40 research outputs found
Influence of low-temperature plasma on green algae culture
Influence of low-temperature plasma, which was formed in a high-resource arc-discharge plasma jet in an argon-air mixture, was studied for a community of green algae as Chlorella vulgaris Beyerinck [Beijerinck] and Stichococcus bacillaris Nägeli. It was found that the plasma treatment for 10 minutes led to partial cell death. At the same time, the species of C. vulgaris were less sensitive to the plasma treatment than the species of S. bacillaris. After plasma exposure, the predominant growth of the latter culture was observed in comparison with the control samples. This effect can be explained by an activation of biochemical processes in the algae due to the interaction with radicals in the low-temperature plasma. The results obtained indicate the selectivity of the low-temperature plasma effect on green algae community
The lightest scalar glueball
Recently performed investigations of meson spectra allow us to determine the
resonance structure for the waves , , ,
= in the mass region up to 1900 MeV, thus
establishing the meson multiplets and .
Experimental data demonstrate that there are five scalar/isoscalar states in
this mass region. Four of them are states, that is, members of the
and nonets, while the fifth state is an extra
one not accomodated by systematics; it has the properties of the
lightest scalar glueball. Analysis of the -wave performed within the
framework of the dispersion relation technique allows us to reconstruct the
mixing of a pure gluonium with neighbouring scalar states belonging
to and nonets: three scalar mesons share the
gluonium state between each other -- those are two comparatively narrow
resonances and and a broad resonance
. The broad state is a descendant of the gluonium,
keeping about 40-50% of its component.Comment: 48 pages, LaTeX, 25 PostScript figures, epsfig.sty. Submitted to
Russian Journal Uspekhi Fiz. Nauk (Phys-Uspekhi
Application of cold plasma to control the microbiota composition on the surface of potato tubers
A study of the effect of low-temperature plasma on potato tubers was carried out. A comparative assessment of changes in the rate of germination, the size of shoots and the mass of shoots was carried out. Changes in the number of bacteria and fungi on the surface of tubers were analysed for different durations of exposure. It was found that growth characteristics did not change. The number of bacteria on the surface of tubers was significantly reduced due to the exposure to low-temperature plasma
SURFACE-ENHANCED RAMAN SCATTERING FROM DYE MOLECULES IN SILICON NANOWIRE STRUCTURES DECORATED BY GOLD NANOPARTICLES
Silicon nanowires (SiNWs) prepared by metal-assisted chemical etching of crystalline
silicon wafers followed by deposition of plasmonic gold (Au) nanoparticles (NPs) were explored
as templates for surface-enhanced Raman scattering (SERS) from probe molecules of Methylene
blue and Rhodamine B. The filling factor by pores (porosity) of SiNW arrays was found to control
the SERS efficiency, and the maximal enhancement was observed for the samples with porosity of
55%, which corresponded to dense arrays of SiNWs. The obtained results are discussed in terms of
the electromagnetic enhancement of SERS related to the localized surface plasmon resonances in
Au-NPs on SiNW’s surfaces accompanied with light scattering in the SiNW arrays. The observed
SERS effect combined with the high stability of Au-NPs, scalability, and relatively simple preparation
method are promising for the application of SiNW:Au-NP hybrid nanostructures as templates in
molecular sensorics