Aspectos Sócio-Econômicos do Desenvolvimento dos Destinos Turísticos Urbanos

The article is devoted to the consideration of socio-economic aspects of the development of urban tourist destinations. A city as a tourist destination is a settlement that possesses a sufficient number of tourist and recreational resources, social infrastructure facilities, at least one type of transport accessibility, positioning itself as a tourist center within the state to which it belongs. Measures for the development of the tourist and recreational sector in tourist cities should provide for a comprehensive solution to the priority problems of the urban development and main tourist zones of cities, further strengthening tourist, excursion, and sanatorium-resort services, expanding the range of recreational and tourist services and creating an appropriate material, technical and personnel base, increasing the volume of income from all type tourist activities in contemporary conditions.El artículo está dedicado a la consideración de los aspectos socioeconómicos del desarrollo de los destinos turísticos urbanos. Una ciudad como destino turístico es un asentamiento que posee un número suficiente de recursos turísticos y recreativos, instalaciones de infraestructura social, al menos un tipo de accesibilidad de transporte, posicionándose como un centro turístico dentro del estado al que pertenece. Las medidas para el desarrollo del sector turístico y recreativo en las ciudades turísticas deben prever una solución integral de los problemas prioritarios del desarrollo urbano y de las principales zonas turísticas de las ciudades, reforzando aún más los servicios turísticos, de excursión y de sanatorio-balneario, ampliando la gama de servicios recreativos y turísticos y creando una base material, técnica y de personal adecuada, aumentando el volumen de ingresos de todo tipo de actividades turísticas en las condiciones contemporáneas.O artigo é dedicado à consideração dos aspectos socioeconômicos do desenvolvimento dos destinos turísticos urbanos. Uma cidade como destino turístico é um povoado que possui um número suficiente de recursos turísticos e recreativos, instalações de infra-estruturas sociais, pelo menos um tipo de acessibilidade de transportes, posicionando-se como centro turístico dentro do estado a que pertence. As medidas para o desenvolvimento do setor turístico e recreativo nas cidades turísticas devem proporcionar uma solução global para os problemas prioritários do desenvolvimento urbano e das principais zonas turísticas das cidades, reforçar ainda mais os serviços turísticos, de excursões e de sanatórios-resorts, expandir a gama de serviços recreativos e turísticos e criar uma base material, técnica e pessoal adequada, aumentando o volume de rendimentos de todo o tipo de atividades turísticas em condições contemporâneas

The Formation Mechanism and Structure of Organic Liquids in the DFT Challenges

In the paper the experimental and theoretical approaches to problem of organic liquids formation mechanism and its structure are reviewed. It was shown that all presented models have the advantages and disadvantages at interpretation of molecular interaction and arrangement in liquid phase. The DFT calculation in different variant of models including paired interaction hydrogen atom transfer, model of transformation and the general conclusion following from this consideration are presented

Manifestation of Spiral Structures under the Action of Upper Ocean Currents

The traditional approach to the interpretation of spirals observed in radar, optical and radiometric panoramas of a sea surface is based on equating the outer spiral scale with the scale of a manifesting eddy, but the validity of this approach has been poorly studied. Using the maximum cross-correlation (MCC) method for multispectral satellite images containing a spiral structure, we found a significant discrepancy between the structures of horizontal velocity fields and the geometrical characteristics of spiral structures in each band. Each velocity field demonstrated a pair of points of zero velocity with a km-scale difference between their positions in different bands. In order to describe the observed features, an analytical description of the upper-ocean current composed of a spiral eddy and of a homogeneous drift (related, in particular, to wind forcing) is proposed. This simple model states that the spiral characteristics and the position of the spiral center depend on a drift current even when the genuine characteristics of the marine eddy are fixed. The studied example shows that the diameter of an eddy core may significantly (2–3 times) differ from the outer scale of the spiral, which demonstrates the incorrectness of the traditional approach of spiral structures interpretation

