the analysis of scientific publications and normative documents concerning properties, fields of using and methods of producing ultrapure water was made. Features of determination of electrical ...conductivity (resistivity) of ultrapure water as the method of the primary control of its quality were considered. The most effective and spread methods of producing ultrapure water on an industrial basis were described as well requirements to the process of its distribution, storage and use, whose fulfillment rules out degradation of water quality.
Abstract
New data about the state of Cr
3+
doping ions in a single crystal of YGa
3
(BO
3
)
4
have been obtained by studying different methods. Using electron paramagnetic resonance, it was found ...that the Cr
3+
ions substitute the trivalent gallium ions. The obtained spin Hamiltonian parameters of the Cr
3+
ions in the YGa
3
(BO
3
)
4
single crystal (g = 1.9743 ± 0.0004; D = −0.465 ± 0.001 cm
−1
; E = −0.013 ± 0.001 cm
−1
) were analyzed and compared with those in TmAl
3
(BO
3
)
4
, EuAl
3
(BO
3
)
4
, and YAl
3
(BO
3
)
4
. The deviation of the Z-axis in the spectrum from the crystallographic axis С
3
is 1,7 degrees in YGa
3
(BO
3
)
4
.
In situ
X-ray diffraction was used to study the structural and elastic properties of huntite-type borates in the temperature range of RT-1073 K. In the radioluminescence (RL) spectra, the Cr
3+
-related emission bands were observed in the red wavelength range, and the presence of other defect-related bands was also registered in some cases. Thermally stimulated luminescence (TSL) glow curves were acquired over a wide temperature range, and the trap depths of the most prominent bands were calculated. The
11
B NMR spectra show that two nonequivalent spectral components exist for BO
3
structural elements.
The possibilities of using active neutral particle diagnostics for measuring local ion temperatures and isotopic ratio of deuterium-tritium plasma at the tokamak with reactor technologies are ...considered. Options for positioning the neutral particle analyzer relative to the diagnostic injector are presented. The fluxes of deuterium and tritium atoms escaping out of plasma were simulated in a wide range of plasma densities and temperatures. It is shown that the neutral particle analyzer active diagnostics will make it possible to measure the plasma parameters mentioned with the spatial and time resolutions of ~14 cm and ~0.01–0.1 s, respectively.
The spectral and luminescent properties of hydrophilic 21-thia-5,10,15,20-tetra(4-sulfonatophenyl)porphyrin and 5,10,15,20-tetra(4-sulfonatophenyl)porphyrin in solutions at 293 K were compared. ...Peculiarities of halochromic effects due to the replacement of a pyrrole by a thiophene ring in the macrocycle were revealed for the first time. Multicenter interactions on the periphery and in the core of the macrocycle led to modulation of spin–orbit couplings, which became apparent in changes of the fluorescence quenching efficiency. Fluorescence of the doubly protonated heteroporphyrins was shown to be quenched as compared to the free bases whereas fluorescence enhancement was observed for the doubly protonated forms.
The formation of Jaggregates of 21-thia-5,10,15,20-(tetra-4-sulfonatophenyl)-porphyrin in acidified aqueous solutions is reported for the first time. The spectral-luminescent properties of these ...species were measured and ascribed to excitonic interactions. The number of coherent interacting monomeric porphyrin molecules in the aggregate was determined. J-Aggregates of this heteroporphyrin were found to fluoresce. The fluorescence quantum yield Φ
fl
was found to be 1.8·10
–4
. The J-aggregates were found to be photolabile. Upon their photo-excitation to the absorption band at 503 nm, these species collapse to the monomeric doubly-protonated molecules. The photomonomerization process is reversible: the J-aggregates form again upon maintenance of the solution in the dark.
A neutron collimator is developed to attenuate the neutron flux and reduce the residual induced activity in the interportal space of the diagnostic system of neutral particle analyzers of the ITER ...tokamak reactor. The collimator is installed in the port plug of the ITER vacuum vessel in front of an inlet to the vacuum pipeline of the diagnostic system. The collimator design has a cellular structure with 80% transparency for the neutral atom beam that goes out of the plasma and is recorded by the analyzers. However, because of increased scattering of neutrons in the collimator, their flux in the interportal room in the service zone of diagnostic systems of equatorial port no. 11 is significantly reduced and allows the equivalent dose rate in this zone to be decreased by several times. Thermal analysis showed that, during the reactor operation in modes with generation of the maximum power of 500 MW, the plasma radiation will cause the heating of the collimating grid to a temperature not exceeding 250°C, which makes it possible to select the stainless steel (316L(N)-ITER grade) as a material for manufacturing the collimator. In this case the cyclic strength of the collimator meets the ITER requirements, and it can be used without replacement during the entire deuterium-tritium experiment of the tokamak reactor.
