The TL dose response was simulated within the framework of a kinetic model with cluster defects which contain electron TL-active traps and deep traps. It was shown that superlinearity of the TL dose ...dependence arises due to the temperature-dependent competition between the intracluster capture of electrons by deep traps and their thermal release into the conduction band. The regularities of the influence of the main parameters of the model (heating rate, activation energies of the ground and excited levels of TL-active traps) on the TL yield and nonlinearity of the dose dependence were found.
•TL dose response was simulated in terms of cluster kinetic model with deep traps.•Superlinearity is due to the temperature-dependent competitive effect of deep traps.•The dependences of the linearity coefficient on the model parameters are studied.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The ideas of heads of Soviet enterprises from different regions of the country concerning the socio-economic development of the USSR, expressed at a meeting in Moscow in 1983, are analyzed. The ...socio-psychological characteristics that were inherent in the Soviet economic leaders at the regional level, who were involved in discussing the problems of ‘improving the economic mechanism’, are studied in detail. The source base of the study includes documents from the Russian State Archive of Socio-Political History and the Center for Documentation of the Recent History of the Yaroslavl Region, oral history data (interviews with representatives of the regional authorities of the 1970s-1980s, which were personally conducted by the author of the article) and scientific literature. It is argued that the opinions of directors of the largest enterprises were perceived by party officials with the same level of trust as the opinions of representatives of the scientific community. It is concluded that the ideas of the party and economic activists intertwined the innovative nature of thinking with the dogmatic patterns of Soviet ideology. It is noted that the activities of the party and economic activists contributed to the formation of a kind of proto-bourgeoisie in the USSR in the 1970s-1980s. It is emphasized that the ideas of the party active on expanding the rights of enterprises and material incentives were a manifestation of latent capitalist tendencies. It is concluded that the main factor in the effective interaction of the regional ‘party economic functionaries’ with Moscow was close informal relations.
The question of the crisis of the USSR economy on the eve of “perestroika” is considered. Attention is paid to archival documents, which are introduced into active scientific circulation for the ...first time. The question of political and ideological support for the transformation of society and economy in the late USSR is raised. The results of a comparative analysis of documents of the official authorities and the expert community are presented. The research focuses on declassified archival materials deposited in the fund of the former chairman of the USSR Council of Ministers N. I. Ryzhkov (F. 653 — Nikolai Ivanovich Ryzhkov) of the Russian State Archive of Social and Political History (RGA SPI). The novelty of the study is seen in the fact that the analyzed documents allow shedding light on unknown crisis phenomena in the economic life of the USSR. In the course of the work, a circle of institutions was identified that monitored the socio-economic situation in the USSR in the first half of the 1980s. The relevance of the study is due to the problems of building a welfare state in modern Russia, improving the relationship between the center and regions in the Russian Federation. Analytical letters of representatives of the academic community and government agencies are studied. The theoretical basis of the work is connected with the ideas of M. A. Beznin and T. M. Dimoni about protobuzhuisia and state capitalism in the USSR, G. G. Popov about the latent conflict in the USSR between the power of experts and political functionaries.
It is found that the energy distribution of traps in Al
2
O
3
–BeO dosimetric ceramics is described by the exponential function. It is shown that taking into account this distribution when simulation ...isothermal decay curves within the classical thermoluminescence model causes an anomalous effect of a decrease decay rate with increasing temperature.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
New Al2O3-BeO ceramics were synthesized from alumina nanopowder in BeO crucibles by high-temperature treatment in reducing conditions. It was found that the TL curve of these ceramics is ...characterized by a dosimetric peak at 520–530 K for a heating rate of 2 K/s. The integrated TL of the peak is not influenced by the heating rate of the samples, unlike that in anion-defective alumina and beryllia crystals. The presence of an energy distribution of the traps which cause dosimetric TL peak is verified by Tm-Tstop and initial rise methods. Linear dependence on dose of the intensity of TL peak at 520–530 K is observed in the 10–300 Gy gamma-dose range. The diversity of TL sensitivity of the ceramic samples synthesized in one cycle does not exceed 10%. The results obtained show that the newly synthesized Al2O3-BeO ceramics are promising materials for TL dosimetry of high doses of ionizing radiation.
•New Al2O3-BeO ceramics were synthesized in vacuum in reducing conditions.•Dosimetric TL peak at 520 K is associated with trap depth distribution.•TL thermal quenching is not observed in Al2O3-BeO samples.•TL dose response in 520 K peak is linear from 10 to 300 Gy.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Possible correlation is studied between Water Equivalent Hydrogen (WEH) in the Martian subsurface, as measured by the DAN (Dynamic Albedo of Neutrons) instrument along the Curiosity traverse, and the ...presence of hydrated minerals on the surface, as seen from the orbit by CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) instrument onboard MRO (Mars Reconnaissance Orbiter). Cross-analysis of the subsurface WEH values from DAN passive measurements with the distribution of hydrated minerals over the surface of Gale crater according to Specialized Browse Product Mosaics is performed for the initial 20 km part of traverse. As a result, we found an increase up to 0.4 wt% of the mean WEH value for the surface areas with the spectral signatures of polyhydrated sulfates. The increase is shown to be higher with the more prominent spectral signature on the surface. Similar WEH increase for the two other types of hydrated minerals, such as monohydrated sulfates and phyllosilicates, was not found for the tested part of the traverse. Polyhydrated sulfates being a part of the sedimentary deposits composing the surface of Gale crater should have considerable thickness that is necessary for the subsurface neutron sensing by DAN measurements.
