Renormalized non-modal theory of the kinetic drift instability of plasma shear flows

The linear and renormalized nonlinear kinetic theory of drift instability of plasma shear flow across the magnetic field, which has the Kelvin's method of shearing modes or so-called non-modal approach as its foundation, is developed. The developed theory proves that the time-dependent effect of the finite ion Larmor radius is the key effect, which is responsible for the suppression of drift turbulence in an inhomogeneous electric field. This effect leads to the non-modal decrease of the frequency and growth rate of the unstable drift perturbations with time. We find that turbulent scattering of the ion gyrophase is the dominant effect, which determines extremely rapid suppression of drift turbulence in shear flow

Mathematical modeling of seismic and acousto-gravitational waves in a heterogeneous earth–atmosphere model

AbstractA numerical–analytical solution to problems of seismic and acoustic-gravitational wave propagation is applied to a heterogeneous Earth–Atmosphere model. The seismic wave propagation in an elastic half-space is described by a system of first order dynamic equations of the elasticity theory. The propagation of acoustic-gravitational waves in the atmosphere is described by the linearized Navier–Stokes equations. The algorithm proposed is based on the integral Laguerre transform with respect to time, the finite integral Bessel transform along the radial coordinate with a finite difference solution of the reduced problem along the vertical coordinate. The algorithm is numerically tested for the heterogeneous Earth–Atmosphere model for different source locations

Absorption of deuterated water vapor in the 1.98 µm spectral region

New spectra of water samples enriched by deuterium were recorded between 4500 and 5800 cm−1 using a Fourier transform spectrometer Bruker IFS 125HR combined to multi-pass cells. The spectra were recorded at room temperature with a non apodized resolution of 0.01 cm−1, using water evaporated from a D2O+H2O mixture in the liquid phase. The water vapor pressure was about 1.5 Torr and the absorption path was more than 100 m. A special attention was paid to the experimental procedure allowing to obtain HDO in the gas phase, and also to determine the partial pressure of all isotopologues. Synthetic spectra were compared to the observed ones. Numerous examples of disagreements between measurements and simulations using existing water line lists were observed for deuterated water species. Some lacks were found in the HITRAN2016 line list. A list of 580 transitions is reported that corrects erroneous and missing lines. © 2021Agence Nationale de la Recherche, ANR, (ANR-16-CE01-0009)Russian Science Foundation, RSF, (18-11-00024-Π)This work was partially funded through WaVIL project funded by Agence Nationale de la Recherche , grant no. ANR-16-CE01-0009 . The author would like to thank Dr. Cyrille Flamant. SM activity was supported in the frame of the Russian Science Foundation , grant no. 18-11-00024-Π

Non-alcoholic fatty liver disease and mineral waters of Ukraine – opportunities of application (experimental-clinical studies)

Non-alcoholic fat liver disease (NAFLD) is an urgent problem of modern healthcare and ranks first among all liver diseases worldwide, assuming the nature of an epidemic. The pathogenesis of NAFLD is complex and insufficiently studied, and therefore pharmacological therapy is not always effective and causes negative side effects (or complications). Treatment with mineral waters (MW) is one of the most effective methods of treating diseases of the digestive system and metabolic disorders. Objective: to study the effect of sulphate MW on metabolic disturbances in rats with the experimental NAFLD model for the purpose of scientifically substantiating its use in the complex of treatment of patients. Morphological studies have established that the use of sulfate MW in healthy animals causes an increase in the functional activity of the liver and stomach, which indicates a pronounced biologic activity of this MW. In animals under the influence of sulphate MW was determined a significant reduction in hepatic steatosis according to the morphological study of biopsy specimens, restoration of the processes of bile formation and bile secretion, positive dynamics in the restoration of energy-dependent transmembrane ion transport. Clinical studies in the complex treatment of NAFLD with the use of sulphate MW established normalization of lipid metabolism, improvement of the functional state of the liver, decreased insulin resistance, recovery of adiponectin secretion

Seasonality of Oestrus ovis infection in sheep in the steppe zone of the Stavropol Territory

