High Speed Visual Insect Swarm Tracker (Hi-VISTA) used to identify the effects of confinement on individual insect flight

Individual insects flying in crowded assemblies perform complex aerial maneuvers by sensing and feeding back neighbor measurements to small changes in their wing motions. To understand the individual feedback rules that permit these fast, adaptive behaviors in group flight, a high-speed tracking system is needed capable of tracking both body motions and more subtle wing motion changes for multiple insects in simultaneous flight. This capability extends tracking beyond the previous focus on individual insects to multiple insects. This paper presents Hi-VISTA, which provides a capability to track wing and body motions of multiple insects using high speed cameras (9000 fps). Processing steps consist of automatic background identification, data association, hull reconstruction, segmentation, and feature measurement. To improve the biological relevance of laboratory experiments and develop a platform for interaction studies, this paper applies the Hi-VISTA measurement system to Apis mellifera foragers habituated to transit flights through a transparent tunnel. Binary statistical analysis (Welch's t-test, Cohen's d effect size) of 95 flight trajectories is presented, quantifying the differences between flights in an unobstructed tunnel and in a confined tunnel volume. The results indicate that body pitch angle, heading rate, flapping frequency, and vertical speed (heave) are all affected by confinement, and other flight variables show minor or statistically insignificant changes. These results form a baseline as swarm tracking and analysis begins to isolate the effects of neighbors from environment.

ATTEMPT TO IMPROVE THE OPERATING AND TECHNOLOGICAL PROPERTIES OF THE COMBINED GRAIN WASHING MACHINE

Washing machines are used in the production lines of grain cleaning departments of flour mills for thorough cleaning of the grain surface, in particular, its grooves from the remnants of organic and mineral dust, microorganisms and mold. In addition, the grain mass during washing is cleaned of hydrodynamically light and heavy impurities - chaff, seeds of waste plants, straw fragments, mineral particles in the form of sand, small stones, lumps of earth, as well as spores and wormwood seeds. At the same time, foreign odors of grain disappear.Experience in the operation of Ж9-БМА machines shows that along with many advantages, they have some disadvantages. In particular, the productivity of the machine 10 t / h does not correspond to the productivity of the conjugated technological equipment of the production line, and the specific water consumption for washing grain is 1.8… 2.0 l / kg, which is too much in modern conditions of acute shortage of drinking water. Enterprises to abandon the use of washing machines. In addition, certain problems and inconveniences are caused by the design of the sieve shell of the impression column. Stamped sieves with scaly asymmetric holes have a low coefficient of living cross section, which complicates the process of dehydration of washed grain, quickly corrode and rub, require special attention during installation or replacement. Therefore, an attempt is made to eliminate these shortcomings.In particular, the reduction of water consumption is achieved due to the elimination of the grain hydraulic conveyor during its transfer from the washing bath to the pressure column. For this purpose, a device for mechanical overloading of grain by a rotary bucket device located within the alloy chamber is used. At the same time, attention was paid to the separation of light organic impurities from the grain. This decision needs further explanation.The functional diagram shows that the initial grain mixture enters the receiving device, which feeds it with a minimum vertical speed into the ascending water streams created by the screws of two grain augers rotating with the same frequency in the opposite direction. The augers pick up the grain and, keeping it afloat in a suspended state, mix it with the water of the washing bath. At the same time the grain is washed and particles are separated from it, which differ from it in terms of density: mineral impurities begin to sink, fall down and through the longitudinal slit in the auger trough fall into the area of the auger for mineral impurities. This auger transports the "stones" in the opposite direction to the funnel with the ejector of the hydrotransporter of mineral particles. Light impurities, during the transportation of grain by grain augers, float to the surface of the water, the level of which in the washing bath is maintained up to the axis of the augers. Together with grain and water, these impurities are pushed out of the bath into the alloy chamber.In the chamber, in the transverse direction, a pipe with a longitudinal absorption slot is installed, the lower edge of which is immersed in water so that the upper layer of water merges into this slot together with light impurities that have surfaced in the washing bath. The amount of water that fuses light impurities can be adjusted by the depth of immersion in water of the lower edge of the absorption hole. To do this, the pipe is rotated relative to its axis with a special handle with a clamp and a pointing scale. One end of the pipe is closed by a plug, and the other passes through a hole in the wall and drains the water with light impurities into the sink sump. The described device provides almost complete removal of light impurities and minimal consumption of floating water. This solution is in the invention according to the copyright certificate 701708404, developed by specialists of the department TOZV. In addition, certain problems and inconveniences are caused by the design of the sieve shell of the squeezing column. Dirt particles tend to stick to the outer surface of the sieve cylinder and block its holes. This can slow down and even stop the separation of water by centrifugation. Therefore, the upper outer surface of the cylinder is washed with water, which in automatic mode is periodically fed to the sieve by the control device and the solenoid valve. It also saves water.

