A series of experiments was performed at the P critical facility of the National Research Center Kurchatov Institute to study neutron characteristics of the VVER type water-uranium fuel compositions ...that contain fuel pins with uranium enriched up to 6.5% in
235
U and erbium oxide (Er
2
O
3
) absorbers. Computational analysis of experiments was carried out by means of the precision MCU-PD code and the best-estimate code TVS-M, which are used for the VVER fuel cycle design. This paper describes the computational models implemented in both of these codes and presents the results of calculations of the main critical parameters in comparison with the experimental data.
This paper presents the results of the mineralogical, petrographic, elemental, and isotopic analysis of the Chelyabinsk meteorite and their geochemical interpretation. It was shown that the meteorite ...can be assigned to LL5-group ordinary chondrites and underwent moderate shock metamorphism (stage S4). The Chelyabinsk meteorite contains a significant fraction (approximately one-third by volume) of shock-melted material similar in composition to the main volume of the meteorite. The results of isotopic analysis suggest that the history of meteorite formation included an impact event approximately 290 Ma ago.
We examine a unique data set from seven Hubble Space Telescope (HST) “visits” that imaged Saturn's northern dayside ultraviolet emissions exhibiting usual circumpolar “auroral oval” morphologies, ...during which Cassini measured the interplanetary magnetic field (IMF) upstream of Saturn's bow shock over intervals of several hours. The auroras generally consist of a dawn arc extending toward noon centered near ~15° colatitude, together with intermittent patchy forms at ~10° colatitude and poleward thereof, located between noon and dusk. The dawn arc is a persistent feature, but exhibits variations in position, width, and intensity, which have no clear relationship with the concurrent IMF. However, the patchy postnoon auroras are found to relate to the (suitably lagged and averaged) IMF Bz, being present during all four visits with positive Bz and absent during all three visits with negative Bz. The most continuous such forms occur in the case of strongest positive Bz. These results suggest that the postnoon forms are associated with reconnection and open flux production at Saturn's magnetopause, related to the similarly interpreted bifurcated auroral arc structures previously observed in this local time sector in Cassini Ultraviolet Imaging Spectrograph data, whose details remain unresolved in these HST images. One of the intervals with negative IMF Bz however exhibits a prenoon patch of very high latitude emission extending poleward of the dawn arc to the magnetic/spin pole, suggestive of the occurrence of lobe reconnection. Overall, these data provide evidence of significant IMF dependence in the morphology of Saturn's dayside auroras.
Key Points
We examine seven cases of joint HST Saturn auroral images and Cassini IMF data
The persistent but variable dawn arc shows no obvious IMF dependence
Patchy postnoon auroras are present for northward IMF but not for southward IMF
The analysis of gamma spectra obtained from the decay of
Au indicated that a ten times higher value was adopted for the quantum yield of the transition of 521.4 keV. Based on the intensity of gamma ...lines corresponding to well-known transitions, the quantum yield for the 521.4 keV transition was calculated. The obtained value was used to correct the adopted value of the intensity of the beta transition that populates 877.0 keV energy state from which gamma radiation of 521.4 keV is emitted.
The chemical composition and the isotopic characteristics of formation waters from the Siberian Platform are presented. The study involved samples of formation brines from depths ranging from 100 to ...∼4000
m at five different sites covering a large area of the Siberian Platform. Four water types were identified. The two main water types that were found are: (1) Ca–Cl brines that are believed to be the residual of an evaporated paleoseawater; and (2) Na–Cl brines that are derived mainly from halite dissolution. The origin of a third group of highly saline samples was not determined. However, the chemical and isotopic characteristics of this group of samples suggest that they were produced by various complex scenarios such as metamorphism, water–rock interaction, permafrost freezing and mixing. The last group of samples represents fresh and brackish waters across the area.
A wide range for the natural variation of Br stable isotopes (between −0.80‰ and +3.35‰) was found. The δ
81Br results obtained during this study indicate that Br stable isotopes can have large natural variations and that different evolutionary processes affecting water chemistry may cause significant fractionation.
