Heavy metals as indirect causative factors of capillaropathy

By applying systemic analysis to a set of random variables, representing blood or urine concentrations of certain enzymes, lipids and metals, three direct causative factors of capillaropathy, in its early stage, i.e. leucine amino peptidase, free erythrocyte protoporphyrin and C(3)-complement, have been found. The interactions between the early stage of capillaropathy and these factors have been quantitatively described and a formula for prognosing the capillaropathy occurrence has been proposed. It has also been shown that the following heavy metals Pb, Cd, Cr, Cu, Mg, Fe and Ca, through their direct or indirect interactions with C(3)-complement, exert an influence on the occurrence and intensity of capillaropathy. Since direct causative factors of a given pathology can serve as its markers, the completeness of the set of the capillaropathy markers, formed from the causative factors, and their contributions to this pathology have been evaluated. The results were obtained by examining a population of male residents chronically exposed to heavy metals (Pb, Cu) in the environment.     

Marginal separation in three-dimensional flows

The boundary layer in the vicinity of the zero skin-friction point on the leeward symmetry line of a prolate spheroid placed at an angle of attack is considered. The existence of this flow was established by Cebeci et al. (1980) for an angle of attack =40°. The current study is based on the results of Brown (1985) who described the marginal separation in the symmetry plane for a zero skin-friction point and on the results of Zametaev (1989) who included the spatial extension of Brown's solution but without interaction between the boundary layer and the outer flow. It is found that the three-dimensional boundary-layer equations in the vicinity of the zero skin-friction point are reduced to a single nonlinear partial differential equation of hyperbolic type which governs the longitudinal skin-friction component. Smooth solutions of this equation may be found which contain separation lines as well as double-valued regions. It is likely that the latter regions are related to the tip of the separation line obtained as a result of calculations of the full boundary-layer equations. The influence of interaction is also considered, in which case the flow is governed by a partial integro-differential equation. Numerical solutions are given for each of these problems.This study was supported by the United Technologies Research Center     

Non-reactive metal/semiconductor interfaces: a combined AES,AFM andPAC study

Thin In films on Ge(100), Si(100) andSi(111) are investigated using Auger-electron spectroscopy (AES), atomic force microscopy (AFM) andperturbed -angular correlation (PAC) spectroscopy, respectively. The growth mode of the metal films is characterized by in situ AES measurements, indicating distinct differences between the different substrate surfaces. Additional AFM investigations are used to monitor the film topography at higher metal coverage. Finally, the local crystalline structure of the films is studied by the PAC technique.