MEDICAL AND SOCIAL ISSUES OF OCCUPATIONAL REHABILITATION IN ELDERLY PATIENTS WITH VASCULAR OPHTHALMOPATHY

Aim: To assess medical and social issues of occupational rehabilitation in elderly patients with vascular eye diseases. Materials and methods: The results of examination of 572 patients and disabled persons after acute occlusion of central retinal artery, central retinal vein or optic nerve ischemia with sequelae were analyzed. Results: The majority of patients (> 70%) with history of acute occlusion of central retinal artery, central retinal vein or optic nerve ischemia were elderly and had extensive professional background. Frequency of acute vascular eye diseases-related disability was as follows: 12.7% after occlusion of central retinal artery, 60.1% after acute occlusion of central retinal vein and 27.2% after acute optic nerve ischemia. Conclusion: Key determinants of occupational abilities in patients with vascular eye diseases are: visual function, positive motivation for work, compensation status of background vascular condition and adequate working environment

Temperature regime reconstruction of two Caucasian Mountain lakes based on diatom analysis

В статье проанализированы данные по диатомовым комплексам из донных отложений оз. Каракель (Республика Карачаево-Черкессия) и оз. Донгузорун (Республика Кабардино-Балкария). Оба озера имеют ледниковое происхождение. Первичный материал был получен в результате бурения озерных осадков в наиболее глубокой части этих озер. Реконструкция температурного режима озер проведена по результатам анализа систематического состава диатомовых комплексов. Расчет изменений температурного режима основан на принципе унификации биоиндикационных методов. Обсуждаются перспективы применения нового метода для палеоклиматических реконструкций. В работе использованы результаты изотопного датирования и геохимического анализа озерных осадков.По диатомовым комплексам выявлены долговременные тенденции изменения температурного режима в исследованных озерах. Кроме того, обнаружены более кратковременные периоды повышения и понижения температуры воды в оз. Донгузорун, которые, вероятно, связаны с сезонными изменениями. Ранее для обоих озер были выделены периоды переотложения донных осадков под воздействием селевых потоков. По результатам диатомового анализа эти процессы всегда совпадали с периодами относительного повышения температуры озерных вод.The authors present the analysis of data on diatom assemblages from the bottom sediments in Lake Karakyol (Karachayevo-Circassian Republic) and Lake Donguzorun (Kabardino-Balkarian Republic). Both lakes are of glacial origin. The sediments samples were drilled in the deepest parts of lakes. The temperature regime of lakes was reconstructed according to taxonomic composition of diatom assemblages. The calculations of temperature variations were based on the unification principle of bioindication methods. The prospects of application of this new method for paleoclimatic reconstructions are discussed. The results of the isotopic dating and the geochemical analysis of lacustrine sediments were used. On the basis of diatom assemblages the long-term trends of temperature variations for study lakes were revealed. Moreover, the authors determined short-term periods of increasing and decreasing of water temperature in Lake Donguzorun which were probably connected with seasonal changes. Previously, the periods of sediment redeposition resulted from mud flow activity have been determined for both lakes. According to the results of diatom analysis it was found that these processes always coincided with periods of the relative temperature increasing in the lake

New Cr-Ni-Base Alloy for High-Temperature Applications Designed on the Basis of First Principles Calculations

We use ab initio calculations to analyze the influence of 4d and 5d transition metal alloying elements on cohesive properties of the bulk and a representative grain boundary in Cr within the framework of the Rice–Thomson–Wang approach. The results obtained for Cr are combined with the analogous results for Ni to select Ta and Nb as promising alloying additions to dual-phase (α/γ) Cr-Ni-base high-temperature alloys. Ta and Nb are added to the alloying system of an existing alloy I (Cr-Ni-W-V-Ti) in an attempt to design a chemical composition of a new alloy II (Cr-Ni-W-V-Ti) + (Ta-Nb). Investigation of the microstructure of the Ta-bearing Cr-Ni-alloy reveals a Ta enrichment of large γ-areas near GBs in α-matrix that we consider as potency to increase the cohesive strength of GBs and the cohesive energy of the bulk in γ-phase. Mechanical testing of alloys I and II demonstrates that the alloy II has improved tensile strength and creep resistance at high temperatures

Heat Transfer Behaviour and Thermohydraulics Code Testing for Supercritical Water Cooled Reactors (SCWRs)

Considering the high interest shown in a number of Member States, the IAEA established in 2008 the Coordinated Research Project (CRP) on Heat Transfer Behaviour and Thermo-hydraulics Code Testing for SCWRs. The aim was to foster international collaboration in the R&D of SCWRs in support of Member States’ efforts and under the auspices of the IAEA nuclear Energy Department’s Technical Working Groups on Advanced Technologies for Light Water Reactors (TWG-LWR) and Heavy Water Reactors (TWG-HWR). The two key objectives of the CRP were to establish accurate databases on the thermohydraulics of supercritical pressure fluids and to test analysis methods for SCWR thermohydraulic behaviour to identify code development needs. In total, 16 institutes from nine Member States and two international organizations were involved in the CRP. The thermohydraulics phenomena investigated in the CRP included heat transfer and pressure loss characteristics of supercritical pressure fluids, development of new heat transfer prediction methods, critical flow during depressurization from supercritical conditions, flow stability and natural circulation in supercritical pressure systems. Two code testing benchmark exercises were performed for steady state heat transfer and flow stability in a heated channel. The CRP was completed with the planned outputs in 2012. This publication consists of the background and objectives, descriptions of current SCWR design concepts, and major technical achievements from the CRP tasks based on the results of R&D at participating institutes and through their close collaboration. It provides researchers and engineers with a comprehensive and reliable database, and the current status of prediction methods in the area of thermohydraulics of supercritical pressure fluids relevant to SCWRs.JRC.F.5-Nuclear Reactor Safety Assessmen

