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Growing fish in a recirculating aquaculture system (RAS) involves various stress factors that directly affect their physiological condition. This study aimed to investigate the effect of a chelated organic-mineral additive including Fe, Mn, Cu, Zn, Co, Se and I; on the rearing performance of juvenilecatfish (Clariasgariepinus) under RAS conditions. Four groups of fish (n=50) were formed: a control group (receiving standard feed) and three experimental groups (receiving standard feed with biogenic elements chelate compounds in different concentrations). At the end of the experiment (30 days), the physiological condition of the fish was evaluated by the growth rate, internal organs condition, blood serum biochemical indices and histological examination of the middle intestine. The survival rate of fish in the experimental groups was 96-98%. According to the results, the absolute increase was 14,30% in group III, 11,13% in group II and 6,71% in group I, compared to the control. However, the use of chelated compounds in high concentrations can cause necrosis and erosion of the apical part of the villi (groups II and III). Blood biochemical analysis of fish (group II and III) receiving medium and high concentrations of chelated compounds showed high ALT activity, which was 23,02% (p

The conclusion of the aircraft to a given track line is considered. The possibility of using for this purpose a nonlinear roll control algorithm with functions of functions is analyzed. The results of modeling of the guidance process are given, showing that the investigated nonlinear algorithm ensures the withdrawal of an aircraft from any points in space on a given path for any initial course in a calm atmosphere and in the presence of wind. Key words: line of a given path, roll control, trajectory control algorithm, motion control of the center of mass, lateral deviation.

The article discusses the current trends in the higher education development. The new approach to the organization of the educational process is needed to develop and form the professional competencies of students. In particular, the use of modern educational technologies, interactive teaching methods in the training process organization. The use of these teaching methods allows students to get a high-paying job and be in demand in the labor market in the future. This is because specialists receive in-depth knowledge on water bodies’ creation under any conditions - from a desert to highlands; usage of special vehicles for fish catching and breeding; managing technological processes; evaluation of the biological parameters of products; environmental testing and determining water bodies’ suitability for fish and crustaceans breeding. Students must undergo an internship that allows them to apply their knowledge and skills in their work.

This article discusses the methodology of developing tools for assessing regulatory factors and managerial impacts on the regional economy and individual sectors and businesses. The potential of projection models is investigated, including balance models, convergence of regional and sectoral projection and compiling reliable and representative data sets capable of describing the current economic situation. An attempt was made to develop a series of models for several regional economies; to that end, the modelling of managerial and regulatory impact assessment was used in combination with the well-known value chain approach. In the interests of effective public administration, one of the requirements is to create sectoral model formats compatible with the regional projection models. Results of pilot modelling managerial and regulatory impacts on Kaliningrad region’s economies are presented through examples of agribusiness, transport, industry, tourism and recreation. Implementation of regulatory impact modelling in the framework of the suggested approach is proved for other regions. The main advantage of the developed models for the regional management is their ability to reduce uncertainty in decision-making due to obtaining estimates of the impact of the decisions on the changing situation and the conditions for the development of sectors and industries.

In the modern practice of hydraulic engineering pressure hydrosystems reach H ≥ 200 m. In these conditions the most efficient spillway structure is the vortex shaft spillway. In this paper, the authors consider the conjugation of the swirled flow at the outlet of the discharge conduit with downstreem by thrown jet with a residual twist. In the scheme with jet drop, the residual twist of the flow during the release from the vortex spillway contributes to the expansion of the jet in the air, reducing the specific flow rate, as well as reducing the dynamic loads on the lower bed. The comparison with the jet thrown from the sock of the drainage dam at the same speed parameters (i.e. at the speed of 20-25 m/s on the lip) is carried out. The formula obtained is simple enough to determine the planned outline of the discarded jet. The scheme of conjugation of the jet with the surface of the lower tail water, as well as the calculation scheme to determine the specific discharge of the downward swirling jet.

This work reflects joint experience of many year co-operations between Samara University and RPC INFOTRANS in design, production, development in serial publication and creation of methods of analysis elastic damping features of means of vibration shock protection for apparatus and equipment in computerized test cars to diagnose railway systems. The specialty of development of these means of vibration protection is considered to be ultra small size of the elements which requires relevant use of ultra small vibration dampers. A great number of standard sizes of vibration dampers was made of multilayer elements, e.g. metal wires, strips and the combination of elastoporous material MR (metal ribbon), developed in Samara University, and wires. The technologies of serial production of vibration dampers were perfected on the base of RPC INFOTRANS in the city of Dimitrovgrad.