The purpose of the research is to study the seasonality of Oestrus ovis infection in sheep depending on the management conditions in the steppe zone of the Stavropol Territory.Materials and methods. The research to study the botfly flight seasonality was conducted on two farms in the Apanasenkovsky District and two farms in the Ipatovsky District of the Stavropol Territory. The number of sheep botflies was studied in the entire flight season by regular inspection and counting of the parasite adult stage on the outer surfaces of sheephouse walls and the side walls of sheds with a 15 day-interval.Results and discussion. The sheep botfly flight season was 5.5 months (from May 25–30 to October 31–November 11). Two increases in the number of botflies were observed during this period: in July and September–October. Infection of sheep with oestrosis in 1971 had two peaks (the first, May to June; the second, August to November). Due to the earlier spring 2022, the first peak started in the second half of March and lasted until the first half of July, and the second peak was observed from the second half of August to the end of November

Оптимизация конструкции встречно-штыревого преобразователя кольцевого резонатора на поверхностных акустических волнах

Introduction. Previous works considered the frequency characteristics and methods for fixing sensitive elements in the form of a wave ring resonator on surface acoustic waves in a housing made of various materials, as well as the influence of external factors on sensitive elements. It was found that the passband in such a case is sufficiently wide, which can affect adversely signal detection when measuring acceleration using the sensitive element under development. Therefore, it has become relevant to reduce the sensitive element’s bandwidth by changing the design of the interdigitated transducer (IDT).Aim. To demonstrate an optimal topology for an IDT with a low bandwidth, leading to improved signal detection when acceleration affects the sensitive element.Materials and methods. The finite element method and mathematical processing in AutoCAD and in COMSOL Multiphysics.Results. Nine topologies of IDT are proposed. All these types were investigated using the COMSOL Multiphysics software on lithium niobate substrates, which material acts as a sensitive element. The frequency characteristics are presented. The data obtained allowed an optimal design of the ring resonator to be proposed: an IDT with rectangular pins without selective withdrawal.Conclusion. Self-generation in a ring resonator can be performed by withdrawing no more than one pair of IDTs for 10 or more periods. In this case, the withdrawal of IDTs should be uniform. With an increase in the number of IDT withdrawals, the geometry of the ring resonator is violated, and the wave leaves the structure. The presence of a shared bus keeps the surface acoustic wave inside the IDT structure, and the narrowing of the periods towards the inner part of the structure makes it possible to improve the frequency characteristics of the ring resonator on surface acoustic waves.Введение. В предыдущих публикациях авторами рассматривались частотные характеристики и способы закрепления чувствительных элементов в виде волнового кольцевого резонатора на поверхностных акустических волнах в корпусе из различных материалов, а также влияние внешних факторов на чувствительные элементы. При анализе полученных результатов было замечено, что полоса пропускания достаточно широкая, что может отрицательно сказаться на детектировании сигнала при измерении ускорения с помощью разрабатываемого чувствительного элемента. Возникла необходимость уменьшить полосу пропускания чувствительного элемента за счет изменения конструкции встречноштыревого преобразователя (ВШП). Используя компьютерное моделирование COMSOL Multiphysics, было продемонстрировано несколько вариантов ВШП и показано, что эта цель может быть достигнута изменением геометрии штыря ВШП.Цель работы. Продемонстрировать оптимальную топологию ВШП с малой полосой пропускания, что влечет за собой улучшение детектирования сигнала при влиянии ускорения на чувствительный элемент.Материалы и методы. Применение метода конечных элементов и математическая обработка в AutoCAD и COMSOL Multiphysics.Результаты. Предложено 9 типов топологий встречно-штыревых преобразователей. Проведены исследования при помощи программного обеспечения COMSOL Multiphysics вышеуказанных типов ВШП на подложках из ниобата лития, выступающего в качестве материала чувствительного элемента, и представлены частотные характеристики. Проведена оценка полученных данных и сделаны выводы об оптимальной конструкции кольцевого резонатора: наиболее эффективной структурой является ВШП с прямоугольными штырями без селективного изъятия.Заключение. Генерация волны в кольцевом резонаторе может быть выполнена при изъятии не более одной пары ВШП на 10 и более периодов. При этом изъятие ВШП должно быть равномерным. При увеличении количества изъятых ВШП нарушается геометрия кольцевого резонатора и волна покидает конструкцию. Наличие общей шины позволяет удерживать поверхностную акустическую волну внутри конструкции ВШП, а сужение периодов к внутренней части конструкции позволяет улучшить частотные характеристики кольцевого резонатора на поверхностных акустических волнах