Seafloor spreading and tectonics at the Charlie Gibbs transform system (52-53ºN, mid atlantic ridge): Preliminary results from R/V A. N. Strakhov expedition S50

The Charlie Gibbs offsetting by ~ 340 km the Mid Atlantic Ridge (MAR) axis at 52°-53° N is one of the main transform systems of the North Atlantic. Located between long mid-ocean ridge segments influenced from the south by the Azores and from the north by the Iceland mantle plumes, this transform system has been active since the early phases of North Atlantic rifting. Object of several surveys in the ’70 and ’80, Charlie Gibbs received great attention for its unique structure characterized by two long-lived right-lateral transform faults linked by a short ~ 40 km-long intra-transform spreading centre (ITR) with parallel fracture zone valleys extending continuously towards the continental margins. In October 2020 expedition S50 of the R/V A.N. Strakhov surveyed an area of 54,552 km2 covering the entire Charlie Gibbs transform system and the adjacent MAR spreading segments. We collected new bathymetric, magnetic and high-resolution single channel seismic data, along with basaltic, gabbroic and mantle rocks from 21 dredges. This work contains preliminary data from cruise S50 and discusses the large-scale architecture of this unique, long-lived transform system

Understanding and Prediction of Thermohydraulic Phenomena Relevant to Supercritical Water Cooled Reactors (SCWRs) - Final Report of a Coordinated Research Project

FOREWORD The supercritical water cooled reactor (SCWR) is an innovative concept that operates at a pressure higher than the thermodynamic critical point of water, allowing the core outlet coolant temperature to be much higher than that of the current generation of WCRs. The key technological advantages of the SCWR include its high thermal efficiency and simplified system configuration compared with conventional WCRs. There has been a high level of interest in research and development of SCWRs in several Member States. In 2007, the IAEA started the coordinated research project (CRP) entitled Heat Transfer Behaviour and Thermo-hydraulics Code Testing for Super-critical Water Cooled Reactors (SCWRs), which promoted international collaboration among 16 institutes from 9 Member States and 2 international organizations. The CRP was successfully completed in September 2012. Information generated from that CRP was documented in numerous IAEA publications and reports. A database of thermohydraulic parameters of interest to SCWR development was compiled and is housed in the Nuclear Energy Agency’s central server. After the completion of the CRP, collaboration continued between several participating institutes. Most of these institutes expressed their strong interest in and support for a new CRP on thermohydraulics of SCWRs to continue the momentum of international collaboration. The overall objective of this second CRP, which started in 2014, was to improve the understanding of thermohydraulic phenomena and the prediction accuracy of thermohydraulic parameters related to SCWRs and to benchmark numerical toolsets for SCWR thermohydraulic analyses. Scientific investigators from participating institutes identified specific research objectives to improve the predictive capability of key technology areas (e.g. heat transfer and pressure drop for SCWR fuel related geometries, parallel channel stability boundary, natural circulation flow, critical heat flux at near critical pressures, critical flow, subchannel and plenum mixing). The predictive capability of subchannel codes and computational fluid dynamic tools was assessed through benchmarking exercises for heat transfer in tubes, annuli and bundles as well as pressure drops in annuli and bundles. In total, 12 institutes from 10 Member States and 2 international organizations were involved in this second CRP, which was completed with the planned outputs in 2019. The present publication provides the background and objectives of the CRP; descriptions of a revised Canadian SCWR design concept and a new SCWR design concept being developed at the Nuclear Power Institute of China; updated information on key technology areas (e.g. heat transfer in simple geometries, stability and critical flow) obtained since the completion of the previous CRP; new experiments and data on supercritical heat transfer in bundles and on critical heat flux; and application of the direct numerical simulation approach for supercritical heat transfer. Results of three benchmarking exercises with subchannel codes and computational fluid dynamic tools are also presented, to demonstrate successes and show areas for further improvement. Experimental information and data were contributed by participating institutes through close collaboration. This publication illustrates the state of the art of SCWR research and development. It is expected to be a key supporting publication for researchers and engineers pursuing the development of SCWRs or equipment/components operating at supercritical pressures. The IAEA is grateful for the contributions of the chief scientific investigators of all participating institutes and of the CRP chairpersons, L. Leung (Canada) and W. Ambrosini (Italy). In particular, the efforts of L. Leung to collect and organize the contributions and to continuously encourage progress in the work are gratefully recognized. The IAEA officers responsible for this publication were T. Jevremovic and K. Yamada of the Division of Nuclear Power