This paper is dedicated to life time research regarding the cable units, which are intended for vibration protection of the tools and equipment of the computerized labor coaches (KVL). These protection units are the serial product of INFOTRANS and they are used on the Russian Railways, in CIS countries and some countries of the West Europe. The object, purpose and tasks of this research is clarifying of possible ways for using of the cable vibration dampers in order to protect the automated hardware units, computers and hard discs for data storage against vibration and shock. These units run under hard conditions of heavy vibration and short-time shocks.

The paper presents data on the biotechnology of growing accumulative cultures of algae Scenedesmus quadricauda when adding organo-mineral complex drag to the culture growth medium. It is shown that the trace elements that make up the drug (trade name “Helavit”), at the studied concentrations, act in various ways stimulating and inhibiting the growth of algological culture. Having a different effect in the concentration range from 0.1 to 1 mg / L. The maximum positive effect is achieved with a drug concentration of 0.3 mg / l (8986 ± 120 103*cells/ ml), which can be recommended for mass cultivation of algae. A possible cause of inhibition of culture growth, at a concentration of 0.1 mg / l (6960 ± 115 103*cells/ ml), are the inhibitory effects of copper and iodine ions.

We discuss the use of multilayered annular-plate dampers as rotor supports in turbopumps of the RD-0120 and RD-0146 rocket engines. We present a technique of calculating the elastic and damping characteristics of multilayer corrugated annular supports in the case of the conical precession of the rotor.

In the hydraulic laboratory of People's Friendship University of Russia a series of experiments to study the various possible external influences on the process of snow melting were carried out at the facility, which allows to measure the amount of seepage flow in time. The laboratory investigations of the continuous snow melting and infiltration of melt water into the ground, depending on the properties of the snow (initial density, thickness and temperature) were carried out. The impact of rain flows and radiation of the sun on the snow-melting process were examined, carried out experiments with exposure to infrared (IR) and ultraviolet (UV) radiation on the snow. The work is a continuation of the study of the dynamics of the coastal slope of the water bodies in a permafrost [1].

The article seeks to conduct research on the possible consequences on existing regimes of the Angara River after the construction of Motyginskaya hydropower plant. Commissioning not only will make significant changes in the existing microclimate of the upstream, but also will violate the existing ice regimes of the Lower Angara. Thorough studies of the effects and model creations of existing regimes changes can contribute to a change in the project in order to prevent possible catastrophic consequences.

The first stage of research deformations shores, on a laboratory model composed of permafrost, under the influence of waves with different characteristics. Traced the relationship between the amount of deformation, their parameters and wave characteristics. Just found a direct dependence of the formation mechanism of the slope on the criteria of wave impacts.

The paper presents the results of the study on the cultivation of lettuce (lactuca sativa kucheryavec odesskiy) in an aquaponics installation using soil in the conditions of closed water supply systems installations developed on the basis of the Russian-Scandinavian aquaculture center of the BiRH Institute of K. G. Razumovsky Moscow State University of Technologies and Management, Moscow. As a result of which, growth and productivity indicators of lettuce in an aquaponics installation were obtained. Hydrochemical studies made it possible to determine the efficiency of consumption of nitrates and phosphates at the maximum plant phytomass and to calculate the optimal power of the hydroponic installation for a given volume of fish tanks.

The paper presents an analysis of the bacterial purification effectiveness by UV radiation of wastewater in modern industrial aquaculture recirculation systems. the effectiveness of water purification in the ultrasound system by a set of filters for mechanical treatment and ultraviolet radiation is experimentally established. UV lamp allows to process water with rays that effectively destroy the organic matter formed in it. Pathogenic and conditionally pathogenic genera, such as: Aeromonas, Pseudomonas, Staphylococcus, Vibrio, Enterobacteria were differentiated.

Purpose – The purpose of this paper is to present and demonstrate the efficiency of utilization of a new approach for estimating parameters of micromechanical gyros (MMG) during their operation. It is shown that the main sources of errors are due to the following three factors: measurement errors of micron deviations of the sensitive element, unknown actual value of difference between the frequencies of primary and secondary oscillations and unknown value of damping constant for the axis of secondary oscillations. The estimation of the last two factors during the operation leads to a significant increase of accuracy of MMG. The solution of the problem is presented in the current paper. Design/methodology/approach – To solve this problem, an original two-level algorithm intended for use in the embedded MMG controller is considered. The identification of the internal MMG parameters is carried out at the first stage. At the second stage, an MMG model is created, based on the results of identification of para...

