Use Of Attractors Research Articles

АТРАКТОРИ ЯК ОДИН З НАПРЯМІВ ЗАБЕЗПЕЧЕННЯ КОНКУРЕНТОСПРОМОЖНОСТІ РЕГІОНУ

The level of competitiveness of regions depends on the influence of a large number of factors, which can be external and internal, independent and interdependent, random and traditional, significant and insignificant, global and local, etc. Some factors can be predicted, while others are unpredictable. Thus, in managing the competitiveness of a region, it is extremely important to study the factors which, based on the results of analysis, minimize the negative impact of the external environment and use positive trends. The purpose of the article is to substantiate the use of attractors to ensure the competitive advantages of a region. The subject of the study is the factors that influence the competitiveness of the region. The object of research is the processes of strategic management of the region. Research methods: logical analysis, generalization, systematization. The article examines the problem of the impact of numerous factors on the development and level of competitiveness of regions, and outlines the factors influencing the competitiveness of a region by areas (economic, socio-cultural, environmental, political, administrative, scientific and technical, demographic, infrastructure, natural and geographical, etc.). It is noted that all factors have a complex effect and, under the influence of certain combinations of factors, a chain reaction and an enhanced synergistic effect may occur. Given that the same factors can have different effects under different conditions, it is important to form such subsystems of factors, such attractors that will "work" to improve the system. It is proposed to use attractors in the formation of competitive advantages of the region. It is proposed to understand attractors as a set of factors that affects other elements of the system, spreading its features/characteristics to them. Taking into account the attractors in the strategic management of the region will ensure the necessary level of their development and competitiveness. The results of this study can be used as a basis for further research on the specification of attractors for specific regions of Ukraine.

EFFICIENCY OF ATTRACTORS AND TRAPS FOR CAPTURE OF SPOTTED-WING DROSOPHILA IN VINEYARDS1

ABSTRACT Pest monitoring is a practice that enables the estimation of populational density of insect-pests in crops. However, it requires the use of attractors and traps that present high efficiency. The objective of this work was to evaluate the efficiency of food attractors using different trap models for the capture of spotted-wing drosophila (Drosophila suzukii) insects, and the capture selectivity of these models in vineyards of Cabernet Sauvignon. The experiment was conducted in the 2018-2019 crop season, in São Joaquim, SC, Brazil. A randomized block design was used, in a 2 × 4 factorial arrangement consisted of two types of traps (PET bottle and plastic container), three attractors (SuzukiTrap®, Droskidrink, and Yeast), and distilled water as a control. The traps were distributed in a minimum distance of 15 m and fixed in the middle third of the plants. The collections and replacing of attractors were done with 21-day intervals. The data were analyzed through generalized linear models, using the Poisson distribution or Poisson with a dispersion parameter. All attractors tested captured adult D. suzukii insects. No significant differences were found between the trap types used. The findings of the present work showed that the trap plastic container with the Droskidrink attractor is the most suitable capture method to be used in monitoring programs for D. suzukii insects in commercial vineyards.

Artificial attractors in small scale fisheries gillnets on Araguaia river, Brazil

The catch and selectivity effectiveness of two artificial attractors-AA (bright gray curly ribbon and green lightsticks) in gillnets was evaluated in order to increase the productivity and income of small scale fishermen. Five expeditions were carried on the Araguaia River, where the two AA treatments were applied to two thirds of the area of gillnets, leaving the remaining third without the use of attractors (control). For a better comparison, the catches were subdivided into ecological groups (carnivores, detritivores, herbivores and omnivores). 541 fish were caught, 197 in the curly ribbon, 177 lightstick and 167 in the control. Carnivorous fishes were predominant in all treatments (p = 0.025 for Kruskal Wallis test and p = 0.03 for Mann-Whitney test). The use of the ribbon and lighstick provided an increase in the catch of carnivorous teleost fish, providing a better gross profit margin. Due the low incomes and fragile economic situation of the fishing communities of Araguaia, the best technological choice in this study is the curly ribbon, as in addition to presenting better productivity, it is accessible low cost and easy to handle.

Energy dissipation in the blade tip region of an axial fan

A study of velocity and pressure fluctuations in the tip clearance flow of an axial fan is presented in this paper. Two different rotor blade tip designs were investigated: the standard one with straight blade tips and the modified one with swept-back tip winglets. Comparison of integral sound parameters indicates a significant noise level reduction for the modified blade tip design. To study the underlying mechanisms of the energy conversion and noise generation, a novel experimental method based on simultaneous measurements of local flow velocity and pressure has also been developed and is presented here. The method is based on the phase space analysis by the use of attractors, which enable more accurate identification and determination of the local flow structures and turbulent flow properties. Specific gap flow energy derived from the pressure and velocity time series was introduced as an additional attractor parameter to assess the flow energy distribution and dissipation within the phase space, and thus determines characteristic sources of the fan acoustic emission. The attractors reveal a more efficient conversion of the pressure to kinetic flow energy in the case of the modified (tip winglet) fan blade design, and also a reduction in emitted noise levels. The findings of the attractor analysis are in a good agreement with integral fan characteristics (efficiency and noise level), while offering a much more accurate and detailed representation of gap flow phenomena.