Optimising observing strategies for monitoring animals using drone-mounted thermal infrared cameras

The proliferation of relatively affordable off-the-shelf drones offers great opportunities for wildlife monitoring and conservation. Similarly the recent reduction in cost of thermal infrared cameras also offers new promise in this field, as they have the advantage over conventional RGB cameras of being able to distinguish animals based on their body heat and being able to detect animals at night. However, the use of drone-mounted thermal infrared cameras comes with several technical challenges. In this paper we address some of these issues, namely thermal contrast problems due to heat from the ground, absorption and emission of thermal infrared radiation by the atmosphere, obscuration by vegetation, and optimizing the flying height of drones for a best balance between covering a large area and being able to accurately image and identify animals of interest. We demonstrate the application of these methods with a case study using field data, and make the first ever detection of the critically endangered riverine rabbit (Bunolagus monticularis) in thermal infrared data. We provide a web-tool so that the community can easily apply these techniques to other studies (http://www.astro.ljmu.ac.uk/~aricburk/uav_calc/)

New palynological data for Toarcian (Lower Jurassic) deep-marine sandstones of the Western Caucasus, southwestern Russia

© 2018 Anna A. Goryacheva et al., published by Sciendo 2018. Information on Jurassic palynomorphs from the Greater Caucasus is potentially of great importance, but its availability to the international research community is severely limited. New palynological data for Toarcian deposits of the Western Caucasus are recorded in the present paper. Particularly, dinoflagellate cysts are described for the first time from the Bagovskaja Formation; palynomorphs are found in sandstone levels within this unit. The most representative assemblage includes pollen (with predominant bisaccate pollen), spores (Cyathidites being commonest), and dinoflagellate cysts amongst which the predominant taxon is Nannoceratopsis spiculata. The dinocyst assemblage implies a late Toarcian age for the upper part of the Bagovskaja Formation. On the basis of these new palynostratigraphical results, the range of the formation is extended; previously, only the lower part had been dated on ammonite evidence

The 2015 edition of the GEISA spectroscopic database

The GEISA database (Gestion et Etude des Informations Spectroscopiques Atmosphériques: Management and Study of Atmospheric Spectroscopic Information) has been developed and maintained by the ARA/ABC(t) group at LMD since 1974. GEISA is constantly evolving, taking into account the best available spectroscopic data. This paper presents the 2015 release of GEISA (GEISA-2015), which updates the last edition of 2011 and celebrates the 40th anniversary of the database. Significant updates and additions have been implemented in the three following independent databases of GEISA. The “line parameters database” contains 52 molecular species (118 isotopologues) and transitions in the spectral range from 10−6 to 35,877.031 cm−1, representing 5,067,351 entries, against 3,794,297 in GEISA-2011. Among the previously existing molecules, 20 molecular species have been updated. A new molecule (SO3) has been added. HDO, isotopologue of H2O, is now identified as an independent molecular species. Seven new isotopologues have been added to the GEISA-2015 database. The “cross section sub-database” has been enriched by the addition of 43 new molecular species in its infrared part, 4 molecules (ethane, propane, acetone, acetonitrile) are also updated; they represent 3% of the update. A new section is added, in the near-infrared spectral region, involving 7 molecular species: CH3CN, CH3I, CH3O2, H2CO, HO2, HONO, NH3. The “microphysical and optical properties of atmospheric aerosols sub-database” has been updated for the first time since 2003. It contains more than 40 species originating from NCAR and 20 from the ARIA archive of Oxford University. As for the previous versions, this new release of GEISA and associated management software facilities are implemented and freely accessible on the AERIS/ESPRI atmospheric chemistry data center website