100 research outputs found
Synthesis of Zinc Ferrites in RF Thermal Plasma Reactor
Formation of nanosized zinc ferrite spinels was studied
from iron- and zinc oxide powders and corresponding
nitrate solutions, respectively in a radiofrequency thermal
plasma reactor. From the viewpoint of applications,
the research was motivated by the potential use of these
materials in advanced magnetic devices on the one
hand, and by their biomedical applications such as drug
carriers or agents for cancer treatment by hyperthermia
on the other. In this work effects of synthesis conditions
on properties of products were studied in details. The
products were characterised for chemical composition,
phase conditions, particle size distribution, morphologies
and saturation magnetisation. Most products exhibited
ferrimagnetic behaviour. Correlations among domain-
and particle sizes were also investigated. Conditions
for the synthesis of nanosized, inverse zinc ferrites
of high saturation magnetisation were established. It
was proved that in thermal plasma conditions normal
and inverse ferrites could be produced in a single step
process
Synthesis of Spinel Ferrites in Radiofrequency Thermal Plasma Reactor
Formation of nanosized zinc-ferrites and nickel-zinc ferrites from iron- and
zinc oxide powders and corresponding nitrate solutions, respectively, was studied in RF
thermal plasma conditions. The products were characterized for chemical composition,
phase conditions, particle size distribution, morphologies and saturation magnetization.
Effects of synthesis conditions on properties of products were studied in details
Structure-property and composition-property relationships for poly(ethylene terephthalate) surfaces modified by helium plasma-based ion implantation
The surfaces of untreated and helium plasma-based ion implantation (He PBII) treated poly(ethylene terephthalate) (PET) samples were characterised by reflectance colorimetry, contact angle studies and measurements of surface electrical resistance. The results were related to the structural and compositional data obtained by the authors earlier on parallel samples by XPS and Raman spectroscopy. Inverse correlations between lightness and ID/IG ratio and between chroma and ID/IG ratio were obtained, suggesting that the PBII-treated PET samples darken and their colourfulness decreases with the increase of the portion of aromatic sp2 carbon rings in the chemical structure of the modified layer. Direct correlation between water contact angle and the ID/IG ratio and inverse correlations between surface energy and ID/IG ratio and between dispersive component of surface energy and ID/IG ratio were found, reflecting that surface wettability, surface energy and its dispersive component decrease with the formation of surface structure, characterised again by enhanced portion of aromatic sp2 carbon rings. The surface electrical resistance decreased with the increase of the surface C-content determined by XPS and also with the increase of the surface concentration of conjugated double bonds, reflected by the increase of the pi-pi* shake-up satellite of the C 1s peak
Crime as Pollution? Theoretical, Definitional and Policy Concerns with Conceptualizing Crime as Pollution
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