On particle separation from turbulent particle plumes in a cross-flow

We present new experiments of particle-driven turbulent plumes issuing from a constant source of dense particle-laden fluid, with buoyancy flux, $B$ , in a uniform horizontal current, $u$ . Experiments show that a turbulent, well-mixed plume develops, in which the downward vertical speed $w$ decreases with depth $z$ according to $w = 0.76 (B/uz)^{1/2}$ while the horizontal speed rapidly asymptotes to the current speed $u$ , provided that the Stokes settling speed of the particles $v<0.92 w$ . For $v > 0.92 w$ , the particles separate from the plume fluid, and their depth $z$ increases according to the simple sedimentation trajectory $\textrm {d}z/{\textrm {d}\kern0.7pt x} = v/u$ . As the particles sediment, they form clusters of particles, which lead to fluctuations in the particle load with position, but do not appear to change the time-average sedimentation speed. We explore the impact of these results for deep-sea mining, in which the fate of the plume water as well as the particles is key for assessing potential environmental impacts.

Changing of surface thermal parameters in the Northern Pacific and some possible climatic affects

В работе на основе базы данных температуры поверхности воды в северной части Тихого океана на климатическом масштабе 1980 - 2019 годы с временным шагом один год исследована зависимость скорости изменения температуры от широты. В летний (август) период отмечается устойчивая зависимость темпов роста средней зональной температуры поверхности в направлении от тропиков к субарктике. Характерная скорость роста температуры в тропических широтах 0,011 0C/год, в субтропиках 0,021 0C/год, в субарктических акваториях выше 400N имеем 0,027 0C/год. В зимний сезон (февраль) такой тенденции не наблюдается. Представлены количественные оценки возможного влияния температурных трендов на глобальную циркуляцию. Рост поверхностной температуры увеличивает вертикальную стратификацию и уменьшает вертикальный обмен вод, относительное ослабление вертикальной скорости не превышает 0,01 % за десятилетие, что представляет незначительным. Представлена количественная оценка уменьшения геострофической составляющей горизонтальной скорости течения продолжения Куросио на восток вследствие климатического сглаживания перепада температуры воды южнее и севернее струи. The change of sea surface temperature (SST) in the North Pacific Ocean on the climatic scale 1980 - 2019 is considered. The rate of temperature change as a function of latitude with the one year time step and the 10 degrees spatial step is investigated. The latitudinal time series for summer and winter are separated. The summer (August) period has the climatic stable dependence of the surface temperature growth rate in the direction from the tropics to the subarctic area. The characteristic rate of temperature rise in tropical latitudes is 0.011 0C / year; in the subtropics is 0.021 0C / year; in subarctic waters above 40 0N this is 0.027 0C / year. The winter season (February) does not have this tendency. The quantitative estimates of the temperature trends influence on global circulation are presented. The SST growth enhances vertical stratification and decreases the vertical water exchange. The estimation of the relative vertical speed decrease is not more than 0.01% / decade. The quantitative assessment of the weakening of the geostrophic horizontal velocity in the Kuroshio extension due to the climatic smoothing of the SST south - north gradient is presented.

Robust GMTI Scheme for Highly Squinted Hypersonic Vehicle-Borne Multichannel SAR in Dive Mode

While there are recent researches on hypersonic vehicle-borne multichannel synthetic aperture radar in ground moving target indication (HSV-MC-SAR/GMTI), this article, which specifically explores a robust GMTI scheme for the highly squinted HSV-MC-SAR in dive mode, is novel. First, an improved equivalent range model (IERM) for stationary targets and GMTs is explored, which enjoys a concise expression and therefore offers the potential to simplify the GMTI process. Then, based on the proposed model, a robust GMTI scheme is derived in detail, paying particular attention to Doppler ambiguity arising from the high-speed and high-resolution wide-swath. Furthermore, it retrieves the accurate two-dimensional speeds of GMTs and realizes the satisfactory performance of clutter rejection and GMT imaging, generating the matched beamforming and enhancing the GMT energy. Finally, it applies the inverse projection to revise the geometry shift induced by the vertical speed. Simulation examples are used to verify the proposed GMTI scheme.

