Electroviscous Forces on a Charged Cylinder Moving Near a Charged Wall

The refined theory of the electroviscous lift forces is presented for the case when the separation distance between the particle and the wall is larger than the double-layer thickness. The theory is based on the lubrication approximation for motion of a long cylinder near a solid wall in creeping flow. The approximate analytical formula for the lift force valid for Pe相似文献   

A simple and versatile PSA system for heavy metal determinations

An easy to build potentiometric stripping analysis system for heavy metal determinations (Zn, Cd, Pb, Cu) is described which reaches good sensitivity and precision. Main components are an IBM compatible computer, an ADDA-conversion card and two selfmade electrodes, so it can be realized for one tenth of the price of complete commercial systems. A graphite pencil lead covered with a Hg-film is used as working electrode and a Ag/AgCl electrode as a combined reference/counter electrode. Reproducibility and calibration measurements are reported, heavy metal determinations on soil samples are compared with AAS results.     

Hypokinetic stress and neuronal porosome complex in the rat brain: the electron microscopic study

Porosomes are the universal secretory machinery in cells, where membrane-bound secretory vesicles transiently dock and fuse to release intravesicular contents to the outside of the cell during cell secretion. Studies using atomic force microscopy, electron microscopy, electron density and 3D contour mapping, provided rich nanoscale information on the structure and assembly of proteins within the neuronal porosome complex in normal brain. However it remains uncertain whether pathological conditions that alter process of neurotransmission, provoke alterations in the porosome structure also. To determine if porosomes are altered in disease states, the current study was undertaken for first time using high resolution electron microscope. One of pathologies that produce subtle alteration at the presynaptic terminals has been demonstrated to be hypokinetic stress. The central nucleus of amygdale is the brain region, where such alterations are mostly expressed. We have examined the width and depth of the neuronal porosome complex and their alterations provoked by chronic hypokinetic stress in above mentioned limbic region. Specifically, we have demonstrated that despite alterations in the presynaptic terminals and synaptic transmission provoked by this pathological condition in this region, the final step/structure in neurosecretion--the porosome--remains unaffected: the morphometric analysis of the depth and diameter of this cup-shaped structure at the presynaptic membrane point out to the heterogeneity of porosome dimensions, but with unchanged fluctuation in norm and pathology.     

A simple and versatile PSA system for heavy metal determinations

An easy to build potentiometric stripping analysis system for heavy metal determinations (Zn, Cd, Pb, Cu) is described which reaches good sensitivity and precision. Main components are an IBM compatible computer, an ADDA-conversion card and two selfmade electrodes, so it can be realized for one tenth of the price of complete commercial systems. A graphite pencil lead covered with a Hg-film is used as working electrode and a Ag/AgCl electrode as a combined reference/counter electrode. Reproducibility and calibration measurements are reported, heavy metal determinations on soil samples are compared with AAS results.     

Phenomenon of delayed reversible deformation (inverse creep) of solids in surface-active media. Steel-3 in gas hydrogen

The tensile test of steel samples within the stress range lower than the yield strength showed that, in a hydrogen gas medium, creep is developed, which is delayed with time and becomes completely reversible with the removal of a medium. It is found that the rate of reversible creep is controlled by the transport of hydrogen gas through structural defects into incipient subcritical cracks formed upon the action of stresses. Original Russian Text ? M.M. Lordkipanidze, 2006, published in Kolloidnyi Zhurnal, 2006, Vol. 68, No. 2, pp. 282–285.