Rate of convergence and Edgeworth-type expansion in the entropic central limit theorem

An Edgeworth-type expansion is established for the entropy distance to the class of normal distributions of sums of i.i.d. random variables or vectors, satisfying minimal moment conditions.Comment: Published in at http://dx.doi.org/10.1214/12-AOP780 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

Electrochemical synthesis of hydrogen with depolarization of the anodic process

A new active composite coating for graphite gas diffusion electrode for hybrid sulfur cycle was proposed. The kinetics of oxidation of SO₂ were studied on porous graphite anodes with different catalytic coatings. It was shown that the most efficient composite coating is based on activated carbon and platinum supported on graphite gas diffusion substrate. The voltage drop in the laboratory electrochemical cell was 1.3 V at a current density of 1000 A·m⁻². This corresponds to a specific consumption of 3.1 kWh electric energy per 1 m³ of hydrogen

Population status of Bupleurum aureum (Apiaceae), a Critically Endangered plant species in a region of European Russia

Protected Areas are considered as an important and widely applied tool for biodiversity conservation. They are especially relevant for conservation of threatened species populations. This paper presents study aimed to investigate population status and suitability of habitat conditions of a regionally Critically Endangered plant species, Bupleurum aureum (Apiaceae). Our research has been conducted in National Park “Smolny” (European Russia). The field studies were carried out in 2008, 2013–2018 in two study sites (Plot1, Plot2). In each study sites, square plots (1×1 m) were established to cover the most number of B. aureum individuals. The population status was assessed on the basis of the morphometric traits of individuals (height of generative individuals, number of umbellulas per umbella, number of schizocarpiums per umbellula), number of individuals per population, age structure of populations, composition of accompanying flora. We analysed relationships between environmental conditions (shadiness, soil moisture, salt regime of soil, soil nitrogen, soil pH, soil moisture variability) and morphometric and population traits of B. aureum to reveal the most influencing environmental factors. We found that at the north-western limit of the range, B. aureum has relatively low abundance and height of individuals in compare to available data from other parts of its range. The population age structure indicated higher habitat suitability in Plot1 due to presence of both vegetative and generative individuals. At the same time, in Plot2, B. aureum population is under serious threat due to a lack of vegetative individuals noted during almost whole study period. We suppose a forthcoming threat of probable loss of this B. aureum population. Environment data obtained in both habitats of B. aureum populations in National Park “Smolny” (Russia) indicated high relationships between soil moisture and the number of inflorescences formed by plants. We suppose a threat of extinction of the B. aureum population due to the building activity of Castor fiber inhabiting the small river Bakhmustika located nearby of study area. If the small river will be dammed, it could lead to decrease in B. aureum population in both studied sites due to the increase in ground water level

Iinfluence of Main Technological Parameters of Drying on Quality of Bagasse From Carrot and Beet

The work studies the drying process of vegetable bagasse, namely of carrot and beet. There is studied the moisture content kinetics of vegetable bagasse and determined the dependence of the process duration on main technological parameters in the work of a vibration vacuum dryer, namely, an amplitude and frequency. There were studied quality parameters of obtained concentrated products, namely the colorimetric estimation of dried bagasse of carrot and beet. Based on obtained results of the study, it was established, that the use of vibration in the process of drying bagasse favors conservation and formation of colorimetric characteristics of a dried product. Determined color characteristics gave a possibility to establish, that at thermal processing it is very important to decrease the drying process duration and temperature. Research data proved prospects of producing concentrated products, namely, dried bagasse of carrot and beet by the offered method. It allows to regulate quality parameters of a ready product: color, brightness, consistence, viscosity and physical-chemical properties. Obtained concentrated products are characterized with high organoleptic indices, food value. This product may be used in the wide spectrum of food industry, such as, for example: juice supplement, stuff for confectionary mass, filling for confectionary products, as biological supplement for healthy nutrition

Radial deformations of working cylinder of hydraulic Legs depending on their extension