Analiza porównawcza metod elektroprzędzenia do wytwarzania włókien i materiałów o przewidywanej strukturze i właściwościach

Various industrial methods of electrospinning are considered. Experimental data of the results of electrospinning from solutions of chlorinated polyvinyl chloride, polyamide-6/66 and fluoroplastic F-42, obtained by various methods are presented.Rozważaniom poddano różne przemysłowe metody elektroprzędzenia. Przedstawiono dane doświadczalne wyników elektroprzędzenia z roztworów chlorowanego polichlorku winylu, poliamidu-6/66 i fluoroplastu F-42

Special monitoring results for determination of radionuclide composition of Russian NPP atmospheric releases

Measurements of activity concentrations of radionuclides in atmospheric releases were performed in 2017–2018 at vent stacks of seven Russian nuclear power plants. The selected instruments and research methods, with detection limits significantly lower than the existing detection limit of Russian NPPs routine control, allowed to reliably determine up to 26 radionuclides. Analysis of experimental data allows to determine the list of radionuclides for calculation the effective dose rates to public and the permissible annual discharge levels for each Russian NPP. Radiocarbon is determined as major contributor for the dose from the atmospheric releases of LWGR reactors – up to 98% for EGP-6 and RBMK-1000 (Smolensk NPP) reactors. For PWR reactors (VVER) radionuclides contribution to the annual dose from atmospheric releases is more complicated, but, in general, dose is formed by tritium, 14C and noble gases. The special monitoring results with ranking of measured radionuclides according to their contribution to the effective dose makes it possible to optimize the list of controlled radionuclides in airborne releases of Russian NPPs from 94 to 8–16 for different NPPs. Keywords: Atmospheric releases, Nuclear power plant, Radioactive effluen

Elektroprzędzenie włókien przy użyciu mieszanych kompozycji na bazie polieterouretanu i polimerów hydrofilowych do produkcji materiałów membranowych

In this paper, the possibility of obtaining micro- and nanofibres, as well as nonwoven materials from polyether-urethane solutions using the method of electrospinning, was studied. The conditions and formulation-technological factors for the production of nonwoven fibrous webs from polyetherurethane (PUR) solutions modified with hydrophilic polymers: polyvinyl alcohol (PVA) and polyacrylic acid (PAA) were studied. The effect of hydrophilic polymers on the structure and average fibre diameter is shown. An increase in the indicators of hygienic properties of modified nonwoven materials was revealed with the aim of their further use in membrane bags for clothes and shoes.W pracy zbadano możliwość otrzymywania mikro- i nanowłókien, a także włóknin z roztworów polieterowo-uretanowych metodą elektroprzędzenia. Badano warunki i czynniki technologiczne niezbędne do produkcji włóknin z roztworów polieterouretanu (PUR) modyfikowanych hydrofilowymi polimerami: polialkoholem winylowym (PVA) i kwasem poliakrylowym (PAA). Zbadano wpływ hydrofilowych polimerów na strukturę i średnią średnicę włókna. Stwierdzono wzrost wskaźników właściwości higienicznych modyfikowanych materiałów włókninowych, co pozwala na zastosowanie wytworzonych materiałów w materiałach membranowych

The Role of Micro Breaking of Small-Scale Wind Waves in Radar Backscattering from Sea Surface