The subject of the present research is a group of autonomously controlled small satellites, the mutual location of which must be maintained during the flight. The first step in solving this problem is to develop a measurement system and the most accurate estimation of the relative distances. It is believed that the group is accompanied by one or two relatively large satellites, the size and power capacity of which allows one to determine their exact coordinates using GPS or GLONASS systems. Objects that make up the group only have radio equipment for exchanging relatively simple navigation messages and a micromechanical inertial unit.

The results of the evaluation of absorbing properties of the plate systems containing a layer of lubricant fluid between the contacting surfaces, dependences of absorptive capacity on the physical properties (adhesion, viscosity, etc.), load, temperature and other operational factors are presented in the article. The impact on the absorptive capacity of a number of lubricants and other fluids is experimentally estimated. The design of the plate elastomeric shock-absorbers is developed on the basis of the received results. Their damping characteristics are estimated.

The laboratory experiments of the deformations of the underwater barriers at step of the extreme waves were conducted. Some relations connecting the volume of deformation of underwater obstacles with the wave parameters and flow dynamics parameters are obtained.

Regardless of the geography of regions, management at the regional level, both in Russia and the Baltic Sea countries, faces many challenges. Hence, it is necessary to search for new effective economic management tools, since traditional approaches and modeling practices at the regional level are not suitable for either analysing various types of impact on regional economy (production, market (product), sector, region), or assessment of their consequences and identification of the necessary measures in any given economic conditions. The authors construct sectoral models to assess regulatory impacts on regional economic performance. Assessments of regulatory impacts on product value chains, economic sectors, and regions as a whole show good repeatability, which makes it possible to provide a rationale for economic decision-making. The authors propose new sectoral models using the Kaliningrad region as an example. The models are used in a comprehensive analysis of conditions for a GRP growth resulting from an increase in sectoral contributions. To this end, the study uses the well-known approaches of simulation modelling, as well as qualitative and quantitative methods in combination with economic-mathematical optimisation models. The article presents a pilot model of regulatory impacts for selected sectors of the Kaliningrad economy. The developed and tested models suggest that a rationale for economic decision-making and consequent actions should be based on the assessment of the impact of different groups of external, internal, and independent factors on value chains, based on the criterion of optimal factor income. In conclusion, the authors offer recommendations for using the proposed models in business, public administration and regional economic modeling.

Change of a water and water levels mode of the rivers when passing the maximum expenses by design probability of excess.

A laboratory study of the process of continuous snowmelt and subsequent infiltration of meltwater into the soil, depending on the properties (different initial density, layer thickness and temperature) of snow. We consider the impact of storm flows in the process of thawing.

At the article features of circulating currents and their use in vortex spillways are considered at design of high-pressure water-engineering systems. Results of special laboratory researches at which carrying out the certain forms of movement replacing each other in certain sequence are recorded are given. At the experiences with the twirled stream similar structures, and also area existence with a contraflow in the central part and its influence on integrated characteristics of a circulating stream in a pipe are found.

Data on the development, research and engineering applications of a metallic porous material with unique damping properties and superhigh elasticity, which is known as a “metallic counterpart of rubber” or briefly as “metallic rubber,” are presented. The process of production of such a material is considered including cold pressing of a metallic preform from coiled wire and formation of a porous structure. Amathematical model of cyclic deformation of articles from metallic rubber is developed and used to compute the parameters of various dampers and vibration isolators.

Methodical aspects of organization of the technical education of pupils through a network of subject-laboratory classes have been described. A scheme for the implementation of the technical education with the goal of sustainabledevelopment of the«school-university» system have been proposed.

L.G. Loytsyansky put and solved system from four differential equations in private derivatives for the laminar twirled movement of viscous liquid in a pipe opening in space [1], filled with the same liquid. It found speeds of particles and pressure in the form of the ranks depending on longitudinal distance. Author considers other decision where there is a vurfovy proportion between three components of speed of a particle of liquid.

