Extreme plasma states in laser-governed vacuum breakdown

Triggering vacuum breakdown at the upcoming laser facilities can provide rapid electron-positron pair production for studies in laboratory astrophysics and fundamental physics. However, the density of the emerging plasma should seemingly stop rising at the relativistic critical density, when the plasma becomes opaque. Here we identify the opportunity of breaking this limit using optimal beam configuration of petawatt-class lasers. Tightly focused laser fields allow plasma generation in a small focal volume much less than ${\lambda}^3$, and creating extreme plasma states in terms of density and produced currents. These states can be regarded as a new object of nonlinear plasma physics. Using 3D QED-PIC simulations we demonstrate the possibility of reaching densities of more than $10^{25}$ cm$^{-3}$, which is an order of magnitude higher than previously expected. Controlling the process via the initial target parameters gives the opportunity to reach the discovered plasma states at the upcoming laser facilities

Intermatrix synthesis: easy technique permitting preparation of polymer-stabilized nanoparticles with desired composition and structure

The synthesis of polymer-stabilized nanoparticles (PSNPs) can be successfully carried out using intermatrix synthesis (IMS) technique, which consists in sequential loading of the functional groups of a polymer with the desired metal ions followed by nanoparticles (NPs) formation stage. After each metal-loading-NPs-formation cycle, the functional groups of the polymer appear to be regenerated. This allows for repeating the cycles to increase the NPs content or to obtain NPs with different structures and compositions (e.g. core-shell or core-sandwich). This article reports the results on the further development of the IMS technique. The formation of NPs has been shown to proceed by not only the metal reduction reaction (e.g. Cu0-NPs) but also by the precipitation reaction resulting in the IMS of PSNPs of metal salts (e.g. CuS-NPs)

Колебания ледников Ключевской группы вулканов во второй половине XX – начале XXI вв.

Changes in sizes of the Klyuchevskaya volcanic group's glaciers had been estimated for the period from 1949–1950 to 2010–2015 using results of analysis of current satellite imagery, data of field observations and historic records. Changes in front positions for some glaciers were analyzed for different periods of time. According to results of comparison between our data and similar ones from the Glacier Inventory the glacier areas decreased by 0.7%. Calculations made with corrected data demonstrated the total increase of the glaciation area by 4.3%. Glaciation of the Klyuchevskoy volcano is characterized by dynamic instability and significant changeability. The Erman glacier, the largest one in this region, did constantly advance since 1945. In 1949‑2015, its area at the front increased by 4.96±0.39 km2, while the front advanced along the valley of the Sukhaya River by approximately 3675±15 m and by 3480±20 m along the valley of the Krutenkaya River. A number of «wandering glaciers» located on the North‑Eastern and Eastern slopes of the volcano, on the contrary, significantly reduced their areas. At the same time, formation of new flows of ice is noticed within the «ice belt». Under the influence of active volcanic processes, the configuration of glacier boundaries on the slopes of Klyuchevskoy volcano does actively change in not only the tongue areas but also in the accumulation areas. Changes in dynamics of the glaciation areas of the Klyuchevskaya group of volcanoes don’t correspond to the present‑day climate changes. The interaction of modern volcanism and glaciation in the area as a whole is conducive to the preservation and development of glaciers, despite the deterioration of climatic conditions of their existence.По результатам анализа современных космических снимков, материалам полевых работ и историческим данным оценено изменение размеров ледников Ключевской группы вулканов с 1949–1950 по 2010–2015 гг. Прослежено изменение фронтов ряда ледников за разные периоды времени. Площадь ледников по сравнению с данными Каталога сократилась на 0,7%, но после коррекции данных выяснилось, что площадь оледенения выросла на 4,3%

Designing smart pulse flow meters using diversion analysis

The operation of modern housing infrastructure is characterized by a constant increase in the cost of the limited resources used. This necessitates the priority implementation in the concept of a smart home of elements aimed at resource saving and their rational management. The study provides an overview of the implementation architectures of the internet of things (IoT) concept in the construction of home automation systems and the requirements they impose on the implementation of smart primary meters of controlled physical quantities. Based on a diversion analysis, a promising smart water meter was developed. The prototype is ergonomic and has a structural form factor convenient for further integration. The designed model of the electronic module of the water flow monitoring system implements, in addition to typical tasks, additional functionality: transfer of recorded indicators and technical information to the cloud storage, warning the user about an emergency situation, accumulation of current data in non-volatile memory. It is possible to use the accumulated statistics for training the predictive analysis module. The proposed architecture option will allow creating energy-efficient elements of home automation systems in the future

Открытие и исследования ледников Камчатки

History of finding and investigation of the present-day glaciers of the Kamchatka Peninsula is described. A degree of our knowledge of such glacier characteristics as the mass balance, sizes, and the area fluctuations for the second half of 20th – beginning of 21st century is discussed. A literature on the Kamchatka glaciations is reviewed. In accordance with purposes of the investigations, methods, and volumes of field researches five periods have been separated in the history. Изложена история открытия и исследований современных ледников Камчатки. Обсуждается изученность баланса массы, размеров и колебаний ледников полуострова за вторую половину XX – начало XXI вв. Приведён обзор литературы по изучению оледенения Камчатки. В исследованиях ледников этого района выделено пять периодов, различающихся объёмами выполненных работ, их целями и методами исследований.