The control of the deuterium–tritium (DT) fuel isotopic ratio has to ensure the best performance of the ITER thermonuclear fusion reactor. The diagnostic system described in this paper allows the ...measurement of this ratio analyzing the hydrogen isotope fluxes (performing neutral particle analysis (NPA)). The development and supply of the NPA diagnostics for ITER was delegated to the Russian Federation. The diagnostics is being developed at the Ioffe Institute. The system consists of two analyzers, viz., LENPA (Low Energy Neutral Particle Analyzer) with 10–200 keV energy range and HENPA (High Energy Neutral Particle Analyzer) with 0.1–4.0MeV energy range. Simultaneous operation of both analyzers in different energy ranges enables researchers to measure the DT fuel ratio both in the central burning plasma (thermonuclear burn zone) and at the edge as well. When developing the diagnostic complex, it was necessary to account for the impact of several factors: high levels of neutron and gamma radiation, the direct vacuum connection to the ITER vessel, implying high tritium containment, strict requirements on reliability of all units and mechanisms, and the limited space available for accommodation of the diagnostic hardware at the ITER tokamak. The paper describes the design of the diagnostic complex and the engineering solutions that make it possible to conduct measurements under tokamak reactor conditions. The proposed engineering solutions provide a safe—with respect to thermal and mechanical loads—common vacuum channel for hydrogen isotope atoms to pass to the analyzers; ensure efficient shielding of the analyzers from the ITER stray magnetic field (up to 1 kG); provide the remote control of the NPA diagnostic complex, in particular, connection/disconnection of the NPA vacuum beamline from the ITER vessel; meet the ITER radiation safety requirements; and ensure measurements of the fuel isotopic ratio under high levels of neutron and gamma radiation.
Microorganisms associated with algae and able to utilize complex substrates (e.g., plant heteropolysaccharides) may be important producers of hydrolytic enzymes. The microbial communities of the red ...algae
Corallina
sp. and
Phyllophora
sp. sampled in the Kandalaksha Gulf basin of the White Sea were analyzed using high-throughput sequencing of the V4-variable region of the 16S rRNA gene. The dominant phyla in microbiomes of both samples were
Pseudomonadota
and
Bacteroidota
(GTDB classification,
https://gtdb.ecogenomic.org/
). For the
Corallina
sp. sample, dominance of the
Vibrio
,
Agarivorans
, and
Photobacterium
genera was shown, while
Granulosicoccus
and
Aliivibrio
dominated in the
Phyllophora
sp. sample. The analyzed red macroalgae with associated microbiota were used as an inocula to obtain microbial enrichment cultures growing on β-1,4-xylan or β-1,3-glucan (curdlan). It was shown that, similar to environmental samples
Pseudomonadota
and
Bacteroidota
phyla representatives were prevalent in all enrichment cultures. However, unlike the environmental samples, in the enrichment cultures the dominant genera were
Marinomonas
,
Reinekea
,
Polaribacter
, and
Pseudoalteromonas
. The latter, as well as the representatives of
Vibrio
sp., were isolated in pure cultures for which the xylanolytic activity was shown.
—
High-performance sequencing of the 16S rRNA gene (V4 region) was used to reveal the most widespread groups of microorganisms in the bottom sediments of the Barents and Kara seas. In the Barents ...Sea, these were uncultured bacteria of the families
Hyphomicrobiaceae
,
Anaerolineaceae
,
Desulfobulbaceae
, and
Desulfosarcinaceae
(Sva0081 sediment group), actinobacteria of the genus
Rhodococcus
, and proteobacteria of the genus
Woeseia
. In the Kara Sea the most represented groups were uncultured bacteria of the order
Sedimentisphaerales
(the SG8-4 cluster, class
Phycisphaerae
, phylum
Planсtomycetota
), bacteria of the family
Anaerolineaceae
, the family
Desulfosarcinaceae
(the SEEP-SRB1 cluster), the deep phylogenetic cluster NB1-j, organotrophic proteobacteria of the genera
Woeseia
and
Pseudomonas
, and sulfate reducers of the genus
Desulfatiglans
. The patterns of microbial distribution were analyzed depending on the depth from the bottom surface and the presence of fluid discharge zones. It was found that according to analysis of the core microbiome, uncultured bacteria of the SG8-4 cluster and uncultured bacteria of the family
Anaerolineaceae
predominated in the methane discharge zones in the Barents and Kara seas.
The applicability of neutral particle diagnostics for studying plasma parameters and additional methods of heating in the Tokamak with Reactor Technologies is analyzed. Options for the arrangement of ...diagnostic equipment, which includes three analyzers of charge-exchange atoms (neutral particle analyzers) for different energy ranges of recorded atomic fluxes, are given. It is shown that the diagnostic complex of analyzers makes it possible to measure the distribution functions of plasma thermal ions and to obtain information on the isotopic ratio of the main plasma ion component in the deuterium–tritium mode of facility operation. In addition, the proposed geometry of the analyzer arrangement makes it possible to measure the energy distribution of fast ions, which arise during neutral beam injection and ion cyclotron heating of plasma.
PDF