Full text
Available for:
FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Trained detection dogs distinguish between urine samples from healthy organisms and organisms with malignant tumors, suggesting that the volatile urine metabolome contains information about tumor ...progression. The aim of this study was to determine whether the stage of tumor growth affects the chemical differences in the urine of mice and to what extent the "olfactory image of disease" perceived by dogs coincides with the "image of disease" recorded by the mass spectrometer. We used a novel laser ionization mass spectrometry method and propose a mass spectrometric analysis without detailed interpretation of the spectrum of volatile metabolomes in urine. The mass spectrometer we use works without sample preparation and registers volatile organic compounds in air at room temperature without changing the pH of the sample, i.e. under conditions similar to those in which dogs solve the same problem. The experimental cancer models were male BDF-f1 hybrid mice transplanted with hepatocarcinoma tissue, and similar mice transplanted with healthy liver tissue were used as controls. Our data show that both dogs and our proposed laser mass spectrometry method are able to detect both the entire spectrum of volatile organic compounds associated with the disease and minor changes in this spectrum during its course.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
New Al2O3–BeO ceramics were synthesized by using high-temperature treatment of the initial compacts of nanostructured alumina in BeO crucible. The decomposition of the pulsed cathodoluminescence ...spectra into Gaussians revealed the luminescence bands related to oxygen vacancies and their aggregates in the ceramics. TL of the synthesized ceramics exposed to high-dose irradiation contained three peaks at 360 (A), 525 (B) and 730 K (C). It was found that optical stimulation at the wavelength of 470 nm causes optical bleaching of the traps responsible for peaks A and B, in contrast to the deep traps of the peak C, and gives rise to OSL. At the same time, there was a shift of the position of peaks A and B to the high-temperature region. This result shows the presence of the energy distribution of the traps responsible for TL peak A. It was found that the range of linearity of the TL dose response after gamma-irradiation is from 0.01 to 1.0 kGy. After irradiation with a pulsed electron beam (130 keV), the linear behavior of the OSL dose response was observed from 3 to 30 kGy.
•The synthesis conditions affects the content, TL and PCL of Al2O3–BeO ceramics.•Emission centers in ceramics are formed by oxygen vacancies and their aggregates.•Irradiation with light at 470 nm causes optical bleaching of traps and OSL.•The traps of TL peak at 525 K are distributed along the energy depth.•TL and OSL of ceramics can be used for high-dose dosimetry (0.01–30 kGy).
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The luminescent and dosimetric properties of nanostructured aluminum oxide which contains a mixture of metastable transition Θ, δ, and κ-phases were investigated. To vary the phase composition of the ...samples, they were annealed in air at 850–1200 оС. It was found that annealing the samples at Т = 850–1100 оС in air results in a change in the percentages of κ- and δ-phases with a slight variation in the Θ-phase concentration. Alpha-phase begins to form in the samples at Т = 1100 оС, its concentration reaches 100% at Т = 1200 оС. The PCL spectra featured bands associated with F- and F2-type centers, the intensity of which decreased with increasing annealing temperature due to thermal destruction of centers. Kinetic TL parameters of the samples irradiated with a pulsed electron beam (130 keV) were found by deconvoluting TL curves into elementary peaks of general order kinetics. These parameters change insignificantly when the annealing temperature increases up to 1000 оС and they change greatly when the temperature grows further and α-phase is formed in the samples. The presence of sublinear sections of the TL dose response at doses of 1.5–45 kGy shows that the use of nanostructured aluminum oxide which contains transition phases for high-dose TL dosimetry of pulsed electron beams is promising.
•The phase transformation in nanostructured Al2O3 during annealing was found.•PCL spectra feature the emission bands of F- and F2-type centers.•TL kinetic parameters were determined by glow curve deconvolution.•TL dose dependences after pulsed electron beam irradiation feature sublinear regions.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Titanium and platinum samples as components of bimetallic implants for the osteoregeneration process have been modified in solutions modeling biological systems and studied by means of cyclic ...voltammetry, electrochemical impedance spectroscopy and scanning probe microscopy. While aspartic and glutamic acids did not adsorb significantly on platinum in the potential region investigated, the presence of the amino acids affects oxide layer growth on the titanium surface under anodic polarization. The two studied amino acids behave differently on the titanium electrode surface due to differences in adsorption modes of these substances. The adsorption of the glutamic acid depends on the polarization potential to a large extent, and most of quantitative adsorption characteristics (EIS data, the surface roughness) undergo drastic change at the polarization potential value of 750 mV (vs. Ag/AgCl) in the presence of this substance. Equivalent circuit modeling of the surface processes has been carried out, and a scheme for aspartic and glutamic acid adsorption onto the titanium surface has proposed.
Display omitted
•Glutamic acid adsorption is determined by potential applied to the titanium electrode.•Aspartic acid adsorbs on a titanium electrode surface through both carboxylic groups.•Titanium surface characteristics depend on both potential and amino acid presence.•Dicarboxylic amino acids interact strongly with a titanium electrode surface.•Aspartic and glutamic amino acids adsorption on platinum electrode is negligible.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
