The article proves the promising nature of using functionalized magnetic nano particles in extraction of metals from process solutions and in treatment of industrial effluents. The experimental ...copper extraction from solutions using a magnetic nanosorbent made of lipoic acid-functionalized magnetite is described. Sorption efficiency is determined as function of the initial concentration of solutions as compared with non-functionalized nano-size magnetite. The copper-bearing sedimentation mechanism includes chemosorption at active centers of lipoic acid, adsorption at clean magnetite surface and re-crystallization of sorbate in intrinsic copper-bearing phases. The phase composition of copper in the sediments is examined, and the copper extractability is illustrated. The conditioning technology is proposed for copper-bearing solutions. The stage-wise use of the magnetic nanosorbent enables process solution purification up to the maximum allowable concentration at simultaneous production of a concentrate suitable for hydrometallurgical processing.
Study of genetic diversity of Staphylococcus aureus strains that colonize nose mucous membrane of children living in an ecologically unfavorable district of Krasnoyarsk.
20 S.aureus strains isolated ...from mucous membrane of anterior part of nose of children were genotyped by RAPD-PCR (random ampliphied polymorphic DNA) with an oligonucleotide primer (10 Sh1 nucleotide).
Presence of 6 genotypes, with 3 of those including 3 and more strains, was detected among the studied strains. The extent of genetic similarity between genotype 1 and 2 was established at 85%.
20 of 63 (31.7%) of examined students were resident carriers of S. aureus. 3 main genotypes of S. aureus that circulate in students were detected by RAPD-PCR. This confirms the necessity to use RAPD-PCR method for timely evaluation of epidemic situation in organized groups of children.
The protective properties of nonwoven materials (Spandbond, SMS) used to manufacture 3-5-layer medical masks, by using model physical and bacterial test aerosols, were experimentally assessed. It was ...shown that the more layers of the materials, the less permeable they became for test aerosols. Three-five-layer masks made from SMS at a density of 42 g/m2 were found to have higher protective properties for oil mist and fine aerosol than those made from Spandbond at a density of 25 g/m2. Five-layer SMS materials at a density of 42 g/m2 have the highest values of bacterial aerosol retention.
The permeability of varying density felts (Spandbond, SMS, Tyvek, Sontara) for throw-away medical overalls was experimentally assessed under statistic and dynamic conditions, by using model test ...aerosols, including bacterial one. Their permeability was shown to decrease with the higher density of the materials under study. Laminated Span-bond contributes to an abrupt reduce in the bacterial penetration of this kind of tissues and enhances their protective properties. The felts CMC, Tyvek, Sontara, and laminated Spanbond were found to have the highest protective properties. In terms of their barrier and protective properties, the felts surpass the tissues used to make re-usable protective medical overalls.
A clinico-psychological study was carried out of a randomly taken group (104 persons) among operators of the Zaporozhye Atomic Power Station. Personality accentuation was found in 91%, with over ...accentuation in 74% and hidden form in 17%. Prophylactic measures are outlined.