The unique protein Dsup of the tardigrade
Ramazzottius varieornatus
increases resistance to radiation and oxidative stress in various organisms and in human cell culture. According to simulation ...data, Dsup forms a complex with DNA with an intermolecular distance of
Å, as a result of which DNA is less damaged by reactive oxygen species generated during radiation exposure. However, the stability of the Dsup protein itself under the effect of ionizing radiation remains unclear, which is important for assessing its radioprotective potential and understanding the molecular mechanisms of action of this protein under conditions of high doses of radiation. In this work, the radiation degradation of the Dsup protein after irradiation with
-quanta using small-angle X-ray scattering (SAXS) and electrophoresis of proteins in polyacrylamide gel under denaturing conditions (SDS-PAGE) was studied for the first time. It was shown that, unlike the control protein bovine serum albumin, the spatial-structural characteristics of the Dsup protein remain almost unchanged even when exposed high doses of radiation (5 and 10 kGy), which indicates its high radiation stability.
The article discusses the history of the development of analytical research at the Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Sciences over the past 22 years. An ...overview of the existing scientific equipment, current analytical techniques and some examples of their application in geological research are provided. It is shown that the availability of highly qualified personnel and modern scientific equipment at the Center for Geodynamics and Geochronology allows, both entirely on its base and in cooperation with other Russian and foreign organizations, to conduct state of the art research with the publication of results in leading international journals.
Currently, in order to decrease the negative effects caused by the presence of a discrete phase in the flow path of steam turbines stages operating in wet-steam area, different technical solutions ...are apply. These methods reduce the number of coarse droplets and wetness of working medium. The implementation of erosion reduction methods requires modifying surfaces of flow path, which can significantly affect the efficiency of the steam turbine. For example application of intrachanel moisture removing and steam injection needs changes of the stator blades surfaces. This article is a part of researches cycle about the efficiency of steam injection on the stator blade surface as the main method of coarse liquid particles diameters reduction in the last stages of high-power steam turbines. The paper presents the results of the analysis and comparison of experimental research unmodified profile to the profile of the stator blade changed by injection slot. The comparison of the profile losses considered blades is present. The analysis of the experimental results showed the feasibility and efficiency of this method of coarse liquid particles diameters reduction in the last stages of high-power steam turbines.
The article is devoted to the actual problem of preserving and improving the favorable environmental conditions in the urban environment, due to the introduction of the recessed buildings and ...structures in the architectural-urban planning and construction activity using 'green' architecture technologies. Such objects will reduce the load on the ecosystem, energy, improve the quality of the visual environment of the city, and maintain the existing natural landscape along with the flora and fauna while increasing the area of green spaces in urban or rural areas. The characteristic features of the recessed buildings, their advantages and limitations are given. Determined techniques of architectural-figurative solutions of recessed buildings. The principle of harmonious synthesis of 'green' technologies and modern achievements in the architecture of the recessed buildings is proposed. Possible solutions to global environmental problems are proposed due to the capabilities of the underlying architecture.
Phase-change materials, such as the well-known ternary alloy Ge
2
Sb
2
Te
5
, are essential to many types of photonic devices, from re-writeable optical disk memories to more recent developments such ...as phase-change displays, reconfigurable optical metasurfaces, and integrated phase-change photonic devices and systems. The successful design and development of such applications and devices requires accurate knowledge of the complex refractive index of the phase-change material being used. To this end, it is common practice to rely on published experimental refractive index data. However, published values can vary quite significantly for notionally the same composition, no doubt due to variations in fabrication/deposition processes. Rather than rely on published data, a more reliable approach to index determination is to measure the properties of as-fabricated films, and this is usually carried out using specialized and dedicated ellipsometric equipment. In this paper, we propose a simple and effective alternative to ellipsometry, based on spectroscopic reflectance measurements of Fabry–Perot phase-change nanocavities. We describe this alternative approach in detail, apply it to measurement of the complex index of the archetypal phase-change materials Ge
2
Sb
2
Te
5
and GeTe, and compare the results to those obtained using conventional ellipsometry, where we find good agreement.
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