. 2, pp. 46–47, February, 1996.     

Band of Selective Transmission of Electromagnetic Radiation by an Absorbing Dielectric Layer

Equations for determining the frequency band near the frequency of selective reflectionless transmission of electromagnetic radiation by a layer of an absorbing dielectric which separates two nonabsorbing media with dissimilar optical densities have been obtained. The absorption band of the wave in the dielectric layer as a function of the dielectric properties and thickness of the layer and of the dielectric properties of the separated media has been evaluated.     

Nonreflective absorption of an electromagnetic wave in its incidence on the two-layer system "magnetic–metal" at an angle

The conditions of nonreflective absorption of an electromagnetic wave in its incidence, at an angle, on a plane layer of absorbing magnetic applied to a metal substrate are found. The dependences of these conditions on the angle of incidence of the wave, the thickness of the layer, and the magnetic properties of the coating material are investigated. The possibility of separating a prescribed polarization component of the incident radiation with the use of the phenomenon of nonreflective wave absorption in the magnetic–metal system is considered.     

The pre- and postsynaptic mechanisms of the involvement of the serotonin of the amygdaloid body in the reproduction of the conditioned passive avoidance reaction in rats

A previous study reported that intercellular adhesion molecule-1 (ICAM-1) expression by human vascular endothelial cells (HUVEC) is augmented by intracellular signal transmission mainly through the protein kinase C (PKC) system stimulated by TXA2 receptors. In the present study, we show that a TXA2 receptor agonist, U46619, augments the expression of not only ICAM-1, but also vascular cell adhesion molecule-1 (VCAM-1) or endothelial leucocyte adhesion molecule-1 (ELAM-1) in HUVEC both at protein and mRNA levels. Pretreatment with SQ29,548 (a TXA2 receptor antagonist) or PKC inhibitors greatly diminished the extent of U46619-induced mRNA accumulation and surface expression of the adhesion molecules. An inhibitor of nuclear factor kappaB (NF-kappaB) activation, PDTC, diminishes U46619-induced VCAM-1 mRNA accumulation. NAC, which inhibits NF-kappaB and activation protein 1 (AP-1) binding activity, inhibits the expression of ICAM-1 or ELAM-1 at protein and mRNA levels. These findings suggest that ICAM-1 or ELAM-1 expression of HUVEC stimulated via TXA2 receptors is augmented by induction of NF-kappaB and AP-1 binding activity through the PKC system, and that VCAM-1 expression is augmented by induction of NF-kappaB binding activity.     

Variational method for measuring dielectric parameters of polar liquids at ultrahigh frequencies

Conclusions Owing to the use of nomograms the above method is universal and rapid. It is independent of the frequency at which the values of and are measured, and it is equally applicable for measuring dielectric parameters of polar liquids which are highly absorbent at ultrahigh frequencies and have one or two clearly expressed minima in the relationship of tol, and for liquids with low dielectric losses in the uhf range, whose measurement with adequate precision is difficult by other methods. Among the deficiencies of the suggested method one should note the two values obtained for _d and tan /2 from the nomogram readings. However, this deficiency can easlly eliminated either by comparing the two values for _d and tan /2 with those obtained for them from a similar nomogram and the second minimum in the relationship of tol, or by an approximate evaluation of _d and tan /2 by means of any other less precise measuring method.Translated from Izmeritel'naya Tekhnika, No. 10, pp. 48–49, October, 1970.     

Laminar-to-turbulent flow transition under the action of acoustic oscillations

The formation of two conical flows in the transition from laminar flow to the turbulent part of a free jet under the action of acoustic oscillations is observed experimentally.