Modeling and development of a fundamentally new way of landing a quadcopter on inclined surfaces

Methods and software and hardware for modeling and developing a fundamentally new way of landing a quadrocopter on inclined surfaces are discussed in the paper. The current state of the project under elaboration is conditioned and described. Various approaches to the solution are feasible due to the complexity of the considered issue. Solutions can differ both in the distribution of control functions between the ground control station and the quadcopter itself, and in the choice of principles that can be used as the basis for the control system and determine its design and dynamic characteristics. Simulation and testing processes demonstrate that reverse thrust alone can increase the landing zone of an average mass quadcopter, almost doubling the maximum tilt angle at which a landing maneuver is made, thus, allowing for a high vertical speed landing. It is clearly shown that low-power adhesion mechanisms such as electrical adhesion, switchable magnets, grippers or dry glue are activated after landing, allowing it to stay on the surface after the back thrust has ceased. This can be useful in situations where sudden interference is likely to occur. Such a result is achieved using a classic quadrocopter as DJI F450 without adding any equipment.

Effect of tag attachment on flight parameters and energetic cost across five raptor species

Bio-logging devices play a fundamental and indispensable role in movement ecology studies, particularly in the wild. However, researchers are becoming increasingly aware of the potential effects that attaching devices can have on animals, particularly on their behaviour, energy expenditure and survival. The way a device is attached to an animal's body has also potential effects on the collected data, and quantifying the type and magnitude of potential bias is fundamental to enable researchers to combine and compare data from different studies. Since over two decades, large terrestrial birds have been in the focus of long-term movement ecology research, employing bio-logging devices attached with different types of harnesses. However, comparative studies investigating the effects of harness type on these species are scarce. In this study, we tested for potential differences in data collected by two commonly used harness types, backpack and leg-loop, on the flight performance of 10 individuals from five raptor species, equipped with high resolution bio-logging devices, in the same area and time. We explored the effect of harness type on vertical speed, horizontal speed, glide ratio, height above sea level, distance travelled, proportion of soaring and flapping behaviour, and VeDBA (a proxy for energy expenditure) between and within individuals, all used as fine-scale measures of flight performance. Birds equipped with leg-loops climbed up to 0.65 ms-1 faster, reached 19% greater heights while soaring and spent less time with active flight compared to birds equipped with backpacks, suggesting that backpack harnesses, compared to leg-loops, might cause additional drag that lowered the birds' flight performance. A lower rate of sinking while gliding, a slightly higher glide ratio, higher horizontal speed while soaring, and lower VeDBA, were also indicative of decreased drag using leg-loops. Our results, add to the pre-existing literature highlighting the design-related advantages of leg-loops, and they are in support of considering leg-loops as a better alternative to backpack harnesses for large soaring birds. Our study also highlights the importance of investigating how the methodology used to measure behavioural information affects the collected data to avoid systematic bias, which would invalidate data comparability and lead to misinterpreting the behaviour being measured.

Analytical model of skip motion taking into account influence of head and balancing ropes

The article describes an analytical model of mine skip dynamics taking into account the presence of the head and balancing ropes and the existing curvilinearity of the guides. Expressions for the forces acting on the skip from the side of the guides have been constructed. It is shown, that the frequencies of natural vibrations of skip depend on the vertical acceleration and the distance traveled during its lifting. A graph (diagram) of skips vertical speed which observance does not lead to the appearance of skips vertical vibrations due to elasticity of the ropes is developed. An algorithm for finding the forces principal vector and the forces principal moment acting on the skip based on the reading of three accelerometers recording horizontal accelerations of skip during its movement is presented.

Choice of the optimal mode of control of the process of emergency landing of an unmanned quadcopter

Peculiarities of the process of emergency landing of an unmanned quadcopter have been studied by mathematical modeling. The method of landing an unmanned quadcopter in case of failure of one of the four pairs of electric motor-propeller is proposed. The basis of this technique is the application of the parachuting effect. Parachuting is achieved by forcibly turning off the power of the motor, which is located at the opposite end of the same traverse as the faulty motor. As a result, the vertical speed of the unmanned quadcopter at the time of landing is significantly reduced and approaches a relatively safe value.

Study of Two Upper Cold Lows and Their Relationship with Locally Intense Rain

The main objective of the research was to determine the synoptic and mesoscale conditions, which, under the influence of two Upper Cold Lows (UCL), favor the occurrence of locally intense rain in Cuba. From the outputs of the Rapid Refresh (RAP) model, the characteristics of two UCL with four cases of locally intense rain associated with them were analyzed. The variables that were studied are relative humidity, temperature, geopotential height, vertical speed, wind force, divergence and vorticity. Mesoscale conditions were analyzed by using the Weather Research and Forecast System (WRF) model. Vertical cuts, numerical soundings and analysis of radar observations and satellite images were carried out. The CAPE shows extreme values higher than 6000 J/kg near the center of both systems and the LI reaches −13. The cases were developed in an environment of weak vertical wind shear in the surface layer −500 hPa and moderate to strong in the upper troposphere. High relative humidity values were identified at low levels, a dry layer was identified at medium levels and an increase in relative humidity was identified in the 300–200 hPa layer.