The study of the microwave scattering mechanisms of the sea surface is extremely important for the development of radar sensing methods. Some time ago, Bragg (resonance) scattering of electromagnetic waves from the sea surface was proposed as the main mechanism of radar backscattering at moderate incidence angles of microwaves. However, it has been recently confirmed that Bragg scattering is often unable to correctly explain observational data and that some other physical mechanisms should be taken into consideration. The newly introduced additional scattering mechanism was characterized as non-polarized, or non-Bragg scattering, from quasi-specular facets appearing due to breaking wave crests, the latter usually occurring in moderate and strong winds. In this paper, it was determined experimentally that such non-polarized radar backscattering appeared not only for rough sea conditions in which wave crests strongly break and “white caps” occur, but also at very low wind velocities close to their threshold values for the wave generation process. The experiments were performed using two polarized Doppler radars. The experiments demonstrated that a polarization ratio, which characterizes relative contributions of non-polarized and Bragg components to the total backscatter, changed slightly with wind velocity and wind direction. Detailed analysis of radar Doppler shifts revealed two types of scatterers responsible for the non-polarized component. One type of scatterer, moving with the velocities of decimeter-scale wind waves, determined radar backscattering at low winds. We identified these scatterers as “microbreakers” and related them to nonlinear features in the profile of decimeter-scale waves, like bulges, toes and parasitic capillary ripples. The scatterers of the second type were associated with strong breaking, moved with the phase velocities of meter-scale breaking waves and appeared at moderate winds additionally to the “microbreakers”. Along with strong breakers, the impact of microbreaking in non-polarized backscattering at moderate winds remained significant; specifically the microbreakers were found to be responsible for about half of the non-polarized component of the radar return. The presence of surfactant films on the sea surface led to a significant suppression of the small-scale non-Bragg scattering and practically did not change the non-Bragg scatterer speed. This effect was explained by the fact that the nonlinear structures associated with dm-scale waves were strongly reduced in the presence of a film due to the cascade mechanism, even if the reduction of the amplitude of dm waves was weak. At the same time, the velocities of non-Bragg scatterers remained practically the same as in non-slick areas since the phase velocity of dm waves was not affected by the film

On Capabilities of Tracking Marine Surface Currents Using Artificial Film Slicks

It is known that films on the sea surface can appear due to ship pollution, river and collector drains, as well as natural biological processes. Marine film slicks can indicate various geophysical processes in the upper layer of the ocean and in the atmosphere. In particular, slick signatures in SAR-imagery of the sea surface at low and moderate wind speeds are often associated with marine currents. Apart from the current itself, other factors such as wind and the physical characteristics of films can significantly influence the dynamics of slick structures. In this paper, a prospective approach aimed at measuring surface currents is developed. The approach is based on the investigation of the geometry of artificial banded slicks formed under the action of marine currents and on the retrieval of the current characteristics from this geometry. The developed approach is applied to quasi stationary slick bands under conditions when the influence of the film spreading effects can be neglected. For the stationary part of the slick band where transition processes of the band formation, e.g., methods of application of surfactants on water, film spreading processes, possible wind transformation etc., become negligible, some empirical relations between the band geometrical characteristics and the characteristics of the surface currents are obtained. The advantage of the approach is a possibility of getting information concerning the spatial structure of marine currents along the entire slick band. The suggested approach can be efficient for remote sensing data verification

New Features of Bragg and Non-Polarized Radar Backscattering from Film Slicks on the Sea Surface

Suppression of radar backscattering from the sea surface has been studied in field experiments with surfactant films carried out from an Oceanographic Platform on the Black Sea and from onboard a research vessel on the Gorky Water Reservoir using an X-C-S-band two co-polarized radar instrument. Bragg and non-polarized (non-Bragg) radar backscatter components, BC and NBC, respectively, were retrieved when measuring the radar backscatter at vertical (VV-) and horizontal (HH-) polarizations. New features of microwave backscattering from the sea surface have been revealed, including a non-monotonic dependence of radar backscatter suppression (contrasts) in slicks on azimuth angle and particularities of BC contrasts on radar wave number. Namely, it is demonstrated that the backscatter contrasts achieve maximum values at azimuth angles in between the upwind and crosswind radar look directions, and BC contrasts increase with radar wave number along the wind and decrease in the crosswind directions. The suppression of BC is discussed in the frame of Bragg’s theory of microwave scattering and of a simple model of the wind wave spectrum, while the suppression of NBC is considered associated with the micro-breaking of wind waves. The obtained new features of radar contrasts can be used for the identification and characterization of marine films