We measured the temperature behavior of the spontaneous electric polarization of a monocrystalline sodium metavanadate NaVO3 sample along the polar axis [010] at temperatures from 20 to 610°C in zero external field. It was found that the spontaneous electric polarization has a wide maximum in the range from 200 to 300°C and remains nonzero up to 610°C. Measurements of electric polarization of the sample, subjected to the thermoelectric treatment, proved that NaVO3 is an electret. The electrical hysteresis loop in an alternating electric field with a frequency of 50 Hz and amplitude of 450 V/cm was measured in the vicinity of the temperature maximum.

Usage of micromechanical gyros (MMG) in space systems is restricted due to their low precision. For this reason development and investigation of methods and algorithms of increasing the precision is a very important problem. Studies have shown that the usage of firmware control in inertial units allows modification of parameters of gyros in the course of their maintenance. Such estimate allows increasing precision of inertial measurement considerably. The paper presents a method and an algorithm for increasing the accuracy of micromechanical gyroscopes. The method is based on using the Kalman filter for estimation of motion of sensing mass relative to the output axis. This estimation is very effective because deflections of sensing mass relative to the output axis are small in practice (on the order of several angular minutes for micromechanical gyros RR scheme). For this reason the level of noise in the measurements is very significant. The paper presents a result of investigations of ability to use Kalman filter for estimating parameters of MMG and the angular rate of the mobile craft in which this gyroscope is installed. Results of simulation are given and issues of implementation are considered.

Results of investigations conducted in the Hydraulics Laboratory of the Russian University for International Friendship are cited. The purpose of these investigations was to substantiate the scales of the possible effect of consequences of construction operations on the marine medium in the area where the “Nord Stream” gas pipeline is to be constructed. A description is given for an experimental device and procedures.

The basic concept of model development for analysis and prediction of drift transport by water flows in urban areas consists in the following. Precipitation and air temperature are determined on the basis of short-range forecasts of the meteorological situation. These data are used to calculate the runoff of water and drift from the land, using models describing their formation. These models [1] include relationships from which the layer of runoff is calculated on the basis of a “kinematic-wave” model. A model describing the transport of drift is then used if there is a problem in determining the channel dynamics of an urban river, or a drift-transfer model, if the transporting capacity of the flow in a storm drain is examined. In the latter case, the amount of the sandgravel mixture flushed from urban street pavements is adopted as an initial condition for the drift. To determine the runoff that forms in a water-catchment area, it is therefore possible to use the models proposed in [2]. A model of drift transport in an urban river usually consists of a drift-balance equation: g xt fd 0, (1)

The paper gives an overview of the design of rope vibration insulators with elastic elements of the center line in the form of two rectilinear and one curved section. In the Russian-language scientific literature this type of rope vibration insulators received a stable name "Γ-shaped vibration insulators" by analogy with the shape of the letter "gamma-Γ" of the Greek alphabet and a similar letter of the Cyrillic alphabet. Despite the wide using of vibration insulators designed on this shape, its mathematical calculation model has not yet been developed. In this connection, in this article, for the first time on the basis of the "Method of Forces" and the "Mohr Method", an analytical technique has been developed for calculating the characteristics of a vibration insulator in the directions of three mutually perpendicular axes. In addition, the article proposes a new structure of a vibration insulator consisting of several tiers of elements of this type, based on a new patented technology for manufacturing quasi-continuous woven rings, proposed by the author of this article in co-authorship with several employees of the Samara National Research University. Simple formulas are obtained for calculating the load characteristics in three mutually perpendicular directions. This makes it possible to calculate the corresponding stiffness and natural frequencies of mechanical vibration protection systems. It is established that the stiffness of the vibration insulator in the direction of the Z axis is greater than the stiffness in the X and Y axis directions, however, if a vibration insulator with equal, or close to equal characteristics, along three axes has to be designed according to the technical specification, this can be done by selecting the parameters included in the equations given in article for load characteristics.

As applied to calculations of all-metal vibration isolators with dry friction, the use of the finite element software is considered. For simulation of friction forces on the contacts based on the analysis of simple dry friction systems, the distributed moment of resistance to curvature variations is proposed. Also presented are an example of the hysteresis loop calculation for the ring-like vibration isolator and comparison with the experimental data.

The theory for calculating elastodamping characteristics of multilayer corrugated dampers being used in the rotor supports of aircraft gas turbine engines (GTEs), turbo-pump assemblies of rocket engines as well as in different articles of machine building industry is presented.