Current methods of calculation of parameters of hydraulic legs of powered supports are in most cases analytical and do not consider all complex of factors. Finite element model was developed to study this problem and used to analyze the influence of hydraulic legs extension on radial deformations of cylinder of different producers of powered supports at variation of hydraulic fluid pressure. It was revealed that radial deformations of cylinders along the axis of hydraulic legs increase in magnitude in direct proportion to the hydraulic fluid pressure and extension. Research results can be recommended to define optimal geometric parameters of hydraulic legs in respect to the minimal radial deformations of hydraulic cylinder increasing its impermeability and improving the work of cup seals. It is recommended to use the obtained results at power support designing

Radial Strains of Double-layer Cylinders in Hydraulic Props of Powered Supports

At present a lot of efforts are made to use double-layer power cylinders in hydraulic props of powered supports. To study the response of these cylinders to loads a special finite-element model has been developed and used for investigations into tension effect and double-layer cylinder thickness – radial strain relation under pressure of hydraulic liquid 50 MPa. It has been revealed that double-layer cylinders are distinguished by much lower radial strains in the zone of cup-like sealing elements as if compared with one-layer cylinders, as well as equivalent stresses are lower, and safety factor is higher. The data of the study can be recommended to calculate appropriate geometrical parameters of hydraulic props with respect to lower radial strains of a hydraulic cylinder, which improve its leak-tightness and functioning of cup-like sealing elements. The obtained results can be useful for design and construction of powered supports

Results of the modal analysis of the underground mine hydraulic leg in various modes of its operation

The article describes the construction of models and the initial conditions for the various modes of legs operation. The article presents the way of setting the initial conditions for the initial thrust with constant pressure and for leg operation in the mode of increased pressure caused by the lowering of the roof. The results of modal analyses conducted for 2 modes of leg operation are shown. It is shown that the form and frequency of natural oscillations of hydraulic legs are determined by their design, pressures of the initial thrust and nominal operating resistance, as well as by the operating modes which differ in schemes of interaction of leg elements with interacting elements of the support and the roof and floor strata. At the same time, changing the operating mode of the legs changes the natural frequency both to the higher and to the lower side, as well as the form of oscillations of certain frequencies. For more accurate calculation of the frequency response of hydraulic legs to the external load of frequencies, it is proposed to take into account not only their design and power properties, but also the modes of their loading

Study of Falling Roof Vibrations in a Production Face at Roof Support Resistance in the Form of Concentrated Force

One of the main reasons of roof support failures in production faces is mismatch of their parameters and parameters of dynamic impact on the metal structure from the falling roof during its secondary convergences. To assess the parameters of vibrational interaction of roof support with the roof, it was suggested to use computational models of forces application and a partial differential equation of fourth order describing this process, its numerical solution allowed to assess frequency, amplitude and speed of roof strata movement depending on physical and mechanical properties of the roof strata as well as on load bearing and geometry parameters of the roof support. To simplify solving of the differential equation, roof support response was taken as the concentrated force

On the reconstruction of planar lattice-convex sets from the covariogram

A finite subset $K$ of $\mathbb{Z}^d$ is said to be lattice-convex if $K$ is the intersection of $\mathbb{Z}^d$ with a convex set. The covariogram $g_K$ of $K\subseteq \mathbb{Z}^d$ is the function associating to each u \in \integer^d the cardinality of $K\cap (K+u)$. Daurat, G\'erard, and Nivat and independently Gardner, Gronchi, and Zong raised the problem on the reconstruction of lattice-convex sets $K$ from $g_K$. We provide a partial positive answer to this problem by showing that for $d=2$ and under mild extra assumptions, $g_K$ determines $K$ up to translations and reflections. As a complement to the theorem on reconstruction we also extend the known counterexamples (i.e., planar lattice-convex sets which are not reconstructible, up to translations and reflections) to an infinite family of counterexamples.Comment: accepted in Discrete and Computational Geometr