The electric polarization induced in ferroelectric terbium molybdate by a magnetic field linearly varying with time is measured. The measurements are performed in fields up to 19 T at different specified rates of change in the magnetic field at temperatures of 273 and 219 K. The results obtained indicate that there are magnetoelectric effects of two types. One of them is a conventional magnetoelectric effect, which is appropriately referred to as the static magnetoelectric effect. The other effect is characterized by the fact that the electric polarization increases with an increase in the rate of change in the magnetic field and relaxes with time to zero at a fixed nonzero field. This phenomenon is termed the dynamic magnetoelectric effect.

The surface potential induced by electron beam irradiation in ferroelectric domains of terbium molybdate Tb 2 (MoO 4 ) 3 has been investigated. Comparative characterisation of the domain surface has been revealed from measurements of secondary electron yield during and after the sample irradiation in the SEM at accelerated voltages of (1–2) kV. At higher electron beam energy a domain boundary contrast was appeared as a result of negative surface charging. Peculiarities of the charge boundary contrast were investigated and analysed.

The temperature dependences of the intensity of the main acoustic resonance peak for two samples of gadolinium molybdate Gd2(MoO4)3 are measured in the temperature range 22–165°C, involving the Curie temperature. It is revealed that low-frequency fluctuations of the amplitude of the resonance current through the samples are observed at temperatures in the vicinity of the Curie point. The amplitudes of the corresponding variations in the voltage at the input of the recording device reach 100 mV. The characteristic times of fluctuations are several tens of seconds.

Results of field studies of Istra River current dynamics over a 35-km reach in the lower pool of a hydrosystem are analyzed. Data on the distribution of current velocities in cross-sections with different morphometry and the characteristics of bottom deposits at significantly different water discharges, and data on variations in the water surface slope are presented. The coefficients of hydraulic friction are assessed.

The absorption spectra were measured in β′-Tb2(MoO4)3 in the non-polarized light in the magnetic field H ⩽ 20 T along the [0 0 1] and [1 1 0] axes at T = 4.2 and 1.7 K. The wave vector of the light was parallel to the magnetic field. The experimental field dependences of the wave numbers of the absorption peaks ν i (H) were obtained. The analysis of those dependences shows that the excited multiplet 5D4 of Tb3+-ion in the crystal field of β′-Tb2(MoO4)3 can be considered as consisting from five singlets and two quasi-doublets. The field dependences of the energy levels E i ( H ) of the 5D4 multiplet were obtained from the experimental data in the magnetic field along the [0 0 1] axis. The experimental dependences E i ( H ) can be described well by the theory of the magnetism of singlets.

It is found that a magnetic field up to 20 T affects photoluminescence absorption spectra in NaCl:Eu crystals in the process of impurity aggregation into complexes. The spectral changes are irreversible and are observed after quenching the crystals at the early stages of the formation of small metastable complexes containing impurity-vacancy Eu2+-V dipoles. Emporal correlations revealed between the occurrence of the magnetoplastic effect and a change in the optical properties of the crystals in a magnetic field.

Spontaneous experimental spread, Δ H s , of the switching field, H s , (switching field fluctuations) during the re-entrant magnetization process of Fe-rich (Fe 65 Si 15 B 15 C 5 ) microwire (metallic nucleus diameter of around 10 μm) exhibiting rectangular hysteresis loop has been observed at room temperature. Shape of the switching field distribution has been measured and analyzed in terms of a thermoactivational mechanism. The model predicts the lineal dependence of the logarithm of Barkhausen jump probability, d w , on reduced switching field fluctuation, Δ h =Δ H s / H sm . Observed d w (Δ h ) dependence fits satisfactorily to the predicted semi-logarithmic dependence.

Nonlinear magnetoelectric effect was investigated experimentally in single crystal single domain samples of metastable orthorhombic ferroelectric ferroelastic g '-phases of rare earth molybdates Tb 2 (MoO 4 ) 3, TbGd(MoO 4 ) 3, DyGd(MoO 4 ) 3, Gd 2 (MoO 4 ) 3 and Sm 2 (MoO 4 ) 3 . The field dependence of the electric polarization was measured in the magnetic field up to 20 Tesla at temperatures down to 0,4 K using the direct current method. The mechanism of the interaction between the magnetic and ferroelectric subsystems based on the magnetostriction is proposed.